JP2004191532A - Image forming method and developer for replenishment used in image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming method which provides good full color images free of fogging and scattering in any environment over a prolonged period of time. <P>SOLUTION: In the image forming method in which an electrostatic latent image on an amorphous silicon-base electrostatic latent image carrier is developed with one or more selected from a black developer comprising a toner containing at least a binder resin and a colorant, a yellow developer, a magenta developer and a cyan developer each comprising a color toner containing at least a binder resin, a colorant and inorganic fine particles, the inorganic fine particles include three or more sorts of particles. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

（式中、ａ及びｂは０〜４の整数であり、ａ＋ｂは４である。Ｒ_１及びＲ_２は炭素数が１〜４０の有機基である。ｍ及びｎは０〜２５の整数であり、ｍとｎは同時に０になることはない。）
【００６６】
【化２】

（式中、ａ’及びｂ’は０〜３の整数であり、ａ’＋ｂ’は１〜３である。Ｒ_１’及びＲ_２’は炭素数が１〜４０の有機基であり、Ｒ_１’とＲ_２’との炭素数差が３以上である。Ｒ_３は水素原子、炭素数が１以上の有機基である。但し、ａ’＋ｂ’＝２のとき、Ｒ_３のどちらか一方は、炭素数が１以上の有機基である。ｋは１〜３の整数である。ｍ’及びｎ’は０〜２５の整数であり、ｍ’とｎ’が同時に０になることはない。）
【００６７】
【化３】

（式中、Ｒ_４及びＲ_６は炭素数６〜３２を有する有機基であり、Ｒ_４とＲ_６は同じものであってもなくても良い。Ｒ_５は炭素数１〜２０を有する有機基を示す。）
【００６８】
【化４】

（式中、Ｒ_７及びＲ_９は炭素数６〜３２を有する有機基であり、Ｒ_７とＲ_９は同じものであってもなくても良い。Ｒ_８は以下に示すいずれかである。
【００６９】
【化５】

（式中、ｘは１〜１０の整数、ｙは１〜２０の整数を示す。））
【００７０】
【化６】

（式中、ｃは０〜４の整数であり、ｄは１〜４の整数であり、ｃ＋ｄは４である。Ｒ_１０は炭素数が１〜４０の有機基である。ｚ及びｗは０〜２５の整数であり、ｚとｗが同時に０になることはない。）
【００７１】
【化７】

