JP4115056B2 - Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus - Google Patents

Description

【００２３】
表中、Ｒは置換基を有してもよいメチル基、エチル基、プロピル基及びブチル基等のアルキル基、置換基を有しても良いベンジル基、フェネチル基、ナフチルメチル基、フルフリル基及びチエニル基等のアラルキル基、置換基を有しても良いフェニル基、ナフチル基及びアンスリル基等のアリール基又は水素原子を示す。
【００２４】
開環重合とは、炭素環、オクソ環及び窒素ヘテロ環等のひずみを有した不安定な環状構造が触媒の作用で活性化され、開環すると同時に重合を繰り返し鎖状高分子物を生成する反応であるが、この場合、基本的にはイオンが活性種として作用するものが大部分である。開環重合性官能基の具体例を表２に示すがこれらに限定されるものではない。
【００２５】
【表２】

【００２６】
表中、Ｒは置換基を有してもよいメチル基、エチル基、プロピル基及びブチル基等のアルキル基、置換基を有しても良いベンジル基、フェネチル基、ナフチルメチル基、フルフリル基及びチエニル基等のアラルキル基、置換基を有しても良いフェニル基、ナフチル基及びアンスリル基等のアリール基又は水素原子を示す。
【００２７】
上記で説明したような本発明に係わる連鎖重合性官能基の中でも、下記の一般式（６）、（１４）及び（１５）で示されるものが好ましい。
【００２８】
【化８】

【００２９】
式中、Ｅは水素原子、フッ素、塩素及び臭素等のハロゲン原子、置換基を有してもよいメチル基、エチル基、プロピル基及びブチル基等のアルキル基、置換基を有してもよいベンジル基、フェネチル基、ナフチルメチル基、フルフリル基及びチエニル基等のアラルキル基、置換基を有してもよいフェニル基、ナフチル基、アンスリル基、ピレニル基、チオフェニル基及びフリル基等のアリール基、メトキシ基、エトキシ基及びプロポキシ基等のアルコキシ基、ＣＮ基、ニトロ基、−ＣＯＯＲ¹³又は−ＣＯＮＲ¹⁴Ｒ¹⁵を示す。
【００３０】
Ｗは置換基を有しても良いフェニレン基、ナフチレン基及びアントラセニレン基等のアリーレン基、置換基を有しても良いメチレン基、エチレン基及びブチレン等のアルキレン基、−ＣＯＯ−、−ＣＨ₂−、−Ｏ−、−ＯＯ−、−Ｓ−又は−ＣＯＮＲ¹⁶−で示される。
【００３１】
Ｒ¹³、Ｒ¹⁴、Ｒ¹⁵及びＲ¹⁶は水素原子、フッ素、塩素、臭素及びヨウ素等のハロゲン原子、置換基を有してもよいメチル基、エチル基、プロピル基及びブチル基等のアルキル基、置換基を有してもよいベンジル基及びフェネチル基等のアラルキル基又は置換基を有してもよいフェニル基、ナフチル基及びアンスリル基等のアリール基を示し、Ｒ¹⁴とＲ¹⁵は互いに同一であっても異なっても良い。また、ｆは０又は１を示す。
【００３２】
Ｅ及びＷ中で有してもよい置換基としては、フッ素、塩素、臭素及びヨウ素等のハロゲン原子；ニトロ基、シアノ基、水酸基；メチル基、エチル基、プロピル基及びブチル基等のアルキル基；メトキシ基、エトキシ基及びプロポキシ基等のアルコキシ基；フェノキシ基及びナフトキシ基等のアリールオキシ基；ベンジル基、フェネチル基、ナフチルメチル基、フルフリル基及びチエニル基等のアラルキル基；又はフェニル基、ナフチル基、アンスリル基及びピレニル基等のアリール基等が挙げられる。
【００３３】
【化９】

【００３４】
式中、Ｒ¹⁷及びＲ¹⁸は水素原子、置換基を有してもよいメチル基、エチル基、プロピル基及びブチル基等のアルキル基、置換基を有してもよいベンジル基及びフェネチル基等のアラルキル基、又は置換基を有してもよいフェニル基及びナフチル基等のアリール基を示し、ｎは１〜１０の整数を示す。
【００３５】
【化１０】

式中、Ｒ¹⁹及びＲ²⁰は水素原子、置換基を有してもよいメチル基、エチル基、プロピル及びブチル基等のアルキル基、置換基を有してもよいベンジル基及びフェネチル基等のアラルキル基、又は置換基を有してもよいフェニル基及びナフチル基等のアリール基を示し、ｎは０〜１０の整数を示す。
【００３６】
なお、上記一般式の（１４）及び（１５）のＲ¹⁷、Ｒ¹⁸、Ｒ¹⁹及びＲ²⁰が有してもよい置換基としてはフッ素、塩素、臭素及びヨウ素等のハロゲン原子；メチル基、エチル基、プロピル基及びブチル基等のアルキル基；メトキシ基、エトキシ基及びプロポキシ基等のアルコキシ基；フェノキシ基及びナフトキシ基等のアリールオキシ基；ベンジル基、フェネチル基、ナフチルメチル基、フルフリル基及びチエニル基等のアラルキル基；又はフェニル基、ナフチル基、アンスリル基及びピレニル基等のアリール基等が挙げられる。
【００３７】
また、上記一般式（６）、（１４）及び（１５）の中でも、更に好ましい連鎖重合性官能基としては、下記一般式（７）〜一般式（１３）で示されるものが挙げられる。
【００３８】
【化１１】

【００３９】
更に、上記一般式（７）〜一般式（１３）の中でも、一般式（７）のアクリロイルオキシ基及び一般式（８）のメタクリロイルオキシ基が、重合特性等の点から特に一番好ましい。
【００４０】
次に、本発明における正孔輸送性材料について説明する。
【００４１】
本発明で『連鎖重合性官能基を有する正孔輸送性化合物』とは、上記で説明した連鎖重合性官能基が下記で説明する正孔輸送性化合物に官能基として好ましくは２つ以上の化学結合している化合物を示す。この場合、それらの連鎖重合性官能基は、全て同一でも異なったものであってもよい。
【００４２】
それらの連鎖重合性官能基を２つ以上有する正孔輸送性化合物としては、下記一般式（１）である場合が好ましい。
【００４３】
【化１２】

【００４４】
式中、Ａは正孔輸送性基を示す。Ｐ¹及びＰ²は連鎖重合性官能基を示す。Ｐ¹とＰ²は同一でも異なっても良い。Ｚは置換基を有しても良い有機基を示す。ａ、ｂ及びｄは０以上の整数を示し、ａ＋ｂ×ｄは２以上の整数を示す。また、ａが２以上の場合Ｐ¹は同一でも異なってもよく、ｄ が２以上の場合、Ｚ及びＰ²は同一でも異なってもよい。
【００４５】
なおここで、『ａが２以上の場合Ｐ¹は同一でも異なっても良く』とは、それぞれ異なるｎ種類の連鎖重合性官能基をＰ¹¹、Ｐ¹²、Ｐ¹³、Ｐ¹⁴、Ｐ¹⁵・・・・Ｐ¹ⁿと示した場合、例えばａ＝３のとき正孔輸送性化合物Ａに直接結合する重合性官能基Ｐ¹は３つとも同じものでも、２つ同じで１つは違うもの（例えば、Ｐ¹¹とＰ¹¹とＰ¹²とか）でも、それぞれ３つとも異なるもの（例えば、Ｐ¹²とＰ¹⁵とＰ¹⁷とか）でも良いということを意味するものである（『ｄが２以上の場合Ｐ²は同一でも異なっても良く』というのも、『ｂが２以上の場合、Ｚ及びＰ²は同一でも異なっても良い』というのもこれと同様なことを意味するものである）。
【００４６】
上記一般式（１）のＡとＰ¹やＺとの結合部位を水素原子に置き換えた正孔輸送化合物は、例えば、オキサゾール誘導体、オキサジアゾール誘導体、イミダゾール誘導体、トリフェニルアミン等のトリアリールアミン誘導体、９−（ｐ−ジエチルアミノスチリル）アントラセン、１，１−ビス−（４−ジベンジルアミノフェニル）プロパン、スチリルアントラセン、スチリルピラゾリン、フェニルヒドラゾン類、チアゾール誘導体、トリアゾール誘導体、フェナジン誘導体、アクリジン誘導体、ベンゾフラン誘導体、ベンズイミダゾール誘導体、チオフェン誘導体及びＮ−フェニルカルバゾール誘導体等が挙げられる。
【００４７】
更に、上記正孔輸送化合物の中でも、下記一般式（４）、（５）、（１６）、（１７）及び（１９）から選ばれる式で示される化合物、あるいは下記一般式（１８）で示される基を有する縮合環炭化水素又は下記一般式（１８）で示される基を有する縮合複素環であるものが好ましい。更に、その中でも、一般式（４）及び（５）で示される化合物である場合が特に好ましい。
【００４８】
【化１３】

【００４９】
上記一般式（４）中、Ｒ⁶、Ｒ⁷及びＲ⁸は置換基を有してもよいメチル基、エチル基、プロピル基及びブチル基等の炭素数１０以下のアルキル基、置換基を有してもよいベンジル基、フェネチル基、ナフチルメチル基、フルフリル基及びチエニル基等のアラルキル基又は置換基を有してもよいフェニル基、ナフチル基、アンスリル基、フェナンスリル基、ピレニル基、チオフェニル基、フリル基、ピリジル基、キノリル基、ベンゾキノリル基、カルバゾリル基、フェノチアジニル基、ベンゾフリル基、ベンゾチオフェニル基、ジベンゾフリル基及びジベンゾチオフェニル基等のアリール基を示す。
【００５０】
但し、Ｒ⁶、Ｒ⁷及びＲ⁸のうち少なくとも２つはアリール基を示し、Ｒ⁶、Ｒ⁷及びＲ⁸はそれぞれ同一であっても異なっていてもよい。更に、その中でもＲ⁶、Ｒ⁷及びＲ⁸の全てがアリール基であるものが特に好ましい。また、上記一般式（４）のＲ⁶又はＲ⁷又はＲ⁸のうち任意の２つはそれぞれ直接もしくは結合基を介して結合しても良く、その結合基としては、メチレン基、エチレン基及びプロピレン基等のアルキレン基、酸素原子及び硫黄原子等のヘテロ原子又はＣＨ＝ＣＨ基等が挙げられる。
【００５１】
【化１４】

【００５２】
上記一般式（５）中、ｍ⁴は０又は１を示し、ｍ⁴＝１である場合が好ましい。Ｒ⁹〜Ｒ¹²は置換基を有してもよいメチル基、エチル基、プロピル基及びブチル基等の炭素数１０以下のアルキル基、置換基を有してもよいベンジル基、フェネチル基、ナフチルメチル基、フルフリル基及びチエニル基等のアラルキル基又は置換基を有してもよいフェニル基、ナフチル基、アンスリル基、フェナンスリル基、ピレニル基、チオフェニル基、フリル基、ピリジル基、キノリル基、ベンゾキノリル基、カルバゾリル基、フェノチアジニル基、ベンゾフリル基、ベンゾチオフェニル基、ジベンゾフリル基及びジベンゾチオフェニル基等のアリール基を示し、Ｒ⁹〜Ｒ¹²はそれぞれ同一でも異なっていてもよい。
【００５３】
Ａｒ⁴は置換基を有しても良いアリーレン基（ベンゼン、ナフタレン、アントラセン、フェナンスレン、ピレン、チオフェン、フラン、ピリジン、キノリン、ベンゾキノリン、カルバゾール、フェノチアジン、ベンゾフラン、ベンゾチオフェン、ジベンゾフラン、ジベンゾチオフェン等より２個の水素原子を取り除いた基）を示し、Ａｒ⁵はｍ⁴＝０の場合、フェニル基、ナフチル基、アンスリル基、フェナンスリル基、ピレニル基、チオフェニル基、フリル基、ピリジル基、キノリル基、ベンゾキノリル基、カルバゾリル基、フェノチアジニル基、ベンゾフリル基、ベンゾチオフェニル基、ジベンゾフリル基及びジベンゾチオフェニル基等のアリール基を示し、ｍ⁴＝１の場合は上記Ａｒ¹と同様なアリーレン基を示す。なお、ｍ⁴＝１の場合は、Ａｒ⁴とＡｒ⁵は同一であっても異なっても良い。
【００５４】
更にその中でも、上記一般式（５）中のＲ⁹〜Ｒ¹²が４つとも全てアリール基である場合が特に好ましい。また、上記一般式（５）のＲ⁹とＲ¹⁰又はＲ¹¹とＲ¹²又はＡｒ⁴とＡｒ⁵は、それぞれ直接もしくは結合基を介して結合しても良く、その結合基としては、メチレン基、エチレン基及びプロピレン基等のアルキレン基、カルボニル基、酸素原子及び硫黄原子等のヘテロ原子又はＣＨ＝ＣＨ基等が挙げられるが、これらの中ではアルキレン基が好ましい。
【００５５】
【化１５】

【００５６】
上記一般式（１６）中、Ｒ²¹、Ｒ²²、Ｒ²³及びＲ²⁴は置換基を有してもよいメチル基、エチル基、プロピル基及びブチル基等の炭素数１０以下のアルキル基、置換基を有してもよいベンジル基、フェネチル基、ナフチルメチル基、フルフリル基及びチエニル基等のアラルキル基又は置換基を有してもよいフェニル基、ナフチル基、アンスリル基、フェナンスリル基、ピレニル基、チオフェニル基、フリル基、ピリジル基、キノリル基、ベンゾキノリル基、カルバゾリル基、フェノチアジニル基、ベンゾフリル基、ベンゾチオフェニル基、ジベンゾフリル基及びジベンゾチオフェニル基等のアリール基を示し、Ｒ²¹、Ｒ²²、Ｒ²³及びＲ²⁴はそれぞれ同一でも異なっていてもよい。Ｒ²⁵及びＲ²⁶は置換基を有しても良いメチレン基、エチレン基及びプロピレン基等の炭素数１０以下のアルキレン基、又は置換基を有しても良いアリーレン基（ベンゼン、ナフタレン、アントラセン、フェナンスレン、ピレン、チオフェン、フラン、ピリジン、キノリン、ベンゾキノリン、カルバゾール、フェノチアジン、ベンゾフラン、ベンゾチオフェン、ジベンゾフラン、ジベンゾチオフェン等より２個の水素原子を取り除いた基）を示し、Ｒ²⁵及びＲ²⁶は同一であっても異なっていても良い。Ｑは置換基を有しても良い有機基を示す。
【００５７】
更にその中でも、上記一般式（１６）中のＲ²¹、Ｒ²²、Ｒ²³及びＲ²⁴のうち少なくとも２つが置換基を有しても良いアリール基であり、かつＲ²⁵及びＲ²⁶が置換基を有しても良いアリーレン基である場合が好ましく、更にＲ²¹、Ｒ²²、Ｒ²³及びＲ²⁴が４つとも全て置換基を有しても良いアリール基である場合が特に好ましい。また、上記一般式（１６）のＲ²¹、Ｒ²²及びＲ²⁵のうち任意の２つあるいはＲ²³、Ｒ²⁴及びＲ²⁶のうち任意の２つはそれぞれ直接もしくは結合基を介して結合しても良く、その結合基としては、メチレン基、エチレン基及びプロピレン基等のアルキレン基、酸素原子及び硫黄原子等のヘテロ原子又はＣＨ＝ＣＨ基等が挙げられる。
【００５８】
【化１６】

