JP4006283B2 - Toner, image forming method and image forming apparatus - Google Patents

Description

【００４７】
【数３】

【００４８】
本発明のトナーのＴＨＦ可溶成分の酸価を測定することができる測定方法の具体例を以下に示す。この測定例における基本操作はＪＩＳ Ｋ−００７０に準ずる。また以下の測定例はトナーを測定対象とする方法であるが、同様にして結着樹脂のＴＨＦ可溶成分の酸価を測定することができる。
【００４９】
＜酸価の測定＞
試料０．５〜２．０（ｇ）を精秤する。試料には必要に応じて粉砕品を用いる。また試料は、着色剤、結着樹脂中の不溶分等のＴＨＦ不溶成分を予め除去して使用するか、ＴＨＦ不溶成分の含有量を予め求めておく。精秤した試料中のＴＨＦ可溶成分の重さをＷ（ｇ）とする。
【００５０】
３００（ｍｌ）のビーカーに試料を入れ、トルエン／エタノール（４／１）の混合液１５０（ｍｌ）を加え溶解する。この溶液に、電位差滴定装置を用いて０．１ｍｏｌ／ｌのＫＯＨのエタノール溶液を滴定する。より具体的には、例えば、京都電子株式会社製の電位差滴定装置ＡＴ−４００（ｗｉｎ ｗｏｒｋｓｔａｔｉｏｎ）とＡＢＰ−４１０電動ビュレットを用いての自動滴定が利用できる。
【００５１】
この時のＫＯＨ溶液の使用量をＳ（ｍｌ）とし、同時にブランクを測定し、この時のＫＯＨ溶液の使用量をＢ（ｍｌ）とする。得られた結果から次式により酸価を計算する。ｆはＫＯＨのファクターである。
【００５２】
【数４】
酸価（ｍｇＫＯＨ／ｇ）＝｛（Ｓ−Ｂ）×ｆ×５．６１｝／Ｗ
【００５３】
本発明のトナーのガラス転移温度を測定することができる測定方法の具体例を以下に示す。
【００５４】
＜ガラス転移温度の測定＞
トナーのガラス転移温度（Ｔｇ）は、示差走査熱量計（ＤＳＣ測定装置）、ＤＳＣ−７（パーキンエルマー社製）や他機種を用いて、ＡＳＴＭ Ｄ３４１８−８２に準じて測定する。
【００５５】
測定試科は５〜２０ｍｇ、好ましくは１０ｍｇを精密に秤量する。これをアルミパン中に入れ、リファレンスとして空のアルミパンを用い、測定温度範囲３０〜２００℃の間で、昇温速度１０℃／ｍｉｎで常温常湿下で測定を行う。この昇温過程で、温度４０〜１００℃の範囲において比熱変化が得られる。このときの比熱変化が出る前と出た後のベースラインの中間点の線と示差熱曲線との交点を、本発明におけるトナーのガラス転移温度Ｔｇとする。
【００５６】
本発明のトナーは結着樹脂を含有し、結着樹脂は、少なくともカルボキシル基を有するビニル樹脂とグリシジル基を有するビニル樹脂の混合物とを含有するか、カルボキシル基とグリシジル基を有するビニル樹脂を含有するか、カルボキシル基とグリシジル基とが反応したビニル樹脂を少なくとも含有する。
【００５７】
前記ビニル樹脂の混合物は、カルボキシル基を有するビニル樹脂とグリシジル基を有するビニル樹脂とを用意し、これらを混合することによって得られる。前記カルボキシル基とグリシジル基を有するビニル樹脂は、例えばカルボキシル基を有するビニル系モノマーと、グリシジル基を有するビニル系モノマーとを共重合することによって得られる。前記カルボキシル基とグリシジル基とが反応したビニル樹脂は、例えばカルボキシル基を有するビニル樹脂のカルボキシル基と、グリシジル基を有するビニル樹脂のグリシジル基とを、グリシジル基の環状エーテルが少なくとも開環する適当な条件下で反応させることによって得られる。
【００５８】
前記カルボキシル基を有するビニル樹脂は、カルボキシル基を有するモノマーの一種又は二種以上を用いて、ビニル系モノマーと公知の重合方法により共重合させることにより得られる。カルボキシル基を有するビニル樹脂を構成する、カルボキシル基を有するモノマーとしては、以下のものが挙げられる。
【００５９】
カルボキシル基を有するモノマーとしては、例えば、アクリル酸、メタクリル酸、α−エチルアクリル酸、クロトン酸、ケイヒ酸、ビニル酢酸、イソクロトン酸、チグリン酸及びアンゲリカ酸等の不飽和モノカルボン酸、及びこれらのα−或いはβ−アルキル誘導体、フマル酸、マレイン酸、シトラコン酸、アルケニルコハク酸、イタコン酸、メサコン酸、ジメチルマレイン酸、ジメチルフマル酸等の不飽和ジカルボン酸、そのモノエステル誘導体、無水物及びα−あるいはβ−アルキル誘導体が挙げられる。
【００６０】
以上のようなカルボキシル基を有するモノマーは、結着樹脂を構成する全モノマー１００質量部に対し０．１〜５０質量部、好ましくは０．１〜３０質量部、より好ましくは０．２〜１５質量部添加すればよい。
【００６１】
カルボキシル基を有するビニル樹脂の酸価は、１００ｍｇＫＯＨ／ｇ以下であることが好ましい。前記樹脂の酸価が１００ｍｇＫＯＨ／ｇ以下であると、均一かつトナーの帯電の適度なバランスがとられ、現像装置における現像剤担持体上におけるブロッチ発生や過剰帯電による凝集現象の加速を抑え、トナー流動性、搬送性、クリーニング性を向上させ、円滑な現像プロセスを実現する上で好ましい。１００ｍｇＫＯＨ／ｇを超える場合には、トナー粒子中の結着樹脂の負帯電性が過剰になり、画像濃度が低下し、カブリが増加することがある。
【００６２】
カルボキシル基を有するビニル樹脂のガラス転移温度（Ｔｇ）は、４０〜７０℃であることが好ましい。Ｔｇが４０℃未満の場合、トナーの耐ブロッキング性が悪化しやすく、７０℃を超える場合はトナーの定着性が悪化しやすい。
【００６３】
カルボキシル基を有するビニル樹脂は、良好な定着性を達成する観点から、数平均分子量が１，０００乃至４０，０００であることが好ましく、良好な耐オフセット性や耐ブロッキング性を達成する観点から、重量平均分子量が１０，０００乃至１，０００，０００であることが好ましい。
【００６４】
カルボキシル基を有するビニル樹脂は、低分子量成分と高分子量成分とを有することが好ましく、良好な定着性を達成する観点から、低分子量成分のピーク分子量は４，０００乃至３０，０００が好ましく、良好な耐オフセット性及び耐ブロッキング性を達成する観点から、高分子量成分のピーク分子量は５０，０００乃至１，０００，０００が好ましい。低分子量成分及び高分子量成分が共に上記分子量分布の範囲を満たす場合では、低温定着性と耐オフセット性の両方をさらに高度に達成できる。
【００６５】
さらに、カルボキシル基を有するビニル樹脂は、トナー構成成分の分散性を向上させる観点から、ＴＨＦ不溶分が１０質量％以下であることが好ましく、さらには５質量％以下であることが良い。
【００６６】
前記カルボキシル基を有するビニル樹脂のうち、高分子量成分の合成方法として本発明に用いることのできる重合法としては、塊状重合法、溶液重合法、乳化重合法や懸濁重合法が挙げられる。
【００６７】
このうち、乳化重合法は、水にほとんど不溶の単量体（モノマー）を乳化剤で小さい粒子として水相中に分散させ、水溶性の重合開始剤を用いて重合を行う方法である。この方法では反応熱の調節が容易であり、重合の行われる相（重合体と単量体からなる油相）と水相とが別であるから停止反応速度が小さく、その結果重合速度が大きく、高重合度のものが得られる。さらに、重合プロセスが比較的簡単であること、及び重合生成物が微細粒子であるために、トナーの製造において、着色剤、及び荷電制御剤等の、その他の添加物との混合が容易であること等の理由から、トナー用結着樹脂の製造方法として有利な点がある。
【００６８】
しかし、添加した乳化剤のため重合体が不純になり易く、重合体を取り出すには塩析等の操作が必要で、この不便を避けるためには懸濁重合法が好都合である。
【００６９】
懸濁重合法においては、水系溶媒１００質量部に対して、モノマー１００質量部以下（好ましくは１０〜９０質量部）で行うことが好ましい。使用可能な分散剤としては、ポリビニルアルコール、ポリビニルアルコール部分ケン化物、リン酸カルシウム等が挙げられ、一般に水系溶媒１００質量部に対して０．０５〜１質量部で用いられる。重合温度は５０〜９５℃が適当であるが、使用する開始剤、目的とするポリマーによって適宜選択される。
【００７０】
前記高分子量成分は、本発明の目的を達成する為に、以下に例示するような多官能性重合開始剤の一種又は二種以上の使用、又は多官能性重合開始剤と単官能性重合開始剤との併用によって生成することが好ましい。
【００７１】
多官能構造を有する多官能性重合開始剤の具体例としては、１，１−ジ−ｔ−ブチルパーオキシ−３，３，５−トリメチルシクロヘキサン、１，３−ビス（ｔ−ブチルパーオキシイソプロピル）ベンゼン、２，５−ジメチル−２，５（ｔ−ブチルパーオキシ）ヘキサン、２，５−ジメチル−２，５−ジ−（ｔ−ブチルパーオキシ）ヘキサン、トリス（ｔ−ブチルパーオキシ）トリアジン、１，１−ジ−ｔ−ブチルパーオキシシクロヘキサン、２，２−ジ−ｔ−ブチルパーオキシブタン、４，４−ジ−ｔ−ブチルパーオキシバレリックアシッド−ｎ−ブチルエステル、ジ−ｔ−ブチルパーオキシヘキサハイドロテレフタレート、ジ−ｔ−ブチルパーオキシアゼレート、ジ−ｔ−ブチルパーオキシトリメチルアジペート、２，２−ビス（４，４−ジ−ｔ−ブチルパーオキシシクロヘキシル）プロパン、２，２−ｔ−ブチルパーオキシオクタン及び各種ポリマーオキサイドのように、パーオキサイド基等の重合開始機能を一分子内に二つ以上有する官能基を有する多官能性重合開始剤、及び、ジアリルパーオキシジカーボネート、ｔ−ブチルパーオキシマレイン酸、ｔ−ブチルパーオキシアリルカーボネート及びｔ−ブチルパーオキシイソプロピルフマレートのように、パーオキサイド基等の重合開始機能を有する官能基と重合性不飽和基との両方を一分子内に有する多官能性重合開始剤等が挙げられる。
【００７２】
これらの内、より好ましいものは、１，１−ジ−ｔ−ブチルパーオキシ−３，３，５−トリメチルシクロヘキサン、１，１−ジ−ｔ−ブチルパーオキシシクロヘキサン、ジ−ｔ−ブチルパーオキシヘキサハイドロテレフタレート、ジ−ｔ−ブチルパーオキシアゼレート、２，２−ビス（４，４−ジ−ｔ−ブチルパーオキシシクロヘキシル）プロパン、及びｔ−ブチルパーオキシアリルカーボネートである。
【００７３】
これらの多官能性重合開始剤は、二官能又は単官能性重合開始剤と併用されることが、トナー用結着樹脂として要求される種々の性能を満足する上で好ましい。特に、半減期１０時間を得る為の分解温度において、前記多官能性重合開始剤よりも低い分解温度の重合開始剤と前記多官能性重合開始剤とを併用することが好ましい。
【００７４】
前記二官能又は単官能性重合開始剤としては、具体的には、ベンゾイルパーオキシド、１，１−ジ（ｔ−ブチルパーオキシ）−３，３，５−トリメチルシクロヘキサン、ｎ−ブチル−４，４−ジ（ｔ−ブチルパーオキシ）バレレート、ジクミルパーオキシド、α，α’−ビス（ｔ−ブチルパーオキシジイソプロピル）ベンゼン、ｔ−ブチルパーオキシクメン、ジ−ｔ−ブチルパーオキシド等の有機過酸化物、アゾビスイソブチロニトリル、ジアゾアミノアゾベンゼン等のアゾ及びジアゾ化合物が挙げられる。
【００７５】
これらの重合開始剤は、前記多官能性重合開始剤と同時にモノマー中に添加しても良いが、前記多官能性重合開始剤の効率を適正に保つ為には、重合工程において前記多官能性重合開始剤の示す半減期を経過した後に添加することが好ましい。またこれらの重合開始剤は、効率の点からモノマー１００質量部に対し０．０１〜１０質量部で用いるのが好ましい。
【００７６】
前記カルボキシル基を有するビニル樹脂のうち、低分子量成分の合成方法としては、公知の方法を用いることができる。しかしながら、塊状重合法では、高温で重合させて停止反応速度を速めることで、低分子量の重合体を得ることができるが、反応をコントロールしにくいという問題点がある。その点、溶液重合法では、溶媒による、ラジカルの連鎖移動の差を利用して、また、開始剤量や反応温度を調整することで、低分子量重合体を温和な条件で容易に得ることができ、前記低分子量成分を得る上で好ましい。
【００７７】
溶液重合で用いる溶媒として、キシレン、トルエン、クメン、酢酸セロソルブ、イソプロピルアルコール又はベンゼンが用いられる。スチレンモノマーを使用する場合、キシレン、トルエン又はクメンが好ましい。重合するポリマーによって溶媒は適宜選択される。反応温度としては、使用する溶媒、重合開始剤、重合するポリマーによって異なるが、通常７０〜２３０℃で行うことが好ましい。溶液重合においては、溶媒１００質量部に対してモノマー３０質量部〜４００質量部で行うことが好ましい。さらに、重合終了時に溶液中で他の重合体を混合することも好ましく、このような操作を行うことにより、数種の重合体を混合できる。
【００７８】
グリシジル基を有するビニル樹脂は、グリシジル基を有するモノマーの一種又は二種以上と、ビニル系モノマーとを用いて、公知の重合方法により共重合させることにより得られる。
【００７９】
前記グリシジル基を有するモノマーとしては、ビニル基とエポキサイドを有する化合物であれば良く、例えば、グリシジルアルコールと不飽和カルボン酸のエステル、不飽和グリシジルエーテル等が挙げられ、例えば、アクリル酸グリシジル、メタクリル酸グリシジル、アクリル酸−β−メチルグリシジル、メタクリル酸−β−メチルグリシジル、アリルグリシジルエーテル、アリル−β−メチルグリシジルエーテル等が挙げられる。特に、下記一般式（１）で表されるグリシジルモノマーが好ましく用いられる。
【００８０】
【化１】

【００８１】
グリシジル基を有するビニル樹脂は、重量平均分子量（Ｍｗ）が２，０００乃至１００，０００であることが好ましく、２，０００乃至５０，０００であることがより好ましく、３，０００乃至４０，０００であることがさらに好ましい。Ｍｗが２，０００未満の場合では、結着樹脂中の架橋反応において分子量が増大しても混練工程においての分子鎖切断が多く、耐オフセット性への効果が少なくなる場合がある。Ｍｗが１００，０００を超える場合には、定着性に影響を及ぼすようになる場合がある。
【００８２】
グリシジル基を有するビニル樹脂は、エポキシ価が０.０１乃至５.０ｅｑ／ｋｇであることが好ましく、０.０１乃至３.０ｅｑ／ｋｇの範囲であることがさらに好ましく、０.０５乃至１.０ｅｑ／ｋｇの範囲であることが特に好ましい。０．０１ｅｑ／ｋｇ未満の場合では、架橋反応が起こりにくく、高分子量成分やＴＨＦ不溶分の生成量が少なく、耐オフセット性への効果が減少する。５．０ｅｑ／ｋｇを超える場合では、架橋反応は起こりやすくなる反面、混練工程においての分子鎖切断が多く、耐オフセット性への効果が減少する。
【００８３】
グリシジル基を有するビニル樹脂は、架橋反応をより効果的に行う観点から、ＴＨＦ不溶分が１０質量％以下であることが好ましく、５質量％以下であることがさらに好ましい。
【００８４】
グリシジル基を有するビニル樹脂のエポキシ価を測定することができる具体的な測定例を以下に示す。前記エポキシ価の測定における基本操作はＪＩＳ Ｋ−７２３６に準ずる。
【００８５】
＜エポキシ価の測定＞
試料を０．５〜２．０（ｇ）を精秤する。グリシジル基を有するビニル樹脂の重さをＷ（ｇ）とする。精秤した試料を３００ｍｌのビーカーに入れ、クロロホルム１０ｍｌ及び酢酸２０ｍｌに溶解する。この溶液に、臭化テトラエチルアンモニウム酢酸溶液１０ｍｌを加える。０．１ｍｏｌ／ｌの過塩素酸酢酸溶液を用いて、電位差滴定装置を用いて滴定する。この滴定には、例えば、京都電子株式会社製の電位差滴定装置ＡＴ−４００（ｗｉｎ ｗｏｒｋｓｔａｔｉｏｎ）とＡＢＰ−４１０電動ビュレットとを用いての自動滴定が利用できる。この滴定による過塩素酸酢酸溶液の使用量をＳ（ｍｌ）とする。一方でブランクを測定し、この時の過塩素酸酢酸溶液の使用量をＢ（ｍｌ）とする。これらの結果から下記式によりエポキシ価を計算する。ｆは過塩素酸酢酸溶液のファクターである。
【００８６】
【数５】
エポキシ価（ｅｑ／ｋｇ）＝０．１×ｆ×（Ｓ−Ｂ）／Ｗ
【００８７】
混合すること又は反応させることを目的に、前述した両ビニル樹脂を用いる場合では、グリシジル基を有するビニル樹脂は、カルボキシル基を有するビニル樹脂中のカルボキシル基１当量に対して、グリシジル基が０．０１乃至１００．０当量、好ましくは０．０３乃至１０．０当量、さらに好ましくは０．０５乃至５．０当量の混合比率で用いられることが好ましい。グリシジル基が０．０１当量未満の場合は、結着樹脂中において、架橋点が少なくなり、耐オフセット性等の架橋反応による効果が発現しにくくなる。また、１００当量を超えると、架橋反応は起こりやすくなる反面、現像性への影響が出る場合がある。
【００８８】
カルボキシル基及びグリシジル基を有するビニル樹脂においては、数平均分子量は、良好な定着性を達成するため、１，０００乃至４０，０００が好ましい。また、重量平均分子量は、良好な耐オフセット性及び耐ブロッキング性を達成するため、１０，０００乃至１，０００，０００が好ましい。これらの分子量を持つ樹脂に対し、前述したような酸価とエポキシ価を導入することで、目的とする樹脂が得られる。前記ビニル樹脂は、トナー構成材料の分散性をよくするために、ＴＨＦ不溶分が１０質量％以下であることが好ましく、さらには５質量％以下であることが良い。
【００８９】
本発明のトナーは、結着樹脂成分中のカルボキシル基とグリシジル基との間に、製造工程中の混練工程等の加熱工程において架橋反応を施しても良い。この架橋性成分は、耐オフセット性の向上と現像性、耐久性に対して有利に働いている。
【００９０】
カルボキシル基を有するモノマー、及びグリシジル基を有するモノマーと共重合させる前記ビニル系モノマーとしては、例えばスチレン；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−フェニルスチレン、ｐ−クロルスチレン、３，４−ジクロルスチレン、ｐ−エチルスチレン、２，４−ジメチルスチレン、ｐ−ｎ−ブチルスチレン、ｐ−ｔｅｒｔ−ブチルスチレン、ｐ−ｎ−ヘキシルスチレン、ｐ−ｎ−オクチルスチレン、ｐ−ｎ−ノニルスチレン、ｐ−ｎ−デシルスチレン及びｐ−ｎ−ドデシルスチレンの如きスチレン誘導体；エチレン、プロピレン、ブチレン及びイソブチレンの如きエチレン不飽和モノオレフィン類；ブタジエン、イソプレンの如き不飽和ポリエン類；塩化ビニル、塩化ビニリデン、臭化ビニル、フッ化ビニルの如きハロゲン化ビニル類；酢酸ビニル、プロピオン酸ビニル、安息香酸ビニルの如きビニルエステル類；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の如きα−メチレン脂肪族モノカルボン酸エステル類；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の如きアクリル酸エステル類；ビニルメチルエーテル、ビニルエチルエーテル、ビニルイソブチルエーテルの如きビニルエーテル類；ビニルメチルケトン、ビニルヘキシルケトン、メチルイソプロペニルケトンの如きビニルケトン類；Ｎ−ビニルピロール、Ｎ−ビニルカルバゾール、Ｎ−ビニルインドール、Ｎ−ビニルピロリドンの如きＮ−ビニル化合物；ビニルナフタリン類；アクリロニトリル、メタクリロニトリル、アクリルアミドの如きアクリル酸誘導体若しくはメタクリル酸誘導体等が挙げられる。これらのビニル系モノマーは、一種又は二種以上が用いられる。
【００９１】
これらの中でもスチレン系共重合体及びスチレン−アクリル系共重合体となるようなモノマーの組み合わせが好ましく、この場合、少なくともスチレン系共重合体成分又はスチレン−アクリル系共重合体成分を６０質量％以上含有することが定着性や混合性の点で好ましい。
【００９２】
本発明のトナーに使用される結着樹脂としては、その他、下記の重合体の使用も可能である。
【００９３】
このような重合体としては、例えば、ポリスチレン、ポリ−ｐ−クロルスチレン、ポリビニルトルエンの如きスチレン及びその置換体の単重合体；スチレン−ｐ−クロルスチレン共重合体、スチレン−ビニルトルエン共重合体、スチレン−ビニルナフタリン共重合体、スチレン−アクリル酸エステル共重合体、スチレン−メタクリル酸エステル共重合体、スチレン−α−クロルメタクリル酸メチル共重合体、スチレン−アクリロニトリル共重合体、スチレン−ビニルメチルエーテル共重合体、スチレン−ビニルエチルエーテル共重合体、スチレン−ビニルメチルケトン共重合体、スチレン−ブタジエン共重合体、スチレン−イソプレン共重合体、スチレン−アクリロニトリル−インデン共重合体の如きスチレン系共重合体；ポリ塩化ビニル、フェノール樹脂、天然変性フェノール樹脂、天然樹脂変性マレイン酸樹脂、アクリル樹脂、メタクリル樹脂、ポリ酢酸ビニル、シリコーン樹脂、ポリエステル樹脂、ポリウレタン、ポリアミド樹脂、フラン樹脂、エポキシ樹脂、キシレン樹脂、ポリビニルブチラール、テルペン樹脂、クマロンインデン樹脂、石油系樹脂等が挙げられる。
【００９４】
本発明に用いられる着色剤には、磁性体や非磁性の染料や顔料等、種々の公知の着色剤を用いることが可能である。本発明のトナーを磁性一成分トナーに適用する場合には、トナーに磁性体が含有される。
【００９５】
本発明において用いられる磁性体としては、マグネタイト、マグヘマイト、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、錫、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の合金及びその混合物が用いられ、その磁性体表面或いは内部に非鉄元素を含有するものが好ましい。さらに本発明のトナーは、結着樹脂１００質量部に対して磁性体を３０〜２００質量部含有する磁性トナーであることが好ましい。この場合、磁性体によって十分な着色効果が得られる。
【００９６】
本発明に用いられる磁性体としては、マグネタイト、マグヘマイト、フェライト等の酸化鉄；鉄、コバルト、ニッケルのような金属あるいはこれらの金属と、アルミニウム、コバルト、銅、鉛、マグネシウム、マンガン、セレン、チタン、タングステン、バナジウムのような金属との合金及びその混合物が用いられ、磁性体表面あるいは内部に非鉄元素を含有するものが好ましい。
【００９７】
本発明に用いられる磁性体は、異種元素を含有するマグネタイト、マグヘマイト、フェライト等の磁性酸化鉄及びその混合物が好ましく用いられる。中でもリチウム、ベリリウム、ボロン、マグネシウム、アルミニウム、シリコン、リン、ゲルマニウム、チタン、ジルコニウム、錫、鉛、亜鉛、カルシウム、バリウム、スカンジウム、バナジウム、クロム、マンガン、コバルト、銅、ニッケル、ガリウム、カドミウム、インジウム、銀、パラジウム、金、水銀、白金、タングステン、モリブデン、ニオブ、オスミウム、ストロンチウム、イットリウム、テクネチウム、ルテニウム、ロジウム、ビスマスから選ばれる少なくとも一つ以上の元素を含有する磁性酸化鉄であることが好ましい。特にリチウム、ベリリウム、ボロン、マグネシウム、アルミニウム、シリコン、リン、ゲルマニウム、ジルコニウム、錫、第４周期の遷移金属元素が好ましい元素である。
【００９８】
これらの元素は酸化鉄結晶格子の中に取り込まれても良いし、酸化物として酸化鉄中に取り込まれても良いし、表面に酸化物あるいは水酸化物として存在しても良い。これらの形態の中でも、酸化物として含有されているのが好ましい形態である。
【００９９】
また、場合により、本発明のトナーに用いられる磁性酸化鉄は、シランカップリング剤、チタンカップリング剤、チタネート、アミノシラン等で処理しても良い。
【０１００】
これらの磁性酸化鉄は、種類によっても異なるが、着色力と現像性や搬送性に係る磁性とを両立させる観点から、結着樹脂１００質量部に対し２０〜２００質量部で好ましく用いられる。より好ましくは４０〜１５０質量部で用いられる。
【０１０１】
本発明に用いられる着色剤としては、上記磁性酸化鉄の他、任意の適当な顔料又は染料が挙げられる。例えば顔料としては、カーボンブラック、アニリンブラック、アセチレンブラック、ナフトールイエロー、ハンザイエロー、ローダミンレーキ、アリザリンレーキ、ベンガラ、フタロシアニンブルー、インダンスレンブルー等が挙げられる。これらは、定着画像の光学濃度を維持するために必要十分な量が用いられ、その配合量は種類等によって異なるが、結着樹脂１００質量部に対し０．１〜２０質量部であることが好ましく、０．２〜１０質量部であることがより好ましい。
【０１０２】
また、同様の目的で、さらに染料が用いられる。染料としては、例えば、アゾ系染料、アントラキノン系染料、キサンテン系染料、メチン系染料が挙げられ、その配合量は種類等によって異なるが、結着樹脂１００質量部に対し０．１〜２０質量部であることが好ましく、０．３〜１０質量部であることがより好ましい。
【０１０３】
本発明のトナーは、磁性トナーとしても非磁性トナーとしもいずれにも用いられるが、重量平均径が２．５〜１０μｍであることが、帯電均一性を促進し、トナーの凝集性を軽減し、画像濃度を向上させ、及びカブリの改善等により現像性を向上させる上で好ましい。特に、重量平均径が２．５〜６．０μｍのトナーにおいてはその効果は顕著であり、極めて高精細な画像が得られる。重量平均径は２．５μｍ以上である方が十分な画像濃度が得られて好ましい。重量平均径は、トナーの製造方法及び製造条件や、分級作業等によって調整することが可能である。
【０１０４】
本発明のトナーの重量平均径及び粒度分布は、コールター法を用いて測定することができ、例えばコールターマルチサイザー（コールター社製）を用いることが可能である。この測定法では電解液が使用されるが、この電解液には、例えば１級塩化ナトリウムを用いて調製された１％ＮａＣｌ水溶液や、ＩＳＯＴＯＮ Ｒ−ＩＩ（コールターサイエンティフィックジャパン社製）が使用できる。
【０１０５】
測定法としては、前記電解水溶液１００〜１５０ｍｌ中に分散剤として界面活性剤（好ましくはアルキルベンゼンスルホン酸塩）を０．１〜５ｍｌ加え、さらに測定試料を２〜２０ｍｇ加える。これを超音波分散器で約１〜３分間分散処理して試料を分散し、アパーチャーとして１００μｍアパーチャーを用い、前記測定装置により２．００μｍ以上のトナー粒子の体積、個数を測定し、体積分布と個数分布とを算出する。それから本発明に係る体積分布から求めた重量基準の重量平均径（Ｄ４）を算出する。
【０１０６】
チャンネルとしては、２．００〜２．５２μｍ未満；２．５２〜３．１７μｍ未満；３．１７〜４．００μｍ未満；４．００〜５．０４μｍ未満；５．０４〜６．３５μｍ未満；６．３５〜８．００μｍ未満；８．００〜１０．０８μｍ未満；１０．０８〜１２．７０μｍ未満；１２．７０〜１６．００μｍ未満；１６．００〜２０．２０μｍ未満；２０．２０〜２５．４０μｍ未満；２５．４０〜３２．００μｍ未満；３２．００〜４０．３０μｍ未満の１３チャンネルを用いる。
【０１０７】
本発明のトナーは、ワックスを含有してもよい。本発明に用いられるワックスには、例えばパラフィンワックス及びその誘導体、モンタンワックス及びその誘導体、マイクロクリスタリンワックス及びその誘導体、フィッシャートロプシュワックス及びその誘導体、ポリオレフィンワックス及びその誘導体、カルナバワックス及びその誘導体等が挙げられる。誘導体には、酸化物、ビニル系モノマーとのブロック共重合物、及びグラフト変性物を含む。
【０１０８】
本発明のトナーにおいては、これらのワックス総含有量は、結着樹脂１００質量部に対し、０．１〜１５質量部であることが好ましく、０．５〜１２質量部であることがより好ましい。また、複数種類のワックスを併用してもよい。
【０１０９】
本発明のトナーは、荷電制御剤を含有することが好ましい。トナーを負荷電性に制御するものとしては、例えば有機金属錯体、キレート化合物が有効であり、モノアゾ金属錯体、アセチルアセトン金属錯体、芳香族ハイドロキシカルボン酸、芳香族ダイカルボン酸系の金属錯体、その他にも、芳香族ハイドロキシカルボン酸、芳香族モノ及びポリカルボン酸及びその金属塩、無水物、エステル類、ビスフェノール等のフェノール誘導体類等が挙げられる。また、トナーを負帯電性に制御する荷電制御剤としては、下記一般式（２）で表されるアゾ系金属錯体が好ましい。
【０１１０】
【化２】

