JP2004020727A - Electrophotographic photoreceptor, method for manufacturing electrophotographic photoreceptor, process cartridge, and electrophotographic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor which can sufficiently prevent degradation in electric characteristics accompanying repetitive use, has high durability and high resolution quality, and can be easily constituted and a method for manufacturing the same, a process cartridge mounted with this electrophotographic photoreceptor, and an electrophotographic device. <P>SOLUTION: The electrophotographic photoreceptor 100 has a conductive support layer 3, a photosensitive layer 6 containing pigment, and an under-coating layer 4 arranged between the conductive support layer and the photosensitive layer. Metal oxide particles subjected to a surface treatment by using an organic metal compound having a hydrolzable functional group are included in the under-coating layer 4 and the moisture content in the state before the layer is subjected to the surface treatment of the metal oxide particles is confined to ≤1.0mass%. <P>COPYRIGHT: (C)2004,JPO

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、Ａｒ^１及びＡｒ^２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、Ｘ^１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、Ｘ^２及びＸ^３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、Ｌ^１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、Ａｒ^３及びＡｒ^４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、Ｌ^２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、Ａｒ^１及びＡｒ^２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Ｘ^１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Ｘ^２及びＸ^３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Ｌ^１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、Ａｒ^３及びＡｒ^４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Ｌ^２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Ｌ^１又は式（８）中のＬ^２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，−ＮＯ_２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、ＳｎＯ_２、ＴｉＯ_２、Ｉｎ_２Ｏ_３、ＭｏＯ_３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１０^２〜１０^１４Ωｃｍ、さらに好ましくは１０^２〜１０^１２Ωｃｍ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：５０ｍ^２／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’−シ゛フェニル−Ｎ，Ｎ’−ヒ゛ス（３−メチルフェニル）−［１、１’］ヒ゛フェニル−４，４’−シ゛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：１８ｍ^２／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７０μｍ，テイカ社製試作品，比表面積：１５ｍ^２／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：４０ｍ^２／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／ｍ^２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／ｍ^２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]
TECHNICAL FIELD 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]
2. Description of the Related Art In recent years, electrophotographic photoreceptors have the advantage that high speed and high printing quality can be obtained, and therefore, they are widely used in fields such as copying machines and laser beam printers. As an electrophotographic photoreceptor used in these electrophotographic apparatuses, compared to conventional electrophotographic photoreceptors using an inorganic photoconductive material such as selenium, a selenium-tellurium alloy, a selenium-arsenic alloy, and cadmium sulfide, the production efficiency and safety are lower. An electrophotographic photoreceptor containing an organic photoconductive material such as a phthalocyanine-based pigment, which has an excellent advantage in that point, as a charge generating substance has become mainstream.
[0003]
Among such photoreceptors, a function-separated type photoreceptor having a photosensitive layer composed of a charge generation layer that generates charges by exposure and a charge transport layer that transports charges, such as sensitivity and chargeability and its repetition stability, It is excellent in electrophotographic characteristics, and various configurations have been proposed and put to 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 material, 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 the electrophotographic apparatus, a charging device of a contact charging type which generates less ozone has been used instead of a corotron. Then, the dispersion state of the charge generating substance (pigment) in the photosensitive layer of the photoreceptor mounted on the electrophotographic apparatus is made sufficiently uniform, the surface of the conductive support layer is formed without irregularities, and contamination is prevented. If it is not enough to prevent contamination, the undercoat layer or photosensitive layer formed by coating on the conductive support layer will be uniformly coated over the entire area where the thickness is coated due to unevenness of the coating. Problems such as the inability to cover the irregularities on the surface of the conductive support layer with the undercoat layer or the photosensitive layer, and the exposure of the irregularities, or the problem that foreign matter is mixed into the photosensitive layer. However, there is a problem that a local defective portion is generated on the photoconductor. In this case, a high electric field is locally applied to a defective portion of the photoconductor at the time of contact charging, and an electric pinhole is generated, which becomes an image quality defect.
[0006]
In addition, the above-mentioned pinhole (pinhole leak) is a phenomenon in which, during operation of an electrophotographic apparatus, conductive foreign substances such as foreign matter, dust, and carrier powder generated from members constituting the electrophotographic apparatus come into contact with the photosensitive member or the photosensitive member. In some cases, it also occurred by penetrating the inside.
[0007]
In order to prevent the occurrence of image quality defects described above and to improve the image quality stability and environmental stability against repeated use of the photoconductor, not only the performance of the photosensitive layer but also the undercoat layer serving as a base of the photosensitive layer Is also required, and the realization of an undercoat layer with less charge accumulation by repeated use is required.
[0008]
Therefore, in order to conceal the defects of the conductive support layer (substrate) and improve the rise of the residual potential while obtaining stable electric characteristics, the layer containing the conductive fine powder is used as the conductive support layer. A method for forming the photoreceptor formed above has been studied.
[0009]
As such a method, for example, a layer containing conductive fine powder is formed on a conductive support layer such as an aluminum base material, and a layer containing the conductive fine powder is formed on a conductive support layer. A method of forming a photoreceptor having a two-layered undercoat layer in which a layer having the same structure as that of the undercoat layer is formed is proposed in, for example, Japanese Patent Application Laid-Open No. 3-59561. 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 to adjust the electric resistance, and the conventional undercoat layer and A layer having a similar structure is provided with a blocking (charge injection control) function.
[0010]
Further, as another method, only a layer containing conductive fine powder is formed as a subbing layer on a conductive support layer, and this layer has both the above-described blocking function and resistance adjusting function. There is a method of forming a photoconductor having the following formula. For example, such a photoconductor and a method of manufacturing the same are disclosed in JP-A-2001-75296.
[0011]
[Problems to be solved by the invention]
However, the present inventors have proposed a structure in which a layer containing a conductive fine powder is formed on a conductive support layer as disclosed in JP-A-3-45961 and JP-A-2001-75296. Even with a conventional electrophotographic photoreceptor having, it is still insufficient to obtain sufficient electrical properties to withstand repeated use, and when the electrophotographic photoreceptor is used repeatedly, the pinhole leak described above may occur. It is liable to occur, so that the chargeability of the photoreceptor is reduced and the image density is reduced with repeated use, and there is still the problem that the residual potential increases with repeated use and fog such as black spots occurs on the image. Was found.
[0012]
The present invention has been made in view of the above-mentioned problems of the related art, and has high durability and high resolution quality that can sufficiently prevent a decrease in 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 of manufacturing the same, and a process cartridge and an electrophotographic apparatus equipped with the electrophotographic photosensitive member.
[0013]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to achieve the above object, and as a result, when performing surface treatment of metal oxide particles to be 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 effect on the dispersion state of the metal oxide particles obtained after the surface treatment in the undercoat layer, and further on the film resistance of the undercoat layer.
[0014]
Further, the present inventors control the water content of the metal oxide particles before the surface treatment, so that the undercoating has a desired film resistance value and has good and stable electric characteristics for repeated use. The inventors have found that a layer can be easily obtained, and arrived at the present invention.
[0015]
That is, the present invention is 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 that have been surface-treated using an organometallic compound having a hydrolyzable functional group. An electrophotographic photoreceptor characterized in that the ratio is 1.0% by mass or less.
[0016]
Here, in the present invention, the "water content" in a state before the surface treatment of the metal oxide particles is performed, before the surface treatment, adsorbed on the surface of the metal oxide particles placed in a normal environment It is a value obtained by dividing the mass of the water present by the total mass of the metal oxide particles containing the water under the same environment, and expressing the obtained value in percentage.
[0017]
Further, in the present specification, metal oxide particles that have been surface-treated using an organometallic compound having a hydrolyzable functional group (hereinafter, referred to as “hydrolyzable organometallic compound”) are referred to as “metal oxide particles”. Particle A ". The metal oxide particles before the surface treatment of the metal oxide particles A are referred to as “metal oxide particles B”. Therefore, the metal oxide particles A are particles in a state where a film made of a hydrolyzable organometallic compound is formed on a part or the entire surface of the metal oxide particles B. Further, in the present invention, the metal element constituting the hydrolyzable organometallic compound includes silicon. 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 photoreceptor of the present invention, only the metal oxide particles A obtained from the metal oxide particles B satisfying the above-mentioned water content conditions are selectively contained in the undercoat layer, so that the undercoat layer is repeatedly used. An excellent undercoat layer having a small charge accumulation property can be formed. Furthermore, by using this undercoat layer, it is possible to easily and reliably construct an electrophotographic photoreceptor having high durability and high resolution quality capable of sufficiently preventing a decrease in electrical characteristics due to repeated use. it can.
[0019]
Details about the fact that by selectively including only the metal oxide particles A satisfying the above-mentioned water content conditions in the undercoat layer, it is possible to form an excellent undercoat layer having little charge accumulation property with repeated use. Although the exact mechanism has not been clearly elucidated, the present inventors think as follows.
[0020]
That is, the present inventors obtain the metal oxide particles B from the surface when the water content of the metal oxide particles B is 1.0% by mass or less when the surface treatment is performed using the hydrolyzable organometallic compound. It is considered that the dispersion state of the metal oxide particles A in the undercoat layer is sufficiently uniform as compared with the conventional technique, and that the undercoat layer can sufficiently suppress the fluctuation of the film resistance due to the change of the environment in which the undercoat layer is placed. ing.
