JP3774970B2 - Toner for electrostatic latent image development, developer and image forming method - Google Patents

Description

【００３１】
〔但し、Ｒ¹は水素原子又は炭素原子数１〜４のアルキル基（例えばメチル基）を示し、Ｒ²は炭素原子数１〜８のアルキレン基、炭素原子数１〜８のアルキレンオキシアルキレン基、フェニレン基、ナフチレン基、フェニレンアルキレン基もしくはこれらの基が二以上組み合わされてなる基を示し、Ｒ³とＲ⁴は互いに同一でも異なっていてもよく、水素原子、炭素原子１〜８のアルキル基、アリール基（例えばフェニル基、ナフチル基）、もしくはフェニルアルキル基を示す。Ｍは単なる結合手又は−ＣＯＮＲ−、−ＣＯＯ−を示し、Ａは２価のベンジル基又はフェネチル基を示す（但しＲは水素原子又はメチル基を示す）。又Ｂはピリジル基、イミダゾリル基を示す。〕
これら一般式（１）〜（７）で表される構成単位に、相当するモノマー（例えば一般式（１）〜（７）において主鎖部分の炭素間の結合を二重結合としたモノマー）を用い、定着性改良剤の母核に導入するか、又は該相当するモノマーと他のモノマーとを共重合して本発明に係る定着性改良剤としてもよい。
【００３２】
前記一般式（１）で表される構成単位に相当するモノマーの例としては、下記の様な化合物を挙げることができる。
【００３３】
Ｎ，Ｎ−ジメチルアミノエチルメタクリレート、Ｎ，Ｎ−ジエチルアミノエチルメタクリレート、Ｎ−メチルアミノエチルメタクリレート、Ｎ，Ｎ−ジメチルアミノメチルメタクリレート、ｐ−Ｎ，Ｎ−ジメチルアミノフェニルメタクリレート、Ｎ，Ｎ−ジメチルアミノエチルアクリレート、Ｎ，Ｎ−ジエチルアミノエチルアクリレート、Ｎ−メチルアミノエチルアクリレート、Ｎ，Ｎ−ジエチルアミノメチルアクリレート、ｐ−Ｎ，Ｎ−ジメチルアミノフェニルアクリレート。
【００３４】
一般式（２）で表される構成単位に相当するモノマーの例としては、下記の様な化合物を挙げることができる。
【００３５】
Ｎ，Ｎ−ジメチルアミノエチルメタクリルアミド、Ｎ，Ｎ−ジエチルアミノエチルメタクリルアミド、Ｎ−メチルアミノエチルメタクリルアミド、Ｎ，Ｎ−ジメチルアミノメチルメタクリルアミド、ｐ−Ｎ，Ｎ−ジメチルアミノフェニルメタクリルアミド、Ｎ，Ｎ−ジメチルアミノエチルアクリルアミド、Ｎ，Ｎ−ジエチルアミノエチルアクリルアミド、Ｎ−メチルアミノエチルアクリルアミド、Ｎ，Ｎ−ジエチルアミノメチルアクリルアミド、ｐ−Ｎ，Ｎ−ジメチルアミノフェニルアクリルアミド。
【００３６】
一般式（３）で表される構成単位に相当するモノマーの例としては、下記の様な化合物を挙げることができる。
【００３７】
Ｎ，Ｎ−ジメチルメタクリルアミド、Ｎ，Ｎ−ジエチルメタクリルアミド、Ｎ−プロピルメタクリルアミド、Ｎ，Ｎ−ジメチルアクリルアミド、Ｎ，Ｎ−ジエチルアクリルアミド、Ｎ−プロピルアクリルアミド。
【００３８】
一般式（４）で表される構成単位に相当するモノマーの例としては、下記の様な化合物を挙げることができる。
【００３９】
ｐ−Ｎ，Ｎ−ジメチルアミノスチレン、ｐ−Ｎ，Ｎ−ジエチルアミノスチレン、ｐ−Ｎ，Ｎ−ジプロピルアミノスチレン、ｐ−Ｎ−メチルアミノスチレン。
【００４０】
一般式（５）で表される構成単位に相当するモノマーの例としては、下記の様な化合物を挙げることができる。
【００４１】
Ｎ−ビニルジメチルアミン、Ｎ−ビニルジエチルアミン、Ｎ−ビニルジプロピルアミン、Ｎ−ビニルプロピルアミン。
【００４２】
一般式（６）で表される構成単位に相当するモノマーの例としては下記の様な化合物を挙げることができる。即ちビニルベンジルジアルキルアミン（アルキル基はｎ＝１〜６の置換又は未置換のアルキル基であり、これらは同一であっても異なっていてもよい。）、ビニルフェネチルジアルキルアミン（アルキル基はｎ＝１〜６の置換又は未置換アルキル基、これらは同一であっても異なっていてもよい。）、ビニルカルバモイルベンジルジアルキルアミン（アルキル基はｎ＝１〜６の置換又は未置換アルキル基、これらは同一であっても異なっていてもよい。）。
【００４３】
一般式（７）で表される構成単位に相当するモノマーの例としては下記の様な化合物を挙げることができる。
【００４４】
４−ビニルピリジン、２−ビニルピリジン、Ｎ−ビニルイミダゾール。
【００４５】
更に上記一般式（１）〜（７）で表される構成単位を第四級アンモニウム塩の型にしたものも用いることが出来、例えば窒素原子に置換した基としては炭素数１〜６のアルキル基（例えばメチル基、エチル基）、ベンジル基、シクロアルキル基等が好ましいものとして挙げられる。
【００４６】
〈ポリオレフィン〉
本発明において好ましく用いられる定着性改良剤に用いられるポリオレフィンとしては、低分子量ポリオレフィン（低分子量ポリエチレン、低分子量ポリプロピレン等）を挙げることができる。ここで言う低分子量とは、数平均分子量（Ｍｎと略記する。）で好ましくは１００〜１０，０００を表す。更に好ましくはＭｎ＝５００〜５，０００の範囲を示す。この低分子量ポリオレフィンは前述したカチオン性ユニットを有するモノマーを用い、常法に従い変性することができる。本発明のカチオン性ユニットを含むモノマーによる低分子量ポリオレフィンへの変性率は、０．０１〜４ｍｍｏｌ／ｇポリオレフィンが好ましい。更に好ましくは、０．０５〜２ｍｍｏｌ／ｇポリオレフィンの範囲が好ましい。
【００４７】
〈定着性改良剤の水性分散液の調製〉
本発明のカチオン性ユニットで変性された定着性改良剤は、乳化重合法を用いて着色重合体微粒子を調製し、更にこれを複数個会合凝集させてトナーとする場合、水性分散液の形で上記乳化重合時に重合系へ添加されることが望ましい。又定着性改良剤の水性分散液は、定着性改良剤の軟化温度以上に加熱した水中に、定着性改良剤を入れ乳化分散することにより得られる。定着性改良剤の軟化温度が１００℃を越える場合には加圧乳化を行えば容易に分散液を調製することができる。これらの定着性改良剤のトナー粒子中での平均ドメイン径は０．０３〜１．０μｍの範囲が好ましい。さらに好ましくは、０．０５〜０．８μｍである。トナー中の定着性改良剤の平均ドメイン径は、上記定着性改良剤の水性分散液の平均粒径に等しい為、水性分散液の平均粒径を本発明の定着性改良剤の平均ドメイン径に合わせた分散液を用いれば良い。
【００４８】
なお、上記定着性改良剤のトナー粒子中での平均ドメイン径は以下の方法により測定される。即ち、トナー粒子を樹脂で包埋し、ミクロトームにより約０．２μｍの厚さの切片を作成する。この切片を透過型電子顕微鏡にてネガ倍率が２８０倍の写真を撮り、引き伸ばして１２００倍の写真を作成する。これを画像解析装置（ＳＰＩＣＣＡ：日本アビオニクス社）にて、ドメイン径を測定する。ここでは、５００個以上のドメインを測定し、円換算のドメイン径として数平均で測定する。
【００４９】
〈着色剤〉
本発明のトナーには着色剤を含有するのが好ましく、該着色剤としては無機顔料、有機顔料を挙げることができる。無機顔料としては公知のものを用いることが可能であり、例えば以下の無機顔料を用いることが可能である。
【００５０】
黒色の無機顔料としては、例えばファーネスブラック、チャネルブラック、アセチレンブラック、サーマルブラック、ランプブラック等のカーボンブラック、更にマグネタイト、フェライト等の磁性粉を挙げることができる。これらの無機顔料は必要に応じて表面処理剤で表面処理を行い使用することができる。表面処理在としては、シランカップリング剤、チタニウムカップリング剤、アルミニウムカップリング剤等が挙げることができる。特に水性媒体中で安定なアルミニウムカップリング剤は有用であり、特にラジカル重合反応を阻害するカーボンブラックを表面処理することでその阻害を軽減することが可能となる。
【００５１】
これらの無機顔料は所望に応じて単独又は複数を選択併用することが可能である。また顔料の添加量は重合体に対して、好ましくは２〜２０重量部であり、更に好ましくは３〜１５重量部が選択される。
【００５２】
また、有機顔料としては公知のものを用いることが可能であり、例えば以下の有機顔料を用いることが可能である。
【００５３】
オレンジ又はイエロー用の有機顔料としては、Ｃ．Ｉ．ピグメントオレンジ３１、Ｃ．Ｉ．ピグメントオレンジ４３、Ｃ．Ｉ．ピグメントイエロー１２、Ｃ．Ｉ．ピグメントイエロー１３、Ｃ．Ｉ．ピグメントイエロー１４、Ｃ．Ｉ．ピグメントイエロー１５、Ｃ．Ｉ．ピグメントイエロー１７、Ｃ．Ｉ．ピグメントイエロー９３、Ｃ．Ｉ．ピグメントイエロー９４、Ｃ．Ｉ．ピグメントイエロー１３８、Ｃ．Ｉ．ピグメントイエロー１８０等が挙げられる。
【００５４】
マゼンタ又はレッド用の有機顔料としては、Ｃ．Ｉ．ピグメントレッド２、Ｃ．Ｉ．ピグメントレッド３、Ｃ．Ｉ．ピグメントレッド５、Ｃ．Ｉ．ピグメントレッド６、Ｃ．Ｉ．ピグメントレッド７、Ｃ．Ｉ．ピグメントレッド１５、Ｃ．Ｉ．ピグメントレッド１６、Ｃ．Ｉ．ピグメントレッド４８：１、Ｃ．Ｉ．ピグメントレッド５３：１、Ｃ．Ｉ．ピグメントレッド５７：１、Ｃ．Ｉ．ピグメントレッド１２２、Ｃ．Ｉ．ピグメントレッド１２３、Ｃ．Ｉ．ピグメントレッド１３９、Ｃ．Ｉ．ピグメントレッド１４４、Ｃ．Ｉ．ピグメントレッド１４９、Ｃ．Ｉ．ピグメントレッド１６６、Ｃ．Ｉ．ピグメントレッド１７７、Ｃ．Ｉ．ピグメントレッド１７８、Ｃ．Ｉ．ピグメントレッド２２２が挙げられる。
【００５５】
グリーン又はシアン用の有機顔料としてはＣ．Ｉ．ピグメントブルー１５、Ｃ．Ｉ．ピグメントブルー１５：２、Ｃ．Ｉ．ピグメントブルー１５：３、Ｃ．Ｉ．ピグメントブルー１６、Ｃ．Ｉ．ピグメントブルー６０、Ｃ．Ｉ．ピグメントグリーン７等が挙げられる。
【００５６】
これらの有機顔料は所望に応じて単独又は複数を選択併用することが可能である。また顔料の添加量はバインダー用樹脂に対して、好ましくは２〜２０重量部であり、より好ましくは３〜１５重量部が選択される。
【００５７】
〔バインダー用樹脂〕
本発明のトナーのバインダー用樹脂は疎水性モノマー及びイオン性モノマーから成る。
【００５８】
〈疎水性モノマー〉
上記疎水性モノマーの例としては、スチレン類例えばスチレン、ｐ−メチルスチレン、ｏ−メチルスチレン、ｍ−メチルスチレン等、アルキルアクリレート類例えばメチルアクリレート、エチルアクリレート、ｎ−ブチルアクリレート等、アルキルメタクリレート類例えばメチルメタクリレート、エチルメタクリレート、ｎ−ブチルメタクリレート等、共役ジエン類例えばブタジエン、イソブレン、ジメチルブタジエン、クロロプレン等、ニトリル類例えばアクリロニトリル、メタクリロニトリル等、更に塩化ビニル、塩化ビニリデン等が挙げられる。
【００５９】
〈イオン性モノマー〉
イオン性モノマーとしては、カチオン性とするのが好ましく、前記一般式（１）〜（７）で表される構成単位に相当するカチオン性モノマー及び前記一般式（１）〜（７）で表される構成単位を第四級アンモニウム塩の型にしたものから少なくとも一種選択される。
【００６０】
ここで、本発明のトナーのバインダー用樹脂が疎水性モノマーとイオン性モノマー、特にカチオン性モノマーとから合成され、前記カチオン性基を含む定着性改良剤と同じ荷電性を有することにより、トナーに対して十分な正帯電性を付与することが出来、且つ凝集反応時に過剰な凝集を抑制してシャープな粒度分布を達成することが出来る。
【００６１】
上記疎水性モノマーとイオン性モノマーとを共重合して得られる共重合体のガラス転移温度は、好ましくは４０〜７０℃になるよう設計される。上記共重合体のガラス転移温度が４０℃未満では、トナーの保存性が悪く、保存中融着してブロッキングを生じ易く、又、ガラス転移温度が７０℃を越えると画像形成時、トナーの定着性が悪くなり易い。
【００６２】
またこの時、イオン性モノマーの疎水性モノマーに対する共重合比率は好ましくは、０．１〜１５重量％の範囲が選択される。又、更に好ましくは、０．５〜１０重量％の共重合比率の範囲が選択される。このとき、共重合比率が０．１重量％未満では、トナーへの正帯電性付与が不十分となり、且つ一次粒子の凝集反応時過剰凝集による粗大粒子の生成を抑制しにくくなる。又共重合比率が１５重量％を越えるトナーの親水性が大きくなり過ぎるため環境によりトナーの帯電量が変化し、不安定になり易い。
【００６３】
〔トナーの製造〕
本発明のトナーを製造する代表的一例としては、先ず、疎水性モノマー、イオン性モノマー、定着性改良剤水性分散液、分散剤（界面活性剤）、水、必要に応じて着色剤水性分散液及び荷電制御剤水性分散液等の混合液を撹拌下に乳化重合温度まで昇温し、水溶性ラジカル重合開始剤を添加して乳化重合を行うことにより着色重合体微粒子水性分散液を調製する。なお、上記定着性改良剤水性分散液、着色剤水性分散液、荷電制御剤水性分散液等は、乳化重合過程又は重合完了後の何れで添加してもよい。
【００６４】
次いで、上記のようにして得られた着色重合体微粒子水性分散液には凝集剤その他粒子特性を改良するための添加剤を添加し、且つ上記イオン性モノマー及び定着性改良剤のカチオン性基が完全解離又は部分解離した状態で会合凝集を行い、更にバインダー用樹脂即ち、前記共重合体のガラス転移温度からガラス転移温度＋５０℃の範囲で加熱を行い、粒子間を熱融着させ着色重合体粒子を得る。この時加熱温度、加熱時間等を変化させることで該着色重合体粒子の形状を真球からラズベリー状の非球形まで任意に制御することが可能である。
【００６５】
このようにして生成した着色重合体粒子は、洗浄による精製、乾燥をへて粉体として取りだされ、更に外添剤を加えてトナーを形成する。
【００６６】
〈荷電制御剤〉
本発明のトナー中に必要に応じて添加される荷電制御剤としては、トナー表面のイオン性基がその機能を果たすため本来必要は無いが、所望に応じて添加することができる。プラスの帯電性を示すものとしてニグロシン系の電子供与性染料、ナフテン酸又は高級脂肪酸の金属塩、アルコキシル化アミン、第四級アンモニウム塩、アルキルアミド、金属錯体、顔料、フッ素処理活性剤等の公知のものが挙げられる。これらは、着色剤と同様に界面活性剤を用い、水相中に微分散し重合時又はトナー化の反応時に所望量を添加することでトナー中に導入することが可能である。
【００６７】
〈分散剤（界面活性剤）〉
本発明のトナーを製造する際の乳化重合及び定着性改良剤の水性分散液の分散剤としては、カチオン性界面活性剤を用いることが好ましい。カチオン性界面活性剤の例としては、アミン塩構造を有するカチオン性界面活性剤、第四級アンモニウム塩構造を有する界面活性剤等が用いられる。アミン塩構造を有するカチオン性界面活性剤の例としては、ラウリルアミンの酸中和物、ステアリルアミンの酸中和物、ステアラミドエチルジアルキルアミンの酸中和物（アルキル基は炭素数１〜３の置換、未置換アルキル基）、トリエタノールアミンモノステアレートの酸中和物、イミダゾリン型カチオン性界面活性剤（２−ヘプタデセニル−ヒドロキシエチルイミダゾリンの酸中和物）等が挙げられる。又第四級アンモニウム塩構造を有する界面活性剤としては、アルキルトリメチルアンモニウム塩（アルキル基は炭素数８〜１８のアルキル基、例えばラウリルトリメチルアンモニウムクロライド等）、アルキルジメチルベンジルアンモニウム塩（アルキル基は炭素数８〜１８のアルキル基、例えばラウリルジメチルベンジルアンモニウムクロライド等）、アルキルピリジニウム塩（アルキル基は炭素数８〜１８のアルキル基、例えばセチルピリジニウムクロライド等）が挙げられる。
【００６８】
〈重合開始剤〉
本発明のトナーを乳化重合法により乳化重合する際に重合開始剤を使用するのが良く、その好ましい例としては、水溶性ラジカル重合開始剤が用いられる。好ましくは、カチオン性基を有するラジカル重合開始剤又は非イオン性ラジカル重合開始剤が用いられる。カチオン性基を有するラジカル重合開始剤の例としては、例えば２，２′−アゾビス（２−メチルプロピオンアミジン）二塩酸塩、２，２′−アゾビス〔２−（２−イミダゾリン−２−イル）プロパン〕二塩酸塩、２，２′−アゾビス〔２−（５−メチル−２−イミダゾリン−２−イル）プロパン〕２塩酸塩、２，２′−アゾビス〔２−（４，５，６，７−テトラヒドロ−１Ｈ−１，３−ジアゼピン−２−イル）プロパン〕２塩酸塩、２，２′−アゾビス〔２−（５−ヒドロキシ−３，４，５，６−テトラヒドロピリミジン−２−イル）２塩酸塩、２，２′−アゾビス（２−メチル−Ｎ−フェニルプロピオンアミド）２塩酸塩、２，２′−アゾビス〔Ｎ−（４−クロロフェニル）−２−メチルプロピオンアミド〕２塩酸塩、２，２′−アゾビス〔Ｎ−（４−ヒドロキシフェニル）−２−メチルプロピオンアミド〕２塩酸塩、２，２′−アゾビス〔２−メチル−Ｎ−（フェニルメチル）プロピオンアミド〕２塩酸塩、２，２′−アゾビス〔２−メチル−Ｎ−（２−プロペニル）プロピオンアミド〕２塩酸塩、２，２′−アゾビス（２−メチルプロピオンアミド）２塩酸塩、２，２′−アゾビス〔Ｎ−（２−ヒドロキシエチル）−２−メチルプロピオンアミド〕２塩酸塩等が挙げられる。
【００６９】
非イオン性ラジカル重合開始剤の例としては、２，２′−アゾビス｛２−メチル−Ｎ−〔１，１−ビス（ヒドロキシメチル）−２−ヒドロキシエチル〕プロピオンアミド｝、２，２′−アゾビス｛２−メチル−Ｎ−〔１，１−ビス（ヒドロキシメチルエチル〕プロピオンアミド｝、２，２′−アゾビス〔２−メチル−Ｎ−（２−ヒドロキシエチル）プロピオンアミド〕、２，２′−アゾビス（２−メチルプロピオンアミド）２水和物、２，２′−アゾビス〔２−（ヒドロキシメチル）プロピオニトリル〕等が挙げられる。
【００７０】
〈着色重合体微粒子の会合凝集〉
乳化重合法を用いて本発明のトナーを製造するには、先ず着色重合体微粒子水性分散液を調製し、更に該着色重合体微粒子水性分散液中の着色重合体微粒子を、凝集剤を添加することにより複数個会合凝集させ、所望の粒径まで成長させると同時に、本発明の共重合体のガラス転移温度以上に加熱し会合粒子間を融着して、強固な着色重合体粒子、即ちトナーとすることができる。この時の加熱温度は、上記共重合体のガラス転移温度から＋５０℃の範囲が好ましい。更に好ましくは、上記共重合体のガラス転移温度＋１０℃から＋４０℃が好ましい範囲である。
【００７１】
