JP4078115B2 - Image forming method - Google Patents

Description

【００８９】
放置後の凝集度Ｇ２も同様にして測定し、下記式により凝集度差ΔＧを得る。
【００９０】
【数１１】
ΔＧ ＝ ｜Ｇ２−Ｇ１｜
【００９１】
尚、Ｇ１を測定する際の低温低湿環境下中での放置時間は１０時間、Ｇ２測定の際の放置時間はＧ１の放置時間より更に４８時間とし、これらの放置時間の経過後に上記凝集度Ｇ１、Ｇ２を測定する。
【００９２】
本発明におけるトナーの円形度、及びそれらの頻度分布とは、トナー粒子の形状を定量的に表現する簡便な方法として用いたものであり、本発明ではフロー式粒子像測定装置ＦＰＩＡ−１０００型（東亜医用電子社製）を用いて測定を行い、下記式を用いて算出した。
【００９３】
【数１２】

【００９４】
ここで、「粒子投影面積」とは二値化されたトナー粒子像の面積であり、「粒子投影像の周囲長」とは該トナー粒子像のエッジ点を結んで得られる輪郭線の長さと定義する。
【００９５】
本発明における円形度はトナー粒子の凹凸の度合いを示す指標であり、トナー粒子が完全な球形の場合には１．０００を示し、表面形状が複雑になる程、円形度は小さな値となる。円形度の頻度分布の平均値を意味する平均円形度Ｃｍと円形度標準偏差ＳＤｃは、粒度分布の分割点ｉでの円形度（中心値）をｃｉ、頻度をｆ_ciとすると、次式から算出される。
【００９６】
【数１３】

【００９７】
【数１４】

【００９８】
具体的な測定方法としては、予め不純固形物などを除去したイオン交換水１０ｍｌを容器中に用意し、その中に分散剤として界面活性剤、好ましくはアルキルベンゼンスルフォン酸塩を加えた後、更に測定試料０．０２ｇを加え、均一に分散させる。分散手段としては、超音波分散機ＵＨ−５０型（エスエムテー社製）に振動子として５ｍｍφのチタン合金チップを装着したものを用い、５分間分散処理を行い、測定用の分散液とする。その際、該分散液の温度が４０℃以上にならないように適宜冷却する。
【００９９】
トナー粒子の形状測定には、フロー式粒子像測定装置「ＦＰＩＡ−１０００型」（東亜医用電子社製）を用い、測定時のトナー粒子濃度が３０００〜１万個／μｌとなるように該分散液濃度を再調整し、トナー粒子を１０００個以上計測し、円相当径分布に基づく数及び規定された円相当径を有する粒子の割合（個数％）を測定する。結果（頻度％及び累積％）は、表１に示す通り、粒径０．０６〜４００μｍの範囲を２２６チャンネル（１オクターブに対し３０チャンネルに分割）に分割して得ることができる。計測後、このデータを用いてトナー粒子の円形度頻度分布等を求める。
【０１００】
【表１】

【０１０１】
本発明のトナー粒径はコールターカウンターにより測定され、コールターカウンター法によるトナー粒子及びトナーの平均粒径の測定装置としては、例えばコールターカウンターＴＡ−IIまたはコールターマルチサイザーII（コールター社製）が用いられる。電解液は、１級塩化ナトリウムを用いて、約１％ＮａＣｌ水溶液を調製する。例えば、ＩＳＯＴＯＮ−II（コールター社製）が使用できる。測定方法としては、前記電解水溶液１００〜１５０ｍｌ中に分散剤として界面活性剤（好ましくはアルキルベンゼンスルフォン酸塩）を０．１〜５ｍｌ加え、更に測定試料を２〜２０ｍｇ加える。試料を懸濁した電解液は超音波分散器で約１〜３分間分散処理を行い、前記測定装置により、アパーチャーとして１００μｍアパーチャーを用いて、トナーの体積、個数を測定して、体積分布と個数分布を算出する。それから、トナーの質量基準の重量平均粒径（Ｄ４）を求める。
【０１０２】
チャンネルとしては、２．００〜２．５２μｍ未満；２．５２〜３．１７μｍ未満；３．１７〜４．００μｍ未満；４．００〜５．０４μｍ未満；５．０４〜６．３５μｍ未満；６．３５〜８．００μｍ未満；８．００〜１０．０８μｍ未満；１０．０８〜１２．７０μｍ未満；１２．７０〜１６．００μｍ未満；１６．００〜２０．２０μｍ未満；２０．２０〜２５．４０μｍ未満；２５．４０〜３２．００μｍ未満；３２．００〜４０．３０μｍ未満の１３チャンネルを使用し、粒径２．００μｍ以上４０．３０μｍ未満の粒子を対象とする。
【０１０３】
次に本発明のトナーについて詳述する。
【０１０４】
本発明のトナーを粉砕方法で製造する際に用いられるトナーの結着樹脂としては、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等のスチレン置換体の単重合体；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−インデン共重合体等のスチレン系共重合体；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；ポリアミド樹脂；フラン樹脂；エポキシ樹脂；キシレン樹脂等が挙げられる。これらの樹脂は、単独で又は混合して使用される。
【０１０５】
スチレン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、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、アクリル酸ドジテル、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、メタクリロニトリル、アクリルアミド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；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のような二重結合を有するジカルボン酸及びその置換体；塩化ビニル、酢酸ビニル、安息香酸ビニルのようなビニルエステル；エチレン、プロピレン、ブチレンのようなエチレン系オレフィン；ビニルメチルケトン、ビニルヘキシルケトンのようなビニルケトン；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のようなビニルエーテルが挙げられる。これらビニル単量体が単独もしくは２つ以上用いられる。
【０１０６】
スチレン共重合体はジビニルベンゼン等の架橋剤で架橋されていることがトナーの定着温度領域を広げ、耐オフセット性を向上させる上で好ましい。
【０１０７】
本発明のトナーを重合方法で製造する際に用いられる重合性単量体としては、ラジカル重合が可能なビニル系重合性単量体が用いられる。該ビニル系重合性単量体としては、単官能性重合性単量体或いは多官能性重合性単量体を使用することが出来る。単官能性重合性単量体としては、スチレン；α−メチルスチレン、β−メチルスチレン、ｏ−メチルスチレン、ｍ−メチルスチレン、ｐ−メチルスチレン、２，４−ジメチルスチレン、ｐ−ｎ−ブチルスチレン、ｐ−ｔｅｒｔ−ブチルスチレン、ｐ−ｎ−ヘキシルスチレン、ｐ−ｎ−オクチルスチレン、ｐ−ｎ−ノニルスチレン、ｐ−ｎ−デシルスチレン、ｐ−ｎ−ドデシルスチレン、ｐ−メトキシスチレン、ｐ−フェニルスチレンのようなスチレン誘導体；メチルアクリレート、エチルアクリレート、ｎ−プロピルアクリレート、ｉｓｏ−プロピルアクリレート、ｎ−ブチルアクリレート、ｉｓｏ−ブチルアクリレート、ｔｅｒｔ−ブチルアクリレート、ｎ−アミルアクリレート、ｎ−ヘキシルアクリレート、２−エチルヘキシルアクリレート、ｎ−オクチルアクリレート、ｎ−ノニルアクリレート、シクロヘキシルアクリレート、ベンジルアクリレート、ジメチルフォスフェートエチルアクリレート、ジエチルフォスフェートエチルアクリレート、ジブチルフォスフェートエチルアクリレート、２−ベンゾイルオキシエチルアクリレートのようなアクリル系重合性単量体；メチルメタクリレート、エチルメタクリレート、ｎ−プロピルメタクリレート、ｉｓｏ−プロピルメタクリレート、ｎ−ブチルメタクリレート、ｉｓｏ−ブチルメタクリレート、ｔｅｒｔ−ブチルメタクリレート、ｎ−アミルメタクリレート、ｎ−ヘキシルメタクリレート、２−エチルヘキシルメタクリレート、ｎ−オクチルメタクリレート、ｎ−ノニルメタクリレート、ジエチルフォスフェートエチルメタクリレート、ジブチルフォスフェートエチルメタクリレートのようなメタクリル系重合性単量体；メチレン脂肪族モノカルボン酸エステル；酢酸ビニル、プロピオン酸ビニル、酪酸ビニル、安息香酸ビニル、ギ酸ビニルのようなビニルエステル；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のようなビニルエーテル；ビニルメチルケトン、ビニルヘキシルケトン、ビニルイソプロピルケトンのようなビニルケトンが挙げられる。
【０１０８】
多官能性重合性単量体としては、ジエチレングリコールジアクリレート、トリエチレングリコールジアクリレート、テトラエチレングリコールジアクリレート、ポリエチレングリコールジアクリレート、１，６−ヘキサンジオールジアクリレート、ネオペンチルグリコールジアクリレート、トリプロピレングリコールジアクリレート、ポリプロピレングリコールジアクリレート、２，２'−ビス（４−（アクリロキシ・ジエトキシ）フェニル）プロパン、トリメチロールプロパントリアクリレート、テトラメチロールメタンテトラアクリレート、エチレングリコールジメタクリレート、ジエチレングリコールジメタクリレート、トリエチレングリコールジメタクリレート、テトラエチレングリコールジメタクリレート、ポリエチレングリコールジメタクリレート、１，３−ブチレングリコールジメタクリレート、１，６−ヘキサンジオールジメタクリレート、ネオペンチルグリコールジメタクリレート、ポリプロピレングリコールジメタクリレート、２，２'−ビス（４−（メタクリロキシ・ジエトキシ）フェニル）プロパン、２，２'−ビス（４−（メタクリロキシ・ポリエトキシ）フェニル）プロパン、トリメチロールプロパントリメタクリレート、テトラメチロールメタンテトラメタクリレート、ジビニルベンゼン、ジビニルナフタリン、ジビニルエーテル等が挙げられる。
【０１０９】
本発明においては、上記した単官能性重合性単量体を単独で或いは２種以上組み合わせて、又は上記した単官能性重合性単量体と多官能性重合性単量体を組み合わせて使用する。多官能性重合性単量体は架橋剤として使用することも可能である。
【０１１０】
上記した重合性単量体の重合の際に用いられる重合開始剤としては、油溶性開始剤及び／又は水溶性開始剤が用いられる。例えば、油溶性開始剤としては、２，２'−アゾビスイソブチロニトリル、２，２'−アゾビス−２，４−ジメチルバレロニトリル、１，１'−アゾビス（シクロヘキサン−１−カルボニトリル）、２，２'−アゾビス−４−メトキシ−２，４−ジメチルバレロニトリルのようなアゾ化合物；アセチルシクロヘキシルスルホニルパーオキサイド、ジイソプロピルパーオキシカーボネート、デカノイルパーオキサイド、ラウロイルパーオキサイド、ステアロイルパーオキサイド、プロピオニルパーオキサイド、アセチルパーオキサイド、ｔ−ブチルパーオキシ−２−エチルヘキサノエート、ベンゾイルパーオキサイド、ｔ−ブチルパーオキシイソブチレート、シクロヘキサノンパーオキサイド、メチルエチルケトンパーオキサイド、ジクミルパーオキサイド、ｔ−ブチルヒドロパーオキサイド、ジ−ｔ−ブチルパーオキサイド、クメンヒドロパーオキサイドのようなパーオキサイド系開始剤が挙げられる。
【０１１１】
水溶性開始剤としては、過硫酸アンモニウム、過硫酸カリウム、２，２'−アゾビス（Ｎ，Ｎ'−ジメチレンイソブチロアミジン）塩酸塩、２，２'−アゾビス（２−アミノジノプロパン）塩酸塩、アゾビス（イソブチルアミジン）塩酸塩、２，２'−アゾビスイソブチロニトリルスルホン酸ナトリウム、硫酸第一鉄又は過酸化水素が挙げられる。
【０１１２】
本発明においては、重合性単量体の重合度を制御する為に、公知の連鎖移動剤、重合禁止剤等を更に添加し用いることも可能である。
【０１１３】
本発明のトナーに用いられる架橋剤としては、２個以上の重合可能な二重結合を有する化合物が用いられる。例えば、ジビニルベンゼン、ジビニルナフタレンのような芳香族ジビニル化合物；エチレングリコールジアクリレート、エチレングリコールジメタクリレート、１，３−ブタンジオールジメタクリレートのような二重結合を２個有するカルボン酸エステル；ジビニルアニリン、ジビニルエーテル、ジビニルスルフィド、ジビニルスルホンのようなジビニル化合物；及び３個以上のビニル基を有する化合物が挙げられる。これらは単独または混合物として用いられる。
【０１１４】
本発明のトナー分子量が１００００未満の場合、最適範囲内のものと比較すると、連続プリント時における着色粒子表面の外添剤が耐久使用によって埋没しやすく、転写性の低下を招きやすくなる。さらに高温オフセット性も悪い。質量平均分子量が１５０００００を超える場合には、低温オフセットが弱く、特に厚紙２次色の定着性が弱くなってしまう。
【０１１５】
本発明のトナーの分子量及び分子量分布ＧＰＣ（ゲルパーミエーションクロマトグラフィ）を用いて以下の方法により測定される。４０℃のヒートチャンバ中でカラムを安定化させ、この温度におけるカラムに、溶媒としてＴＨＦ（テトラハイドロフラン）を毎分１ｍｌの流速で流し、ＴＨＦ試料溶液を約１００μｌ注入して測定する。試料の分子量測定にあたっては、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成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。検量線作成用の標準ポリスチレン試料としては、たとえば、東ソー社製あるいは、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。
【０１１６】
検出器にはＲＩ（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複数本組み合わせるのが良く、たとえば昭和電工社製のｓｈｏｄｅｘ ＧＰＣ ＫＦ−８０１，８０２，８０３，８０４，８０５，８０６，８０７，８００Ｐの組み合わせや、東ソー社製のＴＳＫｇｅｌＧ１０００Ｈ（ＨＸＬ），Ｇ２０００Ｈ（ＨＸＬ），Ｇ３０００Ｈ（ＨＸＬ），Ｇ４０００Ｈ（ＨＸＬ），Ｇ５０００Ｈ（ＨＸＬ），Ｇ６０００Ｈ（ＨＸＬ），Ｇ７０００Ｈ（ＨＸＬ），ＴＳＫｇｕａｒｄｃｏｌｕｍｎの組み合わせが挙げられる。
【０１１７】
試料は以下のようにして作製する。試料をテトラヒドロフラン（ＴＨＦ）中に入れ、数時間放置した後、十分振とうしＴＨＦと良く混ぜ（試料の合一体がなくなるまで）、更に１２時間以上静置する。このときＴＨＦ中への放置時間が２４時間以上となるようにする。その後、サンプル処理フィルター（ポアサイズ０．４５〜０．５μｍ、たとえば、マイショリディスクＨ−２５−５ 東ソー社製、エキクロディスク２５ＣＲ ゲルマン サイエンス ジャパン社製などが利用できる）を通過させたものを、ＧＰＣの試料とする。試料濃度は、樹脂成分が０．５〜５ｍｇ／ｍｌとなるように調整する。
【０１１８】
本発明のトナーに用いられる離型剤としては、キャンデリラワックス、カルナウバワックス、ライスワックス、木ろう、ホホバ油のような植物系ワックス、蜜蝋、ラノリン及び鯨ろうのような動物系ワックス、モンタンワックス、オゾケライト及びセレシンのような鉱物系ワックス、パラフィンワックス、マイクロクリスタリンワックス、ペトロラクタムのような石油ワックス、ポリオレフィンワックス、フィッシャートロピッシュワックスのような合成炭化水素；アミドワックス；ケトンワックス；エステルワックス；高級脂肪酸；高級脂肪酸金属塩；長鎖アルキルアルコールが挙げられる。必要に応じて、これらのグラフト化、ブロック化、蒸留などしても構わない。
【０１１９】
本発明の効果をより発現させるためには、上記離型剤の中でもカルナウバワックス、ライスワックス、モンタンワックス、パラフィンワックス、マイクロクリスタリンワックス、ポリオレフィンワックス、フィッシャートロピッシュワックス、エステルワックス、アミドワックス、ケトンワックスが好ましい。より好ましくは、カルナウバワックス、ライスワックス、パラフィンワックス、ポリオレフィンワックス、フィッシャートロピッシュワックス、エステルワックス、アミドワックス、ケトンワックスである。
【０１２０】
以下にエステルワックス、アミドワックス、ケトンワックスの一例を挙げるが、これら以外のものでも構わない。
【０１２１】
エステルワックスとしては下記一般式で表されるものを例示できる。
【０１２２】
【化１】

（式中、ａ及びｂは０〜４の整数であり、ａ＋ｂは４である。Ｒ₁及びＲ₂は炭素数が１〜４０の有機基であり、Ｒ₁とＲ₂との炭素数差が３以上である。ｍ及びｎは０〜４０の整数であり、ｍとｎは同時に０になることはない。）
【０１２３】
【化２】

（式中、ａ及びｂは０〜３の整数であり、ａ＋ｂは１〜３である。Ｒ₁及びＲ₂は炭素数が１〜４０の有機基である。Ｒ₃は水素原子または炭素数が１以上の有機基である。ｋは１〜３の整数であり、ａ＋ｂ＋ｋ＝４である。ｍ及びｎは０〜４０の整数であり、ｍとｎが同時に０になることはない。）
【０１２４】
【化３】

（式中、Ｒ₁及びＲ₃は炭素数１〜４０の有機基であり、Ｒ₁とＲ₃は同じものであっても異なっていても良い。Ｒ₂は炭素数１〜４０の有機基を示す。）
【０１２５】
【化４】

（式中、Ｒ₁及びＲ₃は炭素数１〜４０の有機基であり、Ｒ₁とＲ₃は同じものであっても異なっていてもよい。Ｒ₂は炭素数１〜４０の有機基を示す。）
【０１２６】
【化５】

（式中、ａは０〜４の整数であり、ｂは１〜４の整数であり、ａ＋ｂは４である。Ｒ₁は炭素数１〜４０の有機基である。ｍ及びｎは０〜４０の整数であり、ｍとｎが同時に０になることはない）。
【０１２７】
アミドワックスとしては、下記式（VI）で表される化合物からなるものが好ましい。
【０１２８】
【化６】

（式中、Ｒ₁、Ｒ₂は炭素数１〜４５を有する有機基であり、Ｒ₁とＲ₂は同じものであっても異なっていても良く、また、Ｒ₁とＲ₂は不飽和基を有していても良い。）
【０１２９】
ケトンワックスとして、下記式（VII）で表される化合物からなるものが良い。
【０１３０】
【化７】

