JP3994638B2 - Electrophotographic photoreceptor, image forming method, image forming apparatus, and process cartridge - Google Patents

Description

【００３３】
【化３】

【００３４】
中でも前記化合物（１）のビスイミダゾールペリレンが最も好ましい。化合物（１）は一般に構造異性体を有している。
【００３５】
一方、前記混成処理に混入される金属原子含有化合物としては中心金属を有するフタロシアニン化合物を用いる。該中心金属を有するフタロシアニン化合物としてはＴｉ、Ｃｕ、Ｆｅ、Ｖ、Ｇａ、Ｓｉ、Ｐｂ、Ａｌ、Ｚｎ、Ｍｇの少なくとも１種の金属を有するフタロシアニン化合物を用いるのが好ましい。更に、Ｔｉ、Ｃｕ、Ｖ、Ｇａが最も好ましい。そしてペリレン混成顔料の金属原子含有量は５０ｐｐｍ〜１００００ｐｐｍであることが好ましい。本発明のペリレン混成顔料が上記範囲の金属原子を含有することにより大光量露光時の感度低下が少なく、繰り返し使用時の休止後も感光体１回転目と２回転目の帯電性の差が少ない良好な感光体を得ることができる。
【００３６】
本願発明ではペリレン混成顔料中の金属フタロシアニン化合物の含有量が０．０１〜１０質量％である。ペリレン混成顔料作製の混成処理時にこのような比率の金属フタロシアニンを混合することにより、ペリレン混成顔料の金属原子含有量を５０ｐｐｍ〜１００００ｐｐｍの範囲に調整することができる。
【００３７】
又、本発明のペリレン混成顔料を得る為に成される混成処理は前記した共蒸着、アシッドペースト処理、溶融混合等の方法があるが、本発明ではアシッドペースト処理による混成処理が好ましい。
【００３８】
本発明でアシッドペースト処理とは顔料を溶解可能な酸（硫酸等）に一度溶解し、必要により不溶分はフィルターで除去した後、該顔料溶液を適当な貧溶媒（例えば水）中に注ぎ、再度粒子化する処理方法である。実例は後記の合成例で示す。
【００３９】
又、本発明の感光体は保護層としてシロキサン系樹脂層を有することを特徴とする。
【００４０】
次に、シロキサン系樹脂層を保護層として有する有機電子写真感光体について記載する。有機電子写真感光体とは電子写真感光体の構成に必要不可欠な電荷発生機能及び電荷輸送機能の少なくとも一方の機能を有機化合物に持たせて構成された電子写真感光体を意味し、公知の有機電荷発生物質又は有機電荷輸送物質から構成された感光体、電荷発生機能と電荷輸送機能を高分子錯体で構成した感光体等公知の有機電子写真感光体を全て含有する。
【００４１】
本発明のシロキサン系樹脂層は電荷輸送性能を有する構造単位を有し、且つ架橋構造を有するシロキサン系樹脂層であることが好ましい。
【００４２】
一般にシロキサン系樹脂層は硬化性有機ケイ素化合物の加水分解生成物を脱水縮合して得られる。代表的には下記一般式（１）で表される有機ケイ素化合物を原料とした塗布組成物を塗布乾燥することにより形成される。これらの原料は親水性溶媒中では加水分解とその後に生じる縮合反応により、溶媒中で有機ケイ素化合物の縮合物（オリゴマー）を形成する。これら塗布組成物を塗布、乾燥することにより、３次元網目構造を形成したシロキサン系樹脂層を形成することができる。
【００４３】
一般式（１） （Ｒ）_n−Ｓｉ−（Ｘ）_4-n
式中、Ｓｉはケイ素原子、Ｒは該ケイ素原子に炭素が直接結合した形の有機基を表し、Ｘは水酸基又は加水分解性基を表し、ｎは０〜３の整数を表す。
【００４４】
一般式（１）で表される有機ケイ素化合物において、Ｒで示されるケイ素に炭素が直接結合した形の有機基としては、メチル、エチル、プロピル、ブチル等のアルキル基、フェニル、トリル、ナフチル、ビフェニル等のアリール基、γ−グリシドキシプロピル、β−（３，４−エポキシシクロヘキシル）エチル等の含エポキシ基、γ−アクリロキシプロピル、γ−メタアクリロキシプロピルの含（メタ）アクリロイル基、γ−ヒドロキシプロピル、２，３−ジヒドロキシプロピルオキシプロピル等の含水酸基、ビニル、プロペニル等の含ビニル基、γ−メルカプトプロピル等の含メルカプト基、γ−アミノプロピル、Ｎ−β（−アミノエチル）−γ−アミノプロピル等の含アミノ基、γ−クロロプロピル、１，１，１−トリフルオロプロピル、ノナフルオロヘキシル、パーフルオロオクチルエチル等の含ハロゲン基、その他ニトロ、シアノ置換アルキル基を挙げられる。特にはメチル、エチル、プロピル、ブチル等のアルキル基が好ましい。又Ｘの加水分解性基としてはメトキシ、エトキシ等のアルコキシ基、ハロゲン基、アシルオキシ基が挙げられる。特には炭素数６以下のアルコキシ基が好ましい。
【００４５】
又一般式（１）で表される有機ケイ素化合物の具体的化合物で、ｎが２以上の場合、複数のＲは同一でも異なっていても良い。同様に、ｎが２以下の場合、複数のＸは同一でも異なっていても良い。又、一般式（１）で表される有機ケイ素化合物を２種以上を用いるとき、Ｒ及びＸはそれぞれの化合物間で同一でも良く、異なっていても良い。
【００４６】
又前記一般式（１）で表される有機ケイ素化合物の中でもは、ｎが１と２の化合物を併用した塗布液から形成されたシロキサン系樹脂層は機械的耐摩耗性が高く、クリーニング性の良好な保護層を形成することができる。
【００４７】
前記一般式（１）で表される有機ケイ素化合物の中でも、ｎが１と２の下記一般式（２）及び一般式（３）の有機ケイ素化合物を併用した塗布液から形成されたシロキサン系樹脂層は良好な表面物性を備えた保護層を形成することができる。
【００４８】
一般式（２） Ｒ₁Ｓｉ（Ｘ）₃
一般式（３） Ｒ₁Ｒ₂Ｓｉ（Ｘ）₂
（式中、Ｒ₁、Ｒ₂は炭素数１〜１０のアルキル基、アリール基、ビニル基、アミノ基、γ−グリシドキシプロピル基、γ−メタクリルオキシプロピル基、Ｃ_nＦ_2n+1Ｃ₂Ｈ₄−を表す。ｎは１〜６の整数、Ｘは水酸基、又は加水分解性基を表す。）
前記一般式（２）及び一般式（３）で表される有機ケイ素化合物若しくはこれらの加水分解生成物、或いは該加水分解生成物から得られる縮合物を使用して得られた前記シロキサン系樹脂層は弾性と剛性を備え、且つ表面自由エネルギーの小さい、トナーや紙粉のフィルミングが発生しにくい表面物性を備えた保護層を形成することができる。
【００４９】
前記一般式（２）の有機ケイ素化合物の具体例としては下記の化合物が挙げられる。
【００５０】
即ち、トリクロロシラン、メチルトリクロロシラン、ビニルトリクロロシラン、エチルトリクロロシラン、アリルトリクロロシラン、ｎ−プロピルトリクロロシラン、ｎ−ブチルトリクロロシラン、クロロメチルトリエトキシシラン、メチルトリメトキシシラン、メルカプトメチルトリメトキシシラン、トリメトキシビニルシラン、エチルトリメトキシシラン、３，３，４，４，５，５，６，６，６−ノナフルオロヘキシルトリクロロシラン、フェニルトリクロロシラン、３，３，３−トリフルオロプロピルトリメトキシシラン、３−クロロプロピルトリメトキシシラン、トリエトキシシラン、３−メルカプトプロピルトリメトキシシラン、３−アミノプロピルトリメトキシシラン、２−アミノエチルアミノメチルトリメトキシシラン、ベンジルトリクロロシラン、メチルトリアセトキシシラン、クロロメチルトリエトキシシラン、エチルトリアセトキシシラン、フェニルトリメトキシシラン、３−アリルチオプロピルトリメトキシシラン、３−グリシドキシプロピルトリメトキシシラン、３−ブロモプロピルトリエトキシシラン、３−アリルアミノプロピルトリメトキシシラン、プロピルトリエトキシシラン、ヘキシルトリメトキシシラン、３−アミノプロピルトリエトキシシラン、３−メタクリロキシプロピルトリメトキシシラン、ビス（エチルメチルケトオキシム）メトキシメチルシラン、ペンチルトリエトキシシラン、オクチルトリエトキシシラン、ドデシルトリエトキシシラン等が挙げられる。
【００５１】
前記一般式（３）の有機ケイ素化合物の具体例としては下記の化合物が挙げられる。
【００５２】
ジメチルジクロロシラン、ジメトキシメチルシラン、ジメトキシジメチルシラン、メチル−３，３，３−トリフルオロプロピルジクロロシラン、ジエトキシシラン、ジエトキシメチルシラン、ジメトキシメチル−３，３，３−トリフルオロプロピルシラン、３−クロロプロピルジメトキシメチルシラン、クロロメチルジエトキシシラン、ジエトキシジメチルシラン、ジメトキシ−３−メルカプトプロピルメチルシラン、３，３，４，４，５，５，６，６，６−ノナフルオロヘキシルメチルジクロロシラン、メチルフェニルジクロロシラン、ジアセトキシメチルビニルシラン、ジエトキシメチルビニルシラン、３−メタクリロキシプロピルメチルジクロロシラン、３−アミノプロピルジエトキシメチルシラン、３−（２−アミノエチルアミノプロピル）ジメトキシメチルシラン、ｔ−ブチルフェニルジクロロシラン、３−メタクリロキシプロピルジメトキシメチルシラン、３−（３−シアノプロピルチオプロピル）ジメトキシメチルシラン、３−（２−アセトキシエチルチオプロピル）ジメトキシメチルシラン、ジメトキシメチル−２−ピペリジノエチルシラン、ジブトキシジメチルシラン、３−ジメチルアミノプロピルジエトキシメチルシラン、ジエトキシメチルフェニルシラン、ジエトキシ−３−グリシドキシプロピルメチルシラン、３−（３−アセトキシプロピルチオ）プロピルジメトキシメチルシラン、ジメトキシメチル−３−ピペリジノプロピルシラン、ジエトキシメチルオクタデシルシラン等が挙げられる。
【００５３】
本発明の最も好ましいシロキサン系樹脂層は該シロキサン系樹脂層自体が電荷輸送性を有し、且つ表面自由エネルギーが小さく、該シロキサン系樹脂層の隣接層との接着性や脆弱性が改質されたシロキサン系樹脂層である。
【００５４】
このようなシロキサン系樹脂層は電荷輸送性能を有する構造単位を有し、且つ架橋構造を有するシロキサン系樹脂層である。該電荷輸送性能を有する構造単位を有し、且つ架橋構造を有するシロキサン系樹脂層は、具体的には下記一般式（４）で示された電荷輸送性化合物と前記有機ケイ素化合物又は該縮合物等との縮合反応により形成される。そして該シロキサン系樹脂層は残留電位上昇が小さく、表面自由エネルギーが小さく、トナーや紙粉のフィルミングが発生しにくい、且つ隣接層との接着性や脆弱性を改質された膜物性を有する最も好ましい保護層を形成できる。
【００５５】
一般式（４） Ｂ−（Ｒ₁−ＺＨ）_m
式中、Ｂは電荷輸送性能を有する構造単位を含む１価又は多価の基を表し、Ｒ₁は単結合又は２価のアルキレン基を表し、Ｚは酸素原子、硫黄原子又はＮＨを表し、ｍは１〜４の整数を表す。
【００５６】
一般式（４）のＢは電荷輸送性化合物構造を含む１価以上の基である。ここでＢが電荷輸送性化合物構造を含むとは、一般式（４）中の（Ｒ₁−ＺＨ）基を除いた化合物構造が電荷輸送性能を有しているか、又は前記一般式（４）中の（Ｒ₁−ＺＨ）基を水素原子で置換したＢＨの化合物が電荷輸送性能を有する事を意味する。
【００５７】
尚、前記の電荷輸送性化合物とは電子或いは正孔のドリフト移動度を有する性質を示す化合物であり、又別の定義としてはＴｉｍｅ−Ｏｆ−Ｆｌｉｇｈｔ法などの電荷輸送性能を検知できる公知の方法により電荷輸送に起因する検出電流が得られる化合物として定義できる。
【００５８】
前記シロキサン系樹脂層中に電荷輸送性能を有する構造単位を有する本発明のシロキサン系樹脂層は前記有機ケイ素化合物と電荷輸送性化合物との縮合反応により形成できれる。本発明のシロキサン系樹脂層は前記一般式（４）で示された電荷輸送性化合物に代えて前記有機ケイ素化合物と反応性を有する電荷輸送性化合物を用いることもできる。
【００５９】
前記シロキサン系樹脂層中に５ｎｍ〜５００ｎｍの無機金属酸化物粒子を含有させることが好ましい。即ち、前記シロキサン系樹脂層は水酸基或いは加水分解性基を有する有機ケイ素化合物、又は該有機ケイ素化合物の縮合生成物と水酸基を有する電荷輸送性能化合物、及び５ｎｍ〜５００ｎｍの無機金属酸化物粒子を含有する組成物と塗布、乾燥させて得られる電荷輸送性を有する複合化された樹脂層が好ましい。
【００６０】
前記５ｎｍから５００ｎｍの金属酸化物粒子は通常は液相法によって合成される。金属原子の例としてはＳｉ、Ｔｉ、Ａｌ、Ｃｒ、Ｚｒ、Ｓｎ、Ｆｅ、Ｍｇ、Ｍｎ、Ｎｉ、Ｃｕなどが挙げられる。これらの金属酸化物粒子はコロイド粒子として得ることができる。
【００６１】
又、前記金属酸化物粒子は該粒子表面に前記有機ケイ素化合物と反応性を有する化合物基を有することが好ましい。該反応性を有する化合物基としては、例えば水酸基、アミノ基等が挙げられる。このような反応性基を有する金属酸化物粒子を用いることにより、本発明の保護層は前記シロキサン系樹脂と該金属酸化物粒子表面が化学結合をした複合化されたシロキサン系樹脂層を形成し、強度と弾性を増強した樹脂層となり、該シロキサン系樹脂層を感光体の保護層として用いるとブレードクリーニング等の擦過に対して摩耗しにくい、電子写真特性の良好な膜を形成する。
【００６２】
前記水酸基又は加水分解性基を有する有機ケイ素化合物、及び水酸基又は加水分解性基を有する有機ケイ素化合物から形成された縮合物との総量（Ｈ）と前記一般式（４）の化合物の量（Ｉ）の組成比としては、質量比で１００：３〜５０：１００であることが好ましく、より好ましくは１００：１０〜５０：１００の間である。
【００６３】
また前記金属酸化物粒子の添加量（Ｊ）は前記総量（Ｈ）＋化合物の量（Ｉ）の総質量１００部に対し（Ｊ）を１〜３０質量部を用いることが好ましい。
【００６４】
前記総量（Ｈ）成分が前記の範囲内で使用されると、本発明の感光体表面層の硬度が高く且つ弾力性がある。一方、前記化合物の量（Ｉ）が前記の範囲内で使用されると感度や残留電位特性等の電子写真特性が良好であり、前記感光体表面層の硬度が高い。
【００６５】
更には前記シロキサン系樹脂層の製造過程の乾燥温度を８０℃以上の高温で行うこと、更に乾燥後のシロキサン系樹脂層を３０℃〜１００℃で数時間以上の再加熱を行うこと等が好ましい。
【００６６】
前記のシロキサン系樹脂層を形成するには縮合反応を促進するために縮合触媒としては以下のような縮合触媒が好ましい。
【００６７】
具体的な縮合触媒としては酸、金属酸化物、金属塩、金属キレート化合物、アルキルアミノシラン化合物など従来シリコーンハードコート材料に用いられてきた公知の触媒を用いることができるが、燐酸、酢酸の他、チタンキレートやアルミニウムキレート及びスズ有機酸塩（スタンナスオクトエート、ジブチルチンジアセテート、ジブチルチンジラウレート、ジブチルチンメルカプチド、ジブチルチンチオカルボキシレート、ジブチルチンマリエート等）等が好ましい。
【００６８】
以下に前記一般式（４）で表される好ましい化合物例をあげるが、本発明においては下記化合物には限定されない。
【００６９】
【化４】