[0021]
On the other hand, when the metal oxide particles B are subjected to surface treatment using a hydrolyzable organometallic compound, if the water content of the metal oxide particles B exceeds 1.0% by mass, the resulting metal oxide The dispersion state of the material particles A in the undercoat layer becomes non-uniform, and the fluctuation of the film resistance increases with a change in the environment in which the undercoat layer is placed. In this case, for example, the film resistance decreases under high humidity conditions, and increases under low humidity conditions. As described above, if the film resistance value of the undercoat layer greatly varies depending on the environment in which the undercoat layer is placed, a serious defect is given to the image quality, the image quality maintenance performance, and the leak resistance of the electrophotographic photosensitive member provided with the undercoat layer.
[0022]
Although the detailed mechanism of the non-uniform dispersion state of the metal oxide particles A in the undercoat layer has not been clearly elucidated, the present inventors have found that the water content of the metal oxide particles B is 1%. When the content exceeds 0.0% by mass, water adsorbed on the metal oxide particles B and the organic metal in the local portion of the surface of the metal oxide particles B are compared with the reaction between the metal oxide particles B and the organometallic compound. This is because 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 present inventors have reported that the metal oxide particles A having many local surface portions that have not been surface-treated as described above are coated with a coating solution (a predetermined solvent and a predetermined solvent) prepared for forming an undercoat layer. It is considered that when mixed in a liquid containing at least a binder resin), the metal oxides A are likely to aggregate with each other, thereby easily causing poor dispersion. Therefore, a good conductive path is not formed in the undercoat layer obtained by applying the coating solution on the conductive support layer, and as a result, the undercoat layer and the electrophotographic photosensitive member including the same are provided. It is considered that it has a drawback that electric characteristics are lowered and image quality defects are likely to occur due to repeated use.
[0024]
Further, according to the present invention, the dispersion state of the metal oxide particles A in the undercoat layer is easily controlled by merely controlling the water content of the metal oxide particles B so as to satisfy the above-described conditions, thereby obtaining a favorable condition. The undercoat layer and the electrophotographic photoreceptor have the electrical characteristics that prevent the deterioration of the electrical characteristics due to repeated use more easily than before. can do.
[0025]
Further, the metal oxide particles A satisfying the above condition of the water content can be easily obtained by performing a process that can be performed by a relatively simple operation such as a heating and drying process. An undercoat layer in which a decrease in electrical characteristics is sufficiently prevented and an electrophotographic photosensitive member having the undercoat layer can be easily formed.
[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 fluctuation of the film resistance of the undercoat layer can be sufficiently suppressed. It is easy to 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]
By increasing the film thickness, it is easy to increase the leakage resistance of the undercoat layer and effectively suppress the occurrence of pinhole leakage. Further, such a thick film effectively prevents foreign substances from adhering to the photosensitive layer during use of the electrophotographic photosensitive member and penetrating into the conductive support layer through the undercoat layer. be able to. Therefore, from the viewpoint that such an undercoat layer can be easily thickened, the manufacturing method of the present invention has a high durability that can sufficiently prevent a decrease in electrical characteristics due to repeated use. An electrophotographic photosensitive member having high resolution and high resolution quality can be obtained.
[0028]
Further, the present invention is 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. The metal oxide particles having a water content of 1% by mass or less are surface-treated with an organometallic compound having a hydrolyzable functional group, and then the undercoat layer is formed using the particles obtained by the surface treatment. And a method for producing an electrophotographic photoreceptor.
[0029]
According to the method for producing an electrophotographic photoreceptor of the present invention, by selectively including only metal oxide particles A obtained from metal oxide particles B satisfying the above-mentioned water content condition in the undercoat layer, The dispersed state of the metal oxide particles A in the pulling layer can be easily and sufficiently made uniform. Therefore, it is possible to manufacture an excellent undercoat layer having a small charge accumulation property with repeated use, and as a result, a high durability and a high resolution quality capable of sufficiently preventing a decrease in electrical characteristics due to repeated use. The above-described electrophotographic photosensitive member of the present invention can be easily and reliably manufactured.
[0030]
In the method for producing an electrophotographic photoreceptor of the present invention, when the metal oxide particles B are subjected to a surface treatment using a hydrolyzable organometallic compound, the water content of the metal oxide particles B exceeds 1.0% by mass. In this case, the dispersion state of the obtained metal oxide particles A in the undercoat layer becomes non-uniform, and the fluctuation of the film resistance increases with the change of the environment in which the undercoat layer is placed.
[0031]
Furthermore, the present invention has the above-described electrophotographic photoreceptor of the present invention and at least one of a charging unit, a developing unit, a cleaning unit, and a static elimination unit integrally, and is detachably attached to an electrophotographic apparatus main body. A process cartridge is provided.
[0032]
Thus, the process cartridge of the present invention can obtain high resolution quality without causing black spots or other fogging on an image when repeatedly used.
[0033]
Further, the present invention provides an electrophotographic photoreceptor of the present invention described above, a charging unit for charging the electrophotographic photoreceptor, and an exposure for exposing the electrophotographic photoreceptor charged by the charging unit to form an electrostatic latent image. An electrophotographic apparatus comprising: a developing unit configured to develop a toner image by developing an electrostatic latent image with toner; and a transfer unit configured to transfer the toner image to a transfer-receiving medium.
[0034]
As a result, the electrophotographic apparatus of the present invention can maintain high resolution quality for a long time without causing fogging such as black spots on a copied image when repeatedly used.
[0035]
BEST MODE FOR CARRYING OUT 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 an electrophotographic photoreceptor of the present invention is obtained by performing a surface treatment on metal oxide particles B satisfying the above-described condition of the water content in the step of forming an undercoat layer of the electrophotographic photoreceptor. The metal oxide particles A may be used, and the procedure and conditions in the manufacturing process of other components of the electrophotographic photoreceptor other than the undercoat layer are not particularly limited. For example, a known thin film manufacturing technique is used. be able to. Therefore, for the preferred embodiment of the method for producing an electrophotographic photoreceptor of the present invention, the description of the process of forming the undercoat layer, which is a main part thereof, will be described below with reference to each embodiment of the electrophotographic photoreceptor of the present invention. It will be described in the description of the layers.
[0037]
[First embodiment]
FIG. 1 is a 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. The 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 of aluminum, copper, iron, zinc, nickel, or the like can be used. In addition, a drum that is conductively treated by vapor-depositing a metal such as aluminum, copper, gold, silver, platinum, palladium, titanium, nickel-chromium, stainless steel, copper-indium on a polymer sheet, paper, plastic, or glass. Shapes, sheets and plates can be used.
[0039]
Furthermore, on a polymer sheet, paper, plastic, or glass, a conductive metal compound such as indium oxide or tin oxide is vapor-deposited, or a conductive metal sheet is laminated to form a drum, sheet, or plate. Can be used. In addition, by dispersing carbon black, indium oxide, tin oxide-antimony oxide powder, metal powder, copper iodide, etc. in a binder resin, and applying it on a polymer sheet, paper, plastic, or glass. Drum-shaped, sheet-shaped, and plate-shaped objects that have been subjected to conductive treatment can also be used.
[0040]
Here, when the metal pipe base material is used as the conductive support layer 3, even if the surface of the base material is a raw tube, it is mirror-polished, etched, anodized, rough-cut, centerless grounded, sandblasted, and wet-honed. It is preferable to perform a treatment such as a coloring treatment. By performing surface treatment and roughening the surface of the base material, it is possible to prevent grain-like density unevenness due to interference light in the photoconductor, which may occur when a coherent light source such as a laser beam is used.
[0041]
As described above, the undercoat layer 4 includes the metal oxide particles A obtained by performing a surface treatment on the metal oxide particles B using the hydrolyzable organometallic compound, and the binder resin. . The undercoat layer 4 has a function of preventing charge injection from the conductive support layer 3 into the photosensitive layer 6 when the photosensitive layer 6 is charged. Further, the undercoat layer 4 also functions as an adhesive layer that integrally holds the photosensitive layer 6 with 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 undercoat layer 4 is as thick as possible, the effect of a penetrating substance from the outside is easily prevented and the leak resistance is improved. On the other hand, the thin film having a layer thickness of, for example, 10 μm or less has a sufficient leak resistance. Does not have. As described above, according to the manufacturing method of the present invention, the thickness of the undercoat layer 4 can be easily increased. From the viewpoint of effectively preventing the occurrence of pinhole leaks by increasing the leakage resistance of the undercoat layer 4, the thickness of the undercoat layer 4 is preferably greater than 15 μm and 50 μm or less, preferably 20 to 50 μm. Is more preferred.
[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 for image quality to deteriorate due to an increase in residual charge increases. Also, in this case, it tends to be difficult to make the layer thickness uniform, and the manufacturing cost may increase.
[0044]
However, when the layer has sufficient leak resistance and there is no concern about the occurrence of the above-described leak defect, the thickness of the undercoat layer can be set to be smaller than 15 μm. It is applicable to a thin film of about 1 μm.