【０１１１】
上記一般式（２）で表される荷電制御剤では、特に、中心金属としてはＦｅ又はＣｒが好ましく、置換基としてはハロゲン、アルキル基、アニリド基が好ましく、カウンターイオンとしては水素、アルカリ金属アンモニウム、脂肪族アンモニウムが好ましい。またカウンターイオンの異なる錯塩の混合物も好ましく用いられる。
【０１１２】
またトナーを負帯電性に制御する荷電制御剤としては、例えば下記一般式（３）で表される塩基性有機酸金属錯体が挙げられる。
【０１１３】
【化３】

【０１１４】
上記一般式（３）で表される荷電制御剤では、特に、中心金属としてはＦｅ、Ｃｒ、Ｓｉ、Ｚｎ、Ａｌが好ましく、置換基としてはアルキル基、アニリド基、アリール基、ハロゲンが好ましく、カウンターイオンは水素、アンモニウム、脂肪族アンモニウムが好ましい。
【０１１５】
上記一般式（３）で表される荷電制御剤の中でもアゾ系金属錯体がより好ましく、さらには下記一般式（４）で表されるアゾ系鉄錯体が最も好ましい。
【０１１６】
【化４】

【０１１７】
上記一般式（４）で表されるアゾ系金属錯体の具体例を下記構造式（５）〜（１０）を以下に示す。
【０１１８】
【化５】

【０１１９】
【化６】

【０１２０】
【化７】

【０１２１】
【化８】

【０１２２】
【化９】

【０１２３】
【化１０】

【０１２４】
本発明のトナーを正帯電性に制御するものとしては、例えばニグロシン及び脂肪酸金属塩等による変成物；トリブチルベンジルアンモニウム−１−ヒドロキシ−４−ナフトスルホン酸塩、テトラブチルアンモニウムテトラフルオロボレート等の四級アンモニウム塩、及びこれらの類似体であるホスホニウム塩等のオニウム塩及びこれらのレーキ顔料、トリフェニルメタン染料及びこれらのレーキ顔料（レーキ化剤としては、リンタングステン酸、リンモリブデン酸、リンタングステンモリブデン酸、タンニン酸、ラウリン酸、没食子酸、フェリシアン化物、フェロシアン化物等）、高級脂肪酸の金属塩；ジブチルスズオキサイド、ジオクチルスズオキサイド、ジシクロヘキシルスズオキサイド等のジオルガノスズオキサイド；ジブチルスズボレート、ジオクチルスズボレート、ジシクロヘキシルスズボレート等のジオルガノスズボレート類；グアニジン化合物、イミダゾール化合物等が挙げられ、これらの一種又は二種以上を用いることができる。これらの中でも、トリフェニルメタン化合物、カウンターイオンがハロゲンでない四級アンモニウム塩が好ましく用いられる。
【０１２５】
また、下記一般式（１１）で表されるモノマーの単重合体；前述したスチレン、アクリル酸エステル、メタクリル酸エステルの如き重合性モノマーとの共重合体を正荷電性制御剤として用いることができる。この場合これらの荷電制御剤は、結着樹脂（の全部又は一部）としての作用をも有する。
【０１２６】
【化１１】

