JP3897725B2 - Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus - Google Patents

Description

（式（１）中、Ａｒ^１１およびＡｒ^１２は、それぞれ独立に、下記式（２）で示される構造を有する。
【外５】

（式（２）中、Ａｒ^２１およびＡｒ^２２は、それぞれ独立に、置換基を有してもよい２価の芳香環基または複素環基を表す。Ａ^２１は、置換基を有してもよいアルキレン基、アミノ基、アゾ基、スルホニル基、酸素原子または硫黄原子を表す。Ｘ^２１は、置換基を有してもよいアルキレン基、シロキサン基、シリレン基、カルボニル基、スルホニル基、酸素原子または硫黄原子を表す。ｐ、ｑは、それぞれ、０または１を表す。ただし、Ａｒ^２１−（Ａ^２１）_ｐ−Ａｒ^２２に関しては、ｐ＝０のときは、Ａｒ^２１−Ａｒ^２２という直接結合は形成せず、Ａｒ^２１−（Ｘ^２１）_ｑ−Ａｒ^２２に関しては、ｑ＝０のときは、Ａｒ^２１−Ａｒ^２２という直接結合を形成する。）また、Ａｒ^１３およびＡｒ^１４は、それぞれ独立に、置換または非置換の芳香環基または複素環基を表す。ｍは０または１を表し、ｎは４以上の整数を表す。ただし、ｍ＋ｎ≧５である。）
で示される構造を有する高分子電荷輸送物質を含有し、かつ、
該電気絶縁性バインダー樹脂が、上記式（１）のＡｒ ^１１ またはＡｒ ^１２ と同一の構造（ただし、Ａｒ ^１１ 、Ａｒ ^１２ の芳香環基、複素環基が有する置換基は異なっていてもよい。）を有する
ことを特徴とする電子写真感光体である。
【００１５】
また、本発明は、上記電子写真感光体を有するプロセスカートリッジおよび電子写真装置である。
【００１６】
【発明の実施の形態】
上記式（１）中のＡｒ^１３およびＡｒ^１４の芳香環基としては、フェニル、ナフチル、アンスリル、ピレニル、フルオレニル、フェナンスリルなどが挙げられ、複素環基としては、キノリル、ジベンゾチェニル、ジベンゾフリル、ｎ−メチルカルバゾル、ｎ−エチルカルバゾル、ｎ−トリルカルバゾルなどが挙げられる。
【００１７】
上記式（２）中のＡｒ^２１およびＡｒ^２２の芳香環基としては、ベンゼン、ナフタレン、アントラセン、ペリレン、フルオレン、ビフェニル、ターフェニルなどの芳香環より２個の水素原子をとった２価の芳香環基が挙げられ、複素環基としては、カルバゾール、フラン、ベンゾフラン、チオフェン、ベンゾチオフェン、キノリン、フェナジンなどの複素環より２個の水素原子をとった２価の複素環基が挙げられる。Ａ^２１のアルキレン基としては、メチレン、エチレン、プロピレン基などが挙げられる。Ｘ^２１のアルキレン基としては、メチレン、エチレン、プロピレン基などが挙げられ、シロキサン基としては、−ＳｉＯ−の数が１〜１０のシロキサン基が挙げられ、シリレン基としては、Ｓｉの数が１〜４のシリレン基が挙げられる。
【００１８】
上記式（１）で示される電荷輸送性高分子化合物は、下記式（３）で示される構成単位を有する重合体であることがより好ましい。
【外６】

（上記式（３）中、Ａｒ^１３およびＡｒ^１４は、上記式（１）中のＡｒ^１３およびＡｒ^１４と同義であり、それぞれ独立に、置換または非置換の芳香環基または複素環基を表す。ｎ’は、３以上の整数を表す。Ｒ^３０１〜Ｒ^３１６は水素原子、ハロゲン原子、置換基を有してもよいアルキル基、置換基を有してもよいアルコキシ基、または、アミノ基を表す。さらに、Ｒ^３０２とＲ^３０５、Ｒ^３１０とＲ^３１３は、結合して環を形成したり、アルキレン基、アミノ基、アゾ基、スルホニル基、酸素原子または硫黄原子を介して環を形成したりしてもよい。Ｘ^３１およびＸ^３２は、置換基を有してもよいアルキレン基、シロキサン基、シリレン基、カルボニル基、スルホニル基、酸素原子または硫黄原子を表す。ｒ、ｓはそれぞれ０または１を表す。）
【００１９】
上記式（３）中のＲ^３０１〜Ｒ^３１６のアルキル基としては、メチル、エチル、プロピルなどが挙げられ、ハロゲン原子としては、フッ素、塩素、臭素などが挙げられ、アルコキシ基としては、メトキシ、エトキシなどが挙げられる。Ｒ^３０２とＲ^３０５、Ｒ^３１０とＲ^３１３が環を形成する際に介してもよいアルキレン基としては、炭素数が１、２のアルキレン基が挙げられる。
【００２０】
また、上記式（１）中、Ａｒ^１１およびＡｒ^１２、すなわち、上記式（２）で示される構造は、以下の式で示される構造であることが好ましい。
【外７】

