JP4154085B2 - Color toner, color image forming method and apparatus unit using the color toner - Google Patents

Description

【００７６】
（トナーのＴＨＦ可溶分の分子量分布の測定）
上記ソックスレイ抽出を行なったトナー試料のＴＨＦ可溶分とＴＨＦとを５〜２５ｍｇ／５ｍｌのの濃度比で混合し室温にて数時間静置のあと十分に振り混ぜ、更に一昼夜静置する。その後サンプル処理フィルタ（ポアサイズ０．４〜０．５μｍ、例えばマイショリディスクＨ−２５−２ 東ソー社製 エキクロディスク２５ＣＲ ゲルマン サイエンスジャパン社製等）を透過させたものを測定サンプルとして用いる。
【００７７】
ＧＰＣ測定装置においては、４０℃のヒートチャンバー中で絡むを安定化させ、この温度におけるカラムに溶媒としてＴＨＦを１ｍｌ／ｍｉｎ．の流速で流し、ＴＨＦ試料溶液を約１００ｍｌ注入して測定する。試料の分子量測定にあったては、試料の有する分子量分布を数種の単分散ポリスチレン標準試料により作製された検量線の対数値とカウント数との関係から算出する。検量線作製用の標準ポリスチレン試料としては、例えば東ソー社製、或は昭和電工社製の分子量が１０²〜１０⁷程度のものを用い、少なくとも１０点程度の標準ポリスチレン試料を用いるのが適当である。検出器には、ＩＲ（屈折率）検出器を用いる。カラムとしては、市販のポリスチレンジェルカラムを数本組み合わせるのが好ましく、昭和電工社製のＳｈｏｄｅｘ ＧＰＣ ＫＦ−８０１，８０２，８０３，８０４，８０５，８０６，８０７，８００Ｐの組み合わせが好ましい。ＧＰＣの測定において、高分子両側はベースラインからクロマトグラムが立ち上がり開始点から測定を始め低分子量側・分子量約４００までを分子量の算出範囲とした。測定装置は、ＧＰＣ−１５０Ｃ（ウォーターズ社）を用いた。
【００７８】
更に、本発明で用いられる結着樹脂（トナー組成物の重合体成分全体）の酸価は、２ｍｇＫＯＨ／ｇ〜２０ｍｇＫＯＨ／ｇであることが好ましい。結着樹脂の酸価が２ｍｇＫＯＨ／ｇ未満の場合は有機金属化合物との相互作用による現像安定性や耐久安定効果を十分に発揮しきれなかったり、有機金属化合物の分散不良に伴うワックスの分散不良による低温定着性の悪化が見られる。一方、２０ｍｇＫＯＨ／ｇを超える場合は吸湿性が強くなり、画像濃度が低下し、カブリが増加する傾向がある。
【００７９】
本発明において、トナー組成物の重合体成分全体の酸価は以下の方法により求める。
【００８０】
（酸価の測定）
基本操作はＪＩＳ Ｋ−００７０に準ずる。
【００８１】
１）試料は予め重合体成分以外の添加物を除去して使用するか、重合体以外の成分の酸価、含有量を予め求めておく。試料の粉砕品０．５〜２．０（ｇ）を精秤し、重合体成分の重さＷ（ｇ）とする。
【００８２】
２）３００（ｍｌ）のビーカーに試料を入れ、トルエン／エタノール（４／１）の混合液１５０（ｍｌ）を加え溶解する。
【００８３】
３）０．１規定のＫＯＨのメタノール溶液を用いて、電位差滴定装置を用いて滴定する（例えば、京都電子株式会社製の電位差滴定装置ＡＴ−４００（ｗｉｎｗｏｒｋｓｔａｔｉｏｎ）とＡＢＰ−４１０電動ビュレットを用いての自動滴定が利用できる。）
【００８４】
４）この時のＫＯＨ溶液の使用量Ｓ（ｍｌ）とし、同時にブランクを測定しこの時のＫＯＨ溶液の使用量をＢ（ｍｌ）とする。
【００８５】
５）次式により酸価を計算する。ｆはＫＯＨのファクターである。
【００８６】
酸価（ｍｇＫＯＨ／ｇ）＝（（Ｓ−Ｂ）×ｆ×５．６１）／Ｗ
【００８７】
本発明に用いられるポリエステル樹脂の好ましい組成を以下に説明する。
【００８８】
本発明に用いられる非線状ポリエステル樹脂Ａは、全成分中の３〜１５ｍｏｌ％が３価以上の多価カルボン酸単量体ユニットからなり、炭素数５〜３０の飽和もしくは不飽和の脂肪族炭化水素基を有する多価カルボン酸単量体ユニット及び／又は多価アルコール単量体ユニット（ソフトセグメント成分）が５〜３０ｍｏｌ％であり、その他が２価の酸成分及び２価のアルコール成分等からなる。また、本発明に用いられる線状ポリエステル樹脂Ｂは、２価の酸成分及び２価のアルコール成分からなる。
【００８９】
本発明に用いられるポリエステル樹脂の構成成分としての３価以上の多価カルボン酸単量体ユニットとしては、１，２，４−ベンゼントリカルボン酸、１，３，５−ベンゼントリカルボン酸、１，２，４−シクロヘキサントリカルボン酸、１，２，４−ナフタレントリカルボン酸、２，５，７−ナフタレントリカルボン酸、１，２，４−ブタントリカルボン酸、１，２，５−ヘキサントリカルボン酸、テトラ（メチレンカルボキシ）メタン、１，３−ジカルボキシル−２−メチル−２−メチレンカルボキシプロパン、１，２，７，８−オクタンテトラカルボン酸等の多価カルボン酸、これらの酸無水物または低級アルキルエステル等が挙げられる。
【００９０】
また、本発明に用いられる非線状ポリエステル樹脂Ａの構成成分としてのソフトセグメントとなる単量体ユニットとしては、炭素数５〜３０の飽和もしくは不飽和の脂肪族炭化水素基を有する多価カルボン酸単量体ユニット及び／又は多価アルコール単量体ユニットであり、ポリエステル樹脂の骨格にブランチ化されて導入される飽和もしくは不飽和の脂肪族炭化水素基を有する単量体ユニットであることが好ましい。ソフトセグメント成分は、ポリエステル樹脂を構成する２価及び３価以上のモノマーのいずれかに炭素数５〜３０の飽和もしくは不飽和の脂肪族炭化水素基を有するものであることが好ましく、ソフトセグメントで置換された脂肪族ジカルボン酸類及び／又はソフトセグメントで置換された脂肪族ジオール類の単量体であることがより好ましい。
【００９１】
ソフトセグメントで置換された脂肪族ジカルボン酸類単量体ユニットとしては、炭素数５〜３０のアルキル基又はアルケニル基（例えばｎ−ドデセニル基，イソドデセニル基，ｎ−ドデシル基，イソドデシル基又はイソオクチル基等）で置換されたこはく酸、アジピン酸、セバシン酸、アゼライン酸の如きアルキルジカルボン酸類又はその無水物が好ましく、特に、ドデセニルこはく酸、オクチルこはく酸及びその無水物が好ましい。
【００９２】
また、ソフトセグメントで置換された脂肪族ジオール類単量体ユニットとしては、炭素数５〜３０のアルキル基又はアルケニル基で置換されたエチレングリコール、１，３−プロピレンジオ−ル，テトラメチルグリコール，１，４−ブチレンジオール，１，５−ペンチルジオール等が挙げられ、ｎ−ドデセニルエチレングリコール、ｎ−ドデセニルトリエチレングリコール等が好ましく用いられる。
【００９３】
また、本発明に用いられるポリエステル樹脂の２価の酸成分としては、フタル酸、テレフタル酸、イソフタル酸、無水フタル酸などのベンゼンジカルボン酸類又はその無水物又はその低級アルキルエステル；こはく酸、アジピン酸、セバシン酸、アゼライン酸の如きアルキルジカルボン酸類又はその無水物又はその低級アルキルエステル；フマル酸、マレイン酸、シトラコン酸、イタコン酸の如き不飽和ジカルボン酸類又はその無水物又はその低級アルキルエステル等が挙げられる。
【００９４】
また、２価のアルコール成分としては、エチレングリコール、プロピレングリコール、１，３−ブタンジオール、１，４−ブタンジオール、２，３−ブタンジオール、ジエチレングリコール、トリエチレングリコール、１，５−ペンタンジオール、１，６−ヘキサンジオール、ネオペンチルグリコール、２−エチル−１，３−ヘキサンジオール、水素化ビスフェノールＡ、また式（イ）で表わされるビスフェノール及びその誘導体；
【００９５】
【化１】

（式中、Ｒはエチレン又はプロピレン基であり、ｘ及びｙはそれぞれ０以上の整数であり、かつ、ｘ＋ｙの平均値は０〜１０である。）
また式（ロ）で示されるジオール類；
【００９６】
【化２】

（式中、Ｒ’はエチレン又はプロピレン基であり、ｘ’及びｙ’はそれぞれ０以上の整数であり、かつ、ｘ’＋ｙ’の平均値は０〜１０である。）
等のジオール類が挙げられる。
【００９７】
これらのうち少なくともプロポキシ化及び／又はエトキシ化したエーテル化ビスフェノールを用いることが好ましい。
【００９８】
更に、本発明に用い得る３価以上のアルコール成分としては、例えばソルビトール、１，２，３，６−ヘキサンテトロール、１，４−ソルビタン、ペンタエリスリトール、ジペンタエリスリトール、トリペンタエリスリトール、ショ糖、１，２，４−メンタトリオール、グリセリン、２−メチルプロパントリオール、２−メチル−１，２，４−ブタントリオール、トリメチロールエタン、トリメチロールプロパン、１，３，５−トリヒドロキシメチルベンゼン等が挙げられる。
【００９９】
本発明に使用される有機金属化合物とは、例えば有機金属錯体、金属塩、キレート化合物であり、モノアゾ金属錯体、アセチルアセトン金属錯体、サルチル酸金属錯体、アルキルサルチル酸金属錯体、ジアルキルサルチル酸金属錯体、オフシナフトエ酸金属錯体、ヒドロキシカルボン酸金属錯体、ポリカルボン酸の金属塩などが挙げられる。錯有機金属錯体、金属塩、キレート化合物を構成する金属元素としては、クロム、鉄、亜鉛、アルミニウム、ジルコニウム等が挙げられ、黒トナーの場合は、無色・有色問わず使用可能であるが、有彩色のカラートナーでは、トナーの色調に影響を与えない無色または淡色のものが好ましい。
【０１００】
本発明において、有機金属化合物の金属元素としては、アルミニウム又はジルコニウムが本発明のポリエステル樹脂との架橋性に安定性があり、粘弾性コントロールが容易に行なえる点で好ましい。
【０１０１】
本発明者らは、本発明に使用される有機金属化合物として、ジルコニウム化合物、特にジルコニウムの錯化合物或いはジルコニウムの芳香族カルボン酸塩と本発明中の結着樹脂構成とを組み合わせて用いることで、低温定着性に優れ、トナー帯電の立ち上がりの良さを保持しつつ、高湿環境下から低湿環境下まで環境の変化に対して比較的安定した帯電量を示すトナーを得ることが出来ることを見出した。
【０１０２】
本発明の有機ジルコニウム化合物はジルコニウムイオンが八配位しやすいことと、カルボキシル基，水酸基などの酸素が配位し易いことなどから、ジルコニウムイオンにカルボキシル基，水酸基などが配位する機会が多くなる。従って、有機ジルコニウム化合物の結着樹脂中へのなじみが良く、分散性に優れた性質と、本発明構成を有したポリエステル樹脂を用いることにより、トナー粒子中からの脱落を防ぎ、帯電均一化と帯電の耐久安定性が得られる。
【０１０３】
また、本発明の金属架橋性をコントロールされたポリエステル樹脂におけるカルボキシル基，水酸基のジルコニウムイオンへの配位を介し、ポリマー鎖の架橋をより効果的に施すことが出来るため、本発明の目的であるゴム弾性のコントロール、粘性のコントロールすることが容易となる。また、離型性に優れ、定着部材の汚れを効果的に防止でき、フルカラーオイルレス定着を達成できる。
【０１０４】
更に、本発明で使用可能な有機ジルコニウム化合物は、本発明のポリエステル樹脂中での他の材料（顔料、染料、ワックス等）の分散を向上させることにより、帯電均一化並びに帯電の耐久安定性が得られる。その上、トナーの透明性への影響が小さくなり、カラートナーにとって鮮やかな色彩を表現するのに好ましいものとなる。
【０１０５】
これら有機ジルコニウム化合物の含有量は、結着樹脂１００重量部に対し０．１〜１０重量部、より好ましくは０．５〜６重量部の範囲で用いるのが効果的であり、従来の技術で述べたような公知の電荷制御剤と組み合わせて使用することもできる。
【０１０６】
本発明においては、有機金属化合物として芳香族ジオール，芳香族ヒドロキシカルボン酸，芳香族ポリカルボン酸のジルコニウム錯体あるいはジルコニウム錯塩を含有するトナーによって、本発明の目的をより高度に達成可能である。
【０１０７】
本発明の有機金属化合物として好ましく用いられるジルコニウム化合物は、配位子として、芳香族ジオール，芳香族ヒドロキシカルボン酸，芳香族ポリカルボン酸を２〜４個キレート形成しているジルコニウム錯体あるいはジルコニウム錯塩であることがより好ましい。塩の場合は芳香族カルボン酸イオン，芳香族ヒドロキシカルボン酸イオン，芳香族ポリカルボン酸イオンを１〜４個有しているものが好ましく、更には２〜３個有しているものが好ましい。また、キレート形成数の異なる錯体，錯塩あるいは配位子の異なる錯体，錯塩であっても良い。更に、酸イオンの数の異なる塩の混合物であっても良い。
【０１０８】
本発明中の有機金属化合物として好ましく用いられるジルコニウム化合物は、配位子として、芳香族ジオール，芳香族ヒドロキシカルボン酸，芳香族ポリカルボン酸を配位しているジルコニウム錯体あるいはジルコニウム錯塩であり、より好ましくは一般式（１）で表せるジルコニウム錯体あるいはジルコニウム錯塩である。
【０１０９】
【化３】

一般式（１）において、Ａｒは置換基としてアルキル基、アリール基、アルアルキル基、シクロアルキル基、アルケニル基、アルコキシ基、アリールオキシ基、水酸基、アルコキシカルボニル基、アリールオキシカルボニル基、アシル基、アシルオキシ基、カルボキシル基、ハロゲン、ニトロ基、シアノ基、アミノ基、アミド基、カルバモイル基を有していてもよい。芳香族残基を表わし、Ｘ，Ｙは−０−、−ＣＯ−Ｏ−を表わし、Ｘ，Ｙは同じであっても異なっていてもよく、Ｌは中性配位子、水、アルコール、アンモニア、アルキルアミン、ピリジンを表わし、Ｃ１は１価のカチオン、水素、１価の金属イオン、アンモニウム、アルキルアンモニウムを表わし、Ｃ２は２価のカチオン、２価の金属イオンを表し、ｎは２、３、４を表わし、ｍは０、２、４を表わす。各錯体または錯塩において配位子となる芳香族カルボン酸類、芳香族ジオール類は同じものであっても異なるものであってもよい。またｎ，ｍの数の異なる錯化合物の混合物であっても良い。結着樹脂中への錯体、錯塩の分散性向上の観点あるいは帯電性向上の観点から、芳香族残基としては、ベンゼン環、ナフタレン環、アントラセン環、フェナントレン環が好ましく、置換基としてはアルキル基、カルボキシル基、水酸基が好ましく、Ｌとしては水が好ましく、Ｃ１としては水素、ナトリウム、カリウム、アンモニウム、アルキルアンモニウムが好ましい。
【０１１０】
更に好ましい錯体あるいは錯塩は一般式（２）、（３）、（４）で表わせるジルコニウム錯体または塩である。
【０１１１】
【化４】

一般式（２）、（３）、（４）において、Ｒは水素、アルキル基、アリール基、アルアルキル基、シクロアルキル基、アルケニル基、アルコキシ基、アリールオキシ基、水酸基、アシルオキシ基、アルコキシカルボニル基、アリールオキシカルボニル基、アシル基、カルボキシル基、ハロゲン、ニトロ基、アミノ基、カルバモイル基を表わし、相互に連結して脂肪族環、芳香環あるいは複素環を形成しても良く、この場合この環に置換基Ｒを有していても良く、置換基Ｒは１から８個持っていてもよく、それぞれ同じであっても、異なっていてもよく、Ｃは１価のカチオン、水素、アルカリ金属、アンモニウム、アルキルアンモニウムを表わし、１は１〜８の整数を表わし、ｎは２、３、４を表わし、ｍは０、２、４を表わし、各錯体または錯塩において配位子となる芳香族カルボン酸類、芳香族ジオール類は同じ物であっても異なるものであってもよい。またｎ，ｍの数の異なる錯化合物の混合物であっても良い。結着樹脂中への錯体、錯塩の分散性向上の観点あるいは帯電性向上の観点から、置換基Ｒとしてはアルキル基、アルケニル基、カルボキシル基、水酸基が好ましく、Ｃとしては水素、ナトリウム、カリウム、アンモニウム、アルキルアンモニウムが好ましい。特に好ましいのは、カウンターイオンを有さない、一般式においてｎ＝２の場合のジルコニウム中性錯体であり、優れた環境安定性が得られ、結着樹脂中への分散性にも優れ、良好な耐久性が得られる。
【０１１２】
本発明に用いられるジルコニワム錯体あるいは錯塩は、六配位または八配位の錯化合物で、八配位の中には、配位子が橋かけした複核錯化合物となり示性式上六配位となる錯化合物がある。このような錯化合物の構造の代表的なものを、以下の一般化学式（５）〜（９）でその構造を例示する。以下の構造の中には配位子Ｌを持たないものも包含する。
【０１１３】
【化５】

【０１１４】
【化６】

本発明に使用される好ましい芳香族カルボン酸のジルコニウム塩を一般式（１０）及び（１１）で示す。
【０１１５】
【化７】

一般式（１０）、（１１）において、Ａｒは置換基としてアルキル基、アリール基、アルアルキル基、シクロアルキル基、アルケニル基、アルコキシ基、アリールオキシ基、水酸基、アシルオキシ基、アルコキシカルボニル基、アリールオキシカルボニル基、アシル基、カルボキシル基、ハロゲン、ニトロ基、シアノ基、アミノ基、アミド基、カルバモイル基を有していてもよい、芳香族残基を表わし、Ａ１は１価のアニオン、ハロゲンイオン、水酸イオン、硝酸イオンを表わし、Ａ２は２価のアニオン、硫酸イオン、リン酸水素イオンを表し、ｎは１，２，３又は４を表わす。各金属塩において酸イオンとなる芳香族カルボン酸類、芳香族ジオール類は同じものであっても異なるものであってもよい。また、ｎの数が異なる塩の混合物であっても良い。結着樹脂中への金属塩の分散性向上の観点あるいは帯電性向上の観点から、芳香族残基としては、ベンゼン環、ナフタレン環、アントラセン環、フェナントレン環が好ましく、置換基としてはアルキル基、カルボキシル基、水酸基、アシルオキシ基が好ましく、一般式（１０）ではｎが４のもの、一般式（１１）ではｎが２のものが好ましい。
【０１１６】
更に好ましい金属塩は一般式（１２）、（１３）で表わせるジルコニウム塩である。
【０１１７】
【化８】

一般式（１２）及び（１３）において、Ｒは水素、アルキル基、アリール基、アルアルキル基、シクロアルキル基、アルケニル基、アルコキシ基、アリールオキシ基、水酸基、アルコキシカルボニル基、アリールオキシカルボニル基、アシルオキシ基、アシル基、カルボキシル基、ハロゲン、ニトロ基、アミノ基、アミド基、カルバモイル基を表わし、相互に連結して脂肪族環、芳香環あるいは複素環を形成しても良く、この場合この環に置換基Ｒを有していても良い、置換基Ｒは１から８個持っていてもよく、それぞれ同じであっても、異なっていてもよく、Ａ１は１価のアニオン、ハロゲンイオン、水酸イオン、硝酸イオンを表わし、Ａ２は２価のアニオン、硫酸イオン、リン酸水素イオンを表し、ｌは１〜８の整数を表わし、ｎは１，２，３又は４を表わす。各金属塩において酸イオンとなる芳香族カルボン酸類、芳香族ジオール類は同じものであっても異なるものであってもよい。また、ｎの数が異なる塩の混合物であっても良い。結着樹脂中への金属塩の分散性向上の観点あるいは帯電性向上の観点から、置換基としてはアルキル基、アルケニル基、カルボキシル基、水酸基、アシルオキシ基が好ましく、一般式（１２）ではｎが４のもの、一般式（１３）ではｎが２のものが好ましく、優れた環境安定性が得られ、結着樹脂中への分散性にも優れ、優れた耐久性が得られる。
【０１１８】
本発明の有機ジルコニウム化合物は、塩化酸化ジルコニウム、硫酸ジルコニウム、有機酸ジルコニウムなどのジルコニウム化合物を水、アルコール、アルコール水溶液に溶解し、芳香族カルボン酸、芳香族ジオールおよびこれらのアルカリ金属塩を添加するか、あるいは芳香族カルボン酸、芳香族ジオールとアルカリ剤を添加することにより合成される。これらの有機ジルコニウム化合物は、アルコール水溶液などで再結晶し、アルコール洗浄で精製する。また、錯塩の場合は、生成物を鉱酸、アルカリ剤、アミン剤で処理することにより種々のカウンターイオンを持つ錯塩が得られる。本発明においては、ジルコニウム錯塩のカウンターイオンに水素イオン、アルカリ金属イオン、アンモニウムイオンなど複数種有しているものも含む。
【０１１９】
以下に、本発明に用いられる有機ジルコニウム化合物の具体例を挙げるが、ここでは、示性式を示す。水分子を２〜４個配位しているものも含まれるが、ここでは水分子の記載を省略する。また、カウンターイオンは複数種有するものも含むが、ここでは一番多いカウンターイオンのみを記載する。
【０１２０】
【化９】

【０１２１】
【化１０】

【０１２２】
【化１１】

【０１２３】
【化１２】

【０１２４】
【化１３】

【０１２５】
【化１４】

【０１２６】
【化１５】

【０１２７】
【化１６】

【０１２８】
【化１７】

【０１２９】
【化１８】

【０１３０】
【化１９】

【０１３１】
【化２０】

【０１３２】
【化２１】

【０１３３】
【化２２】

【０１３４】
【化２３】

【０１３５】
【化２４】

【０１３６】
【化２５】

【０１３７】
【化２６】

【０１３８】
【化２７】

【０１３９】
【化２８】

【０１４０】
【化２９】

【０１４１】
【化３０】

【０１４２】
【化３１】

【０１４３】
【化３２】

【０１４４】
本発明に用いられる着色剤としては、従来公知の着色剤が使用できる。
【０１４５】
例えば、シアントナーに用いられるシアン着色剤としては、銅フタロシアニン化合物及びその誘導体，アンスラキノン化合物，塩基染料レーキ化合物等が利用できる。具体的には、Ｃ．Ｉ．ピグメントブルー１、７、１５、１５：１、１５：２、１５：３、１５：４、６０、６２、６６等が好適に利用できる。
【０１４６】
マゼンタトナーに用いられるマゼンタ着色剤としては、縮合アゾ化合物，ジケトピロロピロール化合物，アンスラキノン，キナクリドン化合物，塩基染料レーキ化合物，ナフトール化合物，ベンズイミダゾロン化合物，チオインジゴ化合物，ペリレン化合物が用いられる。具体的には、Ｃ．Ｉ．ピグメントレッド２、３、５、６、７、２３、４８；２、４８；３、４８；４、５７；１、８１；１、１２２、１４４、１４６、１６６、１６９、１７７、１８４、１８５、２０２、２０６、２２０、２２１、２５４が好ましい。
【０１４７】
イエロートナーに用いられるイエロー着色剤としては、縮合アゾ化合物，イソインドリノン化合物，アンスラキノン化合物，アゾ金属錯体，メチン化合物，アリルアミド化合物に代表される化合物が用いられる。具体的には、Ｃ．Ｉ．ピグメントイエロー１２、１３、１４、１５、１７、６２、７４、８３、９３、９４、９５、１０９、１１０、１１１、１２８、１２９、１４７、１６８等が好ましい。
【０１４８】
ブラックトナーに用いられるブラック着色剤としては、カーボンブラック、磁性体、上記に示したシアン／マゼンタ／イエロー着色剤を用い黒色に調色されたもの等が利用できる。
【０１４９】
これらの着色剤は、単独又は混合し更には固溶体の状態で用いることができる。本発明において着色剤は、色相角，彩度，明度，耐候性，ＯＨＰ透明性，トナー中への分散性の点から選択される。該着色剤の添加量は、樹脂成分１００重量部に対し１〜２０重量部添加して用いることが好ましい。
【０１５０】
上記有彩色の着色剤の中でも、シアントナーは銅フタロシアニン系の有機顔料を含有させることが、マゼンタトナーはキナクリドン系の有機顔料を含有することが、イエロートナーはジアリーリド系の有機顔料を含有していることが、トナーの良好な帯電性、流動性及び分光反射特性を得られる点で特に好ましく良い。
【０１５１】
銅フタロシアニン系の有機顔料としては、Ｃ．Ｉ．ピグメントブルー１５；１５：１；１５：２；１５：３；１５：４が挙げられる。さらに式（ハ）で示される構造を有するフタロシアニン骨格にフタルイミドメチル基を１〜５個置換したフタロシアニン顔料が挙げられる。他の置換基のついた銅フタロシアニン系の顔料であっても良い。
【０１５２】
【化３３】