【００５９】
但し上記一般式（１７）中、Ｒ²⁷、Ｒ²⁸及びＡｒ⁶のうち少なくとも一つは、下記一般式（１８）で示される基を少なくとも一つ有する。
【００６０】
【化１７】

【００６１】
上記一般式（１７）及び（１８）中、Ａｒ⁶及びＡｒ⁷は置換基を有してもよいフェニル基、ナフチル基、アンスリル基、フェナンスリル基、ピレニル基、チオフェニル基、フリル基、ピリジル基、キノリル基、ベンゾキノリル基、カルバゾリル基、フェノチアジニル基、ベンゾフリル基、ベンゾチオフェニル基、ジベンゾフリル基及びジベンゾチオフェニル基等のアリール基を示し、Ｒ²⁷、Ｒ²⁸、Ｒ²⁹及びＲ³⁰は置換基を有してもよいメチル基、エチル基、プロピル基及びブチル基等の炭素数１０以下のアルキル基、置換基を有してもよいベンジル基、フェネチル基、ナフチルメチル基、フルフリル基及びチエニル基等のアラルキル基、置換基を有してもよいフェニル基、ナフチル基、アンスリル基、フェナンスリル基、ピレニル基、チオフェニル基、フリル基、ピリジル基、キノリル基、ベンゾキノリル基、カルバゾリル基、フェノチアジニル基、ベンゾフリル基、ベンゾチオフェニル基、ジベンゾフリル基及びジベンゾチオフェニル基等のアリール基を示し、Ｒ²⁹及びＲ³⁰はこれらのアルキル基、アラルキル基及びアリール基に加え水素原子を示す。更に、Ｒ²⁷とＲ²⁸及びＲ²⁹とＲ³⁰はそれぞれ同一であっても異なっていてもよい。
【００６２】
また、Ｒ²⁷又はＲ²⁸又はＡｒ⁶のうち任意の２つ、又はＡｒ⁷及びＲ³⁰はそれぞれ直接もしくは結合基を介して結合しても良く、その結合基としては、メチレン基、エチレン基及びプロピレン基等のアルキレン基、酸素原子及び硫黄原子等のヘテロ原子又はＣＨ＝ＣＨ基等が挙げられる。ｎ¹は０〜２の整数を示す。なお、その中でもＲ³⁰がアリール基である場合が好ましく、更にＲ²⁷とＲ²⁸がアリール基である場合が特に好ましい。
【００６３】
更に、上記一般式（１８）で示される基を有する化合物としては、置換基を有してもよい、ナフタレン基、アントラセン基、フェナンスレン基、ペレン基、フルオレン基、フルオランセン基、アズレン基、インデン基、ペリレン基、クリセン基及びコロネン基等の縮合環炭化水素又は置換基を有しても良いベンゾフラン基、インドール基、カルバゾール基、ベンズカルバゾール基、アクリジン基、フェノチアジン基及びキノリン基等の縮合複素環が挙げられる。
【００６４】
【化１８】

【００６５】
但し、上記一般式（１９）は、下記一般式（２０）で示される基を少なくとも一つ有する。
【００６６】
【化１９】

【００６７】
上記一般式（１９）及び（２０）中、Ａｒ⁸、Ａｒ⁹及びＡｒ¹⁰は置換基を有してもよいフェニル基、ナフチル基、アンスリル基、フェナンスリル基、ピレニル基、チオフェニル基、フリル基、ピリジル基、キノリル基、ベンゾキノリル基、カルバゾリル基、フェノチアジニル基、ベンゾフリル基、ベンゾチオフェニル基、ジベンゾフリル基及びジベンゾチオフェニル基等のアリール基を示し、Ｒ³¹、Ｒ³²及びＲ³³は置換基を有してもよいメチル基、エチル基、プロピル基及びブチル基等の炭素数１０以下のアルキル基、置換基を有してもよいベンジル基、フェネチル基、ナフチルメチル基、フルフリル基及びチエニル基等のアラルキル基、置換基を有してもよいフェニル基、ナフチル基、アンスリル基、フェナンスリル基、ピレニル基、チオフェニル基、フリル基、ピリジル基、キノリル基、ベンゾキノリル基、カルバゾリル基、フェノチアジニル基、ベンゾフリル基、ベンゾチオフェニル基、ジベンゾフリル基及びジベンゾチオフェニル基等のアリール基を示し、Ｒ³²及びＲ³³はこれらのアルキル基、アラルキル基及びアリール基に加え水素原子を示す。なお、Ａｒ⁸及びＡｒ⁹とＲ³²とＲ³³はそれぞれ同一であっても異なっていてもよい。
【００６８】
その中でも、Ｒ³¹及びＲ³²がアリール基である場合が好ましい。また、Ｒ³¹、Ａｒ⁸又はＡｒ⁹のうち任意の２つ、又はＡｒ¹⁰及びＲ³³はそれぞれ直接もしくは結合基を介して結合しても良く、その結合基としては、メチレン基、エチレン基及びプロピレン基等のアルキレン基、酸素原子及び硫黄原子等のヘテロ原子又はＣＨ＝ＣＨ基等が挙げられる。ｎ²は０〜２の整数を示す。
【００６９】
また、上記一般式（１）中のＺ及び上記一般式（１６）中のＱは置換基を有してもよいアルキレン基、置換基を有してもよいアリーレン基、ＣＲ¹＝ＣＲ²（Ｒ¹及びＲ²はアルキル基、アリール基又は水素原子を示し、Ｒ¹及びＲ²は同一でも異なっても良い）、Ｃ＝Ｏ、Ｓ＝Ｏ、ＳＯ₂、酸素原子又は硫黄原子より一つあるいは任意に組み合わされた有機基を示す。その中でも下記一般式（２）で示されるものが好ましく、下記一般式（３）で示されるものが特に好ましい。
【００７０】
【化２０】

【００７１】
【化２１】

【００７２】
上記一般式（２）中、Ｘ¹〜Ｘ³は置換基を有してもよいメチレン基、エチレン基及びプロピレン基等の炭素数２０以下のアルキレン基、（ＣＲ³＝ＣＲ⁴）_m1、Ｃ＝Ｏ、Ｓ＝Ｏ、ＳＯ₂、酸素原子又は硫黄原子を示し、Ａｒ¹及びＡｒ²は置換基を有してもよいアリーレン基（ベンゼン、ナフタレン、アントラセン、フェナンスレン、ピレン、チオフェン、フラン、ピリジン、キノリン、ベンゾキノリン、カルバゾール、フェノチアジン、ベンゾフラン、ベンゾチオフェン、ジベンゾフラン、ジベンゾチオフェン等より２個の水素原子を取り除いた基）を示す。Ｒ³及びＲ⁴は置換基を有してもよいメチル基、エチル基、プロピル基及びブチル基等のアルキル基、置換基を有してもよいフェニル基、ナフチル基及びチオフェニル基等のアリール基又は水素原子を示し、Ｒ³及びＲ⁴は同一でも異なっても良い。ｍ¹は１〜５の整数、ｐ〜ｔは０〜１０の整数を示す（但し、ｐ〜ｔは同時に０であることはない）。
【００７３】
上記一般式（３）中、Ｘ⁴及びＸ⁵は（ＣＨ₂）_m2、（ＣＨ＝ＣＲ⁵）_m3、Ｃ＝Ｏ、又は酸素原子を示し、Ａｒ³は置換基を有してもよいアリーレン基（ベンゼン、ナフタレン、アントラセン、フェナンスレン、ピレン、チオフェン、フラン、ピリジン、キノリン、ベンゾキノリン、カルバゾール、フェノチアジン、ベンゾフラン、ベンゾチオフェン、ジベンゾフラン、ジベンゾチオフェン等より２個の水素原子を取り除いた基）を示す。Ｒ⁵は置換基を有してもよいメチル基、エチル基、プロピル基及びブチル基等のアルキル基、置換基を有しても良いフェニル基、ナフチル基及びチオフェニル基等のアリール基又は水素原子を示す。ｍ²は１〜１０の整数、ｍ³は１〜５の整数、ｕ〜ｗは０〜１０の整数を示す（特に、０〜５の整数の時が特に好ましい。但し、ｕ〜ｗは同時に０であることはない）。
【００７４】
なお、上述の一般式（１）〜（３）、（５）、（６）及び（１４）〜（２０）のＲ¹〜Ｒ⁵、Ｒ⁹〜Ｒ³³、Ａｒ¹〜Ａｒ¹⁰、Ｘ¹〜Ｘ⁵、Ｚ及びＱがそれぞれ有してもよい置換基としてはフッ素、塩素、臭素及びヨウ素等のハロゲン原子；ニトロ基、シアノ基、水酸基；メチル基、エチル基、プロピル基及びブチル基等のアルキル基；メトキシ基、エトキシ基及びプロポキシ基等のアルコキシ基；フェノキシ基、ナフトキシ基等のアリールオキシ基；ベンジル基、フェネチル基、ナフチルメチル基、フルフリル基及びチエニル基等のアラルキル基；フェニル基、ナフチル基、アンスリル基及びピレニル基等のアリール基が挙げられる。また、一般式（４）のＲ⁶〜Ｒ⁸が有しても良い置換基としてはアリール基を除いた上記置換基及びジフェニルアミノ基及びジ（ｐ−トリル）アミノ基等のジアリールアミノ基が挙げられる。
【００７５】
また、本発明における同一分子内に１つ以上の連鎖重合性官能基を有する正孔輸送性化合物は、酸化電位が１．２（Ｖ）以下であることが好ましく、特には０．４〜１．２（Ｖ）であることが好ましい。それは、酸化電位が１．２（Ｖ）超えると電荷発生材料からの電荷（正孔）の注入が起こり難く残留電位の上昇、感度悪化及び繰り返し使用時の電位変動が大きくなる等の問題が生じ易く、また０．４（Ｖ）未満では帯電能の低下等の問題の他に、化合物自体が容易に酸化されるために劣化し易く、それに起因した感度悪化、画像ボケ及び繰り返し使用時の電位変動が大きくなる等の問題が生じ易くなるためである。
【００７６】
なお、ここで述べている酸化電位は、以下の方法によって測定される。
【００７７】
（酸化電位の測定法）
飽和カロメル電極を参照電極とし、電解液に０．１Ｎ(ｎ−Ｂｕ)₄Ｎ⁺ＣｌＯ₄ ^-アセトニトリル溶液を用い、ポテンシャルスイーパによって作用電極（白金）に印加する電位をスイープし、得られた電流−電位曲線がピークを示したときの電位を酸化電位とした。詳しくは、サンプルを０．１Ｎ(ｎ−Ｂｕ)₄Ｎ⁺ＣｌＯ₄ ^-アセトニトリル溶液に５〜１０ｍｍｏｌ％程度の濃度になるように溶解する。そしてこのサンプル溶液に作用電極によって電圧を加え、電圧を低電位（０Ｖ）から高電位（＋１．５Ｖ）に直線的に変化させた時の電流変化を測定し、電流−電位曲線を得る。この電流−電位曲線において、電流値がピーク（ピークが複数ある場合には最初のピーク）を示したときのピークトップの位置の電位を酸化電位とした。
【００７８】
また更に、上記連鎖重合性官能基を有する正孔輸送性化合物は、正孔輸送能として１×１０^-7（ｃｍ²／Ｖ．ｓｅｃ)以上のドリフト移動度を有しているものが好ましい（但し、印加電界：５×１０⁴Ｖ／ｃｍ）。１×１０^-7（ｃｍ²／Ｖ．ｓｅｃ)未満では電子写真感光体として露光後現像までに正孔が十分に移動できないため見かけ上感度が低減し、残留電位も高くなってしまう問題が発生する場合がある。
【００７９】
以下に本発明に係わる、連鎖重合性官能基を有する正孔輸送性化合物の代表例を挙げるがこれらに限定されるものではない。
【００８０】
【化２２】