（式中、Ｒ_１１及びＲ_１２は同一又は異なる炭素数１５〜４５の炭化水素基を示す。）
【００７２】
本発明の画像形成方法に係わるカラートナーにおいて、これらのワックス成分の含有量としては、結着樹脂１００質量部に対して０．５〜２５質量部の範囲が好ましい。含有量が０．５質量部未満では感光体上へのトナー融着抑制効果に乏しく、２５質量部を超えてしまうと長期間の保存性が悪化すると共に、他のカラートナー材料の分散性が悪くなり、トナーの流動性の悪化や画像特性の低下につながる。
【００７３】
本発明に係わるカラートナー粒子を粉砕法により製造する場合の結着樹脂としては、ポリスチレン、ポリビニルトルエンなどのスチレン及びその置換体の単重合体；スチレン−プロピレン共重合体、スチレン−ビニルトルエン共重合体、スチレン−ビニルナフタリン共重合体、スチレン−アクリル酸メチル共重合体、スチレン−アクリル酸エチル共重合体、スチレン−アクリル酸ブチル共重合体、スチレン−アクリル酸オクチル共重合体、スチレン−アクリル酸ジメチルアミノエチル共重合体、スチレン−メタクリル酸メチル共重合体、スチレン−メタクリル酸エチル共重合体、スチレン−メタクリル酸ブチル共重合体、スチレン−メタクリル酸ジメチルアミノエチル共重合体、スチレン−ビニルメチルエーテル共重合体、スチレン−ビニルエチルエーテル共重合体、スチレン−ビニルメチルケトン共重合体、スチレン−ブタジエン共重合体、スチレン−イソプレン共重合体、スチレン−マレイン酸共重合体、スチレン−マレイン酸エステル共重合体などのスチレン系共重合体；ポリメチルメタクリレート、ポリブチルメタクリレート、ポリ酢酸ビニル、ポリエチレン、ポリプロピレン、ポリビニルブチラール、シリコーン樹脂、ポリエステル樹脂、ポリアミド樹脂、エポキシ樹脂、ポリアクリル樹脂などが単独或いは混合して使用できる。特に、スチレン系共重合体及びポリエステル樹脂が現像特性や定着性等の点で好ましい。
【００７４】
本発明に係るカラートナーを重合法により製造する場合、結着樹脂成分を構成する重合性単量体としては以下のものが挙げられる。
【００７５】
スチレン、ｏ−メチルスチレン、ｍ−メチルスチレン、ｐ−メチルスチレン、ｐ−メトキシスチレン、ｐ−エチルスチレン等のスチレン系単量体；アクリル酸メチル、アクリル酸エチル、アクリル酸ｎ−ブチル、アクリル酸イソブチル、アクリル酸ｎ−プロピル、アクリル酸ｎ−オクチル、アクリル酸ドデシル、アクリル酸２−エチルヘキシル、アクリル酸ステアリル、アクリル酸２−クロルエチル、アクリル酸フェニル等のアクリル酸エステル類；メタクリル酸メチル、メタクリル酸エチル、メタクリル酸ｎ−プロピル、メタクリル酸ｎ−ブチル、メタクリル酸イソブチル、メタクリル酸ｎ−オクチル、メタクリル酸ドデシル、メタクリル酸２−エチルヘキシル、メタクリル酸ステアリル、メタクリル酸フェニル、メタクリル酸ジメチルアミノエチル、メタクリル酸ジエチルアミノエチル等のメタクリル酸エステル類；その他のアクリロニトリル、メタクリロニトリル、アクリルアミド等の単量体が挙げられる。これらの単量体は単独または混合して使用し得る。上述の単量体の中でも、スチレンまたはスチレン誘導体を単独で、あるいはほかの単量体と混合して使用することがカラートナーの現像特性及び耐久性の点から好ましい。
【００７６】
本発明においては、カラートナーがポリエステル樹脂を含有することが好ましい。
【００７７】
本発明者らの検討によれば、ポリエステル樹脂を添加することによりトナー表面の強度が増し、カラートナー粒子とともに、無機微粒子等の添加剤を外添して用いた場合、トナー粒子表面の無機微粒子が長期間の耐久によりトナー粒子中に埋没するのを防止する効果が大きくなり、長期間の耐久による画像濃度低下を防止できる。
【００７８】
前記ポリエステル樹脂は、重量平均分子量（Ｍｗ）が６０００〜１０００００であることが好ましい。Ｍｗ６０００未満の場合には外添剤のトナー粒子中への埋没を防止する効果が小さく、耐久による画像濃度低下の防止効果が見られない。一方、Ｍｗが１０００００を超える場合には、トナー粒子中への縮合系樹脂の分散が悪化し、最終的に得られるトナーの粒度分布がブロードになる。
【００７９】
なお、重合法・粉砕法どちらの場合においても結着樹脂のガラス転移温度（Ｔｇ）は、４０〜７０℃であることが好ましく、４５〜６５℃の範囲がさらに好ましい。これらは単独、または一般的には出版物ポリマーハンドブック第２版ＩＩＩ−ｐ１３９〜１９２（ＪｏｈｎＷｉｌｅｙ＆Ｓｏｎｓ社製）に記載の理論ガラス転移温度（Ｔｇ）が、４０〜７０℃を示すように単量体を適宜混合して用いられる。
【００８０】
本発明におけるカラートナーは、着色力を付与するために着色剤を含有する。本発明に好ましく使用される有機顔料または染料として以下のものが挙げられる。
【００８１】
シアン系着色剤としての有機顔料又は有機染料としては、銅フタロシアニン化合物及びその誘導体、アントラキノン化合物、塩基染料レーキ化合物等が利用できる。具体的には、Ｃ．Ｉ．ピグメントブルー１、Ｃ．Ｉ．ピグメントブルー７、Ｃ．Ｉ．ピグメントブルー１５、Ｃ．Ｉ．ピグメントブルー１５：１、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１５：４、Ｃ．Ｉ．ピグメントブルー６０、Ｃ．Ｉ．ピグメントブルー６２、Ｃ．Ｉ．ピグメントブルー６６等が挙げられる。
【００８２】
マゼンタ系着色剤としての有機顔料又は有機染料としては、縮合アゾ化合物、ジケトピロロピロール化合物、アントラキノン、キナクリドン化合物、塩基染料レーキ化合物、ナフトール化合物、ベンズイミダゾロン化合物、チオインジゴ化合物、ペリレン化合物が用いられる。具体的には、Ｃ．Ｉ．ピグメントレッド２、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．ピグメントバイオレット１９、Ｃ．Ｉ．ピグメントレッド２３、Ｃ．Ｉ．ピグメントレッド４８：２、Ｃ．Ｉ．ピグメントレッド４８：３、Ｃ．Ｉ．ピグメントレッド４８：４、Ｃ．Ｉ．ピグメントレッド５７：１、Ｃ．Ｉ．ピグメントレッド８１：１、Ｃ．Ｉ．ピグメントレッド１２２、Ｃ．Ｉ．ピグメントレッド１４４、Ｃ．Ｉ．ピグメントレッド１４６、Ｃ．Ｉ．ピグメントレッド１６６、Ｃ．Ｉ．ピグメントレッド１６９、Ｃ．Ｉ．ピグメントレッド１７７、Ｃ．Ｉ．ピグメントレッド１８４、Ｃ．Ｉ．ピグメントレッド１８５、Ｃ．Ｉ．ピグメントレッド２０２、Ｃ．Ｉ．ピグメントレッド２０６、Ｃ．Ｉ．ピグメントレッド２２０、Ｃ．Ｉ．ピグメントレッド２２１、Ｃ．Ｉ．ピグメントレッド２５４等が挙げられる。
【００８３】
イエロー系着色剤としての有機顔料又は有機染料としては、縮合アゾ化合物、イソインドリノン化合物、アントラキノン化合物、アゾ金属錯体、メチン化合物、アリルアミド化合物に代表される化合物が用いられる。具体的には、Ｃ．Ｉ．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６２、Ｃ．Ｉ．ピグメントイエロー７４、Ｃ．Ｉ．ピグメントイエロー８３、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９５、Ｃ．Ｉ．ピグメントイエロー９７、Ｃ．Ｉ．ピグメントイエロー１０９、Ｃ．Ｉ．ピグメントイエロー１１０、Ｃ．Ｉ．ピグメントイエロー１１１、Ｃ．Ｉ．ピグメントイエロー１２０、Ｃ．Ｉ．ピグメントイエロー１２７、Ｃ．Ｉ．ピグメントイエロー１２８、Ｃ．Ｉ．ピグメントイエロー１２９、Ｃ．Ｉ．ピグメントイエロー１４７、Ｃ．Ｉ．ピグメントイエロー１５１、Ｃ．Ｉ．ピグメントイエロー１５４、Ｃ．Ｉ．ピグメントイエロー１６８、Ｃ．Ｉ．ピグメントイエロー１７４、Ｃ．Ｉ．ピグメントイエロー１７５、Ｃ．Ｉ．ピグメントイエロー１７６、Ｃ．Ｉ．ピグメントイエロー１８０、Ｃ．Ｉ．ピグメントイエロー１８１、Ｃ．Ｉ．ピグメントイエロー１９１、Ｃ．Ｉ．ピグメントイエロー１９４等が挙げられる。
【００８４】
これらの着色剤は、単独又は混合しさらには固溶体の状態で用いることができる。本発明におけるカラートナーに用いられる着色剤は、色相角、彩度、明度、耐光性、ＯＨＰ透明性、トナーへの分散性の点から選択される。
【００８５】
前記着色剤の添加量は、結着樹脂１００質量部に対し１〜２０質量部添加して用いられる。
【００８６】
本発明に係わるカラートナーには、荷電特性を安定化するために荷電制御剤を配合しても良い。荷電制御剤としては公知のものが利用でき、特に帯電スピードが速く、かつ、一定の帯電量を安定して維持できる荷電制御剤が好ましい。さらに、カラートナーを重合法により製造する場合には、重合阻害性が低く、水系分散媒体への可溶化物が実質的にない荷電制御剤が特に好ましい。具体的な化合物としては、負帯電性荷電制御剤としてサリチル酸、アルキルサリチル酸、ジアルキルサリチル酸、ナフトエ酸、ダイカルボン酸等の芳香族カルボン酸の金属化合物、アゾ染料あるいはアゾ顔料の金属塩または金属錯体、スルホン酸又はカルボン酸基を側鎖に持つ高分子型化合物、ホウ素化合物、尿素化合物、ケイ素化合物、カリックスアレーン等が挙げられる。正帯電性荷電制御剤として四級アンモニウム塩、該四級アンモニウム塩を側鎖に有する高分子型化合物、グアニジン化合物、ニグロシン系化合物、イミダゾール化合物等が挙げられる。
【００８７】
荷電制御剤は樹脂１００質量部に対し０．５〜１０質量部使用することが好ましい。しかしながら、本発明の画像形成方法に関わる非磁性トナーは、荷電制御剤の添加は必須ではなく、トナー層厚規制部材や現像剤担持体との摩擦帯電を積極的に利用することでカラートナー粒子中に必ずしも荷電制御剤を含む必要はない。
【００８８】
本発明に係わるカラートナー粒子を重合法により製造する場合、カラートナー粒子の製造において使用される重合開始剤としては、重合反応時に半減期０．５〜３０時間であるものを、重合性単量体１００質量部に対し０．５〜２０質量部の割合で用いることが好ましく、カラートナーに望ましい強度と適当な溶融特性を与えることができる。重合開始剤としては、２，２’−アゾビス−（２，４−ジメチルバレロニトリル）、２，２’−アゾビスイソブチロニトリル、１，１’−アゾビス（シクロヘキサン−１−カルボニトリル）、２，２’−アゾビス−４−メトキシ−２，４−ジメチルバレロニトリル、アゾビスイソブチロニトリル等のアゾ系またはジアゾ系重合開始剤；ベンゾイルパーオキサイド、メチルエチルケトンパーオキサイド、ジイソプロピルパーオキシカーボネート、クメンヒドロパーオキサイド、２，４−ジクロロベンゾイルパーオキサイド、ラウロイルパーオキサイド、ｔ−ブチルパーオキシ２−エチルヘキサノエート等の過酸化物系重合開始剤が挙げられる。
【００８９】
本発明に係わるカラートナー粒子を重合法により製造する場合、架橋剤を添加しても良く、好ましい添加量としては、重合性単量体組成物の０．００１〜１５質量％である。
【００９０】
ここで架橋剤としては、主として２個以上の重合可能な二重結合を有する化合物が用いられ、例えば、ジビニルベンゼン、ジビニルナフタレン等のような芳香族ージビニル化合物；例えばエチレングリコールジアクリレート、エチレングリコールジメタクリレート、１，３−ブタンジオールジメタクリレート等のような二重結合を２個有するカルボン酸エステル；ジビニルアニリン、ジビニルエーテル、ジビニルスルフィド、ジビニルスルホン等のジビニル化合物；及び３個以上のビニル基を有する化合物；等が単独もしくは混合物として用いられる。
【００９１】
本発明に係わるカラートナー粒子を重合法により製造する場合、一般に上述のカラートナー組成物、すなわち重合性単量体中に着色剤、離型剤、可塑剤、荷電制御剤、架橋剤等トナーとして必要な成分及びその他の添加剤を適宜加えて、ホモジナイサー、ボールミル、コロイドミル、超音波分散機等の分散機によって均一に溶解または分散させた重合性単量体系を、分散安定剤を含有する水系媒体中に懸濁する。この時、高速撹拌機もしくは超音波分散機のような高速分散機を使用して一気に所望のトナー粒子のサイズとするほうが、得られるトナー粒子の粒径がシャープになる。重合開始剤添加の時期としては、重合性単量体中に他の添加剤を添加するとき同時に加えても良いし、水系媒体中に懸濁する直前に混合しても良い。また、造粒直後、重合反応を開始する前に重合性単量体あるいは溶媒に溶解した重合開始剤を加えることもできる。
【００９２】
造粒後は、通常の撹拌機を用いて、粒子状態が維持され且つ粒子の浮遊・沈降が防止される程度の撹拌を行えば良い。
【００９３】
本発明に係わるカラートナーを重合法により製造する場合には、分散安定剤として公知の界面活性剤や有機・無機分散剤が使用でき、中でも無機分散剤が有害な超微粉を生じ難く、その立体障害性により分散安定性を得ているので反応温度を変化させても安定性が崩れ難く、洗浄も容易でトナーに悪影響を与え難いので、好ましく使用できる。こうした無機分散剤の例としては、燐酸カルシウム、燐酸マグネシウム、燐酸アルミニウム、燐酸亜鉛等の燐酸多価金属塩；炭酸カルシウム、炭酸マグネシウム等の炭酸塩；メタ硅酸カルシウム、硫酸カルシウム、硫酸バリウム等の無機塩；水酸化カルシウム、水酸化マグネシウム、水酸化アルミニウム、シリカ、ベントナイト、アルミナ等の無機酸化物が挙げられる。
【００９４】
これらの無機分散剤は、重合性単量体１００質量部に対して、０．２〜２０質量部を単独で使用することが望ましいが、超微粒子を発生し難いもののトナーを微粒化するには不十分であるので、０．００１〜０．１質量部の界面活性剤を併用しても良い。界面活性剤としては、例えばドデシルベンゼン硫酸ナトリウム、テトラデシル硫酸ナトリウム、ペンタデシル硫酸ナトリウム、オクチル硫酸ナトリウム、オレイン酸ナトリウム、ラウリル酸ナトリウム、ステアリン酸ナトリウム、ステアリン酸カリウム等が挙げられる。
【００９５】
これら無機分散剤を用いる場合には、そのまま使用しても良いが、より細かい粒子を得るため、水系媒体中にて該無機分散剤粒子を生成させることができる。例えば、燐酸カルシウムの場合、高速撹拌下、燐酸ナトリウム水溶液と塩化カルシウム水溶液とを混合して、水不溶性の燐酸カルシウムを生成させることができ、より均一で細かな分散が可能となる。この時、同時に水溶性の塩化ナトリウム塩が副生するが、水系媒体中に水溶性塩が存在すると、重合性単量体の水への溶解が抑制されて、乳化重合による超微粒トナーが発生し難くなるので、より好都合である。重合反応終期に残存重合性単量体を除去する時には障害となることから、水系媒体を交換するか、イオン交換樹脂で脱塩したほうが良い。無機分散剤は、重合終了後酸あるいはアルカリで溶解して、ほぼ完全に取り除くことができる。
【００９６】
前記重合工程においては、重合温度は４０℃以上、一般には５０〜９０℃の温度に設定して重合を行うことが好ましい。残存する重合性単量体を消費するために、重合反応終期ならば、反応温度を９０〜１５０℃にまで上げることは可能である。
【００９７】
重合トナー粒子は重合終了後、公知の方法によって濾過、洗浄、乾燥を行い、無機微粒子等の外添剤を混合し表面に付着させることで、トナーを得ることができる。また、製造工程に分級工程を入れ、粗粉や微粉をカットすることも、本発明の望ましい形態の一つである。
【００９８】
本発明に係わるカラートナー粒子を粉砕法により製造する場合は、公知の方法が用いられるが、例えば、結着樹脂、離型剤、荷電制御剤、着色剤等のカラートナー粒子として必要な成分及びその他の添加剤等をヘンシェルミキサー、ボールミル等の混合機により十分混合してから加熱ロール、ニーダー、エクストルーダーの如き熱混練機を用いて溶融混練して樹脂類をお互いに相溶させ、冷却固化、粉砕後、分級、必要に応じて表面処理を行ってトナー粒子を得ることができる。分級及び表面処理の順序はどちらが先でもよい。分級工程においては生産効率上、多分割分級機を用いることが好ましい。
【００９９】
粉砕工程は、機械衝撃式、ジェット式等の公知の粉砕装置を用いた方法により行うことができる。特定の円形度を有するカラートナーを得るためには、さらに熱をかけて粉砕したり、あるいは補助的に機械的衝撃を加える処理をすることが好ましい。また、微粉砕（必要に応じて分級）されたカラートナー粒子を熱水中に分散させる湯浴法、熱気流中を通過させる方法などを用いても良い。
【０１００】
機械的衝撃力を加える手段としては、例えば、ホソカワミクロン社製のメカノフュージョンシステムや奈良機械製作所製のハイブリダイゼーションシステム等の装置のように、高速回転する羽根により非磁性トナー粒子をケーシングの内側に遠心力により押しつけ、圧縮力、摩擦力等の力によりトナー粒子に機械的衝撃力を加える方法が挙げられる。
【０１０１】
さらにまた、本発明に係わるカラートナー粒子は、特公昭５６−１３９４５号公報等に記載のディスク又は多流体ノズルを用い溶融混合物を空気中に霧化し球状のトナー粒子を得る方法や、重合法として懸濁重合法の他にも単量体には可溶で得られる重合体が不溶な水系有機溶剤を用い直接トナー粒子を生成する分散重合方法、又は水溶性極性重合開始剤存在下で直接重合しトナー粒子を生成するソープフリー重合方法に代表される乳化重合方法等を用い、トナー粒子を製造する方法でも製造が可能である。
【０１０２】
本発明の画像形成方法に用いるカラー現像剤（イエロー色現像剤、マゼンタ色現像剤、シアン色現像剤）は、少なくとも結着樹脂及びカラー着色剤、無機微粒子とキャリアを含有してなる二成分現像剤であっても良い。
【０１０３】
本発明に好ましく用いられるキャリア粒子について説明する。
【０１０４】
本発明のカラー現像剤に用いられるキャリアとしては、例えば、表面酸化または未酸化の鉄、ニッケル、銅、亜鉛、コバルト、マンガン、クロム、及び希土類の如き磁性金属、それらの磁性合金、それらの磁性酸化物、それらの磁性フェライトからなるグループから選択される磁性粒子、及び樹脂中に磁性粉が分散された磁性体分散型キャリアが挙げられる。
【０１０５】
中でも本発明に用いられるキャリア粒子は、少なくとも無機化合物粒子とバインダー樹脂を有する磁性分散型キャリア粒子であることが好ましい。
【０１０６】
キャリア粒子の体積平均粒径は２０〜６０μｍが好ましく、特に２５〜４５μｍが好ましい。
【０１０７】
キャリア粒子の体積平均粒径は、光学顕微鏡又は走査型電子顕微鏡により、ランダムに１００個以上を抽出し、水平方向最大弦長を持って体積粒度分布を算出し、その５０％平均粒径を持って体積平均粒径としてもよいし、又、レーザー回折式粒度分布測定装置ＨＥＲＯＳ（日本電子製）を用いて、０．０５μｍ〜２００μｍの範囲を３２対数分割して測定し、５０％平均粒径をもって体積平均粒径としてもよい。
【０１０８】
本発明において、磁性粒子分散型樹脂キャリア粒子に用いる無機化合物粒子は、下記式（ＶＩＩ）又は（ＶＩＩＩ）で表される磁性を有するマグネタイト又はフェライト等の金属化合物粒子が挙げられる。
ＭＯ・Ｆｅ_２Ｏ_３（ＶＩＩ）
Ｍ・Ｆｅ_２Ｏ_４（ＶＩＩＩ）
（式中、Ｍは３価、２価又は１価の金属イオンを示す。）
【０１０９】
上記式（ＶＩＩ）及び（ＶＩＩＩ）中のＭとしては、Ｍｇ、Ａｌ、Ｓｉ、Ｃａ、Ｓｃ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｚｎ、Ｓｒ、Ｙ、Ｚｒ、Ｎｂ、Ｍｏ、Ｃｄ、Ｓｎ、Ｂａ、Ｐｂ及びＬｉ等が挙げられ、これらは、単独或いは複数で用いることができる。
【０１１０】
上記の磁性を有する金属化合物粒子の具体的化合物としては、例えば、マグネタイト、Ｚｎ−Ｆｅ系フェライト、Ｍｎ−Ｚｎ−Ｆｅ系フェライト、Ｎｉ−Ｚｎ−Ｆｅフェライト、Ｍｎ−Ｍｇ−Ｆｅ系フェライト、Ｃａ−Ｍｎ−Ｆｅ系フェライト、Ｃａ−Ｍｇ−Ｆｅ系フェライト、Ｌｉ−Ｆｅ系フェライト及びＣｕ−Ｚｎ−Ｆｅ系フェライト等の鉄系酸化物が挙げられる。
【０１１１】
本発明に用いる磁性粒子分散型樹脂キャリア粒子のバインダー樹脂としては、熱硬化性樹脂が好ましく、さらには一部又は全部が３次元的に架橋されている樹脂、例えばフェノール樹脂を含有する熱硬化性樹脂であることが好ましい。この樹脂を用いることにより、分散する無機化合物粒子を強固に結着できる為、磁性粒子分散型樹脂キャリア粒子の強度を高めることができ、多数枚の複写においても無機化合物粒子の脱離が起り難くなる。
【０１１２】
磁性粒子分散型キャリア粒子を得る方法としては、特に以下に記載する方法に限定されるものではないが、本発明においては、バインダー樹脂となるモノマーと上記無機化合物粒子と溶媒が均一に分散又は溶解されている様な溶液中でモノマーを重合させることにより得る方法が挙げられる。
【０１１３】
なお、本発明においては、上記磁性粒子分散型キャリア粒子をキャリアコアとして、樹脂層でコートされた磁性コートキャリア粒子を用いることも好ましい形態である。
【０１１４】
本発明に用いられるキャリア粒子として、具体的には、無機化合物粒子としての強磁性鉄化合物と非磁性鉄化合物粒子とを、フェノール樹脂を結着成分として結合してなる球状複合体芯粒子の表面に熱硬化性樹脂からなる被覆層を形成してなる体積平均粒径２０〜６０μｍの球状複合体粒子からなる樹脂キャリア等が、長期耐久による帯電安定性の面から好ましく用いられる。
【０１１５】
本発明に用いるキャリアの比抵抗は１×１０^８〜１×１０^１６Ω・ｃｍであることが好ましい。
【０１１６】
本発明に係るカラー現像剤において、上述のキャリア粒子とカラートナー粒子の混合比率はカラー現像剤中のカラートナー濃度として３．０〜１２．０質量％、好ましくは５．０〜９．０質量％にすると通常良好な結果が得られる。トナー濃度が３．０質量％未満では画像濃度が低く実用不可となる他、キャリアの劣化を早め、現像剤寿命を縮める結果となってしまう。１２．０％超ではカブリや機内飛散を増加させ、同じく現像剤の耐用寿命を短める。
【０１１７】