【０１５３】
その含有量としては、結着樹脂１００重量部に対して０．１〜１２重量部であり、好ましくは０．５〜１０重量部、より好ましくは１〜８重量部が良い。１２重量部を上回るとシアントナーの彩度、明度が低下し、色再現能力が低下する。
【０１５４】
キナクリドン系の有機顔料としては、Ｃ．Ｉ．ピグメントレッド１２２が好ましく、Ｃ．Ｉ．ピグメントレッド１９２，２０２，２０６，２０７，２０９も好ましい。さらにＣ．Ｉ．ピグメントバイオレット１９も好ましい。Ｃ．Ｉ．ピグメントレッド１２２をベース顔料として、他の着色剤と併用しても良い。その際用いられる顔料としては、Ｃ．Ｉ．ピグメントレッド１，２，３，４，５，６，７，８，９，１０，１１，１２，１３，１４，１５，１６，１７，１８，１９，２１，２２，２３，３０，３１，３２，３７，３８，３９，４０，４１，４８，４９，５０，５１，５２，５３，５４，５５，５７，５８，６０，６３，６４，６８，８１，８３，８７，８８，８９，９０，１１２，１１４，１２３，１４６，１５０，１６３，１８４，１８５，２３８；Ｃ．Ｉ．ピグメントバイオレット１９；Ｃ．Ｉ．バットレッド１，２，１０，１３，１５，２３，２９，３５等が挙げられる。キサンテン系染料に代表される様な染料を一部併用しても良い。
【０１５５】
その含有量は結着樹脂１００重量部に対して、０．１〜１５重量部であり、好ましくは１〜１２重量部、より好ましくは１〜１０重量部である。他の染顔料と併用する場合であっても、他の染顔料は、キナクリドン系顔料１００重量部に対して５０重量部以下、好ましくは２５重量部以下が良い。
【０１５６】
ジアリーリド系の有機顔料としては、Ｃ．Ｉ．ピグメントイエロー１２，１３，１４，１７，８１，１０６，１１３が好ましく、さらに、Ｃ．Ｉ．ピグメントイエロー５５，６３，８３，８７，９０，１１４，１２１，１２４，１２６，１２７，１３６，１５２，１７０，１７１，１７２，１７４，１７６，１８８であっても良い。
【０１５７】
さらに、Ｃ．Ｉ．ピグメントイエロー１２，１３，１４，１７，８１をベース顔料として、他のイエロー着色剤と併用しても良く、イエロー系の染料と一部併用しても特に何ら構ない。
【０１５８】
その含有量は、結着樹脂１００重量部に対して０．１〜１２重量部であり、好ましくは０．５〜１０重量部、より好ましくは１〜８重量部が良い。
【０１５９】
ブラック着色剤として、特に磁性体を用いる場合には、他の着色剤と異なり、樹脂成分１００重量部に対し２０〜２００重量部、特に好ましくは４０〜１５０重量部添加して用いることが良い。
【０１６０】
磁性体としては、マグネタイト，マグヘマタイト，フェライト等の酸化鉄；鉄，コバルト，ニッケルのような金属あるいはこれらの金属とアルミニウム，コバルト，銅，鉛，マグネシウム，マンガン，セレン，チタン，タングステン，バナジウムのような金属の合金及びその混合物が用いられ、その磁性体表面あるいは内部に非鉄元素を含有するものが好ましい。
【０１６１】
これら磁性体は、異種元素を含有するマグネタイト，マグヘマイト，フェライト等の磁性酸化鉄及びその混合物が好ましく用いられる。中でもリチウム，ベリリウム，ボロン，マグネシウム，アルミニウム，シリコン，リン，ゲルマニウム，チタン，ジルコニウム，錫，鉛，亜鉛，カルシウム，バリウム，スカンジウム，バナジウム，クロム，マンガン，コバルト，銅，ニッケル，ガリウム，カドミウム，インジウム，銀，パラジウム，金，水銀，白金，タングステン，モリブデン，ニオブ，オスミウム，ストロンチウム，イットリウム，テクネチウム，ルテニウム，ロジウム，ビスマスから選ばれる少なくとも一つ以上の元素を含有する磁性酸化鉄であることが好ましい。特にリチウム，ベリリウム，ボロン，マグネシウム，アルミニウム，シリコン，リン，ゲルマニウム，ジルコニウム，錫，第４周期の遷移金属元素が好ましい元素である。これらの元素は酸化鉄結晶格子の中に取り込まれても良いし、酸化物として酸化鉄中に取り込まれても良いし、表面に酸化物あるいは水酸化物として存在しても良い。また、酸化物として含有されているのが好ましい形態である。
【０１６２】
また、これらの磁性体は粒度分布が揃い、その結着樹脂への分散性とあいまって、トナーの帯電性を安定化することが出来る。近年はトナー粒径の小径化が進んでおり、重量平均粒径１０μｍ以下のような場合でも、帯電均一性が促進され、トナーの凝集性も軽減され、画像濃度の向上，カブリの改善等現像性が向上する。特に重量平均粒径６．０μｍ以下のトナーにおいてはその効果は顕著であり、きわめて高精細な画像が得られる。重量平均粒径は２．５μｍ以上である方が十分な画像濃度が得られて好ましい。
【０１６３】
これらの異種元素の含有率は磁性酸化鉄の鉄元素を基準として０．０５〜１０重量％であることが好ましい。更に好ましくは０．１〜７重量％であり、特に好ましくは０．２〜５重量％、更には０．３〜４重量％である。０．０５重量％より少ないと、これら元素の含有効果が得られなく、良好な分散性，帯電均一性が得られなくなる。また、１０重量％より多くなると、電荷の放出が多くなり帯電不足を生じ、画像濃度が低くなったり、カブリが増加することがある。
【０１６４】
これら磁性体中の異種元素の含有分布においては、磁性体の表面に近い方に多く存在しているものが好ましい。例えば、酸化鉄の鉄元素溶解率が２０重量％までに存在する異種元素の含有量Ｂと該磁性酸化鉄の異種元素の全含有量Ａとの比（Ｂ／Ａ）×１００が４０％以上であることが好ましい。さらには４０〜８０％が好ましく６０〜８０％が特に好ましい。表面存在量を多くすることにより分散効果や電気的拡散効果を、より向上させることが出来る。また、トナー中に含有される量としては樹脂成分１００重量部に対して、２０〜２００重量部、特に好ましくは樹脂成分１００重量部に対して４０〜１５０重量部がより良い。
【０１６５】
また、本発明の磁性トナーに用いる磁性酸化鉄は、シランカップリング剤、チタンカップリング剤、チタネート、アミノシラン等で処理しても良い。
【０１６６】
本発明の磁性酸化鉄中の元素量は、蛍光Ｘ線分析装置ＳＹＳＴＥＭ３０８０（理学電機工業（株）社製）を使用し、ＪＩＳ Ｋ０１１９蛍光Ｘ線分析通則に従って、蛍光Ｘ線分析を行うことにより測定した。元素分布については、塩酸溶解しながらの元素量をプラズマ発光分光（ＩＣＰ）により測定定量し、各元素の全溶時の濃度に対する各溶解時の各元素濃度からその溶解率を求めた。
【０１６７】
本発明のトナーに使用される結着樹脂は、本発明中のポリエステル樹脂に加えて、本発明に悪影響の無い程度で他の樹脂との併用が可能である。
【０１６８】
例えば、ポリスチレン，ポリ−ｐ−クロルスチレン，ポリビニルトルエンなどのスチレンおよびその置換体の単重合体；スチレン−ｐ−クロルスチレン共重合体，スチレン−ビニルトルエン共重合体，スチレン−ビニルナフタリン共重合体，スチレン−アクリル酸エステル共重合体，スチレン−メタクリル酸エステル共重合体，スチレン−α−クロルメタクリル酸メチル共重合体，スチレン−アクリロニトリル共重合体，スチレン−ビニルメチルエーテル共重合体，スチレン−ビニルエチルエーテル共重合体，スチレン−ビニルメチルケトン共重合体，スチレン−ブタジエン共重合体，スチレン−イソプレン共重合体，スチレン−アクリロニトリル−インデン共重合体などのスチレン系共重合体；ポリ塩化ビニル，フェノール樹脂，天然変性フェノール樹脂，天然樹脂変性マレイン酸樹脂，アクリル樹脂，メタクリル樹脂，ポリ酢酸ビニール，シリコーン樹脂，ポリエステル樹脂，ポリウレタン，ポリアミド樹脂，フラン樹脂，エポキシ樹脂，キシレン樹脂，ポリビニルブチラール，テルペン樹脂，クマロンインデン樹脂，石油系樹脂などが使用できる。好ましい結着物質としては、スチレン系共重合体がある。
【０１６９】
スチレン系共重合体のスチレンモノマーに対するコモノマーとしては、例えば、アクリル酸，アクリル酸メチル，アクリル酸エチル，アクリル酸ブチル，アクリル酸ドデシル，アクリル酸オクチル，アクリル酸−２−エチルヘキシル，アクリル酸フェニル，メタクリル酸，メタクリル酸メチル，メタクリル酸エチル，メタクリル酸ブチル，メタクリル酸オクチル，アクリロニトリル，メタクリニトリル，アクリルアミドなどのような二重結合を有するモノカルボン酸もしくはその置換体；例えば、マレイン酸，マレイン酸ブチル，マレイン酸メチル，マレイン酸ジメチルなどのような二重結合を有するジカルボン酸およびその置換体；例えば塩化ビニル，酢酸ビニル，安息香酸ビニルなどのようなビニルエステル類；例えばエチレン，プロピレン，ブチレンなどのようなエチレン系オレフィン類；例えばビニルメチルケトン，ビニルヘキシルケトンなどのようなビニルケトン類；例えばビニルメチルエーテル，ビニルエチルエーテル，ビニルイソブチルエーテルなどのようなビニルエーテル類；等のビニル単量体が単独もしくは２つ以上用いられる。
【０１７０】
本発明に係る樹脂組成物は、保存性の観点から、ガラス転移温度（Ｔｇ）が４５〜７５℃、好ましくは５０〜７０℃であり、Ｔｇが４５℃より低いと高温雰囲気下でトナーが劣化し易く、定着時にオフセットが発生し易くなる。また、Ｔｇが７５℃を超えると、定着性が低下する傾向にある。
【０１７１】
また、本発明のトナーには、無機微粉体または疎水性無機微粉体が混合されることが好ましい。例えば、シリカ微粉末、アルミナ微粉末、酸化チタン微粉末を添加して用いることがより好ましい。
【０１７２】
本発明に用いられるシリカ微粉体は、ケイ素ハロゲン化合物の蒸気相酸化により生成されたいわゆる乾式法またはヒュームドシリカと称される乾式シリカ及び水ガラス等から製造されるいわゆる湿式シリカの両方が使用可能であるが、表面及び内部にあるシラノール基が少なく、製造残渣のない乾式シリカの方が好ましい。
【０１７３】
さらに本発明に用いるシリカ微粉体等は疎水化処理されているものが好ましい。疎水化処理するには、シリカ微粉体と反応あるいは物理吸着する有機ケイ素化合物などで化学的に処理することによって付与される。好ましい方法としては、ケイ素ハロゲン化合物の蒸気相酸化により生成された乾式シリカ微粉体をシランカップリング剤で処理した後、あるいはシランカップリング剤で処理すると同時にシリコーンオイルの如き有機ケイ素化合物で処理する方法が挙げられる。
【０１７４】
疎水化処理に使用されるシランカップリング剤としては、例えばヘキサメチルジシラザン、トリメチルシラン、トリメチルクロルシラン、トリメチルエトキシシラン、ジメチルジクロルシラン、メチルトリクロルシラン、アリルジメチルクロルシラン、アリルフェニルジクロルシラン、ベンジルジメチルクロルシラン、ブロムメチルジメチルクロルシラン、α−クロルエチルトリクロルシラン、β−クロルエチルトリクロルシラン、クロルメチルジメチルクロルシラン、トリオルガノシランメルカプタン、トリメチルシリルメルカプタン、トリオルガノシリルアクリレート、ビニルジメチルアセトキシシラン、ジメチルエトキシシラン、ジメチルジメトキシシラン、ジフェニルジエトキシシラン、ヘキサメチルジシロキサン、１，３−ジビニルテトラメチルジシロキサン、１，３−ジフェニルテトラメチルジシロキサンが挙げられる。
【０１７５】
有機ケイ素化合物としては、シリコーンオイルが挙げられる。好ましいシリコーンオイルとしては、２５℃における粘度がおよそ３０〜１，０００センチストークスのものが用いられ、例えばジメチルシリコーンオイル、メチルフェニルシリコーンオイル、α−メチルスチレン変性シリコーンオイル、クロルフェニルシリコーンオイル、フッ素変性シリコーンオイル等が好ましい。
【０１７６】
シリコーンオイル処理の方法は、例えばシランカップリング剤で処理されたシリカ微粉体とシリコーンオイルとをヘンシェルミキサー等の混合機を用いて直接混合しても良いし、ベースとなるシリカヘシリコーンオイルを噴射する方法によっても良い。あるいは適当な溶剤にシリコーンオイルを溶解あるいは分散せしめた後、ベースのシリカ微粉体とを混合し、溶剤を除去して作製しても良い。
【０１７７】
本発明中のトナーには、必要に応じて上記無機微粉体以外の外部添加剤を添加してもよい。
【０１７８】
例えば帯電補助剤、導電性付与剤、流動性付与剤、ケーキング防止剤、熱ロール定着時の離型剤、滑剤、研磨剤等の働きをする樹脂微粒子や無機微粒子である。
【０１７９】
例えばテフロン，ステアリン酸亜鉛，ポリ弗化ビニリデンの如き滑剤、中でもポリ弗化ビニリデンが好ましい。或いは酸化セリウム，炭化ケイ素，チタン酸ストロンチウム等の研磨剤、中でもチタン酸ストロンチウムが好ましい。或いは例えば酸化チタン，酸化アルミニウム等の流動性付与剤、中でも特に疎水性のものが好ましい。ケーキング防止剤、或いは例えばカーボンブラック，酸化亜鉛，酸化アンチモン，酸化スズ等の導電性付与剤、また逆極性の白色微粒子及び黒色微粒子を現像性向上剤として少量用いることもできる。
【０１８０】
トナーと混合される無機微粉体または疎水性無機微粉体は、トナー１００重量部に対して０．１〜５重量部（好ましくは、０．１〜３重量部）使用するのが良い。
【０１８１】
本発明に係るトナーを作製するには、上述したようなトナー構成材料をボールミル，ヘンシェルミキサー等の混合機により十分混合した後、熱ロールニーダー，エクストルーダーの熱混練機を用いてよく混練し、冷却固化後、機械的な粉砕、分級によってトナーを得る方法が好ましく、本発明に係るトナーを製造することが出来る。
【０１８２】
次に、本発明の画像形成方法について説明する。
【０１８３】
本発明の画像形成方法は、潜像保持体を帯電する帯電工程；帯電された潜像保持体に静電潜像を形成する潜像形成工程；該静電潜像をトナーによって現像してトナー画像を形成する現像工程；現像されたトナー画像を中間転写体を介して、又は介さずに記録材上に転写する転写工程；及び記録材上に転写されたトナー画像の表面に定着部材を接触させ、且つ該トナー画像に熱及び圧力を付与することにより、該トナー画像を該記録材上に定着する定着工程；を有しており、
該現像工程が、少なくとも結着樹脂、ワックス、有機金属化合物及び着色剤を有するカラートナーを用いる工程であって、
該結着樹脂が、少なくとも３価以上の多価カルボン酸単量体ユニットと、炭素数５〜３０の飽和もしくは不飽和の脂肪族炭化水素基を有する多価カルボン酸単量体ユニット及び／又は多価アルコール単量体ユニットを含有し、該結着樹脂中の該３価以上の多価カルボン酸単量体ユニットの含有量をＸａ ｍｏｌ％、該炭素数５〜３０の飽和もしくは不飽和の脂肪族炭化水素基を有する多価カルボン酸単量体ユニット及び／又は多価アルコール単量体ユニットの含有量をＹａ ｍｏｌ％としたとき、下記条件
０．５＜Ｘａ＜１５
５＜Ｙａ＜３０
２≦Ｙａ／Ｘａ≦１０
を満足する非線状ポリエステル樹脂Ａ、及び、３価以上の多価カルボン酸単量体ユニット及び３価以上の多価アルコール単量体ユニット含有しない線状のポリエステル樹脂Ｂからなり、
非線状ポリエステル樹脂Ａと線状ポリエステル樹脂Ｂの混合重量比が、２５／７５〜７５／２５であり、
且つ、示差走査熱量計（ＤＳＣ）測定による最大吸熱ピークが６０〜１３５℃にある本発明中の特定のカラートナーを用いて静電潜像を現像してトナー画像を形成する工程であることを特徴とする。
【０１８４】
トナー画像に熱及び圧力を付与することにより、該トナー画像を該記録材上に定着する定着工程に関しては、種々の方法や装置が開発されているが、現在最も一般的な方法は熱ローラーによる圧着加熱方式である。従来、熱ローラーの如き記録材上に転写されたトナー画像の表面に定着部材を接触させ、且つ該トナー画像に熱及び圧力を付与することにより、トナー画像を記録材上に定着する定着方式では、定着部材表面とトナー像とが溶融状態で加圧下で接触するためにトナー像の一部が定着部材表面に付着、転移し、次の被定着シートを汚すことがある（オフセット現象）。
【０１８５】
また、色材の３原色であるイエロー、マゼンタ、シアンの３色のトナー又はそれに黒色トナーを加えた４色のトナーを用いて、各色トナーを重ねあわて加熱定着し、トナーの混色によりフルカラー色再現を行なうカラー画像形成方式では、多色画像を紙或いはオバーヘッドプロジェクターシート（ＯＨＴ）等の被定着シート上に定着し、色再現・ＯＨＴ画像の透過性を満足しなくてはならない。このため被定着シート上のトナー層を十分に溶融し、画像表面を平滑にすることが要求される。このため、画像の平滑性とオフセット防止を両立することが求められる。
【０１８６】
これらに対し本発明は、本発明中の定着部材との離型性及び混色性に優れる特定のカラートナーを適用することで、画像の平滑性とオフセット防止を両立するものである。
【０１８７】
本発明においては、定着工程は、定着部材から記録材のトナー画像の定着面に供給される定着オイルの記録材単位面積当たりの塗布量が０〜１×１０^-7ｇ／ｃｍ²で、トナー画像を記録材上に定着する工程であることが好ましい。
【０１８８】
画像の平滑性とオフセット防止を両立する目的で、定着部材にシリコーンオイル等の定着オイルを離型剤として供給しローラ上に均一に被覆する手段が広く用いられている。定着部材から記録材のトナー画像の定着面に供給される定着オイル（例えばシリコーンオイル）の記録材単位面積当たりの塗布量の規制手段としては、ウェブ、パッド或いはローラー等にオイルを含浸させ供給する形態が可能であり、定着部材（例えばシリコーンゴムローラー）にオイルを含浸させたものでも可能である。
【０１８９】
しかし、定着オイルを塗布及び又は供給する場合、被定着シートの定着オイルによるベタツキ感、得られるカラー画像のてかり等の問題があり、初期と長期間使用後での離型剤供給量が異なることで、得られる画質（例えばグロス、オイルのベタツキ感等）が変動し易く、離型剤供給量を一定化するためには煩雑な離型剤の塗布及び又は供給機構が必要となる。簡易な手段で本発明の如く極微量の離型剤を塗布しようとする場合、オイルの塗布ムラを生じ易く、得られる画像上でのオイルの付着ムラは画像品位を大幅に低下させる。定着オイルの塗布機構或いはオイルの補充等が小型化、安価な装置、低ランニングコスト等の阻害因子となっている。
【０１９０】
これらに対し、定着部材から記録材のトナー画像の定着面に供給される定着オイルの記録材単位面積当たりの塗布量を０〜１×１０^-7ｇ／ｃｍ²とすることで、画像のてかりを抑制することが可能である。本発明中の特定のカラートナーを適用することで、画像のてかりを抑制しつつ、画像の平滑性とオフセット防止を両立することが可能である。
【０１９１】
好ましくは、カラー画像の定着オイルによるグロスのムラを抑制するために、定着部材から記録材のトナー画像の定着面に供給される定着オイルの記録材単位面積当たりの塗布量は、０〜３×１０^-8ｇ／ｃｍ²であることが良く、より好ましくは０〜１×１０^-8ｇ／ｃｍ²であることが良い。
【０１９２】
更に本発明においては、定着工程は、定着部材から記録材に定着オイルを供給することなくトナー画像を記録材上に定着する工程であることが好ましく良い。
【０１９３】
本発明の目的の一つである完全オイルレス定着、即ちシリコーンオイル等の定着オイルを塗布しない（定着部材が転写材上のトナー画像に接触する表面の定着オイル存在量が実質的に０ｇ／ｃｍ²）ことによって、カラー画像形成装置の小型化、低コスト化が可能であり、繰り返し使用或いは経時での定着オイルの供給量の変化によるカラー画像品位の変化がなくなる。本発明中の特定のカラートナーを適用することで、完全オイルレス定着においても、オフセットを防止しつつ、画像の平滑性に優れ適度で安定したグロスを示すカラー画像を小型、低コストの装置で得ることが可能となる。
【０１９４】
次に、本発明の画像形成方法における定着工程について、熱ロール定着を例として図９を基に説明する。
【０１９５】
本発明の画像形成方法における定着工程は、記録材上に形成されているトナー画像の表面に定着部材を接触させ、且つトナー画像に熱及び圧力を付与することにより、トナー画像を記録材に定着するものであり、このトナー画像を形成するためのトナーとして上述した本発明中の特定のトナーを用いるものである。
【０１９６】
例えば、記録材上に転写された未定着のトナー画像は、図９に示す加熱ローラ１５３及び加圧ローラ１５４を有する加熱加圧定着装置へ導入され加熱定着される。
【０１９７】
定着装置の機械的構成としては、記録材１６０上のトナー画像１６１が直接接触する側の定着ローラー１５３として弾性ローラーを使用することが好ましい。即ち、定着ローラーが弾性を有する場合は、未定着のトナー画像表面の凹凸に対して定着ローラー表面自身が変形して押圧するために、トナー画像の均一な加熱、加圧が可能となり、光沢性の均一化に一層効果的である。
【０１９８】
本発明の画像形成方法においては、記録材上１６０に重ねられた複数色のカラートナー画像を、接触加熱及び加圧する定着部材によって定着する工程を有しており、記録材１６０へのトナー画像１６１の定着時に、定着部材である定着ローラー１５３から記録材１６０のトナー画像１６１の定着面に供給されるシリコーンオイルの記録材単位面積当たりの塗布量が０〜１×１０^-7ｇ／ｃｍ²、好ましくは０乃至３×１０^-8ｇ／ｃｍ²、より好ましくはシリコーンオイルを塗布しない（０ｇ／ｃｍ²）ことが良い。
【０１９９】
また、必要に応じて記録材１６０と定着ローラー１５３または加圧ローラー１５４との分離爪１５９が定着装置に設けられる。
【０２００】
本発明の定着部材へのシリコーンオイルの塗布形態としては、ウェブ或はパッド等にシリコーンオイルのを含浸させ供給する簡易な形態が可能である。また、予め定着部材、例えばシリコーンゴムローラにオイルを含浸させたものでも可能である。
【０２０１】
定着温度は１４０〜１８０℃程度の範囲が好ましく、加圧力は２０〜６０ｋｇｆ程度が好ましい。
【０２０２】
本発明においては、上記の画像形成方法の説明で用いた画像形成装置を構成する各構成部材のうち複数の構成部材をユニット化して、画像形成装置本体に脱離可能に装着できる装置ユニットを構成することができる。
【０２０３】
本発明の装置ユニットは、静電潜像を現像するためのトナー、該トナーを保有するためのトナー容器、該トナー容器に保有されているトナーを担持し、且つ現像領域に搬送するためのトナー担持体、及び該トナー担持体に担持されるトナーの層厚を規制するためのトナー層厚規制部材を少なくとも有しており、画像形成装置本体に脱離可能に装着されるものであり、このトナーとして上述した本発明のトナーを用いる。
【０２０４】
このような装置ユニットとしては、例えば図７に示す現像装置１７０及び図８に示す現像装置１８０が挙げられる。
【０２０５】
図７に示す現像装置１７０を装置ユニットとする場合には、トナー容器としての現像容器１７１、トナーとしての一成分現像剤１７６、トナー担持体としての現像スリーブ１７２、及びトナー層厚規制部材としての弾性ブレード１７４に加えて、現像剤スリーブ１７２上に一成分現像剤を供給するための供給ローラー１７３をユニット化して構成しても良い。
【０２０６】
図８に示す現像装置１８０を装置ユニットとする場合には、トナー容器としての現像容器１８１、トナーとしての一成分現像剤１８８、トナー担持体としての弾性ローラー１８２、及び、トナー層厚規制部材としての弾性ブレード１８６に加えて、弾性ローラー１８２上に一成分現像剤を供給するための供給ローラー１８５及び現像容器内１８１内の一成分現像剤１８８を攪拌するための攪拌部材１８７をユニット化して構成しても良い。
【０２０７】
更に図７に示す現像装置１７０又は図８に示す現像装置１８０を、例えば図３に示すフルカラー画像形成装置の現像手段１７ａ、１７ｂ、１７ｃ及び１７ｄにそれぞれ用いる場合、装置ユニットとして現像手段１７ａと潜像保持体としての感光ドラム１９ａとをユニット化して装置ユニットを構成することができ、この装置ユニットを画像形成装置本体に脱離可能に装着することができる。同様に現像手段１７ｂと感光ドラム１９ｂとを、現像手段１７ｃと感光ドラム１９ｃとを、現像手段１７ｄと感光ドラム１９ｄとをそれぞれユニット化して装置ユニットを構成することができる。
【０２０８】
この場合には、現像手段１７ａ及び感光ドラム１９ａに加えて、クリーニング手段１８ａを加えてユニット化した装置ユニットを構成することができる。
【０２０９】
本発明の画像形成方法及び画像形成装置について詳細に説明する。
【０２１０】
本発明の画像形成方法は、
潜像保持体を帯電する帯電工程；
帯電された潜像保持体に静電潜像を形成する潜像形成工程；
該静電潜像をトナーによって現像してトナー画像を形成する現像工程；
現像されたトナー画像を中間転写体を介して、又は介さずに記録材上に転写する転写工程；
及び記録材上に転写されたトナー画像の表面に定着部材を接触させ、且つ該トナー画像に熱及び圧力を付与することにより、該トナー画像を該記録材上に定着する定着工程；
を有するものであり、現像工程において用いるトナーとして上述の如く本発明中の特定のトナーを用いるものである。
【０２１１】
帯電工程において、帯電部材としては、コロナ帯電器の如き潜像担持体の表面に非接触で帯電を行う非接触帯電部材、ブレード、ローラー及びブラシの如き潜像担持体の表面に接触して帯電を行う接触帯電部材、ブレード及びローラー如き帯電部材を潜像担持体の表面に（１ｍｍ以下に）近接させて帯電を行う近接帯電部材のいずれも用いることができるが、帯電時のオゾンの発生を少なくできることから、接触帯電部材或いは近接帯電部材を用いることが好ましい。
【０２１２】
接触帯電は、感光体に、ローラー型、ブレード型、ブラシ型、磁気ブラシ型等の電荷供給部材としての帯電部材を接触させ、この接触帯電部材に所定の帯電バイアスを印加して感光体面を所定の極性・電位に一様帯電させるものである。コロナ帯電器による帯電処理との対比において、電源の低電圧化が図れ、オゾンの発生量が少ない、低電力化等の長所を有している。この中でも特に接触帯電部材として導電ローラー（帯電ローラー）を用いたローラー帯電方式が帯電の安定性という点から好ましく用いられている。
【０２１３】
具体的には、帯電は帯電部材から被帯電体への放電によって行なわれるため、ある閾値電圧以上の電圧を印加することによって帯電が開始される。例を示すと、ある有機感光体に対して帯電ローラーを加圧当接させた場合には、約６４０Ｖ以上の電圧を印加すれば感光体の表面電位が上昇を始め、それ以降は印加電圧に対して傾き１で線形に感光体表面電位が増加する。以後、この閾値電圧を放電開始電圧（帯電開始電圧）Ｖｔｈと定義する（接触帯電部材に直流電圧を印加して被帯電体としての像担持体の帯電が開始する場合の接触帯電部材への印加電圧値）。
【０２１４】
このようにしてＤＣ電圧のみを接触帯電部材に印加して帯電を行なう方式を「ＤＣ帯電方式」と称す。
【０２１５】
しかし、ＤＣ帯電方式においては環境変動等によって接触帯電部材の抵抗値が変動するため、また感光体が削れることによって膜厚が変化すると放電開始電圧Ｖｔｈが変動するため、感光体の電位を所望の値にすることが難しかった。
【０２１６】
そこで、更なる帯電の均一化を図るために特開昭６３−１４９６６９号公報に開示されるように、所望の被帯電体表面電位Ｖに相当するＤＣ電圧に２×Ｖｔｈ以上のピーク間電圧を持つ交流電圧成分（ＡＣ電圧成分）を重畳した電圧（交番電圧・脈流電圧・振動電圧；時間とともに電圧値が周期的に変化する電圧）を接触帯電部材に印加する「ＡＣ帯電方式」が用いられる。これはＡＣ電圧による電位のならし効果を目的としたものであり、被帯電体の電位はＡＣ電圧のピークの中央である電位Ｖに収束し、環境等の外乱には影響されることはなく、接触帯電方法として優れた方法である。
【０２１７】
ここで、ＡＣ電圧の波形としては、正弦波、矩形波、三角波等適宜使用可能である。また直流電源を周期的にオン／オフすることによって形成された矩形波であってもよい。このようにＡＣ電圧の波形としては周期的にその電圧値が変化するようなバイアスが使用できる。
【０２１８】
被帯電体としての像担持体の表面に電荷注入層（充電層）を具備させ、電圧を印加した接触帯電部材で電荷注入層に直接に電荷を注入して像担持体面を所定の極性・電位に帯電させる注入帯電方式もあり、これも接触帯電の範疇である。
【０２１９】
近接帯電は、帯電部材は被帯電体面に必ずしも接触させなくとも帯電部材と被帯電体面との間に、ギャップ間電圧とパッシェンカーブで決まる放電可能領域さえ確実に保証されれば、非接触で近接した配設形態であっても被帯電体の帯電を行なわせることができることを利用したものである。
【０２２０】
近接帯電は、帯電部材を被帯電体面に対して数１０〜数１００μｍ程度の僅少な空隙部を存在させて非接触に対向配設し、該帯電部材にＤＣ電圧あるいはＤＣ＋ＡＣ電圧を印加することで被帯電体面を所定の極性・電位に一様帯電させるものである。
【０２２１】
近接帯電もコロナ帯電器による帯電処理との対比において、電源の低電圧化が図れ、オゾンの発生量が少ない上、さらに帯電部材が被帯電体に非接触であるため被帯電体に損傷を与えないメリットがある。
【０２２２】
潜像担持体としては、アモルファスセレン，硫化カドミウム，酸化亜鉛，有機光導電体，アモルファスシリコンの様な光導電絶縁物質層を持つ電子写真感光体・静電記録誘電体等が例示され、感光体ドラムもしくは感光ベルト等として用いられる。これらのうち、潜像担持体としては、アモルファスシリコン感光層又は有機系感光層を有する感光体が好ましく用いられる。
【０２２３】
有機感光層としては、感光層が電荷発生物質及び電荷輸送性能を有する物質を同一層に含有する単一層型でもよく、又は、電荷輸送層と電荷発生層を成分とする機能分離型感光層であってもよい。導電性基体上に電荷発生層、次いで電荷輸送層の順で積層されている構造の積層型感光層は好ましい例のひとつである。
【０２２４】
本発明に用いられる像担持体の好ましい態様のひとつを以下に説明する。
【０２２５】
導電性基体としては、アルミニウム、ステンレスの如き金属；アルミニウム合金、酸化インジウム−酸化錫合金による被膜層を有するプラスチック；導電性粒子を含浸させた紙、プラスチック、導電性ポリマーを有するプラスチック等の円筒状シリンダー及びフィルムが用いられる。すなわち、導電材料をそのままドラム形状或いはベルト等のフィルム形状に成形加工してもよいし、塗料として、或いは蒸着、エッチング、プラズマ処理等によって加工してもよい。
【０２２６】
これら導電性基体上には、感光層の接着性向上、塗工性改良、基体の保護、基体上の欠陥の被覆、基体からの電荷注入性改良、感光層の電気的破壊に対する保護を目的として下引き層を設けても良い。下引き層は、ポリビニルアルコール、ポリ−Ｎ−ビニルイミダゾール、ポリエチレンオキシド、エチルセルロース、メチルセルロース、ニトロセルロース、エチレン−アクリル酸コポリマー、ポリビニルブチラール、フェノール樹脂、カゼイン、ポリアミド、共重合ナイロン、ニカワ、ゼラチン、ポリウレタン、酸化アルミニウム等の材料によって形成される。その膜厚は通常０．１〜１０μｍ、より好ましくは０．１〜３μｍが良い。
【０２２７】
電荷発生層は、アゾ系顔料、フタロシアニン系顔料、インジゴ系顔料、ペリレン系顔料、多環キノン系顔料、スクワリリウム色素、ピリリウム塩類、チオピリリウム塩類、トリフェニルメタン系色素の如き有機化合物又は非晶質シリコンの如き無機物質で形成されている電荷発生物質を適当な結着材に分散し塗工あるいは蒸着により形成される。結着材としては、広範囲な結着性樹脂から選択できる。例えば、ポリカーボネート樹脂、ポリエステル樹脂、ポリビニルブチラール樹脂、ポリスチレン樹脂、アクリル樹脂、メタクリル樹脂、フェノール樹脂、シリコーン樹脂、エポキシ樹脂、酢酸ビニル樹脂等が挙げられる。電荷発生層中に含有される結着材の量は８０重量％以下、好ましくは０〜４０重量％が良い。電荷発生層の膜厚は５μｍ以下、特には０．０５〜２μｍが好ましい。
【０２２８】
電荷輸送層は、電荷の存在下で電荷発生層から電荷キャリアを受け取り、これを輸送する機能を有している。電荷輸送層は電荷輸送物質を必要に応じて結着樹脂と共に溶剤中に溶解し、塗工することによって形成され、その膜厚は一般的には５〜４０μｍである。電荷輸送物質としては、主鎖または側鎖にビフェニレン、アントラセン、ピレン、フェナントレンの如き構造を有する多環芳香族化合物、インドール、カルバゾール、オキサジアゾール、ピラゾリンの如き含窒素環式化合物、ヒドラゾン化合物、スチリル化合物、非晶質シリコン等が挙げられる。
【０２２９】
これら電荷輸送物質を分散させる結着樹脂としては、ポリカーボネート樹脂、ポリエステル樹脂、ポリメタクリル酸エステル、ポリスチレン樹脂、アクリル樹脂、ポリアミド樹脂の如き樹脂；ポリ−Ｎ−ビニルカルバゾール、ポリビニルアントラセンの如き有機光導電性ポリマー等が挙げられる。
【０２３０】
また、本発明方法に用いられる有機感光体の別の様態としては、上述の電荷発生物質及び電荷輪送能を有する物質を同一層に含有させた感光層を導電性基体上に形成したもの等も挙げられる。
【０２３１】
また、表面層として、保護層を設けてもよい。保護層の樹脂としては、ポリエステル樹脂、ポリカーボネイト樹脂、アクリル樹脂、エポキシ樹脂、フェノール樹脂、あるいはこれらの樹脂を硬化剤で硬化させたものが挙げられる。これらは単独あるいは２種以上組み合わされて用いられる。
【０２３２】
保護層の樹脂中の導電性微粒子を分散してもよい。導電性微粒子としては、金属又は金属酸化物が挙げられる。好ましくは、酸化亜鉛、酸化チタン、酸化スズ、酸化アンチモン、酸化インジウム、酸化ビスマス、酸化スズ被膜酸化チタン、スズ被膜酸化インジウム、アンチモン被膜酸化スズ、酸化ジルコニウムで形成されている超微粒子がある。これらは単独で用いても２種以上を混合して用いても良い。一般的に保護層に粒子を分散させる場合、分散粒子による入射光の散乱を防ぐために入射光の波長よりも粒子の粒径の方が小さいことが好ましい。保護層に分散される導電性粒子又は絶縁性粒子の粒径としては０．５μｍ以下であることが好ましい。保護層中での含有量は、保護層総重量に対して２〜９０重量％が好ましく、５〜８０重量％がより好ましい。保護層の膜厚は、０．１〜１０μｍが好ましく、１〜７μｍがより好ましい。
【０２３３】
表面層の塗工は、樹脂分散液をスプレーコーティング、ビームコーティングあるいは浸透コーティングすることによって行うことができる。
【０２３４】
また、表面層に離型性を付与することも好ましく、この効果により、トナーの転写効率を改良することができる。潜像担持体表面が高分子結着材を主体として構成される場合、例えば、セレン、アモルファスシリコンの如き無機感光体の上に樹脂を主体とした保護膜を設ける場合、又は機能分離型有機感光体の電荷輪送層として、電荷輸送剤と樹脂からなる表面層をもつ場合、さらにその上に保護層を設ける場合に特に有効である。
【０２３５】
表面層に離型性を付与する手段としては、イ）膜を構成する樹脂自体に表面エネルギーの低いものを用いる、ロ）撥水、親油性を付与するような添加剤を加える、ハ）高い離型性を有する材料を粉体状にして分散するが挙げられる。イ）の例としては、樹脂の構造中にフッ素含有基、シリコン含有基を導入することにより達成し得る。ロ）としては、界面活性剤を添加剤とすればよい。ハ）としては、フッ素原子を含む化合物（例えば、四フッ化エチレン、ポリフッ化ビニリデン、フッ化カーボン等）の粉体が挙げられる。この中でも特にポリ４フッ化エチレンが好適である。特に含フッ素樹脂の如き離型性粉体の最表面層への分散が好適である。
【０２３６】
これらの粉体を表面に含有させるためには、バインダー樹脂中に該粉体を分散させた層を像担持体最表面に設けるか、あるいは、元々樹脂を主体として構成されている有機像担持体であれば、新たに表面層を設けなくても、最上層に該粉体を分散させれば良い。
【０２３７】
該粉体の表面層への添加量は、表面層総重量に対して、１〜６０重量％、さらには２〜５０重量％が好ましい。１重量％より少ないと転写効率が改善されず、６０重量％を超えると膜の強度が低下したり、像担持体ヘの入射光量が低下したりするため、好ましくない。また、該粉体の粒径については、画質の面から１μｍ以下、より好ましくは０．５μｍ以下が良い。１μｍより大きいと入射光の散乱によりラインの切れが悪くなる。
【０２３８】
更に、表面層として、電荷注入層を有することも本発明の画像形成方法の好ましい様態の一つである。
【０２３９】
この電荷注入層の体積抵抗値は、十分な帯電性と画像流れを起こさないよう１×１０⁸〜１×１０¹⁵Ωｃｍであることが好ましく、より好ましくは画像流れなどの点から、体積抵抗値が１×１０¹⁰〜１×１０¹⁵Ωｃｍ、更に体積抵抗値の環境変動なども考慮すると、体積抵抗値が１×１０¹⁰〜１×１０¹⁴Ωｃｍのものを用いるのが望ましい。１×１０⁸Ωｃｍ未満では高湿環境で帯電電荷が表面方向に保持されないため画像流れを生じ、１×１０¹⁵Ωｃｍを超えると帯電部材からの帯電電荷を十分注入・保持できず、帯電不良を生じる傾向にある。このような機能層を感光体表面に設けることによって、帯電部材から注入された帯電電荷を保持する役割を果たし、更に光露光時にこの電荷を感光体基体に逃す役割を果たし、残留電位を低減させる。このような感光体と注入帯電用の接触帯電部材とを用いる構成をとることによって、帯電開始電圧Ｖｔｈが小さく、感光体帯電電位を帯電部材に印加する電圧のほとんど９０％以上までに帯電させることが可能となる。
【０２４０】
例えば、帯電部材に絶対値で１００〜２０００Ｖの直流電圧を印加した時、電荷注入層を有する電子写真感光体の帯電電位は印加電圧の８０％以上、更には９０％以上にすることができる。これに対し、従来の放電を利用した帯電によって得られる感光体の帯電電位は、印加電圧が放電開始電圧以下ではほとんど０Ｖであり、１０００Ｖの直流電圧でも印加電圧の５０％に満たない程度の帯電電位しか得られかった。
【０２４１】
電荷注入層は金属蒸着膜などの無機の層、あるいは導電性微粒子を結着樹脂中に分散させた導電性微粒子分散層などによって構成され、蒸着膜は蒸着、導電性微粒子分散膜は浸漬塗工法、スプレー塗工法、ロールコート塗工、及びビーム塗工法などの適当な塗工法にて塗工することによって形成される。また、絶縁性のバインダーに光透過性の高いイオン導電性を持つ樹脂を混合、もしくは共重合させて構成するもの、または中抵抗で光導電性のある樹脂単体で構成するものでもよい。導電性微粒子分散膜の場合、導電性微粒子の添加量は結着樹脂１００重量部に対して２〜２５０重量部、更には２〜１９０重量部であることが好ましい。２重量部未満の場合には、所望の体積抵抗値を得にくくなり、また２５０重量部を超える場合には膜強度が低下してしまい電荷注入層が削り取られ易くなり、感光体の寿命が短くなる傾向になるからであり、また抵抗が低くなってしまい、潜像電位が流れることによる画像不良を生じ易くなるからである。
【０２４２】
電荷注入層の結着樹脂としては、ポリエステル樹脂、ポリカーボネート樹脂、アクリル樹脂、エポキシ樹脂、フェノール樹脂、あるいはこれらの樹脂を硬化剤で硬化させたものが挙げられる。これらは単独あるいは２種以上組み合わされて用いられる。また、電荷注入層の結着樹脂は下層の結着樹脂と同じとすることも可能であるが、この場合には電荷注入層の塗工時に電荷輸送層の塗工面を乱してしまう可能性があるため、コート法を特に選択する必要がある。更に、感光層がアモルファスシリコンである場合は、電荷注入層はＳｉＣであることが好ましい。
【０２４３】
また、多量の導電性微粒子を分散させる場合には、反応性モノマーや反応性オリゴマーに導電性微粒子等を分散させて、感光体に塗布した後に光や熱によって硬化することが好ましい。
【０２４４】
電荷注入層の結着樹脂中に分散させる導電性微粒子としては、金属又は金属酸化物が挙げられる。好ましくは、酸化亜鉛、酸化チタン、酸化スズ、酸化アンチモン、酸化インジウム、酸化ビスマス、酸化スズ被膜酸化チタン、スズ被膜酸化インジウム、アンチモン被膜酸化スズ、酸化ジルコニウムの如き超微粒子がある。これらは単独で用いても２種以上を混合して用いても良い。電荷注入層に分散される導電性粒子又は絶縁性粒子の粒径としては０．５μｍ以下であることが好ましい。
【０２４５】
また、電荷注入層が潤滑性粉体を含有することも好ましい。その理由は、帯電時に感光体と注入帯電部材の摩擦が低減されるために帯電ニップが拡大し、帯電特性が向上するためである。特に潤滑性粉体としては臨界表面張力の低いフッ素系樹脂、シリコーン系樹脂、またはポリオレフィン系樹脂を用いるのがより望ましい。更に好ましくは４フッ化エチレン樹脂（ＰＴＦＥ）が用いられる。この場合、潤滑性粉体の添加量は、結着樹脂１００重量部に対して２〜５０重量部、更には５〜４０重量部が好ましい。２重量部未満では潤滑性粉体の量が十分ではないために、帯電特性の向上が十分でなく、また５０重量部を超えると、画像の分解能、感光体の感度が大きく低下してしまうからである。
【０２４６】
電荷注入層の膜厚は０．１〜１０μｍであることが好ましく、更には１〜７μｍであることが好ましい。膜厚が０．１μｍ未満であると微少な傷に対する耐性がなくなり、結果として注入不良による画像欠陥を生じ、１０μｍを超えると注入電荷の拡散により画像が乱れ易くなってしまう。
【０２４７】
ここで、電荷注入層の体積抵抗値の測定方法は、表面に導電膜を蒸着させたポリエチレンテレフタレート（ＰＥＴ）フィルム上に電荷注入層を作製し、これを体積抵抗測定装置（ヒューレットパッカード社製４１４０Ｂ ｐＡＭＡＴＥＲ）にて、２３℃，６５％の環境で１００Ｖの電圧を印加して測定するというものである。
【０２４８】
電荷注入層を有さない感光体では、少ないトラップ点に効率良く電荷注入をしなければならないため帯電部材の抵抗値は１×１０³Ω以下であることが必要である反面、帯電部材の抵抗値が１×１０⁴Ωｃｍ以下になってしまうと感光体表面に生じたキズ、ピンホールなどに対して接触帯電部材から過大なリーク電流が流れ込み、周辺の帯電不良や、ピンホールの拡大、帯電部材の通電破壊が生じるため良好な電荷注入帯電を行うことができなかった。これに対し、電荷注入層を設けた場合には感光体表面に電荷を保持できる領域が増加するため、もっと高い抵抗値の帯電部材を用いても良好な帯電が行える。すなわち、中抵抗の接触帯電部材を用いながら、感光体への電荷注入帯電効率を向上させる手段として、感光体への電荷注入を助けるための電荷注入層を感光体表面に設ける構成が良好な電荷注入帯電を行うには必要である。
【０２４９】
注入帯電の本質的な帯電機構は、帯電部材表層が感光体表面の電荷注入層に接触することで帯電部材表層から電荷注入層に電荷注入を行うと考えられる。従って、帯電部材として要請される特性は、該電荷注入層表面に十分な密度と、電荷の移動にかかる適正な抵抗を持つことである。
【０２５０】
中抵抗の接触帯電部材で、中抵抗の表面抵抗を持つ感光体表面に電荷注入を行うものであるが、好ましくは感光体表面材質の持つトラップ電位に電荷を注入するものではなく、光透過性で絶縁性の結着樹脂に導電性微粒子を分散した電荷注入層の導電性微粒子に電荷を充電して帯電を行う。
【０２５１】
具体的には、電荷輸送層を誘電体、アルミニウム支持体と電荷注入層内の導電性微粒子を両電極板とする微小なコンデンサーに、接触帯電部材で電荷を充電する理論に基づくものである。この際、導電性微粒子は互いに電気的には独立であり、一種の微小なフロート電極を形成している。このため、マクロ的には感光体表面は均一電位に充電、帯電されているように見えるが、実際には微小な無数の充電された導電性微粒子が感光体表面を覆っているような状況となっている。このため、画像露光を行ってもそれぞれの導電性微粒子は電気的に独立なため、静電潜像を保持することが可能になる。
【０２５２】
従って、従来の通常感光体表面に少ないながらも存在していたトラップ準位を導電性微粒子で代用することで、電荷注入性、電荷保持性が向上するのである。
【０２５３】
注入帯電における帯電部材の抵抗値は、注入帯電性と上述の耐ピンホールリーク性から１×１０⁴〜１×１０⁷Ωｃｍであることが好ましい。
【０２５４】
注入帯電部材の形状は、ブレード状、ブラシ状でもよいが、周速差を適性に設定する上では、回転可能なローラー状、ベルト状、ブラシローラー状（ブラシロール）が有利と考えられる。
【０２５５】
ローラー状の接触帯電部材としては、材質としては、例えば特開平１−２１１７９９号公報などに開示があるが、導電性基体として、鉄、銅、ステンレスなどの金属、カーボン分散樹脂、金属あるいは、金属酸化物分散樹脂などが使用できる。弾性ローラーの構成としては、導電性基体上に弾性層、導電層、抵抗層を設けたものが用いられ、ローラー弾性層としては、クロロプレンゴム、イソプレンゴム、ＥＰＤＭゴム、ポリウレタンゴム、エポキシゴム、ブチルゴムなどのゴムまたはスポンジや、スチレン−ブタジエンサーモプラスチックエラストマー、ポリウレタン系サーモプラスチックエラストマー、ポリエステル系サーモプラスチックエラストマー、エチレン−酢ビサーモプラスチックエラストマーなどのサーモプラスチックエラストマーなどで形成することができ、導電層としては、体積抵抗率が１０⁷Ωｃｍ以下、望ましくは１０⁶Ωｃｍ以下である。例えば、金属蒸着膜、導電性粒子分散樹脂、導電性樹脂などが用いられ、具体例として、金属蒸着膜としては、アルミニウム、インジウム、ニッケル、銅、鉄などの蒸着膜が挙げられ、導電性粒子分散樹脂の例としては、カーボン、アルミニウム、ニッケル、酸化チタンなどの導電性粒子をウレタン、ポリエステル、酢酸ビニル−塩化ビニル共重合体ポリメタクリル酸メチルなどの樹脂中に分散したものなどが挙げられる。導電性樹脂としては、４級アンモニウム塩含有ポリメタクリル酸メチル、ポリビニルアニリン、ポリビニルピロール、ポリジアセチレン、ポリエチレンイミンなどが挙げられる。抵抗層は、例えば、体積抵抗率が１０⁶〜１０¹²Ωｃｍの層であり、半導性樹脂、導電性粒子分散絶縁樹脂などを用いることができる。半導性樹脂としては、エチルセルロース、ニトロセルロース、メトキシメチル化ナイロン、エトキシメチル化ナイロン、共重合ナイロン、ポリビニルヒドリン、カゼインなどの樹脂が用いられる。導電性粒子分散樹脂の例としては、カーボン、アルミニウム、酸化インジウム、酸化チタンなどの導電性粒子をウレタン、ポリエステル、酢酸ビニル−塩化ビニル共重合体、ポリメタクリル酸メチルなどの絶縁性樹脂中に少量分散したものなどが挙げられる。
【０２５６】
また、接触帯電部材が感光体に対して周速差をもって移動することが好ましい。接触帯電部材の周速表面の移動速度と該感光体表面移動速度が異なるようにすることにより、帯電安定性を長期間にわたり得ながら、感光体の高寿命を保ちつつ、かつ帯電ローラの高寿命を同時に達成することが可能であり、帯電の高安定化、画像形成システムの高寿命化が達成できる。すなわち、接触帯電部材の表面にはトナーが付着しやすく、この付着トナーが帯電を阻害する傾向にあり、感光体表面移動速度と接触帯電部材表面移動速度を異ならせることにより、同一感光体表面に対し実質的により多くの接触帯電部材表面を供給できるために帯電阻害に対し効果を得る。つまり、トナーが帯電部位に来た場合、感光体との付着力の小さいトナーは電界によって帯電部材の方へ移動し、帯電部材表面の抵抗が局所的に変化するため、放電経路が遮断されて、感光体表面に電位がのりにくくなり、その結果帯電不良を発生させるという問題点を効果的に解消する。
【０２５７】
潜像形成工程においては、画像露光手段として、レーザー及びＬＥＤの如き公知の手段が用いられる。近年の高解像性、高画質への要求を鑑みて、より小さなスポット径を露光できる手段が好ましく、パワーの面からレーザーが特に好ましく用いられる。
【０２５８】
現像工程において、静電潜像を現像するための現像手段としては、トナーのみよりなる一成分系現像剤を用いる一成分系現像方式、及びトナー及びキャリアよりなる二成分系現像剤を用いる二成分系現像方式を用いることができる。
【０２５９】
一成分系現像方式として、磁性体をトナーに含有せしめた磁性トナーを用いる場合、現像スリーブ中に内蔵せしめたマグネットによる磁気拘束力を利用し、磁性トナーを搬送及び帯電せしめ、現像する方法がある。更に、一成分系現像剤として、磁性体を含有しない非磁性トナーを用いる場合には、ブレード部材、ローラー部材又はブラシ部材等を用い、現像スリーブに強制的に非磁性トナーを圧接せしめることにより、非磁性トナーを摩擦帯電し、現像スリーブ上にトナーを付着せしめることで搬送せしめ、現像する方法がある。
【０２６０】
また、二成分系現像方式は、トナー及びキャリアよりなる二成分系現像剤を現像剤担持体上で循環搬送し、潜像保持体とそれに対向する現像剤担持体の現像領域で潜像保持体に保持されている潜像を、該現像剤担持体上の二成分系現像剤のトナーで現像するものである。
【０２６１】
転写工程において、転写手段としては、コロナ帯電器、転写ローラー、転写ブレード又は転写ベルトが用いられる。
【０２６２】
転写工程において、紙、ＯＨＴシート等の記録材上に潜像保持体上に形成されているトナー像を直接転写することに加えて、中間転写体を用いて、潜像保持体上に形成されているトナー像をこの中間転写体上に一次転写し、中間転写体上に転写されたトナー像を中間転写体上から記録材上に二次転写することも可能である。
【０２６３】
本発明の画像形成方法は、潜像保持体を帯電する第１の帯電工程；
帯電された潜像保持体に静電潜像を形成する第１の潜像形成工程；
該静電潜像を第１のトナーにより現像して第１のトナー画像を形成する第１の現像工程；
現像された第１のトナー画像を中間転写体上に転写する第１の転写工程；
潜像保持体を帯電する第２の帯電工程；
帯電された潜像保持体に静電潜像を形成する第２の潜像形成工程；
該静電潜像を第２のトナーにより現像して第２のトナー画像を形成する第２の現像工程；
現像された第２のトナー画像を第１のトナー画像が転写されている中間転写体に転写する第２の転写工程；
潜像保持体を帯電する第３の帯電工程；
帯電された潜像保持体に静電潜像を形成する第３の潜像形成工程；
該静電潜像を第３のトナーにより現像して第３のトナー画像を形成する第３の現像工程；
現像された第３のトナー画像を第１のトナー画像及び第２のトナー画像が転写されている中間転写体上に転写する第３の転写工程；
潜像保持体を帯電する第４の帯電工程；
帯電された潜像保持体に静電潜像を形成する第４の潜像形成工程；
該静電潜像を第４のトナーにより現像して第４のトナー画像を形成する第４の現像工程；
現像された第４のトナー画像を第１のトナー画像、第２のトナー画像及び第３のトナー画像が転写されている中間転写体上に転写する第４の転写工程；
該中間転写体上に転写された第１のトナー画像、第２のトナー画像、第３のトナー画像及び第４のトナー画像を有する多色トナー画像を記録材上に一括して２次転写する一括転写工程；及び
記録材上に一括して２次転写された該多色トナー画像の表面に定着部材を接触させ、且つ該多色トナー画像に熱及び圧力を付与することにより、該多色トナー画像を該記録材に定着する定着工程；
を有する画像形成方法において、
該第１のトナーは、シアントナー、マゼンタトナー、イエロートナー及びブラックトナーからなるグループから選択されるカラートナーであり、
該第２のトナーは、第１のトナーとして選択されたカラートナーを除く残りのグループから選択されるカラートナーであり、
該第３のトナーは、第１のトナーとして選択されたカラートナー及び第２のトナーとして選択されたカラートナーを除く残りのグループから選択されるカラートナーであり、
該第４のトナーは、第１のトナーとして選択されたカラートナー、第２のトナーとして選択されたカラートナー及び第３のトナーとして選択されたカラートナーを除く残りのカラートナーであるカラー画像形成方法であることが好ましい。
【０２６４】
上記の中間転写体を用いて多重トナー像を記録材に一括転写し、多重トナー像を記録材上に定着する画像形成方法を図２をもとに説明する。
【０２６５】
潜像保持体としての感光体ドラム３に接触しながら回転する帯電ローラ２により感光ドラム３上に表面電位を持たせ露光手段１により静電潜像を形成する。静電潜像は第１現像器４，第２現像器５，第３現像器６及び第４現像器７により順次現像されそれぞれトナー像が形成され、このトナー像は一色ごとに中間転写体１１上に多重転写され、多重トナー像が形成される。中間転写体１１はドラム状のものが用いられ、外周面に保持部材を張設したもの、基材上に導電付与部材、例えばカーボンブラック，酸化亜鉛，酸化錫，炭化珪素又は酸化チタンを十分分散させた弾性層（例えばニトリルブタジエンラバー）を有するものが好ましく用いられる。ベルト状の中間転写体を用いても良い。中間転写体の硬度は１０〜５０度（ＪＩＳ Ｋ−６３０１）の弾性層から構成されることや、転写ベルトの場合では転写材（記録材）への転写部でこの硬度を有する弾性層を持つ支持部材で構成されていることが好ましい。感光体ドラム３から中間転写体１１への転写は、電源１３より中間転写体１１の芯金９の上にバイアスを付与することで転写電流が得られトナー像の転写が行なわれる。保持部材、ベルトの背面からのコロナ放電やローラ帯電を利用しても良い。中間転写体１１上の多重トナー像は転写帯電手段１４により記録材Ｓ上に一括転写される。転写帯電手段はコロナ帯電器や転写ローラ、転写ベルトを用いた静電転写手段が好ましく用いられる。
【０２６６】
また、本発明の画像形成方法は、潜像保持体を帯電する第１の帯電工程；
帯電された潜像保持体に静電潜像を形成する第１の潜像形成工程；
該静電潜像を第１のトナーにより現像して第１のトナー画像を形成する第１の現像工程；
現像された第１のトナー画像を中間転写体を介さずに記録材上に転写する第１の転写工程；
潜像保持体を帯電する第２の帯電工程；
帯電された潜像保持体に静電潜像を形成する第２の潜像形成工程；
該静電潜像を第２のトナーにより現像して第２のトナー画像を形成する第２の現像工程；現像された第２のトナー画像を第１のトナー画像が転写されている記録材上に転写する第２の転写工程；
潜像保持体を帯電する第３の帯電工程；
帯電された潜像保持体に静電潜像を形成する第３の潜像形成工程；
該静電潜像を第３のトナーにより現像して第３のトナー画像を形成する第３の現像工程；
現像された第３のトナー画像を第１のトナー画像及び第２のトナー画像が転写されている記録材上に転写する第３の転写工程；
潜像保持体を帯電する第４の帯電工程；
帯電された潜像保持体に静電潜像を形成する第４の潜像形成工程；
該静電潜像を第４のトナーにより現像して第４のトナー画像を形成する第４の現像工程；
現像された第４のトナー画像を第１のトナー画像、第２のトナー画像及び第３のトナー画像が転写されている記録材上に転写する第４の転写工程；
記録材上に順次転写された第１のトナー画像、第２のトナー画像、第３のトナー画像及び第４のトナー画像を有する多色トナー画像の表面に定着部材を接触させ、且つ該多色トナー画像に熱及び圧力を付与することにより、該多色トナー画像を該記録材に定着する定着工程；
を有する画像形成方法において、
該第１のトナーは、シアントナー、マゼンタトナー、イエロートナー及びブラックトナーからなるグループから選択されるカラートナーであり、
該第２のトナーは、第１のトナーとして選択されたカラートナーを除く残りのグループから選択されるカラートナーであり、
該第３のトナーは、第１のトナーとして選択されたカラートナー及び第２のトナーとして選択されたカラートナーを除く残りのグループから選択されるカラートナーであり、
該第４のトナーは、第１のトナーとして選択されたカラートナー、第２のトナーとして選択されたカラートナー及び第３のトナーとして選択されたカラートナーを除く残りのカラートナーであるカラー画像形成方法であることが好ましく良い。
【０２６７】
上記の中間転写体を介することなく記録材上に順次転写された多重トナー像を記録材に定着する画像形成方法を一例として図３を基に説明する。
【０２６８】
ここでは、第１，第２，第３および第４の画像形成部２９_a，２９_b，２９_c，２９_dが並設されており、各画像形成部はそれぞれ専用の静電潜像保持体、いわゆる感光ドラム１９_a，１９_b，１９_cおよび１９_dを具備している。
【０２６９】
感光ドラム１９_a乃至１９_dはその外周側に潜像形成手段２３_a，２３_b，２３_cおよび２３_d、現像部１７_a，１７_b，１７_cおよび１７_d、転写用放電部２４_a，２４_b，２４_cおよび２４_d、ならびにクリーニング部１８_a，１８_b，１８_cおよび１８_dが配置されている。
【０２７０】
このような構成にて、先ず、第１画像形成部２９_aの感光ドラム１９_a上に潜像形成手段２３_aによって原稿画像における、例えばイエロー成分色の潜像が形成される。該潜像は現像手段１７_aのイエロートナーを有する現像剤で可視画像とされ、転写部２４_aにて、記録材Ｓに転写される。
【０２７１】
上記のようにイエロー画像が記録材Ｓに転写されている間に、第２画像形成部２９_bではマゼンタ成分色の潜像が感光ドラム１９_b上に形成され、続いて現像手段１７_bのマゼンタトナーを有する現像剤で可視画像とされる。この可視画像（マゼンタトナー像）は、上記の第１画像形成部２９_aでの転写が終了した記録材Ｓが転写部２４_bに搬入されたときに、該記録材Ｓの所定位置に重ねて転写される。
【０２７２】
以下、上記と同様な方法により第３，第４の画像形成部２９_c，２９_dによってシアン色，ブラック色の画像形成が行なわれ、上記同一の記録材Ｓに、シアン色，ブラック色を重ねて転写するのである。このような画像形成プロセスが終了したならば、記録材Ｓは定着部２２に搬送され、記録材Ｓ上の画像を定着する。これによって記録材Ｓ上には多色画像が得られるのである。転写が終了した各感光ドラム１９_a，１９_b，１９_cおよび１９_dはクリーニング部１８_a，１８_b，１８_cおよび１８_dにより残留トナーを除去され、引き続き行なわれる次の潜像形成のために供せられる。
【０２７３】
なお、上記画像形成装置では、記録材Ｓの搬送のために、搬送ベルト２５が用いられており、図３において、記録材Ｓは右側から左側への搬送され、その搬送過程で、各画像形成部２９_a，２９_b，２９_cおよび２９_dにおける各転写部２４_a，２４_b，２４_cおよび２４_dを通過し、転写をうける。
【０２７４】
この画像形成方法において、記録材を搬送する搬送手段として加工の容易性及び耐久性の観点からテトロン繊維のメッシュを用いた搬送ベルトおよびポリエチレンテレフタレート系樹脂、ポリイミド系樹脂、ウレタン系樹脂の如き薄い誘電体シートを用いた搬送ベルトが好ましく利用される。
【０２７５】
記録材Ｓが第４画像形成部２９_dを通過すると、ＡＣ電圧が除電器２０に加えられ、記録材Ｓは除電され、ベルト２５から分離され、その後、定着器２２に入り、画像定着され、排出口２６から排出される。
【０２７６】
図１は、本発明の画像形成方法を実施可能なさらに別の画像形成装置の概略図を示す。
【０２７７】
画像形成装置本体には、第１画像形成ユニットＰａ、第２画像形成ユニットＰｂ、第３画像形成ユニットＰｃ及び第４画像形成ユニットＰｄが併設され、各々異なった色の画像が潜像、現像、転写のプロセスを経て記録材上に形成される。
【０２７８】
画像形成装置に併設される各画像形成ユニットの構成について第１の画像形成ユニットＰａを例に挙げて説明する。
【０２７９】
第１の画像形成ユニットＰａは、潜像保持体としての３０φの電子写真感光体ドラム６１ａを具備し、この感光体ドラム６１ａは矢印ａ方向へ回転移動される。６２ａは帯電手段としての一次帯電器であり、感光ドラム６１ａと接触するように１６φスリーブに担持された磁気ブラシ帯電器が用いられている。６７ａは、一次帯電器６２ａにより表面が均一に帯電されている感光体ドラム６１ａに静電潜像を形成するための潜像形成手段としての露光装置である。６３ａは、感光体ドラム６１ａ上に担持されている静電潜像を現像してカラートナー画像を形成するための現像手段としての現像器でありカラートナーを保持している。６４ａは、感光体ドラム６１ａの表面に形成されたカラートナー画像を、ベルト状の記録材担持体６８によって搬送されて来る記録材の表面に転写するための転写手段としての転写ブレードであり、この転写ブレード６４ａは、記録材担持体６８の裏面に当接して転写バイアスを印加し得るものである。
【０２８０】
この第１の画像形成ユニットＰａは、一次帯電器６２ａによって帯電部において感光体ドラム６１ａの感光体を均一に一次帯電した後、露光装置６７ａにより感光体に静電潜像を形成し、現像器６３ａによって、現像部において静電潜像をカラートナーを用いて現像し、この現像されたトナー画像を第１の転写部（感光体と記録材の当接位置）で記録材を担持搬送するベルト状の記録材担持体６８の裏面側に当接する転写ブレード６４ａから転写バイアスを印加することによって記録材の表面に転写する。
【０２８１】
この第１の画像形成ユニットＰａは、感光体ドラムの表面に当接して、転写残トナーを感光体ドラムの表面から除去するためのクリーニング部材を転写部と帯電部との間及び帯電部と現像部との間に有しておらず、現像器が感光体上に存在する転写残トナーのクリーニングを兼ねる現像兼クリーニング方式を用いている。
【０２８２】
本画像形成装置は、上記のような第１の画像形成ユニットＰａと同様の構成であり、現像器に保有されるカラートナーの色の異なる第２の画像形成ユニットＰｂ、第３の画像形成ユニットＰｃ、第４の画像形成ユニットＰｄの４つの画像形成ユニットを併設するものである。例えば、第１の画像形成ユニットＰａにイエロートナー、第２の画像形成ユニットＰｂにマゼンタトナー、第３の画像形成ユニットＰｃにシアントナー、及び第４の画像形成ユニットＰｄにブラックトナーをそれぞれ用い、各画像形成ユニットの転写部で各カラートナーの記録材上への転写が順次行なわれる。この工程で、レジストレーションを合わせつつ、同一記録材上に一回の記録材の移動で各カラートナーは重ね合わせられ、終了すると分離帯電器６９によって記録材担持体６８上から記録材が分離され、搬送ベルトの如き搬送手段によって定着器７０に送られ、ただ一回の定着によって最終のフルカラー画像が得られる。
【０２８３】
定着器７０は、一対の４０φの定着ローラ７１と３０φの加圧ローラ７２を有し、定着ローラ７１は、内部に加熱手段７５及び７６を有している。７３は、定着ローラ上の汚れを除去するウェッブである。本発明の場合、７３のウェッブ機構はなくてもかまわない。
【０２８４】
記録材上に転写された未定着のカラートナー画像は、この定着器７０の定着ローラ７１と加圧ローラ７２との圧接部を通過することにより、熱及び圧力の作用により記録材上に定着される。
【０２８５】
図１において、記録材担持体６８は、無端のベルト状部材であり、このベルト状部材は、８０の駆動ローラによって矢印ｅ方向に移動するものである。７９は、転写ベルトクリーニング装置であり、８１はベルト従動ローラであり、８２は、ベルト除電器である。８３は記録材ホルダー内の記録材を記録材担持体６８に搬送するための一対のレジストローラである。
【０２８６】
転写手段としては、記録材担持体の裏面側に当接する転写ブレードに代えてローラ状の転写ローラの如き記録材担持体の裏面側に当接して転写バイアスを直接印加可能な接触転写手段を用いることが可能である。
【０２８７】
さらに、上記の接触転写手段に代えて、一般的に用いられている記録材担持体の裏面側に非接触で配置されているコロナ帯電器から転写バイアスを印加して転写を行う非接触の転写手段を用いることも可能である。
【０２８８】
しかしながら、転写バイアス印加時のオゾンの発生量を制御できる点で接触転写手段を用いることがより好ましい。
【０２８９】
更に他の実施形態のフルカラー画像を形成するための画像形成方法を例にして図４に基づいて説明する。
【０２９０】
感光ドラム３３上に適当な手段で形成された静電潜像は、矢印の方向へ回転する回転現像ユニット３９に取り付けられた現像手段としての現像器３６中に第１のカラートナー及びキャリアを有する二成分系現像剤により可視化される。感光体ドラム３３上のカラートナー画像は、グリッパー４７によって転写ドラム４８上に保持されている記録材Ｓに、転写帯電器４４により転写される。
【０２９１】
転写帯電器４４には、コロナ帯電器又は接触帯電器が利用され、転写帯電器４４にコロナ帯電器が使われる場合には、−１０ｋＶ〜＋１０ｋＶの電圧が印加され、転写電流は−５００μＡ〜＋５００μＡである。転写ドラム４８の外周面には保持部材が張設され、この保持部材はポリフッ化ビニリデン樹脂フィルムやポリエチレンテレフタレートの如きフィルム状誘電体シートによって構成される。例えば、厚さ１００μｍ〜２００μｍ，体積抵抗１０¹²〜１０¹⁴Ω・ｃｍのシートが用いられる。
【０２９２】
次に２色目として回転現像ユニットが回転し、現像器３５が感光ドラム３３に対向する。そして現像器３５中の第２のカラートナー及びキャリアを有する現像剤により現像され、このカラートナー画像も前記と同一の記録材上に重ねて転写される。
【０２９３】
更に３色目、４色目も同様に行なわれる。このように転写ドラム４８は記録材を把持したまま所定回数だけ回転し所定色数のトナー像が多重転写される。静電転写するための転写電流は、一色目＜二色目＜三色目＜四色目の順に高めることが感光ドラム上に残る転写残留トナーを少なくするために好ましい。
【０２９４】
多重転写された記録材Ｓは、分離帯電器４５により転写ドラム４８より分離され、シリコーンオイルを含浸している、あるいは、オイルを含浸しないウェッブを有する加熱加圧ローラー定着器３２（あるいはウェッブ機構のない定着器）で定着され、定着時に加色混合されることにより、フルカラー複写画像となる。
【０２９５】
現像器３４〜３７に供給される補給トナーは各色ごとに具備した補給ホッパーより、補給信号に基づいた一定量をトナー搬送ケーブルを経由して、回転現像ユニットの中心にあるトナー補給筒に搬送され、各現像器に送られる。
【０２９６】
また、多重現像一括転写方法について、フルカラー電子写真法プリンターを例にして図５に基づいて説明する。
【０２９７】
感光ドラム１０３上に帯電器１０２とレーザー光を用いた露光部１０１で形成された静電潜像は現像器１０４，１０５，１０６，１０７により順次トナーを現像して可視化される。現像プロセスにおいては、非接触現像方法が好ましく用いられる。非接触現像方法によれば現像器中の現像剤層が像形成体の表面を擦ることがないので、２回目以降の現像工程において先行の現像工程で形成された像を乱すことなく現像を行なうことができる。現像する順は、多色の場合は黒以外の色で、明度，彩度の高い色から現像するのが好ましい。フルカラーの場合は、イエロー、ついでマゼンタあるいはシアンのどちらか、ついでマゼンタあるいはシアンの残った方、最後に黒の順で現像することが好ましい。
【０２９８】
感光ドラム１０３上に形成された多色多重画像，フルカラー画像は転写帯電器１０９により記録材Ｓに転写される。転写工程においては、静電転写法が好ましく用いられ、コロナ放電又は接触転写方法が利用される。コロナ放電転写方法とは、記録材Ｓを介しコロナ放電を生じさせる転写帯電器１０９を像に対向するように配置し、記録材Ｓの背面からコロナ放電を作用させ静電的に転写する方法である。接触転写方法とは、記録材Ｓを介し、転写ローラー、転写ベルトを像形成体に接触させてローラーにバイアスを印加させるか、ベルトの背面から静電的に転写する方法である。この静電転写方法により感光ドラム１０３の表面に担持された多色トナー像が一括して記録材Ｓに転写される。
【０２９９】
多色トナー像が一括転写された記録材Ｓは、感光ドラム１０３から分離され熱ローラー定着器１１２で定着されることにより多色画像となる。
【０３００】
次に本発明に使用可能な現像器の構成について図面を用いて詳細に説明する。
【０３０１】
本発明において、現像領域で感光体表面に現像剤担持体に担持される現像剤を接触させて現像を行なう接触現像方式と、現像領域で感光体表面に現像剤担持体に担持されている現像剤を感光体と現像剤層が非接触となるような間隔に設定した現像剤担持体から飛翔させて現像を行なう非接触現像方式のいずれを用いることも可能である。
【０３０２】
接触現像方式としては、トナー及びキャリアを有する二成分系現像剤を用いる現像方法（図６）と一成分系現像剤を用いる現像方法（図８）が挙げられる。
【０３０３】
接触二成分系現像方法としては、トナーと磁性キャリアとを混合した二成分系現像剤を例えば図６に示すような現像装置１２０を用い、現像を行なうことができる。
【０３０４】
現像装置１２０は、二成分系現像剤１２８を収納する現像容器１２６、現像容器１２６に収納されている二成分系現像剤１２８を担持し、現像領域に搬送するための現像剤担持体としての現像スリーブ１２１、現像スリーブ１２１上に形成されるトナー層の層厚を規制するための現像剤層厚規制手段としての現像ブレード１２７を有している。
【０３０５】
現像スリーブ１２１は、非磁性のスリーブ基体１２２内にマグネット１２３を内包している。
【０３０６】
現像容器１２６の内部は、隔壁１３０によって現像室（第１室）Ｒ₁と撹拌室（第２室）Ｒ₂とに区画され、撹拌室Ｒ₂の上方には隔壁１３０を隔てトナー貯蔵室Ｒ₃が形成されている。現像室Ｒ₁及び撹拌室Ｒ₂内には現像剤１２８が収容されており、トナー貯蔵室Ｒ₃内には補給用トナー（非磁性トナー）１２９が収容されている。なお、トナー貯蔵室Ｒ₃には補給口１３１が設けられ、補給口１３１を経て消費されたトナーに見合った量の補給用トナー１２９が撹拌室Ｒ₂内に落下補給される。
【０３０７】
現像室Ｒ₁内には搬送スクリュー１２４が設けられており、この搬送スクリュー１２４の回転駆動によって現像室Ｒ₁内の現像剤１２８は、現像スリーブ１２１の長手方向に向けて搬送される。同様に、撹拌室Ｒ₂内には搬送スクリュー１２５が設けられ、搬送スクリュー１２５の回転によって、補給口１３１から撹拌室Ｒ₂内に落下したトナーを現像スリーブ１２１の長手方向に沿って搬送する。
【０３０８】
現像剤１２８は、非磁性トナーと磁性キャリアとを有した二成分系現像剤である。
【０３０９】
二成分系現像剤に使用されるキャリアとしては、例えば表面酸化または未酸化の鉄、ニッケル、銅、亜鉛、コバルト、マンガン、クロム及び希土類の如き磁性金属、それらの磁性合金、それらの磁性酸化物及びそれらの磁性フェライトからなるグループから選択される磁性粒子が挙げられる。
【０３１０】
さらには、樹脂中に磁性粉が分散されたバインダー型のキャリアも用いることができる。
【０３１１】
キャリアは、上記の磁性粒子のキャリアコアの表面を被覆材で被覆した被覆キャリアを用いることが好ましい。この被覆キャリアにおいて、キャリアコアの表面を被覆材で被覆する方法としては、被覆材を溶剤中に溶解もしくは懸濁せしめて塗布しキャリアコアに付着せしめる方法、あるいは単に粉体状態で混合する方法が適用できる。
【０３１２】
キャリアコアの被覆材としては、ポリテトラフルオロエチレン、モノクロロトリフルオロエチレン重合体、ポリフッ化ビニリデン、シリコーン樹脂、ポリエステル樹脂、スチレン系樹脂、アクリル系樹脂、ポリアミド、ポリビニルブチラール、アミノアクリレート樹脂が挙げられる。これらは、単独或は複数で用いるのが適当である。
【０３１３】
上記材料の処理量は、適宜決定すれば良いが、一般には総量でキャリアに対し０．１〜３０重量％（好ましくは０．５〜２０重量％）が好ましい。
【０３１４】
本発明に用いられるキャリアは、平均粒径が好ましくは１０〜１００μｍ、より好ましくは２０〜７０μｍであることが良い。
【０３１５】
キャリアの平均粒径が１０μｍ未満の場合には、二成分系現像剤のパッキングが強まり、トナーとキャリアとの混合性が低下し、トナーの帯電性が安定しにくくなり、さらにキャリアの感光体ドラム表面への付着が生じやすくなる。
【０３１６】
キャリアの平均粒径が１００μｍを超える場合には、トナーとの接触機会が減ることから、低帯電量のトナーが混在し、カブリが発生しやすくなる。さらにトナー飛散が生じやすい傾向にあるため二成分系現像剤中のトナー濃度の設定を低めにする必要があり、高画像濃度の画像形成ができなくなることがある。
【０３１７】
特に好ましいキャリアとしては、磁性フェライトコア粒子の如き磁性コア粒子の表面をシリコーン樹脂、フッ素系樹脂、スチレン系樹脂、アクリル系樹脂及びメタクリレート系樹脂の如き樹脂を、好ましくは０．０１〜５重量％、より好ましくは０．１〜１重量％をコーティングし、２５０メッシュパス・４００メッシュオンのキャリア粒子を７０重量％以上含有し、かつ上記平均粒径を有するように粒度分布を調整した磁性キャリアであるものが挙げられる。
【０３１８】
上記磁性コートキャリアは粒径分布がシャープな場合、本発明のカラートナーに対し好ましい摩擦帯電性が得られ、さらに電子写真特性を向上させる効果がある。
【０３１９】
カラートナーとキャリアとを混合して二成分系現像剤を調製する場合、その混合比率は現像剤中のトナー濃度として、２重量％〜１５重量％、好ましくは３重量％〜１３重量％、より好ましくは４重量％〜１０重量％にすると通常良好な結果が得られる。トナー濃度が２重量％未満では画像濃度が低くなりやすく、１５重量％を超える場合ではカブリや機内飛散が生じやすく、現像剤の耐用寿命が短くなる傾向がある。
【０３２０】
キャリアの磁気特性は、現像スリーブに内蔵されたマグネットローラによって影響され、現像剤の現像特性及び搬送性に大きく影智を及ぼすものである。
【０３２１】
本発明においては、マグネットローラを内蔵した現像スリーブ上で、マグネットローラを固定して現像スリーブを単体で回転し、磁性粒子からなるキャリアと絶縁性カラートナーからなる二成分系現像剤を現像スリーブ上で循環搬送し、核二成分系現像剤にて静電潜像保持体表面に保持された静電潜像を現像するに際して、▲１▼該マグネットローラが反発極を有する極構成とし、▲２▼現像領域における磁束密度を５００〜１２００ガウスとし、▲３▼キャリアの飽和磁化が２０〜７０Ａｍ²／ｋｇのとき、カラー複写において画像の均一性や階調再現性にすぐれ好適である。
【０３２２】
キャリアの飽和磁化が７０Ａｍ²／ｋｇ（３０００エルステッドの印加磁場に対し）を超える場合であると、現像時に感光体上の静電潜像に対向した現像スリーブ上のキャリアとトナーにより構成されるブラシ状の穂立ちが固く締まった状態となり、階調性や中間調の再現が悪くなる。また、２０Ａｍ²／ｋｇ未満であると、トナー及びキャリアを現像スリーブ上に良好に保持することが困難になり、キャリア付着やトナー飛散抑制が悪化するという問題点が発生しやすくなる。
【０３２３】
現像容器１２６の感光体ドラム１１９に近接する部位には開口部が設けられ、該開口部から現像スリーブ１２１が外部に吐出し、現像スリーブ１２１と感光体ドラム１１９との間には間隙が設けられている。非磁性材にて形成される現像スリーブ１２１には、バイアスを印加するためのバイアス印加手段１３２が配置されている。
【０３２４】
スリーブ基体１２２に固定された磁界発生手段としてのマグネットローラー、即ち磁石１２３は、上述したように、現像磁極Ｓ₁とその下流に位置する磁極Ｎ₃と、現像剤１２８を搬送するための磁極Ｎ₂、Ｓ₂、Ｎ₁とを有する。磁石１２３は、現像磁極Ｓ₁が感光体ドラム１１９に対抗するようにスリーブ基体１２２内に配置されている。現像磁極Ｓ₁は、現像スリーブ１２１と感光体ドラム１１９との間の現像部の近傍に磁界を形成し、該磁界によって磁気ブラシが形成される。
【０３２５】
現像スリーブ１２１の上方に配置され、現像スリーブ１２１上の現像剤１２８の層厚を規制する規制ブレード１２７は、アルミニウム、ＳＵＳ３１６の如き非磁性材料で作製される。非磁性ブレード１２７の端部と現像スリーブ１２１面との距離Ａは３００〜１０００μｍ、好ましくは４００〜９００μｍである。この距離が３００μｍより小さいと、磁性キャリアがこの間に詰まり現像剤層にムラを生じやすいと共に、良好な現像を行なうのに必要な現像剤を塗布することができず濃度の薄いムラの多い現像画像しか得られないという問題点がある。現像剤中に混在している不用粒子による不均一塗布（いわゆるブレードづまり）を防止するためには、４００μｍ以上が好ましい。１０００μｍより大きいと現像スリーブ１２１上へ塗布される現像剤量が増加し所定の現像剤層厚の規制が行えず、感光体ドラム１１９への磁性キャリア粒子の付着が多くなると共に現像剤の循環、非磁性の現像ブレード１２７による現像規制が弱まりトナーのトリボが不足しカブリやすくなるという問題点がある。
【０３２６】
この二成分系現像装置１２０の現像は、交番電界を印加しつつ、トナーと磁性キャリアとにより、構成される磁気ブラシ潜像担持体（例えば、感光体ドラム）１１９に接触している状態で現像を行うことが好ましい。現像剤担持体（現像スリーブ）１２１と感光体ドラム１１９との距離（Ｓ−Ｄ間距離）Ｂは１００〜１０００μｍであることがキャリア付着防止及びドット再現性の向上において良好である。１００μｍより狭いと現像剤の供給が不十分になりやすく、画像濃度が低くなり、１０００μｍを超えると磁石Ｓ₁からの磁力線が広がり磁気ブラシの密度が低くなり、ドット再現性に劣ったり、キャリアを拘束する力が弱まりキャリア付着が生じやすくなる。
【０３２７】
交番電界のピーク間の電圧は５００〜５０００Ｖが好ましく、周波数は５００〜１００００Ｈｚ、好ましくは５００〜３０００Ｈｚであり、それぞれプロセスに適宜選択して用いることができる。この場合、波形としては三角波、矩形波、正弦波、或いはＤｕｔｙ比を変えた波形から選択して用いることができる。印加電圧が、５００Ｖより低いと十分な画像濃度がえられにくく、非画像部のカブリトナーを良好に回収することができない場合がある。５０００Ｖを超える場合には磁気ブラシを介して、静電像を乱してしまい、画質低下を招く場合がある。
【０３２８】
良好に帯電したトナーを有する二成分系現像剤を使用することで、カブリ取り電圧（Ｖｂａｃｋ）を低くすることができ、感光体の一次帯電を低めることができるために感光体寿命を長寿命化できる。Ｖｂａｃｋは、現像システムにもよるが１５０Ｖ以下、より好ましくは１００Ｖ以下が良い。
【０３２９】
コントラスト電位としては、十分画像濃度ができるように２００Ｖ〜５００Ｖが好ましく用いられる。
【０３３０】
周波数が５００Ｈｚより低いとプロセススピードにも関係するが、キャリアへの電荷注入が起こるためキャリア付着、あるいは潜像を乱すことで画質を低下させる場合がある。１００００Ｈｚを超えると電界に対してトナーが追随できず画質低下を招きやすい。
【０３３１】
十分が画像濃度を出し、ドット再現性に優れ、かつキャリア付着のない現像を行なうために現像スリーブ１２１上の磁気ブラシの感光体ドラム１１９との接触幅（現像ニップＣ）を好ましくは３〜８ｍｍにすることである。現像ニップＣが３ｍｍより狭いと十分な画像濃度とドット再現性を良好に満足することが困難であり、８ｍｍより広いと、現像剤のパッキングが起き機械の動作を留めてしまったり、またキャリア付着を十分に抑えることが困難になる。現像ニップの調整方法としては、現像剤規制部材１２７と現像スリーブ１２１との距離Ａを調整したり、現像スリーブ１２１と感光体ドラム１１９との距離Ｂを調整することでニップ幅を適宜調整する。
【０３３２】
なお、感光体上の転写残トナーは、上記の現像器のトナーとキャリアとからなる磁気ブラシによって、現像時に回収される。
【０３３３】
接触一成分現像方法としては、非磁性トナーを用いて、例えば図８に示すような現像装置１８０を用い現像することが可能である。
【０３３４】
現像装置１８０は、磁性又は非磁性のトナーを有する一成分現像剤１８８を収容する現像容器１８１、現像容器１８１に収納されている一成分現像剤１８８を担持し、現像領域に搬送するための現像剤担持体１８２、現像剤担持体上に現像剤を供給するための供給ローラー１８５、現像剤担持体上の現像剤層厚を規制するための現像剤層厚規制部材としての弾性ブレード１８６、現像容器１８１内の現像剤１８８を撹拌するための撹拌部材１８７を有している。
【０３３５】
現像剤担持体上１８２としては、ローラー基体１８３上に、発泡シリコーンゴムの如き弾性を有するゴム又は樹脂の如き弾性部材によって形成された弾性層１８４を有する弾性ローラーを用いることが好ましい。
【０３３６】
この弾性ローラー１８２は、潜像保持体としての感光体ドラム１８９の表面に圧接して、弾性ローラー表面に塗布されている一成分系現像剤１８８により感光体に形成されている静電潜像を現像する共に、転写後に感光体上に存在する不要な一成分現像剤１８８を回収する。
【０３３７】
接触一成分現像方法では、現像剤担持体は実質的に感光体表面と接触している。これは、現像剤担持体から一成分系現像剤を除いたときに現像剤担持体が感光体と接触しているということを意味する。このとき、現像剤を介して、感光体と現像剤担持体との間に働く電界によってエッジ効果のない画像が得れれると同時にクリーニングが行なわれる。現像剤担持体としての弾性ローラー表面或いは、表面近傍が電位を持ち感光体表面と弾性ローラー表面間で電界を有する必要性がある。このため、弾性ローラーの弾性ゴムが中抵抗領域に抵抗制御されて感光体表面との導通を防ぎつつ電界を保つか、又は導電性ローラーの表面層に薄層の誘電層を設ける方法も利用できる。さらには、導電性ローラー上に感光体表面と接触する側の面を絶縁性物質により被覆した導電性樹脂スリーブ或いは、絶縁性スリーブで感光体と接触しない側の面に導電層を設けた構成も可能である。
【０３３８】
この一成分系現像剤を担持する弾性ローラーは、感光体ドラムと同方向に回転しても良いし、逆方向に回転しても良い。その回転が同方向である場合、感光体ドラムの周速に対して、周速比で１００％より大きいことが好ましい。１００％以下であるとラインの鮮明性が悪いなどの画像品質に問題を生じやすい。周速比が高まれば高まるほど、現像部位に供給される現像剤の量は多く、静電潜像に対し現像剤の脱着頻度が多くなり、不要な部分の現像剤は掻き落とされ、必要な部分には現像剤が付与されるという繰り返しにより、静電潜像に忠実な画像が得られる。さらに好ましくは周速比は１００％以上が良い。
【０３３９】
現像剤層厚規制部材１８６は、現像剤担持体１８２の表面に弾性力で圧接するものであれば、弾性ブレードに限られることなく、弾性ローラーを用いることも可能である。
【０３４０】
弾性ブレード、弾性ローラーとしては、シリコーンゴム、ウレタンゴム、ＮＢＲの如きゴム弾性体；ポリエチレンテレフタレートの如き合成樹脂弾性体；ステンレス、鋼の如き金属弾性体が使用できる。さらに、それらの複合体であっても使用できる。
【０３４１】
弾性ブレードの場合には、弾性ブレード上辺部側である基部は現像剤容器側に固定保持され、下辺部側をブレードの弾性に抗して現像スリーブの順方向或いは逆方向にたわめ状態にしてブレード内面側（逆方向の場合には外面側）をスリーブ表面に適度に弾性押圧をもって当接させる。
【０３４２】
供給ローラー１８５はポリウレタンフォームの如き発泡材より成っており、現像剤担持体に対して、順又は逆方向に０でない相対速度をもって回転し、一成分系現像剤の供給とともに、現像剤担持体上の現像後の現像剤（未現像現像剤）の剥ぎ取りも行っている。
【０３４３】
現像領域において、現像剤担持体上の一成分系現像剤によって感光体の静電潜像を現像する際には、現像剤担持体と感光体ドラムとの間に直接及び／又は交流の現像バイアスを印加して現像することが好ましい。
【０３４４】
次に非接触現像方式について説明する。
【０３４５】
非接触現像方式としては、非磁性トナーを有する一成分系磁性現像剤を用いる現像方法が挙げられる。
【０３４６】
ここでは、非磁性トナーを有する一成分系非磁性現像剤を用いる現像方法を図７に示す概略構成図に基づいて説明する。
【０３４７】
現像装置１７０は、非磁性トナーを有する非磁性一成分系現像剤１７６を収容する現像容器１７１、現像容器１７１に収容されている一成分系非磁性現像剤１７６を担持し、現像領域に搬送するための現像剤担持体１７２、現像剤担持体上に一成分系非磁性現像剤を供給するための供給ローラー１７３、現像剤担持体上の現像剤層厚を規制するための現像剤層厚規制部材としての弾性ブレード１７４、現像容器１７１内の一成分系非磁性現像剤１７６を撹拌するための撹拌部材１７５を有している。
【０３４８】
１６９は静電潜像保持体であり、潜像形成は図示しない電子写真プロセス手段又は静電記録手段によりなされる。１７２は現像剤担持体としての現像スリーブであり、アルミニウム或いはステンレスからなる非磁性スリーブからなる。
【０３４９】
現像スリーブは、アルミニウム、ステンレスの粗管をそのまま用いてもよいが、好ましくはその表面をガラスビーズを吹き付けて均一に荒らしたものや、鏡面処理したもの、或いは樹脂でコートしたものが良い。
【０３５０】
一成分系非磁性現像剤１７６は現像容器１７１に貯蔵されており、供給ローラー１７３によって現像剤担持体１７２上へ供給される。供給ローラー１７３はポリウレタンフォームの如き発泡材より成っており、現像剤担持体に対して、順又は逆方向に０でない相対速度をもって回転し、現像剤の供給とともに、現像剤担持体１７２上の現像後の現像剤（未現像現像剤）の剥ぎ取りも行っている。現像剤担持体１７２上に供給された一成分系非磁性現像剤は現像剤層厚規制部材としての弾性ブレード１７４によって均一且つ薄層に塗布される。
【０３５１】
弾性塗布ブレードと現像剤担持体との当接圧力は、現像スリーブ母線方向の線圧として０．３〜２５ｋｇ／ｍ、好ましくは０．５〜１２ｋｇ／ｍが有効である。当接圧力が０．３ｋｇ／ｍより小さい場合、一成分系非磁性現像剤の均一塗布が困難となり、一成分系非磁性現像剤の帯電量分布がブロードとなりカブリや飛散の原因となる。当接圧力が２５ｋｇ／ｍを超えると、一成分系非磁性現像剤に大きな圧力がかかり、一成分系非磁性現像剤が劣化するため、一成分系非磁性現像剤の凝集が発生するなど好ましくない。また、現像剤担持体を駆動させるために大きなトルクを要するため好ましくない。即ち、当接圧力を０．３〜２５ｋｇ／ｍに調整することで、本発明のトナーを用いた一成分系非磁性現像剤の凝集を効果的にほぐすことが可能になり、さらに、一成分系非磁性現像剤の帯電量を瞬時に立ち上げることが可能になる。
【０３５２】
現像剤層厚規制部材は、弾性ブレード、弾性ローラーを用いることができ、これらは所望の極性に現像剤を帯電するのに適した摩擦帯電系列の材質のものを用いることが好ましい。
【０３５３】
本発明において、シリコーンゴム、ウレタンゴム、スチレンブタジエンゴムが好適である。さらに、ポリアミド、ポリイミド、ナイロン、メラミン、メラミン架橋ナイロン、フェノール樹脂、フッ素系樹脂、シリコーン樹脂、ポリエステル樹脂、ウレタン樹脂、スチレン系樹脂の如き有機樹脂層を設けても良い。導電性ゴム、導電性樹脂を使用し、さらに金属酸化物、カーボンブラック、無機ウイスカー、無機繊維の如きフィラーや荷電制御剤をブレードのゴム中・樹脂中に分散することにより適度の導電性、帯電付与性を与え、一成分系非磁性現像剤を適度に帯電させることができて好ましい。
【０３５４】
この非磁性一成分現像方法において、ブレードにより現像スリーブ上に一成分系非磁性現像剤を薄層コートする系においては、十分な画像濃度を得るために、現像スリーブ上の一成分系非磁性現像剤層の厚さを現像スリーブと潜像保持体との対抗空隙長βよりも小さくし、この空隙に交番電場を印加することが好ましい。即ち図７に示すバイアス電源１７７により、現像スリーブ１７２と潜像保持体１６９との間に交番電場又は交番電場に直流電場を重畳した現像バイアスを印加することにより、現像スリーブ上から潜像保持体への一成分系非磁性現像剤の移動を容易にし、更に良質の画像を得ることができる。
【０３５５】
【実施例】
以下実施例にもとづいて具体的に本発明について説明する。しかしながら、これによって本発明の実施の態様がなんら限定されるものではない。実施例中の部数は重量部である。
【０３５６】
実施例に用いられる樹脂として、表１に記載のモノマー組成のポリエステル樹脂を脱水縮合法により合成し、樹脂骨格にドデセニル基がブランチ化して導入されている非線状ポリエステル樹脂Ａ１〜Ａ１１と、表２示す組成及び表３に示す分子量を有する線状ポリエステル樹脂Ｂ１〜Ｂ２を得た。
【０３５７】
＜実施例１＞
・非線状ポリエステル樹脂Ａ−１（表１に記載） ６０重量部
・線状ポリエステル樹脂Ｂ−１（表２及び３に記載） ４０重量部
・銅フタロシアニン系顔料 ４重量部
（Ｃ．Ｉ．Ｐｉｇｍｅｎｔ Ｂｌｕｅ １５：３）
・ポリエチレンワックス １．５重量部
（ｍｐ＝１０６℃、Ｍｎ＝６７０、Ｍｗ／Ｍｎ＝１．３５）
・ジルコニウム化合物（１４） ５重量部
上記材料をヘンシェルミキサーで前混合した後、１１０℃に設定した二軸混練押し出し機によって、溶融混練した。溶融混練時に徐々に混練物の粘度が上昇したことから、新たな架橋が形成されたことが確認された。
【０３５８】
得られた混練物を冷却し、カッターミルで粗粉砕した後、ジェット気流を用いた微粉砕機で粉砕し、得られた微粉砕粉末をコアンダ効果を利用した多分割分級機を用いて分級し、重量平均粒径６．４μｍのトナー粒子Ａを得た。表４にその処方・物性を示す。
【０３５９】
トナー粒子Ａ１００重量部に対し、疎水化処理したメタノールウエッタビリティ８０％，ＢＥＴ比表面積１２０ｍ²／ｇの疎水性シリカ微粉体（シリカ微粉体１００重量部に対してヘキサメチルジシラザン１０重量部とジメチルシリコーン１０重量部で処理）１．２重量部を外添混合してトナーＡを調製した。
【０３６０】
このシアントナーＡ６．０重量部に対して、スチレン−メタクリル酸メチル（共重合体重量比６５：３５）を約０．３５重量％コーティングした平均粒径４５μｍのＣｕ−Ｚｎ−Ｆｅ系フェライトキャリアを総重量１００重量部になるように混合し、二成分現像剤とした。二成分現像剤中のトナー濃度は６．０重量％にした。
【０３６１】
このトナーＡを定着オイル供給機構を伴わない定着器（定着スピード１３０ｍｍ／ｓｅｃ．、定着ローラー径Φ４０ｍｍ、加圧ローラー径Φ４０ｍｍ、定着・加圧ローラー表層ＰＦＡ［パーフロロアルコキシエチレン］２０μｍ、ニップ幅８ｍｍ、総加圧力４０ｋｇｆ）において、定着・加圧ローラー表面に定着オイルがない状態で定着性と耐オフセット性の評価を行った。
【０３６２】
その結果、定着開始点は１１０℃と低く、非オフセット幅も大である。また、フルカラートナーに重要なグロス１０以上となる領域が存在し、グロスコントロール可能であった。また、ＯＨＴ上に画像をＯＨＴモードとして１７０℃，４０ｍｍ／ｓｅｃ．の定着スピードで定着試験を行なった。このカラー画像をオバーヘッドプロジェクター（ＯＨＰ）に投影し、評価を行なった。得られた画像はオフセットすることなく、透明性に優れ、明暗ムラもなく、淡いハーフトーンの色調に至るまで色再現性も優れていた。
【０３６３】
また、市販のフルカラー複写機（カラーレザーコピア８００，キヤノン社製）定着器構成を上記のオイル塗布機構を伴わない定着器に改造したものを用いて１５℃，１０％ＲＨの環境と３０℃，８０％ＲＨの環境で１万枚のプリント試験を行った。１万枚プリント後の現像性（画像濃度）及びカブリを評価した。耐久濃度推移、カブリ抑制は良好であった。評価結果は表５に示す。
【０３６４】
＜実施例２〜３、参考例４、実施例５及び比較例１〜５＞
実施例１で用いた非線状ポリエステル樹脂Ａ−１の代わりに、表１に記載の非線状ポリエステル樹脂Ａ−２〜Ａ−５及び比較用非線状ポリエステル樹脂Ａ−７〜Ａ−１１を用いる以外は実施例１と同様にトナーＢ〜Ｊを作製し、同様の試験をした結果を表５に示す。
【０３６５】
＜実施例６〜８及び比較例６〜７＞
実施例１で用いた非線状ポリエステル樹脂Ａ−１の代わりに表１に記載の非線状ポリエステル樹脂Ａ−６を用い、線状ポリエステル樹脂Ｂ−１の代わりに表２及び３に記載の非線状ポリエステル樹脂Ｂ−２を用いて、表４に示すような処方とする以外は実施例１と同様にトナーＫ〜Ｏを作製し、同様の試験をした結果を表５に示す。但し、実施例１のジルコニウム化合物（１４）から有機金属化合物をジルコニウム化合物（２７）に変更した。
【０３６６】
＜参考例９〜１０、実施例１１、参考例１２〜１４、実施例１５及び比較例８＞
表４に記載の処方で実施例１と同様にトナーＰ〜Ｗを作製し、同様の試験をした結果を表５に示す。但し、トナーＱは実施例１のシアン顔料をカーボンブラック５重量部に変更した。また、トナーＰ及びＱでは、有機金属化合物として亜鉛化合物及びクロム化合物である下記化合物（１３６）〜（１３７）を使用した。但し、配位している水分子は省略する。
【０３６７】
【化３４】