（式中、Ｒ^１〜Ｒ^３は水素原子、置換基を有してもよいアルキル基または置換基を有してもよい芳香環基を示す。）
【００２１】
上記式（１）〜（３）中のＡｒ^１１〜Ａｒ^１４、Ａｒ^２１〜Ａｒ^２２、Ａ^２１，Ｘ^２１、Ｘ^３１、Ｘ^３２、Ｒ^３０１〜Ｒ^３１６が有してもよい置換基としては、メチル、エチル、プロピルおよびブチルなどのアルキル基や、メトキシ、エトキシおよびプロポキシなどのアルコキシ基や、フェノキシおよびナフトキシなどのアリールオキシ基や、フッ素、塩素および臭素などのハロゲン原子や、ジメチルアミノ、ジエチルアミノおよびジフェニルアミノなどのジ置換アミノ基などが挙げられる。
【００２２】
本発明に用いる高分子電荷輸送物質の具体例を以下に示すが、本発明はこれらに限定されるものではない。
【００２３】
以下の具体例の中でも、ＣＴ−１４、ＣＴ−２４、ＣＴ−２５、ＣＴ−２８、ＣＴ−３０が好ましく、ＣＴ−２４、ＣＴ−２５がより好ましい。
【外８】

【００２４】
【外９】

【００２５】
【外１０】

【００２６】
【外１１】

【００２７】
【外１２】

【００２８】
【外１３】

【００２９】
【外１４】

【００３０】
【外１５】

【００３１】
【外１６】

【００３２】
【外１７】

【００３３】
【外１８】

【００３４】
【外１９】

【００３５】
【外２０】

【００３６】
【外２１】

【００３７】
【外２２】

【００３８】
本発明においては、電気絶縁性バインダー樹脂の中でも、ポリカーボネート樹脂、ポリアリレート樹脂が機械的強度の観点から好ましい。
【００３９】
本発明に用いる電気絶縁性バインダー樹脂の具体例を以下に示すが、本発明はこれらに限定されるものではない。以下の具体例の中では、Ｂ−２、Ｂ−６、Ｂ−２３、Ｂ−２４、Ｂ−３７が好ましく、Ｂ−６、Ｂ−２４がより好ましい。
【外２３】