【０１２７】
前記正帯電性の荷電制御剤としては、特に下記一般式（１２）で表される化合物が好ましい。
【０１２８】
【化１２】

【０１２９】
荷電制御剤をトナーに含有させる方法としては、トナー内部に添加する方法と外添する方法がある。これらの荷電制御剤の使用量としては、結着樹脂の種類、他の添加剤の有無、分散方法を含めたトナー製造方法によって決定されるもので、一義的に限定されるものではないが、結着樹脂１００質量部に対して０．１〜１０質量部であることが好ましく、０．１〜５質量部であることがより好ましい。
【０１３０】
本発明のトナーは、結着樹脂や着色剤を少なくとも含有するトナー粒子に、粒径の小さな粒子を外添剤として外添することが好ましい。このような外添剤としては、例えばシリカ、アルミナ、酸化チタン等の無機酸化物や、カーボンブラック、フッ化カーボンの如き粒径の細かい粒子等が挙げられる。
【０１３１】
特にシリカ、アルミナ及び酸化チタン微粉体は、トナーの流動性を向上させる効果が大きく好ましい。このような観点から、前記無機酸化物の粒子は、個数平均粒径が５〜２００ｎｍであることが好ましく、１０〜１００ｎｍであることがより好ましい。
【０１３２】
また前記無機酸化物の粒子は、ＢＥＴ法で測定した窒素吸着による比表面積が３０ｍ²／ｇ以上であることが好ましく、６０〜４００ｍ²／ｇであることがより好ましい。また前記無機酸化物の粒子は、表面を疎水化処理して用いても良く、このような表面処理された無機酸化物の粒子の前記比表面積は、２０ｍ²／ｇ以上であることが好ましく、４０〜３００ｍ²／ｇであることがより好ましい。
【０１３３】
前記無機酸化物の粒子の適用量は、トナー粒子１００質量部に対して、０．０３〜５質量部であることが、トナー粒子の表面を前記粒子で適度に被覆する上で好ましい。
【０１３４】
前記無機酸化物の粒子は、疎水化度がメタノールウェッタビリティーで３０％以上であることが好ましく、５０％以上であることがより好ましい。好ましい疎水化処理剤としては、含ケイ素表面処理剤であるシラン化合物、及びシリコーンオイルが挙げられる。
【０１３５】
前記シラン化合物としては、例えば、ジメチルジメトキシシラン、トリメチルエトキシシラン、ブチルトリメトキシシラン等のアルキルアルコキシシランや、ジメチルジクロルシラン、トリメチルクロルシラン、アリルジメチルクロルシラン、ヘキサメチルジシラザン、アリルフェニルジクロルシラン、ベンジルジメチルクロルシラン、ビニルトリエトキシシラン、γ−メタクリルオキシプロピルトリメトキシシラン、ビニルトリアセトキシシラン、ジビニルクロルシラン、ジメチルビニルクロルシラン等のシラン化合物が挙げられる。またシリコーンオイルとしては、公知のものを使用することができる。シラン化合物及びシリコーンオイルは併用することも可能である。
【０１３６】
また、本発明のトナーには、トナーの現像性、耐久性を向上させる観点から、他の無機粉体を外添剤として添加することも好ましい。このような無機粉体としては、例えばマグネシウム、亜鉛、アルミニウム、セリウム、コバルト、鉄、ジルコニウム、クロム、マンガン、ストロンチウム、錫、アンチモン等の金属酸化物；チタン酸カルシウム、チタン酸マグネシウム、チタン酸ストロンチウム等の複合金属酸化物；炭酸カルシウム、炭酸マグネシウム、炭酸アルミニウム等の金属塩；カオリン等の粘土鉱物；アパタイト等リン酸化合物；炭化ケイ素、窒化ケイ素等のケイ素化合物；カーボンブラックやグラファイト等の炭素粉末が挙げられる。中でも、酸化亜鉛、酸化アルミニウム、酸化コバルト、二酸化マンガン、チタン酸ストロンチウム、チタン酸マグネシウム等が好ましい。
【０１３７】
さらに、本発明のトナーには、ポリフッ化エチレン、ポリフッ化ビニリデン等のフッ素樹脂；フッ化カーボン等のフッ素化合物等の滑剤粉末を外添剤として添加することもできる。
【０１３８】
本発明のトナーは、公知の方法によって製造することができる。本発明のトナーを製造する方法としては、上述したようなトナー構成材料をボールミルその他の混合機により十分混合した後、熱ロールニーダー、エクストルーダーの如き熱混練機を用いて良く混練し、冷却固化後、機械的に粉砕し、粉砕粉を分級する方法が好ましい。
【０１３９】
他には、結着樹脂を構成すべき単量体に所定の材料を混合して乳化懸濁液とした後に、重合させてトナーを得る重合法トナー製造法；コア材及びシェル材から成るいわゆるマイクロカプセルトナーにおいて、コア材あるいはシェル材、あるいはこれらの両方に所定の材料を含有させる方法；結着樹脂溶液中に構成材料を分散した後、噴霧乾燥することによりトナーを得る方法が挙げられる。
【０１４０】
さらに、前述したこれらの方法によって得られたトナー粒子に、必要に応じ所望の外添剤をヘンシェルミキサーの如き混合機により十分に混合し、本発明のトナーを製造することができる。
【０１４１】
本発明のトナーを製造する際に使用される機器としては、特に限定されないが、例えば混合機としては、ヘンシェルミキサー（三井鉱山社製）；スーパーミキサー（カワタ社製）；リボコーン（大川原製作所社製）；ナウターミキサー、タービュライザー、サイクロミックス（ホソカワミクロン社製）；スパイラルピンミキサー（太平洋機工社製）；レーディゲミキサー（マツボー社製）が挙げられる。
【０１４２】
混練機としては、例えばＫＲＣニーダー（栗本鉄工所社製）；ブス・コ・ニーダー（Ｂｕｓｓ社製）；ＴＥＭ型押出機（東芝機械社製）；ＴＥＸ二軸混練機（日本製鋼所社製）；ＰＣＭ混練機（池貝鉄工所社製）；三本ロールミル、ミキシングロールミル、ニーダー（井上製作所社製）；ニーデックス（三井鉱山社製）；ＭＳ式加圧ニーダー、ニダールーダー（森山製作所社製）；バンバリーミキサー（神戸製鋼所社製）が挙げられる。
【０１４３】
粉砕機としては、例えばカウンタージェットミル、ミクロンジェット、イノマイザ（ホソカワミクロン社製）；ＩＤＳ型ミル、ＰＪＭジェット粉砕機（日本ニューマチック工業社製）；クロスジェットミル（栗本鉄工所社製）；ウルマックス（日曹エンジニアリング社製）；ＳＫジェット・オー・ミル（セイシン企業社製）；クリプトロン（川崎重工業社製）；ターボミル（ターボ工業社製）；スーパーローター（日清エンジニアリング社製）が挙げられる。
【０１４４】
分級機としては、例えばクラッシール、マイクロンクラッシファイアー、スペディッククラシファイアー（セイシン企業社製）；ターボクラッシファイアー（日清エンジニアリング社製）；ミクロンセパレータ、ターボプレックス（ＡＴＰ）、ＴＳＰセパレータ（ホソカワミクロン社製）；エルボージェット（日鉄鉱業社製）、ディスパージョンセパレータ（日本ニューマチック工業社製）；ＹＭマイクロカット（安川商事社製）が挙げられる。
【０１４５】
粗粒等をふるい分けるために用いられる篩い装置としては、例えばウルトラソニック（晃栄産業社製）；レゾナシーブ、ジャイロシフター（徳寿工作所社）；バイブラソニックシステム（ダルトン社製）；ソニクリーン（新東工業社製）；ターボスクリーナー（ターボ工業社製）；ミクロシフター（槙野産業社製）；円形振動篩い等が挙げられる。
【０１４６】
次に、本発明の画像形成方法を説明する。
本発明の画像形成方法は、前述した本発明のトナーを用いること、及び記録材上に未定着トナー画像を形成し、一方で金属製の基層を有する伝熱層をこの伝熱層に接触する加熱体によって加熱し、未定着トナー画像が形成された記録材を加熱した伝熱層に圧接させて、未定着トナー画像を記録材に定着させることを特徴とする。
【０１４７】
本発明の画像形成方法において、記録材上に未定着トナー画像を形成するまでの工程は、前述した本発明のトナーを用いること以外は特に限定されない。本発明の画像形成方法では、例えば感光体の帯電、静電潜像の形成、トナーによる静電潜像の現像、及び記録材へのトナー画像の転写等、公知の工程で記録材上に未定着トナー画像を形成することができる。また、本発明の画像形成方法では、他の工程をさらに採用しても良く、例えば転写後における感光体上のトナーを除去するためのクリーニング工程、現像時に感光体上のトナーを回収する現像兼クリーニング工程、フルカラー画像形成に適用したときの中間転写工程、中間転写体のクリーニング工程、帯電前の感光体の表面電位を揃えるための前露光工程等を任意に採用することができる。
【０１４８】
本発明の画像形成方法では、前述したフィルム加熱方式の定着装置におけるフィルムに金属製の基層を有する伝熱層を用いる定着装置を好適に用いることができる。すなわち本発明の画像形成方法では、伝熱層は、円筒状金属素管を基層として有し、加熱体は、円筒状金属素管の円筒内側に配置され、伝熱層を介して加熱体に対向しかつ伝熱層に接触して配置される加圧部材と伝熱層との間に形成される定着ニップ部に、未定着トナー画像が形成された記録材を通過させることにより、記録材を伝熱層に圧接させることが好ましい。
【０１４９】
本発明の画像形成方法では、熱伝導性が良好な伝熱層を内側から加熱体により接触加熱することにより、画像形成装置の高速化に対応した加熱定着を高い熱効率で実施することが可能となる。
【０１５０】
また本発明の画像形成方法では、定着時における加熱効率が良いことから、画像形成装置がプリント信号を受信していない状態のスタンバイ中に、加熱体への通電をシャットダウンしておくことが可能となり、省エネルギーの加熱定着を実現する上で好ましい。
【０１５１】
また本発明の画像形成方法では、室温状態から画像形成装置の電源をＯＮした場合でも、即座にプリント信号受信可能になるため、作業者を待たせることがない。すなわち画像形成装置が高速化した場合でも、クイックスタート性に優れ、ファーストプリントタイムも速い定着が可能となる。
【０１５２】
また本発明の画像形成方法では、樹脂製フィルムに比べ剛性の高い金属製の基層を有する伝熱層を使用することで、加圧力を高く設定することが可能になり、さらに画像形成装置の高速化に対応することが可能になる。
【０１５３】
また本発明の画像形成方法では、加熱体を伝熱層に接触して配置する場合に、加熱体の表面を耐熱性のあるポリイミド樹脂等の樹脂部材とすると、加熱体表面において伝熱層をスムーズに摺動させ、高耐久の加熱定着を実現する上で好ましい。
【０１５４】
また本発明の画像形成方法では、円筒状金属素管に所定範囲内において周方向のスジ加工を施すことが、円筒状金属素管の回転をスムーズにし、加熱体の損傷を抑制する上で好ましい。
【０１５５】
また本発明の画像形成方法では、定着時に、トナーと逆極性のバイアスを加圧ローラ側に印加し、伝熱層を接地あるいはダイオード接続することが、紙粉、トナー等が伝熱層に吸着されることを防止する上で好ましい。これにより、耐久によって伝熱層が汚れる等の問題もなく、耐久性をさらに向上させることが可能となる。
【０１５６】
本発明で採用する定着方式は、高速プロセスにおいて尾引きを起こし易い。尾引きとは、定着ニップ部分をトナー像が通過する際に、トナー像間の空気がトナーと共に噴出されて発生する現象である。この尾引きに対し、前記バイアスを強めると、記録材上でのトナー形状を記録材に引き付ける方向に働き、トナー像間の空気の噴出しよりも強くトナーに影響させることができ、尾引きの発生を抑制する上で効果的である。一方で、前記バイアスを強めることは、一部の帯電能の低いトナーや逆極性に帯電している不安定帯電のトナーを伝熱層へ飛翔させ易くし、静電気が起因のオフセットの発生を起こし易い。
【０１５７】
しかしながら、前述した本発明のトナーは高温オフセットが発生しにくいので、本発明の画像形成方法に用い、前述のバイアス印加してもオフセットを誘発しにくい。また、本発明のトナーは良好な転写を得られるため、トナー像間の空気の噴出しに影響されないレベルまで前記録材上に引き付けられ、バイアスの非印加時のオフセットも軽減できる。このように、本発明の画像形成方法では、前述したトナーと定着方式とを採用することにより、耐オフセット性及び尾引き防止の両立を図ることができる。
【０１５８】
本発明の画像形成方法は、公知の部材及び手段等を適宜組み合わせて実現することができる。より具体的には、本発明の画像形成方法は、前述した定着工程を実現する定着装置を搭載する改造を、公知の画像形成装置に施すことによって実現することが可能である。本発明の画像形成方法を実現する上で好適な画像形成装置である本発明の画像形成装置を以下に説明する。
【０１５９】
本発明の画像形成装置は、前述した本発明のトナーを用いるものであって、記録材上に未定着トナー画像を形成する手段と、未定着トナー画像を記録材に定着させる定着装置とを有する画像形成装置において、定着装置は、加熱体と、加熱体に対向して設けられる加圧部材と、加熱体と加圧部材の間に介在し加熱体によって加熱される伝熱層とを有し、加熱体は、伝熱層に接触して配置され、伝熱層は、金属製の基層を有し、加圧部材は、加熱体との対向部において伝熱層に接触して配置されている。
【０１６０】
また本発明の画像形成装置は、金属製の基層は円筒状金属素管であり、加熱体は、円筒状金属素管の円筒内側に配置されていることが好ましい。
以下、本発明の画像形成装置について、図面を用いてより具体的に説明する。
【０１６１】
本発明の画像形成装置は、例えば図１に示すように、感光体１と、感光体１に接触して配置され感光体１を帯電させる帯電ローラ２と、帯電した感光体１の表面にレーザビーム３を照射して静電潜像を形成する不図示の静電潜像形成手段と、静電潜像が形成された感光体１に本発明のトナーを供給してトナー画像を形成する現像装置４と、感光体１上に形成されたトナー画像を記録材Ｐに転写して記録材Ｐ上に未定着トナー画像を形成する転写ローラ５と、記録材Ｐ上に形成された未定着トナー画像を記録材Ｐに定着させる定着装置６と、転写後の感光体１に残留するトナーを除去するクリーニング装置７と、記録材Ｐの位置を検出するセンサ８とによって構成される。
【０１６２】
感光体１は、ＯＰＣ、アモルファスＳｅ、アモルファスＳｉ等の感光材料が、アルミニウムやニッケル等のシリンダ状の基材上に層状に形成されたものである。帯電ローラ２及び転写ローラ５は、芯金の周面を導電性の弾性層で被覆したものであり、芯金には図示しない電源が接続され、それぞれのローラに所望の電圧を印加できるように構成されている。前記静電潜像形成手段は、形成すべき画像の情報に応じたレーザビーム３を照射する手段である。現像装置４は、トナーを収容する現像容器と、現像容器の開口部に回転自在に設けられる現像剤担持体とを有し、現像剤担持体上のトナーを感光体１に供給する。現像装置４の構成は、トナーの種類及び所望の現像方式に応じて選択される。クリーニング装置７は、廃トナー容器と、感光体１に当接する弾性のクリーニングブレードとを有している。定着装置６については後述する。
【０１６３】
前記画像形成装置では、感光体１は矢印の方向に回転駆動され、まず、その表面は帯電装置としての帯電ローラ２によって一様帯電される。次に、画像情報に応じてＯＮ／ＯＦＦ制御されたレーザビーム３による走査露光が施され、静電潜像が形成される。この静電潜像は、現像装置４で現像、可視化される。現像方法としては、ジャンピング現像法、二成分現像法、ＦＥＥＤ現像法等が用いられ、イメージ露光と反転現像とを組み合わせた現像方法も用いられる。可視化されたトナー画像は、転写装置としての転写ローラ５により、所定のタイミングで搬送された記録材Ｐ上に感光体１上より転写される。転写ローラ５への記録材Ｐの搬送は、感光体１上のトナー像の画像形成位置と記録材Ｐの先端の書き出し位置が合致するように、センサ８にて記録材Ｐの先端を検知し、タイミングを合わせて行われる。
【０１６４】
所定のタイミングで搬送された記録材Ｐは、感光体１と転写ローラ５に一定の加圧力で挟持搬送される。トナー画像が転写された記録材Ｐは、定着装置６へと搬送され、定着される。
【０１６５】
一方で、感光体１上に残存する転写残りの残留トナーは、クリーニング装置７により感光体１表面より除去される。
【０１６６】
定着装置６は、図２に示されるように、定着部材１０と、加圧部材２０とを有する。定着部材１０と加圧部材２０は、互いに圧接させて定着ニップ部Ｎを形成している。記録材Ｐは、図２において不図示の供給手段によって適宜供給され、耐熱性の定着入口ガイド１５に沿って定着部材１０と加圧部材２０によって形成される定着ニップ部Ｎに搬送される。
【０１６７】
定着部材１０は、加熱体としてのヒータ１１と、ヒータ１１を加圧部材２０に向けて支持する断熱性のステイホルダ１２と、ヒータ１１及びステイホルダ１２を内包しヒータ１１及び加圧部材２０によって一部の周面が挟持される円筒状の定着スリーブ１３と、ヒータ１１の温度を検出する温度検知素子１４とを有している。
【０１６８】
加圧部材２０は、円柱状の芯金２１と、芯金２１の周面に形成された弾性層２２と、弾性層２２の周面に形成された離型性層２３とを有している。弾性層２２は、シリコーンゴムやフッ素ゴム等の耐熱ゴム、あるいは耐熱ゴムの発泡体で形成することができる。離型性層２３は、ＰＦＡ、ＰＴＦＥ、ＦＥＰ（テトラフルオロエチレン−ヘキサフルオロプロピレン共重合体）等、耐熱性と離型性とに優れる樹脂化合物のフィルムやチューブによって形成することができる。
【０１６９】
ヒータ１１は、定着スリーブ１３の内側に具備され、定着ニップ部Ｎで加熱を行い、これにより記録材Ｐ上のトナーを溶融し、トナー画像を定着させる。ヒータ１１近傍の構成を図３に示す。ヒータ１１は、ヒータ基板１１ａと、ヒータ基板１１ａの表面に支持される通電発熱抵抗層１１ｂと、ヒータ基板１１ａ上において通電発熱抵抗層１１ｂを被覆する摺動層１１ｃとを有する。なお。ヒータ１１の温度を検知するサーミスタ等の温度検知素子１４は、通常、ヒータ１１に配置される。
【０１７０】
ヒータ基板１１ａは、アルミナ、ＡｌＮ（チッ化アルミ）等の高絶縁性のセラミックスや、ポリイミド、ＰＰＳ（ポリフェニレンスルフィド）、液晶ポリマー等の耐熱性樹脂のように、耐熱性と絶縁性とを有する材料で形成することができる。
【０１７１】
通電発熱抵抗層１１ｂは、例えばＡｇ／Ｐｄ（銀パラジウム）、ＲｕＯ₂、Ｔａ₂Ｎ等のように、通電により発熱する材料を用い、ヒータ基板１１ａの長手方向に沿って、スクリーン印刷等の方法により、厚み１０μｍ程度、幅１〜５ｍｍ程度の線状若しくは細帯状に塗工して形成することができる。
【０１７２】
摺動層１１ｃは、通電発熱抵抗層１１ｂの表面に形成された薄層であり、例えばフッ素樹脂層、ポリイミド、ポリアミドイミド、ＰＥＥＫ（ポリエーテルエーテルケトン）等のように、定着スリーブ１３との摺擦に耐えることが可能な耐熱性樹脂化合物を用い、公知の方法で形成することができる。
【０１７３】
ヒータ基板１１ａとして熱伝導性の良好なＡｌＮ（チッ化アルミ）等を用いた場合には、図４に示されるように、通電発熱抵抗層１１ｂをヒータ基板１１ａに対して定着ニップ部Ｎと反対側に形成しても良い。この場合では、ヒータ１１は、ヒータ基板１１ａと、通電発熱抵抗層１１ｂと、保護層１１ｄと、摺動層１１ｅとを有する。温度検知素子１４は、図３と同様に、定着スリーブ１３の内側側に、ヒータ１１に接触して配置されている。保護層１１ｄは、通電発熱抵抗層１１ｄと温度検知素子１４の間の耐電圧を満足するために設けられており、例えばガラスコート、フッ素樹脂層等のような耐熱性及び絶縁性を有する材料で形成することができる。摺動層１１ｅは摺動層１１ｃと同様に形成することができる。
【０１７４】
ヒータ１１は、ヒータ１１の定着ニップ部Ｎ側の形状を曲面とすると、ヒータ１１表面を通過する際の定着スリーブ１３への屈曲負荷が低減し、長寿命の定着部材を形成する上で好ましい。このようなヒータ１１としては、例えばヒータ基板の定着ニップ部Ｎとは反対側に絶縁層、通電発熱抵抗層を順次積層し、ヒータ基板は定着ニップ部Ｎ側が定着スリーブと同方向に湾曲した形状であるヒータが挙げられる。
【０１７５】
ステイホルダ１２は、ヒータ１１を保持し、定着ニップ部Ｎと反対方向への放熱を防ぐための断熱部材であり、液晶ポリマー、フェノール樹脂、ＰＰＳ、ＰＥＥＫ等により形成することができる。ステイホルダ１２は、移動する定着スリーブ１３の軌道を形成する形状に形成しても良い。この場合のステイホルダ１２の形状は、用いる伝熱層の形態に応じて形成すれば良い。またこのような場合では、ヒータ１１及びステイホルダ１２の表面には、耐熱性グリース等の潤滑剤を少量介在させることが、ヒータ１１及びステイホルダ１２と定着スリーブ１３の間の摩擦抵抗を小さく抑え、定着スリーブ１３をスムーズに回転させる上で好ましい。
【０１７６】
ステイホルダ１２には、定着スリーブ１３が余裕をもってルーズに外嵌されていて、矢印の方向に回転自在に配置されている。
【０１７７】
定着スリーブ１３は、円筒状に形成された伝熱層であり、円筒状金属素管と、離型性層と、円筒状金属素管及び離型性層を接着する接着層とによって形成することができる。定着スリーブ１３は、熱容量の小さな金属製のスリーブであり、クイックスタートを可能にするために、１００μｍ以下の厚みに形成されている。定着スリーブ１３は、例えばＳＵＳ、Ａｌ、Ｎｉ、Ｃｕ、Ｚｎ等の金属部材あるいはこれらの金属を含む合金部材のような、耐熱性、高熱伝導性を有する金属製の層を基層として形成することができる。
【０１７８】
前記円筒状金属素管は、伝熱層における金属製の基層であり、長寿命の加熱定着装置を構成するために十分な強度を持ち、耐久性に優れた金属製スリーブを構成する観点から、厚さ２０μｍ以上の厚みを有することが好ましい。すなわち定着スリーブ１３の厚みとしては２０μｍ以上１００μｍ以下が好ましい。
【０１７９】
前記離型性層は、さらにオフセット防止や記録材の分離性を確保するために、円筒状金属素管の表面に被覆された層であり、例えばＰＴＦＥ（ポリテトラフルオロエチレン）、ＰＦＡ（テトラフルオロエチレン−パーフルオロアルキルビニルエーテル共重合体）、ＦＥＰ（テトラフルオロエチレン−ヘキサフルオロプロピレン共重合体）、ＥＴＦＥ（エチレン−テトラフルオロエチレン共重合体）、ＣＴＦＥ（ポリクロロトリフルオロエチレン）、ＰＶＤＦ（ポリビニリデンフルオライド）等のフッ素樹脂、シリコーン樹脂等の離型性の良好な耐熱樹脂の一種又は二種以上により形成することができる。
【０１８０】
前記接着層は、前記離型性層を円筒状金属素管の表面に支持、固定するための層であり、離型性層そのものや離型性層の加工前材料等を円筒状金属素管表面に接着できるものであれば特に限定されない。このような接着層には、例えばプライマー層が挙げられ、接着層を用いる離型性層の形成としては、例えば円筒状金属素管の外面にプライマー層を塗布した後、上記ディッピング、粉体スプレー等の塗布によって離型性層を形成する方法が挙げられる。接着層は、例えばチューブ状に形成された離型性層を円筒状金属素管の表面に被せる等、離型性層の形態によっては不要な場合があり、このような場合では設けなくても良い。
【０１８１】
なお、前記離型性層と前記接着層は、これらの層厚の総和が２０μｍ以下であることが、定着時における加熱効率を向上させ、かつ耐久性を維持する上で好ましい。
【０１８２】
定着部材１０は、図５に示されるように、定着部材１０の長手方向両端部において、ステイホルダ１２の一部、若しくはステイホルダ１２と嵌合等により取り付けられた部材を、バネ等の加圧手段１７により加圧部材２０に向けて付勢することにより、加圧部材２０に接触して配置され、所望の定着ニップ部Ｎを形成している。
【０１８３】
ヒータ基板１１ａの長手方向端部には、電極部１１ｆ及び１１ｇが形成されており、通電発熱抵抗層１１ｂに印加される電圧は、これらの電極部から印加される。すなわち温度検知素子１４の信号に応じて、通電発熱抵抗層１１ｂに印加される電圧のデューティー比や波数等を適切に制御することで、定着ニップ部Ｎにおける温度を略一定に保ち、記録材Ｐ上のトナー像を定着するのに必要な加熱を行う。温度検知素子１４から不図示の温度制御部へのＤＣ通電は、不図示のＤＣ通電部及びＤＣ電極部を介して不図示のコネクタにより達成している。
【０１８４】
また、加圧部材２０の芯金２１端部には駆動ギア１６が取り付けられており、このような構成により加圧部材２０を回転駆動させ、加圧部材２０表面と定着スリーブ１３表面の摩擦により定着スリーブ１３を所定の速度に従動回転させる。
【０１８５】
本発明では、前記円筒状金属素管の内面の表面粗さを３μｍ以下とすることが、接触熱抵抗を低く抑え、定着ニップ部への伝熱を良好にする上で好ましい。さらに前記円筒状金属素管の外面の表面粗さを３μｍ以下とすることが、良好な定着性を実現する上で好ましい。
【０１８６】
ここで定着スリーブ１３の内外面の表面粗さ、離型性層の厚み等に関して以下に説明する。
【０１８７】
まず、定着スリーブ１３の内面は、ヒータ１１と所定の接触幅をもって接触してヒータ１１より発した熱を定着ニップ部Ｎへ伝熱する。ヒータ１１と接触伝熱する定着スリーブ１３内面の表面粗さは、熱効率に大いに影響する。特にヒータ１１の摺動層（１１ｃあるいは１１ｅ）の表面と定着スリーブ１３の内面との接触熱抵抗が大きくなると、熱効率が悪化し、定着不良を起こしやすい。仮に熱伝導グリース等を介在させた場合でも、所定以下の表面粗さに抑えることが、熱効率の高い定着装置を構成する上で好ましい。
【０１８８】
また、定着スリーブ１３の外面に離型性層を形成する場合では、離型性層は一般にフッ素樹脂より形成され、離型性層の熱伝導性は、定着スリーブ１３の熱伝導性に比べ極端に低くなる。よって、離型性層をあまり厚く形成すると、熱伝導の悪化を招き、画像形成装置の高速化に対し、定着ニップ部Ｎで記録材Ｐ上のトナー画像に対し十分な熱供給ができなくなる。したがって薄い離型性層を定着スリーブ１３上に形成する必要がある。したがって、定着スリーブ１３外面の表面粗さは所定以下に抑える必要がある。
【０１８９】
すなわち薄い離型性層では、定着スリーブ１３外面の表面粗さを緩和する効果が小さく、離型性層の形成後における定着スリーブ１３外面の表面粗さは、離型性層形成前に比べて同等か若干小さくなる程度である。よって、円筒状金属素管の表面粗さが大きいと、離型性層を塗布形成後も大きな表面粗さとなり、定着ニップ部Ｎで記録材Ｐとの密着力が十分に得られず、定着不良を引き起こす可能性が大きくなる。
【０１９０】
以上のことから、定着スリーブ１３の外面の表面粗さを所定以下とし、接着層としてのプライマー層を含み離型性層を所定以下の厚みで塗布形成することにより、十分な定着性能が得られ、画像形成装置の高速化に対応可能となる。
【０１９１】
定着スリーブ１３は、定着スリーブ１３の周方向に適度な凹凸形状を施すことにより所定以下の表面粗さを達成するものであると、定着スリーブ１３の回転をよりスムーズにすると共に、ヒータ１１の表面にコーティングした離型性層を傷つけにくくし、さらに高耐久の高速対応可能な加熱定着用定着スリーブ１３を提供する上で好ましい。
【０１９２】
定着スリーブ１３の製造から表面加工までの一例を、図を用いて以下に説明する。
定着スリーブ１３は、図６に示されるように、円形の内型（ポンチ）３２と、円筒容器状の外型（ダイス）３３とにより、金属平板（プランク）３１を深絞り加工することにより、図７に示すようなカップ状の金属製円筒部材３４を製造する。
【０１９３】
金属平板３１には、厚さ０．１ｍｍ〜０．５ｍｍ程度のＳＵＳ、Ａｌ、Ｎｉ、Ｃｕ、Ｚｎ等の金属平板、又はこれらの金属を含む合金の金属平板が用いられる。内型３２及び外型３３は、例えば金属材料の表面に超硬メッキ等を施した金型であり、内型３２には一般的な深絞り製法における円形内型が用いられ、外型３３には、一般的な深絞り製法における、円筒容器状の外型が用いられる。
【０１９４】
図６において、金属平板３１を内型３２と外型３３の間に挟み矢印の方向に内型３２を外型３３の方向へ押し込む。金属平板３１と外型３３の間には、粘度の高い潤滑油、あるいは黒鉛、二硫化モリブデン等の固体潤滑剤を介在させ、絞り性を良くする。以上の工程を通常は２〜４回程度、異なる金型で深絞り加工する。
【０１９５】
次に、この金属製円筒部材３４が所定の厚みに形成されるようにしごき加工を施す。しごき加工としては、圧延加工、引き抜き加工、絞り加工等どのような加工を途中に経緯してもよいが、最終加工としては、以下に示すような加工方法により、金属製円筒部材３４の周方向に所定以下の凹凸を有する加工を施す。
【０１９６】
金属製円筒部材３４の周方向に所定以下の凹凸を有する加工としては、例えば図８及び図９に示すような加工方法がある。図８は一般的な絞りスピニング加工であり、固定台３６ｃに取り付けられた軸３６ｂに、回転自在に取り付けられた押し当てローラ３６ａを、金属製内型３５と所定の距離だけ常に離間した状態で金属製内型３５方向へ押し付ける。金属製内型３５には、金属製円筒部材３４がはめ込まれており、押さえ部材３７によって金属製円筒部材３４のカップ形状底部が金属製内型３５に密着して固定される。
【０１９７】
この状態で金属製内型３５、金属製円筒部材３４、押さえ部材３７を図の矢印の方向に回転させながら、紙面右方へ徐々に送り込む。端部からは金属製内型３５と所定距離を保って回転自在のローラが押し当てられる。これにより、金属製円筒部材３４の端部から徐々にしごき加工により薄肉化され、最終的には図１０に示すように、定着スリーブ１３の所定厚みにまで加工されたカップ状の金属製円筒部材３９がしごき加工により形成される。金属製円筒部材３９には、周方向に絞りスピニング加工時のローラ押し当ての凹凸跡３９ａが残る。最終的には、金属製円筒部材３９のカップ形状底部を切り落とすことにより、定着スリーブ１３を得る。
【０１９８】
また、図９に示すように、押し当てローラの代わりに、段階的に内径が小さく形成された連続ダイス３８ａ、３８ｂ、３８ｃの内側に、金属製内型３５と押さえ部材３７とにより固定された金属製円筒部材３４を回転させながら、送り込みしごき加工により薄肉化し、周方向の凹凸形状を付与させる方式であっても良い。その他、へら絞り加工等、定着スリーブ１３の周方向に所定量以下の凹凸を形成できる方法であれば、どのようなしごき加工の加工方法であってもかまわない。
【０１９９】
以上の製法で製造した定着スリーブ１３を用いて、未定着画像が形成された記録材Ｐを加熱定着する場合、熱伝導の観点から、上記周方向の凹凸は３μｍ以下に抑えることが好ましい。
【０２００】
定着スリーブ１３の周方向に３μｍ以下の凹凸を形成することが、定着装置の回転駆動負荷を低く抑え、回転をスムーズにすると共に、円筒状金属素管内面に接触するヒータの樹脂コートが耐久によって傷つくことを抑制し、定着装置のさらなる高耐久、高速化を達成する上で好ましく、さらには、長手方向の表面粗さＲｚを３μｍ以下とし、周方向の表面粗さＲｚ’との関係をＲｚ＞Ｒｚ’とすることがより好ましい。
【０２０１】
さらに、定着スリーブ１３と加圧部材２０の間に電位差を形成し、かつ定着スリーブ１３を接地状態、もしくはダイオードを介して接地状態とすることで定着スリーブ１３に紙粉やトナーを付着しにくい構成とすることが、耐久を通じて離型性を維持する定着装置を提供する上で好ましい。
【０２０２】
本発明の実施の形態としてさらに好適な一例の定着装置を図１１及び図１２に示す。
【０２０３】
図１１及び図１２において、加圧部材２０の弾性層２２は、導電性シリコーンゴム、導電性シリコーンスポンジ等からなる導電性付与された弾性層であり、芯金２１、あるいは導電性の弾性層２２に、導電性カーボンチップ等よりなるチップ電極２５を介してバイアス印加手段２４によってトナー画像と逆極性のバイアスを印加する。図では、トナーが現像部でマイナス帯電される画像形成装置を元に図示しており、芯金２１にプラスバイアスが印加される構成を示している。よってトナーが現像部でプラス帯電される画像形成装置の場合、芯金２１には、マイナスバイアスが印加される構成となる。
【０２０４】
また、図では、定着スリーブ１３の端部では、接着層としてのプライマー層、フッ素樹脂層からなる離型性層がコーティングされていない円筒状金属素管がむき出しになっている部位１３ａを設け、この部位１３ａよりアモルファス導電繊維よりなる導電ブラシ１８を介して定着スリーブ１３が接地する構成を示している。あるいは定着スリーブ１３は、トナー画像と同電位の電荷が円筒性金属素管に保持されるようにダイオード接続されていても良い。
【０２０５】
以上のように、加圧部材２０側に積極的にバイアス印加する構成とすることで、定着スリーブ１３への紙粉、トナー等の吸着をより一層抑制することが可能となる。よって、パルプ材を主原料とするカット紙等に形成されたトナー画像を加熱定着する場合の上記定着装置においては、表面粗さを３μｍ以下とした定着スリーブ１３の、表面の離型性層には、静電気的にも紙粉やトナーの汚染が発生しにくく、耐久による離型性の損失が抑制され、さらに長寿命の定着装置を提供することが可能となる。
【０２０６】
なお、本発明に用いられる定着装置は、定着部材の離型性を維持するためのオイルを定着部材に塗布するオイル塗布方式の定着装置であっても良いし、オイルレス系の定着装置であっても良く、これらの方式の違いによらず同様に効果を奏する。
【０２０７】
また、本発明に用いられる定着装置において、加熱体は、通電により発熱するものであれば、通電時の抵抗によって発熱するものに限定されず、例えば通電時の電磁誘導によって発熱する電磁誘導発熱性部材によって形成することもできる。
【０２０８】
また、本発明に用いられる定着装置は、記録材上のトナーの加熱に広く適用することが可能であり、例えば記録材上の画像を仮定着処理する像加熱装置、つや等の画像表面性を改質する像加熱装置等にも適用することが可能である。
【０２０９】
また、前述した実施の形態では、伝熱層として円筒状の定着スリーブ１３を示したが、本発明に用いられる伝熱層は円筒形状以外の無端形状であっても良い。また伝熱層は、金属製の基層のみから構成されていても良い。
【０２１０】
また、前述した実施の形態では、定着部材１０を加圧部材２０に向けて付勢する構成を示したが、本発明はこの構成に限定されず、加圧部材２０を定着部材１０に向けて付勢しても良く、また定着部材１０及び加圧部材２０の両方を互いに接近する方向に付勢しても良い。
【０２１１】
また、前述した実施の形態では、バネに代表されるような、十分な付勢力を発現する加圧手段１７による付勢によって定着ニップ部Ｎを形成する構成を示したが、本発明はこの構成に限定されず、定着部材１０と加圧部材２０の位置を固定して所望の定着ニップ部Ｎを形成しても良い。
【０２１２】
【実施例】
以下に、実施例をあげて本発明をより具体的に説明するが、これは本発明を何ら限定するものではない。また、実施例中「部」は「質量部」を意味する。
【０２１３】
［結着樹脂製造例］
＜高分子量成分Ｃ−１の製造例＞
・スチレン ７８．５質量部
・アクリル酸−ｎ−ブチル ２０質量部
・メタクリル酸 １．５質量部
・２，２−ビス（４，４−ジ−ｔ−ブチルパーオキシシクロヘキシル）プロパン
１．０質量部
４つ口フラスコ内でキシレン２００質量部を撹拌しながら容器内を十分に窒素で置換し、１２０℃に昇温させた後、上記各成分を４時間かけて滴下した。さらにキシレン還流下で重合を行った。このようにして得られた樹脂をＣ−１とする。
【０２１４】
＜高分子量成分Ｃ−２の製造例＞
スチレン７５質量部、アクリル酸−ｎ−ブチル２３質量部、マレイン酸モノブチル２質量部、２，２−ビス（４，４−ジ−ｔ−ブチルパーオキシシクロヘキシル）プロパン０．６質量部を用い、Ｃ−１と同様にして樹脂Ｃ−２を得た。
【０２１５】
＜高分子量成分Ｃ−３の製造例＞
スチレン８０質量部、アクリル酸−ｎ−ブチル１９質量部、メタクリル酸１質量部、１，１−ジ−ｔ−ブチルパーオキシ−３，３，５−トリメチルシクロヘキサン２質量部を用い、フラスコ内の温度を１３０℃に変更した以外はＣ−１と同様にして樹脂Ｃ−３を得た。
【０２１６】
＜高分子量成分Ｃ−４の製造例＞
スチレン８０質量部、アクリル酸−ｎ−ブチル２０質量部、２，２−ビス（４，４−ジ−ｔ−ブチルパーオキシシクロヘキシル）プロパン１質量部を用い、Ｃ−１と同様にして樹脂Ｃ−４を得た。
【０２１７】
＜高分子量成分Ｃ−５の製造例＞
スチレン７２質量部、アクリル酸−ｎ−ブチル１８質量部、メタクリル酸１０質量部、２，２−ビス（４，４−ジ−ｔ−ブチルパーオキシシクロヘキシル）プロパン１質量部を用い、Ｃ−１と同様にして樹脂Ｃ−５を得た。
【０２１８】
＜高分子量成分Ｃ−６の製造例＞
スチレン８１．８質量部、アクリル酸−ｎ−ブチル１８質量部、マレイン酸モノブチル０．２質量部、２，２−ビス（４，４−ジ−ｔ−ブチルパーオキシシクロヘキシル）プロパン１質量部を用い、Ｃ−１と同様にして樹脂Ｃ−６を得た。
【０２１９】
＜カルボキシル基含有ビニル樹脂Ａ−１の製造例＞
・高分子量成分樹脂Ｃ−１ ２５質量部
・スチレン ６０．２質量部
・アクリル酸−ｎ−ブチル １４質量部
・メタクリル酸 ０．８質量部
・ジ−ｔ−ブチルパーオキサイド ２質量部
上記材料のうちモノマー及び重合開始剤をキシレン２００質量部中に４時間かけて滴下した。さらに、キシレン還流下で重合を行い、この重合が終了した後に、樹脂成分が２５質量部相当になるようにＣ−１の重合溶液を添加し、減圧下で溶媒を蒸留除去した。このようにして得られた樹脂をＡ−１とする。
【０２２０】
＜カルボキシル基含有ビニル樹脂Ａ−２の製造例＞
高分子量成分樹脂Ｃ−２を２５質量部、スチレン５９．８質量部、アクリル酸−ｎ−ブチル１５質量部、メタクリル酸０．２質量部、ジ−ｔ−ブチルパーオキサイド１．５質量部を用い、Ａ−１と同様にして樹脂Ａ−２を得た。
【０２２１】
＜カルボキシル基含有ビニル樹脂Ａ−３の製造例＞
高分子量成分樹脂Ｃ−３を２５質量部、スチレン６８質量部、アクリル酸−ｎ−ブチル６質量部、メタクリル酸１質量部、ジ−ｔ−ブチルパーオキサイド５質量部を用い、Ａ−１と同様にして樹脂Ａ−３を得た。
【０２２２】
＜ビニル樹脂Ａ−４の製造例＞
高分子量成分樹脂Ｃ−４を２５質量部、スチレン６１質量部、アクリル酸−ｎ−ブチル１４質量部、ジ−ｔ−ブチルパーオキサイド２．４質量部を用い、Ａ−１と同様にして樹脂Ａ−４を得た。
【０２２３】
＜カルボキシル基含有ビニル樹脂Ａ−５の製造例＞
高分子量成分樹脂Ｃ−５を２５質量部、スチレン５８質量部、アクリル酸−ｎ−ブチル１４質量部、メタクリル酸３質量部、ジ−ｔ−ブチルパーオキサイド２．４質量部を用い、Ａ−１と同様にして樹脂Ａ−５を得た。
【０２２４】
＜カルボキシル基含有ビニル樹脂Ａ−６の製造例＞
高分子量成分樹脂Ｃ−６を５０質量部、スチレン４２質量部、アクリル酸−ｎ−ブチル８質量部、ジ−ｔ−ブチルパーオキサイド０．７質量部を用い、Ａ−１と同様にして樹脂Ａ−６を得た。
【０２２５】
＜グリシジル基含有ビニル樹脂Ｂ−１の製造例＞
・スチレン ７５質量部
・アクリル酸−ｎ−ブチル １８質量部
・メタクリル酸グリシジル ７質量部
・ジ−ｔ−ブチルパーオキサイド ５質量部
４つ口フラスコ内でキシレン２００質量部を撹拌しながら容器内を十分に窒素で置換し、１２０℃に昇温させた後、上記各成分を４時間かけて滴下した。さらにキシレン還流下で重合を行い、減圧下で溶媒を蒸留除去した。このようにして得られた樹脂をＢ−１とする。
【０２２６】
＜グリシジル基含有ビニル樹脂Ｂ−２の製造例＞
スチレン７５．７質量部、アクリル酸−ｎ−ブチル２０質量部、メタクリル酸グリシジル４．３質量部、ジ−ｔ−ブチルパーオキサイド２質量部を用い、Ｂ−１と同様にして樹脂Ｂ−２を得た。
【０２２７】
＜グリシジル基含有ビニル樹脂Ｂ−３の製造例＞
スチレン７５．７質量部、アクリル酸−ｎ−ブチル２０質量部、メタクリル酸グリシジル４．３質量部、ジ−ｔ−ブチルパーオキサイド１０質量部を用い、Ｂ−１と同様にして樹脂Ｂ−３を得た。
【０２２８】
＜グリシジル基含有ビニル樹脂Ｂ−４の製造例＞
スチレン６０質量部、アクリル酸−ｎ−ブチル２０質量部、メタクリル酸グリシジル２０質量部、ジ−ｔ−ブチルパーオキサイド５質量部を用い、Ｂ−１と同様にして樹脂Ｂ−４を得た。
【０２２９】
樹脂Ａ−１〜Ａ−６を表１に、樹脂Ｂ−１〜Ｂ−４を表２にそれぞれ示す。
【０２３０】
【表１】