【００７０】
【化５】

【００７１】
【化６】

【００７２】
前記シロキサン系樹脂層には酸化防止剤を含有させることが好ましい。該酸化防止剤とは、その代表的なものは有機感光体中ないしは有機感光体表面に存在する自動酸化性物質に対して、光、熱、放電等の条件下で酸素の作用を防止ないし、抑制する性質を有する物質である。代表的には下記の化合物群が挙げられる。
【００７３】
【化７】

【００７４】
【化８】

【００７５】
【化９】

【００７６】
次に、前記保護層以外の本発明の感光体構成について記載する。本発明の有機電子写真感光体の層構成は、特に限定はないが、電荷発生層、電荷輸送層、或いは電荷発生・電荷輸送層（電荷発生と電荷輸送の機能を同一層に有する層）等の感光層とその上に保護層を塗設した構成をとるのが好ましい。
【００７７】
以下に本発明に用いられる感光体の構成について記載する。
導電性支持体
本発明の感光体に用いられる導電性支持体としてはシート状、円筒状のどちらを用いても良いが、画像形成装置をコンパクトに設計するためには円筒状導電性支持体の方が好ましい。
【００７８】
本発明の円筒状導電性支持体とは回転することによりエンドレスに画像を形成できるに必要な円筒状の支持体を意味し、真直度で０．１ｍｍ以下、振れ０．１ｍｍ以下の範囲にある導電性の支持体が好ましい。この真円度及び振れの範囲を超えると、良好な画像形成が困難になる。
【００７９】
導電性の材料としてはアルミニウム、ニッケルなどの金属ドラム、又はアルミニウム、酸化錫、酸化インジュウムなどを蒸着したプラスチックドラム、又は導電性物質を塗布した紙・プラスチックドラムを使用することができる。導電性支持体としては常温で比抵抗１０³Ωｃｍ以下が好ましい。
【００８０】
本発明で用いられる導電性支持体は、その表面に封孔処理されたアルマイト膜が形成されたものを用いても良い。アルマイト処理は、通常例えばクロム酸、硫酸、シュウ酸、リン酸、硼酸、スルファミン酸等の酸性浴中で行われるが、硫酸中での陽極酸化処理が最も好ましい結果を与える。硫酸中での陽極酸化処理の場合、硫酸濃度は１００〜２００ｇ／ｌ、アルミニウムイオン濃度は１〜１０ｇ／ｌ、液温は２０℃前後、印加電圧は約２０Ｖで行うのが好ましいが、これに限定されるものではない。又、陽極酸化被膜の平均膜厚は、通常２０μｍ以下、特に１０μｍ以下が好ましい。
【００８１】
中間層
本発明においては導電性支持体と感光層の間に、バリヤー機能を備えた中間層を設けることもできる。
【００８２】
本発明においては導電性支持体と前記感光層のとの接着性改良、或いは該支持体からの電荷注入を防止するために、該支持体と前記感光層の間に中間層（下引層も含む）を設けることもできる。該中間層の材料としては、ポリアミド樹脂、塩化ビニル樹脂、酢酸ビニル樹脂並びに、これらの樹脂の繰り返し単位のうちの２つ以上を含む共重合体樹脂が挙げられる。これら下引き樹脂の中で繰り返し使用に伴う残留電位増加を小さくできる樹脂としてはポリアミド樹脂が好ましい。又、これら樹脂を用いた中間層の膜厚は０．０１〜０．５μｍが好ましい。
【００８３】
又本発明に最も好ましく用いられる中間層はシランカップリング剤、チタンカップリング剤等の有機金属化合物を熱硬化させた硬化性金属樹脂を用いた中間層が挙げられる。硬化性金属樹脂を用いた中間層の膜厚は、０．１〜２μｍが好ましい。
【００８４】
感光層
本発明の感光体の感光層構成は前記中間層上に電荷発生機能と電荷輸送機能を１つの層に持たせた単層構造の感光層構成でも良いが、より好ましくは感光層の機能を電荷発生層（ＣＧＬ）と電荷輸送層（ＣＴＬ）に分離した構成をとるのがよい。機能を分離した構成を取ることにより繰り返し使用に伴う残留電位増加を小さく制御でき、その他の電子写真特性を目的に合わせて制御しやすい。負帯電用の感光体では中間層の上に電荷発生層（ＣＧＬ）、その上に電荷輸送層（ＣＴＬ）の構成を取ることが好ましい。正帯電用の感光体では前記層構成の順が負帯電用感光体の場合の逆となる。本発明の最も好ましい感光層構成は前記機能分離構造を有する感光体構成である。
【００８５】
以下に機能分離感光体の感光層構成について説明する。
電荷発生層
電荷発生層：電荷発生層には電荷発生物質（ＣＧＭ）として前記ペリレン混成顔料を含有する。その他の物質としては必要によりバインダー樹脂、その他添加剤を含有しても良い。
【００８６】
電荷発生物質（ＣＧＭ）としては前記ペリレン混成顔料以外に必要により、公知の電荷発生物質（ＣＧＭ）を用いることができる。例えばフタロシアニン顔料、アゾ顔料、ペリレン顔料、アズレニウム顔料などを用いることができる。
【００８７】
電荷発生層にＣＧＭの分散媒としてバインダーを用いる場合、バインダーとしては公知の樹脂を用いることができるが、最も好ましい樹脂としてはホルマール樹脂、ブチラール樹脂、シリコーン樹脂、シリコーン変性ブチラール樹脂、フェノキシ樹脂等が挙げられる。バインダー樹脂と電荷発生物質との割合は、バインダー樹脂１００質量部に対し２０〜６００質量部が好ましい。これらの樹脂を用いることにより、繰り返し使用に伴う残留電位増加を最も小さくできる。電荷発生層の膜厚は０．０１μｍ〜２μｍが好ましい。
【００８８】
電荷輸送層
電荷輸送層：電荷輸送層には電荷輸送物質（ＣＴＭ）及びＣＴＭを分散し製膜するバインダー樹脂を含有する。その他の物質としては必要により酸化防止剤等の添加剤を含有しても良い。
【００８９】
電荷輸送物質（ＣＴＭ）としては公知の電荷輸送物質（ＣＴＭ）を用いることができる。例えばトリフェニルアミン誘導体、ヒドラゾン化合物、スチリル化合物、ベンジジン化合物、ブタジエン化合物などを用いることができる。これら電荷輸送物質は通常、適当なバインダー樹脂中に溶解して層形成が行われる。これらの中で繰り返し使用に伴う残留電位増加を最も小さくできるＣＴＭは高移動度で、且つ組み合わされるＣＧＭとのイオン化ポテンシャル差が０．５（ｅＶ）以下の特性を有するものであり、好ましくは０．２５（ｅＶ）以下である。
【００９０】
ＣＧＭ、ＣＴＭのイオン化ポテンシャルは表面分析装置ＡＣ−１（理研計器社製）で測定される。
【００９１】
電荷輸送層（ＣＴＬ）に用いられる樹脂としては、例えばポリスチレン、アクリル樹脂、メタクリル樹脂、塩化ビニル樹脂、酢酸ビニル樹脂、ポリビニルブチラール樹脂、エポキシ樹脂、ポリウレタン樹脂、フェノール樹脂、ポリエステル樹脂、アルキッド樹脂、ポリカーボネート樹脂、シリコーン樹脂、メラミン樹脂並びに、これらの樹脂の繰り返し単位のうちの２つ以上を含む共重合体樹脂。又これらの絶縁性樹脂の他、ポリ−Ｎ−ビニルカルバゾール等の高分子有機半導体が挙げられる。
【００９２】
これらＣＴＬのバインダーとして最も好ましいものはポリカーボネート樹脂である。ポリカーボネート樹脂はＣＴＭの分散性、電子写真特性を良好にすることにおいて、最も好ましい。バインダー樹脂と電荷輸送物質との割合は、バインダー樹脂１００質量部に対し１０〜２００質量部が好ましい。又、電荷輸送層の膜厚は１０〜４０μｍが好ましい。
【００９３】
保護層
感光体の保護層として、前記シロキサン系樹脂層を設けることにより、本発明の最も好ましい層構成を有する感光体を得ることができる。
【００９４】
本発明の中間層、感光層、保護層等の層形成に用いられる溶媒又は分散媒としては、ｎ−ブチルアミン、ジエチルアミン、エチレンジアミン、イソプロパノールアミン、トリエタノールアミン、トリエチレンジアミン、Ｎ，Ｎ−ジメチルホルムアミド、アセトン、メチルエチルケトン、メチルイソプロピルケトン、シクロヘキサノン、ベンゼン、トルエン、キシレン、クロロホルム、ジクロロメタン、１，２−ジクロロエタン、１，２−ジクロロプロパン、１，１，２−トリクロロエタン、１，１，１−トリクロロエタン、トリクロロエチレン、テトラクロロエタン、テトラヒドロフラン、ジオキソラン、ジオキサン、メタノール、エタノール、ブタノール、イソプロパノール、酢酸エチル、酢酸ブチル、ジメチルスルホキシド、メチルセロソルブ等が挙げられる。本発明はこれらに限定されるものではないが、ジクロロメタン、１，２−ジクロロエタン、メチルエチルケトン等が好ましく用いられる。また、これらの溶媒は単独或いは２種以上の混合溶媒として用いることもできる。
