JP4019809B2 - Electrophotographic photosensitive member, method for manufacturing electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus - Google Patents

Description

【００９１】
上記の式（１）〜（６）中、クロロガリウムフタロシアニンとしては、Cukα線を用いたX線回折スペクトルにおいて、ブラッグ角度(2θ±0.2°)の値が7.4°,16.6°,25.5°,28.3°である位置に回折ピークを少なくとも有するものが好ましい。また、オキソチタニルフタロシアニンとしては、Cukα線を用いたX線回折スペクトルにおいて、ブラッグ角度(2θ±0.2°)の値が9.6°,24.1°,27.3°である位置に回折ピークを少なくとも有し、最大ピークを27.3°に有するものが好ましい。
【００９２】
また、下記式（１）〜（６）に示されるフタロシアニン顔料以外に、式（４）の配位中心となるＧａに結合しているＣｌ原子を−ＯＨ基に置換したヒドロキシガリウムフタロシアニンも好ましい。このようなヒドロキシガリウムフタロシアニンとしては、Cukα線を用いたX線回折スペクトルにおいて、ブラッグ角度(2θ±0.2°)の値が7.5°,9.9°,12.5°,16.3°,18.6°, 25.1°,28.1°である位置に回折ピークを少なくとも有するものが好ましい。
【００９３】
更に、このような顔料は、公知の方法で製造される顔料結晶を、自動乳鉢、遊星ミル、振動ミル、CFミル、ローラーミル、サンドミル、ニーダー等で機械的に乾式粉砕するか、乾式粉砕後、溶剤と共にボールミル、乳鉢、サンドミル、ニーダー等を用いて湿式粉砕処理を行うことによって製造することができる。
【００９４】
上記の湿式粉砕処理において使用される溶剤としては、芳香族類(トルエン、クロロベンゼン等)、アミド類(ジメチルホルムアミド、N-メチルピロリドン等)、脂肪族アルコール類(メタノール、エタノール、ブタノール等)、脂肪族多価アルコール類(エチレングリコール、グリセリン、ポリエチレングリコール等)、芳香族アルコール類(ベンジルアルコール、フェネチルアルコール等)、エステル類(酢酸エステル、酢酸ブチル等)、ケトン類(アセトン、メチルエチルケトン等)、ジメチルスルホキシド、エーテル類(ジエチルエーテル、テトラヒドロフラン等)、さらには数種の混合系、水とこれら有機溶剤の混合系が挙げられる。
【００９５】
また、この溶剤は、顔料結晶に対して、１〜２００質量部、好ましくは１０〜１００質量部の範囲で使用する。更に、処理温度は、０℃〜溶剤の沸点、好ましくは１０〜６０℃の範囲で行う。また、粉砕の際に食塩、ぼう硝等の磨砕助剤を用いることもできる。
【００９６】
そして磨砕助剤は顔料に対し0.5〜20倍、好ましくは1〜10倍用いればよい。また、公知の方法で製造される顔料結晶を、アシッドペースティングあるいはアシッドペースティングと前述したような乾式粉砕あるいは湿式粉砕を組み合わせることにより、結晶制御することもできる。
【００９７】
アシッドペースティングに用いる酸としては、硫酸が好ましく、濃度（質量パーセント濃度）７０〜１００%、好ましくは９５〜１００%のものが使用され、溶解温度は、−２０〜１００℃好ましくは−２０〜６０℃の範囲に設定される。濃硫酸の量は、顔料結晶の重量に対して、１〜１００倍、好ましくは３〜５０倍の範囲に設定される。析出させる溶剤としては、水あるいは、水と有機溶剤の混合溶剤、アンモニア水等が任意の量で用いられる。析出させる温度については特に制限はないが、発熱を防ぐために、氷等で冷却することが好ましい。
【００９８】
また、顔料の含有量は、電荷発生層１の全質量に対して、１０〜９０質量％であることが好ましく、４０〜７０質量％であることがより好ましい。顔料の含有量がそれぞれ上記の数値範囲の下限値未満となると、十分な感度が得られにくくなる。一方、顔料の含有量がそれぞれ上記の数値範囲の上限値を超えると、帯電性の低下、感度の低下などの弊害が発生する傾向が大きくなる。
【００９９】
電荷発生層１に含有されるバインダー樹脂は、絶縁性樹脂であれば特に限定されるものではなく、広範な絶縁性樹脂から選択して使用することができる。例えば、好ましいバインダー樹脂としては、ポリビニルアセタール樹脂、ポリアリレート樹脂(ビスフェノールAとフタル酸の重縮合体等)、ポリカーボネート樹脂、ポリエステル樹脂、フェノキシ樹脂、塩化ビニル-酢酸ビニル共重合体、ポリアミド樹脂、アクリル樹脂、ポリアクリルアミド樹脂、ポリビニルピリジン樹脂、セルロース樹脂、ウレタン樹脂、エポキシ樹脂、カゼイン、ポリビニルアルコール樹脂、ポリビニルピロリドン樹脂等の絶縁性樹脂をあげることができる。
【０１００】
電荷発生層１用のバインダー樹脂としては、顔料の分散性の観点から、特にポリビニルアセタール樹脂及び塩化ビニル−酢酸ビニル共重合体が好ましく用いられる。なお、上記のバインダー樹脂は、単独あるいは2種以上を混合して用いてもよい。
【０１０１】
また、顔料とバインダー樹脂との配合比(質量比)は、電荷発生層１の場合、10:1〜1:10の範囲が好ましい。顔料の質量に対してバインダー樹脂の質量が上記の配合比で示される値未満となると、成膜性が悪くなる等の弊害が発生する傾向が大きくなる。一方、顔料の質量に対してバインダー樹脂の質量が上記の配合比で示される値を超えると、膜中の含有量が相対的に少なくなるため十分な感度が得られなくなる傾向が大きくなる。
【０１０２】
更に、電荷発生層１を形成するための塗布液に含まれる有機溶剤は、バインダー樹脂を溶かす事ができる溶剤であり、かつ、顔料（電荷発生物質）の結晶型を変化させる影響を及ぼさないものであれば特に限定されるものではなく、公知の有機溶剤を使用することができる。
【０１０３】
例えば、アルコール系、芳香族系、ハロゲン化炭化水素系、ケトン系、ケトンアルコール系、エーテル系、エステル系等から任意で選択することができる。具体的には、例えば、メタノール、エタノール、n-プロパノール、iso-プロパノール、n-ブタノール、ベンジルアルコール、メチルセルソルブ、エチルセルソルブ、アセトン、メチルエチルケトン、シクロヘキサノン、酢酸メチル、酢酸エチル、酢酸n-ブチル、ジオキサン、テトラヒドロフラン、メチレンクロライド、クロロホルム、クロロベンゼン、トルエン等の通常の有機溶剤を用いることができる。そして、これらの有機溶剤は単独あるいは2種以上混合して用いることができる。
【０１０４】
この電荷発生層１には、その電気特性の向上、画質向上などのために下引き層４の説明において記載したものと同じ他の添加剤を添加することもできる。
【０１０５】
更に、電荷発生層１の層厚は、良好な電気特性と画質を与えるために、０．０５〜５μｍであることが好ましく、０．１〜１μｍであることがより好ましい。電荷発生層１の厚みが０．０５μｍ未満であると、十分な感度を与えることができない。一方、電荷発生層１の厚みが５μｍを超えると、帯電性の不良などの弊害を生じさせ易い。
【０１０６】
電荷発生層１は、顔料（電荷発生物質）、有機溶剤、バインダー樹脂、添加剤（例えば、顔料の分散助剤等）等を混合して塗布液を調製し、これを下引き層４上に塗布して更に乾燥させることにより形成することができる。また、電荷発生層１は、電荷発生物質を下引き層４上に真空蒸着することによっても形成することができる。
【０１０７】
電荷発生層１の形成用の塗布液を調製するには、顔料、バインダー樹脂、有機溶剤、その他の添加剤（例えば、顔料の分散助剤等）等とともに混合する。顔料を液中に高分散させる方法としては、ロールミル、ボールミル、振動ボールミル、アトライター、サンドミル、コロイドミル、ペイントシェーカーなどの分散方法を用いることができる。
【０１０８】
更に、成膜性の観点から、電荷発生層１を形成するための塗布液に含まれる顔料などの分散粒子の粒子径は、0.5μm以下であることが好ましく、0.3μm以下であることがより好ましく、0.15μm以下であることが更に好ましい。分散粒子の粒子径が0.5μmを超えると、電荷発生層１の成膜性が悪くなり、画質欠陥を生じ易い。
【０１０９】
電荷発生層１の形成用の塗布液を下引き層４上に塗布する場合の塗布方法としては、ブレードコーティング法、ワイヤーバーコーティング法、スプレーコーティング法、浸漬コーティング法、ビードコーティング法、エアーナイフコーティング法、カーテンコーティング法等の通常の方法を用いることができる。
【０１１０】
次に電荷輸送層２について説明する。電荷輸送層２に含有される電荷輸送物質は、特に限定されるものではなく、公知の物質を使用することができる。
【０１１１】
例えば、2,5-ビス(p-ジエチルアミノフェニル)-1,3,4-オキサジアゾール等のオキサジアゾール誘導体、1,3,5-トリフェニル-ピラゾリン、1-[ピリジル-(2)]-3-(p-ジエチルアミノスチリル)-5-(p-ジエチルアミノスチリル)ピラゾリン等のピラゾリン誘導体、トリフェニルアミン、トリ(P-メチル)フェニルアミン、N,N’-ビス(3,4-ジメチルフェニル)ビフェニル-4-アミン、ジベンジルアニリン、9,9-ジメチル-N,N’-ジ(p-トリル)フルオレノン-2-アミン等の芳香族第3級アミノ化合物、N,N’-ジフェニル-N,N’-ビス(3-メチルフェニル)-[1,1-ビフェニル]-4,4’-ジアミン等の芳香族第3級ジアミノ化合物、3-(4’ジメチルアミノフェニル)-5,6-ジ-(4’-メトキシフェニル)-1,2,4-トリアジン等の1,2,4-トリアジン誘導体、4-ジエチルアミノベンズアルデヒド-1,1-ジフェニルヒドラゾン、4-ジフェニルアミノベンズアルデヒド-1,1-ジフェニルヒドラゾン、[p-(ジエチルアミノ)フェニル](1-ナフチル)フェニルヒドラゾンなどのヒドラゾン誘導体、2-フェニル-4-スチリル-キナゾリン等のキナゾリン誘導体、6-ヒドロキシ-2,3-ジ(p-メトキシフェニル)-ベンゾフラン等のベンゾフラン誘導体、p-(2,2-ジフェニルビニル)-N,N’-ジフェニルアニリン等のα-スチルベン誘導体、エナミン誘導体、N-エチルカルバゾール等のカルバゾール誘導体、ポリ-N-ビニルカルバゾール及びその誘導体等の正孔輸送物質、クロラニル、ブロモアニル、アントラキノン等のキノン系化合物、テトラシアノキノジメタン系化合物、2,4,7-トリニトロフルオレノン、2,4,5,7-テトラニトロ-9-フルオレノン等のフルオレノン化合物、2-(4-ビフェニル)-5-(4-t-ブチルフェニル)-1,3,4-オキサジアゾール、2,5-ビス(4-ナフチル)-1,3,4-オキサジアゾール、2,5-ビス(4-ジエチルアミノフェニル)1,3,4オキサジアゾール等のオキサジアゾール系化合物、キサントン系化合物、チオフェン化合物、3,3',5,5'テトラ-t-ブチルジフェノキノン等のジフェノキノン化合物などの電子輸送物質等が挙げられる。
【０１１２】
更には、電荷輸送物質は、以上例示した化合物の基本構造を主鎖又は側鎖に有する重合体等も挙げられる。そして、これらの電荷輸送材料は、1種又は2種以上を組み合せて使用することもできる。
【０１１３】
また、電荷輸送層２に含有されるバインダー樹脂は特に限定されるものではなく、公知のものを使用することができるが、電機絶縁性のフィルムを形成することが可能な樹脂が好ましい。
【０１１４】
例えば、ポリカーボネート樹脂、ポリエステル樹脂、メタクリル樹脂、アクリル樹脂、ポリ塩化ビニル樹脂、ポリ塩化ビニリデン樹脂、ポリスチレン樹脂、ポリビニルアセテート樹脂、スチレンーブタジエン共重合体、塩化ビニリデンーアクリロニトリル共重合体、塩化ビニル-酢酸ビニル共重合体、塩化ビニル-酢酸ビニル-無水マレイン酸共重合体、シリコン樹脂。シリコン−アルキッド樹脂、フェノールーホルムアルデヒド樹脂、スチレンーアルキッド樹脂、ポリ−Ｎ−カルバゾール、ポリビニルブチラール、ポリビニルフォルマール、ポリスルホン、カゼイン、ゼラチン、ポリビニルアルコール、エチルセルロース、フェノール樹脂、ポリアミド、カルボキシーメチルセルロース、塩化ビニリデン系ポリマーワックス、ポリウレタン等が挙げられる。
【０１１５】
そして、これらのバインダー樹脂は、単独又は2種類以上混合して用いることができる。特に、ポリカーボネート樹脂、ポリエステル樹脂、メタクリル樹脂、アクリル樹脂が電荷輸送物質との相溶性、溶剤への溶解性、強度の点で優れているので好ましく用いられる。
【０１１６】
また、バインダー樹脂と電荷輸送物質との配合比(質量比)は電気特性低下、膜強度低下に考慮しつつ任意に設定することができる。この電荷輸送層２の層厚は5〜50μmであることが好ましく、10〜35μmであることがより好ましい。
【０１１７】
電荷輸送層２は、電荷輸送物質、有機溶剤、バインダー樹脂等を混合して塗布液を調製し、これを電荷発生層１上に塗布して更に乾燥させることにより形成することができる。
【０１１８】
電荷輸送層２の形成用の塗布液を調製するには、電荷輸送物質、有機溶剤、バインダー樹脂等とともに混合する。電荷輸送物質を液中に高分散させる方法としては、ロールミル、ボールミル、振動ボールミル、アトライター、サンドミル、コロイドミル、ペイントシェーカーなどの分散方法を用いることができる。
【０１１９】
更に、成膜性の観点から、電荷輸送層２を形成するための塗布液に含まれる顔料などの分散粒子の粒子径は、0.5μm以下であることが好ましく、0.3μm以下であることがより好ましく、0.15μm以下であることが更に好ましい。分散粒子の粒子径が0.5μmを超えると、電荷輸送層２の成膜性が悪くなり、画質欠陥を生じ易い。
【０１２０】
更に、電荷輸送層２の形成用の塗布液に用いる溶剤としては、ジオキサン、テトラヒドロフラン、メチレンクロライド、クロロホルム、クロロベンゼン、トルエン等の通常の有機溶剤を単独あるいは2種以上混合して用いることができる。
【０１２１】
電荷輸送層２の塗布方法としては、ブレードコーティング法、ワイヤーバーコーティング法、スプレーコーティング法、浸漬コーティング法、ビードコーティング法、エアーナイフコーティング法、カーテンコーティング法等の通常の方法を用いることができる。
【０１２２】
［第二実施形態］
図２は、本発明の電子写真感光体の第二実施形態を示す断面図である。図２に示す電子写真感光体１１０は、感光層６を単層構造とした以外は図１に示した電子写真感光体１００と同様の構成を有する。
【０１２３】
図２に示す感光層６は、図１に示した電荷発生層１と電荷輸送層２に含有される電荷発生物質と電荷輸送物質をはじめとする物質を合わせて含有する層である。
【０１２４】
感光層６がこのように単層型の場合には、顔料の含有量は、感光層６の全質量に対して、０．１〜５０質量％であることが好ましく、１〜２０質量％であることがより好ましい。また、顔料の含有量が上記の数値範囲の下限値未満となると、十分な感度が得られにくくなる。一方、顔料の含有量が上記の数値範囲の上限値を超えると、帯電性の低下、感度の低下などの弊害が発生する傾向が大きくなる。
【０１２５】
また、このように感光層６が単層型の場合、バインダー樹脂としては、正孔輸送性材料との相溶性の観点から、特にポリカーボネート樹脂及びメタクリル樹脂が好ましく用いられる。更に、これらの樹脂のポリ-N-ビニルカルバゾール、ポリビニルアントラセン、ポリビニルピレン、ポリシランなどの有機光導電性ポリマーの中から選択して使用してもよい。なお、上記のバインダー樹脂は、単独あるいは2種以上を混合して用いてもよい。
【０１２６】
この感光層６も、上述した電荷輸送物質、上述した電荷輸送物質、上述した有機溶剤、バインダー樹脂等を混合して塗布液を調製し、上述と同様の方法により導電性支持体層３上に塗布して更に乾燥させることにより形成することができる。
【０１２７】
［第三実施形態］
図３は、本発明の電子写真感光体の第三実施形態を示す断面図である。図３に示す電子写真感光体１２０は、感光層６上に保護層５を備えること以外は図１に示した電子写真感光体１００と同様の構成を有する。
【０１２８】
保護層５は、電子写真感光体１２０の帯電時の電荷輸送層２の化学的変化を防止したり、感光層６の機械的強度をさらに改善する為に用いられる。この保護層５は、導電性材料を適当なバインダー樹脂中に含有させた塗布液を感光層６上に塗布することにより形成することができる。
【０１２９】
この導電性材料は特に限定されるものではなく、例えば、N,N'-ジメチルフェロセン等のメタロセン化合物、N,N'-ジフェニル-N,N'-ビス(3-メチルフェニル)-[1,1'-ビフェニル]-4,4'-ジアミン等の芳香族アミン化合物、酸化モリブデン、酸化タングステン、酸化アンチモン、酸化錫、酸化チタン、酸化インジウム、酸化錫とアンチモン、硫酸バリウムと酸化アンチモンとの固溶体の担体、上記金属酸化物の混合物、酸化チタン、酸化スズ、酸化亜鉛又は硫酸バリウムの単一粒子中に上記の金属酸化物を混合したもの、或いは、酸化チタン、酸化スズ、酸化亜鉛又は硫酸バリウムの単一粒子中に上記の金属酸化物を被覆したものが挙げられる。
【０１３０】
この保護層５に用いるバインダー樹脂としては、ポリアミド樹脂、ポリビニルアセタール樹脂、ポリウレタン樹脂、ポリエステル樹脂、エポキシ樹脂、ポリケトン樹脂、ポリカーボネート樹脂、ポリビニルケトン樹脂、ポリスチレン樹脂、ポリアクリルアミド樹脂、ポリイミド樹脂、ポリアミドイミド樹脂等の公知の樹脂が用いられる。また、これらは必要に応じて互いに架橋させて使用することもできる。
【０１３１】
また保護層５は、電荷輸送性高分子化合物により形成することもできる。この電荷輸送性高分子化合物を含む層としては、ポリビニカルバゾール等の電荷輸送能を有する基を側鎖に含む高分子化合物、特開平5-232727号公報等に開示されているような電荷輸送能を有する基を主鎖に含む高分子化合物、およびポリシラン等をあげることができる。また、電荷輸送性高分子化合物として、電荷輸送性ブロックと絶縁性ブロックよりなるブロック共重合体またはグラフト共重合体を使用することもできる。
【０１３２】
更に電荷輸送性高分子化合物が、トリアリールアミン構造を繰り返し単位として含有する場合は、高い電荷輸送能と好ましい機械的特性を有しているので好ましく、また、トリアリールアミン構造がペンダント型ではなく、主鎖中に含有している場合は、さらに好ましい。ペンダント型であると、ペンダント同士が会合し、電荷トラップを形成し電荷輸送性を悪化する場合が多いが、主鎖中に含有されていることでこのような問題を回避できる。さらに、前記トリアリールアミン構造が下記式(７)又は(８)で表される構造の少なくとも1種以上を繰り返し単位として含有する場合は特に好ましい。
【０１３３】
【化２】