【０２３１】
【表２】

【０２３２】
＜実施例１＞
カルボキシル基含有ビニル樹脂Ａ−１を９５質量部、及びグリシジル基含有ビニル樹脂Ｂ−１を５質量部、をヘンシェルミキサーにて混合後、二軸混練押し出し機にて２００℃で混練し、冷却粉砕し、結着樹脂１を得た。
【０２３３】
・上記結着樹脂１ １００質量部
・マグネタイト ９０質量部
・ポリエチレンワックス ４質量部
・前記構造式（５）で表されるアゾ系鉄化合物 ２質量部
上記材料をヘンシェルミキサーで十分に前混合した後、１５０℃に設定した二軸混練押し出し機によって溶融混練した。得られた混練物を冷却し、カッターミルで粗粉砕した後、ジェット気流を用いた微粉砕機を用いて微粉砕し、得られた微粉砕物をさらに風力分級機で分級し、重量平均径６．３μｍの分級微粉体（トナー粒子）を得た。
【０２３４】
得られた分級微粉体は、グリシジル基含有ビニル樹脂（Ｂ−１）を添加していないものに比べ、溶融混練時の溶融粘度の上昇がみられ、架橋反応していることが確認された。さらにトナー化に伴い、カルボキシル基とグリシジル基の反応により架橋成分が生成し、ＴＨＦ不溶分が生成した。
【０２３５】
このトナー粒子１００質量部に負帯電性疎水性シリカ１．２質量部をヘンシェルミキサーで外添混合し、目開き１００μｍのメッシュで篩い、負帯電性磁性トナー１を調製した。得られたトナー１のＧＰＣにおける分子量分布、重量平均径及び酸価を、発明の実施の形態において述べた方法と同様の方法を用いて測定した。このトナー１の物性を表３に示す。
【０２３６】
次に、この調製された現像剤を、以下に示すような方法によって評価した。評価結果を表４に示す。
【０２３７】
［定着試験］
本試験に用いた加熱定着装置の基本的構成として、ヒータ１１としては、図４及び図５の構成のものを用いた。即ち、ＡｌＮをヒータ基板１１ａとし、このヒータ基板１１ａ上の定着ニップ部Ｎと反対方向に、Ａｇ／Ｐｄの導電剤と、マトリックス成分としてのリン酸系ガラスの混合物と、有機溶剤、バインダー、分散剤等とを混合してペースト状にしたものをスクリーン印刷して６００℃で焼成したものを通電発熱抵抗層１１ｂとして用いた。また、ＡｌＮのヒータ基板１１ａの定着ニップ部Ｎ側には、摺動性の良好なポリイミド層１１ｅを、スクリーン印刷にて１０μｍの厚さに形成した。
【０２３８】
また、定着スリーブ１３は、内径３０ｍｍ、厚み５０μｍの円筒状ステンレス鋼にプライマー層を５μｍ、ＰＦＡ樹脂を１０μｍ、それぞれディッピングによって塗布することによって、外径３０．１３ｍｍの円筒状に形成した。定着スリーブ１３の内面の表面粗さＲｚを２μｍ、外面の表面粗さＲｚを２μｍとした。
【０２３９】
また、加圧部材２０は、直径２０ｍｍのＡｌ芯金２１に、シリコーンゴム層を厚み５ｍｍで形成し、さらに外層にはＰＦＡチューブを被覆して形成した。
【０２４０】
本試験では、画像形成装置の記録材搬送スピードを１９３ｍｍ／ｓｅｃに調整して、ヒータ１１の温度を任意に制御できるようにした前記加熱定着装置を用いた。そして、ヒータ１１の温度を任意に制御し、ヒータ１１の通電発熱抵抗層１１ｂへの通電を開始してから５秒後に、未定着トナー像が形成された記録材Ｐを定着ニップ部Ｎに挿入し、各項目に対して確認した。
【０２４１】
低温定着性については、この前記加熱定着装置を１１０〜２４０℃の温度範囲でヒータ１１の温度を５℃おきに制御し、普通紙（７５ｇ／ｍ²）を用いたベタ黒未定着画像の定着をそれぞれの温度で行い、得られた画像を４．９ｋＰａの荷重をかけたシルボン紙で５往復摺擦し、摺擦前後の画像濃度の濃度低下率が１０％以下になる定着温度を低温定着性とした。この温度が低いほど低温定着性に優れたトナーである。
【０２４２】
耐高温オフセット性については、上記の定着条件において、紙上のトナー現像量を０．６ｍｇ／ｃｍ²に設定したベタ黒画像を未定着画像として用い、画像上のオフセット現象による汚れを目視で確認し、発生した温度を耐高温オフセット性とした。この温度が高いほど高温オフセット性に優れたトナーである。
【０２４３】
耐高温オフセット性の試験は、定着装置の金属スリーブへバイアスを印加した場合と印加しない場合の二通りで行った。バイアス印加の方法は、加圧ローラに５００Ｖの直流バイアスを印加する方法であり、バイアスを印加する場合では金属スリーブを接地した。
【０２４４】
［現像耐久試験］
市販のレーザービームプリンタＬａｓｅｒＪｅｔ ４１００（Ａ４、２４枚／分：Ｈｅｗｌｅｔｔ Ｐａｃｋａｒｄ社製）を、プロセススピード１９３ｍｍ／ｓｅｃ、Ａ４、３６枚／分に改造し、Ａ４サイズの画像面積率５％の原稿で、Ａ４サイズの７５ｇ／ｍ²の転写紙に、常温常湿（２３℃、５０％ ＲＨ）環境で５０００枚の画出し試験を行い、試験後のベタ黒画像の画像濃度測定を行った。画像濃度は、マクベス濃度計（マクベス社製）でＳＰＩフィルターを使用して反射濃度の測定を行い、測定値の５点平均で算出して求めた。
【０２４５】
［尾引き］
現像耐久試験と同様の装置を用いて、５ｍｍ間隔の横罫線を連続３０枚プリントし、３０枚目の画像について以下の基準で評価した。紙の進行方向とは逆側に、とげ状又は糸状の小さなささくれ線が横罫線から発生するレベルにより尾引きを判定した。
Ａ：全く尾引きがない
Ｂ：軽微な尾引きが数点発生している
Ｃ：軽微な尾引きに混じって大きな尾引きが数点発生している
Ｄ：大きな尾引きが多数見られる。
【０２４６】
本尾引き試験は、定着装置の金属スリーブへバイアスを印加した場合と印加しない場合の二通りで行った。バイアス印加の方法は、加圧ローラに５００Ｖの直流バイアスを印加する方法であり、バイアスを印加する場合では金属スリーブを接地した。
【０２４７】
＜実施例２〜５＞
表３に記載されているようにトナーの処方を代えた以外は、実施例１と同様の方法を用いてトナー２〜５を製造し、実施例１と同様の方法により物性の測定を行った。トナー物性を表３に示す。これらトナー２〜５について、実施例１と同様の評価を行った。評価結果を表４に示す。
【０２４８】
＜比較例１、２＞
表３に記載されているようにトナーの処方を代えた以外は、実施例１と同様の方法を用いてトナー６、７を製造し、実施例１と同様の方法により物性の測定を行った。トナー物性を表３に示す。これらトナー６、７について、実施例１と同様の評価を行った。評価結果を表４に示す。
【０２４９】
【表３】