【００４０】
【外２４】

【００４１】
【外２５】

【００４２】
本発明による電荷輸送層は、電荷輸送物質が高分子量であるため、電荷輸送物質を添加することによる樹脂の膜強度の低下が小さく、耐キズ性、耐摩耗性に優れている。さらに、高分子電荷輸送物質と絶縁性の樹脂バインダーが同一な部分構造を持つことで、相分離をおこすことなく均一な膜を形成できる。
【００４３】
電気絶縁性バインダー樹脂（Ｂ）および前記高分子電荷輸送物質（Ｄ）の含有比率（Ｄ／Ｂ）は、０．０９以上１．０以下（質量比）であることが好ましい。
【００４４】
本発明の高分子電荷輸送物質と電気絶縁性バインダー樹脂が有する同一構造とは、Ａｒ^１１またはＡｒ^１２がとりうる芳香環基または複素環基の基本骨格が同一であることを示し、それらが有する置換基は異なっていてもよい。
【００４５】
また、電気絶縁性バインダー樹脂は、高分子電荷輸送物質と同一構造を有する繰り返し構造単位を、電気絶縁性バインダー樹脂全体の３０ｍｏｌ％以上含有することが好ましい。より好ましくは５０ｍｏｌ％以上であり、さらに好ましくは７０ｍｏｌ％以上である。
【００４６】
本発明の電子写真感光体においては、本発明による高分子電荷輸送物質が１種類であっても、２種類以上の別種のものであってもよい。
【００４７】
さらに、既存の低分子電荷輸送物質と混合して使用してもよい。ただし、この場合は、本発明の高分子電荷輸送物質が、６０ｍｏｌ％以上存在するのが好ましい。
【００４８】
以下に、本発明に用いる電子写真感光体の構成について説明する。
本発明における電子写真感光体は、感光層が電荷発生物質と電荷輸送物質とを同一の層に含有する単層型であっても、電荷発生物質を含有する電荷発生層と電荷輸送物質を含有する電荷輸送層とに分離した積層型でもよいが、電子写真特性の観点からは積層型が好ましく、電荷発生層、電荷輸送層をこの順に積層した順積層型がより好ましい。
【００４９】
使用する支持体は導電性を有するものであればよく、アルミニウム、ステンレスなどの金属、あるいは導電層を設けた金属、紙、プラスチックなどが挙げられ、形状はシート状、円筒状などがあげられる。
【００５０】
ＬＢＰなど画像入力がレーザー光の場合は、散乱による干渉縞防止または基盤の傷を被覆することを目的とした導電層を設けてもよい。これはカーボンブラック、金属粒子などの導電性粒子をバインダー樹脂に分散させて形成することができる。導電層の膜厚は５〜４０μｍが好ましく、１０〜３０μｍがより好ましい。
【００５１】
それらの上に接着機能を有する中間層を設けてもよい。中間層の材料としてはポリアミド、ポリビニルアルコール、ポリエチレンオキシド、エチルセルロース、カゼイン、ポリウレタン、ポリエーテルウレタンなどが挙げられる。これらは適当な溶剤に溶解して塗布される。中間層の膜厚は０．０５〜５μｍが好ましく、０．３〜１μｍがより好ましい。
それらの上に感光層が形成される。順積層型の場合は電荷発生層である。
【００５２】
本発明に用いられる電荷発生物質としてはセレン−テルル、ピリリウム、チアピリリウム系染料、フタロシアニン、アントアントロン、ジベンズピレンキノン、トリスアゾ、シアニン、ジスアゾ、モノアゾ、インジゴ、キナクリドン、非対称キノシアニン系の各顔料が挙げられる。積層型の場合、電荷発生層は前記電荷発生物質を０．３〜４倍量の結着剤樹脂および溶剤とともにホモジナイザー、超音波分散、ボールミル、振動ボールミル、サンドミル、アトライター、ロールミルおよび液衝突型高速分散機などの方法でよく分散し、分散液を塗布、乾燥させて形成される。電荷発生層の膜厚は５μｍ以下、好ましくは０．１〜２μｍが適当である。
【００５３】
電荷輸送層は主として本発明の電気絶縁性バインダー樹脂と電荷輸送物質とを溶剤中に溶解させた塗料を塗工乾燥して形成する。電荷輸送物質は０．５〜２倍量のバインダー樹脂と組み合わされ塗工、乾燥し電荷輸送層を形成する。電荷輸送層の膜厚は５〜４０μｍが好ましく、１５〜３０μｍがより好ましい。
【００５４】
本発明においては、前もって電荷輸送物質と樹脂とを部分的に反応させてシロキサン結合をもたせてもよい。この場合には電子写真感光体への塗布に支障のない溶液または分散液であれば用いることができる。
【００５５】
また、電荷輸送物質とバインダー樹脂の架橋硬化には、必ずしも触媒が必要ではないが、硬化に要する時間、硬化温度などを考慮してジブチル錫ジアセテート、ジブチル錫ジウラレート、ジブチル錫オクマエートなどのアルキル錫有機酸塩などまたはノルマルブチルチタネートなどの有機チタン酸エステルから適宜選択される。
【００５６】
図１に本発明の電子写真感光体を有する電子写真装置の概略構成を示す。
図において、１はドラム状の本発明の電子写真感光体であり、軸２を中心に矢印方向に所定の周速度で回転駆動される。感光体１は、回転過程において、一次帯電手段３によりその周面に正または負の所定電位の均一帯電を受け、次いで、スリット露光やレーザービーム走査露光などの露光手段（不図示）からの露光光４を受ける。こうして感光体１の周面に静電潜像が順次形成されていく。
【００５７】
形成された静電潜像は、次いで、現像手段５によりトナー現像され、現像されたトナー現像像は、不図示の給紙部から感光体１と転写手段６との間に感光体１の回転と同期取り出されて給紙された転写材７に、転写手段６により順次転写されていく。
【００５８】
像転写を受けた転写材７は、感光体面から分離されて像定着手段８へ導入されて像定着を受けることにより複写物（コピー）として装置外へプリントアウトされる。
【００５９】
像転写後の感光体１の表面は、クリーニング手段９によって転写残りトナーの除去を受けて清浄面化され、さらに、前露光手段（不図示）からの前露光光１０により除電処理された後、繰り返し像形成に使用される。なお、図のように、一次帯電手段３が帯電ローラーなどを用いた接触帯電手段である場合は、前露光は必ずしも必要ではない。
【００６０】
本発明においては、上述の電子写真感光体１、一次帯電手段３、現像手段５およびクリーニング手段９などの構成要素のうち、複数のものをプロセスカートリッジとして一体に結合して構成し、このプロセスカートリッジを複写機やレーザービームプリンターなどの電子写真装置本体に対して着脱可能に構成してもよい。例えば、一次帯電手段３、現像手段５およびクリーニング手段９の少なくとも１つを感光体１とともに一体に支持してカートリッジ化して、装置本体のレール１２などの案内手段を用いて装置本体に着脱可能なプロセスカートリッジ１１とすることができる。
【００６１】
また、露光光４は、電子写真装置が複写機やプリンターである場合には、原稿からの反射光や透過光、あるいは、センサーで原稿を読取り、信号化し、この信号にしたがって行われるレーザービームの走査、ＬＥＤアレイの駆動および液晶シャッターアレイの駆動などにより照射される光である。
【００６２】
本発明の電子写真感光体は電子写真複写機に利用するのみならず、レーザービームプリンター、ＣＲＴプリンター、ＬＥＤプリンター、液晶プリンター、レーザー製版など電子写真応用分野にも広く用いることができる。
【００６３】
なお、本発明の効果は、電子写真プロセススピード（上述の、電子写真感光体を帯電し、露光による潜像形成、トナーによる現像、紙などへの転写後に、感光体表面をクリーニングするというプロセスの稼動速度。）が速い系（１３５ｍｍ／ｓ以上）や、クリーニング手段にクリーニングブレードを用いた系において顕著に現れる。
【００６４】
また、重量平均分子量（Ｍｗ）は、ゲルパーミエーションクロマトグラフィー装置ＨＬＣ８１２０ＧＰＣ（東ソー（株））を用い、標準ポリスチレン換算で示される値で示した。
【００６５】
【実施例】
以下、実施例にしたがって説明する。なお、「部」とあるのは質量部を意味する。
【００６６】
（実施例１）
直径３０ｍｍ、長さ３５７．５ｍｍのアルミニウムシリンダーを支持体とし、それに、以下の材料より構成される塗料を支持体上に浸漬法で塗布し１４０℃、３０分熱硬化して１８μｍの導電層を形成した。
導電性顔料：ＳｎＯ_２コート処理硫酸バリウム １０部
抵抗調節用顔料：酸化チタン ２部
バインダー樹脂：フェノール樹脂 ６部
レベリング材：シリコーンオイル ０．００１部
溶剤：メタノール、メトキシプロパノール ０．２／０．８ ２０部
【００６７】
次にこの上にＮメトキシメチル化ナイロン３部および共重合ナイロン３部をメタノール６５部、ｎブタノール３０部の混合溶媒に溶解した溶液を浸漬法で塗布し０．６μｍの中間層を形成した。
【００６８】
次に、ＣｕＫα特性Ｘ線回折におけるブラッグ角２θ±０．２°の７．５°、９．９°、１６．３°、１８．６°、２５．１°および２８．３°に強いピークを有するヒドロキシガリウムフタロシアニン４部とポリビニルブチラール（商品名：エスレックＢＸ−１、積水化学製）２部およびシクロヘキサノン６０部を直径１ｍｍのガラスビーズを用いたサンドミル装置で４時間分散した後、エチルアセテート１００部を加えて電荷発生層用分散液を調製した。これを浸漬法で塗布し、０．２μｍの電荷発生層を形成した。
【００６９】
次に、前記合成例にしたがって合成した電荷輸送物質（ＣＴ−５）４部と電気絶縁性バインダー樹脂（（Ｂ−２３）／（Ｂ−２４）、共重合比６０／４０）１０部をモノクロロベンゼン３０部、ジクロロメタン７０部の混合溶媒に溶解した。
この塗料を浸漬法で塗布し１２０℃２時間乾燥し、２５μｍの電荷輸送層を形成した。
このようにして、電子写真感光体を作製した。
【００７０】
次に評価について説明する。
装置はキヤノン（株）製ＬＢＰ−９５０（プロセススピード１４４．５ｍｍ／ｓ）を改造して用いた。改造は、一次帯電の制御を定電流制御から定電圧制御に変更し、かつ、ピーク間電圧を２０％増加させた。作製した電子写真感光体を、この装置で２８℃９０％ＲＨ（Ｈ／Ｈ）下で通紙耐久を行った。シーケンスはプリント１枚ごとに１回停止する間欠モードとした。トナーがなくなったならば補給し画像で問題がでるまで耐久した。
【００７１】
まず、研磨テープを用いたテーバー摩耗試験機を用い２５分摩耗させそのときの重量減少分を測定した。
【００７２】
また、電子写真感光体の一部に３０００ｌｕｘ、３０分間の白色蛍光灯の光を当て、４分間放置後明部電位を測定し、光を当てる前から明部電位がどれだけ下がったかを測定しフォトメモリー値とした。
【００７３】
さらに、ソルベントクラック性は表面に指脂を付着させ７２時間放置し、顕微鏡観察によりソルベントクラックの有無を観察した。
【００７４】
（実施例２〜１０）
電荷輸送層の電荷輸送物質および電気絶縁性バインダー樹脂を表１に示すものを用いた以外は、実施例１と同様に電子写真感光体を作製し、評価した。
【００７５】
（比較例１）
電気絶縁性バインダー樹脂を（Ｂ−２３）にかえた以外は、実施例１と同様にして電子写真感光体を作製し、評価した。
【００７６】
（比較例２）
電気絶縁性バインダー樹脂を（Ｂ−２２）にかえた以外は、実施例２と同様にして電子写真感光体を作製し、評価した。
評価結果を表１に示す。
【００７７】
【表１】