本発明の画像形成方法においては、カラー色用補給用二成分現像剤を補給しながら現像を行うことも好ましく用いられる。この場合、キャリア粒子１質量部に対してカラートナーを２〜５０質量部の割合で混合したカラー色用補給用現像剤を用いることが好ましい。長期耐久においては、キャリア汚染に起因する画像濃度低下の発生が起きやすく、特に感光体としてアモルファスシリコン感光体を用いる場合、現像コントラストが小さく、画像濃度低下が起きやすい。このような系において長期耐久後半も画像濃度を維持するためには、キャリア粒子を一定量含有させた補給用現像剤を用い、補給されたキャリア粒子に見合う量のキャリアを本体から本体外へ排出する現像方式に用いることが好ましい。
【０１１８】
＜２＞本発明における黒色現像剤
本発明に使用する黒色現像剤について説明する。
【０１１９】
本発明に係る黒色現像剤は、少なくとも結着樹脂及び着色剤を有する。
【０１２０】
本発明における黒色トナーは、重量平均粒径が３〜１０μｍのトナーであることが好ましい。平均粒径の測定方法は、カラートナーの測定方法に準ずる。
【０１２１】
黒色トナーの結着樹脂としては、ポリスチレン、ポリビニルトルエンなどのスチレン及びその置換体の単重合体；スチレン−プロピレン共重合体、スチレン−ビニルトルエン共重合体、スチレン−ビニルナフタリン共重合体、スチレン−アクリル酸メチル共重合体、スチレン−アクリル酸エチル共重合体、スチレン−アクリル酸ブチル共重合体、スチレン−アクリル酸ジメチルアミノエチル共重合体、スチレン−メタアクリル酸メチル共重合体、スチレン−メタアクリル酸エチル共重合体、スチレン−メタクリル酸ジメチルアミノエチル共重合体、スチレン−ビニルメチルエーテル共重合体、スチレン−ビニルエチルエーテル共重合体、スチレン−ビニルメチルケトン共重合体、スチレン−ブタジエン共重合体、スチレン−イソプレン共重合体、スチレン−マレイン酸共重合体、スチレン−マレイン酸エステル共重合体などのスチレン系共重合体；ポリメチルメタクリレート、ポリブチルメタクリレート、ポリ酢酸ビニル、ポリエチレン、ポリプロピレン、ポリビニルブチラール、ポリアクリル酸樹脂、ロジン、変性ロジン、テルペン樹脂、フェノール樹脂、ポリエステル樹脂などが挙げられる。これらは単独或いは混合して使用できる。
【０１２２】
本発明における黒色トナーは、ワックスを含有していることが好ましい。ワックスとしては、例えばポリオレフィンワックス、パラフィンワックス、ライスワックス、アミド系ワックス、脂肪酸系ワックス、エステルワックス、高級アルコール、カルナバワックス等を挙げることができる。ワックスの含有割合はトナーの結着樹脂１００質量部に対し０．５〜２０質量部が好ましく、特に１〜１２質量部が好ましい。
【０１２３】
本発明における黒色トナーは、磁性体粒子を含有した磁性トナーであることが好ましい。
【０１２４】
本発明に好ましく用いられる磁性トナー中に含まれる磁性体としては、マグネタイト、ヘマタイト、フェライト等の酸化鉄；鉄、コバルト、ニッケルのような金属、或いはこれらの金属とアルミニウム、コバルト、銅、鉛、マグネシウム、スズ、亜鉛、アンチモン、ベリリウム、ビスマス、カドミウム、カルシウム、マンガン、セレン、チタン、タングステン、バナジウムのような金属との合金及びその混合物が挙げられる。
【０１２５】
磁性体は窒素吸着法によるＢＥＴ比表面積が好ましくは１〜２０ｍ^２／ｇ、特に２．５〜１２ｍ^２／ｇが良い。さらにモース硬度が５〜７の磁性体が好ましい。この磁性体の含有量は磁性一成分トナーに対して１０〜７０質量％が良い。
【０１２６】
黒色トナーの製造法は、特に限定はないが、熱ロール、ニーダー、エクストルーダーの如き熱混練機によって、トナーの構成材料を良く混練した後、粉砕、分級によって得る方法や重合法によって得る方法等が挙げられる。
【０１２７】
また、黒色トナーの構成材料としては、上記結着樹脂、磁性体、ワックス以外に、カラートナーと同様の荷電制御剤等を用いることができる。
【０１２８】
本発明の黒色トナーは、カラートナーで使用可能無機微粒子をヘンシェルミキサー等の混合機で乾式混合することにより調製することができる。
【０１２９】
＜３＞本発明における感光体
次に、本発明に使用する感光体について説明する。
【０１３０】
本発明に使用する感光体は、非晶質珪素を主成分とする光導電層を有するアモルファスシリコン感光体であって、具体的には図１に示すような層構成を有することが好ましい。
【０１３１】
図１（ａ）に示すアモルファスシリコン感光体１００は、感光体用支持体１０１の上に、感光層１０２が設けられている。該感光層１０２はａ−Ｓｉ：Ｈ、Ｘ（Ｈは水素原子、Ｘはハロゲン原子）からなり光導電性を有する光導電層１０３で構成されている。
【０１３２】
図１（ｂ）に示すアモルファスシリコン感光体１００は、感光体用支持体１０１の上に、感光層１０２が設けられている。該感光層１０２はａ−Ｓｉ：Ｈ、Ｘからなり光導電性を有する光導電層１０３と、アモルファスシリコン系表面層１０４とから構成されている。
【０１３３】
図１（ｃ）に示すアモルファスシリコン感光体１００は、感光体用支持体１０１の上に、感光層１０２が設けられている。該感光層１０２はａ−Ｓｉ：Ｈ、Ｘからなり光導電性を有する光導電層１０３と、アモルファスシリコン系表面層１０４と、アモルファスシリコン系電荷注入阻止層１０５とから構成されている。
【０１３４】
図１（ｄ）に示すアモルファスシリコン感光体１００は、感光体用支持体１０１の上に、感光層１０２が設けられている。該感光層１０２は光導電層１０３を構成するａ−Ｓｉ：Ｈ、Ｘからなる電荷発生層１０６ならびに電荷輸送層１０７と、アモルファスシリコン系表面層１０４とから構成されている。
【０１３５】
これらの光導電層、表面層、電荷注入阻止層、電荷発生層、電荷輸送層等は、通常のアモルファスシリコン感光体を構成するものと同様のものが挙げられる。
【０１３６】
アモルファスシリコン感光体に使用される支持体としては、導電性でも電気絶縁性であってもよい。導電性支持体としては、Ａｌ、Ｃｒ、Ｍｏ、Ａｕ、Ｉｎ、Ｎｂ、Ｔｅ、Ｖ、Ｔｉ、Ｐｔ、Ｐｄ、Ｆｅ等の金属、およびこれらの合金、例えばステンレス等が挙げられる。また、ポリエステル、ポリエチレン、ポリカーボネート、セルロースアセテート、ポリプロピレン、ポリ塩化ビニル、ポリスチレン、ポリアミド等の合成樹脂のフィルムまたはシート、ガラス、セラミック等の電気絶縁性支持体の少なくとも感光層を形成する側の表面を導電処理した支持体も用いることができる。
【０１３７】
＜４＞本発明の画像形成方法
本発明の画像形成方法は、上記黒色現像剤及びカラー現像剤を適宜用いて可視像を形成させて現像する現像工程を有し、感光体として上記アモルファスシリコン感光体を用いるカラー画像形成方法である。
【０１３８】
本発明の画像形成方法は、カラー現像剤として、カラートナー濃度が３．０〜１２．０質量％、好ましくは５．０〜９．０質量％のものを用いることが好ましい。また、カラー色用補給用現像剤として、キャリア１質量部に対して、カラートナー２〜５０質量部の配合割合で含有してなるものを用いることで、環境に左右されることなくカラー現像剤の帯電性が安定し、良好な画質を長期にわたって得ることができる。トナーが２質量部未満であると、本発明の磁性微粒子分散型キャリアを用いても、耐久によるカブリあるいはトナー飛散等が生じやすく、サービスマンによる現像剤の交換が必要となり好ましくない。一方、５０質量部を超えると、現像剤の寿命は向上するものの、キャリア量が多いために、補給現像剤量が重くなり、補給現像剤容器から、現像器への排出性が悪化したり、回収した劣化現像剤の回収手段が複雑になったりして好ましくない。さらに、補給現像剤容器内の実質トナー量が減少して、トナー容器の交換頻度が多くなり、ユーザーの負荷が増えるばかりでなく、コストＵＰにもなり好ましくない。
【０１３９】
本発明の画像形成方法においては、現像によりカラートナーが消費され、カラートナー／キャリア粒子（Ｔ／Ｃ）比が低下すると、その低下をコイルのインダクタンスを利用して、カラー現像剤の透磁率の変化を測定するトナー濃度検知センサー等で検知し、消費されたカラートナー量に応じて補給用現像剤を収容する収容装置から補給用現像剤を補給することが好ましい。
【０１４０】
本発明の画像形成方法においては、静電潜像担持体上に形成される可視の色現像画像は、中間転写体上に転写、担持し、すべての色現像画像を該中間転写体上に重ね合わせて転写した後、転写材に一括転写する中間転写方式であることが、色ずれを防止し、高画質が得られるばかりか、装置の小型化などの観点からも好ましい。
【０１４１】
本発明の画像形成方法においては、プロセススピードが２００ｍｍ／ｓｅｃ以上であることが高速化を達成するという観点から好ましい。
【０１４２】
本発明の画像形成方法においては、現像剤担持体は、プロセススピードの１．０倍〜２．０倍の周速で回転しながら現像させることが、好ましい。１．０倍未満であると、現像に必要なトナーを供給できなくなるため充分な画像濃度を得ることができなくなる。また、２．０倍超であると現像器内でのシェアが大きくなり、トナー、キャリアとも劣化が激しくなり、耐久安定性にかけてしまう。また、飛散による機内汚れ、画像汚れ等も引き起こしてしまう。
【０１４３】
また、本発明画像形成方法は、いかなるシステムでも用いることができ、例えば、高速システム用現像剤、オイルレス定着用現像剤、クリーナーレス用現像剤等、公知の現像方法に適用可能である。
【０１４４】
本発明の画像形成方法は、例えば図２に示すような現像手段を有する画像形成装置を用い現像を行うことができる。
【０１４５】
図２は、ロータリー回転方式の各色毎にロータリー現像ユニットを有する現像器交換体１３及び中間転写体４５を搭載した電子写真方式のフルカラー画像形成装置の一例の概略構成図である。静電潜像担持体１は、帯電装置１５によりその表面を負極性に一様に帯電される。次に露光装置１４により、一色目、例えばイエロー画像に対応する像露光がなされ、静電潜像担持体１の表面にはイエロー画像に対応する静電潜像が形成される。
【０１４６】
現像器交換体１３は回転移動式の構成であり、概略構成図を図４に示す。前記イエロー画像に対応する静電潜像の先端が現像位置に到達する以前に、イエロー現像器が静電潜像担持体１に対向し、その後磁気ブラシが静電潜像を摺擦して、前記静電潜像担持体上にイエロートナー像を形成する。
【０１４７】
図３は、図２、４の現像器２、３、４および５の概略構成図である。なお、オートリフレッシュ現像方式を用いないカラー用現像器２，３，４については、３４〜３９の現像剤回収機能部を有していない。
【０１４８】
現像に用いられる各現像器には、図３に示すように、例えば、現像剤担持体としての現像スリーブ６、マグネットローラ８、規制部材７、現像剤搬送スクリュー１０、１１、図示されていないスクレーパ等が設けられている。
【０１４９】
図２、３、４を用いて現像器内の現像剤が現像されるまでの搬送されていく流れを説明する。現像スリーブ６は固定したマグネットローラ８を内包し、静電潜像担持体１の周面との間に所定の現像間隔を保ち駆動回転される。なお、現像スリーブ６と静電潜像担持体１とは接触している場合もある。規制部材７は剛性かつ磁性を有し、現像スリーブ６に対し現像剤が介在しない状態で所定の荷重をもって圧接されるものや、現像スリーブ６との間に所定の間隔を保って配されるもの等、種々のものがある。一対の現像剤搬送スクリュー１０、１１は、スクリュー構造を持ち、互いに逆方向に現像剤を搬送循環させて、トナーとキャリアを十分撹拌混合した上、現像剤として現像スリーブ６に送る作用をするものである。マグネットローラ８は、例えば、Ｎ極およびＳ極を交互に等間隔に配置した等磁力の４極の磁石から構成されるもの、６極の磁石から構成されるもの、或いは、スクレーパに接する部分において反発磁界を形成し、現像剤の剥離を容易にするために、１極欠落させて５極とし、前記現像スリーブ６内で固定した状態で内包させたものであっても良い。
【０１５０】
上記一対の現像剤搬送スクリュー１０、１１は、互いに相反する方向に回転する撹拌部材を兼ねる部材であって、補給用現像剤収容容器（図４：２ａ、３ａ、４ａ、５ａ）から補給用現像剤収容装置９のスクリューの推力によって補給される補給用現像剤を搬送すると共に、トナーとキャリアとの混合作用によって、摩擦帯電がなされた均質な二成分の現像剤とされ、現像スリーブ６の周面上にその二成分系現像剤を層状に付着する。
【０１５１】
現像スリーブ６の表面の現像剤は、マグネットローラ８の磁極に対向して設けた規制部材７により、均一な層を形成する。均一に形成された現像剤層は、現像領域において、静電潜像担持体１の周面上の潜像を現像し、トナー像を形成する。
【０１５２】
そして、このトナー像は、転写装置３１で中間転写体４５に転写されることになる。
【０１５３】
上記のイエローのコピーサイクルが終了すると、イエロートナーの転写を終えた静電潜像担持体１は、その後、必要に応じてクリーニング前処理が施された後、除電装置で除電され、クリーニング装置１８により表面に残ったイエロートナーが掻き取られる。
【０１５４】
そして、現像装置１３が回転し、順次現像器３、４、５が静電潜像担持体１に対抗するように切り替わり、上記と同様のコピーサイクルで、マゼンタ、シアン、ブラックのトナー像が中間転写体４５に転写されることとなる。
【０１５５】
上記の各コピーサイクルが実行されると、各色成分別のトナー像は、転写装置４０により中間転写体４５の同位置へ転写されることになり、各色成分別のトナーが重ねられることで完成したひとつのトナー像を形成することになる。一方、給紙トレイ２５に収容された用紙または透明シート等の転写材１２は、送り出しローラ２８により１枚ずつレジストレーションローラー２５に給紙され、中間転写体４５に同期して転写材１２を中間転写体４５と転写ローラ４３との間に搬送する。搬送された転写材１２は、転写ローラ４３により中間転写体４５のトナー像が転写された後、剥離フィンガー４４により中間転写体４５から分離され、搬送ベルト２０により定着装置２１へ導入される。そして、転写材１２へのカラートナー像の定着が行われた後、外部へ排出されることで、１回のコピーモードが終了することになる。
【０１５６】
また、転写材にトナー像を転写した中間転写体４５は、その表面を図示されていない除電装置で除電した後、クリーニング装置２３で表面クリーニングが行われ、次のコピーサイクルを待つことになる。
【０１５７】
上記のような複写動作が繰り返されると、図３の現像器内の現像槽１７内に収納されている現像剤中のトナーは徐々に消費され、キャリアに対するトナーの比率、すなわちトナー濃度が低下していく。このトナー濃度の変化は、現像槽１７に設けられた図示しないトナー濃度センサによりトナー濃度が現像に必要な適性範囲内に常に入るようにフィードバック制御される。
【０１５８】
上記制御により、補給用現像剤収容容器から補給用現像剤が補給用現像剤収容装置９に排出され、ついで、スクリューの推進力によって補給用現像剤収容装置９の補給口から、補給用現像剤が現像器内の現像槽１７に供給される。
【０１５９】
また、オートリフレッシュ現像方式を用いたブラック用現像器５においては、本発明のトナーとキャリアを混合した補給用現像剤が、補給用現像剤収容容器５ａから、補給用現像剤収容装置９の補給口をえて、ブラック用現像器５に補給される。
【０１６０】
次に、図２に示した回転移動する現像器交換体１３内の回転移動を利用したブラック用現像器５からの過剰になった現像剤の排出について図３、４を用いて説明する。
【０１６１】
回転移動方式を採用したロータリー現像ユニットを有する現像器交換体１３を具備するフルカラー画像形成装置において、現像器２、３、４、５は、現像器交換体１３の内部で回転移動し、現像時、静電潜像担持体１に対向する位置に回転移動して現像を行い、非現像時は静電潜像担持体１に対向していない位置に回転移動する。
【０１６２】
現像器５が静電潜像担持体１に対向し、現像動作を行っている位置で、過剰になった現像剤（劣化したキャリア）は、現像器５に設けられた現像器側現像剤排出口３４から溢出され、回転動作により現像剤回収オーガ３６内を移動し、ロータリー回転方式現像装置の回転中心軸に設けられた現像剤回収容器３９に排出される。
【０１６３】
本発明における現像方法は、具体的には、現像スリーブに交流電圧を印加して、現像領域に交番電界を形成しつつ、磁気ブラシが静電潜像担持体１に接触している状態で現像を行うことが好ましい。現像スリーブ６と静電潜像担持体１の距離（Ｓ−Ｄ間距離）は、１００〜１０００μｍであることがキャリア付着防止及びドット再現性の向上において良好である。１００μｍより狭いと現像剤の供給が不十分になりやすく画像濃度が低くなり、１０００μｍを超えると磁極Ｓ１からの磁力線が広がり磁気ブラシの密度が低くなり、ドット再現性に劣ったり、キャリアを拘束する力が弱まりキャリア付着が生じやすくなる。
【０１６４】
交番電界のピーク間の電圧は３００〜３０００Ｖが好ましく、周波数は５００〜１００００Ｈｚであり、それぞれプロセスにより適宜選択して用いることができる。この場合、交番電界を形成するための交流バイアスの波形としては三角波、矩形波、正弦波、あるいはＤｕｔｙ比を変えた波形が挙げられる。ときにトナー像の形成速度の変化に対応するためには、非連続の交流バイアス電圧を有する現像バイアス電圧（断続的な交番重畳電圧）を現像スリーブに印加して現像を行うことが好ましい。印加電圧が３００Ｖより低いと十分な画像濃度が得られにくく、また非画像部のカブリトナーを良好に回収することができない場合がある。また、３０００Ｖを超える場合には磁気ブラシを介して、潜像を乱してしまい、画質低下を招く場合がある。
【０１６５】
良好に帯電したトナーを有する二成分系現像剤を使用することで、カブリ取り電圧（Ｖｂａｃｋ）を低くすることができ、静電潜像担持体の一次帯電を低めることができるために静電潜像担持体寿命を長寿命化できる。Ｖｂａｃｋは、現像システムにもよるが２００Ｖ以下、より好ましくは１５０Ｖ以下が良い。コントラスト電位としては、十分画像濃度が出るように１００〜４００Ｖが好ましく用いられる。
【０１６６】
また、周波数が５００Ｈｚより低いと、プロセススピードにも関係するが、静電潜像担持体に接触したトナーが現像スリーブに戻される際に、十分な振動が与えられずカブリが生じやすくなる。１００００Ｈｚを超えると、電界に対してトナーが追随できず画質低下を招きやすい。
【０１６７】
本発明において現像方法で重要なことは、十分な画像濃度を出しドット再現性に優れ、かつキャリア付着のない現像を行うために、現像スリーブ６上の磁気ブラシの静電潜像担持体１との接触幅（現像当接部）を好ましくは３〜８ｍｍにすることである。現像当接部が３ｍｍより狭いと十分な画像濃度とドット再現性を良好に満足することが困難であり、８ｍｍより広いと現像剤のパッキングが起き機械の動作を止めてしまったり、またキャリア付着を十分に抑えることが困難になる。
【０１６８】
現像当接部の調整方法としては、規制部材７と現像スリーブ６との距離を調整したり、現像スリーブ６と静電潜像担持体１との距離（Ｓ−Ｄ間距離）を調整することで当接幅を適宜調整する方法がある。
【０１６９】
静電潜像担持体の構成としては、通常の画像形成装置に用いられる静電潜像担持体と同じで良く、例えば、アルミニウム、ＳＵＳ等の導電性基体の上に、順に導電層、下引き層、電荷発生層、電荷輸送層、必要に応じて電荷注入層を設ける構成の感光体が挙げられる。導電層、下引き層、電荷発生層、電荷輸送層は、通常の感光体に用いられるもので良い。感光体の最表面層として、例えば電荷注入層あるいは保護層を用いてもよい。
【０１７０】
【実施例】
以下、実施例により本発明の効果を具体的に説明する。なお、本発明はこれらの実施例に限定されるものではない。
【０１７１】
＜１＞カラートナーの製造
カラートナーの製造例１：
イオン交換水４０５質量部に０．１Ｍ−Ｎａ_３ＰＯ_４水溶液２５０質量部を投入し６０℃に加温した後、１．０７Ｍ−ＣａＣｌ_２水溶液４０．０質量部を徐々に添加して燐酸カルシウム塩を含む水系媒体を得た。
【０１７２】
一方、下記処方をアトライター（三井三池化工機（株））を用いて均一に分散混合した。
スチレン ８０質量部
ｎ−ブチルアクリレート ２０質量部
ジビニルベンゼン ０．２質量部
飽和ポリエステル樹脂 ４．０質量部
（Ｍｗ＝４１０００）
負帯電性荷電制御剤（ジアルキルサリチル酸の金属化合物） １質量部
Ｃ．Ｉ．ピグメントイエロー１７ ８．０質量部
【０１７３】
この単量体組成物を６０℃に加温し、そこにベヘニン酸ベヘニルを主体とするエステルワックス（ＤＳＣにおける昇温測定時の最大吸熱ピーク７２℃）１２質量部を添加混合溶解し、これに重合開始剤２，２’−アゾビス（２，４−ジメチルバレロニトリル）［ｔ_１／２＝１４０分，６０℃条件下］３質量部を溶解した。
【０１７４】
前記水系媒体中に上記重合性単量体系を投入し、６０．５℃，Ｎ_２雰囲気下においてＴＫ式ホモミキサー（特殊機化工業（株））を用いて１０，０００ｒｐｍで１５分間撹拌し、造粒した。その後パドル撹拌翼で撹拌しつつ、６０．５℃で６時間反応させた。その後液温を８０℃とし更に４時間撹拌を続けた。反応終了後、８０℃で更に３時間蒸留を行い、その後、懸濁液を冷却し、塩酸を加えて燐酸カルシウム塩を溶解し、濾過・水洗を行い、湿潤着色粒子を得た。
【０１７５】
次に、上記粒子を４０℃にて１２時間乾燥して着色粒子（トナー粒子）を得た。
【０１７６】
トナー粒子 １００質量部
シリコーンオイルで処理したＢＥＴ値が１３０ｍ^２／ｇであり、一次粒径が１２ｎｍの疎水性シリカ微粒子 ０．４質量部
シリコーンオイルで処理したＢＥＴ値が３０ｍ^２／ｇであり、一次粒径が５０ｎｍの疎水性シリカ微粒子 ０．４質量部
シリコーンオイルで処理したＢＥＴ値が８０ｍ^２／ｇであり、一次粒径が３０ｎｍの疎水性チタニア微粒子 ０．４質量部
をヘンシェルミキサー（三井三池化工機（株））で混合して、カラートナー（イエロートナー）Ａ（重量平均粒径６．７μｍ）を得た。
【０１７７】
カラートナーの製造例２：
