JP4113451B2 - Electrophotographic photoreceptor, method for producing the same, and image forming apparatus and process cartridge using the same - Google Patents

Description

一般的に低ブチラール・アセタール化で低分子量の樹脂は接着性に優れている。ブチルアルデヒドにてアセタール化した樹脂を中間層に用いると、高温高湿又は低温低湿環境下における電位変動等の環境安定性が向上するが、電荷輸送層との接着性が低下する。しかしながら、ブチルアルデヒド以外のアルデヒドにてアセタール化した樹脂を混合すると、電荷輸送層との接着性が向上し、高温高湿又は低温低湿環境化における電位変動等の環境安定性も満足するものとなる。
【００１６】
【発明の実施の形態】
本発明の第１の態様に係る電子写真用感光体は、導電性支持体上に、少なくとも電荷発生層、中間層、電荷輸送層の順に積層してなる電子写真用感光体において、前記電荷発生層が有機顔料の蒸着膜であり、前記中間層に、ポリビニルアルコールをブチルアルデヒドにてアセタール化した樹脂（Ｉ）とブチルアルデヒド以外のアルデヒドにてアセタール化した樹脂（ＩＩ）を含有する構成を採る。
【００１７】
この構成によれば、有機顔料の蒸着膜からなる電荷発生層上に、ポリビニルアルコールをブチルアルデヒドにてアセタール化した樹脂（Ｉ）と、ブチルアルデヒド以外のアルデヒドにてアセタール化した樹脂（ＩＩ）とからなる中間層を形成することで、電荷輸送層との接着性を向上しつつ、高温高湿又は低温低湿環境化における電位変動等の環境安定性をも向上することができる。この結果、環境安定性に優れ、かつ、導電性支持体との接着性に優れた電子写真用感光体を実現することができる。
【００１８】
本発明の第２の態様は、第１の態様に係る電子写真用感光体において、前記電荷発生層の有機顔料蒸着膜と前記中間層の樹脂の質量比が１対１〜２の範囲である構成を採る。
【００１９】
この構成によれば、電荷発生層の有機顔料蒸着膜の質量１に対する中間層の樹脂の質量比を０．５〜３の範囲に含めることで、より環境安定性に優れ、かつ、導電性支持体との接着性に優れた電子写真用感光体を実現することができる。
【００２４】
本発明の第３の態様に係る電子写真用感光体の製造方法は、導電性支持体上に、少なくとも電荷発生層、中間層、電荷輸送層の順に積層してなる電子写真用感光体の製造方法において、加熱気化させた有機顔料を導電性支持体上に蒸着することにより前記電荷発生層を形成する工程と、さらにポリビニルアルコールをブチルアルデヒドにてアセタール化した樹脂（Ｉ）とブチルアルデヒド以外のアルデヒドにてアセタール化した樹脂（ＩＩ）からなる塗料を用いて前記中間層を形成する工程とを含むようにしたものである。
【００２５】
この方法によれば、有機顔料の蒸着膜からなる電荷発生層上に、ポリビニルアルコールをブチルアルデヒドにてアセタール化した樹脂（Ｉ）と、ブチルアルデヒド以外のアルデヒドにてアセタール化した樹脂（ＩＩ）とからなる中間層を形成することで、電荷輸送層との接着性を向上しつつ、高温高湿又は低温低湿環境化における電位変動等の環境安定性をも向上することができる。この結果、環境安定性に優れ、かつ、導電性支持体との接着性に優れた電子写真用感光体を製造することができる。
【００２６】
本発明の第４の態様は、第３の態様に係る電子写真用感光体の製造方法において、前記電荷発生層の有機顔料蒸着膜と前記中間層の樹脂との質量比が１対１〜２の範囲であるものである。
【００２７】
この方法によれば、電荷発生層の有機顔料蒸着膜の質量１に対する中間層の樹脂の質量比を１〜２の範囲に含めることで、より環境安定性に優れ、かつ、導電性支持体との接着性に優れた電子写真用感光体を製造することができる。
【００３２】
本発明の第５の態様に係る画像形成装置は、電子写真用感光体を用い、帯電、像露光、現像、転写・分離、クリーニング工程を経て画像形成を行う画像形成装置において、第１、２の態様のいずれかの電子写真用感光体を用いる構成を採る。
【００３３】
この構成によれば、画像形成装置において、第１、２の態様のいずれかの電子写真用感光体が奏する効果を得ることができる。この結果、どのような環境下でも安定した画像が得ることができる画像形成装置を実現することができる。
【００３４】
本発明の第６の態様は、第５の態様に係る画像形成装置において、前記電子写真用感光体と現像工程に用いられる現像ローラとの間隔を保持する部材が、当該電子写真用感光体の最表面層で接触する構成を採る。
【００３５】
この構成によれば、電子写真用感光体と現像ローラとの間隔を保持する部材を当該電子写真用感光体の最表面層で接触させるので、簡単な構成で電子写真用感光体と現像ローラとの間隔を一定間隔に維持することができ、電子写真用感光体と現像ローラとの間隔を一定間隔に保持する機構を別途設ける必要がない。
【００３６】
なお、当該部材を電子写真用感光体の最表面層で接触させた場合には、電子写真用感光体の表面層の剥離が問題として発生し得るが、本画像形成装置においては、特に第１、２の態様のいずれかの電子写真用感光体を用いて各層の密着性を高めているため、かかる問題の発生を低減することができる。
【００３７】
本発明の第７の態様に係るプロセスカートリッジは、電子写真用感光体を用い、帯電、像露光、現像、転写・分離、クリーニング工程を経て画像形成を行う画像形成装置に使用するプロセスカートリッジにおいて、第１、２の態様のいずれかに記載の電子写真用感光体と、帯電部、像露光部、現像部、転写又は分離部、クリーニング部のいずれか１つとを組み合わせてつくられている構成を採る。
【００３８】
この構成によれば、画像形成装置に使用するプロセスカートリッジにおいて、第１、２の態様のいずれかの電子写真用感光体が奏する効果を得ることができる。この結果、どのような環境下でも安定した画像が得ることができるプロセスカートリッジを実現することができる。
【００３９】
本発明の第８の態様は、第７の態様に係るプロセスカートリッジにおいて、前記電子写真用感光体と現像部の現像ローラとの間隔を保持する部材が、当該電子写真用感光体の最表面層で接触する構成を採る。
【００４０】
この構成によれば、電子写真用感光体と現像ローラとの間隔を保持する部材を当該電子写真用感光体の最表面層で接触させるので、簡単な構成で電子写真用感光体と現像ローラとの間隔を一定間隔に維持することができ、電子写真用感光体と現像ローラとの間隔を一定間隔に保持する機構を別途設ける必要がない。
【００４１】
なお、当該部材を電子写真用感光体の最表面層で接触させた場合には、電子写真用感光体の表面層の剥離が問題として発生し得るが、本プロセスカートリッジにおいては、特に第１、２の態様のいずれかの電子写真用感光体を用いて各層の密着性を高めているため、かかる問題の発生を低減することができる。
【００４２】
以下、本発明の実施の形態について図面を参照して詳細に説明する。
【００４３】
（実施の形態１）
図１は、本発明の実施の形態１に係る電子写真用感光体の構成を模式的に示した断面図である。図１において、電子写真用感光体１０は、導電性支持体１１上に電荷発生層１２、中間層１３、電荷輸送層１４を積層して形成されている。
【００４４】
導電性支持体１１は、従来から知られている導電性を有するものであればよく、例えば、アルミニウムなどの金属材料からなる管（円筒状）、板、シート状支持体、プラスティックや紙などからなる管、板、シート状支持体上に金属材料を蒸着あるいは導電性塗料により導電性を付与したもの、導電性プラスティックを成形してなる管、板、シート状支持体などが用いられる。
【００４５】
特に、アルミニウム合金に切削等の加工を施した管やポリエチレンテレフタレートフィルム上にアルミニウムを蒸着したシートなどがよく用いられる。また、導電性支持体１１に、アルミニウム管を用いる場合には、電荷発生層１２を形成する前に、界面活性剤、有機溶剤を用いた洗浄や真空中グロー放電処理による支持体表面の浄化が必要である。アルミニウム管の洗浄の不備は、付着している金属切削粉による電気的障害から起こる画像欠陥や、本発明で課題としている接着性の低下を引き起こす。
【００４６】
導電性支持体１１上に形成される電荷発生層１２は、電荷発生物質として有機顔料を用い、６×１０^-3Ｐａ以下の圧力下、抵抗加熱による蒸着法にて０．０３〜０．５μｍの範囲の薄膜を形成することにより得られる。長さ２５４ｍｍ、外径３０ｍｍのアルミニウム管上に、１本当りの付着量はおおよそ１〜１０ｍｇである。
【００４７】
有機顔料としては、フタロシアニン系顔料、ペリレン系顔料、アントラキノン系顔料、スクアリリウム系顔料などを用いることができる。その中でも、フタロシアニン系顔料が好適であり、特にオキソチタニウムフタロシアニンが用いられる。これらの有機顔料は、公知の合成法にて得られた粗顔料を洗浄にて高結晶性顔料とするか、あるいはそれを昇華精製したものを用いる。
【００４８】
有機顔料を蒸着するための蒸着装置は、導電性支持体１１の全体に均一に成膜できるものであればよく、導電性支持体１１がアルミニウム管であれば、図２に示すような装置が用いられる。図２は、蒸着装置のチャンバー２１の内部を示した概略図である。
【００４９】
図２に示す蒸着装置においては、チャンバー２１の内部に装着されたアルミニウム管２２がチャンバー２１内を自公転し、蒸着源２３の上部にて成膜される。排気口２４には、油拡散ポンプなどを装着し、６×１０^-3Ｐａ以下（単位）の圧力を達成する。蒸着源２３は、融点が蒸着する有機顔料の昇華点（約５００℃）以上の金属であればよく、タングステン、モリブデン、タンタル、ニオブあるいはそれらの合金など高融点金属がよく用いられる。
【００５０】
さらに、直流電源により電流を与えることにより蒸着源２３を加熱し、蒸着源２３に充填した有機顔料２０を昇華させ、導電性支持体であるアルミニウム管２２上に堆積させ所定の膜厚を得るものである。膜厚が所定膜厚以下であれば、感光体として必要な感度が得られず、所定膜厚以上であれば、感光体として必要な帯電性が得られない。
【００５１】
このようにして形成された有機顔料の蒸着膜は非晶質状態であり、有機系溶剤の蒸気にさらすか、あるいは有機系溶剤中に浸漬することにより結晶化することができる。もちろん中間層あるいは電荷輸送層形成時に塗料中に浸漬することによっても結晶変換させることも可能である。
【００５２】
導電性支持体１１上に電荷発生層１２を形成した後、ポリビニルアルコールをブチルアルデヒドにてアセタール化した樹脂（Ｉ）とブチルアルデヒド以外のアルデヒドにてアセタール化した樹脂（ＩＩ）からなる中間層１３を電荷発生層１２上に形成する。この際、上述の樹脂及び有機系溶剤からなる中間層用塗料を用い、浸漬塗工法などの公知の塗工手段にて電荷発生層１２上に形成する。
【００５３】
前記ポリビニルアルコールをブチルアルデヒドにてアセタール化した樹脂（Ｉ）は、一般式(化２)で示されるもので、分子量１×１０⁴〜１５×１０⁴、ブチラール化度５０％以上のものが好ましい。同様に、ポリビニルアルコールをブチルアルデヒド以外のアルデヒドにてアセタール化した樹脂（ＩＩ）は、一般式（化３：Ｒ (i) の代表例はメチル基ＣＨ ₃ ）で示されるもので、分子量１×１０⁴〜１５×１０⁴、ブチラール化度５０％以上のものが好ましい。
【００５４】
これらの樹脂（Ｉ）と樹脂（ＩＩ）との割合は、全体量に対して、樹脂（ＩＩ）が１０％から５０％程度含まれていることが好ましい。樹脂（ＩＩ）を含まないと電荷輸送層との密着性が低下する。一方、樹脂（ＩＩ）の量が多いと高温高湿、低温低湿環境下における電子写真特性変動は大きくなる。