[0045]
The binder resin used in the undercoat layer of the electrophotographic photoreceptor of the present invention includes acetal resins such as polyvinyl butyral, polyvinyl alcohol resins, casein, polyamide resins, cellulose resins, gelatin, polyurethane resins, polyester resins, and methacrylic resins. , 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]
Among them, a resin insoluble in the upper layer coating solvent is preferably used, and particularly, a phenol resin, a phenol-formaldehyde resin, a melamine resin, a urethane resin, an epoxy resin and the like are preferably used. The mixing ratio between 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 electric resistance value of the undercoat layer 4 is 10 ⁴ -10 ¹³ Ωcm, preferably 10 Ωcm. ⁸ -10 ¹³ Ωcm, more preferably ⁹ -10 ¹² More preferably, it is Ωcm. Resistance value is 10 ⁴ If it is less than Ωcm, it tends to be difficult to obtain sufficient leakage resistance, ¹³ If it exceeds Ωcm, the tendency to cause a rise in the residual potential increases. The electric resistance value of the undercoat layer 4 can be controlled by changing the electric resistance value of the metal oxide particles A itself and the amount thereof added, and by changing the dispersion state of the metal oxide particles 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 is such that the desired properties can be obtained and the metal oxide particles B can be dispersed in the coating liquid for forming the undercoat layer. Any particle diameter can be used as long as it can be applied on the surface and is equal to or less than the thickness of the undercoat layer 4, but the average particle diameter is preferably 100 nm or less. Here, the particle size means an average primary particle size. As the metal oxide particles B, the powder resistance value is 10 ² -10 ¹¹ Ωcm can be used, but from the viewpoint of obtaining excellent leakage resistance of the undercoat layer 4, the powder resistance value is particularly preferably 10 Ωcm. ⁴ -10 ¹⁰ Ω · cm is preferred. 10 ² If it is less than Ωcm, sufficient leak resistance cannot be obtained and 10 ¹¹ If it exceeds Ωcm, the tendency for the residual potential to increase increases.
[0050]
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. Specific surface area value is 10m ² If it is less than / g, the tendency of the undercoat layer 4 to be more likely to cause a decrease in chargeability is increased.
[0051]
The water content of the metal oxide particles B is adjusted to 1.0% by mass or less from the viewpoint of suppressing a change in the electric resistance value of the undercoat layer 4 due to a change in temperature or humidity in a use environment. The surface of the metal oxide particles B is 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 that greatly affects 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. You can control.
[0052]
Here, the surface treatment is a treatment in which a hydrolyzable organometallic compound is adsorbed on the surface of the metal oxide particles B, and a hydrolytic group of the hydrolyzable organometallic compound is hydrolyzed there.
[0053]
In the present invention, the hydrolyzable organometallic compound is preferably represented by the following general formula (I).
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 represent 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 an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group and an octyl group, an alkenyl group such as a vinyl group and an allyl group, a cycloalkyl group such as a cyclohexyl group, a phenyl group, and a naphthyl group. Alkaryl group such as tolyl group, alkenyl group such as benzyl group, phenylethyl group, arylalkenyl group such as styryl group, furyl group, thienyl group, pyrozinyl group, heterocyclic residue such as imidazolyl group. The residue is not particularly limited as long as it is an organic compound residue such as The organic group R in the hydrolyzable organometallic compound may be one type selected from the above-described organic compound residues, or may be two or more types.
[0056]
Examples of the hydrolyzable functional group Y include methoxy group, ethoxy group, propoxy group, butoxy group, cyclohexyloxy group, phenoxy group, ether group such as benzyloxy group, acetoxy group, propionyloxy group, acryloxy group, methacryloxy group. Groups, benzoyloxy group, methanesulfonyloxy group, benzenesulfonyloxy group, ester group such as benzyloxycarbonyl group, and halogen atom such as chlorine atom.
[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, Metals such as rhodium, palladium, indium, tin, platinum and the like can be mentioned.
[0058]
Examples of the hydrolyzable organic metal compound having the organic group R and the hydrolyzable functional group Y include a silane coupling agent and a titanate-based coupling agent in which the organic group and the hydrolyzable functional group are substituted. And at least one selected from the group consisting of aluminate-based coupling agents and organic zirconium compounds, and more preferably silane coupling agents. These hydrolyzable organometallic compounds can be used alone or in combination of two or more.
[0059]
Examples of the silane coupling agent include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 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-based coupling agents include isopropyl triisostearoyl titanate, bis (dioctyl pyrophosphate), and isopropyl tri (N-aminoethyl-aminoethyl) titanate.
[0061]
Examples of the aluminate-based coupling agent include acetoalkoxy aluminium diisopropylate.
[0062]
Further, among the above 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]
The amount of the hydrolyzable organometallic compound used is such that the above-mentioned amount of the metal oxide particles A can be obtained by combining the amount of the hydrolyzable organometallic compound or the metal oxide particles B used for the surface treatment. The temperature and 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 are optimized and set in accordance with the surface treatment conditions.
[0064]
Next, a method for adjusting the content of the metal oxide particles B to 1.0 wt% or less will be described. As a method of adjusting the content of the metal oxide particles B to 1.0 wt% or less, a method of drying by heating to 100 ° C. or more is effective. 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 the surface treatment agent is added, and the azeotropic distillation is performed. To remove water. The content of the metal oxide particles B is measured by thermogravimetric analysis or Karl Fischer method.
[0065]
Next, a method for surface treatment of the metal oxide particles B will be described. The method of surface treatment of the metal oxide particles B with the hydrolyzable organometallic compound is not particularly limited, and for example, a known method such as a dry method, a wet method, and 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 expression (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 having good reproducibility for obtaining the metal oxide particles A satisfying the condition of the formula (1) are easily optimized and grasped in advance. If it can be kept, 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 a surface treatment based on a dry method will be described. First, before the surface treatment, the metal oxide particles B are pre-dried at a temperature of 100 to 150 ° C. to remove the 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 pre-dried while being stirred by 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, the hydrolyzable organometallic compound is sprayed together with dry air or nitrogen gas while stirring the metal oxide particles B with a mixer having a large shearing force, or the hydrolyzable organometallic compound is mixed with a solvent (organic solvent, Water) is sprayed together with dry air or nitrogen gas. Thereby, the hydrolyzable organic metal 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 at least 50 ° C. When a solvent is used, it is preferable to carry out the reaction at a temperature near the boiling point of the solvent.
[0070]
Then, a baking process is performed at a temperature of 100 ° C. or higher. This allows the hydrolysis reaction of the hydrolyzable organometallic compound to proceed sufficiently. The baking treatment is preferably performed at a temperature of 150 to 250C. When the temperature is lower than 150 ° C., the hydrolysis reaction of the hydrolyzable organometallic compound may not be able to proceed sufficiently. If the temperature exceeds 250 ° C., the hydrolyzable organometallic compound may be decomposed.
[0071]
Next, if necessary, the metal oxide particles A after the surface treatment are pulverized. 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 using an ultrasonic wave, a sand mill, an attritor, a ball mill, or the like, and then a liquid containing a hydrolyzable organometallic compound is added thereto, and the mixture is stirred. Allow the treatment reaction to proceed. Thereafter, the solvent is distilled off from this liquid by distillation. Further, the solid obtained after removing the solvent may be further baked at 100 ° C. or higher. In addition, in this wet method as well as in the dry method, water adsorbed on the surface of the metal oxide particles B may be removed before the surface treatment. As the method for removing the surface adsorbed water, in addition to the removal by heating and drying in the same manner as the dry method, a method of removing while stirring and heating in a solvent used for surface treatment, a method of azeotropic removal with the solvent, and the like can be given. .
[0073]
The undercoat layer 4 may contain other additives for improving its electrical characteristics, improving the shape stability in a use environment, and improving image quality.
[0074]
For example, quinone-based compounds such as chloranyl, bromoanil, and anthraquinone; tetracyanoquinodimethane-based compounds; fluorenone compounds such as 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone; -(4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3,4-oxadiazole, Oxadiazole-based compounds such as 1,5-bis (4-diethylaminophenyl) 1,3,4oxadiazole, xanthone-based compounds, thiophene compounds, 3,3 ′, 5,5′tetra-t-butyldiphenoquinone Electron-transporting substances such as diphenoquinone compounds, etc .; electron-transporting pigments such as polycyclic condensed and azo-based compounds; zirconium chelate compounds; DOO compounds, aluminum chelate compounds, titanium alkoxide compounds, may contain a known material such as an organic titanium compound.
[0075]
Examples of the titanium chelate compound include, for example, 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 triethanol aminate, polyhydroxytitanium stearate and the like.
[0076]
Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxyaluminum diisopropylate, aluminum butyrate, diethylacetoacetate aluminum diisopropylate, and aluminum tris (ethylacetoacetate). These compounds can be used alone or as a mixture or a polycondensate of a plurality of compounds.
[0077]
In addition, from the viewpoint of preventing foreign matter such as conductive powder from the outside, which causes current leakage at the time of contact charging, from penetrating the photoconductor, and forming the highly durable undercoat layer 4, It is effective to increase the hardness of the undercoat layer 4, and it is preferable that the Vickers hardness of the undercoat layer 4 is 30 or more, preferably 35 or more as an index of the hardness.
[0078]
Further, from the viewpoint of preventing moire images, the surface roughness of the undercoat layer 4 is adjusted to （n (n is the refractive index of the upper layer) to λ when the exposure laser wavelength λ is used. Is preferred. The surface referred to 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 the polishing method, buffing, sand blasting, wet honing, grinding, or the like can also be used.
