JP4204209B2 - Electrophotographic photosensitive member, manufacturing method thereof, electrophotographic method, and electrophotographic apparatus - Google Patents

Description

式中、Ｒ₁，Ｒ₂，Ｒ₃はそれぞれ独立して置換もしくは無置換のアルキル基又はハロゲン原子、Ｒ₄は水素原子又は置換もしくは無置換のアルキル基、Ｒ₅ ，Ｒ₆ は置換もしくは無置換のアリール基、ｏ，ｐ，ｑはそれぞれ独立して０〜４の整数を表わす。ｋ，ｊは組成割合を表わし、ｋ＋ｊを１とした場合、０．１≦ｋ≦１、０≦ｊ≦０．９であり、ｎは繰り返し単位数を表わし５〜５０００の整数である。Ｘは脂肪族の２価基、環状脂肪族の２価基、または下記一般式で表わされる２価基を表わす。
【００６６】
【化２】

式中、Ｒ₁₀₁，Ｒ₁₀₂は各々独立して置換もしくは無置換のアルキル基、アリール基またはハロゲン原子を表わす。ｌ、ｍは０〜４の整数、Ｙは単結合、炭素原子数１〜１２の直鎖状、分岐状もしくは環状のアルキレン基、−Ｏ−，−Ｓ−，−ＳＯ−，−ＳＯ₂−，−ＣＯ−，−ＣＯ−Ｏ−Ｚ−Ｏ−ＣＯ−（式中Ｚは脂肪族の２価基を表わす。）または、
【００６７】
【化３】

（式中、ａは１〜２０の整数、ｂは１〜２０００の整数、Ｒ₁₀₃、Ｒ₁₀₄は置換または無置換のアルキル基又はアリール基を表わす。）を表わす。ここで、Ｒ₁₀₁とＲ₁₀₂，Ｒ₁₀₃とＲ₁₀₄は、それぞれ同一でも異なってもよい。
【００６８】
【化４】

式中、Ｒ₇，Ｒ₈は置換もしくは無置換のアリール基、Ａｒ₁，Ａｒ₂，Ａｒ₃は同一あるいは異なるアリーレン基を表わす。Ｘ，ｋ，ｊおよびｎは、一般式（Ｉ）の場合と同じである。
【００６９】
【化５】

式中、Ｒ₉，Ｒ₁₀は置換もしくは無置換のアリール基、Ａｒ₄，Ａｒ₅，Ａｒ₆は同一あるいは異なるアリーレン基を表わす。Ｘ，ｋ，ｊおよびｎは、一般式（Ｉ）の場合と同じである。
【００７０】
【化６】

式中、Ｒ₁₁，Ｒ₁₂は置換もしくは無置換のアリール基、Ａｒ₇，Ａｒ₈，Ａｒ₉は同一あるいは異なるアリーレン基、ｐは１〜５の整数を表わす。Ｘ，ｋ，ｊおよびｎは、一般式（Ｉ）場合と同じである。
【００７１】
【化７】

式中、Ｒ₁₃，Ｒ₁₄は置換もしくは無置換のアリール基、Ａｒ₁₀，Ａｒ₁₁，Ａｒ₁₂は同一あるいは異なるアリーレン基、Ｘ₁，Ｘ₂は置換もしくは無置換のエチレン基、又は置換もしくは無置換のビニレン基を表わす。Ｘ，ｋ，ｊおよびｎは、一般式（Ｉ）の場合と同じである。
【００７２】
【化８】

式中、Ｒ₁₅，Ｒ₁₆，Ｒ₁₇，Ｒ₁₈は置換もしくは無置換のアリール基、Ａｒ₁₃，Ａｒ₁₄，Ａｒ₁₅，Ａｒ₁₆は同一あるいは異なるアリーレン基、Ｙ₁，Ｙ₂，Ｙ₃は単結合、置換もしくは無置換のアルキレン基、置換もしくは無置換のシクロアルキレン基、置換もしくは無置換のアルキレンエーテル基、酸素原子、硫黄原子、ビニレン基を表わし同一であっても異なってもよい。Ｘ，ｋ，ｊおよびｎは、一般式（Ｉ）の場合と同じである。
【００７３】
【化９】

式中、Ｒ₁₉，Ｒ₂₀は水素原子、置換もしくは無置換のアリール基を表わし、Ｒ₁₉とＲ₂₀は環を形成していてもよい。Ａｒ₁₇，Ａｒ₁₈，Ａｒ₁₉は同一あるいは異なるアリーレン基を表わす。Ｘ，ｋ，ｊおよびｎは、一般式（Ｉ）の場合と同じである。
【００７４】
【化１０】

式中、Ｒ₂₁は置換もしくは無置換のアリール基、Ａｒ₂₀，Ａｒ₂₁，Ａｒ₂₂，Ａｒ₂₃は同一あるいは異なるアリーレン基を表わす。Ｘ，ｋ，ｊおよびｎは、一般式（Ｉ）の場合と同じである。
【００７５】
【化１１】

式中、Ｒ₂₂，Ｒ₂₃，Ｒ₂₄，Ｒ₂₅は置換もしくは無置換のアリール基、Ａｒ₂₄，Ａｒ₂₅，Ａｒ₂₆，Ａｒ₂₇，Ａｒ₂₈は同一あるいは又は異なるアリーレン基を表わす。Ｘ，ｋ，ｊおよびｎは、一般式（Ｉ）の場合と同じである。
【００７６】
【化１２】

