JP4292715B2 - Two-component developer and carrier production method - Google Patents

Description

【０１０８】
【化２】

【０１０９】
上記離型剤のトナー中への添加量は、トナー全体に対して好ましくは１〜３０質量％、より好ましくは２〜２０質量％、さらに好ましくは３〜１５質量％である。本発明におけるトナーは、重合性単量体中にエステル系離型剤を溶解させたものを水中に分散し、重合させ、該エステル系離型剤を内包させた粒子を形成させ、着色剤粒子ととも会合／融着／塩析して着色樹脂粒子を得、これに外添剤加添加して製造されるのが好ましい。
《トナーの製造工程》
本発明のトナーは、エステル系離型剤、を溶解した重合性単量体の溶液を水系媒体中に分散し、ついで重合法により該エステル系離型剤を内包した樹脂微粒子を調整する工程、前記樹脂微粒子分散液を用いて水系媒体中で、着色剤粒子とともに樹脂微粒子を塩析／融着させる工程、得られた粒子を水系媒体中より濾過し界面活性剤などを除去する洗浄工程、得られた着色樹脂粒子を乾燥させる工程、さらに乾燥させて得られた着色樹脂粒子に外添剤などを添加する外添剤添加工程などから構成される重合法で製造することが好ましい。また、着色剤や離型剤に限らず、トナーの構成要素である荷電制御剤等も本工程で粒子として添加することができる。
【０１１０】
なお、ここで水系媒体とは主成分として水からなるもので、水の含有量が５０質量％以上であるものを示す。水以外のものとしては、水に溶解する有機溶媒を挙げることができ、例えば、メタノール、エタノール、イソプロパノール、ブタノール、アセトン、メチルエチルケトン、テトラヒドロフランなどをあげることができる。好ましくは樹脂を溶解しない有機溶媒である、メタノール、エタノール、イソプロパノール、ブタノールのようなアルコール系有機溶媒が特に好ましい。
【０１１１】
本発明での好ましい重合法としては、離型剤を溶解した重合性単量体溶液を臨界ミセル濃度以下の界面活性剤を溶解させた水系媒体中に機械的エネルギーによって油滴分散させた分散液に、水溶性重合開始剤を加え、ラジカル重合させる方法をあげることができる。この場合、重合性単量体溶液中に油溶性の重合開始剤を加えて使用してもよい。
【０１１２】
この油滴分散を行うための分散機としては特に限定されるものでは無いが、例えばクレアミックス、超音波分散機、機械式ホモジナイザー、マントンゴーリンや圧力式ホモジナイザー等をあげることができる。
【０１１３】
着色剤自体は表面改質して使用してもよい。着色剤の表面改質法は、溶媒中に着色剤を分散し、その中に表面改質剤を添加した後昇温し反応を行う。反応終了後、ろ過し同一の溶媒で洗浄ろ過を繰り返し乾燥させ表面改質剤で処理された顔料を得る。
【０１１４】
着色剤粒子は着色剤を水系媒体中に分散して調製される方法がある。この分散は、水中で界面活性剤濃度を臨界ミセル濃度（ＣＭＣ）以上にした状態で行われる。
【０１１５】
顔料分散時の分散機は特に限定されないが、好ましくはクレアミックス、超音波分散機、機械的ホモジナイザー、マントンゴーリンや圧力式ホモジナイザー等の加圧分散機、サンドグラインダー、ゲッツマンミルやダイヤモンドファインミル等の媒体型分散機が挙げられる。ここで使用される界面活性剤は、前述の界面活性剤を使用することができる。
【０１１６】
塩析／融着を行う工程は、樹脂微粒子及び着色剤粒子とが存在している水中にアルカリ金属塩やアルカリ土類金属塩等からなる塩析剤を臨界凝集濃度以上の凝集剤として添加し、ついで樹脂微粒子のガラス転移点以上に加熱することで塩析を進行させると同時に融着を行う工程である。
【０１１７】
ここで、塩析剤であるアルカリ金属塩及びアルカリ土類金属塩は、アルカリ金属として、リチウム、カリウム、ナトリウム等が挙げられ、アルカリ土類金属として、マグネシウム、カルシウム、ストロンチウム、バリウムなどが挙げられ、好ましくはカリウム、ナトリウム、マグネシウム、カルシウム、バリウムが挙げられる。また塩を構成するものとしては、塩素塩、臭素塩、沃素塩、炭酸塩、硫酸塩等が挙げられる。
【０１１８】
また、本発明では、樹脂微粒子の分散液をできるだけ速やかに昇温し、樹脂微粒子のガラス転移温度以上に加熱する方法を使用することが好ましい。この昇温までの時間としては３０分未満、好ましくは１０分未満である。さらに、昇温を速やかに行う必要があるが、昇温速度としては、１℃／分以上が好ましい。上限としては特に明確では無いが、急速な塩析／融着の進行により粗大粒子の発生を抑制する観点で、１５℃／分以下が好ましい。特に好ましい形態としては、塩析／融着をガラス転移温度以上になった時点でも継続して進行させる方法をあげることができる。この方法とすることで、粒子の成長とともに融着を効果的に進行させることができ、最終的なトナーとしての耐久性を向上することができる。
【０１１９】
トナーは、着色剤、離型剤以外にトナー用材料として種々の機能を付与することのできる材料を加えてもよい。具体的には荷電制御剤等が挙げられる。これらの成分は前述の塩析／融着段階で樹脂微粒子と着色剤粒子と同時に添加し、トナー中に包含する方法、樹脂微粒子自体に添加する方法等種々の方法で添加することができる。
【０１２０】
荷電制御剤も同様に種々の公知のもので、且つ水中に分散することができるものを使用することができる。具体的には、ニグロシン系染料、ナフテン酸または高級脂肪酸の金属塩、アルコキシル化アミン、第４級アンモニウム塩化合物、アゾ系金属錯体、サリチル酸金属塩あるいはその金属錯体等が挙げられる。
【０１２１】
樹脂微粒子を水系媒体中で会合あるいは融着させる重合法トナーでは、融着段階での反応容器内の媒体の流れおよび温度分布を制御することで、さらには融着後の形状制御工程において加熱温度、攪拌回転数、時間を制御することで、トナー全体の形状分布および形状を任意に変化させることができる。
【０１２２】
すなわち、樹脂微粒子を会合あるいは融着させる重合法トナーでは、反応装置内の流れを層流とし、内部の温度分布を均一化することができる攪拌翼および攪拌槽を使用して、融着工程および形状制御工程での温度、回転数、時間を制御することにより、本発明の形状係数および均一な形状分布を有するトナーを形成することができる。この理由は、層流を形成させた場で融着させると、凝集および融着が進行している粒子（会合あるいは凝集粒子）に強いストレスが加わらず、かつ流れが加速された層流においては攪拌槽内の温度分布が均一である結果、融着粒子の形状分布が均一になると推定される。さらに、その後の形状制御工程での加熱、攪拌により融着粒子は徐々に球形化し、トナー粒子の形状を任意に制御できる。
【０１２３】
本発明の形状に制御するためには、塩析と融着を同時進行させることが好ましい。凝集粒子を形成した後に加熱する方法ではその形状に分布を生じやすく、さらに微粒子の発生を抑制することができない。すなわち、凝集粒子を水系媒体中で攪拌しながら加熱するために凝集粒子の再分断が発生し、小粒径の成分が発生しやすいものと推定される。
【０１２４】
《外添剤》
本発明のトナーには、流動性、帯電性の改良およびクリーニング性の向上などの目的で、いわゆる外添剤を添加して使用することができる。これら外添剤としては特に限定されるものでは無く、種々の無機微粒子、有機微粒子及び滑剤を使用することができる。
【０１２５】
無機微粒子としては、従来公知のものを使用することができる。具体的には、シリカ、チタン、アルミナ微粒子等が好ましく用いることができる。これら無機微粒子としては疎水性のものが好ましい。具体的には、シリカ微粒子として、例えば日本アエロジル社製の市販品Ｒ−８０５、Ｒ−９７６、Ｒ−９７４、Ｒ−９７２、Ｒ−８１２、Ｒ−８０９、ヘキスト社製のＨＶＫ−２１５０、Ｈ−２００、キャボット社製の市販品ＴＳ−７２０、ＴＳ−５３０、ＴＳ−６１０、Ｈ−５、ＭＳ−５等が挙げられる。
【０１２６】
チタン微粒子としては、例えば、日本アエロジル社製の市販品Ｔ−８０５、Ｔ−６０４、テイカ社製の市販品ＭＴ−１００Ｓ、ＭＴ−１００Ｂ、ＭＴ−５００ＢＳ、ＭＴ−６００、ＭＴ−６００ＳＳ、ＪＡ−１、富士チタン社製の市販品ＴＡ−３００ＳＩ、ＴＡ−５００、ＴＡＦ−１３０、ＴＡＦ−５１０、ＴＡＦ−５１０Ｔ、出光興産社製の市販品ＩＴ−Ｓ、ＩＴ−ＯＡ、ＩＴ−ＯＢ、ＩＴ−ＯＣ等が挙げられる。
【０１２７】
アルミナ微粒子としては、例えば、日本アエロジル社製の市販品ＲＦＹ−Ｃ、Ｃ−６０４、石原産業社製の市販品ＴＴＯ−５５等が挙げられる。また、有機微粒子としては数平均一次粒子径が１０〜２０００ｎｍ程度の球形の有機微粒子を使用することができる。このものとしては、スチレンやメチルメタクリレートなどの単独重合体やこれらの共重合体を使用することができる。
【０１２８】
滑剤には、例えばステアリン酸の亜鉛、アルミニウム、銅、マグネシウム、カルシウム等の塩、オレイン酸の亜鉛、マンガン、鉄、銅、マグネシウム等の塩、パルミチン酸の亜鉛、銅、マグネシウム、カルシウム等の塩、リノール酸の亜鉛、カルシウム等の塩、リシノール酸の亜鉛、カルシウムなどの塩等の高級脂肪酸の金属塩が挙げられる。
【０１２９】
これら外添剤の添加量は、トナーに対して０．１〜５質量％が好ましい。外添剤の添加方法としては、タービュラーミキサー、ヘンシェルミキサー、ナウターミキサー、Ｖ型混合機などの種々の公知の混合装置を使用することができる。
【０１３０】
【実施例】
次に、本発明の実施態様を具体的に述べるが、本発明はこの態様に限定されるものではない。なお、文中「部」とは「質量部」を表す。
【０１３１】
〔キャリアの製造〕
〈キャリアコア製造例１〉
Ｌｉ₂ＣＯ₃を２２モル％、Ｆｅ₂Ｏ₃を７８モル％を湿式ボールミルにて２時間粉砕混合し、乾燥させ、９００℃にて２時間保持することで仮焼成した。このものを再度ボールミルにて３時間粉砕し、スラリー化した。分散剤及びバインダーを加え、スプレードライヤーにより造粒乾燥することで、一次粒子を調整し、さらに１２００℃にて３時間本焼成を行って平均粒径が６３μｍのフェライトキャリアコアを得た。これを「キャリアコア１」とした。
【０１３２】
〈キャリアコア製造例２〉
Ｌｉ₂ＣＯ₃を２３モル％、Ｍｇ（ＯＨ）₂を７モル％、Ｆｅ₂Ｏ₃を７０モル％を使用し、本焼成の温度を１２５０℃とした他はキャリアコア製造例１と同様にして平均粒径が５３μｍのフェライトキャリアコアを得た。これを「キャリアコア２」とした。
【０１３３】
〈キャリアコア製造例３〉
Ｌｉ₂ＣＯ₃を２０モル％、ＭｎＯを８モル％、Ｆｅ₂Ｏ₃を７２モル％使用した他はキャリアコア製造例１と同様にして平均粒径が４５μｍのフェライトキャリアコアを得た。これを「キャリアコア３」とした。
【０１３４】
〈キャリアコア製造例４〉
Ｍｇ（ＯＨ）₂を１０モル％、ＭｎＯを８モル％、Ｆｅ₂Ｏ₃を８２モル％使用し本焼成の温度を１２８０℃とした他はキャリアコア製造例１と同様にして平均粒径が５５μｍのフェライトキャリアコアを得た。これを「キャリアコア４」とした。
【０１３５】
〈キャリアの製造例１〉
乳化重合法で調製したスチレン：グリシジルメタクリレート：アクリル酸共重合体（質量比＝８６：７：７）樹脂微粒子（Ｔｇ＝９８℃／数平均一次粒子径＝０．１μｍ）２質量部と前述の「キャリアコア１」１００質量部を混合し、図１の乾式コーティング装置を使用し、９０℃の温度条件、水平方向の回転速度を１３ｍ／ｓｅｃとして２０分間攪拌し樹脂被覆を行った。ついで内部の温度を１２０℃に調整し攪拌条件を５ｍ／ｓｅｃとし、３０分間加熱処理を行いキャリアを得た。ここで得られたキャリアのＭＥＫ不溶分は４０質量％であり、これを「本発明キャリア１」とした。
【０１３６】
〈キャリアの製造例２〉
キャリアの製造例１においてキャリアコア１の代わりにキャリアコア２を使用し、１２０℃での攪拌時間を１５分にした他は同様にしてキャリアを得た。ここで得られたキャリアのＭＥＫ不溶分は３５質量％であり、これを「本発明キャリア２」とした。
【０１３７】
〈キャリアの製造例３〉
キャリアの製造例１においてキャリアコア１の代わりにキャリアコア３を使用し、１２０℃での攪拌時間を４５分にした他は同様にしてキャリアを得た。ここで得られたキャリアのＭＥＫ不溶分は５９質量％であり、これを「本発明キャリア３」とした。
【０１３８】
〈キャリアの製造例４〉
キャリアの製造例１においてキャリアコア１の代わりにキャリアコア４を使用し、樹脂微粒子として乳化重合法で調製したスチレン：グリシジルメタクリレート：アクリル酸共重合体（質量比＝８０：１０：１０）樹脂微粒子（Ｔｇ＝９７℃／数平均一次粒子径＝０．１μｍ）を使用し、さらに１２０℃での攪拌を１３０℃とし、攪拌時間を３０分にした他は同様にしてキャリアを得た。ここで得られたキャリアのＭＥＫ不溶分は７３質量％であり、これを「本発明キャリア４」とした。
【０１３９】
〈キャリアの製造例５〉
キャリアの製造例１において、樹脂微粒子として乳化重合法で調製したスチレン：グリシジルメタクリレート：２エチルヘキシルアクリレート共重合体（質量比＝８０：１０：１０）樹脂微粒子（Ｔｇ＝９３℃／数平均一次粒子径＝０．１μｍ）を使用し、さらに１２０℃での攪拌時間を４５分にした他は同様にしてキャリアを得た。ここで得られたキャリアのＭＥＫ不溶分は３６質量％であり、これを「本発明キャリア５」とした。
【０１４０】
〈キャリアの製造例６〉
キャリアの製造例１において、キャリアコア１の代わりにキャリアコア４を使用し、樹脂微粒子として乳化重合法で製造したスチレン：グリシジルメタクリレート：ジエチルアミノエチルメタクリレート：ブチルアクリレート共重合体（質量比＝７５：１０：１０：５）樹脂微粒子（Ｔｇ＝９４℃／数平均一次粒子径＝０．１μｍ）を使用し、さらに１２０℃での攪拌時間を４５分にした他は同様にしてキャリアを得た。ここで得られたキャリアのＭＥＫ不溶分は４９質量％であり、これを「本発明キャリア６」とした。
【０１４１】
〈比較用キャリアの製造例１〉
キャリアの製造例１において、１２０℃での攪拌処理をしないものを使用した。ここで得られたキャリアのＭＥＫ不溶分は１３質量％であり、これを「比較用キャリア１」とした。
【０１４２】
〈比較用キャリアの製造例２〉
キャリアの製造例４において、１３０℃での攪拌時間を１２０分とした。ここで得られたキャリアのＭＥＫ不溶分は９９質量％であり、これを「比較用キャリア２」とした。
【０１４３】
上記の様にして得た各キャリアの平均粒径は、前記したように走査型電子顕微鏡観察にて２５０倍に拡大した写真を使用し、その最大長径を５００個のキャリアについて測定した時の平均値で示した。また、粒度分布の測定は篩法により行われた。
【０１４４】
【表１】