（式中、Ｒ₁、Ｒ₂は炭素数１〜４０の有機基を示す。）
【０１３１】
本発明で用いられる離型剤のＤＳＣ吸熱曲線における吸熱ピーク値はＡＳＴＭＤ３４１８−８２に準拠して測定される。本発明で用いられる離型剤の上記吸熱ピーク値は５０〜１００℃であることが好ましく、加えて、ＤＳＣ曲線の接線離脱温度が４０℃以上であることがより好ましい。
【０１３２】
吸熱ピーク値が５０℃未満であると、離型剤の自己凝集力が弱い為に、着色粒子の製造時に着色粒子表面に離型剤が必要以上存在してしまい、本発明で用いられる接触一成分現像システムにおいては、帯電ローラや感光体を汚染し易くなり、転写性の悪化を生じる。またブロッキング性も劣るため、連続プリント時に現像機内でトナーパッキングを引き起こしやすい。
【０１３３】
一方、吸熱ピークが１２０℃を超えると、定着時に瞬時に離型剤が浸み出しにくく、低温時の定着性や、トナー現像量が多い２次色（レッド、グリーン、ブルー）の定着性を悪化させてしまう。更に、直接重合方法により着色粒子を生成する場合には、重合性単量体組成物中への離型剤の溶解性が低下し、水系媒体中での重合性単量体組成物の着色粒子径サイズの液滴の造粒中に離型剤が析出して造粒が困難となるだけでなく、反応釜の付着物も増加させてしまう。
【０１３４】
離型剤の分子量としては、質量平均分子量（Ｍｗ）が３００〜１，５００のものが好ましい。
【０１３５】
質量平均分子量が３００未満だと吸熱ピーク値が５０℃未満の時と同様の傾向を示してしまう。１５００を超えると低温定着性が低下しかつ、フルカラー画像を出力する際には、ＯＨＴ透明性やヘイズを悪化させてしまう。質量平均分子は、４００〜１，２５０の範囲のものが特に好ましい。
【０１３６】
離型剤の分子量はＧＰＣにより次の条件で測定される。
（ＧＰＣ測定条件）
装置 ：ＧＰＣ−１５０Ｃ（ウォーターズ社製）
カラム：ＧＭＨ−ＭＴ３０ｃｍ２連（東ソー社製）
温度 ：１３５℃
溶媒 ：ｏ−ジクロロベンゼン（０．１％アイオノール添加）
流速 ：１．０ｍｌ／ｍｉｎ
試料 ：０．１５％の試料を０．４ｍｌ注入
以上の条件で測定し、試料の分子量算出にあたっては単分散ポリスチレン標準試料により作成した分子量較正曲線を使用する。さらに、Ｍａｒｋ−Ｈｏｕｗｉｎｋ粘度式から導き出される換算式でポリエチレン換算することによって算出される。
【０１３７】
離型剤は、溶融混練粉砕法により着色粒子を生成する場合は、結着樹脂１００質量部に対して３〜３０質量部使用することが好ましく、５〜２０質量部使用することがより好ましい。重合性単量体組成物を使用して、水系媒体中で直接的に着色粒子を生成する場合には、重合性単量体１００質量部に対して３〜３０質量部、より好ましくは５〜２０質量部を配合し、結果として、重合性単量体から生成された結着樹脂１００質量部当たり離型剤５〜３０質量部、より好ましくは、５〜２０質量部着色粒子に含有されるのが良い。
【０１３８】
離型剤の含有量が結着樹脂１００質量部に対して３質量部未満の場合には、トナーを上記凝集度に調整するための無機微粉末の添加量が多くなり、その結果、連続プリント時のキーパーツ汚染へつながってしまう。上記離型剤の添加量が３０質量部を越える場合には、上記凝集度を有する本発明のトナーを得ることが困難となる。
【０１３９】
溶融混練粉砕法による乾式トナー製法に比べ重合法によるトナー製法においては、着色粒子内部に極性樹脂により多量の離型剤を内包化させ易いため、一般に多量の離型剤を用いることが可能となり、定着時のオフセット防止効果には特に有効となる。
【０１４０】
本発明のトナーに含有される着色剤の一例を挙げるがこれら以外のものでも構わない。
【０１４１】
黒色着色剤としては、カーボンブラック、以下に示すイエロー／マゼンタ／シアン着色剤を用い黒色に調色されたものが利用される。
【０１４２】
イエロー着色剤としては、下記に示すような顔料および／または染料を好ましく用いることができる。顔料としては、縮合アゾ化合物、イソインドリノン化合物、アントラキノン化合物、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．Ｐｉｇｍｅｎｔ Ｙｅｌｌｏｗ３、７、１０、１２、１３、１４、１５、１７、２３、２４、６０、６２、７４、７５、８３、９３、９４、９５、９９、１００、１０１、１０４、１０８、１０９、１１０、１１１、１１７、１２３、１２８、１２９、１３８、１３９、１４７、１４８、１５０、１６６、１６８、１６９、１７７、１７９、１８０、１８１、１８３、１８５、１９１：１、１９１、１９２、１９３、１９９等が好適に用いられる。
【０１４３】
染料としては、例えば、Ｃ．Ｉ．ｓｏｌｖｅｎｔ Ｙｅｌｌｏｗ３３、５６、７９、８２、９３、１１２、１６２、１６３、Ｃ．Ｉ．ｄｉｓｐｅｒｓｅ Ｙｅｌｌｏｗ４２、６４、２０１、２１１などが挙げられる。
【０１４４】
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、アントラキノン、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、１４６、１５０、１６６、１６９、１７７、１８４、１８５、２０２、２０６、２２０、２２１、２５４、Ｃ．Ｉ．ピグメントバイオレッド１９が特に好ましい。
【０１４５】
シアン着色剤としては、フタロシアニン化合物及びその誘導体，アントラキノン化合物、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等が特に好適に利用される。
【０１４６】
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。本発明で用いられる着色剤は、色相角、彩度、明度、耐侯性、ＯＨＰ透明性、トナー中への分散性の点から選択される。着色剤の添加量として、結着樹脂１００質量部に対し１〜２０質量部が用いられる。
【０１４７】
本発明のトナーは、荷電制御剤を併用しても構わない。トナーを負荷電性に制御するものとして下記物質がある。一例を挙げるがこれら以外のものでも構わない。
【０１４８】
例えば、有機金属化合物、キレート化合物が有効であり、モノアゾ金属化合物、アセチルアセトン金属化合物、芳香族オキシカルボン酸、芳香族ダイカルボン酸、オキシカルボン酸及びダイカルボン酸系の金属化合物がある。他には、芳香族オキシカルボン酸、芳香族モノ及びポリカルボン酸並びにその金属塩、無水物、エステル類、ビスフェノール等のフェノール誘導体類などがある。
【０１４９】
さらに、尿素誘導体、含金属サリチル酸系化合物、含金属ナフトエ酸系化合物、ホウ素化合物、４級アンモニウム塩、カリックスアレーン、樹脂系帯電制御剤等が挙げられる。
【０１５０】
トナーを正荷電性に制御するものとして下記物質がある。一例を挙げられるがこれら以外のものでも構わない。
【０１５１】
ニグロシン及び脂肪酸金属塩等によるニグロシン変性物、グアニジン化合物、イミダゾール化合物、トリブチルベンジルアンモニウム−１−ヒドロキシ−４−ナフトスルフォン酸塩、テトラブチルアンモニウムテトラフルオロボレートのような４級アンモニウム塩；これらの類似体であるホスホニウム塩のようなオニウム塩及びこれらのレーキ顔料；トリフェニルメタン染料及びこれらのレーキ顔料（レーキ化剤としては、燐タングステン酸、燐モリブデン酸、燐タングステンモリブデン酸、タンニン酸、ラウリン酸、没食子酸、フェリシアン化物、フェロシアン化物など）；高級脂肪酸の金属塩；ジブチルスズオキサイド、ジオクチルスズオキサイド、ジシクロヘキシルスズオキサイドのようなジオルガノスズオキサイド；ジブチルスズボレート、ジオクチルスズボレート、ジシクロヘキシルスズボレートのようなジオルガノスズボレート類、樹脂系帯電制御剤等が挙げられる。これらを単独で或いは２種類以上組み合わせて用いることができる。
【０１５２】
荷電制御剤は、結着樹脂１００質量部当たり０．０１〜２０質量部、より好ましくは０．５〜１０質量部使用するのが良い。
【０１５３】
本発明のトナーが重合法により製造される場合に縮合系樹脂を添加しても良い。一例を挙げられるがこれら以外のものでも構わない。
【０１５４】
本発明で用いられる縮合系樹脂は例えば、ポリエステル、ポリカーボネート、フェノール樹脂、エポキシ樹脂、ポリアミド、セルロースなどが挙げられる。より好ましくは材料の多様性からポリエステルが望まれる。上記縮合系樹脂は結着樹脂１００質量部当たり０．０１〜２０質量部、より好ましくは０．５〜１０質量部使用するのが良い。
【０１５５】
本発明で用いられる無機微粉末は、酸化チタン（アナターゼ型、ルチル型、非結晶性）、酸化アルミニウム、チタン酸ストロンチウム、酸化セリウム、酸化マグネシウムなどの金属酸化合物及びその混合物；窒化ケイ素などの窒化物；炭化ケイ素などの炭化物；硫酸カルシウム、硫酸バリウム、炭酸カルシウムなどの金属塩；フッ化カーボン、ケイ素化合物微粉末（シリカ微粉末、シリコーン樹脂微粉末）などが挙げられる。場合によっては、有機微粉末をさらに添加しても構わない。
【０１５６】
上記無機微粉末は疎水化されていてもいなくても構わない。疎水化処理する場合には、湿式法または乾式法のいずれを用いても良い。
【０１５７】
疎水化剤としてはシランカップリング剤、チタン系カップリング剤、アルミネート系カップリング剤、ジルコアルミニウム系カップリング剤、シリコーンオイルが挙げられる。
【０１５８】
酸化チタン（アナターゼ型、ルチル型、非結晶性）、酸化アルミニウム、チタン酸ストロンチウム、酸化セリウム、酸化マグネシウムなどの金属酸化合物；窒化ケイ素などの窒化物、炭化ケイ素などの炭化物；硫酸カルシウム、硫酸バリウム、炭酸カルシウムなどの金属塩；フッ化カーボンなどに関しては、シランカップリング剤が上記疎水化剤として特に好ましく用いられる。
【０１５９】
本発明において無機微粉末は、着色粒子１００質量部に対し好ましくは０．０１〜５質量部、より好ましくは０．０２〜４質量部を着色粒子と混合して使用することが良い。
【０１６０】
無機微粉末の添加量が０．０１質量部未満の場合には、着色粒子に対する流動性付与能が充分ではなく、５質量部を超える場合には、着色粒子から遊離した外添剤が現像ブレード、現像ローラ及び感光体汚染を生じ、画像欠陥が生じる。
【０１６１】
以下に本発明のトナー製造方法の一例を示す。
本発明のトナーが粉砕法により製造されたトナーである場合には、少なくとも結着樹脂および着色剤を、加圧ニーダーやエクストルーダー、或いはメディア分散機等を用いて混練、均一に分散させた後、機械的又はジェット気流下でターゲットに衝突させて所望のトナー粒径に微粉砕化させ、更に分級工程を経た後、機械的手段を用いて所望の円形度を有する着色粒子とする。さらに、上記微粉砕化された着色粒子を湿式あるいは乾式の熱球形化処理しても構わない。このようにして得られた着色粒子は、公知の方法を用いて無機微粉末が混合・付着されて本発明のトナーとなる。
【０１６２】
本発明のトナーが重合法により製造されたトナーである場合には、特に制約を受けるものではないが、特公昭３６−１０２３１号公報、特開昭５９−５３８５６号公報、特開昭５９−６１８４２号公報に述べられている懸濁重合法を用いて直接着色粒子を生成する方法；単量体には可溶で水溶性重合開始剤の存在下で直接重合させて着色粒子を生成するソープフリー重合法に代表される、乳化重合法による着色粒子の製造が挙げられる。また、マイクロカプセル製法のような界面重合法、ｉｎ−ｓｉｔｅ重合法、コアセルベーション法などによる製造も挙げられる。さらに、特開昭６２−１０６４７３号公報や特開昭６３−１８６２５３号公報に開示されている様な、少なくとも１種以上の微粒子を凝集させ所望の粒径のものを得る界面会合法なども挙げられる。
【０１６３】
上記各重合法の中でも、小粒径の着色粒子が容易に得られる懸濁重合方法が特に好ましい。さらに一旦得られた重合粒子に更に単量体を吸着させた後、重合開始剤を用い重合させるシード重合方法も本発明に好適に利用することができる。このとき、吸着せしめる単量体中に、極性を有する化合物を分散あるいは溶解させて使用することも可能である。
【０１６４】
懸濁重合をする場合には、通常単量体組成物１００質量部に対して水３００〜３０００質量部を分散媒体として使用するのが好ましい。用いる分散剤として例えば、無機系酸化物としてリン酸三カルシウム、リン酸マグネシウム、リン酸アルミニウム、リン酸亜鉛、炭酸カルシウム、炭酸マグネシウム、水酸化カルシウム、水酸化マグネシウム、水酸化アルミニウム、メタケイ酸カルシウム、硫酸カルシウム、硫酸バリウム、ベントナイト、シリカ、アルミナ、ドデシル硫酸ナトリウム等が挙げられる。有機系化合物としては例えばポリビニルアルコール、ゼラチン、メチセルロース、メチルヒドロキシプロピルセルロース、エチルセルロース、カルボキシメチルセルロースのナトリウム塩、デンプン等が使用されている。
【０１６５】
これら分散剤は、重合性単量体１００質量部に対して０．１〜５．０質量部を使用することが好ましい。これら分散剤の微細化のために０．００１〜０．１質量％の界面活性剤を併用しても良い。具体的には市販のノニオン、アニオン、カチオン型の界面活性剤が利用できる。例えばドデシル硫酸ナトリウム、テトラデシル硫酸ナトリウム、ペンタデシル硫酸ナトリウム、オクチル硫酸ナトリウム、オレイン酸ナトリウム、ラウリル酸ナトリウム、ステアリン酸カリウム、オレイン酸カルシウム等が好ましく用いられる。
【０１６６】
重合法を用いる場合も粉砕法を用いた場合と同様に、得られた着色粒子に公知の方法を用いて無機微粉末を混合させ、本発明のトナーを得ることができる。
【０１６７】
以下、上記本発明のトナーを用いた本発明の画像形成方法について説明する。
【０１６８】
図１は本発明の画像形成方法に好適に用いられる画像形成装置の模式的断面図である。まず、本発明の画像形成方法に用いられる中間転写ベルトについて説明する。
【０１６９】
本発明で用いる中間転写体としての中間転写ベルトは、図１に示すような無端のベルト形状を有している。中間転写ベルトは、表面の平滑性についても考慮する必要があり、表面の粗さＲａが１μｍを超えると転写性能に影響が出てハーフトーン画像のガサツキや細線の再現性が低下することがある。また、二次転写残トナーに与える電荷にムラができるため、転写残トナーが感光体に十分に戻らず、連続プリント時の次に印字された画像に前の画像が残る中間転写ベルトクリーニング不良も発生する。
【０１７０】
また、中間転写ベルトの肉厚は４０〜３００μｍの範囲が好ましい。肉厚が４０μｍ未満では中間転写ベルトの成形安定性に欠け、厚さムラを生じ易く、耐久強度も不十分で、ベルトの破断や割れが発生する場合がある。一方で肉厚が３００μｍを超えると材料が増えコストが高くなる上に、プリンター等の架張軸部位での内面と外面の周速差が大きくなり、外面の収縮による画像飛び散り等の問題が発生し易く、屈曲耐久性の低下やベルトの剛性が高くなりすぎて駆動トルクが増大し、本体の大型化やコスト増加を招くといった問題も生じる。
【０１７１】
本発明で用いられる中間転写ベルトは、樹脂を主体とする弾性層と、必要に応じて該弾性層上に形成される被覆層とにより構成される。
【０１７２】
被覆層は、弾性層が合成ゴムからなる場合に、抵抗調整やベルト寿命を伸ばす目的で設けられることが多い。被覆層に用いられる材料としては、例えば熱可塑性樹脂が挙げられる。
【０１７３】
上記弾性層の材料としては合成ゴムや熱可塑性樹脂が挙げられる。合成ゴムとしては、例えば、スチレン−ブタジエンゴム、ハイスチレンゴム、ブタジエンゴム、イソプレンゴム、エチレン−プロピレン共重合体、ニトリルブタジエンゴム（ＮＢＲ）、クロロプレンゴム、ブチルゴム、シリコーンゴム、フッ素ゴム、ニトリルゴム、ウレタンゴム、アクリルゴム、エピクロロヒドリンゴム及びノルボルネンゴム、エラストマー等が挙げられる。
【０１７４】
熱可塑性樹脂としては、例えば、エチレン−ビニルアルコール共重合体（ＥＶＯＨ）、ポリエチレン、ポリプロピレン、ポリスチレン、アクリロニトリル・ブタジエン・スチレン樹脂（ＡＢＳ樹脂）、ポリアセタール、ポリカーボネート、ポリエステル（ポリエチレンテレフタレート、ポリブチレンテレフタレート等）、メタクリル樹脂、脂肪族又は脂肪族以外のポリアミド、変性ポリフェニレンエーテル、ポリフェニレンスルフィド、ポリアリレート、ポリサルホン、ポリエーテルサルホン、ポリアミドイミド、熱可塑性ポリイミド、ポリエーテルイミド、ポリエーテル・エーテルケトン、ポリエーテルケトン、ポリエーテルニトリル、脂肪族ポリケトン、ポリメチルペンテン、フッ素樹脂（ポリフッ化ビニリデン、エチレン−４フッ化エチレン共重合体、４フッ化エチレン−パーフロロアルキルビニルエーテル共重合体、フッ化エチレンプロピレン共重合体、４フッ化エチレン等）等から選ばれる１種類あるいは２種類以上を使用することができ、またその他公知の熱可塑性樹脂（例えば、ポリマーアロイ）等、上記の材料に限定されるものではない。
【０１７５】
また、本発明で用いられる中間転写ベルトは抵抗値の調整が必要である。良好な画像が得られる中間転写ベルトの体積抵抗率の範囲は１×１０⁶〜８×１０¹³Ω・ｃｍである。体積抵抗率が１×１０⁶Ω・ｃｍ未満では抵抗が低過ぎて十分な転写電界が得られず、画像の抜けやガサツキを生じ易い。一方で体積抵抗率が８×１０¹³Ω・ｃｍより高いと転写電圧も高くする必要があり、電源の大型化やコストの増大を招くため好ましくない。抵抗を制御するためには、本発明の顕著な効果を得ることができる範囲内で導電剤を適時添加することができる。
【０１７６】
導電剤としては、各種の導電性無機粒子及びカーボンブラック、イオン系導電剤、導電性樹脂及び導電性粒子分散樹脂等が挙げられる。具体的には、導電性無機粒子として酸化チタン、酸化スズ、硫酸バリウム、酸化アルミニウム、チタン酸ストロンチウム、酸化マグネシウム、酸化ケイ素、炭化ケイ素及び窒化ケイ素等の粒子に必要に応じて酸化スズ、酸化アンチモン及びカーボン等で表面処理を行ったものが挙げられる。これらの形状は、球状、繊維状、板状及び不定形等いかなる形状でもよい。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、ポリジアセチレン及びポリエチレンイミン等が挙げられる。また、導電性粒子分散樹脂としてはカーボン、アルミニウム及びニッケル等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及びポリメタクリル酸メチル等の樹脂中に分散したものが挙げられる。
【０１７７】
また、上記イオン系導電剤として、以下のものを挙げることができる。例えば、ラウリルトリメチルアンモニウム、ステアリルトリメチルアンモニウム、オクタドデシルトリメチルアンモニウム、ドデシルトリメチルアンモニウム、ヘキサデシルトリメチルアンモニウム、変性脂肪酸・ジメチルエチルアンモニウニウム塩の過塩素酸塩、塩素酸塩、ホウフッ化水素酸塩、硫酸塩、エトサルフェート塩、ハロゲン化ベンジル塩（臭化ベンジル塩、塩化ベンジル塩等）等の第四級アンモニウム塩のような陽イオン性界面活性剤；脂肪族スルホン酸塩、高級アルコール硫酸エステル塩、高級アルコールエチレンオキサイド付加硫酸エステル塩、高級アルコール燐酸エステル塩、高級アルコールエチレンオキサイド付加燐酸エステル塩等の陰イオン界面活性剤；各種ベタイン等の両性イオン界面活性剤；高級アルコールエチレンオキサイド、ポリエチレングリコール脂肪酸エステル、多価アルコール脂肪酸エステル等の非イオン性帯電防止剤等の帯電防止剤；ＬｉＣＦ₃ＳＯ₃、ＮａＣｌＯ₄、ＬｉＣｌＯ₄、ＬｉＡｓＦ₆、ＬｉＢＦ₄、ＮａＳＣＮ、ＫＳＣＮ、ＮａＣｌ等のＬｉ⁺、Ｎａ⁺、Ｋ⁺等の周期律表第１族の金属塩、ＮＨ⁴⁺の塩等の電解質、またＣａ（ＣｌＯ₄）₂等のＣａ²⁺、Ｂａ²⁺等の周期律表第２族の金属塩及びこれらの帯電防止剤が、少なくとも１個の水酸基、カルボキシル基、一級ないし二級アミン基等のイソシアネートと反応する活性水素を有する基を持ったものが挙げられる。
【０１７８】
更に、上記したもの等と、１，４−ブタンジオール、エチレングリコール、ポリエチレングリコール、プロピレングリコール、ポリエチレングリコール等の多価アルコールとその誘導体等との錯体、またはエチレングリコールモノメチルエーテル、エチレングリコールモノエチルエーテル等のモノオールとの錯体が挙げられ、これらの中から選ばれる１種類あるいは２種類以上を使用することができる。ただし、その他公知のイオン系導電剤も用いることができ、上記の材料に限定されない。
【０１７９】
必要な構成材料を、上記弾性層を構成する樹脂材料中に混合、分散する方法も公知のものを適宜用いることができる。樹脂材料がエラストマーの場合には、ロールミル、ニーダー及びバンバリーミキサー等の装置が用いられ、液状の場合には、ボールミル、ビーズミル、ホモジナイザー、ペイントシェーカー及びナノマイザーもしくはそれに類する装置を使用して分散することができる。
【０１８０】
本発明で用いられる中間転写ベルトは、例えば以下の方法によって製造される。樹脂材料をチューブ状に押し出し成形し、単層のシームレスベルト中間転写体を得る方法；弾性層を押し出し成形し、加硫後にスプレー塗工または浸漬塗工等により被覆層を形成して２層構成のベルト状中間転写体を得る方法；または遠心成形により単層もしくは２層以上のベルト状中間転写体を成形する方法等を挙げることができる。
【０１８１】
次に、本発明の画像形成方法について説明する。
【０１８２】
本発明の画像形成方法は、上記本発明の非磁性一成分トナーを用いて画像形成を行う方法であり、
（ｉ）感光体上に形成された静電潜像を色の異なる２以上の非磁性一成分トナーによって可視化して各色のトナー像を形成する工程であって、それぞれの色に対応した静電潜像を各色の非磁性一成分トナーによって順次可視化する現像工程と、
（ii）前記現像工程において可視化された前記各色のトナー像を、前記感光体に常時当接する中間転写ベルト上に順次重ねて転写することにより前記中間転写体上にカラートナー像を形成する中間転写工程と、
（iii）前記中間転写体上のカラートナー像を転写材上に転写する転写工程と、を少なくとも有する。
【０１８３】
図１は電子写真プロセスを利用したカラー画像形成装置（複写機あるいはレーザービームプリンター）である。図１において、中間転写ベルトと感光体とは常時当接して一体に支持された転写ユニット（中間転写ベルト−感光体一体カートリッジ）を構成している。１は第１の画像担持体として繰り返し使用される回転ドラム型の感光体（以下感光体と記す）であり、矢示の方向に所定の周速度（プロセススピード）をもって回転駆動される。
【０１８４】
感光体１は、回転過程で一次帯電器２により所定の極性・電位に一様に帯電処理される（帯電工程）。一次帯電器の電源３２は、直流電圧に交流電圧を重畳して印加しているが、直流電圧のみでもよい。次いで、不図示の露光手段（カラー原稿画像の色分解・結像露光光学系、画像情報の時系列電気デジタル画素信号に対応して変調されたレーザービームを出力するレーザースキャナによる走査露光系等）による画像露光３を受けることにより目的のカラー画像の第１の色成分像（例えば、イエロー色成分像）に対応した静電潜像が形成される（潜像形成工程）。
【０１８５】
次いで、その静電潜像が第１の現像器（イエロー色現像器４１）により第１色であるイエロートナーＹにより現像される（現像工程）。このとき用いられる現像方法は、接触一成分現像方法であることが好ましい。この時、第２〜第４の現像器（マゼンタ色現像器４２、シアン色現像器４３及びブラック色現像器４４）の各現像器は作動状態がオフになっていて感光体１には作用せず、上記第１色のイエロートナー画像は上記第２〜第４の現像器により影響を受けない。
【０１８６】
中間転写ベルト５は、図中時計方向に感光体１と同じ周速度をもって回転駆動されている。感光体１上に形成担持された上記第１色のイエロートナー画像が、感光体１と中間転写ベルト５とのニップ部を通過する過程で、一次転写ローラ６から中間転写ベルト５に印加される一次転写バイアスにより形成される電界により、中間転写ベルト５の外周面に順次一次転写されていく（中間転写工程）。
【０１８７】
中間転写ベルト５に対応する第一色のイエロートナー画像の転写を終えた感光体１の表面は、クリーニング装置１３により清掃される（クリーニング工程）。
【０１８８】
以下、一次帯電器により再度感光体１表面が帯電処理され、第２色のマゼンタトナー画像、第３色のシアントナー画像、第４色のブラックトナー画像に対応する静電潜像が感光体１に形成され、各色のトナーによって順次現像が行われる。現像工程において感光体１上に形成されたトナー像は順次中間転写ベルト５上に重ね合わせて転写され、目的のカラー画像に対応した合成カラートナー像が中間転写ベルト５上に形成される。
【０１８９】
７は二次転写ローラで、二次転写対向ローラ８に対応し平行に軸受けされ、中間転写ベルト５の外面に離間可能な状態に配設されている。すなわち、感光体１から中間転写ベルト５への第１〜第４色のトナー画像の一次転写工程において、二次転写ローラ７は中間転写ベルト５から離間させることが可能である。
【０１９０】
感光体１から中間転写ベルト５への第１〜第４色のトナー画像の順次重畳転写のための一次転写バイアスは、トナーとは逆極性（＋）でバイアス電源３０から印加される。その印加電圧は、例えば＋１００Ｖ〜２ｋＶの範囲である。
【０１９１】
中間転写ベルト５上に転写された合成カラートナー画像の第２の画像担持体である転写材Ｐへの転写（転写工程）は以下のように行われる。二次転写ローラ７が中間転写ベルト５に当接されると共に、転写材Ｐが給紙ローラ１１から転写材ガイド１０を通って、中間転写ベルト５と二次転写ローラ７との当接ニップに所定のタイミングで給送され、二次転写バイアスが電源３１から二次転写ローラ７に印加される。この二次転写バイアスにより中間転写ベルト５から第２の画像担持体である転写材Ｐへ合成カラートナー像が二次転写される。トナー像の転写を受けた転写材Ｐは、定着器１５へ導入され加熱定着される（定着工程）。
【０１９２】
転写材Ｐへの画像転写終了後、中間転写ベルト５には離接自在に配置されたクリーニングローラ機構としてのクリーニング用帯電部材９が当接され、感光体１とは逆極性のバイアスを印加することにより、転写材Ｐに転写されずに中間転写ベルト５上に残留している転写残トナーに一次転写時と逆極性の電荷が付与される。バイアス電源３３は、直流電圧に交流電圧を重畳して印加している。一次転写時と逆極性に帯電された前記転写残トナーは、中間転写ベルト５と感光体１のニップ部及びその近傍において感光体１に静電的に転写されることにより、中間転写ベルトがクリーニングされる。この工程は一次転写と同時に行うことができるため、スループットの低下を生じない。
【０１９３】
図２は、本発明で用いられる中間転写ベルト−感光体一体カートリッジの模式的断面図である。以下、上記カートリッジについて説明する。図２に示すように、本発明で用いられるカートリッジは中間転写ベルト５と感光体１、中間転写ベルトクリーニング機構９及び感光体のクリーニング装置１３が一体のユニットとして構成され、電子写真装置本体に容易に着脱可能である。中間転写ベルト５のクリーニング機構は、前述のように転写残トナーを一次転写と逆の極性に帯電させ、一次転写部で感光体に戻すために必要な機構であり、本図では中抵抗の弾性体からなるクリーニングローラ９を装備している。感光体のクリーニングは、ブレードクリーニングである。
【０１９４】
本カートリッジには非図示の廃トナー容器も一体となっており、中間転写ベルト−感光体双方の転写残トナーもカートリッジ交換時に同時に廃棄されるため、メンテナンス性の向上に貢献している。また、中間転写ベルトは８と１２の２本のローラで張架され部品点数の削減と小型化を図っている。ここで、８は駆動ローラであると同時にクリーニングローラの対向ローラとなっている。中間転写ベルトに従動して回転するテンションローラ１２は、スライドする機構を有しており、圧縮ばねにより矢印の方向に圧接され、中間転写ベルトに張力を与えている。そのスライド幅は１〜５ｍｍ程度で、ばねの圧力合計は５〜１００Ｎ程度である。また、感光体１と駆動ローラ８は非図示のカップリングを有し、本体から回転駆動力が伝達される構成となっている。
【０１９５】
【実施例】
本発明を以下に実施例を示すことでより具体的に説明するが、これは本発明になんら限定をするものではない。
【０１９６】
〈実施例１〉イエロートナーＮｏ．１の製造
本発明に用いるイエロートナーは次のように調製した。高速撹拌装置ＴＫ−ホモミキサーを備えた３リットル用四つ口フラスコ中に、イオン交換水９１０質量部とポリビニルアルコール２質量部、ドデシル硫酸ナトリウム１質量部を添加し回転数を１００００回転／分に調整し、６０℃に加温して分散剤系とした。
【０１９７】
一方、分散質系は、
・スチレン単量体 ６０質量部
・２−エチルヘキシルアクリレート単量体 ４０質量部
・縮合アゾ顔料 １０質量部
・ホウ素化合物 １．０質量部
・飽和ポリエステル樹脂 １０質量部
（プロピレンオキサイド変性ビスフェノールＡとフタル酸との重縮合物）
上記混合物をメディア式分散機を用い４時間分散させた後、離型剤（ライスワックス ＤＳＣピーク８０℃）２０質量部を添加し、内温を７０℃にして３０分間保温した。その後、重合開始剤である２，２'−アゾビス（２，４−ジメチルバレロニトリル）３質量部を添加した分散物を、上記分散媒中に投入し１５０００回転／分を維持しつつ５分間造粒した。その後高速撹拌装置からプロペラ撹拌羽根に撹拌器を代え１５０回転で重合を１０時間行った。重合終了後スラリーを冷却し、水洗、乾燥をしてイエロー着色粒子を得た。
【０１９８】
得られたイエロー着色粒子１００質量部に対し、無機微粉末を表２に示す処方で添加し、ヘンシェルミキサー（三井三池化工機社製）にて３０００回転／分で１分外添混合した。その後、疎水化シリカ微粉末（一次粒径１２ｎｍ）０．８質量部を添加し、同様に３０００回転／分で３分外添混合することにより、疎水性シリカおよび無機微粉末をイエロー着色粒子表面に均一固着させたイエロートナーＮｏ．１を得た。イエロートナーＮｏ．１の物性を表２に示す。
【０１９９】
〈実施例２〉イエロートナーＮｏ．２の製造
実施例１において、離型剤の量、無機微粉末の量、無機微粉末の粒径を表２に記載するように変更した以外は、上記実施例１と同様の方法を用いてイエロートナーＮｏ．２を得た。イエロートナーＮｏ．２の物性を表２に示す。
【０２００】
〈実施例３〉イエロートナーＮｏ．３の製造
実施例１において、離型剤の量および無機微粉末の粒径を表２に記載するように変更した以外は、上記実施例１と同様の方法を用いてイエロートナーＮｏ．３を得た。イエロートナーＮｏ．３の物性を表２に示す。
【０２０１】
〈実施例４〉イエロートナーＮｏ．４の製造
（１）顔料の分散溶液の調製
縮合アゾ顔料４質量部に対して市販の界面活性剤であるラウリルトリメチルアンモニウムクローライド３質量部と、Ｎ₂ガス置換したイオン交換水１００質量部を混合し、超音波分散装置により２０分間分散を行った。これより分散された縮合アゾ顔料分散液を得た。
【０２０２】
（２）着色重合体粒子の合成
内容積３リットルの丸底セパラブルフラスコに、温度センサ、窒素導入管、ディスクタービン型撹拌翼、冷却管を取り付けて重合反応装置を準備した。この重合反応装置にＮ₂置換したイオン交換水３００質量部、スチレン単量体６０質量部、２−エチルヘキシルアクリレート単量体４０質量部を仕込み、７０℃まで加熱したところで、重合開始剤であるペルオキソ二硫酸カリウム５質量部を溶解したイオン交換水５０質量部添加し、重合反応を開始させた。
【０２０３】
この重合反応の重合転化率が、８５％となったところで縮合アゾ顔料分散溶液及び離型剤として市販のワックスエマルション（ポリエチレンワックス ＤＳＣピーク１１０℃）を添加速度１．０ｍｌ／ｍｉｎで反応系に添加し、添加終了後、この重合反応系の温度を９０℃まで高めて反応を進行させながら、イエロー顔料の重合体粒子への固定化を行い、反応を完結させてイエロー着色粒子を得た。
【０２０４】
得られたイエロー着色粒子に、実施例１と同様の方法を用いて疎水性シリカおよび無機微粉末を外添混合して、イエロートナーＮｏ．４を得た。なお、このときの無機微粉末の添加量を上記イエロー着色粒子１００質量部に対して０．４質量部とした。イエロートナーＮｏ．４の物性を表２に示す。
【０２０５】
〈トナーの比較製造例１〉イエロートナーＮｏ．５の製造
実施例１において、無機微粉末の粒径および量を表２に記載するように変更した以外は上記実施例１と同様の方法を用いて、イエロートナーＮｏ．５を得た。イエロートナーＮｏ．５の物性を表２に示す。
【０２０６】
〈トナーの比較製造例２〉イエロートナーＮｏ．６の製造
実施例１において、無機微粉末の粒径を表２に記載するように変更した以外は上記実施例１と同様の方法を用いて、イエロートナーＮｏ．６を得た。イエロートナーＮｏ．６の物性を表２に示す。
【０２０７】
〈実施例５〉マゼンタトナーＮｏ．１の製造
実施例１において、縮合アゾ顔料の代わりにキナクリドン顔料を用いた以外は上記実施例１と同様の方法を用いて、マゼンタトナーＮｏ．１を得た。マゼンタトナーＮｏ．１の物性を表２に示す。
【０２０８】
〈実施例６〉マゼンタトナーＮｏ．２の製造
実施例４において、縮合アゾ顔料の代わりにキナクリドン顔料を用いた以外は上記実施例４と同様の方法を用いて、マゼンタトナーＮｏ．２を得た。マゼンタトナーＮｏ．２の物性を表２に示す。
【０２０９】
〈トナーの比較製造例３〉マゼンタトナーＮｏ．３の製造
実施例１において、縮合アゾ顔料の代わりにキナクリドン顔料を用い、無機微粉末の粒径および量を表２に記載するように変更した以外は、上記実施例１と同様の方法を用いてマゼンタトナーＮｏ．３を得た。マゼンタトナーＮｏ．３の物性を表２に示す。
【０２１０】
〈トナーの比較製造例４〉マゼンタトナーＮｏ．４の製造
実施例１において、縮合アゾ顔料の代わりにキナクリドン顔料を用い、無機微粉末の粒径を表２に記載するように変更した以外は、上記実施例１と同様の方法を用いてマゼンタトナーＮｏ．４を得た。マゼンタトナーＮｏ．４の物性を表２に示す。
【０２１１】
〈実施例７〉シアントナーＮｏ．１の製造
実施例１において、縮合アゾ顔料の代わりに銅フタロシアニン顔料を用いた以外は上記実施例１と同様の方法を用いてシアントナーＮｏ．１を得た。シアントナーＮｏ．１の物性を表２に示す。
【０２１２】
〈実施例８〉シアントナーＮｏ．２の製造
実施例４において、縮合アゾ顔料の代わりに銅フタロシアニン顔料を用いた以外は上記実施例４と同様の方法を用いてシアントナーＮｏ．２を得た。シアントナーＮｏ．２の物性を表２に示す。
【０２１３】
〈トナーの比較製造例５〉シアントナーＮｏ．３の製造
実施例１において、縮合アゾ顔料の代わりに銅フタロシアニン顔料を用い、無機微粉末の粒径および量を表２に記載するように変更した以外は、上記実施例１と同様の方法を用いてシアントナーＮｏ．３を得た。シアントナーＮｏ．３の物性を表２に示す。
【０２１４】
〈トナーの比較製造例６〉シアントナーＮｏ．４の製造
実施例１において、縮合アゾ顔料の代わりに銅フタロシアニン顔料を用い、無機微粉末の粒径を表２に記載するように変更した以外は、上記実施例１と同様の方法を用いてシアントナーＮｏ．４を得た。シアントナーＮｏ．４の物性を表２に示す。
【０２１５】
〈実施例９〉ブラックトナーＮｏ．１の製造
実施例１において、縮合アゾ顔料の代わりにグラフト化カーボンブラックを用いた以外は、上記実施例１と同様の方法を用いてブラックトナーＮｏ．１を得た。ブラックトナーＮｏ．１の物性を表２に示す。
【０２１６】
〈実施例１０〉ブラックトナーＮｏ．２の製造
実施例４において、縮合アゾ顔料の代わりにグラフト化カーボンブラックを用いた以外は、上記実施例４と同様の方法を用いてブラックトナーＮｏ．２を得た。ブラックトナーＮｏ．２の物性を表２に示す。
【０２１７】
〈トナーの比較製造例７〉ブラックトナーＮｏ．３の製造
実施例１において、縮合アゾ顔料の代わりにグラフト化カーボンブラックを用い、無機微粉末の粒径と量を表２に記載するように変更した以外は、上記実施例１と同様の方法を用いてブラックトナーＮｏ．３を得た。ブラックトナーＮｏ．３の物性を表２に示す。
【０２１８】
〈トナーの比較製造例８〉ブラックトナーＮｏ．４の製造
実施例１において、縮合アゾ顔料の代わりにグラフト化カーボンブラックを用い、無機微粉末の粒径を表２に記載するように変更した以外は、上記実施例１と同様の方法を用いてブラックトナーＮｏ．４を得た。ブラックトナーＮｏ．４の物性を表２に示す。
【０２１９】
【表２】