【００９５】
次に本発明の有機電子写真感光体を製造するための塗布加工方法としては、浸漬塗布、スプレー塗布、円形量規制型塗布等の塗布加工法が用いられるが、感光層の上層側の塗布加工は下層の膜を極力溶解させないため、又、均一塗布加工を達成するためスプレー塗布又は円形量規制型（円形スライドホッパ型がその代表例）塗布等の塗布加工方法を用いるのが好ましい。なお本発明の保護層は前記円形量規制型塗布加工方法を用いるのが最も好ましい。前記円形量規制型塗布については例えば特開昭５８−１８９０６１号公報に詳細に記載されている。
【００９６】
図１は本発明の画像形成装置の１例としての断面図である。
図１において５０は像担持体である感光体ドラム（感光体）で、有機感光層をドラム上に塗布し、その上に本発明の樹脂層を塗設した感光体で、接地されて時計方向に駆動回転される。５２はスコロトロンの帯電器で、感光体ドラム５０周面に対し一様な帯電をコロナ放電によって与えられる。この帯電器５２による帯電に先だって、前画像形成での感光体の履歴をなくすために発光ダイオード等を用いた露光部５１による露光を行って感光体周面の除電をしてもよい。
【００９７】
感光体への一様帯電ののち像露光器５３により画像信号に基づいた像露光が行われる。この図の像露光器５３は図示しないレーザーダイオードを露光光源とする。回転するポリゴンミラー５３１、ｆθレンズ等を経て反射ミラー５４２により光路を曲げられた光により感光体ドラム上の走査がなされ、静電潜像が形成される。
【００９８】
その静電潜像は次いで現像器５４で現像される。感光体ドラム５０周縁にはトナーとキャリアとから成る現像剤を内蔵した現像器５４が設けられていて、マグネットを内蔵し現像剤を保持して回転する現像スリーブ５４１によって現像が行われる。現像剤は、例えば前述のフェライトをコアとしてそのまわりに絶縁性樹脂をコーティングしたキャリアと、前述のスチレンアクリル系樹脂を主材料としてカーボンブラック等の着色剤と荷電制御剤と本発明の低分子量ポリオレフィンからなる着色粒子に、シリカ、酸化チタン等を外添したトナーとからなるもので、現像剤は層形成手段によって現像スリーブ５４１上に１００〜６００μｍの層厚に規制されて現像域へと搬送され、現像が行われる。この時通常は感光体ドラム５０と現像スリーブ５４１の間に直流バイアス、必要に応じて交流バイアス電圧をかけて現像が行われる。また、現像剤は感光体に対して接触あるいは非接触の状態で現像される。
【００９９】
記録紙Ｐは画像形成後、転写のタイミングの整った時点で給紙ローラー５７の回転作動により転写域へと給紙される。
【０１００】
転写域においては転写のタイミングに同期して感光体ドラム５０の周面に転写ローラー（転写器）５８が圧接され、給紙された記録紙Ｐを挟着して転写される。
【０１０１】
次いで記録紙Ｐは転写ローラーとほぼ同時に圧接状態とされた分離ブラシ（分離器）５９によって除電がなされ、感光体ドラム５０の周面により分離して定着装置６０に搬送され、熱ローラー６０１と圧着ローラー６０２の加熱、加圧によってトナーを溶着したのち排紙ローラー６１を介して装置外部に排出される。なお前記の転写ローラー５８及び分離ブラシ５９は記録紙Ｐの通過後感光体ドラム５０の周面より退避離間して次なるトナー像の形成に備える。
【０１０２】
一方記録紙Ｐを分離した後の感光体ドラム５０は、クリーニング器６２のブレード６２１の圧接により残留トナーを除去・清掃し、再び露光部５１による除電と帯電器５２による帯電を受けて次なる画像形成のプロセスに入る。
【０１０３】
尚、７０は感光体、帯電器、転写器・分離器及びクリーニング器が一体化されている着脱可能なプロセスカートリッジである。
【０１０４】
電子写真画像形成装置としては、上述の感光体と、現像器、クリーニング器等の構成要素をプロセスカートリッジとして一体に結合して構成し、このユニットを装置本体に対して着脱自在に構成しても良い。又、帯電器、像露光器、現像器、転写又は分離器、及びクリーニング器の少なくとも１つを感光体とともに一体に支持してプロセスカートリッジを形成し、装置本体に着脱自在の単一ユニットとし、装置本体のレールなどの案内手段を用いて着脱自在の構成としても良い。
【０１０５】
プロセスカートリッジには、一般には以下に示す一体型カートリッジ及び分離型カートリッジがある。一体型カートリッジとは、帯電器、像露光器、現像器、転写又は分離器、及びクリーニング器の少なくとも１つを感光体とともに一体に構成し、装置本体に着脱可能な構成であり、分離型カートリッジとは感光体とは別体に構成されている帯電器、像露光器、現像器、転写又は分離器、及びクリーニング器であるが、装置本体に着脱可能な構成であり、装置本体に組み込まれた時には感光体と一体化される。本発明におけるプロセスカートリッジは上記双方のタイプのカートリッジを含む。
【０１０６】
又、上記画像形成装置は、感光体ドラムと、帯電器、現像器、クリーニング器あるいはリサイクル部材等の少なくとも一つを含むプロセスカートリッジを搭載する形態にすることもできる。
【０１０７】
次に、転写紙は代表的には普通紙であるが、現像後の未定着像を転写可能なものなら、特に限定されず、ＯＨＰ用のＰＥＴベース等も無論含まれる。
【０１０８】
像露光は、電子写真画像形成装置を複写機やプリンターとして使用する場合には、原稿からの反射光や透過光を感光体に照射すること、或いはセンサーで原稿を読み取り信号化し、この信号に従ってレーザービームの走査、ＬＥＤアレイの駆動、又は液晶シャッターアレイの駆動を行い感光体に光を照射することなどにより行われる。
【０１０９】
尚、ファクシミリのプリンターとして使用する場合には、像露光器５３は受信データをプリントするための露光を行うことになる。
【０１１０】
本発明の電子写真感光体は、複写機、レーザープリンター、ＬＥＤプリンター、液晶シャッター式プリンター等の電子写真装置一般に適用し得るものであるが、更には電子写真技術を応用したディスプレイ、記録、軽印刷、製版、ファクシミリ等の装置にも広く適用し得るものである。
【０１１１】
次に、本発明のペリレン混成顔料、及び比較例の顔料の合成例を以下に示す。
合成例１
チタニルフタロシアニン０．３ｇと化合物（１）のビスイミダゾールペリレン３０ｇを９００ｍｌの濃硫酸に室温で加え、さらに２時間撹拌を行った。この硫酸溶液をガラスフィルターで濾過し不溶物を除いた後、３０℃以下の水温を保って水１５リットルに注ぎ込んだ。析出した粒子を濾過した後、さらに５リットルの水で３回洗浄した。濾過により得られたウエットケーキを一旦凍結した後、解凍し濾過、乾燥してペリレン混成顔料（１）を２８ｇ得た。
【０１１２】
合成例２
チタニルフタロシアニンの代わりにバナジュウムオキシフタロシアニン０．１ｇを用いた他は合成例１と同様にペリレン混成顔料（２）を２６．５ｇ得た。
【０１１３】
合成例３
チタニルフタロシアニンの代わりにヒドロキシガリウムフタロシアニン０．１５ｇを用いた他は合成例１と同様にペリレン混成顔料（３）を２７ｇ得た。
【０１１４】
合成例４
チタニルフタロシアニンの代わりに銅フタロシアニン０．３ｇを用いた他は合成例１と同様にペリレン混成顔料（４）を２７ｇ得た。
【０１１５】
合成例５（比較合成例）
合成例１のチタニルフタロシアニンの代わりに無金属フタロシアニンを用いた他は合成例１と同様にして作製した作製したペリレン混成顔料粒子を一旦乾燥した後、２−ブタノン５００ｍｌ中で環流下６時間加熱、撹拌した。さらにメタノールで充分洗浄後乾燥してペリレン混成顔料（５）を２５．８ｇ得た。
【０１１６】
合成例１〜５の各顔料のＣｕ−Ｋα特性Ｘ線によるＸ線回折分析による回折角度２θ：６．２、１０．１、１２．２、の回折ピークの有無、及び金属原子含有の有無及びその含有量を下記表１に示す。
【０１１７】
【表１】