上記着色重合体微粒子水性分散液中の着色重合体微粒子の複数個を会合凝集する際には、会合反応前又はその過程で着色重合体微粒子表面に存在するイオン性解離基が少なくとも一部イオン解離している状態で用いることが好ましい。即ち、陰イオン性解離基の場合アルカリで一部解離した状態にすることが好ましい。又陽イオン性解離基の場合、逆に酸で一部解離するか又は第四級アンモニウム塩構造を取っていることが好ましい。このイオン性解離基を少なくとも一部イオン解離状態にすることで、所望の粒径範囲から外れた所謂粗大粒子の生成が著しく抑制され、結果として粒度分布の狭いトナー粒子を生成することができる。
【００７２】
上記着色重合体微粒子水性分散液中の着色重合体微粒子の複数個を会合凝集させる凝集剤としては、１価、２価及び３価の金属の塩から選択される塩、有機または、無機の酸等が挙げられる。上記１価、２価または３価の金属の塩としては、例えば塩化ナトリウム、塩化カリウム、塩化リチウム、塩化マグネシウム、塩化カルシウム、塩化アルミニウム等を挙げることが出来、又上記酸としては、塩酸、硫酸、酢酸等を挙げることが出来る。好ましくは１価の金属塩、即ち塩化ナトリウム、塩化カリウム、塩化リチウムが挙げられる。
【００７３】
更に、必要に応じて水に無限溶解する有機溶媒や界面活性剤を添加することができる。これらは、生成する着色重合体粒子の形状を整え、粒度分布をシャープにするために用いられる。水に無限溶解する有機溶媒としては、バインダー用として使用する上記共重合体を溶解しないアルコール類、ケトン類の中から選択される。特に好ましくはイソプロピルアルコールである。又界面活性剤としてはノニオン性界面活性剤が挙げられる。
【００７４】
上記のように、本発明のトナーの製造方法では、疎水性モノマー、イオン性モノマー、定着性改良剤、必要に応じて着色剤、荷電制御剤及び界面活性剤を含有する水性分散液を撹拌下に所望の温度まで昇温した後、水溶性ラジカル重合開始剤を添加し一定時間重合反応を行い、着色重合体微粒子を含有する着色重合体微粒子水性分散液を得、更に該着色重合体微粒子を会合凝集させて、着色重合体粒子（トナー）を得る。
【００７５】
このとき、適正な粒子の粒径、比表面積及び粒度分布を有し、電子写真特性に優れた着色重合体粒子（トナー）を得るため、着色重合体微粒子水性分散液のｐＨをアニオン性解離基を有する場合は、中性からアルカリ性領域に、カチオン性解離基を有する場合は中性から酸性領域に調整して着色重合体微粒子表面のイオン性基の解離度の調整を行う工程、電解質又は電解質水溶液から成る凝集剤を添加する工程、着色重合体微粒子の過凝集を抑制し、凝集の安定性を維持するためにノニオン界面活性剤を添加する工程、着色重合体微粒子の形状制御を目的として水に無限溶解する有機溶媒を添加する工程及びトナーに使用する共重合体のガラス転移温度からガラス転移温度＋５０℃の温度に加熱し所定の時間、この温度に維持して反応を行う工程等を有するのが望ましく、これら各工程の順序は以下の６種類の何れであってもよい。
【００７６】
（１）着色重合体微粒子表面のイオン性基の解離度を調整した着色重合体微粒子水性分散液に電解質又は電解質水溶液、水に無限溶解する有機溶媒、ノニオン界面活性剤又はその水溶液を順次添加し、上記樹脂のガラス転移温度からガラス転移温度＋５０℃の温度に加熱し所定の時間、この温度に維持し反応を行う。
【００７７】
（２）着色重合体微粒子表面のイオン性基の解離度を調整した着色重合体微粒子水性分散液にノニオン界面活性剤又はその水溶液、電解質又は電解質水溶液、水に無限溶解する有機溶媒を順次添加し、上記共重合体のガラス転移温度からガラス転移温度＋５０℃の温度に加熱し所定の時間、この温度に維持し反応を行う。
【００７８】
（３）着色重合体微粒子表面のイオン性基の解離度を調整した着色重合体微粒子水性分散液に、水に無限溶解する有機溶媒、ノニオン界面活性剤又はその水溶液、電解質又は電解質水溶液を順次添加し、上記共重合体のガラス転移温度からガラス転移温度＋５０℃の温度に加熱し所定の時間、この温度に維持し反応を行う。
【００７９】
（４）着色重合体微粒子表面のイオン性基の解離度を調整した着色重合体微粒子水性分散液に、電解質又は電解質水溶液、水に無限溶解する有機溶媒、に溶解したノニオン界面活性剤を順次添加し、上記共重合体のガラス転移温度からガラス転移温度＋５０℃の温度に加熱し所定の時間、この温度に維持し反応を行う。
【００８０】
（５）着色重合体微粒子表面のイオン性基の解離度を調整した着色重合体微粒子水性分散液に、ノニオン界面活性剤及び電解質を共に溶解した水溶液、水に無限溶解する有機溶媒を順次添加し、上記共重合体のガラス転移温度からガラス転移温度＋５０℃の温度に加熱し所定の時間、この温度に維持し反応を行う。
【００８１】
（６）着色重合体微粒子表面のイオン性基の解離度を調整した着色重合体微粒子水性分散液に、電解質又は電解質水溶液、水に無限溶解する有機溶媒、ノニオン界面活性剤又はその水溶液を同時に添加し、上記共重合体のガラス転移温度からガラス転移温度＋５０℃の温度に加熱し所定の時間、この温度に維持し反応を行う。
【００８２】
それらの外、着色重合体微粒子表面のイオン性基の解離度を調整した着色重合体微粒子水性分散液を上記共重合体のガラス転移温度からガラス転移温度＋５０℃の温度に加熱した後、上記添加順序に従い添加剤を添加し、所定の時間加熱反応を行うことも可能である。
【００８３】
又着色重合体微粒子を所望の着色重合体粒子径まで成長させる方法として、異なる電荷を有する二種類の着色重合体微粒子を用い、ヘテロ凝集法を用い成長させることも可能である。
【００８４】
このようにして生成した着色重合体粒子は、洗浄濾過を繰り返して電解質、界面活性剤等の夾雑物を除去した後、乾燥を行い、更に必要な外添剤を加えトナーとする。
【００８５】
〈トナーの特性〉
上記の様にして生成されたトナーは、好ましくは３〜１５μｍの平均粒径を持ち、且つＢＥＴ比表面積が、好ましくは５〜１００ｍ²／ｇである。
【００８６】
本発明のトナーの平均粒径が３μｍ未満の場合は、実用上その製造が難しく、且つ画像形成時カブリが発生し易く、１５μｍを越えると画像形成時、解像力が低下し、画質が悪化し易い。なお、上記トナーの粒径は、体積平均粒径であり、コールターカウンターＴＡ−１１により測定される。
【００８７】
又、本発明のトナーのＢＥＴ比表面積が５ｍ²／ｇ未満の場合はトナーの帯電の立ち上がりが遅く、且つ十分な帯電量を確保することが出来ないことがあり、又、トナーのＢＥＴ比表面積が１００ｍ²／ｇを越えると、トナーが吸湿し易くなり、帯電量が不安定になり、且つ画像形成時カブリが発生し易くなる。
【００８８】
なお、本発明のトナーにおいては、そのＢＥＴ比表面積を５〜１００ｍ²／ｇとすることと、トナー粒子表面にイオン解離性基を有することとが相乗的に作用して、非常に早い帯電の立ち上がりと、目的の極性の帯電性を安定して確保することが出来る。又このため、敢えて荷電制御剤の添加を必要としないという利点を有する。
【００８９】
ところで、上記トナーのＢＥＴ比表面積は窒素吸着法の１点法で測定されるもので、具体的な測定装置としてはフローソープ２３００（島津製作所）が挙げられる。
【００９０】
〈現像剤〉
上記本発明のトナーは、通常キャリアと一定比率で混合され、２成分現像剤として用いられる。上記キャリアとしては、鉄、フェライト等の磁性材料で構成される非被覆キャリア、或いは磁性材料表面を樹脂等によって被覆して成る樹脂被覆キャリアがあり、このキャリアの体積平均粒径は３０〜１５０μｍが好ましい。又、２成分現像剤におけるトナーとキャリアとの混合割合は、キャリア１００重量部に対してトナー１〜１０重量部である。
【００９１】
〈画像形成方法〉
以下に、本発明の画像形成方法について説明する。
【００９２】
本発明の画像形成方法は、前述してきた本発明のトナー、好ましくはＢＥＴ比表面積が５〜１００ｍ²／ｇである本発明のトナーを用いて、感光体上に形成された静電荷潜像を現像してトナー像を形成し、これを転写材上に転写し、定着して画像形成を行う。
【００９３】
本発明のトナーを使用する現像方式としては特に限定されず、接触現像方式あるいは非接触現像方式等に好適に使用することができる。接触現像方式とする場合は、本発明のトナーを有する現像剤の層厚を現像領域に於いて０．１〜８ｍｍ、好ましくは０．４〜５ｍｍとし、現像領域において現像剤の穂立を形成させ、該穂立を感光体に接触させて現像する所謂磁気ブラシ現像方式で現像される。又、この場合、感光体と現像剤担持体（以後単にスリーブと称する）との間隙は、０．１５〜７ｍｍ、特に、０．２〜４ｍｍであることが好ましい。
【００９４】
又、非接触現像方式とする場合は、スリーブ上に形成された現像剤層と感光体とが接触しないものであり、この現像方式を構成するために現像剤層は薄層で形成されることが好ましい。この方法はスリーブ表面の現像領域で２０〜５００μｍの現像剤層を形成させ、感光体とスリーブとの間隙を該現像剤層よりも大きい間隙を有するものとする。
【００９５】
特に本発明のトナーは、高い帯電立ち上がり性を有しており、特に非接触現像方式に有用である。即ち、非接触現像方式では現像電界の変化が大きいことから、微少な帯電の変化が現像自体に大きく影響し、トナーの帯電量の微妙な変化が、画像の画質や画像濃度等を大きく変動し易いなどの問題があるが、本発明のトナーは帯電立ち上がり性が優れていることから、帯電の変化が少なく、安定した帯電量を確保することができ、非接触現像方式でも安定した画像を長期に亘って形成することが出来る。
【００９６】
非接触現像方式において、薄層形成は磁気の力を使用する磁性ブレードやスリーブ表面に現像剤層規制棒を押圧する方式等で形成される。更に、ウレタンブレードや燐青銅板等をスリーブ表面に接触させ現像剤層を規制する方法もある。押圧規制部材の押圧力としては１〜１５ｇｆ／ｍｍが好適である。押圧力が小さい場合には規制力が不足するために搬送が不安定になり易く、一方、押圧力が大きい場合には現像剤に対するストレスが大きくなるため、現像剤の耐久性が低下し易い。好ましい範囲は３〜１０ｇｆ／ｍｍである。更に、非接触現像方式においては、現像に際して現像バイアス電圧を付加するのが好ましいが、この場合、直流成分のみを付与する方式でも良いし、交流バイアスを重畳印加する方式のいずれでも良い。
【００９７】
なお、本発明のトナーは、カブリの発生が少なく、且つ転写性が優れているため複数の色トナー像を重ね合わせてカラー画像を形成するカラー画像形成方法において特に有用である。
【００９８】
以下、本発明の画像形成方法の代表的例を図１及び図２を用いて説明する。
【００９９】
図１は、カラー画像形成装置の一例を示す概略図であり、非接触現像方式で且ついわゆる逐次転写方式のカラー画像形成装置である。
【０１００】
図中、１は帯電電極である帯電器、Ｌはアナログ又はデジタル像露光であり、２はイエロー、マゼンタ、シアン、黒のトナーを各々に装填する現像器からなる現像ユニットで、４色のトナーに対応する４つの現像器に分かれている。これらは、何れも非接触方式の磁気ブラッシ現像器である。４は感光体ドラム、３はクリーニングユニット、５は搬送手段６により搬送された転写材Ｐを巻き付け、感光体ドラム４と同期して回転する転写ドラムで、感光体ドラム４上に各色トナー像が形成される度に上記転写ドラム５に巻き付けられた転写材Ｐ上に重ね合わせて転写され、該転写材Ｐ上にカラートナー像３０が形成される。７は転写ドラム５の内部に設けられ、内部からコロナ放電し、転写材Ｐを転写ドラム５に静電吸着する吸着電極、８は感光体ドラム４上に形成された色トナー像を逐次転写ドラム５に転写させる転写電極、９は転写ドラム５上に静電吸着した転写材Ｐを剥離するための剥離電極、１０は転写材Ｐの剥離後、転写ドラム５に残留する電荷を除去する除去電極である。又、１２は転写材Ｐを転写ドラム５から分離するための分離部材である。又１６は上記カラートナー像３０を定着するための熱ローラ定着装置であり、該熱ローラ定着装置は熱ローラ１７と圧着ローラ１８とから構成される。
【０１０１】
上記装置において、カラー画像を形成するには、感光体ドラム４上に帯電電極１により、一様に電荷を形成し、その後、第１の像露光Ｌにより第１の静電荷潜像を形成する。この静電荷潜像は、現像ユニット２の第１の色トナー（例えば黒トナー）を保有する現像器により現像され、第１の色トナー像が感光体ドラム４上に形成される。一方搬送手段６により転写ドラム５上に搬送された転写材Ｐは吸着電極７により転写ドラム５上に静電吸着され、転写部に搬送される。
【０１０２】
この搬送された転写材Ｐへは、転写部において、感光体ドラム４に形成されている上記第１の色トナー像を転写する。次いで第２の像露光Ｌにより第２の静電荷潜像を形成する。この静電荷潜像は、現像ユニット２の第２の色トナー（例えばシアントナー）を保有する現像器により現像され、第２の色トナー像が感光体ドラム４に形成され、上記第１の色トナー像を有する転写材Ｐ上に第２の色トナー像が重ね合わせて転写される。以後、同様にして、第３の像露光Ｌにより第３の静電荷潜像の形成、第３の色トナー（例えばマゼンタトナー）による現像、転写及び第４の像露光Ｌにより第４の静電荷潜像の形成、第４の色トナー（例えばイエロートナー）による現像、転写が繰り返されて転写材Ｐ上に第１、第２、第３及び第４の色トナー像が重ね合わせて転写されてカラートナー像３０が形成される。このカラートナー像３０が転写された転写材Ｐは剥離電極９及び分離部材１２の作用で転写ドラム５から分離されて矢印方向に搬送され、熱ローラ定着装置１６により定着されてカラー画像が形成され、次のカラー画像形成プロセスに備えられる。
【０１０３】
一方、転写ドラム５は残留している電荷を除去電極１０により除去され、次のプロセスに使用される。
【０１０４】
次に図２は、カラー画像形成装置の他の例を示す概略図であり、非接触現像方式で且つ、いわゆる一括転写方式のカラー画像形成装置である。装置の各部は図１と共通する部分が多く、同じ内容には同じ符号が付される。但し、１１は転写材Ｐを転写部に搬送するベルト状搬送部材である。図２のカラー画像形成装置を用いてカラー画像を形成するには、感光体ドラム４に帯電電極１により一様に電荷を形成し、その後第１の像露光Ｌを施して第１の静電荷潜像形を形成する。この静電荷潜像は、現像ユニット２の第１の色トナー（例えばイエロートナー）を保有する現像器により現像され、第１の色トナー像が感光体ドラムに形成される。この色トナー像は転写材に転写されることなく、そのまま第１の色トナー像を有している感光体ドラム４に再度、帯電電極１により一様に電荷を形成し、更に第２の像露光Ｌを施して第２の静電荷潜像形を形成する。この静電荷潜像は、現像ユニット２の第２の色トナー（例えばマゼンタトナー）を保有する現像器により現像され、第２の色トナー像が第１の色トナー像上に重ね合わせて形成される。同様にして、第３の像露光Ｌを施して第３の静電荷潜像形の形成第３の色トナー（例えばシアントナー）を保有する現像器により現像して、第３の色トナー像を形成し、これを上記第１、第２の色トナー像上に重ね合わせて形成し、且つ第４の像露光Ｌを施して第４の静電荷潜像形を形成し、これを第４の色トナー（例えばシアントナー）を保有する現像器により現像して、第４の色トナー像を形成し、これを上記第１、第２、第３の色トナー像上に重ね合わせて形成し、感光体上にカラートナー像を形成する。このカラートナー像はベルト状搬送部材１１により転写部に搬送された転写材Ｐ上に転写電極８の作用で一括転写され、転写されたカラートナー像３０を担持した転写材Ｐは矢印方向に搬送され熱ローラ定着装置１６により定着されてカラー画像が形成される。上記カラートナー像を転写した後の感光体ドラム４上にはトナーが残留するのでクリーニングユニット３によりクリーニングされ、次のカラー画像形成プロセスに備えられる。なお熱ローラ定着装置は図１の場合と同様熱ローラ１７と圧着ローラ１８とから構成される。
【０１０５】
本発明のトナーは、微粒子、狭い粒径分布、比較的に大きい比表面積を有するトナーであり、帯電特性が優れている外、転写特性が優れているので、複数の色トナー像を重ね合わせて転写する工程を有する上記各種カラー画像形成装置において、繰り返して画像形成の過程で、カブリがなく、高解像力、鮮明なカラー画像が安定して得られる。
【０１０６】
【実施例】
以下、本発明を実施例によって説明するが、本発明の実施の態様はこれによって限定されるものではない。
【０１０７】
〈定着性改良剤の調製〉
低分子量ポリプロピレン（数平均分子量（Ｍｎ）＝３，３００、分子量分布（Ｍｗ／Ｍｎ）＝４．５）に、常法に従ってＮ，Ｎ−ジメチルアミノエチルメタクリレート（ＤＭＡＥＭＡ）、又はビニルベンジル−Ｎ，Ｎ−ジメチル−Ｎ−ベンジルアンモニウムクロリド（ＶＢＤＭＢＡ）の添加量（ｍｍｏｌ／ｇ）を表１の如く変化して加えて変成させ、得られた７種類の変性低分子量ポリプロピレンの１６０℃における熔融粘度（ｃｐｓ）を測定し、その後これらを、水溶液に塩酸を溶解したノニルフェノキシポリエトキシエタノール（エトキシユニット付加モル数２０、ＨＬＢ＝１６．０）水溶液に添加し、熔融温度以上に加温し、撹拌を行い、本発明用の７種類の定着性改良剤の水性分散液を得た。なお、上記７種類の変性低分子量ポリプロピレンの１６０℃における熔融粘度（ｃｐｓ）及び上記水性分散液中の７種類の定着性改良剤の平均粒径（ｎｍ）を表１に示した。
【０１０８】
又、上記低分子量ポリプロピレンに、マレイン酸（ＭＡ）を表１の添加量（ｍｍｏｌ／ｇ）で加えて変性させ、得られた変性低分子量ポリプロピレンの１６０℃における熔融粘度（ｃｐｓ）を測定し、その後これを、水溶液に水酸化カリウムを溶解したノニルフェノキシポリエトキシエタノール水溶液に添加し、熔融温度以上に加温し、撹拌を行い、比較用の定着性改良剤の水性分散液を得た。上記比較用変性低分子量ポリプロピレンの１６０℃における熔融粘度（ｃｐｓ）及び比較用の水性分散液中に分散された定着性改良剤の平均粒径（ｎｍ）を表１に示した。ここで、上記本発明用及び比較用の定着性改良剤を分散含有する水性分散液の固形分濃度は２０重量パーセントに調整した。
【０１０９】
なお、上記ＨＬＢ（Ｈｙｄｒｏｐｈｉｌｅ Ｌｉｐｏｐｈｉｌｅ Ｂａｌａｎｃｅ）は、界面活性剤の親水性と疎水性とのバランスを示す指標である。例えばノニオン界面活性剤のＨＬＢは、
ＨＬＢ＝｛（親水性基部分の分子量）／（疎水性基部分の分子量）｝×１００／５で表される。
【０１１０】
又、変性低分子量ポリプロピレンの１６０℃における熔融粘度（ｃｐｓ）は「Ｂ型粘度計」（東京計器（株）社製）を用いて測定される。
【０１１１】
さらに又、水性分散液中に分散された定着性改良剤の平均粒径（ｎｍ）は電気泳動光散乱光度計「ＥＬＳ−８００」（大塚電子（株）社製）を用いて測定される。
【０１１２】
【表１】