式中、Ｒ₂₆，Ｒ₂₇は置換もしくは無置換のアリール基、Ａｒ₂₉，Ａｒ₃₀，Ａｒ₃₁は同一あるいは異なるアリーレン基を表わす。Ｘ，ｋ，ｊおよびｎは、一般式（Ｉ）の場合と同じである。
【００７７】
本発明においては、前記保護層に各種添加剤を添加することが可能であり、有効かつ有用である。添加剤としては、可塑剤、酸化防止剤、潤滑性物質等、従来公知の添加剤をすべて使用することが可能である。
【００７８】
酸化防止剤には、フェノール系化合物類、ヒンダードフェノール系化合物類、ヒンダードアミン系化合物類、パラフェニレンジアミン類、ハイドロキノン類、有機硫黄化合物類、有機リン化合物類、ベンゾフェノン類、サルシレート類、ベンゾトリアゾール類、クエンチャー（金属錯塩系）等、従来公知の酸化防止剤、紫外線吸収剤、光安定剤等の添加剤がすべて含まれる。また、これらの酸化防止剤を２種以上混合して使用することも可能であり、その組合せによっては相乗効果が得られる場合がある。しかし、その添加量によっては著しい残留電位上昇を引き起こす傾向が強く見られるものがある。これらの酸化防止剤の中で、ＮＯｘやオゾンガスによる画像ボケあるいは帯電低下、感度低下等に対し効果が大きなものとしては、特にヒンダードフェノール系化合物及びヒンダードアミン系化合物が有用であることが知られている。
【００７９】
潤滑性物質としては、それらの添加によって保護層の表面の潤滑性を高める効果を有するものであり、液体状のものでも固体状のものでも構わない。残留電位の上昇や塗膜の変質が起こらない範囲で保護層表面に潤滑性を付与することには、耐摩耗性の向上やクリーニング性の向上等に非常に有効である。これらの潤滑性物質としては、シリコーンオイル類や固体粉末あるいは樹脂等、多くの種類があるが、その中でも固体粉末状の潤滑性物質を保護層中に分散した方が、潤滑性の持続性が高くより好ましい。これらの中でもステアリン酸亜鉛等の金属石鹸やフッ素系微粒子等は、特に有用である。
【００８０】
前記フィラー材料は、少なくとも有機溶剤、分散剤とともにボールミル、アトライター、サンドミル、超音波などの従来方法を用いて分散することができる。この中でも、フィラーと分散剤との接触効率を高くすることができ、外界からの不純物の混入が少ないボールミルが分散性の点からより好ましい。使用されるメディアの材質については、従来使用されているジルコニア、アルミナ、メノウ等すべてのメディアを使用することができるが、フィラーの分散性及び残留電位低減効果の点から特にアルミナを使用することが好ましく、耐摩耗性に優れたα型アルミナが特に好ましい。ジルコニアは分散時のメディアの摩耗量が比較的大きく、摩耗粉の混入によって残留電位が増加したり、分散性が低下する傾向が若干ある。一方、メディアにアルミナを使用した場合には、分散時のメディアの摩耗量は低く抑えられる上に、混入した摩耗粉が残留電位あるいは分散性に与える影響が小さい。従って、分散に使用するメディアにはアルミナを使用することがより好ましい。また、分散剤は、塗工液中のフィラーの凝集、さらにはフィラーの沈降性を抑制し、フィラーの分散性を著しく向上させることから、フィラーや有機溶剤とともに分散前より添加することが好ましい。一方、バインダー樹脂や電荷輸送物質、酸化防止剤等は、分散前に添加することも可能であるが、その場合、分散性が低下する場合が見られるため、有機溶剤に溶解された状態で分散後に添加することが好ましい。
【００８１】
以上のようにして得られた分散液の塗工法としては、浸漬塗工法、スプレーコート、ビートコート、ノズルコート、スピナーコート、リングコート等、従来の塗工方法を用いることができるが、比較的薄い膜を均一に、かつフィラー分散性の良好な膜を形成するためにはスプレー塗工が最も適している。スプレー塗工においては、必要な膜厚を一度に塗工するよりも、数度に分けて塗り重ねる方がフィラーの分散性を高める上でより有効である。そうすることによって、塗工時における塗液のタレを抑制することもできるため、塗膜品質の向上においても効果がある。
【００８２】
保護層全体の膜厚としては、０．５μｍ〜１０μｍ、好ましくは１〜６μｍが適当である。保護層の膜厚は、膜の均一性、耐摩耗性、残留電位の上昇、及び光透過率の低下により解像度やドット再現性の低下に影響を与える場合がある。
【００８３】
本発明の感光体においては、導電性支持体（３１）と感光層との間に下引き層を設けることができる。下引き層は一般には樹脂を主成分とするが、これらの樹脂はその上に感光層を溶剤で塗布することを考えると、一般の有機溶剤に対して耐溶剤性の高い樹脂であることが望ましい。このような樹脂としては、ポリビニルアルコール、カゼイン、ポリアクリル酸ナトリウム等の水溶性樹脂、共重合ナイロン、メトキシメチル化ナイロン等のアルコール可溶性樹脂、ポリウレタン、メラミン樹脂、フェノール樹脂、アルキッド−メラミン樹脂、エポキシ樹脂等、三次元網目構造を形成する硬化型樹脂等が挙げられる。また、下引き層にはモアレ防止、残留電位の低減等のために酸化チタン、シリカ、アルミナ、酸化ジルコニウム、酸化スズ、酸化インジウム等で例示できる金属酸化物の微粉末顔料を加えてもよい。これらの下引き層は、前述の感光層の如く適当な溶媒及び塗工法を用いて形成することができる。更に、本発明の下引き層として、シランカップリング剤、チタンカップリング剤、クロムカップリング剤等を使用することもできる。さらに、各種分散剤を添加することも可能である。この他、本発明の下引き層には、Ａｌ₂Ｏ₃を陽極酸化にて設けたものや、ポリパラキシリレン（パリレン）等の有機物やＳｉＯ₂、ＳｎＯ₂、ＴｉＯ₂、ＩＴＯ、ＣｅＯ₂等の無機物を真空薄膜作成法にて設けたものも良好に使用できる。このほかにも公知のものを用いることができる。さらに、下引き層は二層積層されていてもよく、地肌汚れの抑制に効果がある。下引き層の膜厚は０〜５μｍが適当である。
【００８４】
本発明の感光体においては、感光層と保護層との間に中間層を設けることも可能である。中間層には、一般にバインダー樹脂を主成分として用いる。これら樹脂としては、ポリアミド、アルコール可溶性ナイロン、水溶性ポリビニルブチラール、ポリビニルブチラール、ポリビニルアルコールなどが挙げられる。中間層の形成法としては、前述のごとく一般に用いられる塗布法が採用される。なお、中間層の厚さは０．０５〜２μｍ程度が適当である。
【００８５】
本発明においては、耐環境性の改善のため、とりわけ、感度低下、残留電位の上昇を防止する目的で、電荷発生層、電荷輸送層、下引き層、保護層、中間層等の各層に従来公知の酸化防止剤、可塑剤、滑剤、紫外線吸収剤、低分子電荷輸送物質およびレベリング剤を添加することが出来る。これらの化合物の代表的な材料を以下に記す。
【００８６】
各層に添加できる酸化防止剤として、例えば下記のものが挙げられるがこれらに限定されるものではない。
（ａ）フェノール系化合物
２，６−ジ−ｔ−ブチル−ｐ−クレゾール、ブチル化ヒドロキシアニソール、２，６−ジ−ｔ−ブチル−４−エチルフェノール、ｎ−オクタデシル−３−（４’−ヒドロキシ−３’，５’−ジ−t−ブチルフェノール）、２，２’−メチレン−ビス−（４−メチル−６−ｔ−ブチルフェノール）、２，２’−メチレン−ビス−（４−エチル−６−ｔ−ブチルフェノール）、４，４’−チオビス−（３−メチル−６−ｔ−ブチルフェノール）、４，４’−ブチリデンビス−（３−メチル−６−ｔ−ブチルフェノール）、１，１，３−トリス−（２−メチル−４−ヒドロキシ−５−ｔ−ブチルフェニル）ブタン、１，３，５−トリメチル−２，４，６−トリス（３，５−ジ−ｔ−ブチル−４−ヒドロキシベンジル）ベンゼン、テトラキス−［メチレン−３−（３’，５’−ジ−ｔ−ブチル−４’−ヒドロキシフェニル）プロピオネート］メタン、ビス［３，３'−ビス（４'−ヒドロキシ−３'−ｔ−ブチルフェニル）ブチリックアッシド］グリコールエステル、トコフェロ−ル類など。
【００８７】
（ｂ）パラフェニレンジアミン類
Ｎ−フェニル−Ｎ’−イソプロピル−ｐ−フェニレンジアミン、Ｎ，Ｎ’−ジ−ｓｅｃ−ブチル−ｐ−フェニレンジアミン、Ｎ−フェニル−Ｎ−ｓｅｃ−ブチル−ｐ−フェニレンジアミン、Ｎ，Ｎ'−ジ−イソプロピル−ｐ−フェニレンジアミン、Ｎ，Ｎ’−ジメチル−Ｎ，Ｎ'−ジ−ｔ−ブチル−ｐ−フェニレンジアミンなど。
【００８８】
（ｃ）ハイドロキノン類
２，５−ジ−ｔ−オクチルハイドロキノン、２，６−ジドデシルハイドロキノン、２−ドデシルハイドロキノン、２−ドデシル−５−クロロハイドロキノン、２−ｔ−オクチル−５−メチルハイドロキノン、２−（２−オクタデセニル）−５−メチルハイドロキノンなど。
【００８９】
（ｄ）有機硫黄化合物類
ジラウリル−３，３’−チオジプロピオネート、ジステアリル−３，３’−チオジプロピオネート、ジテトラデシル−３，３’−チオジプロピオネートなど。
【００９０】
（ｅ）有機燐化合物類
トリフェニルホスフィン、トリ（ノニルフェニル）ホスフィン、トリ（ジノニルフェニル）ホスフィン、トリクレジルホスフィン、トリ（２，４−ジブチルフェノキシ）ホスフィンなど。
【００９１】
各層に添加できる可塑剤として、例えば下記のものが挙げられるがこれらに限定されるものではない。
（ａ）リン酸エステル系可塑剤
リン酸トリフェニル、リン酸トリクレジル、リン酸トリオクチル、リン酸オクチルジフェニル、リン酸トリクロルエチル、リン酸クレジルジフェニル、リン酸トリブチル、リン酸トリ−２−エチルヘキシル、リン酸トリフェニルなど。
【００９２】
（ｂ）フタル酸エステル系可塑剤
フタル酸ジメチル、フタル酸ジエチル、フタル酸ジイソブチル、フタル酸ジブチル、フタル酸ジヘプチル、フタル酸ジ−２−エチルヘキシル、フタル酸ジイソオクチル、フタル酸ジ−ｎ−オクチル、フタル酸ジノニル、フタル酸ジイソノニル、フタル酸ジイソデシル、フタル酸ジウンデシル、フタル酸ジトリデシル、フタル酸ジシクロヘキシル、フタル酸ブチルベンジル、フタル酸ブチルラウリル、フタル酸メチルオレイル、フタル酸オクチルデシル、フマル酸ジブチル、フマル酸ジオクチルなど。
【００９３】
（ｃ）芳香族カルボン酸エステル系可塑剤
トリメリット酸トリオクチル、トリメリット酸トリ−ｎ−オクチル、オキシ安息香酸オクチルなど。
【００９４】
（ｄ）脂肪族二塩基酸エステル系可塑剤
アジピン酸ジブチル、アジピン酸ジ−ｎ−ヘキシル、アジピン酸ジ−２−エチルヘキシル、アジピン酸ジ−ｎ−オクチル、アジピン酸−ｎ−オクチル−ｎ−デシル、アジピン酸ジイソデシル、アジピン酸ジカプリル、アゼライン酸ジ−２−エチルヘキシル、セバシン酸ジメチル、セバシン酸ジエチル、セバシン酸ジブチル、セバシン酸ジ−ｎ−オクチル、セバシン酸ジ−２−エチルヘキシル、セバシン酸ジ−２−エトキシエチル、コハク酸ジオクチル、コハク酸ジイソデシル、テトラヒドロフタル酸ジオクチル、テトラヒドロフタル酸ジ−ｎ−オクチルなど。
【００９５】
（ｅ）脂肪酸エステル誘導体
オレイン酸ブチル、グリセリンモノオレイン酸エステル、アセチルリシノール酸メチル、ペンタエリスリトールエステル、ジペンタエリスリトールヘキサエステル、トリアセチン、トリブチリンなど。
【００９６】
（ｆ）オキシ酸エステル系可塑剤
アセチルリシノール酸メチル、アセチルリシノール酸ブチル、ブチルフタリルブチルグリコレート、アセチルクエン酸トリブチルなど。
【００９７】
（ｇ）エポキシ可塑剤
エポキシ化大豆油、エポキシ化アマニ油、エポキシステアリン酸ブチル、エポキシステアリン酸デシル、エポキシステアリン酸オクチル、エポキシステアリン酸ベンジル、エポキシヘキサヒドロフタル酸ジオクチル、エポキシヘキサヒドロフタル酸ジデシルなど。
【００９８】
（ｈ）二価アルコールエステル系可塑剤
ジエチレングリコールジベンゾエート、トリエチレングリコールジ−２−エチルブチラートなど。
【００９９】
（ｉ）含塩素可塑剤
塩素化パラフィン、塩素化ジフェニル、塩素化脂肪酸メチル、メトキシ塩素化脂肪酸メチルなど。
【０１００】
（ｊ）ポリエステル系可塑剤
ポリプロピレンアジペート、ポリプロピレンセバケート、ポリエステル、アセチル化ポリエステルなど。
【０１０１】
（ｋ）スルホン酸誘導体
ｐ−トルエンスルホンアミド、ｏ−トルエンスルホンアミド、ｐ−トルエンスルホンエチルアミド、ｏ−トルエンスルホンエチルアミド、トルエンスルホン−Ｎ−エチルアミド、ｐ−トルエンスルホン−Ｎ−シクロヘキシルアミドなど。
【０１０２】
（ｌ）クエン酸誘導体
クエン酸トリエチル、アセチルクエン酸トリエチル、クエン酸トリブチル、アセチルクエン酸トリブチル、アセチルクエン酸トリ−２−エチルヘキシル、アセチルクエン酸−ｎ−オクチルデシルなど。
【０１０３】
（ｍ）その他
テルフェニル、部分水添テルフェニル、ショウノウ、２−ニトロジフェニル、ジノニルナフタリン、アビエチン酸メチルなど。
【０１０４】
各層に添加できる潤滑性物質としては、例えば下記のものが挙げられるがこれらに限定されるものではない。
（ａ）炭化水素系化合物
流動パラフィン、パラフィンワックス、マイクロワックス、低重合ポリエチレンなど。
【０１０５】
（ｂ）脂肪酸系化合物
ラウリン酸、ミリスチン酸、パルチミン酸、ステアリン酸、アラキジン酸、ベヘン酸など。
【０１０６】
（ｃ）脂肪酸アミド系化合物
ステアリルアミド、パルミチルアミド、オレインアミド、メチレンビスステアロアミド、エチレンビスステアロアミドなど。
【０１０７】
（ｄ）エステル系化合物
脂肪酸の低級アルコールエステル、脂肪酸の多価アルコールエステル、脂肪酸ポリグリコールエステルなど。
【０１０８】
（ｅ）アルコール系化合物
セチルアルコール、ステアリルアルコール、エチレングリコール、ポリエチレングリコール、ポリグリセロールなど。
【０１０９】
（ｆ）金属石鹸
ステアリン酸鉛、ステアリン酸カドミウム、ステアリン酸バリウム、ステアリン酸カルシウム、ステアリン酸亜鉛、ステアリン酸マグネシウムなど。
【０１１０】
（ｇ）天然ワックス
カルナウバロウ、カンデリラロウ、蜜ロウ、鯨ロウ、イボタロウ、モンタンロウなど。
【０１１１】
（ｈ）その他
シリコーン化合物、フッ素化合物など。
【０１１２】
各層に添加できる紫外線吸収剤として、例えば下記のものが挙げられるがこれらに限定されるものではない。
（ａ）ベンゾフェノン系
２−ヒドロキシベンゾフェノン、２，４−ジヒドロキシベンゾフェノン、２，２’，４−トリヒドロキシベンゾフェノン、２，２’，４，４'−テトラヒドロキシベンゾフェノン、２，２’−ジヒドロキシ４−メトキシベンゾフェノンなど。
【０１１３】
（ｂ）サルシレート系
フェニルサルシレート、２，４ジ−ｔ−ブチルフェニル３，５−ジ−ｔ−ブチル４ヒドロキシベンゾエートなど。
【０１１４】
（ｃ）ベンゾトリアゾール系
（２’−ヒドロキシフェニル）ベンゾトリアゾール、（２’−ヒドロキシ５’−メチルフェニル）ベンゾトリアゾール、（２’−ヒドロキシ５’−メチルフェニル）ベンゾトリアゾール、（２’−ヒドロキシ３’−ターシャリブチル５’−メチルフェニル）５−クロロベンゾトリアゾールなど。
【０１１５】
（ｄ）シアノアクリレート系
エチル−２−シアノ−３，３−ジフェニルアクリレート、メチル２−カルボメトキシ３（パラメトキシ）アクリレートなど。
【０１１６】
（ｅ）クエンチャー（金属錯塩系）
ニッケル（２，２’チオビス（４−t−オクチル）フェノレート）ノルマルブチルアミン、ニッケルジブチルジチオカルバメート、ニッケルジブチルジチオカルバメート、コバルトジシクロヘキシルジチオホスフェートなど。
【０１１７】
（ｆ）ＨＡＬＳ（ヒンダードアミン）
ビス（２，２，６，６−テトラメチル−４−ピペリジル）セバケート、ビス（１，２，２，６，６−ペンタメチル−４−ピペリジル）セバケート、１−［２−〔３−（３，５−ジ−ｔ−ブチル−４−ヒドロキシフェニル）プロピオニルオキシ〕エチル］−４−〔３−（３，５−ジ−ｔ−ブチル−４−ヒドロキシフェニル）プロピオニルオキシ〕−２，２，６，６−テトラメチルピリジン、８−ベンジル−７，７，９，９−テトラメチル−３−オクチル−１，３，８−トリアザスピロ〔４，５〕ウンデカン−２，４−ジオン、４−ベンゾイルオキシ−２，２，６，６−テトラメチルピペリジンなど。
【０１１８】
次に、図面を用いて本発明の電子写真方法ならびに電子写真装置を詳しく説明する。
図４は、本発明の電子写真プロセス及び電子写真装置を説明するための概略図であり、下記のような例も本発明の範疇に属するものである。
図４において、感光体（１）は少なくとも感光層が設けられ、最表面の保護層にフィラー及びアクリル樹脂を含有してなる。感光体（１）はドラム状の形状を示しているが、シート状、エンドレスベルト状のものであってもよい。帯電チャージャー（３）、転写前チャージャー（７）、転写チャージャー（１０）、分離チャージャー（１１）、クリーニング前チャージャー（１３）には、コロトロン、スコロトロン、固体帯電器（ソリッド・ステート・チャージャー）、帯電ローラー、帯電ブラシ、転写ローラー等が用いられ、公知の手段がすべて使用可能である。これらの帯電部材は感光体に接触していても非接触であってもよい。特に、感光体を帯電する際に用いられる帯電ローラーは、コロトロンやスコロトロンに比べて発生するオゾン量が少ないことから、本発明においても有効に用いられる。しかし、帯電ローラーが感光体と接触していると、感光体表面の汚染の影響が増加する場合があるため、帯電ローラーと感光体とが画像領域において非接触であるほうがより好ましい場合がある。また、帯電時に直流成分に交流成分を重畳させることによって、帯電の安定性が高まる場合があるため有効である。
転写手段には、一般に上記の帯電器が使用できるが、図に示されるように転写チャージャーと分離チャージャーを併用したものが効果的である。
【０１１９】
また、画像露光部（５）、除電ランプ（２）等の光源には、蛍光灯、タングステンランプ、ハロゲンランプ、水銀灯、ナトリウム灯、発光ダイオード（ＬＥＤ）、半導体レーザー（ＬＤ）、エレクトロルミネッセンス（ＥＬ）などの発光物全般を用いることができる。そして、所望の波長域の光のみを照射するために、シャープカットフィルター、バンドパスフィルター、近赤外カットフィルター、ダイクロイックフィルター、干渉フィルター、色温度変換フィルターなどの各種フィルターを用いることもできる。
【０１２０】
光源等は、図４に示される工程の他に光照射を併用した転写工程、除電工程、クリーニング工程、あるいは前露光などの工程を設けることにより、感光体に光が照射される。但し、除電工程における感光体への露光は、感光体に与える疲労の影響が大きく、特に残留電位の上昇が顕著に発生する場合がある。従って、露光による除電ではなく、帯電工程やクリーニング工程において逆バイアスを印可することによっても除電することが可能な場合もあり、感光体の耐久性の面から好ましい。
【０１２１】
さて、現像ユニット（６）により感光体（１）上に現像されたトナーは、転写紙（９）に転写されるが、全部が転写されるわけではなく、感光体（１）上に残存するトナーも生ずる。このようなトナーは、ファーブラシ（１４）およびブレード（１５）により、感光体より除去される。クリーニングは、クリーニングブラシだけで行なわれることもあり、クリーニングブラシにはファーブラシ、マグファーブラシを始めとする公知のものが用いられる。
【０１２２】
クリーニングは、転写後に感光体上に残ったトナー等を除く工程であるが、上記のブレードあるいはブラシ等がトナーとともに感光体表面を擦ることにより、感光体の摩耗が促進されたり、傷がついたりし、それが異常画像の発生に発展することがある。また、クリーニング不良によって感光体表面の汚染の影響が増加すると異常画像の発生の原因となるだけでなく、感光体の寿命を大幅に低減させることにつながる。特に、耐摩耗性の向上のためにフィラーを含有させた層を感光体表面に有する場合には、耐摩耗性が高い故に感光体表面に付着した汚染物質が除去されにくく、フィルミングや画像劣化の影響が増大するため、その影響はより一層大きくなる。従って、感光体のクリーニング性を高めることは感光体の高耐久化あるいは高画質化に対し非常に有効である。
【０１２３】
感光体のクリーニング性を高める手段としては、感光体表面の摩擦係数を低減させる方法が知られている。感光体表面の摩擦係数を低減させる方法としては、前述したとおり各種の潤滑性物質を感光体表面に含有させる方法と、外部より感光体表面に潤滑性物質を供給させる方法とに二分される。前者は、エンジン廻りのレイアウトの自由度が高いため小径感光体には有利であるが、繰り返し使用によって摩擦係数は顕著に増加するため、その持続性に課題が残されている。一方、後者は潤滑性物質を供給する部品を備える必要があるが、持続性に優れていることから感光体の高耐久化に対しては有効な手段である。その中で、潤滑性物質を現像剤に含有させることによって現像時に感光体に付着させる方法は、エンジン廻りのレイアウトにも制約を受けずに、感光体表面の摩擦係数低減効果の持続性も高いため、感光体の高耐久化やクリーニング性の向上に対して非常に有効な手段である。これらの潤滑性物質としては、シリコーンオイル、フッ素オイル等の潤滑性液体、ＰＴＦＥ・ＰＦＡ・ＰＶＤＦ等の各種フッ素樹脂、シリコーン樹脂、ポリオレフィン系樹脂、シリコングリース、フッ素グリース、パラフィンワックス、脂肪酸エステル類、ステアリン酸亜鉛等の脂肪酸金属塩、黒鉛、二硫化モリブデン等の潤滑性液体や固体、粉体等が挙げられるが、現像剤に混合させる場合には、粉末状の物質が好ましく、特にステアリン酸亜鉛は、悪影響が少なく極めて有効に使用することができる。
【０１２４】
電子写真感光体に負（正）帯電を施し、画像露光を行なうと、感光体表面上には負（正）の静電潜像が形成される。これを正（負）極性のトナー（検電微粒子）で現像すれば、ポジ画像が得られるし、また負（正）極性のトナーで現像すれば、ネガ画像が得られる。
かかる現像手段には、公知の方法が適用され、また、除電手段にも公知の方法が用いられる。
【０１２５】
図５には、本発明による電子写真プロセスの別の例を示す。感光体（２１）は少なくとも感光層を有し、さらに最表面層にフィラー及びアクリル樹脂からなる保護層を含有しており、駆動ローラー（２２ａ），（２２ｂ）により駆動され、帯電器（２３）による帯電、光源（２４）による像露光、現像（図示せず）、帯電器（２５）を用いる転写、光源（２６）によるクリーニング前露光、ブラシ（２７）によるクリーニング、光源（２８）による除電が繰返し行なわれる。図５においては、感光体（２１）（勿論この場合は支持体が透光性である）に支持体側よりクリーニング前露光の光照射が行なわれる。
【０１２６】
以上の図示した電子写真プロセスは、本発明における実施形態を例示するものであって、もちろん他の実施形態も可能である。例えば、図５において支持体側よりクリーニング前露光を行なっているが、これは感光層側から行なってもよいし、また、像露光、除電光の照射を支持体側から行なってもよい。
一方、光照射工程は、像露光、クリーニング前露光、除電露光が図示されているが、他に転写前露光、像露光のプレ露光、およびその他公知の光照射工程を設けて、感光体に光照射を行なうこともできる。
【０１２７】
以上に示すような画像形成手段は、複写装置、ファクシミリ、プリンター内に固定して組み込まれていてもよいが、プロセスカートリッジの形でそれら装置内に組み込まれてもよい。プロセスカートリッジとは、感光体を内蔵し、他に帯電手段、露光手段、現像手段、転写手段、クリーニング手段、除電手段を含んだ１つの装置（部品）であり、本発明のプロセスカートリッジは前述の感光体とともに、これらの手段のうちの一部のみを含むものもあってもよい。プロセスカートリッジの形状等は多く挙げられるが、本発明の例として、図６に示すものが挙げられる。感光体（１６）は、導電性支持体上に少なくとも感光層を有し、かつ最表面の保護層には少なくともフィラー及びアクリル樹脂を含有してなる。このプロセスカートリッジは、本発明の電子写真感光体（１６）、帯電チャージャ（１７）、クリーニングブラシ（１８）、画像露光部（１９）、現像ローラ（２０）からなるものである。
【０１２８】
【実施例】
以下、本発明について実施例を挙げて説明するが、本発明が実施例により制約を受けるものではない。なお、部はすべて重量部である。なお、電荷輸送物質のイオン化ポテンシャルＩｐは、表面分析装置（理研計器製、ＡＣ−１）にて測定した。
【０１２９】
（実施例１）
アルミニウムシリンダー上に下記組成の下引き層塗工液、電荷発生層塗工液、および電荷輸送層塗工液を、浸漬塗工によって順次塗布、乾燥し、約３．０μｍの下引き層、約０．２μｍの電荷発生層、約２０μｍの電荷輸送層を形成した。
[下引き層塗工液］
アルキッド樹脂 ６部
（「ベッコゾール1307-60」大日本インキ化学工業製）
メラミン樹脂 ４部
（「スーパーベッカミンG-821-60」大日本インキ化学工業製）
酸化チタン粉末 ４０部
（「タイペールＣＲ−ＥＬ」石原産業社製）
メチルエチルケトン ５０部
【０１３０】
［電荷発生層塗工液］
下記構造式（１）の非対称ビスアゾ顔料 ２．５部
【０１３１】
【化１３】

ポリビニルブチラール（「ＸＹＨＬ」ＵＣＣ製） ０．５部
メチルエチルケトン ８０部
シクロヘキサノン ２００部
【０１３２】
［電荷輸送層塗工液］
ビスフェノールＺポリカーボネート １０部
（パンライトＴＳ−２０５０、帝人化成製）
下記構造式（２）の電荷輸送物質（Ｉｐ：５．４ｅＶ） １０部
【０１３３】
【化１４】