【０２２０】
〈中間転写ベルトの製造例１〉
・ポリブチレンテレフタレート樹脂 ６０質量部
・ポリカーボネート樹脂 ４０質量部
・導電剤（カーボンブラック ） ８質量部
上記の材料を２軸の押出し混練機で混練し、所望の電気抵抗になるように過塩素酸リチウムをバインダー樹脂（混練物）中に充分に均一分散させ、成型用原料を得た。更に、これを１〜２ｍｍの粒径の混練物とした。
【０２２１】
次に、１軸押出し機へ上記混練物を投入し、加熱溶融押し出しにより、溶融体とした。溶融体は引き続き直径１００ｍｍ、厚さ３００μｍの環状単層用押出しダイスに導かれ、更に気体導入路より空気を吹き込み膨張させ、最終的な形状寸法として直径１４０ｍｍ、肉厚１２０μｍの中間転写ベルト１を得た。得られた中間転写ベルト１の抵抗値は６．０×１０⁹Ω・ｃｍであった。
【０２２２】
〈中間転写ベルトの製造例２〉
中間転写ベルトの製造例１において、カーボンブラックの量を５質量部に変更した以外は、上記製造例１と同様の方法を用いて中間転写ベルト２を得た。得られた中間転写ベルト２の抵抗値は８．０×１０⁹Ω・ｃｍであった。
【０２２３】
〈中間転写ベルトの製造例３〉
中間転写ベルトの製造例１において、カーボンブラックの量を４０質量部に変更した以外は、上記製造例１と同様の方法を用いて中間転写ベルト３を得た。得られた中間転写ベルト３の抵抗値は８．０×１０⁵Ω・ｃｍであった。
【０２２４】
〈中間転写ベルトの製造例４〉
円筒状の金型に、予めチューブ状に押し出したゴムパウンドを被せ、その上から直径１５０μｍのポリエステル糸を０．８ｍｍのピッチで螺旋状に巻き付けた。さらにその上に上記と同様なゴムパウンドを被せ、その上からポリエステルテープを巻き付けてゴムパウンドを金型に十分密着させ、ゴムパウンドを加硫した。加硫後、ポリエステルテープを剥がしてゴムを研磨し、繊維を配列した弾性層（弾性体チューブ）を得た。ゴムパウンドの材料配合は下記の通りである。
・ＮＢＲ ７０質量部
・ＥＰＤＭ ３０質量部
・加硫剤（沈降硫黄） １．５質量部
・加硫助剤（亜鉛華） ２質量部
・加硫促進剤（ＭＢＴ） １．５質量部
・加硫促進剤（ＴＭＴＭ） １．２質量部
・導電剤（カーボンブラック） ２５質量部
・分散助剤（ステアリン酸） １質量部
・可塑剤（ナフテン系プロセスオイル） ４０質量部
【０２２５】
次に、この弾性層上に被覆層を形成するための塗料を下記処方により作製した。
・ポリカーボネート系ポリウレタン １００質量部
・ＰＴＦＥ樹脂微粉末 ７０質量部
・フッ素系グラフトコポリマー ３質量部
・メチルエチルケトン ５００質量部
・メチルイソブチルケトン ２００質量部
・Ｎ−メチルピロリドン １００質量部
上記の塗料を弾性層上に塗布し、室温で指触乾燥後、１３０℃で２時間加熱することにより残存溶剤を除去して、弾性層上に厚さ１８μｍの被覆層を１層有する中間転写ベルト４を得た。得られた中間転写ベルト４の抵抗値は１×１０⁷Ω・ｃｍであった。
【０２２６】
〈中間転写ベルトの製造例５〉
中間転写ベルト１の製造例４において、導電剤（カーボンブラック）の量を５０質量部に変更した以外は、上記製造例４と同様の方法を用いて中間転写ベルト５を得た。得られた中間転写ベルト５の抵抗値は５×１０⁵Ω・ｃｍであった。
【０２２７】
〈実施例１１〉
図１に示す接触一成分現像システムの画像形成装置に、中間転写ベルトの製造例１で得られた中間転写ベルト１を装着し、各現像器４１〜４４内にイエロートナーＮｏ．１をセットし、低温低湿環境下（１５℃／１０％ＲＨ）でフルカラーモード、印字比率５％で連続プリントを行った。サンプリングのタイミングは、１０枚目、２０００枚目、４０００枚目とし、全ベタ画像のクリーニング性と転写均一性を評価した。評価方法を以下に示す。なお、本実施例において全ベタ画像とは、トナー乗り量０．５５〜０．７５ｍｇ／ｃｍ²の画像を言う。
【０２２８】
（１）クリーニング性
クリーニング性は、上記低温低湿環境下における連続印字後に得られた全ベタ画像から下記基準に従い評価した。
【０２２９】
Ａ：画像上のクリーニング性は良好。クリーニング部材裏面も非常に綺麗である。
Ｂ：画像上のクリーニング性は良好。クリーニング部材裏面に若干のトナー汚れが確認される。
Ｃ：画像上のクリーニング性は実用上問題ないレベル。クリーニング部材裏面に多量のトナー汚れが確認される。
Ｄ：画像上のクリーニング性は悪く、実用上問題あるレベル。クリーニング部材裏面に多量のトナー汚れが確認される。
【０２３０】
（２）転写性（均一性）
転写の均一性は、上記低温低湿環境下における連続印字後に得られた全ベタ画像から下記基準に従い評価した。
【０２３１】
Ａ：平滑紙（キヤノンカラーレーザー ８０ｇ／ｍ²）、ラフ紙（ゼロックス４０２４、７５ｇ／ｍ²）のどちらにおいても良好な均一性の高い画像が得られる。
Ｂ：平滑紙（キヤノンカラーレーザー ８０ｇ／ｍ²）は、良好な均一性の高い画像が得られる。ラフ紙（ゼロックス４０２４、７５ｇ／ｍ²）において、均一性が若干低下した画像が得られる。実用上問題ないレベル。
Ｃ：平滑紙（キヤノンカラーレーザー ８０ｇ／ｍ²）、ラフ紙（ゼロックス４０２４、７５ｇ／ｍ²）のどちらにおいても均一性が若干低下した画像が得られる。実用上問題ないレベル。
Ｄ：平滑紙（キヤノンカラーレーザー ８０ｇ／ｍ²）、ラフ紙（ゼロックス４０２４、７５ｇ／ｍ²）のどちらにおいても均一性が著しく低下した画像が得られる。実用上問題あるレベル。
【０２３２】
〈実施例１２〜１７〉
実施例１１において、中間転写ベルトの種類、転写工程における中間転写ベルトと感光体との離間およびクリーニングローラの有無を変化させ、表３に示すような種々の画像形成プロセスとした。表３において、ドラムとの離間「無し」は中間転写ベルトが感光体に常時当接することを意味し、「有り」は中間転写ベルトがドラムと当接していない、または当接していても離間する時があることを意味する。また、クリーニングローラの有無は、クリーニングローラ（図１中の９）を用いた場合と用いない場合とを示す。なお、上記実施例１１の中間転写ローラ１を用いた画像形成方法は、表３に示す「プロセス１」を用いたものある。
【０２３３】
【表３】