【０１１８】
表中；○は回折ピークがあることを示す。
Ｘ線回折測定
合成例１のペリレン混成顔料粒子を後記する実施例１記載の方法で分散した後、塗布、乾燥して形成した約１ｍｍの厚さの塗膜の粉末Ｘ線回折の結果を図２に示す。
【０１１９】
金属原子の有無確認方法
本発明のペリレン混成顔料中の金属原子は蛍光Ｘ線（ＷＤＸ）、原子吸光分析、ＩＣＰ等の手段により、金属原子の有無、及びその含有量を測定することができる。
【０１２０】
【実施例】
以下、実施例をあげて本発明を詳細に説明するが、本発明の様態はこれに限定されない。なお、文中「部」とは「質量部」を表す。
【０１２１】
下記のごとくして感光体を作製した
感光体１の作製
〈下引き層〉
チタンキレート化合物（ＴＣ−７５０：松本製薬製） ３０ｇ
シランカップリング剤（ＫＢＭ−５０３：信越化学社製） １７ｇ
２−プロパノール １５０ｍｌ
上記下引き層塗布液を用いてφ８０ｍｍの円筒形の導電性支持体上に、乾燥膜厚０．５μｍとなるよう塗布した。
【０１２２】
〈電荷発生層〉
電荷発生物質（合成例１のペリレン混成顔料） ６０ｇ
シリコーン変性ブチラール樹脂（Ｘ−４０−１２１１Ｍ：信越化学社製）７００ｇ
２−ブタノン ２０００ｍｌ
を混合し、サンドミルを用いて１０時間分散し、電荷発生層塗布液を調製した。この塗布液を前記下引き層の上に浸漬塗布法で塗布し、乾燥膜厚０．２μｍの電荷発生層を形成した。
【０１２３】
〈電荷輸送層〉
電荷輸送物質〔Ｎ−（４−メチルフェニル）−Ｎ−｛４−（β−フェニルスチリル）フェニル｝−ｐ−トルイジン〕 ２２５ｇ
ポリカーボネート（粘度平均分子量３０，０００） ３００ｇ
酸化防止剤（例示化合物１−３） ６ｇ
ジクロロメタン ２０００ｍｌ
を混合し、溶解して電荷輸送層塗布液を調製した。この塗布液を前記電荷発生層の上に浸漬塗布法で塗布し、乾燥膜厚２０μｍの電荷輸送層を形成した。
【０１２４】
〈保護層〉
メチルトリメトキシシラン １８２ｇ
例示化合物（Ｂ−１） ５０ｇ
酸化防止剤（例示化合物２−１） １ｇ
１−ブタノール ２２５ｇ
コロイダルシリカ（３０％メタノール溶液） １００ｇ
２％酢酸 １０６ｇ
アルミニウムトリスアセチルアセトナート １ｇ
シラン化合物と１−ブタノール、２％酢酸を混合し、撹拌しながら４０℃の温度で１６時間撹拌した後、例示化合物（Ｂ−１）、酸化防止剤、アルミニウムトリスアセチルアセトナートを加えて更に室温で１時間撹拌して保護層用の塗布液を調製した。この塗布液を前記電荷輸送層の上に円形量規制型塗布装置により乾燥膜厚１μｍの樹脂層を形成し、この樹脂層を１１０℃、１時間の加熱硬化を行い、電荷輸送性能を有する構造単位を有し、且つ架橋構造を有するシロキサン系樹脂層の保護層を形成し感光体１を作製した。
【０１２５】
感光体２〜５の作製
感光体１の電荷発生層の合成例１のペリレン混成顔料に代えて合成例２〜５のペリレン混成顔料に変更した以外は感光体１と同じにして、感光体２〜５を作製した。
感光体６の作製
感光体１と同様にして電荷輸送層までを作製した。
【０１２６】
〈保護層〉
メチルトリメトキシシラン ５５ｇ
ジメチルジメトキシシラン １２７ｇ
例示化合物（Ｂ−１） ５０ｇ
酸化防止剤（例示化合物２−１） １ｇ
１−ブタノール ２２５ｇ
２％酢酸 １０６ｇ
アルミニウムトリスアセチルアセトナート １ｇ
シラン化合物と１−ブタノール、２％酢酸を混合し、撹拌しながら４０℃の温度で１６時間撹拌した後、例示化合物（Ｂ−１）、酸化防止剤、アルミニウムトリスアセチルアセトナートを加えて更に室温で１時間撹拌して保護層用の塗布液を調製した。この塗布液を前記電荷輸送層の上に円形量規制型塗布装置により乾燥膜厚１μｍの樹脂層を形成し、この樹脂層を１１０℃、１時間の加熱硬化を行い、電荷輸送性能を有する構造単位を有し、且つ架橋構造を有するシロキサン系樹脂層の保護層を形成し感光体６を作製した。
感光体７の作製
感光体１の作製において、保護層をのぞき、電荷輸送層の乾燥膜厚を２１μｍに変更した以外は感光体１の作製と同じにして感光体７を作製した。
【０１２７】
〈評価〉
繰り返し複写時の画像及び電位安定性を確認するために以下の評価を行った。
【０１２８】
感光体１〜７を用いてデジタル複写機Ｋｏｎｉｃａ−７０５０（帯電極性：負、反転現像、６８０ｎｍ光源）改造機を用いて温度３０℃、湿度８０％ＲＨの環境下でＡ３サイズ１０万枚のコピーを行った。コピーは７％文字画像、黒地画像、白地画像、ハーフトーン画像がそれぞれ１／４のオリジナル画像を用いてＡ４紙に連続コピーを行い評価した。評価は初期及び１０万枚のコピー後、１時間休止後に下記に記した評価を行った。尚、上記複写機の作像条件としては感光体の１回転目から画像形成を行うように設定してある。感光体の電位測定は像露光光と現像部の間に電位センサーを設け測定した。
【０１２９】
評価項目と評価基準
帯電性変化（ΔＶ₁₂）； 感光体の劣化により１回転目の帯電電位（ＶＨ₁）が２回転目帯電電位（ＶＨ₂）と比較して著しく低下して、１回転目から画像形成を行うとカブリや濃度ムラが発生する欠陥。
【０１３０】
ＶＬ；黒地画像（露光部）の帯電電位を示す。ＶＬの数値が大きくなると画像濃度の低下や白地カブリの原因となる。
【０１３１】
白地カブリ、黒ポチ； 白地帯電電位（ＶＨ）の低下により本来白地の部分全体にトナーが現像されてしまう画像欠陥。
【０１３２】
◎： 目視でＡ３白地画像上に黒ポチ３個以下でかぶりなし
○： 〃 １０個未満でかぶりなし
×： 〃 １０個以上若しくはかぶり発生
〈評価結果〉
上記複写画像と電位安定性の評価結果を下記表２（初期評価）、表３（１０万コピー後の評価）に示す。
【０１３３】
【表２】