【０２５０】
【表４】

【０２５１】
【発明の効果】
以上説明したように本発明によれば、記録材上に未定着トナー画像を形成し、一方で金属製の基層を有する伝熱層をこの伝熱層に接触する加熱体によって加熱し、未定着トナー画像が形成された記録材を加熱した伝熱層に圧接させて未定着トナー画像を記録材に定着させる画像形成方法に、カルボキシル基を有するビニル樹脂とグリシジル基を有するビニル樹脂との混合物、カルボキシル基とグリシジル基とを有するビニル樹脂、及びカルボキシル基とグリシジル基とが反応したビニル樹脂からなるグループから選択される一種以上の樹脂を含有する結着樹脂、及び着色剤を少なくとも含有するトナーを適用することから、より速度の速いプロセススピードにおける定着性が向上し、定着装置へのバイアス印加時においても静電気によるオフセットレベルの向上を図れ、定着尾引きを軽減することができる。
【０２５２】
本発明では、ゲルパーミエーションクロマトグラフィーにより測定されるテトラヒドロフラン可溶分の分子量分布において、数平均分子量が１，０００乃至４０，０００であり、重量平均分子量が１０，０００乃至１０，０００，０００であると、定着性、耐オフセット性及び耐ブロッキング性のバランスをとる上でより一層効果的である。
【０２５３】
本発明では、ゲルパーミエーションクロマトグラフィーにより測定されるテトラヒドロフラン可溶分の分子量分布において、分子量４，０００乃至３０，０００の領域に少なくとも一つのメインピーク、分子量４，０００乃至３０，０００の領域及び分子量５０，０００乃至１０，０００，０００の領域にそれぞれ少なくとも一つのピーク、分子量４，０００乃至３０，０００の領域及び分子量８００，０００乃至１０，０００，０００の領域にそれぞれ少なくとも一つのピーク、又は、分子量４，０００乃至３０，０００の領域、分子量５０，０００乃至８００，０００の領域、及び分子量８００，０００乃至１０，０００，０００の領域にそれぞれ少なくとも一つのピークを有すると、定着性、耐オフセット性及び耐ブロッキング性を向上させる上でより一層効果的である。
【０２５４】
本発明では、結着樹脂は、テトラヒドロフラン不溶分を０．１乃至６０質量％含有すると、耐オフセット性を向上させる上でより一層効果的である。
【０２５５】
本発明では、テトラヒドロフラン可溶成分の酸価が５０ｍｇＫＯＨ／ｇ未満であると、より良好な現像性、スリーブ及び定着プロセスの汚染を防止する上でより一層効果的である。
【０２５６】
本発明では、着色剤は磁性酸化鉄であり、結着樹脂１００質量部に対して２０〜２００質量部含有されていると、本発明の優れた効果を奏する磁性一成分トナーを提供することができる。
【０２５７】
本発明では、重量平均径が２．５〜１０μｍであると、画像濃度や現像性を向上させる上でより一層効果的である。
【０２５８】
本発明では、伝熱層は、基層としての円筒状金属素管と、伝熱層の外表面を形成する離型性層と、円筒状金属素管及び離型性層を接着する接着層とを有し、加熱体は、円筒状金属素管の円筒内側に配置され、円筒状金属素管の内外面の表面粗さが３μｍ以下であり、接着層及び離型性層の厚みの総和が２０μｍ以下であると、より高速な定着を可能とし、さらにこの高速定着に対応し、低温低着性、及び耐高温オフセット性に優れ、かつ優れた現像性を実現する上でより一層効果的である。
【図面の簡単な説明】
【図１】本発明の画像形成装置における一実施の形態を示す概略構成図である。
【図２】図１に示す定着装置の概略構成を示す図である。
【図３】図２に示す定着部材の一例における定着ニップ部近傍を示す図である。
【図４】図２に示す定着部材の他の例における定着ニップ部近傍を示す図である。
【図５】図１に示す定着装置における定着部材と加圧部材の配置例を示す図である。
【図６】本発明に用いられる円筒状金属素管の製造例を説明する図である。
【図７】図５に示す製造例で得られる円筒状金属素管の中間製造物を示す図である。
【図８】図７に示す中間生成物の表面粗さ及び厚みを調整するための加工の一例を説明する図である。
【図９】図７に示す中間生成物の表面粗さ及び厚みを調整するための加工の他の例を説明する図である。
【図１０】図８又は図９に示す加工により形成された円筒状金属素管を示す図である。
【図１１】本発明に用いられる定着装置の他の実施の形態を示す概略構成図である。
【図１２】図１１に示す定着装置を正面から見た概略構成図である。
【図１３】従来のローラ加熱方式の定着装置の一例を示す概略構成図である。
【図１４】従来のフィルム加熱方式の定着装置の一例を示す概略構成図である。
【符号の説明】
１ 感光体
２ 帯電ローラ
３ レーザビーム
４ 現像装置
５ 転写ローラ
６ 定着装置
７ クリーニング装置
８ センサ
１０、６０ 定着部材
１１、６１ ヒータ
１１ａ ヒータ基板
１１ｂ 通電発熱抵抗層
１１ｃ、１１ｅ 摺動層
１１ｄ 保護層
１１ｆ、１１ｇ 電極部
１２、６２ ステイホルダ
１３ 定着スリーブ
１３ａ 部位
１４、６４ 温度検知素子
１５ 定着入口ガイド
１６ 駆動ギア
１７ 加圧手段
１８ 導電ブラシ
２０ 加圧部材
２１、５１ 芯金
２２、５２ 弾性層
２３、４３、５３ 離型性層
２４ バイアス印加手段
２５ チップ電極
３１ 金属平板
３２ 内型
３３ 外型
３４、３９ 金属製円筒部材
３５ 金属製内型
３６ａ 押し当てローラ
３６ｂ 軸
３６ｃ 固定台
３７ 押さえ部材
３８ａ〜３８ｃ 連続ダイス
３９ａ 凹凸跡
４０ 定着ローラ
４１ ハロゲンランプ
４２ 中空芯金
４４ サーミスタ
５０ 加圧ローラ
６３ 定着フィルム
Ｎ 定着ニップ部
Ｐ 記録材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toner used in an image forming method such as electrophotography, electrostatic recording, electrostatic printing, and toner jet, and an image forming method and an image forming apparatus using the toner.
[0002]
[Prior art]
In a fixing device provided in an image forming apparatus that employs an electrophotographic method, an electrostatic recording method, or the like, a recording material carrying an unfixed toner image is formed by a fixing roller and a pressure roller that rotate in pressure contact with each other. 2. Description of the Related Art A roller heating type fixing device that fixes a recording material by passing through a nip portion is widely used.
[0003]
For example, as shown in FIG. 13, the roller heating type fixing device includes a fixing roller 40 and a pressure roller 50 facing the fixing roller 40. The fixing roller 40 is disposed inside the hollow cored bar 42, a releasable layer 43 that covers the outer surface of the hollow cored bar 42, a thermistor 44 that detects the surface temperature of the fixing roller 40, and the hollow cored bar 42. And a halogen lamp 41 which is a heating body. The pressure roller 50 includes a metal core 51, an elastic layer 52 that covers the outer peripheral surface of the metal core 51, and a release layer 53 that covers the surface of the elastic layer 52.
[0004]
The hollow core metal 42 is made of, for example, aluminum and is formed with a thickness of about 1 mm to 4 mm so as to satisfy the mechanical strength. The releasable layer 43 is formed of a polymer compound such as polytetrafluoroethylene (PTFE) or perfluoroalkoxytetrafluoroethylene copolymer (PFA) that exhibits performance with excellent releasability. The elastic layer 52 is formed of an elastic member such as a silicone rubber molded body or a silicone rubber foam. The fixing roller 40 and the pressure roller 50 are provided so as to be pressed against each other by, for example, a pressure spring (not shown), and form a fixing nip portion N.
[0005]
Examples of the fixing device provided in the image forming apparatus are described in JP-A-63-313182, JP-A-2-157878, JP-A-4-44075, JP-A-4-204980, and the like. A film heating type fixing device is known.
[0006]
For example, as shown in FIG. 14, the film heating type fixing device includes a fixing member 60 and a pressure roller 50 facing the fixing member 60. The fixing member 60 is interposed between the heating body 61, the stay holder 62 that supports the heating body 61 toward the pressure roller 50, and the heating body 61 and the pressure roller 50. It has a fixing film 63 to be sandwiched and a temperature detecting means 64 provided on the back surface of the heating body 61. The fixing member 60 and the pressure roller 50 are provided so as to be in pressure contact with each other by a pressure spring (not shown), for example, and a fixing nip portion N is formed at a facing portion between the heating body 61 and the pressure roller 50.
[0007]
The heating element 61 is, for example, a ceramic heater in which the energized heat generating resistor layer generates heat when the energized heat generating resistor layer is energized, and the entire heater including the ceramic substrate / glass protective layer is rapidly heated.
[0008]
The fixing film 63 is, for example, a cylindrical, endless belt-shaped, or roll-wrapped web-shaped member, and the surface of the heating body 61 at the fixing nip portion N by a driving means (not shown) or the rotational force of the pressure roller 50. It moves in the direction of the arrow while closely contacting and sliding. The fixing film 63 is generally formed to be as thin as 20 to 70 μm from the viewpoint of improving the heating efficiency from the heating body 61. The fixing film 63 has, for example, a three-layer structure of a film base layer, a conductive primer layer, and a release layer, and is formed of a suitable material from a polymer material such as a highly insulating polymer compound or fluororesin. Yes.
[0009]
Since the roller heating type fixing device has a configuration in which the pressure roller and the fixing roller are in pressure contact with each other, a certain degree of mechanical strength is required to maintain durability. However, when the mechanical strength is increased, the heat capacity of the member increases, the heating efficiency of the heating body decreases, and this is not preferable from the viewpoint of labor saving. On the other hand, when the pressure is applied with a weak pressure in consideration of the durability, the toner fixability may be insufficient.
[0010]
The film heating type fixing device has better heating efficiency than the roller heating type fixing device and is preferable from the viewpoint of labor saving. However, when a polymer compound is used as the material of the fixing film, the thermal conductivity is poor, and the process There is room for improvement in achieving even higher speeds.
[0011]
Further, the durability of the film heating type fixing device is liable to decrease when the pressure is increased. Further, if the pressure is lowered, the heating amount needs to be increased. However, as the heating amount increases, heat is further stored in the pressure roller. For example, a small recording material such as a postcard to an A4 size plain paper is used. When switching from a large recording material to a large recording material, a high temperature offset tends to occur at the latter end.
[0012]
Therefore, in order to realize both a fixing property and durability, and further improve the fixing process to realize a better image forming process such as simplification of configuration, labor-saving operation, and further speeding up of the process, the fixing device However, since the type and structure of the fixing device is likely to be limited, it is more important to improve the toner used together. In particular, from the viewpoint of offset prevention technology, development of a toner having a large effect on toner characteristics, a wide fixing temperature range, and high offset resistance is desired.
[0013]
For such toner, various attempts have been made to improve the binder resin. For example, JP-A-62-294260, JP-A-6-11890, JP-A-6-222612, In JP-A-7-20654, JP-A-9-185182, JP-A-9-244295, JP-A-9-319410, JP-A-10-87837, and JP-A-10-90943, glycidyl is used. For toners with improved fixing and offset resistance by controlling molecular weight distribution, gel content, acid value, epoxy value, etc. in resin compositions composed of carboxyl group-containing resins using group-containing resins as crosslinking agents Binder compositions and toners have been proposed.
[0014]
These toners have an excellent effect on the improvement of offset resistance. However, when applied to a high-speed process speed system, or when applied to simplification and energy saving of a fixing device, There is still room for improvement for further improvement of the high temperature offset resistance.
[0015]
[Problems to be solved by the invention]
An object of the present invention is to provide a toner that has solved the above-described problems, an image forming method using the toner, and an image forming apparatus.
[0016]
That is, the present invention makes it possible to fix at a higher speed, and furthermore, a toner, an image forming method, and an image forming apparatus corresponding to the high speed fixing, having excellent low temperature and low adhesion, high temperature offset resistance, and excellent developability. It is an issue to provide.
[0017]
[Means for Solving the Problems]
The present invention provides an image forming process including a fixing process that achieves both good fixability and durability and enables higher-speed fixing, and a toner applied to the image forming process.
[0018]
That is, according to the present invention, an unfixed toner image is formed on a recording material, while an unfixed toner image is formed by heating a heat transfer layer having a metal base layer with a heating body in contact with the heat transfer layer. A toner used in an image forming method in which a recording material is pressed against a heated heat transfer layer to fix an unfixed toner image on the recording material. The toner contains at least a binder resin and a colorant. One or more resins selected from the group consisting of a mixture of a vinyl resin having a glycidyl group and a vinyl resin having a glycidyl group, a vinyl resin having a carboxyl group and a glycidyl group, and a vinyl resin in which a carboxyl group and a glycidyl group are reacted A toner is provided.
[0019]
The present invention also provides An unfixed toner image is formed on the recording material, and the heat transfer layer having a metal base layer of the film is heated by a heating body in contact with the heat transfer layer, and the recording material on which the unfixed toner image is formed Image formation using a film heating type fixing method in which the unfixed toner image is fixed on a recording material by passing through a fixing nip formed between the heated heat transfer layer and a pressure member. A method in which a bias having a polarity opposite to that of toner is applied to the pressure member side, the heat transfer layer is grounded or diode-connected, and a mixture of a vinyl resin having a carboxyl group and a vinyl resin having a glycidyl group, Binder tree containing one or more resins selected from the group consisting of vinyl resins having a glycidyl group and a vinyl resin having a carboxyl group and a glycidyl group reacted And an image forming method which comprises using a toner containing at least a colorant And an image forming apparatus applied to the image forming method.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
The toner of the present invention includes a mixture of a vinyl resin having a carboxyl group and a vinyl resin having a glycidyl group, a vinyl resin having a carboxyl group and a glycidyl group, and a vinyl resin in which a carboxyl group and a glycidyl group are reacted. It contains at least a binder resin containing one or more selected resins and a colorant.
[0021]
A recording in which an unfixed toner image is formed on the recording material by forming an unfixed toner image on the recording material, while heating the heat transfer layer having a metal base layer with a heating body in contact with the heat transfer layer. Achieves excellent low temperature and low adhesion, high temperature offset resistance, developability, and quick start by using the image forming method to fix the unfixed toner image on the recording material by pressing the material to the heated heat transfer layer. It becomes possible to do.
[0022]
The toner of the present invention preferably has a number average molecular weight of 1,000 to 40,000 in the molecular weight distribution of tetrahydrofuran (THF) soluble matter measured by gel permeation chromatography (GPC). More preferably, it is 3,000 to 20,000, and particularly preferably 3,000 to 15,000. The weight average molecular weight is preferably 10,000 to 10,000,000, more preferably 20,000 to 5,000,000, and particularly preferably 30,000 to 1,000,000. preferable. The toner of the present invention preferably exhibits the above average molecular weight in order to balance the fixing property, offset resistance and blocking resistance.
[0023]
In the toner of the present invention, the average molecular weight in the molecular weight distribution is preferably within the above range in order to achieve good fixability and blocking resistance. When the number average molecular weight is less than 1,000, or when the weight average molecular weight is less than 10,000, blocking resistance is likely to deteriorate, and when the number average molecular weight exceeds 40,000, or the weight average molecular weight is 10 If it exceeds 1,000,000, it is difficult to obtain sufficient improvement in fixability.
[0024]
The toner of the present invention preferably has a main peak in the molecular weight region of 4,000 to 30,000 in the molecular weight distribution of THF-soluble matter measured by GPC, and in the molecular weight region of 5,000 to 20,000. More preferably, it has a main peak. The toner of the present invention preferably has the main peak in order to improve the fixing property, the offset resistance and the blocking resistance. When the main peak has a molecular weight of less than 4,000, blocking resistance tends to deteriorate, and when the molecular weight exceeds 30,000, good fixability tends to decrease.
[0025]
The toner of the present invention has at least one peak at a molecular weight of 4,000 to 30,000 and a molecular weight of 50,000 to 10,000,000 in the molecular weight distribution of THF-soluble matter measured by GPC. It is preferable to have at least one peak. The molecular weight distribution of the latter is more preferably a molecular weight of 800,000 to 10,000,000, and more preferably at least one for each of a molecular weight of 50,000 to 800,000 and a molecular weight of 800,000 to 10,000,000. Even more preferably, it has two peaks.
[0026]
The toner of the present invention preferably exhibits the above peak profile in order to improve the fixing property, the offset resistance and the blocking resistance. In the toner of the present invention, having at least one peak at a molecular weight of 4,000 to 30,000 is effective for achieving good fixing properties and anti-blocking properties, and has a molecular weight of 50,000 to 10,000,000. Having at least one peak at 000 is effective in achieving good offset resistance.
[0027]
In the toner of the present invention, in the case where a plurality of molecular weight ranges having peaks are defined, the peak in the molecular weight region of 4,000 to 30,000 is the maximum peak (main peak) from the viewpoint of improving the fixing property. To preferred.
[0028]
In the above case, the sub-peak in the molecular weight region of 800,000 to 10,000,000 is a component generated by the crosslinking reaction of the binder resin, and is effective in improving the offset resistance. In addition, when the molecular weight is in the range of 100,000 to less than 800,000, a component having a molecular weight of 4,000 to 30,000 and a component having a molecular weight of 800,000 to 10,000,000 having a large difference in melt viscosity is included. It is effective in improving developability and fixing characteristics by improving dispersibility and dispersibility of the THF-insoluble component in the toner.
[0029]
In the toner of the present invention, the binder resin preferably contains 0.1 to 60% by mass of a THF-insoluble component in order to improve the offset resistance.
[0030]
Further, the THF-insoluble content is more preferably 5 to 60% by mass, still more preferably 7 to 55% by mass, still more preferably 9 to 50% by mass, and 10 to 45% by mass. Most preferably. It is preferable that the content of the THF-insoluble component is in the above range in order to improve the fixing property and the offset resistance in a well-balanced manner, and particularly preferable in order to develop a good release property.
[0031]
By exhibiting such a good releasability, the releasability of the fixed image from the fixing member is improved, and even if an image appears on the leading edge of the recording material, the occurrence of jamming due to poor fixing separation is prevented. However, even if a jam occurs in the fixing unit and the toner adheres to the heat transfer layer, most of the adhering toner can be discharged by passing only one sheet of recording material, and the backside dirt is removed. Effective in minimizing. In particular, when applied to a high-speed machine, the amount of toner offset to a heat transfer layer such as a fixing film is reduced, which is effective in extending the service life.
[0032]
When the THF-insoluble content is less than 5% by mass, the above-mentioned excellent effects begin to decrease. When the THF-insoluble content exceeds 60% by mass, not only the fixability is deteriorated but also the chargeability is not uniform in the toner. It is easy to become.
[0033]
Further, in the present invention, it is considered that the delicate balance of the viscosity of the binder resin born from the THF-insoluble matter and the GPC characteristics increases the exposure of the wax to the toner surface when the wax is contained in the toner. This mechanism is effective in reducing contamination of the heat transfer layer with toner.
[0034]
In the toner of the present invention, it is preferable that the acid value of the tetrahydrofuran-soluble component is less than 50 mgKOH / g from the viewpoint of better developability and prevention of contamination of the sleeve and the fixing process.
[0035]
The toner of the present invention preferably has a glass transition temperature (Tg) of 50 to 70 ° C. When Tg is less than 50 ° C., blocking resistance tends to deteriorate, and when it exceeds 70 ° C., fixability tends to decrease.
[0036]
Specific examples of the measurement method capable of measuring the molecular weight distribution of the THF soluble matter measured by GPC of the toner of the present invention and the binder resin used in the present invention are shown below.
[0037]
<Measurement of molecular weight distribution by GPC>
The sample is prepared as follows.
The toner or binder resin to be measured is put in THF, left for several hours, shaken well, mixed well with THF until the measurement object is not united, and allowed to stand for 12 hours or more. At that time, the standing time in THF is set to 24 hours or more. Thereafter, a sample processing filter (pore size 0.2 to 0.5 μm, for example, Mysori Disc H-25-2 (manufactured by Tosoh Corporation) or the like can be used) is passed, and the obtained solution is used as a GPC sample. The sample concentration is adjusted so that the resin component is 0.5 to 5 mg / ml.
[0038]
An RI (refractive index) detector is used as the detector. As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns. TSKgel G1000H (H _XL ), G2000H (H _XL ), G3000H (H _XL ), G4000H (H _XL ), G5000H (H _XL ), G6000H (H _XL ), G7000H (H _XL ), A combination of TSKgull column.
[0039]
The column is stabilized in a heat chamber at 40 ° C., and THF as a solvent is allowed to flow through the column at this temperature at a flow rate of 1 ml per minute, and about 100 μl of the THF sample solution is injected and measured.
[0040]
In the molecular weight measurement, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of the calibration curve prepared from several types of monodisperse polystyrene standard samples and the count value. As a standard polystyrene sample for preparing a calibration curve, for example, a molecular weight of 10 manufactured by Tosoh Corporation or Showa Denko KK ² -10 ⁷ It is appropriate to use a standard polystyrene sample of at least about 10 points.
[0041]
Toner of the present invention and used in the present invention THF insoluble matter in binder resin Specific examples of measurement methods that can measure the above are shown below.
[0042]
<Measurement of THF-insoluble matter>
Binder resin or toner 0.5-1.0g is weighed (W1g), put into a cylindrical filter paper (for example, No. 86R manufactured by Toyo Roshi Kaisha, Ltd.), and applied to a Soxhlet extractor. The solvent is extracted with 200 ml of THF for 10 hours, the soluble component solution extracted with the solvent is evaporated, and then dried in vacuum at 100 ° C. for several hours, and the amount of THF soluble resin component is weighed (W2 g). On the other hand, when measuring the THF-insoluble content of the toner, the weight of the combustion residual ash content in the toner is obtained (W3 g).
[0043]
The combustion residue ash is obtained by the following procedure. About 2.0 g of a sample is placed in a 30 ml magnetic crucible that has been accurately weighed in advance, and weighed accurately, and the mass (Wa) g of the sample is precisely weighed. The crucible is put in an electric furnace, heated at about 900 ° C. for 3 hours, allowed to cool in the electric furnace, allowed to cool in a desiccator for 1 hour or more at room temperature, and the crucible mass is precisely weighed. From this, combustion ash content (Wb) g is obtained. From these results, the combustion residual ash content in the toner is obtained by the following formula, and the weight of the combustion residual ash in the sample is obtained from this content.
[0044]
[Expression 1]
(Wb / Wa) × 100 = combustion residual ash content (mass%)
[0045]
The THF-insoluble content is obtained from the following formula (1) in the case of toner and from the following formula (2) in the case of binder resin.
[0046]
[Expression 2]

[0047]
[Equation 3]

[0048]
Specific examples of the measuring method capable of measuring the acid value of the THF soluble component of the toner of the present invention are shown below. The basic operation in this measurement example conforms to JIS K-0070. Further, the following measurement example is a method for measuring toner, but the acid value of the THF-soluble component of the binder resin can be similarly measured.
[0049]
<Measurement of acid value>
Sample 0.5-2.0 (g) is precisely weighed. A pulverized product is used for the sample as necessary. The sample is used after removing insoluble THF components such as insoluble matter in the colorant and binder resin in advance, or the content of the insoluble THF component is obtained in advance. The weight of the THF-soluble component in the accurately weighed sample is defined as W (g).
[0050]
A sample is put into a 300 (ml) beaker, and a mixed solution 150 (ml) of toluene / ethanol (4/1) is added and dissolved. This solution is titrated with a 0.1 mol / l ethanol solution of KOH using a potentiometric titrator. More specifically, for example, automatic titration using a potentiometric titrator AT-400 (win workstation) manufactured by Kyoto Electronics Co., Ltd. and an ABP-410 electric burette can be used.
[0051]
The amount of KOH solution used at this time is S (ml), and a blank is measured at the same time. The amount of KOH solution used at this time is B (ml). The acid value is calculated from the obtained result by the following formula. f is a factor of KOH.
[0052]
[Expression 4]
Acid value (mgKOH / g) = {(SB) × f × 5.61} / W
[0053]
Specific examples of the measuring method capable of measuring the glass transition temperature of the toner of the present invention are shown below.
[0054]
<Measurement of glass transition temperature>
The glass transition temperature (Tg) of the toner is measured according to ASTM D3418-82 using a differential scanning calorimeter (DSC measuring device), DSC-7 (manufactured by Perkin Elmer) or other models.
[0055]
The measurement trial accurately weighs 5 to 20 mg, preferably 10 mg. This is put in an aluminum pan, and an empty aluminum pan is used as a reference, and measurement is performed at a temperature rise rate of 10 ° C./min at room temperature and normal humidity within a measurement temperature range of 30 to 200 ° C. In this temperature rising process, a specific heat change is obtained in the temperature range of 40 to 100 ° C. At this time, the intersection of the intermediate point line of the baseline before and after the change in specific heat and the differential heat curve is defined as the glass transition temperature Tg of the toner in the present invention.
[0056]
The toner of the present invention contains a binder resin, and the binder resin contains at least a vinyl resin having a carboxyl group and a mixture of vinyl resins having a glycidyl group, or a vinyl resin having a carboxyl group and a glycidyl group. Or at least the vinyl resin which the carboxyl group and the glycidyl group reacted is contained.
[0057]
The vinyl resin mixture is obtained by preparing a vinyl resin having a carboxyl group and a vinyl resin having a glycidyl group and mixing them. The vinyl resin having a carboxyl group and a glycidyl group can be obtained, for example, by copolymerizing a vinyl monomer having a carboxyl group and a vinyl monomer having a glycidyl group. The vinyl resin in which the carboxyl group and the glycidyl group have reacted is, for example, a suitable one in which the cyclic ether of the glycidyl group opens at least the carboxyl group of the vinyl resin having a carboxyl group and the glycidyl group of the vinyl resin having a glycidyl group. Obtained by reacting under conditions.
[0058]
The vinyl resin having a carboxyl group can be obtained by copolymerizing with a vinyl monomer by a known polymerization method using one or two or more kinds of monomers having a carboxyl group. The following are mentioned as a monomer which has a carboxyl group which comprises the vinyl resin which has a carboxyl group.
[0059]
Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, α-ethylacrylic acid, crotonic acid, cinnamic acid, vinyl acetic acid, isocrotonic acid, tiglic acid, and angelic acid. α- or β-alkyl derivatives, fumaric acid, maleic acid, citraconic acid, alkenyl succinic acid, itaconic acid, mesaconic acid, dimethylmaleic acid, dimethylfumaric acid and other unsaturated dicarboxylic acids, monoester derivatives, anhydrides and α -Or β-alkyl derivatives.
[0060]
The monomer having a carboxyl group as described above is 0.1 to 50 parts by mass, preferably 0.1 to 30 parts by mass, and more preferably 0.2 to 15 parts by mass with respect to 100 parts by mass of all monomers constituting the binder resin. What is necessary is just to add a mass part.
[0061]
The acid value of the vinyl resin having a carboxyl group is preferably 100 mgKOH / g or less. When the acid value of the resin is 100 mgKOH / g or less, a uniform and appropriate balance of charging of the toner is obtained, and the occurrence of blotch on the developer carrying member in the developing device and the acceleration of aggregation phenomenon due to overcharging are suppressed, and the toner It is preferable for improving fluidity, transportability, and cleaning properties and realizing a smooth development process. When it exceeds 100 mgKOH / g, the negative chargeability of the binder resin in the toner particles becomes excessive, the image density may decrease, and the fog may increase.
[0062]
The glass transition temperature (Tg) of the vinyl resin having a carboxyl group is preferably 40 to 70 ° C. When Tg is less than 40 ° C., the blocking resistance of the toner tends to deteriorate, and when it exceeds 70 ° C., the toner fixing property tends to deteriorate.
[0063]
From the viewpoint of achieving good fixability, the vinyl resin having a carboxyl group preferably has a number average molecular weight of 1,000 to 40,000, and from the viewpoint of achieving good offset resistance and blocking resistance. The weight average molecular weight is preferably 10,000 to 1,000,000.
[0064]
The vinyl resin having a carboxyl group preferably has a low molecular weight component and a high molecular weight component. From the viewpoint of achieving good fixability, the peak molecular weight of the low molecular weight component is preferably 4,000 to 30,000, preferably From the viewpoint of achieving excellent offset resistance and blocking resistance, the peak molecular weight of the high molecular weight component is preferably 50,000 to 1,000,000. When both the low molecular weight component and the high molecular weight component satisfy the above molecular weight distribution range, both the low-temperature fixability and the offset resistance can be achieved to a higher degree.
[0065]
Further, the vinyl resin having a carboxyl group preferably has a THF-insoluble content of 10% by mass or less, and more preferably 5% by mass or less, from the viewpoint of improving the dispersibility of the toner constituent components.
[0066]
Among the vinyl resins having a carboxyl group, examples of the polymerization method that can be used in the present invention as a method for synthesizing a high molecular weight component include a bulk polymerization method, a solution polymerization method, an emulsion polymerization method, and a suspension polymerization method.
[0067]
Among them, the emulsion polymerization method is a method in which a monomer (monomer) almost insoluble in water is dispersed as small particles in an aqueous phase with an emulsifier, and polymerization is performed using a water-soluble polymerization initiator. In this method, the reaction heat can be easily adjusted, and the termination reaction rate is low because the phase in which the polymerization is carried out (the oil phase consisting of the polymer and the monomer) and the aqueous phase are separate, resulting in a high polymerization rate. A product having a high degree of polymerization is obtained. Furthermore, since the polymerization process is relatively simple and the polymerization product is fine particles, it is easy to mix with other additives such as colorants and charge control agents in the production of toner. For these reasons, there is an advantage as a method for producing a binder resin for toner.
[0068]
However, because of the added emulsifier, the polymer tends to become impure, and an operation such as salting out is necessary to take out the polymer. To avoid this inconvenience, the suspension polymerization method is convenient.
[0069]
In the suspension polymerization method, it is preferable to carry out with 100 parts by mass or less (preferably 10 to 90 parts by mass) of monomers with respect to 100 parts by mass of the aqueous solvent. Examples of the dispersant that can be used include polyvinyl alcohol, partially saponified polyvinyl alcohol, calcium phosphate, and the like. Generally, 0.05 to 1 part by mass is used with respect to 100 parts by mass of the aqueous solvent. The polymerization temperature is suitably 50 to 95 ° C., but is appropriately selected depending on the initiator used and the target polymer.
[0070]
In order to achieve the object of the present invention, the high molecular weight component may be one or more of the polyfunctional polymerization initiators exemplified below, or the polyfunctional polymerization initiator and the monofunctional polymerization start. It is preferable to produce | generate by combined use with an agent.
[0071]
Specific examples of the polyfunctional polymerization initiator having a polyfunctional structure include 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,3-bis (t-butylperoxyisopropyl). ) Benzene, 2,5-dimethyl-2,5 (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di- (t-butylperoxy) hexane, tris (t-butylperoxy) Triazine, 1,1-di-t-butylperoxycyclohexane, 2,2-di-t-butylperoxybutane, 4,4-di-t-butylperoxyvaleric acid-n-butyl ester, di- t-butylperoxyhexahydroterephthalate, di-t-butylperoxyazelate, di-t-butylperoxytrimethyladipate, 2,2-bis (4,4- -T-Butylperoxycyclohexyl) propane, 2,2-t-butylperoxyoctane, and various polymer oxides having a functional group having two or more polymerization initiation functions in one molecule such as a peroxide group Functional polymerization initiators and polymerization initiation functions such as peroxide groups such as diallyl peroxydicarbonate, t-butylperoxymaleic acid, t-butylperoxyallylcarbonate and t-butylperoxyisopropyl fumarate And a polyfunctional polymerization initiator having both a functional group having a polymerizable unsaturated group and a polymerizable unsaturated group in one molecule.
[0072]
Of these, more preferred are 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-t-butylperoxycyclohexane, di-t-butylperoxy. Hexahydroterephthalate, di-t-butylperoxyazelate, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, and t-butylperoxyallyl carbonate.
[0073]
These polyfunctional polymerization initiators are preferably used in combination with a bifunctional or monofunctional polymerization initiator in order to satisfy various performances required as a binder resin for toner. In particular, at the decomposition temperature for obtaining a half-life of 10 hours, it is preferable to use a polymerization initiator having a lower decomposition temperature than the polyfunctional polymerization initiator and the polyfunctional polymerization initiator in combination.
[0074]
Specific examples of the bifunctional or monofunctional polymerization initiator include benzoyl peroxide, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4, Organic such as 4-di (t-butylperoxy) valerate, dicumyl peroxide, α, α'-bis (t-butylperoxydiisopropyl) benzene, t-butylperoxycumene, di-t-butylperoxide Examples thereof include azo and diazo compounds such as peroxide, azobisisobutyronitrile, and diazoaminoazobenzene.
[0075]
These polymerization initiators may be added to the monomer at the same time as the polyfunctional polymerization initiator, but in order to keep the efficiency of the polyfunctional polymerization initiator properly, the polyfunctional polymerization initiator is used in the polymerization step. It is preferably added after the half-life indicated by the polymerization initiator has elapsed. Moreover, it is preferable to use these polymerization initiators at 0.01-10 mass parts with respect to 100 mass parts of monomers from the point of efficiency.
[0076]
Among the vinyl resins having a carboxyl group, a known method can be used as a method for synthesizing a low molecular weight component. However, in the bulk polymerization method, a polymer having a low molecular weight can be obtained by polymerizing at a high temperature to increase the termination reaction rate, but there is a problem that the reaction is difficult to control. On the other hand, in the solution polymerization method, a low molecular weight polymer can be easily obtained under mild conditions by utilizing the difference in chain transfer of radicals depending on the solvent and adjusting the initiator amount and reaction temperature. It is preferable for obtaining the low molecular weight component.
[0077]
As a solvent used in the solution polymerization, xylene, toluene, cumene, cellosolve acetate, isopropyl alcohol or benzene is used. When using a styrene monomer, xylene, toluene or cumene is preferred. The solvent is appropriately selected depending on the polymer to be polymerized. The reaction temperature varies depending on the solvent to be used, the polymerization initiator, and the polymer to be polymerized, but it is usually preferable to carry out at 70 to 230 ° C. In solution polymerization, it is preferable to carry out by 30 mass parts-400 mass parts of monomers with respect to 100 mass parts of solvent. Furthermore, it is also preferable to mix other polymers in the solution at the end of the polymerization, and several kinds of polymers can be mixed by performing such an operation.
[0078]
The vinyl resin having a glycidyl group can be obtained by copolymerization by a known polymerization method using one or more monomers having a glycidyl group and a vinyl monomer.
[0079]
The monomer having a glycidyl group may be a compound having a vinyl group and an epoxide, and examples thereof include glycidyl alcohol and unsaturated carboxylic acid ester, unsaturated glycidyl ether, and the like, for example, glycidyl acrylate, methacrylic acid, and the like. Examples thereof include glycidyl, acrylic acid-β-methyl glycidyl, methacrylic acid-β-methyl glycidyl, allyl glycidyl ether, and allyl-β-methyl glycidyl ether. In particular, a glycidyl monomer represented by the following general formula (1) is preferably used.
[0080]
[Chemical 1]