【００５５】
【化２】

【化３】

【００５６】
さらに、中間層用塗料を調整するために樹脂を溶解する有機系溶剤としては、アルコール類、エチレングリコール誘導体類、ケトン系、芳香族炭化水素系などの有機系溶剤を用いることができる。溶剤は、蒸着された有機顔料の求められる結晶状態に応じて選択し、所定量を電荷発生層上に形成するために、樹脂分濃度を１〜５％に調整する。電荷発生層の蒸着された有機顔料１重量部に対して、１重量部より少ないと、高温高湿と低温低湿環境下における電子写真特性、特に、露光後電位に差が生じる。また、２重量部より多いと、繰り返し印字により露光後電位が上昇する。
【００５７】
また、図３に示すような浸漬塗工装置３１にて中間層を形成する。具体的には、循環用ポンプ３５及びフィルタユニット３６が配管されたポット３２に中間層用塗料３０を満たし、電荷発生物質が蒸着された導電性支持体であるアルミニウム管３３を、把持装置を備えた可動部３４に装着し、可動部を上下動作させることにより浸漬塗工する。
【００５８】
引上げ速度は、１０〜３００ｍｍ／分で、所定量の中間層が形成できるように調整する。また、有機顔料の状態によっては、スプレー塗工法にて形成することも可能である。最終的には、塗工後、自然乾燥あるいは加熱乾燥することで、中間層が形成される。
【００５９】
このように導電性支持体１１上に電荷発生層１２、中間層１３が形成された後、電荷輸送物質とバインダ樹脂からなる電荷輸送層１４が、電荷輸送物質、バインダ樹脂並びに有機系溶剤からなる電荷輸送層用塗料を用いて、浸漬塗工法などの公知の塗工手段にて中間層１３上に積層される。
【００６０】
電荷輸送物質としては、電子供与性のオキサゾール化合物、オキサジアゾール化合物、ピラゾリン化合物、ヒドラゾン化合物、スチルベン化合物、テトラフェニルブタジエン化合物、ビフェニル化合物、及びこれらの化合物の誘導体を用いることができる。また、これらの化合物を２種以上混合して用いることもできる。
【００６１】
バインダ樹脂としては、ポリエステル、ポリカーボネート、ポリスルホン、ポリアリレート、ポリメチルメタクリレートなどの樹脂を用いることができるが、電荷輸送物質との相溶性、膜強度、塗料化溶剤への溶解性、塗料としての安定性の点からポリカーボネートが好ましい。
【００６２】
これらのバインダ樹脂と前記電荷輸送物質の構成比は、重量比でバインダ樹脂１に対して０．２５から３の範囲で用いられる。また、電荷輸送物質、バインダ樹脂の他に、これらの物質の劣化を防止するために酸化防止剤、紫外線吸収剤などを添加することもできる。
【００６３】
さらに、これらの電荷輸送物質とバインダ樹脂を溶解し、電荷輸送層用塗料とするための有機系溶剤としては、ジクロロメタン、クロロホルムなどの塩素系炭化水素類、ジオキサン、テトラヒドロフランなどの環状エーテル類、トルエン、キシレンなどの芳香族系炭化水素類などが用いられる。これらの有機系溶剤は、１種あるいは２種以上を混合して用いることができ、電荷輸送層用塗料中の不揮発分の濃度を１０から４０重量％の範囲に調整して用いる。
【００６４】
一般的には、このようにして調整された電荷輸送層用塗料を用い、図４に示すような浸漬塗工装置４１にて電荷輸送層１４を形成する。具体的には、電荷発生層１２及び中間層１３が形成された導電性支持体であるアルミニウム管４３を、把持装置を備えた可動部４４に装着し、電荷輸送層用塗料４０の入ったにポット４２に浸漬した後、所定の速度で引き上げることにより電荷輸送層が形成される。ポット４２には循環用ポンプ４５及びフィルタユニット４６が配管されている。浸漬塗工後、熱風乾燥機などにより有機系溶剤分を揮発させ、乾燥後膜厚として５から４０μｍ程度の範囲の電荷輸送層が形成される。
【００６５】
このように実施の形態１の電子写真用感光体１０によれば、有機顔料の蒸着膜からなる電荷発生層１２上に、ポリビニルアルコールをブチルアルデヒドにてアセタール化した樹脂（Ｉ）と、ブチルアルデヒド以外のアルデヒドにてアセタール化した樹脂（ＩＩ）とからなる中間層１３を形成することで、電荷輸送層１４との接着性を向上しつつ、高温高湿又は低温低湿環境化における電位変動等の環境安定性をも向上することができる。この結果、環境安定性に優れ、かつ、導電性支持体との接着性に優れた電子写真用感光体を実現することができる。
【００６６】
（実施の形態２）
本発明の実施の形態１に係る電子写真用感光体が導電性支持体の全領域に電荷発生層を形成するのに対し、実施の形態２に係る電子写真用感光体は、当該感光体の電子写真特性を必要とする領域にのみ電荷発生層を形成する点で相違する。
【００６７】
図５は、本発明の実施の形態２に係る電子写真用感光体の構成を模式的に示している。図５においては、その一例として、上方に円筒状アルミニウム管上に形成した電子写真用感光体（以下、「円筒状電子写真用感光体」という）の構成を模式的に示す表面図を示し、下方に円筒状電子写真用感光体の構成を模式的に示す断面図を示している。
【００６８】
図５において、円筒状電子写真用感光体５０は、図１と同様、導電性支持体５１上に、電荷発生層５２、中間層５３、電荷輸送層５４の順に積層して形成されたものである。各構成は、図１と同様のものであるが、実施の形態２に係る電子写真用感光体５０は、感光体の電子写真特性を必要とする領域５５にのみ電荷発生層を形成した構成になっている。
【００６９】
具体的には、図２の蒸着装置において、導電性支持体５１の両端部に有機顔料が付着しないように遮蔽板を装着して電荷発生層５２を形成する。これにより、電子写真特性を必要としない部分である導電性支持体５１の両端部には有機顔料が付着するのを防止できる。さらに、その上に中間層５３及び電荷輸送層５４を電荷発生層５２が形成された導電性支持体５１の全領域に順次積層し、円筒状電子写真用感光体５０を完成する。
【００７０】
このように実施の形態２の円筒状電子写真用感光体５０によれば、電子写真特性を必要とする領域にのみ電荷発生層５２を形成する一方、導電性支持体５１上全域に樹脂を主成分とする中間層５３及び電荷輸送層５４を形成することで、電荷発生層５２が形成されていない領域において電荷輸送層５４の導電性支持体５１に対する密着性を向上することができる。
【００７１】
また、実施の形態２においても、実施の形態１と同様に、電荷発生層５２上に、ポリビニルアルコールをブチルアルデヒドにてアセタール化した樹脂（Ｉ）と、ブチルアルデヒド以外のアルデヒドにてアセタール化した樹脂（ＩＩ）とからなる中間層５３を形成することで、電荷輸送層５４との接着性を向上しつつ、高温高湿又は低温低湿環境化における電位変動等の環境安定性をも向上することができる。この結果、環境安定性に優れ、かつ、導電性支持体との接着性に優れた電子写真用感光体を実現することができる。
【００７２】
図６は、本発明の実施の形態１及び実施の形態２に係る電子写真用感光体１０及び５０を搭載した画像形成装置の概略構成を示す断面図である。
【００７３】
同図に示す画像形成装置は、筐体６０１上部に原稿を走査して画像を読取る読取りユニット６０２が設けられ、読取りユニット６０２の上面に原稿読取り面を開閉する上部カバー６０３が開閉自在に取り付けられている。
【００７４】
筐体６０１には、読取りユニット６０２の下方部に記録紙を排出するための排出空間６０４が形成されており、排出空間６０４の下面が排紙トレイ６０５として機能する。また、筐体６０１下部に記録紙を収納する給紙カセット６０６が配置されている。
【００７５】
給紙カセット６０６の給紙側端部上方にピックアップローラ６０７が昇降自在に配置され、ピックアップローラ６０７に近接して給紙ローラ６０８及び分離ローラ６０９が対向配置される。給紙ローラ６０８は、ピックアップローラ６０７により給紙カセット６０６から取り出された記録紙を搬送路へ繰出すためのローラであり、分離ローラ６０９は、給紙カセット６０６から重ねて取り出された複数枚の記録紙から１枚を分離するためのローラである。
【００７６】
記録紙の搬送路が筐体６０１下部より略垂直上方に向けて形成されている。この搬送路上に本発明に係る電子写真用感光体１０（５０）が配置されている。電子写真用感光体１０（５０）を通過する記録紙の搬送タイミングを制御するレジストローラ６１０が搬送路の入り口付近に配置されている。電子写真用感光体１０（５０）はプロセスカートリッジ６１１に保持されている。プロセスカートリッジ６１１よりも装置の内側にレーザスキャンユニット（ＬＳＵ）６１２が配置されている。ＬＳＵ６１２は、電子写真用感光体１０（５０）に潜像を形成する。また、電子写真用感光体１０（５０）に転写ローラ６１３が対向配置されており、かかる転写ローラ６１３は、電子写真用感光体１０（５０）に付着したトナーを記録紙へ転写する。
【００７７】
記録紙の搬送路におけるプロセスカートリッジ６１１よりも下流側に定着ユニット６１４が設置されている。定着ユニット６１４は、定着ローラ６１５とこの定着ローラ６１５に対して所定の圧力で押圧される加圧ローラ６１６とを有する。定着ローラ６１５及び加圧ローラ６１６から送り出された記録紙は、定着ユニット６１４の排出空間６０４側に設けられた排出ローラ６１７により排紙トレイ６０５に排出される。
【００７８】
図７は、本発明に係る電子写真用感光体１０（５０）を保持したプロセスカートリッジ６１１を拡大した概略断面図である。
【００７９】
プロセスカートリッジ６１１において、電子写真用感光体１０（５０）は、回転軸を通じて接地され、図中矢印で示すように反時計方向に駆動回転される。電子写真用感光体１０（５０）に対する帯電は、帯電部７０１の帯電ローラ７０２で行う。具体的には、帯電ローラ７０２が直流バイアスあるいは交流バイアスを重畳し電子写真用感光体１０（５０）上に均一な電荷を与える。
【００８０】
電子写真用感光体１０（５０）に対して一様に帯電された後、上述のＬＳＵ６１２からの画像信号に基づいた像露光が行われる。ＬＳＵ６１２に用いられる光源は半導体レーザであり、ポリゴンミラー、ｆθレンズ等の光学系によりレーザ光が電子写真用感光体１０（５０）上に走査され、電子写真用感光体１０（５０）の光電変換機能により電子写真用感光体１０（５０）上に静電潜像が形成される。
【００８１】
次いで、静電潜像は現像部７０３にて現像され、電子写真用感光体１０（５０）上にトナー像が形成される。具体的には、磁性一成分トナーの場合、マグネット７０４を内蔵する現像ローラ７０５上に現像ブレード７０６にて規制されたトナー層を形成し、電子写真用感光体１０（５０）と現像ローラ７０５との間に直流バイアスあるいは交流バイアスをかけて現像が行われる。なお、現像ローラ７０５は、図中矢印で示すように時計方向に駆動回転する。
【００８２】
現像ローラ７０５と電子写真用感光体１０（５０）との間隔は、現像ローラ７０５に取り付けられたギャップスペーサ７０７により一定に維持されている。ギャップスペーサ７０７は、現像ローラ７０５における周面の両端部（図７に示す奥側と手前側の端部）に取り付けられ、電子写真用感光体１０（５０）の最表面層（周面）の両端部に接触する。特に実施の形態２に係る電子写真用感光体５０においては、電荷発生層５２を形成していない部分において接触する。
【００８３】
このように電子写真用感光体１０（５０）と現像ローラ７０５との間隔を保持する部材であるギャップスペーサ７０７を当該電子写真用感光体１０（５０）の最表面層で接触させるので、簡単な構成で電子写真用感光体１０（５０）と現像ローラ７０５との間隔を一定間隔に維持することができ、電子写真用感光体１０（５０）と現像ローラ７０５との間隔を一定間隔に保持する機構を別途設ける必要がない。