[0080]
Next, a method of forming the undercoat layer 4 (a step of forming the undercoat layer 4) will be described. The undercoat layer 4 is a metal oxide A obtained after subjecting the above-described metal oxide particles B to a surface treatment using at least one or more hydrolyzable metal compounds, the particles satisfying the condition of the formula (1). Is dispersed in the binder resin described above, and a coating solution obtained by coating is coated on the conductive support layer 3.
[0081]
As a solvent for adjusting the coating liquid for forming the undercoat layer 4, a known organic solvent such as an alcohol, an aromatic, a halogenated hydrocarbon, a ketone, a ketone alcohol, an ether, and an ester may be used. 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]
The solvents used for these dispersions can be used alone or in combination of two or more. At the time of mixing, any solvent can be used as long as it can dissolve the binder resin as a mixed solvent.
[0084]
As a method for dispersing the metal oxide particles A in the binder resin, a method such as a roll mill, a ball mill, a vibration ball mill, an attritor, a sand mill, a colloid mill, a paint shaker, or the like can be used. Further, as an application method used when providing the undercoat layer, a usual 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, a curtain coating method, etc. 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 substance) contained in the charge generation layer 1 is not particularly limited, and a known pigment can be used.
[0087]
For the photoreceptor utilizing infrared light, for example, phthalocyanine pigment, squarylium pigment, bisazo pigment, trisazo pigment, perylene pigment, dithioketopyrrolopyrrole pigment can be used. In the case of a photoreceptor using a visible light laser, for example, condensed polycyclic pigments, bisazo pigments, perylene pigments, trigonal selenium, dye-sensitized metal oxides, and the like can be used.
[0088]
Among the above-mentioned pigments, it is preferable to use a phthalocyanine pigment because an excellent image can be obtained. This makes it easy to configure an electrophotographic photoreceptor that has particularly high sensitivity and can stably obtain good image quality even when used repeatedly.
[0089]
The phthalocyanine-based pigment generally has several crystal forms, and any crystal form can be used as long as the desired sensitivity is obtained. In particular, among the phthalocyanine pigments, phthalocyanine pigments represented by the following formulas (1) to (6) are preferably used.
[0090]
Embedded image

[0091]
In the above formulas (1) to (6), chlorogallium phthalocyanine has a Bragg angle (2θ ± 0.2 °) of 7.4 °, 16.6 in an X-ray diffraction spectrum using Cuka radiation. Those having at least diffraction peaks at the positions of °, 25.5 ° and 28.3 ° are preferred. Further, as oxotitanyl phthalocyanine, in the X-ray diffraction spectrum using Cukα ray, the value of the Bragg angle (2θ ± 0.2 °) is 9.6 °, 24.1 °, 27.3 °. Those having at least a diffraction peak and a maximum 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 the Cl atom bonded to Ga which is the coordinating center of the formula (4) is substituted with an -OH group is also preferable. Such hydroxygallium phthalocyanine has a Bragg angle (2θ ± 0.2 °) of 7.5 °, 9.9 °, 12.5 °, 16.5 ° in an X-ray diffraction spectrum using Cuka radiation. Those having at least diffraction peaks at positions of 3 °, 18.6 °, 25.1 °, and 28.1 ° are preferred.
[0093]
Further, such a pigment is obtained by mechanically dry-pulverizing a pigment crystal produced by a known method using an automatic mortar, a planetary mill, a vibration mill, a CF mill, a roller mill, a sand mill, a kneader, or the like. It can be manufactured by performing wet pulverization using a ball mill, a mortar, a sand mill, a kneader or the like together with a solvent.
[0094]
Solvents used in the wet grinding treatment include aromatics (toluene, chlorobenzene, etc.), amides (dimethylformamide, N-methylpyrrolidone, etc.), aliphatic alcohols (methanol, ethanol, butanol, etc.), fatty acids Aromatic polyhydric alcohols (ethylene glycol, glycerin, polyethylene glycol, etc.), aromatic alcohols (benzyl alcohol, phenethyl alcohol, etc.), esters (acetate, butyl acetate, etc.), ketones (acetone, methyl ethyl ketone, etc.), dimethyl Examples thereof include sulfoxides, ethers (diethyl ether, tetrahydrofuran, etc.), a mixture of several kinds, and a mixture of water and these organic solvents.
[0095]
The solvent is used in an amount of 1 to 200 parts by mass, preferably 10 to 100 parts by mass, based on the pigment crystals. Further, the treatment temperature is in the range of 0 ° C to the boiling point of the solvent, preferably 10 to 60 ° C. In addition, at the time of pulverization, a grinding aid such as salt and sodium sulfate can be used.
[0096]
The grinding aid may be used 0.5 to 20 times, preferably 1 to 10 times the pigment. Further, the crystal of the pigment crystal produced by a known method can be controlled by acid pasting or by combining acid pasting with the above-mentioned dry pulverization or wet pulverization.
[0097]
As the acid used for the acid pasting, sulfuric acid is preferable, and a concentration (mass percent concentration) of 70 to 100%, preferably 95 to 100% is used, and the dissolution temperature is −20 to 100 ° C., preferably −20 to 100 ° C. 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, aqueous ammonia, or the like is used in an arbitrary amount. The temperature for the precipitation is not particularly limited, but is preferably cooled with ice or the like in order to prevent heat generation.
[0098]
Further, the content of the pigment is preferably 10 to 90% by mass, more preferably 40 to 70% by mass, based on the total mass of the charge generation layer 1. When the content of each pigment is less than the lower limit of the above numerical range, it becomes difficult to obtain sufficient sensitivity. On the other hand, when the content of each pigment exceeds the upper limit of the above numerical range, adverse effects such as a decrease in chargeability and a decrease in sensitivity tend to occur.
[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 used by selecting from a wide range of insulating resins. For example, preferred 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 Insulating resins such as resin, polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, and polyvinyl pyrrolidone resin can be given.
[0100]
As the binder resin for the charge generation layer 1, from the viewpoint of the dispersibility of the pigment, a polyvinyl acetal resin and a vinyl chloride-vinyl acetate copolymer are particularly preferably used. The above binder resins may be used alone or in combination of two or more.
[0101]
In the case of the charge generation layer 1, the compounding 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 is less than the value indicated by the above-mentioned mixing ratio with respect to the mass of the pigment, adverse effects such as poor film formability tend to occur. On the other hand, if the mass of the binder resin exceeds the mass ratio of the pigment, the content in the film becomes relatively small, so that the sensitivity tends to be insufficient.
[0102]
Further, the organic solvent contained in the coating solution for forming the charge generation layer 1 is a solvent capable of dissolving the binder resin and does not affect the crystal form of the pigment (charge generation substance). The solvent is not particularly limited as long as it is used, and a 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]
The same other additives as those described in the description of the undercoat layer 4 can be added to the charge generation layer 1 in order to improve its electric characteristics and image quality.
[0105]
Further, the thickness of the charge generation layer 1 is preferably 0.05 to 5 μm, more preferably 0.1 to 1 μm, in order to provide good electric characteristics and image quality. If the thickness of the charge generation layer 1 is less than 0.05 μm, sufficient sensitivity cannot be provided. On the other hand, when the thickness of the charge generation layer 1 exceeds 5 μm, adverse effects such as poor charging properties are likely to occur.
[0106]
The charge generation layer 1 is prepared by mixing a pigment (charge generation substance), an organic solvent, a binder resin, an additive (for example, a pigment dispersing aid) and the like to prepare a coating solution, and depositing the coating solution on the undercoat layer 4. It can be formed by coating and further drying. The charge generation layer 1 can also be formed by vacuum-depositing a charge generation substance on the undercoat layer 4.
[0107]
In order to prepare a coating liquid for forming the charge generation layer 1, it is mixed with a pigment, a binder resin, an organic solvent, and other additives (for example, a pigment dispersing aid). 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, and a paint shaker can be used.
[0108]
Further, from the viewpoint of film formability, the particle diameter of the dispersed particles such as the pigment contained in the coating liquid for forming the charge generation layer 1 is preferably 0.5 μm or less, and 0.3 μm or less. Is more preferable, and further preferably 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]
When the coating liquid for forming the charge generation layer 1 is coated on the undercoat layer 4, the coating method includes blade coating, wire bar coating, spray coating, dip coating, bead coating, 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)] Pyrazoline derivatives such as -3- (p-diethylaminostyryl) -5- (p-diethylaminostyryl) 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) fluorenone-2-amine, N, N'-diphenyl- Aromatic tertiary diamino compounds such as N, N'-bis (3-methylphenyl)-[1,1-biphenyl] -4,4'-diamine; L) -5,6-di- (4'-methoxyphenyl) -1,2,4-triazine and other 1,2,4-triazine derivatives, 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, 4-diphenyl Hydrazone derivatives such as aminobenzaldehyde-1,1-diphenylhydrazone, [p- (diethylamino) phenyl] (1-naphthyl) phenylhydrazone, quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline, 6-hydroxy-2, Benzofuran derivatives such as 3-di (p-methoxyphenyl) -benzofuran, α-stilbene derivatives such as p- (2,2-diphenylvinyl) -N, N′-diphenylaniline, enamine derivatives, N-ethylcarbazole and the like Carbazole derivative, poly-N-vinyl carbazole and derivatives thereof Hole transport materials, chloranyl, bromoanil, quinone compounds such as anthraquinone, tetracyanoquinodimethane compounds, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone, etc. Fluorenone compound, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3,4-oxa Oxadiazole compounds such as diazole, 2,5-bis (4-diethylaminophenyl) 1,3,4oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5′tetra-t- Electron transport substances such as diphenoquinone compounds such as butyl diphenoquinone;
[0112]
Furthermore, examples of the charge transporting material include polymers 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]
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 electric 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, carboxy-methyl cellulose, vinylidene chloride Polymer wax, polyurethane and the like.