【０１３４】
【表３】

【０１３５】
表中膜厚減耗量は以下のようにして測定した。
感光層（感光層と保護層）の膜厚は均一膜厚部分をランダムに１０ケ所測定し、その平均値を感光層の膜厚とする。膜厚測定器は渦電流方式の膜厚測定器ＥＤＤＹ５６０Ｃ（ＨＥＬＭＵＴ ＦＩＳＣＨＥＲ ＧＭＢＴＥ ＣＯ社製）を用いて行い、実写試験前後の感光層膜厚の差を膜厚減耗量とする。
【０１３６】
表２及び表３より、本発明のペリレン混成顔料を用い、且つシロキサン系樹脂層を有する感光体１〜４及び感光体６を用いた実施例は複写時の感光体１回転目と２回転目の電位変動が小さく、１枚目のコピー画像に白地カブリが発生していない。一方、本発明外の金属原子を含有しないペリレン混成顔料を用いた感光体５やシロキサン系樹脂層を除いた感光体７は前記電位変動が大きく、１枚目のコピー画像に白地カブリが発生している。この傾向は初期、及び１０万コピーの複写画像でも同じである。一方、本発明のペリレン混成顔料を用いても、保護層としてシロキサン系樹脂層を有さない感光体７は初期特性は良好であるが、１０万コピー後は感光層の摩耗による膜厚減耗が大きく、このため白地カブリが発生している。
【０１３７】
【発明の効果】
本発明の感光体を用いることにより長期の繰り返し使用において安定した電気特性及び画像特性が得られ、且つ反転現像の画像形成時に発生する黒ポチ等の画像欠陥にも強く、且つ感光体の１回転目からの画像形成が可能な電子写真画像形成プロセスを実現することができる。
【図面の簡単な説明】
【図１】本発明の画像形成装置の１例としての断面図。
【図２】合成例１の顔料粒子分散後の粉末Ｘ線回折図。
【符号の説明】
５０ 感光体ドラム（又は感光体）
５１ 露光部
５２ 帯電器
５３ 像露光器
５４ 現像器
５７ 給紙ローラー
５８ 転写ローラー（転写器）
５９ 分離ブラシ（分離器）
６０ 定着装置
６１ 排紙ローラー
６２ クリーニング器
７０ プロセスカートリッジ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic photosensitive member, and more particularly to an electrophotographic photosensitive member useful for a printer, a copying machine, and the like, and to an image forming method, an image forming apparatus, and a process cartridge using the electrophotographic photosensitive member.
[0002]
[Prior art]
Currently, with the development of electronic devices, copiers, printers, etc. have become more sensitive and faster at the same time as digitalization. As a result, advanced materials are required. In particular, in the field of electrophotographic photoreceptors (hereinafter also simply referred to as photoreceptors), perylene imidazole perylene pigments have attracted attention as materials that are sensitive to semiconductor lasers having an oscillation wavelength from infrared to near red light. The perylene pigment is an excellent pigment having stable characteristics of repeated charging when the pigment is used as a charge generation material. However, there are still problems to be solved.
[0003]
One of them is a problem of black spots that occur during the image formation of reversal development. In general, a reversal development process is used for digital electrophotographic image formation. However, in this reversal development image formation process, partial charge leakage is liable to occur on the photosensitive member during charging. Black spots tend to occur in the subsequent white background image. The perylene pigment has small crystal particles of the pigment, and the pigment particles tend to aggregate in the dispersion of the charge generation layer. The aggregated and coarsened pigment particles cause black spots when formed as a charge generation layer. Further, in the case of a perylene pigment, the dependency on the film thickness of the photosensitive layer is particularly large, and the black spot level is further deteriorated as the film thickness is reduced by repeated use. For this reason, when using a perylene pigment, it is desirable to reduce the film thickness fluctuation | variation in repeated use as much as possible.
[0004]
In addition to the above problems, the first and second charging potential fluctuations and the light attenuation characteristics are greatly dependent on the film thickness, and the potential characteristics greatly fluctuate due to film thickness wear during repeated use, causing the problem of image defects. . The first and second potential fluctuations are as follows: When the photoconductor is charged with a corona charger or the like, the potential is not stable at the first charge (the charge potential is low). In the normal development process in which the exposed portion is white, the effect is relatively small, but in the reverse development process in which reverse bias development is performed, the white background (unexposed portion) is likely to be fogged in the first copy. The problem is likely to occur. It has been clarified that this phenomenon becomes more prominent if there is an increase in electric field intensity due to a decrease in the photosensitive layer thickness. For this reason, many copying machines and the like use a process in which the first copy is idle and used from the second copy. However, it is needless to say that development of a photoreceptor that can be used from the first copy is desired from the viewpoint of quick response and energy saving.
[0005]
This ΔV₁₂This phenomenon is observed in phthalocyanines in general and in some condensed polycyclic pigments, and is relatively small in other pigments, but this problem must be solved when using the perylene pigment exhibiting excellent characteristics for semiconductor lasers. Don't be. Although the cause is not well understood, some people, including the present inventor, have shown that phthalocyanines exhibit the properties of P-type semiconductors and many of the condensed polycyclic pigments exhibit properties as N-type semiconductors, while ΔV₁₂In general, I think that the relatively small of is related to not being biased to either property. That is, when the charge generating pigment is too biased to be P-type (phthalocyanines) or N-type (condensed polycyclic pigment), there is an electron (or hole) trap in the pigment particle, and this trap is The potential stabilizes only after it is buried. This is ΔV₁₂This is probably one of the causes of the outbreak. Based on this idea, it has already been carried out to put an electron transporting substance such as quinones into the charge generation layer, but adding an organic impurity causes another problem such as a potential drop in a long-term repetition.
[0006]
On the other hand, bisimidazole perylene, which is a condensed polycyclic pigment, has a problem in that the sensitivity decreases when continuous strong exposure is continued. Therefore, it is necessary to solve this problem when using a laser beam having a high exposure intensity. Since this decrease in sensitivity is recovered when paused, it is considered that this is caused by some temporary electronic trap, and since it is not an essential deterioration of the charge generating pigment, a solution that can be used without pausing was sought. .
[0007]
[Problems to be solved by the invention]
An object of the present invention is to improve the above-mentioned problems. Specifically, the stability of the charging potential of an electrophotographic photosensitive member for a semiconductor laser, particularly the ΔV₁₂An electrophotographic photosensitive member with improved sensitivity and deterioration in sensitivity due to repeated image formation, and an image forming method, an image forming apparatus, and a process cartridge using the photosensitive member. .
[0008]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have found that the above object can be achieved by the configuration described below.
[0009]
  1. In an electrophotographic photosensitive member having a photosensitive layer and a protective layer on a conductive support, the photosensitive layer is used as a charge generating substance.0.01 to 10% by mass of metal phthalocyanine compoundAn electrophotographic photosensitive member comprising a perylene hybrid pigment contained therein, and wherein the protective layer is a siloxane-based resin layer.
[0010]
  2. SaidOf metal phthalocyanine compounds2. The electrophotographic photosensitive member according to 1 above, wherein the metal atom is at least one of Ti, Cu, Fe, V, Ga, Si, Pb, Al, Zn, and Mg.
[0014]
  3. The perylene hybrid pigment contains the bisimidazole perylene of the compound (1) represented by the structure described above.Or 2The electrophotographic photoreceptor described in 1.
[0015]
  4. The X-ray diffraction pattern of the perylene hybrid pigment has a diffraction peak at least 6.2, 10.1, 12.2 at a 2θ (2θ ± 0.2) angle of Cu-Kα characteristic X-ray diffraction. 1 to3The electrophotographic photosensitive member according to any one of the above.
[0016]
  5. The siloxane-based resin layer is a siloxane-based resin layer having a structural unit having charge transport performance and a crosslinked structure.4The electrophotographic photosensitive member according to any one of the above.
[0017]
  6. In the image forming method including charging, image exposure, development, and transfer steps around the electrophotographic photosensitive member,5An image forming method using the electrophotographic photoreceptor according to any one of the above.
[0018]
  7. In the image forming apparatus having each means of charging, image exposure, development, and transfer around the electrophotographic photosensitive member, the electrophotographic photosensitive member may be any one of5An image forming apparatus using the electrophotographic photosensitive member according to any one of the above.
[0019]
  8. Process cartridges used in an image forming apparatus having each means of charging, image exposure, development, and transfer around the electrophotographic photosensitive member are the above-mentioned 1 to 3.5The electrophotographic photosensitive member according to claim 1 and at least one of a charging unit, an image exposure unit, a developing unit, and a transfer unit are combined and designed to be freely taken in and out of the image forming apparatus. A process cartridge characterized by that.
[0020]
The present invention will be described below.
The characteristics of the metal atom-containing state in the pigment, which is the main technique of the present invention, will be described. Here, the pigment of the present invention is an image of a granular pigment, and is equivalent to the pigment particle. That is, the pigment of the present invention means pigment particles.
[0021]
In the present invention, a pigment obtained through a means for mixing other pigments and compounds after producing a specific pigment is referred to as pigment mixing (or pigment mixed particles).
[0022]
In addition, an operation of once dissolving the pigment and other pigments and compounds in a specific pigment preparation stage and mixing the plurality of substances at a molecular level is called a hybrid process, and a plurality of pigments manufactured through the hybrid process The pigment particles having a compound are referred to as a hybrid pigment (or hybrid pigment particle). The pigment particles of the present invention were developed using this hybrid pigment as a basic technology.
[0023]
Here, the hybrid pigment described in the present invention will be described in detail.
First, the hybrid pigment is characterized in that it has undergone a hybrid treatment in which a plurality of substances (for example, a pigment and a metal atom-containing compound) are once mixed at a molecular level in the pigment particle production stage. In order to perform the operation of forming particles after the hybrid treatment, the particles are formed as pigment particles containing a plurality of substances and compounds simultaneously.
[0024]
Since some of the hybridized materials and compounds are incorporated into the pigment particles in the molecular state, the impurity level may be reduced in the crystal mechanism of the charge generation material depending on the materials incorporated in the pigment particles and the energy levels of the compounds. It is speculated that it could be a solution to various problems that seem to be caused by trap levels in the particles.
[0025]
In addition, even after the dispersion treatment is performed on the mixed pigment to make it possible to form a photosensitive layer that does not cause image defects, the pigment particles retain the state in which a plurality of substances and compounds are contained in the pigment particles by the mixed treatment. Has been.
[0026]
On the other hand, in the case of mixing pigments, specific pigment particles are prepared and then mixed and dispersed with other pigments and compounds. Even if there are multiple pigments in these mixing and dispersion processes, each pigment particle exists independently. What is a mixed pigment obtained from a uniformly dispersed state at the molecular level such as hybrid even if some particles form aggregates or penetrate into the particles in a dissolved state? The state is different.
[0027]
The hybrid pigment of the present invention is a perylene hybrid pigment obtained by hybridizing a perylene compound and one or more other metal atom-containing compounds. That is, the electrophotographic photosensitive member using the perylene hybrid pigment of the present invention obtained by the hybrid treatment of perylene and the metal atom-containing compound as a charge generating material has a small sensitivity decrease at the time of exposure to a large amount of light, and pauses after repeated use. After that, the difference in chargeability between the first rotation and the second rotation of the photosensitive member is small. In addition, it exhibits very stable electrophotographic performance against changes in environmental conditions such as temperature and humidity, and maintains excellent electrophotographic performance even when used repeatedly for a long time. These excellent characteristics can provide a stable electrophotographic image in various environments and electrophotographic process conditions.
[0028]
Further, the X-ray diffraction pattern of the perylene hybrid pigment has a diffraction peak at least 6.2, 10.1, 12.2 at a 2θ (2θ ± 0.2) angle of Cu-Kα characteristic X-ray diffraction. preferable.
[0029]
That is, the X-ray diffraction pattern of the perylene hybrid pigment of the present invention obtained by the hybrid treatment of perylene and the metal atom-containing compound is at least 6.2 at a 2θ (2θ ± 0.2) angle of Cu-Kα characteristic X-ray diffraction. 10. Since the perylene hybrid pigment has a diffraction peak at 10.1, 12.2, the electrophotographic photosensitive member using the perylene hybrid pigment as a charge generation material has little decrease in sensitivity when exposed to a large amount of light, and is repeated. The difference in chargeability between the first and second rotations of the photosensitive member is small even after a pause during use. In addition, it exhibits very stable electrophotographic performance against changes in environmental conditions such as temperature and humidity, and maintains excellent electrophotographic performance even when used repeatedly for a long time. These excellent characteristics can provide a stable electrophotographic image in various environments and electrophotographic process conditions.
[0030]
Examples of materials and layer configurations that can be used in constructing an electrophotographic photosensitive member will be described below in order to specifically describe the excellent characteristics of the present invention, but the essence of the present invention is limited by these specific examples. It is not what is done.
[0031]
Examples of the perylene compound in the present invention include compounds as shown below.
[0032]
[Chemical 2]

[0033]
[Chemical 3]