Ｃ．Ｉ．ピグメントイエロー１７を８．０質量部の代わりに、Ｃ．Ｉ．ピグメントレッド１２２を８．０質量部としたこと以外は、カラートナーの製造例１と同様にしてカラートナー（マゼンタトナー）Ｂ（重量平均粒径６．８μｍ）を得た。
【０１７８】
カラートナーの製造例３：
Ｃ．Ｉ．ピグメントイエロー１７を８．０質量部の代わりに、Ｃ．Ｉ．ピグメントブルー１５：３を７．５質量部用としたこと以外は、カラートナーの製造例１と同様にしてカラートナー（シアントナー）Ｃ（重量平均粒径６．７μｍ）を得た。
【０１７９】
カラートナーの製造例４：
シリコーンオイルで処理したＢＥＴ値が３０ｍ^２／ｇであり、一次粒径が５０ｎｍの疎水性シリカ微粒子を０．４質量部の代わりに、シリコーンオイルで処理したＢＥＴ値が６０ｍ^２／ｇであり、粒径が４５ｎｍの疎水性アルミナ微粒子０．４質量部に変更することを除いてはカラートナーの製造例１と同様にしてカラートナー（イエロートナー）Ｄ（重量平均粒径６．７μｍ）を得た。
【０１８０】
カラートナーの製造例５：
シリコーンオイルで処理したＢＥＴ値が３０ｍ^２／ｇであり、一次粒径が５０ｎｍの疎水性シリカ微粒子を０．４質量部の代わりに、シリコーンオイルで処理したＢＥＴ値が６０ｍ^２／ｇであり、粒径が４５ｎｍの疎水性アルミナ微粒子０．４質量部に変更することを除いてはカラートナーの製造例２と同様にしてカラートナー（マゼンタトナー）Ｅ（重量平均粒径６．８μｍ）を得た。
【０１８１】
カラートナーの製造例６：
シリコーンオイルで処理したＢＥＴ値が３０ｍ^２／ｇであり、一次粒径が５０ｎｍの疎水性シリカ微粒子を０．４質量部の代わりに、シリコーンオイルで処理したＢＥＴ値が６０ｍ^２／ｇであり、粒径が４５ｎｍの疎水性アルミナ微粒子０．４質量部に変更することを除いてはカラートナーの製造例３と同様にしてカラートナー（シアントナー）Ｆ（重量平均粒径６．７μｍ）を得た。
【０１８２】
カラートナーの製造例７：
シリコーンオイルで処理したＢＥＴ値が３０ｍ^２／ｇであり、一次粒径が５０ｎｍの疎水性シリカ微粒子を０．４質量部の代わりに、ＢＥＴ値が７０ｍ^２／ｇであり、一次粒径が４００ｎｍのポリフッ化ビニリデン微粒子０．４質量部に変更し、シリコーンオイルで処理したＢＥＴ値が８０ｍ^２／ｇであり、一次粒径が３０ｎｍの疎水性チタニア微粒子を０．４質量部の代わりにシリコーンオイルで処理したＢＥＴ値が１０ｍ^２／ｇで一次粒径が２９０ｎｍの疎水性酸化亜鉛微粒子を０．４質量部に変更することを除いてはカラートナーの製造例１と同様にしてカラートナー（イエロートナー）Ｇ（重量平均粒径６．７μｍ）を得た。
【０１８３】
カラートナーの製造例８：
シリコーンオイルで処理したＢＥＴ値が３０ｍ^２／ｇであり、一次粒径が５０ｎｍの疎水性シリカ微粒子を０．４質量部の代わりに、ＢＥＴ値が７０ｍ^２／ｇであり、一次粒径が４００ｎｍのポリフッ化ビニリデン微粒子０．４質量部に変更し、シリコーンオイルで処理したＢＥＴ値が８０ｍ^２／ｇであり、一次粒径が３０ｎｍの疎水性チタニア微粒子を０．４質量部の代わりにシリコーンオイルで処理したＢＥＴ値が１０ｍ^２／ｇで一次粒径が２９０ｎｍの疎水性酸化亜鉛微粒子を０．４質量部に変更することを除いてはカラートナーの製造例２と同様にしてカラートナー（マゼンタトナー）Ｈ（重量平均粒径６．８μｍ）を得た。
【０１８４】
カラートナーの製造例９：
シリコーンオイルで処理したＢＥＴ値が３０ｍ^２／ｇであり、一次粒径が５０ｎｍの疎水性シリカ微粒子を０．４質量部の代わりに、ＢＥＴ値が７０ｍ^２／ｇであり、一次粒径が４００ｎｍのポリフッ化ビニリデン微粒子０．４質量部に変更し、シリコーンオイルで処理したＢＥＴ値が８０ｍ^２／ｇであり、一次粒径が３０ｎｍの疎水性チタニア微粒子を０．４質量部の代わりにシリコーンオイルで処理したＢＥＴ値が１０ｍ^２／ｇで一次粒径が２９０ｎｍの疎水性酸化亜鉛微粒子を０．４質量部に変更することを除いてはカラートナーの製造例３と同様にしてカラートナー（シアントナー）Ｉ（重量平均粒径６．７μｍ）を得た。
【０１８５】
カラートナーの製造例１０：
シリコーンオイルで処理したＢＥＴ値が８０ｍ^２／ｇであり、一次粒径が３０ｎｍの疎水性チタニア微粒子を０．４質量部を添加しないことを除いてはカラートナーの製造例１と同様にしてカラートナー（イエロートナー）Ｊ（重量平均粒径６．７μｍ）を得た。
【０１８６】
カラートナーの製造例１１：
シリコーンオイルで処理したＢＥＴ値が８０ｍ^２／ｇであり、一次粒径が３０ｎｍの疎水性チタニア微粒子を０．４質量部を添加しないことを除いてはカラートナーの製造例２と同様にしてカラートナー（マゼンタトナー）Ｋ（重量平均粒径６．８μｍ）を得た。
【０１８７】
カラートナーの製造例１２：
シリコーンオイルで処理したＢＥＴ値が８０ｍ^２／ｇであり、一次粒径が３０ｎｍの疎水性チタニア微粒子を０．４質量部を添加しないことを除いてはカラートナーの製造例２と同様にしてカラートナー（シアントナー）Ｌ（重量平均粒径６．７μｍ）を得た。
【０１８８】
カラートナーの製造例１３：
スチレン／ｎ−ブチルアクリレート共重合体 ８０質量部
（質量比８５／１５、Ｍｗ＝３３００００）
飽和ポリエステル樹脂 ４．５質量部
（Ｍｗ＝１８０００）
負荷電性制御剤（ジアルキルサリチル酸の金属化合物） ３質量部
Ｃ．Ｉ．ピグメントイエロー１７ ７質量部
ベヘニン酸ベヘニルを主体とするエステルワックス ５質量部
（ＤＳＣにおける昇温測定時の最大吸熱ピーク７２℃）
上記材料をブレンダーにて混合し、１１０℃に加熱した二軸エクストルーダーで溶融混練し、冷却した混練物をハンマーミル（ホソカワミクロン（株）製）で粗粉砕し、次いでエアージェット方式による微粉砕機で微粉砕した。衝突板は衝突する方向に対して９０度となるよう調整した。得られた微粉砕物を風力分級してトナー粒子を得た。その後バッチ式の衝撃式表面処理装置で球形化処理を行った（処理温度４０℃、回転式処理ブレード周速７５ｍ／ｓｅｃ、処理時間３分）。
【０１８９】
得られた球形化トナー粒子 １００質量部
シリコーンオイルで処理したＢＥＴ値が１３０ｍ^２／ｇであり、一次粒径が１２ｎｍの疎水性シリカ微粒子 ０．４質量部
シリコーンオイルで処理したＢＥＴ値が３０ｍ^２／ｇであり、一次粒径が５０ｎｍの疎水性シリカ微粒子 ０．４質量部
シリコーンオイルで処理したＢＥＴ値が８０ｍ^２／ｇであり、一次粒径が３０ｎｍの疎水性チタニア微粒子 ０．４質量部
をヘンシェルミキサー（三井三池化工機（株））で混合して、カラートナー（イエロートナー）Ｍ（重量平均粒径６．９μｍ）を得た。
【０１９０】
カラートナーの製造例１４：
Ｃ．Ｉ．ピグメントイエロー１７を７．０質量部の代わりに、Ｃ．Ｉ．ピグメントレッド１２２を７．０質量部としたこと以外は、カラートナーの製造例１３と同様にしてカラートナー（マゼンタトナー）Ｎ（重量平均粒径６．８μｍ）を得た。
【０１９１】
カラートナーの製造例１５：
Ｃ．Ｉ．ピグメントイエロー１７を７．０質量部の代わりに、Ｃ．Ｉピグメントブルー１５：３を６．５質量部用としたこと以外は、カラートナーの製造例１３と同様にしてカラートナー（シアントナー）Ｏ（重量平均粒径６．８μｍ）を得た。
【０１９２】
＜２＞黒色トナーの製造
黒色トナーの製造例１：
Ｃ．Ｉ．ピグメントイエロー１７を８．０質量部の代わりに、カーボンブラック１０質量部としたこと以外は、カラートナーの製造例１と同様にして黒色トナー（ブラックトナー）Ｐ（重量平均粒径７．０μｍ）を得た。
【０１９３】
黒色トナーの製造例２：
スチレン−ｎ−ブチルメタクリレート−ジビニルベンゼン共重合体１００質量部
（質量比７０：２９：１、Ｍｗ＝２８万）
磁性体（ＢＥＴ値７．５ｍ^２／ｇ） １００質量部
負荷電性制御剤（モノアゾ染料のＦｅ化合物） ０．５質量部
低分子ポリプロピレンワックス ３質量部
上記混合物を、１４０℃に加熱された２軸エクストルーダーで溶融混練し、冷却した混練物をハンマーミルで粗粉砕し、粗粉砕物をジェットミルで微粉砕し、得られた微粉砕粉を風力分級して磁性分級粉（磁性トナー粒子）（Ｔｇ６０℃）を得た。
【０１９４】
この磁性トナー粒子１００質量部と、シリコーンオイルで処理したＢＥＴ値が１３０ｍ^２／ｇであり、一次粒径が１２ｎｍの疎水性シリカ微粒子１．２質量部とをヘンシェルミキサー（三井三池化工機（株））で混合して、黒色トナーＱ（重量平均粒径７．３μｍ）を得た。
【０１９５】
＜３＞キャリア粒子の製造
キャリア粒子の製造例１：
下記材料及び水を４０℃に保ちながら、１時間混合を行った。
フェノール： ７．６質量部
ホルマリン溶液： １１．３質量部
（ホリムアルデヒド約４０％、メタノール約１０％、残りは水）
γ−グリシドキシプロピルトリメトキシシラン１．０質量％で親油化処理したマグネタイト微粒子： ５２．０質量部
（平均粒径０．２３μｍ、比抵抗４×１０^５Ω・ｃｍ）
γ−グリシドキシプロピルトリメトキシシラン１．０質量％で親油化処理したα
−Ｆｅ_２Ｏ_３微粒子： ３３．０質量部
（平均粒径０．５７μｍ、比抵抗２．２×１０^９Ω・ｃｍ）
【０１９６】
このスラリーに塩基性触媒としてアンモニア水、及び水をフラスコに入れ、攪拌・混合しながら４０分間で８５℃まで昇温・保持し、３時間反応させ、フェノール樹脂を生成し硬化させた。その後冷却し、水を添加した後上澄み液を除去し、沈殿物を水洗いし、減圧下で乾燥して、フェノール樹脂を結着樹脂としたマグネタイト微粒子含有球状磁性キャリアコア粒子を得た。
【０１９７】
この粒子を６０メッシュ及び１００メッシュの篩によって、粗大粒子の除去を行いキャリアコア粒子を得た。得られたキャリアコア粒子に対して、トルエン溶媒を用いて希釈したγ−アミノプロピルトリメトキシシラン０．４質量％でコア表面の処理を行った。引き続き、置換基が全てメチル基であるストレートシリコーン樹脂０．５質量％及び、γ−アミノプロピルトリメトキシシラン０．０２質量％の混合物をトルエンを溶媒としてコートした。更に、この磁性コートキャリアを１４０℃で焼き付け、１００メッシュの篩で凝集した粗大粒子をカットし、次いで多分割風力分級機で微粉及び粗粉を除去して粒度分布を調整し、体積平均粒径４０μｍの磁性コートキャリア粒子ａを得た。
【０１９８】
キャリア粒子の製造例２：
モル比で、Ｆｅ_２Ｏ_３＝４８モル％、ＣｕＯ＝２８モル％、ＺｎＯ＝２４モル％になる様に秤量し、ボールミルを用いて混合を行った。これを温度１０００℃で仮焼きした後、可焼成物をボールミルにより粉砕を行った。得られた粉末１００質量部ポリメタクリル酸ナトリウム０．５質量部及び水を湿式ボールミルに入れて混合し、スラリーを得た。得られたスラリーを、スプレードライヤーにより造粒を行った。これを温度１３００℃で焼結し、キャリアコア粒子を得た。得られたキャリアコア粒子の抵抗を測定したところ、４．５×１０^８Ω・ｃｍであった。
【０１９９】
このキャリアコア粒子の表面に熱硬化性のシリコーン樹脂が１２質量％となるようにコートした。この磁性コートキャリア粒子を２５０℃で１時間キュアし、解砕した後１００メッシュの篩で分級して、体積平均粒径４６μｍの磁性コートキャリア粒子ｂを得た。
【０２００】
＜４＞画像形成装置
次に、実施例１〜９及び比較例１〜２において用いられる画像形成装置について説明する。
【０２０１】
実施例１〜９及び比較例１〜２の画像評価を行う評価機としては、図２に示すようにキヤノン製カラーレーザーコピア５００の改造機を用いることとした。現像手段として感光体に対しロータリー型の現像装置を配置したものに改造し、ロータリー型現像装置の４ステーションのうち、実施例４以外は（（ｂ）、（ｃ）、（ｄ））をカラートナー現像のための二成分現像装置、１ステーション（ａ）を磁性トナーを現像するための磁性一成分現像（ジャンピング）現像装置になるよう改造した。実施例４に関しては、全てのステーションを非磁性二成分現像装置に改造した。さらに、（（ｂ）、（ｃ）、（ｄ））のカラートナー現像のための二成分現像装置は、現像器の公転に伴い、現像剤が徐々に排出する構成、いわゆるトリクル現像方式ができるように改造した。
【０２０２】
転写工程においては、中間転写ベルトを用い、中間転写体上で多層の現像像を形成し転写材上に一括転写する手段とし、本実施例に用いるカラー画像形成装置にした。
【０２０３】
（二成分現像装置）
現像スリーブとしてアルミコートスリーブを使用し、スリーブとａ−Ｓｉドラム間を４５０μｍに設定した。現像に使用する交流バイアスはピークトゥピークの電界強度で１３００Ｖｐｐ、周波数は２０００Ｈｚとした。
【０２０４】
（一成分現像装置）
現像スリーブとしてアルミコートスリーブを使用し、スリーブとａ−Ｓｉドラム間を２８０μｍに設定した。現像に使用する、交流バイアスはピークトゥピークの電界強度で１３００Ｖｐｐ、周波数は２０００Ｈｚとした。
【０２０５】
さらに、帯電工程として非接触型のコロナ帯電方式を使用し、印加電圧条件としては交流電界を使用した。
【０２０６】
現像コントラストは２００Ｖに設定した。
【０２０７】
［実施例１］
カラートナーＡ、カラートナーＢ、カラートナーＣをそれぞれ８質量部とキャリアａ９２質量部を秤量し各々をＶ型混合機で混合し、カラー現像剤Ａ、Ｂ、Ｃとし、黒色トナーＱを黒色現像剤Ｑとした。それぞれの現像剤を図２に記載の４ステーションを有する画像形成装置に各々投入し、各々のステーションに対応する補給用現像剤ををそれぞれ補給しながら、画像面積３０％のオリジナル原稿を使用し、２２０ｍｍ／ｓｅｃの画像形成速度（プロセススピード）、スリーブ周速をプロセススピード×１．５倍の速度で、高温高湿環境下（３０℃，８０％ＲＨ）にてフルカラー２０００枚、Ｂｋ単色８０００枚を１サイクルとした画出し試験を５０サイクル行ない、合計５０万枚の画出し試験を行った。
【０２０８】
ここで、補給用現像剤は、カラートナーＡ、カラートナーＢ、カラートナーＣをそれぞれ１０質量部とキャリアａ１質量部を秤量し各々をＶ型混合機で混合し、補給用シアン現像剤Ａ、補給用現像剤Ｂ補給用現像剤Ｃとした。黒色トナーに関しては、現像器の公転に伴い、現像剤が徐々に排出しないよう、排出口をふさぎ、補給にあたっては、トナーのみを補給した。
【０２０９】
そして、感光体表面へのトナー融着、転写効率、帯電安定性、画像濃度、トナー飛散、カブリに関して、以下の評価方法に基づいて評価したところ、良好な結果が得られた。評価結果を表１に示す。尚、下記評価結果Ａ〜Ｆにおいて、Ａ〜Ｃまでを実用レベルとした。
【０２１０】
（感光体表面へのトナー融着）
感光体表面へのトナー融着については、耐久５０万枚時点で、黒色トナーで出力したベタ黒画像における白ポチの数で評価した。評価基準は以下のとおりである。
Ａ：全く融着しない
Ｂ：Ａ４ベタ黒中に１〜３点の融着
Ｃ：Ａ４ベタ黒中に４〜６点の融着
Ｄ：Ａ４ベタ黒中に７〜９点の融着
Ｅ：Ａ４ベタ黒中に１０〜１５点の融着
Ｆ：Ａ４ベタ黒中に１６点以上の融着
【０２１１】
（転写効率）
転写効率の評価は、５０万枚の複写テストを行なった後、感光体ドラム上にベタ黒画像を形成し、そのベタ黒画像を透明な粘着テープで採取し、その画像濃度（Ｄ１）をカラー反射濃度計（ｃｏｌｏｒ ｒｅｆｌｅｃｔｉｏｎ ｄｅｎｓｉｔｏｍｅｔｅｒ Ｘ−ＲＩＴＥ ４０４Ａ ｍａｎｕｆａｃｔｕｒｅｄ ｂｙ Ｘ−Ｒｉｔｅ Ｃｏ．）で測定した。次に再度、ベタ黒画像を感光体ドラム上に形成し、ベタ黒画像を記録材へ転写し、記録材上に転写されたベタ黒画像を透明な粘着テープで採取し、その画像濃度（Ｄ２）を測定した。転写効率は、得られた画像濃度（Ｄ１）及び（Ｄ２）から下式に基づいて算出した。
転写効率（％）＝（Ｄ２／Ｄ１）×１００
【０２１２】
（帯電安定性）
帯電安定性は、５０万枚の複写テストを行ない、現像剤の帯電量変化から帯電安定性を評価した。評価は、１０００枚複写時の帯電量と終了時の帯電量の変化幅を％で表わし、以下の基準で行なった。
Ａ：帯電量の変化幅が１０％未満
Ｂ：帯電量の変化幅が１０〜２０％未満
Ｃ：帯電量の変化幅が２０〜３０％未満
Ｄ：帯電量の変化幅が３０〜４０％未満
Ｅ：帯電量の変化幅が４０〜５０％未満
Ｆ：帯電量の変化幅が５０％以上
【０２１３】
（トナー飛散）
トナー飛散は、５０万枚画出しの後、現像器を取り出し、空回転機にセットする。現像器のスリーブ真下を中心にＡ４の紙を置き、１０分間の空回転を行ない、紙上に落ちたトナーの質量を測定し、以下の基準により評価した。
Ａ：３ｍｇ未満
Ｂ：３〜６ｍｇ未満
Ｃ：６〜９ｍｇ未満
Ｄ：９〜１２ｍｇ未満
Ｅ：１２〜１５ｍｇ未満
Ｆ：１５ｍｇ以上
【０２１４】
（カブリ）
カブリに関しては、高温高湿下で反射濃度計（ｄｅｎｓｉｔｏｍｅｔｅｒ ＴＣ６ＭＣ：（有）東京電色技術センター）を用いて、白紙の反射濃度、及び５０万枚目の画像における非画像部の反射濃度を測定し、両者の反射濃度の差を白紙の反射濃度を基準として評価した。
Ａ：０．５％未満
Ｂ：０．５〜１．０％未満
Ｃ：１．０〜１．５％未満
Ｄ：１．５〜２．０％未満
Ｅ：２．０〜４．０％未満
Ｆ：４．０％以上
【０２１５】
（画像濃度）
画像濃度は、初期及び５０万枚の複写終了後にベタ黒画像を複写し、その濃度を、カラー反射濃度計（Ｃｏｌｏｒ ｒｅｆｌｅｃｔｉｏｎ ｄｅｎｓｉｔｏｍｅｔｅｒ Ｘ−ＲＩＴＥ ４０４Ａ ｍａｎｕｆａｃｔｕｒｅｄ ｂｙ Ｘ−Ｒｉｔｅ Ｃｏ．）で測定した。
【０２１６】
［実施例２］
表１に示した条件になるように現像剤、補給用現像剤にすることを除いては実施例１と同様に画出し試験を行なったところ、カラートナーの画像特性が実施例１と比較して若干悪化したものの実用上問題無い結果が得られた。評価結果を表１に示す。
【０２１７】
若干悪化した原因は、３種類の無機微粒子が全て異なった元素を含んでいたために、帯電分布がブロードになってしまったためであると推測している。
【０２１８】
［実施例３］
表１に示した条件になるように現像剤、補給用現像剤にすることを除いては実施例１と同様に画出し試験を行なったところ、カラートナーの画像特性が実施例１と比較して若干悪化したものの実用上問題無い結果が得られた。評価結果を表１に示す。若干悪化した原因は、帯電助剤としての役割が充分でなかったことと、材料的にトナーへの付着力が弱く、耐久試験に伴い、遊離が進み、スペーサーとしての機能が低下していってしまったためであると推測している。
【０２１９】
［実施例４］
表１に示した条件になるように現像剤、補給用現像剤にすることを除いては実施例１と同様に画出し試験を行なったところ、トナー融着が実施例１と比較して若干悪化したものの実用上問題無い結果が得られた。評価結果を表１に示す。若干悪化した原因は、磁性トナーが無くなったことで感光体上に付着した融着物の研磨効果がなくなってしまったためであると推測している。
【０２２０】
［実施例５］
表１に示した条件になるように現像剤、補給用現像剤にすることを除いては実施例１と同様に画出し試験を行なったところ、カラートナーの転写効率及びカブリが実施例１と比較して若干悪化したものの実用上問題無い結果が得られた。評価結果を表１に示す。若干悪化した原因は、粉砕法による球形化度の低下と、耐久により微粉の蓄積が進んでしまったためであると推測している。
【０２２１】
［実施例６］
表１に示した条件になるように現像剤にし、現像器の公転に伴い、現像剤が徐々に排出しないよう、排出口をふさぎ、補給にあたっては、トナーのみを補給しながら実施例１と同様に試験を行なったところ、トナーのみを補給しながら実施例１と同様に試験を行なったところ、カラートナーの画像特性が実施例１と比較して若干悪化したものの実用上問題無い結果が得られた。評価結果を表１に示す。若干悪化した原因は、キャリアの入れ替わりが無く、フレッシュなキャリアが補給されなかったため、試験が進むにつれてキャリアへのトナースペントといったキャリア劣化が進んでしまったためであると推測している。
【０２２２】
［実施例７］
表１に示した条件になるように現像剤にし、現像器の公転に伴い、現像剤が徐々に排出しないよう、排出口をふさぎ、補給にあたっては、トナーのみを補給しながら実施例１と同様に試験を行なったところ、カラートナーの画像特性が実施例１と比較して若干悪化したものの実用上問題無い結果が得られた。評価結果を表１に示す。若干悪化した原因は、キャリアの入れ替わりが無く、フレッシュなキャリアが補給されなかったことと、キャリアの真比重および磁気特性が高いために、剤圧縮が高くなったことでトナー自身の劣化やキャリアへのトナースペントを引き起こしたためであると推測している。
【０２２３】
［実施例８］
表１に示した条件になるように現像剤、補給用現像剤にすることを除いては実施例１と同様に画出し試験を行なったところ、良好な結果が得られた。評価結果を表１に示す。但し、補給用現像剤ボトル及び廃現像剤容器の交換回数が多かったため、ランニングコストｕｐの要因となる。
【０２２４】
［実施例９］
表１に示した条件になるように現像剤、補給用現像剤にすることを除いては実施例１と同様に画出し試験を行なったところ、カラートナーの画像特性が実施例１と比較して若干悪化したものの実用上問題無い結果が得られた。評価結果を表１に示す。若干悪化した原因は、補給された現像剤中のキャリア量が少なかったために、フレッシュなキャリアが充分に供給されなかったためであると推測している。
【０２２５】
［比較例１］
表２に示した条件になるように現像剤、補給用現像剤にすることを除いては実施例１と同様に画出し試験を行なったところ、カラートナーの画像特性が悪化した。評価結果を表２に示す。これは、無機微粒子の機能のうち帯電助剤機能が足りないため、初期剤の帯電が必要以上にチャージアップし、補給された現像剤の帯電立ち上がりが耐久が進むにつれて、うまく立ち上がらなくなってしまったためと推測している。
【０２２６】
［比較例２］
表２に示した条件になるように現像剤、補給用現像剤、ドラムにすることを除いては実施例１と同様に画出し試験を行なったところ、１０万枚時点で画像欠陥が多発したため試験を終了した。評価結果を表２に示す。これは、削れによりＯＰＣドラムの膜厚が足りなくなってしまったために起きた問題であると推測している。
【０２２７】
【表１】