【０１１３】
〈本発明の着色重合体粒子合成例１〉
カーボンブラック「リーガル３３０Ｒ」（キャボット（株）社製）をアルミニウムカップリング剤「プレンアクトＡＬ」（味の素（株）社製）で処理した処理済みカーボンブラック４９．８ｇをセチルトリメチルアンモニウムクロリド２３ｇを蒸留水４１２ｍｌ溶解したカチオン界面活性剤水溶液中に添加し、超音波ホモジナイザーを用いて分散を行った。
【０１１４】
更に、撹拌装置、冷却管、温度センサー及び窒素導入管を装着した１リットルの４頭フラスコに、上記カーボンブラック分散液５４．９ｇ、蒸留水４４６ｍｌ、スチレン４９．４ｇ、ｎ−ブチルアクリレート９．２ｇ、Ｎ，Ｎ−ジメチルアミノエチルメタアクリレート２．４５ｇ、ｔｅｒｔ−ドデシルメルカプタン１．６３ｇ及び本発明の定着性改良剤（１）１８．３ｇを添加し、撹拌速度３５０ｒｐｍで撹拌し且つ窒素を流しつつフラスコ内温が７５℃になるまで加熱した。７５℃に内温を維持しつつ、２，２′−アゾビス（２−アミジノプロパン）２塩酸塩２．１４ｇを純水１００ｍｌに溶解した重合開始剤水溶液を添加し、窒素気流下内温７５℃、撹拌速度３５０ｒｐｍを維持しつつ６時間重合を行った。重合終了後室温まで内温を低下させた後、一部分取しゲルパーミュエーションクロマトグラフィ（以下ＧＰＣと略す）を用い分子量を測定した。
【０１１５】
更にこの着色重合体微粒子水性分散液５００ｍｌを１Ｎ塩酸を用いｐＨ＝２．０に調節した後、撹拌装置、冷却管、温度センサーを装着した１リットル４頭フラスコに入れ、２５０ｒｐｍで撹拌を行った。ここに、塩化カリウム３８．７６ｇを２５０ｍｌの蒸留水に溶解した電解質水溶液を添加し、更にイソプロピルアルコール１２２．６ｍｌ、トリトンＸ−１００ ３．５２ｇを蒸留水１６６．５ｍｌに溶解したノニオン界面活性剤水溶液を順次添加した後、内温を８５℃まで昇温し６時間反応を行った。
【０１１６】
反応液を濾過後、蒸留水を加え再分散し５Ｎの塩酸を用いｐＨを１に調節し水洗、濾過を繰り返し、界面活性剤及び電解質を除去した後乾燥を行い、本発明の着色重合体粒子（１）を得た。これを乾燥後体積平均粒径（ｄ₅₀μｍ）及び粒度分布（σ₅₀／ｄ₅₀）をコールターカウンターを用いて測定し、且つＢＥＴ比表面積（ｍ²／ｇ）を前記窒素吸着法により測定し、その結果を表２に示した。
【０１１７】
〈本発明の着色重合体粒子合成例２〉
カーボンブラック「リーガル３３０Ｒ」（キャボット（株）社製）をアルミニウムカップリング剤「プレンアクトＡＬ」（味の素（株）社製）で処理した処理済みカーボンブラック４９．８ｇをセチルトリメチルアンモニウムクロリド２３ｇを蒸留水４１２ｍｌ溶解したカチオン界面活性剤水溶液中に添加し、超音波ホモジナイザーを用い分散を行った。
【０１１８】
更に、撹拌装置、冷却管、温度センサー及び窒素導入管を装着した１リットルの４頭フラスコに、上記カーボンブラック分散液１４．８ｇ、蒸留水１２２．５ｍｌ、スチレン１３．４ｇ、ｎ−ブチルアクリレート２．５ｇ、４−ビニルビリジン０．８４ｇ、ｔｅｒｔ−ドデシルメルカプタン０．０２３ｇ及び本発明の定着性改良剤（１）５ｇを添加し、撹拌速度３５０ｒｐｍで撹拌し且つ窒素を流しつつフラスコ内温が７５℃になるまで加熱した。７５℃に内温を維持しつつ、２，２′−アゾビス（２−アミジノプロパン）２塩酸塩０．５８ｇを純水１００ｍｌに溶解した重合開始剤水溶液を添加し、窒素気流下内温７５℃、撹拌速度３５０ｒｐｍを維持しつつ３時間重合を行った。重合終了後室温まで内温を低下させた後更にカーボンブラック分散液４９ｇ、純水３２３．２ｍｌ、スチレン３６．３ｇ、ｎ−ブチルアクリレート６．７２ｇ、４−ビニルピリジン２．２６ｇ、ｔｅｒｔ−ドデシルメルカプタン１．１９ｇ、本発明の定着性改良剤分散液（２）１３．６ｇを加え撹拌速度３５０ｒｐｍで撹拌し且つ窒素を流しつつフラスコ内温が７５℃になるまで加熱した。７５℃に内温を維持しつつ、２，２′−アゾビス（２−アミジノプロパン）２塩酸塩１．５６ｇを純水７３．４ｍｌに溶解した重合開始剤水溶液を添加し、窒素気流下内温７５℃、撹拌速度３５０ｒｐｍを維持しつつ３時間重合を行い、着色重合体微粒子を得た。内温を室温まで冷却し更に反応液の一部を分取し乾燥の後ＧＰＣを用い分子量を測定した。
【０１１９】
更にこの着色重合体微粒子の水性分散液５００ｍｌを１Ｎ塩酸を用いｐＨ＝１．５に調節した後、撹拌装置、冷却管、温度センサーを装着した１リットル４頭フラスコに入れ、２５０ｒｐｍで撹拌を行った。ここに、塩化カリウム３８．７６ｇを２５０ｍｌの蒸留水に溶解した電解質水溶液を添加し、更にイソプロピルアルコール１２２．６ｍｌ、トリトンＸ−１００ ３．５２ｇを蒸留水１６６．５ｍｌに溶解したノニオン界面活性剤水溶液を順次添加した後、内温を８５℃まで昇温し６時間反応を行った。
【０１２０】
反応液を濾過後、蒸留水を加え再分散し５Ｎの塩酸を用いｐＨを１に調節し水洗、濾過を繰り返し、界面活性剤及び電解質を除去した後乾燥を行い、本発明の着色重合体粒子（２）を得た。これを乾燥後体積平均粒径（ｄ₅₀μｍ）及び粒度分布（σ₅₀／ｄ₅₀）をコールターカウンターを用いて測定し、且つＢＥＴ比表面積（ｍ²／ｇ）を前記窒素吸着法により測定し、その結果を表２に示した。
【０１２１】
〈本発明の着色重合体粒子合成例３〉
カーボンブラック「リーガル３３０Ｒ」（キャボット（株）社製）をアルミニウムカップリング剤「プレンアクトＡＬ」（味の素（株）社製）で処理した処理済みカーボンブラック４９．８ｇをセチルトリメチルアンモニウムクロリド２３ｇを蒸留水４１２ｍｌ溶解したカチオン界面活性剤水溶液中に添加し、超音波ホモジナイザーを用いて分散を行った。
【０１２２】
更に、撹拌装置、冷却管、温度センサー及び窒素導入管を装着した１リットルの４頭フラスコに、上記カーボンブラック分散液１４．８ｇ、蒸留水１２２．５ｍｌ、スチレン１３．４ｇ、ｎ−ブチルアクリレート２．５ｇ、ビニルベンジル−Ｎ，Ｎ−ジメチル−Ｎ−ベンジルアンモニウムクロリド０．８４ｇ、ｔｅｒｔ−ドデシルメルカプタン０．０２３ｇ及び本発明の定着性改良剤（１）５ｇを添加し、撹拌速度３５０ｒｐｍで撹拌し且つ窒素を流しつつフラスコ内温が７５℃になるまで加熱した。７５℃に内温を維持しつつ、２，２′−アゾビス（２−アミジノプロパン）２塩酸塩０．５８ｇを純水１００ｍｌに溶解した重合開始剤水溶液を添加し、窒素気流下内温７５℃、撹拌速度３５０ｒｐｍを維持しつつ３時間重合を行った。重合終了後室温まで内温を低下させた後更内温を室温まで冷却し更にカーボンブラック分散液４９ｇ、純水３２３．２ｍｌ、スチレン３６．３ｇ、ｎ−ブチルアクリレート６．７２ｇ、ビニルベンジル−Ｎ，Ｎ−ジメチル−Ｎ−ベンジルアンモニウムクロリド２．２６ｇ、ｔｅｒｔ−ドデシルメルカプタン１．１９ｇ、本発明の定着性改良剤分散液（２）１３．６ｇを加え撹拌速度３５０ｒｐｍで撹拌し且つ窒素を流しつつフラスコ内温が７５℃になるまで加熱した。７５℃に内温を維持しつつ、２，２′−アゾビス（２−アミジノプロパン）２塩酸塩１．５６ｇを純水７３．４ｍｌに溶解した重合開始剤水溶液を添加し、窒素気流下内温７５℃、撹拌速度３５０ｒｐｍを維持しつつ３時間重合を行った。反応液の一部分取し乾燥の後ＧＰＣを用い分子量を測定した。
【０１２３】
更にこの着色剤含有樹脂微粒子分散液５００ｍｌを塩酸を用いｐＨ＝１．５に調節した後、撹拌装置、冷却管、温度センサーを装着した１リットル４頭フラスコに入れ、２５０ｒｐｍで撹拌を行った。ここに、塩化カリウム３８．７６ｇを２５０ｍｌの蒸留水に溶解した電解質水溶液を添加し、更にイソプロピルアルコール１２２．６ｍｌ、トリトンＸ−１００ ３．５２ｇを蒸留水１６６．５ｍｌに溶解したノニオン界面活性剤水溶液を順次添加した後、内温を８５℃まで昇温し６時間反応を行った。
【０１２４】
反応液を濾過後、蒸留水を加え再分散し５Ｎの塩酸を用いｐＨを１３に調節し水洗、濾過を繰り返し、界面活性剤及び電解質を除去した後乾燥を行い、本発明の着色重合体粒子（３）を得た。これを乾燥後体積平均粒径（ｄ₅₀μｍ）及び粒度分布（σ₅₀／ｄ₅₀）をコールターカウンターを用いて測定し、且つＢＥＴ比表面積（ｍ²／ｇ）を前記窒素吸着法により測定し、その結果を表２に示した。
【０１２５】
〈本発明の着色重合体粒子合成例４〉
本発明の着色重合体粒子合成例３の定着性改良剤（１）を本発明の定着性改良剤（２）に変えた以外は同様にして本発明の着色重合体粒子４を合成した。
【０１２６】
〈本発明の着色重合体粒子合成例５〉
本発明の着色重合体粒子合成例３の定着性改良剤（１）を本発明の定着性改良剤（３）に変えた以外は同様にして本発明の着色重合体粒子５を合成した。
【０１２７】
〈本発明の着色重合体粒子合成例６〉
本発明の着色重合体粒子合成例３の定着性改良剤（１）を本発明の定着性改良剤（４）に変えた以外は同様にして本発明の着色重合体粒子６を合成した。
【０１２８】
〈本発明の着色重合体粒子合成例７〉
本発明の着色重合体粒子合成例３の定着性改良剤（１）を本発明の定着性改良剤（５）に変えた以外は同様にして本発明の着色重合体粒子７を合成した。
【０１２９】
〈本発明の着色重合体粒子合成例８〉
本発明の着色重合体粒子合成例３の定着性改良剤（１）を本発明の定着性改良剤（６）に変えた以外は同様にして本発明の着色重合体粒子８を合成した。
【０１３０】
〈本発明の着色重合体粒子合成例９〉
本発明の着色重合体粒子合成例３のアルミニウムカップリング剤で処理したカーボンブラックをＣ．Ｉ．ピグメントイエロー１７に変えた以外は同様にして本発明の着色重合体粒子９を合成した。
【０１３１】
〈本発明の着色重合体粒子合成例１０〉
本発明の着色重合体粒子合成例３のアルミニウムカップリング剤で処理したカーボンブラックをＣ．Ｉ．ピグメントレッド１２２にに変えた以外は同様にして本発明の着色重合体粒子１０を合成した。
【０１３２】
〈本発明の着色重合体粒子合成例１１〉
本発明の着色重合体粒子合成例３のアルミニウムカップリング剤で処理したカーボンブラックをＣ．Ｉ．ピグメントブルー１５：３に変えた以外は同様にして本発明の着色重合体粒子１１を合成した。
【０１３３】
〈本発明の着色重合体粒子合成例１２〉
本発明の着色重合体粒子合成例３の定着性改良剤（１）を本発明の定着性改良剤（７）に変えた以外は同様にして本発明の着色重合体粒子１２を合成した。
【０１３４】
〈比較着色重合体粒子合成例１〉
本発明の着色重合体粒子合成例３の定着性改良剤（１）を比較定着性改良剤に変えた以外は同様にして比較着色重合体粒子１を合成した。
【０１３５】
〈比較着色重合体粒子合成例２〉
本発明の着色重合体粒子合成例９の定着性改良剤（１）を比較定着性改良剤に変えた以外は同様にして比較着色重合体粒子２を合成した。
【０１３６】
〈比較着色重合体粒子合成例３〉
本発明の着色重合体粒子合成例１０の定着性改良剤（１）を比較定着性改良剤に変えた以外は同様にして比較着色重合体粒子３を合成した。
【０１３７】
〈比較着色重合体粒子合成例４〉
本発明の着色重合体粒子合成例１１の定着性改良剤（１）を比較定着性改良剤に変えた以外は同様にして比較着色重合体粒子４を合成した。
【０１３８】
上記本発明の着色重合体粒子合成例１〜１２及び比較着色重合体粒子１〜４の体積平均粒径（ｄ₅₀μｍ）、粒度分布（σ₅₀／ｄ₅₀）及びＢＥＴ比表面積（ｍ²／ｇ）を表２に示す。
【０１３９】
【表２】