【０３６８】
以下、本発明の実施例におけるトナー評価方法・評価基準に関して記載する。
【０３６９】
（１）現像性
３０℃，８０％ＲＨの環境下で、通常の複写機用普通紙（７５ｇ／ｍ²）に１万枚プリントアウト終了時の画像濃度維持により評価した。尚、画像濃度は「マクベス反射濃度計」（マクベス社製）を用いて、原稿濃度が０．００の白地部分のプリントアウト画像に対する相対濃度を測定した。
Ａ：１．４０以上
Ｂ：１．３０以上１．４０未満
Ｃ：１．２０以上１．３０未満
Ｄ：１．２０未満
【０３７０】
（２）カブリ
カブリ測定は、２３℃，５％ＲＨの環境下で通常の複写機用普通紙（７５ｇ／ｍ²）に１万枚プリントアウト画像の白地部分の白色度をリフレクトメーター（東京電色社製）により測定し、その白色度と転写紙の白色度の差から、カブリ濃度（％）を算出し、評価した。
Ａ：非常に良好（１．０％未満）
Ｂ：良好（１．０％以上２．０％未満）
Ｃ：普通（２．０％以上３．０％未満）
Ｄ：悪い（３．０％以上）
【０３７１】
（３）定着性及びグロス
定着性は、定着画像のトナーのり量を０．６ｇ／ｃｍ²のベタ画像とし、この画像に対し５０ｇ／ｃｍ²の荷重をかけ、柔和な薄紙により定着画像を摺擦し、摺擦前後での画像濃度の低下率（％）が２０％以下となる温度を定着開始温度として評価した。
【０３７２】
耐オフセット性は、同様に定着画像のトナーのり量を０．６ｇ／ｃｍ²のベタ画像とし、定着時の定着ローラーの汚れ（トナーの転移）が始まる温度を高温側のオフセット温度として評価した。
【０３７３】
また、同一定着画像の光沢度（グロス）ハンディ光沢度計グロスメーターＰＧ−３Ｄ（日本電色工業製）を用いて、光の入射角７５°の条件で測定した。
【０３７４】
定着温度条件としては、１１０℃から５℃毎に２００℃まで行なった。
【０３７５】
（４）耐久オフセット性
耐久オフセット性は、定着温度１９０℃で画像面積率約５％のサンプル画像をプリントアウトし、連続３０００枚の画像上の汚れの程度、３０００枚後の定着・加圧ローラーの表面観察により評価した。
Ａ：画像上・ローラー上全くない。；実用可
Ｂ：画像上には全くないがローラー上にわずかだがトナーの痕跡有り。：実用可
Ｃ：画像裏面にややトナー痕跡がある画像が５枚存在し、ローラー上にわずかだがトナーの痕跡有り。；実用不可
Ｄ：画像上・ローラー上にオフセットが発生する頻度が高い。；実用不可
Ｅ：定着器に巻き付いて耐久不可。：実用不可
【０３７６】
（５）ＯＨＴ画像透明性
ＯＨＴ画像透明性の評価は、ＯＨＴ上に画像をＯＨＴモードとして１７０℃、４０ｍｍ／ｓｅｃ．の定着スピードで定着試験を行い、このカラー画像をオバーヘッドプロジェクター（ＯＨＰ）に投影し、評価を行なった。
【０３７７】
ＯＨＴ上画像のＯＨＰ投影像での色再現性では、淡色（ハーフトーン）部分の色再現の評価がより厳しい評価となる。定着前のＯＨＴ画像上のトナー粒子が孤立して存在するため、個々のトナー粒子が完全に溶融して発色しなければならないためである。
◎：得られた画像はオフセットすることなく、透明性に優れ、明暗ムラもなく、色再現性も優れる。；実用可
○：若干の明暗ムラがあるものの、実用上問題無い。
△：明暗ムラがあり、色再現に乏しい。；実用不可
×：透明性が著しく劣り、ほとんど色再現されない。；実用不可
【０３７８】
【表１】