【０２２８】
【表２】

【０２２９】
【発明の効果】
本発明によれば、あらゆる環境においても、また高速でのフルカラー画像形成においても、長期に渡り安定した画像を得ることができる。
【図面の簡単な説明】
【図１】アモルファスシリコン感光体の模式的構成図である。
【図２】ロータリー回転方式の現像装置、中間転写体を備えた画像形成装置の構成図である。
【図３】現像装置の現像器の断面図である。
【図４】現像装置の拡大構成図である
【符号の説明】
１００ アモルファスシリコン感光体
１０１ 支持体
１０２ 感光層
１０３ 光導電層
１０４ アモルファスシリコン系表面層
１０５ 電荷注入阻止層
１０６ 電荷発生層
１０７ 電荷輸送層
Ｌ レーザ光
Ｐａ〜Ｐｄ 画像形成ユニット
Ｒ１ 現像剤室
Ｒ２ 撹拌室
Ｒ３ 補給用現像剤収容室
Ｔ 二成分現像剤
Ｔａ トナー
１ 静電潜像担持体
２、３、４、５ 現像器
２ａ、３ａ、４ａ、５ａ、９９ａ、９９ｄ 補給用現像剤収容容器
６ 現像スリーブ
７ 規制部材
８ マグネットローラ
９、６６ａ 補給用現像剤収容装置
１０ 現像剤搬送スクリュー
１１ 現像剤搬送スクリュー
１２ 転写材
１３ 現像器交換体
１４ 露光装置
１５ 帯電装置
１５ａ 帯電ローラ
１６ 除電装置
１７ 現像槽
１８ クリーニング装置
２０ 搬送ベルト
２１、７０ 定着装置
２３ クリーニング装置
２５ 一度レジストレーションローラ
２６ 給送トレイ
２８ 送出ローラ
３４ 現像器側現像剤排出口
３６ 現像剤回収オーガ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming method used in a recording method using an electrophotographic method, an electrostatic recording method, or the like. More specifically, the present invention relates to an image forming method used for a copying machine, a printer, and a facsimile that forms an image by forming a toner image on an amorphous silicon electrostatic latent image carrier and transferring the toner image onto a transfer material.
[0002]
[Prior art]
In recent years, devices using electrophotography have been applied to devices such as fax machines and printers in addition to conventional copying machines. As the range of devices has expanded, demands for higher speed, longer life, higher stability, and full color have become stronger.
[0003]
Above all, the needs for full-color electrophotography are increasing, such as the output of maps, design pictures, photographs, etc., and excellent in color reproduction, without crushing or breaking down to the details, and extremely fine And it is required to be faithfully reproduced.
[0004]
On the other hand, a full-color image device requires processing such as reading of a color image, transfer of large image data, and switching of a developing device as compared with a monochrome image device, and the output speed of the image is slow. In most cases, the output is monochrome, and the output frequency in full color is low.
[0005]
However, even in ordinary offices, full-color images, which contain more information than monochrome images, are indispensable for creating easy-to-understand images and materials using transparency sheets for overhead projectors (hereinafter abbreviated as "OHT"). It is becoming something. In addition, there is a need for faster and more stable systems. In such a situation, monochrome electrophotographic devices with high durability and high reliability are equipped with full-color functions (including improved OHT transparency). Such an electrophotographic apparatus is desired.
[0006]
Therefore, the development of mounting amorphous silicon photoconductors, which are extremely excellent in stability and wear resistance, and most suitable for ultra-high-speed heavy-duty machines, on full-color electrophotographic devices is under way. Considering the development situation, it is considered that a combination with the development of non-magnetic toner is required.
[0007]
The amorphous silicon photoreceptor has a photoconductor's unique high hardness characteristics and a jumping method using magnetic toner that has been put to practical use. Is what it is.
[0008]
Patent Literature 1 discloses an image forming method using an amorphous silicon drum and a high-resistance carrier. However, Japanese Patent Application Laid-Open No. H11-163,972 aims to reduce carrier adhesion and fog even in an amorphous silicon drum having a relatively low resistance and to achieve a long life, but from the toner side conscious of color reproducibility in a full-color image. Approach has not been made, leaving room for improvement.
[0009]
Patent Document 2 proposes to apply an amorphous silicon drum for black toner and an OPC drum for other color toners with respect to the configuration of a full-color image forming apparatus. However, Patent Document 2 provides an image forming apparatus having long-term reliability by applying an amorphous silicon drum to frequently used black toner, and does not have long-term reliability for full-color images. Some improvement is needed.
[0010]
Patent Literature 3 discloses an image forming method and apparatus using an amorphous silicon drum and a non-magnetic developer. However, Patent Document 3 aims at achieving high definition, high image quality, and improving durability while achieving both color reproducibility and drum life. Therefore, Patent Document 3 aims at improving toner particle size, colorant, binder resin, carrier particle size, and the like. However, approaches from other additives and carrier materials have not been made. Further, there is still room for improvement with respect to ever-increasing demands from users, such as output of higher-definition images, prolongation of life, achievement of high stability, and reduction of running cost due to high transfer efficiency.
[0011]
[Patent Document 1]
JP-A-09-281806
[Patent Document 2]
JP-A-11-24358
[Patent Document 3]
JP-A-2002-023443
[0012]
[Problems to be solved by the invention]
An object of the present invention is to solve the above-mentioned problems of the conventional technology. That is, an object of the present invention is to provide an image forming method capable of obtaining a stable image throughout the life of the main body in any environment.
[0013]
It is a further object of the present invention to provide an image forming method capable of obtaining a stable image even in high-speed full-color image formation.
[0014]
A further object of the present invention is to provide an image forming method capable of providing an image without toner fusion to a photosensitive drum for a long period of time.
[0015]
A further object of the present invention is to provide an image forming method capable of providing a good full-color image free of fog and scattering for a long period of time.
[0016]
A further object of the present invention is to provide an image forming method capable of obtaining good light transmittance when using OHT.
[0017]
It is a further object of the present invention to provide an image forming method with high developability, high transfer efficiency and low running cost.
[0018]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors have found that the above-mentioned problem can be solved by the following image forming method, and have completed the present invention.
That is, the present invention is as follows.
[0019]
(1) A black developer composed of a toner containing at least a binder resin and a colorant, and a color toner containing at least a binder resin, a colorant, and inorganic fine particles. An image forming method comprising selecting and developing one or more colors of a yellow developer, a magenta developer, and a cyan developer, wherein the inorganic fine particles contain at least three types of inorganic fine particles. Forming method.
[0020]
(2) The image forming method according to (1), wherein the inorganic fine particles are at least selected from silica, titanium oxide, alumina, strontium titanate, and magnesium oxide, and contain or do not contain the same element.
[0021]
(3) The image forming method according to (1) or (2), wherein at least two of the inorganic fine particles are the same element.
[0022]
(4) The image forming method according to any one of (1) to (3), wherein the black developer contains magnetic particles.
[0023]
(5) The yellow color developer, the magenta color developer, and the cyan color developer are a yellow two-component developer, a magenta two-component developer, and a cyan two-component developer containing a carrier. The image forming method according to any one of (1) to (4), wherein
[0024]
(6) The image forming method according to (5), wherein the carrier is a magnetic material-dispersed carrier in which metal compound particles are dispersed in a binder resin.
[0025]
(7) After the visible color developed image formed on the electrostatic latent image carrier is transferred and carried on the intermediate transfer body, and all the color developed images are superimposed and transferred on the intermediate transfer body, The image forming method according to any one of (1) to (6), wherein the image forming method is an intermediate transfer method that performs batch transfer to a transfer material.
[0026]
(8) The image forming method according to any one of (1) to (7), wherein the process speed is 200 mm / sec or more.
[0027]
(9) The development according to (1) to (8), wherein the color toner is developed while replenishing a yellow replenishing developer, a magenta replenishing developer, and a cyan replenishing developer comprising a color toner and a carrier. Replenishing developer for image forming method.
[0028]
(10) The replenishing developer is contained in an amount of 2 to 50 parts by mass of a toner selected from the group consisting of a yellow toner, a magenta toner, and a cyan toner with respect to 1 part by mass of carrier particles. The replenishing developer according to (9), wherein
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail by showing embodiments of the present invention.
[0030]
The image forming method of the present invention uses an amorphous silicon photoreceptor as a photoreceptor and contains three or more types of inorganic fine particles as toners of a color developer of a yellow developer, a magenta developer, and a cyan developer. A major feature is that toner is applied.
[0031]
Amorphous silicon drums are characterized by high hardness, less abrasion of the drum as occurs in OPC, and excellent durability. It also has the advantage that dot reproducibility is good and high quality images can be obtained.
[0032]
However, the amorphous silicon drum has a problem that image deletion occurs under a high-temperature and high-humidity condition and a surface potential changes due to a temperature change. In order to solve this, a control is performed in which a drum heater is inserted inside the photoconductor to keep the temperature constant.
[0033]
On the other hand, the full-color image forming apparatus has a configuration in which toners of respective colors are multi-fixed. Therefore, particularly by setting the softening point of the color toner low, the color mixing property of the fixing device is increased, and the color reproducibility is improved.
[0034]
When such a toner having a low softening point is used in a high-speed full-color image forming apparatus, a mechanical share is large in a contact portion between a cleaner unit, a transfer unit roller and a photoconductor, and a calorific value of the photoconductor is also increased. And the toner easily melts on the photoreceptor.
[0035]
In particular, when the temperature of the photoconductor is controlled by a drum heater, the problem is more conspicuous, and there is a problem of adhesion of the toner to the photoconductor and a problem of filming in which the toner resin is uniformly deposited on the surface of the photoconductor. Occurred.
[0036]
Therefore, even when an amorphous silicon drum is used, maintenance of the photoconductor is required, and the advantage of the long life of the amorphous silicon drum cannot be fully obtained.
[0037]
In such a system, a toner containing three or more types of inorganic fine particles is used as a toner of a color developer such as a yellow developer, a magenta developer, and a cyan developer, so that the toner is fused to a photoconductor. It has been found that color reproducibility in fixing can be achieved while suppressing the problem described above.
[0038]
In addition, an amorphous silicon drum is more difficult to obtain a high surface potential (charge potential) than an OPC drum. For this reason, particularly when used in a high-speed full-color image forming apparatus, a high-density image cannot be obtained, and a sufficiently high-quality image cannot be provided.
[0039]
Using a toner containing three or more types of inorganic fine particles as a toner for a yellow developer, a magenta developer, and a cyan developer, it is possible to exhibit high developability even in low potential development. Was.
[0040]
In addition, other advantages such as reduced running cost due to high transfer efficiency, good cleaning performance, and less fogging and scattering even in high-speed development can be found, and good color images can be obtained for long-term use and high-speed full-color image forming equipment. We found that the output was stable. Further, the transmittance of the OHT sheet was also good.
[0041]
Although the reason for each of these effects is not clear, it is thought that the function separation of each inorganic fine particle was successfully achieved. In other words, one of them is a spacer particle that appropriately reduces the cohesion or adhesion between toner-toner, toner-carrier, toner-drum, etc. to prevent toner deterioration due to packing and suppress carrier deterioration. And reduce drum fusion and improve transfer efficiency. One is that as a fluidity imparting agent, the role of improving the mixing property of the developer, maintaining an appropriate charge amount even in long-term image output, and improving the recoverability of transfer residual toner by a cleaner, and First, as a charge control agent, a role for obtaining a desired charge amount, or as a polishing agent utilizing the characteristics of amorphous silicon which is strong against abrasion, the toner is interposed in a cleaner portion to lightly polish the surface of the drum. It has a role of removing the fused material. As described above, in the system using the amorphous silicon drum, features not found in the OPC drum can be seen. Therefore, by clarifying the respective roles as in the present invention, long-term maintenance of high image quality can be achieved. It seems to have led to
[0042]
<1> Developer in the present invention
The color developer (yellow developer, magenta developer, cyan developer) used in the image forming method of the present invention is a toner containing at least a binder resin, a colorant, and inorganic fine particles.
[0043]
The inorganic fine particles used in the present invention will be described.
[0044]
In the present invention, the color toner contains inorganic fine particles, and the inorganic fine particles preferably have a primary average particle size of 4 to 80 nm.
[0045]
The specific surface area by nitrogen adsorption measured by the BET method is 10 m.²/ G or more, especially 30 to 400 m²/ G is preferable because it can give good results.
[0046]
It is more preferable that the inorganic fine particles are subjected to a hydrophobic treatment in order to keep the charge amount of the toner particles high even under a high humidity environment and to prevent toner scattering.
[0047]
As the hydrophobic treatment of the inorganic fine particles, for example, as a first step reaction, a silylation reaction is performed with a silane coupling agent or the like to eliminate silanol groups by chemical bonding, and a hydrophobic thin film is formed on the surface with silicone oil. The method is applicable.
[0048]
Examples of the silane coupling agent used in the hydrophobic treatment include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, and allylphenyldichlorosilane. , Benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilanemercaptan, trimethylsilylmercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, Dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyl Examples include tetramethyldisiloxane and 1,3-diphenyltetramethyldisiloxane.
[0049]
Preferred silicone oils have a viscosity of about 30 to 1,000 mm at 25 ° C.²/ S (cSt), for example, dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, fluorine-modified silicone oil and the like are preferable.
[0050]
In the method of treating silicone oil, for example, inorganic fine particles treated with a silane coupling agent and silicone oil may be directly mixed using a mixer such as a Henschel mixer, or silicone oil may be injected into the inorganic fine particles serving as a base. It is good depending on the method. Alternatively, it may be prepared by dissolving or dispersing silicone oil in a suitable solvent, mixing with a base inorganic fine particle, and removing the solvent.
[0051]
As the inorganic fine particles used in the present invention, fine particles such as silica, titanium oxide, alumina, strontium titanate, and magnesium oxide can be preferably used.
[0052]
Further, the color toner used in the present invention includes, for example, a lubricant powder such as a polyfluoroethylene powder, a zinc stearate powder, and a polyvinylidene fluoride powder; or an abrasive such as a cerium oxide powder, a silicon carbide powder, and a strontium titanate powder; In addition, for the purpose of improving cleaning properties, such as spherical silica particles, inorganic or organic fine particles having a primary particle diameter of more than 30 nm close to inorganic or organic spherical particles, such as fine particles of medium to large particle diameter, other organic particles of opposite polarity, and inorganic particles. A small amount can be used as a developability improver. These additives can also be used after the surface is hydrophobized.
[0053]
For example, as the silica fine particles, both a so-called dry method produced by vapor phase oxidation of a silicon halide or a so-called dry silica called a fumed silica, and a so-called wet silica produced from water glass or the like can be used. However, there are few silanol groups on the surface and inside the silica fine particles, and Na₂O, SO₃ ^2-Dry silica with less production residue such as is preferred. In the case of fumed silica, it is also possible to obtain a composite fine powder of silica and another metal oxide by using another metal halide such as aluminum chloride and titanium chloride together with a silicon halide in the production process. Is also included.
[0054]
The total amount of the inorganic fine particles is preferably from 0.1 to 3.0 parts by mass with respect to 100 parts by mass of the color toner particles. When the amount exceeds 0.0 parts by mass, the fixing property is deteriorated.
[0055]
The color toner used in the present invention contains three or more types of inorganic fine particles, but may contain the same element, or all inorganic fine particles may be made of different elements. Preferably, when at least two of the three types are made of the same element, the charge distribution is easily maintained sharp, fog and scattering are not caused, and high image quality can be stably obtained over a long period of time.
[0056]
The inorganic fine particles may be added internally or externally to the toner. However, it is preferable that the inorganic fine particles be present near the surface of the toner by externally adding to prevent the toner from being fused to the amorphous silicon drum. In addition, it is easy to obtain the effects of maintaining high developing performance and high transferability, toner scattering, and fog reduction.
[0057]
At least one of the three types of inorganic fine particles has a relatively small specific surface area due to nitrogen adsorption measured by the BET method, that is, 10 to 60 m.²/ G is preferable in order to obtain high developability and high transferability and maintain high image quality due to long-term durability.
[0058]
At least one of the three types of inorganic fine particles has a relatively large specific surface area by nitrogen adsorption measured by the BET method, that is, 100 to 400 m.²/ G is preferable because the effect of reducing toner scattering and fogging can be easily obtained.
[0059]
Hereinafter, the production of the color toner particles and the color toner, the material of the color toner used in the production, and the like will be described.
[0060]
The color toner in the present invention is preferably a toner having a weight average particle diameter of 3 to 10 μm. When a toner having a particle size of less than 3 μm is used, the fluidity tends to deteriorate particularly in a low humidity environment. Further, the toner itself has low handling properties as a powder. If it exceeds 10 μm, the toner and the carrier tend to be separated particularly under high temperature and high humidity. Further, in terms of developability, since one toner particle is large, it is difficult to obtain a high-resolution and dense image. Further, when electrostatic transfer is performed, scattering of toner is likely to occur.
[0061]
The weight average particle size of the toner can be determined, for example, as follows.
[0062]
To 100 to 150 ml of pure water, 1 to 5 ml of a surfactant (for example, an alkylbenzene sulfonate) is added, and 2 to 20 mg of a measurement sample is added thereto. The electrolytic solution in which the sample is suspended is subjected to dispersion treatment for 1 to 3 minutes with an ultrasonic disperser, and the weight average particle diameter is measured using a laser scan particle size distribution analyzer CIS-100 (manufactured by GALAI).
[0063]
The color toner according to the present invention preferably contains a release agent, and by incorporating an appropriate amount of wax as the release agent, it is possible to achieve both high resolution and offset resistance while melting the toner onto the photoreceptor. It is possible to prevent wearing.
[0064]
Examples of the wax that can be used for the color toner according to the present invention include petroleum waxes such as paraffin wax, microcrystalline wax, petrol tact and derivatives thereof, montan wax and derivatives thereof, and hydrocarbon waxes and derivatives thereof by the Fischer-Tropsch method. Polyolefin wax represented by polypropylene and polyethylene and its derivatives, carnauba wax, natural wax such as candelilla wax and its derivatives, etc. Derivatives include oxides, block copolymers with vinyl monomers, and graft modified products . Furthermore, higher fatty alcohols, fatty acids such as stearic acid and palmitic acid, or compounds thereof, acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, vegetable waxes, animal waxes and the like can also be used. In the present invention, ester waxes represented by the following general formulas (I) to (VI) are preferably used.
[0065]
Embedded image

(Where a and b are integers from 0 to 4, and a + b is 4. R₁And R₂Is an organic group having 1 to 40 carbon atoms. m and n are integers from 0 to 25, and m and n do not become 0 at the same time. )
[0066]
Embedded image

(Where a 'and b' are integers of 0 to 3, and a '+ b' is 1 to 3. R₁’And R₂′ Is an organic group having 1 to 40 carbon atoms;₁’And R₂Is 3 or more. R₃Is a hydrogen atom and an organic group having 1 or more carbon atoms. However, when a '+ b' = 2, R₃Is an organic group having 1 or more carbon atoms. k is an integer of 1 to 3. m 'and n' are integers from 0 to 25, and m 'and n' do not become 0 at the same time. )
[0067]
Embedded image

(Where R₄And R₆Is an organic group having 6 to 32 carbon atoms;₄And R₆May or may not be the same. R₅Represents an organic group having 1 to 20 carbon atoms. )
[0068]
Embedded image

(Where R₇And R₉Is an organic group having 6 to 32 carbon atoms;₇And R₉May or may not be the same. R₈Is one of the following:
[0069]
Embedded image

(In the formula, x represents an integer of 1 to 10, and y represents an integer of 1 to 20.)
[0070]
Embedded image

(In the formula, c is an integer of 0 to 4, d is an integer of 1 to 4, and c + d is 4. R₁₀Is an organic group having 1 to 40 carbon atoms. z and w are integers of 0 to 25, and z and w do not become 0 at the same time. )
[0071]
Embedded image