【００７８】
【発明の効果】
本発明により、耐キズ性および耐摩耗性の機械的強度が強く、かつ、接触帯電による放電に対する耐電気特性が良好であり、かつ、繰り返し安定性に優れた電子写真感光体を安価に提供することが可能となった。
【図面の簡単な説明】
【図１】 本発明の電子写真感光体を有する電子写真装置の概略構成の例を示す図である。
【符号の説明】
１ 電子写真感光体
２ 軸
３ 一次帯電手段
４ 露光光
５ 現像手段
６ 転写手段
７ 転写材
８ 像定着手段
９ クリーニング手段
１０ 前露光光
１１ プロセスカートリッジ
１２ レール[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus, and more particularly, a highly durable electrophotographic photosensitive member containing a specific charge transporting polymer having high mobility, and a process cartridge having the electrophotographic photosensitive member. And an electrophotographic apparatus.
[0002]
[Prior art]
Conventionally, as an electrophotographic photoreceptor, an inorganic electrophotographic photoreceptor having a photosensitive layer containing an inorganic photoconductive compound such as selenium, zinc oxide, cadmium sulfide as a main component has been widely used. However, these have problems such as heat stability, moisture resistance, durability, productivity, and safety.
[0003]
In order to overcome the drawbacks of inorganic electrophotographic photoreceptors, development of organic electrophotographic photoreceptors mainly composed of various organic photoconductive compounds has been actively conducted in recent years. For example, US Pat. No. 3,838,851 discloses an electrophotographic photosensitive member having a charge transport layer containing triallylpyrazoline. U.S. Pat. No. 3,871,880 discloses an electrophotographic photoreceptor having a charge generation layer made of a derivative of perylene pigment and a charge transport layer made of a condensation product of 3-propylene and formaldehyde.
[0004]
Furthermore, the organic photoconductive compound can freely select the photosensitive wavelength region of the electrophotographic photosensitive member depending on the compound. For example, as azo pigments, those having high sensitivity in the visible region are disclosed in JP-A Nos. 61-272754 and 56-167759. JP-A-57-19567 and JP-A-61-228453 disclose compounds having sensitivity up to the infrared region.
[0005]
Among these materials, those showing sensitivity in the infrared region are used in laser beam printers (hereinafter abbreviated as LBP) and LED printers that have made remarkable progress in recent years, and the frequency of demand thereof has increased.
[0006]
Electrophotographic photoreceptors using these organic photoconductive compounds are used as functionally separated electrophotographic photoreceptors in which a charge transport layer and a charge generation layer are laminated in order to satisfy both electrical and mechanical characteristics. There are many cases. As a matter of course, the electrophotographic photosensitive member is required to have sensitivity, electrical characteristics, and optical characteristics according to the applied electrophotographic process.
[0007]
In particular, in an electrophotographic photosensitive member that is repeatedly used, electrical and mechanical external forces such as corona or contact charging, image exposure, toner development, transfer process, and surface cleaning are directly applied to the surface of the electrophotographic photosensitive member. Therefore, durability against them is also required.
[0008]
Means for improving the wear resistance of the organic electrophotographic photoreceptor include a method of increasing the molecular weight of the binder resin, a method of adding a filler in the binder, or a siloxane structure or a fluorine-containing substituent in the binder resin structure. A method for reducing the friction coefficient with the cleaning blade by introducing a structure for imparting lubricity or adding a solid lubricant such as polytetrafluoroethylene (PTFE) is known. .
[0009]
In addition, the use of various binder resins with excellent mechanical strength has been proposed, but even if the binder resin itself has excellent mechanical strength, a low molecular weight charge transport material is used in combination, so the binder resin itself This film strength cannot be fully utilized, and sufficient durability in terms of wear resistance and scratch resistance has not been obtained. In order to make use of the inherent film strength of the binder resin, the amount of the charge transport material to be added may be reduced, but in that case, a problem arises that the electrophotographic sensitivity is lowered and the residual potential is increased, Neither film strength nor electrophotographic characteristics have been achieved at the same time.
[0010]
Further, the method of imparting lubricity to the photosensitive layer and reducing the coefficient of friction with the cleaning blade also causes a decrease in the film strength of the photosensitive layer, and sufficient durability cannot be obtained.
[0011]
On the other hand, in JP-A 64-9964, JP-A 2-282263, JP-A 3-221522, JP-A 8-208820, etc., there is a decrease in film strength due to the addition of a low molecular weight charge transport material. For the purpose of improvement, the use of charge transporting polymer compounds has been proposed, but many of these do not necessarily have sufficient wear resistance, even if they have a certain degree of film strength, The manufacturing cost is very high and it is not suitable for practical use.
[0012]
[Problems to be solved by the invention]
An object of the present invention is to solve the problems of the surface layer of a conventional electrophotographic photosensitive member, and to provide an electrophotographic material having high scratch resistance and abrasion resistance mechanical strength and excellent repeat stability. It is to provide a photoreceptor at low cost.
[0013]
[Means for Solving the Problems]
That is, the present invention relates to an electrophotographic photosensitive member having a support and a photosensitive layer formed on the support .
The surface layer of the electrophotographic photosensitive member has an electrically insulating binder resin and the following formula (1 ):
[0014]
[Outside 4]