シリコーンオイル（「ＫＦ５０」信越化学製） ０．００２部
テトラヒドロフラン １００部
【０１３４】
上記電荷輸送層上にさらに下記組成の保護層塗工液を用いて、スプレー塗工によって膜厚が約３μｍの保護層を形成し、電子写真感光体１を作製した。
［保護層塗工液］
アルミナ ２．５部
（平均一次粒径：０．３μｍ、「AA-03」住友化学工業製）
不飽和ポリカルボン酸ポリマー ０．０６部
（酸価１８０ｍｇＫＯＨ／ｇ、不揮発分５０％
「BYK-P104」ＢＹＫケミー製）
ビスフェノールＺポリカーボネート ９部
（パンライトＴＳ−２０５０、帝人化成製）
アクリル樹脂 ２部
（水酸基価１５（ｍｇＫＯＨ／ｇ）、不揮発分５０％、
「ヒタロイド３００１」日立化成製）
テトラヒドロフラン ３２０部
シクロヘキサノン ９０部
【０１３５】
（実施例２）
実施例１において、保護層塗工液を下記の組成に変更し、保護層の膜厚を約２μｍとした以外は、すべて実施例１と同様にして電子写真感光体２を作製した。
［保護層塗工液］
アルミナ １．０部
（平均一次粒径：０．３μｍ、「AA-03」住友化学工業製）
ビスフェノールＺポリカーボネート ９部
（パンライトＴＳ−２０５０、帝人化成製）
アクリル樹脂 ２部
（水酸基価１５（ｍｇＫＯＨ／ｇ）、不揮発分５０％、
「ヒタロイド３００１」日立化成製）
テトラヒドロフラン ２８０部
シクロヘキサノン ８０部
【０１３６】
（実施例３）
実施例１において、保護層塗工液を下記の組成に変更し、保護層の膜厚を約５μｍとした以外は、すべて実施例１と同様にして電子写真感光体３を作製した。
［保護層塗工液］
アルミナ ５．０部
（平均一次粒径：０．３μｍ、「AA-03」住友化学工業製）
不飽和ポリカルボン酸ポリマー ０．１５部
（酸価１８０ｍｇＫＯＨ／ｇ、不揮発分５０％
「BYK-P104」ＢＹＫケミー製）
ビスフェノールＺポリカーボネート ９部
（パンライトＴＳ−２０５０、帝人化成製）
アクリル樹脂 ２部
（水酸基価２５（ｍｇＫＯＨ／ｇ）、不揮発分５０％、
「ヒタロイド３０２０」日立化成製）
上記構造式（２）の電荷輸送物質（Ｉｐ：５．４ｅＶ） ７部
テトラヒドロフラン ５５０部
シクロヘキサノン １５０部
【０１３７】
（実施例４）
実施例３において、保護層塗工液を下記の組成に変更した以外は、すべて実施例３と同様にして電子写真感光体４を作製した。
［保護層塗工液］
アルミナ ５．０部
（平均一次粒径：０．３μｍ、「AA-03」住友化学工業製）
不飽和ポリカルボン酸ポリマー ０．１５部
（酸価１８０ｍｇＫＯＨ／ｇ、不揮発分５０％
「BYK-P104」ＢＹＫケミー製）
ビスフェノールＺポリカーボネート ５部
（パンライトＴＳ−２０５０、帝人化成製）
アクリル樹脂 １０部
（水酸基価２５（ｍｇＫＯＨ／ｇ）、不揮発分５０％、
「ヒタロイド３０２０」日立化成製）
上記構造式（２）の電荷輸送物質（Ｉｐ：５．４ｅＶ） ７部
テトラヒドロフラン ５５０部
シクロヘキサノン １５０部
【０１３８】
（実施例５）・・・参考例
実施例３において、保護層塗工液を下記の組成に変更した以外は、すべて実施例３と同様にして電子写真感光体５を作製した。
［保護層塗工液］
アルミナ ５．０部
（平均一次粒径：０．３μｍ、「AA-03」住友化学工業製）
不飽和ポリカルボン酸ポリマー ０．１５部
（酸価１８０ｍｇＫＯＨ／ｇ、不揮発分５０％
「BYK-P104」ＢＹＫケミー製）
アクリル樹脂 ２０部
（水酸基価２５（ｍｇＫＯＨ／ｇ）、不揮発分５０％、
「ヒタロイド３０２０」日立化成製）
上記構造式（２）の電荷輸送物質（Ｉｐ：５．４ｅＶ） ７部
テトラヒドロフラン ５５０部
シクロヘキサノン １５０部
【０１３９】
（実施例６）
実施例３において、保護層塗工液を下記の組成に変更した以外は、すべて実施例３と同様にして電子写真感光体６を作製した。
［保護層塗工液］
アルミナ ５．０部
（平均一次粒径：０．３μｍ、「AA-03」住友化学工業製）
不飽和ポリカルボン酸ポリマー ０．１５部
（酸価１８０ｍｇＫＯＨ／ｇ、不揮発分５０％
「BYK-P104」ＢＹＫケミー製）
ビスフェノールＺポリカーボネート ８部
（パンライトＴＳ−２０５０、帝人化成製）
アクリル樹脂（「BR-605」三菱レーヨン製） ２部
上記構造式（２）の電荷輸送物質（Ｉｐ：５．４ｅＶ） ７部
テトラヒドロフラン ５５０部
シクロヘキサノン １５０部
【０１４０】
（実施例７）
実施例３において、保護層塗工液を下記の組成に変更した以外は、すべて実施例３と同様にして電子写真感光体７を作製した。
［保護層塗工液］
アルミナ ４．０部
（平均一次粒径：０．３μｍ、「AA-03」住友化学工業製）
不飽和ポリカルボン酸ポリマー ０．１０部
（酸価１８０ｍｇＫＯＨ／ｇ、不揮発分５０％
「BYK-P104」ＢＹＫケミー製）
ビスフェノールＺポリカーボネート ９部
（パンライトＴＳ−２０５０、帝人化成製）
メタクリル酸メチルポリマー（和光純薬製） １部
上記構造式（２）の電荷輸送物質（Ｉｐ：５．４ｅＶ） ７部
テトラヒドロフラン ５３０部
シクロヘキサノン １４５部
【０１４１】
（実施例８）
実施例３において、保護層塗工液を下記の組成に変更した以外は、すべて実施例３と同様にして電子写真感光体８を作製した。
［保護層塗工液］
アルミナ ４．０部
（平均一次粒径：０．３μｍ、「AA-03」住友化学工業製）
不飽和ポリカルボン酸ポリマー
（酸価１８０ｍｇＫＯＨ／ｇ、不揮発分５０％
「BYK-P104」ＢＹＫケミー製） ０．１０部
ポリアリレート（「ＵポリマーU-6000」ユニチカ製） ８部
アクリル樹脂 ３．３部
（水酸基価６０（ｍｇＫＯＨ／ｇ）、不揮発分６０％、
「ヒタロイド３０８３」日立化成製）
上記構造式（２）の電荷輸送物質（Ｉｐ：５．４ｅＶ） ７部
テトラヒドロフラン ５３０部
シクロヘキサノン １４５部
【０１４２】
（比較例１）
実施例１において、保護層塗工液を下記の組成に変更した以外は、すべて実施例１と同様にして電子写真感光体９を作製した。
［保護層塗工液］
ビスフェノールＺポリカーボネート ８部
（パンライトＴＳ−２０５０、帝人化成製）
アクリル樹脂 ４部
（水酸基価２５（ｍｇＫＯＨ／ｇ）、不揮発分５０％、
「ヒタロイド３０２０」日立化成製）
上記構造式（２）の電荷輸送物質（Ｉｐ：５．４ｅＶ） ７部
テトラヒドロフラン ５００部
【０１４３】
（比較例２）
実施例３において、保護層塗工液を下記の組成に変更した以外は、すべて実施例３と同様にして電子写真感光体１０を作製した。
［保護層塗工液］
アルミナ ５．０部
（平均一次粒径：０．３μｍ、「AA-03」住友化学工業製）
不飽和ポリカルボン酸ポリマー ０．１５部
（酸価１８０ｍｇＫＯＨ／ｇ、不揮発分５０％
「BYK-P104」ＢＹＫケミー製）
ビスフェノールＺポリカーボネート １０部
（パンライトＴＳ−２０５０、帝人化成製）
上記構造式（２）の電荷輸送物質（Ｉｐ：５．４ｅＶ） ７部
テトラヒドロフラン ５５０部
シクロヘキサノン １５０部
【０１４４】
（比較例３）
実施例３において、保護層塗工液を下記の組成に変更した以外は、すべて実施例３と同様にして電子写真感光体１１を作製した。
［保護層塗工液］
アクリル樹脂 １４部
（水酸基価２５（ｍｇＫＯＨ／ｇ）、不揮発分５０％、
「ヒタロイド３０２０」日立化成製）
グアナミン樹脂（熱架橋硬化性樹脂） ４．５部
（不揮発分７０％、「マイコート１１２８」三井サイテック製）
芳香族スルホン酸（硬化触媒） ０．０２部
（不揮発分４０％、「キャタリスト４０４０」三井サイテック製）
テトラヒドロフラン ２５０部
シクロヘキサノン ７０部
【０１４５】
（比較例４）
実施例３において、保護層塗工液を下記の組成に変更した以外は、すべて実施例３と同様にして電子写真感光体１２を作製した。
［保護層塗工液］
アルミナ ３．０部
（平均一次粒径：０．３μｍ、「AA-03」住友化学工業製）
不飽和ポリカルボン酸ポリマー ０．０９部
（酸価１８０ｍｇＫＯＨ／ｇ、不揮発分５０％
「BYK-P104」ＢＹＫケミー製）
アクリル樹脂 １４部
（水酸基価２５（ｍｇＫＯＨ／ｇ）、不揮発分５０％、
「ヒタロイド３０２０」日立化成製）
グアナミン樹脂（熱架橋硬化性樹脂） ４．０部
（不揮発分７７％、「マイコート１０６」三井サイテック製）
芳香族スルホン酸（硬化触媒） ０．０２部
（不揮発分４０％、「キャタリスト４０４０」三井サイテック製）
テトラヒドロフラン ３３０部
シクロヘキサノン ９０部
【０１４６】
（比較例５）
実施例３において、保護層塗工液を下記の組成に変更した以外は、すべて実施例３と同様にして電子写真感光体１３を作製した。
［保護層塗工液］
アルミナ ５．０部
（平均一次粒径：０．３μｍ、「AA-03」住友化学工業製）
不飽和ポリカルボン酸ポリマー ０．１５部
（酸価１８０ｍｇＫＯＨ／ｇ、不揮発分５０％
「BYK-P104」ＢＹＫケミー製）
アクリル樹脂 １４部
（水酸基価２５（ｍｇＫＯＨ／ｇ）、不揮発分５０％、
「ヒタロイド３０２０」日立化成製）
メラミン樹脂（熱架橋硬化性樹脂） ３部
（「サイメル３０３」、三井サイテック製）
芳香族スルホン酸（硬化触媒） ０．０２部
（不揮発分４０％、「キャタリスト４０４０」三井サイテック製）
上記構造式（２）の電荷輸送物質（Ｉｐ：５．４ｅＶ） ７部
テトラヒドロフラン ５５０部
シクロヘキサノン １５０部
【０１４７】
（実施例９）
実施例１において、保護層塗工液を下記の組成に変更した以外は、すべて実施例１と同様にして電子写真感光体１４を作製した。
［保護層塗工液］
酸化チタン ４．０部
（平均一次粒径：０．３μｍ、「ＣＲ−ＥＬ」石原産業製）
不飽和ポリカルボン酸ポリマー ０．１２部
（酸価１８０ｍｇＫＯＨ／ｇ、不揮発分５０％
「BYK-P104」ＢＹＫケミー製）
ビスフェノールＺポリカーボネート ８部
（パンライトＴＳ−２０５０、帝人化成製）
アクリル樹脂 ４部
（水酸基価１５（ｍｇＫＯＨ／ｇ）、不揮発分５０％、
「ヒタロイド３００１」日立化成製）
上記構造式（２）の電荷輸送物質（Ｉｐ：５．４ｅＶ） ８部
テトラヒドロフラン ５５０部
シクロヘキサノン １５０部
【０１４８】
（実施例１０）
実施例１において、保護層塗工液を下記の組成に変更した以外は、すべて実施例１と同様にして電子写真感光体１５を作製した。
［保護層塗工液］
シリカ ２．０部
（平均一次粒径：０．１μｍ、「ＫＭＰＸ−１００」信越シリコーン製）
ビスフェノールＺポリカーボネート ７部
（パンライトＴＳ−２０５０、帝人化成製）
アクリル樹脂 ６部
（水酸基価２５（ｍｇＫＯＨ／ｇ）、不揮発分５０％、
「ヒタロイド３０２０」日立化成製）
上記構造式（２）の電荷輸送物質（Ｉｐ：５．４ｅＶ） １０部
テトラヒドロフラン ５５０部
シクロヘキサノン １５０部
【０１４９】
（実施例１１）
実施例３において、保護層塗工液を下記の組成に変更した以外は、すべて実施例３と同様にして電子写真感光体１６を作製した。
［保護層塗工液］
チタネートカップリング処理アルミナ ４．０部
（平均一次粒径：０．３μｍ、「AA-03」住友化学工業製）
不飽和ポリカルボン酸ポリマー ０．０８部
（酸価１８０ｍｇＫＯＨ／ｇ、不揮発分５０％
「BYK-P104」ＢＹＫケミー製）
ビスフェノールＺポリカーボネート ６部
（パンライトＴＳ−２０５０、帝人化成製）
アクリル酸／ヒドロキシエチルメタクリレート共重合体 ８部
（不揮発分４０％、三洋化成製）
上記構造式（２）の電荷輸送物質（Ｉｐ：５．４ｅＶ） ７部
テトラヒドロフラン ５３０部
シクロヘキサノン １４５部
【０１５０】
（実施例１２）
実施例３において、保護層塗工液を下記の組成に変更した以外は、すべて実施例３と同様にして電子写真感光体１７を作製した。
［保護層塗工液］
アルミナ ２．５部
（平均一次粒径：０．０１３μｍ、「Al2O3-C」アエロジル製）
不飽和ポリカルボン酸ポリマー ０．０５部
（酸価１８０ｍｇＫＯＨ／ｇ、不揮発分５０％
「BYK-P104」ＢＹＫケミー製）
ビスフェノールＺポリカーボネート ８部
（パンライトＴＳ−２０５０、帝人化成製）
アクリル樹脂 ４部
（水酸基価１５（ｍｇＫＯＨ／ｇ）、不揮発分５０％、
「ヒタロイド３００１」日立化成製）
上記構造式（２）の電荷輸送物質（Ｉｐ：５．４ｅＶ） ８部
テトラヒドロフラン ５１０部
シクロヘキサノン １４０部
【０１５１】
（実施例１３）
実施例３において、保護層塗工液を下記の組成に変更した以外は、すべて実施例３と同様にして電子写真感光体１８を作製した。
［保護層塗工液］
アルミナ ４．０部
（平均一次粒径：０．４μｍ、「AA-０４」住友化学工業製）
不飽和ポリカルボン酸ポリマー ０．０５部
（酸価３６５ｍｇＫＯＨ／ｇ、「BYK-P105」ＢＹＫケミー製）
ビスフェノールＺポリカーボネート ７部
（パンライトＴＳ−２０５０、帝人化成製）
アクリル樹脂 ５部
（水酸基価６０（ｍｇＫＯＨ／ｇ）、不揮発分５０％、
「ヒタロイド３０８３」日立化成製）
下記構造式（６）の電荷輸送物質（Ｉｐ：５．３ｅＶ） ７部
テトラヒドロフラン ５３０部
シクロヘキサノン １４５部
【０１５２】
【化１５】

【０１５３】
（実施例１４）・・・参考例
実施例３において、保護層塗工液を下記の組成に変更した以外は、すべて実施例３と同様にして電子写真感光体１９を作製した。
［保護層塗工液］
アルミナ ４．０部
（平均一次粒径：０．３μｍ、「AA-03」住友化学工業製）
不飽和ポリカルボン酸ポリマー ０．１０部
（酸価１８０ｍｇＫＯＨ／ｇ、不揮発分５０％
「BYK-P104」ＢＹＫケミー製）
アクリル樹脂 ６部
（水酸基価２５（ｍｇＫＯＨ／ｇ）、不揮発分５０％、
「ヒタロイド３０２０」日立化成製）
下記構造式（７）の高分子電荷輸送物質（Ｉｐ：５．４ｅＶ） １５部
【０１５４】
【化１６】

テトラヒドロフラン ５５０部
シクロヘキサノン １５０部
【０１５５】
（実施例１５）
実施例３において、電荷発生層塗工液、電荷輸送層塗工液及び保護層塗工液を下記のものに変更した以外は、実施例３と同様にして、電子写真感光体２０を作製した。
［電荷発生層塗工液］
ポリビニルブチラール（「エスレックＢＸ−１」積水化学工業製） ５部
メチルエチルケトン ４００部
図７に示したＸＤスペクトルを有するチタニルフタロシアニン ８部
［電荷輸送層塗工液］
ビスフェノールＺポリカーボネート １０部
（パンライトＴＳ−２０５０、帝人化成製）
上記構造式（６）の電荷輸送物質 １０部
シリコーンオイル（「ＫＦ５０」信越化学製） ０．００２部
テトラヒドロフラン １００部
［保護層塗工液］
アルミナ ３．０部
（平均一次粒径：０．３μｍ、「AA-03」住友化学工業製）
不飽和ポリカルボン酸ポリマー ０．０９部
（酸価１８０ｍｇＫＯＨ／ｇ、不揮発分５０％
「BYK-P104」ＢＹＫケミー製）
ビスフェノールＺポリカーボネート ８部
（パンライトＴＳ−２０５０、帝人化成製）
アクリル樹脂 ４部
（水酸基価２５（ｍｇＫＯＨ／ｇ）、不揮発分５０％、
「ヒタロイド３０２０」日立化成製）
上記構造式（６）の電荷輸送物質 １０部
テトラヒドロフラン ５７０部
シクロヘキサノン １６０部
【０１５６】
以上のように作製した電子写真感光体１〜２０を、電子写真装置用プロセスカートリッジ（ただし、クリーニング前露光はなし）に装着し、画像露光光源の波長が６５５ｎｍ（但し、電子写真感光体Ｎｏ．２０のみ７８０ｎｍ）の半導体レーザーを用いた（株）リコー製ｉｍａｇｉｏＭＦ２２００改造機にて、初期時の明部電位測定及び画像評価を行ない、その後連続してトータル３万枚の印刷を行ない、３万枚印刷後の明部電位測定及び画像評価を実施した。さらに、初期持及び３万枚印刷後における膜厚差より摩耗量の評価を行なった。これらの結果を表１に示した。
【０１５７】
【表１】

注）実施例５及び１４は参考例である。
表１の評価結果より、アクリル樹脂を架橋させた保護層を有する電子写真感光体は、３万枚印刷後の摩耗量が非常に多く耐摩耗性が乏しい上、地肌汚れの増加も確認された。また、フィラーを含有し、かつアクリル樹脂を架橋させた保護層を有する電子写真感光体は、十分な耐摩耗性が得られていない上に、スジ状の画像欠陥の発生が確認された。それに対して、本発明によるフィラー及びアクリル樹脂を含有した保護層を有する電子写真感光体は、摩耗量が少なく、３万枚印刷後においても良好な画像が得られた。さらに、保護層に分散剤あるいは電子輸送物質を添加することによって、明部電位の低減や耐摩耗性の向上が確認され、画質の向上が認められた。
【０１５８】
（実施例１６〜２０、比較例６）・・・実施例１８は参考例
実施例３、４、５、６、１５（実施例５は参考例）及び比較例２において作製された電子写真感光体３、４、５、６、１０、２０について、窒素酸化物の曝露による加速劣化試験（窒素酸化物濃度５０ｐｐｍ、５０時間）を行ない、曝露終了後に画像評価を行なった。曝露の前後には、これらの電子写真感光体を電子写真プロセス用カートリッジに装着し、画像露光光源の波長が ６５５ｎｍ（但し、電子写真感光体Ｎｏ．２０のみ７８０ｎｍ）の半導体レーザーを用いたリコー製ｉｍａｇｉｏＭＦ２２００改造機にて画像評価を実施した。その結果を表２に示した。なお、画像ランクは下記の水準で区分した。
画質ランク ◎：高画質と判断できるレベル
○：若干画質が低下したが、問題ないレベル
△：明らかに画質低下が認められるレベル
×：画像の判別が困難なレベル
【０１５９】
【表２】