【０２３４】
実施例１１においてトナーおよび画像形成プロセスを表４に示すように変えた以外は、上記実施例１１と同様の方法により評価を行った。
【０２３５】
〈比較例１〜５〉
実施例１１においてトナーおよび画像形成プロセスを表４に示すように変えた以外は、上記実施例１１と同様の方法により評価を行った。
実施例１１〜１７および比較例１〜５の評価結果を表４に示す。
【０２３６】
【表４】

【０２３７】
〈実施例１８〉
図１に示す接触一成分現像システムの画像形成装置に、中間転写ベルトの製造例１で得られた中間転写ベルト１を装着し、各現像器４１〜４４内にイエロートナーＮｏ．１、マゼンタトナーＮｏ．１、シアントナーＮｏ．１、ブラックトナーＮｏ．１をセットし、プロセス１の条件で、低温低湿環境下（１５℃／１０％ＲＨ）でフルカラーモード、印字比率５％で連続プリントを行った。サンプリングのタイミングは、１０枚目、２０００枚目、４０００枚目とし、全ベタ画像のクリーニング性と色ずれを評価した。クリーニング性の評価は実施例１１と同様の方法により行った。色ずれの評価を以下に示す。
【０２３８】
（３）転写性（色ずれ）
転写時の色ずれは、上記低温低湿環境下における連続印字後に得られた全ベタ画像から下記基準に従い評価した。
【０２３９】
Ａ：平滑紙（キヤノンカラーレーザー ８０ｇ／ｍ²）、ラフ紙（ゼロックス４０２４、７５ｇ／ｍ²）のどちらにおいても色ずれのない良好な均一性の高い画像が得られる。
Ｂ：平滑紙（キヤノンカラーレーザー ８０ｇ／ｍ²）は、色ずれのない良好な均一性の高い画像が得られる。ラフ紙（ゼロックス４０２４、７５ｇ／ｍ²）において、色ずれが若干低下した画像が得られる。実用上問題ないレベル。
Ｃ：平滑紙（キヤノンカラーレーザー ８０ｇ／ｍ²）、ラフ紙（ゼロックス４０２４、７５ｇ／ｍ²）のどちらにおいても色ずれが若干低下した画像が得られる。実用上問題ないレベル。
Ｄ：平滑紙（キヤノンカラーレーザー ８０ｇ／ｍ²）、ラフ紙（ゼロックス４０２４、７５ｇ／ｍ²）のどちらにおいても色ずれが著しく低下した画像が得られる。実用上問題あるレベル。
【０２４０】
〈実施例１９〉
実施例１８においてトナーおよび画像形成プロセスを表５に示すように変えた以外は、上記実施例１８と同様の方法により評価を行った。
【０２４１】
〈比較例６〜９〉
実施例１８においてトナーおよび画像形成プロセスを表５に示すように変えた以外は、上記実施例１８と同様の方法により評価を行った。
実施例１８、１９および比較例６〜９の評価結果を表５に示す。
【０２４２】
【表５】