【０１３４】
ここで、式(７)中、Ar¹及びAr²はそれぞれ独立に置換もしくは未置換のアリール基を示し、X¹は芳香族環構造を有する2価の炭化水素基またはヘテロ原子含有炭化水素基を示し、X²及びX³はそれぞれ独立に置換もしくは未置換のアリーレン基を示し、L¹は枝分れもしくは環構造を含んでもよい2価の炭化水素基またはヘテロ原子含有炭化水素基を示し、m及びnは、それぞれ0または1から選ばれる整数を示す。
【０１３５】
【化３】

【０１３６】
ここで、式（８）中、Ar³及びAr⁴はそれぞれ独立に置換もしくは未置換のアリール基を示し、L²は芳香族環構造を有する3価の炭化水素基またはヘテロ原子含有炭化水素基を示す。
【０１３７】
更に、先に述べたように上述の式(７)中、Ar¹及びAr²はそれぞれ独立に置換もしくは未置換のアリール基から選ばれ、該アリール基の具体例としては、フェニル基、ビフェニル基、ナフチル基、ピレニル基等が挙げられる。また、置換基としては、メチル基、エチル基、メトキシ基、ハロゲン原子等が挙げられる。
【０１３８】
また、先に述べたように上述の式(７)中X¹は芳香族環構造を有する2価の炭化水素基またはヘテロ原子含有炭化水素基から選ばれる。具体例としては、フェニレン基、ビフェニレン基、ターフェニレン基、ナフチレン基、メチレンジフェニル基、シクロヘキシリデンジフェニル基、オキシジフェニル基、チオジフェニル基等、およびこれらのメチル置換体、エチル置換体、メトキシ置換体、またはハロゲン置換体等が挙げられ、この中でも特に置換もしくは未置換のビフェニレン基が電荷輸送性の点で、特に好ましい。
【０１３９】
更に、先に述べたように上述の式(７)中X²及びX³はそれぞれ独立に置換もしくは未置換のアリーレン基から選ばれ、具体的には、フェニレン基、ビフェニレン基、ターフェニレン基、ナフチレン基等、およびこれらのメチル置換体、エチル置換体、メトキシ置換体、またはハロゲン置換体等が挙げられる。
【０１４０】
また、先に述べたように上述の式(７)中L¹は枝分れもしくは環構造を含んでもよい2価の炭化水素基またはヘテロ原子含有炭化水素基から選ばれ、上記の好ましい特性の少なくとも1つを発揮するかぎり任意であるが、エーテル結合、エステル結合、カーボネート結合、シロキサン結合等から選ばれる結合基を含み、且つ炭素数が20以下であるものが好ましい。その具体例としては、下記式（９）〜式（１６）で表されるものが挙げられる。
【０１４１】
【化４】

【０１４２】
更に、先に述べたように上述の式(８)中、Ar³及びAr⁴はそれぞれ独立に置換もしくは未置換のアリール基から選ばれ、該アリール基の具体例としては、フェニル基、ビフェニル基、ナフチル基、ピレニル基等が挙げられる。また、置換基としては、炭素数1〜12個のアルキル基またはアルコキシ基、ジアリールアミノ基、ハロゲン原子等が挙げられる。
【０１４３】
また、先に述べたように上述の式(８)中L²は芳香族環構造を有する3価の炭化水素基またはヘテロ原子含有炭化水素基から選ばれ、上記の好ましい特性の少なくとも1つを発揮するかぎり任意であるが、炭素数が20以下のものが好ましい。その具体例としては、下記式（１７）〜式（２１）で表されるものが挙げられる。
【０１４４】
【化５】