【０１４５】
〔トナーの製造〕
〈ＨＰ（高重合）ラテックス製造例１〉
撹拌装置、温度センサー、冷却管、窒素導入装置を付けた５０００ｍｌのセパラブルフラスコに予めアニオン系活性剤（ドデシルスルフォン酸ナトリウム：ＳＤＳ）７．０８ｇをイオン交換水（２７６０ｇ）に溶解させた溶液を添加する。窒素気流下２３０ｒｐｍの撹拌速度で撹拌しつつ、内温を８０℃に昇温させた。一方でスチレン１１５．１ｇ、ｎ−ブチルアクリレート４２．０ｇ、メタクリル酸１０．９ｇからなるモノマー溶液を作製した。ついで、重合開始剤（過硫酸カリウム：ＫＰＳ）０．４２ｇをイオン交換水２００ｇに溶解させた溶液を添加し、その後７５℃に昇温し、前記モノマー溶液を１時間で滴下し、さらに７５℃にて２時間撹拌下に加熱、反応させたことでラテックス粒子を作製した。このラテックス粒子をＨＰ−１とした。
【０１４６】
ここで得られたラテックス粒子ＨＰ−１のピーク分子量をＧＰＣにて測定したところ、５１．８万であった。
【０１４７】
〈ＨＰラテックス製造例２〉
ＨＰラテックス製造例１において、反応温度を８５℃にした他は同様にしてラテックス粒子を得た。このラテックス粒子をＨＰ−２とした。
【０１４８】
ここで得られたラテックス粒子のピーク分子量は４２．１万であった。
〈ＭＰ（中重合）ラテックス製造例１〉
攪拌装置を有するフラスコにてスチレン３８３．６ｇ、ｎ−ブチルアクリレート１４０．０ｇ、メタクリル酸３６．４ｇ、ｎ−オクチル−３−メルカプトプロピオン酸エステル４．６ｇの溶液に例示化合物１９）７２．０ｇを８０℃に加熱し溶解する。ついで、ＳＤＳ＝１．６ｇを２０００ｍｌの水に溶解させた溶液を８０℃に加熱し、そのＳＤＳ水溶液へ循環経路を有する機械式分散機（クレアミックス）により上記モノマーへ例示化合物１９）を加熱させた溶液を混合分散させ、均一な分散粒子径を有する乳化粒子を含む乳化液を作製した。
【０１４９】
引き続いて重合開始剤（ＫＰＳ）１９．１ｇをイオン交換水２４０ｍｌに溶解させた溶液を添加し、さらに水７５０ｍｌを添加し、８０℃に加熱する。８０℃にて３時間反応させ、ラテックス粒子を得た。ここで得られたラテックス粒子をＭＰ−１とした。
【０１５０】
ラテックス粒子ＭＰ−１のピーク分子量は１０．３万であった。
〈ＭＰラテックス製造例２〉
ＭＰラテックス製造例１において、ｎ−オクチル−３−メルカプトプロピオン酸エステルの添加量を８．３ｇとした他は同様にしてラテックス粒子を得た。ここで得られたラテックス粒子をＭＰ−２とした。
【０１５１】
ラテックス粒子ＭＰ−２のピーク分子量は８．１万であった。
〈ＬＰ（低重合）ラテックス製造例１〉
撹拌装置、温度センサー、冷却管、窒素導入装置を付けたフラスコに予めＳＤＳ＝６０ｇをイオン交換水（５０００ｍｌ）に溶解させた溶液を添加した。窒素気流下２３０ｒｐｍの撹拌速度で攪拌しながら、ＫＰＳ＝２２．８ｇを水２００ｍｌに溶解した溶液を加え、さらに８０℃に保った状態で、スチレン＝８５０ｇ、ブチルアクリレート＝２５２ｇ、メタクリル酸＝９８ｇ及びｎ−オクチル−３−メルカプトプロピオン酸エステル＝３２ｇとを混合した溶液を１時間かけて滴下する。ついで、２時間反応させ、目的とするラテックス粒子を得た。ここで得られたラテックス粒子をＬＰ−１とした。ラテックス粒子ＬＰ−１のピーク分子量は１．８万であった。
【０１５２】
〈着色剤分散液Ｂｋの製造〉
ｎ−ドデシル硫酸ナトリウム＝９０ｇをイオン交換水１６００ｍｌに撹拌溶解した。この液に、撹拌下、モーガルＬ（キャボット社製カーボンブラック）２００ｇを徐々に加え、ついで、クレアミックスを用いて分散した。大塚電子社製の電気泳動光散乱光度計ＥＬＳ−８００を用いて、上記分散液の粒径を測定した結果、重量平均径で１０１ｎｍであった。この分散液を「着色剤分散液Ｂｋ」とした。
【０１５３】
〈会合工程〉
前述の「ＨＰ−１」、「ＨＰ−２」、「ＭＰ−１」、「ＭＰ−２」及び「ＬＰ−１」の５種類のラテックスをそれぞれ表２の如く組み合わせで混合し、さらにイオン交換水２０００ｍｌ及び「着色剤分散液Ｂｋ」を、温度センサー、冷却管、窒素導入装置、攪拌装置を付けた反応容器に入れて撹拌した後、３０℃に調整した後、この溶液に５Ｍの水酸化ナトリウム水溶液を加え、ｐＨを１１．０に調整した。ついで、塩化マグネシウム６水和物５２６ｇをイオン交換水７２０ｍｌに溶解した水溶液を攪拌下、３０℃にて１０分間で添加した。その後、３分間放置した後に、昇温を開始し、液温度９０℃まで６分で昇温した（昇温速度＝１０℃／分）。その状態で粒径をコールターカウンターＴＡIIにて測定し、個数平均粒径が６．５μｍになった時点で塩化ナトリウム１１５０ｇをイオン交換水７０００ｍｌに溶解した水溶液を添加し粒子成長を停止させ、さらに継続して液反応温度を８０〜９５℃の範囲で、また、攪拌時間（反応時間）を１時間から１０時間まで変化させ塩析／融着させた。その後、８℃／ｍｉｎの条件で３０℃まで冷却し、塩酸を添加し、ｐＨを２．０に調整し、撹拌を停止した。生成した着色樹脂粒子を濾過し、イオン交換水で繰り返し洗浄し、その後、４０℃の温風で乾燥し、種々の形状の異なる表２の８種類の着色樹脂粒子（着色樹脂粒子１Ｂｋ〜着色樹脂粒子８Ｂｋ）を得、該８種類の着色樹脂粒子番号及びそれらの着色樹脂粒子作製時の液反応温度及び反応時間を表２に示した。
【０１５４】
また、上記着色樹脂粒子１Ｂｋの製造例において、カーボンブラックの代わりにＣ．Ｉ．ソルベントイエロー９３を使用した他は同様にしたものを着色樹脂粒子１Ｙとし、カーボンブラックの代わりにＣ．Ｉ．ピグメントレッド１２２を使用した他は同様にしたものを着色樹脂粒子１Ｍとし、カーボンブラックの代わりにＣ．Ｉ．ピグメントブルー１５：３を使用した他は同様にしたものを着色樹脂粒子１Ｃとして３種類の着色樹脂粒子を得、該３種類の着色樹脂粒子（着色樹脂粒子１Ｙ、着色樹脂粒子１Ｍ、着色樹脂粒子１Ｃ）の着色樹脂粒子番号及びそれらの着色樹脂粒子作製時の液反応温度及び反応時間を表２に示した。
【０１５５】
【表２】

【０１５６】
次に、上記着色樹脂粒子１Ｂｋ〜着色樹脂粒子８Ｂｋ、着色樹脂粒子１Ｙ、着色樹脂粒子１Ｍ及び着色樹脂粒子１Ｃの１１種類の着色樹脂粒子の形状係数、形状係数の変動係数、個数平均粒径、個数粒径分布の個数変動係数を前記測定方法により測定し、その結果を表３に示した。
【０１５７】
【表３】