注）実施例１８は参考例である。
フィラーを有しアクリル樹脂を含まない保護層を有する電子写真感光体は、表１の評価結果より優れた耐摩耗性を有することが確認された。しかし、表２の評価結果より、窒素酸化物のガスの曝露によって著しい画像ボケが発生し画像の判別ができないほどの画像劣化を引き起こすことが確認された。しかし、本発明によるフィラーとともにアクリル樹脂を含有させた保護層を有する電子写真感光体は、高濃度の窒素酸化物による過酷な曝露条件においても良好な画像を得ることが可能となった。また、アクリル樹脂の中でも、特に水酸基価を有するアクリル樹脂の方がその効果が高く、それらの添加量が多い方がその効果が高くなる傾向があることが確認された。
【０１６０】
【発明の効果】
以上、詳細かつ具体的な説明から明かなように、本発明によれば、保護層にフィラー、及びバインダー樹脂として、アクリル系樹脂、メタクリル系樹脂またはそれらの共重合体から選ばれるアクリル樹脂と、ポリカーボネート樹脂、ポリアリレート樹脂のうち少なくとも一種の樹脂とを含有する混合樹脂を含有させることにより、耐摩耗性の大幅な向上が実現されると同時に、窒素酸化物のガス曝露に対しても画像ボケの抑制を可能とする電子写真感光体が提供され、さらに、保護層に分散剤や電荷輸送物質を同時に加えることにより、フィラーの分散性や電荷の注入性あるいは移動性を向上させることが可能となり、高抵抗のフィラーを含有しているにもかかわらず、残留電位を低減することが可能となり、以上のように、電子写真感光体の耐摩耗性の向上、残留電位の低減、クラックや膜剥がれの抑制、及び窒素酸化物のガスによる画像ボケの発生を同時に抑制することが可能となり、高耐久化及び高画質化を実現する電子写真感光体を提供することが可能となり、さらに、本発明の電子写真感光体を用いることにより、高耐久性と高画質を併せ持つ画像形成装置、画像形成方法及び画像形成装置用プロセスカートリッジが提供されるという極めて優れた効果を奏するものである。
【図面の簡単な説明】
【図１】本発明の電子写真感光体を表わす断面図である。
【図２】本発明の電子写真感光体の別の構成例を示す断面図である。
【図３】本発明の電子写真感光体の更に別の構成例を示す断面図である。
【図４】本発明の電子写真プロセス及び電子写真装置を説明するための概略図である。
【図５】本発明による電子写真プロセスの別の例を示した図である。
【図６】本発明におけるプロセスカートリッジを示した一般的な図である。
【図７】実施例７におけるＸＤスペクトルを示した図である。
【符号の説明】
１ 感光体
２ 除電ランプ
３ 帯電チャージャ
４ イレーサ
５ 画像露光部
６ 現像ユニット
７ 転写前チャージャ
８ レジストローラ
９ 転写紙
１０ 転写チャージャ
１１ 分離チャージャ
１２ 分離爪
１３ クリーニングチャージャ
１４ ファーブラシ
１５ クリーニングブラシ
１６ 感光体
１７ 帯電チャージャ
１８ クリーニングブラシ
１９ 画像露光部
２０ 現像ローラ
２１ 感光体
２２ａ 駆動ローラ
２２ｂ 駆動ローラ
２３ 帯電チャージャ
２４ 像露光源
２５ 転写チャージャ
２６ クリーニング前露光
２７ クリーニングブラシ
２８ 除電光源
３１ 導電性支持体
３３ 感光層
３５ 電荷発生層
３７ 電荷輸送層
３９ 保護層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic photoreceptor having high durability and realizing high image quality, and a method for manufacturing the same. In addition, the present invention relates to an electrophotographic method, an electrophotographic apparatus, and an electrophotographic process cartridge using those photoconductors.
[0002]
[Prior art]
In recent years, there has been a remarkable development in information processing system machines using electrophotography. In particular, laser printers and digital copying machines that convert information into digital signals and record information using light have significantly improved print quality and reliability. Furthermore, they have been applied to laser printers or digital copiers capable of full-color printing by fusing with high-speed technology. From such a background, high image quality has become a particularly important issue in recent years as one of the required functions of a photoreceptor.
[0003]
As photoconductors used in these electrophotographic laser printers, digital copiers, etc., those using organic photosensitive materials are generally widely applied for reasons such as cost, productivity and non-pollution. Yes. The organic electrophotographic photoreceptor includes a photoconductive resin typified by polyvinylcarbazole (PVK), a charge transfer complex type typified by PVK-TNF (2,4,7-trinitrofluorenone), A pigment dispersion type typified by a phthalocyanine-binder is known, and at present, a functional separation type (stacked type) photoreceptor using a combination of a charge generation material and a charge transport material is widely applied.
[0004]
The mechanism of electrostatic latent image formation in the function-separated type photoreceptor is that the charge transport layer is laminated on the charge generation layer. Passes and is absorbed by the charge generation material in the charge generation layer to generate a charge. The charges generated thereby are injected into the charge transport layer at the interface between the charge generation layer and the charge transport layer, and further moved in the charge transport layer toward the outermost surface by an electric field to neutralize the surface charge of the photoreceptor. An electrostatic latent image is formed.
[0005]
However, organic photoreceptors are subject to wear due to repeated use, and when the wear of the photosensitive layer progresses, deterioration of the charged potential of the photoreceptor, deterioration of photosensitivity, deterioration of image quality such as density reduction and background contamination are promoted. The tendency is strong, and the abrasion resistance of the photoconductor has been cited as a major problem. Furthermore, in recent years, with the increase in the speed of the electrophotographic apparatus or the reduction in the diameter of the photoreceptor accompanying the downsizing of the electrophotographic apparatus, it has become an even more important issue to improve the durability of the photoreceptor. Therefore, in an organic electrophotographic photosensitive member, it has been cited as the most important issue particularly to achieve both high image quality and high durability.
[0006]
In order to achieve high durability of the photoreceptor, it is necessary to improve the abrasion resistance of the photoreceptor as described above. As the film thickness of the photosensitive layer of the photoconductor becomes thinner due to wear, for example, in the case of reversal development, the electric field strength increases and image defects such as background stains tend to occur remarkably. On the other hand, when the film thickness of the photosensitive layer is increased more than necessary, there is a tendency that the resolution is greatly lowered and the image quality is deteriorated. Also, if the amount of film thickness reduction is large during repeated use, the image quality tends to fluctuate and the photoconductor must be replaced in a short cycle. Therefore, reducing the variation in the film thickness of the photoreceptor is very important not only for high durability but also for high image quality.
[0007]
As a means for improving the abrasion resistance of the photoreceptor, a method in which a polymer charge transport material is contained in the outermost surface layer of the photoreceptor or a method in which a protective layer is formed on the outermost surface of the photoreceptor is effective. In particular, a method for forming a protective layer is widely known, and a method for imparting lubricity to the protective layer, curing the protective layer, or containing a filler in the protective layer is effective and useful.
[0008]
However, although these methods are effective for enhancing the durability of the photoreceptor, the required durability has not been sufficiently satisfied. In the method using the polymer charge transport material, there is still room for improvement in durability, and the production cost is greatly increased. Although the method of imparting lubricity to the protective layer has an effect on the abrasion resistance, the effect disappears rapidly during repeated use, so that the actual life of the photoreceptor is not satisfied by itself. It is.
[0009]
On the other hand, the method of curing by crosslinking the protective layer tends to improve the abrasion resistance, but the residual potential is often increased, and the protective layer is cracked or scratched or the film is peeled off. Sometimes. The prior art discloses a method for improving the wear resistance by forming a protective layer that is crosslinked and cured using a thermosetting resin or a photo-curing resin such as acrylic resin, melamine resin, and guanamine resin. However, when a protective layer containing these curable resins is applied on the photosensitive layer and then cured by cross-linking, cracking occurs due to shrinkage, the protective layer peels off, or the film becomes brittle. In fact, the actual situation is that the high durability of the photoreceptor has not been fully satisfied. In particular, it is known that when the difference between the film hardness of the charge transport layer and the film hardness of the protective layer is too large, the influences thereof are remarkably generated.
[0010]
In addition, the method of adding a filler to the protective layer is one of effective methods for improving the wear resistance because it can stably maintain the wear resistance over a relatively long period of time. Inclusion of the filler may increase the charge trap sites and increase the residual potential. In the case of reversal development, the increase in the residual potential leads to a high bright portion potential in the electrophotographic apparatus, which causes a significant decrease in image density and gradation, and causes image quality deterioration. In order to compensate for this, it is necessary to increase the dark part potential, but if the dark part potential is increased, the electric field strength increases and not only image defects such as background stains are likely to occur, but also the wear amount of the photoreceptor increases. This leads to a significant decrease in life.
[0011]
As described above, in order to achieve high durability of the photoreceptor, it is indispensable to improve the wear resistance and at the same time, prevent cracks, scratches, film peeling, etc., and suppress the increase in residual potential. However, another problem that cannot be avoided in realizing high durability and high image quality of the photosensitive member is so-called image blur in which the contour of the image is blurred. Image blur tends to be more noticeable in a high temperature and high humidity environment or in an oxidizing gas atmosphere such as NOx or ozone. The general idea is that these image blurs are manifested by a lateral movement of charges on the surface of the photoreceptor due to a decrease in electrical resistance on the surface of the photoreceptor. In particular, the constituent material of the photoconductor is decomposed or altered by ozone or NOx generated at the time of charging, or a substance generated thereby adheres to the surface of the photoconductor, thereby reducing the resistance on the surface of the photoconductor. It is thought that blurring is likely to occur.
[0012]
Conventionally, in a photoconductor having insufficient durability, the surface of the photoconductor is scraped by repeated use, so that these contaminants are removed and image blurring hardly occurs. However, as the durability of photoconductors has increased, the amount of wear on the photoconductors has decreased, making it difficult for these substances to be removed, and the problem of image blurring has become apparent.
[0013]
Therefore, the coexistence of high durability and high image quality of the photoconductor is realized for the first time by suppressing image blur caused by oxidizing gas such as ozone and NOx as well as suppressing cracks, scratches, film peeling or residual potential rise. Will be. As methods for suppressing image blur in the prior art, methods for polishing the surface of a photoreceptor (Japanese Patent Laid-Open Nos. 2-52373 and 3-92822) are disclosed. However, this method sacrifices the durability of the photoreceptor, and cannot be said to be an effective method for increasing the durability of the photoreceptor. Also disclosed are methods for heating the photoreceptor (Japanese Patent Laid-Open Nos. 1-191883, 1-2206386, 1-233474, etc.). Although this method has a high image blur suppression effect, it is necessary to bring the drum heater into contact with the photoconductor, so that it cannot be applied to a photoconductor having a relatively small diameter. It causes a decrease in speed and further increases in power consumption, and is not a preferable method.
[0014]
On the other hand, methods for incorporating an antioxidant into the photosensitive layer (JP 59-136744 A, JP 2-64549 A, JP 2-64550 A, JP 8-292585 A, etc.) are disclosed. ing. This method exhibits a great effect depending on the antioxidant, but in most cases, it causes a rise in residual potential and is not sufficiently effective in suppressing image blur.
[0015]
From the above, in order to achieve both high durability and high image quality of the photoconductor, it is possible to improve the wear resistance of the photoconductor, suppress cracks, scratches, film peeling, etc. It is necessary to suppress the occurrence of blurring. However, the fact is that no effective means for solving these problems has been found at the same time, and development of a photoconductor that achieves both high durability and high image quality has been eagerly desired.
[0016]
[Problems to be solved by the invention]
An object of the present invention is to provide an electrophotographic photosensitive member having high durability, suppressing an increase in residual potential or image blurring, and capable of stably obtaining a high-quality image even for repeated use over a long period of time. It is to provide a manufacturing method. In addition, by using these photoconductors, it is not necessary to replace the photoconductors, and it is possible to reduce the size of the apparatus associated with high-speed printing or a reduction in the diameter of the photoconductor, so that high-quality images can be stably obtained even in long-term use. It is an object to provide an electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus.
[0017]
[Means to solve the problem]
In order to realize high durability of the electrophotographic photosensitive member, as described above, at the same time as improving the wear resistance, it is less affected by cracks, scratches or film peeling, and suppresses the increase in residual potential and the occurrence of image blur. There is a need.
For the wear resistance of the photoconductor, the present inventors have found that the wear amount of the photoconductor is not necessarily related to the hardness of the surface of the photoconductor. That is, it was confirmed that the brittleness of the film becomes obvious and the wear resistance may be rather lowered when the hardness is increased by crosslinking the protective layer. In addition, adding a crosslinking agent or a catalyst necessary for crosslinking or applying heat or light irradiation necessary for crosslinking greatly increases the residual potential, charge deterioration, photodegradation, etc. There were many cases of adverse effects. In addition, when the protective layer to which the filler is added is cured, the film shrinkage at the time of curing becomes very large, which not only increases the effects of cracks, scratches or film peeling, but also makes the filler detachable. The required wear resistance could not be obtained.
[0018]
Therefore, in the present invention, by satisfying the following configuration requirements, it is possible to achieve both high durability and high image quality, and an electrophotographic photosensitive member capable of stably obtaining high-quality images even when repeatedly used, and The present invention has been completed by providing a manufacturing method thereof, and providing an electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus that can stably obtain a high-quality image even in repeated use.
[0019]
  That is, the above-described problem is solved by (1) the electrophotographic photosensitive member in which a photosensitive layer containing at least a charge generating substance and a charge transporting substance and a protective layer are provided on a conductive support. Contains at least a filler and a binder resin, and the binder resin contains at leastSelected from acrylic resins, methacrylic resins or copolymers thereofContains acrylic resin,Moreover, the binder resin is a mixed resin containing at least one kind of a polycarbonate resin and a polyarylate resin,And an electrophotographic photoreceptor characterized in that the protective layer is not cured by cross-linking ”, (2)“ a charge generation layer containing at least a charge generation material and a charge transport layer containing a charge transport material. The electrophotographic photosensitive member according to item (1), wherein the acrylic resin is a copolymer, wherein the acrylic resin is a copolymer. Alternatively, the electrophotographic photosensitive member according to item (2), (4), wherein the acrylic resin has a hydroxyl value of 10 (mgKOH / g) or more. The electrophotographic photosensitive member according to any one of items 1), (5) "In the binder resin,SaidThe acrylic resin content is in the range of 1 to 50% by weight with respect to the total binder resin.Any one of the items (1) to (4)Electrophotographic photosensitive member described in ", (6) “The filler is at least one kind of inorganic pigment,” the items (1) to (5The electrophotographic photosensitive member according to any one of items 1), (7) “The inorganic pigment is at least one kind of metal oxide (6Electrophotographic photosensitive member according to item), (8) “The inorganic pigment or the metal oxide is subjected to a surface treatment with at least one surface treatment agent.Item (6) or Item (7)Electrophotographic photosensitive member described in ", (9) "The above-mentioned (characterized in that the ratio of the surface treatment agent used is 2 to 30% by weight with respect to the inorganic pigment or metal oxide."8Electrophotographic photosensitive member according to item), (10) “The average primary particle size of the inorganic pigment or metal oxide is 0.01 μm to 0.5 μm.9The electrophotographic photosensitive member according to any one of items 1), (11) “Items (1) to ((1), wherein the protective layer contains a dispersant.10The electrophotographic photosensitive member according to any one of items 1), (12) “The dispersing agent is an organic compound having at least one carboxyl group in the chemical structure.11Electrophotographic photosensitive member according to item), (13) “The dispersing agent is a polycarboxylic acid derivative.11) Or number (12Electrophotographic photosensitive member according to item), (14) "The above-mentioned dispersant is characterized by having an acid value of 10 to 400 (mg KOH / g).11) To (13The electrophotographic photosensitive member according to any one of items 1), (15) “The content of the dispersant satisfies the following relational expression with respect to the acid value of the dispersant and the content of the filler:14Electrophotographic photosensitive member according to item);
[0020]
[Equation 3]
  0.1 ≦ (dispersant content × dispersant acid value) / (filler content) ≦ 20
, (16) "Items (1) to (1), wherein the protective layer contains at least one charge transport material.15The electrophotographic photosensitive member according to any one of items 1), (17) “The following relational expression is established between the ionization potential (Ip) of the charge transport material and the Ip of the charge transport material contained in the photosensitive layer:16Electrophotographic photosensitive member according to item);
[0021]
[Expression 4]
      Ip ≦ of the charge transport material contained in the protective layer
                  Ip of charge transport material contained in photosensitive layer
, (18) “The charge transport material is a polymer charge transport material,16) Or number (17This is achieved by the electrophotographic photosensitive member according to the item).
[0022]
  In addition, the above problem is19) “The spray coating method is used as the method for forming the protective layer.18Or the manufacturing method of the electrophotographic photosensitive member according to any one of items 1), (20) “In an electrophotographic method in which at least charging, image exposure, development, and transfer are repeatedly performed using an electrophotographic photosensitive member, the electrophotographic photosensitive member is the item (1) to (18And an electrophotographic photosensitive member according to any one of items 1) to 3).21) “Using an electrophotographic photosensitive member, at least charging, image exposure, development and transfer are repeated, and at the time of image exposure, an electrostatic latent image is written on the photosensitive member by a beam exposure element such as an LD or LED. In the digital electrophotographic method performed, the electrophotographic photosensitive member is the item (1) to (18And an electrophotographic photosensitive member according to any one of the above items).
[0023]
  In addition, the above problem is22"An electrophotographic apparatus comprising at least a charging means, an image exposing means, a developing means, a transferring means, and an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is defined in claims 1 to 3.18Or an electrophotographic photosensitive member according to any one of 1), (23) "In an electrophotographic apparatus comprising at least a charging means, an image exposing means, a developing means, a transferring means, and an electrophotographic photosensitive member, on the photosensitive member by using a beam exposing element such as an LD or LED as the image exposing means. An electrostatic latent image is written on the digital electrophotographic apparatus, wherein the electrophotographic photosensitive member is the item (1) to (18And an electrophotographic photosensitive member according to any one of the above items),24) “A roller-shaped charging member is used as the charging means of the electrophotographic apparatus, and the charging member and the photosensitive member are not in contact with each other in the image area.22) Or number (23The electrophotographic apparatus according to any one of items 1), (25) “The first (characteristic) comprising means for adhering a lubricating substance to the outermost surface of the photosensitive member (22) Or number (23The electrophotographic apparatus described in the item "), (26) “The developing means develops the developer used when developing the latent image on the photosensitive member with a developer containing at least one lubricating substance, whereby the surface of the photosensitive member is lubricated. Characterized in that it is accompanied by means for adhering a sexual substance.25The electrophotographic apparatus described in the item "), (27) “The lubricating substance is at least one of a metal soap or a fluorine-based compound.25) Or number (26This is achieved by the electrophotographic apparatus according to the item).
[0024]
  In addition, the above problem is28) “A process cartridge for an electrophotographic apparatus comprising at least an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is the item (1) to (18The process cartridge for an electrophotographic apparatus, characterized in that it is an electrophotographic photosensitive member according to any one of the above items), (29) “The process cartridge is the first (24) To (27) Characterized in that it comprises at least one means described in any one of the above items.28And the process cartridge for an electrophotographic apparatus according to the item).
[0025]
For electrophotographic photoreceptors that contain a filler in the protective layer, there are still problems such as insufficient wear resistance and a large effect of residual potential and image blurring, especially in high-temperature and high-humidity environments. In addition, the influence of image blur in an NOx and ozone atmosphere could not be avoided. However, as a result of intensive studies, the present inventors confirmed that these image blurs are affected by the type of resin contained in the protective layer, and in particular, contained one type of acrylic resin in the protective layer. It was found that the image blur can be suppressed by causing Furthermore, it has become possible to improve the wear resistance and residual potential by controlling the type and particle size of the filler or its dispersibility.
[0026]
Conventionally, when an acrylic resin is contained in a protective layer, it has been used in applications where it is applied in the presence of a crosslinking agent, a catalyst, etc., and then cured by applying heat or light. However, cracks often occur due to shrinkage during curing, and the film peels off. Further, the brittleness of the film becomes conspicuous, and depending on the electrophotographic process used, the wear resistance is greatly reduced. In addition, when the protective layer contains a filler, it was confirmed that the wear resistance was improved when the film was made flexible without being cured. In addition, the crosslinking agent or catalyst added to crosslink the protective layer, or the application of heat or light may cause deterioration of electrophotographic characteristics and promote image quality deterioration. It is not always necessary to cure the protective layer. It has been found that it is not an effective method for improving the durability and image quality of the body.
[0027]
Therefore, in the present invention, by adding a filler to the protective layer and imparting flexibility without curing the protective layer, moderate wear resistance is maintained, and at the same time, generation of cracks, scratches or film peeling is prevented. In addition, it has been found that image blur due to NOx and ozone can be suppressed by adding one kind of acrylic resin to the protective layer. At the same time, by improving the dispersibility of the filler, it is possible to suppress uneven wear and increase in residual potential, and the present invention has been completed.
[0028]
As the acrylic resin to be added, the effect of suppressing blurring of the image is higher when the copolymer is a copolymer and has a hydroxyl value, and the effect is recognized even when the amount of addition is small. In this case, since no crosslinking agent or catalyst is added, it is not cured, and the protective layer has appropriate flexibility, thereby reducing the effects of cracks and scratches and film peeling, and wear resistance. It was confirmed that the property improved rather than the cured film. Further, it was confirmed that the effects of residual potential, charging deterioration, light deterioration and the like are reduced because no crosslinking agent or catalyst is added and it is not necessary to apply heat or light.