【０１４５】
【化６】

【０１４６】
また、上述の式(７)中のL¹又は式(８)中のL²がエステル結合を有する場合は、機械的特性に優れ、電荷輸送能に優れるため、本発明において特に好ましい。
【０１４７】
保護層５の厚みは１〜２０μｍであることが好ましく、２〜１０μｍであることがより好ましい。この保護層５を形成するための塗布液の塗布方法としては、ブレードコーティング法、ワイヤーバーコーティング法、スプレーコーティング法、浸漬コーティング法、ビードコーティング法、エアーナイフコーティング法、カーテンコーティング法等の通常の方法を用いることができる。
【０１４８】
また、保護層５を形成するための塗布液に用いる溶剤としては、ジオキサン、テトラヒドロフラン、メチレンクロライド、クロロホルム、クロロベンゼン、トルエン等の通常の有機溶剤を単独あるいは2種以上混合して用いることができるが、できるだけこの塗布液が塗布される感光層６を溶解しにくい溶剤を用いることが好ましい。
【０１４９】
［第四実施形態］
図４は、本発明の電子写真感光体の第四実施形態を示す断面図である。図４に示す電子写真感光体１３０は、感光層６を単層構造とし、感光層６上に保護層５を備える以外は図２に示した電子写真感光体１１０と同様の構成を有する。
【０１５０】
［第五実施形態］
図５は、本発明の電子写真感光体の第五実施形態を示す断面図である。図５に示す電子写真感光体１４０は、感光層６と下引き層４との間に中間層４２を備える以外は図１に示した電子写真感光体１００と同様の構成を有する。この中間層４２は、感光体１４０の電気特性の向上、画質の向上、感光層６の接着性向上のために設けられている。
【０１５１】
この中間層４２の構成材料は特に限定されず、合成樹脂、有機物質或いは無機物質の粉末、電子輸送性物質等から任意に選択することができる。
【０１５２】
中間層４２の合成樹脂としては、ポリビニルブチラールなどのアセタール樹脂、ポリビニルアルコール樹脂、カゼイン、ポリアミド樹脂、セルロース樹脂、ゼラチン、ポリウレタン樹脂、ポリエステル樹脂、メタクリル樹脂、アクリル樹脂、ポリ塩化ビニル樹脂、ポリビニルアセテート樹脂、塩化ビニル-酢酸ビニル-無水マレイン酸樹脂、シリコーン樹脂、シリコーン-アルキッド樹脂、フェノール-ホルムアルデヒド樹脂、メラミン樹脂等の高分子樹脂化合物、ジルコニウムキレート化合物、チタニウムキレート化合物、アルミニウムキレート化合物、チタニウムアルコキシド化合物、有機チタニウム化合物、シランカップリング剤等の公知の材料を用いることができる。
【０１５３】
そして、これらの化合物は単独にあるいは複数の化合物の混合物あるいは重縮合物として用いることができる。更にこれらの中でも、ジルコニウムキレート化合物、シランカップリング剤は残留電位が低く環境による電位変化が少なく、また繰り返し使用による電位の変化が少ないなど性能上優れている。
【０１５４】
上記のシランカップリング剤の例としてはビニルトリメトキシシラン、γ-メタクリルオキシプロピル-トリス(β-メトキシエトキシ)シラン、β-(3,4-エポキシシクロヘキシル)エチルトリメトキシシラン、γ-グリシドキシプロピルトリメトキシシラン、ビニルトリアセトキシシラン、γ-メルカプトプロピルトリメトキシシラン、γ-アミノプロピルトリエトキシシラン、N-β-(アミノエチル)-γ-アミノプロピルトリメトキシシラン、N-β-(アミノエチル)-γ-アミノプロピルメチルメトキシシラン、N,N-ビス(β-ヒドロキシエチル)-γ-アミノプロピルトリエトキシシラン、γ-クロルプロピルトリメトキシシランなどが挙げられる。
【０１５５】
これらの中でも特に好ましく用いられるシリコン化合物としては、ビニルトリエトキシシラン、ビニルトリス(2-メトキシエトキシシラン)、3-メタクリロキシプロピルトリメトキシシラン、3-グリシドキシプロピルトリメトキシシラン、2-(3,4-エポキシシクロヘキシル)エチルトリメトキシシラン、N-2-(アミノエチル)3-アミノプロピルトリメトキシシラン、N-2-(アミノエチル)3-アミノプロピルメチルジメトキシシラン、3-アミノプロピルトリエトキシシラン、N-フェニル-3-アミノプロピルトリメトキシシラン、3-メルカプトプロピルトリメトキシシラン、3-クロロプロピルトリメトキシシラン等のシランカップリング剤が挙げられる。
【０１５６】
ジルコニウムキレート化合物としては、ジルコニウムブトキシド、ジルコニウムアセト酢酸エチル、ジルコニウムトリエタノールアミン、アセチルアセトネートジルコニウムブトキシド、アセト酢酸エチルジルコニウムブトキシド、ジルコニウムアセテート、ジルコニウムオキサレート、ジルコニウムラクテート、ジルコニウムホスホネート、オクタン酸ジルコニウム、ナフテン酸ジルコニウム、ラウリン酸ジルコニウム、ステアリン酸ジルコニウム、イソステアリン酸ジルコニウム、メタクリレートジルコニウムブトキシド、ステアレートジルコニウムブトキシド、イソステアレートジルコニウムブトキシド等が挙げられる。
【０１５７】
チタニウムキレート化合物としては、テトライソプロピルチタネート、テトラノルマルブチルチタネート、ブチルチタネートダイマー、テトラ(2-エチルヘキシル)チタネート、チタンアセチルアセトネート、ポリチタンアセチルアセトネート、チタンオクチレングリコレート、チタンラクテートアンモニウム塩、チタンラクテート、チタンラクテートエチルエステル、チタントリエタノールアミネート、ポリヒドロキシチタンステアレート等が挙げられる。
【０１５８】
アルミニウムキレート化合物としては、アルミニウムイソプロピレート、モノブトキシアルミニウムジイソプロピレート、アルミニウムブチレート、ジエチルアセトアセテートアルミニウムジイソプロピレート、アルミニウムトリス(エチルアセトアセテート)等が挙げられる。
【０１５９】
中間層４２中には、電気特性の向上や光散乱性の向上などの目的により、各種の有機化合物の微粉末もしくは無機化合物の微粉末を添加することができる。特に、酸化チタン、酸化亜鉛、亜鉛華、硫化亜鉛、鉛白、リトポン等の白色顔料やアルミナ、炭酸カルシウム、硫酸バリウム等の体質顔料としての無機顔料やテフロン樹脂粒子、ベンゾグアナミン樹脂粒子、スチレン樹脂粒子などが有効である。
【０１６０】
添加微粉末の粒径は０．０１〜２μｍのものが用いられる。微粉末は必要に応じて添加されるが、その添加量は中間層４２の固形分の総質量に対して、質量比で１０〜９０質量％であることが好ましく、３０〜８０質量％であることがより好ましい。
【０１６１】
また、中間層４２中には、先に説明した電子輸送性物質、電子輸送性顔料等を含有させることも低残留電位化や環境安定性の観点から有効である。更に、中間層４２の厚みは０．０１〜３０μｍであることが好ましく、０．０５〜２５μｍであることがより好ましい。
【０１６２】
また、中間層４２を形成するための塗布液の調製する際に、微粉末状の物質を添加する場合には樹脂成分を溶解した溶液中に添加して分散処理が行われる。この分散処理方法としては、ロールミル、ボールミル、振動ボールミル、アトライター、サンドミル、コロイドミル、ペイントシェーカーなどの方法を用いることができる。
【０１６３】
更に、この中間層４２は導電性支持体層３上に中間層４２を形成するための塗布液を塗布し、乾燥させることにより形成することができる。このときの塗布方法としては、ブレードコーティング法、ワイヤーバーコーティング法、スプレーコーティング法、浸漬コーティング法、ビードコーティング法、エアーナイフコーティング法、カーテンコーティング法等の通常の方法を用いることができる。
【０１６４】
［第六実施形態］
図６は、本発明の電子写真感光体の第六実施形態を示す断面図である。図６に示す電子写真感光体１５０は、感光層６を単層構造とし、感光層６と下引き層４との間に中間層４２を備える以外は図１に示した電子写真感光体１００と同様の構成を有する。
【０１６５】
そして、中間層４２は、上述の図５に示した感光体１４０と同様の構成を有する。
【０１６６】
［第七実施形態］
図７は、本発明の電子写真感光体の第七実施形態を示す断面図である。
図７に示す電子写真感光体１６０は、感光層６上に保護層５を設け、感光層６と下引き層４との間に中間層４２を備える以外は図１に示した電子写真感光体１００と同様の構成を有する。
【０１６７】
そして、中間層４２は、上述の図５に示した感光体１４０の中間層４２と同様の構成を有する。また、保護層５も上述の図３に示した感光体１２０の保護層５と同様の構成を有する。
【０１６８】
［第八実施形態］
図８は、本発明の電子写真感光体の第七実施形態を示す断面図である。
図８に示す電子写真感光体１７０は、感光層６上に保護層５を設け、感光層６を単層構造とし、感光層６と下引き層４との間に中間層４２を備える以外は図１に示した電子写真感光体１００と同様の構成を有する。
【０１６９】
そして、中間層４２は、上述の図５に示した感光体１４０の中間層４２と同様の構成を有する。また、保護層５も上述の図３に示した感光体１２０の保護層５と同様の構成を有する。更に、感光層６も上述の図２に示した感光体１１０の感光層６と同様の構成を有する。
【０１７０】
以上、本発明の電子写真感光体の好適な実施形態について詳細に説明したが、本発明の電子写真感光体は上記実施形態に限定されるものではない。
【０１７１】
例えば、本発明の電子写真感光体の感光層には、図１、図３及び図５に示した感光体１００、１２０及び１４０のように２層からなる構成の場合、図２、図４及び図６に示した感光体１１０、１３０及び１５０のように単層構造の場合の何れにおいても、電子写真装置中で発生するオゾンや酸化性ガス、あるいは光・熱による感光体の劣化を防止する目的で、酸化防止剤・光安定剤・熱安定剤などの添加剤を添加してもよい。
【０１７２】
例えば、酸化防止剤としてはヒンダードフェノール、ヒンダードアミン、パラフェニレンジアミン、アリールアルカン、ハイドロキノン、スピロクロマン、スピロインダノン及びそれらの誘導体、有機硫黄化合物、有機燐化合物などが挙げられる。
【０１７３】
酸化防止剤の具体的な化合物例として、フェノール系酸化防止剤では2,6-ジ-t-ブチル-4-メチル フェノール、スチレン化フェノール、n-オクタデシル-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、2,2'-メチレン-ビス-(4-メチル-6-t-ブチル フェノール)、2-t-ブチル-6-(3'-t-ブチル-5'-メチル-2'-ヒドロキシベンジル)-4-メチルフェニル アクリレート、4,4'-ブチリデン-ビス-(3-メチル-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)、1,3,5-トリス(4-t-ブチル-3-ヒドロキシ-2,6-ジメチル ベンジル)イソシアヌレート、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、3,9-ビス[2-[3-(3-t-ブチル-4-ヒドロキシ-5-メチル フェニル)プロピオニルオキシ]-1,1-ジメチル エチル]-2,4,8,10-テトラオキサスピロ[5,5]ウンデカンなどが挙げられる。
【０１７４】
ヒンダードアミン系化合物としては、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-テトラメチルピペリジン、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、コハク酸ジメチル-1-(2-ヒドロキシエチル)-4-ヒドロキシ-2,2,6,6-テトラメチルピペリジン重縮合物、ポリ[[6-(1,1,3,3-テトラメチルブチル)イミノ-1,3,5-トリアジン-2,4-ジイミル][(2,2,6,6-テトラメチル-4-ピペリジル)イミノ]ヘキサメチレン[(2,3,6,6-テトラメチル-4-ピペリジル)イミノ]]、2-(3,5-ジ-t-ブチル-4-ヒドロキシベンジル)-2-n-ブチルマロン酸ビス(1,2,2,6,6-ペンタメチル-4-ピペリジル)、N,N'-ビス(3-アミノプロピル)エチレンジアミン-2,4-ビス[N-ブチル-N-(1,2,2,6,6,-ペンタメチル-4ピペリジル)アミノ]-6-クロロ-1,3,5-トリアジン縮合物などが挙げられる。
【０１７５】
有機イオウ系酸化防止剤としては、ジラウリル-3,3'-チオジプロピオネート、ジミリスチル-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、ペンタエリスリトール-テトラキス-(β-ラウリル-チオプロピオネート)、ジトリデシル-3,3'-チオジプロピオネート、2-メルカプト ベンズイミダゾールなどが挙げられる。有機燐系酸化防止剤としてトリスノニルフェニル フォスフィート、トリフェニル フォスフィート、トリス(2,4-ジ-t-ブチル フェニル)-フォスフィートなどが挙げられる。
【０１７６】
有機硫黄系および有機燐系酸化防止剤は2次酸化防止剤と言われフェノール系あるいはアミン系などの1次酸化防止剤と併用することにより相乗効果を得ることができる。
【０１７７】
光安定剤としては、ベンゾフェノン系、ベンゾトリアゾール系、ジチオカルバメート系、テトラメチルピペリジン系などの誘導体が挙げられる。例えば、ベンゾフェノン系光安定剤としては、2-ヒドロキシ-4-メトキシ ベンゾフェノン、2-ヒドロキシ-4-オクトキシ 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が挙げられる。
【０１７８】
ベンゾトリアゾール系系光安定剤としては、2-(-2'-ヒドロキシ-5'メチル フェニル-)-ベンゾトリアゾール、2-[2'-ヒドロキシ-3'-(3'',4'',5'',6''-テトラ-ヒドロフタルイミド-メチル)-5'-メチルフェニル]-ベンゾトリアゾール、2-(-2'-ヒドロキシ-3'-t-ブチル 5'-メチルフェニル-)-5-クロロ ベンゾトリアゾール、2-(2'-ヒドロキシ-3'-t-ブチル 5'-メチルフェニル-)-5-クロロ ベンゾトリアゾール、2-(2'-ヒドロキシ-3',5'-t-ブチルフェニル-)-ベンゾトリアゾール、2-(2'-ヒドロキシ-5'-t-オクチル フェニル)-ベンゾトリアゾール、2-(2'-ヒドロキシ 3',5'-ジ-t-アミル フェニル-)-ベンゾトリアゾールなどが挙げられる。
【０１７９】
その他の化合物としては、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、ニッケル ジブチル-ジチオカルバメートなどがある。
【０１８０】
また、感光層６には、感度の向上、残留電位の低減、繰り返し使用時の疲労低減等を目的として少なくとも1種の電子受容性物質を含有させることができる。
【０１８１】
使用可能な電子受容性物質としては、例えば無水琥珀酸、無水マレイン酸、ジブロム無水マレイン酸、無水フタル酸、テトラブロム無水フタル酸、テトラシアノエチレン、テトラシアノキノジメタン、o-ジニトロベンゼン、ｍ−ジニトロベンゼン、クロラニル、ジニトロアントラキノン、トリニトロフルオレノン、ピクリン酸、o-ニトロ安息香酸、p-ニトロ安息香酸、フタル酸などが挙げられる。
【０１８２】
これらのうち、フルオレノン系、キノン系や、−Cl,−CN,−NO₂等の電子吸引性置換基を有するベンゼン誘導体が特に好ましく用いられる。更に、本発明の感光層形成用塗布液には、塗膜の平滑性向上のためのレベリング剤としてシリコーンオイルを微量添加することもできる。
【０１８３】
以上説明した本発明の本発明の電子写真感光体は、近赤外光もしくは可視光に発光するレーザービームプリンター、デイジタル複写機、LEDプリンター、レーザーファクシミリなどの電子写真装置や、このような電子写真装置に備えれられるプロセスカートリッジに搭載することができる。また、本発明の電子写真感光体は一成分系、二成分系の正規現像剤あるいは反転現像剤とも合わせて用いることができる。また本発明の電子写真感光体は帯電ローラーや帯電ブラシを用いた接触帯電方式の電子写真装置に搭載されても電流リークの発生が少ない良好な特性が得られる。
【０１８４】
次に、本発明の本発明の電子写真感光体を搭載した電子写真装置及びプロセスカートリッジについて説明する。
【０１８５】
図９は、本発明の電子写真装置の好適な一実施形態の基本構成を概略的に示す断面図である。図９に示す電子写真装置２００は、電子写真感光体７と、電子写真感光体７をコロナ放電方式により帯電させるコロトロンやスコロトロンなどの帯電手段８と、帯電手段８に接続された電源９と、帯電手段８により帯電される電子写真感光体７を露光して静電潜像を形成する露光手段１０と、露光手段１０により形成された静電潜像をトナーにより現像してトナー像を形成する現像手段１１と、現像手段１１により形成されたトナー像を被転写媒体に転写する転写手段１２と、クリーニング装置１３と、除電器１４と、定着装置１５とを備える。
【０１８６】
また、図１０は、図９に示す本発明の電子写真装置の別の実施形態の基本構成を概略的に示す断面図である。
【０１８７】
図１０に示す電子写真装置２１０は、電子写真感光体７を接触方式により帯電させる帯電手段８を備えていること以外は、図９に示した電子写真装置２００と同様の構成を有する。特に、直流電圧に交流電圧を重畳した接触式の帯電手段を採用する電子写真装置においては、優れた耐摩耗性を有するため、好ましく使用できる。なお、この場合には、除電器１４が設けられていないものもある。
【０１８８】
帯電手段（帯電用部材）８は、感光体７の表面に接触するように配置され、感光体に電圧を均一に印加し、感光体表面を所定の電位に帯電させるものである。帯電手段８にはアルミニウム、鉄、銅などの金属、ポリアセチレン、ポリピロール、ポリチオフェンなどの導電性高分子材料、ポリウレタンゴム、シリコーンゴム、エピクロロヒドリンゴム、エチレンプロピレンゴム、アクリルゴム、フッソゴム、スチレンーブタジエンゴム、ブタジエンゴム等のエラストマー材料にカーボンブラック、沃化銅、沃化銀、硫化亜鉛、炭化けい素、金属酸化物などの金属酸化物粒子を分散したものなどを用いることができる。
【０１８９】
この金属酸化物の例としてはZｎO、SnO₂、TiO₂、In₂O₃、MoO₃等、あるいはこれらの複合酸化物が挙げられる。また、帯電手段８にはエラストマー材料中に過塩素酸塩を含有させて導電性を付与したものを使用しても良い。
【０１９０】
更に、帯電手段８にはその表面に被覆層を設けてもよい。被覆層を形成する材料としては、N-アルコキシメチル化ナイロン、セルロース樹脂、ビニルピリジン樹脂、フェノール樹脂、ポリウレタン、ポリビニルブチラール、メラミン等が単独、あるいは併用して用いられる。また、エマルジョン樹脂系材料、たとえば、アクリル樹脂エマルジョン、ポリエステル樹脂エマルジョン、ポリウレタン、特にソープフリーのエマルジョン重合により合成されたエマルジョン樹脂を用いることも出来る。
【０１９１】
これらの樹脂にはさらに抵抗率を調整するために、導電剤粒子を分散してもよいし、劣化を防止するために酸化防止剤を含有させることもできる。また、被覆層を形成する時の成膜性を向上させるために、エマルジョン樹脂にレベリング剤または界面活性剤を含有させることもできる。また、この接触帯電用部材の形状としては、ローラー型、ブレード型、ベルト型、ブラシ型、などが挙げられる。
【０１９２】
さらに、帯電手段８の電気抵抗値は、好ましくは10²〜10¹⁴Ωcm、さらに好ましくは10²〜10¹²Ωcmの範囲が良い。また、この接触帯電用部材への印加電圧は、直流、交流いずれも用いることができる。又、直流＋交流の形で印加することもできる。
【０１９３】
図１１は図９に示す本発明の電子写真装置の更に別の実施形態の基本構成を概略的に示す断面図である。図１１に示す電子写真装置２２０は中間転写方式の電子写真装置であり、ハウジング４００内において４つの電子写真感光体４０１ａ〜４０１ｄが中間転写ベルト４０９に沿って相互に並列に配置されている。
【０１９４】
ここで、電子写真装置２２０に搭載されている電子写真感光体４０１ａ〜４０１ｄは、それぞれ本発明の電子写真感光体である。例えば、先に述べた電子写真感光体１００、電子写真感光体１１０、電子写真感光体１２０、電子写真感光体１３０、電子写真感光体１４０、電子写真感光体１５０、電子写真感光体１６０、電子写真感光体１７０のいずれかが搭載されていてもよい。
【０１９５】
電子写真感光体４０１ａ〜４０１ｄのそれぞれは所定の方向（紙面上は反時計回り）に回転可能であり、その回転方向に沿って帯電ロール４０２ａ〜４０２ｄ、現像装置４０４ａ〜４０４ｄ、１次転写ロール４１０ａ〜４１０ｄ、クリーニングブレード１５ａ〜１５ｄが配置されている。現像装置４０４ａ〜４０４ｄのそれぞれにはトナーカートリッジ４０５ａ〜４０５ｄに収容されたブラック、イエロー、マゼンタ、シアンの４色のトナーが供給可能であり、また、１次転写ロール４１０ａ〜４１０ｄはそれぞれ中間転写ベルト４０９を介して電子写真感光体４０１ａ〜４０１ｄに当接している。
【０１９６】
更に、ハウジング４００内の所定の位置にはレーザ光源（露光手段）４０３が配置されており、レーザ光源４０３から出射されたレーザー光を帯電後の電子写真感光体４０１ａ〜４０１ｄの表面に照射することが可能となっている。これにより、電子写真感光体４０１ａ〜４０１ｄの回転工程において帯電、露光、現像、１次転写、クリーニングの各工程が順次行われ、各色のトナー像が中間転写ベルト４０９上に重ねて転写される。
【０１９７】
中間転写ベルト４０９は駆動ロール４０６、バックアップロール４０８及びテンションロール４０７により所定の張力をもって支持されており、これらのロールの回転によりたわみを生じることなく回転可能となっている。また、２次転写ロール４１３は、中間転写ベルト４０９を介してバックアップロール４０８と当接するように配置されている。バックアップロール４０８と２次転写ロール４１３との間を通った中間転写ベルト４０９はクリーニングブレード１４により清浄面化された後、次の画像形成プロセスに繰り返し供される。
【０１９８】
また、ハウジング４００内の所定の位置にはトレイ（被転写媒体トレイ）４１１が設けられており、トレイ４１１内の紙などの被転写媒体５００が移送ロール４１２により中間転写ベルト４０９と２次転写ロール４１３との間、さらには相互に当接する２個の定着ロール４１４の間に順次移送された後、ハウジング４００の外部に排紙される。
【０１９９】
更に、図１２は、本発明のプロセスカートリッジの好適な一実施形態の基本構成を概略的に示す断面図である。プロセスカートリッジ３００は、電子写真感光体７とともに、帯電手段８、現像手段１１、クリーニング装置（クリーニング手段）１３、露光のための開口部１８、及び除電器１４を取り付けレール１６を用いて組み合せ、そして一体化したものである。
【０２００】
そして、このプロセスカートリッジ３００は、転写手段１２と、定着装置１５と、図示しない他の構成部分とからなる電子写真装置本体に対して着脱自在としたものであり、電子写真装置本体とともに電子写真装置を構成するものである。
【０２０１】
【実施例】
以下、実施例及び比較例を挙げて本発明の内容をさらに詳しく説明するが、本発明はこれらの実施例に何ら限定されるものではない。
【０２０２】
以下に示す手順により図１に示した電子写真感光体１００と同様の構成を有する実施例１〜実施例４、比較例１〜比較例４の電子写真感光体を作製した。
【０２０３】
（実施例１）
以下の手順にて図１に示した電子写真感光体１００と同様の構成を有する感光体を作製した。
【０２０４】
酸化スズ（商品名：Ｓ１，三菱マテリアル製，比表面積：５０ｍ²／ｇ）を空気中、１５０℃で５時間加熱乾燥させ、その含水率を調節した。熱重量分析の結果、得られた酸化スズ粒子の含水率は０．２質量％であった。この酸化スズ粒子１００質量部をトルエン５００質量部と攪拌混合し、シランカップリング剤（商品名：Ａ１１００，日本ユニカー社製）：１５質量部を添加し、５時間攪拌した。その後、トルエンを減圧蒸留にて留去し、１００℃で２時間焼き付けを行った。
【０２０５】
次に、得られた表面処理後の酸化スズ粒子３５質量部と、硬化剤（ブロック化イソシアネート スミジュール3175，住友バイエルンウレタン社製） ：１５質量部と、ブチラール樹脂 BM-1 (積水化学社製)：６質量部と、メチルエチルケトン：４４質量部とを混合し、1mmφのガラスビーズを用いてサンドミルにて２時間の分散を行い分散液を得た。
【０２０６】
得られた分散液に触媒としてジオクチルスズジラウレート：０．００５質量部と、シリコーンオイルＳＨ２９ＰＡ（東レダウコーニングシリコーン社製）：０．０１質量部とを添加し、下引き層用塗布液を得た。この塗布液を浸漬塗布法にて直径３０ｍｍ、長さ３４０ｍｍ、厚さ１ｍｍのアルミニウム基材（導電性支持体層）上に塗布し、１６０℃、１００分の乾燥硬化を行い厚さ２０μｍの下引き層を形成した。
【０２０７】
次に、下引き層上に２層構造の感光層を形成した。まず、電荷発生物質としてのCukα線を用いたＸ線回折スペクトルのブラッグ角度(２θ±０．２°)が少なくとも７．４゜，１６．６゜，２５．５゜，２８．３゜の位置に回折ピークを有する塩化ガリウムフタロシアニン：１５質量部、バインダー樹脂となる塩化ビニル・酢酸ビニル共重合体樹脂（ＶＭＣＨ、日本ユニカー社製）１０質量部、ｎ-ブチルアルコール：３００質量部からなる混合物を、１ｍｍφのガラスビーズを用いてサンドミルにて４時間分散した。
【０２０８】
得られた分散液を電荷発生層形成用の塗布液として下引き層上に浸漬塗布し、乾燥して、層厚が０．２μｍの電荷発生層を形成した。
【０２０９】
さらに、N,N'-ジフェニル-N,N'-ビス(3-メチルフェニル)-[1、1']ビフェニル-4,4'-ジアミン：４質量部と、ビスフェノールＺポリカーボネート樹脂（粘度平均分子量４万）：６質量部とをクロロベンゼン：８０質量部に加えて溶解した。得られた分散液を電荷輸送層形成用の塗布液として電荷発生層上に浸漬塗布し、１３０℃、４０分の乾燥を行うことにより層厚が２５μｍの電荷輸送層を形成した。
【０２１０】
（実施例２）
以下の手順にて図１に示した電子写真感光体１００と同様の構成を有する感光体を作製した。
【０２１１】
酸化チタン（商品名：ＴＡＦ５００J，富士チタン社製，比表面積：１８ｍ²／ｇ）を空気中、１５０℃で５時間加熱乾燥させ、その含水率を調節した。熱重量分析の結果、得られた酸化チタン粒子の含水率は０．１質量％であった。この酸化チタン粒子１００質量部をミキサ中で攪拌しながら、これにトルエン１０質量部とシランカップリング剤（商品名：ＫＢＭ５０３，信越化学社製）：２質量部との混合液を添加し、１０分間攪拌した。その後、トルエンを減圧蒸留にて留去し、１７０℃で２時間焼き付けを行った。
【０２１２】
次に、得られた表面処理後の酸化チタン粒子５０質量部と、硬化剤（ブロック化イソシアネート スミジュール3175，住友バイエルンウレタン社製） ：１５質量部と、ブチラール樹脂 BM-1 (積水化学社製)：６質量部と、メチルエチルケトン：６０質量部とを混合し、1ｍｍφのガラスビーズを用いてサンドミルにて４時間の分散を行い分散液を得た。
【０２１３】
得られた分散液に触媒としてジオクチルスズジラウレート：０．００５質量部と、シリコーンオイルＳＨ２９ＰＡ（東レダウコーニングシリコーン社製）：０．０１質量部とを添加し、下引き層用塗布液を得た。この塗布液を浸漬塗布法にて直径３０ｍｍ、長さ３４０ｍｍ、厚さ１ｍｍのアルミニウム基材（導電性支持体層）上に塗布し、１６０℃、１００分の乾燥硬化を行い厚さ２０μｍの下引き層を形成した。
【０２１４】
次に、実施例１と同様の手順で電荷発生層と電荷輸送層とを順次形成し、電子写真感光体を作製した。
【０２１５】
（実施例３）
以下の手順にて図１に示した電子写真感光体１００と同様の構成を有する感光体を作製した。
【０２１６】
酸化亜鉛（平均粒子径７０ｎｍ，テイカ社製試作品，比表面積：１５ｍ²／ｇ）を空気中、１５０℃で５時間加熱乾燥させ、その含水率を調節した。熱重量分析の結果、得られた酸化亜鉛粒子の含水率は０．１質量％であった。この酸化亜鉛粒子１００質量部をトルエン５００質量部と撹拌混合し、これにシランカップリング剤（商品名：ＫＢＭ６０３，信越化学社製）：１．５質量部を添加し、２時間攪拌した。その後、トルエンを減圧蒸留にて留去し、１５０℃で２時間焼き付けを行った。
【０２１７】
次に、得られた表面処理後の酸化亜鉛粒子６０質量部と、硬化剤（ブロック化イソシアネート スミジュール3175，住友バイエルンウレタン社製） ：１５質量部と、ブチラール樹脂 BM-1 (積水化学社製)：１５質量部と、メチルエチルケトン：８５質量部とを混合した。得られた液：８質量部とメチルエチルケトン：２５質量部とを混合し、1ｍｍφのガラスビーズを用いてサンドミルにて２時間の分散を行い分散液を得た。
【０２１８】
得られた分散液に触媒としてジオクチルスズジラウレート：０．００５質量部と、シリコーンオイルＳＨ２９ＰＡ（東レダウコーニングシリコーン社製）：０．０１質量部とを添加し、下引き層用塗布液を得た。この塗布液を浸漬塗布法にて直径３０ｍｍ、長さ３４０ｍｍ、厚さ１ｍｍのアルミニウム基材（導電性支持体層）上に塗布し、１６０℃、１００分の乾燥硬化を行い厚さ２０μｍの下引き層を形成した。
【０２１９】
次に、下引き層上に２層構造の感光層を形成した。まず、電荷発生物質としてのCukα線を用いたＸ線回折スペクトルのブラッグ角度(２θ±０．２°)が少なくとも７．３゜，１６．０゜，２４．９゜，２８．０゜の位置に回折ピークを有するヒドロキシガリウムフタロシアニン：１５質量部、バインダー樹脂となる塩化ビニル・酢酸ビニル共重合体樹脂（ＶＭＣＨ、日本ユニカー社製）１０質量部、ｎ-酢酸ブチル：３００質量部からなる混合物を、1ｍｍφのガラスビーズを用いてサンドミルにて４時間分散した。
【０２２０】
得られた分散液を電荷発生層形成用の塗布液として下引き層上に浸漬塗布し、乾燥して、層厚が０．２μｍの電荷発生層を形成した。次に、実施例１と同様の手順で電荷輸送層を形成し、電子写真感光体を作製した。
【０２２１】
（実施例４）
以下の手順にて図１に示した電子写真感光体１００と同様の構成を有する感光体を作製した。
【０２２２】
酸化亜鉛（商品名：ＭＺ３００，テイカ社製，比表面積：４０ｍ²／ｇ）を空気中、１５０℃で５時間加熱乾燥させ、その含水率を調節した。熱重量分析の結果、得られた酸化亜鉛粒子の含水率は０．１質量％であった。この酸化亜鉛粒子１００質量部をトルエン５００質量部と攪拌混合し、これにシランカップリング剤（商品名：KBM４０３，信越化学社製）：５質量部を添加し、２時間攪拌した。その後、トルエンを減圧蒸留にて留去し、１５０℃で２時間焼き付けを行った。
【０２２３】
次に、表面処理後の酸化亜鉛：６０質量部と、硬化剤（ブロック化イソシアネート スミジュール3175，住友バイエルンウレタン社製） ：１５質量部と、ブチラール樹脂 ＢＭ−１(積水化学社製)：１５質量部と、メチルエチルケトン：８５質量部とを混合した。得られた液：３８質量部とメチルエチルケトン：２５質量部とを混合し、1ｍｍφのガラスビーズを用いてサンドミルにて２時間の分散を行い分散液を得た。
【０２２４】
得られた分散液に触媒としてジオクチルスズジラウレート：０．００５質量部と、シリコーンオイルＳＨ２９ＰＡ（東レダウコーニングシリコーン社製）：０．０１質量部とを添加し、下引き層用塗布液を得た。この塗布液を浸漬塗布法にて直径３０ｍｍ、長さ３４０ｍｍ、厚さ１ｍｍのアルミニウム基材（導電性支持体層）上に塗布し、１６０℃、１００分の乾燥硬化を行い厚さ２０μｍの下引き層を形成した。
【０２２５】
次に、下引き層上に２層構造の感光層を形成した。まず、電荷発生物質としてのCukα線を用いたＸ線回折スペクトルのブラッグ角度(２θ±０．２°)が少なくとも２７．３゜の位置に回折ピークを有するオキシチタニルフタロシアニン：１５質量部、バインダー樹脂となる塩化ビニル・酢酸ビニル共重合体樹脂（ＶＭＣＨ、日本ユニカー社製）１０質量部、ｎ-酢酸ブチル：３００質量部からなる混合物を、１ｍｍφのガラスビーズを用いてサンドミルにて４時間分散した。
【０２２６】
得られた分散液を電荷発生層形成用の塗布液として下引き層上に浸漬塗布し、乾燥して、層厚が０．２μｍの電荷発生層を形成した。次に、実施例１と同様の手順で電荷輸送層を形成し、電子写真感光体を作製した。
【０２２７】
（比較例１）
実施例１で用いた金属酸化物粒子を加熱処理せずに使用したこと以外は、実施例１と同様にして電子写真感光体を作製した。熱重量分析の結果、使用した金属酸化物粒子の含水率は１．５質量％であった。
【０２２８】
（比較例２）
実施例２で用いた金属酸化物粒子を加熱処理せずに使用したこと以外は、実施例２と同様にして電子写真感光体を作製した。熱重量分析の結果、使用した金属酸化物粒子の含水率は１．２質量％であった。
【０２２９】
（比較例３）
実施例３で用いた金属酸化物粒子を加熱処理せずに使用したこと以外は、実施例３と同様にして電子写真感光体を作製した。熱重量分析の結果、使用した金属酸化物粒子の含水率は１．１質量％であった。
【０２３０】
（比較例４）
実施例４で用いた金属酸化物粒子を加熱処理せずに使用したこと以外は、実施例４と同様にして電子写真感光体を作製した。熱重量分析の結果、使用した金属酸化物粒子の含水率は１．３質量％であった。
【０２３１】
［電子写真感光体の電子写真特性評価試験］
（１）使用初期の特性評価（初期電位測定）
実施例１〜実施例４及び比較例１〜比較例４の電子写真感光体を図９と同様の構造を有するレーザープリンタ−スキャナー（商品名：XP-15の改造機、富士ゼロックス社製）に搭載し、それぞれの電子写真感光体の電子写真特性を以下のように評価した。
【０２３２】
常温常湿（２０℃、４０％ＲＨ）環境下、グリッド印加電圧−７００Ｖのスコロトロン帯電器で各電子写真感光体を帯電させたときの各電子写真感光体の表面の電位Ａ［Ｖ］を測定した。次に、７８０ｎｍの半導体レーザーを用いて、帯電させてから1秒後の各電子写真感光体に１０ｍＪ/ｍ²の光を照射して放電を行わせ、このときの各電子写真感光体の表面の電位Ｂ［Ｖ］を測定した。続いて、放電させてから３秒後各電子写真感光体に５０ｍＪ/ｍ²の赤色ＬＥＤ光を照射して除電を行い、このときの各電子写真感光体の表面の電位Ｃ［Ｖ］を測定した。
【０２３３】
ここで、電位Ａの値が高いほど、電子写真感光体の受容電位が高いので、コントラストを高く取ることができることになる。また、電位Ｂの値が低いほど高感度な電子写真感光体であることになる。更に、電位Ｃの値が低いほど残留電位が少なく、画像メモリーやいわゆるかぶりが少ない電子写真感光体と評価される。これらの結果を表１に示す。
【０２３４】
（２）初期（１０枚プリント後）の画質評価
実施例１〜実施例４及び比較例１〜比較例４の電子写真感光体を図１１と同様の構造を有する接触帯電装置、中間転写装置を有するフルカラープリンター（商品名：Docu Centre Color 400、富士ゼロックス社製）に搭載し、１０枚の紙への連続プリントテストを行った。
【０２３５】
そして、１０枚プリント後の画質を、「異常なし」；良好な画質が得られた、「カブリ僅かに発生」；紙面の１００ｍｍ×２００ｍｍの範囲に微細な黒点が２０個以下、「カブリ発生」；１００ｍｍ×２００ｍｍの範囲に微細な黒点が１０００個以上確認できる、とした評価基準のもとで評価した。これらの結果を表１に示す。
【０２３６】
（３）繰り返し使用後の特性評価
上述の（１）で説明した操作を1万回繰り返し、帯電、露光後の電位Ａ〜電位Ｃの測定を行った。これらの結果を表１に示す。
【０２３７】
（４）使用環境の変化に対する安定性評価
上記の操作を低温低湿（10℃、15％ＲＨ）、高温高湿（28℃、85%ＲＨ）の２つの異なる環境下で行い、帯電、露光後の電位Ａ〜電位Ｃの測定を行った。そして、これらの異なる環境間での電位Ａ〜電位Ｃの値の変動量（ΔＡ、ΔＢ、ΔＣ）を測定し、使用環境の変化に対する各電子写真感光体の安定性評価を行った。これらの結果を表１に示す。
【０２３８】
（５）１万枚プリント後の画質評価
実施例１〜実施例４及び比較例１〜比較例４の電子写真感光体を図１１と同様の構造を有する接触帯電装置、中間転写装置を有するフルカラープリンター（商品名：Docu Centre Color 400、富士ゼロックス社製）に搭載し、１万枚の紙への連続プリントテストを行った。
【０２３９】
そして、１万枚プリント後の画質を、「異常なし」；良好な画質が得られた、「全面かぶり発生」；紙面全体に微細な黒点がみられる、「黒点発生」；紙面に大きな黒点がみられる、とした評価基準のもとで評価した。これらの結果を表１に示す。
【０２４０】
【表１】

