JP4166380B2 - Electrophotographic photoreceptor - Google Patents

Description

【００１５】
〔式中、Ｒ₁〜Ｒ₁₂は、各々独立に炭素数１〜６のアルキル基又は炭素数６〜１２の芳香族炭化水素基のいずれかを表し、ａ〜ｃは２〜６の整数を表し、ｄは０〜２００の整数を表す。〕
【００１６】
【化１９】

【００１７】
〔式中、Ｒ₂₃は、水素原子又は炭素数１〜４のアルキル基のいずれかを表し、Ｒ₂₄〜Ｒ₂₆は、同一であっても異なっていてもよく、各々独立に水素原子、ハロゲン原子、置換基を有してもよい炭素数１〜４のアルキル基若しくはアルコキシ基、置換アミノ基又は炭素数６〜１２のアリール基のいずれかを表す。〕
【００１８】
【化２０】

【００１９】
〔式中、Ｒ_{23 ′}は、水素原子又は炭素数１〜４のアルキル基のいずれかを表し、Ｒ_{24 ′}〜Ｒ_{26 ′}は、同一であっても異なっていてもよく、各々独立に水素原子、ハロゲン原子、置換基を有してもよい炭素数１〜４のアルキル基若しくはアルコキシ基、置換アミノ基又は炭素数６〜１２のアリール基のいずれかを表す。〕
【００２０】
かかる構成を有する請求項１記載の発明にあっては、感光層中に結着樹脂として一般式〔Ｉ〕で表されるシロキサン構造からなる繰り返し単位を含むポリカーボネート共重合体を含有することによって、離型性及び潤滑性が向上するため、感光層の摩擦係数が低減する。
【００２１】
また、電荷移動剤として一般式〔ＩＶ〕及び（又は）〔ＩＶ’〕で表される化合物を含有することによって、光疲労しにくくなる。
【００２２】
この場合、請求項２記載の発明のように、請求項１記載の発明において、感光層中に結着樹脂として一般式〔Ｉ〕、一般式〔ＩＩ〕及び一般式〔ＩＩＩ〕で表される繰り返し単位からなるポリカーボネート共重合体を含有することもできる。
【００２３】
【化２１】

【００２４】
〔式中、Ｒ₁〜Ｒ₁₂は、各々独立に炭素数１〜６のアルキル基又は炭素数６〜１２の芳香族炭化水素基のいずれかを表し、ａ〜ｃは２〜６の整数を表し、ｄは０〜２００の整数を表す。〕
【００２５】
【化２２】

【００２６】
〔式中、Ａは、単結合、−Ｏ−、−ＣＯ−、−Ｓ−、−ＳＯ−、−ＳＯ₂−、
−ＣＲ₁₅Ｒ₁₆−（但し、Ｒ₁₅及びＲ₁₆は、各々独立に水素原子、トリフルオロメチル基、炭素数１〜６のアルキル基、炭素数６〜１２のアリール基又は置換アリール基のいずれかを表す。）、炭素数５〜８の１，１−シクロアルキリデン基、９，９−フルオレニリデン基又は炭素数２〜１２のα，ω-アルキレン基のいずれかを表す。
また、Ｒ₁₃及びＲ₁₄は、各々独立にハロゲン原子、炭素数１〜６のアルキル基、炭素数６〜１２のアリール基又は置換アリール基のいずれかを表し、ｅ及びｆは、各々独立に０〜４の整数を表す。〕
【００２７】
【化２３】

【００２８】
〔式中、Ｂは、単結合、−Ｏ−、−ＣＯ−、−Ｓ−、−ＳＯ−、−ＳＯ₂−、
−ＣＲ₁₉Ｒ₂₀−（但し、Ｒ₁₉及びＲ₂₀は、各々独立に水素原子、トリフルオロメチル基、炭素数１〜６のアルキル基、炭素数６〜１２のアリール基又は置換アリール基のいずれかを表す。）、炭素数５〜８の１，１−シクロアルキリデン基、炭素数２〜１２のα，ω-アルキレン基又は一般式〔ＩＩＩ’〕で表される官能基のいずれかを表す。
また、Ｒ₁₇及びＲ₁₈は、各々独立にハロゲン原子、炭素数１〜６のアルキル基、炭素数６〜１２のアリール基又は置換アリール基のいずれかを表す。
ここで、Ｂが−Ｏ−、−ＣＯ−、−Ｓ−、−ＳＯ−、−ＳＯ₂−、−ＣＲ₁₉Ｒ₂₀−、炭素数５〜８の１,１−シクロアルキリデン基、炭素数２〜１２のα，ω-アルキレン基のいずれかの場合、ｇ及びｈは、各々独立に１〜４の整数を表す。
Ｂが単結合、または一般式〔ＩＩＩ’〕の場合、ｇ及びｈは、各々独立に０〜４の整数を表す。〕
【００２９】
【化２４】