[0029]
With the above method, electrophotography that improves wear resistance, avoids the effects of cracks, scratches, and film peeling, suppresses image blurring, and achieves both high durability and high image quality. It has become possible to obtain a photoreceptor, and an electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus using the same.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the electrophotographic photosensitive member used in the present invention will be described in detail with reference to the drawings.
FIG. 1 is a sectional view showing an electrophotographic photosensitive member of the present invention, and a photosensitive layer (33) mainly composed of a charge generating material and a charge transporting material is provided on a conductive support (31). . Furthermore, a plurality of protective layers (39) containing at least a filler and an acrylic resin are laminated thereon.
FIG. 2 shows a structure in which a charge generation layer (35) mainly composed of a charge generation material and a charge transport layer (37) mainly composed of a charge transport material are laminated on a conductive support (31). Have taken. Furthermore, a plurality of protective layers (39) containing at least a filler and an acrylic resin are laminated thereon.
FIG. 3 shows a structure in which a charge transport layer (37) mainly composed of a charge transport material and a charge generation layer (35) mainly composed of a charge generation material are laminated on a conductive support (31). I'm taking it. Furthermore, a plurality of protective layers (39) containing at least a filler and an acrylic resin are laminated thereon.
[0031]
The conductive support (31) has a volume resistance of 10^TenFilms having conductivity of Ω · cm or less, for example, metal such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, metal oxide such as tin oxide, indium oxide, etc. are deposited or sputtered. Shaped or cylindrical plastic, paper-coated, or aluminum, aluminum alloy, nickel, stainless steel, etc., and after making them into tubes by methods such as extrusion and drawing, cutting, superfinishing, polishing, etc. A surface-treated tube or the like can be used. Further, an endless nickel belt and an endless stainless steel belt disclosed in Japanese Patent Application Laid-Open No. 52-36016 can be used as the conductive support (31).
[0032]
In addition, the conductive support dispersed in a suitable binder resin and coated on the support can also be used as the conductive support (31) of the present invention. Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc, and silver, or metal oxide powder such as conductive tin oxide and ITO. It is done. The binder resin used at the same time is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic, thermosetting resins, and photocurable resins such as melamine resin, urethane resin, phenol resin, and alkyd resin. Such a conductive layer can be provided by dispersing and coating these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, and toluene.
[0033]
Further, a heat shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, polytetrafluoroethylene-based fluororesin on a suitable cylindrical substrate. Those provided with a conductive layer can be used favorably as the conductive support (31) of the present invention.
[0034]
Next, the photosensitive layer will be described. The photosensitive layer may be a single layer or a laminate, but first, a case of a laminate configuration comprising a charge generation layer (35) and a charge transport layer (37) will be described. The charge generation layer (35) is a layer mainly composed of a charge generation material, in which the charge generation material, the binder resin, or the like is dispersed or dissolved in an appropriate solvent, and this is formed on the conductive support or the undercoat layer. It can be formed by coating and drying. The charge generation layer (35) is mainly composed of a charge generation material, a solvent, and a binder resin, and includes any additive such as a sensitizer, a dispersant, a surfactant, and silicone oil. It may be.
[0035]
For the charge generation layer (35), it is possible to use all known charge generation materials, and typical examples thereof include phthalocyanine pigments such as titanyl phthalocyanine, vanadyl phthalocyanine, copper phthalocyanine, hydroxygallium phthalocyanine, and metal-free phthalocyanine, monoazo Azo pigments such as pigments, disazo pigments, asymmetric disazo pigments, trisazo pigments, perylene pigments, perinone pigments, indigo pigments, pyrrolopyrrole pigments, anthraquinone pigments, quinacridone pigments, quinone condensed polycyclic compounds, squalium pigments, etc. Known materials can be mentioned, and these are usefully used. These charge generating materials can be used alone or in combination of two or more.
[0036]
In the charge generation layer (35), the charge generation material is dispersed in a suitable solvent together with a binder resin if necessary using a ball mill, attritor, sand mill, ultrasonic wave, etc., and this is applied onto the conductive support. And formed by drying.
[0037]
The binder resin used for the charge generation layer (35) as necessary may be polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly -N-vinyl carbazole, polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulosic resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone Etc. The amount of the binder resin is suitably 0 to 500 parts by weight, preferably 10 to 300 parts by weight with respect to 100 parts by weight of the charge generating material. The binder resin may be added before or after dispersion.
[0038]
Examples of the solvent used here include isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, and ligroin. In particular, ketone solvents, ester solvents, and ether solvents are preferably used. These may be used alone or in combination of two or more.
[0039]
As a coating method of the coating liquid containing the charge generating substance, the binder and the solvent, methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, and ring coating can be used. The film thickness of the charge generation layer (35) is suitably about 0.01 to 5 μm, preferably 0.1 to 2 μm.
[0040]
The charge transport layer (37) can be formed by dissolving or dispersing a charge transport material and a binder resin in a suitable solvent, and applying and drying the solution on the charge generation layer. Further, it is useful because it is possible to add one or more kinds of plasticizers, leveling agents, antioxidants, lubricating substances, etc. as necessary.
[0041]
The charge transport material includes a hole transport material and an electron transport material, and all conventionally known materials can be used. Representative examples of the electron transport material include, for example, chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3, Examples thereof include electron-accepting substances such as 7-trinitrodibenzothiophene-5,5-dioxide and benzoquinone derivatives.
[0042]
Representative examples of the hole transport material include poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, Oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene Derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, enamine derivatives Other known materials such as conductors can be used. These charge transport materials may be used alone or in combination of two or more.
[0043]
As the binder resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, Polyvinylidene chloride, polyarylate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, Well-known materials, such as alkyd resin, are mentioned. These binder resins are used alone or in combination of two or more.
[0044]
The amount of the charge transport material is appropriately 20 to 300 parts by weight, preferably 40 to 150 parts by weight with respect to 100 parts by weight of the binder resin. The thickness of the charge transport layer is preferably 25 μm or less, more preferably 20 μm or less, from the viewpoint of resolution and responsiveness. The lower limit varies depending on the system to be used (particularly charging potential), but is preferably at least 5 μm.
[0045]
As the solvent used here, tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone and the like are used. These may be used alone or in combination of two or more.
[0046]
Next, the case where the photosensitive layer has a single layer configuration (33) will be described.
The photosensitive layer is formed by dissolving or dispersing the above-described charge generating substance, charge transporting substance, binder resin and the like in an appropriate solvent, and coating and drying this on a conductive support. If necessary, various additives such as a plasticizer, a leveling agent, an antioxidant, and a lubricating substance can be added. As the charge generation material and the charge transport material, the materials mentioned in the charge generation layer (35) and the charge transport layer (37) can be used. Further, as the binder resin, in addition to the binder resin previously mentioned in the charge transport layer (37), the binder resin mentioned in the charge generation layer (35) may be mixed and used. The amount of the charge generating material with respect to 100 parts by weight of the binder resin is preferably 5 to 40 parts by weight, and the amount of the charge transporting material is preferably 0 to 190 parts by weight, and more preferably 50 to 150 parts by weight. The photosensitive layer comprises a coating solution in which a charge generating material and a binder resin are dispersed together with a charge transporting material using a solvent such as tetrahydrofuran, dioxane, dichloroethane, and cyclohexane, such as dip coating, spray coating, bead coating, and ring coating. It can be formed by coating using a method and drying. The film thickness of the photosensitive layer is suitably about 5 to 25 μm.
[0047]
On the outermost surface of the photosensitive layer, at least a filler and an acrylic resin, in some cases, other binder resin, dispersant, charge transport material, antioxidant, etc. are dispersed or dissolved in a suitable solvent for the purpose of improving durability, The protective layer (39) is formed by applying and drying.
[0048]
  Contained in the protective layerSelected from acrylic resins, methacrylic resins or copolymers thereofAcrylic resin is a resin obtained from acrylic acid, methacrylic acid, or derivatives thereof, and various copolymers and oligomers based on these, such as conventionally known acrylic or methacrylic resins and copolymers thereof. Is included and can be used effectively and usefully. Among these, those obtained by copolymerizing various monomers with methyl methacrylate are preferable, and a copolymer using a monomer having a hydroxyl group in the structure such as hydroxyethyl methacrylate has a high effect of suppressing image blur and is particularly effective. It is. In addition, by changing the copolymerization ratio and copolymerization type of these copolymers, it is possible to adjust the hydroxyl value and film properties, so it is possible to control image blur suppression and residual potential reduction effects. Further, it is possible to impart film properties and flexibility of the film, and to control the dispersibility of the filler.
[0049]
These resins having a hydroxyl value are generally used as monomers in the case of crosslinking, but in the present invention, they are not intended for crosslinking and are effectively used as additives or resins for suppressing image blur. Is. Accordingly, it is not necessary to add a crosslinking agent or a catalyst necessary for crosslinking, and to apply heat or light to the photoconductor, thereby avoiding side effects such as an increase in residual potential and light fatigue.
[0050]
The hydroxyl value of these acrylic resins contained in the protective layer is effectively from 0 to 150 (mgKOH / g), and more preferably from 10 to 100 (mgKOH / g) in suppressing image blur. it can. When the hydroxyl value becomes very high, the residual potential may increase or the temperature and humidity may be easily affected. Such adverse effects are avoided by, for example, reducing the amount of resin used.
[0051]
  These acrylic resins or copolymers thereof can be used alone as a binder resin, but are effective because they can be mixed with other binder resins. Even if the content of the acrylic resin is small, it is effective in suppressing the image blur. Further, when adding a problem such as dispersibility of the filler or an increase in residual potential, the ratio to the total binder resin is 1 to 50 wt% is preferable. When used in combination with other binder resins, the effect on image blur is exhibited even when mixed with two or more types of resins. However, as a resin to be mixed, the residual potential increases due to differences in compatibility. In addition, those which do not cause loss of smoothness or gloss of the coating film are desirable. Specifically, polystyrene, polyester, polyarylate, polycarbonate and the like are effectively used.However, in the present invention, at least one of polyarylate and polycarbonate is used..
[0052]
A filler material is added to the protective layer for the purpose of improving wear resistance. Fillers are mainly classified into organic fillers and inorganic fillers, and examples of organic filler materials include fluororesin powders such as polytetrafluoroethylene, silicone resin powders, a-carbon powders, and the like. Doped with metal powder such as copper, tin, aluminum, indium, tin oxide, zinc oxide, titanium oxide, alumina, zirconium oxide, indium oxide, antimony oxide, bismuth oxide, calcium oxide, antimony doped tin oxide, tin And metal oxides such as indium oxide, metal fluorides such as tin fluoride, calcium fluoride, and aluminum fluoride, and inorganic materials such as potassium titanate and boron nitride. Among these fillers, the use of an inorganic filler is advantageous for improving the wear resistance.
[0053]
Among the fillers used, depending on the type of filler or its dispersibility, the wear resistance, residual potential, and image blur may be affected. When the conductive filler is used as the filler, the influence of the residual potential is reduced, but the influence of the image blur becomes very large. On the other hand, when a high resistance filler is used, the occurrence of image blur can be reduced, but the residual potential rises remarkably. However, the increase in the residual potential due to the addition of these fillers can be suppressed by improving the dispersibility of the filler or controlling the resistance. Further, the pH when these fillers are dispersed in water is preferably at least 4 or more from the viewpoint of image blur suppression, and more preferably 5 or more. Depending on the method for producing these metal oxides, hydrochloric acid may remain. If the amount of the remaining hydrochloric acid is large, the electrical resistance decreases and the risk of image blurring increases. It is considered that there is a correlation between the residual amount of hydrochloric acid and the pH when the filler is dispersed in water.
[0054]
In the present invention, among the aforementioned fillers, non-acidic fillers having a relatively high resistance such as titanium oxide and alumina are used. Among them, α-type alumina having a hexagonal close-packed structure with high thermal stability and high wear resistance is particularly useful in terms of suppressing image blur and improving wear resistance.
[0055]
The average primary particle size of the filler is preferably 0.01 to 0.5 μm from the viewpoint of light transmittance and wear resistance of the protective layer. When the average primary particle size of the filler is 0.01 μm or less, the wear resistance is reduced due to the aggregation and dispersibility of the filler, and the increase in the specific surface area of the filler causes the occurrence of image blur due to NOx and ozone. The fear increases. When the average primary particle size of the filler is 0.5 μm or more, the sedimentation property of the filler may be promoted, or an abnormal image may be generated in an image obtained by the photoreceptor.
[0056]
These fillers can be surface-treated with at least one kind of surface treatment agent, and it is preferable to do so from the viewpoint of dispersibility of the filler. Lowering the dispersibility of the filler not only increases the residual potential, but also may decrease the transparency of the coating film, cause coating film defects, and also decrease the wear resistance and increase uneven wear. It may be disadvantageous in terms of durability or high image quality. As the surface treatment agent, all conventionally known surface treatment agents can be used. For example, titanate coupling agents, aluminum coupling agents, zircoaluminate coupling agents, metal salts such as higher fatty acids or aluminum stearate, or mixed treatments thereof, Al₂O_ThreeTiO₂, ZrO₂, Silicone, or a mixed treatment thereof is preferable from the viewpoint of filler dispersibility and image blur. The single treatment with a silane coupling agent may increase the risk of image blurring particularly at high temperatures and high humidity. In such a case, the above-described surface treatment agent and silane coupling agent are mixed. The effect can be reduced. About the usage-amount of a surface treating agent, although it changes with average primary particle diameters of the filler to be used, 2-30 wt% is suitable and 3-20 wt% is more preferable. If the amount of the surface treatment agent used is less than this, it is difficult to obtain the filler dispersing effect, and if it is too much, the residual potential may be increased.
[0057]
By containing these fillers, improvement in wear resistance is realized. However, if the dispersibility of the filler is low, the residual potential increases, wear resistance decreases or uneven wear increases. In order to suppress these influences, it is also an effective method to improve the dispersibility of the filler by adding a dispersant.
[0058]
As the dispersant in the present invention, a known dispersant can be used, but an organic compound having a structure containing at least one carboxyl group is preferable, and a polycarboxylic acid derivative is more preferable. The carboxylic acid site in the dispersant plays an important role in increasing dispersibility. As described above, hydrophilic inorganic fillers have low affinity with organic solvents and binder resins and cannot be dispersed well as they are. However, the dispersant used as a suitable material in the present invention has a high affinity with the inorganic filler at the carboxylic acid site, and a high affinity with the binder resin or organic solvent at the other polymer site. It becomes possible to increase the affinity between the inorganic filler and the organic solvent or binder resin through the agent. Thereby, the dispersibility of a filler can be improved significantly. Furthermore, as for the dispersant, the polycarboxylic acid derivative is more effective in improving the dispersibility of the filler and reducing the residual potential. In that case, not only the affinity between the dispersant and the filler is further increased, but also the affinity between the dispersants can be maintained, thereby improving the dispersibility of the filler and at the same time suppressing the sedimentation of the filler. In addition, it is possible to obtain an effect of improving the dispersion stability.
Specific dispersants used in the present invention include natural water-soluble polycarboxylic acids such as alginic acid and casein acid, water-soluble synthetic polycarboxylic acids having acrylic monocarboxylic acid units such as polyacrylic acid and polymethacrylic acid, A water-soluble alkyd resin, for example, a water-soluble alkyd resin containing a trimet acid structure moiety, a polymer of unsaturated dicarboxylic acid having a polymerizable unsaturated bond such as polymaleic acid, polyfumaric acid, polyitaconic acid, the acrylic monocarboxylic acid and Examples thereof include a copolymer with the aliphatic unsaturated dicarboxylic acid and a copolymer of the acrylic monocarboxylic acid, unsaturated dicarboxylic acid and methyl vinyl ether.
[0059]
In order to obtain the residual potential reducing effect, it is necessary to improve the dispersibility of the filler by adding a dispersant. However, when the dispersant has an acid value, a higher effect can be obtained. The acid value is defined as the number of milligrams of potassium hydroxide required to neutralize free fatty acids contained in 1 g. The acid value of the dispersant is preferably 10 to 400 mgKOH / g, more preferably 30 to 200 mgKOH / g. When the acid value is higher than necessary, the influence of image blur increases, and when the acid value is too low, the effect of reducing the residual potential becomes insufficient. The acid value of the dispersant does not directly affect the residual potential reduction effect, but is greatly influenced by the structure or molecular weight of the dispersant used, the type of filler, dispersibility, and the like. In addition, these dispersants may be a mixture of two or more kinds, and the use of a mixture of these materials and organic fatty acids may increase the residual potential reduction effect. The amount of the dispersant added preferably satisfies the following relational expression depending on the acid value of the dispersant to be used, but is more preferably set to the necessary minimum amount.
[0060]
[Equation 5]
0.1 ≦ (addition amount of dispersing agent × acid value of dispersing agent) / (addition amount of filler) ≦ 20
Depending on the type of filler, if the amount of filler added is increased more than necessary, image blur may appear, and if the amount added is too small, the effect of improving dispersibility and reducing the residual potential will not be sufficiently exhibited. It may cause an abnormal image.
[0061]
Since the dispersant in the present invention has an acid value, the effect of reducing the residual potential is increased. However, this may increase the influence of resolution reduction due to NOx or ozone gas. Thus, it is difficult to solve the problem because the residual potential and the image blur are in a trade-off relationship. However, in the present invention, the occurrence of image blur due to NOx or ozone, which is a side effect of the dispersant, can be suppressed without significantly affecting the residual potential by including the acrylic resin in the protective layer. It was. However, since the dispersibility of the filler may be somewhat lowered by the addition of the acrylic resin, it is more preferable to use these dispersants in combination with the acrylic resin in order to maintain the dispersibility of the filler.
[0062]
The protective layer in the present invention can contain a charge transport material, which is effective for reducing the residual potential. As the charge transport material contained in the protective layer, all of the charge transport materials contained in the charge transport layer (37) can be used. However, the charge transport material contained in the protective layer and the photosensitive layer can be used. The charge transport materials contained in each may be different from each other. In that case, the charge transport material contained in the protective layer has a lower ionization potential than the charge transport material contained in the photosensitive layer, thereby improving the charge injection property at the photosensitive layer / protective layer interface. It is possible to reduce the residual potential.
[0063]
Further, it is possible to contain a plurality of charge transport materials in the protective layer. In this case, the outermost surface side of the protective layer than the charge transport material contained on the interface side of the protective layer / photosensitive layer. In some cases, the charge transporting substance contained in has a lower ionization potential, thereby further enhancing the effect of suppressing the increase in residual potential. Note that the ionization potential can be measured using various methods such as a spectroscopic method and an electrochemical method.
[0064]
In the present invention, the case where a polymer charge transport material having a function as a charge transport material and a function as a binder resin is used for the protective layer is also good. The charge transport layer composed of these polymer charge transport materials is excellent in wear resistance. As the polymer charge transport material, known materials can be used, and in particular, a polycarbonate containing a triarylamine structure in the main chain and / or side chain is preferably used. Among these, polymer charge transport materials represented by the general formulas (I) to (X) are preferably used. These are illustrated below and specific examples are shown.
[0065]
[Chemical 1]