【０１４０】
実施例１
上記本発明の着色重合体粒子１〜１２及び比較着色粒子１〜４に疎水性シリカ２％を添加し外添処理を行った。更に、平均粒径３５μｍのマグネタイトコアにスチレン／メチルメタアクリレート共重合体をコートしたキャリアをトナー濃度５％になるよう混合した。これらを本発明の現像剤１〜１２及び比較現像剤１〜４とした。これら現像剤を十分撹拌した後１分経過時及び６０分経過時の帯電量（μＣ／ｇ）をブローオフ法を用いて測定した。得られた測定結果を表３に示す。
【０１４１】
【表３】

【０１４２】
上記結果から明らかなように、本発明の現像剤は比較現像剤に比べて帯電の立ち上がりが早く、且つ安定していことが解る。
【０１４３】
実施例２
実施例１で用いた本発明の現像剤２〜５、９〜１１及び比較現像剤１を使用し、接触現像方式の電子複写機「Ｕ−ＢＩＸ３１３５」（コニカ（株）社製）を用い評価を行った。尚、現像剤層厚は１．５ｍｍ、感光体とスリーブとの間隙（Ｄｓｄ）は０．５ｍｍである。
【０１４４】
また、感光体のクリーニングは、図３（クリーニング手段の説明図）に記載したカウンター方式のクリーニング部材２０を用いて行われ、該クリーニング部材２０は、ホルダー２２と感光体ドラム４に対して２２°の圧接角度（θ）で圧接するクリーニングブレード２１とから構成され、該クリーニングブレード２１の材料としては、ウレタンゴムが用いられ、そのゴム硬度は６５°のものであり、厚みは２ｍｍ、ホルダー部外の長さは８ｍｍとした。更に感光体ドラム４に対する圧接力は１５ｇｆ／ｍｍである。更に転写方式はコロナ転写方式を用いた。
【０１４５】
評価は低温低湿（１０℃，１０％ＲＨ）環境下で１万枚連続印字及び２４時間放置、引き続き次の１万枚連続印字及び２４時間放置を６回繰り返して、合計６万枚の印字を行い、初期及び各回の印字終了時の画像のカブリ濃度を測定した。濃度測定は紙の濃度を０とした時の相対濃度で示し、測定にはマクベス濃度計「ＲＤ−９１８」（マクベス（株）社製）を使用した。
【０１４６】
【表４】

【０１４７】
表４より本発明の現像剤は繰り返し画像形成の過程でカブリの発生が極めて少ないが、比較現像剤は印字枚数の増加と共にカブリが増大することが解る。
【０１４８】
実施例３
非接触現像方式で、且つ一括転写方式のカラー複写機「Ｋｏｎｉｃａ９０２８」（コニカ社（株）社製）の改造機を用い、感光体として積層型有機感光体を用い、現像剤として本発明の現像剤３、９、１０、１１を組み合わせて成る本発明のカラー現像剤及び比較現像剤１〜４を組み合わせて成る比較カラー現像剤を用い、カラー原稿として画素率が７５％の画像を用いて印字テストを行った。印字テストは１０００枚連続印字及び２４時間放置、引き続き１０００枚連続印字及び２４時間放置を１０回繰り返して、合計１万枚のカラー印字を行い、その間に転写ムラを発生するに至った枚数を記録し、その結果を表５に示した。
【０１４９】
なお、上記カラー複写機の印字条件は下記の条件である。
【０１５０】
感光体表面電位＝−５５０Ｖ
ＤＣバイアス＝−７５０Ｖ
ＡＣバイアス＝Ｖｐ−ｐ：１．６ｋＶ（イエロー、マゼンタ、シアン）、１．８ｋＶ（ブラック）
交番電界周波数＝１８００Ｈｚ
Ｄｓｄ＝３００μｍ
押圧規制力＝１０ｇｆ／ｍｍ
押圧規制棒＝ＳＵＳ４１６（磁性ステンレス製）／直径３ｍｍ
現像剤層厚＝１５０μｍ
現像スリーブ＝２０ｍｍ
【０１５１】
【表５】

【０１５２】
表５より本発明のカラー現像剤は、非接触現像方式で、且つ一括転写方式のカラー複写機に用いた場合でも転写ムラの発生がなく、良質のカラー画像を形成することが出来るが、比較カラー現像剤を用いた場合は初期より３５００枚から転写ムラを発生し、実用性に乏しいことが解る。
【０１５３】
実施例４
非接触現像方式で、且つ逐次転写方式のカラー複写機「ＣＬＣ−５００」（キャノン（株）社製）の改造機を用い、感光体として積層型有機感光体を用い、現像剤として本発明の現像剤３、９、１０、１１を組み合わせて成る本発明のカラー現像剤及び比較現像剤１〜４を組み合わせて成る比較カラー現像剤を用い、カラー原稿として画素率が７５％の画像を用いた外は上記カラー複写機「ＣＬＣ−５００」の基本動作条件に従って印字テストを行った。印字テストは１０００枚連続印字及び２４時間放置、引き続き１０００枚連続印字及び２４時間放置を１０回繰り返して、合計１万枚のカラー印字を行い、その間に転写ムラを発生するに至った枚数を記録し、その結果を表６に示した。
【０１５４】
【表６】