【０２４１】
【発明の効果】
以上説明したように、本発明によれば、繰り返し使用に伴う電気特性の低下を充分に防止することのできる高い耐久性と高い解像品質を有しており然も容易に構成することのできる電子写真感光体及びその製造方法を提供することができる。そして、このような電子写真感光体を備えることにより、長期にわたり繰り返し使用しても高い解像品質を得ることのできるプロセスカートリッジ並びに電子写真装置を提供することできる。
【図面の簡単な説明】
【図１】本発明の電子写真感光体の第一実施形態を示す断面図である。
【図２】本発明の電子写真感光体の第二実施形態を示す断面図である。
【図３】本発明の電子写真感光体の第三実施形態を示す断面図である。
【図４】本発明の電子写真感光体の第四実施形態を示す断面図である。
【図５】本発明の電子写真感光体の第五実施形態を示す断面図である。
【図６】本発明の電子写真感光体の第六実施形態を示す断面図である。
【図７】本発明の電子写真感光体の第七実施形態を示す断面図である。
【図８】本発明の電子写真感光体の第八実施形態を示す断面図である。
【図９】本発明の電子写真装置の好適な一実施形態の基本構成を概略的に示す断面図である。
【図１０】図９に示す本発明の電子写真装置の別の実施形態の基本構成を概略的に示す断面図である。
【図１１】図９に示す本発明の電子写真装置の更に別の実施形態の基本構成を概略的に示す断面図である。
【図１２】本発明のプロセスカートリッジの好適な一実施形態の基本構成を概略的に示す断面図である。
【符号の説明】
１…電荷発生層、３…導電性支持体層、４…下引き層、５…保護層、６…感光層、７…電子写真感光体、８…帯電手段、９…電源、１０…露光手段、１１…現像手段、１２…転写手段、１３…クリーニング装置、１４…除電器、１６…取り付けレール、１８…露光のための開口部、４２…中間層、１００，１１０，１２０，１３０，１４０，１５０，１６０，１７０…電子写真感光体、２００…電子写真装置、２１０…電子写真装置、３００…プロセスカートリッジ、４００・・・ハウジング、４０１ａ〜４０１ｄ・・・電子写真感光体、４０２ａ〜４０２ｄ・・・帯電ロール、４０３・・・レーザ光源（露光装置）、４０４ａ〜４０４ｄ・・・現像装置、４０５ａ〜４０５ｄ・・・トナーカートリッジ、４０６・・・駆動ロール、４０７・・・テンションロール、４０８・・・バックアップロール、４０９・・・中間転写ベルト、４１０ａ〜４１０ｄ・・・１次転写ロール、４１１・・・トレイ（被転写体トレイ）、４１２・・・移送ロール、４１３・・・２次転写ロール、４１４・・・定着ロール、５００・・・被転写媒体。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic photosensitive member, a method for manufacturing an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus.
[0002]
[Prior art]
In recent years, an electrophotographic photosensitive member has an advantage that high-speed and high printing quality can be obtained, and is therefore widely used in fields such as copying machines and laser beam printers. As an electrophotographic photoreceptor used in these electrophotographic apparatuses, it is less expensive and more manufacturable and safer than conventional electrophotographic photoreceptors using inorganic photoconductive materials such as selenium, selenium-tellurium alloy, selenium-arsenic alloy, cadmium sulfide. An electrophotographic photosensitive member containing an organic photoconductive material such as a phthalocyanine-based pigment having excellent advantages in terms of a charge generating substance has come to dominate.
[0003]
Among such photoreceptors, the function-separated type photoreceptor having a photosensitive layer composed of a charge generation layer that generates a charge upon exposure and a charge transport layer that transports the charge has sensitivity, chargeability, repeat stability, and the like. It is excellent in terms of electrophotographic characteristics, and various configurations have been proposed and put into practical use.
[0004]
In the case of this function-separated type photoreceptor, at present, an undercoat layer is formed on a conductive support layer such as an aluminum base, and then a charge generation layer and a charge transport layer are sequentially formed on the undercoat layer. Many.
[0005]
In particular, in recent years, in electrophotographic apparatuses, contact charging type charging apparatuses that generate less ozone have been used instead of corotron. Then, the charge generation material (pigment) in the photosensitive layer of the photoconductor mounted on the electrophotographic apparatus is sufficiently dispersed, the surface of the conductive support layer is formed without unevenness, If it is insufficient to prevent mixing, the undercoat layer or photosensitive layer formed by coating on the conductive support layer is uniformly distributed over the entire area where the thickness is applied due to unevenness of the coating film, etc. The problem that it becomes impossible, the uneven part on the surface of the conductive support layer cannot be sufficiently covered with the undercoat layer or the photosensitive layer, and the uneven part is exposed, or the foreign substance is mixed in the photosensitive layer, etc. There is a problem in that a local defect site is generated on the photoreceptor. In this case, a high electric field is locally applied to the defective portion of the photoconductor during contact charging to generate an electrical pinhole, which becomes an image quality defect.
[0006]
In addition, the above pinhole (pinhole leak) is caused when a conductive foreign matter such as foreign matter, dust, or carrier powder generated from a member constituting the device comes into contact with the photosensitive member during operation of the electrophotographic device. It could also occur by penetrating inside.
[0007]
In order to prevent the above-mentioned image quality defect from occurring and improve the stability of the image quality and the environmental stability with respect to repeated use of the photoreceptor, not only the improvement of the performance of the photosensitive layer but also the undercoat layer serving as the foundation of the photosensitive layer Therefore, it is necessary to realize an undercoat layer with less charge accumulation by repeated use.
[0008]
Therefore, in order to improve the increase in residual potential while concealing defects in the conductive support layer (base material) and obtain stable electric characteristics, the layer containing the conductive fine powder is replaced with the conductive support layer. A method for forming the photoconductor formed above has been studied.
[0009]
As such a method, for example, a layer containing a conductive fine powder is formed on a conductive support layer such as an aluminum base material, and further a conventional lower layer is formed on the layer containing the conductive fine powder. A method for forming a photoreceptor having an undercoat layer having a two-layer structure in which a layer having the same structure as that of the draw layer is proposed in, for example, Japanese Patent Application Laid-Open No. 3-46961. In the case of this method, the layer containing the conductive fine powder is made to conceal defects such as irregularities and dirt on the surface of the conductive support layer, and the electrical resistance is adjusted, so that the conventional undercoat layer and A layer having the same configuration is provided with a blocking (charge injection control) function.
[0010]
As another method, only the layer containing conductive fine powder is formed on the conductive support layer as an undercoat layer, and this layer has both the blocking function and the resistance adjusting function described above. For example, such a photoconductor and a method for manufacturing the photoconductor are disclosed in JP-A-2001-75296.
[0011]
[Problems to be solved by the invention]
However, the present inventors have a structure in which a layer containing a conductive fine powder is formed on a conductive support layer including the above-mentioned Japanese Patent Application Laid-Open Nos. 3-45761 and 2001-75296. Even with the conventional electrophotographic photosensitive member, it is still insufficient to obtain sufficient electrical characteristics that can withstand repeated use, and when the electrophotographic photosensitive member is used repeatedly, the above-described pinhole leak may occur. There is still a problem that the chargeability of the photosensitive member is lowered, the image density is lowered with repeated use, and the residual potential is raised with repeated use, and a fog such as black spots is generated on the image. I found.
[0012]
The present invention has been made in view of the above-described problems of the prior art, and has high durability and high resolution quality that can sufficiently prevent deterioration of electrical characteristics due to repeated use. It is an object of the present invention to provide an electrophotographic photosensitive member that can be configured as described above, a method for manufacturing the same, and a process cartridge and an electrophotographic apparatus on which the electrophotographic photosensitive member is mounted.
[0013]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventors have surface-treated the metal oxide particles contained in the undercoat layer with an organometallic compound having a hydrolyzable functional group. It has been found that the water content of the metal oxide particles before the surface treatment has a great influence on the dispersion state in the undercoat layer of the metal oxide particles obtained after the surface treatment, and thus the film resistance of the undercoat layer.
[0014]
Further, the present inventors have controlled the moisture content of the metal oxide particles before the surface treatment, thereby having a desired film resistance value and having a good and stable electrical property for repeated use. The inventors have found that the layer can be easily obtained and have reached the present invention.
[0015]
That is, the present invention is an electrophotographic photosensitive member having a conductive support layer, a photosensitive layer containing a pigment, and an undercoat layer disposed between the conductive support layer and the photosensitive layer, The undercoat layer contains metal oxide particles surface-treated with an organometallic compound having a hydrolyzable functional group, and the water content in the state before the surface treatment of the metal oxide particles is performed. The electrophotographic photosensitive member is characterized in that the ratio is 1.0% by mass or less.
[0016]
Here, in the present invention, the “water content” in the state before the surface treatment of the metal oxide particles is adsorbed on the surface of the metal oxide particles placed in a normal environment before the surface treatment. This is a value obtained by dividing the mass of the moisture contained by the total mass of the metal oxide particles containing the moisture under the same environment and expressing the obtained value as a percentage.
[0017]
In the present specification, the metal oxide particles after surface treatment with an organometallic compound having a hydrolyzable functional group (hereinafter referred to as “hydrolyzable organometallic compound”) are referred to as “metal oxide”. This is referred to as “Particle A”. Further, the metal oxide particles before the surface treatment is performed on the metal oxide particles A are referred to as “metal oxide particles B”. Therefore, the metal oxide particle A is a particle in a state in which a coating using a hydrolyzable organometallic compound as a raw material is formed on part or all of the surface of the metal oxide particle B. Furthermore, in the present invention, silicon is also included in the metal element constituting the hydrolyzable organometallic compound. Further, the water content of the metal oxide particles B can be measured by a thermogravimetric analysis method or a Karl Fischer method.
[0018]
According to the electrophotographic photosensitive member of the present invention, only the metal oxide particles A obtained from the metal oxide particles B satisfying the above-described moisture content condition are selectively contained in the undercoat layer, whereby repeated use is accompanied. An excellent undercoat layer with little charge storage property can be formed. Furthermore, by using this undercoat layer, it is possible to easily and surely constitute an electrophotographic photosensitive member having high durability and high resolution quality that can sufficiently prevent deterioration of electrical characteristics due to repeated use. it can.
[0019]
Details about the fact that only the metal oxide particles A satisfying the above-mentioned moisture content can be selectively contained in the undercoat layer, whereby an excellent undercoat layer with little charge storage property due to repeated use can be constituted. The mechanism is not clearly elucidated, but the present inventors consider as follows.
[0020]
That is, when the metal oxide particles B are surface-treated with a hydrolyzable organometallic compound, the present inventors can obtain the metal oxide particles B if the water content is 1.0% by mass or less. It is considered that the dispersion state in the undercoat layer of the metal oxide particles A becomes sufficiently uniform as compared with the conventional case, and the undercoat layer sufficiently suppresses fluctuations in film resistance due to changes in the environment in which it is placed. ing.
[0021]
On the other hand, when the metal oxide particles B are surface-treated with a hydrolyzable organometallic compound, if the water content of the metal oxide particles B exceeds 1.0% by mass, the metal oxidation obtained therefrom The dispersion state in the undercoat layer of the object particle A becomes non-uniform, and the fluctuation of the film resistance increases with the change of the environment where the undercoat layer is placed. In this case, for example, a decrease in the film resistance value occurs under a high humidity condition, and an increase in the film resistance value occurs under a low humidity condition. As described above, when the film resistance value of the undercoat layer varies greatly depending on the environment in which it is placed, a serious defect is caused in the image quality, image quality maintenance, and leak resistance of the electrophotographic photosensitive member having the undercoat layer.
[0022]
Although the detailed mechanism about the non-uniform dispersion state in the undercoat layer of the metal oxide particles A has not been clearly clarified, the present inventors have found that the water content of the metal oxide particles B is 1 When the amount exceeds 0.0 mass%, the water and the organic metal adsorbed on the metal oxide particles B in the local portion of the surface of the metal oxide particles B compared to the reaction between the metal oxide particles B and the organometallic compound. It is considered that the hydrolysis reaction with the compound proceeds preferentially, and the metal oxide particles B cannot be sufficiently and uniformly surface-treated with the organometallic compound.
[0023]
The inventors of the present invention applied the coating liquid (predetermined solvent and predetermined solution) prepared to form the undercoat layer to the metal oxide particles A having many local surface portions that have not been surface-treated as described above. When mixed in a liquid containing at least a binder resin), it is considered that the metal oxides A aggregate together, thereby causing poor dispersion. Therefore, a good conductive path is not formed in the undercoat layer obtained after applying the coating liquid on the conductive support layer, and as a result, the undercoat layer and the electrophotographic photosensitive member having the undercoat layer are formed. It is considered that there are drawbacks that easily cause deterioration of electrical characteristics and image quality defect due to repeated use.
[0024]
In addition, according to the present invention, it is possible to easily control the dispersion state of the metal oxide particles A in the undercoat layer only by controlling the water content of the metal oxide particles B so as to satisfy the above-described conditions. Since it can be efficiently put into a state, the undercoat layer and the electrophotographic photosensitive member having the electric characteristics in which the deterioration of the electric characteristics due to repeated use is sufficiently prevented than in the past can be easily and reliably constructed with high reproducibility. can do.
[0025]
Moreover, since the metal oxide particles A satisfying the above-described moisture content can be easily obtained by performing a treatment that can be performed by a relatively simple operation such as a heat drying treatment, this is also accompanied by repeated use. An undercoat layer in which deterioration of electrical characteristics is sufficiently prevented and an electrophotographic photosensitive member having the undercoat layer can be easily configured.
[0026]
Furthermore, in the electrophotographic photoreceptor obtained by the present invention, the metal oxide particles A are uniformly dispersed in the undercoat layer, and environmental fluctuations in the film resistance value of the undercoat layer can be sufficiently suppressed. It is possible to easily increase the thickness of the pulling layer (hereinafter referred to as thickening). For example, it can be formed by adjusting the thickness of the undercoat layer to, for example, 15 μm or more.
[0027]
With such a thick film, it is possible to easily suppress the occurrence of pinhole leakage by increasing the leakage resistance of the undercoat layer. In addition, such a thickening effectively prevents foreign matter from adhering to the photosensitive layer during use of the electrophotographic photosensitive member and penetrating through the undercoat layer to the conductive support layer. be able to. Therefore, also from the viewpoint that such an undercoat layer can be easily thickened, according to the production method of the present invention, it is possible to sufficiently prevent deterioration in electrical characteristics due to repeated use. An electrophotographic photosensitive member having high resolution and high resolution quality can be obtained.
[0028]
The present invention also relates to a method for producing an electrophotographic photosensitive member having at least a conductive support layer, a photosensitive layer containing a pigment, and an undercoat layer disposed between the conductive support layer and the photosensitive layer. Then, the metal oxide particles having a water content of 1% by mass or less are surface-treated using an organometallic compound having a hydrolyzable functional group, and then the subbing layer is formed using the particles obtained by the surface treatment. And a method for producing an electrophotographic photoreceptor, comprising the step of forming
[0029]
According to the method for producing an electrophotographic photosensitive member of the present invention, only the metal oxide particles A obtained from the metal oxide particles B satisfying the above moisture content condition are selectively contained in the undercoat layer. The dispersion state of the metal oxide particles A in the pulling layer can be made uniform easily and sufficiently. Therefore, it is possible to produce an excellent undercoat layer with little charge accumulation due to repeated use, and consequently high durability and high resolution quality that can sufficiently prevent deterioration of electrical characteristics due to repeated use. The above-described electrophotographic photosensitive member of the present invention can be easily and reliably produced.
[0030]
Also in the method for producing an electrophotographic photoreceptor of the present invention, when the metal oxide particles B are surface-treated with a hydrolyzable organometallic compound, the water content of the metal oxide particles B exceeds 1.0% by mass. If this is the case, the dispersion state in the undercoat layer of the metal oxide particles A obtained therefrom becomes non-uniform, and the fluctuation of the film resistance increases with the change of the environment in which this undercoat layer is placed.
[0031]
Furthermore, the present invention integrally includes the above-described electrophotographic photosensitive member of the present invention and at least one of a charging unit, a developing unit, a cleaning unit, and a charge eliminating unit, and is detachable from the main body of the electrophotographic apparatus. A process cartridge is provided.
[0032]
As a result, the process cartridge of the present invention can obtain high resolution quality without causing fogging such as black spots on the image when repeatedly used.
[0033]
Further, the present invention is an exposure for forming an electrostatic latent image by exposing the electrophotographic photosensitive member of the present invention described above, a charging unit for charging the electrophotographic photosensitive member, and the electrophotographic photosensitive member charged by the charging unit. There is provided an electrophotographic apparatus comprising: a developing unit that develops an electrostatic latent image with toner to form a toner image; and a transfer unit that transfers the toner image to a transfer medium.
[0034]
As a result, the electrophotographic apparatus of the present invention can maintain high resolution quality for a long period of time without causing fogging such as black spots on the copy image when it is used repeatedly.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.
[0036]
The method for producing the electrophotographic photosensitive member of the present invention is obtained by surface-treating the metal oxide particles B that satisfy the above-mentioned moisture content in the step of forming the undercoat layer of the electrophotographic photosensitive member. What is necessary is just to use the metal oxide particle A, The procedure in the manufacturing process of the other components of the electrophotographic photosensitive member other than the undercoat layer and the conditions at that time are not particularly limited. For example, a known thin film manufacturing technique is used. be able to. Therefore, for a preferred embodiment of the method for producing the electrophotographic photosensitive member of the present invention, the description of the formation process of the undercoat layer as the main part thereof will be described below. It will be done in the description of the layers.
[0037]
[First embodiment]
FIG. 1 is a cross-sectional view showing a first embodiment of the electrophotographic photosensitive member of the present invention. As shown in FIG. 1, the electrophotographic photosensitive member 100 includes a conductive support layer 3, an undercoat layer 4, and a photosensitive layer 6. This electrophotographic photosensitive member 100 is manufactured by the above-described method for manufacturing an electrophotographic photosensitive member of the present invention.
[0038]
The conductive support layer 3 is not particularly limited as long as it has conductivity. For example, a metal drum such as aluminum, copper, iron, zinc, or nickel can be used. In addition, drums that have been conductively treated by depositing metals such as aluminum, copper, gold, silver, platinum, palladium, titanium, nickel-chromium, stainless steel, copper-indium, etc. on polymer sheets, paper, plastic, or glass Can be used in the form of a sheet, sheet or plate.
[0039]
In addition, drums, sheets, and plates are conductively treated by vapor-depositing conductive metal compounds such as indium oxide and tin oxide on polymer sheets, paper, plastic, or glass, or by laminating metal foil. Can be used. In addition to this, carbon black, indium oxide, tin oxide-antimony oxide powder, metal powder, copper iodide, etc. are dispersed in a binder resin and coated on a polymer sheet, paper, plastic, or glass. A drum-like, sheet-like, or plate-like material subjected to conductive treatment can also be used.
[0040]
Here, when a metal pipe substrate is used as the conductive support layer 3, even if the surface remains as a raw tube, mirror cutting, etching, anodizing, rough cutting, centerless grinding, sand blasting, wet honing are performed in advance. It is preferable to perform a treatment such as a coloring treatment. By performing the surface treatment and roughening the surface of the base material, it is possible to prevent grain-like density spots due to interference light in the photoconductor that may occur when a coherent light source such as a laser beam is used.
[0041]
As described above, the undercoat layer 4 includes metal oxide particles A obtained by surface-treating metal oxide particles B using a hydrolyzable organometallic compound, and a binder resin. . The undercoat layer 4 has a function of preventing charge injection from the conductive support layer 3 to the photosensitive layer 6 when the photosensitive layer 6 is charged. The undercoat layer 4 also functions as an adhesive layer that allows the photosensitive layer 6 to be integrally adhered and held to the conductive support layer 3. Further, the undercoat layer 4 has a function of preventing light reflection of the conductive support layer 3.
[0042]
When the thickness of the undercoat layer 4 is as thick as possible, it is easy to prevent the effect of the penetrating substance from the outside and the leak resistance is improved. On the other hand, a thin film having a thickness of 10 μm or less is sufficient. Does not have. As described above, according to the manufacturing method of the present invention, the undercoat layer 4 can be easily thickened. From the viewpoint of enhancing the leak resistance of the undercoat layer 4 and effectively preventing the occurrence of pinhole leak, the thickness of the undercoat layer 4 is preferably greater than 15 μm and not greater than 50 μm, and preferably 20-50 μm. Is more preferable.
[0043]
Here, when the thickness of the undercoat layer 4 exceeds 50 μm, it becomes difficult to maintain good dispersibility of the contained material such as metal oxide particles, and the tendency of image quality deterioration due to an increase in residual charge increases. In this case, the tendency to make the layer thickness uniform is also increased, which may increase the manufacturing cost.
[0044]
However, when it has sufficient leakage resistance and the occurrence of the above-described leakage defect is not a concern, the thickness of the undercoat layer can be set to be thinner than 15 μm. A thin film of about 1 μm can be applied.
[0045]
The binder resin used in the undercoat layer of the electrophotographic photosensitive member of the present invention is an acetal resin such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, or methacrylic resin. , Acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol resin, phenol-formaldehyde resin, melamine resin, urethane resin, etc. A molecular resin compound, a charge transporting resin having a charge transporting group, a conductive resin such as polyaniline, or the like can be used.
[0046]
Of these, resins insoluble in the upper coating solvent are preferably used, and phenol resins, phenol-formaldehyde resins, melamine resins, urethane resins, epoxy resins, and the like are particularly preferably used. In addition, the compounding ratio of the metal oxide particles B and the binder resin can be arbitrarily set as long as desired characteristics of the electrophotographic photosensitive member can be obtained.
[0047]
The electrical resistance value of the undercoat layer 4 is 10 ^Four -10 ¹³ Preferably it is Ωcm. ⁸ ~Ten ¹³ More preferably Ωcm, 10 ⁹ ~Ten ¹² More preferably, it is Ωcm. Resistance value is 10 ^Four If it is less than Ωcm, it tends to be difficult to obtain sufficient leak resistance. ¹³ If it exceeds Ωcm, the tendency to cause a rise in residual potential increases. The electrical resistance value of the undercoat layer 4 can be controlled by changing the electrical resistance value of the metal oxide particle A itself and its addition amount, and changing the dispersion state of the metal oxide particle A in the binder resin. it can.
[0048]
The metal oxide particles B are preferably at least one kind of particles selected from the group consisting of tin oxide, titanium oxide and zinc oxide.
[0049]
The particle size of the metal oxide particles B provides desired characteristics and can be dispersed in the coating solution for forming the undercoat layer. The coating solution for forming the undercoat layer is applied to the conductive support layer 3. Any particle size can be used as long as it can be applied on the surface and the thickness of the undercoat layer 4 or less, but the average particle size is preferably 100 nm or less. In addition, a particle size here means an average primary particle size. The metal oxide particles B have a powder resistance value of 10 ² -10 ¹¹ Those having a resistance of Ωcm can be used. From the viewpoint of obtaining the excellent leak resistance of the undercoat layer 4, in particular, the powder resistance value is 10 ^Four -10 ^Ten Those having Ω · cm are preferred. 10 ² If it is less than Ωcm, sufficient leak resistance cannot be obtained. ¹¹ When it exceeds Ωcm, the residual potential tends to increase.
[0050]
Further, since the specific surface area of the metal oxide particles B greatly affects the electrophotographic characteristics, the specific surface area of the metal oxide particles B is 10 m. ² / G or more is preferable. Specific surface area value is 10m ² If it is less than / g, the tendency of the undercoat layer 4 to easily deteriorate the chargeability increases.
[0051]
From the viewpoint of suppressing fluctuations in the electrical resistance value of the undercoat layer 4 due to fluctuations in temperature and humidity in the use environment, the moisture content of the metal oxide particles B is adjusted to 1.0 mass% or less. The metal oxide particles B are surface-treated with a hydrolyzable organometallic compound to form metal oxide particles A. By forming the metal oxide particles A by the surface treatment, the dispersion state of the metal oxide particles having a great influence on the electric resistance of the undercoat layer 4 can be easily changed to a state suitable for obtaining the above-described preferable electric resistance value. Can be controlled.
[0052]
Here, the surface treatment refers to a treatment in which a hydrolyzable organometallic compound is adsorbed on the surface of the metal oxide particles B, and a hydrolyzable group of the hydrolyzable organometallic compound is hydrolyzed there.
[0053]
In the present invention, as the hydrolyzable organometallic compound, those represented by the following general formula (I) are preferable.
RpMYq (I)
[0054]
In the formula (I), R represents an organic group, M represents a metal element or silicon, Y represents a hydrolyzable functional group, p and q each represents an integer of 1 to 4, and the sum of p and q Corresponds to the valence of M.
[0055]
Examples of the organic group R include alkyl groups such as methyl, ethyl, propyl, butyl, and octyl groups, alkenyl groups such as vinyl and allyl groups, cycloalkyl groups such as cyclohexyl groups, phenyl groups, and naphthyl groups. Heterocyclic groups such as aryl groups such as aryl groups such as aryl groups, arylalkenyl groups such as benzyl groups and phenylethyl groups, arylalkenyl groups such as styryl groups, furyl groups, thienyl groups, pyrrolidinyl groups and imidazolyl groups The organic compound residue is not particularly limited. The organic group R in the hydrolyzable organometallic compound may be one type selected from the above organic compound residues, or two or more types.
[0056]
Examples of the hydrolyzable functional group Y include ether groups such as methoxy group, ethoxy group, propoxy group, butoxy group, cyclohexyloxy group, phenoxy group, benzyloxy group, acetoxy group, propionylaxyl group, acryloxy group, methacryloxy group. Groups, benzoyloxy groups, methanesulfonyloxy groups, benzenesulfonyloxy groups, ester groups such as benzyloxycarbonyl groups, halogen atoms such as chlorine atoms, and the like.
[0057]
Further, M is not particularly limited as long as it is not an alkali metal, and silicon, zirconium, titanium, aluminum, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, ruthenium, Examples include metals such as rhodium, palladium, indium, tin, and platinum.
[0058]
And as a hydrolysable organometallic compound which has said organic group R and hydrolysable functional group Y, the silane coupling agent and titanate coupling agent which substituted said organic group and hydrolysable functional group are mentioned. It is preferably at least one selected from the group consisting of an aluminate coupling agent and an organic zirconium compound, and more preferably a silane coupling agent. These hydrolyzable organometallic compounds can be used alone or in combination of two or more.
[0059]
Examples of silane coupling agents include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-glycidoxypropyl. Trimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, and the like.
[0060]
Examples of titanate coupling agents include isopropyl triisostearoyl titanate, bis (dioctyl pyrophosphate), isopropyl tri (N-aminoethyl-aminoethyl) titanate, and the like.
[0061]
Examples of the aluminate coupling agent include acetoalkoxy aluminium diisopropylate.
[0062]
Of the hydrolyzable organometallic compounds, a silane coupling agent is preferably used, a silane coupling agent having a mercapto group is more preferably used, and γ-mercaptopropyltrimethoxysilane is preferably used.
[0063]
In addition, the amount of the hydrolyzable organometallic compound used is a combination of the hydrolyzable organometallic compound and the metal oxide particles B used for the surface treatment in such an amount that the metal oxide particles A described above can be obtained. The temperature is optimized and set in accordance with the surface treatment conditions such as the temperature of the surface treatment reaction, the apparatus used for the surface treatment and the scale of the metal oxide particles A to be prepared.
[0064]
Next, the metal oxide particles B Moisture content A method for adjusting the content to 1.0 wt% or less will be described. Of metal oxide particles B Moisture content As a method of adjusting the content to 1.0 wt% or less, a method of drying by heating to 100 ° C. or more is effective. In addition, when the surface treatment of the metal oxide particles B described later is performed by a wet method, the metal oxide particles B are heated together with the solvent used for the surface treatment before adding the surface treatment agent, and azeotropically. It is also possible to remove moisture. Of the metal oxide particles B Moisture content Is measured by thermogravimetric analysis or Karl Fischer method.
[0065]
Next, a surface treatment method for the metal oxide particles B will be described. The method of surface treatment of the metal oxide particles B with a hydrolyzable organometallic compound is not particularly limited, and for example, a known method such as a dry method, a wet method, or a gas phase method may be used.
[0066]
In the present invention, for example, after the surface treatment of the metal oxide particles B, the metal oxide particles A satisfying the formula (1) may be separated from the obtained metal oxide particles A. However, for example, if possible, the surface treatment conditions of the metal oxide particles B with good reproducibility for obtaining the metal oxide particles A satisfying the condition of the formula (1) are easily optimized and grasped in advance. In the case where it can be stored, all of the metal oxide particles A obtained by the optimized surface treatment conditions of the metal oxide particles B may be used for forming the undercoat layer.
[0067]
For example, an example of a procedure for performing surface treatment based on a dry method will be described. First, before the surface treatment, the metal oxide particles B are preliminarily dried at a temperature of 100 to 150 ° C. to remove surface adsorbed water. By removing the surface adsorbed water before the treatment, the hydrolyzable organometallic compound can be uniformly adsorbed on the surface of the metal oxide particles B. At this time, the metal oxide particles B may be preliminarily dried while stirring with a mixer having a large shearing force.
[0068]
Next, the hydrolyzable organometallic compound is adsorbed on the surface of the metal oxide particles B. At this time, while stirring the metal oxide particles B with a mixer having a large shearing force, the hydrolyzable organometallic compound is sprayed with dry air or nitrogen gas, or the hydrolyzable organometallic compound is dissolved in a solvent (organic solvent, A liquid dissolved in water or the like is sprayed with dry air or nitrogen gas. Thereby, the hydrolyzable organometallic compound is uniformly adsorbed on the surface of the metal oxide particles B.
[0069]
The temperature at which the hydrolyzable organometallic compound is adsorbed on the surface of the metal oxide particles B is preferably 50 ° C. or higher. Moreover, when using a solvent, it is preferable to carry out at the temperature of the boiling point vicinity of a solvent.
[0070]
Then, a baking process is performed at a temperature of 100 ° C. or higher. Thereby, the hydrolysis reaction of the hydrolyzable organometallic compound can sufficiently proceed. The baking treatment is preferably performed at a temperature of 150 to 250 ° C. If it is lower than 150 ° C., the hydrolysis reaction of the hydrolyzable organometallic compound may not be sufficiently advanced. If it exceeds 250 ° C, the hydrolyzable organometallic compound may be decomposed.
[0071]
Next, the surface-treated metal oxide particles A are crushed as necessary. Thereby, since the aggregate of the metal oxide particles A can be crushed, the dispersibility of the metal oxide particles in the undercoat layer 4 can be improved.
[0072]
Next, an example of a procedure for performing a surface treatment based on a wet method will be described. First, the metal oxide particles B are dispersed in a solvent by using an ultrasonic wave, a sand mill, an attritor, a ball mill, etc., and then a liquid containing a hydrolyzable organometallic compound is added thereto and stirred. Allow the processing reaction to proceed. Thereafter, the solvent is distilled off from this liquid by distillation. Moreover, you may bake the solid substance obtained after solvent removal at 100 degreeC or more further. Further, in this wet method as well as the dry method, the surface adsorbed water of the metal oxide particles B may be removed before the surface treatment. As this surface adsorbed water removal method, in addition to the removal by heating and drying as in the dry method, a method of removing with stirring and heating in the solvent used for the surface treatment, a method of removing by azeotropy with the solvent, and the like can be mentioned. .
[0073]
The undercoat layer 4 can contain other additives in order to improve its electrical characteristics, improve shape stability in the use environment, and improve image quality.
[0074]
For example, quinone compounds such as chloranil, bromoanil, anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2 -(4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3,4-oxadiazole, 2 Oxadiazole compounds such as 1,5-bis (4-diethylaminophenyl) 1,3,4 oxadiazole, xanthone compounds, thiophene compounds, 3,3 ', 5,5' tetra-t-butyldiphenoquinone Electron transporting substances such as diphenoquinone compounds such as polycyclic condensation systems, electron transporting pigments such as azo systems, zirconium chelate compounds, titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, etc. Can be contained.
[0075]
Examples of titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt. , Titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, polyhydroxy titanium stearate and the like.
[0076]
Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like. These compounds can be used alone or as a mixture or polycondensate of a plurality of compounds.
[0077]
In addition, from the viewpoint of preventing foreign matters such as conductive powder from the outside from penetrating the photoconductor, which causes current leakage during contact charging, and forming the highly durable undercoat layer 4, the undercoat layer It is effective to increase the hardness of 4, and the Vickers hardness of the undercoat layer 4 is 30 or more, preferably 35 or more, as an index of hardness.
[0078]
Further, from the viewpoint of preventing moire images, the surface roughness of the undercoat layer 4 is adjusted to 1/4 n (n is the refractive index of the upper layer) to λ when the exposure laser wavelength λ is used. It is preferable. The surface here is the surface of the undercoat layer 4 on the photosensitive layer 6 side. Further, particles may be added to the undercoat layer 4 for adjusting the surface roughness. As the particles, silicone resin particles, cross-linked polymethyl methacrylate resin (PMMA), silicon oxide particles, and the like can be used.
[0079]
Further, the surface of the undercoat layer 4 may be polished to adjust the surface roughness. As a polishing method, buffing, sand blasting, wet honing, grinding, or the like can be used.
[0080]
Next, a method for forming the undercoat layer 4 (a process for forming the undercoat layer 4) will be described. This undercoat layer 4 is a particle satisfying the formula (1) among the metal oxide A obtained after surface-treating the above-described metal oxide particles B with at least one hydrolyzable metal compound. Can be formed by coating the conductive support layer 3 with a coating solution obtained by dispersing the above in the binder resin described above.
[0081]
As a solvent for adjusting the coating liquid for forming the undercoat layer 4, a known organic solvent, for example, alcohol, aromatic, halogenated hydrocarbon, ketone, ketone alcohol, ether, ester, etc. Can be selected arbitrarily.
[0082]
For example, methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, Usual organic solvents such as methylene chloride, chloroform, chlorobenzene, and toluene can be used.
[0083]
Moreover, the solvent used for these dispersion | distribution can be used individually or in mixture of 2 or more types. When mixing, any solvent can be used as long as it can dissolve the binder resin as the mixed solvent.
[0084]
As a method for dispersing the metal oxide particles A in the binder resin, methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker can be used. Furthermore, as an application method used when providing this undercoat layer, a normal method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method is used. Can be used.
[0085]
Next, the photosensitive layer 6 will be described. As shown in FIG. 1, the photosensitive layer 6 includes a charge generation layer 1 and a charge transport layer 2.
[0086]
The pigment (charge generating material) contained in the charge generation layer 1 is not particularly limited, and a known pigment can be used.
[0087]
In a photoreceptor using infrared light, for example, a phthalocyanine pigment, a squarylium pigment, a bisazo pigment, a trisazo pigment, a perylene pigment, or a dithioketopyrrolopyrrole pigment can be used. In the photoreceptor using a visible light laser, for example, a condensed polycyclic pigment, a bisazo pigment, a perylene pigment, trigonal selenium, a dye-sensitized metal oxide, or the like can be used.
[0088]
Among the pigments described above, it is preferable to use a phthalocyanine pigment because an excellent image can be obtained. This makes it easy to construct an electrophotographic photosensitive member that is particularly sensitive and can stably obtain good image quality even when used repeatedly.
[0089]
Phthalocyanine pigments generally have several crystal forms, and any of these crystal forms can be used as long as it is a crystal form capable of obtaining a sensitivity suitable for the purpose. In particular, phthalocyanine pigments represented by the following formulas (1) to (6) are preferably used among phthalocyanine pigments.
[0090]
[Chemical 1]