(In formula (1), Ar ¹¹ and Ar ¹² each independently have a structure represented by the following formula (2).
[Outside 5]

(In the formula (2), Ar ²¹ and Ar ²² each independently represent a divalent aromatic ring group or heterocyclic group which may have a substituent. A ²¹ may have a substituent. X ²¹ represents a good alkylene group, amino group, azo group, sulfonyl group, oxygen atom or sulfur atom, X ²¹ may have a substituent, alkylene group, siloxane group, silylene group, carbonyl group, sulfonyl group, oxygen atom or .p representing a sulfur atom, q each represent 0 or 1 provided ^that, Ar ²¹ -. with respect to _(a 21) p ^{-Ar 22,} when the p = ^0, bonded directly that Ar 21 ^{-Ar 22} does not ^form, Ar ²¹ -. with respect to _(X 21) q ^{-Ar 22,} when the q = ^0, to form a direct bond that Ar 21 ^{-Ar 22)} Further, ^{Ar 13} and ^{Ar 14} are each independently In A substituted or unsubstituted aromatic ring group or a heterocyclic group. m represents 0 or 1, and n represents an integer of 4 or more. However, m + n ≧ 5. )
A polymer charge transport material having a structure represented by:
The electrically insulating binder resin has the same structure as Ar ¹¹ or Ar ^{12 in} the above formula (1) (provided that the aromatic ring group and the heterocyclic group of Ar ¹¹ and Ar ¹² have different substituents. )
An electrophotographic photosensitive member characterized by the above.
[0015]
The present invention also provides a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the aromatic ring group of Ar ¹³ and Ar ^{14 in} the above formula (1) include phenyl, naphthyl, anthryl, pyrenyl, fluorenyl, phenanthryl, etc., and examples of the heterocyclic group include quinolyl, dibenzocenyl, dibenzofuryl, Examples thereof include n-methyl carbazole, n-ethyl carbazole, and n-tolyl carbazole.
[0017]
As the aromatic ring group of Ar ²¹ and Ar ^{22 in} the above formula (2), a divalent aromatic group in which two hydrogen atoms are taken from an aromatic ring such as benzene, naphthalene, anthracene, perylene, fluorene, biphenyl, and terphenyl. Examples of the heterocyclic group include divalent heterocyclic groups in which two hydrogen atoms are taken from a heterocyclic ring such as carbazole, furan, benzofuran, thiophene, benzothiophene, quinoline, and phenazine. Examples of the alkylene group for A ²¹ include methylene, ethylene, and propylene groups. Examples of the alkylene group of X ²¹ include methylene, ethylene, and propylene groups, examples of the siloxane group include siloxane groups having 1 to 10 —SiO—, and examples of the silylene group include 1 Si. ˜4 silylene groups.
[0018]
The charge transporting polymer compound represented by the above formula (1) is more preferably a polymer having a structural unit represented by the following formula (3).
[Outside 6]