Where R₁, R₂, R_ThreeEach independently represents a substituted or unsubstituted alkyl group or a halogen atom, R_FourIs a hydrogen atom or a substituted or unsubstituted alkyl group, R_Five , R₆ Is a substituted or unsubstituted aryl group, o, p, q are each independently an integer of 0-4. k, j represents a composition ratio, and when k + j is 1, 0.1 ≦ k ≦ 1, 0 ≦ j ≦ 0.9, and n represents the number of repeating units and is an integer of 5 to 5000. X represents an aliphatic divalent group, a cycloaliphatic divalent group, or a divalent group represented by the following general formula.
[0066]
[Chemical formula 2]

Where R₁₀₁, R₁₀₂Each independently represents a substituted or unsubstituted alkyl group, aryl group or halogen atom. l and m are integers of 0 to 4, Y is a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, -O-, -S-, -SO-, -SO₂-, -CO-, -CO-O-Z-O-CO- (wherein Z represents an aliphatic divalent group) or
[0067]
[Chemical 3]

(Wherein, a is an integer of 1 to 20, b is an integer of 1 to 2000, R₁₀₃, R₁₀₄Represents a substituted or unsubstituted alkyl group or aryl group. ). Where R₁₀₁And R₁₀₂, R₁₀₃And R₁₀₄May be the same or different.
[0068]
[Formula 4]

Where R₇, R₈Is a substituted or unsubstituted aryl group, Ar₁, Ar₂, Ar_ThreeRepresent the same or different arylene groups. X, k, j, and n are the same as in the general formula (I).
[0069]
[Chemical formula 5]

Where R₉, R_TenIs a substituted or unsubstituted aryl group, Ar_Four, Ar_Five, Ar₆Represent the same or different arylene groups. X, k, j, and n are the same as in the general formula (I).
[0070]
[Chemical 6]

Where R₁₁, R₁₂Is a substituted or unsubstituted aryl group, Ar₇, Ar₈, Ar₉Are the same or different arylene groups, and p is an integer of 1 to 5. X, k, j and n are the same as those in the general formula (I).
[0071]
[Chemical 7]

Where R₁₃, R₁₄Is a substituted or unsubstituted aryl group, Ar_Ten, Ar₁₁, Ar₁₂Are the same or different arylene groups, X₁, X₂Represents a substituted or unsubstituted ethylene group or a substituted or unsubstituted vinylene group. X, k, j, and n are the same as in the general formula (I).
[0072]
[Chemical 8]

Where R₁₅, R₁₆, R₁₇, R₁₈Is a substituted or unsubstituted aryl group, Ar₁₃, Ar₁₄, Ar₁₅, Ar₁₆Are the same or different arylene groups, Y₁, Y₂, Y_ThreeRepresents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group, which may be the same or different. X, k, j, and n are the same as in the general formula (I).
[0073]
[Chemical 9]

Where R₁₉, R₂₀Represents a hydrogen atom, a substituted or unsubstituted aryl group, and R₁₉And R₂₀May form a ring. Ar₁₇, Ar₁₈, Ar₁₉Represent the same or different arylene groups. X, k, j, and n are the same as in the general formula (I).
[0074]
[Chemical Formula 10]

Where R_{twenty one}Is a substituted or unsubstituted aryl group, Ar₂₀, Ar_{twenty one}, Ar_{twenty two}, Ar_{twenty three}Represent the same or different arylene groups. X, k, j, and n are the same as in the general formula (I).
[0075]
Embedded image

Where R_{twenty two}, R_{twenty three}, R_{twenty four}, R_{twenty five}Is a substituted or unsubstituted aryl group, Ar_{twenty four}, Ar_{twenty five}, Ar₂₆, Ar₂₇, Ar₂₈Represent the same or different arylene groups. X, k, j, and n are the same as in the general formula (I).
[0076]
Embedded image

Where R₂₆, R₂₇Is a substituted or unsubstituted aryl group, Ar₂₉, Ar₃₀, Ar₃₁Represent the same or different arylene groups. X, k, j, and n are the same as in the general formula (I).
[0077]
In the present invention, various additives can be added to the protective layer, which is effective and useful. As the additive, it is possible to use all conventionally known additives such as a plasticizer, an antioxidant and a lubricating substance.
[0078]
Antioxidants include phenolic compounds, hindered phenolic compounds, hindered amine compounds, paraphenylenediamines, hydroquinones, organic sulfur compounds, organic phosphorus compounds, benzophenones, salsylates, benzotriazoles , Quenchers (metal complex salts) and the like, all of the conventionally known antioxidants, ultraviolet absorbers, light stabilizers and the like are all included. Further, two or more kinds of these antioxidants can be mixed and used, and a synergistic effect may be obtained depending on the combination. However, depending on the amount added, there is a strong tendency to cause a significant increase in residual potential. Among these antioxidants, hindered phenolic compounds and hindered amine compounds are known to be particularly useful as those having great effects on image blurring due to NOx or ozone gas, or reduction in charge and sensitivity. Yes.
[0079]
The lubricating substance has an effect of increasing the lubricity of the surface of the protective layer by adding them, and may be liquid or solid. Giving lubricity to the surface of the protective layer within a range where the residual potential does not increase and the coating film does not change is very effective in improving wear resistance and cleaning properties. There are many types of these lubricating substances, such as silicone oils, solid powders, or resins. Among them, it is more durable to disperse the solid powdery lubricating substance in the protective layer. Higher and more preferred. Among these, metal soaps such as zinc stearate and fluorine-based fine particles are particularly useful.
[0080]
The filler material can be dispersed by using a conventional method such as a ball mill, an attritor, a sand mill, or an ultrasonic wave together with at least an organic solvent and a dispersant. Among these, a ball mill that can increase the contact efficiency between the filler and the dispersant and has less impurities from the outside is more preferable from the viewpoint of dispersibility. As for the material of the media used, all media such as zirconia, alumina, and agate that have been used in the past can be used, but alumina is particularly used from the viewpoint of filler dispersibility and residual potential reduction effect. Α-type alumina excellent in wear resistance is particularly preferable. Zirconia has a relatively large amount of media wear at the time of dispersion, and there is a tendency for residual potential to increase or dispersibility to decrease due to the mixing of wear powder. On the other hand, when alumina is used as the medium, the amount of wear of the medium at the time of dispersion can be kept low, and the influence of the mixed wear powder on the residual potential or dispersibility is small. Therefore, it is more preferable to use alumina as a medium used for dispersion. Further, the dispersant is preferably added before the dispersion together with the filler and the organic solvent, since it suppresses the aggregation of the filler in the coating liquid and further suppresses the sedimentation of the filler and remarkably improves the dispersibility of the filler. On the other hand, binder resins, charge transport materials, antioxidants, etc. can be added before dispersion, but in that case, dispersibility may be reduced, so that the dispersion is performed in a state dissolved in an organic solvent. It is preferable to add it later.
[0081]
As a coating method of the dispersion obtained as described above, conventional coating methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating, etc. can be used. Spray coating is most suitable for forming a thin film uniformly and with a good filler dispersibility. In spray coating, it is more effective to improve the dispersibility of the filler by coating several times than applying the required film thickness at once. By doing so, sagging of the coating liquid at the time of coating can also be suppressed, and this is effective in improving the coating film quality.
[0082]
The film thickness of the entire protective layer is 0.5 μm to 10 μm, preferably 1 to 6 μm. The film thickness of the protective layer may affect the resolution and dot reproducibility due to film uniformity, wear resistance, increase in residual potential, and decrease in light transmittance.
[0083]
In the photoreceptor of the present invention, an undercoat layer can be provided between the conductive support (31) and the photosensitive layer. In general, the undercoat layer is mainly composed of a resin. However, considering that the photosensitive layer is coated with a solvent on these resins, the resin may be a resin having high solvent resistance with respect to a general organic solvent. desirable. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin. Further, a metal oxide fine powder pigment exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like may be added to the undercoat layer in order to prevent moire and reduce residual potential. These undercoat layers can be formed using an appropriate solvent and a coating method like the above-mentioned photosensitive layer. Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer of the present invention. Furthermore, various dispersing agents can be added. In addition, the undercoat layer of the present invention includes Al.₂O_ThreeAnodic oxidation, organic materials such as polyparaxylylene (parylene), and SiO₂, SnO₂TiO₂, ITO, CeO₂A material provided with an inorganic material such as a vacuum thin film can also be used favorably. In addition, known ones can be used. Further, the undercoat layer may be laminated in two layers, which is effective in suppressing background stains. The thickness of the undercoat layer is suitably from 0 to 5 μm.
[0084]
In the photoreceptor of the present invention, an intermediate layer can be provided between the photosensitive layer and the protective layer. In the intermediate layer, a binder resin is generally used as a main component. Examples of these resins include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. As a method for forming the intermediate layer, a generally used coating method as described above is employed. In addition, about 0.05-2 micrometers is suitable for the thickness of an intermediate | middle layer.
[0085]
In the present invention, in order to improve environment resistance, in particular, for the purpose of preventing a decrease in sensitivity and an increase in residual potential, each layer such as a charge generation layer, a charge transport layer, an undercoat layer, a protective layer, and an intermediate layer is conventionally used. Known antioxidants, plasticizers, lubricants, ultraviolet absorbers, low molecular charge transport materials and leveling agents can be added. Representative materials of these compounds are described below.
[0086]
Examples of the antioxidant that can be added to each layer include, but are not limited to, the following.
(A) Phenolic compounds
2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, n-octadecyl-3- (4′-hydroxy-3 ′, 5 '-Di-t-butylphenol), 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2,2'-methylene-bis- (4-ethyl-6-t-butylphenol) 4,4′-thiobis- (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis- (3-methyl-6-tert-butylphenol), 1,1,3-tris- (2- Methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis- [Michile -3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, bis [3,3′-bis (4′-hydroxy-3′-t-butylphenyl) buty Rick acid] glycol ester, tocopherols and the like.
[0087]
(B) Paraphenylenediamines
N-phenyl-N'-isopropyl-p-phenylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylenediamine, N, N'- Di-isopropyl-p-phenylenediamine, N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine and the like.
[0088]
(C) Hydroquinones
2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2- (2-octadecenyl) ) -5-methylhydroquinone and the like.
[0089]
(D) Organic sulfur compounds
Dilauryl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, ditetradecyl-3,3'-thiodipropionate, and the like.
[0090]
(E) Organophosphorus compounds
Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine, and the like.
[0091]
Examples of the plasticizer that can be added to each layer include, but are not limited to, the following.
(A) Phosphate ester plasticizer
Triphenyl phosphate, tricresyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, trichlorethyl phosphate, cresyl diphenyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate and the like.
[0092]
(B) Phthalate ester plasticizer
Dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dibutyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, diisooctyl phthalate, di-n-octyl phthalate, dinonyl phthalate, diisononyl phthalate, phthalic acid Diisodecyl, diundecyl phthalate, ditridecyl phthalate, dicyclohexyl phthalate, butyl benzyl phthalate, butyl lauryl phthalate, methyl oleyl phthalate, octyl decyl phthalate, dibutyl fumarate, dioctyl fumarate, etc.
[0093]
(C) Aromatic carboxylic ester plasticizer
Trioctyl trimellitic acid, tri-n-octyl trimellitic acid, octyl oxybenzoate, and the like.
[0094]
(D) Aliphatic dibasic acid ester plasticizer
Dibutyl adipate, di-n-hexyl adipate, di-2-ethylhexyl adipate, di-n-octyl adipate, n-octyl adipate, diisodecyl adipate, dicapryl adipate, diazeylate 2-ethylhexyl, dimethyl sebacate, diethyl sebacate, dibutyl sebacate, di-n-octyl sebacate, di-2-ethylhexyl sebacate, di-2-ethoxyethyl sebacate, dioctyl succinate, diisodecyl succinate, Dioctyl tetrahydrophthalate, di-n-octyl tetrahydrophthalate and the like.
[0095]
(E) Fatty acid ester derivatives
Butyl oleate, glycerol monooleate, methyl acetylricinoleate, pentaerythritol ester, dipentaerythritol hexaester, triacetin, tributyrin and the like.
[0096]
(F) Oxyester plasticizer
Methyl acetyl ricinoleate, butyl acetyl ricinoleate, butyl phthalyl butyl glycolate, tributyl acetyl citrate and the like.
[0097]
(G) Epoxy plasticizer
Epoxidized soybean oil, epoxidized linseed oil, butyl epoxy stearate, decyl epoxy stearate, octyl epoxy stearate, benzyl epoxy stearate, dioctyl epoxy hexahydrophthalate, didecyl epoxy hexahydrophthalate and the like.
[0098]
(H) Dihydric alcohol ester plasticizer
Diethylene glycol dibenzoate, triethylene glycol di-2-ethylbutyrate, etc.
[0099]
(I) Chlorine-containing plasticizer
Chlorinated paraffin, chlorinated diphenyl, chlorinated fatty acid methyl, methoxychlorinated fatty acid methyl, etc.
[0100]
(J) Polyester plasticizer
Polypropylene adipate, polypropylene sebacate, polyester, acetylated polyester, etc.
[0101]
(K) Sulfonic acid derivative
p-toluenesulfonamide, o-toluenesulfonamide, p-toluenesulfoneethylamide, o-toluenesulfoneethylamide, toluenesulfone-N-ethylamide, p-toluenesulfone-N-cyclohexylamide and the like.
[0102]
(L) Citric acid derivative
Triethyl citrate, triethyl citrate citrate, tributyl citrate, tributyl acetyl citrate, tri-2-ethylhexyl acetyl citrate, acetyl citrate-n-octyldecyl and the like.
[0103]
(M) Other
Terphenyl, partially hydrogenated terphenyl, camphor, 2-nitrodiphenyl, dinonylnaphthalene, methyl abietate and the like.
[0104]
Examples of the lubricating substance that can be added to each layer include, but are not limited to, the following.
(A) Hydrocarbon compounds
Liquid paraffin, paraffin wax, microwax, low-polymerized polyethylene, etc.
[0105]
(B) Fatty acid compounds
Lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, etc.
[0106]
(C) Fatty acid amide compounds
Stearylamide, palmitylamide, oleinamide, methylenebisstearamide, ethylenebisstearamide, etc.
[0107]
(D) Ester compound
Lower alcohol esters of fatty acids, polyhydric alcohol esters of fatty acids, fatty acid polyglycol esters, and the like.
[0108]
(E) Alcohol compounds
Cetyl alcohol, stearyl alcohol, ethylene glycol, polyethylene glycol, polyglycerol, etc.
[0109]
(F) Metal soap
Lead stearate, cadmium stearate, barium stearate, calcium stearate, zinc stearate, magnesium stearate, etc.
[0110]
(G) Natural wax
Carnauba wax, candelilla wax, beeswax, whale wax, ibota wax, montan wax, etc.
[0111]
(H) Other
Silicone compounds, fluorine compounds, etc.
[0112]
Examples of the ultraviolet absorber that can be added to each layer include, but are not limited to, the following.
(A) Benzophenone series
2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,2 ', 4-trihydroxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, and the like.
[0113]
(B) Salsylate type
Phenyl salsylate, 2,4 di-t-butylphenyl 3,5-di-t-butyl 4-hydroxybenzoate, and the like.
[0114]
(C) Benzotriazole type
(2′-hydroxyphenyl) benzotriazole, (2′-hydroxy5′-methylphenyl) benzotriazole, (2′-hydroxy5′-methylphenyl) benzotriazole, (2′-hydroxy3′-tertiarybutyl 5) '-Methylphenyl) 5-chlorobenzotriazole and the like.
[0115]
(D) Cyanoacrylate type
Ethyl-2-cyano-3,3-diphenyl acrylate, methyl 2-carbomethoxy 3 (paramethoxy) acrylate, and the like.
[0116]
(E) Quencher (metal complex)
Nickel (2,2'thiobis (4-t-octyl) phenolate) normal butylamine, nickel dibutyldithiocarbamate, nickel dibutyldithiocarbamate, cobalt dicyclohexyldithiophosphate and the like.
[0117]
(F) HALS (hindered amine)
Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3- (3 5-di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6 6-tetramethylpyridine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4-benzoyloxy- 2,2,6,6-tetramethylpiperidine and the like.
[0118]
Next, the electrophotographic method and the electrophotographic apparatus of the present invention will be described in detail with reference to the drawings.
FIG. 4 is a schematic diagram for explaining the electrophotographic process and the electrophotographic apparatus of the present invention, and the following examples also belong to the category of the present invention.
In FIG. 4, the photoreceptor (1) is provided with at least a photosensitive layer, and the outermost protective layer contains a filler and an acrylic resin. The photoreceptor (1) has a drum shape, but may be a sheet shape or an endless belt shape. The charging charger (3), pre-transfer charger (7), transfer charger (10), separation charger (11) and pre-cleaning charger (13) include corotron, scorotron, solid state charger, and charging. A roller, a charging brush, a transfer roller, etc. are used, and all known means can be used. These charging members may be in contact with the photoreceptor or non-contact. In particular, the charging roller used for charging the photosensitive member is effectively used in the present invention because the amount of ozone generated is smaller than that of corotron or scorotron. However, when the charging roller is in contact with the photoconductor, the influence of contamination on the surface of the photoconductor may increase, so it may be more preferable that the charging roller and the photoconductor are not in contact with each other in the image area. Further, it is effective because the charging stability may be increased by superimposing the AC component on the DC component during charging.
As the transfer means, the above charger can be generally used. However, as shown in the figure, a combination of a transfer charger and a separation charger is effective.
[0119]
Further, light sources such as an image exposure unit (5) and a charge removal lamp (2) include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LD), and electroluminescence (EL). ) And other luminescent materials can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.
[0120]
In addition to the steps shown in FIG. 4, the light source and the like are provided with a transfer step, a static elimination step, a cleaning step, a pre-exposure step and the like using light irradiation, so that the photosensitive member is irradiated with light. However, the exposure of the photoconductor in the static elimination step has a great influence of fatigue on the photoconductor, and in particular, the increase in the residual potential may occur remarkably. Therefore, there are cases where it is possible to eliminate static electricity by applying a reverse bias in the charging process or cleaning process instead of static elimination by exposure, which is preferable from the viewpoint of durability of the photoreceptor.
[0121]
The toner developed on the photoconductor (1) by the developing unit (6) is transferred to the transfer paper (9), but not all is transferred and remains on the photoconductor (1). Toner is also produced. Such toner is removed from the photoreceptor by the fur brush (14) and the blade (15). Cleaning may be performed only with a cleaning brush, and a known brush such as a fur brush or a mag fur brush is used as the cleaning brush.
[0122]
Cleaning is a process of removing toner remaining on the photoconductor after transfer, but the above-described blade or brush rubs the photoconductor surface with the toner to promote wear or damage to the photoconductor. However, this may lead to the generation of abnormal images. Further, an increase in the influence of contamination on the surface of the photoreceptor due to poor cleaning not only causes an abnormal image, but also significantly reduces the life of the photoreceptor. In particular, when the photosensitive member surface has a layer containing a filler for improving the abrasion resistance, it is difficult to remove contaminants attached to the photosensitive member surface due to the high abrasion resistance. As the impact of increases, the impact is even greater. Therefore, improving the cleaning property of the photosensitive member is very effective for improving the durability or improving the image quality of the photosensitive member.
[0123]
As means for improving the cleaning property of the photosensitive member, a method of reducing the coefficient of friction on the surface of the photosensitive member is known. As described above, the method for reducing the coefficient of friction on the surface of the photoconductor is divided into a method for containing various types of lubricating substances on the surface of the photoconductor and a method for supplying a lubricating substance to the surface of the photoconductor from the outside. The former is advantageous for small-diameter photoreceptors because of the high degree of freedom in layout around the engine, but the coefficient of friction increases remarkably with repeated use, and there remains a problem in its sustainability. On the other hand, the latter needs to be provided with a component for supplying a lubricating substance, but is an effective means for increasing the durability of the photoreceptor because of its excellent sustainability. Among them, the method of adhering to the photoreceptor during development by incorporating a lubricant into the developer is not restricted by the layout around the engine, and the effect of reducing the friction coefficient on the photoreceptor surface is high. Therefore, this is a very effective means for improving the durability of the photoreceptor and improving the cleaning property. These lubricating substances include silicone oil, lubricating liquid such as fluorine oil, various fluororesins such as PTFE / PFA / PVDF, silicone resin, polyolefin resin, silicone grease, fluorine grease, paraffin wax, fatty acid esters, Examples include fatty acid metal salts such as zinc stearate, lubricating liquids such as graphite and molybdenum disulfide, solids, powders, and the like, but when mixed with a developer, a powdery substance is preferable, particularly zinc stearate. Can be used very effectively with little adverse effects.
[0124]
When negative (positive) charging is performed on the electrophotographic photosensitive member and image exposure is performed, a negative (positive) electrostatic latent image is formed on the surface of the photosensitive member. If this is developed with a positive (negative) polarity toner (detection fine particles), a positive image can be obtained, and if developed with a negative (positive) toner, a negative image can be obtained.
A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.
[0125]
FIG. 5 shows another example of the electrophotographic process according to the present invention. The photoreceptor (21) has at least a photosensitive layer, and further includes a protective layer made of a filler and an acrylic resin on the outermost surface layer. The photoreceptor (21) is driven by driving rollers (22a) and (22b), and is charged by a charger (23). Charging by the light source (24), image exposure by the light source (24), development (not shown), transfer using the charger (25), pre-cleaning exposure by the light source (26), cleaning by the brush (27), neutralization by the light source (28). Repeatedly. In FIG. 5, the photoconductor (21) (of course, the support is translucent in this case) is irradiated with pre-cleaning exposure light from the support side.
[0126]
The above illustrated electrophotographic process is illustrative of an embodiment of the present invention, and of course other embodiments are possible. For example, in FIG. 5, the pre-cleaning exposure is performed from the support side, but this may be performed from the photosensitive layer side, or image exposure and neutralization light irradiation may be performed from the support side.
On the other hand, the light irradiation process is illustrated as image exposure, pre-cleaning exposure, and static elimination exposure. In addition, a pre-transfer exposure, a pre-exposure of image exposure, and other known light irradiation processes are provided to light the photosensitive member. Irradiation can also be performed.
[0127]
The image forming means as described above may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge. The process cartridge is a single device (part) that contains a photosensitive member, and further includes a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit. Some of them may include only a part of these means together with the photoreceptor. There are many shapes and the like of the process cartridge, but an example of the present invention is shown in FIG. The photoreceptor (16) has at least a photosensitive layer on a conductive support, and the outermost protective layer contains at least a filler and an acrylic resin. This process cartridge comprises the electrophotographic photosensitive member (16) of the present invention, a charging charger (17), a cleaning brush (18), an image exposure unit (19), and a developing roller (20).
[0128]
【Example】
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not restrict | limited by an Example. All parts are parts by weight. The ionization potential Ip of the charge transport material was measured with a surface analyzer (manufactured by Riken Keiki Co., Ltd., AC-1).
[0129]
Example 1
An undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution having the following composition are sequentially applied onto an aluminum cylinder by dip coating and dried, and an undercoat layer of about 3.0 μm, about A 0.2 μm charge generation layer and an approximately 20 μm charge transport layer were formed.
[Undercoat layer coating solution]
Alkyd resin 6 parts
("Beccosol 1307-60" manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 4 parts
("Super Becamine G-821-60" manufactured by Dainippon Ink and Chemicals, Inc.)
40 parts of titanium oxide powder
("Typer CR-EL" manufactured by Ishihara Sangyo Co., Ltd.)
50 parts of methyl ethyl ketone
[0130]
[Charge generation layer coating solution]
2.5 parts of asymmetric bisazo pigment of the following structural formula (1)
[0131]
Embedded image