[0091]
In the above formulas (1) to (6), the chlorogallium phthalocyanine has a Bragg angle (2θ ± 0.2 °) of 7.4 °, 16.6 °, 25.5 °, 28.3 in the X-ray diffraction spectrum using Cukα rays. Those having at least a diffraction peak at a position of ° are preferable. In addition, as oxo titanyl phthalocyanine, in the X-ray diffraction spectrum using Cukα ray, it has at least a diffraction peak at a position where the value of Bragg angle (2θ ± 0.2 °) is 9.6 °, 24.1 °, 27.3 °, and the maximum Those having a peak at 27.3 ° are preferred.
[0092]
In addition to the phthalocyanine pigments represented by the following formulas (1) to (6), hydroxygallium phthalocyanine in which a Cl atom bonded to Ga serving as a coordination center in formula (4) is substituted with an —OH group is also preferable. As such hydroxygallium phthalocyanine, in the X-ray diffraction spectrum using Cukα ray, the values of Bragg angles (2θ ± 0.2 °) are 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 °, 28.1. Those having at least a diffraction peak at a position of ° are preferable.
[0093]
Furthermore, such pigments can be obtained by mechanically dry-pulverizing pigment crystals produced by a known method with an automatic mortar, planetary mill, vibration mill, CF mill, roller mill, sand mill, kneader, or the like. It can be produced by wet pulverization using a ball mill, mortar, sand mill, kneader or the like together with a solvent.
[0094]
Solvents used in the above wet grinding treatment include aromatics (toluene, chlorobenzene, etc.), amides (dimethylformamide, N-methylpyrrolidone, etc.), aliphatic alcohols (methanol, ethanol, butanol, etc.), fatty acids Polyhydric alcohols (ethylene glycol, glycerin, polyethylene glycol, etc.), aromatic alcohols (benzyl alcohol, phenethyl alcohol, etc.), esters (acetic ester, butyl acetate, etc.), ketones (acetone, methyl ethyl ketone, etc.), dimethyl Examples thereof include sulfoxides, ethers (diethyl ether, tetrahydrofuran, etc.), several mixed systems, and mixed systems of water and these organic solvents.
[0095]
Moreover, this solvent is used in 1-200 mass parts with respect to a pigment crystal, Preferably it is 10-100 mass parts. Further, the treatment temperature is 0 ° C. to the boiling point of the solvent, preferably 10 to 60 ° C. In addition, grinding aids such as sodium chloride and sodium nitrate can be used during grinding.
[0096]
The grinding aid may be used 0.5 to 20 times, preferably 1 to 10 times the pigment. In addition, the pigment crystals produced by a known method can be controlled by combining acid pasting or acid pasting with dry pulverization or wet pulverization as described above.
[0097]
As an acid used for acid pasting, sulfuric acid is preferable, and a concentration (mass percent concentration) of 70 to 100%, preferably 95 to 100% is used, and a dissolution temperature is -20 to 100 ° C, preferably -20 to 20%. It is set in the range of 60 ° C. The amount of concentrated sulfuric acid is set in the range of 1 to 100 times, preferably 3 to 50 times the weight of the pigment crystals. As the solvent to be precipitated, water, a mixed solvent of water and an organic solvent, ammonia water or the like is used in an arbitrary amount. The temperature for precipitation is not particularly limited, but it is preferably cooled with ice or the like in order to prevent heat generation.
[0098]
The pigment content is preferably 10 to 90 mass%, more preferably 40 to 70 mass%, based on the total mass of the charge generation layer 1. When the pigment content is less than the lower limit of the above numerical range, it is difficult to obtain sufficient sensitivity. On the other hand, when the pigment content exceeds the upper limit of the above numerical range, there is a greater tendency for adverse effects such as a decrease in chargeability and a decrease in sensitivity.
[0099]
The binder resin contained in the charge generation layer 1 is not particularly limited as long as it is an insulating resin, and can be selected from a wide range of insulating resins. For example, preferable binder resins include polyvinyl acetal resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin. Examples thereof include insulating resins such as resins, polyacrylamide resins, polyvinyl pyridine resins, cellulose resins, urethane resins, epoxy resins, caseins, polyvinyl alcohol resins, and polyvinyl pyrrolidone resins.
[0100]
As the binder resin for the charge generation layer 1, polyvinyl acetal resin and vinyl chloride-vinyl acetate copolymer are particularly preferably used from the viewpoint of dispersibility of the pigment. In addition, you may use said binder resin individually or in mixture of 2 or more types.
[0101]
In the case of the charge generation layer 1, the blending ratio (mass ratio) of the pigment and the binder resin is preferably in the range of 10: 1 to 1:10. When the mass of the binder resin with respect to the mass of the pigment is less than the value indicated by the above blending ratio, there is a greater tendency for adverse effects such as poor film formability to occur. On the other hand, if the mass of the binder resin with respect to the mass of the pigment exceeds the value indicated by the above-mentioned blending ratio, the content in the film is relatively reduced, so that there is a tendency that sufficient sensitivity cannot be obtained.
[0102]
Furthermore, the organic solvent contained in the coating liquid for forming the charge generation layer 1 is a solvent that can dissolve the binder resin and does not affect the crystal form of the pigment (charge generation material). If it is, it will not specifically limit, A well-known organic solvent can be used.
[0103]
For example, it can be arbitrarily selected from alcohols, aromatics, halogenated hydrocarbons, ketones, ketone alcohols, ethers, esters, and the like. Specifically, for example, methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate Ordinary organic solvents such as dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene can be used. These organic solvents can be used alone or in combination of two or more.
[0104]
To the charge generation layer 1, other additives same as those described in the description of the undercoat layer 4 can be added for the purpose of improving the electrical characteristics and improving the image quality.
[0105]
Furthermore, the layer thickness of the charge generation layer 1 is preferably 0.05 to 5 μm, and more preferably 0.1 to 1 μm, in order to give good electrical characteristics and image quality. If the thickness of the charge generation layer 1 is less than 0.05 μm, sufficient sensitivity cannot be given. On the other hand, when the thickness of the charge generation layer 1 exceeds 5 μm, it is easy to cause problems such as poor charging properties.
[0106]
The charge generation layer 1 is prepared by mixing a pigment (charge generation material), an organic solvent, a binder resin, an additive (for example, a pigment dispersion aid), etc. It can be formed by coating and further drying. The charge generation layer 1 can also be formed by vacuum-depositing a charge generation material on the undercoat layer 4.
[0107]
In order to prepare a coating solution for forming the charge generation layer 1, it is mixed with a pigment, a binder resin, an organic solvent, other additives (for example, a pigment dispersion aid) and the like. As a method for highly dispersing the pigment in the liquid, a dispersion method such as a roll mill, a ball mill, a vibration ball mill, an attritor, a sand mill, a colloid mill, or a paint shaker can be used.
[0108]
Furthermore, from the viewpoint of film formability, the particle diameter of the dispersed particles such as pigments contained in the coating liquid for forming the charge generation layer 1 is preferably 0.5 μm or less, more preferably 0.3 μm or less. Preferably, it is 0.15 μm or less. When the particle diameter of the dispersed particles exceeds 0.5 μm, the film forming property of the charge generation layer 1 is deteriorated and image quality defects are likely to occur.
[0109]
The coating method for applying the coating solution for forming the charge generation layer 1 onto the undercoat layer 4 is blade coating method, wire bar coating method, spray coating method, dip coating method, bead coating method, air knife coating. Ordinary methods such as a method and a curtain coating method can be used.
[0110]
Next, the charge transport layer 2 will be described. The charge transport material contained in the charge transport layer 2 is not particularly limited, and a known material can be used.
[0111]
For example, oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-triphenyl-pyrazoline, 1- [pyridyl- (2)] -3- (p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazolin derivatives such as pyrazoline, triphenylamine, tri (P-methyl) phenylamine, N, N'-bis (3,4-dimethylphenyl) ) Aromatic tertiary amino compounds such as biphenyl-4-amine, dibenzylaniline, 9,9-dimethyl-N, N'-di (p-tolyl) fluorenon-2-amine, N, N'-diphenyl- Aromatic tertiary diamino compounds such as N, N'-bis (3-methylphenyl)-[1,1-biphenyl] -4,4'-diamine, 3- (4'dimethylaminophenyl) -5,6 1,2,4-triazine derivatives such as -di- (4'-methoxyphenyl) -1,2,4-triazine, 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, 4-diphenylamino Hydrazone derivatives such as benzaldehyde-1,1-diphenylhydrazone, [p- (diethylamino) phenyl] (1-naphthyl) phenylhydrazone, quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline, 6-hydroxy-2,3 Benzofuran derivatives such as -di (p-methoxyphenyl) -benzofuran, α-stilbene derivatives such as p- (2,2-diphenylvinyl) -N, N'-diphenylaniline, enamine derivatives, carbazole such as N-ethylcarbazole Derivatives, hole transport materials such as poly-N-vinylcarbazole and its derivatives, quinone compounds such as chloranil, bromoanil, anthraquinone, tetracyanoquinodimethane compounds, 2,4,7-trinitrofluorenone, 2,4 , 5,7-tetranitro-9-fluorenone, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-biolone (4-naphthyl) -1,3,4-oxadiazole, oxadiazole compounds such as 2,5-bis (4-diethylaminophenyl) 1,3,4 oxadiazole, xanthone compounds, thiophene compounds, And electron transport materials such as diphenoquinone compounds such as 3,3 ′, 5,5 ′ tetra-t-butyldiphenoquinone.
[0112]
Furthermore, examples of the charge transport material include a polymer having the basic structure of the compound exemplified above in the main chain or side chain. These charge transport materials can be used alone or in combination of two or more.
[0113]
Moreover, the binder resin contained in the charge transport layer 2 is not particularly limited, and a known resin can be used, but a resin capable of forming an electrical insulating film is preferable.
[0114]
For example, polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-acetic acid Vinyl copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin. Silicon-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-carbazole, polyvinyl butyral, polyvinyl formal, polysulfone, casein, gelatin, polyvinyl alcohol, ethyl cellulose, phenol resin, polyamide, carboxymethyl cellulose, vinylidene chloride System polymer wax, polyurethane and the like.
[0115]
These binder resins can be used alone or in combination of two or more. In particular, a polycarbonate resin, a polyester resin, a methacrylic resin, and an acrylic resin are preferably used because they are excellent in compatibility with a charge transport material, solubility in a solvent, and strength.
[0116]
Further, the blending ratio (mass ratio) of the binder resin and the charge transporting material can be arbitrarily set in consideration of a decrease in electrical characteristics and a decrease in film strength. The layer thickness of the charge transport layer 2 is preferably 5 to 50 μm, and more preferably 10 to 35 μm.
[0117]
The charge transport layer 2 can be formed by preparing a coating liquid by mixing a charge transport material, an organic solvent, a binder resin, and the like, coating this on the charge generation layer 1 and further drying.
[0118]
In order to prepare a coating solution for forming the charge transport layer 2, it is mixed with a charge transport material, an organic solvent, a binder resin and the like. As a method for highly dispersing the charge transport material in the liquid, a dispersion method such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, or a paint shaker can be used.
[0119]
Furthermore, from the viewpoint of film formability, the particle diameter of dispersed particles such as pigments contained in the coating liquid for forming the charge transport layer 2 is preferably 0.5 μm or less, more preferably 0.3 μm or less. Preferably, it is 0.15 μm or less. When the particle diameter of the dispersed particles exceeds 0.5 μm, the film formability of the charge transport layer 2 is deteriorated and image quality defects are likely to occur.
[0120]
Furthermore, as a solvent used for the coating liquid for forming the charge transport layer 2, ordinary organic solvents such as dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene can be used alone or in admixture of two or more.
[0121]
As a method for applying the charge transport layer 2, a normal method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method can be used.
[0122]
[Second Embodiment]
FIG. 2 is a cross-sectional view showing a second embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photoreceptor 110 shown in FIG. 2 has the same configuration as the electrophotographic photoreceptor 100 shown in FIG. 1 except that the photosensitive layer 6 has a single layer structure.
[0123]
The photosensitive layer 6 shown in FIG. 2 is a layer that contains both the charge generating material and the charge transporting material contained in the charge generating layer 1 and the charge transporting layer 2 shown in FIG.
[0124]
When the photosensitive layer 6 is thus a single layer type, the pigment content is preferably 0.1 to 50% by mass, and 1 to 20% by mass with respect to the total mass of the photosensitive layer 6. More preferably. Moreover, when the pigment content is less than the lower limit of the above numerical range, it is difficult to obtain sufficient sensitivity. On the other hand, when the pigment content exceeds the upper limit of the above numerical range, the tendency for adverse effects such as a decrease in chargeability and a decrease in sensitivity increases.
[0125]
In addition, when the photosensitive layer 6 is a single layer type as described above, a polycarbonate resin and a methacrylic resin are particularly preferably used as the binder resin from the viewpoint of compatibility with the hole transporting material. Furthermore, these resins may be selected from organic photoconductive polymers such as poly-N-vinyl carbazole, polyvinyl anthracene, polyvinyl pyrene and polysilane. In addition, you may use said binder resin individually or in mixture of 2 or more types.
[0126]
The photosensitive layer 6 is also prepared by mixing the above-described charge transporting material, the above-described charge transporting material, the above-mentioned organic solvent, the binder resin, etc., and preparing a coating solution on the conductive support layer 3 by the same method as described above. It can be formed by coating and further drying.
[0127]
[Third embodiment]
FIG. 3 is a cross-sectional view showing a third embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photoreceptor 120 shown in FIG. 3 has the same configuration as the electrophotographic photoreceptor 100 shown in FIG. 1 except that the protective layer 5 is provided on the photosensitive layer 6.
[0128]
The protective layer 5 is used to prevent chemical change of the charge transport layer 2 when the electrophotographic photosensitive member 120 is charged or to further improve the mechanical strength of the photosensitive layer 6. The protective layer 5 can be formed by applying a coating solution containing a conductive material in a suitable binder resin on the photosensitive layer 6.
[0129]
The conductive material is not particularly limited, and examples thereof include metallocene compounds such as N, N′-dimethylferrocene, N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1, Aromatic amine compounds such as 1'-biphenyl] -4,4'-diamine, molybdenum oxide, tungsten oxide, antimony oxide, tin oxide, titanium oxide, indium oxide, tin oxide and antimony, solid solution of barium sulfate and antimony oxide Carrier, mixture of the above metal oxides, titanium oxide, tin oxide, zinc oxide or barium sulfate mixed in a single particle, or titanium oxide, tin oxide, zinc oxide or barium sulfate The above-mentioned metal oxide is coated on a single particle.
[0130]
As the binder resin used for the protective layer 5, polyamide resin, polyvinyl acetal resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinyl ketone resin, polystyrene resin, polyacrylamide resin, polyimide resin, polyamideimide resin Known resins such as these are used. These can also be used by cross-linking each other as necessary.
[0131]
The protective layer 5 can also be formed of a charge transporting polymer compound. The layer containing the charge transporting polymer compound includes a polymer compound containing a group having a charge transporting ability such as polyvinylcarbazole in the side chain, and charge transport as disclosed in JP-A-5-232727. Examples thereof include a polymer compound containing a functional group in the main chain and polysilane. In addition, as the charge transporting polymer compound, a block copolymer or a graft copolymer comprising a charge transporting block and an insulating block can be used.
[0132]
Further, when the charge transporting polymer compound contains a triarylamine structure as a repeating unit, it is preferable because it has a high charge transporting ability and favorable mechanical properties, and the triarylamine structure is not a pendant type. When it is contained in the main chain, it is more preferable. In the case of the pendant type, pendants are often associated with each other to form charge traps and deteriorate the charge transport property, but such problems can be avoided by being contained in the main chain. Furthermore, it is particularly preferable when the triarylamine structure contains at least one of the structures represented by the following formula (7) or (8) as a repeating unit.
[0133]
[Chemical 2]