【０１５５】
表６より本発明のカラー現像剤は、非接触現像方式で、且つ逐次転写方式のカラー複写機に用いた場合でも転写ムラの発生がなく、良質のカラー画像を形成することが出来るが、比較カラー現像剤を用いた場合は初期より３０００枚から転写ムラが発生し、実用性に乏しいことが解る。
【０１５６】
【発明の効果】
実施例で実証されたように、本発明のトナー、現像剤及び画像形成方法によれば、帯電の立ち上がりが早く、帯電が均一且つ安定で、繰り返し画像形成の過程で高耐久性であり、トナー像の転写材への転写性にも優れていてカブリのない鮮明な画像が安定して得られる等、優れた効果を有する。
【図面の簡単な説明】
【図１】カラー画像形成装置の一例を示す概略図である。
【図２】カラー画像形成装置の他の例を示す概略図である。
【図３】クリーニング手段の説明図である。
【符号の説明】
１ 帯電器
２ 現像ユニット
３ クリーニングユニット
４ 感光体ドラム
５ 転写ドラム
６ 搬送手段
７ 吸着電極
８ 転写電極
９ 剥離電極
１０ 除去電極
１１ ベルト状搬送部材
１２ 分離部材
１６ 熱ローラ定着装置
１７ 熱ローラ
１８ 圧着ローラ
２０ クリーニング部材
２１ クリーニングブレード
２２ ホルダー
３０ カラートナー像
Ｌ 像露光
θ 圧接角度[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toner for developing an electrostatic latent image used for electrophotography, electrostatic recording, and the like, a developer, and an image forming method using the developer.
[0002]
[Prior art]
As a method for developing an electrostatic latent image formed on an electrophotographic photosensitive member or an electrostatic recording member, a method using a liquid developer (wet development method), a binder resin, a colorant, and a fixability improver Further, if necessary, a toner for developing an electrostatic latent image (hereinafter also simply referred to as toner) obtained by a so-called pulverization granulation method in which a charge control agent and a magnetic material are mixed, melted, cooled, pulverized and classified. In general, a method using a one-component developer or a two-component developer in which a toner is mixed with a carrier (dry development method) is employed.
[0003]
The wet development method and the dry development method each have advantages and disadvantages, but at present, the dry development method is generally used in many cases.
[0004]
In electrophotography using a dry development method, in recent years, high image quality and high speed have been demanded. For this purpose, the toner has a small particle size, a narrow particle size distribution, and a rise in charge. Therefore, there is a demand for a toner that is fast, stable in chargeability, has little charge deterioration, and exhibits uniform chargeability.
[0005]
In electrophotography, an electrostatic latent image is formed on an electrophotographic photosensitive member (hereinafter also simply referred to as a photosensitive member) by charging and image exposure, and the electrostatic latent image is developed by a dry development method. An image is formed by repeating a process of forming a toner image and transferring the toner image onto a transfer material. Therefore, in order to achieve high image quality in electrophotography, it is required that the toner image is further excellently transferred to a transfer material.
[0006]
In a general method for producing conventional toner, a binder resin, a colorant, a fixability improving agent and, if necessary, a charge control agent are mixed, melted, kneaded and then used in a mechanical or air collision type pulverizer. A method of pulverizing and classifying has been used. In this conventional method, the dispersion of the colorant, fixability improver, and other charge control agent added to the toner is not uniform, so that the particle size distribution is narrow, the particle size is small, and the charging uniformity. There is a drawback that it is impossible to obtain a toner excellent in charging stability and charge rising property. Therefore, the use of conventional toners has the disadvantage that the chargeability is lowered and fogging occurs in the process of repeated image formation, and the transferability onto the transfer material is lowered, resulting in image deterioration. Was.
[0007]
Therefore, the present inventors have repeated research on producing a toner by a polymerization granulation method using an emulsion polymerization method or a suspension polymerization method, and the chargeability of the resin monomer for the binder of the toner, for example, fixing. It is important to deal with the chargeability of additives such as a property improver. If the chargeability of the resin monomer for the binder of the toner and the chargeability of the additive such as a fixability improver are different, stable charging It has been found that it is difficult to obtain a toner having properties. Furthermore, when the toner is produced by the polymerization granulation method, a step of associating and aggregating the primary fine particles obtained by polymerization and heat-sealing to obtain a desired particle size is necessary. It turns out that it is difficult and requires advanced technology.
[0008]
[Problems to be solved by the invention]
The object of the present invention is to solve the problems of the prior art, the rise of charge is fast, the charge is uniform and stable, it is highly durable in the process of repeated image formation, and the transferability of the toner image to the transfer material is also improved. An object of the present invention is to provide a toner, a developer and an image forming method capable of obtaining a clear and excellent image with no fog.
[0009]
[Means for Solving the Problems]
The object of the present invention is achieved by the following constitution.
[0010]
1. With hydrophobic monomers Kachi An electrostatic latent image developing toner containing a copolymer comprising an on-off monomer and a fixability improver, wherein the fixability improver is a fixability improver modified with a unit containing a cationic group An electrostatic charge latent image developing toner.
[0011]
2. 2. The electrostatic latent image developing toner according to 1, wherein the cationic group is at least one cationic group selected from an amino group, an amide group, and a quaternary ammonium base.
[0012]
3. 3. The monomer according to 1 or 2 above, wherein the monomer corresponding to the unit containing a cationic group is at least one vinyl monomer selected from vinyl monomers containing an amino group, an amide group and a quaternary ammonium base. Toner for developing electrostatic latent image.
[0013]
4). 4. The electrostatic charge latent image developing as described in any one of 1 to 3 above, wherein an average domain diameter of the fixing improver modified with the unit containing a cationic group is 0.01 to 1 μm. toner.
[0014]
5. 5. The electrostatic latent image developing toner according to any one of 1 to 4, wherein the fixing property improving agent is a polyolefin modified with a unit containing a cationic group.
[0016]
6 . Said Kachi The above-mentioned 1 to 3, wherein the ionic monomer is at least one ionic monomer selected from vinyl monomers containing an amino group, an amide group and a quaternary ammonium base. 5 The toner for developing an electrostatic latent image according to any one of the above.
[0017]
7 . The toner has a BET specific surface area of 5 to 100 m. ² / G. 6 The toner for developing an electrostatic latent image according to any one of the above.
[0018]
8 . A developer comprising a toner for developing an electrostatic latent image, comprising a resin comprising a hydrophobic monomer and a cationic monomer, and a fixing property-improving agent modified with a unit containing a cationic group.
[0019]
9 . In an image forming method in which an electrostatic charge latent image formed on an electrophotographic photosensitive member is exposed to form a toner image, the toner on which the toner image is formed is a hydrophobic monomer and Kachi An image forming method comprising: a toner for developing an electrostatic latent image, comprising a resin comprising an on-on monomer and a fixing property-improving agent modified with a unit containing a cationic group.
[0020]
1 0 . In an image forming method for transferring a toner image formed on an electrophotographic photosensitive member to a transfer material, the toner on which the toner image is formed is a hydrophobic monomer. Kachi An image forming method comprising: a toner for developing an electrostatic latent image, comprising a resin comprising an on-on monomer and a fixing property-improving agent modified with a unit containing a cationic group.
[0021]
1 1 . In an image forming method in which a toner image formed on an electrophotographic photosensitive member is transferred onto a transfer material and then the toner remaining on the photosensitive member is cleaned and removed, the toner forming the toner image is a hydrophobic monomer When Kachi An image forming method comprising: a toner for developing an electrostatic latent image, comprising a resin comprising an on-on monomer and a fixing property-improving agent modified with a unit containing a cationic group.
[0022]
1 2 . In an image forming method in which a toner image formed on an electrophotographic photoreceptor is transferred to a transfer material, and the transfer material carrying the toner image is thermally fixed, the toner on which the toner image is formed is a hydrophobic monomer. Kachi A toner for developing an electrostatic latent image, comprising: a copolymer comprising an on-on monomer; and a fixability improving agent modified with a unit containing a cationic group.
[0023]
1 3 . The toner image carried on the transfer material is fixed by heat roller fixing. 2 The image forming method described in 1.
[0024]
Hereinafter, the present invention will be described in more detail.
[0025]
The present invention is a resin comprising a hydrophobic monomer and an ionic monomer, a resin comprising a copolymer having a glass transition temperature of preferably in the range of 40 to 70 ° C., a fixing property improver comprising a cationic unit, If necessary, it contains a colorant, a charge control agent, etc., preferably a BET specific surface area of 5 to 100 m. ² / G toner, a developer containing the toner, and an image forming method using the developer. Further, the toner of the present invention can be prepared by using a dispersion containing the above-mentioned hydrophobic monomer, ionic monomer, fixing unit containing a cationic unit, colorant, charge control agent, etc. Granulation polymerization is performed by a polymerization method such as a polymerization method to obtain colored polymer fine particles, and the colored polymer fine particles are aggregated and aggregated by an aggregation method to produce a toner, and preferably a binder resin and a fixability improving agent Are characterized by the same chargeability and both cationicity.
[0026]
In addition, the unit containing a cationic group in the present invention includes not only a unit in which the unit itself is cationic but also a unit for charging the toner cationically when it is contained in the toner.
[0027]
Although the production method of the toner of the present invention is not limited, the present invention will be described below using a production example of a polymerized toner using an emulsion polymerization method which is a preferred production method of the present invention.
[0028]
[Fixability improver]
As the fixing property improver containing a cationic unit of the present invention, a polyolefin obtained by introducing a structural unit represented by the following general formula into a polyolefin is preferably used.
[0029]
<Constitutional unit having a cationic group>
As the structural unit having a cationic group, a structural unit having at least one cationic group selected from an amino group, an amide group, and a quaternary ammonium base is preferably used. As the structural unit, structural units represented by the following general formulas (1) to (7) are preferable.
[0030]
[Chemical 1]