【００８４】
なお、ギャップスペーサ７０７を電子写真用感光体１０（５０）の最表面層で接触させた場合には、電子写真用感光体１０（５０）の表面層の剥離が問題と発生し得るが、本画像形成装置においては、上述の各層の密着性を向上させた電子写真用感光体１０（５０）を用いているため、かかる問題の発生を低減することができる。特に実施の形態２に係る電子写真用感光体５０を用いた場合には、より密着性が向上している電子写真用感光体５０の両端でギャップスペーサ７０７と接触するため、かかる問題の発生をより低減させることができる。
【００８５】
電子写真用感光体１０（５０）上に形成されたトナー像は、上述の転写ローラ６１３によって給紙カセット６０６から供給された記録紙に対して転写される。トナー像が転写された記録紙は、電子写真用感光体１０（５０）から分離され、定着ユニット６１４に送り込まれる。定着ユニット６１４で記録紙にトナー像が加熱定着された後、記録紙は、排紙トレイ６０５に排出される。
【００８６】
一方、電子写真用感光体１０（５０）においては、クリーニング部７０８のクリーンングブレード７０９の圧接により残留トナーを除去し、表面が清掃された状態で帯電部７０１に戻り、次なる画像形成のプロセスに入る。
【００８７】
なお、以上の説明から明らかなように、図７に示すプロセスカートリッジ６１１は、電子写真用感光体１０（５０）、帯電ローラ７０２を有する帯電部７０１、現像ローラ７０５を有する現像部７０３、クリーニングブレード７０９を有するクリーニング部７０８を一体として備えた構成になっている。しかし、これらの機能を全て備える場合に限定されず、プロセスカートリッジ６１１の構成としては、これらの機能の一部を組み合わせて構成するようにしてもよい。
【００８８】
【実施例】
以下、本発明の実施の形態に係る電子写真用感光体における具体的な実施例及び比較例を説明する。
【００８９】
（実施例１）
外径３０ｍｍ、内径２８．５ｍｍ、長さ２５４ｍｍのアルミニウム（アルミニウム−マグネシウム−シリコン系合金）切削管を、脱脂用洗剤（花王株式会社製クリンスルーＬＣ８７０）及びイオン交換水にて洗浄し、図２の蒸着装置に装着する。５×１０^-3Ｐａの減圧下、アルミニウム管上にオキソチタニウムフタロシアニン蒸着膜を形成した。アルミニウム管１本当りのオキソチタニウムフタロシアニン量は、２ｍｇであった。
【００９０】
次に、エタノール（関東化学株式会社製一級試薬）１００重量部に対してポリビニルアルコールをブチルアルデヒドにてアセタール化した樹脂（Ｉ）（積水化学工業株式会社製 エスレックBL−１）を２重量部、ブチルアルデヒド以外のアルデヒドにてアセタール化した樹脂（ＩＩ）（積水化学工業株式会社製 エスレックＢＸ−１）を０．５重量部添加した溶液中に、蒸着膜が形成されたアルミニウム管を図３の浸漬処理装置にて中間層を浸漬塗工する。中間層のアルミニウム管１本当りの樹脂量は、３ｍｇであった。すなわち、電荷発生層の有機顔料蒸着膜であるオキソチタニウムフタロシアニン量２ｍｇの１．５倍の量である。引き続き、２−メチル−４−ジベンジルアミノベンズアルデヒド−Ｎ，Ｎ−ジフェニルヒドラゾン１８重量部と１，１−ビス（ｐ−ジエチルアミノフェニル）−４，４−ジフェニル−１，３−ブタジエン２重量部、ポリカーボネート（出光興産株式会社製タフゼットＰ−３００）２０重量部、ジクロロメタン１００重量部からなる塗料を用い、図４の浸漬塗工装置にて乾燥後膜厚が２５μｍになるように電荷輸送層を設け感光体を完成させた。
【００９１】
評価は、松下電送システム株式会社製パナファックスＵＦ７７０のプロセスカートリッジに得られた感光体を装着し、現像部分に表面電位計（トレック社製 ＭＯＤＥＬ３４４）を取り付け、現像器位置での帯電電位Ｖ０及び露光後電位ＶＬを測定した。この電位測定の結果を表１に示す。また、同様の測定を、高温高湿環境下（３５℃７０％）及び低温低湿環境下（１０℃１５％）でも行った。さらに、繰り返し８０００枚印字後の電位測定結果（８０００枚印字後特性）、及び低温低湿環境下で現像ローラ７０５との間隔を保持するギャップスペーサ７０７で感光層の剥れ（ギャップ部剥れ）が発生した印字枚数もあわせて表１に示す。
【００９２】
（実施例２）
実施例２では、実施例１における樹脂（Ｉ）を２．２５重量部、樹脂（ＩＩ）を０．２５重量部にした以外は、実施例１と同様に感光体を作成し評価を行った。この結果を表１に示す。
【００９３】
（実施例３）
実施例３では、実施例１における樹脂（Ｉ）を１．２５重量部、樹脂（ＩＩ）を１．２５重量部にした以外は、実施例１と同様に感光体を作成し評価を行った。この結果を表１に示す。
【００９４】
（実施例４）
実施例４では、中間層塗料の樹脂分濃度を１．８％にし、実施例１における中間層のアルミニウム管１本当りの樹脂量を２ｍｇにした以外は、実施例１と同様に感光体を作成し評価を行った。すなわち、中間層の樹脂量が電荷発生層の有機顔料蒸着膜であるオキソチタニウムフタロシアニン量２ｍｇと同量の場合である。この結果を表１に示す。
【００９５】
（実施例５）
実施例５では、中間層塗料の樹脂分濃度を３％にし、実施例１における中間層のアルミニウム管１本当りの樹脂量を４ｍｇにした以外は、実施例１と同様に感光体を作成し評価を行った。中間層の樹脂量が電荷発生層の有機顔料蒸着膜であるオキソチタニウムフタロシアニン量２ｍｇの２倍の量の場合である。この結果を表１に示す。
【００９６】
（実施例６）
実施例６では、オキソチタニウムフタロシアニン蒸着膜形成の際に、蒸着装置内部に遮蔽板を設け、アルミニウム管の両端部１０ｍｍに蒸着膜が付着しないようにした。それ以外は、実施例１と同様に感光体を作成し評価を行った。すなわち、上述の実施の形態２に係る電子写真用感光体５０を用いて評価を行ったものである。この結果を表１に示す。ここでは、表１に示すように、特にギャップ部剥れの評価において良好な結果を得ることができた。
【００９７】
（比較例１）
比較例１では、実施例１における中間層を設けない以外、実施例１と同様に感光体を作成し評価を行った。この結果を表１に示す。ここでは、表１に示すように、特に環境変動及び繰り返し変動に大きな変動が生じていることが分かる。また、ギャップ部剥れの評価においても、感光層の膜強度が不足していることが認識できる。
【００９８】
（比較例２）
比較例２では、実施例１における樹脂（Ｉ）を２．５重量部で樹脂（ＩＩ）を用いない以外、実施例１と同様に感光体を作成し評価を行った。この結果を表１に示す。ここでは、ギャップ部剥れの評価において、実施例１等の評価に比べて感光層の膜強度が不足していることが認識できる。
【００９９】
（比較例３）
比較例３では、実施例１における樹脂（ＩＩ）を２．５重量部で樹脂（Ｉ）を用いない以外、実施例１と同様に感光体を作成し評価を行った。この結果を表１に示す。ここでは、ギャップ部剥れの評価において多少の改善はみられるものの、環境変動及び繰り返し変動、特に高温多湿における環境変動及び繰り返し変動に大きな変動が生じていることが分かる。
【０１００】
（比較例４）
比較例４では、中間層塗料の樹脂分濃度を５％にし、実施例１における中間層のアルミニウム管１本当りの樹脂量を７ｍｇにした以外は、実施例１と同様に感光体を作成し評価を行った。中間層の樹脂量が電荷発生層の有機顔料蒸着膜であるオキソチタニウムフタロシアニン量２ｍｇの３．５倍の量の場合である。この結果を表１に示す。ここでは、環境変動及び繰り返し変動、特に高温多湿における環境変動及び繰り返し変動に大きな変動が生じていることが分かる。
【０１０１】
【表１】

表１に示す結果から明らかなように、本実施の形態に係る電子写真用感光体では、良好な電子写真特性を示すとともに、環境変動、繰り返し変動が小さく、感光層の膜強度も優れた性能を示す。特に、上記実施例では、中間層を形成しない場合（比較例１）、中間層の樹脂量を、電荷発生層の有機顔料蒸着膜であるオキソチタニウムフタロシアニン量２ｍｇと同量にした場合（実施例４）、オキソチタニウムフタロシアニン量２ｍｇの１．５倍にした場合（実施例１）、２倍にした場合（実施例５）及び３．５倍にした場合（比較例４）について評価を行っている。この評価結果から中間層の樹脂量は、電荷発生層の有機顔料蒸着膜の質量の１〜２倍の量とした場合に良好な電子写真特性を示すとともに、環境変動、繰り返し変動が小さく、感光層の膜強度も優れた性能を示すことが認識できる。
【０１０２】
【発明の効果】
以上説明したように、本発明によれば、環境安定性に優れ、接着性が高く、半導体レーザ光に対して高感度を示すとともに、感度や帯電性、これらの感光体特性の繰り返し安定性にも優れた電子写真用感光体及びその製造方法を提供することができる。
【０１０３】
また、その電子写真用感光体を用いることにより、どのような環境下でも安定した画像が得ることができる画像形成装置及びプロセスカートリッジを提供することができる。
【図面の簡単な説明】
【図１】本発明の実施の形態に係る電子写真用感光体の構成を模式的に示した断面図
【図２】本発明の実施例で使用した蒸着装置の構成を示した概略図
【図３】本発明の実施例で使用した中間層形成用浸漬塗工装置の構成を示した概略図
【図４】本発明の実施例で使用した電荷輸送層形成用浸漬塗工装置の構成を示した概略図
【図５】本発明の実施の形態に係る電子写真用感光体の構成を模式的に示した断面図
【図６】本発明の実施の形態に係る電子写真用感光体を搭載した画像形成装置の断面図
【図７】本発明の実施の形態に係る電子写真用感光体を搭載したプロセスユニットの断面図
【符号の説明】
１０ 電子写真用感光体
１１ 導電性支持体
１２ 電荷発生層
１３ 中間層
１４ 電荷輸送層
２０ 有機顔料（電荷発生物質（オキソチタニウムフタロシアニン））
２１ 蒸着装置のチャンバー
２２ アルミニウム管（導電性支持体）
２３ 蒸着源
２４ 排気口
３０ 中間層用塗料
３１ 浸漬塗工装置
３２ ポット
３３ アルミニウム管（電荷発生物質が蒸着された導電性支持体）
３４ 把持装置を備えた可動部
３５ 循環用ポンプ
３６ フィルタユニット
４０ 電荷輸送層用塗料
４１ 浸漬塗工装置
４２ ポット
４３ アルミニウム管（電荷発生層、中間層が形成された導電性支持体）
４４ 把持装置を備えた可動部
４５ 循環用ポンプ
４６ フィルタユニット
５０ 電子写真用感光体（円筒状電子写真用感光体）
５１ 導電性支持体（アルミニウム管）
５２ 電荷発生層
５３ 中間層
５４ 電荷輸送層
５５ 電子写真特性が必要な領域
６０６ 給紙カセット
６１１ プロセスカートリッジ
６１２ レーザスキャンユニット（ＬＳＵ）
６１３ 転写ローラ
６１４ 定着ユニット
７０１ 帯電部
７０２ 帯電ローラ
７０３ 現像部
７０５ 現像ローラ
７０６ 現像ブレード
７０８ クリーニング部
７０９ クリーニングブレード[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic photoreceptor for use in electrophotographic apparatuses and process cartridges such as copying machines, printers and facsimiles, and a method for producing the same, and particularly has electrophotographic characteristics excellent in environmental stability and suitable for mass production. The present invention relates to an electrophotographic photoreceptor and a method for producing the same.