[0134]
Here, in formula (7), Ar ¹ And Ar ² Each independently represents a substituted or unsubstituted aryl group, and X ¹ Represents a divalent hydrocarbon group or heteroatom-containing hydrocarbon group having an aromatic ring structure, and X ² And X ^Three Each independently represents a substituted or unsubstituted arylene group, and L ¹ Represents a divalent hydrocarbon group or heteroatom-containing hydrocarbon group which may contain a branched or ring structure, and m and n each represents an integer selected from 0 or 1.
[0135]
[Chemical 3]

[0136]
Here, in formula (8), Ar ^Three And Ar ^Four Each independently represents a substituted or unsubstituted aryl group, and L ² Represents a trivalent hydrocarbon group or a heteroatom-containing hydrocarbon group having an aromatic ring structure.
[0137]
Further, as described above, in the above formula (7), Ar ¹ And Ar ² Are independently selected from a substituted or unsubstituted aryl group, and specific examples of the aryl group include a phenyl group, a biphenyl group, a naphthyl group, and a pyrenyl group. Examples of the substituent include a methyl group, an ethyl group, a methoxy group, and a halogen atom.
[0138]
Further, as described above, in the above formula (7), X ¹ Is selected from a divalent hydrocarbon group having an aromatic ring structure or a heteroatom-containing hydrocarbon group. Specific examples include a phenylene group, a biphenylene group, a terphenylene group, a naphthylene group, a methylene diphenyl group, a cyclohexylidene diphenyl group, an oxydiphenyl group, a thiodiphenyl group, and the like, and methyl-substituted, ethyl-substituted, methoxy-substituted thereof. And substituted or unsubstituted biphenylene groups are particularly preferred from the viewpoint of charge transportability.
[0139]
Further, as described above, in the above formula (7), X ² And X ^Three Are each independently selected from a substituted or unsubstituted arylene group, specifically, a phenylene group, a biphenylene group, a terphenylene group, a naphthylene group, etc., and their methyl-substituted, ethyl-substituted, methoxy-substituted, or And halogen-substituted products.
[0140]
Further, as described above, L in the above formula (7) ¹ Is selected from a divalent hydrocarbon group or a heteroatom-containing hydrocarbon group which may contain a branched or ring structure, and may be any one as long as it exhibits at least one of the above-mentioned preferable characteristics. And those having a linking group selected from a carbonate bond, a siloxane bond and the like and having 20 or less carbon atoms. Specific examples thereof include those represented by the following formulas (9) to (16).
[0141]
[Formula 4]

[0142]
Further, as described above, in the above formula (8), Ar ^Three And Ar ^Four Are independently selected from a substituted or unsubstituted aryl group, and specific examples of the aryl group include a phenyl group, a biphenyl group, a naphthyl group, and a pyrenyl group. Moreover, as a substituent, a C1-C12 alkyl group or an alkoxy group, a diarylamino group, a halogen atom, etc. are mentioned.
[0143]
Further, as described above, L in the above formula (8) ² Is selected from a trivalent hydrocarbon group having an aromatic ring structure or a heteroatom-containing hydrocarbon group, and may be any as long as it exhibits at least one of the above preferred characteristics, but preferably has 20 or less carbon atoms . Specific examples thereof include those represented by the following formulas (17) to (21).
[0144]
[Chemical formula 5]