【０３７９】
【表２】

【０３８０】
【表３】

【０３８１】
【表４】

【０３８２】
【表５】

【０３８３】
【発明の効果】
本発明によって、定着オイルの使用無しに定着を行なうことのできる耐オフセット性に優れ、より低温定着が可能なカラートナーを得ることが可能となる。また、定着温度を低く設定したオイルレス定着によっても、適度の光沢性やつやを有し、高彩度な色調に至るまで色再現性に優れるフルカラー画像が得られる。また、オバーヘッドプロジェクターシート（ＯＨＴ）上でオイルのベタツキ感がなく、色再現・透過性を満足するカラートナーを得ることが可能となる。更に、ＯＨＴ上でオフセットすることなくハーフトーンまで高い透明性で鮮やかに発色させ、ＯＨＴの投影像で淡色部分まで明るく鮮やかに再現することが可能となる。また、低湿下で使用しても、高湿下で使用しても高い画像品質が得られ、経時において画像欠陥を生じないカラートナーを得ることが可能となる。
【図面の簡単な説明】
【図１】本発明の画像形成方法を実施し得る好適な画像形成装置の例を示す概略図である。
【図２】本発明の画像形成方法を実施し得る画像形成装置の他の例を示す概略図である。
【図３】本発明の画像形成方法を実施し得る画像形成装置の他の例を示す概略図である。
【図４】本発明の画像形成方法を実施し得る画像形成装置の他の例を示す概略図である。
【図５】本発明の画像形成方法を実施し得る画像形成装置の他の例を示す概略図である。
【図６】二成分系現像剤を用いる画像形成装置の概略図である。
【図７】非接触一成分現像方法による現像装置の概略図である。
【図８】接触一成分現像方法による現像装置の概略図である。
【図９】加熱加圧定着装置の一例としての熱ロール定着装置の概略図である。
【符号の説明】
１ 露光手段
２ 帯電ローラ
３ 感光ドラム
４ 現像器
５ 現像器
６ 現像器
７ 現像器
８ 感光ドラムクリーナー
９ 芯金
１０ 保持部材
１１ 中間転写体
１２ 中間転写体クリーナー
１３ 電源
１４ 転写帯電器
１５ 分離除電器
１６ 帯電器
１７ 現像器
１８ 感光ドラムクリーナー
１９ 感光ドラム
２０ 分離除電器
２２ 定着器
２３ 潜像形成部
２４ 転写放電部
２５ 搬送ベルト
２６ 排出部
２７ 吸着帯電器
２８ 分離除電放電部
２９ 画像形成部
３１ 露光手段
３２ 定着器
３３ 感光ドラム
３４ 現像器
３５ 現像器
３６ 現像器
３７ 現像器
３８ 感光ドラムクリーナー
３９ 回転現像ユニット
４０ 転写ドラムユニット
４４ 転写帯電器
４５ 分離帯電器
４６ 帯電器
４７ グリッパー
４８ 転写ドラム
４９ 分離爪
６０ａ 転写バイアス印加手段（接地していても良い）
６１ａ 感光体ドラム
６２ａ 一次帯電器
６３ａ 現像器
６４ａ 転写ブレード
６５ａ トナーホッパー
６６ａ 補給ローラ
６７ａ 露光装置
６８ 記録材担持体
６９ 分離帯電器
７０ 定着器
７１ 定着ローラ
７２ 加圧ローラ
７３ ウェッブ
７５，７６ 加熱手段
７８ 温度検知手段
７９ 転写ベルトクリーニング装置
８０ 駆動ローラ
８１ ベルト従動ローラ
８２ ベルト除電器
８３ レジストローラ
８４ 給紙ローラ
１０１ 露光手段
１０２ 帯電手段
１０３ 感光ドラム
１０４ 現像器
１０５ 現像器
１０６ 現像器
１０７ 現像器
１０８ 感光ドラムクリーナー
１０９ 転写帯電器
１１０ 分離除電器
１１１ 除電器
１１２ 定着器
１１９ 感光体ドラム
１２０ 現像装置
１２１ 現像スリーブ（現像剤担持体）
１２２ スリーブ基体
１２３ 磁石
１２４ 搬送スクリュー
１２５ 搬送スクリュー
１２６ 現像容器
１２７ 現像ブレード
１２８ 二成分現像剤
１２９ 補給用トナー
１３０ 隔壁
１３１ 補給口
１６９ 静電潜像保持体（感光体ドラム）
１７０ 現像装置
１７１ 現像容器
１７２ 現像スリーブ（現像剤担持体）
１７３ 現像剤供給ローラー
１７４ 弾性ブレード（現像ブレード）
１７５ 撹拌部材
１７６ 一成分非磁性現像剤
１８０ 現像装置
１８１ 現像容器
１８２ 現像スリーブ（現像剤担持体）
１８３ ローラー基体
１８４ 弾性層
１８５ 現像剤供給ローラー
１８６ 弾性ブレード（現像ブレード）
１８７ 撹拌部材
１８８ 一成分現像剤
１８９ 感光体ドラム[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a color toner used in an electrophotographic method, an image forming method for developing an electrostatic latent image, or a color toner used in a toner jet method, a color image forming method using the color toner, and The present invention relates to an apparatus unit that is detachably attached to an image forming apparatus main body.
[0002]
[Prior art]
Conventionally, as an electrophotographic method, many methods are known as described in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910, Japanese Patent Publication No. 43-24748, and the like. In general, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means, and then the latent image is developed with toner to form a visible image, and if necessary, paper is used. After transferring the toner to a transfer material such as heat, the toner image is fixed on the transfer material by heat, pressure, etc. to obtain a copy, and the toner remaining on the photosensitive member without being transferred can be obtained by various methods. And the above process is repeated.
[0003]
In recent years, such a copying apparatus has been strictly pursued to be smaller, lighter, faster, and more reliable. In addition, it is not only used as a general-purpose copying machine for copying original documents, but also used for copying high-definition images such as digital printers or graphic designs as computer output.
[0004]
In addition, with the spread of computer devices for personal users, full-color video communication is becoming widespread as a video information transmission mechanism.
[0005]
Under such circumstances, printers and copiers, which are one of output devices, are rapidly becoming full color, and color images are becoming more familiar to general users.
[0006]
Therefore, higher definition and higher image quality are required as full color image quality, and as a result, the performance required for toner has become higher.
[0007]
By the way, fixing performance is the most important performance required for toner in full-color copying of digital full-color printers and high-definition images.
[0008]
Various methods and apparatuses have been developed for the fixing process, but the most common method at present is a pressure heating method using a heat roller.
[0009]
The pressure heating method using a heating roller allows the toner image surface of the fixing sheet to pass through the surface of a heat roller formed with a material having releasability to the toner (silicone rubber or fluororesin) under pressure. By doing so, fixing is performed. In this method, since the surface of the heat roller and the toner image of the fixing sheet are in contact with each other under pressure, the thermal efficiency when fusing the toner image on the fixing sheet is extremely good, and the fixing is performed quickly. Can do. However, in the above method, since the surface of the heat roller and the toner image are in contact with each other under pressure in a molten state, a part of the toner image may adhere to and transfer to the surface of the fixing roller, and the next fixing sheet may be soiled ( Offset phenomenon). Preventing toner from adhering to the surface of the heat fixing roller is an essential condition for the heat roller fixing method.
[0010]
In the case of full color, color reproduction is generally performed using three color toners of three colors, yellow, magenta, and cyan, or four color toners including black toner. Is fixed on a sheet to be fixed such as paper or an overhead projector sheet (OHT), and the color reproduction and the transparency of the OHT image must be satisfied. For this reason, it is required to sufficiently melt the toner layer and smooth the image surface. In order to achieve both image smoothness and offset prevention, it is essential to supply oil such as silicone oil to the fixing roll and coat it uniformly on the roller, which is necessary for designing a small and inexpensive system. It is an inhibitory factor.
[0011]
As methods for imparting good fixing property and offset resistance to the toner itself, JP-A-52-3304, JP-A-52-3305, JP-A-57-52574, JP-A-61-138259 are disclosed. No. 56, 87051, JP-A 63-188158, JP-A 63-113558, and JP-A-8-030036 disclose techniques for incorporating waxes in toner. Has been.
[0012]
Waxes are used to improve toner offset resistance and fixability at low temperatures, and many copying machines, printers, and the like are commercially available as electrophotographic apparatuses realizing oilless fixing. However, as a high-quality full-color electrophotographic apparatus that requires pictorial full-color images, it is insufficient in that the image has adequate gloss and satisfactory color reproduction and transparency on an overhead projector sheet (OHT). It is.
[0013]
In addition, these waxes deteriorate the blocking resistance, developability when exposed to heat due to temperature rise of a copying machine, etc., or deteriorate the developability due to blooming of the wax when left for a long period of time. To do. Furthermore, these waxes are difficult to uniformly disperse in the toner, and free or unevenly distributed wax tends to adversely affect developability, durability, etc., and sufficient releasability cannot be obtained with an additive amount that does not affect the wax. Therefore, it is essential to use a release agent such as oil on the fixing device side.
[0014]
Further, as a method for imparting good fixability and offset resistance as a toner binder, JP-A-47-12334, JP-A-57-37353 and JP-A-57-208559 disclose ethers. And a monomer component comprising a bisphenol monomer, a dicarboxylic acid monomer, a trihydric or higher polyhydric alcohol monomer and / or a trihydric or higher polyhydric carboxylic acid monomer. There has been proposed a toner containing a polyester made of a linear copolymer as a binder. In this technique, a polyester comprising an etherified bisphenol monomer and a dicarboxylic acid monomer is mixed with a large amount of a trihydric or higher polyhydric alcohol monomer and / or a trivalent or higher polyvalent carboxylic acid monomer. By incorporating a polyester obtained by crosslinking with a monomer component as a binder, the toner has anti-offset performance. However, when these toners are used for full-color image formation, the high-temperature offset resistance is at a level that can be put into practical use, but its softening point is high, and good low-temperature fixing is difficult, and sharp melt properties are improved. Due to the difficulty, color mixing and color reproducibility by superimposing full color toners using the polyester is not sufficient.
[0015]
In JP-A-57-109825, JP-A-62-78568, JP-A-62-78569, JP-B-63-57785 and JP-A-59-29256, the etherified bisphenol is simply described. A monomer, a dicarboxylic acid monomer introduced with a long-chain aliphatic hydrocarbon, other dicarboxylic acid monomer, a trihydric or higher polyhydric alcohol monomer, and / or a trivalent or higher polyvalent carboxylic acid monomer. A non-linear copolymer obtained from a monomer component containing a monomer, and containing a polyester having a saturated or unsaturated aliphatic hydrocarbon group having 3 to 22 carbon atoms in its side chain as a binder Although toners are disclosed, these polyester resins are mainly intended for high-speed fixing toners, and the viscoelastic properties of the resins are completely opposite to the aforementioned viscosity-oriented polyesters, Enhance sexual, in which markedly allowed lower the high-temperature offset to the roller. At the time of fixing, the pressure and heating of the heat roller are increased as much as possible, the toner is pushed in between the fibers of the transfer paper in a semi-molten state, and pressure and heat fixing are performed to achieve the object. is there. Therefore, it is almost impossible to obtain a smooth surface by melting the toner layer necessary for the color image, and the fixed toner exists in a particle state on the transfer paper, and the resulting color image is dull. It becomes a terrible thing and is terrible for saturation. In the OHT image, light is scattered and diffused on the surface of the toner particles, hardly transmits light, and is practically unusable.
[0016]
As described in Japanese Patent Publication Nos. 55-6895 and 56-98202, there is a method of suppressing the offset phenomenon by widening the molecular weight distribution of the binder resin. It is necessary to set the fixing temperature to be higher and higher.
[0017]
Further, as described in JP-B-57-493, JP-A-50-44836, and JP-A-57-37353, the offset phenomenon is suppressed by making the resin non-linear or cross-linking. Method: As described in JP-A-61-213858, JP-A-1-295269, JP-A-1-30061, JP-A-1-302267, and JP-A-3-96964, a polyester resin is converted into a metal ion. A method for improving the offset phenomenon by crosslinking is proposed.
[0018]
As a method for improving the offset resistance of the toner, a toner using a covalently crosslinked resin or a branched resin using a polyfunctional monomer called a crosslinked polymer or a polyfunctional initiator (Japanese Patent Laid-Open No. 3-203746, special No. 4-24648) and toners using ion-bonded cross-linked polymers in which metal oxides and polymers are firmly bonded (Japanese Patent Laid-Open Nos. 61-213858 and 6-175395). Has been proposed). In both cases, the anti-offset property is improved, but the inherent fixability of the binder resin is lowered, and the polymer molecules are strongly entangled. Therefore, the resin component due to crosslinking represented by tetrahydrofuran insoluble matter is bound to the colorant or charge control agent. It is difficult to disperse in a resin and it is not suitable as a full color toner. Further, the pulverizability of the toner kneaded product at the time of toner production is also lowered.
[0019]
Further, JP-A-63-225244 to 63-225246 disclose a toner containing two types of non-linear polyesters for the purpose of improving low-temperature fixability, high-temperature offset resistance, and blocking resistance. Has been. JP-A-60-214368, JP-A-2-08267, JP-A-2-158747, JP-A-4-338773, JP-A-7-261659, and JP-A-8-101530. For example, a method of blending two kinds of polyesters having different physical properties to improve the toner fixing property and offset resistance has been proposed. Although the application amount of the fixing roller is reduced, it is indispensable, and a complete oil-less full color toner has not yet been obtained.
[0020]
Further, in Japanese Patent Laid-Open No. 3-188468, a polyester resin as a binder in toner particles has the following conditions (A) to (C): (A) The acid value of the polyester resin is Av and the hydroxyl value is OHv. Av is in the range of 20 to 35 (KOHmg / g), Av / OHv = 1.0 to 1.5, (B) tetrahydrofuran insoluble content is 10% or less, (C) tetrahydrofuran is acceptable. In the molecular weight distribution by gel permeation chromatography (GPC) of the solute, the ratio of the weight average molecular weight Mw to the number average molecular weight Mn is Mw / Mn ≧ 10, and the number average molecular weight is 3,000 to 8,000. It has at least one peak (low molecular side peak) in the region, and a peak or shoulder (polymer side) in the region having a number average molecular weight of 100,000 to 600,000 Over h) one has, and the toner satisfies the, the polymer side peak region is present 5-15% has been proposed. However, the polyester of JP-A-3-188468 has an acid value as high as 20 (KOHmg / g) or more, and contains a soft segment component, but has a large amount of polyvalent carboxylic acid and a high proportion of crosslinking components ( Even in the examples, 2% or more of the THF-insoluble matter is present), so that the full color fixability (coincidence of gloss control and offset resistance) is not satisfied.
[0021]
Further, JP-A-7-234537 discloses a toner containing a wax having a polyester resin having a soft segment having 5 to 30 carbon atoms and having defined heat characteristics, and a non-linear polyester resin and a wire satisfying the toner. Toners using a mixture of polyester resins have been proposed. However, although the polyester of JP-A-7-234537 contains a soft segment component, it has a large amount of trivalent or higher polyvalent monomer component with respect to the soft segment component, so that full color fixing properties (gloss control and offset resistance are compatible). ) Is not satisfied.
[0022]
Thus, while satisfying the color reproducibility of pictorial full-color images with moderate gloss and color reproduction / transparency on the Overhead Projector Sheet (OHT), good low-temperature fixing performance and offset resistance As an excellent color toner that can be used for oilless fixing, there are still problems to be improved along with image characteristics described later.
[0023]
In addition, in order to meet the demands for energy saving, curling after fixing of transfer material, and improvement of toner storage stability, the resulting full-color image shows excellent offset resistance with oilless fixing at a lower temperature, It suppresses irregular reflection by particles as much as possible, has moderate glossiness and gloss, has transparency that does not interfere with toner layers of different tones under the toner layer, and has excellent color reproducibility up to high chroma color tone There is a need for color toners.
[0024]
On the other hand, due to the recent miniaturization and miniaturization of copiers and printers, the temperature in the developing machine is likely to rise, and the storage stability of toner at a high temperature is desired to be higher than before. Therefore, there is a need for a toner that sufficiently satisfies both stable developability and good transferability at the same time.
[0025]
In order to obtain stable developability and good transferability, charge control of toner particles is essential. In order to retain the charge in the toner, it is possible to use the triboelectric charging property of the resin, which is a component of the toner. However, since this method does not stabilize the charging of the toner, the rise of density is slow and fogging is easy. Therefore, a charge control agent is added in order to impart a desired triboelectric chargeability to the toner.
[0026]
As a charge control agent known in the technical field today, a negative triboelectric charge control agent includes a metal complex salt of a monoazo dye, a metal complex salt such as a hydroxycarboxylic acid, a dicarboxylic acid, an aromatic diol, and an acid component. Resins and the like are known. As the positive triboelectric charge control agent, nigrosine dyes, azine dyes, triphenylmethane dyes and pigments, quaternary ammonium salts, polymers having quaternary ammonium salts in the side chain, and the like are known.
[0027]
However, depending on the charge control agent, it is difficult to balance the image density and fog, it is difficult to obtain a sufficient image density in a high humidity environment, the dispersibility to the resin is poor, and the storage stability, the fixing property and the offset resistance are adversely affected. And so on. Conventionally, metal complexes and metal salts of aromatic carboxylic acids are disclosed in JP-A-53-127726, JP-A-57-111541, JP-A-57-124357, JP-A-57-104940, JP-A-61-69073, JP-A-61-73893, JP-A-61-267058, JP-A-62-105156, JP-A-62-145255, JP-A-62- Several proposals have been made, including Japanese Patent No. 163061, Japanese Patent Laid-Open No. 63-208865, Japanese Patent Laid-Open No. 3-276166, Japanese Patent Laid-Open No. 4-84141, and Japanese Patent Laid-Open No. 8-160668. However, those proposed in these publications are all excellent from the viewpoint of imparting frictional charge, but particularly when applied to full-color toner, environmental changes, aging, Regardless of the conditions of use, there are few that can achieve stable developability. Furthermore, it has been difficult to achieve both the fixing performance required for the color toner as described above and stable developability.
[0028]
[Problems to be solved by the invention]
It is an object of the present invention to provide a color toner and a color image forming method that solve the above-mentioned conventional problems.
[0029]
That is, an object of the present invention is to provide a color toner that is excellent in offset resistance and can be fixed at a low temperature, which can be fixed by using a small amount of fixing oil and without using a fixing oil.
[0030]
Another object of the present invention is to set a low fixing temperature, use a slight amount of fixing oil, or use oilless fixing, and the resulting full-color image has appropriate glossiness and gloss, and has a color mixing property (color developing property). It is an object of the present invention to provide a color toner and a color image forming method that are excellent in color reproducibility up to a high-saturation color tone.
[0031]
It is another object of the present invention to provide a color toner which does not have a sticky feeling of oil on a recording material, particularly on an overhead projector sheet (OHT), and satisfies color reproduction and transparency.
[0032]
A further object of the present invention is to provide a color toner and a color image forming method which can obtain a stable image quality free from gloss unevenness and having no gloss fluctuation even after repeated use.
[0033]
Another object of the present invention is to provide an apparatus unit having a small-sized and low-cost color image forming apparatus with a simple oil application mechanism or without an oil application mechanism.
[0034]
It is a further object of the present invention to provide an apparatus unit having a color image forming apparatus that does not require replenishment of fixing oil and can reduce running costs by reducing the number of consumable parts in the fixing unit.
[0035]
A further object of the present invention is to provide a color toner that can obtain high image quality even when used under low humidity or high humidity and does not cause image defects over time, and a color image forming method using the color toner Another object of the present invention is to provide an apparatus unit having a color image forming apparatus using the color toner.
[0036]
[Means for Solving the Problems]
  The present invention relates to a color toner having at least a binder resin, a wax, an organometallic compound, and a colorant.
  The binder resin comprises a polyvalent carboxylic acid monomer unit having at least a trivalent or higher polyvalent carboxylic acid monomer unit and a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms.TheAnd the content of the trivalent or higher polyvalent carboxylic acid monomer unit in the binder resin is Xa mol%, the number of carbon atoms having 5 to 30 saturated or unsaturated aliphatic hydrocarbon groups. Carboxylic acid monomer unitToWhen the content is Ya mol%, the following conditions
      0.5 <Xa <15
      5 <Ya <30
      3.75≦ Ya / Xa ≦9.00
A non-linear polyester resin A satisfying the above, and at least a linear polyester resin B not containing a trivalent or higher polyvalent carboxylic acid monomer unit and a trivalent or higher polyhydric alcohol monomer unit,
  TheNon-linear polyester resin A andTheThe mixing weight ratio of the linear polyester resin B is 25/75 to 75/25,
  TheMaximum endothermic peak measured by differential scanning calorimetry (DSC) of wax is 60 to 135 ° C.The ratio Mw / Mn of the number average molecular weight (Mn) and the weight average molecular weight (Mw) in the GPC molecular weight distribution of the wax is 1.0 to 2.0, and the content weight ratio of the wax is in the color toner. 0.3 to 4.5% by weight, and
  The resin component of the toner contains 0% by weight or more and 8% by weight or less of THF-insoluble matter.The present invention relates to a color toner.
[0037]
  Furthermore, the present inventionThe diveA charging step for charging the image carrier;
A latent image forming step of forming an electrostatic latent image on a charged latent image carrier;
A developing step of developing the electrostatic latent image with toner to form a toner image;
A transfer step of transferring the developed toner image onto a recording material with or without an intermediate transfer member;
And a fixing step of fixing the toner image on the recording material by bringing a fixing member into contact with the surface of the toner image transferred onto the recording material and applying heat and pressure to the toner image;
In an image forming method having
  The developing step is a step of using a color toner having at least a binder resin, a wax, an organometallic compound, and a colorant,
  The binder resin comprises a polyvalent carboxylic acid monomer unit having at least a trivalent or higher polyvalent carboxylic acid monomer unit and a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms.TheAnd the content of the trivalent or higher polyvalent carboxylic acid monomer unit in the binder resin is Xa mol%, the number of carbon atoms having 5 to 30 saturated or unsaturated aliphatic hydrocarbon groups. Carboxylic acid monomer unitToWhen the content is Ya mol%, the following conditions
      0.5 <Xa <15
      5 <Ya <30
      3.75≦ Ya / Xa ≦9.00
A non-linear polyester resin A satisfying the above, and at least a linear polyester resin B not containing a trivalent or higher polyvalent carboxylic acid monomer unit and a trivalent or higher polyhydric alcohol monomer unit,
  TheNon-linear polyester resin A andTheThe mixing weight ratio of the linear polyester resin B is 25/75 to 75/25,
  TheMaximum endothermic peak measured by differential scanning calorimetry (DSC) of wax is 60 to 135 ° C.The ratio Mw / Mn of the number average molecular weight (Mn) and the weight average molecular weight (Mw) in the GPC molecular weight distribution of the wax is 1.0 to 2.0, and the content weight ratio of the wax is in the color toner. 0.3 to 4.5% by weight, and
  The resin component of the toner contains 0% by weight or more and 8% by weight or less of THF-insoluble matter.The present invention relates to a color image forming method characterized in that the toner image is formed by developing an electrostatic latent image using a color toner.
[0038]
  Further, the present invention provides at least a toner for developing an electrostatic latent image, a toner container for holding the toner, and a toner carrier for carrying the toner held in the toner container and transporting it to the development area. And a toner layer thickness regulating member for regulating the layer thickness of the toner carried on the toner carrier,
  The toner is a color toner having at least a binder resin, a wax, an organometallic compound, and a colorant,
  The binder resin comprises a polyvalent carboxylic acid monomer unit having at least a trivalent or higher polyvalent carboxylic acid monomer unit and a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms.TheAnd the content of the trivalent or higher polyvalent carboxylic acid monomer unit in the binder resin is Xa mol%, the number of carbon atoms having 5 to 30 saturated or unsaturated aliphatic hydrocarbon groups. Carboxylic acid monomer unitToWhen the content is Ya mol%, the following conditions
      0.5 <Xa <15
      5 <Ya <30
      3.75≦ Ya / Xa ≦9.00
A non-linear polyester resin A satisfying the above, and at least a linear polyester resin B not containing a trivalent or higher polyvalent carboxylic acid monomer unit and a trivalent or higher polyhydric alcohol monomer unit,
  TheNon-linear polyester resin A andTheThe mixing weight ratio of the linear polyester resin B is 25/75 to 75/25,
  TheMaximum endothermic peak measured by differential scanning calorimetry (DSC) of wax is 60 to 135 ° C.The ratio Mw / Mn of the number average molecular weight (Mn) and the weight average molecular weight (Mw) in the GPC molecular weight distribution of the wax is 1.0 to 2.0, and the content weight ratio of the wax is in the color toner. 0.3 to 4.5% by weight, and
  The resin component of the toner contains 0% by weight or more and 8% by weight or less of THF-insoluble matter.The present invention relates to an apparatus unit that is detachably attached to a color image forming apparatus main body.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, various resin systems and waxes have been intensively studied for the purpose of oilless full color fixing. As a result, in a specific configuration, oilless fixing (fixing roller non-rolling performance, offset resistance), image gloss control, OHT permeability It has been found that the fixing temperature can be set lower than the above.
[0040]
That is, in a color toner having at least a binder resin, a wax, an organometallic compound, and a colorant, the binder resin includes at least a trivalent or higher polyvalent carboxylic acid monomer unit and a saturated or A polyvalent carboxylic acid monomer having an unsaturated aliphatic hydrocarbon group and / or a polyhydric alcohol monomer unit, the trivalent or higher polyvalent carboxylic acid monomer in the binder resin The content of the unit is Xa mol%, and the content of the polyvalent carboxylic acid monomer unit and / or the polyhydric alcohol monomer unit having a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms is When Ya mol%, the following conditions
0.5 <Xa <15
5 <Ya <30
2 ≦ Ya / Xa ≦ 10
A non-linear polyester resin A satisfying the above, and at least a linear polyester resin B not containing a trivalent or higher polyvalent carboxylic acid monomer unit and a trivalent or higher polyhydric alcohol monomer unit,
The mixing weight ratio of the non-linear polyester resin A and the linear polyester resin B is 25/75 to 75/25,
In addition, this is achieved by a color toner characterized in that the maximum endothermic peak by differential scanning calorimetry (DSC) measurement of the wax is 60 to 135 ° C.
[0041]
In general, it is known that an organometallic compound is bonded to a terminal polar group of a polyester and is metal-crosslinked.
[0042]
As a method for controlling the degree of this metal crosslinking in the polymer, the present inventors have used a polyvalent carboxylic acid monomer unit having at least a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms and / or In a toner containing a polyester resin having a polyhydric alcohol monomer unit or a trivalent or higher polycarboxylic acid monomer unit as a constituent monomer unit, an organometallic compound and a wax, A polyvalent carboxylic acid monomer unit and / or a polyhydric alcohol monomer unit (soft segment component) having an obstructive saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms, Non-linear polyester resin with limited content and content ratio of trivalent or higher polyvalent carboxylic acid monomer units with high reaction probability, (2) Yes It is preferable to use a linear polyester resin which has a relatively low metal crosslinkability with a metal compound and enhances the sharp melt property of the toner, and (3) a wax having a maximum endothermic peak of 60 to 135 ° C. as measured by a differential scanning calorimeter (DSC). They found it important to achieve both gloss control and offset resistance required for full-color fixing.
[0043]
That is, a trivalent or higher polyvalent carboxylic acid monomer unit and a polyvalent carboxylic acid monomer unit and / or a polyhydric alcohol monomer having a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms. The content of the unit (soft segment component) and its ratio are specified, and the metal cross-linking with the organometallic compound is blended at a predetermined ratio with a linear polyester resin that has a relatively low metal cross-linking property with the organometallic compound and increases the sharp melt property of the toner. It has been found that by adding a polyester resin with a controlled density and a specific wax to this, the oil-free color fixability is remarkably improved, leading to the present invention.
[0044]
When the content of the trivalent or higher polyvalent carboxylic acid monomer unit in the non-linear polyester resin A in the present invention is less than 0.5 mol%, the crosslinking reaction with the organometallic compound does not proceed and the non-offset region is narrow. It will be a thing. In addition, when the content of the trivalent or higher polyvalent carboxylic acid monomer unit is less than 3 mol%, it is difficult to take a sufficiently large non-offset region. When a color image is formed on both sides, the second side At the time of fixing, the smoothness of the image is lowered and a color image with low gloss is generated, or an offset occurs. Therefore, it is more preferable that the content of the trivalent or higher polyvalent carboxylic acid monomer unit of the non-linear polyester resin A is 3 mol% or higher.
[0045]
On the other hand, if the content of the trivalent or higher polyvalent carboxylic acid monomer unit exceeds 15 mol%, the non-offset region is expanded by the crosslinking reaction with the organometallic compound, but the fixing property is impaired, and the sharp melt linear polyester. Even when the resin B is blended as a binder resin, the gloss required for the color image is lowered and the OHT permeability is also deteriorated. In order to further improve the fixability and obtain bright and excellent color reproducibility on the OHP projected image up to the light color portion on the OHT, the content of the trivalent or higher polyvalent carboxylic acid monomer unit is 10 mol% or less. More preferably.
[0046]
In addition, when the content of the soft segment component is less than 5 mol% in the non-linear polyester resin in the present invention, the steric hindrance effect on the metal crosslinking reaction of the soft segment component is not sufficient, and the polyester resin and the organometallic compound The metal cross-linking reaction easily proceeds and the cross-linking density of the metal cross-linking increases even if the content of the trivalent or higher polyvalent carboxylic acid monomer unit or the organometallic compound is reduced. Since the mobility with respect to heat becomes dull, the fixability is impaired, the gloss required for the color image is lowered, and the OHT permeability is also deteriorated. Conversely, when the content of the soft segment component exceeds 30 mol%, the steric hindrance to the metal cross-linking reaction exhibited by the soft segment component is excessive, and the metal cross-linking reaction between the polyester resin and the organometallic compound does not proceed, and the non-offset region. Is narrow.
[0047]
Furthermore, when the ratio (Ya / Xa) of the content Xa mol% of the trivalent or higher polyvalent carboxylic acid monomer unit in the non-linear polyester resin A and the content Ya mol% of the soft segment component is less than 2, The cross-linking reaction with the organometallic compound is further promoted and the non-offset region is widened, but the fixability is impaired, the gloss required for the color image is lowered, and the OHT permeability is also deteriorated. When the ratio (Ya / Xa) exceeds 10, the crosslinkability decreases due to steric hindrance to the metal crosslinking reaction of the soft segment component, and the non-offset region becomes narrow.
[0048]
Furthermore, in the present invention, it is possible to mix the non-linear polyester resin A with the linear polyester resin B having a sharp melt property at a weight ratio of 25/75 to 75/25 at a lower fixing temperature setting. It is necessary to achieve both the gloss control and offset resistance required in When the mixing weight ratio of the non-linear polyester resin A and the linear polyester resin B is smaller than 25/75, the offset resistance as the total binder resin is not sufficient, and the mixing weight ratio is 75/25. If this is exceeded, it will be difficult to satisfy full color fixing at a lower fixing temperature setting. Increasing the fixing temperature setting will not only increase the power consumption but also reduce the toner fluidity and blocking in the image forming apparatus. This causes various problems such as shortening the life of the fixing member and increasing the curl of the obtained image transfer material.
[0049]
In addition, the wax used in the present invention is selected from a differential scanning calorimeter (selecting a wax melting property that better matches the melting behavior of the binder resin, and achieving oilless full color fixing at a lower fixing temperature setting ( It is necessary that the maximum endothermic peak measured by DSC) be in the range of 60 to 135 ° C. When the maximum endothermic peak measured by differential scanning calorimetry (DSC) of the wax is less than 60 ° C., the storage stability and durability of the color toner are deteriorated. The releasability with toner is not exhibited.
[0050]
In the present invention, the content of the organometallic compound in the toner is 0.2 to 10% by weight, and the total content of the trivalent or higher polyvalent carboxylic acid monomer units in the binder resin. It is preferable that Xc mol% and the content Z weight% of the organometallic compound in the toner satisfy the following formula.
[0051]
2 ≦ Xc × Z ≦ 50
[0052]
When the content of the organometallic compound in the toner is less than 0.2% by weight, the cross-linking reaction does not proceed and the non-offset region becomes narrow. When the content exceeds 10% by weight, the cross-linking reaction is further promoted and the non-offset region However, the fixability is impaired, the gloss required for the color image is lowered, and the OHT permeability is also deteriorated.
[0053]
  Also,The binder resinTotal content X of trivalent or higher polyvalent carboxylic acid monomer unitsc  When the product (Xc × Z) of mol% and the content Z weight% of the organometallic compound in the toner is less than 2, the crosslinkability is lowered and the non-offset region becomes narrow. When (Xc × Z) exceeds 50, the crosslinking reaction is further promoted and the non-offset region is widened, but the fixability is impaired, the gloss required for the color image is lowered, and the OHT permeability is also deteriorated. That is, in addition to the content of the soft segment and the trivalent or higher polyvalent carboxylic acid monomer unit and the limitation of the content ratio, the trivalent or higher polyvalent polyhydric acid content and the metal bridging reaction probability are high. By using a polyester resin in which the content ratio of the entire binder resin component to the organometallic compound of the carboxylic acid monomer unit is limited, it is preferable to achieve both gloss control and offset resistance required for full-color fixing. Presenting.
[0054]
The toner of the present invention needs to contain a wax having a maximum endothermic peak of 60 to 135 ° C. as measured by differential scanning calorimetry (DSC) of the wax. In order to further improve the releasability of the color toner starting to melt at a lower temperature, it is more preferable that the maximum endothermic peak measured by differential scanning calorimetry (DSC) of the wax is 60 to 120 ° C.
[0055]
Examples of these waxes include those having the maximum endothermic peak in differential thermal analysis at 60 ° C. or higher and 135 ° C. or lower among the waxes listed below.
[0056]
Examples of waxes used in the toner of the present invention include petroleum waxes such as paraffin wax, microcrystalline wax, petrolactam and derivatives thereof, montan wax and derivatives thereof, hydrocarbon waxes and derivatives thereof according to the Fischer-Tropsch method, and polyethylene. Polyolefin waxes and derivatives thereof, natural waxes such as carnauba wax and candelilla wax and derivatives thereof, and the derivatives include oxides, block copolymers with vinyl monomers, and graft modified products. 60 endothermic peaks in differential thermal analysis among fatty acids such as higher aliphatic alcohols, stearic acid, palmitic acid or the like, compounds thereof, acid amides, esters, ketones, hydrogenated castor oil and derivatives thereof, plant waxes, animal waxes, etc. The temperature is in the range of 135 ° C.
[0057]
Among these, it is preferable in the present invention that the compound having the maximum endothermic peak in differential thermal analysis at 60 ° C. or more and 135 ° C. or less is a polyolefin, a hydrocarbon wax or a petroleum-based wax by the Fischer-Tropsch method, particularly preferably a carbonization. Hydrogen wax and polyethylene wax are preferred.
[0058]
Furthermore, in the present invention, the ratio Mw / Mn of the number average molecular weight (Mn) to the weight average molecular weight (Mw) in the GPC molecular weight distribution of the wax is preferably 1.0 to 2.0. By selecting and limiting the molecular weight distribution of the wax component so that the maximum endothermic peak in the differential thermal analysis of the wax more closely matches the melting behavior of the binder resin specified in the present invention, and sharper melting properties at that temperature. In addition, low temperature fixability is imparted in oilless full color fixing, and OHT transparency can be further enhanced while satisfying offset resistance performance. When the ratio Mw / Mn of the number average molecular weight (Mn) and the weight average molecular weight (Mw) in the GPC molecular weight distribution of the wax exceeds 2.0, the releasability of the color toner that starts melting at a low temperature of the present invention is low. It is not demonstrated efficiently. In order to obtain sufficient releasability, it is necessary to increase the amount of wax added. This increase in the amount of added wax not only impairs OHT transparency, but also makes the wax uniform in the polyester resin as a binder resin. Dispersal becomes difficult, causing the blocking resistance to deteriorate and the developability to deteriorate.
[0059]
The content ratio of the wax is preferably 0.3 to 4.5% by weight with respect to the toner. If the wax content is less than 0.3% by weight, the releasing effect is not sufficient, and if it exceeds 4.5% by weight, the OHT transparency is impaired as described above, resulting in deterioration in blocking resistance and developability. Invite. Therefore, in the color toner of the present invention, the addition amount of the wax is preferably as small as possible within a range where a sufficient releasing effect can be obtained, and more preferably 3% by weight or less. Moreover, you may use together with other waxes, as long as it does not have a bad influence.
[0060]
Further, the wax in the present invention is preferably one having a small polarity or a nonpolar one. The smaller the polarity of the wax is, the more it is possible to improve the offset resistance with a small amount of addition, which is advantageous in increasing the transparency of a color image having high saturation and excellent color reproducibility, and a color image on OHT. When the polyester resin is mainly used as the binder resin as in the present invention, it is considered that the wax having a small polarity deteriorates the dispersibility in the binder resin. However, according to the study by the present inventors, when a large amount of wax having a small polarity is added to the polyester resin, the dispersibility of the wax in the binder resin is deteriorated, and the development characteristics and the toner fluidity are deteriorated. In general, when 4.5% by weight is added, the wax exists in a finely dispersed diameter in the binder resin of the present invention, and there is no adverse effect such as a decrease in development characteristics and a decrease in toner fluidity. It has been found that can be increased. In order to further improve the transparency and color reproducibility of the color image on the OHT, the amount of wax added is more preferably 3% by weight or less. That is, when the polyester resin is mainly used as the binder resin as in the present invention, the wax having the maximum endothermic peak in the differential thermal analysis at 60 ° C. or more and 135 ° C. or less is a polyolefin having a small polarity or a nonpolar property. Alternatively, a hydrocarbon wax or a petroleum wax by Fischer-Tropsch method is more preferable, and a hydrocarbon wax or polyethylene wax is particularly preferable.
[0061]
Furthermore, the wax used in the present invention preferably has an onset temperature of 55 to 105 ° C. when the temperature rises in the DSC curve. By using such a wax, a toner excellent in blocking resistance and fixing ability can be obtained.
[0062]
When the onset temperature is less than 55 ° C., the toner particles undergo a plastic change from a relatively low temperature, so that the blocking resistance is inferior, and the developability is liable to deteriorate with increasing temperature. On the other hand, when the temperature exceeds 105 ° C., the rate of plastic change due to heating becomes slow, and the low-temperature offset resistance and fixability become poor.
[0063]
Furthermore, the wax used in the present invention has a number average molecular weight (Mn) of 200 to 2000, a weight average molecular weight (Mw) of 200 to 2500 (more preferably Mn 300 to 1000, Mw 300 to 1200), and Mw / Mn is It is preferable that it is 2 or less.
[0064]
By having the molecular weight within the above range, the toner can have preferable thermal characteristics. That is, when the molecular weight is smaller than the above range, it is susceptible to thermal influence, resulting in poor blocking resistance and developability. If the molecular weight is larger than the above range, heat from the outside cannot be effectively used, and it is difficult to obtain excellent fixing properties and offset resistance. When Mw / Mn is larger than 2, the molecular weight distribution is wide, so that the melting behavior is not sharp with respect to heat, and the fixing temperature range in which good color reproducibility (color mixing of toner in the fixing step) can be obtained. It becomes small and it becomes difficult to obtain a region satisfying both good fixing property and offset resistance.
[0065]
The maximum endothermic peak temperature and onset temperature in the DSC curve of the wax used in the present invention can be obtained from the DSC curve measured by a differential scanning calorimeter. For example, DSC-7 manufactured by Perkin Elmer can be used as the measuring device.
[0066]
The measurement method is performed according to ASTM D3418-82. The DSC curve used in the present invention is a DSC curve that is measured when the temperature is raised after raising the temperature once and taking the previous history, then lowering the temperature in the range of 30 to 160 ° C. Is used.
[0067]
The molecular weight of the wax used in the present invention can be measured by the following method.
[0068]
(GPC measurement conditions)
Apparatus: GPC-150C (Waters)
Column: GMH-HT 30 cm 2 series (manufactured by Tosoh Corporation)
Temperature: 135 ° C
Solvent: o-dichlorobenzene (0.1% ionol added)
Flow rate: 1.0 ml / min
Sample: 0.4 ml of 0.15% sample was injected
Measurement is performed under the above conditions, and a molecular weight calibration curve prepared from a monodisperse polyester standard sample is used in calculating the molecular weight of the sample. Furthermore, it calculates by converting into polyethylene by the conversion formula derived from the Mark-Houwink viscosity formula.
[0069]
Furthermore, in the present invention, the binder resin component of the color toner preferably contains a THF soluble component and 0% by weight or more and less than 5.0% by weight of a THF insoluble component. In molecular weight distribution, less than 10,000 component content (M1) 45 to 65%, 10,000 to 50,000 component content (M2) 25 to 50%, 50,000 to 500,000 component content (M3) 2 It is preferable that the content of the component (M4) exceeds 20% and 500,000, and satisfies the relationship of M1> M2> M3> M4.
[0070]
When the toner binder resin contains 5.0% by weight or more of a THF insoluble matter as a gel component, the presence of a gel that does not melt at a low temperature only thickens the system and deteriorates the low-temperature fixability required for a color toner. In addition, even when a sharp melt component that melts at a low temperature, which is required for color toners, is contained, the viscosity of the toner surface at the time of fixing is low even though the internal viscosity is increased due to the melting temperature difference. Also lower. In addition, when a large amount of THF-insoluble matter is contained, the smoothness of the obtained color image is also adversely affected, and an image having low gloss or non-homogeneity tends to be formed. In order to stably obtain an image having a homogeneous gloss, it is more preferable that the THF-insoluble content of the toner binder resin is less than 2.0% by weight.
[0071]
Moreover, in the GPC molecular weight distribution of the THF-soluble component, the component content (M1) of less than 10,000 is 45 to 65%, the component content of 10,000 to 50,000 (M2) is 25 to 50%, and 50,000 to 500,000. Component content (M3) 2 to 20%, component content (M4) more than 500,000 0.1 to 10%, 50,000 or less components are 80% or more of the total, and M1> M2> M3 When the relationship of> M4 is not satisfied, the low-temperature fixability, gloss, OHT permeability and offset resistance required for the color toner are not compatible.
[0072]
In the present invention, the linear polyester resin B used by mixing with the non-linear polyester resin A has a number average molecular weight (Mn) of 2000 to 8000 and a weight average molecular weight (Mw) of 8000 to 30000. The ratio Mw / Mn of the number average molecular weight (Mn) to the weight average molecular weight (Mw) is preferably 2 to 3.5. If the molecular weight is less than the lower limit, the viscosity at the time of melt-fixing is significantly reduced with respect to the non-linear polyester resin A to be mixed, so that the offset resistance is lowered, and if the molecular weight exceeds the upper limit, the linear polyester resin B The effect of lowering the fixing temperature by mixing is not obtained. Further, Mw / Mn is preferably as small as possible in order to obtain sharp melt properties. When Mw / Mn exceeds 3.5, the sharp melt properties decrease, and the linear polyester resin B is mixed to adjust the fixing temperature. Lowering effect is small.
[0073]
In the present invention, the GPC molecular weight distribution of the THF-insoluble and THF-soluble components of the binder resin (the whole polymer component of the toner composition) and the linear polyester resin B was measured according to the following method.
[0074]
(Measurement of toner insoluble matter in toner)
The THF-insoluble matter of the present invention refers to “a weight ratio of a polymer component that is insoluble in a THF solvent in a toner” calculated by a Soxhlet extraction method. That is, 1.0 g of a toner sample was weighed (W1 g), placed in a cylindrical filter paper (for example, No. 86R manufactured by Toyo Filter Paper), subjected to a Soxhlet extractor, extracted using 200 ml of THF as a solvent, and extracted for 12 hours. After evaporating the soluble component, it is vacuum-dried overnight at 100 ° C., and the amount of the resin component soluble in THF is weighed (W2 g). When the THF-insoluble content of the toner is measured, the weight other than the resin component such as a pigment is (W3 g) and is obtained from the following formula.
[0075]
[Expression 1]