[0115]
These binder resins can be used alone or in combination of two or more. In particular, polycarbonate resins, polyester resins, methacrylic resins, and acrylic resins are preferably used because they are excellent in compatibility with a charge transport substance, solubility in a solvent, and strength.
[0116]
Further, the mixing ratio (mass ratio) of the binder resin and the charge transport material can be arbitrarily set in consideration of a decrease in electric characteristics and a decrease in film strength. The thickness of the charge transport layer 2 is preferably from 5 to 50 μm, and more preferably from 10 to 35 μm.
[0117]
The charge transporting layer 2 can be formed by mixing a charge transporting substance, an organic solvent, a binder resin, and the like to prepare a coating solution, applying the coating solution on the charge generating layer 1, and further drying the coating solution.
[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 a liquid, a dispersion method such as a roll mill, a ball mill, a vibration ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker can be used.
[0119]
Further, 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 transport layer 2 is preferably 0.5 μm or less, and 0.3 μm or less. Is more preferable, and further preferably 0.15 μm or less. If the particle size of the dispersed particles exceeds 0.5 μm, the film formability of the charge transport layer 2 will be poor, and image quality defects will easily occur.
[0120]
Further, as a solvent used for a coating solution for forming the charge transport layer 2, a common organic solvent such as dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene can be used alone or in combination of two or more.
[0121]
As a method of applying the charge transport layer 2, a usual 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, a curtain coating method, or the like can be used.
[0122]
[Second embodiment]
FIG. 2 is a sectional view showing a second embodiment of the electrophotographic photoreceptor of the present invention. The electrophotographic photoconductor 110 shown in FIG. 2 has the same configuration as the electrophotographic photoconductor 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 containing the charge generation material and the charge transport material and other substances contained in the charge generation layer 1 and the charge transport layer 2 shown in FIG.
[0124]
When the photosensitive layer 6 is a single-layer type as described above, the content of the pigment is preferably 0.1 to 50% by mass, and more preferably 1 to 20% by mass based on the total mass of the photosensitive layer 6. More preferably, there is. On the other hand, if 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, adverse effects such as a decrease in chargeability and a decrease in sensitivity are likely to occur.
[0125]
When the photosensitive layer 6 is a single-layer type, 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. Further, these resins may be used by selecting from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene and polysilane. The above binder resins may be used alone or in combination of two or more.
[0126]
This photosensitive layer 6 is also prepared by coating the above-mentioned charge transporting substance, the above-mentioned charge transporting substance, the above-mentioned organic solvent, the binder resin and the like to prepare a coating solution, and 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 sectional view showing a third embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photosensitive member 120 shown in FIG. 3 has the same configuration as the electrophotographic photosensitive member 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 a chemical change of the charge transport layer 2 when the electrophotographic photosensitive member 120 is charged, and 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 an appropriate binder resin onto the photosensitive layer 6.
[0129]
The conductive material is not particularly limited. For example, a metallocene compound such as N, N′-dimethylferrocene, N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1, 1'-biphenyl] -4,4'-diamine and other aromatic amine compounds, molybdenum oxide, tungsten oxide, antimony oxide, tin oxide, titanium oxide, indium oxide, tin oxide and antimony, and barium sulfate and antimony oxide as a solid solution , A mixture of the above metal oxides, a mixture of the above metal oxides in a single particle of titanium oxide, tin oxide, zinc oxide or barium sulfate, or titanium oxide, tin oxide, zinc oxide or barium sulfate In which the above-mentioned metal oxide is coated in single particles of the above.
[0130]
Examples of the binder resin used for the protective layer 5 include a polyamide resin, a polyvinyl acetal resin, a polyurethane resin, a polyester resin, an epoxy resin, a polyketone resin, a polycarbonate resin, a polyvinyl ketone resin, a polystyrene resin, a polyacrylamide resin, a polyimide resin, and a polyamideimide resin. And other known resins. These can be used by cross-linking each other if necessary.
[0131]
Further, the protective layer 5 can also be formed of a charge transporting polymer compound. The layer containing the charge-transporting polymer compound may be a polymer compound having a group having a charge-transporting ability such as polyvinylcarbazole in a side chain, or a charge-transporting polymer such as disclosed in JP-A-5-232727. And high molecular compounds containing a functional group in the main chain, and polysilanes. Further, as the charge transporting polymer compound, a block copolymer or a graft copolymer comprising a charge transporting block and an insulating block can also be used.
[0132]
Further, when the charge-transporting polymer compound contains a triarylamine structure as a repeating unit, it is preferable because it has high charge-transporting ability and preferable mechanical properties, and the triarylamine structure is not a pendant type. , Is more preferable when it is contained in the main chain. In the case of the pendant type, the pendants often associate with each other to form a charge trap and deteriorate the charge transporting property. However, such a problem can be avoided by being contained in the main chain. Further, it is particularly preferable that the triarylamine structure contains at least one kind of a structure represented by the following formula (7) or (8) as a repeating unit.
[0133]
Embedded image

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

[0136]
Here, in the formula (8), Ar ³ And Ar ⁴ Each independently represents a substituted or unsubstituted aryl group; ² Represents a trivalent hydrocarbon group having an aromatic ring structure or a hetero atom-containing hydrocarbon group.
[0137]
Further, as described above, in the above formula (7), Ar ¹ And Ar ² Are each 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, X in the above equation (7) ¹ Is selected from a divalent hydrocarbon group having an aromatic ring structure and a heteroatom-containing hydrocarbon group. Specific examples include a phenylene group, a biphenylene group, a terphenylene group, a naphthylene group, a methylenediphenyl group, a cyclohexylidenediphenyl group, an oxydiphenyl group, a thiodiphenyl group, and the like, and methyl-substituted, ethyl-substituted, and methoxy-substituted thereof. And substituted or unsubstituted biphenylene groups. Of these, a substituted or unsubstituted biphenylene group is particularly preferred from the viewpoint of charge transportability.
[0139]
Further, as described above, X in the above equation (7) ² And X ³ Are each independently selected from substituted or unsubstituted arylene groups, specifically, phenylene group, biphenylene group, terphenylene group, naphthylene group and the like, and methyl-substituted, ethyl-substituted, methoxy-substituted, or And halogen-substituted products.
[0140]
Further, as described above, L in the above equation (7) ¹ Is selected from a divalent hydrocarbon group or a heteroatom-containing hydrocarbon group which may have a branched or ring structure, and is optional as long as it exhibits at least one of the above-mentioned preferable properties, but is preferably an ether bond or an ester bond. It is preferable that the compound has a bonding group selected from a group consisting of, a carbonate bond, a siloxane bond and the like, and has 20 or less carbon atoms. Specific examples thereof include those represented by the following formulas (9) to (16).
[0141]
Embedded image

[0142]
Further, as described above, in the above formula (8), Ar ³ And Ar ⁴ Are each 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 an alkyl group or an alkoxy group having 1 to 12 carbon atoms, a diarylamino group, and a halogen atom.
[0143]
Further, as described above, L in the above equation (8) ² Is selected from a trivalent hydrocarbon group having an aromatic ring structure or a heteroatom-containing hydrocarbon group, and is optional as long as it exhibits at least one of the above preferable characteristics. . Specific examples thereof include those represented by the following formulas (17) to (21).
[0144]
Embedded image

[0145]
Embedded image

[0146]
Also, L in the above equation (7) ¹ Or L in the formula (8) ² Is particularly preferred in the present invention when it has an ester bond, because it has excellent mechanical properties and excellent charge transport ability.
[0147]
The thickness of the protective layer 5 is preferably from 1 to 20 μm, more preferably from 2 to 10 μm. Examples of a method of applying the coating solution for forming the protective layer 5 include ordinary coating 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, and a curtain coating method. A method can be used.
[0148]
As a solvent used for a coating solution for forming the protective layer 5, a common organic solvent such as dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene can be used alone or as a mixture of two or more. It is preferable to use a solvent that hardly dissolves the photosensitive layer 6 to which the coating liquid is applied as much as possible.
[0149]
[Fourth embodiment]
FIG. 4 is a sectional view showing a fourth embodiment of the electrophotographic photoreceptor of the present invention. The electrophotographic photosensitive member 130 shown in FIG. 4 has the same configuration as the electrophotographic photosensitive member 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 photosensitive member 140 shown in FIG. 5 has the same configuration as the electrophotographic photosensitive member 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 for improving the electrical characteristics of the photoconductor 140, improving the image quality, and improving the adhesiveness of the photosensitive layer 6.
[0151]
The constituent material of the intermediate layer 42 is not particularly limited, and can be arbitrarily selected from a synthetic resin, an organic or inorganic substance powder, an electron transporting substance, and the like.