Polyvinyl butyral ("XYHL" manufactured by UCC) 0.5 part
80 parts of methyl ethyl ketone
200 parts of cyclohexanone
[0132]
[Charge transport layer coating solution]
10 parts of bisphenol Z polycarbonate
(Panlite TS-2050, manufactured by Teijin Chemicals)
10 parts of charge transport material of the following structural formula (2) (Ip: 5.4 eV)
[0133]
Embedded image

Silicone oil ("KF50" manufactured by Shin-Etsu Chemical) 0.002 parts
Tetrahydrofuran 100 parts
[0134]
A protective layer having a film thickness of about 3 μm was formed on the charge transport layer by spray coating using a protective layer coating solution having the following composition to produce an electrophotographic photoreceptor 1.
[Protective layer coating solution]
2.5 parts of alumina
(Average primary particle size: 0.3 μm, “AA-03” manufactured by Sumitomo Chemical)
Unsaturated polycarboxylic acid polymer 0.06 parts
(Acid value 180 mgKOH / g, nonvolatile content 50%
"BYK-P104" manufactured by BYK Chemie)
9 parts of bisphenol Z polycarbonate
(Panlite TS-2050, manufactured by Teijin Chemicals)
Acrylic resin 2 parts
(Hydroxyl value 15 (mgKOH / g), non-volatile content 50%,
"Hitaroid 3001" manufactured by Hitachi Chemical)
320 parts of tetrahydrofuran
90 parts of cyclohexanone
[0135]
(Example 2)
In Example 1, the electrophotographic photosensitive member 2 was produced in the same manner as in Example 1 except that the protective layer coating solution was changed to the following composition and the thickness of the protective layer was about 2 μm.
[Protective layer coating solution]
1.0 part of alumina
(Average primary particle size: 0.3 μm, “AA-03” manufactured by Sumitomo Chemical)
9 parts of bisphenol Z polycarbonate
(Panlite TS-2050, manufactured by Teijin Chemicals)
Acrylic resin 2 parts
(Hydroxyl value 15 (mgKOH / g), non-volatile content 50%,
"Hitaroid 3001" manufactured by Hitachi Chemical)
280 parts of tetrahydrofuran
80 parts of cyclohexanone
[0136]
(Example 3)
In Example 1, the electrophotographic photoreceptor 3 was produced in the same manner as in Example 1 except that the protective layer coating solution was changed to the following composition and the thickness of the protective layer was about 5 μm.
[Protective layer coating solution]
Alumina 5.0 parts
(Average primary particle size: 0.3 μm, “AA-03” manufactured by Sumitomo Chemical)
Unsaturated polycarboxylic acid polymer 0.15 parts
(Acid value 180 mgKOH / g, nonvolatile content 50%
"BYK-P104" manufactured by BYK Chemie)
9 parts of bisphenol Z polycarbonate
(Panlite TS-2050, manufactured by Teijin Chemicals)
Acrylic resin 2 parts
(Hydroxyl value 25 (mgKOH / g), non-volatile content 50%,
"Hitaroid 3020" manufactured by Hitachi Chemical)
7 parts of charge transport material of the above structural formula (2) (Ip: 5.4 eV)
550 parts of tetrahydrofuran
150 parts of cyclohexanone
[0137]
(Example 4)
In Example 3, an electrophotographic photoreceptor 4 was produced in the same manner as in Example 3 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
Alumina 5.0 parts
(Average primary particle size: 0.3 μm, “AA-03” manufactured by Sumitomo Chemical)
Unsaturated polycarboxylic acid polymer 0.15 parts
(Acid value 180 mgKOH / g, nonvolatile content 50%
"BYK-P104" manufactured by BYK Chemie)
Bisphenol Z polycarbonate 5 parts
(Panlite TS-2050, manufactured by Teijin Chemicals)
Acrylic resin 10 parts
(Hydroxyl value 25 (mgKOH / g), non-volatile content 50%,
"Hitaroid 3020" manufactured by Hitachi Chemical)
7 parts of charge transport material of the above structural formula (2) (Ip: 5.4 eV)
550 parts of tetrahydrofuran
150 parts of cyclohexanone
[0138]
(Example 5)... Reference examples
  In Example 3, an electrophotographic photoreceptor 5 was produced in the same manner as in Example 3 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
    Alumina 5.0 parts
    (Average primary particle size: 0.3 μm, “AA-03” manufactured by Sumitomo Chemical)
    Unsaturated polycarboxylic acid polymer 0.15 parts
    (Acid value 180 mgKOH / g, nonvolatile content 50%
    "BYK-P104" manufactured by BYK Chemie)
    20 parts acrylic resin
    (Hydroxyl value 25 (mgKOH / g), non-volatile content 50%,
    "Hitaroid 3020" manufactured by Hitachi Chemical)
    7 parts of charge transport material of the above structural formula (2) (Ip: 5.4 eV)
    550 parts of tetrahydrofuran
    150 parts of cyclohexanone
[0139]
(Example 6)
In Example 3, an electrophotographic photosensitive member 6 was produced in the same manner as in Example 3 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
Alumina 5.0 parts
(Average primary particle size: 0.3 μm, “AA-03” manufactured by Sumitomo Chemical)
Unsaturated polycarboxylic acid polymer 0.15 parts
(Acid value 180 mgKOH / g, nonvolatile content 50%
"BYK-P104" manufactured by BYK Chemie)
Bisphenol Z polycarbonate 8 parts
(Panlite TS-2050, manufactured by Teijin Chemicals)
Acrylic resin ("BR-605" manufactured by Mitsubishi Rayon) 2 parts
7 parts of charge transport material of the above structural formula (2) (Ip: 5.4 eV)
550 parts of tetrahydrofuran
150 parts of cyclohexanone
[0140]
(Example 7)
In Example 3, an electrophotographic photoreceptor 7 was produced in the same manner as in Example 3 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
Alumina 4.0 parts
(Average primary particle size: 0.3 μm, “AA-03” manufactured by Sumitomo Chemical)
Unsaturated polycarboxylic acid polymer 0.10 parts
(Acid value 180 mgKOH / g, nonvolatile content 50%
"BYK-P104" manufactured by BYK Chemie)
9 parts of bisphenol Z polycarbonate
(Panlite TS-2050, manufactured by Teijin Chemicals)
1 part of methyl methacrylate polymer (Wako Pure Chemical Industries)
7 parts of charge transport material of the above structural formula (2) (Ip: 5.4 eV)
530 parts of tetrahydrofuran
145 parts of cyclohexanone
[0141]
(Example 8)
In Example 3, an electrophotographic photosensitive member 8 was produced in the same manner as in Example 3 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
Alumina 4.0 parts
(Average primary particle size: 0.3 μm, “AA-03” manufactured by Sumitomo Chemical)
Unsaturated polycarboxylic acid polymer
(Acid value 180 mgKOH / g, nonvolatile content 50%
"BYK-P104" BYK Chemie) 0.10 parts
Polyarylate ("U Polymer U-6000" manufactured by Unitika) 8 parts
Acrylic resin 3.3 parts
(Hydroxyl value 60 (mgKOH / g), non-volatile content 60%,
"Hitaroid 3083" manufactured by Hitachi Chemical)
7 parts of charge transport material of the above structural formula (2) (Ip: 5.4 eV)
530 parts of tetrahydrofuran
145 parts of cyclohexanone
[0142]
(Comparative Example 1)
In Example 1, an electrophotographic photosensitive member 9 was produced in the same manner as in Example 1 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
Bisphenol Z polycarbonate 8 parts
(Panlite TS-2050, manufactured by Teijin Chemicals)
Acrylic resin 4 parts
(Hydroxyl value 25 (mgKOH / g), non-volatile content 50%,
"Hitaroid 3020" manufactured by Hitachi Chemical)
7 parts of charge transport material of the above structural formula (2) (Ip: 5.4 eV)
Tetrahydrofuran 500 parts
[0143]
(Comparative Example 2)
In Example 3, the electrophotographic photosensitive member 10 was produced in the same manner as in Example 3 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
Alumina 5.0 parts
(Average primary particle size: 0.3 μm, “AA-03” manufactured by Sumitomo Chemical)
Unsaturated polycarboxylic acid polymer 0.15 parts
(Acid value 180 mgKOH / g, nonvolatile content 50%
"BYK-P104" manufactured by BYK Chemie)
10 parts of bisphenol Z polycarbonate
(Panlite TS-2050, manufactured by Teijin Chemicals)
7 parts of charge transport material of the above structural formula (2) (Ip: 5.4 eV)
550 parts of tetrahydrofuran
150 parts of cyclohexanone
[0144]
(Comparative Example 3)
In Example 3, an electrophotographic photosensitive member 11 was produced in the same manner as in Example 3 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
Acrylic resin 14 parts
(Hydroxyl value 25 (mgKOH / g), non-volatile content 50%,
"Hitaroid 3020" manufactured by Hitachi Chemical)
Guanamin resin (thermal crosslinking curable resin) 4.5 parts
(Non-volatile content 70%, “My Coat 1128” manufactured by Mitsui Cytec)
Aromatic sulfonic acid (curing catalyst) 0.02 parts
(Non-volatile content 40%, “Catalyst 4040” manufactured by Mitsui Cytec)
250 parts of tetrahydrofuran
70 parts of cyclohexanone
[0145]
(Comparative Example 4)
In Example 3, an electrophotographic photosensitive member 12 was produced in the same manner as in Example 3 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
Alumina 3.0 parts
(Average primary particle size: 0.3 μm, “AA-03” manufactured by Sumitomo Chemical)
Unsaturated polycarboxylic acid polymer 0.09 parts
(Acid value 180 mgKOH / g, nonvolatile content 50%
"BYK-P104" manufactured by BYK Chemie)
Acrylic resin 14 parts
(Hydroxyl value 25 (mgKOH / g), non-volatile content 50%,
"Hitaroid 3020" manufactured by Hitachi Chemical)
Guanamin resin (thermal crosslinking curable resin) 4.0 parts
(Non-volatile content 77%, "My Coat 106" manufactured by Mitsui Cytec)
Aromatic sulfonic acid (curing catalyst) 0.02 parts
(Non-volatile content 40%, “Catalyst 4040” manufactured by Mitsui Cytec)
330 parts of tetrahydrofuran
90 parts of cyclohexanone
[0146]
(Comparative Example 5)
In Example 3, an electrophotographic photosensitive member 13 was produced in the same manner as in Example 3 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
Alumina 5.0 parts
(Average primary particle size: 0.3 μm, “AA-03” manufactured by Sumitomo Chemical)
Unsaturated polycarboxylic acid polymer 0.15 parts
(Acid value 180 mgKOH / g, nonvolatile content 50%
"BYK-P104" manufactured by BYK Chemie)
Acrylic resin 14 parts
(Hydroxyl value 25 (mgKOH / g), non-volatile content 50%,
"Hitaroid 3020" manufactured by Hitachi Chemical)
Melamine resin (thermal cross-linking curable resin) 3 parts
("Cymel 303", made by Mitsui Cytec)
Aromatic sulfonic acid (curing catalyst) 0.02 parts
(Non-volatile content 40%, “Catalyst 4040” manufactured by Mitsui Cytec)
7 parts of charge transport material of the above structural formula (2) (Ip: 5.4 eV)
550 parts of tetrahydrofuran
150 parts of cyclohexanone
[0147]
Example 9
In Example 1, an electrophotographic photosensitive member 14 was produced in the same manner as in Example 1 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
Titanium oxide 4.0 parts
(Average primary particle size: 0.3 μm, “CR-EL” manufactured by Ishihara Sangyo)
Unsaturated polycarboxylic acid polymer 0.12 parts
(Acid value 180 mgKOH / g, nonvolatile content 50%
"BYK-P104" manufactured by BYK Chemie)
Bisphenol Z polycarbonate 8 parts
(Panlite TS-2050, manufactured by Teijin Chemicals)
Acrylic resin 4 parts
(Hydroxyl value 15 (mgKOH / g), non-volatile content 50%,
"Hitaroid 3001" manufactured by Hitachi Chemical)
8 parts of the charge transport material of the above structural formula (2) (Ip: 5.4 eV)
550 parts of tetrahydrofuran
150 parts of cyclohexanone
[0148]
(Example 10)
In Example 1, an electrophotographic photoreceptor 15 was produced in the same manner as in Example 1 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
Silica 2.0 parts
(Average primary particle size: 0.1 μm, “KMPX-100” manufactured by Shin-Etsu Silicone)
7 parts of bisphenol Z polycarbonate
(Panlite TS-2050, manufactured by Teijin Chemicals)
Acrylic resin 6 parts
(Hydroxyl value 25 (mgKOH / g), non-volatile content 50%,
"Hitaroid 3020" manufactured by Hitachi Chemical)
10 parts of charge transport material of the above structural formula (2) (Ip: 5.4 eV)
550 parts of tetrahydrofuran
150 parts of cyclohexanone
[0149]
(Example 11)
In Example 3, an electrophotographic photosensitive member 16 was produced in the same manner as in Example 3 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
Titanate coupling-treated alumina 4.0 parts
(Average primary particle size: 0.3 μm, “AA-03” manufactured by Sumitomo Chemical)
Unsaturated polycarboxylic acid polymer 0.08 parts
(Acid value 180 mgKOH / g, nonvolatile content 50%
"BYK-P104" manufactured by BYK Chemie)
Bisphenol Z polycarbonate 6 parts
(Panlite TS-2050, manufactured by Teijin Chemicals)
8 parts acrylic acid / hydroxyethyl methacrylate copolymer
(Non-volatile content 40%, manufactured by Sanyo Chemical)
7 parts of charge transport material of the above structural formula (2) (Ip: 5.4 eV)
530 parts of tetrahydrofuran
145 parts of cyclohexanone
[0150]
Example 12
In Example 3, an electrophotographic photoreceptor 17 was produced in the same manner as in Example 3 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
2.5 parts of alumina
(Average primary particle size: 0.013 μm, “Al2O3-C” Aerosil)
Unsaturated polycarboxylic acid polymer 0.05 parts
(Acid value 180 mgKOH / g, nonvolatile content 50%
"BYK-P104" manufactured by BYK Chemie)
Bisphenol Z polycarbonate 8 parts
(Panlite TS-2050, manufactured by Teijin Chemicals)
Acrylic resin 4 parts
(Hydroxyl value 15 (mgKOH / g), non-volatile content 50%,
"Hitaroid 3001" manufactured by Hitachi Chemical)
8 parts of the charge transport material of the above structural formula (2) (Ip: 5.4 eV)
Tetrahydrofuran 510 parts
140 parts of cyclohexanone
[0151]
(Example 13)
In Example 3, an electrophotographic photosensitive member 18 was produced in the same manner as in Example 3 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
Alumina 4.0 parts
(Average primary particle size: 0.4 μm, “AA-04” manufactured by Sumitomo Chemical)
Unsaturated polycarboxylic acid polymer 0.05 parts
(Acid value 365 mgKOH / g, “BYK-P105” manufactured by BYK Chemie)
7 parts of bisphenol Z polycarbonate
(Panlite TS-2050, manufactured by Teijin Chemicals)
Acrylic resin 5 parts
(Hydroxyl value 60 (mgKOH / g), non-volatile content 50%,
"Hitaroid 3083" manufactured by Hitachi Chemical)
7 parts of charge transport material (Ip: 5.3 eV) of the following structural formula (6)
530 parts of tetrahydrofuran
145 parts of cyclohexanone
[0152]
Embedded image