[0002]
[Prior art]
In recent years, the advantages of electrophotographic devices such as high speed, low noise, high image quality, and the ability to record on plain paper have been attracting attention. It is becoming popular. Furthermore, as a recent trend, in the field of printers and facsimiles, the form of use is shifting from office use to personal use, and further miniaturization, cost reduction, and maintenance-free are required. On the other hand, with the improvement of image processing techniques such as colorization of documents, higher resolution and higher quality image forming techniques are required.
[0003]
As a photoconductor used in the electrophotographic apparatus, an organic photoconductor made of an organic photoconductive material having advantages such as low cost and non-pollution has been actively developed, so that it can be installed in many apparatuses. It has become. Most of these practically used photoreceptors are multilayer photoreceptors in which a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material are sequentially formed on a conductive support. By separating the functions in this way, the characteristics such as sensitivity and durability required for the electrophotographic apparatus have been satisfied. Among them, a photoconductor having absorption in the oscillation wavelength region of a semiconductor laser, that is, a near-infrared wavelength region, has been actively developed. In particular, an electrophotographic photoconductor using an organic pigment such as phthalocyanine as a charge generation material. Is attracting attention.
[0004]
There are a coating method and a vapor deposition method as a method for forming a charge generation layer using an organic pigment such as phthalocyanine as a charge generation material. The coating method includes techniques such as dip coating and spray coating, but the dip coating method immerses the conductive support in a dispersion paint composed of at least a specific crystal type organic pigment, a binder resin and a solvent, This is a method of forming a charge generation layer on a conductive support by pulling up. The vapor deposition method is a method in which a heat-vaporized organic pigment is deposited on a conductive support, and a charge transport layer is formed directly on the deposited film, or in an organic solvent solution or its vapor before the charge transport layer is formed. Is subjected to crystal transformation to form a predetermined charge generation layer. This vapor deposition method can form a uniform film at the molecular level and can be said to be a production method suitable for high-resolution and high-quality electrophotographic apparatuses.
[0005]
In addition, a method of forming an intermediate layer of polyvinyl butyral resin has been proposed for the purpose of preventing the charge generating material from being dissolved in the charge transport layer coating (see, for example, Patent Document 1).
[0006]
[Patent Document 1]
JP-A-11-84692
[0007]
[Problems to be solved by the invention]
However, when a charge generation layer is formed by a vapor deposition method compared to a coating method using a charge generation material and a resin dispersion paint on a conductive support, characteristic fluctuations due to the environment such as high temperature and high humidity and low temperature and low humidity are large. . Further, since the resin component is not contained, the adhesion with the support is poor and the photosensitive layer is easily peeled off. Specifically, in an electrophotographic apparatus, there is a problem that scratches due to contact between the developing roller and the spacer portion that keeps the distance between the photosensitive members constant are enlarged, and the photosensitive layer in the vicinity thereof is peeled off.
[0008]
As a solution to these problems, it may be possible to provide an adhesive layer made of a resin component such as vinyl acetate resin or vinyl chloride-vinyl acetate copolymer between the support and the charge generation layer. At present, it is not possible to achieve both adhesion and characteristics. In addition, even when the method for forming an intermediate layer of polyvinyl butyral resin is used for the purpose of preventing the charge generating material from dissolving into the above-mentioned charge transport layer coating material, the adhesion between the photosensitive layer and the support is sufficiently satisfied. It has not been done.
[0009]
The present invention has been made in view of such problems, and is a problem of an electrophotographic photoreceptor in which the charge generation layer is formed of a vapor deposition film of an organic pigment, that is, variation in potential characteristics at high temperature and high humidity or low temperature and low humidity. An object of the present invention is to solve a decrease in adhesion between the photosensitive layer and the support.