[0081]
The vinyl resin having a glycidyl group preferably has a weight average molecular weight (Mw) of 2,000 to 100,000, more preferably 2,000 to 50,000, and 3,000 to 40,000. More preferably it is. When Mw is less than 2,000, even if the molecular weight increases in the crosslinking reaction in the binder resin, there are many cases where the molecular chain is broken in the kneading step, and the effect on the offset resistance may be reduced. When Mw exceeds 100,000, the fixability may be affected.
[0082]
The vinyl resin having a glycidyl group preferably has an epoxy value of 0.01 to 5.0 eq / kg, more preferably in the range of 0.01 to 3.0 eq / kg, and 0.05 to 1.0. A range of 0 eq / kg is particularly preferable. In the case of less than 0.01 eq / kg, the crosslinking reaction is unlikely to occur, the amount of high molecular weight components and THF insolubles produced is small, and the effect on offset resistance is reduced. When it exceeds 5.0 eq / kg, the crosslinking reaction tends to occur, but on the other hand, there are many molecular chain breaks in the kneading step, and the effect on the offset resistance is reduced.
[0083]
The vinyl resin having a glycidyl group preferably has a THF insoluble content of 10% by mass or less, and more preferably 5% by mass or less, from the viewpoint of more effectively performing a crosslinking reaction.
[0084]
Specific measurement examples capable of measuring the epoxy value of the vinyl resin having a glycidyl group are shown below. The basic operation in the measurement of the epoxy value conforms to JIS K-7236.
[0085]
<Measurement of epoxy value>
The sample is accurately weighed from 0.5 to 2.0 (g). The weight of the vinyl resin having a glycidyl group is defined as W (g). The precisely weighed sample is placed in a 300 ml beaker and dissolved in 10 ml chloroform and 20 ml acetic acid. To this solution is added 10 ml of tetraethylammonium bromide acetic acid solution. Titrate with a potentiometric titrator using 0.1 mol / l perchloric acid acetic acid solution. For this titration, for example, automatic titration using a potentiometric titrator AT-400 (win workstation) manufactured by Kyoto Electronics Co., Ltd. and an ABP-410 electric burette can be used. The amount of perchloric acid acetic acid solution used by this titration is S (ml). On the other hand, a blank is measured, and the amount of perchloric acid acetic acid solution used at this time is B (ml). From these results, the epoxy value is calculated by the following formula. f is a factor of the perchloric acid acetic acid solution.
[0086]
[Equation 5]
Epoxy value (eq / kg) = 0.1 × f × (SB) / W
[0087]
In the case of using both vinyl resins described above for the purpose of mixing or reacting, the vinyl resin having a glycidyl group has a glycidyl group of 0. 1 with respect to 1 equivalent of the carboxyl group in the vinyl resin having a carboxyl group. It is preferably used in a mixing ratio of 01 to 100.0 equivalents, preferably 0.03 to 10.0 equivalents, more preferably 0.05 to 5.0 equivalents. When the glycidyl group is less than 0.01 equivalent, the number of cross-linking points in the binder resin is reduced, and effects due to a cross-linking reaction such as offset resistance are hardly exhibited. On the other hand, when the amount exceeds 100 equivalents, the crosslinking reaction tends to occur, but the development property may be affected.
[0088]
In the vinyl resin having a carboxyl group and a glycidyl group, the number average molecular weight is preferably 1,000 to 40,000 in order to achieve good fixability. The weight average molecular weight is preferably 10,000 to 1,000,000 in order to achieve good offset resistance and blocking resistance. By introducing the acid value and the epoxy value as described above into the resin having these molecular weights, the target resin can be obtained. The vinyl resin preferably has a THF-insoluble content of 10% by mass or less, and more preferably 5% by mass or less in order to improve the dispersibility of the toner constituting material.
[0089]
The toner of the present invention may be subjected to a crosslinking reaction between a carboxyl group and a glycidyl group in the binder resin component in a heating process such as a kneading process in the manufacturing process. This crosslinkable component works advantageously for improvement in offset resistance, developability and durability.
[0090]
Examples of the vinyl monomer to be copolymerized with a monomer having a carboxyl group and a monomer having a glycidyl group include styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-phenylstyrene. P-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn Styrene derivatives such as octyl styrene, pn-nonyl styrene, pn-decyl styrene and pn-dodecyl styrene; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; butadiene, isoprene, etc. Unsaturated polyenes; vinyl chloride, salt Vinylidene, vinyl bromide, such as vinyl halides of vinyl fluoride, vinyl acetate, vinyl propionate, benzoic acid Vinyl esters such as vinyl; methyl methacrylate, ethyl methacrylate, propyl methacrylate, -n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, methacrylic acid (2-ethylhexyl), methacryl Α-methylene aliphatic monocarboxylic acid esters such as stearyl acid, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, acrylic Acrylic acid esters such as propyl acid, acrylic acid-n-octyl, dodecyl acrylate, acrylic acid (2-ethylhexyl), stearyl acrylate, acrylic acid (2-chloroethyl), phenyl acrylate Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl compounds such as N-vinylpyrrolidone; vinylnaphthalenes; acrylic acid derivatives or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide. These vinyl monomers are used alone or in combination of two or more.
[0091]
Among these, a combination of monomers that becomes a styrene copolymer and a styrene-acrylic copolymer is preferable. In this case, at least 60% by mass or more of the styrene copolymer component or the styrene-acrylic copolymer component is used. It is preferable to contain it from the viewpoint of fixing property and mixing property.
[0092]
In addition, as the binder resin used in the toner of the present invention, the following polymers can also be used.
[0093]
Examples of such polymers include homopolymers of styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene, and substituted products thereof; styrene-p-chlorostyrene copolymers, and styrene-vinyltoluene copolymers. Styrene-vinyl naphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinylmethyl Styrene copolymers such as ether copolymers, styrene-vinyl ethyl ether copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers. Polymer: polyvinyl chloride, Enol resin, natural modified phenolic resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin , Coumarone indene resin, petroleum resin and the like.
[0094]
As the colorant used in the present invention, various known colorants such as a magnetic substance, a non-magnetic dye, and a pigment can be used. When the toner of the present invention is applied to a magnetic one-component toner, the toner contains a magnetic substance.
[0095]
Examples of magnetic materials used in the present invention include iron oxides such as magnetite, maghemite, and ferrite; metals such as iron, cobalt, and nickel, or these metals and aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, Metal alloys such as beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium, and mixtures thereof are used, and those containing non-ferrous elements on the surface or inside of the magnetic material are preferable. Further, the toner of the present invention is preferably a magnetic toner containing 30 to 200 parts by mass of a magnetic material with respect to 100 parts by mass of the binder resin. In this case, a sufficient coloring effect can be obtained by the magnetic material.
[0096]
Examples of magnetic materials used in the present invention include iron oxides such as magnetite, maghemite, and ferrite; metals such as iron, cobalt, and nickel, or these metals, and aluminum, cobalt, copper, lead, magnesium, manganese, selenium, and titanium. Alloys with metals such as tungsten and vanadium and mixtures thereof are used, and those containing non-ferrous elements on the surface or inside of the magnetic material are preferred.
[0097]
As the magnetic material used in the present invention, magnetic iron oxides such as magnetite, maghemite, and ferrite containing different elements and mixtures thereof are preferably used. Among them, lithium, beryllium, boron, magnesium, aluminum, silicon, phosphorus, germanium, titanium, zirconium, tin, lead, zinc, calcium, barium, scandium, vanadium, chromium, manganese, cobalt, copper, nickel, gallium, cadmium, indium It is preferably a magnetic iron oxide containing at least one element selected from silver, palladium, gold, mercury, platinum, tungsten, molybdenum, niobium, osmium, strontium, yttrium, technetium, ruthenium, rhodium, and bismuth. . In particular, lithium, beryllium, boron, magnesium, aluminum, silicon, phosphorus, germanium, zirconium, tin, and transition metal elements of the fourth period are preferable elements.
[0098]
These elements may be incorporated into the iron oxide crystal lattice, may be incorporated into the iron oxide as oxides, or may exist on the surface as oxides or hydroxides. Among these forms, the preferred form is contained as an oxide.
[0099]
In some cases, the magnetic iron oxide used in the toner of the present invention may be treated with a silane coupling agent, a titanium coupling agent, titanate, aminosilane, or the like.
[0100]
These magnetic iron oxides are preferably used in an amount of 20 to 200 parts by mass with respect to 100 parts by mass of the binder resin from the viewpoint of making both coloring power and magnetism related to developability and transportability compatible with each other. More preferably, it is used at 40 to 150 parts by mass.
[0101]
Examples of the colorant used in the present invention include any appropriate pigment or dye in addition to the above magnetic iron oxide. Examples of the pigment include carbon black, aniline black, acetylene black, naphthol yellow, hansa yellow, rhodamine lake, alizarin lake, bengara, phthalocyanine blue, and indanthrene blue. These are used in an amount necessary and sufficient to maintain the optical density of the fixed image, and the blending amount varies depending on the type and the like, but is 0.1 to 20 parts by mass with respect to 100 parts by mass of the binder resin. Preferably, it is 0.2-10 mass parts.
[0102]
For the same purpose, a dye is further used. Examples of the dye include azo dyes, anthraquinone dyes, xanthene dyes, and methine dyes. The amount of the dye varies depending on the type and the like, but is 0.1 to 20 parts by mass with respect to 100 parts by mass of the binder resin. It is preferable that it is 0.3-10 mass parts.
[0103]
The toner of the present invention can be used as both a magnetic toner and a non-magnetic toner, but a weight average diameter of 2.5 to 10 μm promotes charging uniformity and reduces toner cohesion. In view of improving the image density and improving the developability by improving the fog, it is preferable. In particular, the effect is remarkable in a toner having a weight average diameter of 2.5 to 6.0 μm, and an extremely fine image can be obtained. A weight average diameter of 2.5 μm or more is preferable because a sufficient image density can be obtained. The weight average diameter can be adjusted by a toner production method and production conditions, classification work, and the like.
[0104]
The weight average particle diameter and particle size distribution of the toner of the present invention can be measured using the Coulter method, and for example, Coulter Multisizer (manufactured by Coulter Co.) can be used. In this measurement method, an electrolytic solution is used. For this electrolytic solution, for example, a 1% NaCl aqueous solution prepared using primary sodium chloride or ISOTON R-II (manufactured by Coulter Scientific Japan) is used. it can.
[0105]
As a measurement method, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. This was dispersed for about 1 to 3 minutes with an ultrasonic disperser to disperse the sample. Using a 100 μm aperture as the aperture, the volume and number of toner particles of 2.00 μm or more were measured with the measuring device, and the volume distribution and The number distribution is calculated. Then, a weight-based weight average diameter (D4) obtained from the volume distribution according to the present invention is calculated.
[0106]
As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 Less than 35 to 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Use 13 channels less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm.
[0107]
The toner of the present invention may contain a wax. Examples of the wax used in the present invention include paraffin wax and derivatives thereof, montan wax and derivatives thereof, microcrystalline wax and derivatives thereof, Fischer-Tropsch wax and derivatives thereof, polyolefin wax and derivatives thereof, carnauba wax and derivatives thereof, and the like. It is done. Derivatives include oxides, block copolymers with vinyl monomers, and graft modified products.
[0108]
In the toner of the present invention, the total content of these waxes is preferably 0.1 to 15 parts by mass and more preferably 0.5 to 12 parts by mass with respect to 100 parts by mass of the binder resin. . A plurality of types of waxes may be used in combination.
[0109]
The toner of the present invention preferably contains a charge control agent. For controlling the toner to be negatively charged, for example, organometallic complexes and chelate compounds are effective, and monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, aromatic dicarboxylic acid metal complexes, and others. In addition, aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and metal salts thereof, anhydrides, esters, phenol derivatives such as bisphenol, and the like. As the charge control agent for controlling the toner to be negatively charged, an azo metal complex represented by the following general formula (2) is preferable.
[0110]
[Chemical 2]

[0111]
In the charge control agent represented by the general formula (2), in particular, Fe or Cr is preferable as the central metal, halogen, alkyl group, or anilide group is preferable as the substituent, and hydrogen or alkali metal ammonium is preferable as the counter ion. Aliphatic ammonium is preferred. A mixture of complex salts having different counter ions is also preferably used.
[0112]
Examples of the charge control agent for controlling the toner to be negatively charged include a basic organic acid metal complex represented by the following general formula (3).
[0113]
[Chemical 3]

[0114]
In the charge control agent represented by the general formula (3), in particular, Fe, Cr, Si, Zn, and Al are preferable as the central metal, and an alkyl group, anilide group, aryl group, and halogen are preferable as the substituent, The counter ion is preferably hydrogen, ammonium, or aliphatic ammonium.
[0115]
Among the charge control agents represented by the general formula (3), an azo metal complex is more preferable, and an azo iron complex represented by the following general formula (4) is most preferable.
[0116]
[Formula 4]

[0117]
Specific examples of the azo metal complex represented by the general formula (4) include the following structural formulas (5) to (10).
[0118]
[Chemical formula 5]

[0119]
[Chemical 6]

[0120]
[Chemical 7]

[0121]
[Chemical 8]

[0122]
[Chemical 9]

[0123]
Embedded image

[0124]
For controlling the toner of the present invention to be positively charged, for example, modified products of nigrosine and fatty acid metal salts, etc .; four kinds of tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, etc. Onium salts such as quaternary ammonium salts and phosphonium salts thereof, and their lake pigments, triphenylmethane dyes and their lake pigments (as rake agents, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdenum) Acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.), higher fatty acid metal salts; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; Over DOO, dioctyl tin borate, diorgano tin borate such as dicyclohexyl tin borate; guanidine compounds, imidazole compounds and the like can be used alone or in combination. Among these, triphenylmethane compounds and quaternary ammonium salts whose counter ions are not halogen are preferably used.
[0125]
Further, a homopolymer of a monomer represented by the following general formula (11); a copolymer with a polymerizable monomer such as styrene, acrylic acid ester or methacrylic acid ester described above can be used as a positive charge control agent. . In this case, these charge control agents also have an action as a binder resin (all or a part thereof).
[0126]
Embedded image

[0127]
As the positively chargeable charge control agent, a compound represented by the following general formula (12) is particularly preferable.
[0128]
Embedded image