[0076]
(Measurement of molecular weight distribution of toner solubles in THF)
The THF-soluble component of the toner sample subjected to the Soxhlet extraction and THF are mixed at a concentration ratio of 5 to 25 mg / 5 ml, allowed to stand at room temperature for several hours, sufficiently shaken, and further allowed to stand overnight. Thereafter, a sample processing filter (pore size 0.4 to 0.5 μm, for example, Mysori Disc H-25-2, Exo Disc 25CR manufactured by Tosoh Corporation, etc., manufactured by Gelman Science Japan Co., Ltd.) is used as a measurement sample.
[0077]
In the GPC measurement apparatus, entanglement is stabilized in a heat chamber at 40 ° C., and THF is added to the column at this temperature as a solvent at 1 ml / min. The sample is poured at a flow rate of about 100 ml and measured by injecting about 100 ml of the THF sample solution. For the measurement of the molecular weight of the sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of the calibration curve prepared from several monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, for example, a molecular weight of 10 manufactured by Tosoh Corporation or Showa Denko KK is 10²-10⁷It is appropriate to use a standard polystyrene sample of about 10 points. An IR (refractive index) detector is used as the detector. As the column, several commercially available polystyrene gel columns are preferably combined, and a combination of Shodex GPC KF-801, 802, 803, 804, 805, 806, 807, and 800P manufactured by Showa Denko KK is preferable. In the GPC measurement, on both sides of the polymer, the chromatogram started from the baseline and measurement was started from the starting point, and the molecular weight calculation range was from the low molecular weight side to about 400 molecular weight. GPC-150C (Waters) was used as the measuring device.
[0078]
Further, the acid value of the binder resin (the whole polymer component of the toner composition) used in the present invention is preferably 2 mgKOH / g to 20 mgKOH / g. When the acid value of the binder resin is less than 2 mgKOH / g, the development stability and durability stability effect due to the interaction with the organometallic compound cannot be fully exhibited, or the wax is poorly dispersed due to the poor dispersion of the organometallic compound. Deterioration of low-temperature fixability due to. On the other hand, when it exceeds 20 mgKOH / g, the hygroscopicity becomes strong, the image density tends to decrease, and the fog tends to increase.
[0079]
In the present invention, the acid value of the entire polymer component of the toner composition is determined by the following method.
[0080]
(Measurement of acid value)
Basic operation conforms to JIS K-0070.
[0081]
1) The sample is used after removing additives other than the polymer component in advance, or the acid value and content of the component other than the polymer are determined in advance. A pulverized sample of 0.5 to 2.0 (g) is precisely weighed to obtain a weight W (g) of the polymer component.
[0082]
2) A sample is put into a 300 (ml) beaker, and a mixed solution 150 (ml) of toluene / ethanol (4/1) is added and dissolved.
[0083]
3) Titrate with a potentiometric titrator using a 0.1N KOH methanol solution (for example, using a potentiometric titrator AT-400 (winworkstation) manufactured by Kyoto Electronics Co., Ltd. and an ABP-410 electric burette. Automatic titration of can be used.)
[0084]
4) The amount of KOH solution used at this time is S (ml), and at the same time, a blank is measured, and the amount of KOH solution used at this time is B (ml).
[0085]
5) Calculate the acid value according to the following formula. f is a factor of KOH.
[0086]
Acid value (mgKOH / g) = ((SB) × f × 5.61) / W
[0087]
A preferred composition of the polyester resin used in the present invention will be described below.
[0088]
The non-linear polyester resin A used in the present invention is composed of a polyvalent carboxylic acid monomer unit in which 3 to 15 mol% of all components are trivalent or higher, and is a saturated or unsaturated aliphatic having 5 to 30 carbon atoms. The polyvalent carboxylic acid monomer unit and / or the polyhydric alcohol monomer unit (soft segment component) having a hydrocarbon group is 5 to 30 mol%, and the others are a divalent acid component and a divalent alcohol component, etc. Consists of. Moreover, the linear polyester resin B used for this invention consists of a bivalent acid component and a bivalent alcohol component.
[0089]
Examples of the trivalent or higher polyvalent carboxylic acid monomer unit as a component of the polyester resin used in the present invention include 1,2,4-benzenetricarboxylic acid, 1,3,5-benzenetricarboxylic acid, 1,2 , 4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, tetra (methylene Carboxy) methane, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, polyvalent carboxylic acids such as 1,2,7,8-octanetetracarboxylic acid, their acid anhydrides or lower alkyl esters, etc. Is mentioned.
[0090]
Moreover, as a monomer unit used as a soft segment as a component of the non-linear polyester resin A used in the present invention, a polyvalent carboxylic acid having a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms is used. It is an acid monomer unit and / or a polyhydric alcohol monomer unit, and is a monomer unit having a saturated or unsaturated aliphatic hydrocarbon group introduced by being branched into the skeleton of the polyester resin. preferable. The soft segment component preferably has a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms in any of divalent and trivalent monomers constituting the polyester resin. More preferably, it is a monomer of a substituted aliphatic dicarboxylic acid and / or an aliphatic diol substituted with a soft segment.
[0091]
As the aliphatic dicarboxylic acid monomer unit substituted with a soft segment, an alkyl group or alkenyl group having 5 to 30 carbon atoms (for example, n-dodecenyl group, isododecenyl group, n-dodecyl group, isododecyl group or isooctyl group) Alkyldicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid substituted with or an anhydride thereof are preferable, and dodecenyl succinic acid, octyl succinic acid and anhydride thereof are particularly preferable.
[0092]
Examples of the aliphatic diol monomer unit substituted with a soft segment include ethylene glycol, 1,3-propylenediol, tetramethyl glycol, substituted with an alkyl group or alkenyl group having 5 to 30 carbon atoms, Examples include 1,4-butylene diol, 1,5-pentyldiol, and n-dodecenyl ethylene glycol, n-dodecenyl triethylene glycol, and the like are preferably used.
[0093]
The divalent acid component of the polyester resin used in the present invention includes benzenedicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride, or anhydrides thereof or lower alkyl esters thereof; succinic acid, adipic acid Alkyl dicarboxylic acids such as sebacic acid and azelaic acid or their anhydrides or lower alkyl esters thereof; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, itaconic acid, their anhydrides or lower alkyl esters thereof, etc. It is done.
[0094]
Examples of the divalent alcohol component include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, and bisphenol represented by formula (I) and derivatives thereof;
[0095]
[Chemical 1]

(In the formula, R is an ethylene or propylene group, x and y are each an integer of 0 or more, and the average value of x + y is 0 to 10.)
In addition, diols represented by the formula (b);
[0096]
[Chemical 2]

(In the formula, R ′ is an ethylene or propylene group, x ′ and y ′ are each an integer of 0 or more, and the average value of x ′ + y ′ is 0 to 10).
Diols such as
[0097]
Of these, at least propoxylated and / or ethoxylated etherified bisphenol is preferably used.
[0098]
Furthermore, examples of trihydric or higher alcohol components that can be used in the present invention include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, and sucrose. 1,2,4-mentatriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. Is mentioned.
[0099]
The organometallic compound used in the present invention is, for example, an organometallic complex, metal salt, chelate compound, monoazo metal complex, acetylacetone metal complex, salicylic acid metal complex, alkylsalicylic acid metal complex, dialkylsalicylic acid metal complex, Examples include off-sinaphtoic acid metal complexes, hydroxycarboxylic acid metal complexes, and polycarboxylic acid metal salts. Examples of metal elements constituting complex organometallic complexes, metal salts, and chelate compounds include chromium, iron, zinc, aluminum, and zirconium. In the case of black toner, it can be used regardless of whether it is colorless or colored. The chromatic color toner is preferably a colorless or light color toner that does not affect the color tone of the toner.
[0100]
In the present invention, as the metal element of the organometallic compound, aluminum or zirconium is preferable since it has a stable crosslinkability with the polyester resin of the present invention and can easily control viscoelasticity.
[0101]
As the organometallic compound used in the present invention, the present inventors use a combination of a zirconium compound, in particular a complex compound of zirconium or an aromatic carboxylate of zirconium, and a binder resin structure in the present invention. It has been found that it is possible to obtain a toner that has excellent low-temperature fixability and that has a relatively stable charge amount against changes in the environment from a high humidity environment to a low humidity environment while maintaining good toner charge rise. .
[0102]
In the organozirconium compound of the present invention, the zirconium ion is likely to be coordinated eight times, and oxygen such as a carboxyl group and a hydroxyl group is likely to be coordinated. . Therefore, the use of the polyester resin having the composition of the present invention and the property that the organic zirconium compound is well-adapted in the binder resin and excellent in dispersibility, prevents the toner particles from falling off, and makes the charging uniform. Durability and stability of charging can be obtained.
[0103]
Another object of the present invention is that the polymer chain can be more effectively cross-linked through the coordination of carboxyl groups and hydroxyl groups to zirconium ions in the polyester resin with controlled metal crosslinkability of the present invention. It becomes easy to control rubber elasticity and viscosity. In addition, it is excellent in releasability, can effectively prevent fouling of the fixing member, and can achieve full color oilless fixing.
[0104]
Furthermore, the organozirconium compound that can be used in the present invention improves the dispersion of other materials (pigments, dyes, waxes, etc.) in the polyester resin of the present invention, thereby improving the charge uniformity and the durability stability of the charge. can get. In addition, the influence on the transparency of the toner is reduced, which is preferable for expressing a vivid color for the color toner.
[0105]
The content of these organic zirconium compounds is effectively 0.1 to 10 parts by weight, more preferably 0.5 to 6 parts by weight with respect to 100 parts by weight of the binder resin. It can also be used in combination with known charge control agents as described.
[0106]
In the present invention, the object of the present invention can be achieved to a higher degree by using a toner containing an aromatic diol, an aromatic hydroxycarboxylic acid, a zirconium complex of an aromatic polycarboxylic acid or a zirconium complex salt as an organometallic compound.
[0107]
The zirconium compound preferably used as the organometallic compound of the present invention is a zirconium complex or zirconium complex salt in which 2 to 4 chelates of aromatic diol, aromatic hydroxycarboxylic acid or aromatic polycarboxylic acid are formed as a ligand. More preferably. In the case of a salt, those having 1 to 4 aromatic carboxylate ions, aromatic hydroxycarboxylate ions and aromatic polycarboxylate ions are preferred, and those having 2 to 3 are preferred. Further, it may be a complex or complex salt having a different number of chelates, or a complex or complex salt having a different ligand. Furthermore, it may be a mixture of salts having different numbers of acid ions.
[0108]
The zirconium compound preferably used as the organometallic compound in the present invention is a zirconium complex or a zirconium complex salt in which an aromatic diol, aromatic hydroxycarboxylic acid, or aromatic polycarboxylic acid is coordinated as a ligand. A zirconium complex or a zirconium complex salt represented by the general formula (1) is preferable.
[0109]
[Chemical 3]

In the general formula (1), Ar is an alkyl group, aryl group, aralkyl group, cycloalkyl group, alkenyl group, alkoxy group, aryloxy group, hydroxyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyl group as a substituent. It may have an acyloxy group, a carboxyl group, a halogen, a nitro group, a cyano group, an amino group, an amide group, or a carbamoyl group. Represents an aromatic residue, X and Y represent -0-, -CO-O-, X and Y may be the same or different, L represents a neutral ligand, water, alcohol, Ammonia, alkylamine, pyridine, C1 represents a monovalent cation, hydrogen, monovalent metal ion, ammonium, alkylammonium, C2 represents a divalent cation, divalent metal ion, n is 2, 3 and 4 are represented, and m represents 0, 2, and 4. The aromatic carboxylic acids and aromatic diols that serve as ligands in each complex or complex salt may be the same or different. Further, it may be a mixture of complex compounds having different numbers of n and m. From the viewpoint of improving the dispersibility of the complex or complex salt in the binder resin or improving the chargeability, the aromatic residue is preferably a benzene ring, naphthalene ring, anthracene ring, or phenanthrene ring, and the substituent is an alkyl group. Carboxyl group and hydroxyl group are preferred, L is preferably water, and C1 is preferably hydrogen, sodium, potassium, ammonium, or alkylammonium.
[0110]
Further preferred complexes or complex salts are zirconium complexes or salts represented by the general formulas (2), (3) and (4).
[0111]
[Formula 4]

In the general formulas (2), (3) and (4), R is hydrogen, alkyl group, aryl group, aralkyl group, cycloalkyl group, alkenyl group, alkoxy group, aryloxy group, hydroxyl group, acyloxy group, alkoxycarbonyl. Group, aryloxycarbonyl group, acyl group, carboxyl group, halogen, nitro group, amino group, carbamoyl group, which may be linked together to form an aliphatic ring, aromatic ring or heterocyclic ring. The ring may have a substituent R, 1 to 8 substituents R may be the same or different, and C is a monovalent cation, hydrogen, alkali 1 represents an integer of 1 to 8, n represents 2, 3, 4, m represents 0, 2, 4, each complex or Aromatic carboxylic acids as the ligand in the salt, aromatic diols may be different even the same. Further, it may be a mixture of complex compounds having different numbers of n and m. From the viewpoint of improving the dispersibility of the complex or complex salt in the binder resin or improving the chargeability, the substituent R is preferably an alkyl group, an alkenyl group, a carboxyl group, or a hydroxyl group, and C includes hydrogen, sodium, potassium, Ammonium and alkylammonium are preferred. Particularly preferred is a zirconium neutral complex having no counter ion and having a general formula of n = 2, which provides excellent environmental stability, excellent dispersibility in the binder resin, and good Durability is obtained.
[0112]
The zirconium complex or complex salt used in the present invention is a hexacoordinate or octacoordinate complex compound. In the octacoordinate, a ligand-bridged binuclear complex compound is formed, and the hexacoordination formula is There is a complex compound. Typical structures of such complex compounds are exemplified by the following general chemical formulas (5) to (9). The following structures include those having no ligand L.
[0113]
[Chemical formula 5]

[0114]
[Chemical 6]

Preferred zirconium salts of aromatic carboxylic acids used in the present invention are represented by general formulas (10) and (11).
[0115]
[Chemical 7]

In the general formulas (10) and (11), Ar is an alkyl group, aryl group, aralkyl group, cycloalkyl group, alkenyl group, alkoxy group, aryloxy group, hydroxyl group, acyloxy group, alkoxycarbonyl group, aryl as a substituent. An oxycarbonyl group, an acyl group, a carboxyl group, a halogen, a nitro group, a cyano group, an amino group, an amide group, or an carbamoyl group, which represents an aromatic residue, A1 is a monovalent anion, a halogen ion , Represents a hydroxide ion and a nitrate ion, A2 represents a divalent anion, a sulfate ion or a hydrogen phosphate ion, and n represents 1, 2, 3 or 4. The aromatic carboxylic acids and aromatic diols that are acid ions in each metal salt may be the same or different. Moreover, the mixture of the salt from which the number of n differs may be sufficient. From the viewpoint of improving the dispersibility of the metal salt in the binder resin or improving the chargeability, the aromatic residue is preferably a benzene ring, naphthalene ring, anthracene ring, or phenanthrene ring, and the substituent is an alkyl group, A carboxyl group, a hydroxyl group, and an acyloxy group are preferable. In general formula (10), n is 4, and in general formula (11), n is 2.
[0116]
Further preferred metal salts are zirconium salts represented by the general formulas (12) and (13).
[0117]
[Chemical 8]

In the general formulas (12) and (13), R is hydrogen, an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group, an alkenyl group, an alkoxy group, an aryloxy group, a hydroxyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, An acyloxy group, an acyl group, a carboxyl group, a halogen, a nitro group, an amino group, an amide group, or a carbamoyl group may be connected to each other to form an aliphatic ring, an aromatic ring, or a heterocyclic ring. May have a substituent R, may have 1 to 8 substituents R, and may be the same or different, and A1 is a monovalent anion, halogen ion, water Represents an acid ion or a nitrate ion, A2 represents a divalent anion, a sulfate ion or a hydrogen phosphate ion, l represents an integer of 1 to 8, n represents 1, It represents 3 or 4. The aromatic carboxylic acids and aromatic diols that are acid ions in each metal salt may be the same or different. Moreover, the mixture of the salt from which the number of n differs may be sufficient. From the viewpoint of improving the dispersibility of the metal salt in the binder resin or improving the chargeability, the substituent is preferably an alkyl group, an alkenyl group, a carboxyl group, a hydroxyl group, or an acyloxy group. In the general formula (12), n is In the general formula (13), n is preferably 2, and excellent environmental stability is obtained, dispersibility in the binder resin is excellent, and excellent durability is obtained.
[0118]
The organic zirconium compound of the present invention is obtained by dissolving a zirconium compound such as chlorinated zirconium oxide, zirconium sulfate, or organic acid zirconium in water, an alcohol, or an alcohol aqueous solution, and adding an aromatic carboxylic acid, an aromatic diol, or an alkali metal salt thereof. Alternatively, it is synthesized by adding an aromatic carboxylic acid, an aromatic diol and an alkali agent. These organic zirconium compounds are recrystallized with an aqueous alcohol solution or the like and purified by washing with alcohol. In the case of complex salts, complex salts having various counter ions can be obtained by treating the product with a mineral acid, an alkali agent, and an amine agent. In this invention, what has multiple types, such as a hydrogen ion, an alkali metal ion, and an ammonium ion, is included in the counter ion of a zirconium complex salt.
[0119]
Specific examples of the organozirconium compounds used in the present invention will be given below, but here, the formulas are shown. Although what has coordinated 2-4 water molecules is also contained, description of a water molecule is abbreviate | omitted here. In addition, although counter ions include those having a plurality of types, only the most counter ions are described here.
[0120]
[Chemical 9]

[0121]
[Chemical Formula 10]

[0122]
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[0123]
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[0124]
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[0125]
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[0126]
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[0127]
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[0128]
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[0129]
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[0130]
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[0131]
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[0132]
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[0133]
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[0134]
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[0135]
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[0136]
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[0137]
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[0138]
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[0139]
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[0140]
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[0141]
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[0142]
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[0143]
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[0144]
A conventionally known colorant can be used as the colorant used in the present invention.
[0145]
For example, as a cyan colorant used in a cyan toner, a copper phthalocyanine compound and a derivative thereof, an anthraquinone compound, a basic dye lake compound, and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 and the like can be suitably used.
[0146]
As the magenta colorant used in the magenta toner, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48; 2, 48; 3, 48; 4, 57; 1, 81; 1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254 are preferred.
[0147]
As yellow colorants used for yellow toners, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168 and the like are preferable.
[0148]
As the black colorant used in the black toner, carbon black, a magnetic material, a color tone adjusted to black using the cyan / magenta / yellow colorant described above, and the like can be used.
[0149]
These colorants can be used alone or in combination and further in the form of a solid solution. In the present invention, the colorant is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. The colorant is preferably added in an amount of 1 to 20 parts by weight with respect to 100 parts by weight of the resin component.
[0150]
Among the chromatic colorants, the cyan toner contains a copper phthalocyanine organic pigment, the magenta toner contains a quinacridone organic pigment, and the yellow toner contains a diarylide organic pigment. It is particularly preferable that the toner has good chargeability, fluidity and spectral reflection characteristics.
[0151]
Examples of copper phthalocyanine-based organic pigments include C.I. I. Pigment blue 15; 15: 1; 15: 2; 15: 3; 15: 4. Furthermore, a phthalocyanine pigment in which 1 to 5 phthalimidomethyl groups are substituted on the phthalocyanine skeleton having the structure represented by the formula (c) can be mentioned. Copper phthalocyanine pigments with other substituents may be used.
[0152]
Embedded image