[0152]
Examples of the synthetic resin of the intermediate layer 42 include an acetal resin such as polyvinyl butyral, a polyvinyl alcohol resin, a casein, a polyamide resin, a cellulose resin, a gelatin, a polyurethane resin, a polyester resin, a methacryl resin, an acrylic resin, a polyvinyl chloride resin, and a 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 an organic titanium compound and a silane coupling agent can be used.
[0153]
These compounds can be used alone or as a mixture or a polycondensate of a plurality of compounds. Among them, the zirconium chelate compound and the silane coupling agent are excellent in performance such as low residual potential, little change in potential due to environment, and little change in potential due to repeated use.
[0154]
Examples of the silane coupling agent 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 that are 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 thereof include silane coupling agents such as N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane.
[0156]
Examples of zirconium chelate compounds include zirconium butoxide, ethyl zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl zirconium butoxide acetoacetate, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, and naphthenic acid. Examples include zirconium, zirconium laurate, zirconium stearate, zirconium isostearate, zirconium butoxide methacrylate, zirconium butoxide stearate, and zirconium butoxide isostearate.
[0157]
Examples of the titanium chelate compound 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 triethanol aminate, polyhydroxytitanium stearate and the like can be mentioned.
[0158]
Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxyaluminum diisopropylate, aluminum butyrate, diethylacetoacetate aluminum diisopropylate, and aluminum tris (ethylacetoacetate).
[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 electric 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 such as alumina, calcium carbonate, and barium sulfate; and Teflon resin particles, benzoguanamine resin particles, and styrene resin particles Etc. are effective.
[0160]
The particle size of the added fine powder is 0.01 to 2 μm. The fine powder is added as needed, and the amount added is preferably from 10 to 90% by mass, and more preferably from 30 to 80% by mass, based on the total mass of the solid content of the intermediate layer 42. Is more preferable.
[0161]
It is also effective to include the above-described electron-transporting substance, electron-transporting pigment, and the like in the intermediate layer 42 from the viewpoint of lowering residual potential and environmental stability. Further, 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 to perform a dispersion treatment. As the dispersion treatment method, a method such as a roll mill, a ball mill, a vibration 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 the coating solution. As a coating method at this time, a usual 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, a curtain coating method, or the like can be used.
[0164]
[Sixth embodiment]
FIG. 6 is a sectional view showing a sixth embodiment of the electrophotographic photoreceptor of the present invention. The electrophotographic photoconductor 150 shown in FIG. 6 has the same structure as the electrophotographic photoconductor 100 shown in FIG. 1 except that 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. It has a similar configuration.
[0165]
The intermediate layer 42 has the same configuration as the photoconductor 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 photoreceptor 160 shown in FIG. 7 is the same as the electrophotographic photoreceptor shown in FIG. 1 except that the protective layer 5 is provided on the photosensitive layer 6 and the intermediate layer 42 is provided between the photosensitive layer 6 and the undercoat layer 4. It has the same configuration as 100.
[0167]
The intermediate layer 42 has the same configuration as the intermediate layer 42 of the photoconductor 140 shown in FIG. The protective layer 5 has the same configuration as the protective layer 5 of the photoconductor 120 shown in FIG.
[0168]
[Eighth Embodiment]
FIG. 8 is a sectional view showing a seventh embodiment of the electrophotographic photosensitive member of the present invention.
The electrophotographic photoreceptor 170 shown in FIG. 8 has the exception 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. It has the same configuration as the electrophotographic photoreceptor 100 shown in FIG.
[0169]
The intermediate layer 42 has the same configuration as the intermediate layer 42 of the photoconductor 140 shown in FIG. The protective layer 5 has the same configuration as the protective layer 5 of the photoconductor 120 shown in FIG. Further, the photosensitive layer 6 has the same configuration as the photosensitive layer 6 of the photoconductor 110 shown in FIG.
[0170]
As described above, the preferred embodiment of the electrophotographic photosensitive member of the present invention has been described in detail, but the electrophotographic photosensitive member 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 according to the present invention has a two-layer structure such as the photosensitive members 100, 120, and 140 shown in FIGS. 1, 3, and 5, FIGS. In any of the single-layer structures like the photoconductors 110, 130, and 150 shown in FIG. 6, deterioration of the photoconductor due to ozone or oxidizing gas generated in the electrophotographic apparatus, or light or heat is prevented. 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 antioxidants include phenolic antioxidants such as 2,6-di-t-butyl-4-methylphenol, styrenated phenol, and n-octadecyl-3- (3 ′, 5′-diphenol. -Tert-butyl 4'-hydroxyphenyl) -propionate, 2,2'-methylene-bis- (4-methyl-6-tert-butylphenol), 2-tert-butyl-6- (3'-tert-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-tert-butyl-4'-hydroxy-phenyl) propionate] -methane, 3,9-bis [2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1 , 1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane.
[0174]
As the hindered amine compound, 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-tetramethylpiperyl succinate Polycondensate, poly [[6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diimyl]] [(2,2,6,6-tetra Methyl-4-piperidyl) imino] hexamethylene [(2,3,6,6-tetramethyl-4-piperidyl) imino]], 2- (3,5-di-t-butyl-4-hydroxybenzyl)- Bis (1,2,2,6,6-pentamethyl-4-piperidyl) 2-n-butylmalonate, N, N'-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl- N- (1,2,2,6,6-pentamethyl-4piperidyl) amino] -6-chloro-1,3,5-triazine condensate and the like.
[0175]
Examples of the organic sulfur-based antioxidants include dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, and pentaerythritol-tetrakis. -(Β-lauryl-thiopropionate), ditridecyl-3,3′-thiodipropionate, 2-mercaptobenzimidazole and the like. Examples of the organophosphorus antioxidant include trisnonylphenyl phosphite, triphenyl phosphite, and tris (2,4-di-t-butylphenyl) -phosphite.
[0176]
The 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 a phenol-based or amine-based primary antioxidant.
[0177]
Examples of the light stabilizer include benzophenone-based, benzotriazole-based, dithiocarbamate-based, and tetramethylpiperidine-based derivatives. For example, examples of the benzophenone-based light stabilizer include 2-hydroxy-4-methoxy benzophenone, 2-hydroxy-4-octoxy benzophenone, and 2,2′-di-hydroxy-4-methoxy benzophenone.
[0178]
Examples of benzotriazole-based light stabilizers include 2-(-2′-hydroxy-5′methylphenyl-)-benzotriazole and 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'-hydroxy3 ', 5'-di-t-amylphenyl-)-benzotriazole Etc. That.
[0179]
Other compounds include 2,4, di-t-butylphenyl 3 ′, 5′-di-t-butyl-4′-hydroxybenzoate, nickel dibutyl-dithiocarbamate, and the like.
[0180]
Further, the photosensitive layer 6 can contain at least one type of electron accepting substance for the purpose of improving sensitivity, reducing residual potential, reducing fatigue when repeatedly used, and the like.
[0181]
Examples of usable electron accepting substances include, for example, succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, and m-dinitrobenzene. Examples include dinitrobenzene, chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, phthalic acid and the like.
[0182]
Among them, fluorenone type, quinone type, -Cl, -CN, -NO ₂ A benzene derivative having an electron-withdrawing substituent such as described above is particularly preferably used. Further, a slight 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 photoreceptor of the present invention described above is a laser beam printer that emits near-infrared light or visible light, a digital copying machine, an LED printer, an electrophotographic apparatus such as a laser facsimile, 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 a reversal developer. Further, the electrophotographic photoreceptor of the present invention can provide good characteristics with less current leakage even when mounted on a contact charging type electrophotographic apparatus using a charging roller or a charging brush.
[0184]
Next, an electrophotographic apparatus and a process cartridge on which the electrophotographic photosensitive member of the present invention is mounted will be described.
[0185]
FIG. 9 is a sectional view schematically showing a basic configuration of a preferred embodiment of the electrophotographic apparatus of the present invention. The electrophotographic apparatus 200 shown in FIG. 9 includes an electrophotographic photosensitive member 7, a charging unit 8 such as a corotron or a scorotron for charging the electrophotographic photosensitive member 7 by a corona discharge method, a power supply 9 connected to the charging unit 8, Exposure means 10 for exposing the electrophotographic photoreceptor 7 charged by the charging means 8 to form an electrostatic latent image, and developing the electrostatic latent image formed by the exposure means 10 with toner to form a toner image 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 sectional view schematically showing a basic configuration of another embodiment of the electrophotographic apparatus of the present invention shown in FIG.
[0187]
The electrophotographic apparatus 210 shown in FIG. 10 has the same configuration as the electrophotographic apparatus 200 shown in FIG. 9 except that the electrophotographic apparatus 210 includes a charging unit 8 for charging the electrophotographic photosensitive member 7 by a contact method. In particular, an electrophotographic apparatus that employs a contact-type charging unit in which an AC voltage is superimposed on a DC voltage can be preferably used because it has excellent wear resistance. In this case, in some cases, the static eliminator 14 is not provided.
[0188]
The charging means (charging member) 8 is arranged so as to be in contact with the surface of the photoreceptor 7, applies a voltage to the photoreceptor uniformly, and charges the photoreceptor surface 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 in which metal oxide particles such as carbon black, copper iodide, silver iodide, zinc sulfide, silicon carbide, and metal oxide are dispersed in an elastomer material such as rubber and butadiene rubber can be used.