【０２４３】
【発明の効果】
本発明によれば、非磁性一成分現像方式を用いた現像工程と、中間転写体を用いた転写工程とを少なくとも有する画像形成方法において、低温低湿環境下における連続プリント時に優れたクリーニング性および転写性を発揮することができ、カブリのない良好なフルカラー画像を形成することができる。
【図面の簡単な説明】
【図１】本発明の非磁性一成分トナーおよび画像形成方法を好適に用いることができる画像形成装置の一例を示す画像形成装置の概略図
【図２】本発明の非磁性一成分トナーおよび画像形成方法を好適に用いることができる中間転写ベルト−感光体一体カートリッジの概略図
【図３】従来技術の画像形成方法を用いた画像形成装置の概略図
【符号の説明】
１ 感光体
２ 一次帯電器
３ 画像露光
５ 中間転写ベルト
６ 一次転写対向ローラ
７ 二次転写ローラ
８ 二次転写対向ローラ
９ クリーニングローラ
１０ 転写材ガイド
１１ 給紙ローラ
１２ テンションローラ
１３ クリーニング装置
１５ 定着器
３０，３１，３２，３３ 電源
４１ イエロートナー現像器
４２ マゼンタトナー現像器
４３ シアントナー現像器
４４ ブラックトナー現像器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toner used in a recording method using electrophotography or the like, and an image forming method. More specifically, the present invention relates to non-magnetic one-component development of an integral transfer unit in which a photoconductor and an intermediate transfer belt are always in contact with each other.
[0002]
[Prior art]
Conventionally, as an electrophotographic method, many methods are known as described in US Pat. No. 2,297,691 and the like. In general, a photoconductive substance is used to form an electrical latent image on a photoreceptor, and then the latent image is developed with toner. If necessary, the toner image is transferred to a transfer material such as paper. It is fixed by heating, pressure, heating and pressurization or solvent vapor to obtain a copy. The toner remaining without being transferred onto the photoreceptor is cleaned by various methods, and the above-described steps are repeated.
[0003]
Such a copying apparatus has begun to be used in the field of not only a general-purpose copying machine for copying an original document but also a printer as a computer output or a personal copy for an individual.
[0004]
In recent years, the penetration rate of color printers has improved. Among them, contact 1 as described in Japanese Patent Application Laid-Open No. 2000-315020, etc. from the viewpoint of high image quality, space saving, maintainability, low cost, and material compatibility. Component development is drawing attention.
[0005]
An example of a color image forming apparatus (copier or laser beam printer) using a conventional electrophotographic process will be described with reference to FIG.
[0006]
Reference numeral 1 denotes a drum-shaped photoconductor as a first image carrier, which is driven to rotate at a predetermined peripheral speed (process speed) in the direction of the arrow in the figure. In the rotation process, the photosensitive member 1 is uniformly charged to a predetermined polarity and potential by the primary charger 2, and then subjected to exposure 3 by an image exposure means (not shown). In this manner, an electrostatic latent image corresponding to the first color component image (for example, a yellow toner image) of the target color image is formed.
[0007]
Next, the electrostatic latent image is developed into a yellow toner image which is the first color by a first developing device (yellow toner developing device 41). At this time, the second to fourth developing units, that is, the magenta toner developing unit 42, the cyan toner developing unit 43, and the black toner developing unit 44 are not operated and do not act on the photoconductor 1. One color yellow toner image is not affected by the second to fourth developing units.
[0008]
On the other hand, the intermediate transfer belt 20 is rotationally driven in the direction of the arrow at the same peripheral speed as that of the photoreceptor 1. The yellow toner image of the first color formed on the photoconductor 1 passes through the nip portion between the photoconductor 1 and the intermediate transfer belt 20 and is transferred from the bias power source 29 to the intermediate transfer belt 20 via the roller 62. The image is sequentially transferred onto the outer peripheral surface of the intermediate transfer belt 20 by an electric field formed by the applied bias. This process is called primary transfer, the roller 62 is called a primary transfer roller, and the applied bias is called a primary transfer bias. The surface of the photoreceptor 1 that has finished transferring the first color yellow toner image corresponding to the intermediate transfer belt 20 is cleaned by the cleaning device 13.
[0009]
Similarly, the second color magenta toner image, the third color cyan toner image, and the fourth color black toner image are sequentially superimposed and transferred onto the intermediate transfer belt 20, and the full color toner corresponding to the target color image is obtained. An image is formed.
[0010]
Next, the color toner image is transferred to a transfer material, and this process is called secondary transfer. Reference numeral 63 denotes a secondary transfer roller which is supported in parallel with the secondary transfer counter roller 64 and is arranged in a state in which it can be separated from the lower surface portion of the intermediate transfer belt 20.
[0011]
A primary transfer bias for transferring the toner image from the photoreceptor 1 to the intermediate transfer belt 20 is applied from a bias power supply 29 with a polarity opposite to that of the toner. The applied voltage is, for example, in the range of +100 V to +2 kV.
[0012]
In the primary transfer process of the first to third color toner images from the photosensitive member 1 to the intermediate transfer belt 20, the secondary transfer roller 63 can be separated from the intermediate transfer belt 20. The full-color image transferred onto the intermediate transfer belt 20 is brought into contact with the intermediate transfer belt 20 by the secondary transfer roller 63. On the other hand, the transfer material P is fed from the paper feed roller 11 to the contact portion between the intermediate transfer belt 20 and the secondary transfer roller 63 at a predetermined timing, and the secondary transfer bias is applied from the bias power source 28 to the secondary transfer roller 63. By being applied, the full color image on the intermediate transfer belt is secondarily transferred to the transfer material P. The transfer material P onto which the toner image has been transferred is introduced into the fixing device 15 and is heated and fixed.
[0013]
After the image transfer to the transfer material P is completed, the toner (transfer residual toner) remaining on the intermediate transfer belt is scraped off by the cleaning blade 50 and carried to a waste toner box.
[0014]
In the case of the color printer of the intermediate transfer belt as shown here, since the intermediate transfer belt is used, the material compatibility is excellent. On the other hand, since the contact frequency between the photoconductor and the intermediate transfer belt is high, there is a problem in that when a large number of sheets are printed, deterioration due to the consumption of both occurs and it is difficult to maintain an initial image.
[0015]
Further, since the photosensitive member and the intermediate transfer belt are in contact with each other, a phenomenon of re-transfer in which the toner once transferred is transferred again onto the photosensitive member is likely to occur. There is also a problem. This is particularly noticeable in a low temperature and low humidity environment.
[0016]
From the above, the contact frequency between the photoconductor and the intermediate transfer belt is high, and in particular, the toner mounted on a machine that is always in contact is required to have a characteristic capable of preventing a cleaning failure due to retransfer. .
[0017]
One of the items that improve toner cleaning properties is the degree of toner aggregation. As prior art in which the toner aggregation degree is described in the intermediate transfer belt configuration, there are JP-A-10-207164, JP-A-11-30876, and JP-A-11-65220.
[0018]
However, the examples described in JP-A-10-207164, JP-A-11-30876, and JP-A-11-65220 all relate to a two-component development system, and there is no discussion about non-magnetic one-component development. It is insufficient. In addition, there is insufficient discussion regarding cleaning properties.
[0019]
In general, when cleaning is performed with a cleaning blade as shown in FIG. 3, the rigidity of the blade material is particularly low in a low-temperature and low-humidity environment, particularly when printing is resumed after leaving it unprinted for a long time. Tend to be difficult to clean.
[0020]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a toner and an image forming method capable of preventing photoconductor contamination due to retransfer even when a large number of sheets are continuously printed in an image forming method using an intermediate transfer member. In particular, it is an object to improve characteristics in a low temperature and low humidity environment.
[0021]
Another object of the present invention is to provide a toner and an image forming method that have good cleanability for full-color images in continuous printing in a low-temperature and low-humidity environment.
[0022]
Another object of the present invention is to provide a toner and an image forming method that have good transferability of a full color image in continuous printing under a low temperature and low humidity environment.
[0023]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors paid attention to the particle size of the inorganic fine powder present on the surface of the colored particles of the non-magnetic one-component toner and the toner aggregation degree in a low-temperature and low-humidity environment, and set these as specific values. Thus, in an image forming method having a development process of a non-magnetic one-component development system and an intermediate transfer process using an intermediate transfer belt that is always in contact with the photoconductor, the photoconductor is provided with good cleaning properties on the intermediate transfer belt. The present inventors have found that re-transfer to the substrate can be prevented, transferability can be improved, and excellent transferability can be achieved.
[0024]
That is, the present invention is as follows.
[0025]
(1) A non-magnetic one-component toner for visualizing an electrostatic latent image carried on a photoreceptor,
(I) A step of visualizing the electrostatic latent image formed on the photosensitive member with two or more non-magnetic one-component toners having different colors to form toner images of the respective colors, wherein static images corresponding to the respective colors are formed. (Ii) a toner image of each color visualized in the developing step is sequentially superimposed on an intermediate transfer belt that is always in contact with the photoconductor; An image having at least an intermediate transfer step of forming a color toner image on the intermediate transfer member by transferring the image together, and (iii) a transfer step of transferring the color toner image on the intermediate transfer member onto a transfer material Used in the forming method,
A colored particle containing at least a binder resin, a colorant, and a release agent, and an inorganic fine powder having a particle diameter of 100 to 1000 nm, which is present on the surface of the colored particle;
A nonmagnetic one-component toner having a cohesion degree G1 of 10 to 80% in a low temperature and low humidity environment.
[0026]
(2) The nonmagnetic one-component toner according to (1), wherein the aggregation degree G1 in the low temperature and low humidity environment is 10 to 60%.
[0027]
(3) The aggregation degree difference ΔG represented by the following formula (1) is 0 to 30 when the aggregation degree after leaving the non-magnetic one-component toner in a low temperature and low humidity environment is G2. (1) or (2) non-magnetic one-component toner.
[0028]
[Equation 5]
ΔG = | G2-G1 | (1)
[0029]
(4) The aggregation degree difference ΔG represented by the following formula (1) is 0 to 25 when the aggregation degree after leaving the non-magnetic one-component toner in a low temperature and low humidity environment is G2. (1) or (2) non-magnetic one-component toner.
[0030]
[Formula 6]
ΔG = | G2-G1 | (1)
[0031]
(5) The nonmagnetic one-component toner according to any one of (1) to (4), wherein the inorganic fine powder has a particle size of 150 to 500 nm.
[0032]
(6) The number-based circle equivalent diameter-circularity scattergram measured by the flow type particle image measuring device has an average circularity of 0.950 to 0.999 and a circularity standard deviation of less than 0.040. The nonmagnetic monocomponent toner according to any one of (1) to (5).
[0033]
(7) The number-based circle equivalent diameter-circularity scattergram measured by the flow type particle image measuring apparatus has an average circularity of 0.965 to 0.999 and a circularity standard deviation of less than 0.038. The nonmagnetic monocomponent toner according to any one of (1) to (5).
[0034]
(8) The nonmagnetic one-component toner according to any one of (1) to (7), wherein the weight average particle diameter is 5 to 9.5 μm.
[0035]
(9) The nonmagnetic one-component toner according to any one of (1) to (7), wherein the weight average particle diameter is 6.0 to 9.0 μm.
[0036]
(10) The nonmagnetic one-component toner according to any one of (1) to (9), wherein the release agent is contained in an amount of 3 to 30 parts by mass with respect to 100 parts by mass of the binder resin.
[0037]
(11) The nonmagnetic one-component toner according to any one of (1) to (9), wherein the release agent is contained in an amount of 5 to 20 parts by mass with respect to 100 parts by mass of the binder resin.
[0038]
(12) In the two or more non-magnetic one-component toners, the aggregation degree G1a of the non-magnetic one-component toner first transferred to the intermediate transfer belt and the non-magnetic one finally transferred to the intermediate transfer belt The nonmagnetic one-component toner according to any one of (1) to (11), wherein the aggregation degree G1b of the one-component toner satisfies a relationship of G1a> G1b.
[0039]
(13) In the transfer step, the non-magnetic one-component toner remaining on the intermediate transfer belt without being transferred onto the transfer material is removed by a cleaning roller mechanism (1) to (12) One of the non-magnetic one-component toners.
[0040]
(14) The nonmagnetic one-component toner according to any one of (1) to (13), wherein the intermediate transfer belt is composed of a resin-based component.
[0041]
(15) The non-magnetic one-component toner according to any one of (1) to (14), wherein the photosensitive member and the intermediate transfer belt are an integral transfer unit in which the photosensitive member and the intermediate transfer belt are always in contact with each other.
[0042]
(16) The nonmagnetic one-component toner according to any one of (1) to (15), wherein the developing step is a step of developing by contact one-component development.
[0043]
(17) (i) A step of visualizing the electrostatic latent image formed on the photoreceptor with two or more non-magnetic one-component toners having different colors to form toner images of the respective colors, corresponding to the respective colors. A developing step of sequentially visualizing the electrostatic latent image with non-magnetic one-component toner of each color; and (ii) the toner image of each color visualized in the developing step on an intermediate transfer belt that is always in contact with the photoreceptor. An intermediate transfer step of forming a color toner image on the intermediate transfer member by sequentially superposing and transferring; and (iii) a transfer step of transferring the color toner image on the intermediate transfer member onto a transfer material. The non-magnetic one-component toner includes colored particles containing at least a binder resin, a colorant, and a release agent, and an inorganic fine powder having a particle diameter of 100 to 1000 nm present on the surface of the colored particles. Have And the cohesion G1 in a low-temperature and low-humidity environment 10% to 80% der Thus, in the two or more non-magnetic one-component toners, the aggregation degree G1a of the non-magnetic one-component toner first transferred onto the intermediate transfer belt and the non-magnetic one-component toner transferred last onto the intermediate transfer belt. The aggregation degree G1b of the component toner satisfies the relationship of G1a> G1b. An image forming method.
[0044]
(18) The image forming method according to (17), wherein the nonmagnetic one-component toner has a degree of aggregation G1 of 10 to 60% in a low temperature and low humidity environment.
[0045]
(19) The aggregation degree difference ΔG represented by the following formula (1) is 0 to 30 when the aggregation degree after leaving the non-magnetic one-component toner in a low temperature and low humidity environment is G2. The image forming method according to (17) or (18).
[0046]
[Expression 7]
ΔG = | G2-G1 | (1)
[0047]
(20) The aggregation degree difference ΔG represented by the following formula (1) is 0 to 25 when the aggregation degree after leaving the non-magnetic one-component toner in a low temperature and low humidity environment is G2. The image forming method according to (17) or (18).
[0048]
[Equation 8]
ΔG = | G2-G1 | (1)
[0049]
(21) The image forming method according to any one of (17) to (20), wherein the inorganic fine powder has a particle size of 150 to 500 nm.
[0050]
(22) An average circularity in a number-based equivalent circle diameter-circularity scattergram measured by the non-magnetic one-component toner flow-type particle image measuring device is 0.950-0.999, and the circularity standard deviation Is less than 0.040, The image forming method according to any one of (17) to (21).
[0051]
(23) The number-based circle equivalent diameter-circularity scattergram measured by the non-magnetic one-component toner flow-type particle image measuring device has an average circularity of 0.965 to 0.999, and the circularity standard deviation Is less than 0.038, The image forming method according to any one of (17) to (21).
[0052]
(24) The image forming method according to any one of (17) to (23), wherein the non-magnetic one-component toner has a weight average particle diameter of 5 to 9.5 μm.
[0053]
(25) The image forming method according to any one of (17) to (23), wherein the non-magnetic one-component toner has a weight average particle diameter of 6.0 to 9.0 μm.
[0054]
(26) The image forming method according to any one of (17) to (25), wherein the release agent is contained in an amount of 3 to 30 parts by mass with respect to 100 parts by mass of the binder resin.
[0055]
(27) The image forming method according to any one of (17) to (25), wherein the release agent is contained in an amount of 5 to 20 parts by mass with respect to 100 parts by mass of the binder resin.
[0057]
( 28 ) In the transfer step, the non-magnetic one-component toner remaining on the intermediate transfer belt without being transferred onto the transfer material is removed by a cleaning roller mechanism (17) to (17) 27 ) Any one of the image forming methods.
[0058]
( 29 The intermediate transfer belt is composed of a resin-based component (17) to (17) 28 ) Any one of the image forming methods.
[0059]
( 30 ) The transfer unit having an integrated configuration in which the photosensitive member and the intermediate transfer belt are always in contact with each other (17) to ( 29 ) Any one of the image forming methods.
[0060]
( 31 ) The developing step is a step of developing by contact one-component development (17) to ( 30 ) Any one of the image forming methods.
[0061]
DETAILED DESCRIPTION OF THE INVENTION
The non-magnetic one-component toner of the present invention (hereinafter sometimes simply referred to as “toner”) is a color image forming method in which a plurality of toner images of different colors are sequentially transferred onto an intermediate transfer belt and transferred. The toner image is used in an image forming method in which the color toner image is transferred onto a transfer material. Such a toner of the present invention includes colored particles containing at least a binder resin, a colorant, and a release agent, and inorganic fine powder having a particle diameter of 100 to 1000 nm present on the surface of the colored particles. The aggregation degree G1 in a low-temperature and low-humidity environment is 10 to 80%.
[0062]
First, the cleaning property and transfer property, which are the problems of the present invention, will be considered. The present inventors consider the mechanism of poor cleaning properties in a low temperature and low humidity environment as follows.
[0063]
When a full-color image is printed using four colors (yellow, magenta, cyan, and black) toner in an image forming method using an intermediate transfer belt, the toner image of the toner that is first developed and transferred is the last toner Rotate 3 degrees on the intermediate transfer belt until developed and transferred. In other words, the toner image first transferred to the intermediate transfer belt comes into contact with the photoconductor three times. As a result, it can be said that the toner developed first among the four developing devices tends to cause retransfer to the photoreceptor most easily.
[0064]
The toner retransferred to the photoconductor is usually collected in a waste toner box by a cleaning mechanism. However, in a case where the amount of retransfer toner is large or in a low temperature and low humidity environment where the rigidity of the cleaning blade is high, the photoconductor is not cleaned as it is. Take me around. Among non-magnetic one-component development, particularly in the case of contact one-component development where the developing roller and the photosensitive member are in contact with each other, the retransfer toner rotating on the photosensitive member attracts the toner on the developing roller, and as a result. A toner image parallel to the paper discharge direction is transferred and fixed, resulting in poor cleaning.
[0065]
Further, the present inventors consider the mechanism of poor transferability and color misregistration under a low temperature and low humidity environment as follows. In the image forming method using the intermediate transfer belt, when the photoconductor and the intermediate transfer belt are always in contact with each other, when continuous printing is performed, the photoconductor and the intermediate transfer belt are consumed due to the friction between both members. Both surface roughness increases. At this time, in the case of an intermediate transfer belt with a rough surface, the transfer current flows non-uniformly, and the transfer current does not apply to the toner on the photoconductor faithfully, resulting in an image with poor uniformity, Color misregistration will occur.
[0066]
Therefore, as a result of intensive studies, the present inventors have determined that the particle size of the inorganic fine powder existing on the colored particle surface of the toner and the toner aggregation degree in a low-temperature and low-humidity environment are limited to a specific range. In an image forming method having a development process using a magnetic one-component development method and an intermediate transfer process using an intermediate transfer belt that is always in contact with the photoreceptor, retransfer to the photoreceptor with good cleaning properties on the intermediate transfer belt It was found that transferability can be improved.
[0067]
The particle size of the inorganic fine powder contained in the toner of the present invention is 100 to 1000 nm. The particle size of the inorganic fine powder is preferably 150 to 500 nm, more preferably 200 to 450 nm.
[0068]
In a system in which the photoconductor and the intermediate transfer belt are always in contact with each other, by setting the particle size of the inorganic fine powder present on the surface of the colored particles within the above range, the inorganic fine powder acts as a spacer for the colored particles, and continuous printing. In this case, toner deterioration due to embedding of the external additive in the colored particles is prevented or slowed. Toner that has no toner deterioration or hardly deteriorates is not easily affected by uneven transfer current even if the intermediate transfer belt is deteriorated by rubbing against the photoreceptor and the surface shape is rough. Therefore, it is considered that good transferability can be maintained. In particular, the above effect can be exhibited in a transfer unit in which a photoconductor and an intermediate transfer belt are integrally formed.
[0069]
When the particle size of the inorganic fine powder is less than 100 nm, toner deterioration is easily promoted, and the effect of the present invention is hardly exhibited in continuous printing. In addition, when the particle size of the inorganic fine powder exceeds 1000 nm, the adhesion of the inorganic fine powder to the toner is weakened, the inorganic fine powder is liberated in continuous printing, the key parts related to charging are contaminated, and the charging characteristics are It is easy to get worse.
[0070]
The particle size of the inorganic fine powder used in the present invention means the number average particle size obtained by observing the surface of the toner particles using an electron microscope.
Specifically, the toner in which the inorganic fine powder is adhered to the surface of the colored particles is photographed using an electron microscope, and the particle diameter of the inorganic fine powder is directly measured from the obtained image to obtain the number average particle diameter. At this time, the number of measurement samples of the inorganic fine powder is 20 or more. In addition, the judgment whether it is an inorganic fine powder is performed by conducting a qualitative analysis by electron beam excitation X-ray elemental analysis.
[0071]
Further, the presence of the inorganic fine powder on the surface of the colored particles reduces the fluidity of the toner and increases the degree of aggregation. A high degree of aggregation is expected to increase the void ratio between the toners. As a result, damage to the toner during continuous printing is reduced and the toner is less likely to deteriorate. In addition, the cleaning property of the toner retransferred on the photoreceptor is improved.
[0072]
Further, the aggregation degree G1 of the toner of the present invention in a low temperature and low humidity environment is 10 to 80%. This G1 is preferably 10 to 60%, more preferably 10 to 40%.
[0073]
By setting the aggregation degree G1 of the toner of the present invention in the above range, the effect of improving transferability due to the suppression of toner deterioration as described above is further improved.
[0074]
The toner of the present invention preferably has an aggregation degree difference ΔG represented by the following formula (1) of 0 to 30%, where G2 is the degree of aggregation after being left in a low temperature and low humidity environment. ΔG is more preferably 0 to 25%.
[0075]
[Equation 9]
ΔG = | G2-G1 | (1)
[0076]
Setting the cohesion degree difference ΔG in the above range is effective for maintaining initial transferability in continuous printing. When the agglomeration degree difference ΔG changes greatly, the toner is charged up, and the developing property and transferability are greatly different from the initial state, and transfer twice (transfer to the intermediate transfer belt and In a system for transferring to a transfer material, transferability is likely to deteriorate significantly.
[0077]
When the aggregation degree G1 of the toner is less than 10%, the void ratio between the toners is small and the toner damage in continuous printing is large, so that not only developability but also transferability is adversely affected. In addition, when the aggregation degree G1 exceeds 80% or the aggregation degree difference ΔG exceeds 30%, it is not suitable for this system for transferring twice, and the optimum transfer condition becomes very narrow, leading to environmental fluctuations. It becomes difficult to deal with.
[0078]
Further, in the image forming method of the present invention, the aggregation degree G1a of the toner in which the toner image is first transferred to the intermediate transfer belt and the aggregation degree G1b of the toner in which the toner image is finally transferred to the intermediate transfer belt are G1a. It is preferable that the relationship> G1b is satisfied. This is because when the order of development and primary transfer is earlier, the number of times of contact with the photosensitive member on the intermediate transfer belt is increased with the rotation of the intermediate transfer belt, so that retransfer to the photosensitive member becomes easier. . By making G1a> G1b, the cleaning property can be improved.
[0079]
When G1a> G1b is not satisfied, cleaning failure of the first transferred toner image when full-color images are continuously printed is likely to occur, and this is particularly remarkable in a low temperature and low humidity environment.
[0080]
The average circularity in the number-based equivalent circle diameter-circularity scattergram measured by the toner flow-type particle image measuring apparatus of the present invention is 0.950 to 0.999, and the circularity standard deviation is 0. Preferably less than 0.038. More preferably, the average circularity is 0.970 to 0.995, and the circularity standard deviation is 0.015 to 0.035.
[0081]
When the average circularity is less than 0.950, the toner transfer efficiency during continuous printing is markedly deteriorated due to the irregular shape of the toner, and a large amount of residual toner remains on the photoconductor. It becomes easy for defective cleaning to occur. On the other hand, when the average circularity exceeds 0.999, reproducibility and yield are remarkably deteriorated in production, leading to an increase in cost.
[0082]
Further, when the circularity standard deviation exceeds 0.04, the toner shape distribution is widened, so that uniform transfer cannot be performed, and the same tendency as when the average circularity is less than 0.950 is shown.
[0083]
Furthermore, the toner of the present invention preferably has a weight average particle diameter of 5 to 9.5 μm. More preferably, it is 6.0-9.0 micrometers.
[0084]
When the weight average particle diameter of the toner is less than 5 μm, the degree of aggregation tends to increase after standing in a low-temperature and low-humidity environment, and transferability deteriorates. Further, when the weight average particle diameter exceeds 9.5 μm, color misregistration tends to occur when performing the transfer twice.
[0085]
In the present invention, by controlling the average circularity, circularity standard deviation, and weight average particle diameter of the toner within the above ranges, the effect of suppressing toner deterioration by adjusting the particle diameter of the inorganic fine powder is further improved.
[0086]
Hereinafter, a specific method for measuring the physical properties of the toner of the present invention will be described.
The measurement of the aggregation degree of the toner of the present invention will be described. Assume that the degree of aggregation under low temperature and low humidity before standing is G1, and the degree of aggregation after standing under low temperature and low humidity is G2. The standing environment is a low temperature and low humidity environment (15 ° C./10% RH (relative humidity)), and the measurement environment is a room temperature and normal humidity environment (25 ° C./60% RH), and the measurement is performed within 1 minute. Details are shown below.
[0087]
Using a powder tester (made by Hosokawa Micron Corporation), a sieve of 400 mesh (aperture 37 μm), 200 mesh (aperture 74 μm), 100 mesh (aperture 147 μm) is overlapped in the order of narrow aperture on the vibration table, that is, , 100 mesh is placed in the order of 400 mesh, 200 mesh, and 100 mesh so that 100 mesh is the highest. Place the sample that has been shaken 50 times on the set 100 mesh sieve in advance, adjust the input voltage to the shaking table to 15 V, and adjust the shaking table amplitude to be in the range of 60 to 90 μm. Apply vibration for 15 seconds. Thereafter, the mass of the sample remaining on each sieve is measured, and the degree of aggregation G1 is obtained based on the following formula. The smaller the cohesion value, the higher the fluidity of the toner.
[0088]
[Expression 10]

[0089]
The degree of aggregation G2 after standing is measured in the same manner, and the degree of aggregation difference ΔG is obtained by the following equation.
[0090]
## EQU11 ##
ΔG = | G2-G1 |
[0091]
Note that the standing time in a low-temperature and low-humidity environment when measuring G1 is 10 hours, and the leaving time when measuring G2 is 48 hours longer than the leaving time of G1, and after the standing time, the aggregation degree G1 G2 is measured.
[0092]
In the present invention, the circularity of the toner and the frequency distribution thereof are used as a simple method for quantitatively expressing the shape of the toner particles. In the present invention, the flow type particle image measuring device FPIA-1000 ( The measurement was performed using Toa Medical Electronics Co., Ltd., and the following formula was used.
[0093]
[Expression 12]

[0094]
Here, the “particle projected area” is the area of the binarized toner particle image, and the “peripheral length of the particle projected image” is the length of the contour line obtained by connecting the edge points of the toner particle image. Define.
[0095]
The circularity in the present invention is an index indicating the degree of unevenness of toner particles, and is 1.000 when the toner particles are perfectly spherical, and the circularity becomes smaller as the surface shape becomes more complicated. The average circularity Cm and the circularity standard deviation SDc, which mean the average value of the frequency distribution of circularity, are ci and circularity (center value) at the division point i of the particle size distribution, and frequency is f _ci Then, it is calculated from the following equation.
[0096]
[Formula 13]

[0097]
[Expression 14]

[0098]
As a specific measuring method, 10 ml of ion-exchanged water from which impure solids have been previously removed is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant therein, and then further measurement is performed. Add 0.02 g of sample and disperse uniformly. As a dispersion means, an ultrasonic disperser UH-50 type (manufactured by SMT Co., Ltd.) equipped with a 5 mmφ titanium alloy chip as a vibrator is used, and subjected to a dispersion treatment for 5 minutes to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of this dispersion may not become 40 degreeC or more.
[0099]
To measure the shape of the toner particles, a flow type particle image measuring device “FPIA-1000” (manufactured by Toa Medical Electronics Co., Ltd.) is used, and the dispersion is performed so that the toner particle concentration at the time of measurement is 3000 to 10,000 particles / μl. The liquid concentration is readjusted, 1000 or more toner particles are measured, and the number based on the equivalent circle diameter distribution and the ratio (number%) of particles having a prescribed equivalent circle diameter are measured. As shown in Table 1, the results (frequency% and cumulative%) can be obtained by dividing the particle size range of 0.06 to 400 μm into 226 channels (divided into 30 channels per octave). After the measurement, the circularity frequency distribution of the toner particles is obtained using this data.
[0100]
[Table 1]