【００８１】
【化２３】

【００８２】
【化２４】

【００８３】
【化２５】

【００８４】
【化２６】

【００８５】
【化２７】

【００８６】
【化２８】

【００８７】
【化２９】

【００８８】
【化３０】

【００８９】
【化３１】

【００９０】
【化３２】

【００９１】
【化３３】

【００９２】
【化３４】

【００９３】
【化３５】

【００９４】
【化３６】

【００９５】
【化３７】

【００９６】
【化３８】

【００９７】
【化３９】

【００９８】
【化４０】

【００９９】
【化４１】

【０１００】
【化４２】

【０１０１】
【化４３】

【０１０２】
【化４４】

【０１０３】
【化４５】

【０１０４】
【化４６】

【０１０５】
【化４７】

【０１０６】
【化４８】

【０１０７】
【化４９】

【０１０８】
【化５０】

【０１０９】
【化５１】

【０１１０】
【化５２】

【０１１１】
【化５３】

【０１１２】
【化５４】

【０１１３】
【化５５】

【０１１４】
【化５６】

【０１１５】
【化５７】

【０１１６】
【化５８】

【０１１７】
【化５９】

【０１１８】
【化６０】

【０１１９】
【化６１】

【０１２０】
【化６２】

【０１２１】
【化６３】

【０１２２】
【化６４】

【０１２３】
【化６５】

【０１２４】
【化６６】

【０１２５】
【化６７】

【０１２６】
【化６８】

【０１２７】
【化６９】

【０１２８】
【化７０】

【０１２９】
【化７１】

【０１３０】
【化７２】

【０１３１】
【化７３】

【０１３２】
【化７４】

【０１３３】
【化７５】

【０１３４】
【化７６】

【０１３５】
【化７７】

【０１３６】
【化７８】

【０１３７】
【化７９】

【０１３８】
【化８０】

【０１３９】
【化８１】

【０１４０】
【化８２】

【０１４１】
【化８３】

【０１４２】
【化８４】

【０１４３】
【化８５】

【０１４４】
【化８６】

【０１４５】
【化８７】

【０１４６】
【化８８】

【０１４７】
【化８９】

【０１４８】
【化９０】

【０１４９】
【化９１】

【０１５０】
【化９２】

【０１５１】
【化９３】

【０１５２】
【化９４】

【０１５３】
【化９５】

【０１５４】
【化９６】

【０１５５】
【化９７】

【０１５６】
【化９８】

【０１５７】
【化９９】

【０１５８】
【化１００】

【０１５９】
【化１０１】

【０１６０】
【化１０２】

【０１６１】
【化１０３】

【０１６２】
【化１０４】

【０１６３】
【化１０５】

【０１６４】
【化１０６】

【０１６５】
【化１０７】

【０１６６】
【化１０８】

【０１６７】
【化１０９】

【０１６８】
【化１１０】

【０１６９】
本発明においては、前記同一分子内に二つ以上の連鎖重合性官能基を有する正孔輸送性化合物を重合することで、保護層中において、正孔輸送能を有する化合物は二つ以上の架橋点をもって３次元架橋構造を形成する。前記正孔輸送性化合物はそれのみを重合させる、あるいは他の連鎖重合性官能基を有する化合物と混合させることのいずれもが可能であり、その種類／比率は全て任意である。ここでいう他の連鎖重合性官能基を有する化合物とは、連鎖重合性官能基を有する単量体あるいはオリゴマー／ポリマーのいずれもが含まれる。
【０１７０】
正孔輸送性化合物の官能基とその他の連鎖重合性化合物の官能基が同一の基あるいは互いに重合可能な基である場合には、両者は共有結合を介した共重合３次元架橋構造をとることが可能である。両者の官能基が互いに重合しない官能基である場合には、保護層は二つ以上の３次元硬化物の混合物あるいは主成分の３次元硬化物中に他の連鎖重合性化合物単量体あるいはその硬化物を含んだものとして構成されるが、その配合比率／製膜方法をうまくコントロールすることで、ＩＰＮ（Ｉｎｔｅｒ Ｐｅｎｅｔｒａｔｉｎｇ Ｎｅｔｗｏｒｋ）すなわち相互進入網目構造を形成することも可能である。
【０１７１】
また、前記正孔輸送性化合物と連鎖重合性官能基以外の重合性基を有する単量体あるいはオリゴマー／ポリマー等から保護層を形成してもよい。また、その他の各種添加剤、フッ素原子含有樹脂微粒子等の潤剤その他を含有してもよい。
【０１７２】
本発明において、連鎖重合性官能基を有する正孔輸送性化合物は熱、可視光や紫外線等の光、更に放射線により重合することができる。従って、本発明における保護層の形成は、保護層用の塗工液に前記連鎖重合性官能基を有する正孔輸送性化合物と必要によっては重合開始剤を含有させ、該塗工液を用いて形成した塗工膜に光又は放射線を照射することによって該連鎖重合性官能基を有する正孔輸送性化合物を重合させる。なお、本発明においては、その中でも放射線によって該連鎖重合性官能基を有する正孔輸送性化合物を重合することが好ましい。放射線による重合の最大の利点は、重合開始剤を必要としない点であり、これにより非常に高純度な３次元保護層の作製が可能となり、良好な耐久性が確保される点である。また、短時間でかつ効率的な重合反応であるがゆえに生産性も高く、更には放射線の透過性の良さから、厚膜時や添加剤等の遮蔽物質が膜中に存在する際の硬化阻害の影響が非常に小さいこと等が挙げられる。但し、連鎖重合性官能基の種類や中心骨格の種類によっては重合反応が進行しにくい場合があり、その際には影響のない範囲内での重合開始剤の添加は可能である。この際、使用する放射線とは電子線及びγ線であるが、特には電子線が好ましい。
【０１７３】
電子線照射をする場合、加速器としてはスキャニング型、エレクトロカーテン型、ブロードビーム型、パルス型及びラミナー型等いずれの形式も使用することができる。電子線を照射する場合に、本発明の電子写真感光体においては電気特性を発現させる上で照射条件が非常に重要である。本発明において、加速電圧は２５０ＫＶ以下が好ましく、最適には１５０ＫＶ以下である。また、線量は好ましくは１Ｍｒａｄ〜１００Ｍｒａｄの範囲、より好ましくは３Ｍｒａｄ〜５０Ｍｒａｄの範囲である。加速電圧が２５０ＫＶを超えると感光体特性に対する電子線照射のダメージが増加する傾向にある。また、照射線量が１Ｍｒａｄよりも少ない場合には硬化が不十分となり易く、線量１００Ｍｒａｄより多い場合には感光体特性の劣化が起こり易いので注意が必要である。
【０１７４】
前記正孔輸送性化合物の量は、重合硬化後の保護層膜の全質量に対して、前記一般式（１）で示される連鎖重合性官能基を有する正孔輸送性基Ａの水素付加物が２０質量％以上が好ましく、特には４０質量％以上含有されていることが好ましい。２０質量％未満であると電荷輸送能が低下し、感度低下及び残留電位の上昇等の問題点が生じ易い。この場合の保護層としての膜厚は０．１〜１０μｍが好ましく、特には０．５〜７μｍが好ましい。
【０１７５】
次に、感光層について説明する。
【０１７６】
前述の如く、保護層として同一分子内に２つ以上の連鎖重合性官能基を有する正孔輸送性化合物を使用することで機械的強度は飛躍的に向上するが、感光層が有機系感光層である場合に感度が十分に得られなかったり、残留電位の上昇がみられることもあった。また、環境の変化に伴い電位が変動してしまい、十分に安定した電位特性を得られないこともあった。
【０１７７】
本発明者らは鋭意検討した結果、保護層と接する感光層中の電荷輸送材料の分子量と感度、残電、及び環境電位変動との間に関係があることを見いだし本発明に至った。すなわち、保護層と接する感光層の電荷輸送材料の分子量を３５０以上にすることで感度の低下、及び残留電位の上昇を抑えることができ、また環境電位変動も抑えることができた。
【０１７８】
本発明のメカニズムは定かではないが以下のように考えられる。保護層として同一分子内に２つ以上の連鎖重合性官能基を有する正孔輸送性化合物を、光及び放射線を照射することによって重合するに際し、保護層下にある感光層にも光及び放射線は到達している。この光及び放射線が、感光層中の電荷発生材料及び電荷輸送材料を劣化させ、感光体特性が低下すると考えられる。分子量の小さい電荷輸送材料は、吸収した光及び放射線エネルギーを分散できずに分子の切断による劣化が生じるが、分子量の大きい電荷輸送材料は吸収した光及び放射線エネルギーを非局在下させることができ、熱エネルギーに変換することで安定化が可能になり劣化が抑えられると思われる。また、電荷輸送材料が光及び放射線エネルギーを熱エネルギーに変換させることで、電荷発生材料の劣化も抑えられると思われる。よって、分子量の大きい電荷輸送材料を用いた場合、光及び放射線による電荷発生材料及び電荷輸送材料の劣化を抑制できると考えられる。
【０１７９】
本発明においては、電荷輸送材料の分子量が３５０以上７００以下であることが好ましい。７００を超えると溶解性が低下するためか、電位特性及び環境変動が悪化する傾向がみられるからである。
【０１８０】
本発明における感光層が含有する電荷輸送材料は、分子量３５０以上であればいずれのものでもよい。例えば、ポリ−Ｎ−ビニルカルバゾール及びポリスチリルアントラセン等の複素環や縮合多環芳香族を有する高分子化合物や、ピラゾリン、イミダゾール、オキサゾール、トリアゾール及びカルバゾール等の複素環化合物、トリフェニルメタン等のトリアリールアルカン誘導体、トリフェニルアミン等のトリアリールアミン誘導体、フェニレンジアミン誘導体、Ｎ−フェニルカルバゾール誘導体、スチルベン誘導体、ヒドラゾン誘導体及びブタジエン誘導体等が挙げられる。
【０１８１】
以下に電荷輸送材料の化合物例とその分子量を示す。化合物例Ｎｏ．１〜Ｎｏ．１１は、分子量３５０未満なので本発明外の化合物である。もちろん本発明に用いられる電荷輸送材料はこれらに限られるものではない。
【０１８２】
【化１１１】

【０１８３】
【化１１２】

【０１８４】
【化１１３】

【０１８５】
【化１１４】

【０１８６】
【化１１５】

【０１８７】
【化１１６】

【０１８８】
【化１１７】

【０１８９】
【化１１８】

【０１９０】
【化１１９】

【０１９１】
【化１２０】

【０１９２】
本発明において、分子量が３５０以上である電荷輸送材料以外の電荷輸送材料を更に添加することができる。但し、本発明の効果を十分に得るためには分子量が３５０以上である電荷輸送材料が感光層中の全電荷輸送材料の５０質量％以上であることが好ましく、更に７０質量％以上であることがより好ましい。
【０１９３】
本発明の電子写真感光体の構成は、保護層下に感光層として電荷発生材料を含有する電荷発生層及び電荷輸送材料と結着樹脂を含有する電荷輸送層をこの順に積層した積層型、また電荷発生材料と電荷輸送材料と結着樹脂を同一層中に有する単層からなる単層型のいずれの構成をとることも可能である。
【０１９４】
以下、積層型の感光層について説明する。
【０１９５】
本発明における電荷輸送層は、電荷輸送材料を結着樹脂と共に溶剤に分散／溶解した溶液を塗布し、乾燥して形成することができる。
【０１９６】
上記電荷輸送材料と共に用いる結着樹脂としては、従来用いられる電荷輸送層用の樹脂を用いることができ、例えば、ポリエステル、ポリカーボネート、ポリアリレート、ポリメタクリル酸エステル及びポリスチレン等が挙げられる。電荷輸送層の厚さは１〜５０μｍであることが好ましく、特には５〜３０μｍであることが好ましい。
【０１９７】
この場合の電荷輸送材料と上記結着樹脂の比率は、両者の全質量を１００とした場合に電荷輸送材料の質量が１０〜１００が好ましく、好ましくは２０〜１００の範囲で適宜選択される。
【０１９８】
本発明における電荷発生層は、電荷発生材料を結着樹脂に分散した溶液を塗布し、乾燥することによって形成することが好ましいが、電荷発生材料のみを蒸着することによって形成してもよい。
【０１９９】
電荷発生材料としては、セレン−テルル、ピリリウム、チアピリリウム系染料、また各種の中心金属及び結晶系、具体的には例えばα、β、γ、ε及びＸ型等の結晶型を有するフタロシアニン化合物、アントアントロン顔料、ジベンズピレンキノン顔料、ピラントロン顔料、トリスアゾ顔料、ジスアゾ顔料、モノアゾ顔料、インジゴ顔料、キナクリドン顔料、非対称キノシアニン顔料、キノシアニン及び特開昭５４−１４３６４５号公報に記載のアモルファスシリコン等が挙げられる。
【０２００】
電荷発生層は、前記電荷発生材料を０．３〜４倍量の結着樹脂及び溶剤と共にホモジナイザー、超音波分散、ボールミル、振動ボールミル、サンドミル、アトライター及びロールミル等の方法で良く分散し、分散液を塗布し、乾燥されて形成されるか、又は前記電荷発生材料の蒸着膜等、単独組成の膜として形成される。その膜厚は５μｍ以下であることが好ましく、特に０．１〜２μｍの範囲であることが好ましい。
【０２０１】
結着樹脂を用いる場合の例は、スチレン、酢酸ビニル、塩化ビニル、アクリル酸エステル、メタクリル酸エステル、フッ化ビニリデン、トリフルオロエチレン、等のビニル化合物の重合体及び共重合体、ポリビニルアルコール、ポリビニルアセタール、ポリカーボネート、ポリエステル、ポリスルホン、ポリフェニレンオキサイド、ポリウレタン、セルロース樹脂、フェノール樹脂、メラミン樹脂、ケイ素樹脂及びエポキシ樹脂等が挙げられる。
【０２０２】
感光層が単層である場合は、上記電荷発生材料及び分子量３５０以上の電荷輸送材料を上記結着樹脂に分散及び溶解した溶液を塗布し、乾燥することによって形成することができる。
【０２０３】
本発明における感光層には、各種添加剤を添加することができる。該添加剤とは、酸化防止剤及び紫外線吸収剤等の劣化防止剤や、フッ素原子含有樹脂微粒子等の潤剤その他である。
【０２０４】
電子写真感光体の支持体としては導電性を有するものであればよく、例えばアルミニウム、銅、クロム、ニッケル、亜鉛及びステンレス等の金属や合金をドラム又はシート状に成形したもの、アルミニウム及び銅等の金属箔をプラスチックフィルムにラミネートしたもの、アルミニウム、酸化インジウム及び酸化錫等をプラスチックフィルムに蒸着したもの、導電性物質を単独又は結着樹脂と共に塗布して導電層を設けた金属、またプラスチックフィルム及び紙等が挙げられる。
【０２０５】
本発明においては、導電性支持体表面を化成処理すなわち酸又はアルカリ水溶液との反応によって化学的に処理して不溶性の皮膜を形成してもよい。
【０２０６】
導電性支持体の上には、バリアー機能と接着機能をもつ下引き層を設けることができる。下引き層は、感光層の接着性改良、塗工性改良、支持体の保護、支持体上の欠陥の被覆、支持体からの電荷注入性改良、また感光層の電気的破壊に対する保護等のために形成される。
【０２０７】
下引き層の材料としては、例えば、ポリエチレン樹脂、アクリル樹脂、メタクリル樹脂、ポリアミド樹脂、塩化ビニル樹脂、酢酸ビニル樹脂、フェノール樹脂、ポリカーボネート樹脂、ポリウレタン樹脂、ポリイミド樹脂、塩化ビニリデン樹脂、ポリビニルアセタール樹脂、塩化ビニル−酢酸ビニル共重合体、ポリビニルアルコール樹脂、水溶性ポリエステル樹脂、アルコール可溶性ナイロン樹脂、ニトロセルロース、カゼイン、ゼラチン、ポリグルタミン酸、澱粉、スターチアセテート、アミノ澱粉、ポリアクリル酸、ポリアクリルアミド等の樹脂、又はシランカップリング剤やジルコニウム、チタニウム、アルミニウム、マンガン等を含有する有機金属化合物等の金属有機化合物を、単独又は２種以上を混合して用いることができる。これらは、それぞれに適した溶剤に溶解されて支持体上に塗布される。その際の膜厚としては、０．１〜５μｍが好ましい。
【０２０８】
これら各層の塗布方法としては、例えば、浸漬コーティング法、スプレーコーティング法、カーテンコーティング法及びスピンコーティング法等が知られているが、効率性／生産性の点からは浸漬コーティング法が好ましい。また、蒸着、プラズマその他の公知の製膜方法が適宜選択できる。
【０２０９】
図１に本発明の電子写真感光体を有するプロセスカートリッジを用いた電子写真装置の概略構成を示す。
【０２１０】
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。電子写真感光体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又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等の露光手段（不図示）から出力される目的の画像情報の時系列電気デジタル画像信号に対応して強調変調された露光光４を受ける。こうして電子写真感光体１の周面に対し、目的の画像情報に対応した静電潜像が順次形成されていく。
【０２１１】
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、不図示の給紙部から電子写真感光体１と転写手段６との間に電子写真感光体１の回転と同期して取り出されて給紙された転写材７に、電子写真感光体１の表面に形成担持されているトナー画像が転写手段６により順次転写されていく。
【０２１２】
トナー画像の転写を受けた転写材７は、電子写真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画像形成物（プリント、コピー）として装置外へプリントアウトされる。
【０２１３】
像転写後の電子写真感光体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、更に前露光手段（不図示）からの前露光光１０により除電処理された後、繰り返し画像形成に使用される。なお、一次帯電手段３が帯電ローラー等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。
【０２１４】
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及びクリーニング手段９等の構成要素のうち、複数のものを容器１１に納めて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等の電子写真装置本体に対して着脱自在に構成してもよい。例えば、一次帯電手段３、現像手段５及びクリーニング手段９の少なくとも一つを電子写真感光体１と共に一体に支持してカートリッジ化して、装置本体のレール等の案内手段１２を用いて装置本体に着脱自在なプロセスカートリッジとすることができる。
【０２１５】
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、この信号に従って行われるレーザービームの走査、ＬＥＤアレイの駆動及び液晶シャッターアレイの駆動等により照射される光である。
【０２１６】
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、ＦＡＸ、液晶プリンター及びレーザー製版等の電子写真応用分野にも広く用いることができる。
【０２１７】
【実施例】
以下、実施例に従って本発明を更に詳細に説明する。なお、実施例中の「部」は質量部を表す。
【０２１８】
（実施例１）
まず導電層用の塗料を以下の手順で調製した。１０質量％の酸化アンチモンを含有する酸化スズで被覆した導電性酸化チタン粉体５０部、フェノール樹脂２５部、メチルセロソルブ２０部、メタノール５部及びシリコーンオイル（ポリジメチルシロキサンポリオキシアルキレン共重合体、平均分子量３０００）０．００２部をφ１ｍｍガラスビーズを用いたサンドミル装置で２時間分散して調製した。この塗料をφ３０ｍｍのアルミニウムシリンダー上に浸漬塗布方法で塗布し、１４０℃で３０分間乾燥することによって、膜厚が２０μｍの導電層を形成した。
【０２１９】
次に、Ｎ−メトキシメチル化ナイロン５部をメタノール９５部中に溶解し、中間層用塗料を調製した。この塗料を前記の導電層上に浸漬コーティング法によって塗布し、１００℃で２０分間乾燥することによって、膜厚が０．６μｍの中間層を形成した。
【０２２０】
次に、ＣｕＫαの特性Ｘ線回折におけるブラッグ角（２θ±０．２度）が９．０度、１４．２度、２３．９度及び２７．１度に強いピ−クを有するオキシチタニウムフタロシアニンを３部、ポリビニルブチラール（商品名：エスレックＢＭ２、積水化学（株）製）３部及びシクロヘキサノン３５部をφ１ｍｍガラスビーズを用いたサンドミル装置で２時間分散して、その後に酢酸エチル６０部を加えて電荷発生層用塗料を調製した。この塗料を前記の中間層の上に浸漬塗布方法で塗布し、５０℃で１０分間乾燥することによって、膜厚が０．２μｍの電荷発生層を形成した。
【０２２１】
次いで、電荷輸送材料として化合物例Ｎｏ．５４を１０部及び下記構造式（２１）の繰り返し単位を有するポリカーボネート樹脂１０部を
【０２２２】
【化１２１】