[0145]
[Chemical 6]

[0146]
In addition, L in the above formula (7) ¹ Or L in formula (8) ² When has an ester bond, it is particularly preferable in the present invention because it has excellent mechanical properties and excellent charge transport ability.
[0147]
The thickness of the protective layer 5 is preferably 1 to 20 μm, and more preferably 2 to 10 μm. As a coating method of the coating liquid for forming this protective layer 5, a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, etc. are used. The method can be used.
[0148]
Moreover, as a solvent used for the coating liquid for forming the protective layer 5, normal organic solvents such as dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene can be used alone or in admixture of two or more. It is preferable to use a solvent that hardly dissolves the photosensitive layer 6 to which the coating solution is applied.
[0149]
[Fourth embodiment]
FIG. 4 is a cross-sectional view showing a fourth embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photoreceptor 130 shown in FIG. 4 has the same configuration as the electrophotographic photoreceptor 110 shown in FIG. 2 except that the photosensitive layer 6 has a single layer structure and the protective layer 5 is provided on the photosensitive layer 6.
[0150]
[Fifth embodiment]
FIG. 5 is a sectional view showing a fifth embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photoreceptor 140 shown in FIG. 5 has the same configuration as the electrophotographic photoreceptor 100 shown in FIG. 1 except that an intermediate layer 42 is provided between the photosensitive layer 6 and the undercoat layer 4. The intermediate layer 42 is provided to improve the electrical characteristics of the photoreceptor 140, improve the image quality, and improve the adhesion of the photosensitive layer 6.
[0151]
The constituent material of the intermediate layer 42 is not particularly limited, and can be arbitrarily selected from synthetic resin, organic substance or inorganic substance powder, electron transporting substance, and the like.
[0152]
Synthetic resins for the intermediate layer 42 include acetal resins such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, and polyvinyl acetate resin. , Vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, polymer resin compound such as melamine resin, zirconium chelate compound, titanium chelate compound, aluminum chelate compound, titanium alkoxide compound, Known materials such as organic titanium compounds and silane coupling agents can be used.
[0153]
These compounds can be used alone or as a mixture or polycondensate of a plurality of compounds. Among these, zirconium chelate compounds and silane coupling agents are excellent in performance, such as low residual potential, little potential change due to environment, and little potential change due to repeated use.
[0154]
Examples of the above silane coupling agents include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxy Propyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl ) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, and the like.
[0155]
Among these, silicon compounds particularly preferably used include vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, Examples include silane coupling agents such as N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane.
[0156]
Zirconium chelate compounds include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, naphthenic acid. Zirconium, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.
[0157]
Titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, titanium Examples include lactate, titanium lactate ethyl ester, titanium triethanolamate, and polyhydroxytitanium stearate.
[0158]
Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, and aluminum tris (ethyl acetoacetate).
[0159]
In the intermediate layer 42, fine powders of various organic compounds or fine powders of inorganic compounds can be added for the purpose of improving electrical characteristics and light scattering properties. In particular, white pigments such as titanium oxide, zinc oxide, zinc white, zinc sulfide, lead white and lithopone, inorganic pigments as extender pigments such as alumina, calcium carbonate and barium sulfate, Teflon resin particles, benzoguanamine resin particles, styrene resin particles Etc. are effective.
[0160]
The added fine powder has a particle size of 0.01 to 2 μm. The fine powder is added as necessary, but the addition amount is preferably 10 to 90% by mass, and 30 to 80% by mass with respect to the total mass of the solid content of the intermediate layer 42. It is more preferable.
[0161]
In addition, it is also effective from the viewpoint of low residual potential and environmental stability to include the above-described electron transporting substance, electron transporting pigment, and the like in the intermediate layer 42. Furthermore, the thickness of the intermediate layer 42 is preferably 0.01 to 30 μm, and more preferably 0.05 to 25 μm.
[0162]
In addition, when preparing a coating liquid for forming the intermediate layer 42, when a fine powdery substance is added, it is added to a solution in which a resin component is dissolved and subjected to a dispersion treatment. As the dispersion treatment method, methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker can be used.
[0163]
Further, the intermediate layer 42 can be formed by applying a coating solution for forming the intermediate layer 42 on the conductive support layer 3 and drying it. As a coating method at this time, usual methods such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, and the like can be used.
[0164]
[Sixth embodiment]
FIG. 6 is a sectional view showing a sixth embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photoreceptor 150 shown in FIG. 6 has the same structure as the electrophotographic photoreceptor 100 shown in FIG. 1 except that the photosensitive layer 6 has a single layer structure and an intermediate layer 42 is provided between the photosensitive layer 6 and the undercoat layer 4. It has the same configuration.
[0165]
The intermediate layer 42 has a configuration similar to that of the photoreceptor 140 shown in FIG.
[0166]
[Seventh embodiment]
FIG. 7 is a sectional view showing a seventh embodiment of the electrophotographic photosensitive member of the present invention.
The electrophotographic photosensitive member 160 shown in FIG. 7 has the protective layer 5 on the photosensitive layer 6 and an intermediate layer 42 between the photosensitive layer 6 and the undercoat layer 4. 100 has the same configuration.
[0167]
The intermediate layer 42 has the same configuration as the intermediate layer 42 of the photoreceptor 140 shown in FIG. Further, the protective layer 5 has the same configuration as the protective layer 5 of the photosensitive member 120 shown in FIG.
[0168]
[Eighth embodiment]
FIG. 8 is a cross-sectional view showing a seventh embodiment of the electrophotographic photosensitive member of the present invention.
An electrophotographic photoreceptor 170 shown in FIG. 8 is provided except that the protective layer 5 is provided on the photosensitive layer 6, the photosensitive layer 6 has a single layer structure, and the intermediate layer 42 is provided between the photosensitive layer 6 and the undercoat layer 4. The configuration is the same as that of the electrophotographic photoreceptor 100 shown in FIG.
[0169]
The intermediate layer 42 has the same configuration as the intermediate layer 42 of the photoreceptor 140 shown in FIG. Further, the protective layer 5 has the same configuration as the protective layer 5 of the photosensitive member 120 shown in FIG. Further, the photosensitive layer 6 has the same configuration as the photosensitive layer 6 of the photosensitive member 110 shown in FIG.
[0170]
The preferred embodiment of the electrophotographic photoreceptor of the present invention has been described in detail above, but the electrophotographic photoreceptor of the present invention is not limited to the above embodiment.
[0171]
For example, in the case where the photosensitive layer of the electrophotographic photosensitive member of the present invention is composed of two layers like the photosensitive members 100, 120, and 140 shown in FIGS. 1, 3, and 5, FIGS. In any case of a single layer structure such as the photoconductors 110, 130, and 150 shown in FIG. 6, the photoconductor is prevented from being deteriorated by ozone, oxidizing gas, or light / heat generated in the electrophotographic apparatus. For the purpose, additives such as an antioxidant, a light stabilizer and a heat stabilizer may be added.
[0172]
For example, examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds.
[0173]
Specific examples of antioxidant compounds include 2,6-di-t-butyl-4-methylphenol, styrenated phenol, n-octadecyl-3- (3 ', 5'-dithiophene for phenolic antioxidants. -t-butyl 4'-hydroxyphenyl) -propionate, 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2-t-butyl-6- (3'-t-butyl -5'-methyl-2'-hydroxybenzyl) -4-methylphenyl acrylate, 4,4'-butylidene-bis- (3-methyl-6-t-butyl-phenol), 4,4'-thio-bis -(3-Methyl 6-t-butylphenol), 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, tetrakis- [methylene-3- (3 ' , 5'-Di-t-butyl-4'-hydroxy-phenyl) propionate] -methane, 3,9-bis [2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyl Oxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspir B [5,5] undecane.
[0174]
Examples of hindered amine compounds include 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-tetramethylpiperidine, 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, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, succinate, Poly [[6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diimyl] [(2,2,6,6-tetramethyl-4-piperidyl ) Imino] hexamethylene [(2,3,6,6-tetramethyl-4-piperidyl) imino]], 2- (3,5-di-t-butyl- 4-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), N, N'-bis (3-aminopropyl) ethylenediamine-2,4- Examples thereof include bis [N-butyl-N- (1,2,2,6,6, -pentamethyl-4piperidyl) amino] -6-chloro-1,3,5-triazine condensate.
[0175]
Organic sulfur antioxidants include dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, pentaerythritol-tetrakis -(β-lauryl-thiopropionate), ditridecyl-3,3′-thiodipropionate, 2-mercaptobenzimidazole and the like. Examples of organophosphorus antioxidants include trisnonylphenyl phosfeto, triphenyl phosfeto, and tris (2,4-di-t-butylphenyl) -phosfte.
[0176]
Organic sulfur-based and organic phosphorus-based antioxidants are referred to as secondary antioxidants, and a synergistic effect can be obtained by using them together with primary antioxidants such as phenols or amines.
[0177]
Examples of the light stabilizer include benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine derivatives. For example, examples of the benzophenone light stabilizer include 2-hydroxy-4-methoxy benzophenone, 2-hydroxy-4-octoxy benzophenone, 2,2′-di-hydroxy-4-methoxy benzophenone, and the like.
[0178]
Benzotriazole-based light stabilizers include 2-(-2'-hydroxy-5'methyl phenyl-)-benzotriazole, 2- [2'-hydroxy-3 '-(3'',4'', 5 '', 6 ''-tetra-hydrophthalimido-methyl) -5'-methylphenyl] -benzotriazole, 2-(-2'-hydroxy-3'-t-butyl 5'-methylphenyl-)-5- Chlorobenzotriazole, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl-)-5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-t-butylphenyl) -)-Benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) -benzotriazole, 2- (2'-hydroxy 3 ', 5'-di-t-amylphenyl-)-benzotriazole Etc.
[0179]
Other compounds include 2,4, di-t-butylphenyl 3 ′, 5′-di-t-butyl-4′-hydroxybenzoate, nickel dibutyl-dithiocarbamate.
[0180]
The photosensitive layer 6 can contain at least one electron accepting substance for the purpose of improving sensitivity, reducing residual potential, reducing fatigue during repeated use, and the like.
[0181]
Usable electron accepting substances include, for example, succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m- Examples include dinitrobenzene, chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, and phthalic acid.
[0182]
Of these, fluorenone, quinone, -Cl, -CN, -NO ₂ A benzene derivative having an electron-withdrawing substituent such as is particularly preferably used. Furthermore, a small amount of silicone oil can be added to the coating solution for forming a photosensitive layer of the present invention as a leveling agent for improving the smoothness of the coating film.
[0183]
The electrophotographic photosensitive member of the present invention described above is an electrophotographic apparatus such as a laser beam printer, a digital copying machine, an LED printer, or a laser facsimile that emits near-infrared light or visible light, and such an electrophotographic apparatus. It can be mounted on a process cartridge provided in the apparatus. The electrophotographic photoreceptor of the present invention can be used in combination with a one-component or two-component regular developer or reversal developer. Further, even when the electrophotographic photosensitive member of the present invention is mounted on a contact charging type electrophotographic apparatus using a charging roller or a charging brush, good characteristics with little occurrence of current leakage can be obtained.
[0184]
Next, an electrophotographic apparatus and a process cartridge equipped with the electrophotographic photosensitive member of the present invention will be described.
[0185]
FIG. 9 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of the electrophotographic apparatus of the present invention. An electrophotographic apparatus 200 shown in FIG. 9 includes an electrophotographic photosensitive member 7, a charging means 8 such as a corotron or a scorotron for charging the electrophotographic photosensitive member 7 by a corona discharge method, a power source 9 connected to the charging means 8, An exposure unit 10 that exposes the electrophotographic photosensitive member 7 charged by the charging unit 8 to form an electrostatic latent image, and a toner image is formed by developing the electrostatic latent image formed by the exposure unit 10 with toner. The image forming apparatus includes a developing unit 11, a transfer unit 12 that transfers a toner image formed by the developing unit 11 to a transfer medium, a cleaning device 13, a static eliminator 14, and a fixing device 15.
[0186]
FIG. 10 is a cross-sectional view schematically showing a basic configuration of another embodiment of the electrophotographic apparatus of the present invention shown in FIG.
[0187]
An electrophotographic apparatus 210 shown in FIG. 10 has the same configuration as that of the electrophotographic apparatus 200 shown in FIG. 9 except that it includes a charging unit 8 that charges the electrophotographic photoreceptor 7 by a contact method. In particular, an electrophotographic apparatus that employs contact-type charging means in which an AC voltage is superimposed on a DC voltage can be preferably used because it has excellent wear resistance. In this case, the static eliminator 14 may not be provided.
[0188]
The charging means (charging member) 8 is disposed so as to be in contact with the surface of the photoconductor 7 and applies a voltage uniformly to the photoconductor to charge the surface of the photoconductor to a predetermined potential. The charging means 8 includes metals such as aluminum, iron and copper, conductive polymer materials such as polyacetylene, polypyrrole and polythiophene, polyurethane rubber, silicone rubber, epichlorohydrin rubber, ethylene propylene rubber, acrylic rubber, fluorine rubber and styrene-butadiene. A material obtained by dispersing metal oxide particles such as carbon black, copper iodide, silver iodide, zinc sulfide, silicon carbide, and metal oxide in an elastomer material such as rubber and butadiene rubber can be used.
[0189]
Examples of this metal oxide are ZnO and SnO. ₂ , TiO ₂ , In ₂ O _Three , MoO _Three Or a complex oxide thereof. Further, the charging means 8 may be made by adding perchlorate in an elastomer material and imparting conductivity.
[0190]
Further, the charging means 8 may be provided with a coating layer on the surface thereof. As a material for forming the coating layer, N-alkoxymethylated nylon, cellulose resin, vinyl pyridine resin, phenol resin, polyurethane, polyvinyl butyral, melamine and the like are used alone or in combination. Also, emulsion resin-based materials such as acrylic resin emulsion, polyester resin emulsion, polyurethane, particularly emulsion resin synthesized by soap-free emulsion polymerization can be used.
[0191]
In these resins, in order to further adjust the resistivity, conductive agent particles may be dispersed, or an antioxidant may be contained in order to prevent deterioration. In addition, in order to improve the film formability when forming the coating layer, the emulsion resin may contain a leveling agent or a surfactant. Examples of the shape of the contact charging member include a roller type, a blade type, a belt type, and a brush type.
[0192]
Furthermore, the electrical resistance value of the charging means 8 is preferably 10 ² ~Ten ¹⁴ Ωcm, more preferably 10 ² ~Ten ¹² The range of Ωcm is good. Further, as the voltage applied to the contact charging member, either direct current or alternating current can be used. It can also be applied in the form of direct current + alternating current.
[0193]
FIG. 11 is a sectional view schematically showing a basic configuration of still another embodiment of the electrophotographic apparatus of the present invention shown in FIG. An electrophotographic apparatus 220 shown in FIG. 11 is an intermediate transfer type electrophotographic apparatus, and four electrophotographic photosensitive members 401 a to 401 d are arranged in parallel with each other along an intermediate transfer belt 409 in a housing 400.
[0194]
Here, the electrophotographic photoreceptors 401a to 401d mounted on the electrophotographic apparatus 220 are respectively the electrophotographic photoreceptors of the present invention. For example, the above-described electrophotographic photoreceptor 100, electrophotographic photoreceptor 110, electrophotographic photoreceptor 120, electrophotographic photoreceptor 130, electrophotographic photoreceptor 140, electrophotographic photoreceptor 150, electrophotographic photoreceptor 160, electrophotographic Any of the photoreceptors 170 may be mounted.
[0195]
Each of the electrophotographic photosensitive members 401a to 401d can be rotated in a predetermined direction (counterclockwise on the paper surface), and the charging rolls 402a to 402d, the developing devices 404a to 404d, and the primary transfer roll 410a along the rotation direction. To 410d and cleaning blades 15a to 15d are arranged. Each of the developing devices 404a to 404d can be supplied with toners of four colors, black, yellow, magenta, and cyan accommodated in toner cartridges 405a to 405d, and the primary transfer rolls 410a to 410d are respectively intermediate transfer belts. 409 is in contact with the electrophotographic photoreceptors 401a to 401d.
[0196]
Further, a laser light source (exposure means) 403 is disposed at a predetermined position in the housing 400, and the surfaces of the charged electrophotographic photosensitive members 401a to 401d are irradiated with laser light emitted from the laser light source 403. Is possible. Accordingly, charging, exposure, development, primary transfer, and cleaning are sequentially performed in the rotation process of the electrophotographic photosensitive members 401a to 401d, and the toner images of the respective colors are transferred onto the intermediate transfer belt 409 in an overlapping manner.
[0197]
The intermediate transfer belt 409 is supported with a predetermined tension by a drive roll 406, a backup roll 408, and a tension roll 407, and can rotate without causing deflection due to the rotation of these rolls. Further, the secondary transfer roll 413 is disposed so as to contact the backup roll 408 via the intermediate transfer belt 409. The intermediate transfer belt 409 passing between the backup roll 408 and the secondary transfer roll 413 is cleaned by the cleaning blade 14 and then repeatedly used in the next image forming process.
[0198]
A tray (transfer medium tray) 411 is provided at a predetermined position in the housing 400, and the transfer medium 500 such as paper in the tray 411 is transferred to the intermediate transfer belt 409 and the secondary transfer roll by the transfer roll 412. Then, the paper is sequentially transferred between the two fixing rolls 414 that are in contact with each other and the two fixing rolls 414 that are in contact with each other.
[0199]
FIG. 12 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of the process cartridge of the present invention. The process cartridge 300 combines the electrophotographic photosensitive member 7 with the charging unit 8, the developing unit 11, the cleaning device (cleaning unit) 13, the opening 18 for exposure, and the static eliminator 14 using the mounting rail 16, and It is an integrated one.
[0200]
The process cartridge 300 is detachable from the main body of the electrophotographic apparatus comprising the transfer means 12, the fixing device 15, and other components not shown, and the electrophotographic apparatus together with the main body of the electrophotographic apparatus. It constitutes.
[0201]
【Example】
Hereinafter, the content of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.
[0202]
The electrophotographic photoreceptors of Examples 1 to 4 and Comparative Examples 1 to 4 having the same configuration as the electrophotographic photoreceptor 100 shown in FIG.
[0203]
Example 1
A photoconductor having the same configuration as that of the electrophotographic photoconductor 100 shown in FIG.
[0204]
Tin oxide (trade name: S1, made by Mitsubishi Materials, specific surface area: 50m ² / G) was heated and dried in air at 150 ° C. for 5 hours to adjust the water content. As a result of thermogravimetric analysis, the water content of the obtained tin oxide particles was 0.2% by mass. 100 parts by mass of the tin oxide particles were mixed with 500 parts by mass of toluene, and 15 parts by mass of a silane coupling agent (trade name: A1100, manufactured by Nihon Unicar Company) was added and stirred for 5 hours. Then, toluene was distilled off under reduced pressure and baked at 100 ° C. for 2 hours.
[0205]
Next, 35 parts by mass of the surface-treated tin oxide particles obtained and a curing agent (blocked isocyanate Sumijoule 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.): 15 parts by mass, butyral resin BM-1 (manufactured by Sekisui Chemical Co., Ltd.) ): 6 parts by mass and methyl ethyl ketone: 44 parts by mass were mixed and dispersed in a sand mill for 2 hours using 1 mmφ glass beads to obtain a dispersion.
[0206]
Dioctyltin dilaurate: 0.005 parts by mass and silicone oil SH29PA (manufactured by Toray Dow Corning Silicone): 0.01 parts by mass were added as catalysts to the resulting dispersion to obtain an undercoat layer coating solution. . This coating solution is applied on an aluminum substrate (conductive support layer) having a diameter of 30 mm, a length of 340 mm, and a thickness of 1 mm by a dip coating method, followed by drying and curing at 160 ° C. for 100 minutes and a thickness of 20 μm or less. A pulling layer was formed.
[0207]
Next, a photosensitive layer having a two-layer structure was formed on the undercoat layer. First, X-ray diffraction spectrum Bragg angles (2θ ± 0.2 °) using Cukα as a charge generating substance are at least 7.4 °, 16.6 °, 25.5 °, and 28.3 °. A mixture comprising 15 parts by mass of gallium chloride phthalocyanine having a diffraction peak, 10 parts by mass of vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Nihon Unicar) serving as a binder resin, and 300 parts by mass of n-butyl alcohol. 1 mmφ glass beads were used for dispersion for 4 hours in a sand mill.
[0208]
The obtained dispersion was dip-coated on the undercoat layer as a charge generation layer forming coating solution and dried to form a charge generation layer having a layer thickness of 0.2 μm.
[0209]
Furthermore, N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1 ′] biphenyl-4,4′-diamine: 4 parts by mass and bisphenol Z polycarbonate resin (viscosity average molecular weight) 40,000): 6 parts by mass and chlorobenzene: 80 parts by mass were dissolved. The obtained dispersion was dip-coated on the charge generation layer as a coating solution for forming a charge transport layer and dried at 130 ° C. for 40 minutes to form a charge transport layer having a layer thickness of 25 μm.
[0210]
(Example 2)
A photoconductor having the same configuration as that of the electrophotographic photoconductor 100 shown in FIG.
[0211]
Titanium oxide (trade name: TAF500J, manufactured by Fuji Titanium Co., Ltd., specific surface area: 18 m ² / G) was heated and dried in air at 150 ° C. for 5 hours to adjust the water content. As a result of thermogravimetric analysis, the water content of the obtained titanium oxide particles was 0.1% by mass. While stirring 100 parts by mass of the titanium oxide particles in a mixer, a mixed solution of 10 parts by mass of toluene and a silane coupling agent (trade name: KBM503, manufactured by Shin-Etsu Chemical Co., Ltd.): 2 parts by mass is added. Stir for minutes. Then, toluene was distilled off under reduced pressure and baked at 170 ° C. for 2 hours.
[0212]
Next, 50 parts by mass of the obtained titanium oxide particles after the surface treatment and a curing agent (blocked isocyanate Sumijour 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.): 15 parts by mass, butyral resin BM-1 (manufactured by Sekisui Chemical Co., Ltd.) ): 6 parts by mass and 60 parts by mass of methyl ethyl ketone were mixed, and dispersion was performed for 4 hours with a sand mill using 1 mmφ glass beads.
[0213]
Dioctyltin dilaurate: 0.005 parts by mass and silicone oil SH29PA (manufactured by Toray Dow Corning Silicone): 0.01 parts by mass were added as catalysts to the resulting dispersion to obtain an undercoat layer coating solution. . This coating solution is applied on an aluminum substrate (conductive support layer) having a diameter of 30 mm, a length of 340 mm, and a thickness of 1 mm by a dip coating method, followed by drying and curing at 160 ° C. for 100 minutes and a thickness of 20 μm or less. A pulling layer was formed.
[0214]
Next, a charge generation layer and a charge transport layer were sequentially formed in the same procedure as in Example 1 to produce an electrophotographic photoreceptor.
[0215]
(Example 3)
A photoconductor having the same configuration as that of the electrophotographic photoconductor 100 shown in FIG.
[0216]
Zinc oxide (average particle size 70 nm , Teica prototype, specific surface area: 15m ² / G) was heated and dried in air at 150 ° C. for 5 hours to adjust the water content. As a result of thermogravimetric analysis, the water content of the obtained zinc oxide particles was 0.1% by mass. 100 parts by mass of the zinc oxide particles were mixed with 500 parts by mass of toluene, and 1.5 parts by mass of a silane coupling agent (trade name: KBM603, manufactured by Shin-Etsu Chemical Co., Ltd.) was added thereto, followed by stirring for 2 hours. Thereafter, toluene was distilled off under reduced pressure and baked at 150 ° C. for 2 hours.
[0217]
Next, 60 parts by mass of the obtained zinc oxide particles after the surface treatment and a curing agent (blocked isocyanate Sumijoule 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.): 15 parts by mass, butyral resin BM-1 (manufactured by Sekisui Chemical Co., Ltd.) ): 15 parts by mass and 85 parts by mass of methyl ethyl ketone were mixed. The obtained liquid: 8 parts by mass and methyl ethyl ketone: 25 parts by mass were mixed and dispersed for 2 hours with a sand mill using 1 mmφ glass beads to obtain a dispersion.
[0218]
Dioctyltin dilaurate: 0.005 parts by mass and silicone oil SH29PA (manufactured by Toray Dow Corning Silicone): 0.01 parts by mass were added as catalysts to the resulting dispersion to obtain an undercoat layer coating solution. . This coating solution is applied on an aluminum substrate (conductive support layer) having a diameter of 30 mm, a length of 340 mm, and a thickness of 1 mm by a dip coating method, followed by drying and curing at 160 ° C. for 100 minutes and a thickness of 20 μm or less. A pulling layer was formed.
[0219]
Next, a photosensitive layer having a two-layer structure was formed on the undercoat layer. First, X-ray diffraction spectrum Bragg angles (2θ ± 0.2 °) using Cukα as a charge generating material are at least 7.3 °, 16.0 °, 24.9 °, and 28.0 °. A mixture comprising 15 parts by mass of a hydroxygallium phthalocyanine having a diffraction peak at 10 parts by mass, 10 parts by mass of vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Nihon Unicar) serving as a binder resin, and 300 parts by mass of n-butyl acetate. 1 mmφ glass beads were dispersed for 4 hours in a sand mill.
[0220]
The obtained dispersion was dip-coated on the undercoat layer as a charge generation layer forming coating solution and dried to form a charge generation layer having a layer thickness of 0.2 μm. Next, a charge transport layer was formed in the same procedure as in Example 1 to produce an electrophotographic photoreceptor.
[0221]
(Example 4)
A photoconductor having the same configuration as that of the electrophotographic photoconductor 100 shown in FIG.
[0222]
Zinc oxide (trade name: MZ300, manufactured by Teika, specific surface area: 40 m ² / G) was heated and dried in air at 150 ° C. for 5 hours to adjust the water content. As a result of thermogravimetric analysis, the water content of the obtained zinc oxide particles was 0.1% by mass. 100 parts by mass of the zinc oxide particles were mixed with 500 parts by mass of toluene, and 5 parts by mass of a silane coupling agent (trade name: KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) was added thereto and stirred for 2 hours. Thereafter, toluene was distilled off under reduced pressure and baked at 150 ° C. for 2 hours.
[0223]
Next, zinc oxide after surface treatment: 60 parts by mass, curing agent (blocked isocyanate Sumijoule 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.): 15 parts by mass, butyral resin BM-1 (manufactured by Sekisui Chemical Co., Ltd.): 15 Part by mass and 85 parts by mass of methyl ethyl ketone were mixed. The obtained liquid: 38 parts by mass and methyl ethyl ketone: 25 parts by mass were mixed and dispersed for 2 hours with a sand mill using glass beads of 1 mmφ to obtain a dispersion.
[0224]
Dioctyltin dilaurate: 0.005 parts by mass and silicone oil SH29PA (manufactured by Toray Dow Corning Silicone): 0.01 parts by mass were added as catalysts to the resulting dispersion to obtain an undercoat layer coating solution. . This coating solution is applied on an aluminum substrate (conductive support layer) having a diameter of 30 mm, a length of 340 mm, and a thickness of 1 mm by a dip coating method, followed by drying and curing at 160 ° C. for 100 minutes and a thickness of 20 μm or less. A pulling layer was formed.
[0225]
Next, a photosensitive layer having a two-layer structure was formed on the undercoat layer. First, oxytitanyl phthalocyanine having a diffraction peak at a position where the Bragg angle (2θ ± 0.2 °) of an X-ray diffraction spectrum using Cukα rays as a charge generation material is at least 27.3 °: 15 parts by mass, binder resin A mixture of 10 parts by mass of vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Nippon Unicar Co., Ltd.) and 300 parts by mass of n-butyl acetate was dispersed in a sand mill for 4 hours using 1 mmφ glass beads. .
[0226]
The obtained dispersion was dip-coated on the undercoat layer as a charge generation layer forming coating solution and dried to form a charge generation layer having a layer thickness of 0.2 μm. Next, a charge transport layer was formed in the same procedure as in Example 1 to produce an electrophotographic photoreceptor.
[0227]
(Comparative Example 1)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the metal oxide particles used in Example 1 were used without heat treatment. As a result of thermogravimetric analysis, the water content of the metal oxide particles used was 1.5% by mass.
[0228]
(Comparative Example 2)
An electrophotographic photosensitive member was produced in the same manner as in Example 2 except that the metal oxide particles used in Example 2 were used without heat treatment. As a result of thermogravimetric analysis, the water content of the metal oxide particles used was 1.2% by mass.
[0229]
(Comparative Example 3)
An electrophotographic photosensitive member was produced in the same manner as in Example 3 except that the metal oxide particles used in Example 3 were used without heat treatment. As a result of thermogravimetric analysis, the water content of the metal oxide particles used was 1.1% by mass.
[0230]
(Comparative Example 4)
An electrophotographic photosensitive member was produced in the same manner as in Example 4 except that the metal oxide particles used in Example 4 were used without heat treatment. As a result of thermogravimetric analysis, the water content of the metal oxide particles used was 1.3% by mass.
[0231]
[Electrophotographic characteristic evaluation test of electrophotographic photosensitive member]
(1) Initial characteristics evaluation (initial potential measurement)
The electrophotographic photosensitive members of Examples 1 to 4 and Comparative Examples 1 to 4 were applied to a laser printer-scanner (trade name: XP-15 modified machine, manufactured by Fuji Xerox Co., Ltd.) having the same structure as FIG. The electrophotographic characteristics of each electrophotographic photosensitive member were evaluated as follows.
[0232]
Measures the surface potential A [V] of each electrophotographic photosensitive member when the electrophotographic photosensitive member is charged with a scorotron charger with a grid applied voltage of −700 V in a normal temperature and normal humidity (20 ° C., 40% RH) environment. did. Next, 10 mJ / m is applied to each electrophotographic photosensitive member 1 second after being charged using a 780 nm semiconductor laser. ² The electric potential B [V] on the surface of each electrophotographic photosensitive member at this time was measured. Subsequently, after 3 seconds from the discharge, 50 mJ / m is applied to each electrophotographic photosensitive member. ² The red LED light was irradiated to remove static electricity, and the surface potential C [V] of each electrophotographic photosensitive member at this time was measured.
[0233]
Here, the higher the value of the potential A, the higher the acceptance potential of the electrophotographic photosensitive member, so that the contrast can be increased. Further, the lower the potential B, the higher the sensitivity of the electrophotographic photosensitive member. Further, the lower the value of the potential C, the smaller the residual potential, and it is evaluated as an electrophotographic photosensitive member with less image memory and so-called fogging. These results are shown in Table 1.
[0234]
(2) Initial image quality evaluation (after 10 prints)
The electrophotographic photosensitive members of Examples 1 to 4 and Comparative Examples 1 to 4 are full-color printers (trade names: Docu Center Color 400, Fuji) having a contact charging device and an intermediate transfer device having the same structure as in FIG. Mounted on Xerox Corporation), and a continuous print test on 10 sheets of paper was performed.
[0235]
Then, the image quality after printing 10 sheets was “no abnormality”; good image quality was obtained, “slightly fogging”; 20 fine black spots or less in the range of 100 mm × 200 mm on the paper surface, “fogging occurred” Evaluation was performed based on an evaluation standard that 1000 or more fine black spots could be confirmed in a range of 100 mm × 200 mm. These results are shown in Table 1.
[0236]
(3) Characteristic evaluation after repeated use
The operation described in the above (1) was repeated 10,000 times, and the potentials A to C after charging and exposure were measured. These results are shown in Table 1.
[0237]
(4) Stability evaluation against changes in usage environment
The above operation was performed in two different environments of low temperature and low humidity (10 ° C., 15% RH) and high temperature and high humidity (28 ° C., 85% RH), and the potentials A to C after charging and exposure were measured. . Then, the fluctuation amounts (ΔA, ΔB, ΔC) of the potentials A to C between these different environments were measured, and the stability of each electrophotographic photosensitive member was evaluated against changes in the usage environment. These results are shown in Table 1.
[0238]
(5) Image quality evaluation after printing 10,000 sheets
The electrophotographic photosensitive members of Examples 1 to 4 and Comparative Examples 1 to 4 are full-color printers (trade names: Docu Center Color 400, Fuji) having a contact charging device and an intermediate transfer device having the same structure as in FIG. Mounted on Xerox Corporation), and a continuous print test on 10,000 sheets of paper was conducted.
[0239]
Then, the image quality after printing 10,000 sheets was “no abnormality”; good image quality was obtained, “overall fogging occurred”; fine black spots were observed on the entire paper surface, “black spot generation”; large black spots on the paper surface The evaluation was made based on the evaluation criteria. These results are shown in Table 1.
[0240]
[Table 1]