[0034]
Among them, bisimidazole perylene of the compound (1) is most preferable. Compound (1) generally has structural isomers.
[0035]
  On the other hand, the metal atom-containing compound mixed in the hybrid treatment is a phthalocyanine compound having a central metal.Use. As the phthalocyanine compound having the central metal, a phthalocyanine compound having at least one metal selected from Ti, Cu, Fe, V, Ga, Si, Pb, Al, Zn, and Mg is preferably used. Further, Ti, Cu, V, and Ga are most preferable. The metal atom content of the perylene hybrid pigment is preferably 50 ppm to 10,000 ppm. The perylene hybrid pigment of the present invention contains a metal atom in the above range, so that there is little decrease in sensitivity at the time of exposure to a large amount of light, and there is little difference in chargeability between the first and second rotations of the photosensitive member even after pausing during repeated use. A good photoreceptor can be obtained.
[0036]
  In the present inventionThe content of the metal phthalocyanine compound in the perylene hybrid pigment is 0.01 to 10% by mass.Ru. By mixing such a ratio of metal phthalocyanine at the time of the hybrid treatment for producing the perylene hybrid pigment, the metal atom content of the perylene hybrid pigment can be adjusted to a range of 50 ppm to 10,000 ppm.
[0037]
Further, the hybrid treatment performed to obtain the perylene hybrid pigment of the present invention includes the above-described methods such as co-evaporation, acid paste treatment, and melt mixing. In the present invention, the hybrid treatment by the acid paste treatment is preferable.
[0038]
In the present invention, the acid paste treatment is once dissolved in an acid capable of dissolving the pigment (sulfuric acid or the like), and if necessary, the insoluble matter is removed by a filter, and then the pigment solution is poured into a suitable poor solvent (for example, water), This is a treatment method in which particles are formed again. Examples are shown in the synthesis examples below.
[0039]
The photoreceptor of the present invention is characterized by having a siloxane resin layer as a protective layer.
[0040]
Next, an organic electrophotographic photoreceptor having a siloxane resin layer as a protective layer will be described. The organic electrophotographic photosensitive member means an electrophotographic photosensitive member formed by providing an organic compound with at least one of a charge generating function and a charge transporting function essential to the constitution of the electrophotographic photosensitive member. It contains all known organic electrophotographic photoreceptors such as a photoreceptor composed of a charge generation material or an organic charge transport material, a photoreceptor composed of a polymer complex with a charge generation function and a charge transport function.
[0041]
The siloxane-based resin layer of the present invention is preferably a siloxane-based resin layer having a structural unit having charge transport performance and having a crosslinked structure.
[0042]
In general, the siloxane-based resin layer is obtained by dehydrating and condensing a hydrolysis product of a curable organosilicon compound. Typically, it is formed by coating and drying a coating composition using an organosilicon compound represented by the following general formula (1) as a raw material. These raw materials form a condensate (oligomer) of an organosilicon compound in a solvent by hydrolysis in a hydrophilic solvent and subsequent condensation reaction. By applying and drying these coating compositions, a siloxane-based resin layer having a three-dimensional network structure can be formed.
[0043]
Formula (1) (R)_n-Si- (X)_4-n
In the formula, Si represents a silicon atom, R represents an organic group in which carbon is directly bonded to the silicon atom, X represents a hydroxyl group or a hydrolyzable group, and n represents an integer of 0 to 3.
[0044]
In the organosilicon compound represented by the general formula (1), examples of the organic group in which carbon is directly bonded to the silicon represented by R include alkyl groups such as methyl, ethyl, propyl, and butyl, phenyl, tolyl, naphthyl, Aryl groups such as biphenyl, epoxy-containing groups such as γ-glycidoxypropyl, β- (3,4-epoxycyclohexyl) ethyl, (meth) acryloyl groups such as γ-acryloxypropyl, γ-methacryloxypropyl, Hydroxyl groups such as γ-hydroxypropyl and 2,3-dihydroxypropyloxypropyl, vinyl-containing groups such as vinyl and propenyl, mercapto groups such as γ-mercaptopropyl, γ-aminopropyl, N-β (-aminoethyl) -Amino-containing groups such as γ-aminopropyl, γ-chloropropyl, 1,1,1-trifluoropropyl, nona Ruorohekishiru, halogen-containing groups such as perfluorooctylethyl, other nitro, and cyano-substituted alkyl group. In particular, alkyl groups such as methyl, ethyl, propyl and butyl are preferred. Examples of the hydrolyzable group for X include alkoxy groups such as methoxy and ethoxy, halogen groups, and acyloxy groups. In particular, an alkoxy group having 6 or less carbon atoms is preferable.
[0045]
In the case of a specific compound of an organosilicon compound represented by the general formula (1) and n is 2 or more, a plurality of R may be the same or different. Similarly, when n is 2 or less, the plurality of Xs may be the same or different. Moreover, when using 2 or more types of organosilicon compounds represented by General formula (1), R and X may be the same between each compound, and may differ.
[0046]
Among the organosilicon compounds represented by the general formula (1), a siloxane-based resin layer formed from a coating solution in which n is a combination of 1 and 2 has high mechanical wear resistance and is easy to clean. A good protective layer can be formed.
[0047]
Among the organosilicon compounds represented by the general formula (1), a siloxane-based resin formed from a coating solution in which the organic silicon compounds of the following general formula (2) and general formula (3) where n is 1 and 2 are used in combination The layer can form a protective layer with good surface properties.
[0048]
General formula (2) R₁Si (X)_Three
General formula (3) R₁R₂Si (X)₂
(Wherein R₁, R₂Is an alkyl group having 1 to 10 carbon atoms, aryl group, vinyl group, amino group, γ-glycidoxypropyl group, γ-methacryloxypropyl group, C_nF_{2n + 1}C₂H_Four-Represents. n represents an integer of 1 to 6, and X represents a hydroxyl group or a hydrolyzable group. )
The siloxane-based resin layer obtained by using the organosilicon compound represented by the general formula (2) and the general formula (3), a hydrolysis product thereof, or a condensate obtained from the hydrolysis product. Can form a protective layer having surface properties that are elastic and rigid, have a small surface free energy, and hardly cause filming of toner or paper powder.
[0049]
Specific examples of the organosilicon compound of the general formula (2) include the following compounds.
[0050]
That is, trichlorosilane, methyltrichlorosilane, vinyltrichlorosilane, ethyltrichlorosilane, allyltrichlorosilane, n-propyltrichlorosilane, n-butyltrichlorosilane, chloromethyltriethoxysilane, methyltrimethoxysilane, mercaptomethyltrimethoxysilane, Trimethoxyvinylsilane, ethyltrimethoxysilane, 3,3,4,4,5,5,6,6,6-nonafluorohexyltrichlorosilane, phenyltrichlorosilane, 3,3,3-trifluoropropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, triethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 2-aminoethylaminomethyltrimethoxysilane, benzene Rutrichlorosilane, methyltriacetoxysilane, chloromethyltriethoxysilane, ethyltriacetoxysilane, phenyltrimethoxysilane, 3-allylthiopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-bromopropyltriethoxysilane 3-allylaminopropyltrimethoxysilane, propyltriethoxysilane, hexyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, bis (ethylmethylketoxime) methoxymethylsilane, pentyltri Examples include ethoxysilane, octyltriethoxysilane, dodecyltriethoxysilane, and the like.
[0051]
Specific examples of the organosilicon compound of the general formula (3) include the following compounds.
[0052]
Dimethyldichlorosilane, dimethoxymethylsilane, dimethoxydimethylsilane, methyl-3,3,3-trifluoropropyldichlorosilane, diethoxysilane, diethoxymethylsilane, dimethoxymethyl-3,3,3-trifluoropropylsilane, 3 -Chloropropyldimethoxymethylsilane, chloromethyldiethoxysilane, diethoxydimethylsilane, dimethoxy-3-mercaptopropylmethylsilane, 3,3,4,4,5,5,6,6,6-nonafluorohexylmethyldi Chlorosilane, methylphenyldichlorosilane, diacetoxymethylvinylsilane, diethoxymethylvinylsilane, 3-methacryloxypropylmethyldichlorosilane, 3-aminopropyldiethoxymethylsilane, 3- (2-aminoethylaminopropyl) Pill) dimethoxymethylsilane, t-butylphenyldichlorosilane, 3-methacryloxypropyldimethoxymethylsilane, 3- (3-cyanopropylthiopropyl) dimethoxymethylsilane, 3- (2-acetoxyethylthiopropyl) dimethoxymethylsilane, Dimethoxymethyl-2-piperidinoethylsilane, dibutoxydimethylsilane, 3-dimethylaminopropyldiethoxymethylsilane, diethoxymethylphenylsilane, diethoxy-3-glycidoxypropylmethylsilane, 3- (3-acetoxypropyl) And thio) propyldimethoxymethylsilane, dimethoxymethyl-3-piperidinopropylsilane, and diethoxymethyloctadecylsilane.
[0053]
The most preferred siloxane-based resin layer of the present invention is that the siloxane-based resin layer itself has a charge transporting property and a small surface free energy, and the adhesion and brittleness with the adjacent layer of the siloxane-based resin layer are modified. A siloxane-based resin layer.
[0054]
Such a siloxane-based resin layer is a siloxane-based resin layer having a structural unit having charge transport performance and having a crosslinked structure. The siloxane-based resin layer having a structural unit having charge transporting performance and having a crosslinked structure is specifically composed of a charge transporting compound represented by the following general formula (4) and the organosilicon compound or the condensate thereof. Formed by a condensation reaction with the like. The siloxane-based resin layer has a small increase in residual potential, a small surface free energy, hardly causes filming of toner and paper powder, and has film properties with improved adhesion and brittleness with adjacent layers. The most preferable protective layer can be formed.
[0055]
General formula (4) B- (R₁-ZH)_m
In the formula, B represents a monovalent or polyvalent group containing a structural unit having charge transport performance, and R₁Represents a single bond or a divalent alkylene group, Z represents an oxygen atom, a sulfur atom or NH, and m represents an integer of 1 to 4.
[0056]
B in the general formula (4) is a monovalent or higher group including a charge transporting compound structure. Here, B includes a charge transporting compound structure means that (R) in the general formula (4)₁The compound structure excluding the —ZH) group has charge transport performance, or (R in the general formula (4))₁It means that a compound of BH in which a -ZH) group is substituted with a hydrogen atom has charge transport performance.
[0057]
The charge transporting compound is a compound having a property of drift mobility of electrons or holes, and another definition is a known method capable of detecting charge transporting performance such as Time-Of-Flight method. Can be defined as a compound that can provide a detected current due to charge transport.
[0058]
The siloxane resin layer of the present invention having a structural unit having charge transport performance in the siloxane resin layer can be formed by a condensation reaction between the organosilicon compound and the charge transport compound. In the siloxane-based resin layer of the present invention, a charge transporting compound having reactivity with the organosilicon compound can be used instead of the charge transporting compound represented by the general formula (4).
[0059]
It is preferable that inorganic metal oxide particles of 5 nm to 500 nm are contained in the siloxane-based resin layer. That is, the siloxane-based resin layer contains an organosilicon compound having a hydroxyl group or a hydrolyzable group, or a condensation product of the organosilicon compound and a charge transport performance compound having a hydroxyl group, and inorganic metal oxide particles of 5 nm to 500 nm. A composite resin layer having a charge transporting property obtained by coating with a composition to be coated and drying is preferable.
[0060]
The metal oxide particles of 5 nm to 500 nm are usually synthesized by a liquid phase method. Examples of metal atoms include Si, Ti, Al, Cr, Zr, Sn, Fe, Mg, Mn, Ni, Cu and the like. These metal oxide particles can be obtained as colloidal particles.
[0061]
The metal oxide particles preferably have a compound group having reactivity with the organosilicon compound on the particle surface. Examples of the reactive compound group include a hydroxyl group and an amino group. By using such metal oxide particles having a reactive group, the protective layer of the present invention forms a composite siloxane resin layer in which the siloxane resin and the surface of the metal oxide particles are chemically bonded. When the siloxane-based resin layer is used as a protective layer for the photoreceptor, a film having good electrophotographic characteristics that hardly wears against abrasion such as blade cleaning is formed.
[0062]
The total amount (H) of the organosilicon compound having the hydroxyl group or hydrolyzable group and the condensate formed from the organosilicon compound having the hydroxyl group or hydrolyzable group and the amount of the compound of the general formula (4) (I The composition ratio is preferably 100: 3 to 50: 100, more preferably 100: 10 to 50: 100 in terms of mass ratio.
[0063]
Moreover, it is preferable that 1-30 mass parts of (J) is used for the addition amount (J) of the said metal oxide particle with respect to 100 masses of total mass of the said total amount (H) + compound amount (I).
[0064]
When the total amount (H) component is used within the above range, the photoreceptor surface layer of the present invention has high hardness and elasticity. On the other hand, when the amount (I) of the compound is used within the above range, the electrophotographic characteristics such as sensitivity and residual potential characteristics are good, and the hardness of the surface layer of the photoreceptor is high.
[0065]
Furthermore, it is preferable to perform the drying temperature in the production process of the siloxane-based resin layer at a high temperature of 80 ° C. or higher, and to reheat the siloxane-based resin layer after drying at 30 ° C. to 100 ° C. for several hours or more. .
[0066]
In order to promote the condensation reaction for forming the siloxane-based resin layer, the following condensation catalyst is preferable as the condensation catalyst.
[0067]
As a specific condensation catalyst, known catalysts conventionally used for silicone hard coat materials such as acids, metal oxides, metal salts, metal chelate compounds, and alkylaminosilane compounds can be used. In addition to phosphoric acid and acetic acid, Titanium chelates, aluminum chelates, and tin organic acid salts (stannas octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutyltin malate, etc.) are preferred.
[0068]
Preferred examples of the compound represented by the general formula (4) are given below, but the present invention is not limited to the following compounds.
[0069]
[Formula 4]

[0070]
[Chemical formula 5]

[0071]
[Chemical 6]

[0072]
The siloxane-based resin layer preferably contains an antioxidant. Typical examples of the antioxidants are those that prevent the action of oxygen under conditions of light, heat, discharge, etc., on auto-oxidizing substances present in the organophotoreceptor or on the organophotoreceptor surface, It is a substance that has the property of inhibiting. Typical examples include the following compound groups.
[0073]
[Chemical 7]

[0074]
[Chemical 8]

[0075]
[Chemical 9]