[0010]
Specifically, it has excellent environmental stability, high adhesiveness, high sensitivity to semiconductor laser light, and sensitivity and chargeability, and excellent repetitive stability of these photoreceptor characteristics. It aims at providing a body and its manufacturing method.
[0011]
It is another object of the present invention to provide an image forming apparatus and a process cartridge that can obtain a stable image under any environment by using the electrophotographic photoreceptor.
[0012]
[Means for Solving the Problems]
  The present inventionVapor deposition film in which organic pigment vaporized by vapor deposition is deposited on conductive supportBy forming an intermediate layer comprising a resin (I) obtained by acetalizing polyvinyl alcohol with butyraldehyde and a resin (II) obtained by acetalization with an aldehyde other than butyraldehyde on the charge generation layer comprising An electrophotographic photoreceptor excellent in stability and adhesiveness to a conductive support is realized. In addition, a stable image can be obtained in any environment using an image forming apparatus and a process cartridge using the electrophotographic photoreceptor.
[0013]
The function of the intermediate layer is determined by a resin obtained by acetalizing polyvinyl alcohol. The configuration is represented by the general formula (Formula 1). The ratio of l, m, and n in the general formula is determined by the degree of saponification of polyvinyl acetate, the degree of butyralization or acetalization of polyvinyl alcohol.
[0014]
[Chemical 1]

Generally, low butyral and acetalized low molecular weight resins are excellent in adhesion. When a resin acetalized with butyraldehyde is used for the intermediate layer, environmental stability such as potential fluctuation in a high-temperature, high-humidity or low-temperature, low-humidity environment is improved, but adhesion to the charge transport layer is reduced. However, when an acetalized resin other than butyraldehyde is mixed, adhesion with the charge transport layer is improved, and environmental stability such as potential fluctuation in high temperature and high humidity or low temperature and low humidity environment is also satisfied. .
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The electrophotographic photoreceptor according to the first aspect of the present invention is the electrophotographic photoreceptor in which at least a charge generation layer, an intermediate layer, and a charge transport layer are laminated in this order on a conductive support. The layer is a vapor deposition film of an organic pigment, and the intermediate layer includes a resin (I) obtained by acetalizing polyvinyl alcohol with butyraldehyde and a resin (II) obtained by acetalization with an aldehyde other than butyraldehyde. .
[0017]
According to this configuration, a resin (I) obtained by acetalizing polyvinyl alcohol with butyraldehyde and a resin (II) acetalized with an aldehyde other than butyraldehyde on a charge generation layer formed of a vapor deposition film of an organic pigment, By forming the intermediate layer made of the above, it is possible to improve environmental stability such as potential fluctuation in a high-temperature, high-humidity or low-temperature, low-humidity environment while improving adhesion with the charge transport layer. As a result, it is possible to realize an electrophotographic photoreceptor excellent in environmental stability and excellent in adhesiveness with a conductive support.
[0018]
  According to a second aspect of the present invention, in the electrophotographic photoreceptor according to the first aspect, the mass ratio of the organic pigment vapor deposition film of the charge generation layer and the resin of the intermediate layer is1 to 1The structure which is the range is taken.
[0019]
According to this configuration, by including the mass ratio of the resin of the intermediate layer to the mass 1 of the organic pigment vapor deposition film of the charge generation layer in the range of 0.5 to 3, it is more excellent in environmental stability and has a conductive support. An electrophotographic photoreceptor excellent in adhesion to the body can be realized.
[0024]
  Of the present inventionThird aspectThe method for producing an electrophotographic photoreceptor according to the present invention is a method for producing an electrophotographic photoreceptor, wherein at least a charge generation layer, an intermediate layer, and a charge transport layer are laminated in this order on a conductive support.Heated vaporized organic pigment on conductive supportUsing the paint comprising the step of forming the charge generation layer by vapor deposition, and a resin (I) obtained by acetalizing polyvinyl alcohol with butyraldehyde and a resin (II) obtained by acetalization with an aldehyde other than butyraldehyde Forming the intermediate layer.
[0025]
According to this method, a resin (I) obtained by acetalizing polyvinyl alcohol with butyraldehyde and a resin (II) acetalized with an aldehyde other than butyraldehyde on a charge generation layer formed of a vapor deposition film of an organic pigment, By forming the intermediate layer made of the above, it is possible to improve environmental stability such as potential fluctuation in a high-temperature, high-humidity or low-temperature, low-humidity environment while improving adhesion with the charge transport layer. As a result, an electrophotographic photoreceptor excellent in environmental stability and adhesiveness to a conductive support can be produced.
[0026]
  Of the present inventionFourth aspectIsThird aspectIn the method for producing an electrophotographic photoreceptor according to the present invention, the mass ratio of the organic pigment deposited film of the charge generation layer and the resin of the intermediate layer is1 to 1It is what is in the range.
[0027]
  According to this method, the mass ratio of the resin of the intermediate layer to the mass 1 of the organic pigment vapor deposition film of the charge generation layer is1-2By including in this range, it is possible to produce an electrophotographic photoreceptor excellent in environmental stability and adhesiveness to a conductive support.
[0032]
  Of the present inventionFifth aspectThe image forming apparatus according to the present invention is an image forming apparatus that uses an electrophotographic photoreceptor and performs image formation through charging, image exposure, development, transfer / separation, and cleaning processes.Of the first and second aspectsA configuration using any one of the electrophotographic photoreceptors is adopted.
[0033]
  According to this configuration, in the image forming apparatus,Of the first and second aspectsThe effect exhibited by any electrophotographic photoreceptor can be obtained. As a result, it is possible to realize an image forming apparatus capable of obtaining a stable image under any environment.
[0034]
  Of the present inventionSixth aspectIsFifth aspectIn the image forming apparatus according to the present invention, a configuration is adopted in which a member that keeps a distance between the electrophotographic photoreceptor and the developing roller used in the developing process is in contact with the outermost surface layer of the electrophotographic photoreceptor.
[0035]
According to this configuration, since the member for maintaining the distance between the electrophotographic photosensitive member and the developing roller is brought into contact with the outermost surface layer of the electrophotographic photosensitive member, the electrophotographic photosensitive member and the developing roller can be configured with a simple configuration. Can be maintained at a constant interval, and there is no need to provide a separate mechanism for maintaining the interval between the electrophotographic photosensitive member and the developing roller at a constant interval.
[0036]
  When the member is brought into contact with the outermost surface layer of the electrophotographic photoreceptor, peeling of the surface layer of the electrophotographic photoreceptor may occur as a problem.First and second aspectsSince any one of the electrophotographic photoconductors is used to improve the adhesion of each layer, the occurrence of such problems can be reduced.
[0037]
  Of the present inventionSeventh aspectThe process cartridge according to the present invention is a process cartridge used in an image forming apparatus that uses an electrophotographic photoreceptor and performs image formation through charging, image exposure, development, transfer / separation, and cleaning processes.Of the first and second aspectsThe electrophotographic photosensitive member according to any one of the above and a charging unit, an image exposure unit, a developing unit, a transfer or separation unit, and a cleaning unit are combined.
[0038]
  According to this configuration, in the process cartridge used for the image forming apparatus,Of the first and second aspectsThe effect exhibited by any electrophotographic photoreceptor can be obtained. As a result, a process cartridge capable of obtaining a stable image under any environment can be realized.
[0039]
  Of the present inventionEighth aspectIsSeventh aspectIn the process cartridge according to the present invention, the member that holds the gap between the electrophotographic photosensitive member and the developing roller of the developing unit contacts the outermost surface layer of the electrophotographic photosensitive member.
[0040]
According to this configuration, since the member for maintaining the distance between the electrophotographic photosensitive member and the developing roller is brought into contact with the outermost surface layer of the electrophotographic photosensitive member, the electrophotographic photosensitive member and the developing roller can be configured with a simple configuration. Can be maintained at a constant interval, and there is no need to provide a separate mechanism for maintaining the interval between the electrophotographic photosensitive member and the developing roller at a constant interval.
[0041]
  When the member is brought into contact with the outermost surface layer of the electrophotographic photoreceptor, peeling of the surface layer of the electrophotographic photoreceptor may occur as a problem.First and second aspectsSince any one of the electrophotographic photoconductors is used to improve the adhesion of each layer, the occurrence of such problems can be reduced.
[0042]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0043]
(Embodiment 1)
FIG. 1 is a cross-sectional view schematically showing the configuration of the electrophotographic photoreceptor according to the first exemplary embodiment of the present invention. In FIG. 1, an electrophotographic photoreceptor 10 is formed by laminating a charge generation layer 12, an intermediate layer 13, and a charge transport layer 14 on a conductive support 11.
[0044]
The conductive support 11 may have any conventionally known conductivity, such as a tube (cylindrical) made of a metal material such as aluminum, a plate, a sheet-like support, plastic or paper. A tube, a plate, a sheet-like support, or the like obtained by depositing a metal material on a tube, plate, or sheet-like support or imparting conductivity by a conductive paint, or molding a conductive plastic is used.
[0045]
In particular, a tube obtained by machining an aluminum alloy or a sheet obtained by evaporating aluminum on a polyethylene terephthalate film is often used. In the case where an aluminum tube is used for the conductive support 11, the surface of the support can be purified by cleaning with a surfactant or an organic solvent or by glow discharge treatment in a vacuum before forming the charge generation layer 12. is necessary. Inadequate cleaning of the aluminum tube causes an image defect resulting from an electrical failure due to the attached metal cutting powder, and a decrease in adhesiveness, which is a problem in the present invention.
[0046]
The charge generation layer 12 formed on the conductive support 11 uses an organic pigment as a charge generation material, and is 6 × 10 6.^-3It is obtained by forming a thin film in the range of 0.03 to 0.5 μm by a vapor deposition method by resistance heating under a pressure of Pa or lower. On an aluminum tube having a length of 254 mm and an outer diameter of 30 mm, the amount of adhesion per one is approximately 1 to 10 mg.