【０１５８】
また、上記１１種類の着色樹脂粒子の形状係数１．２〜１．６の個数％、角無しトナーの個数比率、個数基準の粒度分布を示すヒストグラムにおける第１頻度のトナー粒子の相対度数（ｍ１）と、第２頻度のトナー粒子の相対度数（ｍ２）との和（個数％）を前記測定方法により測定し、その結果を表４に示した。
【０１５９】
【表４】

【０１６０】
〈トナー１Ｂｋ〜トナー１Ｃ製造例〉
次いで、上記１１種類の着色樹脂粒子にそれぞれ疎水性シリカ（数平均一次粒子径＝１０ｎｍ、疎水化度＝６３）を１質量％及び疎水性酸化チタン（数平均一次粒子径＝２５ｎｍ、疎水化度＝６０）１質量％添加し、ヘンシェルミキサーにより混合してトナーを得た。これらを「トナー１Ｂｋ」〜「トナー１Ｃ」とした。
【０１６１】
なお、粒子の形状及び粒径等の物性に関しては、着色樹脂粒子とトナーとで差異は無い。
【０１６２】
上記トナーの各々に対して本発明キャリア１〜６及び比較用キャリア１、２を組み合わせてトナー濃度が５質量％の２４種類の現像剤（本発明用の黒現像剤１〜１３、Ｙ現像剤１、Ｍ現像剤１、Ｃ現像剤１及び比較用の黒現像剤１及び２、比較用のＹ現像剤１及び２、比較用のＭ現像剤１及び２、比較用のＣ現像剤１及び２）を調製した。表６に上記各現像剤番号と、これらに対応するトナー番号及びキャリアの番号を示した。
【０１６３】
【表５】

【０１６４】
実施例１〜１３及び比較例１、２
〈実写による画像評価〉
黒現像剤（本発明用の黒現像剤１〜１３及び比較用黒現像剤１、２）についてトナーリサイクル方式を有するコニカ（株）製デジタル複写機７０３０を使用し、実施例１〜１３及び比較例１、２の画像実写テストを行い、実写画像の評価結果を表６に示した。定着方式としては圧接方式の加熱定着装置を用いた。具体的構成は下記の如くである。
【０１６５】
表面をＰＦＡ（テトラフロオロエチレン−パーフルオロアルキルビニルエーテル共重合体）のチューブで被覆した（厚み：１２０μｍ）内径３０ｍｍで全幅が３１０ｍｍの、ヒーターを中央部に内蔵した円柱状の厚み０．８ｍｍのアルミ合金を加熱ローラー（上ローラー）として有し、表面が同様にスポンジ状シリコーンゴム（アスカーＣ硬度＝４８：厚み２ｍｍ）で構成された内径３０ｍｍの肉厚１．０ｍｍの鉄芯金を有する加圧ローラー（下ローラー）を有している。ニップ幅は３．８ｍｍとした。この定着装置を使用して、印字の線速を１８０ｍｍ／ｓｅｃに設定した。
【０１６６】
なお、定着装置のクリーニング機構としてポリジフェニルシリコーン（２０℃の粘度が１０Ｐａ・ｓのもの）を含浸したウェッブ方式の供給方式を使用した。定着の温度は上ロールの表面温度で制御し、１８０℃の設定温度とした。なお、シリコーンオイルの塗布量は、０．１ｍｇ／Ａ４とした。
【０１６７】
評価は、１枚間欠印字にて５％画素率の原稿を３０℃／８０％ＲＨ環境の高温高湿環境にて２０万枚印字した。その際、初期と２０万枚後の画像濃度及びカブリ濃度を測定した。なお、画像濃度はベタ黒画像を使用し、その反射濃度をマクベス社製ＲＤ−９１８を使用し、絶対濃度で評価した。カブリ濃度はベタ白画像を使用し、マクベス社製ＲＤ−９１８を使用し、紙の反射濃度を「０」とした相対濃度で評価した。
【０１６８】
【表６】

【０１６９】
表６より、本発明のキャリアを含む現像剤を用いた実施例１〜１３は連続２０万枚に及ぶ画像形成の過程で、カブリがなく、高濃度鮮明な画像が得られたが、比較例の現像剤１及び２を用いた場合は連続２０万枚に及ぶ画像形成の過程で画像濃度低下またはカブリ発生の何れかが発生していて、実用性に乏しいことが分かる。
【０１７０】
実施例１４及び比較例３、４
次に、「黒現像剤１」「Ｙ現像剤１」「Ｍ現像剤１」「Ｃ現像剤１」の組み合わせ（実施例１４）、「比較用黒現像剤１」「比較用Ｙ現像剤１」「比較用Ｍ現像剤１」「比較用Ｃ現像剤１」の組み合わせ（比較例３）、「比較用黒現像剤２」「比較用Ｙ現像剤２」「比較用Ｍ現像剤２」「比較用Ｃ現像剤２」を使用し、中間転写体を有するキヤノン社製カラー複写機ピクセル２１００を使用して実施例１４及び比較例３、４のカラー画像実写テストを行い、得られた画像の色差劣化の評価を行い、その結果を表７に示した。
【０１７１】
なお、上記カラー複写機では、Ｙ／Ｍ／Ｃ／Ｂｋの現像器を積層型有機感光体の周囲に配置し、各色をそれぞれ該有機感光体上に現像した後に中間転写体上に各色ずつ転写し、中間転写体上にフルカラー画像を形成した後に画像形成支持体である紙に転写する中間転写体を有する構成のものを使用した。なお、有機感光体のクリーニングはブレードクリーニング方式を採用した。
【０１７２】
定着方式としては圧接方式の加熱定着装置を用いた。
具体的構成は下記の如くである。
【０１７３】
表面をＰＦＡ（テトラフロオロエチレン−パーフルオロアルキルビニルエーテル共重合体）のチューブで被覆した（厚み：１２０μｍ）内径４０ｍｍで全幅が３１０ｍｍの、ヒーターを中央部に内蔵した円柱状の厚み１．０ｍｍのアルミ合金を加熱ローラー（上ローラー）として有し、表面が同様にスポンジ状シリコーンゴム（アスカーＣ硬度＝４８：厚み２ｍｍ）で構成された内径４０ｍｍの肉厚２．０ｍｍの鉄芯金を有する加圧ローラー（下ローラー）を有している。ニップ幅は５．８ｍｍとした。この定着装置を使用して、印字の線速を２５０ｍｍ／ｓｅｃに設定した。
【０１７４】
なお、定着装置のクリーニング機構としてポリジフェニルシリコーン（２０℃の粘度が１０Ｐａ・ｓのもの）を含浸したウェッブ方式の供給方式を使用した。
【０１７５】
定着の温度は上ロールの表面温度で制御し、１７５℃の設定温度とした。なお、シリコーンオイルの塗布量は、０．６ｍｇ／Ａ４とした。
【０１７６】
評価は、連続印字にて２５％のフルカラー画素率の原稿を２５℃／８０％ＲＨ環境の常温高湿環境にて５万枚印字した。その際、初期と５万枚後のクロマ（色度）の差、即ち色差を下記方法により評価した。評価方法：１枚目の形成画像および５万枚目の形成画像各々における二次色（レッド、ブルー、グリーン）のソリッド画像部の色を「Ｍａｃｂｅｔｈ Ｃｏｌｏｒ−Ｅｙｅ７０００」により測定し、ＣＭＣ（２：１）色差式を用いて色差を算出した。色差の評価において、ＣＭＣ（２：１）色差式で求められた色差が５以下であれば、形成された画像の色味の変化が許容できる程度といえる。
【０１７７】
【表７】