[0153]
The content is 0.1 to 12 parts by weight, preferably 0.5 to 10 parts by weight, and more preferably 1 to 8 parts by weight with respect to 100 parts by weight of the binder resin. If it exceeds 12 parts by weight, the saturation and lightness of the cyan toner are lowered, and the color reproduction ability is lowered.
[0154]
Examples of quinacridone organic pigments include C.I. I. Pigment Red 122 is preferable, and C.I. I. Pigment red 192, 202, 206, 207, and 209 are also preferable. Furthermore, C.I. I. Pigment violet 19 is also preferable. C. I. Pigment Red 122 may be used as a base pigment in combination with other colorants. Examples of the pigment used at that time include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 123, 146, 150, 163, 184, 185, 238; I. Pigment violet 19; C.I. I. Bat red 1, 2, 10, 13, 15, 23, 29, 35, etc. are mentioned. A part of the dye represented by xanthene dye may be used in combination.
[0155]
The content is 0.1 to 15 parts by weight, preferably 1 to 12 parts by weight, and more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. Even when used in combination with other dyes and pigments, the other dyes and pigments are used in an amount of 50 parts by weight or less, preferably 25 parts by weight or less based on 100 parts by weight of the quinacridone pigment.
[0156]
Examples of diarylide organic pigments include C.I. I. Pigment Yellow 12, 13, 14, 17, 81, 106, 113 are preferable. I. Pigment Yellow 55, 63, 83, 87, 90, 114, 121, 124, 126, 127, 136, 152, 170, 171, 172, 174, 176, 188 may be used.
[0157]
Furthermore, C.I. I. Pigment Yellow 12, 13, 14, 17, 81 may be used as a base pigment in combination with other yellow colorants, or may be used in part with yellow dyes.
[0158]
The content is 0.1 to 12 parts by weight with respect to 100 parts by weight of the binder resin, preferably 0.5 to 10 parts by weight, and more preferably 1 to 8 parts by weight.
[0159]
When a magnetic material is used as the black colorant, it is preferable to add 20 to 200 parts by weight, particularly preferably 40 to 150 parts by weight, based on 100 parts by weight of the resin component, unlike other colorants.
[0160]
Magnetic materials include iron oxides such as magnetite, maghematite, and ferrite; metals such as iron, cobalt, and nickel, or these metals and aluminum, cobalt, copper, lead, magnesium, manganese, selenium, titanium, tungsten, and vanadium. Such metal alloys and mixtures thereof are used, and those containing a non-ferrous element on or inside the magnetic material are preferred.
[0161]
As these magnetic materials, magnetic iron oxides such as magnetite, maghemite and ferrite containing different elements and mixtures thereof are preferably used. Among them, lithium, beryllium, boron, magnesium, aluminum, silicon, phosphorus, germanium, titanium, zirconium, tin, lead, zinc, calcium, barium, scandium, vanadium, chromium, manganese, cobalt, copper, nickel, gallium, cadmium, indium It is preferably a magnetic iron oxide containing at least one element selected from silver, palladium, gold, mercury, platinum, tungsten, molybdenum, niobium, osmium, strontium, yttrium, technetium, ruthenium, rhodium, and bismuth. . In particular, lithium, beryllium, boron, magnesium, aluminum, silicon, phosphorus, germanium, zirconium, tin, and transition metal elements in the fourth period are preferable elements. These elements may be incorporated into the iron oxide crystal lattice, may be incorporated into the iron oxide as oxides, or may exist on the surface as oxides or hydroxides. Moreover, it is a preferable form to contain as an oxide.
[0162]
In addition, these magnetic materials have a uniform particle size distribution and, together with their dispersibility in the binder resin, can stabilize the chargeability of the toner. In recent years, the toner particle size has been reduced, and even when the weight average particle size is 10 μm or less, the charging uniformity is promoted, the toner cohesion is reduced, and development such as improvement of image density and improvement of fogging is performed. Improves. In particular, the effect is remarkable in a toner having a weight average particle diameter of 6.0 μm or less, and an extremely fine image can be obtained. A weight average particle diameter of 2.5 μm or more is preferable because a sufficient image density can be obtained.
[0163]
The content of these different elements is preferably 0.05 to 10% by weight based on the iron element of magnetic iron oxide. More preferably, it is 0.1-7 weight%, Most preferably, it is 0.2-5 weight%, Furthermore, it is 0.3-4 weight%. If it is less than 0.05% by weight, the effect of containing these elements cannot be obtained, and good dispersibility and charging uniformity cannot be obtained. On the other hand, when the amount is more than 10% by weight, the discharge of electric charge increases, resulting in insufficient charging, and the image density may be lowered or fog may increase.
[0164]
In the distribution of the content of different elements in these magnetic materials, it is preferable that they are present more in the vicinity of the surface of the magnetic material. For example, the ratio (B / A) × 100 of the content B of different elements present in the iron oxide dissolution rate of iron oxide up to 20% by weight and the total content A of different elements of the magnetic iron oxide is 40% or more. It is preferable that Furthermore, 40 to 80% is preferable and 60 to 80% is particularly preferable. By increasing the surface abundance, the dispersion effect and the electric diffusion effect can be further improved. Further, the amount contained in the toner is preferably 20 to 200 parts by weight, more preferably 40 to 150 parts by weight based on 100 parts by weight of the resin component, with respect to 100 parts by weight of the resin component.
[0165]
The magnetic iron oxide used in the magnetic toner of the present invention may be treated with a silane coupling agent, a titanium coupling agent, titanate, aminosilane, or the like.
[0166]
The amount of element in the magnetic iron oxide of the present invention is measured by performing fluorescent X-ray analysis using a fluorescent X-ray analyzer SYSTEM3080 (manufactured by Rigaku Denki Kogyo Co., Ltd.) according to JIS K0119 general X-ray fluorescence analysis rules. did. Regarding the element distribution, the amount of element while dissolving hydrochloric acid was measured and quantified by plasma emission spectroscopy (ICP), and the dissolution rate was determined from the concentration of each element at the time of dissolution relative to the concentration of each element at the time of total dissolution.
[0167]
In addition to the polyester resin in the present invention, the binder resin used in the toner of the present invention can be used in combination with other resins to the extent that the present invention is not adversely affected.
[0168]
For example, homopolymers of styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene, and substituted products thereof; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer , Styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl Styrene copolymers such as ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer; polyvinyl chloride, phenol Resin, natural modification Enol resin, natural resin-modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, coumarone indene resin Petroleum resin can be used. A preferable binder is a styrene copolymer.
[0169]
Examples of the comonomer for the styrene monomer of the styrene-based copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid. Monocarboxylic acid having a double bond such as acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide and the like; for example, maleic acid, butyl maleate, Dicarboxylic acids having a double bond such as methyl maleate, dimethyl maleate, and the like; and vinyl esters such as vinyl chloride, vinyl acetate, vinyl benzoate; Ethylene-based olefins such as ethylene and butylene; vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; A single monomer or two or more monomers are used.
[0170]
From the viewpoint of storage stability, the resin composition according to the present invention has a glass transition temperature (Tg) of 45 to 75 ° C., preferably 50 to 70 ° C. When Tg is lower than 45 ° C., the toner deteriorates in a high temperature atmosphere. It is easy to cause an offset at the time of fixing. On the other hand, when Tg exceeds 75 ° C., fixability tends to be lowered.
[0171]
The toner of the present invention is preferably mixed with inorganic fine powder or hydrophobic inorganic fine powder. For example, it is more preferable to add and use silica fine powder, alumina fine powder, and titanium oxide fine powder.
[0172]
As the silica fine powder used in the present invention, both a so-called dry process produced by vapor phase oxidation of a silicon halide compound or a so-called wet silica produced from water glass or the like can be used. However, dry silica having less silanol groups on the surface and inside and having no production residue is preferable.
[0173]
Further, the silica fine powder used in the present invention is preferably hydrophobized. The hydrophobizing treatment is performed by chemically treating with an organosilicon compound that reacts or physically adsorbs with silica fine powder. As a preferable method, a dry silica fine powder produced by vapor phase oxidation of a silicon halogen compound is treated with a silane coupling agent or with a silane coupling agent and simultaneously with an organosilicon compound such as silicone oil. Is mentioned.
[0174]
Examples of silane coupling agents used for hydrophobizing treatment include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, and allylphenyldichlorosilane. , Benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilane mercaptan, trimethylsilyl mercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, Dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyl Examples thereof include tetramethyldisiloxane and 1,3-diphenyltetramethyldisiloxane.
[0175]
Examples of the organosilicon compound include silicone oil. As a preferable silicone oil, one having a viscosity at 25 ° C. of about 30 to 1,000 centistokes is used. For example, dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, fluorine modified Silicone oil or the like is preferable.
[0176]
Silicone oil treatment methods include, for example, mixing silica fine powder treated with a silane coupling agent and silicone oil directly using a mixer such as a Henschel mixer, or injecting silica silicone oil as a base. Depending on how you do it. Alternatively, the silicone oil may be dissolved or dispersed in an appropriate solvent, and then mixed with the base silica fine powder to remove the solvent.
[0177]
If necessary, an external additive other than the inorganic fine powder may be added to the toner in the present invention.
[0178]
Examples thereof include resin fine particles and inorganic fine particles that function as a charge auxiliary agent, a conductivity imparting agent, a fluidity imparting agent, an anti-caking agent, a release agent at the time of heat roll fixing, a lubricant, and an abrasive.
[0179]
For example, lubricants such as Teflon, zinc stearate, and polyvinylidene fluoride are preferable, and among them, polyvinylidene fluoride is preferable. Alternatively, a polishing agent such as cerium oxide, silicon carbide, strontium titanate, etc., among which strontium titanate is preferable. Alternatively, for example, a fluidity imparting agent such as titanium oxide or aluminum oxide, particularly a hydrophobic one is preferable. A small amount of an anti-caking agent, or a conductivity imparting agent such as carbon black, zinc oxide, antimony oxide or tin oxide, or white and black fine particles having opposite polarity can be used in small amounts.
[0180]
The inorganic fine powder or hydrophobic inorganic fine powder mixed with the toner is preferably used in an amount of 0.1 to 5 parts by weight (preferably 0.1 to 3 parts by weight) with respect to 100 parts by weight of the toner.
[0181]
In order to produce the toner according to the present invention, after sufficiently mixing the toner constituent materials as described above with a mixer such as a ball mill, a Henschel mixer, etc., the mixture is well kneaded using a heat kneader such as a hot roll kneader or an extruder, A method of obtaining toner by mechanical pulverization and classification after cooling and solidification is preferable, and the toner according to the present invention can be produced.
[0182]
Next, the image forming method of the present invention will be described.
[0183]
The image forming method of the present invention comprises a charging step of charging a latent image holding member; a latent image forming step of forming an electrostatic latent image on the charged latent image holding member; A developing step for forming an image; a transferring step for transferring the developed toner image onto a recording material with or without an intermediate transfer member; and a fixing member in contact with the surface of the toner image transferred on the recording material And fixing the toner image on the recording material by applying heat and pressure to the toner image,
The developing step is a step of using a color toner having at least a binder resin, a wax, an organometallic compound, and a colorant,
The binder resin is a polyvalent carboxylic acid monomer unit having at least a trivalent or higher polyvalent carboxylic acid monomer unit, a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms, and / or A polyhydric alcohol monomer unit is contained, and the content of the trivalent or higher polyvalent carboxylic acid monomer unit in the binder resin is Xa mol%, the saturated or unsaturated carbon number of 5 to 30 When the content of the polyvalent carboxylic acid monomer unit and / or the polyhydric alcohol monomer unit having an aliphatic hydrocarbon group is Ya mol%, the following conditions
0.5 <Xa <15
5 <Ya <30
2 ≦ Ya / Xa ≦ 10
A non-linear polyester resin A satisfying the above, and a linear polyester resin B not containing a trivalent or higher polyvalent carboxylic acid monomer unit and a trivalent or higher polyhydric alcohol monomer unit,
The mixing weight ratio of the non-linear polyester resin A and the linear polyester resin B is 25/75 to 75/25,
In addition, it is a step of forming a toner image by developing an electrostatic latent image using a specific color toner in the present invention having a maximum endothermic peak of 60 to 135 ° C. measured by a differential scanning calorimeter (DSC). Features.
[0184]
Various methods and apparatuses have been developed for the fixing process for fixing the toner image on the recording material by applying heat and pressure to the toner image. The most common method at present is by a heat roller. It is a pressure heating system. Conventionally, in a fixing method in which a fixing member is brought into contact with the surface of a toner image transferred onto a recording material such as a heat roller and the toner image is fixed on the recording material by applying heat and pressure to the toner image. Since the surface of the fixing member and the toner image are in contact with each other under pressure in a molten state, a part of the toner image may adhere to and transfer to the surface of the fixing member, and the next fixing sheet may be soiled (offset phenomenon).
[0185]
In addition, using the three primary colors of yellow, magenta, and cyan, or four colors of toner, including black toner, the color toners are overlaid and heat-fixed, and full color reproduction is achieved by mixing the toners. In the color image forming system that performs the above, a multicolor image must be fixed on a sheet to be fixed such as paper or an overhead projector sheet (OHT), and the color reproduction and transparency of the OHT image must be satisfied. For this reason, it is required that the toner layer on the fixing sheet is sufficiently melted to smooth the image surface. For this reason, it is required to achieve both image smoothness and offset prevention.
[0186]
On the other hand, the present invention achieves both smoothness of image and prevention of offset by applying a specific color toner excellent in releasability and color mixing with the fixing member in the present invention.
[0187]
In the present invention, in the fixing step, the application amount per unit area of the recording material of the fixing oil supplied from the fixing member to the fixing surface of the toner image of the recording material is 0 to 1 × 10.^-7g / cm²Thus, it is preferable that the toner image is fixed on the recording material.
[0188]
In order to achieve both image smoothness and offset prevention, a means for supplying a fixing oil such as silicone oil as a release agent to the fixing member and uniformly covering the roller is widely used. As a means for controlling the amount of fixing oil (for example, silicone oil) supplied from the fixing member to the fixing surface of the toner image of the recording material per unit area of the recording material, the web, pad or roller is impregnated with oil and supplied. The fixing member (for example, a silicone rubber roller) impregnated with oil is also possible.
[0189]
However, when the fixing oil is applied and / or supplied, there are problems such as a sticky feeling of the fixing sheet due to the fixing oil, and the color image obtained, and the supply amount of the release agent differs between the initial and long-term use. Thus, the obtained image quality (for example, gloss, oily stickiness, etc.) is likely to fluctuate, and a complicated release agent application and / or supply mechanism is required to keep the release agent supply amount constant. When an extremely small amount of a release agent is applied as in the present invention by simple means, uneven application of oil is likely to occur, and uneven adhesion of oil on the obtained image greatly reduces the image quality. Fixing oil application mechanism or oil replenishment is an impediment to downsizing, inexpensive equipment, low running cost, and the like.
[0190]
In contrast, the application amount per unit area of the recording material of the fixing oil supplied from the fixing member to the fixing surface of the toner image of the recording material is 0 to 1 × 10.^-7g / cm²By doing so, it is possible to suppress the image exposure. By applying the specific color toner in the present invention, it is possible to achieve both image smoothness and offset prevention while suppressing image blur.
[0191]
Preferably, in order to suppress gloss unevenness due to the fixing oil of the color image, the coating amount of the fixing oil supplied from the fixing member to the fixing surface of the toner image of the recording material is 0 to 3 ×. 10^-8g / cm²And more preferably 0-1 × 10^-8g / cm²It is good to be.
[0192]
Furthermore, in the present invention, the fixing step is preferably a step of fixing the toner image on the recording material without supplying fixing oil from the fixing member to the recording material.
[0193]
One of the objects of the present invention is complete oil-less fixing, that is, fixing oil such as silicone oil is not applied (the amount of fixing oil on the surface where the fixing member contacts the toner image on the transfer material is substantially 0 g / cm).²Thus, the color image forming apparatus can be reduced in size and cost, and the color image quality can be prevented from changing due to repeated use or change in the amount of fixing oil supplied over time. By applying the specific color toner in the present invention, even in complete oil-less fixing, it is possible to produce a color image that exhibits excellent smoothness of the image and exhibits an appropriate and stable gloss even in complete oil-less fixing with a small and low-cost apparatus. Can be obtained.
[0194]
Next, the fixing step in the image forming method of the present invention will be described with reference to FIG.
[0195]
In the fixing step in the image forming method of the present invention, the fixing member is brought into contact with the surface of the toner image formed on the recording material, and the toner image is fixed on the recording material by applying heat and pressure to the toner image. The specific toner in the present invention described above is used as the toner for forming the toner image.
[0196]
For example, an unfixed toner image transferred onto a recording material is introduced into a heat and pressure fixing device having a heat roller 153 and a pressure roller 154 shown in FIG.
[0197]
As a mechanical configuration of the fixing device, an elastic roller is preferably used as the fixing roller 153 on the side where the toner image 161 on the recording material 160 is in direct contact. That is, when the fixing roller has elasticity, the surface of the fixing roller itself is deformed and pressed against the unevenness of the surface of the unfixed toner image, so that the toner image can be uniformly heated and pressed, and glossiness is achieved. It is more effective for uniformization.
[0198]
The image forming method of the present invention includes a step of fixing the color toner images of a plurality of colors superimposed on the recording material 160 by a fixing member that performs contact heating and pressurization, and the toner image 161 on the recording material 160 is provided. At the time of fixing, the application amount per unit area of the recording material of the silicone oil supplied from the fixing roller 153 as a fixing member to the fixing surface of the toner image 161 of the recording material 160 is 0 to 1 × 10.^-7g / cm², Preferably 0 to 3 × 10^-8g / cm²More preferably, no silicone oil is applied (0 g / cm²) Good.
[0199]
Further, if necessary, a separation claw 159 between the recording material 160 and the fixing roller 153 or the pressure roller 154 is provided in the fixing device.
[0200]
As a form of application of silicone oil to the fixing member of the present invention, a simple form in which silicone oil is impregnated and supplied to a web or a pad is possible. Alternatively, a fixing member such as a silicone rubber roller impregnated with oil may be used.
[0201]
The fixing temperature is preferably in the range of about 140 to 180 ° C., and the applied pressure is preferably about 20 to 60 kgf.
[0202]
In the present invention, a plurality of constituent members among the constituent members constituting the image forming apparatus used in the above description of the image forming method are unitized to form an apparatus unit that can be detachably attached to the main body of the image forming apparatus. can do.
[0203]
The apparatus unit of the present invention includes a toner for developing an electrostatic latent image, a toner container for holding the toner, a toner for carrying the toner held in the toner container and transporting the toner to the development area And a toner layer thickness regulating member for regulating the thickness of the toner carried on the toner carrier, and is detachably attached to the image forming apparatus main body. The toner of the present invention described above is used as the toner.
[0204]
Examples of such an apparatus unit include a developing device 170 shown in FIG. 7 and a developing device 180 shown in FIG.
[0205]
When the developing device 170 shown in FIG. 7 is an apparatus unit, a developing container 171 as a toner container, a one-component developer 176 as a toner, a developing sleeve 172 as a toner carrier, and a toner layer thickness regulating member In addition to the elastic blade 174, a supply roller 173 for supplying a one-component developer onto the developer sleeve 172 may be configured as a unit.
[0206]
When the developing device 180 shown in FIG. 8 is an apparatus unit, a developing container 181 as a toner container, a one-component developer 188 as a toner, an elastic roller 182 as a toner carrier, and a toner layer thickness regulating member In addition to the elastic blade 186, a supply roller 185 for supplying the one-component developer on the elastic roller 182 and a stirring member 187 for stirring the one-component developer 188 in the developing container 181 are unitized. You may do it.
[0207]
Further, when the developing device 170 shown in FIG. 7 or the developing device 180 shown in FIG. 8 is used for the developing means 17a, 17b, 17c and 17d of the full color image forming apparatus shown in FIG. An apparatus unit can be configured by uniting the photosensitive drum 19a as the image holding member, and the apparatus unit can be detachably mounted on the image forming apparatus main body. Similarly, the developing unit 17b and the photosensitive drum 19b, the developing unit 17c and the photosensitive drum 19c, and the developing unit 17d and the photosensitive drum 19d can be unitized to form an apparatus unit.
[0208]
In this case, in addition to the developing unit 17a and the photosensitive drum 19a, a cleaning unit 18a can be added to form a unit unit.
[0209]
The image forming method and the image forming apparatus of the present invention will be described in detail.
[0210]
The image forming method of the present invention comprises:
A charging step for charging the latent image carrier;
A latent image forming step of forming an electrostatic latent image on a charged latent image carrier;
A developing step of developing the electrostatic latent image with toner to form a toner image;
A transfer step of transferring the developed toner image onto a recording material with or without an intermediate transfer member;
And a fixing step of fixing the toner image on the recording material by bringing a fixing member into contact with the surface of the toner image transferred onto the recording material and applying heat and pressure to the toner image;
As described above, the specific toner in the present invention is used as a toner used in the development process.
[0211]
In the charging process, the charging member is a non-contact charging member that performs non-contact charging on the surface of the latent image carrier such as a corona charger, and is charged in contact with the surface of the latent image carrier such as a blade, roller, and brush. Any of the proximity charging members that perform charging by bringing a charging member such as a contact charging member, a blade, and a roller close to the surface of the latent image carrier (less than 1 mm) can be used. Since it can be reduced, it is preferable to use a contact charging member or a proximity charging member.
[0212]
In the contact charging, a charging member as a charge supply member such as a roller type, a blade type, a brush type, or a magnetic brush type is brought into contact with the photoconductor, and a predetermined charging bias is applied to the contact charging member so that the surface of the photoconductor is predetermined. It is charged uniformly to the polarity and potential of. In comparison with the charging process using a corona charger, the power supply can be reduced in voltage, the amount of ozone generated is small, and the power consumption is reduced. Among these, a roller charging method using a conductive roller (charging roller) as a contact charging member is particularly preferably used from the viewpoint of charging stability.
[0213]
Specifically, since charging is performed by discharging from a charging member to an object to be charged, charging is started by applying a voltage higher than a certain threshold voltage. As an example, when a charging roller is pressed against a certain organic photoreceptor, the surface potential of the photoreceptor starts to rise when a voltage of about 640 V or more is applied, and thereafter, the applied voltage becomes the applied voltage. On the other hand, the photoreceptor surface potential increases linearly with an inclination of 1. Hereinafter, this threshold voltage is defined as a discharge start voltage (charging start voltage) Vth (application to the contact charging member in the case where charging of the image carrier as a charged body is started by applying a DC voltage to the contact charging member. Voltage value).
[0214]
A method of charging by applying only the DC voltage to the contact charging member in this way is referred to as a “DC charging method”.
[0215]
However, in the DC charging method, the resistance value of the contact charging member fluctuates due to environmental fluctuations, and the discharge start voltage Vth fluctuates when the film thickness changes due to the photoconductor being scraped. It was difficult to make value.
[0216]
Therefore, as disclosed in Japanese Patent Laid-Open No. 63-149669, in order to further uniform charge, a peak-to-peak voltage of 2 × Vth or more is applied to a DC voltage corresponding to a desired charged body surface potential V. Uses the “AC charging method” to apply a voltage (alternating voltage, pulsating voltage, vibration voltage; voltage whose voltage value periodically changes with time) superimposed on the alternating current voltage component (AC voltage component) to the contact charging member It is done. This is for the purpose of smoothing the potential due to the AC voltage. The potential of the charged object converges to the potential V, which is the center of the peak of the AC voltage, and is not affected by disturbances such as the environment. It is an excellent method as a contact charging method.
[0217]
Here, as the waveform of the AC voltage, a sine wave, a rectangular wave, a triangular wave, or the like can be used as appropriate. Further, it may be a rectangular wave formed by periodically turning on / off a DC power source. In this manner, a bias that periodically changes the voltage value can be used as the waveform of the AC voltage.
[0218]
A charge injection layer (charge layer) is provided on the surface of the image carrier as a member to be charged, and a charge is directly injected into the charge injection layer by a contact charging member to which a voltage is applied, so that the surface of the image carrier has a predetermined polarity and potential. There is also an injection charging method in which charging is performed, and this is also a category of contact charging.
[0219]
Proximity charging is a non-contact approach as long as the dischargeable area determined by the voltage between the gap and the Paschen curve is reliably guaranteed between the charging member and the surface of the charged body without necessarily contacting the surface of the charged body. The fact that the charged object can be charged even in the arrangement form described above is utilized.
[0220]
Proximity charging is performed by placing a charging member with a small gap of about several tens to several hundreds of μm with respect to the surface of the object to be charged in a non-contact manner, and applying a DC voltage or a DC + AC voltage to the charging member. The surface to be charged is uniformly charged to a predetermined polarity and potential.
[0221]
Compared with the charging process using a corona charger, proximity charging can also reduce the power supply voltage, reduce the amount of ozone generated, and damage the charged object because the charging member is not in contact with the charged object. There are no merits.
[0222]
Examples of the latent image carrier include amorphous selenium, cadmium sulfide, zinc oxide, an organic photoconductor, and an electrophotographic photosensitive member / electrostatic recording dielectric having a photoconductive insulating material layer such as amorphous silicon. Used as a drum or a photosensitive belt. Among these, as the latent image carrier, a photoreceptor having an amorphous silicon photosensitive layer or an organic photosensitive layer is preferably used.
[0223]
The organic photosensitive layer may be a single layer type in which the photosensitive layer contains a charge generating substance and a substance having charge transporting performance in the same layer, or a functional separation type photosensitive layer having a charge transporting layer and a charge generating layer as components. There may be. A laminated photosensitive layer having a structure in which a charge generation layer and then a charge transport layer are laminated in this order on a conductive substrate is one preferred example.
[0224]
One preferred embodiment of the image carrier used in the present invention will be described below.
[0225]
Examples of conductive substrates include metals such as aluminum and stainless steel; plastics having a coating layer of aluminum alloy and indium oxide-tin oxide alloy; cylindrical shapes such as paper impregnated with conductive particles, plastic, and plastics having a conductive polymer Cylinders and films are used. In other words, the conductive material may be directly processed into a drum shape or a film shape such as a belt, or may be processed as a paint, or by vapor deposition, etching, plasma treatment, or the like.
[0226]
For the purpose of improving the adhesion of the photosensitive layer, improving the coatability, protecting the substrate, coating defects on the substrate, improving the charge injection from the substrate, and protecting the photosensitive layer from electrical breakdown on these conductive substrates. An undercoat layer may be provided. Undercoat layer is polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, nitrocellulose, ethylene-acrylic acid copolymer, polyvinyl butyral, phenol resin, casein, polyamide, copolymer nylon, glue, gelatin, polyurethane It is made of a material such as aluminum oxide. The film thickness is usually 0.1 to 10 μm, more preferably 0.1 to 3 μm.
[0227]
The charge generation layer is composed of organic compounds such as azo pigments, phthalocyanine pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, squarylium dyes, pyrylium salts, thiopyrylium salts, triphenylmethane dyes, or amorphous silicon. Such a charge generating material formed of an inorganic material is dispersed in a suitable binder and formed by coating or vapor deposition. The binder can be selected from a wide range of binder resins. For example, polycarbonate resin, polyester resin, polyvinyl butyral resin, polystyrene resin, acrylic resin, methacrylic resin, phenol resin, silicone resin, epoxy resin, vinyl acetate resin and the like can be mentioned. The amount of the binder contained in the charge generation layer is 80% by weight or less, preferably 0 to 40% by weight. The thickness of the charge generation layer is preferably 5 μm or less, particularly preferably 0.05 to 2 μm.
[0228]
The charge transport layer has a function of receiving charge carriers from the charge generation layer in the presence of charges and transporting them. The charge transport layer is formed by dissolving a charge transport material in a solvent together with a binder resin as required, and coating, and the film thickness is generally 5 to 40 μm. Examples of charge transport materials include polycyclic aromatic compounds having a structure such as biphenylene, anthracene, pyrene, and phenanthrene in the main chain or side chain, nitrogen-containing cyclic compounds such as indole, carbazole, oxadiazole, and pyrazoline, hydrazone compounds, Examples include styryl compounds and amorphous silicon.
[0229]
Examples of binder resins for dispersing these charge transport materials include polycarbonate resins, polyester resins, polymethacrylic acid esters, polystyrene resins, acrylic resins, polyamide resins; organic photoconductive materials such as poly-N-vinylcarbazole and polyvinylanthracene. Include a functional polymer.
[0230]
Further, as another mode of the organic photoreceptor used in the method of the present invention, a photosensitive layer in which the above-described charge generating substance and a substance having charge transporting ability are contained in the same layer is formed on a conductive substrate, etc. Also mentioned.
[0231]
Moreover, you may provide a protective layer as a surface layer. Examples of the resin for the protective layer include polyester resin, polycarbonate resin, acrylic resin, epoxy resin, phenol resin, and those obtained by curing these resins with a curing agent. These may be used alone or in combination of two or more.
[0232]
The conductive fine particles in the resin of the protective layer may be dispersed. Examples of the conductive fine particles include metals and metal oxides. Preferably, there are ultrafine particles formed of zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin oxide-coated titanium oxide, tin-coated indium oxide, antimony-coated tin oxide, and zirconium oxide. These may be used alone or in combination of two or more. In general, when the particles are dispersed in the protective layer, it is preferable that the particle diameter of the particles is smaller than the wavelength of the incident light in order to prevent scattering of incident light by the dispersed particles. The particle diameter of the conductive particles or insulating particles dispersed in the protective layer is preferably 0.5 μm or less. The content in the protective layer is preferably 2 to 90% by weight, more preferably 5 to 80% by weight, based on the total weight of the protective layer. The thickness of the protective layer is preferably from 0.1 to 10 μm, more preferably from 1 to 7 μm.
[0233]
The surface layer can be applied by spray coating, beam coating or osmotic coating of the resin dispersion.
[0234]
It is also preferable to impart releasability to the surface layer, and this effect can improve toner transfer efficiency. When the surface of the latent image carrier is mainly composed of a polymer binder, for example, when a protective film mainly composed of a resin is provided on an inorganic photoreceptor such as selenium or amorphous silicon, or a function separation type organic photosensitive This is particularly effective in the case of having a surface layer composed of a charge transport agent and a resin as the charge transport layer of the body and further providing a protective layer thereon.
[0235]
As means for imparting releasability to the surface layer, a) a resin having a low surface energy is used for the resin constituting the film, b) an additive that imparts water repellency and lipophilicity is added, c) high And a material having releasability is dispersed in powder form. As an example of a), it can be achieved by introducing a fluorine-containing group or a silicon-containing group into the resin structure. (B) A surfactant may be used as an additive. Examples of c) include powders of compounds containing fluorine atoms (for example, tetrafluoroethylene, polyvinylidene fluoride, carbon fluoride, etc.). Of these, polytetrafluoroethylene is particularly preferred. In particular, it is preferable to disperse a releasable powder such as a fluorine-containing resin in the outermost surface layer.
[0236]
In order to contain these powders on the surface, a layer in which the powder is dispersed in a binder resin is provided on the outermost surface of the image carrier, or an organic image carrier originally composed mainly of a resin In this case, the powder may be dispersed in the uppermost layer without newly providing a surface layer.
[0237]
The amount of the powder added to the surface layer is preferably 1 to 60% by weight, more preferably 2 to 50% by weight, based on the total weight of the surface layer. If the amount is less than 1% by weight, the transfer efficiency is not improved, and if it exceeds 60% by weight, the strength of the film is lowered or the amount of incident light on the image carrier is undesirably reduced. The particle size of the powder is 1 μm or less, more preferably 0.5 μm or less from the viewpoint of image quality. If it is larger than 1 μm, the line breakage becomes worse due to scattering of incident light.
[0238]
Furthermore, it is one of the preferable modes of the image forming method of the present invention to have a charge injection layer as the surface layer.
[0239]
The volume resistance value of the charge injection layer is 1 × 10 so as not to cause sufficient chargeability and image flow.⁸~ 1x10¹⁵It is preferably Ωcm, and more preferably, the volume resistance value is 1 × 10 from the viewpoint of image flow and the like.^Ten~ 1x10¹⁵In consideration of Ωcm and environmental variation of the volume resistance value, the volume resistance value is 1 × 10^Ten~ 1x10¹⁴It is desirable to use a Ωcm one. 1 × 10⁸If it is less than Ωcm, the charged charge is not held in the surface direction in a high humidity environment, causing image flow and 1 × 10¹⁵If it exceeds Ωcm, the charged charge from the charging member cannot be sufficiently injected and held, and there is a tendency to cause charging failure. By providing such a functional layer on the surface of the photoconductor, it plays a role of holding the charged charge injected from the charging member, and further plays a role of releasing this charge to the photoconductor substrate during light exposure, thereby reducing the residual potential. . By adopting a configuration using such a photoreceptor and a contact charging member for injection charging, the charging start voltage Vth is small, and the photoreceptor charging potential is charged to almost 90% or more of the voltage applied to the charging member. Is possible.
[0240]
For example, when a DC voltage having an absolute value of 100 to 2000 V is applied to the charging member, the charging potential of the electrophotographic photosensitive member having the charge injection layer can be 80% or more, more preferably 90% or more of the applied voltage. On the other hand, the charging potential of the photoreceptor obtained by charging using the conventional discharge is almost 0 V when the applied voltage is equal to or lower than the discharge start voltage, and the charging potential is less than 50% of the applied voltage even at a DC voltage of 1000 V. Only potential was obtained.
[0241]
The charge injection layer is composed of an inorganic layer such as a metal vapor deposition film or a conductive fine particle dispersion layer in which conductive fine particles are dispersed in a binder resin. The vapor deposition film is vapor-deposited, and the conductive fine particle dispersion film is a dip coating method. It is formed by coating by an appropriate coating method such as spray coating, roll coating, or beam coating. Further, it may be constituted by mixing or copolymerizing a resin having high light-transmitting ion conductivity with an insulating binder, or may be constituted by a single resin having medium resistance and photoconductivity. In the case of the conductive fine particle dispersed film, the addition amount of the conductive fine particles is preferably 2 to 250 parts by weight, more preferably 2 to 190 parts by weight with respect to 100 parts by weight of the binder resin. When the amount is less than 2 parts by weight, it is difficult to obtain a desired volume resistance value. When the amount exceeds 250 parts by weight, the film strength is reduced and the charge injection layer is easily scraped, and the life of the photoreceptor is shortened. This is because the resistance becomes low and image defects are liable to occur due to the flow of the latent image potential.
[0242]
Examples of the binder resin for the charge injection layer include polyester resins, polycarbonate resins, acrylic resins, epoxy resins, phenol resins, and those obtained by curing these resins with a curing agent. These may be used alone or in combination of two or more. The binder resin for the charge injection layer can be the same as the binder resin for the lower layer. In this case, however, the coating surface of the charge transport layer may be disturbed when the charge injection layer is applied. Therefore, it is necessary to select a coating method in particular. Furthermore, when the photosensitive layer is amorphous silicon, the charge injection layer is preferably SiC.
[0243]
When a large amount of conductive fine particles are dispersed, it is preferable to disperse the conductive fine particles or the like in a reactive monomer or reactive oligomer and apply it to a photoreceptor, followed by curing with light or heat.
[0244]
Examples of the conductive fine particles dispersed in the binder resin of the charge injection layer include metals and metal oxides. Preferably, there are ultrafine particles such as zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin oxide-coated titanium oxide, tin-coated indium oxide, antimony-coated tin oxide, and zirconium oxide. These may be used alone or in combination of two or more. The particle diameter of the conductive particles or insulating particles dispersed in the charge injection layer is preferably 0.5 μm or less.
[0245]
It is also preferred that the charge injection layer contains a lubricating powder. This is because the friction between the photosensitive member and the injection charging member during charging is reduced, so that the charging nip is enlarged and the charging characteristics are improved. In particular, it is more desirable to use a fluorine resin, a silicone resin, or a polyolefin resin having a low critical surface tension as the lubricating powder. More preferably, tetrafluoroethylene resin (PTFE) is used. In this case, the addition amount of the lubricating powder is preferably 2 to 50 parts by weight, and more preferably 5 to 40 parts by weight with respect to 100 parts by weight of the binder resin. If the amount is less than 2 parts by weight, the amount of the lubricating powder is not sufficient, so that the charging characteristics are not sufficiently improved. If the amount exceeds 50 parts by weight, the resolution of the image and the sensitivity of the photoreceptor are greatly reduced. It is.
[0246]
The thickness of the charge injection layer is preferably 0.1 to 10 μm, and more preferably 1 to 7 μm. When the film thickness is less than 0.1 μm, resistance to minute scratches is lost, and as a result, an image defect due to poor injection occurs. When the film thickness exceeds 10 μm, the image tends to be disturbed due to diffusion of injected charges.
[0247]
Here, the volume resistance value of the charge injection layer is measured by preparing a charge injection layer on a polyethylene terephthalate (PET) film having a conductive film deposited on the surface, and using this as a volume resistance measuring device (4140B manufactured by Hewlett-Packard Company). pAMATER) and measuring by applying a voltage of 100 V in an environment of 23 ° C. and 65%.
[0248]
In a photoconductor that does not have a charge injection layer, the charge member must have a resistance value of 1 × 10 because charges must be efficiently injected into a small number of trap points.^ThreeOn the other hand, the resistance value of the charging member is 1 × 10 6 while being required to be Ω or less.^FourIf it becomes less than Ωcm, excessive leakage current flows from the contact charging member to scratches, pinholes, etc. on the surface of the photoconductor, resulting in peripheral charging failure, pinhole enlargement, and energization breakdown of the charging member. Therefore, good charge injection charging could not be performed. On the other hand, when the charge injection layer is provided, the region where the charge can be held on the surface of the photoreceptor increases, so that even if a charging member having a higher resistance value is used, good charging can be performed. That is, as a means for improving the charge injection charging efficiency to the photoconductor while using a medium resistance contact charging member, a charge injection layer for assisting charge injection to the photoconductor is provided on the surface of the photoconductor. Necessary for injection charging.
[0249]
The essential charging mechanism of injection charging is considered to be that charge injection from the surface of the charging member to the charge injection layer occurs when the surface of the charging member contacts the charge injection layer on the surface of the photoreceptor. Therefore, the characteristics required as a charging member are that the surface of the charge injection layer has a sufficient density and an appropriate resistance for charge transfer.
[0250]
Medium resistance contact charging member that injects charges into the surface of the photoreceptor having a surface resistance of medium resistance, but preferably does not inject charges into the trapping potential of the material of the photoreceptor surface. Then, charging is performed by charging the conductive fine particles of the charge injection layer in which conductive fine particles are dispersed in an insulating binder resin.
[0251]
Specifically, this is based on the theory that a charge is charged by a contact charging member to a minute capacitor having a charge transport layer as a dielectric, an aluminum support and conductive fine particles in the charge injection layer as both electrode plates. At this time, the conductive fine particles are electrically independent from each other and form a kind of minute float electrode. Therefore, macroscopically, the surface of the photoconductor appears to be charged and charged to a uniform potential. However, in reality, a small number of charged conductive fine particles cover the surface of the photoconductor. It has become. For this reason, even if image exposure is performed, each conductive fine particle is electrically independent, so that an electrostatic latent image can be held.
[0252]
Therefore, the charge injection property and the charge retention property are improved by substituting the conductive traps for the trap level which is present in a small amount on the surface of the conventional ordinary photoreceptor.
[0253]
The resistance value of the charging member in the injection charging is 1 × 10 due to the injection charging property and the above-described pinhole leak resistance.^Four~ 1x10⁷It is preferably Ωcm.
[0254]
The shape of the injection charging member may be a blade shape or a brush shape, but in order to appropriately set the peripheral speed difference, a rotatable roller shape, a belt shape, or a brush roller shape (brush roll) is considered advantageous.
[0255]
The roller-shaped contact charging member has a material disclosed in, for example, Japanese Patent Laid-Open No. 1-211799. However, as a conductive substrate, a metal such as iron, copper, and stainless steel, a carbon dispersion resin, a metal, or a metal An oxide dispersion resin or the like can be used. As the structure of the elastic roller, a conductive substrate provided with an elastic layer, a conductive layer, and a resistance layer is used. As the roller elastic layer, chloroprene rubber, isoprene rubber, EPDM rubber, polyurethane rubber, epoxy rubber, butyl rubber are used. It can be formed from rubber or sponge such as styrene-butadiene thermoplastic elastomer, polyurethane-based thermoplastic elastomer, polyester-based thermoplastic elastomer, ethylene-vinyl acetate thermoplastic elastomer, etc., as the conductive layer , Volume resistivity is 10⁷Ωcm or less, preferably 10⁶Ωcm or less. For example, metal vapor deposition film, conductive particle dispersion resin, conductive resin, etc. are used. Specific examples of the metal vapor deposition film include vapor deposition films of aluminum, indium, nickel, copper, iron, etc. Examples of the dispersion resin include those obtained by dispersing conductive particles such as carbon, aluminum, nickel, and titanium oxide in a resin such as urethane, polyester, and vinyl acetate-vinyl chloride copolymer polymethyl methacrylate. Examples of the conductive resin include quaternary ammonium salt-containing polymethyl methacrylate, polyvinyl aniline, polyvinyl pyrrole, polydiacetylene, and polyethyleneimine. For example, the resistive layer has a volume resistivity of 10⁶-10¹²The layer is an Ωcm layer, and a semiconductive resin, a conductive particle-dispersed insulating resin, or the like can be used. As the semiconductive resin, resins such as ethyl cellulose, nitrocellulose, methoxymethylated nylon, ethoxymethylated nylon, copolymerized nylon, polyvinyl hydrin, and casein are used. Examples of conductive particle-dispersed resins include small amounts of conductive particles such as carbon, aluminum, indium oxide, and titanium oxide in insulating resins such as urethane, polyester, vinyl acetate-vinyl chloride copolymer, and polymethyl methacrylate. Examples include dispersed ones.
[0256]
Further, it is preferable that the contact charging member moves with a peripheral speed difference with respect to the photoreceptor. By making the moving speed of the peripheral surface of the contact charging member different from the moving speed of the photoconductor surface, charging stability can be obtained over a long period of time, while maintaining the long life of the photoconductor, and the long life of the charging roller. Can be achieved at the same time, and high stabilization of charging and long life of the image forming system can be achieved. That is, the toner tends to adhere to the surface of the contact charging member, and this adhering toner tends to inhibit charging. By making the surface speed of the surface of the photoreceptor different from the speed of movement of the surface of the contact charging member, On the other hand, since substantially more contact charging member surfaces can be supplied, an effect on charging inhibition is obtained. In other words, when the toner comes to the charged part, the toner having a small adhesion force to the photoconductor moves toward the charging member due to the electric field, and the resistance of the surface of the charging member changes locally. This effectively eliminates the problem that the potential on the surface of the photosensitive member becomes difficult to be applied, and as a result, charging failure occurs.
[0257]
In the latent image forming step, known means such as a laser and an LED are used as the image exposure means. In view of the recent demand for high resolution and high image quality, a means capable of exposing a smaller spot diameter is preferable, and a laser is particularly preferably used in terms of power.
[0258]
In the development process, as a developing means for developing the electrostatic latent image, a one-component developing method using a one-component developer consisting only of toner and a two-component using a two-component developer consisting of toner and carrier A system development method can be used.
[0259]
As a one-component development system, when using a magnetic toner in which a magnetic material is contained in a toner, there is a method of developing by transporting and charging the magnetic toner using a magnetic binding force by a magnet built in the developing sleeve. . Furthermore, when a non-magnetic toner that does not contain a magnetic material is used as a one-component developer, a blade member, a roller member, a brush member, or the like is used to force the non-magnetic toner into pressure contact with the developing sleeve, There is a method in which non-magnetic toner is triboelectrically charged and transported by depositing the toner on the developing sleeve for development.
[0260]
In the two-component development system, a two-component developer composed of toner and carrier is circulated and conveyed on the developer carrier, and the latent image carrier is developed in the development area of the latent image carrier and the developer carrier opposite thereto. The latent image held on the developer is developed with toner of a two-component developer on the developer carrying member.
[0261]
In the transfer step, a corona charger, a transfer roller, a transfer blade, or a transfer belt is used as the transfer means.
[0262]
In the transfer process, in addition to directly transferring the toner image formed on the latent image holding member onto a recording material such as paper or an OHT sheet, it is formed on the latent image holding member using an intermediate transfer member. It is also possible to primarily transfer the toner image on the intermediate transfer member and secondarily transfer the toner image transferred onto the intermediate transfer member from the intermediate transfer member onto the recording material.
[0263]
The image forming method of the present invention includes a first charging step of charging the latent image holding member;
A first latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A first developing step of developing the electrostatic latent image with a first toner to form a first toner image;
A first transfer step of transferring the developed first toner image onto the intermediate transfer member;
A second charging step for charging the latent image carrier;
A second latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A second developing step of developing the electrostatic latent image with a second toner to form a second toner image;
A second transfer step of transferring the developed second toner image to an intermediate transfer body onto which the first toner image is transferred;
A third charging step for charging the latent image carrier;
A third latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A third developing step of developing the electrostatic latent image with a third toner to form a third toner image;
A third transfer step of transferring the developed third toner image onto the intermediate transfer body onto which the first toner image and the second toner image are transferred;
A fourth charging step for charging the latent image carrier;
A fourth latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A fourth developing step of developing the electrostatic latent image with a fourth toner to form a fourth toner image;
A fourth transfer step of transferring the developed fourth toner image onto the intermediate transfer body onto which the first toner image, the second toner image, and the third toner image are transferred;
The multicolor toner image having the first toner image, the second toner image, the third toner image, and the fourth toner image transferred onto the intermediate transfer member is collectively transferred onto the recording material. Batch transfer process; and
The multicolor toner image is recorded on the recording material by bringing a fixing member into contact with the surface of the multicolor toner image that has been secondarily transferred onto the recording material and applying heat and pressure to the multicolor toner image. Fixing process for fixing to the material;
In an image forming method having
The first toner is a color toner selected from the group consisting of cyan toner, magenta toner, yellow toner and black toner;
The second toner is a color toner selected from the remaining group excluding the color toner selected as the first toner,
The third toner is a color toner selected from the remaining group excluding the color toner selected as the first toner and the color toner selected as the second toner,
The fourth toner is the color toner selected as the first toner, the color toner selected as the second toner, and the remaining color toner excluding the color toner selected as the third toner. A method is preferred.
[0264]
An image forming method in which multiple toner images are collectively transferred onto a recording material using the above intermediate transfer member, and the multiple toner images are fixed on the recording material will be described with reference to FIG.
[0265]
A charging roller 2 that rotates while contacting the photosensitive drum 3 as a latent image holding member gives a surface potential to the photosensitive drum 3, and an electrostatic latent image is formed by the exposure unit 1. The electrostatic latent images are sequentially developed by the first developing unit 4, the second developing unit 5, the third developing unit 6 and the fourth developing unit 7 to form toner images, respectively. The toner images are intermediate transfer body 11 for each color. Multiple transfer is performed on the top to form a multiple toner image. The intermediate transfer member 11 is in the form of a drum, with a holding member stretched on the outer peripheral surface, and a conductive member such as carbon black, zinc oxide, tin oxide, silicon carbide or titanium oxide is sufficiently dispersed on the substrate. Those having an elastic layer (for example, nitrile butadiene rubber) are preferably used. A belt-like intermediate transfer member may be used. The intermediate transfer member is composed of an elastic layer having a hardness of 10 to 50 degrees (JIS K-6301). In the case of a transfer belt, the intermediate transfer member has an elastic layer having this hardness at a transfer portion to a transfer material (recording material). It is preferable that the support member is used. In the transfer from the photosensitive drum 3 to the intermediate transfer body 11, a bias current is applied to the core 9 of the intermediate transfer body 11 from the power source 13, whereby a transfer current is obtained and the toner image is transferred. Corona discharge or roller charging from the back surface of the holding member or belt may be used. The multiple toner images on the intermediate transfer member 11 are collectively transferred onto the recording material S by the transfer charging unit 14. The transfer charging means is preferably an electrostatic transfer means using a corona charger, a transfer roller, or a transfer belt.
[0266]
The image forming method of the present invention includes a first charging step for charging the latent image holding member;
A first latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A first developing step of developing the electrostatic latent image with a first toner to form a first toner image;
A first transfer step of transferring the developed first toner image onto a recording material without using an intermediate transfer member;
A second charging step for charging the latent image carrier;
A second latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A second development step of developing the electrostatic latent image with a second toner to form a second toner image; on the recording material onto which the first toner image has been transferred; A second transfer step for transferring to
A third charging step for charging the latent image carrier;
A third latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A third developing step of developing the electrostatic latent image with a third toner to form a third toner image;
A third transfer step of transferring the developed third toner image onto a recording material onto which the first toner image and the second toner image are transferred;
A fourth charging step for charging the latent image carrier;
A fourth latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A fourth developing step of developing the electrostatic latent image with a fourth toner to form a fourth toner image;
A fourth transfer step of transferring the developed fourth toner image onto a recording material onto which the first toner image, the second toner image, and the third toner image are transferred;
A fixing member is brought into contact with the surface of a multicolor toner image having a first toner image, a second toner image, a third toner image, and a fourth toner image sequentially transferred onto a recording material, and the multicolor A fixing step of fixing the multicolor toner image to the recording material by applying heat and pressure to the toner image;
In an image forming method having
The first toner is a color toner selected from the group consisting of cyan toner, magenta toner, yellow toner and black toner;
The second toner is a color toner selected from the remaining group excluding the color toner selected as the first toner,
The third toner is a color toner selected from the remaining group excluding the color toner selected as the first toner and the color toner selected as the second toner,
The fourth toner is the color toner selected as the first toner, the color toner selected as the second toner, and the remaining color toner excluding the color toner selected as the third toner. The method is preferably good.
[0267]
An image forming method for fixing the multiple toner images sequentially transferred onto the recording material without going through the intermediate transfer member to the recording material will be described with reference to FIG.
[0268]
Here, the first, second, third and fourth image forming portions 29 are used._a, 29_b, 29_c, 29_dAre arranged in parallel, and each image forming unit has its own electrostatic latent image holding member, so-called photosensitive drum 19._a, 19_b, 19_cAnd 19_dIt has.
[0269]
Photosensitive drum 19_aThru 19_dIs a latent image forming means 23 on its outer peripheral side._a, 23_b, 23_cAnd 23_d, Developing unit 17_a, 17_b, 17_cAnd 17_d, The discharge part 24 for transfer_a, 24_b, 24_cAnd 24_dAnd the cleaning unit 18_a, 18_b, 18_cAnd 18_dIs arranged.
[0270]
With this configuration, first, the first image forming unit 29_aThe photosensitive drum 19_aOn top of the latent image forming means 23_aThus, for example, a yellow component color latent image is formed in the original image. The latent image is developed by the developing means 17._aA visible image is formed with a developer having a yellow toner, and the transfer unit 24_aThen, the image is transferred to the recording material S.
[0271]
While the yellow image is transferred to the recording material S as described above, the second image forming unit 29_bThen, the latent image of the magenta component color is the photosensitive drum 19._bFormed on top, followed by developing means 17_bA visible image is formed with a developer having a magenta toner. This visible image (magenta toner image) is the first image forming unit 29 described above._aThe recording material S that has been transferred in the transfer is transferred to the transfer portion 24._bWhen the recording material S is loaded, the recording material S is transferred to a predetermined position on the recording material S.
[0272]
Thereafter, the third and fourth image forming units 29 are processed in the same manner as described above._c, 29_dThus, cyan and black images are formed, and the cyan and black colors are transferred onto the same recording material S. When such an image forming process is completed, the recording material S is conveyed to the fixing unit 22 and the image on the recording material S is fixed. As a result, a multicolor image is obtained on the recording material S. Each photosensitive drum 19 that has been transferred._a, 19_b, 19_cAnd 19_dIs the cleaning section 18_a, 18_b, 18_cAnd 18_dThus, the residual toner is removed and used for the subsequent latent image formation.
[0273]
In the image forming apparatus, the conveyance belt 25 is used to convey the recording material S. In FIG. 3, the recording material S is conveyed from the right side to the left side, and each image formation is performed in the conveyance process. Part 29_a, 29_b, 29_cAnd 29_dEach transfer section 24 in FIG._a, 24_b, 24_cAnd 24_dPass through and be transcribed.
[0274]
In this image forming method, a transport belt using a Tetron fiber mesh as a transport means for transporting a recording material and a thin dielectric such as a polyethylene terephthalate resin, a polyimide resin, and a urethane resin are used. A conveyor belt using a body sheet is preferably used.
[0275]
The recording material S is the fourth image forming unit 29._dThen, the AC voltage is applied to the static eliminator 20, and the recording material S is neutralized and separated from the belt 25, and then enters the fixing unit 22, where the image is fixed, and is discharged from the discharge port 26.
[0276]
FIG. 1 is a schematic view of still another image forming apparatus capable of performing the image forming method of the present invention.
[0277]
The image forming apparatus main body is provided with a first image forming unit Pa, a second image forming unit Pb, a third image forming unit Pc, and a fourth image forming unit Pd. It is formed on a recording material through a transfer process.
[0278]
The configuration of each image forming unit provided in the image forming apparatus will be described by taking the first image forming unit Pa as an example.
[0279]
The first image forming unit Pa includes a 30φ electrophotographic photosensitive drum 61a as a latent image holding member, and the photosensitive drum 61a is rotated in the direction of arrow a. 62a is a primary charger as a charging means, and a magnetic brush charger carried on a 16φ sleeve so as to come into contact with the photosensitive drum 61a is used. 67a is an exposure device as a latent image forming means for forming an electrostatic latent image on the photosensitive drum 61a whose surface is uniformly charged by the primary charger 62a. Reference numeral 63a denotes a developing device as developing means for developing the electrostatic latent image carried on the photosensitive drum 61a to form a color toner image, and holds the color toner. Reference numeral 64a denotes a transfer blade as transfer means for transferring the color toner image formed on the surface of the photosensitive drum 61a onto the surface of the recording material conveyed by the belt-like recording material carrier 68. The transfer blade 64 a is in contact with the back surface of the recording material carrier 68 and can apply a transfer bias.
[0280]
In the first image forming unit Pa, the primary charger 62a uniformly charges the photosensitive member of the photosensitive drum 61a at the charging unit, and then forms an electrostatic latent image on the photosensitive member by the exposure device 67a. 63a develops the electrostatic latent image using color toner in the developing unit and carries the developed toner image on the first transfer unit (contact position between the photosensitive member and the recording material) with the recording material. The recording material is transferred onto the surface of the recording material by applying a transfer bias from a transfer blade 64 a that is in contact with the back side of the recording material carrier 68.
[0281]
The first image forming unit Pa is in contact with the surface of the photosensitive drum, and a cleaning member for removing the transfer residual toner from the surface of the photosensitive drum is provided between the transfer unit and the charging unit and between the charging unit and the developing unit. A developing and cleaning method is used in which the developing unit also serves to clean the transfer residual toner existing on the photosensitive member.
[0282]
The present image forming apparatus has the same configuration as the first image forming unit Pa as described above, and the second image forming unit Pb and the third image forming unit having different color toner colors held in the developing device. Four image forming units of Pc and fourth image forming unit Pd are provided side by side. For example, yellow toner is used for the first image forming unit Pa, magenta toner is used for the second image forming unit Pb, cyan toner is used for the third image forming unit Pc, and black toner is used for the fourth image forming unit Pd. The transfer of each color toner onto the recording material is sequentially performed in the transfer section of each image forming unit. In this step, the color toners are superposed by the movement of the recording material once on the same recording material while aligning the registration. When finished, the recording material is separated from the recording material carrier 68 by the separation charger 69. Then, it is sent to the fixing device 70 by a conveying means such as a conveying belt, and a final full-color image is obtained by only one fixing.
[0283]
The fixing device 70 has a pair of a 40φ fixing roller 71 and a 30φ pressure roller 72, and the fixing roller 71 has heating means 75 and 76 therein. Reference numeral 73 denotes a web for removing dirt on the fixing roller. In the present invention, the web mechanism 73 may be omitted.
[0284]
The unfixed color toner image transferred onto the recording material passes through the pressure contact portion between the fixing roller 71 and the pressure roller 72 of the fixing device 70 and is fixed on the recording material by the action of heat and pressure. The
[0285]
In FIG. 1, a recording material carrier 68 is an endless belt-like member, and this belt-like member is moved in the direction of arrow e by 80 drive rollers. 79 is a transfer belt cleaning device, 81 is a belt driven roller, and 82 is a belt static eliminator. Reference numeral 83 denotes a pair of registration rollers for conveying the recording material in the recording material holder to the recording material carrier 68.
[0286]
As the transfer means, a contact transfer means capable of directly applying a transfer bias by contacting the back side of the recording material carrier, such as a roller-shaped transfer roller, is used instead of the transfer blade contacting the back side of the recording material carrier. It is possible.
[0287]
Further, in place of the above contact transfer means, non-contact transfer is performed by applying a transfer bias from a corona charger arranged in a non-contact manner on the back side of a commonly used recording material carrier. It is also possible to use means.
[0288]
However, it is more preferable to use the contact transfer means in that the amount of ozone generated when the transfer bias is applied can be controlled.
[0289]
Further, an image forming method for forming a full color image of another embodiment will be described as an example with reference to FIG.
[0290]
The electrostatic latent image formed on the photosensitive drum 33 by appropriate means has the first color toner and carrier in the developing unit 36 as developing means attached to the rotary developing unit 39 rotating in the direction of the arrow. Visualized by two-component developer. The color toner image on the photosensitive drum 33 is transferred by the transfer charger 44 to the recording material S held on the transfer drum 48 by the gripper 47.
[0291]
As the transfer charger 44, a corona charger or a contact charger is used. When the corona charger is used as the transfer charger 44, a voltage of −10 kV to +10 kV is applied, and the transfer current is −500 μA to +500 μA. It is. A holding member is stretched on the outer peripheral surface of the transfer drum 48, and the holding member is made of a film-like dielectric sheet such as a polyvinylidene fluoride resin film or polyethylene terephthalate. For example, the thickness is 100 μm to 200 μm, and the volume resistance is 10¹²-10¹⁴A sheet of Ω · cm is used.
[0292]
Next, the rotary developing unit rotates as the second color, and the developing unit 35 faces the photosensitive drum 33. Then, it is developed by the developer having the second color toner and the carrier in the developing device 35, and this color toner image is also transferred onto the same recording material as above.
[0293]
Further, the third color and the fourth color are similarly performed. In this way, the transfer drum 48 rotates a predetermined number of times while holding the recording material, and a toner image of a predetermined number of colors is multiplex-transferred. The transfer current for electrostatic transfer is preferably increased in the order of the first color <second color <third color <fourth color in order to reduce transfer residual toner remaining on the photosensitive drum.
[0294]
The recording material S that has been subjected to multiple transfer is separated from the transfer drum 48 by a separation charger 45 and impregnated with silicone oil, or a heating and pressure roller fixing device 32 having a web not impregnated with oil (or a web mechanism). A full-color copy image is obtained by adding and mixing at the time of fixing.
[0295]
The replenishment toner supplied to the developing devices 34 to 37 is conveyed from a replenishment hopper provided for each color to a toner replenishing cylinder at the center of the rotary developing unit through a toner conveyance cable by a predetermined amount based on a replenishment signal. , And sent to each developing device.
[0296]
The multiple development batch transfer method will be described with reference to FIG. 5, taking a full-color electrophotographic printer as an example.
[0297]
The electrostatic latent image formed by the charger 102 and the exposure unit 101 using laser light on the photosensitive drum 103 is visualized by developing the toner sequentially by the developing units 104, 105, 106, and 107. In the development process, a non-contact development method is preferably used. According to the non-contact developing method, the developer layer in the developing unit does not rub the surface of the image forming body, so that development is performed without disturbing the image formed in the preceding developing step in the second and subsequent developing steps. be able to. In the order of development, in the case of multiple colors, it is preferable to develop from a color other than black and from a color with high brightness and saturation. In the case of full color, it is preferable to develop in the order of yellow, then magenta or cyan, then the remaining magenta or cyan, and finally black.
[0298]
The multicolor multiple image and full color image formed on the photosensitive drum 103 are transferred to the recording material S by the transfer charger 109. In the transfer step, an electrostatic transfer method is preferably used, and a corona discharge or contact transfer method is used. The corona discharge transfer method is a method in which a transfer charger 109 that generates corona discharge through the recording material S is disposed so as to face the image, and electrostatic transfer is performed by applying corona discharge from the back surface of the recording material S. is there. The contact transfer method is a method in which a transfer roller or a transfer belt is brought into contact with the image forming body via the recording material S and a bias is applied to the roller, or electrostatic transfer is performed from the back surface of the belt. By this electrostatic transfer method, the multicolor toner images carried on the surface of the photosensitive drum 103 are collectively transferred to the recording material S.
[0299]
The recording material S onto which the multicolor toner images have been collectively transferred is separated from the photosensitive drum 103 and fixed by the heat roller fixing device 112, thereby forming a multicolor image.
[0300]
Next, the structure of the developing device that can be used in the present invention will be described in detail with reference to the drawings.
[0301]
In the present invention, in the development region, a contact development method in which development is performed by bringing a developer carried on the developer carrying member into contact with the surface of the photosensitive member, and development carried on the developer carrying member on the photosensitive member surface in the development region. It is possible to use any of the non-contact development systems in which development is performed by flying the developer from a developer carrying member set at an interval such that the photosensitive member and the developer layer are in non-contact.
[0302]
Examples of the contact development method include a development method using a two-component developer having a toner and a carrier (FIG. 6) and a development method using a one-component developer (FIG. 8).
[0303]
As the contact two-component development method, development can be performed using a two-component developer obtained by mixing a toner and a magnetic carrier, for example, using a developing device 120 as shown in FIG.
[0304]
The developing device 120 carries a developer container 126 that contains a two-component developer 128, a two-component developer 128 that is contained in the developer container 126, and development as a developer carrier for transporting the developer component to the development area. A sleeve 121 and a developing blade 127 as developer layer thickness regulating means for regulating the layer thickness of the toner layer formed on the developing sleeve 121 are provided.
[0305]
The developing sleeve 121 includes a magnet 123 in a nonmagnetic sleeve base 122.
[0306]
The inside of the developing container 126 is a developing chamber (first chamber) R by a partition wall 130.₁And stirring chamber (second chamber) R₂And stirring chamber R₂The toner storage chamber R is spaced above the partition wall 130._ThreeIs formed. Development chamber R₁And stirring chamber R₂A developer 128 is accommodated in the toner storage chamber R._ThreeA replenishing toner (nonmagnetic toner) 129 is accommodated therein. The toner storage chamber R_ThreeIs provided with a replenishing port 131, and an amount of replenishing toner 129 commensurate with the toner consumed via the replenishing port 131 is supplied to the stirring chamber R₂Dropped into the inside.
[0307]
Development chamber R₁A conveying screw 124 is provided inside, and the developing chamber R is driven by rotation of the conveying screw 124.₁The developer 128 is conveyed toward the longitudinal direction of the developing sleeve 121. Similarly, stirring chamber R₂A conveyance screw 125 is provided inside, and the rotation of the conveyance screw 125 causes a stirring chamber R to be supplied from the replenishing port 131.₂The toner dropped in is conveyed along the longitudinal direction of the developing sleeve 121.
[0308]
The developer 128 is a two-component developer having a nonmagnetic toner and a magnetic carrier.
[0309]
Carriers used in two-component developers include, for example, surface oxidized or unoxidized iron, nickel, copper, zinc, cobalt, manganese, chromium and rare earth magnetic metals, their magnetic alloys, their magnetic oxides And magnetic particles selected from the group consisting of those magnetic ferrites.
[0310]
Furthermore, a binder-type carrier in which magnetic powder is dispersed in a resin can also be used.
[0311]
The carrier is preferably a coated carrier in which the surface of the carrier core of the magnetic particles is coated with a coating material. In this coated carrier, the method of coating the surface of the carrier core with a coating material includes a method in which the coating material is dissolved or suspended in a solvent and applied to the carrier core, or a method of simply mixing in a powder state. Applicable.
[0312]
Examples of the carrier core coating material include polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, styrene resin, acrylic resin, polyamide, polyvinyl butyral, and aminoacrylate resin. These may be used alone or in plural.
[0313]
The treatment amount of the above material may be determined as appropriate, but generally it is preferably 0.1 to 30% by weight (preferably 0.5 to 20% by weight) based on the carrier in total amount.
[0314]
The carrier used in the present invention preferably has an average particle size of 10 to 100 μm, more preferably 20 to 70 μm.
[0315]
When the average particle size of the carrier is less than 10 μm, the packing of the two-component developer is strengthened, the mixing property of the toner and the carrier is lowered, the toner charging property is difficult to be stabilized, and the carrier photosensitive drum Adhesion to the surface is likely to occur.
[0316]
When the average particle diameter of the carrier exceeds 100 μm, the chance of contact with the toner is reduced, so that low-charge toner is mixed and fogging is likely to occur. Furthermore, since toner scattering tends to occur, it is necessary to lower the toner concentration setting in the two-component developer, and it may be impossible to form an image with a high image density.
[0317]
As a particularly preferred carrier, the surface of a magnetic core particle such as a magnetic ferrite core particle is made of a resin such as a silicone resin, a fluorine resin, a styrene resin, an acrylic resin, or a methacrylate resin, preferably 0.01 to 5% by weight. More preferably, a magnetic carrier coated with 0.1 to 1% by weight, containing 70% by weight or more of 250 mesh pass / 400 mesh on carrier particles, and having a particle size distribution adjusted to have the above average particle size. Some are listed.
[0318]
When the particle size distribution of the magnetic coat carrier is sharp, preferable triboelectric chargeability is obtained with respect to the color toner of the present invention, and the electrophotographic characteristics are further improved.
[0319]
When a two-component developer is prepared by mixing a color toner and a carrier, the mixing ratio is 2 wt% to 15 wt%, preferably 3 wt% to 13 wt% as the toner concentration in the developer. When the content is preferably 4 to 10% by weight, good results are usually obtained. If the toner concentration is less than 2% by weight, the image density tends to be low, and if it exceeds 15% by weight, fogging or in-machine scattering tends to occur, and the useful life of the developer tends to be shortened.
[0320]
The magnetic characteristics of the carrier are influenced by a magnet roller built in the developing sleeve, and greatly influence the developing characteristics and transportability of the developer.
[0321]
In the present invention, the two-component developer consisting of a carrier made of magnetic particles and an insulating color toner is placed on the developing sleeve by fixing the magnet roller and rotating the developing sleeve alone on the developing sleeve containing the magnet roller. When developing an electrostatic latent image held on the surface of the electrostatic latent image holding body with a nuclear two-component developer, (1) the magnet roller has a pole configuration having a repulsive pole, and (2) ▼ The magnetic flux density in the development area is 500 to 1200 gauss, and ③ the saturation magnetization of the carrier is 20 to 70 Am.²/ Kg is excellent in image uniformity and gradation reproducibility in color copying.
[0322]
Carrier saturation magnetization is 70 Am²/ Kg (with respect to an applied magnetic field of 3000 oersteds), the brush-like ears composed of the carrier and the toner on the developing sleeve facing the electrostatic latent image on the photoconductor are firmly tightened during development. And the gradation and halftone reproduction deteriorate. 20 Am²If it is less than / kg, it becomes difficult to hold the toner and carrier satisfactorily on the developing sleeve, and problems such as deterioration of carrier adhesion and suppression of toner scattering tend to occur.
[0323]
An opening is provided in a portion of the developing container 126 close to the photosensitive drum 119, the developing sleeve 121 discharges from the opening to the outside, and a gap is provided between the developing sleeve 121 and the photosensitive drum 119. ing. A bias applying means 132 for applying a bias is disposed on the developing sleeve 121 formed of a nonmagnetic material.
[0324]
As described above, the magnet roller as the magnetic field generating means fixed to the sleeve base 122, that is, the magnet 123, is the developing magnetic pole S.₁And magnetic pole N located downstream thereof_ThreeAnd a magnetic pole N for conveying the developer 128₂, S₂, N₁And have. The magnet 123 is a developing magnetic pole S.₁Is disposed in the sleeve base 122 so as to oppose the photosensitive drum 119. Development magnetic pole S₁Forms a magnetic field in the vicinity of the developing portion between the developing sleeve 121 and the photosensitive drum 119, and a magnetic brush is formed by the magnetic field.
[0325]
The regulating blade 127 that is disposed above the developing sleeve 121 and regulates the layer thickness of the developer 128 on the developing sleeve 121 is made of a nonmagnetic material such as aluminum or SUS316. The distance A between the end of the nonmagnetic blade 127 and the surface of the developing sleeve 121 is 300 to 1000 μm, preferably 400 to 900 μm. If this distance is less than 300 μm, the magnetic carrier is clogged in the meantime, and the developer layer is likely to be uneven, and the developer necessary for good development cannot be applied, and the developed image is light and uneven. There is a problem that can only be obtained. In order to prevent uneven application (so-called blade clogging) due to unnecessary particles mixed in the developer, the thickness is preferably 400 μm or more. If it is larger than 1000 μm, the amount of developer applied onto the developing sleeve 121 increases, and the predetermined developer layer thickness cannot be regulated, and the adhesion of magnetic carrier particles to the photosensitive drum 119 increases and the developer circulates. There is a problem that the development regulation by the non-magnetic developing blade 127 is weakened and the toner tribo is insufficient and fogging easily occurs.
[0326]
The development by the two-component developing device 120 is performed while applying an alternating electric field and in contact with a magnetic brush latent image carrier (for example, a photosensitive drum) 119 constituted by toner and a magnetic carrier. It is preferable to carry out. The distance (SD distance) B between the developer carrying member (developing sleeve) 121 and the photosensitive drum 119 is preferably 100 to 1000 μm in terms of preventing carrier adhesion and improving dot reproducibility. If it is narrower than 100 μm, the supply of developer tends to be insufficient, the image density becomes low, and if it exceeds 1000 μm, the magnet S₁The magnetic lines of force spread and the density of the magnetic brush is lowered, so that the dot reproducibility is inferior, or the force for restraining the carrier is weakened, and the carrier adheres easily.
[0327]
The voltage between the peaks of the alternating electric field is preferably 500 to 5000 V, and the frequency is 500 to 10000 Hz, preferably 500 to 3000 Hz, which can be appropriately selected and used for each process. In this case, the waveform can be selected from a triangular wave, a rectangular wave, a sine wave, or a waveform with a changed duty ratio. When the applied voltage is lower than 500 V, it is difficult to obtain a sufficient image density, and the fog toner in the non-image area may not be recovered well. If it exceeds 5000 V, the electrostatic image may be disturbed via the magnetic brush, resulting in a reduction in image quality.
[0328]
By using a two-component developer with well-charged toner, the anti-fogging voltage (Vback) can be lowered and the primary charge of the photoreceptor can be lowered, thus extending the life of the photoreceptor. it can. Vback is 150 V or less, more preferably 100 V or less, although it depends on the development system.
[0329]
The contrast potential is preferably 200 V to 500 V so that a sufficient image density can be obtained.
[0330]
If the frequency is lower than 500 Hz, it is related to the process speed, but charge injection into the carrier occurs, so that the image quality may be deteriorated by carrier adhesion or disturbing the latent image. If it exceeds 10,000 Hz, the toner cannot follow the electric field, and the image quality is liable to deteriorate.
[0331]
The contact width (development nip C) of the magnetic brush on the developing sleeve 121 with respect to the photosensitive drum 119 is preferably 3 to 8 mm in order to sufficiently develop image density, excellent dot reproducibility, and development without carrier adhesion. Is to do. If the development nip C is narrower than 3 mm, it is difficult to satisfactorily satisfy a sufficient image density and dot reproducibility. If the development nip C is wider than 8 mm, the developer packing occurs and the operation of the machine is stopped, or the carrier adheres. It is difficult to sufficiently suppress As a method for adjusting the developing nip, the nip width is appropriately adjusted by adjusting the distance A between the developer regulating member 127 and the developing sleeve 121 or by adjusting the distance B between the developing sleeve 121 and the photosensitive drum 119.
[0332]
The transfer residual toner on the photosensitive member is collected during development by the magnetic brush composed of the toner of the developing device and the carrier.
[0333]
As a contact one-component developing method, it is possible to develop using non-magnetic toner, for example, using a developing device 180 as shown in FIG.
[0334]
The developing device 180 carries a developing container 181 containing a one-component developer 188 having a magnetic or non-magnetic toner, and the one-component developer 188 stored in the developing container 181 for carrying it to the developing area. Developer carrier 182, supply roller 185 for supplying developer onto developer carrier, elastic blade 186 as a developer layer thickness regulating member for regulating developer layer thickness on developer carrier, development A stirring member 187 for stirring the developer 188 in the container 181 is provided.
[0335]
As the developer carrier 182, it is preferable to use an elastic roller having an elastic layer 184 formed of an elastic member such as rubber or resin having elasticity such as foamed silicone rubber on the roller base 183.
[0336]
The elastic roller 182 is in pressure contact with the surface of the photosensitive drum 189 as a latent image holding member, and generates an electrostatic latent image formed on the photosensitive member by the one-component developer 188 applied to the elastic roller surface. At the same time as development, unnecessary one-component developer 188 present on the photoreceptor after transfer is recovered.
[0337]
In the contact one-component development method, the developer carrying member is substantially in contact with the surface of the photoreceptor. This means that when the one-component developer is removed from the developer carrier, the developer carrier is in contact with the photoreceptor. At this time, an image having no edge effect can be obtained through the developer by an electric field acting between the photosensitive member and the developer carrying member, and at the same time, cleaning is performed. There is a need for the surface of the elastic roller as the developer carrying member or the vicinity of the surface to have an electric potential between the surface of the photosensitive member and the surface of the elastic roller. Therefore, it is possible to use a method in which the elastic rubber of the elastic roller is resistance controlled to the middle resistance region to keep the electric field while preventing conduction with the surface of the photoconductor, or a method of providing a thin dielectric layer on the surface layer of the conductive roller. . Furthermore, there is a configuration in which a conductive resin sleeve in which the surface that contacts the surface of the photoreceptor is covered with an insulating material on the conductive roller or a conductive layer is provided on the surface that does not contact the photoreceptor with an insulating sleeve. Is possible.
[0338]
The elastic roller carrying the one-component developer may rotate in the same direction as the photosensitive drum, or may rotate in the opposite direction. When the rotations are in the same direction, the peripheral speed ratio is preferably greater than 100% with respect to the peripheral speed of the photosensitive drum. If it is 100% or less, problems such as poor line definition are likely to occur. The higher the peripheral speed ratio is, the more developer is supplied to the development site, the more frequently the developer is desorbed from the electrostatic latent image, and the unnecessary part of the developer is scraped off. An image faithful to the electrostatic latent image is obtained by repeatedly applying the developer to the portion. More preferably, the peripheral speed ratio is 100% or more.
[0339]
The developer layer thickness regulating member 186 is not limited to an elastic blade as long as it is in pressure contact with the surface of the developer carrier 182 by an elastic force, and an elastic roller can also be used.
[0340]
As the elastic blade and elastic roller, a rubber elastic body such as silicone rubber, urethane rubber and NBR; a synthetic resin elastic body such as polyethylene terephthalate; and a metal elastic body such as stainless steel and steel can be used. Furthermore, even those complexes can be used.
[0341]
In the case of an elastic blade, the base, which is the upper side of the elastic blade, is fixedly held on the developer container side, and the lower side is bent in the forward or reverse direction of the developing sleeve against the elasticity of the blade. Then, the inner surface of the blade (the outer surface in the case of the opposite direction) is brought into contact with the sleeve surface with an appropriate elastic pressure.
[0342]
The supply roller 185 is made of a foam material such as polyurethane foam, and rotates with a relative speed other than 0 in the forward or reverse direction with respect to the developer carrier, and with the supply of the one-component developer, The developer after development (undeveloped developer) is also stripped off.
[0343]
When developing the electrostatic latent image on the photosensitive member with a one-component developer on the developer carrying member in the developing region, a direct and / or alternating development bias is provided between the developer carrying member and the photosensitive drum. It is preferable to apply and develop.
[0344]
Next, the non-contact development method will be described.
[0345]
Examples of the non-contact development method include a development method using a one-component magnetic developer having a non-magnetic toner.
[0346]
Here, a developing method using a one-component nonmagnetic developer having a nonmagnetic toner will be described based on a schematic configuration diagram shown in FIG.
[0347]
The developing device 170 carries a developing container 171 containing a non-magnetic one-component developer 176 having non-magnetic toner, and a one-component non-magnetic developer 176 contained in the developing container 171 and transports it to the developing area. Developer carrier 172 for supply, supply roller 173 for supplying a one-component non-magnetic developer onto the developer carrier, developer layer thickness regulation for regulating the developer layer thickness on the developer carrier An elastic blade 174 as a member and a stirring member 175 for stirring the one-component nonmagnetic developer 176 in the developing container 171 are provided.
[0348]
Reference numeral 169 denotes an electrostatic latent image holding member, and the latent image is formed by an electrophotographic process means or electrostatic recording means (not shown). Reference numeral 172 denotes a developing sleeve as a developer carrying member, which is a non-magnetic sleeve made of aluminum or stainless steel.
[0349]
As the developing sleeve, a rough tube of aluminum or stainless steel may be used as it is, but it is preferable that the surface is uniformly roughened by spraying glass beads, mirror-finished, or coated with a resin.
[0350]
The one-component nonmagnetic developer 176 is stored in the developing container 171 and is supplied onto the developer carrier 172 by the supply roller 173. The supply roller 173 is made of a foam material such as polyurethane foam, and rotates with a relative speed that is not zero in the forward or reverse direction with respect to the developer carrier, and the developer on the developer carrier 172 is developed along with the supply of the developer. The subsequent developer (undeveloped developer) is also stripped off. The one-component nonmagnetic developer supplied onto the developer carrier 172 is uniformly and thinly applied by an elastic blade 174 as a developer layer thickness regulating member.
[0351]
The contact pressure between the elastic coating blade and the developer carrying member is 0.3 to 25 kg / m, preferably 0.5 to 12 kg / m as the linear pressure in the developing sleeve bus direction. When the contact pressure is less than 0.3 kg / m, it is difficult to uniformly apply the one-component nonmagnetic developer, and the charge amount distribution of the one-component nonmagnetic developer becomes broad, which causes fogging and scattering. When the contact pressure exceeds 25 kg / m, a large pressure is applied to the one-component nonmagnetic developer, and the one-component nonmagnetic developer is deteriorated. Absent. Further, it is not preferable because a large torque is required to drive the developer carrying member. That is, by adjusting the contact pressure to 0.3 to 25 kg / m, it becomes possible to effectively loosen the aggregation of the one-component nonmagnetic developer using the toner of the present invention. It becomes possible to instantly raise the charge amount of the nonmagnetic developer.
[0352]
As the developer layer thickness regulating member, an elastic blade or an elastic roller can be used, and it is preferable to use a material of a triboelectric charge series suitable for charging the developer to a desired polarity.
[0353]
In the present invention, silicone rubber, urethane rubber, and styrene butadiene rubber are suitable. Furthermore, an organic resin layer such as polyamide, polyimide, nylon, melamine, melamine cross-linked nylon, phenol resin, fluorine resin, silicone resin, polyester resin, urethane resin, or styrene resin may be provided. Conductive rubber and conductive resin are used, and fillers and charge control agents such as metal oxide, carbon black, inorganic whiskers, and inorganic fibers are dispersed in the rubber and resin of the blade to achieve appropriate conductivity and charging. It is preferable because it imparts impartability and can charge the one-component non-magnetic developer appropriately.
[0354]
In this non-magnetic one-component developing method, in a system in which a one-component non-magnetic developer is thinly coated on the developing sleeve with a blade, in order to obtain a sufficient image density, the one-component non-magnetic developing on the developing sleeve is performed. It is preferable to make the thickness of the agent layer smaller than the opposing gap length β between the developing sleeve and the latent image holding member, and to apply an alternating electric field to this gap. That is, the bias power source 177 shown in FIG. 7 applies an alternating electric field or a developing bias in which a DC electric field is superimposed on the alternating electric field between the developing sleeve 172 and the latent image holding member 169 to thereby form a latent image holding member from above the developing sleeve. This makes it easy to move the one-component non-magnetic developer to the surface, and a higher quality image can be obtained.
[0355]
【Example】
Hereinafter, the present invention will be specifically described based on examples. However, this does not limit the embodiment of the present invention. The number of parts in the examples is parts by weight.
[0356]
As resins used in Examples, non-linear polyester resins A1 to A11 in which a polyester resin having a monomer composition described in Table 1 is synthesized by a dehydration condensation method and dodecenyl groups are branched and introduced into the resin skeleton, 2 and linear polyester resins B1 to B2 having the molecular weights shown in Table 3 were obtained.
[0357]
<Example 1>
Non-linear polyester resin A-1 (described in Table 1) 60 parts by weight
-Linear polyester resin B-1 (described in Tables 2 and 3) 40 parts by weight
・ Copper phthalocyanine pigment 4 parts by weight
(C.I. Pigment Blue 15: 3)
・ 1.5 parts by weight of polyethylene wax
(Mp = 106 ° C., Mn = 670, Mw / Mn = 1.35)
・ Zirconium compound (14) 5 parts by weight
The above materials were premixed with a Henschel mixer and then melt kneaded with a biaxial kneading extruder set at 110 ° C. Since the viscosity of the kneaded material gradually increased during melt kneading, it was confirmed that new crosslinks were formed.
[0358]
The obtained kneaded product is cooled, coarsely pulverized with a cutter mill, pulverized with a fine pulverizer using a jet stream, and the obtained finely pulverized powder is classified using a multi-division classifier utilizing the Coanda effect. Thus, toner particles A having a weight average particle diameter of 6.4 μm were obtained. Table 4 shows the formulation and physical properties.
[0359]
Hydrophobized methanol wettability of 80%, BET specific surface area of 120m per 100 parts by weight of toner particles A²/ G hydrophobic silica fine powder (treated with 10 parts by weight of hexamethyldisilazane and 10 parts by weight of dimethyl silicone with respect to 100 parts by weight of silica fine powder) was externally added and mixed to prepare toner A. .
[0360]
A Cu—Zn—Fe ferrite carrier having an average particle size of 45 μm coated with about 0.35% by weight of styrene-methyl methacrylate (copolymer weight ratio 65:35) with respect to 6.0 parts by weight of the cyan toner A. A two-component developer was prepared by mixing to a total weight of 100 parts by weight. The toner concentration in the two-component developer was 6.0% by weight.
[0361]
This toner A is a fixing device without a fixing oil supply mechanism (fixing speed 130 mm / sec., Fixing roller diameter Φ40 mm, pressure roller diameter Φ40 mm, fixing / pressure roller surface layer PFA [perfluoroalkoxyethylene] 20 μm, nip width 8 mm. At a total pressure of 40 kgf), the fixing property and the offset resistance were evaluated in a state where there was no fixing oil on the surface of the fixing / pressure roller.
[0362]
As a result, the fixing start point is as low as 110 ° C., and the non-offset width is also large. In addition, there is a region of gloss 10 or more which is important for full-color toner, and gloss control is possible. In addition, the image is placed on the OHT in the OHT mode at 170 ° C. and 40 mm / sec. The fixing test was performed at a fixing speed of. This color image was projected on an overhead projector (OHP) and evaluated. The obtained image was excellent in transparency without offset, excellent in light and darkness, and excellent in color reproducibility up to a light halftone color tone.
[0363]
In addition, a commercially available full-color copying machine (Color Leather Copier 800, manufactured by Canon Inc.) is modified to a fixing device without the oil application mechanism described above, and the environment is 15 ° C., 10% RH and 30 ° C. A print test of 10,000 sheets was performed in an environment of 80% RH. The developability (image density) and fog after printing 10,000 sheets were evaluated. Durability concentration transition and fog suppression were good. The evaluation results are shown in Table 5.
[0364]
  <Example 23. Reference example 4, Example5 and Comparative Examples 1 to 5>
  Instead of the non-linear polyester resin A-1 used in Example 1, the non-linear polyester resins A-2 to A-5 and comparative non-linear polyester resins A-7 to A-11 shown in Table 1 were used. Table 5 shows the results of preparing toners B to J in the same manner as in Example 1 and using the same test, except that is used.
[0365]
<Examples 6-8 and Comparative Examples 6-7>
Instead of the non-linear polyester resin A-1 used in Example 1, the non-linear polyester resin A-6 described in Table 1 was used, and instead of the linear polyester resin B-1 described in Tables 2 and 3 Using the non-linear polyester resin B-2, toners K to O were prepared in the same manner as in Example 1 except that the formulation shown in Table 4 was used, and the results of the same test are shown in Table 5. However, the organometallic compound was changed from the zirconium compound (14) of Example 1 to the zirconium compound (27).
[0366]
  <Reference Examples 9-10, Example 11, Reference Examples 12-14, Example 15And Comparative Example 8>
  Toners P to W were prepared in the same manner as in Example 1 with the formulation shown in Table 4, and the results of the same tests are shown in Table 5. However, for toner Q, the cyan pigment of Example 1 was changed to 5 parts by weight of carbon black. In toners P and Q, the following compounds (136) to (137), which are zinc compounds and chromium compounds, were used as organometallic compounds. However, coordinated water molecules are omitted.
[0367]
Embedded image