モノクロロベンゼン５０部／ジクロロメタン３０部の混合溶媒中に溶解し、電荷輸送層用塗布液を調製した。この塗布液を前記の電荷発生層上に浸漬コーティングし、１１０℃で１時間乾燥することによって、膜厚が２０μｍの電荷輸送層を形成した。
【０２２３】
次いで、化合物例Ｎｏ．６の正孔輸送性化合物６０部をモノクロロベンゼン５０部／ジクロロメタン５０部の混合溶媒中に溶解し保護層用塗料を調製した。この塗料をスプレーコーティング法により、先の電荷輸送層上に塗布し、加速電圧１５０ＫＶ、線量３０Ｍｒａｄの条件で電子線を照射し樹脂を硬化することによって、膜厚が５μｍの保護層を形成し、電子写真感光体を得た。
【０２２４】
作製した電子写真感光体をキヤノン（株）製ＬＢＰ−ＳＸに装着して初期電子写真特性を評価した。初期の感光体特性［光減衰感度（暗部電位−７００Ｖ設定で−２００Ｖに光減衰させるために必要な光量）及び残留電位Ｖｓｌ（光減衰感度の光量の３倍の光量を照射したときの電位）］を常温常湿環境下（２３℃／５０％ＲＨ）の環境で測定して求めた。その後、環境を高温高湿下（３２℃／８５％ＲＨ）（Ｈ／Ｈ）に変え、Ｖｌの常温常湿環境下からの変動量（ΔＶｌ）を測定した。結果を表３に示す。
【０２２５】
（実施例２〜２２及び比較例１〜４）
実施例１の保護層中の正孔輸送性化合物、あるいは感光層中の電荷輸送材料を表３の様に代えた以外は、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。その結果を表３に示す。
【０２２６】
（実施例２３）
実施例１の電荷輸送材料の化合物例Ｎｏ．５４ １０部を化合物例Ｎｏ．１９８部及び化合物例Ｎｏ．５４ ２部に代えた以外は、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。結果を表４に示す。
【０２２７】
（実施例２４）
実施例１の電荷輸送材料の化合物例Ｎｏ．５４ １０部を化合物例Ｎｏ．５ ３部及び化合物例Ｎｏ．５４ ７部に代えた以外は、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。結果を表４に示す。
【０２２８】
（実施例２５）
実施例１の電荷輸送材料の化合物例Ｎｏ．５４ １０部を化合物例Ｎｏ．５ ７部及び化合物例Ｎｏ．５４ ３部に代えた以外は、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。結果を表４に示す。
【０２２９】
（実施例２６）
まず、電子写真用感光体支持体を以下の手順で得た。φ３０ｍｍアルミニウムシリンダーを用意し、有機りん酸としてフィチン酸及び金属としてチタニウムを含有するノンクロメート化成処理剤液（商品名：パルコ−ト３７５３、日本パーカライジング株式会社製 ）を４０℃の温度に保ち、この液中に上記のアルミニウムシリンダーを浸漬し、１分間化成処理を行った後、純水で洗浄し、自然乾燥させて支持体とした。
【０２３０】
上記支持体上に実施例１と同様にして電荷発生層、電荷輸送層、保護層を形成し、評価した。結果を表４に示す。
【０２３１】
（実施例２７及び２８）
実施例２６の電荷輸送材料の化合物例Ｎｏ．５４を化合物例Ｎｏ．２９及び化合物例Ｎｏ．６８に代えた以外は、実施例２６と同様にして電子写真感光体を作製し、評価した。結果を表４に示す。
【０２３２】
（実施例２９）
φ３０ｍｍアルミニウムシリンダーをホーニング処理し、超音波水洗浄したものを導電性支持体とした。
【０２３３】
次に、メトキシエタノール１６０部にジルコニウムテトラ−ｎ−ブトキサイドの８５％ブタノール溶液（関東化学社製）６４部（０．０６ｍｏｌ）及びチタニウムテトラ−ｎ−ブトキサイド（キシダ化学社製）２２部（０．１４ｍｏｌ）を滴下し、メトキシエタノール／純水＝１６０部／１１部の混合溶液を更に加える。更に、アセチルアセトン２０部をメタノール２００部に加えた溶液を滴下した後、ヒドロキシプロピルセルロース（東京化成工業社製）の１０質量％メタノール液５５部を混合して得た中間層塗布液をアルミニウムシリンダー支持体上に浸漬塗布し、１２０℃で１５分間加熱乾燥させることによって、膜厚が０．３μｍの中間層を形成した。
【０２３４】
上記中間層上に実施例１と同様にして電荷発生層、電荷輸送層、保護層を形成し、評価した。結果を表４に示す。
【０２３５】
（実施例３０及び３１）
実施例２９の電荷輸送材料の化合物例Ｎｏ．５４を化合物例Ｎｏ．３２及び化合物例Ｎｏ．４０に代えた以外は、実施例２９と同様にして電子写真感光体を作製し、評価した。結果を表４に示す。
【０２３６】
（実施例３２）
電荷輸送層用塗布液を以下のように調製した以外は、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。結果を表４に示す。
【０２３７】
電荷輸送材料の化合物例Ｎｏ．５４ １６部、前記構造式（２１）の繰り返し単位を有するポリカーボネート樹脂４部及び酸化防止剤（商品名：イルガノックス１３３０、チバガイギー社製）１部をモノクロロベンゼン５０部／ジクロロメタン３０部の混合溶媒中に溶解し、電荷輸送層用塗布液を調製した。
【０２３８】
（実施例３３）
電荷輸送層用塗布液を以下のように調製した以外は、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。結果を表４に示す。
【０２３９】
電荷輸送材料の化合物例Ｎｏ．９８ ３部と化合物例Ｎｏ．８９ １部、前記構造式（２１）の繰り返し単位を有するポリカーボネート樹脂１６部、酸化防止剤（商品名：ＳｕｍｉｌｉｚｅｒＧＳ、住友化学（株）製）０．５部及び酸化防止剤（商品名：ＩＲＧＡＦＯＳ−１６８、日本チバガイギー社製）０．５部をモノクロロベンゼン５０部／ジクロロメタン３０部の混合溶媒中に溶解し、電荷輸送層用塗布液を調製した。
【０２４０】
表３及び表４の実施例に示すように、分子量３５０以上の電荷輸送材料を用いると電位特性及び環境特性が良好であるのに対し、比較例に示すように分子量３５０未満の電荷輸送材料を用いると感度低下、残留電位の上昇を生じたものもあったり、また環境変動の大きなものもあった。
【０２４１】
【表３】