【０１７８】
表７より、本発明のキャリアを含む現像剤を用いて連続５万枚に及ぶカラー画像を形成した場合は、終始色差の劣化がなく、色調鮮明なカラー画像が得られたが、比較用のキャリアを含む現像剤を用いて連続５万枚に及ぶカラー画像を形成した場合はカラー画像の色差の劣化が著しく実用性に乏しいことが分かる。
【０１７９】
【発明の効果】
実施例により実証されたように、本発明の二成分現像剤、特には本発明の製造法により得られたキャリアを含む現像剤によれば、長期に亘り画像形成に使用した場合でもカブリの発生がなく、高濃度鮮明な画像が得られ、さらに長期に亘りカラー画像形成に使用した場合、色差の劣化が少なく、色調鮮明なカラー画像が得られる等優れた効果を有する。
【図面の簡単な説明】
【図１】乾式コーティング装置の構成図である。
【図２】角なしまたは角ありトナーを説明する模式図である。
【符号の説明】
１０ 本体容器
１１ 本体上蓋
１２ 原料投入口
１３ 投入弁
１４ フィルター
１５ 点検口
１６ 品温計
１７ ジャケット
１８ 水平方向回転体
１８ａ、１８ｃ 水平方向回転体翼部
１８ｄ 水平方向回転体中心部
１９ 垂直方向回転体
２０ 製品排出口
２１ 排出弁
２２ モーター[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a two-component developer comprising a resin-coated carrier and a toner, and a method for producing the carrier.
[0002]
[Prior art]
Conventionally, as a developer used for electrophotography and the like, a two-component developer composed of a toner and a carrier can easily control the chargeability and charge amount of the toner, and there is a range of color tone that can be applied to the toner. Widely used because it is suitable for color image formation. The carrier used for the two-component developer is preferably a carrier in which the surface of the carrier core of magnetic particles is coated with a resin in order to improve the durability, triboelectric chargeability and the like. In order to manufacture the carrier, wet coating methods such as a fluidized bed spray coating method and a dip coating method are known. However, since the above wet coating method uses an organic solvent, there are disadvantages such as environmental degradation, an increase in the size of the processing apparatus and an increase in cost, and when the solvent is evaporated and the resin film is fixed to the carrier core, the resins are bonded together. There is a problem that coarse resin particles formed by agglomeration are mixed in the carrier, the carrier shape becomes irregular, and a carrier having good triboelectric chargeability cannot be obtained. It was. Therefore, a dry coating method has been proposed instead of the wet coating method. For example, JP-A-60-59369, JP-A-60-60656-60660, JP-A-2-158750, JP-A-3-269546, and the like have proposed dry coating techniques, which are provided on a carrier core. A method in which resin particles are adhered by a mechanical impact force and fixed by heating is used.
[0003]
However, all of the carriers described in the above publications have a weak coating film, and when used as a developer for a long period of time, they cause wear or peeling, resulting in poor charging, resulting in fogging or a decrease in image density in the resulting image. The problem of poor durability remained.
[0004]
[Problems to be solved by the invention]
The present invention has been proposed in view of the above circumstances, and the object of the present invention is that no fog occurs even when it is repeatedly used for image formation over a long period of time, and a high-density clear image is obtained. An object of the present invention is to provide a two-component developer capable of obtaining a clear color image without deterioration of color difference when used for color image formation over a long period of time and a method for producing a carrier used for the developer.
[0005]
[Means for Solving the Problems]
The object of the present invention is achieved by the following constitution.
[0006]
  1. In a two-component developer comprising a carrier having a magnetic particle surface coated with a resin and a toner, the carrier comprises a ferrite carrier core represented by the above general formula (I), and the carrier has an average particle size of 10 to 10. 100 μm, and the coating resin contains 20 to 95 mass% of methyl ethyl ketone solvent-insoluble matter.In addition, the toner has a ratio of toner particles having a shape factor in the range of 1.2 to 1.6 of 65% by number or more.A two-component developer.
[0007]
  2.The two-component developer described in 1 aboveCarrier manufacturing methodBecauseA method for producing a carrier, comprising mixing resin particles and magnetic particles in a dry manner and applying a mechanical impact force and heat to form a resin coating layer containing 20 to 95% by mass of a methylethylketone solvent-insoluble component.
[0008]
  3. A method for producing a carrier for a two-component developer as described in 1 above, wherein the magnetic particles and the resin particles are mixed in a dry manner, a mechanical impact force and heat are applied to form a resin coating layer, and the resin particles A method for producing a carrier comprising a thermosetting resin.
[0009]
As a result of intensive studies on dry and resin-coated carriers used in two-component developers, the present inventors prefer to make the coating resin into a crosslinked structure, but not simply to make the coating resin into a crosslinked structure. The inventors have found that it is important to have a certain degree of wear and have completed the present invention.
[0010]
That is, the deterioration of the carrier includes depletion of the resin coating layer and adhesion of the toner material to the layer. By suppressing the depletion, fluctuations in the charging property of the carrier itself can be suppressed, and the life can be extended. Can do. However, it is a common phenomenon that fine components in the toner adhere to the surface of the carrier to cause a change in charging property. As a result of intensive studies on a method for solving both the deterioration of charging property due to the depletion of the resin coating layer and the deterioration of charging property due to adhesion of fine components in the toner to the carrier surface, By making the resin of the coating layer into an appropriate cross-linked structure, the resin coating layer is strengthened, and a minute wear-out property is given to exert a refreshing effect on the surface of the resin-coated carrier, thereby extending the life of the carrier. I found what I could do. Conventionally, a resin-coated carrier containing a resin having a crosslinked structure has been known only by a wet method (JP-A-60-59369). However, in the present invention, a method for producing this by a dry method has been found. is there.
[0011]
The present invention will be described in detail below.
[Two-component developer]
The two-component developer of the present invention (hereinafter also simply referred to as a developer) is a developer composed of a dry-type resin-coated carrier (also referred to as a carrier of the present invention) and a toner. It is an essential requirement that the resin coated with 20% to 95% by mass of a solvent insoluble in methyl ethyl ketone (hereinafter also referred to as MEK insoluble) is less than 20% by mass. When it is used, the film tends to be worn or peeled off, resulting in insufficient image density during image formation. On the other hand, if it exceeds 95% by mass, the physical properties of the coating resin are too strong, and when used as a developer for a long time, the refreshing effect of the coating resin surface becomes insufficient, and the carrier surface is fatigued and fogging occurs during image formation. To do.
[0012]
(Resin component for cross-linked resin coating)
As a resin component for coating the resin having the above-mentioned crosslinked structure, a monomer having a functional group that reacts with heat (also referred to as a monomer) is used as a copolymer component. Examples of the monomer having the functional group include the following. Acrylic acid, methacrylic acid, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-aminoethyl acrylate, 2-aminoethyl methacrylate, etc. Examples thereof include acid, methacrylic acid, and derivatives thereof. Moreover, the combination of the monomer which has the said functional group may be sufficient.
[0013]
Examples of other monomers that may be copolymerized with monomers having functional groups that react with each other by heat include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pt-butylstyrene, pn-hexylstyrene, pn-octylstyrene, styrene or styrene derivatives such as pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, T-butyl methacrylate, n-octyl methacrylate, methacrylic acid -Methacrylate derivatives such as ethylhexyl, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, Acrylate derivatives such as t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, etc. Are specifically mentioned as monomers constituting the resin, and these can be used alone or in combination. Further, α-ethylacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, maleic acid monobutyl ester, maleic acid monooctyl ester, cinnamic acid anhydride, alkenyl succinic acid methyl half ester and the like can also be mentioned.
[0014]
In addition, you may contain monomers other than the above as a copolymerization component, and the component which bridge | crosslinks should just be 1-50 mass% preferably in all resin compositions.
[0015]
(Career core)
Typical examples of the carrier core used in the production of the carrier of the present invention include ferrite and magnetite, and a ferrite carrier core represented by the following general formula (I) is preferably used.
[0016]
Formula (I) (M_yO_x)_a(Fe₂O_Three)_b
In the formula, M is a metal selected from Ca, Li, Mg, Fe, Mn, Cu, and Zn, and a plurality of these may be used.
[0017]
x: 2 or 1
y: 2 or 1
a + b = 1
a and b are molar ratios, and a relationship of a <b is preferable from the viewpoint of magnetic properties. Also, (M_yO_x) The number of moles of the component is 15.0 to 40.0 mol%, preferably 20 to 30 mol%. By setting it within this range, it is possible to achieve both the magnetic properties of the carrier and the polishing effect due to the use of light metal. Further, other metal elements may be used in combination. When other metal elements are used in combination, it is preferably less than 10.0 mol%, and when it is 10.0 mol% or more, it is affected by other metals, for example, due to poor magnetic properties or increased polishing effect. There are problems such as acceleration of photoreceptor deterioration.
[0018]
The particle diameter of the carrier of the present invention: The average particle diameter is preferably 10 to 100 μm, more preferably 25 to 80 μm, still more preferably 35 to 70 μm, and the measurement is a photograph magnified 250 times by observation with a scanning electron microscope And measuring the maximum major axis diameter of the particles. At that time, 500 carrier particles are measured, and the average value is taken as the carrier particle size.
[0019]
Regarding the particle size distribution of the carrier, those less than 25 μm are 15% by mass or less, 25 μm to less than 37 μm are 1 to 35% by mass, 37 μm to less than 44 μm are 3 to 70% by mass, 44 μm to less than 63 μm are 2 to 70% by mass, It is preferable that 63 to 75 μm is 45% by mass or less and 75 μm or more is 20% by mass or less. For this distribution, standard sieves having openings of 25 μm, 37 μm, 44 μm, 63 μm, and 75 μm are used, and the sieves are stacked in descending order of openings, and 100.0 g of carrier is put on the top. Next, it is obtained by sieving with a vibrator for 15 minutes under the conditions of the number of horizontal turns = 285 times / minute and the number of vibrations = 150 times / minute, and measuring the remaining amount of each sieve and the mass flowing out from the lowermost layer.
[0020]
(MEK insoluble matter measurement method)
Place 50 ml of MEK in a 200 ml glass beaker and add 10 g of the carrier to be measured. Next, ultrasonic vibration is applied for 20 minutes at room temperature, the supernatant is removed while holding the carrier with a magnet, and 50 ml of MEK is added and washed. Then, the mass difference from the carrier before drying and MEK treatment is obtained. This is referred to as MEK soluble content (X). Separately, the mass (Y) of the resin covering the carrier is determined using a carbon analyzer “EMAIA-500” manufactured by HORIBA, Ltd. The difference (Y−X) between this and the above-mentioned MEK soluble component is (Z), and (Z) / (Y) × 100% is the MEK insoluble component.
[0021]
<Carrier manufacturing method>
The carrier of the present invention is produced by coating a resin on the carrier core in a dry manner, and the resin particles and the carrier core are stirred and mixed to electrostatically adhere the resin particles to the surface of the carrier core. Then, mechanical impact force is repeatedly applied, and the resin particles are spread on the surface of the carrier core to coat the resin.
[0022]
At the time of applying the mechanical impact force, the heating is performed under the condition of the glass transition temperature or less of the resin. The treatment time is not particularly limited, but is about 10 to 30 minutes, and the peripheral speed of stirring is preferably 5 to 20 m / sec.
[0023]
Thereafter, thermosetting is performed, and the conditions at that time are preferably conditions in which adhesion between particles does not occur at the same time as the reaction proceeds. It is preferable to set the temperature to be equal to or lower than the softening point of the resin. Although the time is selected depending on the material, it is preferable to heat-treat for 10 to 90 minutes. In that case, stirring may be continued and you may heat-process in a stationary state separately.
[0024]
As the apparatus for producing the resin-coated carrier, for example, the dry coating apparatus shown in FIG. 1 is preferably used.
[0025]
In the figure, reference numeral 11 denotes a main body upper cover. The main body upper cover 11 is provided with a charging valve 13 and a raw material charging port 12, a filter 14, and an inspection port 15. The raw material charged from the raw material charging port 12 through the charging valve 13 is given an impact force by a horizontal rotating body 18 driven by a motor 22.
[0026]
The horizontal rotating body 18 includes a center portion 18d and wing portions 18a, (18b) and 18c. Further, the wing has an angle of 35 ° with respect to the bottom 10 a of the main body container 10. For this, the raw material is scraped upward. Further, the tip of the wing portion of the horizontal rotating body 18 is oriented in the same direction as the inner wall of the lower portion of the chamber.
[0027]
The raw material that has been scooped collides with the inner wall of the upper part of the chamber inclined toward the center of the horizontal rotating body 18 or the inner wall of the lower part of the chamber, and rotates the wings 18a, (18b), 18c of the horizontal rotating body. Fall into range.
[0028]
Here, the wing portions 18a, (18b) and 18c are radially fixed to the central portion 18d at intervals of 120 ° C. Note that (18b) is not shown in FIG. 1 because it is located behind the center portion 18d in the drawing.
[0029]
In the manufacturing apparatus, the vertical rotating body 19 is provided on the horizontal rotating body 18. The vertical rotating body 19 composed of two wings rotates in the vertical direction and collides with the raw material reflected on the inner wall of the chamber. At this time, the number of wing portions of the vertical rotating body is not limited to two, and may be three or more. Thus, the vertical rotating body 19 accelerates the stirring of the raw material and crushes the aggregated raw material.
[0030]
In addition, although the aggregated raw material is crushed by the horizontal rotating body 18, it is effective to use the vertical rotating body.
[0031]
The raw material is given an impact force by the collision with the horizontal rotating body 18, the vertical rotating body 19, and the inner wall of the chamber, or the collision between the raw materials, and the resin particles are fixed on the surface of the core material. The deposited carrier opens the discharge valve 21 and is taken out from the product discharge port 20.
[0032]
The jacket 17 covers the outer wall of the chamber up to a height of about 3/4 of the chamber, that is, the height at which the vertical rotating body 19 is mounted.
[0033]
The product temperature is measured by the product thermometer 16. The thermometer 16 is a chromel-alumel thermocouple with a cover made of stainless steel (SUS304) having a length of 10 cm and a diameter of 6.4 mm (manufactured by Hayashi Denko Co., Ltd., T40-K-2-6.4-100-U-304KX). -G-3000). The thermometer is attached to the main body container 10 by being inserted from a point approximately one third of the main body container 10 toward the center of the horizontal rotating body 18 in parallel with the bottom 10a of the main body container. To do. The depth of insertion is set so that the tip of the thermometer is positioned approximately 1/5 from the tip of the wing.
[0034]
In addition, although this manufacturing apparatus is equipped with the vertical direction rotary body 19, it does not need to be equipped with this.
[0035]
<toner>
The toner in the present invention may be produced by pulverization and classification, but it is preferably produced by a polymerization method. In the case of production by the polymerization method, resin fine particles obtained by polymerization are salted out / fused. The manufacturing method is particularly preferred.
[0036]
Preferred characteristics required for the toner of the present invention include the following characteristics. By satisfying these characteristics, the object and effect of the present invention (no fogging during long-term image formation, A high-density clear image can be obtained, and color difference deterioration is not caused during color image formation, and an excellent color tone image can be obtained), and the effects described below can also be achieved.
[0037]
(1) The toner in the present invention preferably has a shape factor in the range of 1.0 to 1.6, and more preferably in the range of 1.2 to 1.6. The shape factor of the toner in the present invention is represented by the following formula and indicates the degree of roundness of the toner particles.
[0038]
Shape factor = ((maximum diameter / 2)²× π) / projection area
Here, the maximum diameter refers to the width of a particle that maximizes the interval between the parallel lines when the projected image of the toner particles on the plane is sandwiched between two parallel lines. The projected area refers to the area of the projected image of the toner particles on the plane.
[0039]
In the present invention, this shape factor is obtained by taking a photograph in which the toner particles are magnified 2000 times with a scanning electron microscope, and then using “SCANNING IMAGE ANALYZER” (manufactured by JEOL Ltd.) based on this photograph. It was measured by performing analysis. At this time, the shape factor is obtained by measuring using 100 toner particles and calculating by the above formula.
[0040]
  (2) The toner in the present invention has its shape factorIs 1. The ratio of the toner particles in the range of 2 to 1.6 is 65% by number or more, and more preferably 70% by number or more.
[0041]
When the ratio of the toner particles having the shape factor in the range of 1.0 to 1.6 is 65% by number or more, the density of toner particles in the toner layer transferred to the transfer material is increased, and the fixing property is improved. In addition, the offset is less likely to occur, the toner particles are less likely to be crushed, the contamination of the charge imparting member (carrier) is reduced, and the chargeability of the toner is stabilized.
[0042]
The method for controlling the shape factor is not particularly limited. For example, a method in which toner particles are sprayed in a hot air stream, a method in which toner particles are repeatedly applied with mechanical energy due to impact force in a gas phase, a method in which a toner is not dissolved in a solvent and a swirl flow is applied. A method of preparing toner particles having a shape factor of 1.0 to 1.6 or 1.2 to 1.6, and adding the toner particles to a normal toner so as to be within the range of the present invention. is there. In addition, toner particles whose shape factor is adjusted to 1.0 to 1.6 or 1.2 to 1.6 are added to normal toner in the same manner by controlling the overall shape at the stage of preparing a so-called polymerization method toner. There is a method to prepare.
[0043]
Among the above methods, the polymerization toner is preferable because it is simple as a production method and has excellent surface uniformity as compared with the pulverized toner.
[0044]
(3) In the toner of the present invention, the variation coefficient of the shape factor is preferably 16% or less, more preferably 14% or less, and the variation coefficient of the shape factor is calculated by the following equation.
[0045]
Variation coefficient of shape factor = [S₁/ K] × 100 (%)
Where S₁Represents the standard deviation of the shape factor of 100 toner particles, and K represents the average value of the shape factor.
[0046]
When the variation coefficient of the shape factor of the toner in the present invention is 16% or less, voids in the transferred toner layer (powder layer) are reduced, fixing property is improved, offset is less likely to occur, The charge amount distribution becomes sharp and the image quality is improved.