[0241]
【The invention's effect】
As described above, according to the present invention, it has a high durability and a high resolution quality that can sufficiently prevent a decrease in electrical characteristics due to repeated use, and can be easily configured. An electrophotographic photoreceptor and a method for producing the same can be provided. By providing such an electrophotographic photosensitive member, it is possible to provide a process cartridge and an electrophotographic apparatus that can obtain high resolution quality even when used repeatedly over a long period of time.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a first embodiment of an electrophotographic photosensitive member of the present invention.
FIG. 2 is a cross-sectional view showing a second embodiment of the electrophotographic photosensitive member of the present invention.
FIG. 3 is a cross-sectional view showing a third embodiment of the electrophotographic photosensitive member of the present invention.
FIG. 4 is a cross-sectional view showing a fourth embodiment of the electrophotographic photosensitive member of the present invention.
FIG. 5 is a cross-sectional view showing a fifth embodiment of the electrophotographic photosensitive member of the present invention.
FIG. 6 is a cross-sectional view showing a sixth embodiment of the electrophotographic photosensitive member of the present invention.
FIG. 7 is a cross-sectional view showing a seventh embodiment of the electrophotographic photosensitive member of the present invention.
FIG. 8 is a sectional view showing an eighth embodiment of the electrophotographic photosensitive member of the present invention.
FIG. 9 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of the electrophotographic apparatus of the present invention.
10 is a cross-sectional view schematically showing a basic configuration of another embodiment of the electrophotographic apparatus of the present invention shown in FIG.
11 is a cross-sectional view schematically showing a basic configuration of still another embodiment of the electrophotographic apparatus of the present invention shown in FIG.
FIG. 12 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of the process cartridge of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Charge generating layer, 3 ... Conductive support layer, 4 ... Undercoat layer, 5 ... Protective layer, 6 ... Photosensitive layer, 7 ... Electrophotographic photosensitive member, 8 ... Charging means, 9 ... Power supply, 10 ... Exposure means 11 ... developing means, 12 ... transfer means, 13 ... cleaning device, 14 ... static discharger, 16 ... mounting rail, 18 ... opening for exposure, 42 ... intermediate layer, 100, 110, 120, 130, 140, 150, 160, 170 ... electrophotographic photosensitive member, 200 ... electrophotographic device, 210 ... electrophotographic device, 300 ... process cartridge, 400 ... housing, 401a-401d ... electrophotographic photosensitive member, 402a-402d. · Charging roll, 403 ··· Laser light source (exposure device), 404a to 404d · Development device, 405a to 405d · Toner cartridge, 406 · · · Drive roll, 407 Tension roll, 408 ... backup roll, 409 ... intermediate transfer belt, 410a to 410d ... primary transfer roll, 411 ... tray (tray to be transferred), 412 ... transfer roll, 413 ... Secondary transfer roll, 414... Fixing roll, 500.

Claims (15)

An electrophotographic photoreceptor having a conductive support layer, a photosensitive layer containing a pigment, and an undercoat layer disposed between the conductive support layer and the photosensitive layer,
The undercoat layer contains metal oxide particles surface-treated with an organometallic compound having a hydrolyzable functional group,
The moisture content in the state before the surface treatment of the metal oxide particles is 1.0% by mass or less,
An electrophotographic photoreceptor characterized by the above. 2. The electrophotographic photosensitive member according to claim 1, wherein the metal oxide particles are at least one kind of particles selected from the group consisting of tin oxide, titanium oxide, and zinc oxide. The electrophotographic photosensitive member according to claim 1, wherein the hydrolyzable organometallic compound is a silane coupling agent. The electrophotographic photosensitive member according to claim 1, wherein the thickness of the undercoat layer is greater than 15 μm and 50 μm or less. The electrophotographic photosensitive member according to claim 1, wherein the pigment contained in the photosensitive layer is a phthalocyanine pigment. 6. The electrophotographic photosensitive member according to claim 5, wherein the phthalocyanine pigment is at least one selected from the group consisting of hydroxygallium phthalocyanine, chlorogallium phthalocyanine, dichlorotin phthalocyanine, oxotitanyl phthalocyanine and phthalocyanine. A method for producing an electrophotographic photoreceptor having at least a conductive support layer, a photosensitive layer containing a pigment, and an undercoat layer disposed between the conductive support layer and the photosensitive layer,
A metal oxide particle having a water content of 1% by mass or less is surface-treated using an organometallic compound having a hydrolyzable functional group, and then the undercoat layer is formed using the particles obtained by the surface treatment. Including the step of forming,
A method for producing an electrophotographic photosensitive member characterized by the above. 8. The method for producing an electrophotographic photoreceptor according to claim 7, wherein the metal oxide particles are at least one kind of particles selected from the group consisting of tin oxide, titanium oxide, and zinc oxide. The method for producing an electrophotographic photosensitive member according to claim 7, wherein the hydrolyzable organometallic compound is a silane coupling agent. The method for producing an electrophotographic photosensitive member according to claim 7, wherein the thickness of the undercoat layer is adjusted to be greater than 15 μm and 50 μm or less. The method for producing an electrophotographic photosensitive member according to any one of claims 7 to 10, wherein the pigment contained in the photosensitive layer is a phthalocyanine pigment. 12. The electrophotographic photosensitive member according to claim 11, wherein the phthalocyanine pigment is at least one selected from the group consisting of hydroxygallium phthalocyanine, chlorogallium phthalocyanine, dichlorotin phthalocyanine, oxotitanyl phthalocyanine and phthalocyanine. Production method. The electrophotographic photosensitive member according to claim 1,
A process cartridge comprising at least one of a charging unit, a developing unit, a cleaning unit, and a charge eliminating unit, and is detachable from an electrophotographic apparatus main body. The electrophotographic photosensitive member according to claim 1,
Charging means for charging the electrophotographic photoreceptor;
Exposure means for exposing the electrophotographic photosensitive member charged by the charging means to form an electrostatic latent image; and
Developing means for developing the electrostatic latent image with toner to form a toner image;
Transfer means for transferring the toner image to a transfer medium;
An electrophotographic apparatus comprising: The transfer method of the transfer means is an intermediate transfer method in which the toner image is primarily transferred to an intermediate transfer member, and the primary transfer image on the intermediate transfer member is secondarily transferred to the transfer medium. The electrophotographic apparatus according to claim 14.

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