【０２４２】
【表４】

【０２４３】
【発明の効果】
本発明によれば、感度が良好であり、残留電位の上昇が少なく、環境による電位変動が小さい等の電子写真特性が非常に良好であり常に安定した性能を発揮することができる電子写真感光体を提供することができた。
【０２４４】
また、上記電子写真感光体の効果は、その電子写真感光体を有するプロセスカートリッジ及び電子写真装置においても当然に発揮され、長期間高画質が維持される。
【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プロセスカートリッジを用い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 帯電手段
４ 露光光
５ 現像手段
６ 転写手段
７ 転写材
８ 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容器
１２ 案内手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus, and more specifically, an electrophotographic photosensitive member containing a specific compound in a surface layer and a charge transport material having a molecular weight of 350 or more in the photosensitive layer, The present invention relates to a process cartridge having an electrophotographic photosensitive member and an electrophotographic apparatus.
[0002]
[Prior art]
Conventionally, inorganic photoconductive materials such as selenium, cadmium sulfide and zinc oxide have been widely used for electrophotographic photoreceptors. On the other hand, as an electrophotographic photoreceptor using an organic photoconductive material, a photoconductive polymer typified by poly-N-vinylcaribazole or 2,5-bis (p-diethylaminophenyl) -1,3,4 is used. Known are those using a low molecular organic photoconductive material such as oxadiazole, and combinations of such organic photoconductive materials with various dyes and pigments.
[0003]
An electrophotographic photosensitive member using an organic photoconductive material has good film forming properties and can be produced by coating, and therefore has an advantage of providing an electrophotographic photosensitive member that is extremely productive and inexpensive. In addition, there has been an advantage that the photosensitive wavelength range can be freely controlled by selecting the dye or pigment to be used, and extensive studies have been made so far. In particular, the development of a function-separated electrophotographic photoreceptor in which a charge generation layer containing an organic photoconductive dye or pigment and a charge transport layer containing a photoconductive polymer or a low molecular organic photoconductive material are laminated. As a result, the sensitivity and durability, which have been regarded as drawbacks of conventional organic electrophotographic photoreceptors, have been remarkably improved, and this has become the mainstream of organic electrophotographic photoreceptors.
[0004]
On the other hand, 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. In particular, in an electrophotographic photosensitive member that is repeatedly used, electrical and mechanical external forces such as charging, image exposure, toner development, transfer to paper, and cleaning are directly applied to the surface of the electrophotographic photosensitive member. , Durability against them is required. Specific examples include durability against surface wear and scratches due to rubbing and surface deterioration due to charging. More specifically, transfer efficiency and slipperiness decrease, and further, electrical characteristics such as sensitivity reduction and potential decrease. Durability against deterioration is also required.
[0005]
In general, the surface of an electrophotographic photoreceptor is a thin resin layer, and the characteristics of the resin are very important. In recent years, acrylic resins and polycarbonate resins have been put to practical use as resins that satisfy the above-mentioned conditions to some extent. However, not all of the above-mentioned characteristics are satisfied with these resins, and in particular, electrophotographic photosensitive resins. In order to increase the durability of the body, it is difficult to say that the coating hardness of the resin is sufficiently high. Even when these resins are used as the resin for forming the surface layer, there is a problem that the surface layer is worn during repeated use, and further scratches are generated.
[0006]
Furthermore, due to the recent demand for higher sensitivity of organic electrophotographic photoreceptors, low molecular weight compounds such as charge transport materials are often added in a relatively large amount. In this case, due to the plasticizer action of these low molecular weight materials. The film strength is remarkably lowered, and the surface layer is worn and damaged when repeatedly used. Further, when the electrophotographic photosensitive member is stored for a long period of time, the above-mentioned low molecular weight component is precipitated, resulting in a problem of layer separation.
[0007]
As means for solving these problems, an attempt to use a curable resin as a resin for a charge transport layer is disclosed in, for example, JP-A-2-127852. Thus, the mechanical strength is increased by curing and crosslinking the charge transport layer using a curable resin as the charge transport layer resin, and the abrasion resistance and scratch resistance during repeated use are greatly improved. However, even when a curable resin is used, the low molecular weight component acts as a plasticizer in the binder resin to the last, so the problems of precipitation and layer separation as described above are not fundamental solutions.
[0008]
In addition, in the charge transport layer composed of the organic charge transport material and the binder resin, the charge transport ability is highly dependent on the resin. For example, a curable resin having a sufficiently high hardness does not have sufficient charge transport ability and is repeated. The residual potential has been increased during use, and both have not been satisfied.
[0009]
In JP-A-5-216249, JP-A-7-72640 and the like, a monomer having a carbon-carbon double bond is contained in the charge transfer layer, and the carbon-carbon double bond and heat of the charge transfer material are added. Alternatively, an electrophotographic photosensitive member in which a charge transfer layer cured film is formed by reacting with light energy is disclosed, but the charge transport material is simply fixed in a pendant form on the polymer main skeleton, and the above-mentioned plastic The mechanical strength is not sufficient because the mechanical action cannot be sufficiently eliminated. In addition, if the concentration of the charge transport material is increased to improve the charge transport capability, the crosslink density is lowered and sufficient mechanical strength cannot be ensured. Furthermore, there is a concern about the influence of the initiators required during polymerization on the electrophotographic characteristics.
[0010]
As another solution, for example, JP-A-8-248649 discloses an electrophotographic photoreceptor in which a charge transporting layer is formed by introducing a group having a charge transporting ability into a thermoplastic polymer main chain. However, compared with conventional molecular dispersion type charge transport layer, it is effective for precipitation and layer separation, and mechanical strength is improved, but it is a thermoplastic resin to the last. There is a limit, and it is difficult to say that handling and productivity including resin solubility are sufficient.
[0011]
Against the background described above, the present inventors have repeatedly studied to achieve both high mechanical strength and charge transport capability. As a result, the electrophotographic photosensitive member containing a compound obtained by polymerizing a hole transporting compound having two or more chain polymerizable functional groups in the same molecule almost achieves both mechanical strength and charge transporting ability. It was confirmed.
[0012]
However, when this is used as a protective layer, the mechanical strength is improved by using a hole transporting compound having two or more chain polymerizable functional groups in the same molecule, but the photosensitive layer is organic. In the case of the photosensitive layer, sufficient sensitivity may not be obtained, or the residual potential may be increased. In addition, the potential fluctuates as the environment changes, and stable potential characteristics may not be obtained.
[0013]
With the recent increase in image quality and durability, it has been necessary to solve these problems in order to provide a better electrophotographic photoreceptor.
[0014]
[Problems to be solved by the invention]
An object of the present invention is to provide an electrophotographic photosensitive member that has good sensitivity even when a protective layer is formed, little increase in residual potential, little potential fluctuation due to environmental changes, and stable electrophotographic characteristics. It is in.
[0015]
Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.
[0016]
[Means for Solving the Problems]
In accordance with the present invention, a compound obtained by polymerizing a hole transporting compound having two or more chain-polymerizable functional groups in the same molecule, in an electrophotographic photosensitive member having a conductive support, a photosensitive layer and a protective layer And a photosensitive layer containing a charge transport material having a molecular weight of 350 or more.
[0017]
According to the present invention, a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member are provided.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Next, the structure of the electrophotographic photosensitive member of the present invention will be described in detail.
[0019]
First, the protective layer in the present invention will be described. First, a hole transporting compound having a chain polymerizable functional group will be described.
[0020]
The chain polymerization in the present invention refers to the former polymerization reaction mode when the polymer formation reaction is largely divided into chain polymerization and sequential polymerization. For details, see, for example, “Basic Chemistry Resin Chemistry” by Tadahiro Miwa. (New Edition) ”July 25, 1995 (1 edition, 8 prints) As described in FIG. 24, the form mainly refers to unsaturated polymerization, ring-opening polymerization, isomerization polymerization, etc. in which the reaction proceeds via an intermediate such as a radical or ion. Chain-polymerizable functional group P in the general formula (1)¹And P²Means a functional group capable of the above-described reaction form, and here, a specific example of an unsaturated polymerization or ring-opening polymerizable functional group that occupies most of the functional group and has a wide application range.
[0021]
Unsaturated polymerization is a reaction in which unsaturated groups such as C═C, C≡C, C═O, C═N, and C≡N are polymerized by radicals, ions, etc., but mainly C═C. It is. Specific examples of the unsaturated polymerizable functional group are shown in Table 1, but are not limited thereto.
[0022]
[Table 1]

[0023]
In the table, R is an optionally substituted alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, an optionally substituted benzyl group, a phenethyl group, a naphthylmethyl group, a furfuryl group, and An aryl group such as a thienyl group, an aryl group such as a phenyl group, a naphthyl group and an anthryl group which may have a substituent, or a hydrogen atom.
[0024]
Ring-opening polymerization means that unstable cyclic structures with distortions such as carbocycles, oxo rings, and nitrogen heterocycles are activated by the action of a catalyst, and at the same time, the polymerization is repeated to produce a chain polymer. In this case, most of the ions basically act as active species. Specific examples of the ring-opening polymerizable functional group are shown in Table 2, but are not limited thereto.
[0025]
[Table 2]

[0026]
In the table, R is an optionally substituted alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, an optionally substituted benzyl group, a phenethyl group, a naphthylmethyl group, a furfuryl group, and An aryl group such as a thienyl group, an aryl group such as a phenyl group, a naphthyl group and an anthryl group which may have a substituent, or a hydrogen atom.
[0027]
Among the chain polymerizable functional groups according to the present invention as described above, those represented by the following general formulas (6), (14) and (15) are preferable.
[0028]
[Chemical 8]

[0029]
In the formula, E may have a hydrogen atom, a halogen atom such as fluorine, chlorine and bromine, an optionally substituted alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, or a substituent. Aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group, furfuryl group and thienyl group, optionally substituted phenyl group, naphthyl group, anthryl group, pyrenyl group, thiophenyl group and furyl group, aryl groups such as Alkoxy groups such as methoxy group, ethoxy group and propoxy group, CN group, nitro group, -COOR¹³Or -CONR¹⁴R¹⁵Indicates.
[0030]
W represents an arylene group such as an optionally substituted phenylene group, naphthylene group and anthracenylene group, an optionally substituted methylene group, an alkylene group such as an ethylene group and butylene, -COO-, -CH₂-, -O-, -OO-, -S- or -CONR¹⁶Indicated by −.
[0031]
R¹³, R¹⁴, R¹⁵And R¹⁶Is a hydrogen atom, a halogen atom such as fluorine, chlorine, bromine and iodine, an optionally substituted methyl group such as an ethyl group, an propyl group and a butyl group, and an optionally substituted benzyl group And an aryl group such as phenyl group, naphthyl group and anthryl group which may have an aralkyl group or a substituent such as phenethyl group, R¹⁴And R¹⁵May be the same or different. F represents 0 or 1.
[0032]
Substituents that may be present in E and W include halogen atoms such as fluorine, chlorine, bromine and iodine; nitro groups, cyano groups, hydroxyl groups; alkyl groups such as methyl groups, ethyl groups, propyl groups and butyl groups Alkoxy groups such as methoxy group, ethoxy group and propoxy group; aryloxy groups such as phenoxy group and naphthoxy group; aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group, furfuryl group and thienyl group; or phenyl group, naphthyl group; And aryl groups such as a group, anthryl group and pyrenyl group.
[0033]
[Chemical 9]

[0034]
Where R¹⁷And R¹⁸Is a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group which may have a substituent, an aralkyl group such as a benzyl group and a phenethyl group which may have a substituent, or a substituent. An aryl group such as a phenyl group and a naphthyl group which may be present, and n represents an integer of 1 to 10.
[0035]
Embedded image

Where R¹⁹And R²⁰Has a hydrogen atom, an alkyl group such as an optionally substituted methyl group, an ethyl group, a propyl and a butyl group, an aralkyl group such as an optionally substituted benzyl group and a phenethyl group, or a substituent. And an aryl group such as a phenyl group and a naphthyl group, and n represents an integer of 0 to 10.
[0036]
In the above general formulas (14) and (15), R¹⁷, R¹⁸, R¹⁹And R²⁰Substituents that may have are halogen atoms such as fluorine, chlorine, bromine and iodine; alkyl groups such as methyl group, ethyl group, propyl group and butyl group; alkoxy groups such as methoxy group, ethoxy group and propoxy group Aryloxy groups such as phenoxy group and naphthoxy group; aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group, furfuryl group and thienyl group; or aryl groups such as phenyl group, naphthyl group, anthryl group and pyrenyl group; Can be mentioned.
[0037]
Among the general formulas (6), (14) and (15), more preferred chain polymerizable functional groups include those represented by the following general formulas (7) to (13).
[0038]
Embedded image

[0039]
Furthermore, among the general formulas (7) to (13), the acryloyloxy group of the general formula (7) and the methacryloyloxy group of the general formula (8) are particularly preferable from the viewpoint of polymerization characteristics and the like.
[0040]
Next, the hole transport material in the present invention will be described.
[0041]
In the present invention, the “hole transportable compound having a chain polymerizable functional group” means that the chain polymerizable functional group described above preferably has two or more chemical groups as functional groups in the hole transportable compound described below. The compound which has couple | bonded is shown. In this case, the chain polymerizable functional groups may all be the same or different.
[0042]
The hole transporting compound having two or more of these chain polymerizable functional groups is preferably the following general formula (1).
[0043]
Embedded image

[0044]
In the formula, A represents a hole transporting group. P¹And P²Represents a chain-polymerizable functional group. P¹And P²May be the same or different. Z represents an organic group which may have a substituent. a, b and d represent an integer of 0 or more, and a + b × d represents an integer of 2 or more. If a is 2 or more, P¹May be the same or different, and when d 1 is 2 or more, Z and P²May be the same or different.
[0045]
Here, “If a is 2 or more, P¹May be the same or different ”means that n different types of chain polymerizable functional groups are represented by P¹¹, P¹², P¹³, P¹⁴, P¹⁵.... P¹ⁿFor example, when a = 3, the polymerizable functional group P directly bonded to the hole transporting compound A¹Are the same for all three, but the same for two but one for different (eg P¹¹And P¹¹And P¹²However, each of the three is different (for example, P¹²And P¹⁵And P¹⁷Or the like) ("P if d is 2 or more P²May be the same or different. ”If b is 2 or more, Z and P²"May be the same or different" means the same thing).
[0046]
A and P in the above general formula (1)¹Examples of the hole transport compound in which the bonding site with Z or Z is replaced with a hydrogen atom include, for example, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triarylamine derivatives such as triphenylamine, 9- (p-diethylaminostyryl) anthracene 1,1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, thiophene derivatives and N-phenylcarbazole derivatives and the like can be mentioned.
[0047]
Further, among the above hole transport compounds, compounds represented by the formula selected from the following general formulas (4), (5), (16), (17) and (19), or represented by the following general formula (18) A condensed ring hydrocarbon having a group or a condensed heterocyclic ring having a group represented by the following general formula (18) is preferable. Furthermore, among these, the case where it is a compound shown by General formula (4) and (5) is especially preferable.
[0048]
Embedded image

[0049]
In the general formula (4), R⁶, R⁷And R⁸Is an alkyl group having 10 or less carbon atoms such as an optionally substituted methyl group, ethyl group, propyl group and butyl group, an optionally substituted benzyl group, phenethyl group, naphthylmethyl group, furfuryl group. And a phenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group, thiophenyl group, furyl group, pyridyl group, quinolyl group, benzoquinolyl group, carbazolyl group, phenol group, which may have an aralkyl group or a substituent such as thienyl group An aryl group such as a thiazinyl group, a benzofuryl group, a benzothiophenyl group, a dibenzofuryl group and a dibenzothiophenyl group is shown.
[0050]
However, R⁶, R⁷And R⁸At least two of them represent an aryl group, and R⁶, R⁷And R⁸May be the same or different. Furthermore, among them, R⁶, R⁷And R⁸Those in which all are aryl groups are particularly preferred. In addition, R in the general formula (4)⁶Or R⁷Or R⁸Any two of them may be bonded directly or via a bonding group, such as a methylene group, an alkylene group such as an ethylene group and a propylene group, a hetero atom such as an oxygen atom and a sulfur atom, or CH = CH group etc. are mentioned.
[0051]
Embedded image