[0047]
In order to uniformly control the shape factor of the toner and the variation coefficient of the shape factor without variation of lots, the resin particles (polymer particles) constituting the toner of the present invention are prepared (polymerized), and the resin particles are fused. In the step of controlling the shape, an appropriate process end time may be determined while monitoring the characteristics of the toner particles (colored particles) being formed.
[0048]
Monitoring means that a measuring device is incorporated in-line, and process conditions are controlled based on the measurement result. In other words, in the case of a polymerization method toner that is formed by incorporating measurement such as shape in-line, for example, by associating or fusing resin particles in an aqueous medium, the shape and particle size are measured while performing sequential sampling in the fusing step. The reaction is stopped when the desired shape is obtained.
[0049]
Although it does not specifically limit as a monitoring method, The flow type particle image analyzer FPIA-2000 (made by Toa Medical Electronics Co., Ltd.) can be used. This apparatus is suitable because the shape can be monitored by performing image processing in real time while passing the sample liquid. That is, a pump or the like is used from the reaction field and is constantly monitored to measure the shape and the like, and the reaction is stopped when the desired shape is obtained.
[0050]
(4) In the toner of the present invention, the number variation coefficient of the toner represented by the following formula is preferably 27% or less, and more preferably 25% or less.
[0051]
Number variation coefficient = [S₂/ D_n] × 100%
Where S₂Indicates the standard deviation in the number particle size distribution, D_nIndicates the number average particle diameter (μm). When the number variation coefficient is 27% or less, voids in the transferred toner layer (powder layer) are reduced, fixing properties are improved, offset is less likely to occur, and charge amount distribution becomes sharper. There are also effects such as higher transfer efficiency and improved image quality.
[0052]
The number particle size distribution and the number variation coefficient of the toner of the present invention are measured by a Coulter Counter TAII or Coulter Multisizer (manufactured by Coulter Co.). In the present invention, a Coulter Multisizer is used, and an interface (manufactured by Nikkaki Co., Ltd.) for outputting a particle size distribution and a personal computer are connected to use. The aperture used in the Coulter Multisizer is 100 μm, and the volume and number of toners of 2 μm or more are measured to calculate the particle size distribution and average particle size. The number particle size distribution represents the relative frequency of the toner particles with respect to the particle diameter.
[0053]
The method for controlling the number variation coefficient in the toner of the present invention is not particularly limited. For example, a method of classifying toner particles by wind force can be used, but classification in a liquid is effective for reducing the number variation coefficient. As a method of classifying in this liquid, there is a method of separating and collecting toner particles according to a difference in sedimentation speed caused by a difference in toner particle diameter by using a centrifuge and controlling the rotation speed.
[0054]
In particular, when a toner is produced by a suspension polymerization method, a classification operation is indispensable in order to make the number variation coefficient in the number particle size distribution 27% or less. In the suspension polymerization method, it is necessary to disperse a polymerizable monomer in an oil droplet having a desired size as a toner in an aqueous medium before polymerization. That is, mechanical shearing with a homomixer or homogenizer is repeated for large oil droplets of a polymerizable monomer to reduce the oil droplets to the size of toner particles. In the method using shearing, the number particle size distribution of the obtained oil droplets is wide, and therefore the particle size distribution of the toner obtained by polymerizing the oil droplets is also wide. For this purpose, classification operation is required.
[0055]
(5) In the toner of the present invention, the proportion of toner without corners in the toner particles is preferably 50% by number or more, and more preferably 70% by number or more.
[0056]
When the ratio of toner particles having no corners is 50% by number or more, voids in the transferred toner layer (powder layer) are reduced, fixing property is improved, offset is less likely to occur, wear, The toner particles that are easily broken and the toner particles having a portion where the charge is concentrated are reduced, the charge amount distribution becomes sharp, the chargeability is stable, and good image quality can be formed over a long period of time. The
[0057]
Here, the toner particles having no corners are toner particles that do not substantially have a protrusion that concentrates electric charges or a protrusion that easily wears due to stress. Toner particles without toner. FIG. 2 is a schematic diagram of a toner with or without corners. Specifically, as shown in FIG. 2A, when the major axis of the toner particle T is L, a circle C having a radius (L / 10) is formed at one point with respect to the peripheral line of the toner particle T. When the inner side is rolled while being in contact with the toner, the case where the circle C does not substantially protrude outside the toner T is referred to as a toner particle having no corners. The case where the protrusion does not substantially protrude refers to the case where the protrusion having the protruding circle is one or less. Further, the major axis of the toner particles refers to the width of the particle that maximizes the interval between the parallel lines when the projected image of the toner particles on the plane is sandwiched between two parallel lines. 2B and 2C show projection images of toner particles having corners, respectively.
[0058]
The ratio of toner particles having no corners is measured as follows. First, an enlarged photograph of the toner particles is taken with a scanning electron microscope, and further enlarged to obtain a 15,000 times photographic image. The photographic image is then measured for the presence or absence of the corners. This measurement is performed on 100 toner particles.
[0059]
A method for obtaining toner having no corners is not particularly limited. For example, as described above as a method for controlling the shape factor, a method in which toner particles are sprayed into a hot air stream, a method in which toner particles are repeatedly applied with mechanical energy by impact force in a gas phase, or a toner is dissolved. It can be obtained by adding in a solvent that does not, and applying a swirling flow.
[0060]
Further, in the polymerization toner formed by associating or fusing the resin particles, the fusing particle surface has many irregularities at the fusing stop stage, and the surface is not smooth, but the temperature in the shape control step, By making the conditions such as the number of revolutions of the stirring blade and the stirring time appropriate, a toner having no corners can be obtained. These conditions vary depending on the physical properties of the resin particles. For example, by setting the number of revolutions to be higher than the glass transition temperature of the resin particles, the surface becomes smooth and a toner having no corners can be formed.
[0061]
(6) In the toner of the present invention, the average particle diameter of the toner particles is preferably 3 to 8 μm in number average particle diameter. When the toner particles are formed by a polymerization method, this particle size is determined in the toner production method described in detail later. Can be controlled by.
[0062]
When the number average particle diameter is 3 to 8 μm, toner particles having high adhesion force that fly and adhere to the heating member and generate offset in the fixing process are reduced, and transfer efficiency is increased and halftone The image quality can be improved, and the image quality of fine lines and dots can be improved.
[0063]
(7) In the toner of the present invention, when the particle diameter of the toner particles is D (μm), the natural logarithm lnD is taken on the horizontal axis, and the horizontal axis is divided into a plurality of classes at intervals of 0.23. In the histogram showing the particle size distribution, the toner is such that the sum (M) of the relative frequency (m1) of the first frequency toner particles and the relative frequency (m2) of the second frequency toner particles is 70% or more. Is preferred. When the sum (M) of the relative frequency (m1) and the relative frequency (m2) is 70% or more, the dispersion of the particle size distribution of the toner particles becomes narrow. Therefore, selective development can be performed by using the toner in the image forming process. It is also possible to reliably suppress the occurrence of this.
[0064]
In the present invention, the histogram showing the particle size distribution based on the number is a natural logarithm lnD (D: particle size of individual toner particles) having a plurality of classes (0 to 0.23: 0.23) at intervals of 0.23. 0.46: 0.46-0.69: 0.69-0.92: 0.92-1.15: 1.15-1.38: 1.38-1.61: 1.61-1. 84: 1.84 to 2.07: 2.07 to 2.30: 2.30 to 2.53: 2.53 to 2.76, and so on). This histogram is prepared by transferring the particle size data of a sample measured by a Coulter Multisizer to a computer via an I / O unit according to the following conditions and using the particle size distribution analysis program in the computer. is there.
[0065]
Aperture: 100 μm
Sample preparation method: Electrolyte [ISOTON R-1 (manufactured by Coulter Scientific Japan)] A suitable amount of a surfactant (neutral detergent) was added to 50 to 100 ml and stirred, and 10 to 20 mg of a measurement sample was added thereto. This system is prepared by dispersing for 1 minute with an ultrasonic disperser.
[0066]
<Toner production>
In the present invention, the toner having the above properties is preferably obtained by a polymerization method such as a suspension polymerization method or an emulsion polymerization method, and is particularly preferably produced by an emulsion polymerization method. The emulsion polymerization method can be obtained by dispersing a polymerizable monomer, a chain transfer agent, a polymerization initiator, a surfactant, other colorants, a surface modifier, a release agent, etc. in an aqueous solvent. The dispersion is polymerized to obtain resin fine particles, and the obtained resin fine particles are associated, fused, and salted out to obtain colored resin particles, and an external additive is added to the colored resin particles.
[0067]
<Polymerizable monomer>
As the polymerizable monomer, a radical polymerizable monomer is used as a constituent component, and a crosslinking agent can be used as necessary. Moreover, it is preferable to contain at least one radical polymerizable monomer having the following acidic group or radical polymerizable monomer having a basic group.
[0068]
(1) Radical polymerizable monomer
The radical polymerizable monomer component is not particularly limited, and a conventionally known radical polymerizable monomer can be used. Moreover, it can be used combining 1 type (s) or 2 or more types so that the required characteristic may be satisfy | filled.
[0069]
Specifically, aromatic vinyl monomers, methacrylic acid ester monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers, halogens An olefinic monomer or the like can be used.
[0070]
Examples of the aromatic vinyl monomer include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, p-methoxy styrene, p-phenyl styrene, p-chloro styrene, p-ethyl styrene, p. -N-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, 2, Examples thereof include styrene monomers such as 4-dimethylstyrene and 3,4-dichlorostyrene and derivatives thereof.
[0071]
Examples of methacrylic acid ester monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, Examples include hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, stearyl γ-aminoacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like.
[0072]
Examples of vinyl ester monomers include vinyl acetate, vinyl propionate, and vinyl benzoate.
[0073]
Examples of the vinyl ether monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether and the like.
[0074]
Examples of the monoolefin monomer include ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene and the like.
[0075]
Examples of the diolefin monomer include butadiene, isoprene, chloroprene and the like.
[0076]
Examples of the halogenated olefin monomer include vinyl chloride, vinylidene chloride, vinyl bromide and the like.
[0077]
(2) Cross-linking agent
As the crosslinking agent, a radical polymerizable crosslinking agent may be added in order to improve the properties of the toner. Examples of the radical polymerizable crosslinking agent include those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diallyl phthalate.
[0078]
(3) As a radical polymerizable monomer having an acidic group or a radical polymerizable monomer having a basic group, a radical polymerizable monomer having an acidic group or a radical polymerizable monomer having a basic group For example, amine-based compounds such as carboxyl group-containing monomers, sulfonic acid group-containing monomers, primary amines, secondary amines, tertiary amines, and quaternary ammonium salts can be used. Examples of the radical polymerizable monomer having an acidic group include carboxylic acid group-containing monomers such as acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, maleic acid monobutyl ester, and maleic acid monoester. An octyl ester etc. are mentioned. Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfosuccinic acid, octyl allyl sulfosuccinate and the like. These may have a structure of an alkali metal salt such as sodium or potassium or an alkaline earth metal salt such as calcium.
[0079]
Examples of the radical polymerizable monomer having a basic group include amine compounds, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and quaternary ammonium salts of the above four compounds, 3-dimethylaminophenyl acrylate, 2-hydroxy-3-methacryloxypropyltrimethylammonium salt, acrylamide, N-butylacrylamide, N, N-dibutylacrylamide, piperidylacrylamide, methacrylamide, N-butylmethacrylamide, N-octadecylacrylamide Vinyl pyridine, vinyl pyrrolidone; vinyl N-methylpyridinium chloride, vinyl N-ethylpyridinium chloride, N, N-diallyl Examples thereof include methylammonium chloride and N, N-diallylethylammonium chloride.
[0080]
As the radical polymerizable monomer used in the present invention, a radical polymerizable monomer having an acidic group or a radical polymerizable monomer having a basic group is used in an amount of 0.1 to 15% by mass based on the whole monomer. The radical polymerizable crosslinking agent is preferably used in the range of 0.1 to 10% by mass with respect to the total radical polymerizable monomer, although it depends on its properties.
[0081]
《Chain transfer agent》
For the purpose of adjusting the molecular weight, it is possible to use a commonly used chain transfer agent.
[0082]
The chain transfer agent is not particularly limited, and for example, octyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, n-octyl-3-mercaptopropionic acid ester, carbon tetrabromide and styrene dimer are used.
[0083]
<Polymerization initiator>
The radical polymerization initiator used in the present invention can be appropriately used as long as it is water-soluble. For example, persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4′-azobis-4-cyanovaleric acid and its salts, 2,2′-azobis (2-amidinopropane) salts, etc.), peroxides Compounds and the like.
[0084]
Furthermore, the radical polymerization initiator can be combined with a reducing agent as necessary to form a redox initiator. By using a redox initiator, the polymerization activity is increased, the polymerization temperature is lowered, and the polymerization time can be further shortened.
[0085]
The polymerization temperature may be any temperature as long as it is equal to or higher than the lowest radical generation temperature of the polymerization initiator, but for example, a range of 50 ° C. to 90 ° C. is used. However, it is also possible to polymerize at room temperature or higher by using a polymerization initiator that starts at room temperature, for example, a combination of hydrogen peroxide and a reducing agent (ascorbic acid or the like).
[0086]
<Surfactant>
In order to perform polymerization using the above-mentioned radical polymerizable monomer, it is necessary to perform oil droplet dispersion in an aqueous medium using a surfactant. Although it does not specifically limit as surfactant which can be used in this case, The following ionic surfactant can be mentioned as an example of a suitable thing.
[0087]
Examples of ionic surfactants include sulfonates (sodium dodecylbenzenesulfonate, sodium arylalkylpolyethersulfonate, 3,3-disulfonediphenylurea-4,4-diazo-bis-amino-8-naphthol-6 Sodium sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-6-sodium sulfonate, etc.), sulfuric acid Ester salts (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.), fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate) Beam, calcium oleate and the like).
[0088]
Nonionic surfactants can also be used. Specifically, polyethylene oxide, polypropylene oxide, combination of polypropylene oxide and polyethylene oxide, ester of polyethylene glycol and higher fatty acid, alkylphenol polyethylene oxide, ester of higher fatty acid and polyethylene glycol, ester of higher fatty acid and polypropylene oxide, sorbitan ester Etc.
[0089]
In the present invention, these are mainly used as an emulsifier at the time of emulsion polymerization, but may be used for other processes or purposes.
[0090]
《Colorant》
Examples of the colorant include inorganic pigments, organic pigments, and dyes.
[0091]
A conventionally well-known thing can be used as an inorganic pigment. Specific inorganic pigments are exemplified below.
[0092]
Examples of the black pigment include carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black, and magnetic powder such as magnetite and ferrite.
[0093]
These inorganic pigments can be used alone or in combination as required. Moreover, the addition amount of a pigment is 2-20 mass% with respect to a polymer, Preferably 3-15 mass% is selected.
[0094]
When used as a magnetic toner, the above-mentioned magnetite can be added. In this case, it is preferable to add 20 to 60% by mass in the toner from the viewpoint of imparting predetermined magnetic properties.
[0095]
Conventionally known organic pigments and dyes can also be used. Specific organic pigments and dyes are exemplified below.
[0096]
Examples of pigments for magenta or red include C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And CI Pigment Red 222.
[0097]
Examples of the orange or yellow pigment include C.I. I. Pigment orange 31, C.I. I. Pigment orange 43, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 185, C.I. I. Pigment yellow 155, C.I. I. Pigment yellow 156, and the like.
[0098]
Examples of pigments for green or cyan include C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16, C.I. I. Pigment blue 60, C.I. I. And CI Pigment Green 7.
[0099]
As the dye, C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95, etc. can be used, and mixtures thereof can also be used.
[0100]
These organic pigments and dyes can be used alone or in combination as desired. Moreover, the addition amount of a pigment is 2-20 mass% with respect to a polymer, Preferably 3-15 mass% is selected.
[0101]
The colorant can also be used as a surface-modified colorant. As the surface modifier, conventionally known ones can be used, and specifically, silane coupling agents, titanium coupling agents, aluminum coupling agents and the like can be preferably used.
[0102]
"Release agent"
The release agent is not particularly limited, and low molecular weight polyolefin waxes such as polypropylene and polyethylene, paraffin wax, Fischer-Tropsch wax, ester wax and the like can be used. The ester wax represented by the following general formula is preferable.
[0103]
R₁-(OCO-R₂)_n
Here, n is an integer of 1 to 4, preferably 2 to 4, more preferably 3 to 4, and particularly preferably 4.
[0104]
R₁, R₂Represents a hydrocarbon group which may have a substituent.
R₁: Carbon number = 1-40, Preferably it is 1-20, More preferably, it is 2-5.
[0105]
R₂: Carbon number = 1-40, Preferably it is 16-30, More preferably, it is 18-26.
[0106]
Specific examples of the release agent represented by the above general formula are shown below.
[0107]
[Chemical 1]