[0189]
Examples of this metal oxide include ZnO, SnO ₂ , TiO ₂ , In ₂ O ₃ , MoO ₃ Or a composite oxide thereof. Further, the charging means 8 may be a material obtained by adding a perchlorate to an elastomer material to impart conductivity.
[0190]
Further, the charging means 8 may be provided with a coating layer on its surface. As the material for forming the coating layer, N-alkoxymethylated nylon, cellulose resin, vinylpyridine resin, phenol resin, polyurethane, polyvinyl butyral, melamine and the like are used alone or in combination. Further, an emulsion resin-based material, for example, an acrylic resin emulsion, a polyester resin emulsion, or a polyurethane, particularly, an emulsion resin synthesized by soap-free emulsion polymerization can be used.
[0191]
To these resins, conductive agent particles may be dispersed for further adjusting the resistivity, or an antioxidant may be contained for preventing deterioration. Further, in order to improve the film forming property 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]
Further, the electric resistance value of the charging means 8 is preferably 10 ² -10 ¹⁴ Ωcm, more preferably 10 ² -10 ¹² The range of Ωcm is good. The voltage applied to the contact charging member may be either direct current or alternating current. Alternatively, the voltage can be applied in the form of DC + AC.
[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 electrophotographic apparatus of an intermediate transfer system. Four electrophotographic photosensitive members 401 a to 401 d are arranged in a housing 400 in parallel with each other along an intermediate transfer belt 409.
[0194]
Here, the electrophotographic photosensitive members 401a to 401d mounted on the electrophotographic apparatus 220 are the electrophotographic photosensitive members of the present invention, respectively. For example, the above-described electrophotographic photosensitive member 100, electrophotographic photosensitive member 110, electrophotographic photosensitive member 120, electrophotographic photosensitive member 130, electrophotographic photosensitive member 140, electrophotographic photosensitive member 150, electrophotographic photosensitive member 160, electrophotographic Any of the photoconductors 170 may be mounted.
[0195]
Each of the electrophotographic photosensitive members 401a to 401d is rotatable in a predetermined direction (counterclockwise on the paper), and along the rotating direction, charging rolls 402a to 402d, developing devices 404a to 404d, and primary transfer roll 410a. To 410d and cleaning blades 15a to 15d. Each of the developing devices 404a to 404d can be supplied with four color toners of black, yellow, magenta, and cyan stored in toner cartridges 405a to 405d, and the primary transfer rolls 410a to 410d are respectively provided with intermediate transfer belts. 409, it contacts the electrophotographic photosensitive members 401a to 401d.
[0196]
Further, a laser light source (exposure means) 403 is disposed at a predetermined position in the housing 400, and irradiates the laser light emitted from the laser light source 403 to the surfaces of the charged electrophotographic photosensitive members 401a to 401d. Is possible. Thus, in the rotation process of the electrophotographic photosensitive members 401a to 401d, the respective processes of charging, exposure, development, primary transfer, and cleaning are sequentially performed, and the toner images of each color are transferred onto the intermediate transfer belt 409 in a superimposed manner.
[0197]
The intermediate transfer belt 409 is supported with a predetermined tension by a driving roll 406, a backup roll 408, and a tension roll 407, and is rotatable without bending due to 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 that has passed between the backup roll 408 and the secondary transfer roll 413 is cleaned by the cleaning blade 14 and then repeatedly used for 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 moved by the transfer roll 412 to the intermediate transfer belt 409 and the secondary transfer roll. 413, and further between the two fixing rolls 414 that are in contact with each other, and then are discharged outside the housing 400.
[0199]
FIG. 12 is a 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 means 8, the developing means 11, the cleaning device (cleaning means) 13, the opening 18 for exposure, and the static eliminator 14 using the mounting rail 16, and It is integrated.
[0200]
The process cartridge 300 is detachable from an electrophotographic apparatus main body including the transfer unit 12, the fixing device 15, and other components (not shown). 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 photosensitive members of Examples 1 to 4 and Comparative Examples 1 to 4 having the same configuration as the electrophotographic photosensitive member 100 shown in FIG.
[0203]
(Example 1)
A photoreceptor having the same configuration as the electrophotographic photoreceptor 100 shown in FIG. 1 was produced by the following procedure.
[0204]
Tin oxide (trade name: S1, manufactured by Mitsubishi Materials, specific surface area: 50m) ² / G) was dried by heating at 150 ° C for 5 hours in the air 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 stirred and mixed with 500 parts by mass of toluene, and 15 parts by mass of a silane coupling agent (trade name: A1100, manufactured by Nippon Unicar) was added, followed by stirring for 5 hours. Thereafter, toluene was distilled off under reduced pressure and baked at 100 ° C. for 2 hours.
[0205]
Next, 35 parts by mass of the obtained tin oxide particles after surface treatment, 15 parts by mass of a curing agent (blocked isocyanate sumidur 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.), and 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]
0.005 parts by mass of dioctyltin dilaurate as a catalyst and 0.01 parts by mass of silicone oil SH29PA (manufactured by Toray Dow Corning Silicone Co., Ltd.) were added to the resulting dispersion to obtain a coating solution for an undercoat layer. . 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, and is dried and cured at 160 ° C. for 100 minutes to obtain a layer having a thickness of 20 μm. A pull layer was formed.
[0207]
Next, a photosensitive layer having a two-layer structure was formed on the undercoat layer. First, the position where the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα ray as the charge generating substance is at least 7.4 °, 16.6 °, 25.5 °, 28.3 °. A mixture comprising: 15 parts by mass of gallium chloride phthalocyanine having a diffraction peak at 10 parts by mass, 10 parts by mass of a vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Nippon Unicar) serving as a binder resin, and 300 parts by mass of n-butyl alcohol The mixture was dispersed in a sand mill using glass beads of 1 mmφ for 4 hours.
[0208]
The resulting dispersion was applied onto the undercoat layer by dip coating as a coating liquid for forming a charge generation layer, followed by drying to form a charge generation layer having a thickness of 0.2 μm.
[0209]
Further, N, N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1 '] diphenyl-4,4'-diamine: 4 parts by mass and a bisphenol Z polycarbonate resin (viscosity average molecular weight (40,000): 6 parts by mass and chlorobenzene: 80 parts by mass. The obtained dispersion was applied by dip coating on the charge generation layer as a coating liquid for forming a charge transport layer, and dried at 130 ° C. for 40 minutes to form a charge transport layer having a thickness of 25 μm.
[0210]
(Example 2)
A photoreceptor having the same configuration as the electrophotographic photoreceptor 100 shown in FIG. 1 was produced by the following procedure.
[0211]
Titanium oxide (trade name: TAF500J, manufactured by Fuji Titanium Co., specific surface area: 18m) ² / G) was dried by heating at 150 ° C for 5 hours in the air 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 2 parts by mass of a silane coupling agent (trade name: KBM503, manufactured by Shin-Etsu Chemical Co., Ltd.) was added thereto, and 10 parts by mass was added. Stirred for minutes. Thereafter, toluene was distilled off under reduced pressure and baked at 170 ° C. for 2 hours.
[0212]
Next, 50 parts by mass of the obtained surface-treated titanium oxide particles, 15 parts by mass of a curing agent (blocked isocyanate Sumidule 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.), and butyral resin BM-1 (manufactured by Sekisui Chemical Co., Ltd.) ): 6 parts by mass and methyl ethyl ketone: 60 parts by mass were mixed and dispersed in a sand mill for 4 hours using 1 mmφ glass beads to obtain a dispersion.
[0213]
0.005 parts by mass of dioctyltin dilaurate as a catalyst and 0.01 parts by mass of silicone oil SH29PA (manufactured by Toray Dow Corning Silicone Co., Ltd.) were added to the resulting dispersion to obtain a coating solution for an undercoat layer. . 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, and is dried and cured at 160 ° C. for 100 minutes to obtain a layer having a thickness of 20 μm. A pull 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 photosensitive member.
[0215]
(Example 3)
A photoreceptor having the same configuration as the electrophotographic photoreceptor 100 shown in FIG. 1 was produced by the following procedure.
[0216]
Zinc oxide (average particle diameter 70 μm, prototype manufactured by Teica, specific surface area: 15 m ² / G) was dried by heating at 150 ° C for 5 hours in the air 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 stirred and 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.
[0219]
Next, 60 parts by mass of the obtained zinc oxide particles after surface treatment, 15 parts by mass of a curing agent (blocked isocyanate Sumidur 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.), and butyral resin BM-1 (manufactured by Sekisui Chemical Co., Ltd.) ): 15 parts by mass and methyl ethyl ketone: 85 parts by mass. The obtained liquid: 8 parts by mass and methyl ethyl ketone: 25 parts by mass were mixed and dispersed for 2 hours by a sand mill using 1 mmφ glass beads to obtain a dispersion.
[0218]
0.005 parts by mass of dioctyltin dilaurate as a catalyst and 0.01 parts by mass of silicone oil SH29PA (manufactured by Toray Dow Corning Silicone Co., Ltd.) were added to the resulting dispersion to obtain a coating solution for an undercoat layer. . 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, and is dried and cured at 160 ° C. for 100 minutes to obtain a layer having a thickness of 20 μm. A pull layer was formed.