[0052]
In the general formula (5), m^FourRepresents 0 or 1, m^Four= 1 is preferable. R⁹~ R¹²Is an alkyl group having 10 or less carbon atoms such as an optionally substituted methyl group, ethyl group, propyl group and butyl group, an optionally substituted benzyl group, phenethyl group, naphthylmethyl group, furfuryl group. And a phenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group, thiophenyl group, furyl group, pyridyl group, quinolyl group, benzoquinolyl group, carbazolyl group, phenol group, which may have an aralkyl group or a substituent such as thienyl group An aryl group such as a thiazinyl group, a benzofuryl group, a benzothiophenyl group, a dibenzofuryl group and a dibenzothiophenyl group;⁹~ R¹²May be the same or different.
[0053]
Ar^FourMay be substituted arylene groups (two from benzene, naphthalene, anthracene, phenanthrene, pyrene, thiophene, furan, pyridine, quinoline, benzoquinoline, carbazole, phenothiazine, benzofuran, benzothiophene, dibenzofuran, dibenzothiophene, etc. A group in which a hydrogen atom is removed), Ar^FiveIs m^Four= 0, phenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group, thiophenyl group, furyl group, pyridyl group, quinolyl group, benzoquinolyl group, carbazolyl group, phenothiazinyl group, benzofuryl group, benzothiophenyl group, An aryl group such as a dibenzofuryl group and a dibenzothiophenyl group;^Four= 1 for Ar¹And the same arylene group. M^FourIf = 1, Ar^FourAnd Ar^FiveMay be the same or different.
[0054]
Among them, R in the above general formula (5)⁹~ R¹²It is particularly preferred that all four are aryl groups. In addition, R in the general formula (5)⁹And R^TenOr R¹¹And R¹²Or Ar^FourAnd Ar^FiveMay be bonded directly or via a bonding group, as the bonding group, an alkylene group such as a methylene group, an ethylene group and a propylene group, a carbonyl group, a heteroatom such as an oxygen atom and a sulfur atom, or CH = CH group etc. are mentioned, Among these, an alkylene group is preferable.
[0055]
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[0056]
In the general formula (16), R^{twenty one}, R^{twenty two}, R^{twenty three}And R^{twenty four}Is an alkyl group having 10 or less carbon atoms such as an optionally substituted methyl group, ethyl group, propyl group and butyl group, an optionally substituted benzyl group, phenethyl group, naphthylmethyl group, furfuryl group. And a phenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group, thiophenyl group, furyl group, pyridyl group, quinolyl group, benzoquinolyl group, carbazolyl group, phenol group, which may have an aralkyl group or a substituent such as thienyl group An aryl group such as a thiazinyl group, a benzofuryl group, a benzothiophenyl group, a dibenzofuryl group and a dibenzothiophenyl group;^{twenty one}, R^{twenty two}, R^{twenty three}And R^{twenty four}May be the same or different. R^{twenty five}And R²⁶Is an alkylene group having 10 or less carbon atoms such as methylene group, ethylene group and propylene group which may have a substituent, or an arylene group which may have a substituent (benzene, naphthalene, anthracene, phenanthrene, pyrene, thiophene) , A group obtained by removing two hydrogen atoms from furan, pyridine, quinoline, benzoquinoline, carbazole, phenothiazine, benzofuran, benzothiophene, dibenzofuran, dibenzothiophene, etc.)^{twenty five}And R²⁶May be the same or different. Q represents an organic group which may have a substituent.
[0057]
Among them, R in the above general formula (16)^{twenty one}, R^{twenty two}, R^{twenty three}And R^{twenty four}At least two of them are optionally substituted aryl groups, and R^{twenty five}And R²⁶Is preferably an arylene group which may have a substituent, and further R^{twenty one}, R^{twenty two}, R^{twenty three}And R^{twenty four}Particularly preferred is a case in which all four are aryl groups which may have a substituent. Further, R in the general formula (16)^{twenty one}, R^{twenty two}And R^{twenty five}Any two of R or R^{twenty three}, R^{twenty four}And R²⁶Any two of them may be bonded directly or via a bonding group, such as a methylene group, an alkylene group such as an ethylene group and a propylene group, a hetero atom such as an oxygen atom and a sulfur atom, or CH = CH group etc. are mentioned.
[0058]
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[0059]
However, in the general formula (17), R²⁷, R²⁸And Ar⁶At least one of them has at least one group represented by the following general formula (18).
[0060]
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[0061]
In the general formulas (17) and (18), Ar⁶And Ar⁷May have a phenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group, thiophenyl group, furyl group, pyridyl group, quinolyl group, benzoquinolyl group, carbazolyl group, phenothiazinyl group, benzofuryl group, benzo An aryl group such as a thiophenyl group, a dibenzofuryl group, and a dibenzothiophenyl group, and R²⁷, R²⁸, R²⁹And R³⁰Is an alkyl group having 10 or less carbon atoms such as an optionally substituted methyl group, ethyl group, propyl group and butyl group, an optionally substituted benzyl group, phenethyl group, naphthylmethyl group, furfuryl group. And an aralkyl group such as a thienyl group, an optionally substituted phenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group, thiophenyl group, furyl group, pyridyl group, quinolyl group, benzoquinolyl group, carbazolyl group, phenol An aryl group such as a thiazinyl group, a benzofuryl group, a benzothiophenyl group, a dibenzofuryl group, and a dibenzothiophenyl group;²⁹And R³⁰Represents a hydrogen atom in addition to these alkyl, aralkyl and aryl groups. In addition, R²⁷And R²⁸And R²⁹And R³⁰May be the same or different.
[0062]
R²⁷Or R²⁸Or Ar⁶Any two of them, or Ar⁷And R³⁰Each may be bonded directly or via a bonding group, such as a methylene group, an alkylene group such as an ethylene group and a propylene group, a hetero atom such as an oxygen atom and a sulfur atom, or a CH═CH group. Can be mentioned. n¹Represents an integer of 0-2. Of these, R³⁰Is preferably an aryl group, and further R²⁷And R²⁸Is particularly preferably an aryl group.
[0063]
Furthermore, as a compound having the group represented by the general formula (18), a naphthalene group, anthracene group, phenanthrene group, perene group, fluorene group, fluoranthene group, azulene group, indene group, which may have a substituent, may be used. Condensed ring hydrocarbons such as perylene group, chrysene group and coronene group or condensed heterocyclic rings such as benzofuran group, indole group, carbazole group, benzcarbazole group, acridine group, phenothiazine group and quinoline group which may have a substituent Is mentioned.
[0064]
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[0065]
However, the general formula (19) has at least one group represented by the following general formula (20).
[0066]
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[0067]
In the general formulas (19) and (20), Ar⁸, Ar⁹And Ar^TenMay have a phenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group, thiophenyl group, furyl group, pyridyl group, quinolyl group, benzoquinolyl group, carbazolyl group, phenothiazinyl group, benzofuryl group, benzo An aryl group such as a thiophenyl group, a dibenzofuryl group, and a dibenzothiophenyl group, and R³¹, R³²And R³³Is an alkyl group having 10 or less carbon atoms such as an optionally substituted methyl group, ethyl group, propyl group and butyl group, an optionally substituted benzyl group, phenethyl group, naphthylmethyl group, furfuryl group. And an aralkyl group such as a thienyl group, an optionally substituted phenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group, thiophenyl group, furyl group, pyridyl group, quinolyl group, benzoquinolyl group, carbazolyl group, phenol An aryl group such as a thiazinyl group, a benzofuryl group, a benzothiophenyl group, a dibenzofuryl group, and a dibenzothiophenyl group;³²And R³³Represents a hydrogen atom in addition to these alkyl, aralkyl and aryl groups. Ar⁸And Ar⁹And R³²And R³³May be the same or different.
[0068]
Among them, R³¹And R³²Is preferably an aryl group. R³¹, Ar⁸Or Ar⁹Any two of them, or Ar^TenAnd R³³Each may be bonded directly or via a bonding group, such as a methylene group, an alkylene group such as an ethylene group and a propylene group, a hetero atom such as an oxygen atom and a sulfur atom, or a CH═CH group. Can be mentioned. n²Represents an integer of 0-2.
[0069]
Z in the general formula (1) and Q in the general formula (16) are an alkylene group which may have a substituent, an arylene group which may have a substituent, CR¹= CR²(R¹And R²Represents an alkyl group, an aryl group or a hydrogen atom, R¹And R²May be the same or different), C = O, S = O, SO₂Represents an organic group in which one or an arbitrary combination of an oxygen atom or a sulfur atom. Among them, those represented by the following general formula (2) are preferable, and those represented by the following general formula (3) are particularly preferable.
[0070]
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[0071]
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[0072]
In the general formula (2), X¹~ X^ThreeIs an alkylene group having 20 or less carbon atoms such as methylene group, ethylene group and propylene group which may have a substituent, (CR^Three= CR^Four)_m1, C = O, S = O, SO₂Represents an oxygen atom or a sulfur atom, Ar¹And Ar²Is an arylene group which may have a substituent (two from benzene, naphthalene, anthracene, phenanthrene, pyrene, thiophene, furan, pyridine, quinoline, benzoquinoline, carbazole, phenothiazine, benzofuran, benzothiophene, dibenzofuran, dibenzothiophene, etc. Group from which a hydrogen atom has been removed. R^ThreeAnd R^FourRepresents an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group which may have a substituent, an aryl group such as a phenyl group, a naphthyl group and a thiophenyl group which may have a substituent, or a hydrogen atom. , R^ThreeAnd R^FourMay be the same or different. m¹Represents an integer of 1 to 5, and p to t represent an integer of 0 to 10 (provided that p to t are not 0 at the same time).
[0073]
In the general formula (3), X^FourAnd X^FiveIs (CH₂)_m2, (CH = CR^Five)_m3, C = O, or an oxygen atom, Ar^ThreeIs an arylene group which may have a substituent (two from benzene, naphthalene, anthracene, phenanthrene, pyrene, thiophene, furan, pyridine, quinoline, benzoquinoline, carbazole, phenothiazine, benzofuran, benzothiophene, dibenzofuran, dibenzothiophene, etc. Group from which a hydrogen atom has been removed. R^FiveRepresents an optionally substituted alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, an optionally substituted aryl group such as a phenyl group, a naphthyl group and a thiophenyl group, or a hydrogen atom. . m²Is an integer from 1 to 10, m^ThreeRepresents an integer of 1 to 5, and u to w represent an integer of 0 to 10 (particularly preferred is an integer of 0 to 5, provided that u to w are not 0 at the same time).
[0074]
In the above general formulas (1) to (3), (5), (6) and (14) to (20)¹~ R^Five, R⁹~ R³³, Ar¹~ Ar^Ten, X¹~ X^Five, Z and Q each may have a halogen atom such as fluorine, chlorine, bromine and iodine; a nitro group, a cyano group, a hydroxyl group; an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group Alkoxy groups such as methoxy group, ethoxy group and propoxy group; aryloxy groups such as phenoxy group and naphthoxy group; aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group, furfuryl group and thienyl group; phenyl group and naphthyl group; , Aryl groups such as anthryl group and pyrenyl group. Further, R in the general formula (4)⁶~ R⁸Examples of the substituent which may have include the above-mentioned substituents excluding the aryl group and diarylamino groups such as a diphenylamino group and a di (p-tolyl) amino group.
[0075]
Further, the hole transporting compound having one or more chain polymerizable functional groups in the same molecule in the present invention preferably has an oxidation potential of 1.2 (V) or less, particularly 0.4 to 1. .2 (V) is preferred. That is, when the oxidation potential exceeds 1.2 (V), injection of charges (holes) from the charge generating material is difficult to occur, resulting in problems such as increase in residual potential, deterioration in sensitivity, and increase in potential fluctuation during repeated use. If it is less than 0.4 (V), in addition to problems such as a decrease in charging ability, the compound itself is easily oxidized and easily deteriorates, resulting in deterioration in sensitivity, image blurring, and potential during repeated use. This is because problems such as large fluctuations are likely to occur.
[0076]
The oxidation potential described here is measured by the following method.
[0077]
(Measurement method of oxidation potential)
Saturated calomel electrode as reference electrode and 0.1N (n-Bu) as electrolyte_FourN⁺ClO_Four ^-Using an acetonitrile solution, the potential applied to the working electrode (platinum) was swept by a potential sweeper, and the potential when the obtained current-potential curve showed a peak was defined as an oxidation potential. Specifically, the sample is 0.1N (n-Bu)_FourN⁺ClO_Four ^-Dissolve in acetonitrile solution to a concentration of about 5-10 mmol%. Then, a voltage is applied to the sample solution with the working electrode, and a current change when the voltage is linearly changed from a low potential (0 V) to a high potential (+1.5 V) is measured to obtain a current-potential curve. In this current-potential curve, the potential at the peak top position when the current value showed a peak (or the first peak when there are a plurality of peaks) was defined as the oxidation potential.
[0078]
Furthermore, the hole transporting compound having the chain polymerizable functional group has a hole transporting ability of 1 × 10^-7(Cm²/ V. sec) or higher drift mobility is preferable (however, the applied electric field: 5 × 10^FourV / cm). 1 × 10^-7(Cm²/ V. If it is less than (sec), holes may not move sufficiently from the post-exposure development to the electrophotographic photosensitive member, so that the apparent sensitivity may be reduced and the residual potential may be increased.
[0079]
Although the typical example of the hole transportable compound which has a chain polymerizable functional group concerning this invention below is given, it is not limited to these.
[0080]
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[0081]
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[0082]
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[0083]
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[0084]
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[0085]
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[0086]
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[0087]
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[0088]
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[0089]
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[0090]
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[0091]
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[0092]
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[0093]
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[0094]
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[0095]
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[0096]
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[0097]
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[0098]
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[0099]
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[0100]
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[0101]
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[0102]
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[0103]
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[0104]
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[0105]
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[0106]
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[0107]
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[0108]
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[0109]
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[0110]
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[0111]
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[0112]
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[0113]
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[0114]
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[0115]
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[0116]
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[0117]
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[0118]
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[0119]
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[0120]
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[0121]
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[0122]
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[0123]
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[0124]
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[0125]
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[0126]
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[0127]
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[0128]
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[0129]
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[0130]
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[0131]
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[0132]
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[0133]
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[0134]
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[0135]
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[0136]
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[0137]
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[0138]
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[0139]
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[0140]
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[0141]
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[0142]
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[0143]
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[0144]
[Chemical Formula 86]