[0108]
[Chemical formula 2]

[0109]
The amount of the release agent added to the toner is preferably 1 to 30% by mass, more preferably 2 to 20% by mass, and still more preferably 3 to 15% by mass with respect to the total toner. The toner in the present invention is obtained by dispersing in water a polymer obtained by dissolving an ester release agent in a polymerizable monomer, polymerizing it, forming particles containing the ester release agent, and forming colorant particles. In addition, it is preferably produced by association / fusion / salting out to obtain colored resin particles and adding external additives thereto.
<Toner manufacturing process>
The toner of the present invention comprises a step of dispersing a solution of a polymerizable monomer in which an ester release agent is dissolved in an aqueous medium, and then adjusting resin fine particles encapsulating the ester release agent by a polymerization method. A step of salting out / fusing resin fine particles together with colorant particles in an aqueous medium using the resin fine particle dispersion, a washing step of filtering the obtained particles from the aqueous medium to remove a surfactant, etc. It is preferable to produce by a polymerization method comprising a step of drying the obtained colored resin particles and a step of adding an external additive to the colored resin particles obtained by drying. In addition to the colorant and the release agent, a charge control agent that is a component of the toner can be added as particles in this step.
[0110]
In addition, an aqueous medium here consists of water as a main component, and shows content whose water content is 50 mass% or more. Examples of substances other than water include organic solvents that dissolve in water, such as methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. Alcohol organic solvents such as methanol, ethanol, isopropanol, and butanol, which are preferably organic solvents that do not dissolve the resin, are particularly preferable.
[0111]
As a preferable polymerization method in the present invention, a dispersion liquid in which a polymerizable monomer solution in which a release agent is dissolved is dispersed in oil droplets by mechanical energy in an aqueous medium in which a surfactant having a critical micelle concentration or less is dissolved. In addition, a method of radical polymerization by adding a water-soluble polymerization initiator can be given. In this case, an oil-soluble polymerization initiator may be added to the polymerizable monomer solution.
[0112]
The disperser for performing the oil droplet dispersion is not particularly limited, and examples thereof include CLEARMIX, ultrasonic disperser, mechanical homogenizer, manton gourin, and pressure homogenizer.
[0113]
The colorant itself may be used after surface modification. In the surface modification method of the colorant, the colorant is dispersed in a solvent, and after the surface modifier is added therein, the temperature is raised and the reaction is performed. After completion of the reaction, the mixture is filtered, washed with the same solvent, repeatedly filtered and dried to obtain a pigment treated with a surface modifier.
[0114]
There is a method in which the colorant particles are prepared by dispersing a colorant in an aqueous medium. This dispersion is performed in a state where the surfactant concentration in water is equal to or higher than the critical micelle concentration (CMC).
[0115]
The disperser at the time of pigment dispersion is not particularly limited, but preferably a medium such as CLEARMIX, ultrasonic disperser, mechanical homogenizer, pressure disperser such as Manton Gorin or pressure homogenizer, sand grinder, Getzmann mill, diamond fine mill, etc. Type disperser. As the surfactant used here, the aforementioned surfactants can be used.
[0116]
In the salting-out / fusion process, a salting-out agent composed of an alkali metal salt or an alkaline earth metal salt is added as a flocculant having a critical coagulation concentration or higher in water in which resin fine particles and colorant particles are present. Next, it is a step of performing fusion at the same time as the salting-out proceeds by heating the resin fine particles above the glass transition point.
[0117]
Here, the alkali metal salt and the alkaline earth metal salt which are salting-out agents include lithium, potassium, sodium and the like as the alkali metal, and examples of the alkaline earth metal include magnesium, calcium, strontium and barium. Preferably, potassium, sodium, magnesium, calcium, and barium are used. Examples of the salt include chlorine salt, bromine salt, iodine salt, carbonate salt, sulfate salt and the like.
[0118]
Further, in the present invention, it is preferable to use a method in which the dispersion temperature of the resin fine particles is raised as quickly as possible and heated to the glass transition temperature or more of the resin fine particles. The time until this temperature rise is less than 30 minutes, preferably less than 10 minutes. Further, although it is necessary to quickly raise the temperature, the rate of temperature rise is preferably 1 ° C./min or more. The upper limit is not particularly clear, but is preferably 15 ° C./min or less from the viewpoint of suppressing the generation of coarse particles due to rapid progress of salting out / fusion. As a particularly preferred embodiment, there can be mentioned a method in which salting-out / fusion is continued even when the glass transition temperature is reached. By adopting this method, the fusion can be effectively advanced as the particles grow, and the durability as the final toner can be improved.
[0119]
In addition to the colorant and the release agent, the toner may be added with a material that can provide various functions as a toner material. Specific examples include charge control agents. These components can be added simultaneously with the resin fine particles and the colorant particles in the salting out / fusion step described above, and can be added by various methods such as a method included in the toner and a method of adding to the resin fine particles themselves.
[0120]
Similarly, various known charge control agents and those that can be dispersed in water can be used. Specific examples include nigrosine dyes, naphthenic acid or higher fatty acid metal salts, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, salicylic acid metal salts or metal complexes thereof.
[0121]
For polymerized toner that associates or fuses resin fine particles in an aqueous medium, by controlling the flow and temperature distribution of the medium in the reaction vessel at the fusing stage, it is further possible to control the heating temperature in the shape control step after fusing. The shape distribution and shape of the entire toner can be arbitrarily changed by controlling the number of rotations of stirring and time.
[0122]
That is, in a polymerization method toner that associates or fuses resin fine particles, the flow in the reaction apparatus is made into a laminar flow, and a stirring blade and a stirring tank that can make the temperature distribution inside are uniform, By controlling the temperature, the number of rotations, and the time in the shape control step, the toner having the shape factor and uniform shape distribution of the present invention can be formed. The reason for this is that if the laminar flow is fused in a place where the laminar flow is formed, strong stress is not applied to the particles (aggregation or agglomerated particles) in which aggregation and fusion proceed, and in laminar flow where the flow is accelerated As a result of the uniform temperature distribution in the stirring tank, the shape distribution of the fused particles is estimated to be uniform. Further, the fused particles gradually become spherical by heating and stirring in the subsequent shape control step, and the shape of the toner particles can be arbitrarily controlled.
[0123]
In order to control to the shape of the present invention, it is preferable that salting-out and fusion are performed simultaneously. In the method of heating after forming the agglomerated particles, the shape tends to be distributed, and the generation of fine particles cannot be suppressed. That is, since the aggregated particles are heated while being stirred in the aqueous medium, it is presumed that the aggregated particles are repartitioned and a component having a small particle size is likely to be generated.
[0124]
<External additive>
To the toner of the present invention, so-called external additives can be added and used for the purpose of improving fluidity, chargeability and cleaning property. These external additives are not particularly limited, and various inorganic fine particles, organic fine particles and lubricants can be used.
[0125]
A conventionally well-known thing can be used as an inorganic fine particle. Specifically, silica, titanium, alumina fine particles and the like can be preferably used. These inorganic fine particles are preferably hydrophobic. Specifically, as silica fine particles, for example, commercially available products R-805, R-976, R-974, R-972, R-812, R-809 manufactured by Nippon Aerosil Co., Ltd., HVK-2150, H manufactured by Hoechst -200, commercially available products TS-720, TS-530, TS-610, H-5, MS-5 and the like manufactured by Cabot Corporation.
[0126]
Examples of the titanium fine particles include commercial products T-805 and T-604 manufactured by Nippon Aerosil Co., Ltd., commercial products MT-100S, MT-100B, MT-500BS, MT-600, MT-600SS, and JA- 1. Commercial products TA-300SI, TA-500, TAF-130, TAF-510, TAF-510T manufactured by Fuji Titanium Co., Ltd. Commercial products IT-S, IT-OA, IT-OB, IT- manufactured by Idemitsu Kosan Co., Ltd. OC etc. are mentioned.
[0127]
Examples of the alumina fine particles include commercial products RFY-C and C-604 manufactured by Nippon Aerosil Co., Ltd. and commercial products TTO-55 manufactured by Ishihara Sangyo Co., Ltd. As the organic fine particles, spherical organic fine particles having a number average primary particle diameter of about 10 to 2000 nm can be used. As this, a homopolymer such as styrene or methyl methacrylate or a copolymer thereof can be used.
[0128]
Examples of lubricants include, for example, zinc stearate, aluminum, copper, magnesium, calcium, etc., zinc oleate, manganese, iron, copper, magnesium, etc., zinc palmitate, copper, magnesium, calcium, etc. And salts of higher fatty acids such as zinc of linoleic acid, salts of calcium, etc., zinc of ricinoleic acid, salts of calcium, etc.
[0129]
The amount of these external additives added is preferably 0.1 to 5% by mass with respect to the toner. As a method for adding the external additive, various known mixing apparatuses such as a Turbuler mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer can be used.
[0130]
【Example】
Next, an embodiment of the present invention will be specifically described, but the present invention is not limited to this embodiment. In the text, “part” means “part by mass”.
[0131]
[Manufacture of carriers]
<Carrier core production example 1>
Li₂CO_Three22 mol%, Fe₂O_Three78 mol% was pulverized and mixed in a wet ball mill for 2 hours, dried, and temporarily calcined by maintaining at 900 ° C. for 2 hours. This was again pulverized in a ball mill for 3 hours to form a slurry. A dispersant and a binder were added, and the primary particles were adjusted by granulating and drying with a spray dryer, and further subjected to main firing at 1200 ° C. for 3 hours to obtain a ferrite carrier core having an average particle diameter of 63 μm. This was designated as “Carrier Core 1”.
[0132]
<Carrier core production example 2>
Li₂CO_Three23 mol%, Mg (OH)₂7 mol%, Fe₂O_ThreeA ferrite carrier core having an average particle size of 53 μm was obtained in the same manner as in Carrier Core Production Example 1 except that 70 mol% was used and the temperature of the main firing was 1250 ° C. This was designated as “Carrier Core 2”.
[0133]
<Carrier core production example 3>
Li₂CO_Three20 mol%, MnO 8 mol%, Fe₂O_ThreeA ferrite carrier core having an average particle size of 45 μm was obtained in the same manner as in Carrier Core Production Example 1 except that 72 mol% was used. This was designated as “Carrier Core 3”.
[0134]
<Carrier Core Production Example 4>
Mg (OH)₂10 mol%, MnO 8 mol%, Fe₂O_ThreeA ferrite carrier core having an average particle size of 55 μm was obtained in the same manner as in Carrier Core Production Example 1 except that 82 mol% was used and the main firing temperature was 1280 ° C. This was designated as “Carrier Core 4”.
[0135]
<Carrier Production Example 1>
2 parts by mass of styrene: glycidyl methacrylate: acrylic acid copolymer (mass ratio = 86: 7: 7) resin fine particles (Tg = 98 ° C./number average primary particle size = 0.1 μm) prepared by emulsion polymerization 100 parts by weight of “Carrier Core 1” was mixed, and the resin coating was performed by using the dry coating apparatus of FIG. 1 and stirring for 20 minutes under a temperature condition of 90 ° C. and a horizontal rotation speed of 13 m / sec. Subsequently, the internal temperature was adjusted to 120 ° C., the stirring condition was 5 m / sec, and heat treatment was performed for 30 minutes to obtain a carrier. The carrier thus obtained had an MEK insoluble content of 40% by mass, and was designated “Invention Carrier 1”.
[0136]
<Carrier Production Example 2>
A carrier was obtained in the same manner as in Carrier Production Example 1 except that carrier core 2 was used instead of carrier core 1 and the stirring time at 120 ° C. was changed to 15 minutes. The carrier thus obtained had an MEK insoluble content of 35% by mass and was designated “present carrier 2”.
[0137]
<Carrier Production Example 3>
A carrier was obtained in the same manner as in Carrier Production Example 1 except that carrier core 3 was used instead of carrier core 1 and the stirring time at 120 ° C. was changed to 45 minutes. The carrier thus obtained had an MEK insoluble content of 59% by mass, and this was designated “present carrier 3”.
[0138]
<Carrier Production Example 4>
Styrene: glycidyl methacrylate: acrylic acid copolymer (mass ratio = 80: 10: 10) resin fine particles prepared by emulsion polymerization method using carrier core 4 instead of carrier core 1 in carrier production example 1 (Tg = 97 ° C./number average primary particle size = 0.1 μm) was used, and the carrier was obtained in the same manner except that the stirring at 120 ° C. was 130 ° C. and the stirring time was 30 minutes. The carrier thus obtained had an MEK insoluble content of 73 mass%, and this was designated “present carrier 4”.
[0139]
<Carrier Production Example 5>
In carrier production example 1, styrene: glycidyl methacrylate: 2 ethylhexyl acrylate copolymer (mass ratio = 80: 10: 10) resin fine particles (Tg = 93 ° C./number average primary particle size) prepared by emulsion polymerization as resin fine particles = 0.1 μm), and a carrier was obtained in the same manner except that the stirring time at 120 ° C. was changed to 45 minutes. The carrier thus obtained had an MEK insoluble content of 36% by mass, and was designated “Invention Carrier 5”.
[0140]
<Carrier Production Example 6>
In carrier production example 1, styrene: glycidyl methacrylate: diethylaminoethyl methacrylate: butyl acrylate copolymer (mass ratio = 75: 10) produced by emulsion polymerization as resin fine particles using carrier core 4 instead of carrier core 1 : 10: 5) Carriers were obtained in the same manner except that resin fine particles (Tg = 94 ° C./number average primary particle size = 0.1 μm) were used and the stirring time at 120 ° C. was changed to 45 minutes. The carrier thus obtained had an MEK insoluble content of 49% by mass, and was designated “Invention carrier 6”.
[0141]
<Comparative carrier production example 1>
In Carrier Production Example 1, a carrier that was not stirred at 120 ° C. was used. The carrier thus obtained had an MEK insoluble content of 13% by mass, and this was designated as “Comparative carrier 1”.
[0142]
<Comparative carrier production example 2>
In Carrier Production Example 4, the stirring time at 130 ° C. was 120 minutes. The carrier thus obtained had an MEK insoluble content of 99% by mass, and was designated as “Comparative carrier 2”.
[0143]
The average particle diameter of each carrier obtained as described above is an average when the maximum major axis is measured for 500 carriers using a photograph enlarged 250 times by observation with a scanning electron microscope as described above. Indicated by value. The particle size distribution was measured by a sieving method.
[0144]
[Table 1]