[0031]
[However, R ¹ Represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms (for example, a methyl group), and R ² Represents an alkylene group having 1 to 8 carbon atoms, an alkyleneoxyalkylene group having 1 to 8 carbon atoms, a phenylene group, a naphthylene group, a phenylenealkylene group or a group formed by combining two or more of these groups, and R ^Three And R ^Four May be the same as or different from each other and each represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group (for example, a phenyl group or a naphthyl group), or a phenylalkyl group. M represents a simple bond, or —CONR— or —COO—, and A represents a divalent benzyl group or phenethyl group (wherein R represents a hydrogen atom or a methyl group). B represents a pyridyl group or an imidazolyl group. ]
In the structural units represented by these general formulas (1) to (7), a corresponding monomer (for example, a monomer in which the bond between carbons of the main chain portion in the general formulas (1) to (7) is a double bond) is used. The fixing property improver according to the present invention may be used by introducing it into the mother nucleus of the fixing property improving agent or by copolymerizing the corresponding monomer with another monomer.
[0032]
Examples of the monomer corresponding to the structural unit represented by the general formula (1) include the following compounds.
[0033]
N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, N-methylaminoethyl methacrylate, N, N-dimethylaminomethyl methacrylate, pN, N-dimethylaminophenyl methacrylate, N, N-dimethylamino Ethyl acrylate, N, N-diethylaminoethyl acrylate, N-methylaminoethyl acrylate, N, N-diethylaminomethyl acrylate, p-N, N-dimethylaminophenyl acrylate.
[0034]
Examples of the monomer corresponding to the structural unit represented by the general formula (2) include the following compounds.
[0035]
N, N-dimethylaminoethyl methacrylamide, N, N-diethylaminoethyl methacrylamide, N-methylaminoethyl methacrylamide, N, N-dimethylaminomethyl methacrylamide, pN, N-dimethylaminophenyl methacrylamide, N , N-dimethylaminoethylacrylamide, N, N-diethylaminoethylacrylamide, N-methylaminoethylacrylamide, N, N-diethylaminomethylacrylamide, pN, N-dimethylaminophenylacrylamide.
[0036]
Examples of the monomer corresponding to the structural unit represented by the general formula (3) include the following compounds.
[0037]
N, N-dimethylmethacrylamide, N, N-diethylmethacrylamide, N-propylmethacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide, N-propylacrylamide.
[0038]
Examples of the monomer corresponding to the structural unit represented by the general formula (4) include the following compounds.
[0039]
pN, N-dimethylaminostyrene, pN, N-diethylaminostyrene, pN, N-dipropylaminostyrene, pN-methylaminostyrene.
[0040]
Examples of the monomer corresponding to the structural unit represented by the general formula (5) include the following compounds.
[0041]
N-vinyldimethylamine, N-vinyldiethylamine, N-vinyldipropylamine, N-vinylpropylamine.
[0042]
Examples of the monomer corresponding to the structural unit represented by the general formula (6) include the following compounds. That is, vinylbenzyldialkylamine (the alkyl group is a substituted or unsubstituted alkyl group of n = 1 to 6, which may be the same or different), vinylphenethyl dialkylamine (the alkyl group is n = 1 to 6 substituted or unsubstituted alkyl groups, which may be the same or different), vinylcarbamoylbenzyldialkylamine (wherein the alkyl group is a substituted or unsubstituted alkyl group of n = 1 to 6, these are They may be the same or different.)
[0043]
Examples of the monomer corresponding to the structural unit represented by the general formula (7) include the following compounds.
[0044]
4-vinylpyridine, 2-vinylpyridine, N-vinylimidazole.
[0045]
Furthermore, what made the structural unit represented by the said General Formula (1)-(7) into the type | mold of the quaternary ammonium salt can also be used, for example, as a group substituted by the nitrogen atom, it is C1-C6 alkyl. A group (for example, a methyl group, an ethyl group), a benzyl group, a cycloalkyl group and the like are preferable.
[0046]
<Polyolefin>
Examples of the polyolefin used for the fixability improver preferably used in the present invention include low molecular weight polyolefins (low molecular weight polyethylene, low molecular weight polypropylene, etc.). The low molecular weight referred to here is preferably a number average molecular weight (abbreviated as Mn) and preferably represents 100 to 10,000. More preferably, the range of Mn = 500-5,000 is shown. This low molecular weight polyolefin can be modified according to a conventional method using the above-mentioned monomer having a cationic unit. The modification rate to low molecular weight polyolefin by the monomer containing the cationic unit of the present invention is preferably 0.01 to 4 mmol / g polyolefin. More preferably, the range of 0.05-2 mmol / g polyolefin is preferable.
[0047]
<Preparation of aqueous dispersion of fixability improver>
The fixability improver modified with the cationic unit of the present invention is prepared in the form of an aqueous dispersion when a colored polymer fine particle is prepared by using an emulsion polymerization method and further agglomerated and aggregated into a toner. It is desirable to add to the polymerization system during the emulsion polymerization. An aqueous dispersion of the fixability improver can be obtained by emulsifying and dispersing the fixability improver in water heated to a temperature higher than the softening temperature of the fixability improver. When the softening temperature of the fixing improver exceeds 100 ° C., a dispersion can be easily prepared by pressure emulsification. The average domain diameter in the toner particles of these fixability improvers is preferably in the range of 0.03 to 1.0 μm. More preferably, it is 0.05-0.8 micrometer. Since the average domain diameter of the fixability improver in the toner is equal to the average particle diameter of the aqueous dispersion of the fixability improver, the average particle diameter of the aqueous dispersion is set to the average domain diameter of the fixability improver of the present invention. A combined dispersion may be used.
[0048]
The average domain diameter in the toner particles of the fixability improver is measured by the following method. That is, the toner particles are embedded with a resin, and a section having a thickness of about 0.2 μm is prepared by a microtome. This section is photographed with a transmission electron microscope at a negative magnification of 280 times and stretched to create a photograph at 1200 times. The domain diameter is measured with an image analysis apparatus (SPICCA: Nippon Avionics Co., Ltd.). Here, 500 or more domains are measured, and measured as a number average as a domain diameter in terms of a circle.
[0049]
<Colorant>
The toner of the present invention preferably contains a colorant, and examples of the colorant include inorganic pigments and organic pigments. Known inorganic pigments can be used. For example, the following inorganic pigments can be used.
[0050]
Examples of the black inorganic 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. These inorganic pigments can be used after surface treatment with a surface treatment agent as required. Examples of the surface treatment include a silane coupling agent, a titanium coupling agent, and an aluminum coupling agent. In particular, an aluminum coupling agent that is stable in an aqueous medium is useful. In particular, the surface treatment of carbon black that inhibits a radical polymerization reaction can reduce the inhibition.
[0051]
These inorganic pigments can be used alone or in combination as required. The addition amount of the pigment is preferably 2 to 20 parts by weight, more preferably 3 to 15 parts by weight with respect to the polymer.
[0052]
Moreover, a well-known thing can be used as an organic pigment, for example, the following organic pigments can be used.
[0053]
Examples of organic pigments for orange or yellow 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. And CI Pigment Yellow 180.
[0054]
Examples of organic 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.
[0055]
Examples of organic 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.
[0056]
These organic pigments can be used alone or in combination as required. The amount of the pigment added is preferably 2 to 20 parts by weight, more preferably 3 to 15 parts by weight with respect to the binder resin.
[0057]
[Binder resin]
The binder resin for the toner of the present invention comprises a hydrophobic monomer and an ionic monomer.
[0058]
<Hydrophobic monomer>
Examples of the hydrophobic monomer include styrenes such as styrene, p-methylstyrene, o-methylstyrene, m-methylstyrene, alkyl acrylates such as methyl acrylate, ethyl acrylate, n-butyl acrylate, alkyl methacrylates such as Examples include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, conjugated dienes such as butadiene, isobrene, dimethyl butadiene, chloroprene, nitriles such as acrylonitrile and methacrylonitrile, and vinyl chloride and vinylidene chloride.
[0059]
<Ionic monomer>
The ionic monomer is preferably cationic and is represented by the cationic monomer corresponding to the structural unit represented by the general formulas (1) to (7) and the general formulas (1) to (7). At least one of the structural units in the form of a quaternary ammonium salt.
[0060]
Here, the binder resin of the toner of the present invention is synthesized from a hydrophobic monomer and an ionic monomer, particularly a cationic monomer, and has the same chargeability as the fixing property improver containing the cationic group. On the other hand, sufficient positive chargeability can be imparted, and excessive agglomeration can be suppressed during agglomeration reaction to achieve a sharp particle size distribution.
[0061]
The glass transition temperature of the copolymer obtained by copolymerizing the hydrophobic monomer and the ionic monomer is preferably designed to be 40 to 70 ° C. When the glass transition temperature of the copolymer is less than 40 ° C., the storage stability of the toner is poor and the toner tends to be fused during storage to cause blocking. When the glass transition temperature exceeds 70 ° C., the toner is fixed during image formation. It is easy to get worse.
[0062]
At this time, the copolymerization ratio of the ionic monomer to the hydrophobic monomer is preferably selected in the range of 0.1 to 15% by weight. More preferably, a copolymerization ratio range of 0.5 to 10% by weight is selected. At this time, when the copolymerization ratio is less than 0.1% by weight, the positive chargeability is not sufficiently imparted to the toner, and it is difficult to suppress the generation of coarse particles due to excessive aggregation during the aggregation reaction of the primary particles. In addition, since the hydrophilicity of the toner having a copolymerization ratio exceeding 15% by weight becomes excessively large, the charge amount of the toner changes depending on the environment, and the toner tends to become unstable.
[0063]
[Production of toner]
As a representative example for producing the toner of the present invention, first, a hydrophobic monomer, an ionic monomer, an aqueous fixing improver dispersion, a dispersant (surfactant), water, and an optional colorant aqueous dispersion The aqueous mixture of the charge control agent aqueous dispersion is heated to the emulsion polymerization temperature with stirring, and a water-soluble radical polymerization initiator is added to carry out the emulsion polymerization to prepare a colored polymer fine particle aqueous dispersion. The fixing improver aqueous dispersion, the colorant aqueous dispersion, the charge control agent aqueous dispersion, and the like may be added either during the emulsion polymerization process or after completion of the polymerization.
[0064]
Subsequently, the colored polymer fine particle aqueous dispersion obtained as described above is added with an aggregating agent and other additives for improving particle characteristics, and the cationic groups of the ionic monomer and the fixing property improving agent are added. Aggregation aggregation is performed in a completely dissociated or partially dissociated state, and further, a resin for binder, that is, heating in the range of the glass transition temperature to the glass transition temperature + 50 ° C. of the copolymer to heat-fuse the particles to form a colored polymer. Get particles. At this time, the shape of the colored polymer particles can be arbitrarily controlled from a true sphere to a raspberry non-spherical shape by changing the heating temperature, the heating time and the like.
[0065]
The colored polymer particles thus produced are taken out as a powder after being purified and dried by washing, and an external additive is further added to form a toner.
[0066]
<Charge control agent>
The charge control agent to be added to the toner of the present invention as necessary is not originally necessary because the ionic group on the toner surface performs its function, but can be added as desired. Known to exhibit positive chargeability, such as nigrosine-based electron-donating dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines, quaternary ammonium salts, alkylamides, metal complexes, pigments, fluorine treatment activators, etc. Can be mentioned. These can be introduced into the toner by using a surfactant in the same manner as the colorant, finely dispersed in the aqueous phase, and adding a desired amount at the time of polymerization or at the time of the toner formation reaction.
[0067]
<Dispersant (surfactant)>
A cationic surfactant is preferably used as the dispersant for the aqueous dispersion of the emulsion polymerization and fixing property improving agent in the production of the toner of the present invention. Examples of the cationic surfactant include a cationic surfactant having an amine salt structure, a surfactant having a quaternary ammonium salt structure, and the like. Examples of the cationic surfactant having an amine salt structure include an acid neutralized product of laurylamine, an acid neutralized product of stearylamine, and an acid neutralized product of stearamide ethyl dialkylamine (the alkyl group has 1 to 3 carbon atoms). Substituted, unsubstituted alkyl group), acid neutralized product of triethanolamine monostearate, imidazoline type cationic surfactant (acid neutralized product of 2-heptadecenyl-hydroxyethylimidazoline) and the like. Examples of surfactants having a quaternary ammonium salt structure include alkyltrimethylammonium salts (wherein the alkyl group is an alkyl group having 8 to 18 carbon atoms, such as lauryltrimethylammonium chloride), alkyldimethylbenzylammonium salts (wherein the alkyl group is carbon). And an alkylpyridinium salt (wherein the alkyl group is an alkyl group having 8 to 18 carbon atoms, such as cetylpyridinium chloride).
[0068]
<Polymerization initiator>
A polymerization initiator is preferably used when the toner of the present invention is emulsion-polymerized by an emulsion polymerization method, and a water-soluble radical polymerization initiator is used as a preferable example. Preferably, a radical polymerization initiator having a cationic group or a nonionic radical polymerization initiator is used. Examples of radical polymerization initiators having a cationic group include, for example, 2,2′-azobis (2-methylpropionamidine) dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) Propane] dihydrochloride, 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (4,5,6, 7-tetrahydro-1H-1,3-diazepin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (5-hydroxy-3,4,5,6-tetrahydropyrimidin-2-yl] ) Dihydrochloride, 2,2'-azobis (2-methyl-N-phenylpropionamide) dihydrochloride, 2,2'-azobis [N- (4-chlorophenyl) -2-methylpropionamide] dihydrochloride 2,2'-azobi [N- (4-hydroxyphenyl) -2-methylpropionamide] dihydrochloride, 2,2'-azobis [2-methyl-N- (phenylmethyl) propionamide] dihydrochloride, 2,2'-azobis [2-Methyl-N- (2-propenyl) propionamide] dihydrochloride, 2,2'-azobis (2-methylpropionamide) dihydrochloride, 2,2'-azobis [N- (2-hydroxyethyl ) -2-methylpropionamide] dihydrochloride and the like.
[0069]
Examples of nonionic radical polymerization initiators include 2,2'-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide}, 2,2'- Azobis {2-methyl-N- [1,1-bis (hydroxymethylethyl) propionamide}, 2,2'-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2 ' -Azobis (2-methylpropionamide) dihydrate, 2,2'-azobis [2- (hydroxymethyl) propionitrile] and the like.
[0070]
<Association and aggregation of colored polymer particles>
In order to produce the toner of the present invention using the emulsion polymerization method, first, an aqueous dispersion of colored polymer fine particles is prepared, and further, a flocculant is added to the colored polymer fine particles in the aqueous dispersion of colored polymer fine particles. In this way, a plurality of aggregates are aggregated and grown to a desired particle size, and at the same time, heated above the glass transition temperature of the copolymer of the present invention and fused between the associated particles to form strong colored polymer particles, ie, toner. It can be. The heating temperature at this time is preferably in the range of + 50 ° C. from the glass transition temperature of the copolymer. More preferably, the glass transition temperature of the copolymer is + 10 ° C to + 40 ° C.
[0071]
When assembling and aggregating a plurality of colored polymer fine particles in the colored polymer fine particle aqueous dispersion, at least part of the ionic dissociation groups present on the surface of the colored polymer fine particles before or during the association reaction is ion dissociated. It is preferable to use it in the state which is carrying out. That is, in the case of an anionic dissociating group, it is preferable that the anionic dissociating group is partially dissociated with alkali. On the other hand, in the case of a cationic dissociation group, it is preferable that it is partially dissociated with an acid or has a quaternary ammonium salt structure. By making this ionic dissociation group at least partially ionic dissociated, the production of so-called coarse particles outside the desired particle size range is remarkably suppressed, and as a result, toner particles having a narrow particle size distribution can be produced.
[0072]
As the flocculant for associating and aggregating a plurality of colored polymer fine particles in the colored polymer fine particle aqueous dispersion, salts selected from monovalent, divalent and trivalent metal salts, organic or inorganic acids Etc. Examples of the monovalent, divalent, or trivalent metal salt include sodium chloride, potassium chloride, lithium chloride, magnesium chloride, calcium chloride, aluminum chloride, and the acid includes hydrochloric acid, sulfuric acid, and the like. And acetic acid. Preferably, monovalent metal salts, that is, sodium chloride, potassium chloride, and lithium chloride are used.
[0073]
Furthermore, an organic solvent or a surfactant that is infinitely soluble in water can be added as necessary. These are used for adjusting the shape of the produced colored polymer particles and sharpening the particle size distribution. The organic solvent infinitely soluble in water is selected from alcohols and ketones that do not dissolve the copolymer used for the binder. Particularly preferred is isopropyl alcohol. Examples of the surfactant include nonionic surfactants.
[0074]
As described above, in the toner production method of the present invention, an aqueous dispersion containing a hydrophobic monomer, an ionic monomer, a fixing property improving agent, and a colorant, a charge control agent, and a surfactant as necessary is stirred. After the temperature is raised to a desired temperature, a water-soluble radical polymerization initiator is added and a polymerization reaction is performed for a certain period of time to obtain a colored polymer fine particle aqueous dispersion containing the colored polymer fine particles. Aggregation and aggregation are performed to obtain colored polymer particles (toner).
[0075]
At this time, in order to obtain colored polymer particles (toner) having an appropriate particle size, specific surface area, and particle size distribution and excellent electrophotographic characteristics, the pH of the colored polymer fine particle aqueous dispersion is changed to an anionic dissociation group. In the neutral to alkaline region, and in the case of having a cationic dissociative group, the neutral to acidic region is adjusted to adjust the dissociation degree of the ionic group on the surface of the colored polymer fine particles, electrolyte or electrolyte Water is added for the purpose of adding a flocculant composed of an aqueous solution, a step of adding a nonionic surfactant to suppress overcoagulation of the colored polymer particles and maintaining the stability of aggregation, and shape control of the colored polymer particles. The step of adding an infinitely soluble organic solvent to the toner and the glass transition temperature of the copolymer used in the toner are heated from the glass transition temperature to a temperature of 50 ° C. and maintained at this temperature for a predetermined time to carry out the reaction. Is desirable to have a degree, etc., the order of these steps may be any of the following six types.
[0076]
(1) An electrolyte or an aqueous electrolyte solution, an organic solvent that is infinitely soluble in water, a nonionic surfactant or an aqueous solution thereof are sequentially added to the colored polymer fine particle aqueous dispersion in which the degree of dissociation of ionic groups on the surface of the colored polymer fine particles is adjusted. The resin is heated from the glass transition temperature of the resin to a temperature of glass transition temperature + 50 ° C. and maintained at this temperature for a predetermined time to carry out the reaction.
[0077]
(2) A nonionic surfactant or an aqueous solution thereof, an electrolyte or an aqueous electrolyte solution, and an organic solvent that is infinitely soluble in water are sequentially added to the colored polymer fine particle aqueous dispersion in which the degree of dissociation of ionic groups on the surface of the colored polymer fine particles is adjusted. The copolymer is heated from the glass transition temperature to the glass transition temperature + 50 ° C. and maintained at this temperature for a predetermined time to carry out the reaction.
[0078]
(3) An organic solvent that is infinitely soluble in water, a nonionic surfactant or an aqueous solution thereof, an electrolyte or an aqueous electrolyte solution are sequentially added to the colored polymer fine particle aqueous dispersion in which the degree of dissociation of ionic groups on the surface of the colored polymer fine particles is adjusted. Then, the copolymer is heated from the glass transition temperature of the copolymer to a temperature of glass transition temperature + 50 ° C. and maintained at this temperature for a predetermined time to carry out the reaction.
[0079]
(4) A nonionic surfactant dissolved in an electrolyte or an aqueous electrolyte solution and an organic solvent infinitely soluble in water is sequentially added to the colored polymer fine particle aqueous dispersion in which the degree of dissociation of ionic groups on the surface of the colored polymer fine particles is adjusted. Then, the copolymer is heated from the glass transition temperature of the copolymer to a temperature of glass transition temperature + 50 ° C. and maintained at this temperature for a predetermined time to carry out the reaction.
[0080]
(5) To an aqueous dispersion of colored polymer fine particles in which the degree of dissociation of ionic groups on the surface of the colored polymer fine particles is adjusted, an aqueous solution in which both a nonionic surfactant and an electrolyte are dissolved, and an organic solvent infinitely soluble in water are sequentially added. The copolymer is heated from the glass transition temperature to the glass transition temperature + 50 ° C. and maintained at this temperature for a predetermined time to carry out the reaction.
[0081]
(6) An electrolyte or an aqueous electrolyte solution, an organic solvent that is infinitely soluble in water, a nonionic surfactant or an aqueous solution thereof is added simultaneously to an aqueous dispersion of colored polymer fine particles in which the degree of dissociation of ionic groups on the surface of the colored polymer fine particles is adjusted. Then, the copolymer is heated from the glass transition temperature of the copolymer to a temperature of glass transition temperature + 50 ° C. and maintained at this temperature for a predetermined time to carry out the reaction.
[0082]
In addition to the above, the aqueous dispersion of colored polymer fine particles in which the degree of dissociation of ionic groups on the surface of the colored polymer fine particles is adjusted is heated from the glass transition temperature of the copolymer to a temperature of glass transition temperature + 50 ° C. It is also possible to add the additives according to the order and perform the heating reaction for a predetermined time.
[0083]
Further, as a method for growing the colored polymer fine particles to a desired colored polymer particle size, it is also possible to use two types of colored polymer fine particles having different charges and grow them using a heteroaggregation method.
[0084]
The colored polymer particles thus produced are repeatedly washed and filtered to remove impurities such as electrolytes and surfactants, and then dried, and further necessary external additives are added to obtain a toner.
[0085]
<Characteristics of toner>
The toner produced as described above preferably has an average particle diameter of 3 to 15 μm and a BET specific surface area of preferably 5 to 100 m. ² / G.
[0086]
When the average particle size of the toner of the present invention is less than 3 μm, it is practically difficult to produce the toner, and fog is likely to occur at the time of image formation. . The particle diameter of the toner is a volume average particle diameter, and is measured by a Coulter counter TA-11.
[0087]
The toner of the present invention has a BET specific surface area of 5 m. ² If the amount is less than / g, the rise of toner charge may be slow and a sufficient charge amount may not be secured, and the toner has a BET specific surface area of 100 m. ² If it exceeds / g, the toner is likely to absorb moisture, the charge amount becomes unstable, and fogging tends to occur during image formation.
[0088]
In the toner of the present invention, the BET specific surface area is 5 to 100 m. ² / G and having an ion dissociable group on the surface of the toner particles synergistically act, and it is possible to stably ensure a very fast rise of charge and a charge property of a desired polarity. . For this reason, there is an advantage that it is not necessary to add a charge control agent.
[0089]
By the way, the BET specific surface area of the toner is measured by a one-point method of nitrogen adsorption method, and a specific measuring apparatus is a flow soap 2300 (Shimadzu Corporation).
[0090]
<Developer>
The toner of the present invention is usually mixed with a carrier at a constant ratio and used as a two-component developer. Examples of the carrier include an uncoated carrier composed of a magnetic material such as iron or ferrite, or a resin-coated carrier obtained by coating the surface of the magnetic material with a resin or the like. The volume average particle diameter of the carrier is 30 to 150 μm. preferable. The mixing ratio of the toner and the carrier in the two-component developer is 1 to 10 parts by weight of the toner with respect to 100 parts by weight of the carrier.
[0091]
<Image forming method>
The image forming method of the present invention will be described below.
[0092]
The image forming method of the present invention is the toner of the present invention described above, preferably having a BET specific surface area of 5 to 100 m. ² The latent electrostatic image formed on the photoconductor is developed using the toner of the present invention, which is / g, to form a toner image, which is transferred onto a transfer material and fixed to form an image.
[0093]
The developing method using the toner of the present invention is not particularly limited, and can be suitably used for a contact developing method or a non-contact developing method. In the case of the contact development system, the layer thickness of the developer having the toner of the present invention is 0.1 to 8 mm, preferably 0.4 to 5 mm in the development region, and the developer spikes are formed in the development region. Then, development is carried out by a so-called magnetic brush development method in which the head is brought into contact with the photosensitive member for development. In this case, the gap between the photosensitive member and the developer carrying member (hereinafter simply referred to as a sleeve) is preferably 0.15 to 7 mm, particularly preferably 0.2 to 4 mm.
[0094]
In the case of the non-contact development method, the developer layer formed on the sleeve and the photosensitive member are not in contact with each other, and the developer layer is formed as a thin layer in order to constitute this development method. Is preferred. In this method, a developer layer having a thickness of 20 to 500 μm is formed in the developing area on the sleeve surface, and the gap between the photoreceptor and the sleeve is larger than the developer layer.
[0095]
In particular, the toner of the present invention has a high charge rising property and is particularly useful for a non-contact development system. That is, in the non-contact development method, since the change in the development electric field is large, the slight change in the charging greatly affects the development itself, and the slight change in the toner charge amount greatly fluctuates the image quality and image density. However, since the toner of the present invention has an excellent charge rising property, there is little change in charge, a stable charge amount can be secured, and a stable image can be obtained for a long time even with a non-contact development method. Can be formed.
[0096]
In the non-contact developing method, the thin layer is formed by a method of pressing a developer layer regulating rod against the surface of a magnetic blade or sleeve using a magnetic force. Further, there is a method of regulating the developer layer by bringing a urethane blade, a phosphor bronze plate or the like into contact with the sleeve surface. The pressing force of the pressing restricting member is preferably 1 to 15 gf / mm. When the pressing force is small, the regulation force is insufficient, and thus the conveyance is likely to be unstable. On the other hand, when the pressing force is large, the stress on the developer is increased, and the durability of the developer is likely to be lowered. A preferred range is 3 to 10 gf / mm. Further, in the non-contact development method, it is preferable to apply a development bias voltage at the time of development, but in this case, either a method of applying only a DC component or a method of applying an AC bias superimposed may be used.
[0097]
The toner of the present invention is particularly useful in a color image forming method for forming a color image by superimposing a plurality of color toner images because of less fog and excellent transferability.
[0098]
A typical example of the image forming method of the present invention will be described below with reference to FIGS.
[0099]
FIG. 1 is a schematic diagram illustrating an example of a color image forming apparatus, which is a non-contact development type and so-called sequential transfer type color image forming apparatus.
[0100]
In the figure, reference numeral 1 denotes a charging device as a charging electrode, L denotes an analog or digital image exposure, 2 denotes a developing unit composed of a developing device loaded with yellow, magenta, cyan, and black toners, respectively. It is divided into four developing units corresponding to. These are all non-contact type magnetic brush developing devices. 4 is a photosensitive drum, 3 is a cleaning unit, 5 is a transfer drum that is wound around the transfer material P conveyed by the conveying means 6 and rotates in synchronization with the photosensitive drum 4, and each color toner image is formed on the photosensitive drum 4. Each time it is formed, it is transferred onto the transfer material P that is wound around the transfer drum 5 so that a color toner image 30 is formed on the transfer material P. Reference numeral 7 is provided inside the transfer drum 5 and corona discharge from the inside to attract the transfer material P to the transfer drum 5 electrostatically. Reference numeral 8 denotes a color toner image formed on the photosensitive drum 4 sequentially. 5 is a transfer electrode to be transferred to 5; 9 is a release electrode for peeling the transfer material P electrostatically adsorbed on the transfer drum 5; It is. Reference numeral 12 denotes a separating member for separating the transfer material P from the transfer drum 5. Reference numeral 16 denotes a heat roller fixing device for fixing the color toner image 30, and the heat roller fixing device includes a heat roller 17 and a pressure roller 18.
[0101]
In the above apparatus, in order to form a color image, the charge is uniformly formed on the photosensitive drum 4 by the charging electrode 1, and then the first electrostatic latent image is formed by the first image exposure L. . This electrostatic charge latent image is developed by a developing unit that holds the first color toner (for example, black toner) of the developing unit 2, and a first color toner image is formed on the photosensitive drum 4. On the other hand, the transfer material P transported onto the transfer drum 5 by the transport means 6 is electrostatically attracted onto the transfer drum 5 by the suction electrode 7 and transported to the transfer section.
[0102]
The first color toner image formed on the photosensitive drum 4 is transferred to the transported transfer material P in the transfer section. Next, a second electrostatic latent image is formed by the second image exposure L. The electrostatic charge latent image is developed by a developing unit that holds a second color toner (for example, cyan toner) of the developing unit 2, and a second color toner image is formed on the photosensitive drum 4. The second color toner image is superimposed and transferred onto the transfer material P having the toner image. Thereafter, similarly, the third electrostatic charge latent image is formed by the third image exposure L, the development by the third color toner (for example, magenta toner), the transfer, and the fourth electrostatic exposure by the fourth image exposure L. The formation of the latent image, the development with the fourth color toner (for example, yellow toner), and the transfer are repeated, and the first, second, third, and fourth color toner images are superimposed and transferred onto the transfer material P. A color toner image 30 is formed. The transfer material P onto which the color toner image 30 has been transferred is separated from the transfer drum 5 by the action of the peeling electrode 9 and the separating member 12, conveyed in the direction of the arrow, and fixed by the heat roller fixing device 16 to form a color image. In the next color image forming process.
[0103]
On the other hand, the transfer drum 5 removes the remaining charges by the removal electrode 10 and is used in the next process.
[0104]
Next, FIG. 2 is a schematic diagram showing another example of a color image forming apparatus, which is a non-contact development type and so-called batch transfer type color image forming apparatus. Each part of the apparatus has many parts in common with FIG. 1, and the same reference numerals are given to the same contents. However, 11 is a belt-like conveying member that conveys the transfer material P to the transfer portion. In order to form a color image using the color image forming apparatus shown in FIG. 2, the charge is uniformly formed on the photosensitive drum 4 by the charging electrode 1, and then the first image exposure L is performed to form the first electrostatic charge. A latent image shape is formed. The electrostatic charge latent image is developed by a developing unit that holds the first color toner (for example, yellow toner) of the developing unit 2, and a first color toner image is formed on the photosensitive drum. The color toner image is not transferred onto the transfer material, and the charge electrode 1 forms a uniform charge again on the photosensitive drum 4 having the first color toner image as it is. Exposure L is performed to form a second electrostatic charge latent image shape. This electrostatic charge latent image is developed by a developing device that holds the second color toner (for example, magenta toner) of the developing unit 2, and the second color toner image is formed on the first color toner image in an overlapping manner. The Similarly, the third image exposure L is performed to form a third electrostatic latent image shape. The third color toner image is developed by a developing device that holds a third color toner (for example, cyan toner). Formed, superimposed on the first and second color toner images, and subjected to a fourth image exposure L to form a fourth electrostatic latent image, Development is performed by a developing device that holds color toner (for example, cyan toner) to form a fourth color toner image, which is formed on the first, second, and third color toner images, A color toner image is formed on the photoreceptor. This color toner image is batch-transferred on the transfer material P conveyed to the transfer portion by the belt-shaped conveyance member 11 by the action of the transfer electrode 8, and the transfer material P carrying the transferred color toner image 30 is conveyed in the direction of the arrow. Then, the image is fixed by the heat roller fixing device 16 to form a color image. Since the toner remains on the photosensitive drum 4 after the color toner image is transferred, the toner is cleaned by the cleaning unit 3 and prepared for the next color image forming process. The heat roller fixing device includes a heat roller 17 and a pressure roller 18 as in FIG.
[0105]
The toner of the present invention is a toner having fine particles, a narrow particle size distribution, and a relatively large specific surface area. In addition to excellent charging characteristics and transfer characteristics, a plurality of color toner images are superposed. In the above-described various color image forming apparatuses having a transferring process, a high-resolution, clear color image can be stably obtained without fogging in the image forming process repeatedly.
[0106]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention, the aspect of this invention is not limited by this.
[0107]
<Preparation of fixability improver>
Low molecular weight polypropylene (number average molecular weight (Mn) = 3,300, molecular weight distribution (Mw / Mn) = 4.5), N, N-dimethylaminoethyl methacrylate (DMAEMA), or vinylbenzyl-N, The addition amount (mmol / g) of N-dimethyl-N-benzylammonium chloride (VBDMBA) was changed as shown in Table 1 to modify the melt viscosity of the seven kinds of modified low molecular weight polypropylenes obtained at 160 ° C ( cps) are then added to an aqueous solution of nonylphenoxypolyethoxyethanol (moles of ethoxy units 20, HLB = 16.0) in which hydrochloric acid is dissolved in the aqueous solution, and the mixture is heated to the melting temperature or higher and stirred. As a result, an aqueous dispersion of seven types of fixability improvers for the present invention was obtained. Table 1 shows the melt viscosity (cps) of the seven types of modified low molecular weight polypropylene at 160 ° C. and the average particle diameter (nm) of the seven types of fixability improvers in the aqueous dispersion.
[0108]
In addition, maleic acid (MA) was added to the low molecular weight polypropylene at an addition amount (mmol / g) shown in Table 1, and the melt viscosity (cps) of the resulting low molecular weight polypropylene at 160 ° C. was measured. Thereafter, this was added to a nonylphenoxypolyethoxyethanol aqueous solution in which potassium hydroxide was dissolved in an aqueous solution, heated to a temperature equal to or higher than the melting temperature, and stirred to obtain an aqueous dispersion of a fixing improver for comparison. Table 1 shows the melt viscosity (cps) of the comparative modified low molecular weight polypropylene at 160 ° C. and the average particle size (nm) of the fixing improver dispersed in the comparative aqueous dispersion. Here, the solid content concentration of the aqueous dispersion containing the above-described fixing improvers for the present invention and for comparison was adjusted to 20 weight percent.
[0109]
The HLB (Hydrophil Lipophil Balance) is an index indicating the balance between hydrophilicity and hydrophobicity of the surfactant. For example, nonionic surfactant HLB is
HLB = {(molecular weight of hydrophilic group portion) / (molecular weight of hydrophobic group portion)} × 100/5.
[0110]
The melt viscosity (cps) of the modified low molecular weight polypropylene at 160 ° C. is measured using a “B-type viscometer” (manufactured by Tokyo Keiki Co., Ltd.).
[0111]
Furthermore, the average particle diameter (nm) of the fixability improver dispersed in the aqueous dispersion is measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.).
[0112]
[Table 1]