[0129]
As a method of incorporating a charge control agent into the toner, there are a method of adding it inside the toner and a method of adding it externally. The amount of these charge control agents used is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and the dispersion method, and is not uniquely limited. The amount is preferably 0.1 to 10 parts by mass and more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the binder resin.
[0130]
In the toner of the present invention, it is preferable to externally add particles having a small particle size as external additives to toner particles containing at least a binder resin and a colorant. Examples of such external additives include inorganic oxides such as silica, alumina, and titanium oxide, and fine particles such as carbon black and carbon fluoride.
[0131]
In particular, silica, alumina and titanium oxide fine powder are preferable because they have a great effect of improving the fluidity of the toner. From such a viewpoint, the number average particle diameter of the inorganic oxide particles is preferably 5 to 200 nm, and more preferably 10 to 100 nm.
[0132]
The inorganic oxide particles have a specific surface area of 30 m by nitrogen adsorption as measured by the BET method. ² / G or more, preferably 60 to 400 m ² / G is more preferable. The inorganic oxide particles may be used after the surface is hydrophobized, and the specific surface area of the surface-treated inorganic oxide particles is 20 m. ² / G or more, preferably 40 to 300 m ² / G is more preferable.
[0133]
The application amount of the inorganic oxide particles is preferably 0.03 to 5 parts by mass with respect to 100 parts by mass of the toner particles in order to appropriately coat the surface of the toner particles with the particles.
[0134]
The inorganic oxide particles preferably have a degree of hydrophobicity of 30% or more, more preferably 50% or more in terms of methanol wettability. Preferred hydrophobizing agents include silane compounds that are silicon-containing surface treating agents and silicone oils.
[0135]
Examples of the silane compound include alkylalkoxysilanes such as dimethyldimethoxysilane, trimethylethoxysilane, and butyltrimethoxysilane, dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethyldisilazane, and allylphenyldichloro. Examples thereof include silane compounds such as silane, benzyldimethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, divinylchlorosilane, and dimethylvinylchlorosilane. Moreover, as a silicone oil, a well-known thing can be used. Silane compounds and silicone oils can be used in combination.
[0136]
In addition, from the viewpoint of improving the developability and durability of the toner, it is also preferable to add other inorganic powder as an external additive to the toner of the present invention. Examples of such inorganic powder include metal oxides such as magnesium, zinc, aluminum, cerium, cobalt, iron, zirconium, chromium, manganese, strontium, tin, and antimony; calcium titanate, magnesium titanate, strontium titanate Composite metal oxides such as: Metal salts such as calcium carbonate, magnesium carbonate and aluminum carbonate; Clay minerals such as kaolin; Phosphoric acid compounds such as apatite; Silicon compounds such as silicon carbide and silicon nitride; Carbon powder such as carbon black and graphite Is mentioned. Of these, zinc oxide, aluminum oxide, cobalt oxide, manganese dioxide, strontium titanate, magnesium titanate and the like are preferable.
[0137]
Furthermore, a lubricant powder such as a fluororesin such as polyvinyl fluoride or polyvinylidene fluoride; a fluorine compound such as carbon fluoride can be added to the toner of the present invention as an external additive.
[0138]
The toner of the present invention can be produced by a known method. As a method for producing the toner of the present invention, the above-described toner constituent materials are sufficiently mixed by a ball mill or other mixer, and then kneaded well using a thermal kneader such as a hot roll kneader or an extruder, and then solidified by cooling. Thereafter, a method of mechanically pulverizing and classifying the pulverized powder is preferable.
[0139]
In addition, a polymerized toner manufacturing method in which a predetermined material is mixed with a monomer to constitute a binder resin to form an emulsion suspension, and then polymerized to obtain a toner; a so-called core material and shell material are used. Examples of the microcapsule toner include a method in which a predetermined material is contained in the core material, the shell material, or both; and a method in which the constituent material is dispersed in the binder resin solution and then spray-dried to obtain the toner.
[0140]
Furthermore, the toner of the present invention can be produced by sufficiently mixing the toner particles obtained by these methods described above with a mixer such as a Henschel mixer as required.
[0141]
The equipment used for producing the toner of the present invention is not particularly limited. For example, as a mixer, a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.); a super mixer (manufactured by Kawata Corporation); ); Nauter mixer, turbulizer, cyclomix (manufactured by Hosokawa Micron Corporation); spiral pin mixer (manufactured by Taiheiyo Kiko Co., Ltd.);
[0142]
As a kneading machine, for example, KRC kneader (manufactured by Kurimoto Iron Works); Bus co-kneader (manufactured by Buss); TEM type extruder (manufactured by Toshiba Machine); TEX twin-screw kneader (manufactured by Nippon Steel Works) PCM kneading machine (Ikegai Iron Works); Three roll mill, mixing roll mill, kneader (Inoue Seisakusho); Needex (Mitsui Mining); MS pressure kneader, Nider Ruder (Moriyama Seisakusho) A Banbury mixer (manufactured by Kobe Steel).
[0143]
Examples of the pulverizer include counter jet mill, micron jet, inomizer (manufactured by Hosokawa Micron); IDS type mill, PJM jet pulverizer (manufactured by Nippon Pneumatic Industry); cross jet mill (manufactured by Kurimoto Iron Works); (Manufactured by Nisso Engineering Co., Ltd.); SK Jet Oh Mill (manufactured by Seishin Enterprise Co., Ltd.); kryptron (manufactured by Kawasaki Heavy Industries, Ltd.); turbo mill (manufactured by Turbo Kogyo Co., Ltd.); .
[0144]
Classifiers include, for example, a class seal, a micron classifier, a speck classifier (manufactured by Seishin Enterprise); a turbo classifier (manufactured by Nisshin Engineering); a micron separator, a turboplex (ATP), a TSP separator (manufactured by Hosokawa Micron) ); Elbow Jet (manufactured by Nippon Steel Mining Co., Ltd.), Dispersion Separator (manufactured by Nippon Pneumatic Industrial Co., Ltd.); YM Microcut (manufactured by Yaskawa Shoji Co., Ltd.).
[0145]
Examples of sieving devices used for sieving coarse particles include Ultrasonic (manufactured by Sakae Sangyo Co., Ltd.); Resonator Sheave, Gyroshifter (Tokuju Kosakusha Co., Ltd.); Vibrasonic System (Dalton Co., Ltd.); Examples include a turbo screener (manufactured by Turbo Industry Co., Ltd.), a micro shifter (manufactured by Kanno Sangyo Co., Ltd.), and a circular vibrating sieve.
[0146]
Next, the image forming method of the present invention will be described.
The image forming method of the present invention uses the toner of the present invention described above, and forms an unfixed toner image on a recording material, while contacting a heat transfer layer having a metal base layer with the heat transfer layer. The recording material is heated by a heating member, and the recording material on which the unfixed toner image is formed is pressed against the heated heat transfer layer, thereby fixing the unfixed toner image on the recording material.
[0147]
In the image forming method of the present invention, the process until the unfixed toner image is formed on the recording material is not particularly limited except that the toner of the present invention described above is used. In the image forming method of the present invention, for example, charging to a photosensitive member, formation of an electrostatic latent image, development of an electrostatic latent image with toner, and transfer of a toner image to a recording material are not yet performed on a recording material by known processes. A contact toner image can be formed. Further, in the image forming method of the present invention, other steps may be further employed. For example, a cleaning step for removing the toner on the photoconductor after transfer, and a developing and collecting step for collecting the toner on the photoconductor during development. A cleaning process, an intermediate transfer process when applied to full-color image formation, an intermediate transfer body cleaning process, a pre-exposure process for aligning the surface potential of the photoreceptor before charging, and the like can be arbitrarily employed.
[0148]
In the image forming method of the present invention, a fixing device using a heat transfer layer having a metal base layer as a film in the above-described film heating type fixing device can be suitably used. That is, in the image forming method of the present invention, the heat transfer layer has a cylindrical metal element tube as a base layer, and the heating element is disposed inside the cylinder of the cylindrical metal element tube, and is connected to the heating element via the heat transfer layer. A recording material on which an unfixed toner image is formed is passed through a fixing nip portion formed between a pressure member and a heat transfer layer that are opposed and in contact with the heat transfer layer. Is preferably brought into pressure contact with the heat transfer layer.
[0149]
In the image forming method of the present invention, it is possible to carry out heat fixing corresponding to speeding up of the image forming apparatus with high thermal efficiency by contacting and heating the heat transfer layer having good thermal conductivity from the inside with a heating body. Become.
[0150]
Further, in the image forming method of the present invention, since the heating efficiency at the time of fixing is good, it is possible to shut down the energization to the heating body during the standby state in which the image forming apparatus is not receiving the print signal. It is preferable for realizing energy-saving heat fixing.
[0151]
Further, in the image forming method of the present invention, even when the image forming apparatus is turned on from room temperature, the print signal can be received immediately, so that the operator does not have to wait. That is, even when the speed of the image forming apparatus is increased, fixing can be performed with excellent quick start characteristics and fast first print time.
[0152]
Further, in the image forming method of the present invention, it is possible to set a high pressing force by using a heat transfer layer having a metal base layer having higher rigidity than a resin film. It becomes possible to cope with the conversion.
[0153]
In the image forming method of the present invention, when the heating body is disposed in contact with the heat transfer layer, if the surface of the heating body is a resin member such as a heat-resistant polyimide resin, the heat transfer layer is formed on the surface of the heating body. It is preferable for realizing smooth heat-fixing by sliding smoothly.
[0154]
In the image forming method of the present invention, it is preferable to subject the cylindrical metal element tube to circumferential streaking within a predetermined range in order to smooth the rotation of the cylindrical metal element tube and suppress damage to the heating body. .
[0155]
In the image forming method of the present invention, a bias having a polarity opposite to that of the toner is applied to the pressure roller side at the time of fixing, and the heat transfer layer is grounded or diode-connected, so that paper dust, toner, etc. are adsorbed to the heat transfer layer. It is preferable for preventing the occurrence of the problem. Thereby, there is no problem that the heat transfer layer becomes dirty due to durability, and the durability can be further improved.
[0156]
The fixing method employed in the present invention is likely to cause tailing in a high-speed process. The tailing is a phenomenon that occurs when the toner image passes through the fixing nip and the air between the toner images is ejected together with the toner. In contrast to this tailing, if the bias is increased, the toner shape on the recording material is attracted to the recording material, and the toner can be influenced more strongly than the ejection of air between the toner images. It is effective in suppressing the occurrence. On the other hand, increasing the bias makes it easy for some of the low-chargeable toner and unstablely charged toner charged to the opposite polarity to fly to the heat transfer layer, causing an offset due to static electricity. easy.
[0157]
However, since the toner of the present invention described above is unlikely to cause a high temperature offset, it is difficult to induce an offset even when the bias is applied as described above. Further, since the toner of the present invention can obtain a good transfer, the toner is attracted onto the front recording material to a level that is not affected by the ejection of air between the toner images, and the offset when no bias is applied can be reduced. As described above, in the image forming method of the present invention, both the anti-offset property and the prevention of tailing can be achieved by employing the toner and the fixing method described above.
[0158]
The image forming method of the present invention can be realized by appropriately combining known members and means. More specifically, the image forming method of the present invention can be realized by applying modification to a known image forming apparatus in which a fixing device that realizes the above-described fixing process is mounted. The image forming apparatus of the present invention, which is a suitable image forming apparatus for realizing the image forming method of the present invention, will be described below.
[0159]
An image forming apparatus of the present invention uses the toner of the present invention described above, and has means for forming an unfixed toner image on a recording material and a fixing device for fixing the unfixed toner image on the recording material. In the image forming apparatus, the fixing device includes a heating body, a pressure member provided to face the heating body, and a heat transfer layer interposed between the heating body and the pressure member and heated by the heating body. The heating body is disposed in contact with the heat transfer layer, the heat transfer layer has a metal base layer, and the pressure member is disposed in contact with the heat transfer layer at a portion facing the heating body. Yes.
[0160]
In the image forming apparatus of the present invention, the metal base layer is preferably a cylindrical metal element tube, and the heating body is preferably disposed inside the cylinder of the cylindrical metal element tube.
Hereinafter, the image forming apparatus of the present invention will be described more specifically with reference to the drawings.
[0161]
For example, as shown in FIG. 1, the image forming apparatus of the present invention includes a photoreceptor 1, a charging roller 2 disposed in contact with the photoreceptor 1 and charging the photoreceptor 1, and a laser on the surface of the charged photoreceptor 1. Electrostatic latent image forming means (not shown) that forms an electrostatic latent image by irradiating the beam 3 and development for forming a toner image by supplying the toner of the present invention to the photosensitive member 1 on which the electrostatic latent image is formed A transfer roller 5 for transferring a toner image formed on the photosensitive member 1 to the recording material P to form an unfixed toner image on the recording material P; and an unfixed toner formed on the recording material P. The image forming apparatus includes a fixing device 6 that fixes an image on the recording material P, a cleaning device 7 that removes toner remaining on the photoreceptor 1 after transfer, and a sensor 8 that detects the position of the recording material P.
[0162]
The photosensitive member 1 is formed by layering a photosensitive material such as OPC, amorphous Se, or amorphous Si on a cylindrical base material such as aluminum or nickel. The charging roller 2 and the transfer roller 5 are obtained by covering the peripheral surface of a core metal with a conductive elastic layer, and a power source (not shown) is connected to the core metal so that a desired voltage can be applied to each roller. It is configured. The electrostatic latent image forming unit is a unit that irradiates a laser beam 3 corresponding to information on an image to be formed. The developing device 4 includes a developing container that contains toner and a developer carrier that is rotatably provided in the opening of the developing container, and supplies the toner on the developer carrier to the photosensitive member 1. The configuration of the developing device 4 is selected according to the type of toner and the desired developing method. The cleaning device 7 includes a waste toner container and an elastic cleaning blade that comes into contact with the photoreceptor 1. The fixing device 6 will be described later.
[0163]
In the image forming apparatus, the photosensitive member 1 is rotationally driven in the direction of the arrow, and first, the surface thereof is uniformly charged by a charging roller 2 as a charging device. Next, scanning exposure is performed by the laser beam 3 which is ON / OFF controlled according to the image information, and an electrostatic latent image is formed. This electrostatic latent image is developed and visualized by the developing device 4. As a developing method, a jumping developing method, a two-component developing method, a FEED developing method or the like is used, and a developing method in which image exposure and reversal development are combined is also used. The visualized toner image is transferred from the photoreceptor 1 onto the recording material P conveyed at a predetermined timing by a transfer roller 5 as a transfer device. The recording material P is transported to the transfer roller 5 by detecting the leading edge of the recording material P with the sensor 8 so that the image forming position of the toner image on the photoreceptor 1 and the writing position of the leading edge of the recording material P coincide. , Done in time.
[0164]
The recording material P conveyed at a predetermined timing is nipped and conveyed between the photosensitive member 1 and the transfer roller 5 with a constant pressure. The recording material P to which the toner image has been transferred is conveyed to the fixing device 6 and fixed.
[0165]
On the other hand, the residual toner remaining on the photosensitive member 1 is removed from the surface of the photosensitive member 1 by the cleaning device 7.
[0166]
As shown in FIG. 2, the fixing device 6 includes a fixing member 10 and a pressure member 20. The fixing member 10 and the pressure member 20 are in pressure contact with each other to form a fixing nip portion N. The recording material P is appropriately supplied by a supply unit (not shown) in FIG. 2, and is conveyed along a heat-resistant fixing inlet guide 15 to a fixing nip N formed by the fixing member 10 and the pressure member 20.
[0167]
The fixing member 10 includes a heater 11 as a heating body, a heat-insulating stay holder 12 that supports the heater 11 toward the pressure member 20, and includes the heater 11 and the stay holder 12. A cylindrical fixing sleeve 13 with a part of the peripheral surface being sandwiched and a temperature detecting element 14 for detecting the temperature of the heater 11 are provided.
[0168]
The pressure member 20 includes a cylindrical cored bar 21, an elastic layer 22 formed on the peripheral surface of the cored bar 21, and a releasable layer 23 formed on the peripheral surface of the elastic layer 22. . The elastic layer 22 can be formed of a heat-resistant rubber such as silicone rubber or fluorine rubber, or a foam of heat-resistant rubber. The releasable layer 23 can be formed of a film or tube of a resin compound having excellent heat resistance and releasability such as PFA, PTFE, FEP (tetrafluoroethylene-hexafluoropropylene copolymer).
[0169]
The heater 11 is provided inside the fixing sleeve 13 and heats at the fixing nip portion N, thereby melting the toner on the recording material P and fixing the toner image. The configuration in the vicinity of the heater 11 is shown in FIG. The heater 11 includes a heater substrate 11a, an energized heating resistor layer 11b supported on the surface of the heater substrate 11a, and a sliding layer 11c that covers the energized heating resistor layer 11b on the heater substrate 11a. Note that. A temperature detection element 14 such as a thermistor for detecting the temperature of the heater 11 is usually disposed in the heater 11.
[0170]
The heater substrate 11a is a material having heat resistance and insulation, such as highly insulating ceramics such as alumina and AlN (aluminum nitride), and heat resistant resins such as polyimide, PPS (polyphenylene sulfide), and liquid crystal polymer. Can be formed.
[0171]
The energization heating resistance layer 11b is made of, for example, Ag / Pd (silver palladium), RuO. ₂ , Ta ₂ Using a material that generates heat when energized, such as N, it is applied in the shape of a line or strip with a thickness of about 10 μm and a width of about 1 to 5 mm by a method such as screen printing along the longitudinal direction of the heater substrate 11a. Can be formed.
[0172]
The sliding layer 11c is a thin layer formed on the surface of the energization heating resistor layer 11b. For example, the sliding layer 11c slides on the fixing sleeve 13 such as a fluororesin layer, polyimide, polyamideimide, PEEK (polyetheretherketone). It can be formed by a known method using a heat resistant resin compound capable of withstanding rubbing.
[0173]
When AlN (aluminum nitride) or the like having a good thermal conductivity is used as the heater substrate 11a, the energization heating resistor layer 11b is opposite to the fixing nip portion N with respect to the heater substrate 11a as shown in FIG. You may form in the side. In this case, the heater 11 includes a heater substrate 11a, an energization heating resistance layer 11b, a protective layer 11d, and a sliding layer 11e. The temperature detection element 14 is disposed in contact with the heater 11 on the inner side of the fixing sleeve 13 as in FIG. The protective layer 11d is provided in order to satisfy the withstand voltage between the energization heating resistor layer 11d and the temperature detecting element 14, and is made of a material having heat resistance and insulation such as a glass coat, a fluororesin layer, and the like. Can be formed. The sliding layer 11e can be formed in the same manner as the sliding layer 11c.
[0174]
When the heater 11 has a curved surface on the fixing nip portion N side of the heater 11, the bending load on the fixing sleeve 13 when passing through the surface of the heater 11 is reduced, which is preferable in forming a long-life fixing member. As such a heater 11, for example, an insulating layer and an energized heating resistance layer are sequentially laminated on the side opposite to the fixing nip portion N of the heater substrate, and the heater substrate has a shape in which the fixing nip portion N side is curved in the same direction as the fixing sleeve. The heater which is is mentioned.
[0175]
The stay holder 12 is a heat insulating member that holds the heater 11 and prevents heat dissipation in the direction opposite to the fixing nip portion N, and can be formed of liquid crystal polymer, phenol resin, PPS, PEEK, or the like. The stay holder 12 may be formed in a shape that forms a track of the moving fixing sleeve 13. The shape of the stay holder 12 in this case may be formed according to the form of the heat transfer layer to be used. In such a case, a small amount of lubricant such as heat-resistant grease is interposed on the surfaces of the heater 11 and the stay holder 12 to suppress the frictional resistance between the heater 11 and the stay holder 12 and the fixing sleeve 13. It is preferable for smoothly rotating the fixing sleeve 13.
[0176]
A fixing sleeve 13 is loosely fitted on the stay holder 12 with a margin, and is arranged to be rotatable in the direction of the arrow.
[0177]
The fixing sleeve 13 is a heat transfer layer formed in a cylindrical shape, and is formed of a cylindrical metal element tube, a release layer, and an adhesive layer that bonds the cylindrical metal element tube and the release layer. Can do. The fixing sleeve 13 is a metal sleeve having a small heat capacity, and is formed to a thickness of 100 μm or less in order to enable quick start. The fixing sleeve 13 may be formed using a metal layer having heat resistance and high thermal conductivity, such as a metal member such as SUS, Al, Ni, Cu, Zn, or an alloy member including these metals, as a base layer. it can.
[0178]
The cylindrical metal element tube is a metal base layer in the heat transfer layer, has a sufficient strength to constitute a long-life heat fixing device, and from the viewpoint of constituting a metal sleeve excellent in durability, It is preferable to have a thickness of 20 μm or more. That is, the thickness of the fixing sleeve 13 is preferably 20 μm or more and 100 μm or less.
[0179]
The releasable layer is a layer coated on the surface of a cylindrical metal base tube in order to further prevent offset and ensure separation of the recording material. For example, PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene) Ethylene-perfluoroalkyl vinyl ether copolymer), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), ETFE (ethylene-tetrafluoroethylene copolymer), CTFE (polychlorotrifluoroethylene), PVDF (polyvinylidene) It can be formed of one or two or more heat-resistant resins having a good releasability such as a fluororesin such as fluoride) and a silicone resin.
[0180]
The adhesive layer is a layer for supporting and fixing the releasable layer to the surface of the cylindrical metal element tube. The releasable layer itself or the material before processing of the releasable layer is used as the cylindrical metal element tube. There is no particular limitation as long as it can be adhered to the surface. Examples of such an adhesive layer include a primer layer. For example, the release layer using the adhesive layer may be formed by, for example, applying the primer layer to the outer surface of a cylindrical metal base tube, and then performing the above dipping or powder spraying. A method of forming a releasable layer by coating such as the above. The adhesive layer may be unnecessary depending on the form of the releasable layer, such as covering the surface of the cylindrical metal base tube with a releasable layer formed in a tube shape, for example. good.
[0181]
In addition, the release layer and the adhesive layer preferably have a total thickness of 20 μm or less in order to improve the heating efficiency at the time of fixing and maintain the durability.
[0182]
As shown in FIG. 5, the fixing member 10 presses a part of the stay holder 12 or a member attached to the stay holder 12 by fitting or the like at both ends in the longitudinal direction of the fixing member 10 with a spring or the like. By urging the pressure member 20 by means 17, it is arranged in contact with the pressure member 20 to form a desired fixing nip portion N.
[0183]
Electrode portions 11f and 11g are formed at the longitudinal ends of the heater substrate 11a, and a voltage applied to the energization heating resistor layer 11b is applied from these electrode portions. That is, by appropriately controlling the duty ratio, wave number, and the like of the voltage applied to the energization heating resistor layer 11b according to the signal from the temperature detection element 14, the temperature at the fixing nip portion N is kept substantially constant, and the recording material P Heating necessary to fix the upper toner image is performed. DC energization from the temperature detection element 14 to a temperature control unit (not shown) is achieved by a connector (not shown) via a DC current supply unit and a DC electrode unit (not shown).
[0184]
Further, the driving gear 16 is attached to the end of the core metal 21 of the pressure member 20, and the pressure member 20 is driven to rotate by such a configuration, and the friction between the surface of the pressure member 20 and the surface of the fixing sleeve 13 is caused. The fixing sleeve 13 is rotated following a predetermined speed.
[0185]
In the present invention, it is preferable that the surface roughness of the inner surface of the cylindrical metal base tube is 3 μm or less in order to keep the contact thermal resistance low and improve the heat transfer to the fixing nip portion. Further, the surface roughness of the outer surface of the cylindrical metal pipe is preferably 3 μm or less in order to achieve good fixing properties.
[0186]
Here, the surface roughness of the inner and outer surfaces of the fixing sleeve 13 and the thickness of the releasable layer will be described below.
[0187]
First, the inner surface of the fixing sleeve 13 contacts the heater 11 with a predetermined contact width and transfers heat generated from the heater 11 to the fixing nip portion N. The surface roughness of the inner surface of the fixing sleeve 13 that transfers heat in contact with the heater 11 greatly affects the thermal efficiency. In particular, when the contact thermal resistance between the surface of the sliding layer (11c or 11e) of the heater 11 and the inner surface of the fixing sleeve 13 is increased, the thermal efficiency is deteriorated and fixing failure is likely to occur. Even in the case where thermal conductive grease or the like is interposed, it is preferable to suppress the surface roughness to a predetermined level or less in constructing a fixing device with high thermal efficiency.
[0188]
In the case where a release layer is formed on the outer surface of the fixing sleeve 13, the release layer is generally formed of a fluororesin, and the thermal conductivity of the release layer is extremely higher than the thermal conductivity of the fixing sleeve 13. It becomes low. Therefore, if the releasable layer is formed too thick, the heat conduction is deteriorated, and sufficient heat cannot be supplied to the toner image on the recording material P at the fixing nip portion N for increasing the speed of the image forming apparatus. Therefore, it is necessary to form a thin release layer on the fixing sleeve 13. Therefore, the surface roughness of the outer surface of the fixing sleeve 13 needs to be suppressed to a predetermined value or less.
[0189]
That is, a thin release layer has a small effect of reducing the surface roughness of the outer surface of the fixing sleeve 13, and the surface roughness of the outer surface of the fixing sleeve 13 after the formation of the release layer is smaller than that before the release layer is formed. Equivalent or slightly smaller. Therefore, if the surface roughness of the cylindrical metal tube is large, the surface roughness is large even after the release layer is applied and formed, and the adhesion with the recording material P cannot be sufficiently obtained at the fixing nip portion N. The possibility of causing defects increases.
[0190]
From the above, sufficient fixing performance can be obtained by applying and forming a release layer having a predetermined thickness or less including a primer layer as an adhesive layer with the surface roughness of the outer surface of the fixing sleeve 13 being a predetermined value or less. Therefore, it is possible to cope with the speeding up of the image forming apparatus.
[0191]
When the fixing sleeve 13 achieves a surface roughness of a predetermined level or less by providing an appropriate uneven shape in the circumferential direction of the fixing sleeve 13, the fixing sleeve 13 rotates more smoothly, and the surface of the heater 11. It is preferable to provide a heat-fixing fixing sleeve 13 that makes it difficult to damage the releasable layer coated thereon, and is highly durable and capable of high-speed operation.
[0192]
An example from manufacture of the fixing sleeve 13 to surface processing will be described below with reference to the drawings.
As shown in FIG. 6, the fixing sleeve 13 is formed by deep drawing a metal flat plate (plank) 31 with a circular inner mold (punch) 32 and a cylindrical container-shaped outer mold (die) 33. A cup-shaped metal cylindrical member 34 as shown in FIG. 7 is manufactured.
[0193]
As the metal flat plate 31, a metal flat plate of SUS, Al, Ni, Cu, Zn or the like having a thickness of about 0.1 mm to 0.5 mm, or a metal flat plate of an alloy containing these metals is used. The inner mold 32 and the outer mold 33 are, for example, molds in which a surface of a metal material is subjected to carbide plating or the like, and the inner mold 32 is a circular inner mold in a general deep drawing method. Is a cylindrical container-shaped outer mold in a general deep drawing method.
[0194]
In FIG. 6, the metal flat plate 31 is sandwiched between the inner mold 32 and the outer mold 33, and the inner mold 32 is pushed in the direction of the outer mold 33 in the direction of the arrow. A highly viscous lubricating oil or a solid lubricant such as graphite or molybdenum disulfide is interposed between the metal flat plate 31 and the outer mold 33 to improve the drawability. The above process is usually deep-drawn with different dies about 2 to 4 times.
[0195]
Next, ironing is performed so that the metal cylindrical member 34 is formed to a predetermined thickness. As the ironing process, any process such as a rolling process, a drawing process, and a drawing process may be performed in the middle, but as a final process, the circumferential direction of the metal cylindrical member 34 is performed by the following processing method. Is processed to have a predetermined unevenness.
[0196]
As processing which has the unevenness | corrugation below predetermined in the circumferential direction of the metal cylindrical member 34, there exists a processing method as shown, for example in FIG.8 and FIG.9. FIG. 8 shows a general drawing spinning process in which a pressing roller 36a rotatably attached to a shaft 36b attached to a fixed base 36c is always separated from the metal inner die 35 by a predetermined distance. Press toward the metal inner mold 35. A metal cylindrical member 34 is fitted into the metal inner mold 35, and a cup-shaped bottom portion of the metal cylindrical member 34 is brought into close contact with and fixed to the metal inner mold 35 by a pressing member 37.
[0197]
In this state, the metal inner die 35, the metal cylindrical member 34, and the pressing member 37 are gradually fed to the right side of the sheet while rotating in the direction of the arrow in the figure. From the end, a rotatable roller is pressed against the metal inner die 35 while maintaining a predetermined distance. As a result, the cup-shaped metal cylindrical member that is gradually thinned from the end of the metal cylindrical member 34 by ironing and is finally processed to a predetermined thickness of the fixing sleeve 13 as shown in FIG. 39 is formed by ironing. On the metal cylindrical member 39, a roller pressing unevenness mark 39a is left in the circumferential direction during drawing and spinning. Finally, the fixing sleeve 13 is obtained by cutting off the cup-shaped bottom of the metal cylindrical member 39.
[0198]
Further, as shown in FIG. 9, instead of the pressing roller, it is fixed inside the continuous dies 38 a, 38 b, 38 c whose inner diameter is gradually reduced by a metal inner die 35 and a pressing member 37. While rotating the metal cylindrical member 34, it may be thinned by feeding and ironing to give a circumferential uneven shape. In addition, any ironing processing method may be used as long as it can form irregularities of a predetermined amount or less in the circumferential direction of the fixing sleeve 13 such as spatula drawing.
[0199]
When the recording material P on which an unfixed image is formed is heat-fixed using the fixing sleeve 13 manufactured by the above manufacturing method, it is preferable to suppress the circumferential unevenness to 3 μm or less from the viewpoint of heat conduction.
[0200]
Forming irregularities of 3 μm or less in the circumferential direction of the fixing sleeve 13 keeps the rotational driving load of the fixing device low, makes the rotation smooth, and improves the durability of the resin coating of the heater that contacts the inner surface of the cylindrical metal tube. It is preferable to suppress damage and achieve further high durability and high speed of the fixing device. Furthermore, the surface roughness Rz in the longitudinal direction is set to 3 μm or less, and the relationship with the surface roughness Rz ′ in the circumferential direction is represented by Rz. More preferably, it is> Rz ′.
[0201]
Further, a configuration in which a potential difference is formed between the fixing sleeve 13 and the pressure member 20 and the fixing sleeve 13 is grounded or is grounded via a diode so that paper dust and toner are not easily attached to the fixing sleeve 13. It is preferable to provide a fixing device that maintains releasability through durability.
[0202]
An example of a fixing device that is more preferable as an embodiment of the present invention is shown in FIGS.
[0203]
11 and 12, the elastic layer 22 of the pressure member 20 is a conductive elastic layer made of conductive silicone rubber, conductive silicone sponge, or the like, and is a core metal 21 or a conductive elastic layer 22. In addition, a bias having a polarity opposite to that of the toner image is applied by a bias applying means 24 through a chip electrode 25 made of a conductive carbon chip or the like. In the drawing, an image forming apparatus in which the toner is negatively charged in the developing unit is illustrated, and a configuration in which a positive bias is applied to the core metal 21 is illustrated. Therefore, in the case of an image forming apparatus in which toner is positively charged at the developing unit, a negative bias is applied to the cored bar 21.
[0204]
Also, in the figure, at the end of the fixing sleeve 13, a primer layer as an adhesive layer and a portion 13a where a cylindrical metal base tube not coated with a release layer made of a fluororesin layer is exposed are provided, A configuration is shown in which the fixing sleeve 13 is grounded from the portion 13a via a conductive brush 18 made of an amorphous conductive fiber. Alternatively, the fixing sleeve 13 may be diode-connected so that a charge having the same potential as that of the toner image is held in the cylindrical metal base tube.
[0205]
As described above, by adopting a configuration in which a bias is positively applied to the pressure member 20 side, it is possible to further suppress the adsorption of paper powder, toner, and the like to the fixing sleeve 13. Therefore, in the above-described fixing device in the case where the toner image formed on the cut paper or the like whose main material is pulp material is heat-fixed, the surface release layer of the fixing sleeve 13 having a surface roughness of 3 μm or less is used. Is less likely to be contaminated with paper dust and toner electrostatically, can prevent loss of releasability due to durability, and can provide a long-life fixing device.
[0206]
The fixing device used in the present invention may be an oil application type fixing device that applies oil for maintaining the releasability of the fixing member to the fixing member, or may be an oilless type fixing device. The same effect can be obtained regardless of the difference between these methods.
[0207]
Further, in the fixing device used in the present invention, the heating body is not limited to one that generates heat due to energization as long as it generates heat when energized, for example, electromagnetic induction exothermicity that generates heat due to electromagnetic induction during energization. It can also be formed by a member.
[0208]
The fixing device used in the present invention can be widely applied to the heating of toner on a recording material. For example, an image heating device that presupposes an image on a recording material and an image surface property such as gloss. The present invention can also be applied to an image heating apparatus that is modified.
[0209]
In the above-described embodiment, the cylindrical fixing sleeve 13 is shown as the heat transfer layer. However, the heat transfer layer used in the present invention may have an endless shape other than the cylindrical shape. Further, the heat transfer layer may be composed only of a metal base layer.
[0210]
In the above-described embodiment, the configuration in which the fixing member 10 is biased toward the pressure member 20 has been described. However, the present invention is not limited to this configuration, and the pressure member 20 is directed toward the fixing member 10. The fixing member 10 and the pressing member 20 may be urged toward each other.
[0211]
Further, in the above-described embodiment, the configuration in which the fixing nip portion N is formed by urging by the pressurizing unit 17 that expresses a sufficient urging force, represented by a spring, is shown in the present invention. However, the fixing member 10 and the pressure member 20 may be fixed to form a desired fixing nip portion N.
[0212]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the examples. In the examples, “part” means “part by mass”.
[0213]
[Binder resin production example]
<Production example of high molecular weight component C-1>
・ Styrene 78.5 parts by mass
-20 parts by mass of acrylic acid-n-butyl
・ 1.5 parts by weight of methacrylic acid
2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane
1.0 part by weight
While stirring 200 parts by mass of xylene in a four-necked flask, the inside of the container was sufficiently replaced with nitrogen, and the temperature was raised to 120 ° C., and then each of the above components was added dropwise over 4 hours. Furthermore, polymerization was carried out under reflux of xylene. The resin thus obtained is designated C-1.
[0214]
<Production example of high molecular weight component C-2>
Using 75 parts by mass of styrene, 23 parts by mass of acrylic acid-n-butyl, 2 parts by mass of monobutyl maleate, and 0.6 parts by mass of 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, Resin C-2 was obtained in the same manner as C-1.
[0215]
<Production example of high molecular weight component C-3>
Using 80 parts by mass of styrene, 19 parts by mass of acrylic acid-n-butyl, 1 part by mass of methacrylic acid, and 2 parts by mass of 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, Resin C-3 was obtained in the same manner as C-1, except that the temperature was changed to 130 ° C.
[0216]
<Production example of high molecular weight component C-4>
Resin C in the same manner as C-1 using 80 parts by mass of styrene, 20 parts by mass of acrylate-n-butyl and 1 part by mass of 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane. -4 was obtained.
[0217]
<Production example of high molecular weight component C-5>
72 parts by mass of styrene, 18 parts by mass of acrylic acid-n-butyl, 10 parts by mass of methacrylic acid, and 1 part by mass of 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane were used. Resin C-5 was obtained in the same manner as above.
[0218]
<Production example of high molecular weight component C-6>
81.8 parts by mass of styrene, 18 parts by mass of acrylic acid-n-butyl, 0.2 part by mass of monobutyl maleate, and 1 part by mass of 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane And resin C-6 was obtained in the same manner as C-1.
[0219]
<Example of production of carboxyl group-containing vinyl resin A-1>
・ 25 parts by mass of high molecular weight component resin C-1
・ Styrene 60.2 parts by mass
-14 parts by mass of acrylic acid-n-butyl
・ 0.8 parts by weight of methacrylic acid
・ Di-t-butyl peroxide 2 parts by mass
Among the above materials, a monomer and a polymerization initiator were dropped into 200 parts by mass of xylene over 4 hours. Further, polymerization was carried out under reflux of xylene. After this polymerization was completed, a polymerization solution of C-1 was added so that the resin component was equivalent to 25 parts by mass, and the solvent was distilled off under reduced pressure. The resin thus obtained is designated as A-1.
[0220]
<Production example of carboxyl group-containing vinyl resin A-2>
25 parts by mass of high molecular weight component resin C-2, 59.8 parts by mass of styrene, 15 parts by mass of acrylic acid-n-butyl, 0.2 parts by mass of methacrylic acid, 1.5 parts by mass of di-t-butyl peroxide And Resin A-2 was obtained in the same manner as A-1.
[0221]
<Production example of carboxyl group-containing vinyl resin A-3>
25 parts by mass of high molecular weight component resin C-3, 68 parts by mass of styrene, 6 parts by mass of acrylic acid-n-butyl, 1 part by mass of methacrylic acid, 5 parts by mass of di-t-butyl peroxide, Resin A-3 was obtained in the same manner.
[0222]
<Production example of vinyl resin A-4>
25 parts by mass of high molecular weight component resin C-4, 61 parts by mass of styrene, 14 parts by mass of acrylic acid-n-butyl, 2.4 parts by mass of di-t-butyl peroxide A-4 was obtained.
[0223]
<Example of production of carboxyl group-containing vinyl resin A-5>
25 parts by mass of high molecular weight component resin C-5, 58 parts by mass of styrene, 14 parts by mass of acrylic acid-n-butyl, 3 parts by mass of methacrylic acid, 2.4 parts by mass of di-t-butyl peroxide were used. 1 to obtain Resin A-5.
[0224]
<Example of production of carboxyl group-containing vinyl resin A-6>
Resin in the same manner as A-1, using 50 parts by mass of high molecular weight component resin C-6, 42 parts by mass of styrene, 8 parts by mass of acrylic acid-n-butyl, and 0.7 parts by mass of di-t-butyl peroxide. A-6 was obtained.
[0225]
<Production example of glycidyl group-containing vinyl resin B-1>
・ 75 parts by mass of styrene
・ Acrylic acid-n-butyl 18 parts by mass
・ 7 parts by mass of glycidyl methacrylate
・ Di-t-butyl peroxide 5 parts by mass
While stirring 200 parts by mass of xylene in a four-necked flask, the inside of the container was sufficiently replaced with nitrogen, and the temperature was raised to 120 ° C., and then each of the above components was added dropwise over 4 hours. Furthermore, polymerization was performed under reflux of xylene, and the solvent was distilled off under reduced pressure. The resin thus obtained is designated B-1.
[0226]
<Production example of glycidyl group-containing vinyl resin B-2>
Resin B-2 in the same manner as B-1 using 75.7 parts by mass of styrene, 20 parts by mass of acrylic acid-n-butyl, 4.3 parts by mass of glycidyl methacrylate, and 2 parts by mass of di-t-butyl peroxide. Got.
[0227]
<Production example of glycidyl group-containing vinyl resin B-3>
Resin B-3 using 75.7 parts by mass of styrene, 20 parts by mass of acrylic acid-n-butyl, 4.3 parts by mass of glycidyl methacrylate, and 10 parts by mass of di-t-butyl peroxide in the same manner as B-1. Got.
[0228]
<Production example of glycidyl group-containing vinyl resin B-4>
Resin B-4 was obtained in the same manner as B-1, using 60 parts by mass of styrene, 20 parts by mass of acrylic acid-n-butyl, 20 parts by mass of glycidyl methacrylate, and 5 parts by mass of di-t-butyl peroxide.
[0229]
Resins A-1 to A-6 are shown in Table 1, and Resins B-1 to B-4 are shown in Table 2, respectively.
[0230]
[Table 1]