[0368]
The toner evaluation methods and evaluation criteria in the examples of the present invention will be described below.
[0369]
(1) Developability
Normal paper for copying machines (75 g / m) in an environment of 30 ° C. and 80% RH²) Was evaluated by maintaining the image density at the end of printing out 10,000 sheets. The image density was measured by using a “Macbeth reflection densitometer” (manufactured by Macbeth Co., Ltd.) to measure a relative density with respect to a printout image of a white background portion having a document density of 0.00.
A: 1.40 or more
B: 1.30 or more and less than 1.40
C: 1.20 or more and less than 1.30
D: Less than 1.20
[0370]
(2) fog
The fog measurement is performed on ordinary copying machine plain paper (75 g / m) in an environment of 23 ° C. and 5% RH.²) Measure the whiteness of the white background of the 10,000 printout image with a reflectometer (manufactured by Tokyo Denshoku), and calculate the fog density (%) from the difference between the whiteness and the whiteness of the transfer paper. evaluated.
A: Very good (less than 1.0%)
B: Good (1.0% or more and less than 2.0%)
C: Normal (2.0% to less than 3.0%)
D: Poor (3.0% or more)
[0371]
(3) Fixability and gloss
The fixability is 0.6 g / cm of the toner amount of the fixed image.²A solid image of 50 g / cm for this image²The fixed image was rubbed with soft thin paper, and the temperature at which the rate of decrease in image density (%) before and after rubbing was 20% or less was evaluated as the fixing start temperature.
[0372]
Similarly, the anti-offset property is 0.6 g / cm of the toner amount of the fixed image.²The temperature at which the fixing roller stains (transfer of toner) at the time of fixing begins as the offset temperature on the high temperature side.
[0373]
Further, the glossiness (gloss) of the same fixed image was measured using a handy glossiness meter gloss meter PG-3D (manufactured by Nippon Denshoku Industries Co., Ltd.) under the condition of a light incident angle of 75 °.
[0374]
The fixing temperature condition was 110 ° C. to 200 ° C. every 5 ° C.
[0375]
(4) Endurance offset
The durability offset property was evaluated by printing out a sample image having an image area ratio of about 5% at a fixing temperature of 190 ° C., and observing the degree of contamination on 3000 consecutive images and observing the surface of the fixing / pressure roller after 3000 images. .
A: No image or roller. Practical use
B: Not on the image at all, but slightly on the roller but with toner traces. : Practical
C: There are five images with a slight toner trace on the back of the image, and there is a slight toner trace on the roller. ; Not practical
D: Frequency of occurrence of offset on the image / roller is high. ; Not practical
E: Wrapped around the fixing device and not durable. : Not practical
[0376]
(5) OHT image transparency
Evaluation of OHT image transparency was performed at 170 ° C. and 40 mm / sec. A fixing test was conducted at a fixing speed of 1, and this color image was projected onto an overhead projector (OHP) for evaluation.
[0377]
In the color reproducibility of the OHT image on the OHP projection image, the color reproduction evaluation of the light color (halftone) portion is more severe. This is because the toner particles on the OHT image before fixing are present in isolation, and the individual toner particles must be completely melted and colored.
(Double-circle): The obtained image is excellent in transparency without offset, light and dark unevenness, and color reproducibility is also excellent. Practical use
○: Although there is slight unevenness in brightness, there is no practical problem.
Δ: Bright and dark unevenness and poor color reproduction. ; Not practical
X: Transparency is remarkably inferior, and almost no color is reproduced. ; Not practical
[0378]
[Table 1]