[0113]
<Synthesis Example 1 of Colored Polymer Particles of the Present Invention>
Carbon black "Regal 330R" (Cabot Co., Ltd.) treated with aluminum coupling agent "Plenact AL" (Ajinomoto Co., Ltd.) 49.8g of treated carbon black 23g of cetyltrimethylammonium chloride distilled water It was added to 412 ml of a dissolved cationic surfactant aqueous solution and dispersed using an ultrasonic homogenizer.
[0114]
Furthermore, in a 1-liter four-headed flask equipped with a stirrer, a cooling tube, a temperature sensor and a nitrogen introduction tube, 54.9 g of the above carbon black dispersion, 446 ml of distilled water, 49.4 g of styrene, 9.2 g of n-butyl acrylate. 2.45 g of N, N-dimethylaminoethyl methacrylate, 1.63 g of tert-dodecyl mercaptan and 18.3 g of the fixing property-improving agent (1) of the present invention were added, and the mixture was stirred at a stirring speed of 350 rpm and flowing nitrogen. The flask was heated until the temperature inside the flask reached 75 ° C. While maintaining the internal temperature at 75 ° C, an aqueous polymerization initiator solution in which 2.14 g of 2,2'-azobis (2-amidinopropane) dihydrochloride was dissolved in 100 ml of pure water was added, and the internal temperature was 75 ° C under a nitrogen stream. The polymerization was carried out for 6 hours while maintaining the stirring speed at 350 rpm. After completion of the polymerization, the internal temperature was lowered to room temperature, and then a part was taken and the molecular weight was measured using gel permeation chromatography (hereinafter abbreviated as GPC).
[0115]
Further, 500 ml of this colored polymer fine particle aqueous dispersion was adjusted to pH = 2.0 using 1N hydrochloric acid, and then placed in a 1-liter four-headed flask equipped with a stirrer, a condenser, and a temperature sensor, and stirred at 250 rpm. . A nonionic surfactant aqueous solution in which 38.76 g of potassium chloride was dissolved in 250 ml of distilled water was added thereto, and 122.6 ml of isopropyl alcohol and 3.52 g of Triton X-100 were dissolved in 166.5 ml of distilled water. Then, the internal temperature was raised to 85 ° C. and the reaction was performed for 6 hours.
[0116]
After the reaction solution is filtered, distilled water is added and redispersed. The pH is adjusted to 1 with 5N hydrochloric acid, washed with water, filtered repeatedly, the surfactant and the electrolyte are removed, and then dried. The colored polymer particles of the present invention (1) was obtained. After drying, the volume average particle size (d ₅₀ μm) and particle size distribution (σ ₅₀ / D ₅₀ ) Using a Coulter counter and the BET specific surface area (m ² / G) was measured by the nitrogen adsorption method, and the results are shown in Table 2.
[0117]
<Synthesis Example 2 of Colored Polymer Particles of the Present Invention>
Carbon black "Regal 330R" (Cabot Co., Ltd.) treated with aluminum coupling agent "Plenact AL" (Ajinomoto Co., Ltd.) 49.8g of treated carbon black 23g of cetyltrimethylammonium chloride distilled water The solution was added to 412 ml of the dissolved cationic surfactant aqueous solution and dispersed using an ultrasonic homogenizer.
[0118]
Furthermore, in a 1 liter four-headed flask equipped with a stirrer, a cooling tube, a temperature sensor and a nitrogen introduction tube, 14.8 g of the above carbon black dispersion, 122.5 ml of distilled water, 13.4 g of styrene, n-butyl acrylate 2 0.5 g, 0.84 g of 4-vinyl pyridine, 0.023 g of tert-dodecyl mercaptan and 5 g of the fixing property-improving agent (1) of the present invention were added, the stirring was carried out at a stirring speed of 350 rpm, and the temperature inside the flask was 75 while flowing nitrogen. Heated to ° C. While maintaining the internal temperature at 75 ° C., a polymerization initiator aqueous solution in which 0.58 g of 2,2′-azobis (2-amidinopropane) dihydrochloride was dissolved in 100 ml of pure water was added, and the internal temperature was 75 ° C. under a nitrogen stream. The polymerization was carried out for 3 hours while maintaining the stirring speed at 350 rpm. After the polymerization, the internal temperature was lowered to room temperature, and then 49 g of carbon black dispersion, 323.2 ml of pure water, 36.3 g of styrene, 6.72 g of n-butyl acrylate, 2.26 g of 4-vinylpyridine, tert-dodecyl mercaptan 1.19 g and 13.6 g of the fixing property-improving agent dispersion (2) of the present invention were added, and the mixture was stirred at a stirring speed of 350 rpm and heated until the flask internal temperature reached 75 ° C. while flowing nitrogen. While maintaining the internal temperature at 75 ° C., an aqueous polymerization initiator solution prepared by dissolving 1.56 g of 2,2′-azobis (2-amidinopropane) dihydrochloride in 73.4 ml of pure water was added, and the internal temperature was maintained under a nitrogen stream. While maintaining at 75 ° C. and a stirring speed of 350 rpm, polymerization was performed for 3 hours to obtain colored polymer fine particles. The internal temperature was cooled to room temperature, a part of the reaction solution was collected, dried, and then measured for molecular weight using GPC.
[0119]
Further, 500 ml of this aqueous dispersion of colored polymer particles was adjusted to pH = 1.5 using 1N hydrochloric acid, and then placed in a 1-liter four-headed flask equipped with a stirrer, a cooling tube and a temperature sensor, and stirred at 250 rpm. It was. A nonionic surfactant aqueous solution in which 38.76 g of potassium chloride was dissolved in 250 ml of distilled water was added thereto, and 122.6 ml of isopropyl alcohol and 3.52 g of Triton X-100 were dissolved in 166.5 ml of distilled water. Then, the internal temperature was raised to 85 ° C. and the reaction was performed for 6 hours.
[0120]
After the reaction solution is filtered, distilled water is added and redispersed. The pH is adjusted to 1 with 5N hydrochloric acid, washed with water, filtered repeatedly, the surfactant and the electrolyte are removed, and then dried. The colored polymer particles of the present invention (2) was obtained. After drying, the volume average particle size (d ₅₀ μm) and particle size distribution (σ ₅₀ / D ₅₀ ) Using a Coulter counter and the BET specific surface area (m ² / G) was measured by the nitrogen adsorption method, and the results are shown in Table 2.
[0121]
<Synthesis Example 3 of Colored Polymer Particles of the Present Invention>
Carbon black "Regal 330R" (Cabot Co., Ltd.) treated with aluminum coupling agent "Plenact AL" (Ajinomoto Co., Ltd.) 49.8g of treated carbon black 23g of cetyltrimethylammonium chloride distilled water It was added to 412 ml of a dissolved cationic surfactant aqueous solution and dispersed using an ultrasonic homogenizer.
[0122]
Furthermore, in a 1 liter four-headed flask equipped with a stirrer, a cooling tube, a temperature sensor and a nitrogen introduction tube, 14.8 g of the above carbon black dispersion, 122.5 ml of distilled water, 13.4 g of styrene, n-butyl acrylate 2 0.5 g, vinylbenzyl-N, N-dimethyl-N-benzylammonium chloride 0.84 g, tert-dodecyl mercaptan 0.023 g and the fixing property-improving agent (1) 5 g of the present invention were added and stirred at a stirring speed of 350 rpm. The flask was heated until the temperature inside the flask reached 75 ° C. while flowing nitrogen. While maintaining the internal temperature at 75 ° C., a polymerization initiator aqueous solution in which 0.58 g of 2,2′-azobis (2-amidinopropane) dihydrochloride was dissolved in 100 ml of pure water was added, and the internal temperature was 75 ° C. under a nitrogen stream. The polymerization was carried out for 3 hours while maintaining the stirring speed at 350 rpm. After completion of the polymerization, the internal temperature was lowered to room temperature, and the further internal temperature was cooled to room temperature. Further, 49 g of carbon black dispersion, 323.2 ml of pure water, 36.3 g of styrene, 6.72 g of n-butyl acrylate, vinylbenzyl-N , N-dimethyl-N-benzylammonium chloride 2.26 g, tert-dodecyl mercaptan 1.19 g, 13.6 g of the fixer-improving agent dispersion (2) of the present invention were added and stirred at a stirring speed of 350 rpm while flowing nitrogen. The flask was heated until the temperature inside the flask reached 75 ° C. While maintaining the internal temperature at 75 ° C., an aqueous polymerization initiator solution prepared by dissolving 1.56 g of 2,2′-azobis (2-amidinopropane) dihydrochloride in 73.4 ml of pure water was added, and the internal temperature was maintained under a nitrogen stream. Polymerization was carried out for 3 hours while maintaining a stirring speed of 350 rpm at 75 ° C. A part of the reaction solution was taken and dried, and the molecular weight was measured using GPC.
[0123]
Further, 500 ml of this colorant-containing resin fine particle dispersion was adjusted to pH = 1.5 using hydrochloric acid, and then placed in a 1-liter four-headed flask equipped with a stirrer, a condenser, and a temperature sensor, and stirred at 250 rpm. A nonionic surfactant aqueous solution in which 38.76 g of potassium chloride was dissolved in 250 ml of distilled water was added thereto, and 122.6 ml of isopropyl alcohol and 3.52 g of Triton X-100 were dissolved in 166.5 ml of distilled water. Then, the internal temperature was raised to 85 ° C. and the reaction was performed for 6 hours.
[0124]
After the reaction solution is filtered, distilled water is added and redispersed. The pH is adjusted to 13 with 5N hydrochloric acid, washed with water, filtered repeatedly, the surfactant and the electrolyte are removed, and then dried. The colored polymer particles of the present invention (3) was obtained. After drying, the volume average particle size (d ₅₀ μm) and particle size distribution (σ ₅₀ / D ₅₀ ) Using a Coulter counter and the BET specific surface area (m ² / G) was measured by the nitrogen adsorption method, and the results are shown in Table 2.
[0125]
<Colored polymer particle synthesis example 4 of the present invention>
The colored polymer particles 4 of the present invention were synthesized in the same manner except that the fixing property improver (1) of the colored polymer particle synthesis example 3 of the present invention was changed to the fixing property improver (2) of the present invention.
[0126]
<Colored polymer particle synthesis example 5 of the present invention>
The colored polymer particles 5 of the present invention were synthesized in the same manner except that the fixing property improver (1) of the colored polymer particle synthesis example 3 of the present invention was changed to the fixing property improver (3) of the present invention.
[0127]
<Colored polymer particle synthesis example 6 of the present invention>
The colored polymer particles 6 of the present invention were synthesized in the same manner except that the fixing property improver (1) of the colored polymer particle synthesis example 3 of the present invention was changed to the fixing property improver (4) of the present invention.
[0128]
<Colored polymer particle synthesis example 7 of the present invention>
The colored polymer particles 7 of the present invention were synthesized in the same manner except that the fixing property improver (1) of the colored polymer particle synthesis example 3 of the present invention was changed to the fixing property improver (5) of the present invention.
[0129]
<Colored polymer particle synthesis example 8 of the present invention>
The colored polymer particles 8 of the present invention were synthesized in the same manner except that the fixing property improver (1) of the colored polymer particle synthesis example 3 of the present invention was changed to the fixing property improver (6) of the present invention.
[0130]
<Colored polymer particle synthesis example 9 of the present invention>
The carbon black treated with the aluminum coupling agent of Colored Polymer Particle Synthesis Example 3 of the present invention was converted into C.I. I. The colored polymer particles 9 of the present invention were synthesized in the same manner except that the pigment yellow 17 was used.
[0131]
<Colored polymer particle synthesis example 10 of the present invention>
The carbon black treated with the aluminum coupling agent of Colored Polymer Particle Synthesis Example 3 of the present invention was converted into C.I. I. The colored polymer particles 10 of the present invention were synthesized in the same manner except that the pigment red 122 was used.
[0132]
<Colored polymer particle synthesis example 11 of the present invention>
The carbon black treated with the aluminum coupling agent of Colored Polymer Particle Synthesis Example 3 of the present invention was converted into C.I. I. The colored polymer particles 11 of the present invention were synthesized in the same manner except that the pigment blue was changed to 15: 3.
[0133]
<Colored polymer particle synthesis example 12 of the present invention>
The colored polymer particles 12 of the present invention were synthesized in the same manner except that the fixing property improving agent (1) of the colored polymer particle synthesis example 3 of the present invention was changed to the fixing property improving agent (7) of the present invention.
[0134]
<Comparative colored polymer particle synthesis example 1>
Comparative colored polymer particles 1 were synthesized in the same manner except that the fixing property improving agent (1) of the colored polymer particle synthesis example 3 of the present invention was changed to a comparative fixing property improving agent.
[0135]
<Comparative Colored Polymer Particle Synthesis Example 2>
Comparative colored polymer particles 2 were synthesized in the same manner except that the fixing property improving agent (1) of the colored polymer particle synthesis example 9 of the present invention was changed to a comparative fixing property improving agent.
[0136]
<Comparative Colored Polymer Particle Synthesis Example 3>
Comparative colored polymer particles 3 were synthesized in the same manner except that the fixing property improving agent (1) of the colored polymer particle synthesis example 10 of the present invention was changed to a comparative fixing property improving agent.
[0137]
<Comparative Colored Polymer Particle Synthesis Example 4>
Comparative colored polymer particles 4 were synthesized in the same manner except that the fixing property improver (1) of the colored polymer particle synthesis example 11 of the present invention was changed to a comparative fixing property improver.
[0138]
Volume average particle diameter (d) of colored polymer particle synthesis examples 1 to 12 and comparative colored polymer particles 1 to 4 of the present invention. ₅₀ μm), particle size distribution (σ ₅₀ / D ₅₀ ) And BET specific surface area (m ² / G) is shown in Table 2.
[0139]
[Table 2]