[0101]
The toner particle size of the present invention is measured by a Coulter counter, and for example, Coulter Counter TA-II or Coulter Multisizer II (manufactured by Coulter Co., Ltd.) is used as a measuring device for toner particles and toner average particle size by the Coulter counter method. . As the electrolyte, first grade sodium chloride is used to prepare an approximately 1% NaCl aqueous solution. For example, ISOTON-II (manufactured by Coulter) can be used. As a measurement method, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion process for about 1 to 3 minutes with an ultrasonic disperser, and the volume and number of toners are measured with the measuring apparatus using a 100 μm aperture as the aperture. Calculate the distribution. Then, a weight average particle diameter (D4) based on the mass of the toner is obtained.
[0102]
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 .35 to less than 8.00 μm; 8.00 to less than 10.08 μm; 10.08 to less than 12.70 μm; 12.70 to less than 16.00 μm; 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm.
[0103]
Next, the toner of the present invention will be described in detail.
[0104]
The toner binder resin used when the toner of the present invention is produced by a pulverization method includes polystyrene; a styrene-substituted monopolymer such as poly-p-chlorostyrene and polyvinyltoluene; and styrene-p-chlorostyrene. Polymer, 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 ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile -Styrene such as indene copolymer Copolymer, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resins; polyester resins; polyamide resin; furan resins, epoxy resins, xylene resins. These resins are used alone or in combination.
[0105]
As comonomer for the styrene monomer of the styrene copolymer, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, doditer acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methacrylic acid Monocarboxylic acid having a double bond such as methyl acid, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide or its substitute; maleic acid, butyl maleate, methyl maleate, maleate Dicarboxylic acids having a double bond such as dimethyl acid and its substitutes; vinyl esters such as vinyl chloride, vinyl acetate and vinyl benzoate; ethylene-based olefins such as ethylene, propylene and butylene; Sulfonyl methyl ketone, vinyl ketones such as vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether, vinyl ethers such as vinyl isobutyl ether. These vinyl monomers are used alone or in combination of two or more.
[0106]
The styrene copolymer is preferably crosslinked with a crosslinking agent such as divinylbenzene in order to widen the fixing temperature range of the toner and improve the offset resistance.
[0107]
As the polymerizable monomer used when the toner of the present invention is produced by the polymerization method, a vinyl polymerizable monomer capable of radical polymerization is used. As the vinyl polymerizable monomer, a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used. Monofunctional polymerizable monomers include styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butyl. Styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p A styrene derivative such as phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl accelerator Acrylic polymer such as n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate Mer: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n -Octyl methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl meta Methacrylic polymerizable monomers such as relate and dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate and vinyl formate; vinylmethyl And vinyl ethers such as ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.
[0108]
As polyfunctional polymerizable monomers, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol Diacrylate, polypropylene glycol diacrylate, 2,2′-bis (4- (acryloxydiethoxy) phenyl) propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol Dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol Dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis (4- (methacryloxy-diethoxy) phenyl) propane, Examples include 2,2′-bis (4- (methacryloxy / polyethoxy) phenyl) propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, and divinyl ether.
[0109]
In the present invention, the above monofunctional polymerizable monomers are used alone or in combination of two or more, or the above monofunctional polymerizable monomers and polyfunctional polymerizable monomers are used in combination. . The polyfunctional polymerizable monomer can also be used as a crosslinking agent.
[0110]
As the polymerization initiator used in the polymerization of the polymerizable monomer described above, an oil-soluble initiator and / or a water-soluble initiator is used. For example, as the oil-soluble initiator, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile) Azo compounds such as 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile; acetylcyclohexylsulfonyl peroxide, diisopropylperoxycarbonate, decanoyl peroxide, lauroyl peroxide, stearoyl peroxide, propionyl Peroxide, acetyl peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, t-butylperoxyisobutyrate, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicumyl peroxide Examples thereof include peroxide-based initiators such as side, t-butyl hydroperoxide, di-t-butyl peroxide and cumene hydroperoxide.
[0111]
Water-soluble initiators include ammonium persulfate, potassium persulfate, 2,2′-azobis (N, N′-dimethyleneisobutyroamidine) hydrochloride, 2,2′-azobis (2-aminodinopropane) hydrochloric acid Salts, sodium azobis (isobutylamidine) hydrochloride, sodium 2,2′-azobisisobutyronitrile sulfonate, ferrous sulfate or hydrogen peroxide.
[0112]
In the present invention, in order to control the degree of polymerization of the polymerizable monomer, a known chain transfer agent, polymerization inhibitor or the like can be further added and used.
[0113]
As the crosslinking agent used in the toner of the present invention, a compound having two or more polymerizable double bonds is used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate; divinylaniline; And divinyl compounds such as divinyl ether, divinyl sulfide, and divinyl sulfone; and compounds having three or more vinyl groups. These are used alone or as a mixture.
[0114]
When the toner molecular weight of the present invention is less than 10,000, the external additive on the surface of the colored particles at the time of continuous printing tends to be buried by durable use, and the transferability is likely to be lowered, as compared with the toner in the optimum range. Furthermore, the high temperature offset property is also poor. When the mass average molecular weight exceeds 1500,000, the low temperature offset is weak, and particularly, the fixability of the secondary color of the cardboard is weak.
[0115]
The molecular weight and molecular weight distribution GPC (gel permeation chromatography) of the toner of the present invention are measured by the following method. The column is stabilized in a 40 ° C. heat chamber, and THF (tetrahydrofuran) as a solvent is allowed to flow through the column at this temperature at a flow rate of 1 ml per minute, and about 100 μl of a THF sample solution is injected and measured. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of 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 10 ² -10 ⁷ It is appropriate to use a standard polystyrene sample of about 10 points.
[0116]
An RI (refractive index) detector is used as the detector. As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, a combination of shodex GPC KF-801, 802, 803, 804, 805, 806, 807, 800P manufactured by Showa Denko KK A combination of TSKgel G1000H (HXL), G2000H (HXL), G3000H (HXL), G4000H (HXL), G5000H (HXL), G6000H (HXL), G7000H (HXL), and TSKguardcolumn is given.
[0117]
The sample is prepared as follows. Place the sample in tetrahydrofuran (THF) and let it stand for several hours, then shake well and mix well with THF (until the sample is no longer united), and let stand for more than 12 hours. At this time, the standing time in THF is set to be 24 hours or longer. Thereafter, a sample processing filter (pore size 0.45 to 0.5 μm, for example, Mysori Disc H-25-5 manufactured by Tosoh Corporation, Excro Disc 25CR manufactured by Gelman Science Japan Co., Ltd., etc.) can be used. A sample of GPC is used. The sample concentration is adjusted so that the resin component is 0.5 to 5 mg / ml.
[0118]
Examples of the release agent used in the toner of the present invention include candelilla wax, carnauba wax, rice wax, waxes, vegetable waxes such as jojoba oil, animal waxes such as beeswax, lanolin and whale wax, and montan. Mineral wax such as wax, ozokerite and ceresin, paraffin wax, microcrystalline wax, petroleum wax such as petrolactam, synthetic hydrocarbon such as polyolefin wax, fisher tropish wax; amide wax; ketone wax; ester wax Higher fatty acids; higher fatty acid metal salts; long chain alkyl alcohols. If necessary, these may be grafted, blocked or distilled.
[0119]
In order to further manifest the effects of the present invention, among the above release agents, carnauba wax, rice wax, montan wax, paraffin wax, microcrystalline wax, polyolefin wax, Fischer tropish wax, ester wax, amide wax, Ketone waxes are preferred. Carnauba wax, rice wax, paraffin wax, polyolefin wax, Fischer tropish wax, ester wax, amide wax, and ketone wax are more preferable.
[0120]
Examples of ester wax, amide wax, and ketone wax are listed below, but other types may be used.
[0121]
Examples of the ester wax include those represented by the following general formula.
[0122]
[Chemical 1]

(Wherein, a and b are integers of 0 to 4, and a + b is 4. R ₁ And R ₂ Is an organic group having 1 to 40 carbon atoms, R ₁ And R ₂ And the carbon number difference is 3 or more. m and n are integers of 0 to 40, and m and n are not 0 at the same time. )
[0123]
[Chemical 2]

(In the formula, a and b are integers of 0 to 3, and a + b is 1 to 3. R ₁ And R ₂ Is an organic group having 1 to 40 carbon atoms. R _Three Is a hydrogen atom or an organic group having 1 or more carbon atoms. k is an integer of 1 to 3, and a + b + k = 4. m and n are integers of 0 to 40, and m and n are not 0 at the same time. )
[0124]
[Chemical 3]

(Wherein R ₁ And R _Three Is an organic group having 1 to 40 carbon atoms, R ₁ And R _Three May be the same or different. R ₂ Represents an organic group having 1 to 40 carbon atoms. )
[0125]
[Formula 4]

(Wherein R ₁ And R _Three Is an organic group having 1 to 40 carbon atoms, R ₁ And R _Three May be the same or different. R ₂ Represents an organic group having 1 to 40 carbon atoms. )
[0126]
[Chemical formula 5]

(In the formula, a is an integer of 0 to 4, b is an integer of 1 to 4, and a + b is 4. ₁ Is an organic group having 1 to 40 carbon atoms. m and n are integers of 0 to 40, and m and n are not 0 at the same time).
[0127]
As an amide wax, what consists of a compound represented by following formula (VI) is preferable.
[0128]
[Chemical 6]

(Wherein R ₁ , R ₂ Is an organic group having 1 to 45 carbon atoms, R ₁ And R ₂ May be the same or different, and R ₁ And R ₂ May have an unsaturated group. )
[0129]
As the ketone wax, those composed of a compound represented by the following formula (VII) are preferable.
[0130]
[Chemical 7]