(In the formula (3), ^{Ar 13} and ^{Ar 14} has the same meaning as ^{Ar 13} and ^{Ar 14} in the formula (1), each independently represent a substituted or unsubstituted aromatic ring group or a heterocyclic group N ′ represents an integer of 3 or more, and R ^{301 to} R ³¹⁶ are a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or an amino group. Furthermore, R ³⁰² and R ³⁰⁵ , R ³¹⁰ and R ³¹³ are bonded to form a ring, or form a ring through an alkylene group, amino group, azo group, sulfonyl group, oxygen atom or sulfur atom. X ³¹ and X ³² each represents an optionally substituted alkylene group, siloxane group, silylene group, carbonyl group, sulfonyl group, oxygen atom, or sulfur atom, and r and s are each represented by 0 It represents 1.)
[0019]
Examples of the alkyl group of R ^{301 to} R ^{316 in} the above formula (3) include methyl, ethyl, propyl, etc., examples of the halogen atom include fluorine, chlorine, bromine, etc., examples of the alkoxy group include methoxy, Examples include ethoxy. ^{Examples of the} alkylene group that may be present when R ³⁰² and R ³⁰⁵ or R ³¹⁰ and R ³¹³ form a ring include alkylene groups having 1 or 2 carbon atoms.
[0020]
In the above formula (1), Ar ¹¹ and Ar ¹² , that is, the structure represented by the above formula (2) is preferably a structure represented by the following formula.
[Outside 7]

(Wherein, shows the R ¹ to R ³ is a hydrogen atom, which may have a an optionally substituted alkyl group or an optionally substituted aromatic ring group.)
[0021]
In the above formulas (1) to (3), Ar ^{11 to} Ar ¹⁴ , Ar ^{21 to} Ar ²² , A ²¹ , X ²¹ , X ³¹ , X ³² , R ^{301 to} R ³¹⁶ may have a substituent. Alkyl groups such as methyl, ethyl, propyl and butyl, alkoxy groups such as methoxy, ethoxy and propoxy, aryloxy groups such as phenoxy and naphthoxy, halogen atoms such as fluorine, chlorine and bromine, dimethylamino and diethylamino And di-substituted amino groups such as diphenylamino.
[0022]
Specific examples of the polymer charge transport material used in the present invention are shown below, but the present invention is not limited thereto.
[0023]
Among the following specific examples, CT-14, CT-24, CT-25, CT-28, and CT-30 are preferable, and CT-24 and CT-25 are more preferable.
[Outside 8]

[0024]
[Outside 9]

[0025]
[Outside 10]

[0026]
[Outside 11]

[0027]
[Outside 12]

[0028]
[Outside 13]

[0029]
[Outside 14]

[0030]
[Outside 15]

[0031]
[Outside 16]

[0032]
[Outside 17]

[0033]
[Outside 18]

[0034]
[Outside 19]

[0035]
[Outside 20]

[0036]
[Outside 21]

[0037]
[Outside 22]

[0038]
In the present invention, among the electrically insulating binder resins, polycarbonate resins and polyarylate resins are preferable from the viewpoint of mechanical strength.
[0039]
Specific examples of the electrically insulating binder resin used in the present invention are shown below, but the present invention is not limited thereto. Among the following specific examples, B-2, B-6, B-23, B-24, and B-37 are preferable, and B-6 and B-24 are more preferable.
[Outside 23]

[0040]
[Outside 24]

[0041]
[Outside 25]