[0219]
Next, a photosensitive layer having a two-layer structure was formed on the undercoat layer. First, a position where the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα ray as a charge generating substance is at least 7.3 °, 16.0 °, 24.9 °, 28.0 °. A mixture consisting of 15 parts by mass of hydroxygallium phthalocyanine having a diffraction peak at 10 parts by mass, 10 parts by mass of a vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Nippon Unicar) serving as a binder resin, and 300 parts by mass of n-butyl acetate The mixture was dispersed in a sand mill using glass beads of 1 mmφ for 4 hours.
[0220]
The resulting dispersion was applied onto the undercoat layer by dip coating as a coating liquid for forming a charge generation layer, followed by drying to form a charge generation layer having a 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 photoreceptor having the same configuration as the electrophotographic photoreceptor 100 shown in FIG. 1 was produced by the following procedure.
[0222]
Zinc oxide (trade name: MZ300, manufactured by Teica, specific surface area: 40 m ² / G) was dried by heating at 150 ° C for 5 hours in the air 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 with stirring, and 5 parts by mass of a silane coupling agent (trade name: KBM403, 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.
[0223]
Next, 60 parts by mass of zinc oxide after surface treatment, 15 parts by mass of a curing agent (blocked isocyanate sumidur 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.), and 15 of butyral resin BM-1 (manufactured by Sekisui Chemical Co., Ltd.): Parts 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 by a sand mill using 1 mmφ glass beads to obtain a dispersion.
[0224]
0.005 parts by mass of dioctyltin dilaurate as a catalyst and 0.01 parts by mass of silicone oil SH29PA (manufactured by Toray Dow Corning Silicone Co., Ltd.) were added to the resulting dispersion to obtain a coating solution for an undercoat layer. . 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, and is dried and cured at 160 ° C. for 100 minutes to obtain a layer having a thickness of 20 μm. A pull layer was formed.
[0225]
Next, a photosensitive layer having a two-layer structure was formed on the undercoat layer. First, 15 parts by mass of oxytitanyl phthalocyanine having a diffraction peak at a position where the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα ray as a charge generating substance is at least 27.3 °: binder resin A mixture of 10 parts by mass of a 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 resulting dispersion was applied onto the undercoat layer by dip coating as a coating liquid for forming a charge generation layer, followed by drying to form a charge generation layer having a 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 used metal oxide particles 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 used metal oxide particles 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 used metal oxide particles 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 used metal oxide particles was 1.3% by mass.
[0231]
[Electrophotographic Photoconductor Evaluation Test]
(1) Characteristic evaluation at the beginning of use (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 (model: XP-15, manufactured by Fuji Xerox Co., Ltd.) having a structure similar to that of FIG. The electrophotographic photosensitive member was mounted, and the electrophotographic characteristics of each electrophotographic photosensitive member were evaluated as follows.
[0232]
In a normal temperature and normal humidity (20 ° C., 40% RH) environment, the potential A [V] on the surface of each electrophotographic photosensitive member when each electrophotographic photosensitive member is charged by a scorotron charger with a grid application voltage of −700 V is measured. did. Next, using a 780 nm semiconductor laser, each electrophotographic photoreceptor was charged 10 mJ / m 1 second after charging. ² To discharge electricity, and the potential B [V] on the surface of each electrophotographic photosensitive member at this time was measured. Subsequently, 50 mJ / m was applied to each electrophotographic photosensitive member 3 seconds after the discharge. ² Of the electrophotographic photoreceptor was measured at this time, and the potential C [V] on the surface of each electrophotographic photosensitive member was measured.
[0233]
Here, the higher the value of the potential A, the higher the received potential of the electrophotographic photosensitive member, so that a higher contrast can be obtained. The lower the value of the potential B, the higher the sensitivity of the electrophotographic photosensitive member. Furthermore, the lower the value of the potential C, the lower the residual potential, and the image memory and the electrophotographic photoreceptor having less so-called fog are evaluated. Table 1 shows the results.
[0234]
(2) Initial (after 10 prints) image quality evaluation
The electrophotographic photoreceptors of Examples 1 to 4 and Comparative Examples 1 to 4 were obtained by contacting a charging device having a structure similar to that shown in FIG. 11 and a full-color printer having an intermediate transfer device (trade name: Docu Center Color 400, Fuji, Japan). (Manufactured by Xerox Corporation), and a continuous print test on 10 sheets of paper was performed.
[0235]
The image quality after printing 10 sheets was “No abnormality”; good image quality was obtained; “Fog slightly occurred”; 20 or less fine black spots in a 100 mm × 200 mm area of the paper surface, “Fog occurred” The evaluation was made based on the evaluation criteria that 1000 or more fine black spots could be confirmed in a range of 100 mm × 200 mm. Table 1 shows the results.
[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. Table 1 shows the results.
[0237]
(4) Stability evaluation against changes in usage environment
The above operation was performed under 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 values of the potentials A to C between these different environments were measured, and the stability of each electrophotographic photosensitive member against a change in the use environment was evaluated. Table 1 shows the results.
[0238]
(5) Image quality evaluation after printing 10,000 sheets
The electrophotographic photoreceptors of Examples 1 to 4 and Comparative Examples 1 to 4 were obtained by contacting a charging device having a structure similar to that shown in FIG. 11 and a full-color printer having an intermediate transfer device (trade name: Docu Center Color 400, Fuji, Japan). (Manufactured by Xerox Corporation), and a continuous print test on 10,000 sheets of paper was performed.
[0239]
The image quality after printing 10,000 sheets is “No abnormality”; good image quality was obtained; “overall fogging”; fine black spots were observed on the entire surface of the paper; “black spots occurred”; large black spots on the paper It was evaluated under the evaluation criteria of Table 1 shows the results.
[0240]
[Table 1]

[0241]
【The invention's effect】
As described above, according to the present invention, it has high durability and 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 manufacturing the same can be provided. By providing such an electrophotographic photoreceptor, it is possible to provide a process cartridge and an electrophotographic apparatus capable of obtaining high resolution quality even when repeatedly used for a long time.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a first embodiment of an electrophotographic photosensitive member of the present invention.
FIG. 2 is a cross-sectional view illustrating a second embodiment of the electrophotographic photosensitive member of the present invention.
FIG. 3 is a cross-sectional view illustrating 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 sectional view showing a fifth embodiment of the electrophotographic photosensitive member of the present invention.
FIG. 6 is a sectional view showing a sixth embodiment of the electrophotographic photosensitive member of the present invention.
FIG. 7 is a 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 sectional view schematically showing a basic configuration of a preferred embodiment of the electrophotographic apparatus of the present invention.
FIG. 10 is a 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 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 generation layer, 3 ... Conductive support layer, 4 ... Undercoat layer, 5 ... Protective layer, 6 ... Photosensitive layer, 7 ... Electrophotographic photoreceptor, 8 ... Charging means, 9 ... Power supply, 10 ... Exposure means , 11: developing means, 12: transferring means, 13: cleaning device, 14: static eliminator, 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 to 401d: electrophotographic photosensitive member, 402a to 402d,. Charging roller, 403: laser light source (exposure device), 404a to 404d: developing device, 405a to 405d: toner cartridge, 406: driving roll, 407 Tension roll 408 Backup roll 409 Intermediate transfer belt 410a to 410d Primary transfer roll 411 Tray (transfer tray) 412 Transfer roll 413 ... Secondary transfer roll, 414 ... Fixing roll, 500 ... Transfer medium.

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 using an organometallic compound having a hydrolyzable functional group,
The water content of the metal oxide particles before the surface treatment is performed is 1.0% by mass or less;
An electrophotographic photosensitive member characterized by the following. The electrophotographic photoreceptor 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. 3. The electrophotographic photoconductor according to claim 1, wherein the hydrolyzable organometallic compound is a silane coupling agent. The electrophotographic photoreceptor according to any one of claims 1 to 3, wherein a thickness of the undercoat layer is more than 15 m and 50 m or less. 5. The electrophotographic photoconductor according to claim 1, wherein the pigment contained in the photosensitive layer is a phthalocyanine pigment. 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 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,
The metal oxide particles having a water content of 1% by mass or less are subjected to a surface treatment with an organometallic compound having a hydrolyzable functional group, and then the undercoat layer is treated with the particles obtained by the surface treatment. Including the step of forming
A method for producing an electrophotographic photosensitive member, comprising: The method 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. 9. The method according to claim 7, wherein the hydrolyzable organometallic compound is a silane coupling agent. The method according to any one of claims 7 to 9, wherein the thickness of the undercoat layer is adjusted to be more than 15 m and not more than 50 m. The method according to any one of claims 7 to 10, wherein the pigment contained in the photosensitive layer is a phthalocyanine pigment. The electrophotographic photoreceptor according to claim 11, wherein the phthalocyanine-based pigment is at least one selected from the group consisting of hydroxygallium phthalocyanine, chlorogallium phthalocyanine, dichlorotin phthalocyanine, oxotitanyl phthalocyanine, and phthalocyanine. Production method. An electrophotographic photosensitive member according to any one of claims 1 to 6,
A process cartridge having at least one of a charging unit, a developing unit, a cleaning unit, and a discharging unit, and being detachable from a main body of the electrophotographic apparatus. An electrophotographic photosensitive member according to any one of claims 1 to 6,
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,
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 system of the transfer unit is an intermediate transfer system in which the toner image is primarily transferred to an intermediate transfer member, and a primary transfer image on the intermediate transfer member is secondarily transferred to the transfer medium. The electrophotographic apparatus according to claim 14, wherein:

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