【００３０】
〔式中、Ｒ₂₁及びＲ₂₂は、各々独立にハロゲン原子、炭素数１〜１２のアルキル基、シクロヘキシル基、炭素数６〜１２のアリール基又は置換アリール基のいずれかを表し、Ｄは単結合、−Ｏ−、−ＣＯ−、−Ｓ−、−ＳＯ−、−ＳＯ₂−のいずれかを表し、ｉ及びｊは０〜４の整数である。〕
【００３１】
請求項２記載の発明の場合、感光層中に結着樹脂として一般式〔Ｉ〕で表される繰り返し単位に加え、一般式〔ＩＩ〕及び一般式〔ＩＩＩ〕で表される繰り返し単位を共重合させてなるポリカーボネート共重合体を含有することによって、耐トナーフィルミング性が向上するようになる。
【００３２】
特に、請求項３記載の発明のように、請求項２記載の発明において、感光層中に結着樹脂として式〔Ｉａ〕、式〔ＩＩａ〕及び式〔ＩＩＩａ〕で表される繰り返し単位からなるポリカーボネート共重合体を含有することもできる。
【００３３】
【化２５】

【００３４】
〔式中、ｄは０〜２００の整数を表し、好ましい範囲は１０〜１００である。〕
【００３５】
【化２６】

【００３６】
【化２７】

【００３７】
請求項３記載の発明は、摩擦係数が小さく、高耐刷性、耐油性の点で好ましいものである。
【００３８】
さらに、請求項４記載の発明のように、請求項２記載の発明において、感光層中に結着樹脂として式〔Ｉａ〕、式〔ＩＩａ〕及び式〔ＩＩＩｂ〕で表される繰り返し単位からなるポリカーボネート共重合体を含有することもできる。
【００３９】
【化２８】

【００４０】
〔式中、ｄは０〜２００の整数を表し、好ましい範囲は１０〜１００である。〕
【００４１】
【化２９】

【００４２】
【化３０】

請求項４記載の発明もまた、摩擦係数が小さく、高耐刷性、耐油性の点で好ましいものである。
【００４３】
また、請求項５記載の発明のように、請求項１乃至４のいずれか１項記載の発明において、電荷移動剤として式〔ＩＶａ〕及び（又は）〔ＩＶａ’〕で表される化合物を用いることもできる。
【００４４】
【化３１】

【００４５】
【化３２】

【００４６】
請求項５記載の発明もまた、感光体の感度が高感度になり、光疲労にも強くなる点で好ましいものである。
【００４７】
さらに、請求項６記載の発明のように、請求項１乃至５のいずれか１項記載の発明において、電荷移動剤として式〔ＩＶｂ〕及び（又は）〔ＩＶｂ’〕で表される化合物を用いることもできる。
【００４８】
【化３３】

【００４９】
【化３４】

【００５０】
請求項６記載の発明もまた、感光体の感度が高感度になり、光疲労にも強くなる点で好ましいものである。
【００５１】
【発明の実施の形態】
以下、本発明に係る電子写真感光体の好ましい実施の形態を詳細に説明する。図１及び図２は、本発明に係る電子写真感光体の好ましい実施の形態の構成を示す断面図である。
図１は、本発明に適用可能な機能分離型の電子写真感光体の構造の一例を示したものであり、円筒状の導電性支持体１上に、電荷発生層２と電荷移動層３とがこの順で形成されており、これら電荷発生層２と前記電荷移動層３とによって感光層４が構成される。
【００５２】
また、図２は、本発明に適用可能な単層型の電子写真感光体の構造の一例を示したものであり、導電性支持体１上に電荷発生剤と電荷移動剤とを含有させた感光層４が形成されている。
【００５３】
本発明に用いることができる導電性支持体１としては、アルミニウム、真鍮、ステンレス鋼、ニッケル、クロム、チタン、金、銀、銅、錫、白金、モリブデン、インジウム等の金属単体やその合金の加工体や、上記金属や炭素等の導電性物質を蒸着、メッキ等の方法で処理し、導電性を持たせたプラスチック板およびフィルム、さらに酸化錫、酸化インジウム、ヨウ化アルミニウムで被覆した導電性ガラス等、種類や形状に制限されることなく、導電性を有する種々の材料を使用して導電性支持体１を構成することができる。また、導電性支持体１の形状については、ドラム状、棒状、板状、シート状、ベルト状のものを使用することができる。
【００５４】
本発明に用いることができる電荷発生剤としては、ジスアゾ顔料やオキシチタニウムフタロシアニンが感度の相性が良い点で望ましいが、それに限定されるものではない。その他、例えば、セレン、セレン−テルル、セレン−砒素、アモルファスシリコン、無金属フタロシアニン、他の金属フタロシアニン顔料、モノアゾ顔料、トリスアゾ顔料、ポリアゾ顔料、インジゴ顔料、スレン顔料、トルイジン顔料、ピラゾリン顔料、ペリレン顔料、キナクリドン顔料、多環キノン顔料、ピリリウム塩等を用いることができる。
【００５５】
これらの電荷発生剤は単体で用いてもよいし、適切な光感度波長や増感作用を得るために２種類以上を混合して用いてもよい。
【００５６】
本発明の電子写真感光体は、その感光層４中に結着樹脂として一般式〔Ｉ〕で表されるシロキサン構造からなる繰り返し単位を含むポリカーボネート共重合体を含有するものである。
【００５７】
【化３５】