[0076]
Next, the structure of the photoreceptor of the present invention other than the protective layer will be described. The layer structure of the organic electrophotographic photoreceptor of the present invention is not particularly limited, but is a charge generation layer, a charge transport layer, or a charge generation / charge transport layer (a layer having functions of charge generation and charge transport in the same layer), etc. The photosensitive layer and a protective layer are preferably coated thereon.
[0077]
The structure of the photoreceptor used in the present invention will be described below.
Conductive support
The conductive support used in the photoreceptor of the present invention may be either a sheet or a cylinder, but a cylindrical conductive support is more preferable for designing an image forming apparatus in a compact manner.
[0078]
The cylindrical conductive support of the present invention means a cylindrical support necessary for forming an endless image by rotating, and the straightness is in the range of 0.1 mm or less and the deflection is 0.1 mm or less. A conductive support is preferred. Exceeding the roundness and shake range makes it difficult to form a good image.
[0079]
As the conductive material, a metal drum such as aluminum or nickel, a plastic drum deposited with aluminum, tin oxide, indium oxide or the like, or a paper / plastic drum coated with a conductive substance can be used. As a conductive support, the specific resistance is 10 at room temperature.^ThreeΩcm or less is preferable.
[0080]
As the conductive support used in the present invention, one having an alumite film that has been sealed on the surface thereof may be used. The alumite treatment is usually performed in an acidic bath such as chromic acid, sulfuric acid, oxalic acid, phosphoric acid, boric acid, sulfamic acid, etc., but anodizing treatment in sulfuric acid gives the most preferable result. In the case of anodizing in sulfuric acid, the sulfuric acid concentration is preferably 100 to 200 g / l, the aluminum ion concentration is 1 to 10 g / l, the liquid temperature is about 20 ° C., and the applied voltage is preferably about 20 V. It is not limited. The average film thickness of the anodized film is usually 20 μm or less, particularly preferably 10 μm or less.
[0081]
Middle class
In the present invention, an intermediate layer having a barrier function may be provided between the conductive support and the photosensitive layer.
[0082]
In the present invention, in order to improve the adhesion between the conductive support and the photosensitive layer, or to prevent charge injection from the support, an intermediate layer (including an undercoat layer) is provided between the support and the photosensitive layer. Including) can also be provided. Examples of the material for the intermediate layer include polyamide resins, vinyl chloride resins, vinyl acetate resins, and copolymer resins containing two or more of these resin repeating units. Of these subbing resins, a polyamide resin is preferable as a resin capable of reducing the increase in residual potential due to repeated use. The film thickness of the intermediate layer using these resins is preferably 0.01 to 0.5 μm.
[0083]
The intermediate layer most preferably used in the present invention includes an intermediate layer using a curable metal resin obtained by thermally curing an organometallic compound such as a silane coupling agent or a titanium coupling agent. As for the film thickness of the intermediate | middle layer using curable metal resin, 0.1-2 micrometers is preferable.
[0084]
Photosensitive layer
The photosensitive layer configuration of the photoreceptor of the present invention may be a single layer photosensitive layer configuration in which a charge generation function and a charge transport function are provided on one layer on the intermediate layer. It is preferable that the generation layer (CGL) and the charge transport layer (CTL) be separated. By adopting a configuration in which the functions are separated, an increase in the residual potential due to repeated use can be controlled to be small, and other electrophotographic characteristics can be easily controlled according to the purpose. In the negatively charged photoconductor, it is preferable that a charge generation layer (CGL) is formed on the intermediate layer, and a charge transport layer (CTL) is formed thereon. In the positively charged photoconductor, the order of the layer configuration is the reverse of that in the negatively charged photoconductor. The most preferred photosensitive layer structure of the present invention is a photoreceptor structure having the function separation structure.
[0085]
The structure of the photosensitive layer of the function separation photoreceptor will be described below.
Charge generation layer
Charge generation layer: The charge generation layer contains the perylene hybrid pigment as a charge generation material (CGM). Other substances may contain a binder resin and other additives as necessary.
[0086]
As the charge generation material (CGM), a known charge generation material (CGM) can be used if necessary in addition to the perylene hybrid pigment. For example, a phthalocyanine pigment, an azo pigment, a perylene pigment, an azulenium pigment, or the like can be used.
[0087]
When a binder is used as the CGM dispersion medium in the charge generation layer, a known resin can be used as the binder, but the most preferred resins include formal resin, butyral resin, silicone resin, silicone-modified butyral resin, phenoxy resin, and the like. Can be mentioned. The ratio of the binder resin to the charge generating material is preferably 20 to 600 parts by mass with respect to 100 parts by mass of the binder resin. By using these resins, the increase in residual potential associated with repeated use can be minimized. The thickness of the charge generation layer is preferably 0.01 μm to 2 μm.
[0088]
Charge transport layer
Charge transport layer: The charge transport layer contains a charge transport material (CTM) and a binder resin in which CTM is dispersed to form a film. Other substances may contain additives such as antioxidants as necessary.
[0089]
A known charge transport material (CTM) can be used as the charge transport material (CTM). For example, a triphenylamine derivative, a hydrazone compound, a styryl compound, a benzidine compound, a butadiene compound, or the like can be used. These charge transport materials are usually dissolved in a suitable binder resin to form a layer. Among these, the CTM capable of minimizing the increase in residual potential due to repeated use has a high mobility and an ionization potential difference from the combined CGM of 0.5 (eV) or less, preferably 0 .25 (eV) or less.
[0090]
The ionization potential of CGM and CTM is measured with a surface analyzer AC-1 (manufactured by Riken Keiki Co., Ltd.).
[0091]
Examples of the resin used for the charge transport layer (CTL) include polystyrene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, and polycarbonate. Resin, silicone resin, melamine resin, and copolymer resin containing two or more of repeating units of these resins. In addition to these insulating resins, high molecular organic semiconductors such as poly-N-vinylcarbazole can be used.
[0092]
Most preferred as a binder for these CTLs is a polycarbonate resin. The polycarbonate resin is most preferable in improving the dispersibility and electrophotographic characteristics of CTM. The ratio of the binder resin to the charge transport material is preferably 10 to 200 parts by mass with respect to 100 parts by mass of the binder resin. The thickness of the charge transport layer is preferably 10 to 40 μm.
[0093]
Protective layer
By providing the siloxane-based resin layer as a protective layer of the photoreceptor, a photoreceptor having the most preferable layer structure of the present invention can be obtained.
[0094]
As the solvent or dispersion medium used for forming the intermediate layer, photosensitive layer, protective layer and the like of the present invention, n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N, N-dimethylformamide, Acetone, methyl ethyl ketone, methyl isopropyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, dichloromethane, 1,2-dichloroethane, 1,2-dichloropropane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, trichloroethylene , Tetrachloroethane, tetrahydrofuran, dioxolane, dioxane, methanol, ethanol, butanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, methyl cello Lube, and the like. Although this invention is not limited to these, Dichloromethane, 1, 2- dichloroethane, methyl ethyl ketone, etc. are used preferably. These solvents may be used alone or as a mixed solvent of two or more.
[0095]
Next, as a coating processing method for producing the organic electrophotographic photoreceptor of the present invention, a coating processing method such as dip coating, spray coating, circular amount regulation type coating or the like is used. In order to prevent the lower layer film from being dissolved as much as possible, it is preferable to use a coating method such as spray coating or circular amount regulation type (circular slide hopper type is a typical example) coating in order to achieve uniform coating processing. It is most preferable that the protective layer of the present invention uses the circular amount regulation type coating method. The circular amount regulation type coating is described in detail in, for example, Japanese Patent Application Laid-Open No. 58-189061.
[0096]
FIG. 1 is a sectional view as an example of the image forming apparatus of the present invention.
In FIG. 1, reference numeral 50 denotes a photosensitive drum (photosensitive member) which is an image bearing member, which is a photosensitive member in which an organic photosensitive layer is coated on the drum and the resin layer of the present invention is coated thereon. Is driven and rotated. Reference numeral 52 denotes a scorotron charger, which uniformly charges the circumferential surface of the photosensitive drum 50 by corona discharge. Prior to charging by the charger 52, in order to eliminate the history of the photoconductor in the previous image formation, exposure by the exposure unit 51 using a light emitting diode or the like may be performed to neutralize the peripheral surface of the photoconductor.
[0097]
After the photoreceptor is uniformly charged, the image exposure unit 53 performs image exposure based on the image signal. The image exposure unit 53 in this figure uses a laser diode (not shown) as an exposure light source. The photosensitive drum is scanned by light whose optical path is bent by the reflecting mirror 542 through the rotating polygon mirror 531 and the fθ lens, and an electrostatic latent image is formed.
[0098]
The electrostatic latent image is then developed by the developing device 54. A developing device 54 containing a developer composed of toner and carrier is provided on the periphery of the photosensitive drum 50, and development is performed by a developing sleeve 541 that contains a magnet and rotates while holding the developer. The developer includes, for example, a carrier in which the above ferrite is used as a core and an insulating resin is coated around the carrier, a colorant such as carbon black, a charge control agent, and the low molecular weight polyolefin of the present invention, which is mainly composed of the above styrene acrylic resin. The developer is made of a toner obtained by externally adding silica, titanium oxide or the like to the colored particles, and the developer is regulated to a layer thickness of 100 to 600 μm on the developing sleeve 541 by the layer forming means and conveyed to the developing area. Development is performed. At this time, usually, development is performed by applying a DC bias between the photosensitive drum 50 and the developing sleeve 541 and, if necessary, an AC bias voltage. Further, the developer is developed in contact with or not in contact with the photoreceptor.
[0099]
The recording paper P is fed to the transfer area by the rotation operation of the paper feed roller 57 when the transfer timing is ready after the image formation.
[0100]
In the transfer area, a transfer roller (transfer device) 58 is pressed against the circumferential surface of the photosensitive drum 50 in synchronization with the transfer timing, and the fed recording paper P is sandwiched and transferred.
[0101]
Next, the recording paper P is neutralized by a separation brush (separator) 59 brought into a pressure contact state almost simultaneously with the transfer roller, separated by the peripheral surface of the photosensitive drum 50, conveyed to the fixing device 60, and pressed against the heat roller 601. After the toner is welded by heating and pressurizing the roller 602, the toner is discharged to the outside of the apparatus via the discharge roller 61. The transfer roller 58 and the separation brush 59 are separated from the peripheral surface of the photosensitive drum 50 after the recording paper P has passed to prepare for the next toner image formation.
[0102]
On the other hand, after the recording paper P is separated, the photosensitive drum 50 removes and cleans residual toner by the pressure contact of the blade 621 of the cleaning device 62, and receives the charge removal by the exposure unit 51 and the charging by the charging device 52 again, and the next image. Enter the formation process.
[0103]
Reference numeral 70 denotes a detachable process cartridge in which a photoconductor, a charger, a transfer device / separator, and a cleaning device are integrated.
[0104]
As an electrophotographic image forming apparatus, the above-described photosensitive member and components such as a developing device and a cleaning device are integrally coupled as a process cartridge, and this unit may be configured to be detachable from the apparatus main body. good. In addition, a process cartridge is formed by integrally supporting at least one of a charger, an image exposure device, a developing device, a transfer or separation device, and a cleaning device together with a photosensitive member, and a single unit that is detachable from the apparatus main body. It is good also as a structure which can be attached or detached using guide means, such as a rail of an apparatus main body.
[0105]
Process cartridges generally include an integral cartridge and a separate cartridge as described below. The integrated cartridge is a structure in which at least one of a charging device, an image exposure device, a developing device, a transfer or separation device, and a cleaning device is integrally formed with a photosensitive member, and is detachable from the apparatus main body. Is a charger, an image exposure device, a developing device, a transfer or separation device, and a cleaning device that are configured separately from the photoconductor. When integrated, it is integrated with the photoreceptor. The process cartridge in the present invention includes both types of cartridges.
[0106]
In addition, the image forming apparatus may be configured to include a photosensitive drum and a process cartridge including at least one of a charging device, a developing device, a cleaning device, and a recycling member.
[0107]
Next, the transfer paper is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and of course includes an OHP PET base.
[0108]
When the electrophotographic image forming apparatus is used as a copying machine or a printer, image exposure is performed by irradiating the photosensitive member with reflected light or transmitted light from the original, or by reading the original with a sensor and converting the signal into a laser. This is performed by irradiating the photosensitive member with light by scanning a beam, driving an LED array, or driving a liquid crystal shutter array.
[0109]
When used as a facsimile printer, the image exposure unit 53 performs exposure for printing received data.
[0110]
The electrophotographic photosensitive member of the present invention can be applied to general electrophotographic apparatuses such as copying machines, laser printers, LED printers, and liquid crystal shutter printers, and further displays, recordings, and light printings using electrophotographic technology. It can be widely applied to apparatuses such as plate making and facsimile.
[0111]
Next, synthesis examples of the perylene hybrid pigment of the present invention and the pigment of the comparative example are shown below.
Synthesis example 1
0.3 g of titanyl phthalocyanine and 30 g of bisimidazole perylene of compound (1) were added to 900 ml of concentrated sulfuric acid at room temperature, followed by further stirring for 2 hours. This sulfuric acid solution was filtered through a glass filter to remove insoluble matters, and then poured into 15 liters of water while maintaining a water temperature of 30 ° C. or lower. The precipitated particles were filtered, and further washed with 5 liters of water three times. The wet cake obtained by filtration was once frozen, and then thawed, filtered and dried to obtain 28 g of perylene hybrid pigment (1).
[0112]
Synthesis example 2
26.5 g of perylene hybrid pigment (2) was obtained in the same manner as in Synthesis Example 1 except that 0.1 g of vanadium oxyphthalocyanine was used instead of titanyl phthalocyanine.
[0113]
Synthesis example 3
27 g of perylene hybrid pigment (3) was obtained in the same manner as in Synthesis Example 1, except that 0.15 g of hydroxygallium phthalocyanine was used instead of titanyl phthalocyanine.
[0114]
Synthesis example 4
27 g of perylene hybrid pigment (4) was obtained in the same manner as in Synthesis Example 1 except that 0.3 g of copper phthalocyanine was used instead of titanyl phthalocyanine.
[0115]
Synthesis Example 5 (Comparative Synthesis Example)
The perylene mixed pigment particles prepared in the same manner as in Synthesis Example 1 except that metal-free phthalocyanine was used in place of the titanyl phthalocyanine of Synthesis Example 1 were once dried and then heated under reflux in 500 ml of 2-butanone for 6 hours. Stir. Furthermore, it was sufficiently washed with methanol and dried to obtain 25.8 g of a perylene hybrid pigment (5).
[0116]
Presence or absence of diffraction peaks of diffraction angles 2θ: 6.2, 10.1, 12.2 by the X-ray diffraction analysis of Cu-Kα characteristic X-rays of the pigments of Synthesis Examples 1 to 5, and the presence or absence of metal atoms The content is shown in Table 1 below.
[0117]
[Table 1]