[0047]
As the organic pigment, phthalocyanine pigments, perylene pigments, anthraquinone pigments, squarylium pigments and the like can be used. Of these, phthalocyanine pigments are preferred, and oxotitanium phthalocyanine is particularly used. These organic pigments are obtained by washing a crude pigment obtained by a known synthesis method into a highly crystalline pigment, or by sublimating and purifying it.
[0048]
The vapor deposition apparatus for vapor-depositing the organic pigment is not particularly limited as long as it can form a film uniformly on the entire conductive support 11, and if the conductive support 11 is an aluminum tube, an apparatus as shown in FIG. Used. FIG. 2 is a schematic view showing the inside of the chamber 21 of the vapor deposition apparatus.
[0049]
In the vapor deposition apparatus shown in FIG. 2, an aluminum tube 22 mounted inside the chamber 21 revolves around the chamber 21 and forms a film on the upper part of the vapor deposition source 23. An oil diffusion pump or the like is attached to the exhaust port 24 to provide 6 × 10^-3A pressure of Pa or less (unit) is achieved. The vapor deposition source 23 may be a metal having a melting point equal to or higher than the sublimation point (about 500 ° C.) of the organic pigment to be vapor deposited, and a high melting point metal such as tungsten, molybdenum, tantalum, niobium, or an alloy thereof is often used.
[0050]
Furthermore, the vapor deposition source 23 is heated by applying a current from a DC power source, the organic pigment 20 filled in the vapor deposition source 23 is sublimated, and deposited on the aluminum tube 22 which is a conductive support to obtain a predetermined film thickness. It is. If the film thickness is less than or equal to the predetermined film thickness, the sensitivity required for the photoconductor cannot be obtained, and if it is greater than the predetermined film thickness, the chargeability necessary for the photoconductor cannot be obtained.
[0051]
The organic pigment vapor-deposited film thus formed is in an amorphous state and can be crystallized by being exposed to the vapor of an organic solvent or immersed in an organic solvent. Of course, it is also possible to transform the crystal by immersing it in the paint when forming the intermediate layer or the charge transport layer.
[0052]
After forming the charge generation layer 12 on the conductive support 11, the intermediate layer 13 is made of a resin (I) obtained by acetalizing polyvinyl alcohol with butyraldehyde and a resin (II) obtained by acetalization with an aldehyde other than butyraldehyde. Is formed on the charge generation layer 12. At this time, the intermediate layer coating material composed of the above-described resin and organic solvent is used and formed on the charge generation layer 12 by a known coating means such as a dip coating method.
[0053]
  The resin (I) obtained by acetalizing polyvinyl alcohol with butyraldehyde is represented by the general formula (Chemical Formula 2) and has a molecular weight of 1 × 10^Four~ 15 × 10^FourA butyral degree of 50% or more is preferred. Similarly, a resin (II) obtained by acetalizing polyvinyl alcohol with an aldehyde other than butyraldehyde has a general formula:(Chemical 3: R (i) Is a methyl group CH _Three )With a molecular weight of 1 × 10^Four~ 15 × 10^FourA butyral degree of 50% or more is preferred.
[0054]
  The ratio of these resin (I) and resin (II) is that resin (II) is based on the total amount.10% to 50%It is preferably included. If the resin (II) is not included, the adhesion with the charge transport layer is lowered. On the other hand, when the amount of the resin (II) is large, the variation in electrophotographic characteristics in a high temperature and high humidity and low temperature and low humidity environment increases.
[0055]
[Chemical 2]

[Chemical Formula 3]

[0056]
  Furthermore, organic solvents such as alcohols, ethylene glycol derivatives, ketones, and aromatic hydrocarbons can be used as the organic solvent that dissolves the resin in order to adjust the coating for the intermediate layer. The solvent is selected according to the required crystal state of the deposited organic pigment, and the resin concentration is adjusted to 1 to 5% in order to form a predetermined amount on the charge generation layer. For 1 part by weight of the organic pigment deposited on the charge generation layer,1 part by weightIf it is less, there will be a difference in electrophotographic characteristics under high-temperature and high-humidity and low-temperature and low-humidity environments, in particular, the post-exposure potential. Also,2 parts by weightIf it is more, the post-exposure potential increases due to repeated printing.
[0057]
Further, an intermediate layer is formed by a dip coating apparatus 31 as shown in FIG. Specifically, a pot 32 provided with a circulation pump 35 and a filter unit 36 is filled with an intermediate layer coating material 30, and an aluminum tube 33 which is a conductive support on which a charge generating material is deposited is provided with a gripping device. The movable part 34 is attached and dip coating is performed by moving the movable part up and down.
[0058]
The pulling rate is adjusted to 10 to 300 mm / min so that a predetermined amount of intermediate layer can be formed. Further, depending on the state of the organic pigment, it can be formed by a spray coating method. Finally, after coating, the intermediate layer is formed by natural drying or heat drying.
[0059]
After the charge generation layer 12 and the intermediate layer 13 are thus formed on the conductive support 11, the charge transport layer 14 made of the charge transport material and the binder resin is made of the charge transport material, the binder resin, and the organic solvent. The charge transport layer coating material is laminated on the intermediate layer 13 by a known coating means such as a dip coating method.
[0060]
As the charge transport material, an electron-donating oxazole compound, oxadiazole compound, pyrazoline compound, hydrazone compound, stilbene compound, tetraphenylbutadiene compound, biphenyl compound, and derivatives of these compounds can be used. Moreover, these compounds can also be used in mixture of 2 or more types.
[0061]
As the binder resin, resins such as polyester, polycarbonate, polysulfone, polyarylate, and polymethyl methacrylate can be used. However, compatibility with charge transport materials, film strength, solubility in coating solvents, and stability as a coating material. From the viewpoint of properties, polycarbonate is preferred.
[0062]
The composition ratio of these binder resins to the charge transport material is in the range of 0.25 to 3 with respect to the binder resin 1 by weight. In addition to the charge transport material and the binder resin, an antioxidant, an ultraviolet absorber and the like can be added to prevent the deterioration of these materials.
[0063]
Furthermore, organic solvents for dissolving these charge transport materials and binder resins to form charge transport layer coatings include chlorinated hydrocarbons such as dichloromethane and chloroform, cyclic ethers such as dioxane and tetrahydrofuran, toluene Aromatic hydrocarbons such as xylene are used. These organic solvents can be used singly or in combination of two or more, and are used by adjusting the concentration of the non-volatile content in the charge transport layer coating material in the range of 10 to 40% by weight.
[0064]
In general, the charge transport layer 14 is formed by a dip coating apparatus 41 as shown in FIG. 4 using the thus prepared charge transport layer coating material. Specifically, an aluminum tube 43 that is a conductive support on which the charge generation layer 12 and the intermediate layer 13 are formed is mounted on a movable portion 44 provided with a gripping device, and the charge transport layer coating 40 is placed in the container. After being immersed in the pot 42, the charge transport layer is formed by pulling up at a predetermined speed. The pot 42 is provided with a circulation pump 45 and a filter unit 46. After the dip coating, the organic solvent component is volatilized by a hot air dryer or the like, and a charge transport layer having a thickness of about 5 to 40 μm is formed after drying.
[0065]
As described above, according to the electrophotographic photoreceptor 10 of the first embodiment, the resin (I) obtained by acetalizing polyvinyl alcohol with butyraldehyde on the charge generation layer 12 formed of a vapor deposition film of an organic pigment, and butyraldehyde By forming the intermediate layer 13 composed of the resin (II) acetalized with an aldehyde other than the above, it is possible to improve the adhesiveness with the charge transport layer 14 and to change the potential in a high temperature / high humidity or low temperature / low humidity environment. Environmental stability can also be improved. As a result, it is possible to realize an electrophotographic photoreceptor excellent in environmental stability and excellent in adhesiveness with a conductive support.
[0066]
(Embodiment 2)
While the electrophotographic photoreceptor according to the first exemplary embodiment of the present invention forms the charge generation layer in the entire region of the conductive support, the electrophotographic photosensitive member according to the second exemplary embodiment includes the photoconductor. The difference is that the charge generation layer is formed only in a region requiring electrophotographic characteristics.
[0067]
FIG. 5 schematically shows the configuration of the electrophotographic photoreceptor according to the second exemplary embodiment of the present invention. In FIG. 5, as an example, a surface view schematically showing the structure of an electrophotographic photoreceptor formed on a cylindrical aluminum tube on the upper side (hereinafter referred to as “cylindrical electrophotographic photoreceptor”) is shown. A sectional view schematically showing the configuration of a cylindrical electrophotographic photoreceptor is shown below.
[0068]
In FIG. 5, a cylindrical electrophotographic photoreceptor 50 is formed by laminating a charge generation layer 52, an intermediate layer 53, and a charge transport layer 54 in this order on a conductive support 51, as in FIG. is there. Each configuration is the same as that shown in FIG. 1, but the electrophotographic photoreceptor 50 according to Embodiment 2 has a configuration in which a charge generation layer is formed only in a region 55 that requires electrophotographic characteristics of the photoreceptor. It has become.
[0069]
  Specifically, in the vapor deposition apparatus of FIG. 2, the charge generation layer 52 is formed by attaching a shielding plate so that the organic pigment does not adhere to both ends of the conductive support 51. ThisElectrophotographic characteristicsIt is possible to prevent the organic pigment from adhering to both end portions of the conductive support 51, which is a portion that does not require the above. Further, the intermediate layer 53 and the charge transport layer 54 are sequentially laminated on the entire region of the conductive support 51 on which the charge generation layer 52 is formed, thereby completing the cylindrical electrophotographic photoreceptor 50.
[0070]
As described above, according to the cylindrical electrophotographic photoreceptor 50 of the second embodiment, the charge generation layer 52 is formed only in the region requiring the electrophotographic characteristics, while the resin is mainly applied to the entire area on the conductive support 51. By forming the intermediate layer 53 and the charge transport layer 54 as components, it is possible to improve the adhesion of the charge transport layer 54 to the conductive support 51 in a region where the charge generation layer 52 is not formed.