(Where R₁₁And R₁₂Represents the same or different hydrocarbon groups having 15 to 45 carbon atoms. )
[0072]
In the color toner according to the image forming method of the present invention, the content of these wax components is preferably in the range of 0.5 to 25 parts by mass with respect to 100 parts by mass of the binder resin. If the content is less than 0.5 part by mass, the effect of suppressing fusion of the toner to the photoreceptor is poor. This leads to deterioration of toner fluidity and image characteristics.
[0073]
When the color toner particles according to the present invention are produced by a pulverization method, the binder resin may be a homopolymer of styrene or a substituted product thereof such as polystyrene and polyvinyl toluene; a styrene-propylene copolymer, and a styrene-vinyl toluene copolymer. Copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-acrylic acid Dimethylaminoethyl copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether Copolymer, styrene-vinyl Styrene copolymers such as tyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer Coalescing: Polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacryl resin and the like can be used alone or in combination. In particular, styrene-based copolymers and polyester resins are preferred in view of development characteristics, fixability and the like.
[0074]
When the color toner according to the present invention is produced by a polymerization method, the polymerizable monomers constituting the binder resin component include the following.
[0075]
Styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene and p-ethylstyrene; methyl acrylate, ethyl acrylate, n-butyl acrylate, acrylic acid Acrylic esters such as isobutyl, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate; methyl methacrylate, methacrylic acid Ethyl, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethyl methacrylate Aminoethyl, methacrylic acid esters such as diethylaminoethyl methacrylate; and other acrylonitrile, methacrylonitrile, and the like monomers acrylamide. These monomers can be used alone or in combination. Among the above-mentioned monomers, it is preferable to use styrene or a styrene derivative alone or in combination with another monomer, from the viewpoint of the development characteristics and durability of the color toner.
[0076]
In the present invention, the color toner preferably contains a polyester resin.
[0077]
According to the study of the present inventors, the strength of the toner surface is increased by adding a polyester resin, and when an additive such as inorganic fine particles is externally added together with the color toner particles, the inorganic fine particles on the surface of the toner particles are Has a greater effect of preventing the toner from being buried in the toner particles due to long-term durability, thereby preventing a decrease in image density due to long-term durability.
[0078]
The polyester resin preferably has a weight average molecular weight (Mw) of 6,000 to 100,000. If the Mw is less than 6000, the effect of preventing the external additive from being buried in the toner particles is small, and the effect of preventing the image density from decreasing due to the durability is not observed. On the other hand, when Mw exceeds 100,000, the dispersion of the condensation resin in the toner particles deteriorates, and the particle size distribution of the finally obtained toner becomes broad.
[0079]
In both cases of the polymerization method and the pulverization method, the glass transition temperature (Tg) of the binder resin is preferably from 40 to 70 ° C, more preferably from 45 to 65 ° C. These can be used alone or in general so that the theoretical glass transition temperature (Tg) described in the published Polymer Handbook, 2nd edition III-p 139 to 192 (manufactured by John Wiley & Sons) is 40 to 70 ° C. It is used by being appropriately mixed.
[0080]
The color toner according to the invention contains a colorant to impart coloring power. The organic pigments or dyes preferably used in the present invention include the following.
[0081]
As an organic pigment or organic dye as a cyan colorant, a copper phthalocyanine compound and its derivative, an anthraquinone compound, a basic dye lake compound and the like can be used. Specifically, C.I. I. Pigment Blue 1, C.I. I. Pigment Blue 7, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 1, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 15: 4, C.I. I. Pigment Blue 60, C.I. I. Pigment Blue 62, C.I. I. Pigment Blue 66 and the like.
[0082]
As organic pigments or organic dyes as magenta colorants, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds are used. . Specifically, 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 Violet 19, C.I. I. Pigment Red 23, C.I. I. Pigment Red 48: 2, C.I. I. Pigment Red 48: 3, C.I. I. Pigment Red 48: 4, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 81: 1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 144, C.I. I. Pigment Red 146, C.I. I. Pigment Red 166, C.I. I. Pigment Red 169, C.I. I. Pigment Red 177, C.I. I. Pigment Red 184, C.I. I. Pigment Red 185, C.I. I. Pigment Red 202, C.I. I. Pigment Red 206, C.I. I. Pigment Red 220, C.I. I. Pigment Red 221, C.I. I. Pigment Red 254 and the like.
[0083]
As the organic pigment or organic dye as a yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, allylamide compounds are used. Specifically, 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 62, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 83, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I. Pigment Yellow 95, C.I. I. Pigment Yellow 97, C.I. I. Pigment yellow 109, C.I. I. Pigment Yellow 110, C.I. I. Pigment yellow 111, C.I. I. Pigment yellow 120, C.I. I. Pigment Yellow 127, C.I. I. Pigment Yellow 128, C.I. I. Pigment yellow 129, C.I. I. Pigment yellow 147, C.I. I. Pigment yellow 151, C.I. I. Pigment yellow 154, C.I. I. Pigment yellow 168, C.I. I. Pigment Yellow 174, C.I. I. Pigment yellow 175, C.I. I. Pigment yellow 176, C.I. I. Pigment yellow 180, C.I. I. Pigment Yellow 181, C.I. I. Pigment Yellow 191, C.I. I. Pigment Yellow 194 and the like.
[0084]
These colorants can be used alone or as a mixture or in the form of a solid solution. The colorant used in the color toner of the present invention is selected from the viewpoints of hue angle, saturation, brightness, light fastness, OHP transparency, and dispersibility in the toner.
[0085]
The colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the binder resin.
[0086]
The color toner according to the present invention may contain a charge control agent for stabilizing the charge characteristics. As the charge control agent, a known charge control agent can be used. In particular, a charge control agent having a high charging speed and capable of stably maintaining a constant charge amount is preferable. Further, when a color toner is produced by a polymerization method, a charge control agent having a low polymerization inhibitory property and having substantially no solubilized substance in an aqueous dispersion medium is particularly preferable. Specific compounds include salicylic acid as a negatively chargeable charge control agent, alkyl salicylic acid, dialkyl salicylic acid, naphthoic acid, a metal compound of an aromatic carboxylic acid such as dicarboxylic acid, a metal salt or metal complex of an azo dye or an azo pigment, Examples include a polymer compound having a sulfonic acid or carboxylic acid group in a side chain, a boron compound, a urea compound, a silicon compound, and calixarene. Examples of the positively chargeable charge control agent include a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in a side chain, a guanidine compound, a nigrosine compound, and an imidazole compound.
[0087]
The charge control agent is preferably used in an amount of 0.5 to 10 parts by mass based on 100 parts by mass of the resin. However, in the non-magnetic toner related to the image forming method of the present invention, the addition of a charge control agent is not essential, and the color toner particles are positively utilized by frictionally charging the toner layer thickness regulating member and the developer carrier. It is not always necessary to include a charge control agent therein.
[0088]
When the color toner particles according to the present invention are produced by a polymerization method, the polymerization initiator used in the production of the color toner particles has a half-life of 0.5 to 30 hours at the time of the polymerization reaction. It is preferably used in a ratio of 0.5 to 20 parts by mass with respect to 100 parts by mass of the body, so that the color toner can have desired strength and appropriate melting characteristics. Examples of the polymerization initiator include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), Azo or diazo polymerization initiators such as 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene Peroxide-based polymerization initiators such as hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, and t-butylperoxy 2-ethylhexanoate are exemplified.
[0089]
When the color toner particles according to the present invention are produced by a polymerization method, a crosslinking agent may be added, and a preferable addition amount is 0.001 to 15% by mass of the polymerizable monomer composition.
[0090]
Here, as the cross-linking agent, a compound having two or more polymerizable double bonds is mainly used, for example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene, or the like; for example, ethylene glycol diacrylate, ethylene glycol diacrylate, or the like. Carboxylic acid esters having two double bonds such as methacrylate and 1,3-butanediol dimethacrylate; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone; and having three or more vinyl groups And the like are used alone or as a mixture.
[0091]
When the color toner particles according to the present invention are produced by a polymerization method, generally, the above-described color toner composition, that is, a colorant, a release agent, a plasticizer, a charge control agent, a crosslinking agent, etc. An aqueous system containing a dispersion stabilizer containing a polymerizable monomer system which is uniformly dissolved or dispersed by a disperser such as a homogenizer, a ball mill, a colloid mill, and an ultrasonic disperser by appropriately adding necessary components and other additives. Suspend in vehicle. At this time, the particle size of the obtained toner particles becomes sharper by using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser to quickly obtain the desired toner particle size. As for the timing of the addition of the polymerization initiator, the polymerization initiator may be added at the same time as the other additives are added to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. Immediately after granulation and before the initiation of the polymerization reaction, a polymerization initiator dissolved in a polymerizable monomer or a solvent may be added.
[0092]
After the granulation, stirring may be performed using an ordinary stirrer to such an extent that the particle state is maintained and the floating and settling of the particles are prevented.
[0093]
When the color toner according to the present invention is produced by a polymerization method, a known surfactant or organic / inorganic dispersant can be used as a dispersion stabilizer, and among them, the inorganic dispersant hardly generates harmful ultrafine powder, Since the dispersion stability is obtained by the hindrance, the stability is hardly lost even if the reaction temperature is changed, the washing is easy, and the toner is hardly adversely affected. Examples of such inorganic dispersants include polyvalent metal phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate; carbonates such as calcium carbonate and magnesium carbonate; calcium metasilicate, calcium sulfate and barium sulfate. Inorganic salts; inorganic oxides such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite, and alumina.
[0094]
It is desirable that these inorganic dispersants be used alone in an amount of 0.2 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. Since it is insufficient, 0.001 to 0.1 parts by mass of a surfactant may be used in combination. Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.
[0095]
When these inorganic dispersants are used, they may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be generated in an aqueous medium. For example, in the case of calcium phosphate, a water-insoluble calcium phosphate can be produced by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring, and more uniform and fine dispersion can be achieved. At this time, a water-soluble sodium chloride salt is simultaneously produced as a by-product, but if the water-soluble salt is present in the aqueous medium, the dissolution of the polymerizable monomer in water is suppressed, and an ultrafine toner is generated by emulsion polymerization. It is more convenient because it is harder to do. Since it becomes an obstacle when removing the residual polymerizable monomer at the end of the polymerization reaction, it is better to replace the aqueous medium or desalinate with an ion exchange resin. The inorganic dispersant can be almost completely removed by dissolving with an acid or an alkali after completion of the polymerization.
[0096]
In the polymerization step, the polymerization is preferably performed at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. In order to consume the remaining polymerizable monomer, it is possible to raise the reaction temperature to 90 to 150 ° C. at the end of the polymerization reaction.
[0097]
After completion of the polymerization, the polymerized toner particles are filtered, washed, and dried by a known method, and an external additive such as inorganic fine particles is mixed and adhered to the surface to obtain a toner. In addition, cutting a coarse powder or a fine powder into a classification step in the manufacturing process is also a desirable embodiment of the present invention.
[0098]
In the case of producing the color toner particles according to the present invention by a pulverization method, a known method is used, for example, a binder resin, a release agent, a charge control agent, components necessary as color toner particles such as a colorant, and the like. After thoroughly mixing other additives with a mixer such as a Henschel mixer or a ball mill, melt-knead using a hot kneader such as a heating roll, kneader, or extruder to make the resins compatible with each other, and then solidify by cooling. After pulverization, classification and, if necessary, surface treatment can be performed to obtain toner particles. Either the classification or the surface treatment may be performed first. In the classifying step, it is preferable to use a multi-segment classifier in terms of production efficiency.
[0099]
The pulverizing step can be performed by a method using a known pulverizing device such as a mechanical impact type or a jet type. In order to obtain a color toner having a specific degree of circularity, it is preferable to further apply heat to pulverize or to perform auxiliary mechanical impact. Further, a hot water bath method in which finely pulverized (classified as necessary) color toner particles are dispersed in hot water, a method in which the toner particles pass through a hot air stream, or the like may be used.
[0100]
Means for applying a mechanical impact force include, for example, centrifuging non-magnetic toner particles inside a casing by a high-speed rotating blade, such as an apparatus such as a mechanofusion system manufactured by Hosokawa Micron Corporation or a hybridization system manufactured by Nara Machinery Works. There is a method of applying a mechanical impact force to the toner particles by a force such as a pressing force or a compressive force or a frictional force.
[0101]
Furthermore, the color toner particles according to the present invention may be obtained by atomizing a molten mixture into air using a disk or a multi-fluid nozzle described in JP-B-56-13945, etc. to obtain spherical toner particles, or as a polymerization method. In addition to the suspension polymerization method, a dispersion polymerization method in which toner particles are directly formed using an aqueous organic solvent in which the obtained polymer is soluble in a monomer and is insoluble, or a direct polymerization in the presence of a water-soluble polar polymerization initiator The toner particles can also be produced by a method of producing toner particles using an emulsion polymerization method represented by a soap-free polymerization method or the like.
[0102]
The color developer (yellow color developer, magenta color developer, and cyan color developer) used in the image forming method of the present invention is a two-component development containing at least a binder resin, a color colorant, inorganic fine particles and a carrier. It may be an agent.
[0103]
The carrier particles preferably used in the present invention will be described.
[0104]
Examples of the carrier used in the color developer of the present invention include surface-oxidized or unoxidized iron, nickel, copper, zinc, cobalt, manganese, chromium, and magnetic metals such as rare earths, their magnetic alloys, and their magnetic alloys. Magnetic particles selected from the group consisting of oxides and their magnetic ferrites, and magnetic substance-dispersed carriers in which magnetic powder is dispersed in a resin are included.
[0105]
In particular, the carrier particles used in the present invention are preferably magnetically dispersed carrier particles having at least inorganic compound particles and a binder resin.
[0106]
The volume average particle size of the carrier particles is preferably from 20 to 60 μm, particularly preferably from 25 to 45 μm.
[0107]
The volume average particle size of the carrier particles is randomly extracted by an optical microscope or a scanning electron microscope, and 100 or more particles are extracted, the volume particle size distribution is calculated with the maximum chord length in the horizontal direction, and the 50% average particle size is calculated. The volume average particle diameter may be determined by using a laser diffraction type particle size distribution analyzer HEROS (manufactured by JEOL Ltd.) by dividing the range of 0.05 μm to 200 μm into 32 logarithms and measuring the 50% average particle diameter. May be used as the volume average particle size.
[0108]
In the present invention, examples of the inorganic compound particles used for the magnetic particle-dispersed resin carrier particles include magnetic compound particles such as magnetite or ferrite having magnetism represented by the following formula (VII) or (VIII).
MO ・ Fe₂O₃(VII)
M ・ Fe₂O₄(VIII)
(In the formula, M represents a trivalent, divalent or monovalent metal ion.)
[0109]
M in the above formulas (VII) and (VIII) is Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Nb , Mo, Cd, Sn, Ba, Pb, and Li, and the like, and these can be used alone or in combination.
[0110]
Specific examples of the metal compound particles having magnetism include magnetite, Zn-Fe-based ferrite, Mn-Zn-Fe-based ferrite, Ni-Zn-Fe ferrite, Mn-Mg-Fe-based ferrite, and Ca- Examples include iron-based oxides such as Mn-Fe-based ferrite, Ca-Mg-Fe-based ferrite, Li-Fe-based ferrite, and Cu-Zn-Fe-based ferrite.
[0111]
As the binder resin of the magnetic particle-dispersed resin carrier particles used in the present invention, a thermosetting resin is preferable, and further, a thermosetting resin containing a resin partially or wholly cross-linked three-dimensionally, for example, a phenol resin. Preferably, it is a resin. By using this resin, the inorganic compound particles to be dispersed can be firmly bound, so that the strength of the magnetic particle-dispersed resin carrier particles can be increased, and the detachment of the inorganic compound particles hardly occurs even in a large number of copies. Become.
[0112]
The method for obtaining the magnetic particle-dispersed carrier particles is not particularly limited to the method described below, but in the present invention, the monomer serving as the binder resin, the inorganic compound particles, and the solvent are uniformly dispersed or dissolved. A method obtained by polymerizing a monomer in a solution as described above.
[0113]
In the present invention, it is also a preferred embodiment to use the magnetic-particle-dispersed carrier particles as a carrier core and use magnetic-coated carrier particles coated with a resin layer.
[0114]
As the carrier particles used in the present invention, specifically, the surface of a spherical composite core particle obtained by binding a ferromagnetic iron compound and a nonmagnetic iron compound particle as inorganic compound particles and a phenol resin as a binder component. A resin carrier made of spherical composite particles having a volume average particle diameter of 20 to 60 μm formed by forming a coating layer made of a thermosetting resin is preferably used from the viewpoint of charging stability due to long-term durability.
[0115]
The specific resistance of the carrier used in the present invention is 1 × 10⁸~ 1 × 10¹⁶It is preferably Ω · cm.
[0116]
In the color developer according to the present invention, the mixing ratio of the above-described carrier particles and color toner particles is 3.0 to 12.0% by mass, preferably 5.0 to 9.0% by mass, as the color toner concentration in the color developer. % Usually gives good results. If the toner concentration is less than 3.0% by mass, the image density is low and the image cannot be used practically. In addition, the deterioration of the carrier is accelerated and the life of the developer is shortened. If it exceeds 12.0%, fog and in-machine scattering are increased, and the useful life of the developer is also shortened.
[0117]
In the image forming method of the present invention, it is also preferable to carry out development while replenishing the two-component developer for replenishing color. In this case, it is preferable to use a color replenishing developer in which the color toner is mixed at a ratio of 2 to 50 parts by mass with respect to 1 part by mass of the carrier particles. In long-term durability, a decrease in image density due to carrier contamination easily occurs. Particularly, when an amorphous silicon photoconductor is used as the photoconductor, the development contrast is small and the image density tends to decrease. In such a system, in order to maintain the image density even in the latter half of long-term durability, a replenishing developer containing a certain amount of carrier particles is used, and an amount of the carrier corresponding to the replenished carrier particles is discharged from the main body to the outside of the main body. It is preferable to use the developing method.
[0118]
<2> Black developer in the present invention
The black developer used in the present invention will be described.
[0119]
The black developer according to the present invention has at least a binder resin and a colorant.
[0120]
The black toner in the present invention is preferably a toner having a weight average particle diameter of 3 to 10 μm. The measuring method of the average particle diameter is based on the measuring method of the color toner.
[0121]
Examples of the binder resin for the black toner include homopolymers of styrene such as polystyrene and polyvinyltoluene and substituted products thereof; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene- Methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-methacryl Ethyl acrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer , Styrene-isoprene copolymer Styrene-based copolymers such as styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, polyacrylic resin, rosin , Modified rosin, terpene resin, phenol resin, polyester resin and the like. These can be used alone or in combination.
[0122]
The black toner in the present invention preferably contains a wax. Examples of the wax include polyolefin wax, paraffin wax, rice wax, amide wax, fatty acid wax, ester wax, higher alcohol, carnauba wax and the like. The content of the wax is preferably from 0.5 to 20 parts by mass, more preferably from 1 to 12 parts by mass, per 100 parts by mass of the binder resin of the toner.
[0123]
The black toner in the present invention is preferably a magnetic toner containing magnetic particles.
[0124]
Examples of the magnetic substance contained in the magnetic toner preferably used in the present invention include iron oxides such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel; or these metals and aluminum, cobalt, copper, lead, and the like. Alloys with metals such as magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium and mixtures thereof.
[0125]
The magnetic material preferably has a BET specific surface area of 1 to 20 m by a nitrogen adsorption method.²/ G, especially 2.5 to 12 m²/ G is good. Further, a magnetic material having a Mohs hardness of 5 to 7 is preferable. The content of the magnetic substance is preferably from 10 to 70% by mass based on the magnetic one-component toner.
[0126]
The method for producing the black toner is not particularly limited, but a method in which a toner kneading material such as a hot roll, a kneader, and an extruder is kneaded well with a toner kneading material, followed by pulverization, classification, and a method of polymerization. Is mentioned.
[0127]
In addition, as a constituent material of the black toner, besides the binder resin, the magnetic substance, and the wax, the same charge control agent as that of the color toner can be used.
[0128]
The black toner of the present invention can be prepared by dry-mixing inorganic fine particles usable for a color toner with a mixer such as a Henschel mixer.
[0129]
<3> Photoconductor in the present invention
Next, the photoreceptor used in the present invention will be described.
[0130]
The photoconductor used in the present invention is an amorphous silicon photoconductor having a photoconductive layer containing amorphous silicon as a main component, and specifically, preferably has a layer configuration as shown in FIG.
[0131]
An amorphous silicon photosensitive member 100 shown in FIG. 1A has a photosensitive layer 102 provided on a photosensitive member support 101. The photosensitive layer 102 is composed of a photoconductive layer 103 made of a-Si: H, X (H is a hydrogen atom, X is a halogen atom) and has photoconductivity.
[0132]
An amorphous silicon photosensitive member 100 shown in FIG. 1B has a photosensitive layer 102 provided on a support 101 for a photosensitive member. The photosensitive layer 102 includes a photoconductive layer 103 made of a-Si: H, X and having photoconductivity, and an amorphous silicon-based surface layer 104.
[0133]
An amorphous silicon photosensitive member 100 shown in FIG. 1C has a photosensitive layer 102 provided on a photosensitive member support 101. The photosensitive layer 102 includes a photoconductive layer 103 made of a-Si: H, X and having photoconductivity, an amorphous silicon-based surface layer 104, and an amorphous silicon-based charge injection blocking layer 105.
[0134]
An amorphous silicon photosensitive member 100 shown in FIG. 1D has a photosensitive layer 102 provided on a support 101 for a photosensitive member. The photosensitive layer 102 includes a charge generation layer 106 made of a-Si: H, X and a charge transport layer 107 constituting the photoconductive layer 103, and an amorphous silicon-based surface layer 104.
[0135]
The photoconductive layer, the surface layer, the charge injection blocking layer, the charge generation layer, the charge transport layer, and the like may be the same as those constituting a normal amorphous silicon photoreceptor.
[0136]
The support used for the amorphous silicon photoreceptor may be conductive or electrically insulating. Examples of the conductive support include metals such as Al, Cr, Mo, Au, In, Nb, Te, V, Ti, Pt, Pd, and Fe, and alloys thereof, such as stainless steel. Further, at least the surface of the electrically insulating support such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polystyrene, polyamide or the like on the side on which the photosensitive layer is formed of an electrically insulative support such as glass, ceramic, etc. A support subjected to a conductive treatment can also be used.
[0137]
<4> Image forming method of the present invention
The image forming method of the present invention includes a developing step of forming and developing a visible image by appropriately using the black developer and the color developer, and a color image forming method using the amorphous silicon photosensitive member as a photosensitive member. is there.
[0138]
In the image forming method of the present invention, it is preferable to use a color developer having a color toner concentration of 3.0 to 12.0% by mass, preferably 5.0 to 9.0% by mass. In addition, by using a color replenishing developer containing 2 to 50 parts by mass of a color toner with respect to 1 part by mass of a carrier, the color developer can be used without being affected by the environment. Is stable, and good image quality can be obtained over a long period of time. If the amount of the toner is less than 2 parts by mass, fogging or toner scattering due to durability is likely to occur even when the magnetic fine particle-dispersed carrier of the present invention is used. On the other hand, when the amount exceeds 50 parts by mass, the life of the developer is improved, but the amount of the replenishment developer is increased due to the large amount of the carrier, and the discharge property from the replenishment developer container to the developing device is deteriorated. The means for collecting the collected deteriorated developer is undesirably complicated. Further, the substantial amount of toner in the replenishment developer container decreases, the frequency of replacing the toner container increases, and not only the load on the user increases, but also the cost increases, which is not preferable.
[0139]
In the image forming method of the present invention, when the color toner is consumed by the development and the ratio of the color toner / carrier particles (T / C) decreases, the decrease is determined by utilizing the inductance of the coil to reduce the magnetic permeability of the color developer. It is preferable to supply the replenishing developer from a storage device that stores the replenishing developer according to the consumed amount of the color toner, which is detected by a toner concentration detection sensor or the like that measures the change.
[0140]
In the image forming method of the present invention, the visible color developed image formed on the electrostatic latent image carrier is transferred and carried on the intermediate transfer body, and all the color developed images are superimposed on the intermediate transfer body. Intermediate transfer, in which transfer is performed collectively and then collectively transferred onto a transfer material, is preferable from the viewpoint of preventing color misregistration, obtaining high image quality, and reducing the size of the apparatus.
[0141]
In the image forming method of the present invention, it is preferable that the process speed is 200 mm / sec or more from the viewpoint of achieving high speed.
[0142]
In the image forming method of the present invention, it is preferable that the developer is developed while rotating at a peripheral speed of 1.0 to 2.0 times the process speed. If the ratio is less than 1.0, it is not possible to supply a toner necessary for development, so that a sufficient image density cannot be obtained. On the other hand, when the ratio is more than 2.0 times, the share in the developing device is increased, and the toner and the carrier are greatly deteriorated, which results in durability stability. In addition, in-machine dirt, image dirt, and the like due to scattering are caused.
[0143]
The image forming method of the present invention can be used in any system, and can be applied to known developing methods such as a developer for a high-speed system, a developer for an oilless fixing, and a developer for a cleanerless one.
[0144]
The image forming method of the present invention can perform development using an image forming apparatus having a developing unit as shown in FIG. 2, for example.
[0145]
FIG. 2 is a schematic configuration diagram of an example of an electrophotographic full-color image forming apparatus in which a developing unit exchange body 13 having a rotary developing unit for each color of a rotary rotation system and an intermediate transfer body 45 are mounted. The surface of the electrostatic latent image carrier 1 is uniformly charged to a negative polarity by the charging device 15. Next, image exposure corresponding to the first color, for example, a yellow image is performed by the exposure device 14, and an electrostatic latent image corresponding to the yellow image is formed on the surface of the electrostatic latent image carrier 1.
[0146]
The developing device exchange body 13 is of a rotary moving type, and a schematic configuration diagram is shown in FIG. Before the tip of the electrostatic latent image corresponding to the yellow image reaches the developing position, the yellow developing device faces the electrostatic latent image carrier 1, and then the magnetic brush rubs the electrostatic latent image, A yellow toner image is formed on the electrostatic latent image carrier.
[0147]
FIG. 3 is a schematic configuration diagram of the developing units 2, 3, 4, and 5 of FIGS. The color developing devices 2, 3, and 4 that do not use the auto-refresh developing method do not have the developer collection function units 34 to 39.
[0148]
As shown in FIG. 3, each developing device used for development includes, for example, a developing sleeve 6 as a developer carrier, a magnet roller 8, a regulating member 7, developer conveying screws 10 and 11, and a scraper (not shown). Etc. are provided.
[0149]
With reference to FIGS. 2, 3, and 4, the flow of the developer until the developer in the developing device is developed will be described. The developing sleeve 6 includes a fixed magnet roller 8 and is driven and rotated while maintaining a predetermined developing interval between the developing sleeve 6 and the peripheral surface of the electrostatic latent image carrier 1. The developing sleeve 6 and the electrostatic latent image carrier 1 may be in contact with each other. The regulating member 7 has rigidity and magnetism and is pressed against the developing sleeve 6 with a predetermined load in a state where the developer is not interposed therebetween, or is disposed at a predetermined interval from the developing sleeve 6. And so on. The pair of developer conveying screws 10 and 11 has a screw structure, and functions to convey and circulate the developer in opposite directions to sufficiently stir and mix the toner and the carrier, and to send the toner and the developer to the developing sleeve 6. It is. The magnet roller 8 includes, for example, a magnet composed of four-pole magnets of equal magnetic force in which N poles and S poles are alternately arranged at equal intervals, a magnet composed of six poles, or a portion in contact with a scraper. In order to form a repulsive magnetic field and facilitate the peeling of the developer, one pole may be removed to make five poles, and the pole may be contained in the developing sleeve 6 in a fixed state.
[0150]
The pair of developer conveying screws 10 and 11 are members that also serve as agitating members that rotate in directions opposite to each other, and are supplied from a replenishment developer container (FIG. 4: 2a, 3a, 4a, and 5a). The replenishing developer replenished by the thrust of the screw of the developer container 9 is transported, and the toner and the carrier are mixed to form a triboelectrically charged homogeneous two-component developer. The two-component developer is deposited in a layer on the surface.
[0151]
The developer on the surface of the developing sleeve 6 forms a uniform layer by the regulating member 7 provided facing the magnetic pole of the magnet roller 8. The uniformly formed developer layer develops a latent image on the peripheral surface of the electrostatic latent image carrier 1 in a development area to form a toner image.
[0152]
Then, the toner image is transferred to the intermediate transfer body 45 by the transfer device 31.
[0153]
When the above-described yellow copy cycle is completed, the electrostatic latent image carrier 1 on which the transfer of the yellow toner has been completed is subjected to a pre-cleaning process, if necessary, and then is discharged by the discharging device, and the cleaning device 18 is removed. As a result, the yellow toner remaining on the surface is scraped off.