(Wherein R ₁ , R ₂ Represents an organic group having 1 to 40 carbon atoms. )
[0131]
The endothermic peak value in the DSC endothermic curve of the release agent used in the present invention is measured according to ASTM D3418-82. The endothermic peak value of the release agent used in the present invention is preferably 50 to 100 ° C. In addition, the tangential separation temperature of the DSC curve is more preferably 40 ° C. or higher.
[0132]
If the endothermic peak value is less than 50 ° C., the self-cohesive force of the release agent is weak, so that the release agent is present more than necessary on the surface of the colored particles during the production of the colored particles. In the component development system, the charging roller and the photosensitive member are easily contaminated, and transferability is deteriorated. In addition, since the blocking property is poor, toner packing is likely to occur in the developing machine during continuous printing.
[0133]
On the other hand, when the endothermic peak exceeds 120 ° C., the release agent is difficult to seep out instantly at the time of fixing, and the fixing property at a low temperature and the fixing property of secondary colors (red, green, blue) having a large amount of toner development are obtained. It gets worse. Further, when the colored particles are produced by the direct polymerization method, the solubility of the release agent in the polymerizable monomer composition is lowered, and the colored particles of the polymerizable monomer composition in the aqueous medium are reduced. Not only does the release agent precipitate during the granulation of diameter-sized droplets, making granulation difficult, but also increasing the amount of deposits in the reaction kettle.
[0134]
As a molecular weight of a mold release agent, a thing with a mass mean molecular weight (Mw) of 300-1,500 is preferable.
[0135]
When the mass average molecular weight is less than 300, the same tendency as when the endothermic peak value is less than 50 ° C. is exhibited. If it exceeds 1500, the low-temperature fixability deteriorates, and OHT transparency and haze are deteriorated when a full-color image is output. The mass average molecule is particularly preferably in the range of 400 to 1,250.
[0136]
The molecular weight of the release agent is measured by GPC under the following conditions.
(GPC measurement conditions)
Apparatus: GPC-150C (manufactured by Waters)
Column: GMH-MT 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 polystyrene 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.
[0137]
The release agent is preferably used in an amount of 3 to 30 parts by weight, and more preferably 5 to 20 parts by weight, based on 100 parts by weight of the binder resin, when the colored particles are produced by the melt-kneading and pulverization method. When using a polymerizable monomer composition and producing | generating colored particles directly in an aqueous medium, 3-30 mass parts with respect to 100 mass parts of polymerizable monomers, More preferably, it is 5-5 mass parts. 20 parts by mass is blended, and as a result, 5 to 30 parts by mass of the release agent per 100 parts by mass of the binder resin produced from the polymerizable monomer, more preferably 5 to 20 parts by mass is contained in the colored particles. Is good.
[0138]
When the content of the release agent is less than 3 parts by mass with respect to 100 parts by mass of the binder resin, the amount of inorganic fine powder added to adjust the toner to the above-described aggregation degree increases, and as a result, continuous printing is performed. It will lead to time key parts contamination. When the amount of the release agent added exceeds 30 parts by mass, it is difficult to obtain the toner of the present invention having the above aggregation degree.
[0139]
Compared to the dry toner manufacturing method using the melt-kneading pulverization method, in the toner manufacturing method using the polymerization method, it is easy to encapsulate a large amount of the release agent with the polar resin inside the colored particles, so that it is generally possible to use a large amount of the release agent. This is particularly effective for preventing the offset during fixing.
[0140]
An example of the colorant contained in the toner of the present invention is given, but other colorants may be used.
[0141]
As the black colorant, carbon black, which is toned to black using the yellow / magenta / cyan colorant shown below, is used.
[0142]
As the yellow colorant, the following pigments and / or dyes can be preferably used. As the pigment, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complex methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 3, 7, 10, 12, 13, 14, 15, 17, 23, 24, 60, 62, 74, 75, 83, 93, 94, 95, 99, 100, 101, 104, 108, 109, 110 111, 117, 123, 128, 129, 138, 139, 147, 148, 150, 166, 168, 169, 177, 179, 180, 181, 183, 185, 191: 1, 191, 192, 193, 199 Etc. are preferably used.
[0143]
Examples of the dye include C.I. I. solvent Yellow 33, 56, 79, 82, 93, 112, 162, 163, C.I. I. Disperse Yellow 42, 64, 201, 211 etc. are mentioned.
[0144]
As the magenta colorant, 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, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254, C.I. I. Pigment Bio Red 19 is particularly preferable.
[0145]
As the cyan colorant, phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, 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 are particularly preferably used.
[0146]
These colorants can be used alone or in combination and further in the form of a solid solution. The colorant used in the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. The added amount of the colorant is 1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.
[0147]
The toner of the present invention may be used in combination with a charge control agent. The following substances are used for controlling the toner to be negatively charged. Although an example is given, things other than these may be used.
[0148]
For example, organometallic compounds and chelate compounds are effective, and there are monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids, and dicarboxylic acid-based metal compounds. Other examples include aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.
[0149]
Furthermore, urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarene, resin charge control agents, and the like can be given.
[0150]
The following substances are used to control the toner to be positively charged. An example is given, but other examples may be used.
[0151]
Modified products of nigrosine, such as nigrosine and fatty acid metal salts, guanidine compounds, imidazole compounds, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate; analogs thereof Onium salts such as phosphonium salts and lake pigments thereof; triphenylmethane dyes and lake pigments thereof (as rake agents include phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, Gallic acid, ferricyanide, ferrocyanide, etc.); metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; Over DOO, dioctyl tin borate, diorgano tin borate such as dicyclohexyl tin borate, resin charge control agent and the like. These can be used alone or in combination of two or more.
[0152]
The charge control agent is used in an amount of 0.01 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the binder resin.
[0153]
When the toner of the present invention is produced by a polymerization method, a condensation resin may be added. An example is given, but other examples may be used.
[0154]
Examples of the condensation resin used in the present invention include polyester, polycarbonate, phenol resin, epoxy resin, polyamide, and cellulose. More preferably, polyester is desired due to the variety of materials. The condensation resin is used in an amount of 0.01 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the binder resin.
[0155]
The inorganic fine powder used in the present invention is composed of titanium oxide (anatase type, rutile type, non-crystalline), aluminum oxide, metal acid compounds such as strontium titanate, cerium oxide, magnesium oxide and mixtures thereof; nitriding such as silicon nitride Examples thereof include: carbides such as silicon carbide; metal salts such as calcium sulfate, barium sulfate and calcium carbonate; carbon fluoride, fine powder of silicon compound (silica fine powder, silicone resin fine powder) and the like. In some cases, organic fine powder may be further added.
[0156]
The inorganic fine powder may or may not be hydrophobized. When hydrophobizing, either a wet method or a dry method may be used.
[0157]
Examples of the hydrophobizing agent include silane coupling agents, titanium coupling agents, aluminate coupling agents, zircoaluminum coupling agents, and silicone oils.
[0158]
Metal oxide compounds such as titanium oxide (anatase type, rutile type, non-crystalline), aluminum oxide, strontium titanate, cerium oxide, magnesium oxide; nitrides such as silicon nitride; carbides such as silicon carbide; calcium sulfate, barium sulfate In regard to metal salts such as calcium carbonate; carbon fluoride and the like, a silane coupling agent is particularly preferably used as the hydrophobizing agent.
[0159]
In the present invention, the inorganic fine powder is preferably used by mixing 0.01 to 5 parts by mass, more preferably 0.02 to 4 parts by mass with the colored particles with respect to 100 parts by mass of the colored particles.
[0160]
When the addition amount of the inorganic fine powder is less than 0.01 part by mass, the fluidity imparting ability to the colored particles is not sufficient, and when the amount exceeds 5 parts by mass, the external additive released from the colored particles is removed from the developing blade. In other words, the developing roller and the photosensitive member are contaminated to cause image defects.
[0161]
An example of the toner manufacturing method of the present invention is shown below.
When the toner of the present invention is a toner produced by a pulverization method, at least a binder resin and a colorant are kneaded and uniformly dispersed using a pressure kneader, an extruder, a media disperser or the like. Then, it is made to collide with a target under a mechanical or jet stream to finely pulverize it to a desired toner particle size, and after passing through a classification step, colored particles having a desired circularity are obtained using mechanical means. Further, the finely pulverized colored particles may be subjected to a wet or dry thermal spheronization treatment. The colored particles thus obtained are mixed and adhered to the inorganic fine powder using a known method to obtain the toner of the present invention.
[0162]
When the toner of the present invention is a toner produced by a polymerization method, there is no particular limitation, but Japanese Patent Publication No. 36-10231, Japanese Patent Publication No. 59-53856, Japanese Patent Publication No. 59-61842. A method for directly producing colored particles by using the suspension polymerization method described in the publication No. 1; a soap-free method in which colored particles are produced by direct polymerization in the presence of a water-soluble polymerization initiator that is soluble in a monomer The production of colored particles by an emulsion polymerization method typified by a polymerization method can be mentioned. In addition, production by an interfacial polymerization method such as a microcapsule production method, an in-site polymerization method, a coacervation method, or the like is also included. Furthermore, as disclosed in JP-A-62-106473 and JP-A-63-186253, an interface association method for aggregating at least one kind of fine particles to obtain a desired particle size, etc. It is done.
[0163]
Among the above polymerization methods, the suspension polymerization method is particularly preferable because colored particles having a small particle diameter can be easily obtained. Further, a seed polymerization method in which a monomer is further adsorbed to the polymer particles once obtained and then polymerized using a polymerization initiator can also be suitably used in the present invention. At this time, it is also possible to use a compound having polarity dispersed or dissolved in the monomer to be adsorbed.
[0164]
When suspension polymerization is performed, it is usually preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer composition. Examples of the dispersant used include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate as inorganic oxides, Examples include calcium sulfate, barium sulfate, bentonite, silica, alumina, and sodium dodecyl sulfate. As the organic compound, for example, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch and the like are used.
[0165]
These dispersants are preferably used in an amount of 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer. You may use 0.001-0.1 mass% surfactant in order to refine | miniaturize these dispersing agents. Specifically, commercially available nonionic, anionic and cationic surfactants can be used. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate and the like are preferably used.
[0166]
In the case of using the polymerization method, similarly to the case of using the pulverization method, the toner of the present invention can be obtained by mixing the obtained colored particles with an inorganic fine powder using a known method.
[0167]
The image forming method of the present invention using the toner of the present invention will be described below.
[0168]
FIG. 1 is a schematic cross-sectional view of an image forming apparatus suitably used in the image forming method of the present invention. First, the intermediate transfer belt used in the image forming method of the present invention will be described.
[0169]
An intermediate transfer belt as an intermediate transfer member used in the present invention has an endless belt shape as shown in FIG. In the intermediate transfer belt, it is necessary to consider the smoothness of the surface. If the surface roughness Ra exceeds 1 μm, the transfer performance is affected and the reproducibility of halftone image roughness and fine lines may be reduced. . In addition, since the charge applied to the secondary transfer residual toner can be uneven, the transfer residual toner does not sufficiently return to the photoreceptor, and the intermediate transfer belt cleaning defect that the previous image remains on the next printed image during continuous printing may also occur. appear.
[0170]
The thickness of the intermediate transfer belt is preferably in the range of 40 to 300 μm. If the thickness is less than 40 μm, the molding stability of the intermediate transfer belt is insufficient, thickness unevenness is likely to occur, the durability is insufficient, and the belt may be broken or cracked. On the other hand, if the wall thickness exceeds 300 μm, the material increases and the cost increases, and the difference in the peripheral speed between the inner and outer surfaces of the stretched shaft of a printer or the like increases, causing problems such as image scattering due to contraction of the outer surface. However, there is a problem that the bending torque is lowered and the rigidity of the belt becomes too high to increase the driving torque, resulting in an increase in the size of the main body and an increase in cost.
[0171]
The intermediate transfer belt used in the present invention includes an elastic layer mainly composed of a resin and a coating layer formed on the elastic layer as necessary.
[0172]
When the elastic layer is made of synthetic rubber, the covering layer is often provided for the purpose of adjusting resistance and extending the belt life. Examples of the material used for the coating layer include a thermoplastic resin.
[0173]
Examples of the material for the elastic layer include synthetic rubber and thermoplastic resin. Examples of the synthetic rubber include styrene-butadiene rubber, high styrene rubber, butadiene rubber, isoprene rubber, ethylene-propylene copolymer, nitrile butadiene rubber (NBR), chloroprene rubber, butyl rubber, silicone rubber, fluorine rubber, nitrile rubber, Examples thereof include urethane rubber, acrylic rubber, epichlorohydrin rubber, norbornene rubber, and elastomer.
[0174]
Examples of the thermoplastic resin include ethylene-vinyl alcohol copolymer (EVOH), polyethylene, polypropylene, polystyrene, acrylonitrile / butadiene / styrene resin (ABS resin), polyacetal, polycarbonate, polyester (polyethylene terephthalate, polybutylene terephthalate, etc.) , Methacrylic resin, aliphatic or non-aliphatic polyamide, modified polyphenylene ether, polyphenylene sulfide, polyarylate, polysulfone, polyethersulfone, polyamideimide, thermoplastic polyimide, polyetherimide, polyether etherketone, polyetherketone , Polyether nitrile, aliphatic polyketone, polymethylpentene, fluororesin (polyvinylidene fluoride, ethylene-4-fluoride 1 type or 2 types or more selected from a len copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, fluorinated ethylene propylene copolymer, tetrafluoroethylene, etc.) In addition, it is not limited to said material, such as a well-known thermoplastic resin (for example, polymer alloy).
[0175]
In addition, the resistance value of the intermediate transfer belt used in the present invention needs to be adjusted. The range of volume resistivity of the intermediate transfer belt from which a good image can be obtained is 1 × 10 ⁶ ~ 8x10 ¹³ Ω · cm. Volume resistivity is 1 × 10 ⁶ If it is less than Ω · cm, the resistance is too low to obtain a sufficient transfer electric field, and image omission and roughness are likely to occur. On the other hand, the volume resistivity is 8 × 10 ¹³ If it is higher than Ω · cm, it is necessary to increase the transfer voltage, which causes an increase in the size and cost of the power source, which is not preferable. In order to control the resistance, a conductive agent can be added in a timely manner within a range in which the remarkable effects of the present invention can be obtained.
[0176]
Examples of the conductive agent include various conductive inorganic particles and carbon black, an ionic conductive agent, a conductive resin, and a conductive particle-dispersed resin. Specifically, as the conductive inorganic particles, particles of titanium oxide, tin oxide, barium sulfate, aluminum oxide, strontium titanate, magnesium oxide, silicon oxide, silicon carbide, silicon nitride, etc., as necessary, tin oxide, antimony oxide And those subjected to surface treatment with carbon or the like. These shapes may be any shape such as a spherical shape, a fiber shape, a plate shape, and an indeterminate shape. Examples of the conductive resin include quaternary ammonium salt-containing polymethyl methacrylate, polyvinyl aniline, polyvinyl pyrrole, polydiacetylene, and polyethyleneimine. Examples of the conductive particle-dispersed resin include those obtained by dispersing conductive particles such as carbon, aluminum, and nickel in resins such as urethane, polyester, vinyl acetate-vinyl chloride copolymer, and polymethyl methacrylate.
[0177]
Examples of the ionic conductive agent include the following. For example, lauryltrimethylammonium, stearyltrimethylammonium, octadodecyltrimethylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium, dechlorinated fatty acid / dimethylethylammonium salt perchlorate, chlorate, borofluoride, sulfate , Cationic surfactants such as quaternary ammonium salts such as ethosulphate salts, benzyl halide salts (benzyl bromide salts, benzyl chloride salts, etc.); aliphatic sulfonates, higher alcohol sulfates, higher Anionic surfactants such as alcohol ethylene oxide addition sulfate ester salt, higher alcohol phosphate ester salt, higher alcohol ethylene oxide addition phosphate ester salt; amphoteric surfactants such as various betaines; higher alcohol ester Alkylene oxide, polyethylene glycol fatty acid esters, polyhydric antistatic agents such as nonionic antistatic agents such as alcohol fatty acid esters; LiCF _Three SO _Three , NaClO _Four LiClO _Four , LiAsF ₆ , LiBF _Four Li, such as NaSCN, KSCN, NaCl ⁺ , Na ⁺ , K ⁺ Group 1 metal salts of the periodic table such as NH ⁴⁺ Electrolytes such as salts of Ca (ClO) _Four ) ₂ Ca ²⁺ , Ba ²⁺ A metal salt of Group 2 of the periodic table and the like and those antistatic agents having at least one group having an active hydrogen that reacts with an isocyanate such as a hydroxyl group, a carboxyl group, or a primary or secondary amine group Can be mentioned.
[0178]
Furthermore, the above-described compounds and complexes of polyhydric alcohols such as 1,4-butanediol, ethylene glycol, polyethylene glycol, propylene glycol, polyethylene glycol and derivatives thereof, or ethylene glycol monomethyl ether, ethylene glycol monoethyl ether And a monool complex such as, and one or two or more types selected from these can be used. However, other known ionic conductive agents can also be used and are not limited to the above materials.
[0179]
As a method of mixing and dispersing necessary constituent materials in the resin material constituting the elastic layer, known methods can be appropriately used. When the resin material is an elastomer, devices such as a roll mill, a kneader, and a Banbury mixer are used. When the resin material is in a liquid state, it can be dispersed using a ball mill, a bead mill, a homogenizer, a paint shaker, a nanomizer, or the like. it can.
[0180]
The intermediate transfer belt used in the present invention is manufactured, for example, by the following method. A method of extruding a resin material into a tube shape to obtain a single layer seamless belt intermediate transfer body; extruding an elastic layer, forming a coating layer by spray coating or dip coating after vulcanization, etc. Or a method of forming a single layer or two or more layers of a belt-shaped intermediate transfer member by centrifugal molding.
[0181]
Next, the image forming method of the present invention will be described.
[0182]
The image forming method of the present invention is a method of forming an image using the non-magnetic one-component toner of the present invention,
(I) A step of visualizing the electrostatic latent image formed on the photosensitive member with two or more non-magnetic one-component toners having different colors to form toner images of the respective colors, and electrostatic images corresponding to the respective colors. A development step of sequentially visualizing the latent image with non-magnetic one-component toner of each color;
(Ii) Intermediate transfer for forming a color toner image on the intermediate transfer member by sequentially superimposing and transferring the toner images of the respective colors visualized in the developing step on an intermediate transfer belt always in contact with the photosensitive member Process,
(Iii) at least a transfer step of transferring the color toner image on the intermediate transfer member onto a transfer material.
[0183]
FIG. 1 shows a color image forming apparatus (copier or laser beam printer) using an electrophotographic process. In FIG. 1, the intermediate transfer belt and the photosensitive member are in contact with each other at all times to constitute a transfer unit (intermediate transfer belt-photosensitive member integrated cartridge). Reference numeral 1 denotes a rotating drum type photoreceptor (hereinafter referred to as a photoreceptor) that is repeatedly used as a first image carrier, and is driven to rotate in a direction indicated by an arrow at a predetermined peripheral speed (process speed).
[0184]
The photosensitive member 1 is uniformly charged to a predetermined polarity and potential by the primary charger 2 during the rotation process (charging step). The power supply 32 of the primary charger applies the AC voltage superimposed on the DC voltage, but only the DC voltage may be applied. Next, exposure means (not shown) (color separation / imaging exposure optical system for color original images, scanning exposure system using a laser scanner that outputs a laser beam modulated in accordance with time-series electric digital pixel signals of image information, etc.) By receiving the image exposure 3 by the above, an electrostatic latent image corresponding to a first color component image (for example, a yellow color component image) of the target color image is formed (latent image forming step).
[0185]
Next, the electrostatic latent image is developed with yellow toner Y as the first color by the first developing device (yellow color developing device 41) (developing process). The developing method used at this time is preferably a contact one-component developing method. At this time, the developing units of the second to fourth developing units (magenta developing unit 42, cyan developing unit 43, and black developing unit 44) are turned off and do not act on the photosensitive member 1. The first color yellow toner image is not affected by the second to fourth developing units.
[0186]
The intermediate transfer belt 5 is rotationally driven in the clockwise direction in the drawing at the same peripheral speed as that of the photoreceptor 1. The yellow toner image of the first color formed and supported on the photoreceptor 1 is applied from the primary transfer roller 6 to the intermediate transfer belt 5 in the process of passing through the nip portion between the photoreceptor 1 and the intermediate transfer belt 5. By the electric field formed by the primary transfer bias, primary transfer is sequentially performed on the outer peripheral surface of the intermediate transfer belt 5 (intermediate transfer process).
[0187]
The surface of the photoreceptor 1 after the transfer of the first color yellow toner image corresponding to the intermediate transfer belt 5 is cleaned by the cleaning device 13 (cleaning step).
[0188]
Thereafter, the surface of the photoconductor 1 is again charged by the primary charger, and electrostatic latent images corresponding to the second color magenta toner image, the third color cyan toner image, and the fourth color black toner image are formed on the photoconductor 1. And are sequentially developed with the toner of each color. The toner images formed on the photoreceptor 1 in the development process are sequentially superimposed and transferred onto the intermediate transfer belt 5, and a composite color toner image corresponding to the target color image is formed on the intermediate transfer belt 5.
[0189]
Reference numeral 7 denotes a secondary transfer roller, which is supported in parallel with the secondary transfer counter roller 8 and is disposed in a state in which it can be separated from the outer surface of the intermediate transfer belt 5. That is, in the primary transfer process of the first to fourth color toner images from the photosensitive member 1 to the intermediate transfer belt 5, the secondary transfer roller 7 can be separated from the intermediate transfer belt 5.
[0190]
A primary transfer bias for sequentially superimposing and transferring the first to fourth color toner images from the photoreceptor 1 to the intermediate transfer belt 5 is applied from a bias power source 30 with a polarity (+) opposite to that of the toner. The applied voltage is, for example, in the range of +100 V to 2 kV.
[0191]
The transfer (transfer process) of the composite color toner image transferred onto the intermediate transfer belt 5 to the transfer material P that is the second image carrier is performed as follows. The secondary transfer roller 7 is brought into contact with the intermediate transfer belt 5, and the transfer material P passes from the paper feed roller 11 through the transfer material guide 10 to the contact nip between the intermediate transfer belt 5 and the secondary transfer roller 7. The sheet is fed at a predetermined timing, and a secondary transfer bias is applied from the power source 31 to the secondary transfer roller 7. By this secondary transfer bias, the composite color toner image is secondarily transferred from the intermediate transfer belt 5 to the transfer material P as the second image carrier. The transfer material P that has received the transfer of the toner image is introduced into the fixing device 15 and heated and fixed (fixing step).
[0192]
After the image transfer to the transfer material P is completed, a cleaning charging member 9 as a cleaning roller mechanism that is detachably disposed is brought into contact with the intermediate transfer belt 5, and a bias having a polarity opposite to that of the photoreceptor 1 is applied. As a result, a charge having a polarity opposite to that at the time of primary transfer is imparted to the transfer residual toner that is not transferred to the transfer material P and remains on the intermediate transfer belt 5. The bias power source 33 applies an AC voltage superimposed on a DC voltage. The transfer residual toner charged to a polarity opposite to that at the time of primary transfer is electrostatically transferred to the photoreceptor 1 at and near the nip portion between the intermediate transfer belt 5 and the photoreceptor 1, thereby cleaning the intermediate transfer belt. Is done. Since this step can be performed simultaneously with the primary transfer, the throughput is not reduced.
[0193]
FIG. 2 is a schematic cross-sectional view of the intermediate transfer belt-photoreceptor integrated cartridge used in the present invention. Hereinafter, the cartridge will be described. As shown in FIG. 2, the cartridge used in the present invention is constituted as a unit in which the intermediate transfer belt 5 and the photosensitive member 1, the intermediate transfer belt cleaning mechanism 9 and the photosensitive member cleaning device 13 are integrated. It is removable. As described above, the cleaning mechanism for the intermediate transfer belt 5 is a mechanism necessary for charging the transfer residual toner to a polarity opposite to that of the primary transfer and returning it to the photosensitive member at the primary transfer portion. Equipped with a body-cleaning roller 9. The cleaning of the photoreceptor is blade cleaning.
[0194]
A waste toner container (not shown) is also integrated with the cartridge, and the transfer residual toner on both the intermediate transfer belt and the photosensitive member is discarded at the same time when the cartridge is replaced, which contributes to improvement in maintainability. The intermediate transfer belt is stretched by two rollers of 8 and 12, thereby reducing the number of parts and reducing the size. Here, 8 is a driving roller and at the same time a counter roller for the cleaning roller. The tension roller 12 that rotates following the intermediate transfer belt has a sliding mechanism, is pressed in the direction of the arrow by a compression spring, and applies tension to the intermediate transfer belt. The slide width is about 1 to 5 mm, and the total pressure of the spring is about 5 to 100N. Further, the photosensitive member 1 and the driving roller 8 have a coupling (not shown) so that a rotational driving force is transmitted from the main body.
[0195]
【Example】
The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the examples.
[0196]
Example 1 Yellow toner no. 1 manufacture
The yellow toner used in the present invention was prepared as follows. 910 parts by mass of ion-exchanged water, 2 parts by mass of polyvinyl alcohol, and 1 part by mass of sodium dodecyl sulfate were added to a 3 liter four-necked flask equipped with a high-speed stirring device TK-homomixer, and the rotation speed was 10,000 rpm. It was adjusted and heated to 60 ° C. to obtain a dispersant system.
[0197]
On the other hand, the dispersoid system is
・ Styrene monomer 60 parts by mass
・ 40 parts by mass of 2-ethylhexyl acrylate monomer
・ Condensed azo pigment 10 parts by mass
-Boron compound 1.0 part by mass
・ Saturated polyester resin 10 parts by mass
(Polycondensation product of propylene oxide modified bisphenol A and phthalic acid)
After the mixture was dispersed for 4 hours using a media type disperser, 20 parts by weight of a release agent (Rice wax DSC peak 80 ° C.) was added, and the internal temperature was kept at 70 ° C. for 30 minutes. Thereafter, a dispersion to which 3 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile), which is a polymerization initiator, was added was put into the dispersion medium, and the mixture was prepared for 5 minutes while maintaining 15000 rpm. Grained. Thereafter, polymerization was carried out for 10 hours at 150 revolutions by replacing the stirrer with a propeller stirring blade from the high speed stirring device. After completion of the polymerization, the slurry was cooled, washed with water and dried to obtain yellow colored particles.
[0198]
To 100 parts by mass of the yellow colored particles obtained, an inorganic fine powder was added according to the formulation shown in Table 2, and externally added for 1 minute at 3000 rpm with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). Thereafter, 0.8 part by mass of hydrophobized silica fine powder (primary particle size 12 nm) was added, and externally added and mixed at 3000 rpm for 3 minutes. Yellow toner no. 1 was obtained. Yellow toner No. The physical properties of 1 are shown in Table 2.
[0199]
Example 2 Yellow toner no. Production of 2
In Example 1, the amount of the release agent, the amount of the inorganic fine powder, and the particle size of the inorganic fine powder were changed as described in Table 2, and the yellow toner No. . 2 was obtained. Yellow toner No. The physical properties of 2 are shown in Table 2.
[0200]
Example 3 Yellow toner no. Production of 3
In Example 1, except that the amount of the release agent and the particle size of the inorganic fine powder were changed as described in Table 2, yellow toner No. 3 was obtained. Yellow toner No. The physical properties of 3 are shown in Table 2.
[0201]
Example 4 Yellow toner no. Production of 4
(1) Preparation of pigment dispersion solution
3 parts by mass of lauryltrimethylammonium chloride, which is a commercially available surfactant, with respect to 4 parts by mass of the condensed azo pigment, ₂ 100 parts by mass of ion-exchanged water subjected to gas substitution were mixed and dispersed for 20 minutes by an ultrasonic dispersion apparatus. From this, a dispersed condensed azo pigment dispersion was obtained.
[0202]
(2) Synthesis of colored polymer particles
A polymerization sensor was prepared by attaching a temperature sensor, a nitrogen introduction tube, a disk turbine type stirring blade, and a cooling tube to a 3 liter round bottom separable flask. In this polymerization reactor, N ₂ When charged with 300 parts by mass of ion-exchanged water, 60 parts by mass of styrene monomer, and 40 parts by mass of 2-ethylhexyl acrylate monomer and heated to 70 ° C., 5 parts by mass of potassium peroxodisulfate as a polymerization initiator was added. 50 parts by mass of dissolved ion exchanged water was added to initiate the polymerization reaction.
[0203]
When the polymerization conversion rate of this polymerization reaction reached 85%, a condensed azo pigment dispersion solution and a commercially available wax emulsion (polyethylene wax DSC peak 110 ° C.) as a release agent were added to the reaction system at an addition rate of 1.0 ml / min. After the addition was completed, the temperature of the polymerization reaction system was increased to 90 ° C., and the reaction was allowed to proceed while fixing the yellow pigment to the polymer particles, and the reaction was completed to obtain yellow colored particles.
[0204]
To the yellow colored particles obtained, hydrophobic silica and inorganic fine powder were externally added and mixed using the same method as in Example 1 to obtain yellow toner no. 4 was obtained. In addition, the addition amount of the inorganic fine powder at this time was 0.4 parts by mass with respect to 100 parts by mass of the yellow colored particles. Yellow toner No. The physical properties of 4 are shown in Table 2.
[0205]
<Toner Comparative Production Example 1> 5 production
In Example 1, except that the particle size and amount of the inorganic fine powder were changed as shown in Table 2, the same procedure as in Example 1 was used to obtain the yellow toner No. 5 was obtained. Yellow toner No. The physical properties of 5 are shown in Table 2.
[0206]
<Toner Comparative Production Example 2> 6 manufacturing
In Example 1, except that the particle size of the inorganic fine powder was changed as shown in Table 2, the same procedure as in Example 1 was used to obtain the yellow toner No. 6 was obtained. Yellow toner No. The physical properties of 6 are shown in Table 2.
[0207]
Example 5 Magenta Toner No. 1 manufacture
In Example 1, a magenta toner No. 1 was prepared in the same manner as in Example 1 except that a quinacridone pigment was used instead of the condensed azo pigment. 1 was obtained. Magenta Toner No. The physical properties of 1 are shown in Table 2.
[0208]
Example 6 Magenta toner No. Production of 2
In Example 4, a magenta toner No. 4 was used in the same manner as in Example 4 except that a quinacridone pigment was used instead of the condensed azo pigment. 2 was obtained. Magenta Toner No. The physical properties of 2 are shown in Table 2.
[0209]
<Toner Comparative Production Example 3> Magenta Toner No. Production of 3
In Example 1, a magenta toner was used in the same manner as in Example 1 except that a quinacridone pigment was used instead of the condensed azo pigment and the particle size and amount of the inorganic fine powder were changed as shown in Table 2. No. 3 was obtained. Magenta Toner No. The physical properties of 3 are shown in Table 2.
[0210]
<Toner Comparative Production Example 4> Magenta Toner No. Production of 4
In Example 1, a magenta toner No. 1 was prepared using the same method as in Example 1 except that a quinacridone pigment was used instead of the condensed azo pigment and the particle size of the inorganic fine powder was changed as shown in Table 2. 4 was obtained. Magenta Toner No. The physical properties of 4 are shown in Table 2.
[0211]
Example 7 Cyan toner no. 1 manufacture
In Example 1, cyan toner No. 1 was used in the same manner as in Example 1 except that a copper phthalocyanine pigment was used instead of the condensed azo pigment. 1 was obtained. Cyan toner no. The physical properties of 1 are shown in Table 2.
[0212]
Example 8 Cyan toner No. Production of 2
In Example 4, cyan toner No. 4 was used in the same manner as in Example 4 except that a copper phthalocyanine pigment was used instead of the condensed azo pigment. 2 was obtained. Cyan toner no. The physical properties of 2 are shown in Table 2.
[0213]
<Toner Comparative Production Example 5> Production of 3
In Example 1, a copper phthalocyanine pigment was used in place of the condensed azo pigment, and the particle size and amount of the inorganic fine powder were changed as described in Table 2, using the same method as in Example 1 above. Toner No. 3 was obtained. Cyan toner no. The physical properties of 3 are shown in Table 2.
[0214]
<Toner Comparative Production Example 6> Production of 4
In Example 1, cyan toner No. was used in the same manner as in Example 1 except that a copper phthalocyanine pigment was used in place of the condensed azo pigment and the particle size of the inorganic fine powder was changed as shown in Table 2. . 4 was obtained. Cyan toner no. The physical properties of 4 are shown in Table 2.
[0215]
Example 9 Black toner no. 1 manufacture
In Example 1, except that grafted carbon black was used instead of the condensed azo pigment, a black toner No. 1 was prepared using the same method as in Example 1 above. 1 was obtained. Black toner no. The physical properties of 1 are shown in Table 2.
[0216]
Example 10 Black toner no. Production of 2
In Example 4, except that grafted carbon black was used instead of the condensed azo pigment, a black toner no. 2 was obtained. Black toner no. The physical properties of 2 are shown in Table 2.
[0217]
<Toner Comparative Production Example 7> Production of 3
In Example 1, a grafted carbon black was used instead of the condensed azo pigment, and the same method as in Example 1 was used, except that the particle size and amount of the inorganic fine powder were changed as shown in Table 2. Black toner no. 3 was obtained. Black toner no. The physical properties of 3 are shown in Table 2.
[0218]
<Toner Comparative Production Example 8> Production of 4
In Example 1, black toner was used in the same manner as in Example 1 except that grafted carbon black was used instead of the condensed azo pigment and the particle size of the inorganic fine powder was changed as shown in Table 2. No. 4 was obtained. Black toner no. The physical properties of 4 are shown in Table 2.
[0219]
[Table 2]