[0145]
[Production of toner]
<HP (High Polymerization) Latex Production Example 1>
A solution prepared by dissolving 7.08 g of an anionic active agent (sodium dodecyl sulfonate: SDS) in ion-exchanged water (2760 g) in a 5000 ml separable flask equipped with a stirrer, temperature sensor, condenser, and nitrogen introduction device. Added. The internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream. On the other hand, a monomer solution consisting of 115.1 g of styrene, 42.0 g of n-butyl acrylate, and 10.9 g of methacrylic acid was prepared. Subsequently, a solution obtained by dissolving 0.42 g of a polymerization initiator (potassium persulfate: KPS) in 200 g of ion-exchanged water was added, and then the temperature was raised to 75 ° C., and the monomer solution was added dropwise over 1 hour. Latex particles were prepared by heating and reacting with stirring for 2 hours. This latex particle was designated as HP-1.
[0146]
It was 518,000 when the peak molecular weight of latex particle | grains HP-1 obtained here was measured by GPC.
[0147]
<HP Latex Production Example 2>
Latex particles were obtained in the same manner as in HP Latex Production Example 1 except that the reaction temperature was 85 ° C. This latex particle was designated as HP-2.
[0148]
The latex particles obtained here had a peak molecular weight of 421,000.
<MP (Medium Polymerization) Latex Production Example 1>
In a flask having a stirrer, 72.0 g of Exemplified Compound 19) was added to a solution of 383.6 g of styrene, 140.0 g of n-butyl acrylate, 36.4 g of methacrylic acid, and 4.6 g of n-octyl-3-mercaptopropionic acid ester. Heat to 80 ° C to dissolve. Next, a solution in which SDS = 1.6 g was dissolved in 2000 ml of water was heated to 80 ° C., and the above compound was heated to Exemplified Compound 19) by a mechanical disperser (CLEAMIX) having a circulation path to the SDS aqueous solution. The resulting solution was mixed and dispersed to prepare an emulsified liquid containing emulsified particles having a uniform dispersed particle size.
[0149]
Subsequently, a solution in which 19.1 g of a polymerization initiator (KPS) is dissolved in 240 ml of ion-exchanged water is added, and further 750 ml of water is added and heated to 80 ° C. Reaction was performed at 80 ° C. for 3 hours to obtain latex particles. The latex particles obtained here were designated as MP-1.
[0150]
The peak molecular weight of latex particle MP-1 was 103,000.
<MP Latex Production Example 2>
Latex particles were obtained in the same manner as in MP Latex Production Example 1 except that the amount of n-octyl-3-mercaptopropionic acid ester added was 8.3 g. The latex particles obtained here were designated as MP-2.
[0151]
The peak molecular weight of the latex particle MP-2 was 81,000.
<LP (Low Polymerization) Latex Production Example 1>
A solution in which SDS = 60 g was previously dissolved in ion-exchanged water (5000 ml) was added to a flask equipped with a stirrer, a temperature sensor, a condenser, and a nitrogen introducing device. While stirring at a stirring speed of 230 rpm under a nitrogen stream, a solution obtained by dissolving KPS = 22.8 g in 200 ml of water was added, and further maintained at 80 ° C., styrene = 850 g, butyl acrylate = 252 g, methacrylic acid = 98 g and A solution prepared by mixing n-octyl-3-mercaptopropionate = 32 g is added dropwise over 1 hour. Subsequently, it was made to react for 2 hours and the target latex particle was obtained. The latex particles obtained here were designated as LP-1. The peak molecular weight of latex particle LP-1 was 18,000.
[0152]
<Manufacture of colorant dispersion Bk>
Sodium n-dodecyl sulfate = 90 g was dissolved in 1600 ml of ion-exchanged water with stirring. To this liquid, 200 g of Mogal L (Carbot Black manufactured by Cabot) was gradually added with stirring, and then dispersed using CLEARMIX. As a result of measuring the particle diameter of the dispersion using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd., the weight average diameter was 101 nm. This dispersion was designated as “colorant dispersion Bk”.
[0153]
<Meeting process>
The above 5 types of latex “HP-1”, “HP-2”, “MP-1”, “MP-2” and “LP-1” were mixed in combinations as shown in Table 2, and ion exchange was further performed. 2000 ml of water and “colorant dispersion Bk” were placed in a reaction vessel equipped with a temperature sensor, a cooling tube, a nitrogen introducing device, and a stirring device, stirred, adjusted to 30 ° C., and 5 M hydroxylated into this solution. A sodium aqueous solution was added to adjust the pH to 11.0. Subsequently, an aqueous solution in which 526 g of magnesium chloride hexahydrate was dissolved in 720 ml of ion-exchanged water was added at 30 ° C. for 10 minutes with stirring. Thereafter, after standing for 3 minutes, temperature increase was started, and the temperature was increased to 90 ° C. in 6 minutes (temperature increase rate = 10 ° C./min). In that state, the particle size was measured with a Coulter Counter TAII. When the number average particle size reached 6.5 μm, an aqueous solution in which 1150 g of sodium chloride was dissolved in 7000 ml of ion-exchanged water was added to stop the particle growth and continue. Then, the liquid reaction temperature was in the range of 80 to 95 ° C., and the stirring time (reaction time) was changed from 1 hour to 10 hours for salting out / fusion. Then, it cooled to 30 degreeC on the conditions of 8 degreeC / min, hydrochloric acid was added, pH was adjusted to 2.0, and stirring was stopped. The produced colored resin particles are filtered, washed repeatedly with ion-exchanged water, and then dried with hot air of 40 ° C., so that the eight kinds of colored resin particles shown in Table 2 having different shapes (colored resin particles 1Bk to colored resin) Particles 8Bk) were obtained, and the eight types of colored resin particle numbers and the liquid reaction temperature and reaction time when producing these colored resin particles are shown in Table 2.
[0154]
In the production example of the colored resin particles 1Bk, C.I. I. A colored resin particle 1Y is obtained in the same manner except that Solvent Yellow 93 is used, and C.I. I. Pigment Red 122 was used in the same manner as colored resin particles 1M, and C.I. I. Pigment Blue 15: 3 was used in the same manner as colored resin particles 1C to obtain three types of colored resin particles, and the three types of colored resin particles (colored resin particles 1Y, colored resin particles 1M, colored resin particles) Table 2 shows the colored resin particle numbers of 1C) and the liquid reaction temperature and reaction time when preparing the colored resin particles.
[0155]
[Table 2]