[0154]
Then, the developing device 13 is rotated, and the developing devices 3, 4, and 5 are sequentially switched so as to oppose the electrostatic latent image carrier 1. In the same copy cycle as above, the magenta, cyan, and black toner images are interposed. The image is transferred to the transfer body 45.
[0155]
When the above-described copy cycles are executed, the toner images of the respective color components are transferred to the same positions of the intermediate transfer member 45 by the transfer device 40, and the toner images of the respective color components are overlaid. One toner image is formed. On the other hand, the transfer material 12 such as a sheet or a transparent sheet stored in the paper feed tray 25 is fed one by one to the registration roller 25 by the feed roller 28, and the transfer material 12 is transferred to the intermediate transfer body 45 in synchronization with the intermediate transfer body 45. The sheet is conveyed between the transfer member 45 and the transfer roller 43. The transferred transfer material 12 is separated from the intermediate transfer member 45 by the peeling finger 44 after the toner image of the intermediate transfer member 45 is transferred by the transfer roller 43, and is introduced into the fixing device 21 by the transfer belt 20. Then, after the color toner image is fixed on the transfer material 12, the image is discharged to the outside, thereby completing one copy mode.
[0156]
The surface of the intermediate transfer member 45 on which the toner image has been transferred onto the transfer material is discharged by a discharging device (not shown), the surface is cleaned by the cleaning device 23, and the next copy cycle is awaited.
[0157]
When the copying operation as described above is repeated, the toner in the developer contained in the developing tank 17 in the developing device in FIG. 3 is gradually consumed, and the ratio of the toner to the carrier, that is, the toner concentration decreases. To go. This change in toner density is feedback-controlled by a toner density sensor (not shown) provided in the developing tank 17 so that the toner density always falls within an appropriate range required for development.
[0158]
With the above control, the replenishment developer is discharged from the replenishment developer storage container to the replenishment developer storage device 9, and then the replenishment developer is supplied from the replenishment opening of the replenishment developer storage device 9 by the thrust of the screw. Is supplied to the developing tank 17 in the developing device.
[0159]
In the black developing device 5 using the auto-refresh developing method, the replenishment developer obtained by mixing the toner and the carrier of the present invention is supplied from the replenishment developer container 5a to the replenishment developer storage device 9. It is supplied to the black developing device 5 with its mouth closed.
[0160]
Next, the discharge of the excess developer from the black developing device 5 using the rotational movement in the rotating developing device exchange body 13 shown in FIG. 2 will be described with reference to FIGS.
[0161]
In a full-color image forming apparatus including a developing unit exchange unit 13 having a rotary developing unit employing a rotational movement system, the developing units 2, 3, 4, and 5 rotate and move inside the developing unit exchange unit 13 to perform development. Then, the developer is rotated to a position opposed to the electrostatic latent image carrier 1 to perform development, and is rotated to a position not opposed to the electrostatic latent image carrier 1 during non-development.
[0162]
At a position where the developing device 5 is opposed to the electrostatic latent image carrier 1 and performing the developing operation, the excess developer (deteriorated carrier) is discharged to the developing device side developer provided in the developing device 5. The developer spills out of the outlet 34, moves in the developer collecting auger 36 by a rotation operation, and is discharged to a developer collecting container 39 provided on a rotation center shaft of a rotary rotary developing device.
[0163]
More specifically, the developing method according to the present invention is performed by applying an AC voltage to the developing sleeve to form an alternating electric field in the developing area while developing the magnetic brush in contact with the electrostatic latent image carrier 1. Is preferably performed. The distance (S-D distance) between the developing sleeve 6 and the electrostatic latent image carrier 1 is preferably 100 to 1000 [mu] m in preventing carrier adhesion and improving dot reproducibility. If it is smaller than 100 μm, the supply of the developer tends to be insufficient and the image density tends to be low. If it is larger than 1000 μm, the lines of magnetic force from the magnetic pole S1 are widened and the density of the magnetic brush is reduced, resulting in poor dot reproducibility or restraining the carrier. The force is weakened and carrier adhesion is likely to occur.
[0164]
The voltage between the peaks of the alternating electric field is preferably 300 to 3000 V, and the frequency is 500 to 10000 Hz. In this case, the waveform of the AC bias for forming the alternating electric field may be a triangular wave, a rectangular wave, a sine wave, or a waveform having a changed duty ratio. In some cases, in order to cope with a change in the toner image forming speed, it is preferable to perform development by applying a developing bias voltage (intermittent alternating superimposed voltage) having a discontinuous AC bias voltage to the developing sleeve. If the applied voltage is lower than 300 V, it is difficult to obtain a sufficient image density, and it may not be possible to satisfactorily collect fog toner in the non-image area. If the voltage exceeds 3000 V, the latent image may be disturbed via the magnetic brush, which may cause deterioration in image quality.
[0165]
By using a two-component developer having a well-charged toner, the fog removal voltage (Vback) can be reduced, and the primary charge of the electrostatic latent image carrier can be reduced. The life of the image carrier can be extended. Vback is preferably 200 V or less, more preferably 150 V or less, depending on the developing system. As the contrast potential, 100 to 400 V is preferably used so that a sufficient image density can be obtained.
[0166]
Further, when the frequency is lower than 500 Hz, although it depends on the process speed, when the toner in contact with the electrostatic latent image carrier is returned to the developing sleeve, sufficient vibration is not given and fog is liable to occur. If the frequency exceeds 10,000 Hz, the toner cannot follow the electric field, and the image quality tends to be reduced.
[0167]
What is important in the developing method according to the present invention is that the electrostatic latent image carrier 1 of the magnetic brush on the developing sleeve 6 is used in order to obtain a sufficient image density, have excellent dot reproducibility, and perform development without carrier adhesion. Is preferably set to 3 to 8 mm. If the developing contact portion is smaller than 3 mm, it is difficult to sufficiently satisfy a sufficient image density and dot reproducibility. If the developing contact portion is wider than 8 mm, packing of the developer occurs, which stops the operation of the machine or causes carrier adhesion. It is difficult to sufficiently suppress this.
[0168]
As a method for adjusting the developing contact portion, the distance between the regulating member 7 and the developing sleeve 6 or the distance between the developing sleeve 6 and the electrostatic latent image carrier 1 (the distance between SD) is adjusted. There is a method of appropriately adjusting the contact width.
[0169]
The configuration of the electrostatic latent image carrier may be the same as that of an electrostatic latent image carrier used in a normal image forming apparatus. For example, a conductive layer and an undercoat are formed on a conductive substrate such as aluminum or SUS in order. A photoreceptor having a structure in which a layer, a charge generation layer, a charge transport layer and, if necessary, a charge injection layer are provided. The conductive layer, the undercoat layer, the charge generation layer, and the charge transport layer may be those commonly used for a photoreceptor. As the outermost surface layer of the photoconductor, for example, a charge injection layer or a protective layer may be used.
[0170]
【Example】
Hereinafter, the effects of the present invention will be specifically described with reference to examples. Note that the present invention is not limited to these examples.
[0171]
<1> Production of color toner
Production Example 1 of Color Toner
0.1 M Na in 405 parts by mass of ion-exchanged water₃PO₄After adding 250 parts by mass of the aqueous solution and heating to 60 ° C., 1.07 M-CaCl₂An aqueous medium containing calcium phosphate was obtained by gradually adding 40.0 parts by mass of the aqueous solution.
[0172]
On the other hand, the following formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Kakoki Co., Ltd.).
80 parts by mass of styrene
20 parts by mass of n-butyl acrylate
Divinylbenzene 0.2 parts by mass
4.0 parts by mass of saturated polyester resin
(Mw = 41000)
Negative charge control agent (metal compound of dialkyl salicylic acid) 1 part by mass
C. I. Pigment Yellow 17 8.0 parts by mass
[0173]
This monomer composition was heated to 60 ° C., and 12 parts by mass of an ester wax mainly composed of behenyl behenate (the maximum endothermic peak at the time of temperature rise measurement in DSC of 72 ° C.) was added, mixed and dissolved therein. Polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) [t_1/2= 140 minutes, 60 ° C conditions].
[0174]
The above-mentioned polymerizable monomer system was introduced into the aqueous medium, and 60.5 ° C.₂Under an atmosphere, the mixture was stirred at 10,000 rpm for 15 minutes using a TK homomixer (Tokiki Kagaku Kogyo Co., Ltd.) to perform granulation. Thereafter, the mixture was reacted at 60.5 ° C. for 6 hours while stirring with a paddle stirring blade. Thereafter, the liquid temperature was set to 80 ° C., and stirring was continued for another 4 hours. After completion of the reaction, distillation was carried out at 80 ° C. for further 3 hours. Thereafter, the suspension was cooled, hydrochloric acid was added to dissolve the calcium phosphate salt, and the mixture was filtered and washed with water to obtain wet colored particles.
[0175]
Next, the particles were dried at 40 ° C. for 12 hours to obtain colored particles (toner particles).
[0176]
100 parts by mass of toner particles
BET value 130m treated with silicone oil²/ G, hydrophobic silica fine particles having a primary particle size of 12 nm 0.4 part by mass
BET value treated with silicone oil is 30m²/ G, hydrophobic silica fine particles having a primary particle size of 50 nm 0.4 part by mass
BET value 80m treated with silicone oil²/ G, 0.4 part by mass of hydrophobic titania fine particles having a primary particle size of 30 nm
Was mixed with a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a color toner (yellow toner) A (weight average particle size: 6.7 μm).
[0177]
Production Example 2 of Color Toner:
C. I. Pigment Yellow 17 instead of 8.0 parts by mass. I. A color toner (magenta toner) B (weight average particle size: 6.8 μm) was obtained in the same manner as in Production Example 1 of the color toner, except that Pigment Red 122 was changed to 8.0 parts by mass.
[0178]
Production Example 3 of Color Toner:
C. I. Pigment Yellow 17 instead of 8.0 parts by mass. I. Pigment Blue 15: 3 was used for 7.5 parts by mass, and a color toner (cyan toner) C (weight average particle size: 6.7 μm) was obtained in the same manner as in Production Example 1 of the color toner.
[0179]
Production Example 4 of Color Toner:
BET value treated with silicone oil is 30m²/ G, and a hydrophobic silica fine particle having a primary particle size of 50 nm was treated with silicone oil instead of 0.4 parts by mass to obtain a BET value of 60 m.²/ G, and a color toner (yellow toner) D (weight average particle diameter of 6) was prepared in the same manner as in Production Example 1 of the color toner except that the particle size was changed to 0.4 parts by mass of hydrophobic alumina fine particles having a particle diameter of 45 nm. 0.7 μm).
[0180]
Production Example 5 of Color Toner:
BET value treated with silicone oil is 30m²/ G, and a hydrophobic silica fine particle having a primary particle size of 50 nm was treated with silicone oil instead of 0.4 parts by mass to obtain a BET value of 60 m.²/ G and a color toner (magenta toner) E (weight average particle diameter of 6) in the same manner as in Production Example 2 of the color toner, except that the particle size is changed to 0.4 parts by mass of hydrophobic alumina fine particles having a particle diameter of 45 nm. .8 μm).
[0181]
Production Example 6 of Color Toner:
BET value treated with silicone oil is 30m²/ G, and a hydrophobic silica fine particle having a primary particle size of 50 nm was treated with silicone oil instead of 0.4 parts by mass to obtain a BET value of 60 m.²/ G and the color toner (cyan toner) F (weight average particle diameter of 6) in the same manner as in Production Example 3 of the color toner, except that the particle size is changed to 0.4 parts by mass of hydrophobic alumina fine particles having a particle diameter of 45 nm. 0.7 μm).
[0182]
Production Example 7 of Color Toner:
BET value treated with silicone oil is 30m²/ G and a BET value of 70 m instead of 0.4 parts by mass of hydrophobic silica fine particles having a primary particle size of 50 nm.²/ G, the primary particle size was changed to 0.4 parts by mass of polyvinylidene fluoride fine particles having a diameter of 400 nm, and the BET value treated with silicone oil was 80 m.²/ G and hydrophobic titania fine particles having a primary particle size of 30 nm were treated with silicone oil instead of 0.4 parts by mass, and the BET value was 10 m.²/ G of the color toner (yellow toner) G (weight average particle diameter) in the same manner as in Production Example 1 of the color toner except that the hydrophobic zinc oxide fine particles having a primary particle size of 290 nm are changed to 0.4 parts by mass. 6.7 μm).
[0183]
Production Example 8 of Color Toner:
BET value treated with silicone oil is 30m²/ G and a BET value of 70 m instead of 0.4 parts by mass of hydrophobic silica fine particles having a primary particle size of 50 nm.²/ G, the primary particle size was changed to 0.4 parts by mass of polyvinylidene fluoride fine particles having a diameter of 400 nm, and the BET value treated with silicone oil was 80 m.²/ G and hydrophobic titania fine particles having a primary particle size of 30 nm were treated with silicone oil instead of 0.4 parts by mass, and the BET value was 10 m.²Color toner (magenta toner) H (weight average particle size) in the same manner as in Production Example 2 of the color toner, except that the hydrophobic zinc oxide fine particles having a primary particle size of 290 nm are changed to 0.4 parts by mass / g. 6.8 μm).
[0184]
Production Example 9 of Color Toner:
BET value treated with silicone oil is 30m²/ G and a BET value of 70 m instead of 0.4 parts by mass of hydrophobic silica fine particles having a primary particle size of 50 nm.²/ G, the primary particle size was changed to 0.4 parts by mass of polyvinylidene fluoride fine particles having a diameter of 400 nm, and the BET value treated with silicone oil was 80 m.²/ G and hydrophobic titania fine particles having a primary particle size of 30 nm were treated with silicone oil instead of 0.4 parts by mass, and the BET value was 10 m.²/ G of the color toner (cyan toner) I (weight average particle diameter) in the same manner as in Production Example 3 of the color toner, except that the hydrophobic zinc oxide fine particles having a primary particle size of 290 nm are changed to 0.4 parts by mass. 6.7 μm).
[0185]
Production Example 10 of Color Toner:
BET value 80m treated with silicone oil²/ G and the color toner (yellow toner) J (weight average particle size) in the same manner as in Production Example 1 of the color toner except that 0.4 parts by mass of hydrophobic titania fine particles having a primary particle size of 30 nm is not added. 6.7 μm in diameter).
[0186]
Production Example 11 of Color Toner:
BET value 80m treated with silicone oil²/ G and a color toner (magenta toner) K (weight average particle size) in the same manner as in Production Example 2 of the color toner except that 0.4 parts by mass of hydrophobic titania fine particles having a primary particle size of 30 nm is not added. (Diameter 6.8 μm).
[0187]
Production Example 12 of Color Toner:
BET value 80m treated with silicone oil²/ G and a color toner (cyan toner) L (weight average particle size) in the same manner as in Production Example 2 of the color toner except that 0.4 parts by mass of hydrophobic titania fine particles having a primary particle size of 30 nm is not added. 6.7 μm in diameter).
[0188]
Production Example 13 of Color Toner:
80 parts by mass of styrene / n-butyl acrylate copolymer
(Mass ratio 85/15, Mw = 330,000)
4.5 parts by mass of saturated polyester resin
(Mw = 18000)
Negative charge control agent (metal compound of dialkyl salicylic acid) 3 parts by mass
C. I. Pigment Yellow 177 7 parts by mass
Ester wax mainly composed of behenyl behenate 5 parts by mass
(Maximum endothermic peak at the time of temperature rise measurement in DSC: 72 ° C)
The above-mentioned materials are mixed in a blender, melt-kneaded in a twin-screw extruder heated to 110 ° C., and the cooled kneaded material is roughly pulverized with a hammer mill (manufactured by Hosokawa Micron Corporation), and then finely pulverized by an air jet method. And pulverized. The collision plate was adjusted to be 90 degrees with respect to the direction of collision. The resulting finely pulverized product was subjected to air classification to obtain toner particles. Thereafter, spheroidizing treatment was performed with a batch-type impact type surface treatment device (treatment temperature: 40 ° C., rotational processing blade peripheral speed: 75 m / sec, treatment time: 3 minutes).
[0189]
100 parts by mass of the obtained spherical toner particles
BET value 130m treated with silicone oil²/ G, hydrophobic silica fine particles having a primary particle size of 12 nm 0.4 part by mass
BET value treated with silicone oil is 30m²/ G, hydrophobic silica fine particles having a primary particle size of 50 nm 0.4 part by mass
BET value 80m treated with silicone oil²/ G, 0.4 part by mass of hydrophobic titania fine particles having a primary particle size of 30 nm
Was mixed with a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a color toner (yellow toner) M (weight average particle size: 6.9 μm).
[0190]
Production Example 14 of Color Toner:
C. I. Pigment Yellow 17 instead of 7.0 parts by mass. I. A color toner (magenta toner) N (weight average particle size: 6.8 μm) was obtained in the same manner as in Production Example 13 of the color toner except that Pigment Red 122 was used in an amount of 7.0 parts by mass.
[0191]
Production Example 15 of Color Toner:
C. I. Pigment Yellow 17 instead of 7.0 parts by mass. A color toner (cyan toner) O (weight average particle size: 6.8 μm) was obtained in the same manner as in Production Example 13 of the color toner, except that I Pigment Blue 15: 3 was used for 6.5 parts by mass.
[0192]
<2> Production of black toner
Production Example 1 of Black Toner
C. I. Pigment Yellow 17 was replaced with 8.0 parts by mass, and instead of 10 parts by mass, black toner (black toner) P (weight-average particle size: 7.0 μm) in the same manner as in Production Example 1 of color toner. Got.
[0193]
Production Example 2 of Black Toner:
100 parts by mass of styrene-n-butyl methacrylate-divinylbenzene copolymer
(Mass ratio 70: 29: 1, Mw = 280,000)
Magnetic material (BET value 7.5m²/ G) 100 parts by mass
Negative charge control agent (Fe compound of monoazo dye) 0.5 parts by mass
Low molecular weight polypropylene wax 3 parts by mass
The above mixture is melt-kneaded with a biaxial extruder heated to 140 ° C., the cooled kneaded material is coarsely pulverized by a hammer mill, the coarsely pulverized material is finely pulverized by a jet mill, and the obtained finely pulverized powder is The particles were classified to obtain a magnetically classified powder (magnetic toner particles) (Tg of 60 ° C.).
[0194]
100 parts by mass of the magnetic toner particles and a BET value treated with silicone oil of 130 m²/ G, and 1.2 parts by mass of hydrophobic silica fine particles having a primary particle size of 12 nm are mixed with a Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) to obtain a black toner Q (weight average particle size of 7.3 μm). Got.
[0195]
<3> Production of carrier particles
Production Example 1 of carrier particles 1:
While keeping the following materials and water at 40 ° C., mixing was performed for 1 hour.
Phenol: 7.6 parts by mass
Formalin solution: 11.3 parts by mass
(About 40% forimaldehyde, about 10% methanol, the rest is water)
Magnetite microparticles lipophilized with 1.0% by mass of γ-glycidoxypropyltrimethoxysilane: 52.0 parts by mass
(Average particle size 0.23 μm, specific resistance 4 × 10⁵Ω ・ cm)
α-lipophilic α-glycidoxypropyltrimethoxysilane at 1.0% by mass
-Fe₂O₃Fine particles: 33.0 parts by mass
(Average particle size 0.57 μm, specific resistance 2.2 × 10⁹Ω ・ cm)
[0196]
Ammonia water and water were added to the slurry as a basic catalyst in a flask, and the temperature was raised to and maintained at 85 ° C. for 40 minutes with stirring and mixing, and the mixture was reacted for 3 hours to form and harden a phenol resin. After cooling, water was added, the supernatant was removed, the precipitate was washed with water, and dried under reduced pressure to obtain spherical magnetic carrier core particles containing magnetite fine particles using a phenol resin as a binder resin.
[0197]
The coarse particles were removed from the particles by using a sieve of 60 mesh and 100 mesh to obtain carrier core particles. The obtained carrier core particles were treated with 0.4% by mass of γ-aminopropyltrimethoxysilane diluted with a toluene solvent on the core surface. Subsequently, a mixture of 0.5% by mass of a straight silicone resin in which all the substituents were methyl groups and 0.02% by mass of γ-aminopropyltrimethoxysilane was coated with toluene as a solvent. Further, the magnetic coated carrier is baked at 140 ° C., and the aggregated coarse particles are cut with a 100-mesh sieve. Then, the fine powder and coarse powder are removed by a multi-split air classifier to adjust the particle size distribution, and the volume average particle diameter is adjusted. Magnetic coated carrier particles a of 40 μm were obtained.
[0198]
Production Example 2 of carrier particles:
In molar ratio, Fe₂O₃= 48 mol%, CuO = 28 mol%, ZnO = 24 mol%, and mixed using a ball mill. After calcined at a temperature of 1000 ° C., the calcinable material was pulverized by a ball mill. 100 parts by mass of the obtained powder and 0.5 part by mass of sodium polymethacrylate and water were put in a wet ball mill and mixed to obtain a slurry. The obtained slurry was granulated by a spray dryer. This was sintered at a temperature of 1300 ° C. to obtain carrier core particles. When the resistance of the obtained carrier core particles was measured, it was 4.5 × 10 4⁸Ω · cm.
[0199]
The surface of the carrier core particles was coated with a thermosetting silicone resin in an amount of 12% by mass. The magnetic coated carrier particles were cured at 250 ° C. for 1 hour, crushed, and classified with a 100-mesh sieve to obtain magnetic coated carrier particles b having a volume average particle diameter of 46 μm.
[0200]
<4> Image forming apparatus
Next, image forming apparatuses used in Examples 1 to 9 and Comparative Examples 1 and 2 will be described.
[0201]
As an evaluator for performing image evaluation in Examples 1 to 9 and Comparative Examples 1 and 2, a modified color laser copier 500 made by Canon was used as shown in FIG. As a developing means, a rotary type developing device was arranged on the photoreceptor, and (b), (c), and (d) of four stations of the rotary type developing device were colored except for Example 4. The two-component developing device for toner development and the one station (a) were modified to be a magnetic one-component developing (jumping) developing device for developing magnetic toner. For Example 4, all stations were converted to non-magnetic two-component developing devices. Further, the two-component developing device ((b), (c), (d)) for developing a color toner can employ a configuration in which the developer is gradually discharged with the revolution of the developing device, that is, a so-called trickle developing system. Modified as follows.
[0202]
In the transfer step, a color image forming apparatus used in the present embodiment was used as a means for forming a multi-layer developed image on the intermediate transfer body and transferring the batch on a transfer material using an intermediate transfer belt.
[0203]
(Two-component developing device)
An aluminum coated sleeve was used as a developing sleeve, and the distance between the sleeve and the a-Si drum was set to 450 μm. The AC bias used for development was 1300 Vpp in peak-to-peak electric field intensity, and the frequency was 2000 Hz.
[0204]
(One-component developing device)
An aluminum coated sleeve was used as a developing sleeve, and the distance between the sleeve and the a-Si drum was set to 280 μm. The AC bias used for development was 1300 Vpp in peak-to-peak electric field intensity, and the frequency was 2000 Hz.
[0205]
Further, a non-contact type corona charging method was used as a charging step, and an AC electric field was used as an applied voltage condition.
[0206]
The development contrast was set to 200V.
[0207]
[Example 1]
Eight parts by weight of each of the color toners A, B and C and 92 parts by weight of the carrier a were weighed and mixed with a V-type mixer to obtain color developers A, B and C. Agent Q was used. Each of the developers is put into an image forming apparatus having four stations shown in FIG. 2, and a replenishing developer corresponding to each of the stations is supplied, and an original document having an image area of 30% is used. Image formation speed (process speed) of 220 mm / sec, sleeve peripheral speed at process speed x 1.5 times, in a high-temperature and high-humidity environment (30 ° C, 80% RH), 2000 full-color sheets, 8000 single-color Bk sheets Was carried out for 50 cycles, and a total of 500,000 sheets were produced.
[0208]
Here, the replenishing developer was prepared by weighing 10 parts by mass of the color toner A, the color toner B and the color toner C and 1 part by mass of the carrier a and mixing them with a V-type mixer. Replenishing developer B Replenishing developer C was used. With respect to the black toner, the discharge port was closed so that the developer was not gradually discharged with the revolution of the developing device, and only the toner was supplied when replenishing.
[0209]
The following evaluation methods were used to evaluate the fusion of the toner to the surface of the photoreceptor, transfer efficiency, charge stability, image density, toner scattering, and fogging. Good results were obtained. Table 1 shows the evaluation results. In the following evaluation results A to F, A to C were regarded as practical levels.
[0210]
(Fusing toner to photoconductor surface)
The fusion of the toner to the photoreceptor surface was evaluated by the number of white spots in a solid black image output with black toner at the time of 500,000 sheets of durability. The evaluation criteria are as follows.
A: No fusion
B: 1 to 3 fusion points in A4 solid black
C: 4 to 6 points fused in A4 solid black
D: 7 to 9 fusion points in A4 solid black
E: Fusion of 10 to 15 points in A4 solid black
F: Fusion of 16 points or more in A4 solid black
[0211]
(Transfer efficiency)
The transfer efficiency was evaluated by performing a 500,000 copy test, forming a solid black image on the photoreceptor drum, collecting the solid black image with a transparent adhesive tape, and measuring the image density (D1) of the solid black image. It measured with the reflection densitometer (color reflection densitometer X-RITE404A manufactured by X-Rite Co.). Next, a solid black image is formed again on the photosensitive drum, the solid black image is transferred to a recording material, the solid black image transferred on the recording material is collected with a transparent adhesive tape, and its image density (D2 ) Was measured. The transfer efficiency was calculated from the obtained image densities (D1) and (D2) based on the following equation.
Transfer efficiency (%) = (D2 / D1) × 100
[0212]
(Charging stability)
As for the charge stability, a copy test was performed on 500,000 sheets, and the charge stability was evaluated from the change in the charge amount of the developer. The evaluation was carried out based on the following criteria, in which the change amount of the charge amount at the time of copying 1000 sheets and the change amount of the charge amount at the time of completion were expressed in%.
A: Change width of charge amount is less than 10%
B: Change width of charge amount is less than 10 to 20%
C: Change width of charge amount is less than 20 to 30%
D: Change width of charge amount is less than 30 to 40%
E: Change width of charge amount is less than 40 to 50%
F: Change width of charge amount is 50% or more
[0213]
(Toner scattering)
For toner scattering, after 500,000 sheets of images have been output, the developing device is taken out and set in an idle rotating machine. A4 paper was placed centering directly below the sleeve of the developing device, and idle rotation was performed for 10 minutes. The mass of the toner dropped on the paper was measured, and evaluated according to the following criteria.
A: Less than 3 mg
B: less than 3-6 mg
C: less than 6-9 mg
D: less than 9 to 12 mg
E: less than 12 to 15 mg
F: 15mg or more
[0214]
(Fog)
With respect to fog, the reflection density of a blank sheet and the reflection density of a non-image portion in the 500,000th sheet image are measured using a reflection densitometer (densitometer TC6MC: Tokyo Denshoku Technical Center) under high temperature and high humidity. Then, the difference between the two reflection densities was evaluated with reference to the reflection density of white paper.
A: less than 0.5%
B: 0.5 to less than 1.0%
C: 1.0 to less than 1.5%
D: less than 1.5 to 2.0%
E: 2.0 to less than 4.0%
F: 4.0% or more
[0215]
(Image density)
For the image density, a solid black image was copied at the initial stage and after copying of 500,000 sheets, and the density was measured with a color reflection densitometer X-RITE 404A manufactured by X-Rite Co.
[0216]
[Example 2]
An image output test was performed in the same manner as in Example 1 except that the developer and the replenishing developer were used so as to satisfy the conditions shown in Table 1. The image characteristics of the color toner were compared with those in Example 1. Although the result slightly worsened, a result having no practical problem was obtained. Table 1 shows the evaluation results.
[0217]
It is presumed that the cause of the slight deterioration was that the charge distribution became broad because all three types of inorganic fine particles contained different elements.
[0218]
[Example 3]
An image output test was performed in the same manner as in Example 1 except that the developer and the replenishing developer were used so as to satisfy the conditions shown in Table 1. The image characteristics of the color toner were compared with those in Example 1. Although the result slightly worsened, a result having no practical problem was obtained. Table 1 shows the evaluation results. The reason for the slight deterioration was that the role as a charging aid was not sufficient, and the adhesion to the toner was weak in material, and with the durability test, liberation proceeded, and the function as a spacer decreased. I guess that is because it has been done.
[0219]
[Example 4]
An image output test was performed in the same manner as in Example 1 except that the developer and the replenishing developer were used so that the conditions shown in Table 1 were satisfied. Although the result slightly deteriorated, a result having no practical problem was obtained. Table 1 shows the evaluation results. It is presumed that the reason for the slight deterioration was that the effect of polishing the fused matter adhered to the photoconductor was lost due to the disappearance of the magnetic toner.
[0220]
[Example 5]
An image output test was performed in the same manner as in Example 1 except that the developer and the replenishing developer were used so that the conditions shown in Table 1 were satisfied. Although the result was slightly deteriorated as compared with, a result having no practical problem was obtained. Table 1 shows the evaluation results. It is presumed that the reason for the slight deterioration was that the degree of spheroidization was reduced by the pulverization method and that the accumulation of fine powder was advanced due to durability.
[0221]
[Example 6]
The developer is made to satisfy the conditions shown in Table 1, and the discharge port is closed so that the developer is not gradually discharged with the revolution of the developing device. When the test was conducted in the same manner as in Example 1 while replenishing only the toner, the result was obtained that although the image characteristics of the color toner were slightly deteriorated as compared with Example 1, there was no practical problem. Was. Table 1 shows the evaluation results. It is presumed that the cause of the slight deterioration was that the carrier was not replaced and fresh carrier was not replenished, so that carrier deterioration such as toner spent on the carrier progressed as the test progressed.
[0222]
[Example 7]
The developer is made to satisfy the conditions shown in Table 1, and the discharge port is closed so that the developer is not gradually discharged with the revolution of the developing device. As a result, the image characteristics of the color toner were slightly deteriorated as compared with Example 1, but the result was no problem in practical use. Table 1 shows the evaluation results. The reason for the slight deterioration was that the carrier was not replaced, fresh carrier was not replenished, and the true specific gravity and magnetic properties of the carrier were high. It is presumed that the toner spent was caused.
[0223]
Example 8
An image output test was conducted in the same manner as in Example 1 except that the developer and the replenishing developer were used so as to satisfy the conditions shown in Table 1. As a result, good results were obtained. Table 1 shows the evaluation results. However, the replacement developer bottle and the waste developer container are frequently replaced, which causes a running cost up.
[0224]
[Example 9]
An image output test was performed in the same manner as in Example 1 except that the developer and the replenishing developer were used so as to satisfy the conditions shown in Table 1. The image characteristics of the color toner were compared with those in Example 1. Although the result slightly worsened, a result having no practical problem was obtained. Table 1 shows the evaluation results. It is presumed that the cause of the slight deterioration was that the amount of carrier in the replenished developer was small, so that fresh carrier was not sufficiently supplied.
[0225]
[Comparative Example 1]
When an image output test was performed in the same manner as in Example 1 except that the developer and the replenishing developer were used so as to satisfy the conditions shown in Table 2, the image characteristics of the color toner were deteriorated. Table 2 shows the evaluation results. This is because, among the functions of the inorganic fine particles, the charge assisting function was insufficient, so that the initial agent was charged more than necessary, and as the charge rising of the replenished developer progressed, it did not rise properly. I guess.
[0226]
[Comparative Example 2]
An image-drawing test was performed in the same manner as in Example 1 except that the developer, the replenishing developer, and the drum were used so that the conditions shown in Table 2 were satisfied. As a result, the test was terminated. Table 2 shows the evaluation results. It is presumed that this is a problem caused by the lack of the thickness of the OPC drum due to the scraping.
[0227]
[Table 1]