[0145]
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[0146]
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[0147]
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[0148]
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[0149]
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[0150]
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[0151]
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[0152]
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[0153]
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[0154]
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[0155]
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[0156]
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[0157]
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[0158]
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[0159]
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[0160]
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[0161]
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[0162]
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[0163]
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[0164]
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[0165]
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[0166]
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[0167]
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[0168]
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[0169]
In the present invention, the hole transporting compound in the protective layer is polymerized with a hole transporting compound having two or more chain polymerizable functional groups in the same molecule, so that the compound having a hole transporting ability has two or more crosslinks. A three-dimensional crosslinked structure is formed with points. The hole transporting compound can be either polymerized alone or mixed with a compound having another chain polymerizable functional group, and the kind / ratio is arbitrary. The compound having another chain polymerizable functional group mentioned here includes any monomer or oligomer / polymer having a chain polymerizable functional group.
[0170]
When the functional group of the hole transporting compound and the functional group of the other chain polymerizable compound are the same group or a group that can be polymerized with each other, they both have a three-dimensional cross-linked copolymer structure via a covalent bond. Is possible. When both functional groups are functional groups that do not polymerize with each other, the protective layer is a mixture of two or more three-dimensional cured products, or other chain-polymerizable compound monomer or the like in the main component three-dimensional cured product. Although it is comprised as what contains hardened | cured material, it is also possible to form IPN (Inter Penetrating Network), ie, an interpenetrating network structure, by controlling the compounding ratio / film forming method well.
[0171]
Further, a protective layer may be formed from a monomer or oligomer / polymer having a polymerizable group other than the hole transporting compound and a chain polymerizable functional group. Further, other various additives, a lubricant such as fluorine atom-containing resin fine particles, and the like may be contained.
[0172]
In the present invention, the hole transporting compound having a chain polymerizable functional group can be polymerized by heat, light such as visible light or ultraviolet light, and radiation. Therefore, in the formation of the protective layer in the present invention, the coating liquid for the protective layer contains the hole transporting compound having the chain polymerizable functional group and, if necessary, a polymerization initiator, and the coating liquid is used. The hole-transporting compound having the chain polymerizable functional group is polymerized by irradiating the formed coating film with light or radiation. In the present invention, it is preferable to polymerize the hole transporting compound having the chain polymerizable functional group by radiation. The greatest advantage of polymerization by radiation is that a polymerization initiator is not required, which makes it possible to produce a very high-purity three-dimensional protective layer and to ensure good durability. In addition, because it is a short and efficient polymerization reaction, the productivity is also high, and furthermore, because of its good radiation transmission, it inhibits curing when a thick film or additives such as additives are present in the film. The influence of the is very small. However, depending on the type of the chain polymerizable functional group and the type of the central skeleton, the polymerization reaction may not easily proceed, and in this case, it is possible to add a polymerization initiator within a range that does not affect the polymerization reaction. In this case, the radiation used is an electron beam and a γ-ray, and an electron beam is particularly preferable.
[0173]
In the case of electron beam irradiation, any type of accelerator such as a scanning type, an electro curtain type, a broad beam type, a pulse type, and a laminar type can be used. In the case of irradiating with an electron beam, the irradiation conditions are very important for developing the electric characteristics in the electrophotographic photosensitive member of the present invention. In the present invention, the acceleration voltage is preferably 250 KV or less, and optimally 150 KV or less. The dose is preferably in the range of 1 Mrad to 100 Mrad, more preferably in the range of 3 Mrad to 50 Mrad. When the acceleration voltage exceeds 250 KV, the electron beam irradiation damage to the characteristics of the photoreceptor tends to increase. In addition, it is necessary to be careful because curing is likely to be insufficient when the irradiation dose is less than 1 Mrad, and the photoreceptor characteristics are likely to deteriorate when the dose is more than 100 Mrad.
[0174]
The amount of the hole transporting compound is a hydrogen adduct of the hole transporting group A having the chain polymerizable functional group represented by the general formula (1) with respect to the total mass of the protective layer film after polymerization and curing. Is preferably 20% by mass or more, and particularly preferably 40% by mass or more. If it is less than 20% by mass, the charge transport ability is lowered, and problems such as a reduction in sensitivity and an increase in residual potential are likely to occur. In this case, the thickness of the protective layer is preferably from 0.1 to 10 μm, particularly preferably from 0.5 to 7 μm.
[0175]
Next, the photosensitive layer will be described.
[0176]
As described above, the use of a hole transporting compound having two or more chain polymerizable functional groups in the same molecule as the protective layer dramatically improves the mechanical strength, but the photosensitive layer is an organic photosensitive layer. In such a case, sufficient sensitivity may not be obtained, or the residual potential may be increased. In addition, the potential fluctuates with changes in the environment, and a sufficiently stable potential characteristic may not be obtained.
[0177]
As a result of intensive studies, the present inventors have found that there is a relationship between the molecular weight of the charge transport material in the photosensitive layer in contact with the protective layer, sensitivity, residual power, and environmental potential fluctuations, leading to the present invention. That is, by setting the molecular weight of the charge transport material of the photosensitive layer in contact with the protective layer to 350 or more, it is possible to suppress a decrease in sensitivity and an increase in residual potential, and it is possible to suppress fluctuations in environmental potential.
[0178]
The mechanism of the present invention is not clear, but is considered as follows. When a hole transporting compound having two or more chain polymerizable functional groups in the same molecule as a protective layer is polymerized by irradiating light and radiation, light and radiation are also applied to the photosensitive layer under the protective layer. Has reached. It is considered that this light and radiation deteriorate the charge generation material and the charge transport material in the photosensitive layer, and the photoreceptor characteristics are deteriorated. Charge transport materials with low molecular weight cannot disperse absorbed light and radiation energy, and degradation due to molecular cleavage occurs, but charge transport materials with high molecular weight can desorb absorbed light and radiation energy, By converting it to thermal energy, stabilization is possible and degradation is expected to be suppressed. In addition, it is considered that the charge transport material converts light and radiation energy into heat energy, thereby suppressing deterioration of the charge generation material. Therefore, when a charge transport material having a large molecular weight is used, it is considered that deterioration of the charge generation material and the charge transport material due to light and radiation can be suppressed.
[0179]
In the present invention, the molecular weight of the charge transport material is preferably 350 or more and 700 or less. This is because, if it exceeds 700, the solubility is lowered, or the potential characteristics and environmental fluctuations tend to deteriorate.
[0180]
The charge transport material contained in the photosensitive layer in the present invention may be any as long as the molecular weight is 350 or more. For example, heterocyclic compounds such as poly-N-vinylcarbazole and polystyrylanthracene, polymer compounds having condensed polycyclic aromatics, heterocyclic compounds such as pyrazoline, imidazole, oxazole, triazole and carbazole, and triaryl such as triphenylmethane. Examples include a reel alkane derivative, a triarylamine derivative such as triphenylamine, a phenylenediamine derivative, an N-phenylcarbazole derivative, a stilbene derivative, a hydrazone derivative, and a butadiene derivative.
[0181]
Examples of charge transport material compounds and their molecular weights are shown below. Compound Example No. 1-No. 11 is a compound outside the present invention because it has a molecular weight of less than 350. Of course, the charge transport material used in the present invention is not limited to these.
[0182]
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[0183]
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[0184]
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[0185]
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[0186]
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[0187]
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[0188]
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[0189]
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[0190]
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[0191]
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[0192]
In the present invention, a charge transport material other than the charge transport material having a molecular weight of 350 or more can be further added. However, in order to sufficiently obtain the effects of the present invention, the charge transporting material having a molecular weight of 350 or more is preferably 50% by weight or more of the total charge transporting material in the photosensitive layer, and more preferably 70% by weight or more. Is more preferable.
[0193]
The electrophotographic photoreceptor of the present invention has a laminate type in which a charge generation layer containing a charge generation material as a photosensitive layer under a protective layer and a charge transport layer containing a charge transport material and a binder resin are laminated in this order, or It is possible to adopt any configuration of a single layer type including a single layer having a charge generation material, a charge transport material, and a binder resin in the same layer.
[0194]
Hereinafter, the laminated photosensitive layer will be described.
[0195]
The charge transport layer in the present invention can be formed by applying a solution in which a charge transport material is dispersed / dissolved in a solvent together with a binder resin and then drying.
[0196]
As the binder resin used together with the charge transport material, conventionally used resins for charge transport layers can be used, and examples thereof include polyester, polycarbonate, polyarylate, polymethacrylate, polystyrene, and the like. The thickness of the charge transport layer is preferably 1 to 50 μm, and particularly preferably 5 to 30 μm.
[0197]
In this case, the ratio of the charge transport material to the binder resin is appropriately selected in the range of 10 to 100, preferably 20 to 100, when the total mass of both is 100.
[0198]
The charge generation layer in the present invention is preferably formed by applying a solution in which a charge generation material is dispersed in a binder resin and drying, but may be formed by vapor deposition of only the charge generation material.
[0199]
Examples of charge generation materials include selenium-tellurium, pyrylium, thiapyrylium dyes, various central metals and crystal systems, specifically phthalocyanine compounds having crystal types such as α, β, γ, ε, and X type, Anthrone pigments, dibenzpyrenequinone pigments, pyranthrone pigments, trisazo pigments, disazo pigments, monoazo pigments, indigo pigments, quinacridone pigments, asymmetric quinocyanine pigments, quinocyanine, and amorphous silicon described in JP-A No. 54-143645 .
[0200]
The charge generation layer is well dispersed by a method such as a homogenizer, ultrasonic dispersion, ball mill, vibration ball mill, sand mill, attritor and roll mill together with 0.3 to 4 times the amount of binder resin and solvent. It is formed by applying a liquid and drying, or formed as a single composition film such as a vapor deposition film of the charge generation material. The film thickness is preferably 5 μm or less, and particularly preferably in the range of 0.1 to 2 μm.
[0201]
Examples of using binder resins are polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinylidene fluoride, trifluoroethylene, polyvinyl alcohol, polyvinyl Examples include acetal, polycarbonate, polyester, polysulfone, polyphenylene oxide, polyurethane, cellulose resin, phenol resin, melamine resin, silicon resin, and epoxy resin.
[0202]
When the photosensitive layer is a single layer, it can be formed by applying and drying a solution in which the charge generating material and a charge transporting material having a molecular weight of 350 or more are dispersed and dissolved in the binder resin.
[0203]
Various additives can be added to the photosensitive layer in the invention. The additive is a deterioration preventing agent such as an antioxidant and an ultraviolet absorber, or a lubricant such as fluorine atom-containing resin fine particles.
[0204]
The electrophotographic photosensitive member may be any support as long as it has conductivity. For example, aluminum, copper, chromium, nickel, zinc, stainless steel, or a metal or alloy formed into a drum or sheet, aluminum, copper, etc. Metal foil laminated with plastic film, aluminum, indium oxide and tin oxide deposited on plastic film, metal with conductive layer applied alone or with binder resin, and plastic film And paper.
[0205]
In the present invention, the surface of the conductive support may be chemically treated by chemical conversion treatment, that is, reaction with an acid or alkali aqueous solution to form an insoluble film.
[0206]
An undercoat layer having a barrier function and an adhesive function can be provided on the conductive support. The undercoat layer is used for improving the adhesion of the photosensitive layer, improving the coatability, protecting the support, covering defects on the support, improving the charge injection from the support, and protecting the photosensitive layer from electrical breakdown. Formed for.
[0207]
As the material of the undercoat layer, for example, polyethylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate resin, polyurethane resin, polyimide resin, vinylidene chloride resin, polyvinyl acetal resin, Vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, water-soluble polyester resin, alcohol-soluble nylon resin, nitrocellulose, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, polyacrylic acid, polyacrylamide, etc. Alternatively, a metal organic compound such as a silane coupling agent or an organic metal compound containing zirconium, titanium, aluminum, manganese, or the like can be used alone or in admixture of two or more. These are dissolved in a solvent suitable for each and coated on a support. As a film thickness in that case, 0.1-5 micrometers is preferable.
[0208]
For example, a dip coating method, a spray coating method, a curtain coating method, a spin coating method, and the like are known as a coating method for each of these layers, but the dip coating method is preferable from the viewpoint of efficiency / productivity. Moreover, vapor deposition, plasma, and other known film forming methods can be appropriately selected.
[0209]
FIG. 1 shows a schematic configuration of an electrophotographic apparatus using a process cartridge having the electrophotographic photosensitive member of the present invention.
[0210]
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 rotating process, the electrophotographic photosensitive member 1 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by the primary charging unit 3, and then from an exposure unit (not shown) such as slit exposure or laser beam scanning exposure. The exposure light 4 that is enhanced and modulated corresponding to the time-series electric digital image signal of the target image information to be output is received. In this way, electrostatic latent images corresponding to the target image information are sequentially formed on the peripheral surface of the electrophotographic photoreceptor 1.
[0211]
The formed electrostatic latent image is then developed with toner by the developing means 5 and is taken out from a paper feeding unit (not shown) between the electrophotographic photoreceptor 1 and the transfer means 6 in synchronism with the rotation of the electrophotographic photoreceptor 1. The toner image formed and supported on the surface of the electrophotographic photosensitive member 1 is sequentially transferred by the transfer means 6 onto the transferred transfer material 7.
[0212]
The transfer material 7 that has received the transfer of the toner image is separated from the surface of the electrophotographic photosensitive member, introduced into the image fixing means 8, and subjected to image fixing to be printed out as an image formed product (print, copy). .
[0213]
After the image transfer, the surface of the electrophotographic photosensitive member 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. When the primary charging unit 3 is a contact charging unit using a charging roller or the like, pre-exposure is not always necessary.
[0214]
In the present invention, among the above-described components such as the electrophotographic photosensitive member 1, the primary charging unit 3, the developing unit 5 and the cleaning unit 9, a plurality of components are housed in a container 11 and integrally combined as a process cartridge. The 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 together with the electrophotographic photosensitive member 1 to form a cartridge, and is attached to and detached from the apparatus main body using a guide unit 12 such as a rail of the apparatus main body. A flexible process cartridge can be obtained.
[0215]
Further, when the electrophotographic apparatus is a copying machine or a printer, the exposure light 4 is reflected or transmitted light from the original, or the original is read by a sensor and converted into a signal, and a laser beam scanning performed according to this signal is performed. Light emitted by driving the LED array, driving the liquid crystal shutter array, or the like.
[0216]
The electrophotographic photoreceptor 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, FAX, liquid crystal printers, and laser plate making. .
[0217]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples. In addition, "part" in an Example represents a mass part.
[0218]
Example 1
First, a coating material for the conductive layer was prepared by the following procedure. 50 parts of conductive titanium oxide powder coated with tin oxide containing 10% by weight of antimony oxide, 25 parts of phenol resin, 20 parts of methyl cellosolve, 5 parts of methanol and silicone oil (polydimethylsiloxane polyoxyalkylene copolymer, An average molecular weight of 3000) 0.002 part was prepared by dispersing for 2 hours in a sand mill using φ1 mm glass beads. This paint was applied on a φ30 mm aluminum cylinder by a dip coating method and dried at 140 ° C. for 30 minutes to form a conductive layer having a thickness of 20 μm.
[0219]
Next, 5 parts of N-methoxymethylated nylon was dissolved in 95 parts of methanol to prepare an intermediate layer coating material. This paint was applied on the conductive layer by a dip coating method and dried at 100 ° C. for 20 minutes to form an intermediate layer having a thickness of 0.6 μm.
[0220]
Next, oxytitanium phthalocyanine having strong peaks at Bragg angles (2θ ± 0.2 degrees) of 9.0, 14.2, 23.9, and 27.1 degrees in characteristic X-ray diffraction of CuKα 3 parts, 3 parts of polyvinyl butyral (trade name: ESREC BM2, manufactured by Sekisui Chemical Co., Ltd.) and 35 parts of cyclohexanone are dispersed for 2 hours in a sand mill using φ1 mm glass beads, and then 60 parts of ethyl acetate is added. Thus, a charge generation layer coating material was prepared. This paint was applied onto the intermediate layer by a dip coating method and dried at 50 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.2 μm.
[0221]
Subsequently, Compound Example No. 1 is used as a charge transport material. 10 parts of a polycarbonate resin having 10 parts of 54 and a repeating unit of the following structural formula (21)
[0222]
Embedded image