[0042]
In the charge transport layer according to the present invention, since the charge transport material has a high molecular weight, the decrease in the film strength of the resin due to the addition of the charge transport material is small, and the scratch resistance and abrasion resistance are excellent. Furthermore, since the polymer charge transport material and the insulating resin binder have the same partial structure, a uniform film can be formed without causing phase separation.
[0043]
The content ratio (D / B) of the electrically insulating binder resin (B) and the polymer charge transport material (D) is preferably 0.09 or more and 1.0 or less (mass ratio).
[0044]
The same structure possessed by the polymer charge transporting material of the present invention and the electrically insulating binder resin indicates that the basic skeleton of the aromatic ring group or heterocyclic group that Ar ¹¹ or Ar ¹² can take is the same. The substituents may be different.
[0045]
The electrically insulating binder resin preferably contains 30 mol% or more of a repeating structural unit having the same structure as that of the polymer charge transporting material based on the entire electrically insulating binder resin. More preferably, it is 50 mol% or more, More preferably, it is 70 mol% or more.
[0046]
In the electrophotographic photosensitive member of the present invention, the polymer charge transport material according to the present invention may be one type or two or more different types.
[0047]
Furthermore, you may mix and use the existing low molecular charge transport material. However, in this case, the polymer charge transport material of the present invention is preferably present in an amount of 60 mol% or more.
[0048]
Hereinafter, the configuration of the electrophotographic photoreceptor used in the present invention will be described.
The electrophotographic photoreceptor of the present invention contains a charge generation layer containing a charge generation material and a charge transport material, even if the photosensitive layer is a single layer type containing a charge generation material and a charge transport material in the same layer. However, from the viewpoint of electrophotographic characteristics, a stacked type is preferable, and a normal stack type in which a charge generation layer and a charge transport layer are stacked in this order is more preferable.
[0049]
The support to be used may be any one having conductivity, and examples thereof include metals such as aluminum and stainless steel, metals provided with a conductive layer, paper, plastics, etc., and examples of the shape include sheets and cylinders.
[0050]
When the image input such as LBP is laser light, a conductive layer may be provided for the purpose of preventing interference fringes due to scattering or covering a scratch on the substrate. This can be formed by dispersing conductive particles such as carbon black and metal particles in a binder resin. The thickness of the conductive layer is preferably 5 to 40 μm, more preferably 10 to 30 μm.
[0051]
An intermediate layer having an adhesive function may be provided thereon. Examples of the material for the intermediate layer include polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane, and polyether urethane. These are dissolved in an appropriate solvent and applied. The thickness of the intermediate layer is preferably 0.05 to 5 μm, more preferably 0.3 to 1 μm.
A photosensitive layer is formed on them. In the case of the forward lamination type, it is a charge generation layer.
[0052]
Examples of the charge generation material used in the present invention include selenium-tellurium, pyrylium, thiapyrylium dyes, phthalocyanine, anthanthrone, dibenzpyrenequinone, trisazo, cyanine, disazo, monoazo, indigo, quinacridone, and asymmetric quinocyanine pigments. It is done. In the case of a laminated type, the charge generation layer is composed of the charge generation material 0.3 to 4 times the amount of binder resin and solvent, homogenizer, ultrasonic dispersion, ball mill, vibration ball mill, sand mill, attritor, roll mill, and liquid collision type. It is well dispersed by a method such as a high-speed disperser, and is formed by applying and drying the dispersion. The film thickness of the charge generation layer is 5 μm or less, preferably 0.1 to 2 μm.
[0053]
The charge transport layer is mainly formed by applying and drying a paint in which the electrically insulating binder resin of the present invention and the charge transport material are dissolved in a solvent. The charge transport material is combined with 0.5 to 2 times the amount of the binder resin, coated and dried to form a charge transport layer. The thickness of the charge transport layer is preferably 5 to 40 μm, and more preferably 15 to 30 μm.
[0054]
In the present invention, the charge transport material and the resin may be partially reacted in advance to give a siloxane bond. In this case, any solution or dispersion that does not hinder the application to the electrophotographic photoreceptor can be used.
[0055]
In addition, a catalyst is not necessarily required for the crosslinking and curing of the charge transporting material and the binder resin, but alkyltins such as dibutyltin diacetate, dibutyltin diurarate, and dibutyltin ocumaate are considered in consideration of the time required for curing and the curing temperature. It is appropriately selected from organic titanates such as organic acid salts and normal butyl titanates.
[0056]
FIG. 1 shows a schematic configuration of an electrophotographic apparatus having the electrophotographic photosensitive member of the present invention.
In the figure, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is rotated about a shaft 2 in the direction of an arrow at a predetermined peripheral speed. In the rotation process, the photosensitive member 1 is uniformly charged with a positive or negative predetermined potential on its peripheral surface by the primary charging unit 3, and then exposed from an exposure unit (not shown) such as slit exposure or laser beam scanning exposure. Receive light 4. In this way, electrostatic latent images are sequentially formed on the peripheral surface of the photoreceptor 1.
[0057]
The formed electrostatic latent image is then developed with toner by the developing unit 5, and the developed toner developed image is rotated between the photoconductor 1 and the transfer unit 6 from a paper supply unit (not shown). Are sequentially transferred by the transfer means 6 to the transfer material 7 taken out in synchronization with and fed.
[0058]
The transfer material 7 that has received the image transfer is separated from the surface of the photosensitive member, introduced into the image fixing means 8, and subjected to image fixing, thereby being printed out as a copy (copy).
[0059]
After the image transfer, the surface of the photoreceptor 1 is cleaned by removing the transfer residual toner by the cleaning unit 9, and is further subjected to charge removal processing by the pre-exposure light 10 from the pre-exposure unit (not shown). Used repeatedly for image formation. As shown in the figure, when the primary charging unit 3 is a contact charging unit using a charging roller or the like, pre-exposure is not necessarily required.
[0060]
In the present invention, a plurality of components such as the above-described electrophotographic photosensitive member 1, primary charging unit 3, developing unit 5, and cleaning unit 9 are integrally coupled as a process cartridge. May be configured to be detachable from an electrophotographic apparatus main body such as a copying machine or a laser beam printer. For example, at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported with the photosensitive member 1 to form a cartridge, and can be attached to and detached from the apparatus main body using guide means such as a rail 12 of the apparatus main body. The process cartridge 11 can be obtained.
[0061]
Further, when the electrophotographic apparatus is a copying machine or a printer, the exposure light 4 is a reflected light or transmitted light from the original, or the original is read by a sensor and converted into a signal, and a laser beam performed in accordance with this signal. The light is emitted by scanning, driving the LED array, driving the liquid crystal shutter array, and the like.
[0062]
The electrophotographic photosensitive member of the present invention can be used not only in electrophotographic copying machines but also widely in electrophotographic application fields such as laser beam printers, CRT printers, LED printers, liquid crystal printers, and laser plate making.
[0063]
The effect of the present invention is that the electrophotographic process speed (the process of charging the electrophotographic photosensitive member and cleaning the surface of the photosensitive member after latent image formation by exposure, development with toner, transfer to paper, etc.) is effective. It appears remarkably in a system having a high operating speed (135 mm / s or more) and a system using a cleaning blade as a cleaning means.
[0064]
Moreover, the weight average molecular weight (Mw) was shown by the value shown by standard polystyrene conversion using the gel permeation chromatography apparatus HLC8120GPC (Tosoh Corporation).
[0065]
【Example】
Hereinafter, it demonstrates according to an Example. “Part” means part by mass.
[0066]
Example 1
An aluminum cylinder having a diameter of 30 mm and a length of 357.5 mm is used as a support, and a coating material composed of the following materials is applied on the support by a dipping method, and is thermally cured at 140 ° C. for 30 minutes to form an 18 μm conductive layer. Formed.
Conductive pigment: SnO ₂ coated barium sulfate 10 parts Resistance adjusting pigment: Titanium oxide 2 parts Binder resin: Phenol resin 6 parts Leveling material: Silicone oil 0.001 part Solvent: Methanol, methoxypropanol 0.2 / 0.8 20 copies [0067]
Next, a solution prepared by dissolving 3 parts of N-methoxymethylated nylon and 3 parts of copolymer nylon in a mixed solvent of 65 parts of methanol and 30 parts of n-butanol was applied by an immersion method to form a 0.6 μm intermediate layer.
[0068]
Next, strong peaks at 7.5 °, 9.9 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction After 4 parts of hydroxygallium phthalocyanine having 2 parts, 2 parts of polyvinyl butyral (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 60 parts of cyclohexanone were dispersed in a sand mill using glass beads having a diameter of 1 mm for 4 hours, ethyl acetate 100 Part was added to prepare a dispersion for charge generation layer. This was applied by a dipping method to form a 0.2 μm charge generation layer.
[0069]
Next, the synthesized according to Synthesis Example and charge transporting material (CT- 5) 4 parts of electrically insulating binder resin ((B- 23) / (B- 24), the copolymerization ratio of 60/40) mono and 10 parts of Dissolved in a mixed solvent of 30 parts of chlorobenzene and 70 parts of dichloromethane.
This paint was applied by an immersion method and dried at 120 ° C. for 2 hours to form a 25 μm charge transport layer.
Thus, an electrophotographic photosensitive member was produced.
[0070]
Next, evaluation will be described.
The apparatus used was a modified LBP-950 (process speed 144.5 mm / s) manufactured by Canon Inc. In the modification, the primary charging control was changed from constant current control to constant voltage control, and the peak-to-peak voltage was increased by 20%. The produced electrophotographic photoreceptor was subjected to paper passing durability at 28 ° C. and 90% RH (H / H) with this apparatus. The sequence was an intermittent mode that stopped once for each printed sheet. If the toner runs out, it is replenished and it lasts until there is a problem with the image.
[0071]
First, it was worn for 25 minutes using a Taber abrasion tester using an abrasive tape, and the weight loss at that time was measured.
[0072]
Also, illuminate 3000 lux for 30 minutes with a white fluorescent light on a part of the electrophotographic photosensitive member, measure the light part potential after leaving it for 4 minutes, and measure how much the light part potential has dropped before the light was applied. Photo memory values were used.
[0073]
Further, the solvent cracking property was obtained by attaching finger grease to the surface and leaving it for 72 hours, and observing the presence or absence of the solvent crack by microscopic observation.
[0074]
(Examples 2 to 10 )
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the charge transport material and the electrically insulating binder resin of the charge transport layer were those shown in Table 1.
[0075]
(Comparative Example 1 )
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the electrically insulating binder resin was changed to (B-23).
[0076]
(Comparative Example 2 )
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 2 except that the electrically insulating binder resin was changed to (B-22).
The evaluation results are shown in Table 1.
[0077]
[Table 1]