[0156]
Next, the shape factor, the variation factor of the shape factor, the number average particle size of the 11 kinds of the colored resin particles 1Bk to 8Bk, the colored resin particle 1Y, the colored resin particle 1M, and the colored resin particle 1C, The number variation coefficient of the number particle size distribution was measured by the measurement method, and the results are shown in Table 3.
[0157]
[Table 3]

[0158]
Also, the relative frequency (m1) of the first frequency toner particles in the histogram showing the number% of the shape factors 1.2 to 1.6 of the 11 kinds of colored resin particles, the number ratio of the cornerless toner, and the number-based particle size distribution. ) And the relative frequency (m2) of the second frequency toner particles (number%) were measured by the measurement method, and the results are shown in Table 4.
[0159]
[Table 4]

[0160]
<Production example of toner 1Bk to toner 1C>
Subsequently, 1% by mass of hydrophobic silica (number average primary particle size = 10 nm, degree of hydrophobicity = 63) and hydrophobic titanium oxide (number average primary particle size = 25 nm, degree of hydrophobicity) were added to each of the 11 types of colored resin particles. = 60) 1% by mass was added and mixed with a Henschel mixer to obtain a toner. These were designated as “Toner 1Bk” to “Toner 1C”.
[0161]
Note that there is no difference between the colored resin particles and the toner in terms of physical properties such as particle shape and particle size.
[0162]
24 types of developers (black developer 1 to 13 for the present invention, Y developer for the present invention) in which the carrier 1 to 6 of the present invention and the carriers 1 and 2 for comparison are combined for each of the above toners 1, M developer 1, C developer 1 and comparative black developer 1 and 2, comparative Y developer 1 and 2, comparative M developer 1 and 2, comparative C developer 1 and 2) was prepared. Table 6 shows the developer numbers, toner numbers corresponding to the developer numbers, and carrier numbers.
[0163]
[Table 5]

[0164]
Examples 1 to 13 and Comparative Examples 1 and 2
<Image evaluation by live-action>
A black developer (black developers 1 to 13 for the present invention and black developers 1 and 2 for comparison) using a digital copying machine 7030 manufactured by Konica Co., Ltd. having a toner recycling method was used to compare Examples 1 to 13 and comparison. The actual image test of Examples 1 and 2 was performed, and the evaluation results of the actual image are shown in Table 6. As the fixing method, a pressure contact type heat fixing device was used. The specific configuration is as follows.
[0165]
The surface was covered with a tube of PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) (thickness: 120 μm) with an inner diameter of 30 mm and a total width of 310 mm. An aluminum alloy is used as a heating roller (upper roller), and the surface has an iron cored bar with an inner diameter of 30 mm and a thickness of 1.0 mm, which is similarly composed of sponge-like silicone rubber (Asker C hardness = 48: thickness 2 mm). It has a pressure roller (lower roller). The nip width was 3.8 mm. Using this fixing device, the linear velocity of printing was set to 180 mm / sec.
[0166]
Note that a web-type supply system impregnated with polydiphenyl silicone (having a viscosity of 10 Pa · s at 20 ° C.) was used as a cleaning mechanism of the fixing device. The fixing temperature was controlled by the surface temperature of the upper roll, and was set to 180 ° C. The amount of silicone oil applied was 0.1 mg / A4.
[0167]
Evaluation was performed by printing 200,000 sheets of a 5% pixel rate original in a high temperature and high humidity environment of 30 ° C./80% RH by intermittent printing of one sheet. At that time, the initial image density and the image density after 200,000 sheets were measured. The image density was a solid black image, and the reflection density was evaluated as an absolute density using RD-918 manufactured by Macbeth. The fog density was evaluated by using a solid white image, using RD-918 manufactured by Macbeth Co., Ltd., and the relative density with the paper reflection density set to “0”.
[0168]
[Table 6]

[0169]
From Table 6, Examples 1 to 13 using the developer containing the carrier of the present invention produced a high-density clear image without fogging in the process of continuous image formation of 200,000 sheets. When the developers 1 and 2 are used, it can be seen that either image density reduction or fogging occurs in the process of image formation on 200,000 continuous sheets, which is not practical.
[0170]
Example 14 and Comparative Examples 3 and 4
Next, a combination of “black developer 1” “Y developer 1” “M developer 1” “C developer 1” (Example 14), “comparative black developer 1” “comparative Y developer 1” “Comparative M Developer 1” “Comparative C Developer 1” (Comparative Example 3) “Comparative Black Developer 2” “Comparative Y Developer 2” “Comparative M Developer 2” “ A color image copying test of Example 14 and Comparative Examples 3 and 4 was performed using a Canon color copier pixel 2100 having an intermediate transfer member using a comparative C developer 2 ". The color difference deterioration was evaluated, and the results are shown in Table 7.
[0171]
In the above color copying machine, a Y / M / C / Bk developing device is disposed around the multilayer organic photosensitive member, and each color is developed on the organic photosensitive member, and then transferred onto the intermediate transfer member for each color. Then, after the full color image was formed on the intermediate transfer member, the one having an intermediate transfer member that was transferred to paper as an image forming support was used. Note that a blade cleaning method was adopted for cleaning the organic photoreceptor.
[0172]
As the fixing method, a pressure contact type heat fixing device was used.
The specific configuration is as follows.
[0173]
The surface was covered with a tube of PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) (thickness: 120 μm) with an inner diameter of 40 mm and a total width of 310 mm. An aluminum alloy is used as a heating roller (upper roller), and the surface has an iron core bar having a thickness of 2.0 mm and an inner diameter of 40 mm, which is similarly composed of sponge-like silicone rubber (Asker C hardness = 48: thickness 2 mm). It has a pressure roller (lower roller). The nip width was 5.8 mm. Using this fixing device, the linear speed of printing was set to 250 mm / sec.
[0174]
Note that a web-type supply system impregnated with polydiphenyl silicone (having a viscosity of 10 Pa · s at 20 ° C.) was used as a cleaning mechanism of the fixing device.
[0175]
The fixing temperature was controlled by the surface temperature of the upper roll, and was set to a set temperature of 175 ° C. The amount of silicone oil applied was 0.6 mg / A4.
[0176]
Evaluation was made by printing 50,000 sheets of originals with a full color pixel ratio of 25% by continuous printing in a room temperature / high humidity environment of 25 ° C./80% RH environment. At that time, the difference between the chroma (chromaticity) after the initial and 50,000 sheets, that is, the color difference was evaluated by the following method. Evaluation Method: The color of the solid image portion of the secondary color (red, blue, green) in each of the first formed image and the 50,000th formed image was measured by “Macbeth Color-Eye 7000”, and CMC (2: 1) The color difference was calculated using the color difference formula. In the color difference evaluation, if the color difference obtained by the CMC (2: 1) color difference formula is 5 or less, it can be said that the change in color of the formed image is acceptable.
[0177]
[Table 7]

[0178]
From Table 7, when a color image of continuous 50,000 sheets was formed using the developer containing the carrier of the present invention, there was no deterioration of the color difference from start to finish, and a clear color image was obtained. It can be seen that when a color image of continuous 50,000 sheets is formed using a developer containing a carrier, the color difference of the color image is significantly deteriorated and the practicality is poor.
[0179]
【The invention's effect】
As demonstrated by the examples, the two-component developer of the present invention, particularly the developer containing the carrier obtained by the production method of the present invention, generates fog even when used for image formation over a long period of time. In the case where a high-density clear image is obtained and used for color image formation over a long period of time, the color difference is hardly deteriorated, and an excellent effect is obtained such that a clear color image can be obtained.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a dry coating apparatus.
FIG. 2 is a schematic diagram illustrating a toner with or without corners.
[Explanation of symbols]
10 Main body container
11 Main body top cover
12 Raw material inlet
13 Input valve
14 Filter
15 Inspection port
16 Thermometer
17 Jacket
18 Horizontal rotating body
18a, 18c Horizontal rotating wings
18d Horizontal rotating body center
19 Vertical rotating body
20 Product outlet
21 Discharge valve
22 motor

Claims (3)

In a two-component developer comprising a carrier coated with resin on the surface of magnetic particles and a toner, the carrier comprises a ferrite carrier core represented by the following general formula (I), and the carrier has an average particle size of 10 to 10 a 100 [mu] m, and the coating resin is seen containing 20 to 95 wt% methyl ethyl ketone solvent-insoluble matter, further the toner is the percentage of toner particles the shape factor is in the range of 1.2 to 1.6 is 65% by number or more two-component developer which is characterized in that it.
General formula _{(I) (M y O x} ) a (Fe 2 O 3) b
However, in the formula, M is a metal selected from Ca, Li, Mg, Fe, Mn, Cu, and Zn, and these may be plural.
x is 2 or 1
y is 2 or 1
a + b = 1
a and b are molar ratios and have a relationship of a <b.   2. The method for producing a carrier for a two-component developer according to claim 1, wherein the resin particles and the magnetic particles are mixed by a dry method, and mechanical impact force and heat are applied to contain 20 to 95% by mass of a methyl ethyl ketone solvent insoluble matter. A method for producing a carrier, comprising forming a resin coating layer.   2. The method for producing a carrier for a two-component developer according to claim 1, wherein the magnetic particles and the resin particles are mixed in a dry method, a mechanical impact force and heat are applied to form a resin coating layer, and the resin particles A method for producing a carrier, characterized in that comprises a thermosetting resin.

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