[0118]
In the table, ◯ indicates that there is a diffraction peak.
X-ray diffraction measurement
FIG. 2 shows the result of powder X-ray diffraction of a coating film having a thickness of about 1 mm formed by dispersing the perylene hybrid pigment particles of Synthesis Example 1 by the method described in Example 1 described later, followed by coating and drying.
[0119]
How to check for metal atoms
The presence or absence of the metal atom and the content of the metal atom in the perylene hybrid pigment of the present invention can be measured by means such as fluorescent X-ray (WDX), atomic absorption analysis, and ICP.
[0120]
【Example】
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the aspect of this invention is not limited to this. In the text, “part” means “part by mass”.
[0121]
A photoconductor was produced as follows.
Production of photoreceptor 1
<Underlayer>
Titanium chelate compound (TC-750: manufactured by Matsumoto Pharmaceutical) 30 g
Silane coupling agent (KBM-503: manufactured by Shin-Etsu Chemical Co., Ltd.) 17g
150 ml of 2-propanol
It coated so that it might become a dry film thickness of 0.5 micrometer on the cylindrical electroconductive support body of (phi) 80mm using the said undercoat layer coating liquid.
[0122]
<Charge generation layer>
Charge generation material (perylene hybrid pigment of Synthesis Example 1) 60 g
700 g of silicone-modified butyral resin (X-40-1211M: manufactured by Shin-Etsu Chemical Co., Ltd.)
2-butanone 2000ml
Were mixed for 10 hours using a sand mill to prepare a charge generation layer coating solution. This coating solution was applied onto the undercoat layer by a dip coating method to form a charge generation layer having a dry film thickness of 0.2 μm.
[0123]
<Charge transport layer>
Charge transport material [N- (4-methylphenyl) -N- {4- (β-phenylstyryl) phenyl} -p-toluidine] 225 g
Polycarbonate (viscosity average molecular weight 30,000) 300g
Antioxidant (Exemplary Compound 1-3) 6 g
Dichloromethane 2000ml
Were mixed and dissolved to prepare a charge transport layer coating solution. This coating solution was applied onto the charge generation layer by a dip coating method to form a charge transport layer having a dry film thickness of 20 μm.
[0124]
<Protective layer>
182 g of methyltrimethoxysilane
Example Compound (B-1) 50g
Antioxidant (Exemplary Compound 2-1) 1 g
1-butanol 225g
Colloidal silica (30% methanol solution) 100g
106g of 2% acetic acid
Aluminum trisacetylacetonate 1g
A silane compound, 1-butanol, and 2% acetic acid were mixed and stirred for 16 hours at a temperature of 40 ° C. with stirring, and then the exemplary compound (B-1), antioxidant, and aluminum trisacetylacetonate were added to further room temperature. For 1 hour to prepare a coating solution for the protective layer. A structure having a charge transporting performance by forming a resin layer having a dry film thickness of 1 μm on the charge transporting layer on the charge transporting layer using a circular amount-regulating coating device, and heating and curing the resin layer at 110 ° C. for 1 hour. A protective layer of a siloxane-based resin layer having a unit and a crosslinked structure was formed to prepare a photoreceptor 1.
[0125]
Production of photoconductors 2 to 5
Photoconductors 2 to 5 were prepared in the same manner as Photoreceptor 1 except that the charge generation layer of Photoreceptor 1 was replaced with the perylene hybrid pigment of Synthesis Examples 2 to 5 instead of the perylene hybrid pigment of Synthesis Example 1.
Production of photoreceptor 6
In the same manner as the photoconductor 1, the layers up to the charge transport layer were prepared.
[0126]
<Protective layer>
Methyltrimethoxysilane 55g
Dimethyldimethoxysilane 127g
Example Compound (B-1) 50g
Antioxidant (Exemplary Compound 2-1) 1 g
1-butanol 225g
106g of 2% acetic acid
Aluminum trisacetylacetonate 1g
A silane compound, 1-butanol, and 2% acetic acid were mixed and stirred for 16 hours at a temperature of 40 ° C. with stirring, and then the exemplary compound (B-1), antioxidant, and aluminum trisacetylacetonate were added to further room temperature. For 1 hour to prepare a coating solution for the protective layer. A structure having a charge transporting performance by forming a resin layer having a dry film thickness of 1 μm on the charge transporting layer on the charge transporting layer using a circular amount-regulating coating device, and heating and curing the resin layer at 110 ° C. for 1 hour. A protective layer of a siloxane-based resin layer having a unit and a crosslinked structure was formed to prepare a photoreceptor 6.
Production of photoconductor 7
Photoreceptor 7 was produced in the same manner as Photoreceptor 1, except that the protective layer was removed and the dry thickness of the charge transport layer was changed to 21 μm.
[0127]
<Evaluation>
The following evaluation was performed to confirm the image and potential stability during repeated copying.
[0128]
Using photoconductors 1-7, a digital copier Konica-7050 (charge polarity: negative, reversal development, 680 nm light source), a modified machine with a temperature of 30 ° C. and humidity of 80% RH, A3 size 100,000 copies Went. The copy was evaluated by making continuous copies on A4 paper using original images of 7% character images, black background images, white background images, and halftone images, respectively. Evaluation was carried out at the initial stage and after copying for 100,000 sheets, after the 1 hour rest, the evaluation described below was performed. The image forming conditions of the copying machine are set so that image formation is performed from the first rotation of the photoreceptor. The potential of the photoconductor was measured by providing a potential sensor between the image exposure light and the developing part.
[0129]
Evaluation items and evaluation criteria
Change in chargeability (ΔV₁₂); Charge potential (VH) of the first rotation due to deterioration of the photoconductor₁) Is the second charging potential (VH)₂) And a defect in which fogging and density unevenness occur when an image is formed from the first rotation.
[0130]
VL: The charging potential of the black background image (exposed portion). When the numerical value of VL increases, it causes a decrease in image density and white background fog.
[0131]
White background fog, black spots: An image defect in which toner is originally developed on the entire white background due to a decrease in the white background charging potential (VH).
[0132]
A: Visually no fogging with 3 or less black spots on an A3 white background image
○: 〃 Less than 10 and no fogging
×: 以上 10 or more or fogging occurred
<Evaluation results>
The evaluation results of the copied image and the potential stability are shown in the following Table 2 (initial evaluation) and Table 3 (evaluation after 100,000 copies).
[0133]
[Table 2]

[0134]
[Table 3]

[0135]
The amount of film thickness loss in the table was measured as follows.
As for the film thickness of the photosensitive layer (photosensitive layer and protective layer), 10 portions of the uniform film thickness are randomly measured, and the average value is defined as the film thickness of the photosensitive layer. The film thickness measuring device is an eddy current type film thickness measuring device EDDY560C (manufactured by HELMUT FISCHER GMBTE CO), and the difference in the photosensitive layer thickness before and after the actual shooting test is defined as the amount of film thickness loss.
[0136]
From Tables 2 and 3, the examples using the perylene hybrid pigment of the present invention and the photoreceptors 1 to 4 and the photoreceptor 6 having the siloxane resin layer are the first and second revolutions of the photoreceptor during copying. The potential fluctuation of the image is small, and white background fog is not generated in the first copy image. On the other hand, the photoconductor 5 using a perylene hybrid pigment not containing a metal atom outside of the present invention and the photoconductor 7 excluding the siloxane-based resin layer have large potential fluctuations, and white background fog occurs in the first copy image. ing. This tendency is the same for the initial and 100,000 copy images. On the other hand, even when the perylene hybrid pigment of the present invention is used, the photoreceptor 7 having no siloxane-based resin layer as a protective layer has good initial characteristics, but after 100,000 copies, the film thickness is reduced due to abrasion of the photosensitive layer. Because of this, white background fog is occurring.
[0137]
【The invention's effect】
By using the photoreceptor of the present invention, stable electrical characteristics and image characteristics can be obtained over a long period of repeated use, and it is also resistant to image defects such as black spots that occur during reversal development image formation, and one revolution of the photoreceptor. An electrophotographic image forming process capable of forming an image from the eyes can be realized.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view as an example of an image forming apparatus of the present invention.
2 is an X-ray powder diffraction diagram after dispersion of pigment particles in Synthesis Example 1. FIG.
[Explanation of symbols]
50 photoconductor drum (or photoconductor)
51 Exposure section
52 Charger
53 Image exposure unit
54 Developer
57 Feed roller
58 Transfer roller
59 Separation brush (separator)
60 Fixing device
61 Paper discharge roller
62 Cleaning device
70 Process cartridge

Claims (8)

An electrophotographic photosensitive member having a photosensitive layer and a protective layer on a conductive support, wherein the photosensitive layer has a perylene hybrid pigment containing 0.01 to 10% by mass of a metal phthalocyanine compound as a charge generating substance, and the protection An electrophotographic photoreceptor, wherein the layer is a siloxane-based resin layer. 2. The electrophotographic photosensitive member according to claim 1, wherein a metal atom of the metal phthalocyanine compound is at least one of Ti, Cu, Fe, V, Ga, Si, Pb, Al, Zn, and Mg. The electrophotographic photosensitive member according to claim 1, wherein the perylene hybrid pigment contains bisimidazole perylene of the compound (1) represented by the following structure .

The X-ray diffraction pattern of the perylene hybrid pigment has a diffraction peak at least 6.2, 10.1, 12.2 at a 2θ (2θ ± 0.2) angle of Cu-Kα characteristic X-ray diffraction. The electrophotographic photosensitive member according to any one of claims 1 to 3. The electrophotographic photosensitive member according to claim 1, wherein the siloxane-based resin layer is a siloxane-based resin layer having a structural unit having charge transport performance and having a crosslinked structure. . In the image forming method having charging, image exposure, development, and transfer steps around the electrophotographic photosensitive member, the electrophotographic photosensitive member according to any one of claims 1 to 5 is used as the electrophotographic photosensitive member. An image forming method. In an image forming apparatus having each means of charging, image exposure, development, and transfer around the electrophotographic photosensitive member, the electrophotographic photosensitive member according to any one of claims 1 to 5 is used as the electrophotographic photosensitive member. An image forming apparatus. The process cartridge used in an image forming apparatus having each means of charging, image exposure, development, and transfer around the electrophotographic photosensitive member is an electrophotographic photosensitive member and a charging unit according to any one of claims 1 to 5, A process cartridge comprising a combination of at least one of an image exposure unit, a development unit, and a transfer unit, and is designed to be freely taken into and out of the image forming apparatus.

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