[0078]
【The invention's effect】
According to the present invention, an electrophotographic photosensitive member having high scratch resistance and abrasion resistance mechanical strength, good electric resistance against discharge by contact charging, and excellent repeat stability is provided at low cost. It became possible.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus having an electrophotographic photosensitive member of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 2 Axis 3 Primary charging means 4 Exposure light 5 Developing means 6 Transfer means 7 Transfer material 8 Image fixing means 9 Cleaning means 10 Pre-exposure light 11 Process cartridge 12 Rail

Claims (6)

In an electrophotographic photoreceptor having a support and a photosensitive layer formed on the support ,
The surface layer of the electrophotographic photosensitive member has an electrically insulating binder resin and the following formula (1 ):
[ Outside 1]

(In formula (1), Ar ¹¹ and Ar ¹² each independently have a structure represented by the following formula (2).
[Outside 2]

(In the formula (2), Ar ²¹ and Ar ²² each independently represent a divalent aromatic ring group or heterocyclic group which may have a substituent. A ²¹ may have a substituent. X ²¹ represents a good alkylene group, amino group, azo group, sulfonyl group, oxygen atom or sulfur atom, X ²¹ may have a substituent, alkylene group, siloxane group, silylene group, carbonyl group, sulfonyl group, oxygen atom or .p representing a sulfur atom, q each represent 0 or 1 provided ^that, Ar ²¹ -. with respect to _(a 21) p ^{-Ar 22,} when the p = ^0, bonded directly that Ar 21 ^{-Ar 22} does not ^form, Ar ²¹ -. with respect to _(X 21) q ^{-Ar 22,} when the q = ^0, to form a direct bond that Ar 21 ^{-Ar 22)} Further, ^{Ar 13} and ^{Ar 14} are each independently In A substituted or unsubstituted aromatic ring group or a heterocyclic group. m represents 0 or 1, and n represents an integer of 4 or more. However, m + n ≧ 5. )
A polymer charge transport material having a structure represented by:
The electrically insulating binder resin has the same structure as Ar ¹¹ or Ar ^{12 in} the above formula (1) (provided that the aromatic ring group and the heterocyclic group of Ar ¹¹ and Ar ¹² have different substituents. )
An electrophotographic photosensitive member characterized by the above. The electrophotographic photosensitive member according to claim 1, wherein at least one of the structures represented by the formula (2) in the formula (1) is selected from the following structural group.
[Outside 3]

(Wherein, shows the R ¹ to R ³ is a hydrogen atom, which may have a an optionally substituted alkyl group or an optionally substituted aromatic ring group.)   The electrophotographic photosensitive member according to claim 1, wherein the electrically insulating binder resin is a polyarylate resin. The content ratio of the electrically insulating binder resin (B) and the polymer charge-transporting material (D) (D / B) is, according to any one of claims 1 to 3, 0.09 to 1.0 Electrophotographic photoreceptor. An electrophotographic photosensitive member according to any one of claims 1-4, charging means, and at least one means selected from the group consisting of the developing means and the cleaning means integrally supported, detachably attached to an electrophotographic apparatus main body Process cartridge characterized by being. The electrophotographic photosensitive member according to any one of claims 1-4, a charging means, an exposure means, the electrophotographic apparatus, characterized in that it comprises a developing means and transfer means.

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