[0153]
(Example 14)... Reference examples
  In Example 3, an electrophotographic photosensitive member 19 was produced in the same manner as in Example 3 except that the protective layer coating solution was changed to the following composition.
[Protective layer coating solution]
    Alumina 4.0 parts
    (Average primary particle size: 0.3 μm, “AA-03” manufactured by Sumitomo Chemical)
    Unsaturated polycarboxylic acid polymer 0.10 parts
    (Acid value 180 mgKOH / g, nonvolatile content 50%
    "BYK-P104" manufactured by BYK Chemie)
    Acrylic resin 6 parts
    (Hydroxyl value 25 (mgKOH / g), non-volatile content 50%,
    "Hitaroid 3020" manufactured by Hitachi Chemical)
    Polymer charge transport material (Ip: 5.4 eV) of the following structural formula (7) 15 parts
[0154]
Embedded image

550 parts of tetrahydrofuran
150 parts of cyclohexanone
[0155]
(Example 15)
In Example 3, the electrophotographic photosensitive member 20 was produced in the same manner as in Example 3 except that the charge generation layer coating solution, the charge transport layer coating solution, and the protective layer coating solution were changed to the following. .
[Charge generation layer coating solution]
5 parts of polyvinyl butyral ("ESREC BX-1" manufactured by Sekisui Chemical Co., Ltd.)
400 parts of methyl ethyl ketone
8 parts titanyl phthalocyanine having the XD spectrum shown in FIG.
[Charge transport layer coating solution]
10 parts of bisphenol Z polycarbonate
(Panlite TS-2050, manufactured by Teijin Chemicals)
10 parts of the charge transport material of the above structural formula (6)
Silicone oil ("KF50" manufactured by Shin-Etsu Chemical) 0.002 parts
Tetrahydrofuran 100 parts
[Protective layer coating solution]
Alumina 3.0 parts
(Average primary particle size: 0.3 μm, “AA-03” manufactured by Sumitomo Chemical)
Unsaturated polycarboxylic acid polymer 0.09 parts
(Acid value 180 mgKOH / g, nonvolatile content 50%
"BYK-P104" manufactured by BYK Chemie)
Bisphenol Z polycarbonate 8 parts
(Panlite TS-2050, manufactured by Teijin Chemicals)
Acrylic resin 4 parts
(Hydroxyl value 25 (mgKOH / g), non-volatile content 50%,
"Hitaroid 3020" manufactured by Hitachi Chemical)
10 parts of the charge transport material of the above structural formula (6)
570 parts of tetrahydrofuran
160 parts of cyclohexanone
[0156]
The electrophotographic photoreceptors 1 to 20 produced as described above are mounted on a process cartridge for an electrophotographic apparatus (however, exposure before cleaning is not performed), and the wavelength of the image exposure light source is 655 nm (provided that the electrophotographic photoreceptor No. 20 is used). (Only 780 nm) Using the Ricoh Co., Ltd. imagio MF2200 remodeling machine, the initial measurement of the bright area potential and image evaluation were performed, and then 30,000 sheets were printed continuously. Later bright part potential measurement and image evaluation were carried out. Further, the amount of wear was evaluated from the initial holding and the film thickness difference after printing 30,000 sheets. These results are shown in Table 1.
[0157]
[Table 1]

  Note) Examples 5 and 14 are reference examples.
  From the evaluation results in Table 1, it was confirmed that the electrophotographic photosensitive member having a protective layer crosslinked with an acrylic resin has a very large amount of wear after printing 30,000 sheets and has poor wear resistance, and an increase in background stains. . In addition, the electrophotographic photosensitive member containing a filler and having a protective layer in which an acrylic resin is crosslinked does not have sufficient abrasion resistance, and generation of streak-like image defects was confirmed. On the other hand, the electrophotographic photosensitive member having a protective layer containing a filler and an acrylic resin according to the present invention has a small amount of wear, and a good image was obtained even after printing 30,000 sheets. Furthermore, by adding a dispersant or an electron transport material to the protective layer, it was confirmed that the bright part potential was reduced and the wear resistance was improved, and that the image quality was improved.
[0158]
(Examples 16 to 20, Comparative Example 6)... Example 18 is a reference example
  Examples 3, 4, 5, 6, 15(Example 5 is a reference example)The electrophotographic photosensitive member 3, 4, 5, 6, 10, 20 produced in Comparative Example 2 was subjected to an accelerated deterioration test by exposure to nitrogen oxides (nitrogen oxide concentration 50 ppm, 50 hours). Image evaluation was performed. Before and after exposure, these electrophotographic photoreceptors are mounted on an electrophotographic process cartridge, and the wavelength of the image exposure light source is 655 nm (however, only 780 nm for the electrophotographic photoreceptor No. 20) is manufactured by Ricoh. Image evaluation was carried out on an imagio MF2200 modified machine. The results are shown in Table 2. The image rank was classified according to the following levels.
Image quality rank ◎: Level that can be judged as high image quality
              ○: Image quality is slightly degraded, but there is no problem
              Δ: Level at which image quality degradation is clearly observed
              ×: Level at which image discrimination is difficult
[0159]
[Table 2]

  Note) Example 18 is a reference example.
  It was confirmed that the electrophotographic photosensitive member having a protective layer containing a filler and not containing an acrylic resin has better abrasion resistance than the evaluation results shown in Table 1. However, from the evaluation results in Table 2, it was confirmed that exposure to the nitrogen oxide gas caused significant image blur and caused image degradation that caused image discrimination. However, the electrophotographic photosensitive member having a protective layer containing an acrylic resin together with the filler according to the present invention can obtain a good image even under severe exposure conditions with a high concentration of nitrogen oxides. In addition, among acrylic resins, it was confirmed that an acrylic resin having a hydroxyl value is particularly effective, and that the effect is higher when the amount of addition is larger.
[0160]
【The invention's effect】
  As described above, as is clear from the detailed and specific description, according to the present invention, the protective layer has a filler,as well asThe binder resin is selected from acrylic resins, methacrylic resins or copolymers thereofacrylic resinAnd a mixed resin containing at least one of a polycarbonate resin and a polyarylate resinIn addition, an electrophotographic photoreceptor capable of suppressing image blur even when nitrogen oxide is exposed to gas is provided, and a protective layer is provided. By simultaneously adding a dispersant and a charge transport material to the filler, it becomes possible to improve the dispersibility of the filler, the charge injection property or the mobility, and the residual potential is reduced despite the inclusion of the high-resistance filler. As described above, it is possible to improve the abrasion resistance of the electrophotographic photosensitive member, reduce the residual potential, suppress cracks and film peeling, and simultaneously suppress the occurrence of image blur due to nitrogen oxide gas. It is possible to provide an electrophotographic photosensitive member that achieves high durability and high image quality. Furthermore, by using the electrophotographic photosensitive member of the present invention, high durability and high image quality can be provided. Image forming apparatus that combines, in which exhibits an extremely excellent effect that the image forming method and an image forming apparatus for the process cartridge is provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an electrophotographic photosensitive member of the present invention.
FIG. 2 is a cross-sectional view showing another configuration example of the electrophotographic photosensitive member of the present invention.
FIG. 3 is a cross-sectional view showing still another structural example of the electrophotographic photosensitive member of the present invention.
FIG. 4 is a schematic view for explaining an electrophotographic process and an electrophotographic apparatus of the present invention.
FIG. 5 is a diagram showing another example of an electrophotographic process according to the present invention.
FIG. 6 is a general view showing a process cartridge according to the present invention.
7 is a diagram showing an XD spectrum in Example 7. FIG.
[Explanation of symbols]
1 Photoconductor
2 Static elimination lamp
3 Charger charger
4 Eraser
5 Image exposure section
6 Development unit
7 Charger before transfer
8 Registration roller
9 Transfer paper
10 Transcription charger
11 Separate charger
12 Separating nails
13 Cleaning charger
14 Fur brush
15 Cleaning brush
16 photoconductor
17 Charger charger
18 Cleaning brush
19 Image exposure unit
20 Development roller
21 photoconductor
22a Driving roller
22b Driving roller
23 Charger charger
24 Image exposure source
25 Transcription Charger
26 Exposure before cleaning
27 Cleaning brush
28 Static elimination light source
31 Conductive support
33 Photosensitive layer
35 Charge generation layer
37 Charge transport layer
39 Protective layer

Claims (29)

In an electrophotographic photosensitive member in which a photosensitive layer containing at least a charge generating substance and a charge transporting substance and a protective layer are provided on a conductive support, the protective layer contains at least a filler and a binder resin. Contains at least an acrylic resin selected from an acrylic resin, a methacrylic resin or a copolymer thereof , and the binder resin is a mixed resin containing at least one kind of resin among a polycarbonate resin and a polyarylate resin, and An electrophotographic photoreceptor, wherein the protective layer is not cured by crosslinking.   2. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer has a laminated structure of a charge generation layer containing at least a charge generation material and a charge transport layer containing a charge transport material.   The electrophotographic photosensitive member according to claim 1, wherein the acrylic resin is a copolymer.   The electrophotographic photosensitive member according to any one of claims 1 to 3, wherein the acrylic resin has a hydroxyl value of 10 (mgKOH / g) or more. Wherein the binder resin, the content of the acrylic resin, electrophotographic photosensitive member according to any one of claims 1 to 4, characterized in that in the range of 1 to 50% by weight relative to the total binder resin. The electrophotographic photosensitive member according to any one of claims 1 to 5, wherein the filler is a type of at least inorganic pigments. The electrophotographic photosensitive member according to claim 6 , wherein the inorganic pigment is at least one kind of metal oxide. 8. The electrophotographic photosensitive member according to claim 6, wherein the inorganic pigment or the metal oxide is subjected to a surface treatment with at least one surface treatment agent. The electrophotographic photosensitive member according to claim 8 , wherein the surface treatment agent is used in an amount of 2 to 30% by weight based on the inorganic pigment or metal oxide. The average primary particle diameter of the inorganic pigments or metal oxide, an electrophotographic photosensitive member according to any one of claims 1 to 9, characterized in that it is a 0.01Myuemu～0.5Myuemu. The electrophotographic photosensitive member according to any one of claims 1 to 10, characterized in that it contains a dispersing agent in the protective layer. The electrophotographic photoreceptor according to claim 11 , wherein the dispersant is an organic compound having at least one carboxyl group in a chemical structure. The dispersing agent is an electrophotographic photosensitive member according to claim 11 or 12, characterized in that the polycarboxylic acid derivative. The dispersing agent is, 10~400 (mgKOH / g) electrophotographic photosensitive member according to any one of claim 11 to 13, characterized in that it has an acid number of. The electrophotographic photosensitive member according to claim 14 , wherein the content of the dispersant satisfies the following relational expression with respect to the acid value of the dispersant and the content of the filler.

The electrophotographic photosensitive member according to any one of claims 1 to 15, characterized in that it contains at least one charge transport material to the protective layer. The electrophotographic photosensitive member according to claim 16 , wherein the following relational expression is established between an ionization potential (Ip) of the charge transport material and an Ip of the charge transport material contained in the photosensitive layer.

The charge transport material, an electrophotographic photosensitive member according to claim 16 or 17, characterized in that a charge transport polymer. The method for producing an electrophotographic photosensitive member according to any one of claims 1 to 18, characterized by using a spray coating method for forming the protective layer. The electrophotographic photosensitive member according to any one of claims 1 to 18 , wherein at least charging, image exposure, development, and transfer are repeated using the electrophotographic photosensitive member. An electrophotographic method characterized by the above. Using an electrophotographic photosensitive member, at least charging, image exposure, development, and transfer are repeated, and at the time of image exposure, an electrostatic latent image is written on the photosensitive member by a beam exposure element such as an LD or LED. A digital electrophotographic method, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of claims 1 to 18 . An electrophotographic apparatus comprising at least a charging unit, an image exposing unit, a developing unit, a transfer unit, and an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is the electrophotographic device according to any one of claims 1 to 18. An electrophotographic apparatus which is a photoconductor. In an electrophotographic apparatus comprising at least a charging unit, an image exposing unit, a developing unit, a transferring unit, and an electrophotographic photosensitive member, the image exposing unit can be statically formed on the photosensitive member by using a beam exposing element such as an LD or LED. An electrophotographic apparatus in which an electrostatic latent image is written, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of claims 1 to 18. apparatus. Wherein as a charging unit of an electrophotographic apparatus, a roller-shaped charging member is used, and electrophotographic apparatus according to claim 22 or 23 charging member and the photosensitive member is characterized in that it is a non-contact in the image area. The electrophotographic apparatus according to claim 22 or 23, characterized in that it comprises means of attaching the lubricant material on the outermost surface of the photoreceptor. The developing means develops the developer used when developing the latent image on the photoreceptor with a developer containing at least one lubricant, thereby the lubricant on the surface of the photoreceptor. 26. The electrophotographic apparatus according to claim 25 , wherein the electrophotographic apparatus is accompanied by means for adhering. 27. The electrophotographic apparatus according to claim 25 or 26 , wherein the lubricating substance is at least one of a metal soap and a fluorine-based compound. An electrophotographic photosensitive member comprising at least an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of claims 1 to 18. Process cartridge for equipment. 29. The process cartridge for an electrophotographic apparatus according to claim 28 , wherein the process cartridge comprises at least one means according to any one of claims 24 to 27 .

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