[0379]
[Table 2]

[0380]
[Table 3]

[0381]
[Table 4]

[0382]
[Table 5]

[0383]
【The invention's effect】
According to the present invention, it is possible to obtain a color toner having excellent offset resistance that can be fixed without using fixing oil and capable of being fixed at a lower temperature. In addition, oilless fixing with a low fixing temperature can provide a full-color image having moderate glossiness and gloss and excellent color reproducibility up to a high color tone. In addition, it is possible to obtain a color toner that has no oil stickiness on the overhead projector sheet (OHT) and satisfies color reproduction and transparency. Furthermore, it is possible to vividly color with high transparency up to a halftone without offset on the OHT, and it is possible to reproduce brightly and vividly even a light-colored portion in an OHT projection image. In addition, it is possible to obtain a color toner which can be obtained with high image quality regardless of whether it is used under low humidity or high humidity, and does not cause image defects over time.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of a suitable image forming apparatus capable of carrying out the image forming method of the present invention.
FIG. 2 is a schematic view showing another example of an image forming apparatus that can carry out the image forming method of the present invention.
FIG. 3 is a schematic view showing another example of an image forming apparatus that can carry out the image forming method of the present invention.
FIG. 4 is a schematic view showing another example of an image forming apparatus that can carry out the image forming method of the present invention.
FIG. 5 is a schematic view showing another example of an image forming apparatus that can carry out the image forming method of the present invention.
FIG. 6 is a schematic view of an image forming apparatus using a two-component developer.
FIG. 7 is a schematic view of a developing device using a non-contact one-component developing method.
FIG. 8 is a schematic view of a developing device by a contact one-component developing method.
FIG. 9 is a schematic view of a heat roll fixing device as an example of a heat and pressure fixing device.
[Explanation of symbols]
1 Exposure means
2 Charging roller
3 Photosensitive drum
4 Developer
5 Developer
6 Developer
7 Developer
8 Photosensitive drum cleaner
9 Core
10 Holding member
11 Intermediate transfer member
12 Intermediate transfer cleaner
13 Power supply
14 Transfer charger
15 Separate static eliminator
16 Charger
17 Developer
18 Photosensitive drum cleaner
19 Photosensitive drum
20 Separate static eliminator
22 Fixing device
23 Latent image forming part
24 Transfer discharge part
25 Conveyor belt
26 Discharge section
27 Adsorption charger
28 Separating static elimination discharge part
29 Image forming unit
31 Exposure means
32 Fixing device
33 Photosensitive drum
34 Developer
35 Developer
36 Developer
37 Developer
38 Photosensitive drum cleaner
39 Rotating development unit
40 Transfer drum unit
44 Transfer charger
45 Separating charger
46 Charger
47 Gripper
48 Transfer drum
49 Separating nails
60a Transfer bias applying means (may be grounded)
61a Photosensitive drum
62a Primary charger
63a Developer
64a transfer blade
65a toner hopper
66a Supply roller
67a Exposure apparatus
68 Recording material carrier
69 Separate charger
70 Fixing device
71 Fixing roller
72 Pressure roller
73 Web
75,76 Heating means
78 Temperature detection means
79 Transfer belt cleaning device
80 Drive roller
81 Belt driven roller
82 Belt static eliminator
83 Registration Roller
84 Paper feed roller
101 Exposure means
102 Charging means
103 Photosensitive drum
104 Developer
105 Developer
106 Developer
107 Developer
108 Photosensitive drum cleaner
109 Transfer charger
110 Separate static eliminator
111 Static eliminator
112 Fixing device
119 Photosensitive drum
120 Developer
121 Development sleeve (developer carrier)
122 Sleeve base
123 Magnet
124 Conveying screw
125 conveying screw
126 Development container
127 Development blade
128 Two-component developer
129 Toner for replenishment
130 Bulkhead
131 Supply port
169 Electrostatic latent image holder (photosensitive drum)
170 Developing device
171 Developer container
172 Development sleeve (developer carrier)
173 Developer supply roller
174 Elastic blade (developing blade)
175 Stirring member
176 One-component non-magnetic developer
180 Developing device
181 Developer container
182 Development sleeve (developer carrier)
183 Roller base
184 Elastic layer
185 Developer supply roller
186 Elastic blade (Developing blade)
187 Stirring member
188 One-component developer
189 Photosensitive drum

Claims (52)

In a color toner having at least a binder resin, a wax, an organometallic compound and a colorant,
The binder resin contains at least a trivalent or higher polyvalent carboxylic acid monomer unit and a polyvalent carboxylic acid monomer unit having a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms. The content of the trivalent or higher polyvalent carboxylic acid monomer unit in the binder resin is Xa mol%, and the polyvalent carboxylic acid having a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms. When the content of the acid monomer unit is Ya mol%, the following conditions are satisfied: 0.5 <Xa <15
5 <Ya <30
3.75 ≦ Ya / Xa ≦ 9.00
A non-linear polyester resin A satisfying the above, and at least a linear polyester resin B not containing a trivalent or higher polyvalent carboxylic acid monomer unit and a trivalent or higher polyhydric alcohol monomer unit,
The mixing weight ratio of the non-linear polyester resin A and the linear polyester resin B is 25/75 to 75/25,
The maximum endothermic peak measured by differential scanning calorimetry (DSC) of the wax is 60 to 135 ° C., and the ratio Mw / Mn of the number average molecular weight (Mn) to the weight average molecular weight (Mw) in the GPC molecular weight distribution of the wax is 1. 0.0 to 2.0, the content ratio of the wax is 0.3 to 4.5% by weight with respect to the color toner, and
A color toner, wherein the resin component of the toner contains 0% by weight or more and 8% by weight or less of THF insoluble matter. The content of the organometallic compound in the toner is 0.2 to 10% by weight, and the total content of trivalent or higher polyvalent carboxylic acid monomer units in the binder resin is Xc mol%, When the content of the organometallic compound in the toner is Z wt%, the following condition 2 ≦ Xc × Z ≦ 50
The color toner according to claim 1, wherein:   The organometallic compound has zirconium as a metal element, and an aromatic compound selected from the group consisting of an aromatic diol, an aromatic hydroxycarboxylic acid, an aromatic monocarboxylic acid and an aromatic polycarboxylic acid is coordinated and / or The color toner according to claim 1, wherein the color toner is a bonded organic zirconium compound. The color toner according to any one of claims 1 to 3 maximum endothermic peak by a differential scanning calorimeter (DSC) measurement of the wax which is characterized in that in 60 to 120 ° C.. The number average molecular weight in the GPC molecular weight distribution of the wax (Mn) is 200 to 2,000, the color toner according to any one of claims 1 to 4 weight-average molecular weight (Mw) characterized in that it is a 200 to 2500 . The wax, the color toner according to any one of claims 1 to 5, characterized in that a hydrocarbon wax. The wax, the color toner according to any one of claims 1 to 6, characterized in that a polyethylene wax. The non-linear polyester resin A, which is a component constituting the binder resin, is that a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms is branched and introduced into the skeleton of the polyester resin. the color toner according to any one of claims 1 to 7, characterized. The linear polyester resin B, which is a component constituting the binder resin, has a number average molecular weight (Mn) in the GPC molecular weight distribution of THF soluble content of 2000 to 8000, and a weight average molecular weight (Mw) of 8000 to 30000. , and the color toner according to any one of claims 1 to 8, characterized in that the ratio Mw / Mn number average molecular weight (Mn) and the weight average molecular weight (Mw) of 2 to 3.5. The color toner according to any one of claims 1 to 9 acid value of the resin component of the toner is characterized by a 2mgKOH / g~20mgKOH / g. The color toner according to any one of claims 1 to 10 , wherein the resin component of the toner contains 0 to less than 5.0% by mass of a THF-insoluble matter. The resin component of the toner has a component content (M1) of less than 10,000 (M1) of 45 to 65% and a component content (M2) of 10,000 to 50,000 (M2) of 25 to 50% in the GPC molecular weight distribution of the THF-soluble component. Component content of 10,000 to 500,000 (M3) is 2 to 20%, component content exceeding 500,000 (M4) is 0.1 to 10%, and satisfies the relationship of M1>M2>M3> M4 the color toner according to any one of claims 1 to 11, wherein the. The toner color according to at least the cyan toner, any one of claims 1 to 12, characterized in that a combination of magenta toner and yellow toner is a cyan toner containing a cyan colorant to form a full color image toner. The toner color according to at least the cyan toner, any one of claims 1 to 12, characterized in that a combination of magenta toner and yellow toner is a magenta toner containing a magenta colorant for forming a full-color image toner. The toner color according to at least the cyan toner, any one of claims 1 to 12, characterized in that a combination of magenta toner and yellow toner is a yellow toner containing a yellow colorant for forming a full-color image toner. The toner comprises at least a cyan toner, a magenta toner, to any one of claims 1 to 12, characterized in that a combination of yellow toner and a black toner is a black toner containing a black colorant for forming a full-color image The color toner described. A charging step for charging the latent image carrier;
A latent image forming step of forming an electrostatic latent image on a charged latent image carrier;
A developing step of developing the electrostatic latent image with toner to form a toner image;
A transfer step of transferring the developed toner image onto a recording material with or without an intermediate transfer member;
And a fixing step of fixing the toner image on the recording material by bringing a fixing member into contact with the surface of the toner image transferred onto the recording material and applying heat and pressure to the toner image;
In an image forming method having
The developing step is a step of using a color toner having at least a binder resin, a wax, an organometallic compound, and a colorant,
The binder resin contains at least a trivalent or higher polyvalent carboxylic acid monomer unit and a polyvalent carboxylic acid monomer unit having a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms. The content of the trivalent or higher polyvalent carboxylic acid monomer unit in the binder resin is Xa mol%, and the polyvalent carboxylic acid having a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms. When the content of the acid monomer unit is Ya mol%, the following conditions are satisfied: 0.5 <Xa <15
5 <Ya <30
3.75 ≦ Ya / Xa ≦ 9.00
A non-linear polyester resin A satisfying the above, and at least a linear polyester resin B not containing a trivalent or higher polyvalent carboxylic acid monomer unit and a trivalent or higher polyhydric alcohol monomer unit,
The mixing weight ratio of the non-linear polyester resin A and the linear polyester resin B is 25/75 to 75/25,
The maximum endothermic peak measured by differential scanning calorimetry (DSC) of the wax is 60 to 135 ° C., and the ratio Mw / Mn of the number average molecular weight (Mn) to the weight average molecular weight (Mw) in the GPC molecular weight distribution of the wax is 1. 0.0 to 2.0, the content ratio of the wax is 0.3 to 4.5% by weight with respect to the color toner, and
The toner resin component is a step of forming a toner image by developing an electrostatic latent image using a color toner containing 0 to 8 wt% of THF insolubles. Method. In the fixing step, the application amount per unit area of the recording material of the fixing oil supplied from the fixing member to the fixing surface of the toner image of the recording material is 0 to 1 × 10 ⁻⁷ g / cm ^2. The color image forming method according to claim 17 , wherein the color image forming method is a step of fixing the image on the recording material. The color image formation according to claim 17 or 18 , wherein the fixing step is a step of fixing the toner image on the recording material without supplying fixing oil from the fixing member to the recording material. Method. In the developing step, the content of the organometallic compound in the toner is 0.2 to 10% by weight, and the total content of the trivalent or higher polyvalent carboxylic acid monomer units in the binder resin is adjusted. When Xc mol% and the content of the organometallic compound in the toner is Z wt%, the following conditions are satisfied: 2 ≦ Xc × Z ≦ 50
The color image forming method according to any one of claims 17 to 19, characterized in that by developing the electrostatic latent image with a color toner satisfying a step of forming a toner image. In the development step, the organometallic compound has zirconium as a metal element, and an aromatic compound selected from the group consisting of an aromatic diol, an aromatic hydroxycarboxylic acid, an aromatic monocarboxylic acid and an aromatic polycarboxylic acid is used. according to any one of claims 17 to 20, characterized in that by developing the electrostatic latent image using a color toner which is an organic zirconium compound which is coordinated and / or bound is a process for forming a toner image Color image forming method. The developing step is a step of forming a toner image by developing an electrostatic latent image using a color toner having a maximum endothermic peak measured by differential scanning calorimetry (DSC) of the wax at 60 to 120 ° C. the color image forming method according to any one of claims 17 to 21, characterized. The developing step is to develop an electrostatic latent image using a color toner having a number average molecular weight (Mn) of 200 to 2000 and a weight average molecular weight (Mw) of 200 to 2500 in the GPC molecular weight distribution of the wax. the color image forming method according to any one of claims 17 to 22, characterized in that a step of forming a toner image. Developing process, according to any one of claims 17 to 23, characterized in that by developing the electrostatic latent image using a color toner which the wax has a hydrocarbon wax is a process for forming a toner image Color image forming method. Developing step, color according to any one of claims 17 to 24, characterized in that the wax is a step of forming a toner image by developing the electrostatic latent image using a color toner having a polyethylene wax Image forming method. In the developing step, the non-linear polyester resin A, which is a component constituting the binder resin, is electrostatically charged using a color toner containing at least 3 mol% of a polyvalent carboxylic acid monomer unit having a valence of 3 or more. the color image forming method according to any one of claims 17 to 25, characterized in that a step of forming a toner image by developing the latent image. In the developing step, a non-linear polyester resin A, which is a component constituting the binder resin, contains a polyvalent carboxylic acid monomer unit having a trivalent or higher valence of 10 mol% or less. the color image forming method according to any one of claims 17 to 26, characterized in that by developing the electrostatic latent image is a step of forming a toner image. In the developing step, the non-linear polyester resin A which is a component constituting the binder resin is introduced by branching a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms into the skeleton of the polyester resin. the color image forming method according to any one of claims 17 to 27, characterized in that a step of forming a toner image by developing the electrostatic latent image using a color toner has. In the developing step, the number average molecular weight (Mn) in the GPC molecular weight distribution of the THF soluble content of the linear polyester resin B which is a component constituting the binder resin is 2000 to 8000, and the weight average molecular weight (Mw) Is 8000 to 30000, and a toner image is formed by developing an electrostatic latent image using a color toner having a ratio Mw / Mn of 2 to 3.5 between the number average molecular weight (Mn) and the weight average molecular weight (Mw). The color image forming method according to any one of claims 17 to 28 , wherein the color image forming method comprises: Developing process according to claim characterized in that it is a step of acid value of the resin component of the toner to form a toner image by developing the electrostatic latent image using a color toner which is 2 to 20 mgKOH / g 17 30. The color image forming method according to any one of items 29 to 29 . The developing step is a step of forming a toner image by developing an electrostatic latent image using a color toner in which the resin component of the toner contains 0 to less than 5.0% by mass of a THF-insoluble component. the color image forming method according to any one of claims 17 to 30. In the developing step, in the GPC molecular weight distribution in which the resin component of the toner is soluble in THF, the component content (M1) less than 10,000 is 45 to 65%, and the component content (M2) 25 is 10,000 to 50,000. 50%, 50,000 to 500,000 component content (M3) 2 to 20%, over 500,000 component content (M4) 0.1 to 10%, and M1>M2>M3> M4 the color image forming method according to any one of claims 17 to 31, characterized in that by developing the electrostatic latent image with a color toner satisfying a step of forming a toner image. A first charging step for charging the latent image carrier;
A first latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A first developing step of developing the electrostatic latent image with a first toner to form a first toner image;
A first transfer step of transferring the developed first toner image onto the intermediate transfer member;
A second charging step for charging the latent image carrier;
A second latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A second developing step of developing the electrostatic latent image with a second toner to form a second toner image;
A second transfer step of transferring the developed second toner image to an intermediate transfer body onto which the first toner image is transferred;
A third charging step for charging the latent image carrier;
A third latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A third developing step of developing the electrostatic latent image with a third toner to form a third toner image;
A third transfer step of transferring the developed third toner image onto the intermediate transfer body onto which the first toner image and the second toner image are transferred;
A fourth charging step for charging the latent image carrier;
A fourth latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A fourth developing step of developing the electrostatic latent image with a fourth toner to form a fourth toner image;
A fourth transfer step of transferring the developed fourth toner image onto the intermediate transfer body onto which the first toner image, the second toner image, and the third toner image are transferred;
The multicolor toner image having the first toner image, the second toner image, the third toner image, and the fourth toner image transferred onto the intermediate transfer member is collectively transferred onto the recording material. A multi-color transfer step; and a fixing member in contact with the surface of the multi-color toner image that is secondarily transferred onto the recording material, and applying heat and pressure to the multi-color toner image. A fixing step of fixing a toner image on the recording material;
In an image forming method having
The first toner is a color toner selected from the group consisting of cyan toner, magenta toner, yellow toner and black toner;
The second toner is a color toner selected from the remaining group excluding the color toner selected as the first toner,
The third toner is a color toner selected from the remaining group excluding the color toner selected as the first toner and the color toner selected as the second toner,
The fourth toner is a color toner selected as the first toner, a color toner selected as the second toner, and a remaining color toner excluding the color toner selected as the third toner. A color image forming method according to any one of claims 17 to 32 . A first charging step for charging the latent image carrier;
A first latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A first developing step of developing the electrostatic latent image with a first toner to form a first toner image;
A first transfer step of transferring the developed first toner image onto a recording material without using an intermediate transfer member;
A second charging step for charging the latent image carrier;
A second latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A second developing step of developing the electrostatic latent image with a second toner to form a second toner image;
A second transfer step of transferring the developed second toner image onto the recording material onto which the first toner image has been transferred;
A third charging step for charging the latent image carrier;
A third latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A third developing step of developing the electrostatic latent image with a third toner to form a third toner image;
A third transfer step of transferring the developed third toner image onto a recording material onto which the first toner image and the second toner image are transferred;
A fourth charging step for charging the latent image carrier;
A fourth latent image forming step of forming an electrostatic latent image on the charged latent image holding member;
A fourth developing step of developing the electrostatic latent image with a fourth toner to form a fourth toner image;
A fourth transfer step of transferring the developed fourth toner image onto a recording material onto which the first toner image, the second toner image, and the third toner image are transferred;
A fixing member is brought into contact with the surface of a multicolor toner image having a first toner image, a second toner image, a third toner image, and a fourth toner image sequentially transferred onto a recording material, and the multicolor A fixing step of fixing the multicolor toner image to the recording material by applying heat and pressure to the toner image;
In an image forming method having
The first toner is a color toner selected from the group consisting of cyan toner, magenta toner, yellow toner and black toner;
The second toner is a color toner selected from the remaining group excluding the color toner selected as the first toner,
The third toner is a color toner selected from the remaining group excluding the color toner selected as the first toner and the color toner selected as the second toner,
The fourth toner is a color toner selected as the first toner, a color toner selected as the second toner, and a remaining color toner excluding the color toner selected as the third toner. A color image forming method according to any one of claims 17 to 32 . At least toner for developing an electrostatic latent image, a toner container for holding the toner, a toner carrier for carrying the toner held in the toner container and transporting it to the development area, and the toner carrying A toner layer thickness regulating member for regulating the layer thickness of the toner carried on the body,
The toner is a color toner having at least a binder resin, a wax, an organometallic compound, and a colorant,
The binder resin contains at least a trivalent or higher polyvalent carboxylic acid monomer unit and a polyvalent carboxylic acid monomer unit having a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms. The content of the trivalent or higher polyvalent carboxylic acid monomer unit in the binder resin is Xa mol%, and the polyvalent carboxylic acid having a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms. When the content of the acid monomer unit is Ya mol%, the following conditions are satisfied: 0.5 <Xa <15
5 <Ya <30
3.75 ≦ Ya / Xa ≦ 9.00
A non-linear polyester resin A satisfying the above, and at least a linear polyester resin B not containing a trivalent or higher polyvalent carboxylic acid monomer unit and a trivalent or higher polyhydric alcohol monomer unit,
The mixing weight ratio of the non-linear polyester resin A and the linear polyester resin B is 25/75 to 75/25,
The maximum endothermic peak measured by differential scanning calorimetry (DSC) of the wax is 60 to 135 ° C., and the ratio Mw / Mn of the number average molecular weight (Mn) to the weight average molecular weight (Mw) in the GPC molecular weight distribution of the wax is 1. 0.0 to 2.0, the content ratio of the wax is 0.3 to 4.5% by weight with respect to the color toner, and
An apparatus unit detachably attached to a color image forming apparatus main body, wherein the resin component of the toner contains 0% by weight or more and 8% by weight or less of THF insolubles. In the toner, the content of the organometallic compound in the toner is 0.2 to 10% by weight, and the total content of trivalent or higher polyvalent carboxylic acid monomer units in the binder resin is Xc. When the content of mol% of the organometallic compound in the toner is Z wt%, the following condition 2 ≦ Xc × Z ≦ 50
36. The apparatus unit according to claim 35 , wherein the apparatus unit is detachably attached to the color image forming apparatus main body. The organometallic compound has zirconium as a metal element, and an aromatic compound selected from the group consisting of an aromatic diol, an aromatic hydroxycarboxylic acid, an aromatic monocarboxylic acid and an aromatic polycarboxylic acid is coordinated and / or detachably mounted by apparatus units in a color image forming apparatus main body according to any one of claims 35 or 36, characterized in that an organic zirconium compound which binds to that. The maximum endothermic peak measured by differential scanning calorimetry (DSC) of the wax is 60 to 120 ° C, and is removably attached to the color image forming apparatus main body according to any one of claims 35 to 37. Equipment unit. The color image according to any one of claims 35 to 38 , wherein the wax has a GPC molecular weight distribution having a number average molecular weight (Mn) of 200 to 2000 and a weight average molecular weight (Mw) of 200 to 2500. An apparatus unit that is detachably attached to the forming apparatus body. The wax, the apparatus unit detachably mounted to the color image forming apparatus main body according to any one of claims 35 to 39 characterized by having a hydrocarbon wax. The wax is detachably mounted by apparatus units in a color image forming apparatus main body according to any one of claims 35 to 40 characterized by having a polyethylene wax. Non-linear polyester resin A which is a component constituting the binder resin is as claimed in claim 35 or 41, characterized in that it contains at least trihydric or higher polycarboxylic acid monomer units than 3 mol% An apparatus unit detachably attached to the color image forming apparatus main body according to any one of the above. Non-linear polyester resin A which is a component constituting the binder resin is claims 35 to 42, characterized in that it at least trihydric or higher polycarboxylic acid monomer unit contained below 10 mol% An apparatus unit detachably attached to the color image forming apparatus main body according to any one of the above. The non-linear polyester resin A, which is a component constituting the binder resin, is that a saturated or unsaturated aliphatic hydrocarbon group having 5 to 30 carbon atoms is branched and introduced into the skeleton of the polyester resin. 44. An apparatus unit detachably attached to the color image forming apparatus main body according to any one of claims 35 to 43 . The number average molecular weight (Mn) in the GPC molecular weight distribution of the THF soluble content of the linear polyester resin B which is a component constituting the binder resin is 2000 to 8000, and the weight average molecular weight (Mw) is 8000 to 30000. There, a color image forming apparatus main body according to any one of claims 35 to 44, characterized in that the ratio Mw / Mn number average molecular weight (Mn) and the weight average molecular weight (Mw) of 2 to 3.5 A device unit that is detachably mounted. Apparatus unit detachably mounted to the color image forming apparatus main body according to any one of claims 35 to 45, wherein the acid value of the resin component of the toner is 2 to 20 mgKOH / g. 47. The toner resin component contains 0 to less than 5.0 mass% of THF-insoluble matter, and is removably attached to the color image forming apparatus main body according to any one of claims 35 to 46. Equipment unit. The resin component of the toner has a component content (M1) of less than 10,000 (M1) of 45 to 65% and a component content (M2) of 10,000 to 50,000 (M2) of 25 to 50% in the GPC molecular weight distribution of the THF-soluble component. Component content of 10,000 to 500,000 (M3) is 2 to 20%, component content exceeding 500,000 (M4) is 0.1 to 10%, and satisfies the relationship of M1>M2>M3> M4 48. An apparatus unit detachably attached to the color image forming apparatus main body according to any one of claims 35 to 47 . The toner color according to at least the cyan toner, any of claims 35 to 48, characterized in that a combination of magenta toner and yellow toner is a cyan toner containing a cyan colorant to form a full color image An apparatus unit that is detachably attached to the image forming apparatus main body. The toner color according to at least the cyan toner, any of claims 35 to 48, characterized in that a combination of magenta toner and yellow toner is a magenta toner containing a magenta colorant for forming a full-color image An apparatus unit that is detachably attached to the image forming apparatus main body. The toner color according to at least the cyan toner, any of claims 35 to 48, characterized in that a combination of magenta toner and yellow toner is a yellow toner containing a yellow colorant for forming a full-color image An apparatus unit that is detachably attached to the image forming apparatus main body. The toner comprises at least a cyan toner, a magenta toner, to any one of claims 35 to 48, characterized in that a combination of yellow toner and a black toner is a black toner containing a black colorant for forming a full-color image An apparatus unit detachably attached to the main body of the color image forming apparatus.

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