It was dissolved in a mixed solvent of 50 parts of monochlorobenzene / 30 parts of dichloromethane to prepare a coating solution for a charge transport layer. This coating solution was dip-coated on the charge generation layer and dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm.
[0223]
Compound Example No. 6 parts of the hole transporting compound No. 6 were dissolved in a mixed solvent of 50 parts of monochlorobenzene / 50 parts of dichloromethane to prepare a coating material for a protective layer. By applying this paint on the previous charge transport layer by spray coating method and irradiating an electron beam under the conditions of an acceleration voltage of 150 KV and a dose of 30 Mrad to cure the resin, a protective layer having a film thickness of 5 μm is formed. An electrophotographic photoreceptor was obtained.
[0224]
The produced electrophotographic photosensitive member was mounted on an LBP-SX manufactured by Canon Inc., and the initial electrophotographic characteristics were evaluated. Initial photoconductor characteristics [light attenuation sensitivity (light amount necessary for light attenuation to −200 V when dark portion potential is set to −700 V) and residual potential Vsl (potential when a light amount three times the light attenuation sensitivity is applied) ] Was measured in a normal temperature and normal humidity environment (23 ° C./50% RH). Thereafter, the environment was changed to high temperature and high humidity (32 ° C./85% RH) (H / H), and the amount of fluctuation (ΔVl) of Vl from the room temperature and normal humidity environment was measured. The results are shown in Table 3.
[0225]
(Examples 2 to 22 and Comparative Examples 1 to 4)
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the hole transporting compound in the protective layer of Example 1 or the charge transporting material in the photosensitive layer was changed as shown in Table 3. . The results are shown in Table 3.
[0226]
(Example 23)
Compound example No. of charge transport material of Example 1 54 10 parts of compound example no. 198 parts and Compound Example No. An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that 542 parts were used. The results are shown in Table 4.
[0227]
(Example 24)
Compound example No. of charge transport material of Example 1 54 10 parts of compound example no. 5 3 parts and Compound Example No. 5 An electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the amount was changed to 547 parts. The results are shown in Table 4.
[0228]
(Example 25)
Compound example No. of charge transport material of Example 1 54 10 parts of compound example no. 5 7 parts and Compound Example No. 5 54 An electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the amount was changed to 3 parts. The results are shown in Table 4.
[0229]
(Example 26)
First, an electrophotographic photoreceptor support was obtained by the following procedure. A φ30 mm aluminum cylinder was prepared, and a non-chromate chemical conversion treatment solution (trade name: PARCOAT 3753, manufactured by Nihon Parkerizing Co., Ltd.) containing phytic acid as organophosphoric acid and titanium as metal was maintained at a temperature of 40 ° C. The aluminum cylinder was immersed in the liquid and subjected to chemical conversion treatment for 1 minute, then washed with pure water and naturally dried to obtain a support.
[0230]
A charge generation layer, a charge transport layer, and a protective layer were formed on the support in the same manner as in Example 1 and evaluated. The results are shown in Table 4.
[0231]
(Examples 27 and 28)
Compound No. of charge transport material of Example 26 54 was compound example no. 29 and Compound Example No. An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 26 except that 68 was used. The results are shown in Table 4.
[0232]
(Example 29)
A 30 mm aluminum cylinder was honed and washed with ultrasonic water to make a conductive support.
[0233]
Next, 160 parts of methoxyethanol, 64 parts (0.06 mol) of an 85% butanol solution of zirconium tetra-n-butoxide (Kanto Chemical Co., Ltd.) and 22 parts of titanium tetra-n-butoxide (Kishida Chemical Co., Ltd.) 14 mol) is added dropwise, and a mixed solution of methoxyethanol / pure water = 160 parts / 11 parts is further added. Further, after dropping a solution obtained by adding 20 parts of acetylacetone to 200 parts of methanol, an intermediate layer coating solution obtained by mixing 55 parts of a 10% by mass methanol solution of hydroxypropylcellulose (manufactured by Tokyo Chemical Industry Co., Ltd.) is supported on an aluminum cylinder. An intermediate layer having a thickness of 0.3 μm was formed by dip-coating on the body and drying by heating at 120 ° C. for 15 minutes.
[0234]
A charge generation layer, a charge transport layer, and a protective layer were formed on the intermediate layer in the same manner as in Example 1 and evaluated. The results are shown in Table 4.
[0235]
(Examples 30 and 31)
Compound No. of charge transport material of Example 29 54 was compound example no. 32 and Compound Example No. An electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 29 except that 40 was used. The results are shown in Table 4.
[0236]
(Example 32)
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 2 except that the charge transport layer coating solution was prepared as follows. The results are shown in Table 4.
[0237]
Compound example No. of charge transport material 54 16 parts, 4 parts of a polycarbonate resin having a repeating unit of the structural formula (21) and 1 part of an antioxidant (trade name: Irganox 1330, manufactured by Ciba Geigy) in a mixed solvent of 50 parts of monochlorobenzene / 30 parts of dichloromethane To prepare a coating solution for charge transport layer.
[0238]
(Example 33)
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the charge transport layer coating solution was prepared as follows. The results are shown in Table 4.
[0239]
Compound example No. of charge transport material 98 3 parts and Compound Example No. 89 1 part, 16 parts of a polycarbonate resin having the repeating unit of the structural formula (21), 0.5 part of an antioxidant (trade name: Sumilizer GS, manufactured by Sumitomo Chemical Co., Ltd.) and an antioxidant (trade name: IRGAFOS- 168, manufactured by Ciba-Geigy Corporation of Japan) was dissolved in a mixed solvent of 50 parts monochlorobenzene / 30 parts dichloromethane to prepare a charge transport layer coating solution.
[0240]
As shown in the examples of Table 3 and Table 4, when a charge transport material having a molecular weight of 350 or more is used, the potential characteristics and environmental characteristics are good, whereas as shown in the comparative example, a charge transport material having a molecular weight of less than 350 is used. When used, there was a decrease in sensitivity and an increase in residual potential, and there was also a significant change in environment.
[0241]
[Table 3]

[0242]
[Table 4]

[0243]
【The invention's effect】
According to the present invention, an electrophotographic photosensitive member having good sensitivity, little increase in residual potential, very good electrophotographic characteristics such as small potential fluctuation due to the environment, etc., and always exhibiting stable performance. Could be provided.
[0244]
The effect of the electrophotographic photosensitive member is naturally exhibited in a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member, and high image quality is maintained for a long time.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus using a process cartridge having an electrophotographic photosensitive member of the present invention.
[Explanation of symbols]
1 Electrophotographic photoreceptor
2 axis
3 Charging means
4 exposure light
5 Development means
6 Transfer means
7 Transfer material
8 Fixing means
9 Cleaning means
10 Pre-exposure light
11 Process cartridge container
12 Guide means

Claims (20)

In the electrophotographic photosensitive member having a conductive support, a photosensitive layer and a protective layer, the protective layer contains a compound obtained by polymerizing a hole transporting compound having two or more chain polymerizable functional groups in the same molecule, An electrophotographic photoreceptor, wherein the photosensitive layer contains a charge transport material having a molecular weight of 350 or more. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains a charge transport material having a molecular weight of 350 to 700. 3. The electrophotographic photosensitive member according to claim 1, wherein a ratio of the charge transport material is 50% by mass or more based on a total charge transport material contained in the photosensitive layer. The electrophotographic photoreceptor according to claim 1, wherein the hole transporting compound having a chain polymerizable functional group is represented by the following general formula (1).

(In the formula, A represents a hole transporting group. P ¹ and P ² represent a chain polymerizable functional group. P ¹ and P ² may be the same or different. Z may have a substituent. A, b and d are integers of 0 or more, a + b × d is an integer of 2 or more, and when a is 2 or more, P ¹ may be the same or different; In the case of 2 or more, Z and P ² may be the same or different) Z in the general formula (1) may have a substituent, an alkylene group, an arylene group which may have a substituent, CR ¹ = CR ² (R ¹ and R ² may have a substituent) A good alkyl group, an aryl group which may have a substituent or a hydrogen atom, and R ¹ and R ² may be the same or different), C═O, S═O, SO ₂ , an oxygen atom or a sulfur atom The electrophotographic photosensitive member according to claim 4, wherein the electrophotographic photosensitive member shows one or an arbitrary combined organic group. The electrophotographic photosensitive member according to claim 4, wherein Z in the general formula (1) is represented by the following general formula (2).

(Wherein X ^{1 to} X ³ represent an alkylene group which may have a substituent, (CR ³ = CR ⁴ ) _m1 , C═O, S═O, SO ₂ , an oxygen atom or a sulfur atom; Ar ^{1 to} Ar ² represent an arylene group which may have a substituent, and R ³ and R ⁴ represent an alkyl group which may have a substituent, an aryl group which may have a substituent, or a hydrogen atom. , R ³ and R ⁴ may be the same or different, m ¹ represents an integer of ¹ to 5, and p to t represent an integer of 0 to 10, provided that p to t are not 0 at the same time. The electrophotographic photosensitive member according to claim 4, wherein Z in the general formula (1) is represented by the following general formula (3).

(In the formula, Ar ³ represents an arylene group which may have a substituent. X ⁴ and X ⁵ represent (CH ₂ ) _{m 2} , (CH═CR ⁵ ) _{m 3} , C═O, or an oxygen atom. R ⁵ represents an alkyl group that may have a substituent, an aryl group that may have a substituent, or a hydrogen atom, m ² is an integer of 1 to 10, m ³ is an integer of 1 to 5, u to w represents an integer of 0 to 10, provided that u to w are not 0 at the same time) The electron according to any one of claims 1 to 7, wherein the oxidation potential of the compound of the hole transporting compound having two or more chain polymerizable functional groups in the same molecule is 0.4 to 1.2 (V). Photoconductor. The hole transporting compound in which the bonding site of A, P ¹ and Z is replaced with a hydrogen atom in the general formula (1) is represented by the following general formula (4). Electrophotographic photoreceptor.

(Wherein R ⁶ , R ⁷ and R ⁸ represent an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or an aryl group which may have a substituent, provided that (At least two of them represent an aryl group, and R ⁶ , R ⁷ and R ⁸ may be the same or different.) The electrophotographic photosensitive member according to claim 9, wherein R ⁶ , R ⁷ and R ^{8 in the} general formula (4) are aryl groups which may have a substituent. The hole transportable compound in which the bonding site of A, P ¹ and Z is replaced by a hydrogen atom in the general formula (1) is represented by the following general formula (5). Electrophotographic photoreceptor.

(In the formula, R ⁹ to R ¹² is an alkyl group which may have a substituent, an aryl group which may have a substituted or unsubstituted aralkyl group or a substituted group. Further, R ⁹ ~ R ¹² may be the same or different, Ar ⁴ and Ar ⁵ each represent an arylene group which may have a substituent, and each may be the same or different, m ⁴ represents 0 or 1 ) The electrophotographic photoreceptor according to claim 11, wherein m ^{4 in the} general formula (5) is 1, and R ^{9 to} R ¹² are aryl groups which may have a substituent. The electrophotographic photosensitive member according to claim 4, wherein one or both of the chain polymerizable functional groups P ¹ and P ² is an unsaturated polymerizable functional group represented by the following general formula (6).

(In the formula, E represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, a cyano group, a nitro group, an alkoxy group, —COOR ¹³ {R ¹³ is A hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent or an aryl group which may have a substituent) or —CONR ¹⁴ R ¹⁵ {R ¹⁴ and R ¹⁵ represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or an aryl group which may have a substituent. W is an arylene group which may have a substituent, an alkylene group which may have a substituent, —COO—, —CH ₂ —, —O—, —OO—, — S— or —CONR ¹⁶ — {R ¹⁶ is a hydrogen atom, a halogen atom, An alkyl group that may have a substituent, an aralkyl group that may have a substituent, or an aryl group that may have a substituent}. f represents 0 or 1; ) The electrophotographic photosensitive member according to any one of claims 4 to 12, wherein one or both of the chain polymerizable functional groups P ¹ and P ² are any one of the following general formulas (7) to (13).

The electrophotographic photosensitive member according to claim 14, wherein one or both of the chain polymerizable functional groups P ¹ and P ² is the general formula (7) or the general formula (8). The electrophotographic photosensitive member according to claim 1, wherein the polymerization is performed by an electron beam. The electrophotographic photosensitive member according to claim 16, wherein an acceleration voltage of the electron beam is 250 KV or less. The electrophotographic photosensitive member according to claim 16 or 17, wherein the electron beam dose is 1 to 100 Mrad. The electrophotographic photosensitive member according to claim 1, a charging means for charging the electrophotographic photosensitive member, a developing means for developing the electrophotographic photosensitive member on which an electrostatic latent image is formed with toner, and a transfer Process cartridge characterized in that it is integrally supported with at least one means selected from the group consisting of cleaning means for collecting toner remaining on the electrophotographic photosensitive member after the process, and is detachable from the main body of the electrophotographic apparatus. . An electrophotographic photosensitive member according to any one of claims 1 to 18, a charging means for charging the electrophotographic photosensitive member, an exposure means for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image, An electrophotographic apparatus comprising: a developing unit that develops toner on an electrophotographic photosensitive member on which a latent image is formed; and a transfer unit that transfers a toner image on the electrophotographic photosensitive member onto a transfer material.

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