[0071]
Also in the second embodiment, as in the first embodiment, a resin (I) obtained by acetalizing polyvinyl alcohol with butyraldehyde and acetalized with an aldehyde other than butyraldehyde on the charge generation layer 52. By forming the intermediate layer 53 made of the resin (II), the adhesiveness with the charge transport layer 54 is improved, and the environmental stability such as potential fluctuation in a high temperature and high humidity or low temperature and low humidity environment is improved. Can do. As a result, it is possible to realize an electrophotographic photoreceptor excellent in environmental stability and excellent in adhesiveness with a conductive support.
[0072]
FIG. 6 is a cross-sectional view showing a schematic configuration of an image forming apparatus equipped with electrophotographic photoreceptors 10 and 50 according to Embodiments 1 and 2 of the present invention.
[0073]
The image forming apparatus shown in FIG. 1 includes a reading unit 602 that scans a document and reads an image on the top of a housing 601, and an upper cover 603 that opens and closes the document reading surface is attached to the upper surface of the reading unit 602 so as to be freely opened and closed. ing.
[0074]
A discharge space 604 for discharging recording paper is formed in the lower portion of the reading unit 602 in the housing 601, and the lower surface of the discharge space 604 functions as a discharge tray 605. In addition, a paper feed cassette 606 that stores recording paper is disposed at the bottom of the housing 601.
[0075]
A pickup roller 607 is disposed above and below the sheet feeding side end of the sheet feeding cassette 606 so as to be movable up and down, and a sheet feeding roller 608 and a separation roller 609 are disposed opposite to each other in the vicinity of the pickup roller 607. The paper feed roller 608 is a roller for feeding the recording paper taken out from the paper feed cassette 606 by the pickup roller 607 to the transport path, and the separation roller 609 is a plurality of sheets taken out from the paper feed cassette 606 in an overlapping manner. A roller for separating one sheet from a recording sheet.
[0076]
A recording paper conveyance path is formed substantially vertically upward from the lower portion of the housing 601. The electrophotographic photoreceptor 10 (50) according to the present invention is disposed on the conveyance path. A registration roller 610 for controlling the conveyance timing of the recording paper passing through the electrophotographic photoreceptor 10 (50) is disposed near the entrance of the conveyance path. The electrophotographic photoreceptor 10 (50) is held by a process cartridge 611. A laser scan unit (LSU) 612 is disposed inside the apparatus with respect to the process cartridge 611. The LSU 612 forms a latent image on the electrophotographic photoreceptor 10 (50). Further, a transfer roller 613 is disposed opposite to the electrophotographic photoreceptor 10 (50), and the transfer roller 613 transfers the toner attached to the electrophotographic photoreceptor 10 (50) onto a recording sheet.
[0077]
A fixing unit 614 is installed on the downstream side of the process cartridge 611 in the recording paper conveyance path. The fixing unit 614 includes a fixing roller 615 and a pressure roller 616 that is pressed against the fixing roller 615 with a predetermined pressure. The recording paper fed from the fixing roller 615 and the pressure roller 616 is discharged to the paper discharge tray 605 by a discharge roller 617 provided on the discharge space 604 side of the fixing unit 614.
[0078]
FIG. 7 is an enlarged schematic sectional view of the process cartridge 611 holding the electrophotographic photoreceptor 10 (50) according to the present invention.
[0079]
In the process cartridge 611, the electrophotographic photoreceptor 10 (50) is grounded through a rotating shaft and is driven to rotate counterclockwise as indicated by an arrow in the figure. The electrophotographic photoreceptor 10 (50) is charged by the charging roller 702 of the charging unit 701. Specifically, the charging roller 702 superimposes a DC bias or an AC bias to give a uniform charge on the electrophotographic photoreceptor 10 (50).
[0080]
After the electrophotographic photoreceptor 10 (50) is uniformly charged, image exposure based on the image signal from the LSU 612 is performed. The light source used for the LSU 612 is a semiconductor laser, and laser light is scanned on the electrophotographic photoreceptor 10 (50) by an optical system such as a polygon mirror and an fθ lens, and photoelectric conversion of the electrophotographic photoreceptor 10 (50) is performed. An electrostatic latent image is formed on the electrophotographic photoreceptor 10 (50) by the function.
[0081]
Next, the electrostatic latent image is developed by the developing unit 703, and a toner image is formed on the electrophotographic photoreceptor 10 (50). Specifically, in the case of magnetic one-component toner, a toner layer regulated by a developing blade 706 is formed on a developing roller 705 containing a magnet 704, and the electrophotographic photoreceptor 10 (50), the developing roller 705, and the like. Development is performed with a DC bias or AC bias applied between the two. The developing roller 705 is driven to rotate clockwise as indicated by an arrow in the figure.
[0082]
The distance between the developing roller 705 and the electrophotographic photoreceptor 10 (50) is kept constant by a gap spacer 707 attached to the developing roller 705. The gap spacer 707 is attached to both ends of the circumferential surface of the developing roller 705 (ends on the back side and the near side shown in FIG. 7), and is the outermost surface layer (circumferential surface) of the electrophotographic photoreceptor 10 (50). Touch both ends. In particular, in the electrophotographic photoreceptor 50 according to the second embodiment, contact is made at a portion where the charge generation layer 52 is not formed.
[0083]
As described above, the gap spacer 707, which is a member for maintaining the distance between the electrophotographic photoreceptor 10 (50) and the developing roller 705, is brought into contact with the outermost surface layer of the electrophotographic photoreceptor 10 (50). With the configuration, the interval between the electrophotographic photoreceptor 10 (50) and the developing roller 705 can be maintained at a constant interval, and the interval between the electrophotographic photoreceptor 10 (50) and the developing roller 705 is maintained at a constant interval. There is no need to provide a separate mechanism.
[0084]
When the gap spacer 707 is brought into contact with the outermost surface layer of the electrophotographic photoreceptor 10 (50), peeling of the surface layer of the electrophotographic photoreceptor 10 (50) may occur as a problem. Since the image forming apparatus uses the electrophotographic photoreceptor 10 (50) in which the adhesion of each layer described above is improved, occurrence of such a problem can be reduced. In particular, when the electrophotographic photoreceptor 50 according to the second embodiment is used, the both ends of the electrophotographic photoreceptor 50 having improved adhesion come into contact with the gap spacer 707, and thus the occurrence of this problem. It can be further reduced.
[0085]
The toner image formed on the electrophotographic photoreceptor 10 (50) is transferred to the recording paper supplied from the paper feed cassette 606 by the transfer roller 613 described above. The recording paper on which the toner image is transferred is separated from the electrophotographic photoreceptor 10 (50) and sent to the fixing unit 614. After the toner image is heated and fixed on the recording paper by the fixing unit 614, the recording paper is discharged to the paper discharge tray 605.
[0086]
On the other hand, in the electrophotographic photoreceptor 10 (50), the residual toner is removed by pressure contact of the cleaning blade 709 of the cleaning unit 708, and the surface is cleaned, and the process returns to the charging unit 701 for the next image forming process. to go into.
[0087]
As is apparent from the above description, the process cartridge 611 shown in FIG. 7 includes the electrophotographic photoreceptor 10 (50), the charging unit 701 having the charging roller 702, the developing unit 703 having the developing roller 705, and the cleaning blade. The cleaning unit 708 having the 709 is integrally provided. However, the present invention is not limited to the case where all of these functions are provided, and the process cartridge 611 may be configured by combining some of these functions.
[0088]
【Example】
Hereinafter, specific examples and comparative examples of the electrophotographic photoreceptor according to the embodiment of the present invention will be described.
[0089]
Example 1
An aluminum (aluminum-magnesium-silicon alloy) cutting tube having an outer diameter of 30 mm, an inner diameter of 28.5 mm, and a length of 254 mm was washed with a degreasing detergent (Clean Through LC870 manufactured by Kao Corporation) and ion-exchanged water. It attaches to the vapor deposition equipment. 5 × 10^-3An oxotitanium phthalocyanine deposited film was formed on an aluminum tube under a reduced pressure of Pa. The amount of oxotitanium phthalocyanine per aluminum tube was 2 mg.
[0090]
Next, 2 parts by weight of resin (I) (Sekisui Chemical Co., Ltd., ESREC BL-1) obtained by acetalizing polyvinyl alcohol with butyraldehyde with respect to 100 parts by weight of ethanol (first grade reagent manufactured by Kanto Chemical Co., Ltd.) The aluminum tube in which the vapor-deposited film was formed in a solution in which 0.5 part by weight of resin (II) (Sekisui Chemical Co., Ltd. S-REC BX-1) acetalized with an aldehyde other than butyraldehyde was added is shown in FIG. The intermediate layer is dip coated with a dip treatment apparatus. The amount of resin per aluminum tube in the intermediate layer was 3 mg. That is, the amount is 1.5 times the amount of 2 mg of oxotitanium phthalocyanine which is the organic pigment vapor deposition film of the charge generation layer. Subsequently, 18 parts by weight of 2-methyl-4-dibenzylaminobenzaldehyde-N, N-diphenylhydrazone and 2 parts by weight of 1,1-bis (p-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene, Using a paint composed of 20 parts by weight of polycarbonate (Tufzette P-300 manufactured by Idemitsu Kosan Co., Ltd.) and 100 parts by weight of dichloromethane, a charge transport layer is provided so that the film thickness after drying is 25 μm in the dip coating apparatus of FIG. The photoreceptor was completed.
[0091]
Evaluation is performed by attaching the obtained photoconductor to a process cartridge of Panafax UF770 manufactured by Matsushita Electric Power Systems Co., Ltd. The post potential VL was measured. The results of this potential measurement are shown in Table 1. The same measurement was also performed under a high temperature and high humidity environment (35 ° C. and 70%) and a low temperature and low humidity environment (10 ° C. and 15%). Further, the photosensitive layer peels off (gap part peeling) at the gap spacer 707 that keeps the distance from the developing roller 705 in the low temperature and low humidity environment, and the potential measurement result after repeated printing of 8000 sheets (characteristic after printing 8000 sheets). Table 1 also shows the number of printed pages.