[0228]
[Table 2]

[0229]
【The invention's effect】
According to the present invention, a stable image can be obtained over a long period of time in any environment and in high-speed full-color image formation.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an amorphous silicon photoconductor.
FIG. 2 is a configuration diagram of an image forming apparatus provided with a rotary rotation type developing device and an intermediate transfer member.
FIG. 3 is a sectional view of a developing device of the developing device.
FIG. 4 is an enlarged configuration diagram of a developing device.
[Explanation of symbols]
100 Amorphous silicon photoreceptor
101 support
102 Photosensitive layer
103 Photoconductive layer
104 Amorphous silicon surface layer
105 charge injection blocking layer
106 charge generation layer
107 charge transport layer
L laser light
Pa-Pd image forming unit
R1 developer chamber
R2 stirring room
R3 replenishment developer storage room
T two-component developer
Ta toner
1 electrostatic latent image carrier
2, 3, 4, 5 developing unit
2a, 3a, 4a, 5a, 99a, 99d Replenishment developer container
6 Developing sleeve
7 Regulation members
8 Magnet roller
9, 66a Replenishment developer storage device
10 Developer transport screw
11 Developer transport screw
12 Transfer material
13 Replacement unit for developer
14 Exposure equipment
15 Charging device
15a Charging roller
16 Static eliminator
17 Developing tank
18 Cleaning device
20 Conveyor belt
21, 70 Fixing device
23 Cleaning device
25 Registration roller once
26 Feeding tray
28 Delivery roller
34 Developer outlet on developer side
36 Developer Recovery Auger

Claims (10)

The electrostatic latent image of the amorphous silicon-based electrostatic latent image carrier is composed of a black developer composed of a toner containing at least a binder resin and a colorant, and a color toner composed of at least a binder resin, a colorant and a fine inorganic particle. In an image forming method for selecting and developing one or more colors among a yellow developer, a magenta developer, and a cyan developer,
An image forming method, comprising at least three kinds of the inorganic fine particles. The image forming method according to claim 1, wherein the inorganic fine particles are at least selected from silica, titanium oxide, alumina, strontium titanate, and magnesium oxide, and contain or do not contain the same element. 3. The image forming method according to claim 1, wherein at least two of the inorganic fine particles are the same element. 4. The image forming method according to claim 1, wherein the black developer contains magnetic particles. The yellow developer, the magenta developer, and the cyan developer are a carrier-containing yellow two-component developer, a magenta two-component developer, and a cyan two-component developer. The image forming method according to claim 1. The image forming method according to claim 5, wherein the carrier is a magnetic material-dispersed carrier in which metal compound particles are dispersed in a binder resin. The visible color developed image formed on the electrostatic latent image carrier is transferred and carried on an intermediate transfer body, and all the color developed images are superimposed and transferred on the intermediate transfer body, and then transferred to a transfer material. The image forming method according to claim 1, wherein the image forming method is an intermediate transfer method that performs batch transfer. 8. The image forming method according to claim 1, wherein a process speed is 200 mm / sec or more. 9. The replenishing development for an image forming method according to claim 1, wherein the developing is performed while replenishing a yellow replenishing developer, a magenta replenishing developer, and a cyan replenishing developer comprising a color toner and a carrier. Agent. The replenishing developer may contain 2 to 50 parts by mass of a toner selected from the group consisting of a yellow toner, a magenta toner, and a cyan toner with respect to 1 part by mass of carrier particles. The replenishing developer according to claim 9, wherein:

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