[0231]
[Table 2]

[0232]
<Example 1>
95 parts by mass of carboxyl group-containing vinyl resin A-1 and 5 parts by mass of glycidyl group-containing vinyl resin B-1 were mixed with a Henschel mixer, then kneaded at 200 ° C. with a biaxial kneading extruder, cooled and pulverized. As a result, a binder resin 1 was obtained.
[0233]
・ Binder resin 1 100 parts by mass
・ 90 parts by mass of magnetite
・ Polyethylene wax 4 parts by mass
-2 parts by mass of an azo-based iron compound represented by the structural formula (5)
The above materials were sufficiently premixed with a Henschel mixer and then melt kneaded with a biaxial kneading extruder set at 150 ° C. The obtained kneaded product is cooled, coarsely pulverized with a cutter mill, then finely pulverized using a fine pulverizer using a jet stream, and the resulting finely pulverized product is further classified with an air classifier, and the weight average diameter A 6.3 μm classified fine powder (toner particles) was obtained.
[0234]
The obtained classified fine powder showed an increase in melt viscosity at the time of melt kneading as compared with the case where the glycidyl group-containing vinyl resin (B-1) was not added, and it was confirmed that a crosslinking reaction occurred. Further, along with the toner formation, a crosslinking component was generated by the reaction of the carboxyl group and the glycidyl group, and a THF insoluble matter was generated.
[0235]
To 100 parts by mass of the toner particles, 1.2 parts by mass of negatively chargeable hydrophobic silica was externally added and mixed with a Henschel mixer, and sieved with a mesh having an opening of 100 μm to prepare negatively chargeable magnetic toner 1. The molecular weight distribution, the weight average diameter, and the acid value in GPC of the obtained toner 1 were measured using the same method as described in the embodiment of the invention. Table 3 shows the physical properties of Toner 1.
[0236]
Next, this prepared developer was evaluated by the following method. The evaluation results are shown in Table 4.
[0237]
[Fixing test]
As the basic configuration of the heat fixing apparatus used in this test, the heater 11 having the configuration shown in FIGS. 4 and 5 was used. That is, AlN is used as a heater substrate 11a, and in the direction opposite to the fixing nip N on the heater substrate 11a, a mixture of Ag / Pd conductive agent and phosphate glass as a matrix component, an organic solvent, a binder, a dispersion A paste formed by mixing an agent or the like was screen-printed and baked at 600 ° C., and used as the energization heating resistor layer 11b. Further, on the fixing nip portion N side of the AlN heater substrate 11a, a polyimide layer 11e having a good slidability was formed to a thickness of 10 μm by screen printing.
[0238]
The fixing sleeve 13 was formed in a cylindrical shape having an outer diameter of 30.13 mm by applying a primer layer of 5 μm and a PFA resin of 10 μm to a cylindrical stainless steel having an inner diameter of 30 mm and a thickness of 50 μm by dipping. The surface roughness Rz of the inner surface of the fixing sleeve 13 was 2 μm, and the surface roughness Rz of the outer surface was 2 μm.
[0239]
Further, the pressure member 20 was formed by forming a silicone rubber layer with a thickness of 5 mm on an Al core 21 having a diameter of 20 mm, and further covering the outer layer with a PFA tube.
[0240]
In this test, the heating and fixing apparatus in which the recording material conveyance speed of the image forming apparatus is adjusted to 193 mm / sec so that the temperature of the heater 11 can be arbitrarily controlled is used. Then, the temperature of the heater 11 is arbitrarily controlled, and the recording material P on which an unfixed toner image is formed is inserted into the fixing nip portion N after 5 seconds from the start of energization of the heater 11 to the energization heating resistor layer 11b. And confirmed for each item.
[0241]
For low-temperature fixability, the heating and fixing device is controlled within a temperature range of 110 to 240 ° C., and the temperature of the heater 11 is controlled every 5 ° C. to obtain plain paper (75 g / m ² The solid black unfixed image was fixed at each temperature, and the resulting image was rubbed 5 times with sylbon paper with a load of 4.9 kPa, and the density reduction rate of the image density before and after the rub. The fixing temperature at which the A is 10% or less was defined as the low temperature fixing property. The lower this temperature, the better the low-temperature fixability.
[0242]
For high temperature offset resistance, the toner development amount on paper is 0.6 mg / cm 2 under the above fixing conditions. ² The solid black image set to 1 was used as an unfixed image, and the stain due to the offset phenomenon on the image was visually confirmed, and the generated temperature was regarded as high temperature offset resistance. The higher this temperature, the better the high temperature offset property.
[0243]
The high temperature offset resistance test was performed in two ways, with or without applying a bias to the metal sleeve of the fixing device. The bias application method is a method in which a DC bias of 500 V is applied to the pressure roller. In the case of applying a bias, the metal sleeve is grounded.
[0244]
[Development durability test]
A commercially available laser beam printer LaserJet 4100 (A4, 24 sheets / min: manufactured by Hewlett Packard) was modified to a process speed of 193 mm / sec, A4, 36 sheets / min, and an A4 size original with an image area ratio of 5%. A4 size 75g / m ² The transfer sheet was subjected to an image printing test of 5000 sheets in a normal temperature and normal humidity (23 ° C., 50% RH) environment, and the image density of the solid black image after the test was measured. The image density was obtained by measuring the reflection density with a Macbeth densitometer (manufactured by Macbeth) using an SPI filter and calculating the average of the measured values at five points.
[0245]
[Tailing]
Using a device similar to the development endurance test, 30 continuous horizontal ruled lines with an interval of 5 mm were printed, and the 30th image was evaluated according to the following criteria. On the opposite side of the paper traveling direction, tailing was determined based on the level at which a small thorn-like or thread-like scissor line was generated from the horizontal ruled line.
A: No tailing
B: Some minor tailing occurs
C: Several large tails are mixed with minor tails
D: Many large tailings are seen.
[0246]
The tailing test was performed in two ways, with and without bias applied to the metal sleeve of the fixing device. The bias application method is a method in which a DC bias of 500 V is applied to the pressure roller. In the case of applying a bias, the metal sleeve is grounded.
[0247]
<Examples 2 to 5>
Toners 2 to 5 were produced using the same method as in Example 1 except that the toner formulation was changed as described in Table 3, and the physical properties were measured by the same method as in Example 1. . Table 3 shows the physical properties of the toner. These toners 2 to 5 were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.
[0248]
<Comparative Examples 1 and 2>
Toners 6 and 7 were produced in the same manner as in Example 1 except that the toner formulation was changed as described in Table 3, and the physical properties were measured in the same manner as in Example 1. . Table 3 shows the physical properties of the toner. These toners 6 and 7 were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.
[0249]
[Table 3]

[0250]
[Table 4]

[0251]
【The invention's effect】
As described above, according to the present invention, an unfixed toner image is formed on a recording material, while a heat transfer layer having a metal base layer is heated by a heating body in contact with the heat transfer layer, and unfixed. A mixture of a vinyl resin having a carboxyl group and a vinyl resin having a glycidyl group in an image forming method in which a recording material on which a toner image is formed is pressed against a heated heat transfer layer to fix an unfixed toner image on the recording material; A toner containing at least a binder resin containing at least one resin selected from the group consisting of a vinyl resin having a carboxyl group and a glycidyl group, and a vinyl resin in which a carboxyl group and a glycidyl group have reacted, and a colorant As a result, the fixability at higher process speeds is improved, and even when bias is applied to the fixing device, it is turned off by static electricity. Hakare the improvement of Ttoreberu, it is possible to reduce the fixation tailing.
[0252]
In the present invention, the number average molecular weight is 1,000 to 40,000 and the weight average molecular weight is 10,000 to 10,000,000 in the molecular weight distribution of the tetrahydrofuran-soluble matter measured by gel permeation chromatography. If it exists, it is much more effective in balancing the fixing property, offset resistance and blocking resistance.
[0253]
In the present invention, in the molecular weight distribution of tetrahydrofuran-soluble matter measured by gel permeation chromatography, at least one main peak in the molecular weight region of 4,000 to 30,000, the molecular weight region of 4,000 to 30,000, and At least one peak each in a region having a molecular weight of 50,000 to 10,000,000, at least one peak each in a region having a molecular weight of 4,000 to 30,000 and a region having a molecular weight of 800,000 to 10,000,000, or Having at least one peak in the molecular weight region of 4,000 to 30,000, the molecular weight region of 50,000 to 800,000, and the molecular weight region of 800,000 to 10,000,000, Improved offset and blocking resistance It is more effective and more over to.
[0254]
In the present invention, when the binder resin contains 0.1 to 60% by mass of tetrahydrofuran-insoluble matter, it is more effective in improving the offset resistance.
[0255]
In the present invention, when the acid value of the tetrahydrofuran-soluble component is less than 50 mgKOH / g, it is even more effective for better developability and prevention of contamination of the sleeve and the fixing process.
[0256]
In the present invention, the colorant is magnetic iron oxide, and when it is contained in an amount of 20 to 200 parts by mass with respect to 100 parts by mass of the binder resin, it is possible to provide a magnetic one-component toner that exhibits the excellent effects of the present invention. it can.
[0257]
In the present invention, when the weight average diameter is 2.5 to 10 μm, it is more effective in improving the image density and developability.
[0258]
In the present invention, the heat transfer layer includes a cylindrical metal element tube as a base layer, a release layer that forms the outer surface of the heat transfer layer, and an adhesive layer that bonds the cylindrical metal element tube and the release layer. The heating body is disposed inside the cylindrical metal base tube, the surface roughness of the inner and outer surfaces of the cylindrical metal base tube is 3 μm or less, and the total thickness of the adhesive layer and the release layer is When the thickness is 20 μm or less, higher-speed fixing is possible, and furthermore, this high-speed fixing is further effective in realizing excellent developability and excellent low-temperature and low-attachment properties and high-temperature offset resistance. is there.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of an image forming apparatus of the present invention.
FIG. 2 is a diagram showing a schematic configuration of the fixing device shown in FIG. 1;
FIG. 3 is a view showing the vicinity of a fixing nip portion in the example of the fixing member shown in FIG. 2;
4 is a view showing the vicinity of a fixing nip portion in another example of the fixing member shown in FIG. 2. FIG.
5 is a diagram illustrating an arrangement example of a fixing member and a pressure member in the fixing device illustrated in FIG. 1. FIG.
FIG. 6 is a diagram for explaining an example of manufacturing a cylindrical metal base tube used in the present invention.
7 is a view showing an intermediate product of a cylindrical metal base tube obtained in the manufacturing example shown in FIG. 5. FIG.
FIG. 8 is a diagram for explaining an example of processing for adjusting the surface roughness and thickness of the intermediate product shown in FIG. 7;
FIG. 9 is a diagram for explaining another example of processing for adjusting the surface roughness and thickness of the intermediate product shown in FIG.
FIG. 10 is a view showing a cylindrical metal element tube formed by the processing shown in FIG. 8 or FIG. 9;
FIG. 11 is a schematic configuration diagram showing another embodiment of a fixing device used in the present invention.
12 is a schematic configuration diagram of the fixing device shown in FIG. 11 as viewed from the front.
FIG. 13 is a schematic configuration diagram illustrating an example of a conventional roller heating type fixing device.
FIG. 14 is a schematic configuration diagram illustrating an example of a conventional film heating type fixing device.
[Explanation of symbols]
1 Photoconductor
2 Charging roller
3 Laser beam
4 Development device
5 Transfer roller
6 Fixing device
7 Cleaning device
8 Sensor
10, 60 Fixing member
11, 61 Heater
11a Heater board
11b Heating resistance layer
11c, 11e Sliding layer
11d protective layer
11f, 11g electrode part
12, 62 Stay holder
13 Fixing sleeve
13a site
14, 64 Temperature sensing element
15 Fixation entrance guide
16 Drive gear
17 Pressurizing means
18 Conductive brush
20 Pressure member
21, 51 cored bar
22, 52 Elastic layer
23, 43, 53 Release layer
24 Bias applying means
25 Chip electrode
31 Metal plate
32 Internal type
33 Outer mold
34, 39 Metal cylindrical member
35 Metal inner mold
36a Pressing roller
36b shaft
36c fixed base
37 Holding member
38a-38c continuous dice
39a Uneven marks
40 Fixing roller
41 Halogen lamp
42 Hollow cored bar
44 Thermistor
50 Pressure roller
63 Fixing film
N Fixing nip
P Recording material

Claims (9)

An unfixed toner image is formed on the recording material, and the heat transfer layer having a metal base layer of the film is heated by a heating body in contact with the heat transfer layer, and the recording material on which the unfixed toner image is formed image formation using by pressure contact by passing through a fixing nip portion formed a fixing method of a film heating type of fixing to the recording material the unfixed toner image between a heated the pressurized heat transfer layer and the pressure member A method ,
Apply a bias of reverse polarity to the toner to the pressure member side, and ground or diode-connect the heat transfer layer ,
One or more selected from the group consisting of a mixture of a vinyl resin having a carboxyl group and a vinyl resin having a glycidyl group, a vinyl resin having a carboxyl group and a glycidyl group, and a vinyl resin in which a carboxyl group and a glycidyl group are reacted An image forming method comprising using a binder resin containing a resin and a toner containing at least a colorant . In the molecular weight distribution of the tetrahydrofuran-soluble matter measured by gel permeation chromatography of the toner , the number average molecular weight is 1,000 to 40,000 and the weight average molecular weight is 10,000 to 10,000,000. The image forming method according to claim 1. 2. The image according to claim 1, wherein in the molecular weight distribution of the tetrahydrofuran-soluble component measured by gel permeation chromatography of the toner, the image has at least one main peak in a region having a molecular weight of 4,000 to 30,000. Forming method . In the molecular weight distribution of the tetrahydrofuran solubles measured by gel permeation chromatography of the toner, at least one peak is present in each of the molecular weight range of 4,000 to 30,000 and the molecular weight range of 50,000 to 10,000,000. 4. The image forming method according to claim 3, further comprising : In the molecular weight distribution of the tetrahydrofuran-soluble matter measured by gel permeation chromatography of the toner, at least one peak is present in each of the molecular weight range of 4,000 to 30,000 and the molecular weight range of 800,000 to 10,000,000. 5. The image forming method according to claim 4, further comprising : In the molecular weight distribution of the tetrahydrofuran-soluble matter measured by gel permeation chromatography of the toner , the molecular weight range is 4,000 to 30,000, the molecular weight range is 50,000 to 800,000, and the molecular weight is 800,000 to 10,000. The image forming method according to claim 4, wherein each region has at least one peak in a region of 1,000,000. 7. The image forming method according to claim 1 , wherein the binder resin of the toner contains 0.1 to 60% by mass of tetrahydrofuran insolubles. The image forming method according to any one of claims 1 to 7, wherein an acid value of a tetrahydrofuran-soluble component of the toner is less than 50 mgKOH / g. The image forming according to any one of claims 1 to 8 , wherein the colorant of the toner is magnetic iron oxide and is contained in an amount of 20 to 200 parts by mass with respect to 100 parts by mass of the binder resin. Way .

Images