[0140]
Example 1
Hydrophobic silica 2% was added to the colored polymer particles 1 to 12 and the comparative colored particles 1 to 4 of the present invention to perform external addition treatment. Further, a carrier obtained by coating a styrene / methyl methacrylate copolymer on a magnetite core having an average particle diameter of 35 μm was mixed so as to have a toner concentration of 5%. These were designated as Developers 1 to 12 and Comparative Developers 1 to 4 of the present invention. After sufficiently stirring these developers, the charge amount (μC / g) at the lapse of 1 minute and at the lapse of 60 minutes was measured using a blow-off method. The obtained measurement results are shown in Table 3.
[0141]
[Table 3]

[0142]
As is clear from the above results, it can be seen that the developer of the present invention has a quick rise in charge and is stable as compared with the comparative developer.
[0143]
Example 2
Using the developers 2 to 5 and 9 to 11 of the present invention and the comparative developer 1 used in Example 1, evaluation was made using a contact developing type electronic copying machine “U-BIX3135” (manufactured by Konica Corporation). Went. The developer layer thickness is 1.5 mm, and the gap (Dsd) between the photoreceptor and the sleeve is 0.5 mm.
[0144]
In addition, the cleaning of the photosensitive member is performed by using a counter type cleaning member 20 shown in FIG. 3 (an explanatory diagram of the cleaning unit). The cleaning member 20 is 22 ° with respect to the holder 22 and the photosensitive drum 4. The cleaning blade 21 is press-contacted at a pressure-contact angle (θ) of the following. Urethane rubber is used as the material of the cleaning blade 21, the rubber hardness is 65 °, the thickness is 2 mm, and the outer part of the holder The length of was 8 mm. Furthermore, the pressure contact force with respect to the photosensitive drum 4 is 15 gf / mm. Further, a corona transfer method was used as the transfer method.
[0145]
The evaluation was 10,000 sheets of continuous printing and 24 hours of standing in a low temperature and low humidity (10 ° C, 10% RH) environment, and then the next 10,000 sheets of continuous printing and 24 hours of standing were repeated 6 times for a total of 60,000 sheets of printing. The fog density of the image at the initial stage and at the end of each printing was measured. Density measurement is shown as a relative density when the paper density is 0, and a Macbeth densitometer “RD-918” (manufactured by Macbeth Co., Ltd.) was used for the measurement.
[0146]
[Table 4]

[0147]
From Table 4, it can be seen that the developer of the present invention generates very little fog in the process of repeated image formation, but the comparative developer increases the fog as the number of printed sheets increases.
[0148]
Example 3
A non-contact development type and batch transfer type color copying machine "Konica 9028" (manufactured by Konica Corporation) is used, a multilayer organic photoreceptor is used as a photoreceptor, and the development of the present invention is used as a developer. Printing using a color developer of the present invention comprising a combination of agents 3, 9, 10 and 11 and a comparative color developer comprising a combination of comparative developers 1 to 4, using a 75% pixel image as a color document Tested. The print test is 1000 continuous prints and left for 24 hours, and then 1000 continuous prints and left for 24 hours is repeated 10 times to make a total of 10,000 color prints, recording the number of prints that caused uneven transfer during that time. The results are shown in Table 5.
[0149]
The printing conditions of the color copying machine are as follows.
[0150]
Photoconductor surface potential = -550V
DC bias = -750V
AC bias = Vp-p: 1.6 kV (yellow, magenta, cyan), 1.8 kV (black)
Alternating electric field frequency = 1800Hz
Dsd = 300 μm
Pressure regulating force = 10 gf / mm
Pressure regulating bar = SUS416 (made of magnetic stainless steel) / diameter 3mm
Developer layer thickness = 150 μm
Development sleeve = 20mm
[0151]
[Table 5]

[0152]
Table 5 shows that the color developer of the present invention can form a high-quality color image without occurrence of uneven transfer even when used in a color copier of a non-contact development type and a batch transfer type. When a color developer is used, transfer unevenness is generated from 3,500 sheets from the beginning, and it is understood that the practicality is poor.
[0153]
Example 4
A non-contact development type and sequential transfer type color copier “CLC-500” (manufactured by Canon Inc.) is used, a laminated organic photoconductor is used as a photoconductor, and a developer of the present invention is used as a developer. An image having a pixel rate of 75% was used as a color document using the color developer of the present invention formed by combining Developers 3, 9, 10, and 11 and the comparative color developer formed by combining Comparative Developers 1 to 4. Outside, a printing test was conducted in accordance with the basic operating conditions of the color copier “CLC-500”. The print test is 1000 continuous prints and left for 24 hours, and then 1000 continuous prints and left for 24 hours is repeated 10 times to make a total of 10,000 color prints, recording the number of prints that caused uneven transfer during that time. The results are shown in Table 6.
[0154]
[Table 6]

[0155]
Table 6 shows that the color developer of the present invention can form a high-quality color image without occurrence of uneven transfer even when used in a non-contact development type and sequential transfer type color copier. When a color developer is used, transfer unevenness occurs from 3000 sheets from the beginning, and it is understood that the practicality is poor.
[0156]
【The invention's effect】
As demonstrated in the examples, according to the toner, developer and image forming method of the present invention, the rising of the charge is quick, the charge is uniform and stable, and the toner is highly durable in the process of repeated image formation. It has excellent effects such as excellent transferability of an image to a transfer material and a stable and clear image without fogging.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating an example of a color image forming apparatus.
FIG. 2 is a schematic diagram illustrating another example of a color image forming apparatus.
FIG. 3 is an explanatory diagram of a cleaning unit.
[Explanation of symbols]
1 Charger
2 Development unit
3 Cleaning unit
4 Photosensitive drum
5 Transfer drum
6 Transport means
7 Adsorption electrode
8 Transfer electrode
9 Peeling electrode
10 Removal electrode
11 Belt-shaped conveying member
12 Separation member
16 Heat roller fixing device
17 Heat roller
18 Pressure roller
20 Cleaning member
21 Cleaning blade
22 Holder
30 Color toner image
L Image exposure
θ Pressure angle

Claims (13)

In the copolymer, and toner for electrostatic latent image development comprising a fixability improving agent consisting of a hydrophobic monomer and a cation-on monomer, a fixability improving agent, wherein the fixing property improving agent is modified with units containing a cationic group A toner for developing an electrostatic latent image, characterized in that:   2. The electrostatic latent image developing toner according to claim 1, wherein the cationic group is at least one cationic group selected from an amino group, an amide group, and a quaternary ammonium base.   The monomer corresponding to the unit containing the cationic group is at least one vinyl monomer selected from vinyl monomers containing an amino group, an amide group and a quaternary ammonium base. Toner for developing electrostatic latent image.   The electrostatic latent image development according to any one of claims 1 to 3, wherein an average domain diameter of the fixing property modifier modified with the unit containing a cationic group is 0.01 to 1 µm. Toner.   The electrostatic charge latent image developing toner according to claim 1, wherein the fixing property improving agent is a polyolefin modified with a unit containing a cationic group. 6. The cationic monomer according to claim 1, wherein the cationic monomer is at least one ionic monomer selected from vinyl monomers containing an amino group, an amide group and a quaternary ammonium base. Toner for developing electrostatic latent image. The toner has a BET specific surface area of 5 to 100 m. ² The toner for developing an electrostatic latent image according to any one of claims 1 to 6, wherein the toner is / g. A developer comprising a toner for developing an electrostatic latent image, comprising a resin comprising a hydrophobic monomer and a cationic monomer, and a fixing property-improving agent modified with a unit containing a cationic group. In an image forming method in which an electrostatic latent image formed on an electrophotographic photosensitive member is exposed to form a toner image, the toner on which the toner image is formed contains a resin composed of a hydrophobic monomer and a cationic monomer and a cationic group An image forming method comprising: a toner for developing an electrostatic latent image containing a fixing property modifier modified by a unit. In an image forming method for transferring a toner image formed on an electrophotographic photosensitive member to a transfer material, the toner on which the toner image is formed is modified with a unit comprising a resin composed of a hydrophobic monomer and a cationic monomer and a cationic group. An image forming method comprising: a toner for developing an electrostatic latent image containing a fixability improver. In the image forming method in which the toner image formed on the electrophotographic photosensitive member is transferred onto a transfer material and then the toner remaining on the electrophotographic photosensitive member is removed by cleaning, the toner on which the toner image is formed is hydrophobic An image forming method comprising: a toner for developing an electrostatic latent image, comprising: a resin comprising a cationic monomer and a cationic monomer; and a fixability improver modified with a unit containing a cationic group. In an image forming method in which a toner image formed on an electrophotographic photosensitive member is transferred to a transfer material, and the transfer material carrying the toner image is thermally fixed, the toner on which the toner image is formed includes a hydrophobic monomer and a cationic monomer. And a toner for developing an electrostatic latent image, comprising a fixing property-improving agent modified with a unit containing a cationic group. The image forming method according to claim 12, wherein the toner image carried on the transfer material is fixed by heat roller fixing.

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