[0092]
(Example 2)
In Example 2, a photoconductor was prepared and evaluated in the same manner as in Example 1 except that 2.25 parts by weight of resin (I) and 0.25 parts by weight of resin (II) in Example 1 were used. . The results are shown in Table 1.
[0093]
(Example 3)
In Example 3, a photoconductor was prepared and evaluated in the same manner as in Example 1 except that the resin (I) in Example 1 was changed to 1.25 parts by weight and the resin (II) was changed to 1.25 parts by weight. . The results are shown in Table 1.
[0094]
Example 4
In Example 4, the photoconductor was prepared in the same manner as in Example 1 except that the resin concentration of the intermediate layer paint was 1.8% and the resin amount per aluminum tube of the intermediate layer in Example 1 was 2 mg. Created and evaluated. That is, this is the case where the amount of resin in the intermediate layer is the same as the amount of oxotitanium phthalocyanine 2 mg that is the organic pigment vapor deposition film of the charge generation layer. The results are shown in Table 1.
[0095]
(Example 5)
In Example 5, a photoconductor was prepared in the same manner as in Example 1 except that the resin concentration of the intermediate layer coating was 3% and the resin amount per aluminum tube of the intermediate layer in Example 1 was 4 mg. Evaluation was performed. This is a case where the amount of resin in the intermediate layer is twice the amount of 2 mg of oxotitanium phthalocyanine which is the organic pigment vapor deposition film of the charge generation layer. The results are shown in Table 1.
[0096]
(Example 6)
In Example 6, when forming the oxotitanium phthalocyanine vapor deposition film, a shielding plate was provided inside the vapor deposition apparatus so that the vapor deposition film did not adhere to both end portions 10 mm of the aluminum tube. Other than that, a photoconductor was prepared and evaluated in the same manner as in Example 1. That is, the evaluation was performed using the electrophotographic photoreceptor 50 according to the second embodiment. The results are shown in Table 1. Here, as shown in Table 1, good results could be obtained particularly in the evaluation of gap part peeling.
[0097]
(Comparative Example 1)
In Comparative Example 1, a photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the intermediate layer in Example 1 was not provided. The results are shown in Table 1. Here, as shown in Table 1, it can be seen that there are particularly large fluctuations in environmental fluctuations and repeated fluctuations. In the evaluation of gap peeling, it can be recognized that the film strength of the photosensitive layer is insufficient.
[0098]
(Comparative Example 2)
In Comparative Example 2, a photoreceptor was prepared and evaluated in the same manner as in Example 1 except that 2.5 parts by weight of the resin (I) in Example 1 was not used and the resin (II) was not used. The results are shown in Table 1. Here, it can be recognized that the film strength of the photosensitive layer is insufficient in the evaluation of the peeling of the gap compared to the evaluation of Example 1 or the like.
[0099]
(Comparative Example 3)
In Comparative Example 3, a photoreceptor was prepared and evaluated in the same manner as in Example 1 except that 2.5 parts by weight of the resin (II) in Example 1 was not used. The results are shown in Table 1. Here, although some improvement is seen in the evaluation of the gap peeling, it can be seen that there are large fluctuations in environmental fluctuations and repeated fluctuations, particularly in high temperature and high humidity.
[0100]
(Comparative Example 4)
In Comparative Example 4, a photoconductor was prepared in the same manner as in Example 1 except that the resin content concentration of the intermediate layer paint was 5% and the amount of resin per aluminum tube in the intermediate layer in Example 1 was 7 mg. Evaluation was performed. This is a case where the amount of resin in the intermediate layer is 3.5 times the amount of 2 mg of oxotitanium phthalocyanine which is the organic pigment vapor deposition film of the charge generation layer. The results are shown in Table 1. Here, it can be seen that there are large fluctuations in environmental fluctuations and repetitive fluctuations, particularly in high temperature and high humidity.
[0101]
[Table 1]

  As is apparent from the results shown in Table 1, the electrophotographic photoreceptor according to the present embodiment exhibits good electrophotographic characteristics, small environmental fluctuations and repeated fluctuations, and excellent film strength of the photosensitive layer. Indicates. In particular, in the above example, when the intermediate layer is not formed (Comparative Example 1), the amount of resin in the intermediate layer is the same as 2 mg of oxotitanium phthalocyanine which is the organic pigment vapor deposition film of the charge generation layer (Example) 4) When the amount of oxotitanium phthalocyanine is 1.5 times the amount of 2 mg (Example 1),DoubleIn the case of (Example 5) and 3.5 times (Comparative Example 4), the evaluation is performed. From this evaluation result, the resin amount of the intermediate layer is the mass of the organic pigment vapor deposition film of the charge generation layer.1 to 2 timesIt can be recognized that when the amount is set to 1, the electrophotographic characteristics are good, the environmental variation and the repetitive variation are small, and the film strength of the photosensitive layer is excellent.
[0102]
【The invention's effect】
As described above, according to the present invention, the environmental stability is excellent, the adhesiveness is high, the sensitivity to the semiconductor laser light is high, and the sensitivity, the charging property, and the repetitive stability of these photoconductor characteristics are improved. In addition, an excellent electrophotographic photoreceptor and a method for producing the same can be provided.
[0103]
Further, by using the electrophotographic photoreceptor, it is possible to provide an image forming apparatus and a process cartridge capable of obtaining a stable image under any environment.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing a configuration of an electrophotographic photoreceptor according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing the configuration of a vapor deposition apparatus used in an example of the present invention.
FIG. 3 is a schematic diagram showing the configuration of an intermediate layer forming dip coating apparatus used in an example of the present invention.
FIG. 4 is a schematic diagram showing the configuration of a dip coating apparatus for forming a charge transport layer used in an example of the present invention.
FIG. 5 is a cross-sectional view schematically showing the configuration of an electrophotographic photoreceptor according to an embodiment of the present invention.
FIG. 6 is a cross-sectional view of an image forming apparatus equipped with an electrophotographic photoreceptor according to an embodiment of the present invention.
FIG. 7 is a sectional view of a process unit on which an electrophotographic photoreceptor according to an embodiment of the present invention is mounted.
[Explanation of symbols]
10 Photoconductor for electrophotography
11 Conductive support
12 Charge generation layer
13 Middle layer
14 Charge transport layer
20 Organic Pigment (Charge-generating substance (oxotitanium phthalocyanine))
21 Chamber of vapor deposition equipment
22 Aluminum tube (conductive support)
23 Deposition source
24 Exhaust port
30 Intermediate layer paint
31 Immersion coating equipment
32 pots
33 Aluminum tube (conductive support with deposited charge generation material)
34 Movable part with gripping device
35 Circulation pump
36 Filter unit
40 Paint for charge transport layer
41 Immersion coating equipment
42 pots
43 Aluminum tube (conductive support with charge generation layer and intermediate layer formed)
44 Movable part with gripping device
45 Circulation pump
46 Filter unit
50 Electrophotographic photoreceptor (cylindrical electrophotographic photoreceptor)
51 Conductive support (aluminum tube)
52 Charge generation layer
53 Middle layer
54 Charge transport layer
55 Areas that require electrophotographic characteristics
606 Paper cassette
611 Process cartridge
612 Laser Scan Unit (LSU)
613 Transfer roller
614 Fixing unit
701 Charging part
702 Charging roller
703 Development section
705 Development roller
706 Development blade
708 Cleaning section
709 Cleaning blade

Claims (8)

An electrophotographic photosensitive member in which at least a charge generation layer, an intermediate layer, and a charge transport layer are laminated in this order on a conductive support, wherein the organic pigment obtained by heating and vaporizing the charge generation layer by vapor deposition is used as the conductive support. A vapor-deposited film deposited thereon, wherein the intermediate layer contains a resin (I) obtained by acetalizing polyvinyl alcohol with butyraldehyde and a resin (II) obtained by acetalization with an aldehyde other than butyraldehyde. An electrophotographic photoreceptor. 2. The electrophotographic photoreceptor according to claim 1, wherein the mass ratio of the organic pigment vapor deposition film of the charge generation layer and the resin of the intermediate layer is in the range of 1: 1 to 2 . In a method for producing an electrophotographic photosensitive member in which at least a charge generation layer, an intermediate layer, and a charge transport layer are laminated in this order on a conductive support, the vaporized organic pigment is vapor-deposited on the conductive support. And the intermediate layer using a paint comprising a resin (I) acetalized with polyvinyl butyraldehyde and a resin (II) acetalized with an aldehyde other than butyraldehyde. And a process for forming an electrophotographic photoreceptor. 4. The method for producing an electrophotographic photoreceptor according to claim 3, wherein a mass ratio of the organic pigment vapor deposition film of the charge generation layer and the resin of the intermediate layer is in a range of 1: 1 to 2. The electrophotographic photoreceptor according to claim 1, wherein the electrophotographic photoreceptor is used in an image forming apparatus that uses an electrophotographic photoreceptor to form an image through charging, image exposure, development, transfer / separation, and cleaning processes. An image forming apparatus. 6. The image forming apparatus according to claim 5, wherein a member for maintaining a distance between the electrophotographic photosensitive member and a developing roller used in a developing step is in contact with an outermost surface layer of the electrophotographic photosensitive member. 3. The electrophotographic apparatus according to claim 1, wherein the electrophotographic photosensitive member is used in an image forming apparatus that forms an image through charging, image exposure, development, transfer / separation, and cleaning processes. A process cartridge comprising a photosensitive member for use in combination with a charging unit, an image exposure unit, a developing unit, a transfer or separation unit, and a cleaning unit. 8. The process cartridge according to claim 7, wherein a member for maintaining a distance between the electrophotographic photosensitive member and a developing roller of the developing unit is in contact with the outermost surface layer of the electrophotographic photosensitive member.

Images