[0220]
<Production Example 1 of Intermediate Transfer Belt>
・ 60 parts by mass of polybutylene terephthalate resin
・ Polycarbonate resin 40 parts by mass
-Conductive agent (carbon black) 8 parts by mass
The above materials were kneaded by a biaxial extrusion kneader, and lithium perchlorate was sufficiently uniformly dispersed in a binder resin (kneaded product) so as to obtain a desired electric resistance, thereby obtaining a molding raw material. Furthermore, this was made into the kneaded material of the particle size of 1-2 mm.
[0221]
Next, the kneaded product was charged into a single screw extruder and heated to melt to obtain a melt. The melt was continuously introduced into an annular single layer extrusion die having a diameter of 100 mm and a thickness of 300 μm, and further air was blown and expanded through a gas introduction path to form an intermediate transfer belt 1 having a diameter of 140 mm and a thickness of 120 μm as a final shape dimension. Obtained. The resistance value of the obtained intermediate transfer belt 1 is 6.0 × 10. ⁹ It was Ω · cm.
[0222]
<Production Example 2 of Intermediate Transfer Belt>
An intermediate transfer belt 2 was obtained using the same method as in Production Example 1 except that the amount of carbon black was changed to 5 parts by mass in Production Example 1 of the intermediate transfer belt. The resistance value of the obtained intermediate transfer belt 2 is 8.0 × 10. ⁹ It was Ω · cm.
[0223]
<Example 3 of intermediate transfer belt production>
An intermediate transfer belt 3 was obtained using the same method as in Production Example 1 except that the amount of carbon black was changed to 40 parts by mass in Production Example 1 of the intermediate transfer belt. The resistance value of the obtained intermediate transfer belt 3 is 8.0 × 10. ^Five It was Ω · cm.
[0224]
<Example 4 of production of intermediate transfer belt>
A cylindrical mold was covered with a rubber compound extruded in a tube shape in advance, and a polyester yarn having a diameter of 150 μm was spirally wound from above on at a pitch of 0.8 mm. Further, a rubber compound similar to the above was placed thereon, and a polyester tape was wound thereon to sufficiently adhere the rubber compound to the mold, and the rubber compound was vulcanized. After vulcanization, the polyester tape was peeled off and the rubber was polished to obtain an elastic layer (elastic tube) in which fibers were arranged. The material composition of the rubber compound is as follows.
・ NBR 70 parts by mass
・ EPDM 30 parts by mass
・ Vulcanizing agent (precipitated sulfur) 1.5 parts by mass
・ Vulcanization aid (zinc flower) 2 parts by mass
・ 1.5 parts by mass of vulcanization accelerator (MBT)
・ Vulcanization accelerator (TMTM) 1.2 parts by mass
-Conductive agent (carbon black) 25 parts by mass
・ Dispersing aid (stearic acid) 1 part by mass
・ 40 parts by mass of plasticizer (naphthenic process oil)
[0225]
Next, the coating material for forming a coating layer on this elastic layer was produced by the following prescription.
・ Polycarbonate polyurethane 100 parts by mass
・ 70 parts by mass of PTFE resin fine powder
・ 3 parts by mass of fluorine-based graft copolymer
・ Methyl ethyl ketone 500 parts by mass
・ 200 parts by mass of methyl isobutyl ketone
・ N-methylpyrrolidone 100 parts by mass
The above-mentioned coating material is applied onto the elastic layer, and after touch-drying at room temperature, the residual solvent is removed by heating at 130 ° C. for 2 hours, and an intermediate transfer having one coating layer having a thickness of 18 μm on the elastic layer A belt 4 was obtained. The resistance value of the obtained intermediate transfer belt 4 is 1 × 10. ⁷ It was Ω · cm.
[0226]
<Example 5 of production of intermediate transfer belt>
An intermediate transfer belt 5 was obtained in the same manner as in Production Example 4 except that the amount of the conductive agent (carbon black) in Production Example 4 of the intermediate transfer belt 1 was changed to 50 parts by mass. The resistance value of the obtained intermediate transfer belt 5 is 5 × 10. ^Five It was Ω · cm.
[0227]
<Example 11>
The intermediate transfer belt 1 obtained in Production Example 1 of the intermediate transfer belt is mounted on the image forming apparatus of the contact one-component development system shown in FIG. 1 was set, and continuous printing was performed in a full color mode under a low temperature and low humidity environment (15 ° C./10% RH) at a printing ratio of 5%. The sampling timing was the 10th, 2000th, and 4000th sheets, and the cleaning property and transfer uniformity of all solid images were evaluated. The evaluation method is shown below. In this embodiment, the all solid image means a toner loading amount of 0.55 to 0.75 mg / cm. ² Say the picture.
[0228]
(1) Cleanability
The cleaning property was evaluated according to the following criteria from all solid images obtained after continuous printing in the low temperature and low humidity environment.
[0229]
A: The cleaning property on the image is good. The back of the cleaning member is also very beautiful.
B: The cleaning property on the image is good. Some toner contamination is confirmed on the back surface of the cleaning member.
C: The cleaning property on the image is at a level where there is no practical problem. A large amount of toner contamination is confirmed on the back surface of the cleaning member.
D: The image is poorly cleaned and has a practically problematic level. A large amount of toner contamination is confirmed on the back surface of the cleaning member.
[0230]
(2) Transferability (uniformity)
The uniformity of transfer was evaluated according to the following criteria from all solid images obtained after continuous printing in the low temperature and low humidity environment.
[0231]
A: Smooth paper (Canon color laser 80g / m ² ), Rough paper (Xerox 4024, 75 g / m ² In both cases, images with good uniformity can be obtained.
B: Smooth paper (Canon color laser 80g / m ² ) Provides a good uniform image. Rough paper (Xerox 4024, 75 g / m ² ), An image with slightly reduced uniformity is obtained. There is no problem in practical use.
C: Smooth paper (Canon color laser 80g / m ² ), Rough paper (Xerox 4024, 75 g / m ² In both cases, an image with slightly reduced uniformity can be obtained. There is no problem in practical use.
D: Smooth paper (Canon color laser 80 g / m ² ), Rough paper (Xerox 4024, 75 g / m ² In both cases, an image with significantly reduced uniformity can be obtained. A practically problematic level.
[0232]
<Examples 12 to 17>
In Example 11, the type of the intermediate transfer belt, the separation between the intermediate transfer belt and the photosensitive member in the transfer process, and the presence or absence of the cleaning roller were changed to obtain various image forming processes as shown in Table 3. In Table 3, “no” separation from the drum means that the intermediate transfer belt always contacts the photosensitive member, and “present” means that the intermediate transfer belt is not in contact with the drum or is separated even if it is in contact. It means that there is time. The presence / absence of the cleaning roller indicates whether or not the cleaning roller (9 in FIG. 1) is used. The image forming method using the intermediate transfer roller 1 of Example 11 uses “Process 1” shown in Table 3.
[0233]
[Table 3]

[0234]
Evaluation was performed in the same manner as in Example 11 except that the toner and the image forming process in Example 11 were changed as shown in Table 4.
[0235]
<Comparative Examples 1-5>
Evaluation was performed in the same manner as in Example 11 except that the toner and the image forming process in Example 11 were changed as shown in Table 4.
Table 4 shows the evaluation results of Examples 11 to 17 and Comparative Examples 1 to 5.
[0236]
[Table 4]

[0237]
<Example 18>
The intermediate transfer belt 1 obtained in Production Example 1 of the intermediate transfer belt is mounted on the image forming apparatus of the contact one-component development system shown in FIG. 1, magenta toner no. 1, cyan toner no. 1, black toner no. 1 was set, and continuous printing was performed under the conditions of Process 1 under a low-temperature and low-humidity environment (15 ° C./10% RH) in a full color mode and a printing ratio of 5%. The sampling timing was the 10th, 2000th, and 4000th sheets, and the cleaning property and color misregistration of all solid images were evaluated. The cleaning property was evaluated by the same method as in Example 11. The evaluation of color shift is shown below.
[0238]
(3) Transferability (color shift)
The color shift at the time of transfer was evaluated according to the following criteria from all solid images obtained after continuous printing in the low temperature and low humidity environment.
[0239]
A: Smooth paper (Canon color laser 80g / m ² ), Rough paper (Xerox 4024, 75 g / m ² In both cases, an image with good uniformity and no color shift can be obtained.
B: Smooth paper (Canon color laser 80g / m ² ) Provides a good and uniform image with no color misregistration. Rough paper (Xerox 4024, 75 g / m ² ), An image with slightly reduced color misregistration is obtained. There is no problem in practical use.
C: Smooth paper (Canon color laser 80g / m ² ), Rough paper (Xerox 4024, 75 g / m ² In both cases, an image with slightly reduced color shift is obtained. There is no problem in practical use.
D: Smooth paper (Canon color laser 80 g / m ² ), Rough paper (Xerox 4024, 75 g / m ² In both cases, an image with significantly reduced color shift can be obtained. A practically problematic level.
[0240]
<Example 19>
Evaluation was performed in the same manner as in Example 18 except that the toner and the image forming process in Example 18 were changed as shown in Table 5.
[0241]
<Comparative Examples 6-9>
Evaluation was performed in the same manner as in Example 18 except that the toner and the image forming process in Example 18 were changed as shown in Table 5.
The evaluation results of Examples 18 and 19 and Comparative Examples 6 to 9 are shown in Table 5.
[0242]
[Table 5]

[0243]
【The invention's effect】
According to the present invention, in an image forming method having at least a development process using a non-magnetic one-component development system and a transfer process using an intermediate transfer body, excellent cleaning properties and transfer during continuous printing in a low temperature and low humidity environment And a good full color image free from fogging can be formed.
[Brief description of the drawings]
FIG. 1 is a schematic view of an image forming apparatus showing an example of an image forming apparatus that can suitably use the nonmagnetic one-component toner and the image forming method of the present invention.
FIG. 2 is a schematic view of an intermediate transfer belt-photoreceptor integrated cartridge in which the nonmagnetic one-component toner and the image forming method of the present invention can be preferably used.
FIG. 3 is a schematic diagram of an image forming apparatus using a conventional image forming method.
[Explanation of symbols]
1 Photoconductor
2 Primary charger
3 Image exposure
5 Intermediate transfer belt
6 Primary transfer counter roller
7 Secondary transfer roller
8 Secondary transfer counter roller
9 Cleaning roller
10 Transfer material guide
11 Paper feed roller
12 Tension roller
13 Cleaning device
15 Fixing device
30, 31, 32, 33 Power supply
41 Yellow toner developer
42 Magenta toner developer
43 Cyan Toner Developer
44 Black toner developer

Claims (15)

( I) A step of visualizing the electrostatic latent image formed on the photosensitive member with two or more non-magnetic one-component toners having different colors to form toner images of the respective colors, and electrostatic images corresponding to the respective colors. ( Ii ) a toner image of each color visualized in the developing step is sequentially superimposed on an intermediate transfer belt that is always in contact with the photosensitive member; And ( iii ) a transfer step of transferring the color toner image on the intermediate transfer body onto a transfer material. The non-magnetic one-component toner has colored particles containing at least a binder resin, a colorant, and a release agent, and inorganic fine powder having a particle diameter of 100 to 1000 nm present on the surface of the colored particles. And The degree of aggregation G1 in a low temperature and low humidity environment is 10 to 80%, and in the two or more non-magnetic one-component toners, the degree of aggregation G1a of the non-magnetic one-component toner first transferred to the intermediate transfer belt And an aggregation degree G1b of the non-magnetic one-component toner finally transferred to the intermediate transfer belt satisfies a relationship of G1a> G1b . 2. The image forming method according to claim 1, wherein the non-magnetic one-component toner has a degree of aggregation G1 of 10 to 60% in a low-temperature and low-humidity environment. The aggregation degree difference ΔG represented by the following formula (1) is 0 to 30 when the aggregation degree after leaving the non-magnetic one-component toner in a low temperature and low humidity environment is G2. Item 3. The image forming method according to Item 1 or 2.
[Expression 1]
ΔG = | G2-G1 | (1) The aggregation degree difference ΔG represented by the following formula (1) is 0 to 25 when the aggregation degree after leaving the non-magnetic one-component toner in a low temperature and low humidity environment is G2. Item 3. The image forming method according to Item 1 or 2.
[Expression 2]
ΔG = | G2-G1 | (1) The image forming method according to claim 1, wherein the inorganic fine powder has a particle size of 150 to 500 nm. The number-based circle equivalent diameter-circularity scattergram measured by the non-magnetic one-component toner flow-type particle image measuring device has an average circularity of 0.950 to 0.999 and a circularity standard deviation of 0. 0. The image forming method according to claim 1, wherein the image forming method is less than 040. The number-based circle equivalent diameter-circularity scattergram measured by the non-magnetic one-component toner flow-type particle image measuring apparatus has an average circularity of 0.965 to 0.999, and a circularity standard deviation of 0.8. The image forming method according to claim 1, wherein the image forming method is less than 038. The image forming method according to claim 1, wherein the non-magnetic one-component toner has a weight average particle diameter of 5 to 9.5 μm. The image forming method according to claim 1, wherein the non-magnetic one-component toner has a weight average particle diameter of 6.0 to 9.0 μm. The image forming method according to claim 1, wherein the release agent is contained in an amount of 3 to 30 parts by mass with respect to 100 parts by mass of the binder resin. The image forming method according to claim 1, wherein the release agent is contained in an amount of 5 to 20 parts by mass with respect to 100 parts by mass of the binder resin. 12. The non-magnetic one-component toner remaining on the intermediate transfer belt without being transferred onto the transfer material in the transfer step is removed by a cleaning roller mechanism. The image forming method described in 1 . The image forming method according to claim 1, wherein the intermediate transfer belt is composed of a resin-based component . The image forming method according to claim 1, wherein the photosensitive member and the intermediate transfer belt are an integral transfer unit that is always in contact with each other . The image forming method according to claim 1, wherein the developing step is a step of developing by contact one-component development .

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