【００５８】
〔式中、Ｒ₁〜Ｒ₁₂は、各々独立に炭素数１〜６のアルキル基又は炭素数６〜１２の芳香族炭化水素基のいずれかを表し、ａ〜ｃは２〜６の整数を表し、ｄは０〜２００の整数を表す。〕
【００５９】
そして、本発明にあっては、シロキサン構造からなる繰り返し単位を含むポリカーボネート共重合体を含有することによって、離型性及び潤滑性が向上するため、感光層の摩擦係数を低減させることができる。
【００６０】
また、本発明のポリカーボネート共重合体は、前記シロキサン構造単位の他に一般式〔ＩＩ〕及び一般式〔ＩＩＩ〕で表されるポリカーボネート構造単位を繰り返し単位とすることができる。これらポリカーボネート構造単位は、その特性、合成の容易さ、あるいは樹脂の用途等により適宜選択することができる。
【００６１】
【化３６】

【００６２】
〔式中、Ａは、単結合、−Ｏ−、−ＣＯ−、−Ｓ−、−ＳＯ−、−ＳＯ₂−、
−ＣＲ₁₅Ｒ₁₆−（但し、Ｒ１５及びＲ１６は、各々独立に水素原子、トリフルオロメチル基、炭素数１〜６のアルキル基、炭素数６〜１２のアリール基又は置換アリール基のいずれかを表す。）、炭素数５〜８の１，１−シクロアルキリデン基、９，９−フルオレニリデン基又は炭素数２〜１２のα，ω-アルキレン基のいずれかを表す。
また、Ｒ₁₃及びＲ₁₄は、各々独立にハロゲン原子、炭素数１〜６のアルキル基、炭素数６〜１２のアリール基又は置換アリール基のいずれかを表し、ｅ及びｆは、各々独立に０〜４の整数を表す。〕
【００６３】
【化３７】

【００６４】
〔式中、Ｂは、単結合、−Ｏ−、−ＣＯ−、−Ｓ−、−ＳＯ−、−ＳＯ₂−、
−ＣＲ₁₉Ｒ₂₀−（但し、Ｒ₁₉及びＲ₂₀は、各々独立に水素原子、トリフルオロメチル基、炭素数１〜６のアルキル基、炭素数６〜１２のアリール基又は置換アリール基のいずれかを表す。）、炭素数５〜８の１，１−シクロアルキリデン基、炭素数２〜１２のα，ω-アルキレン基又は一般式〔ＩＩＩ’〕で表される官能基のいずれかを表す。
また、Ｒ₁₇及びＲ₁₈は、各々独立にハロゲン原子、炭素数１〜６のアルキル基、炭素数６〜１２のアリール基又は置換アリール基のいずれかを表す。
ここで、Ｂが−Ｏ−、−ＣＯ−、−Ｓ−、−ＳＯ−、−ＳＯ₂−、−ＣＲ₁₉Ｒ₂₀−、炭素数５〜８の１,１−シクロアルキリデン基、炭素数２〜１２のα，ω-アルキレン基のいずれかの場合、ｇ及びｈは、各々独立に１〜４の整数を表す。
Ｂが単結合、または一般式〔ＩＩＩ’〕の場合、ｇ及びｈは、各々独立に０〜４の整数を表す。〕
【００６５】
【化３８】

【００６６】
〔式中、Ｒ₂₁及びＲ₂₂は、各々独立にハロゲン原子、炭素数１〜１２のアルキル基、シクロヘキシル基、炭素数６〜１２のアリール基又は置換アリール基のいずれかを表し、Ｄは単結合、−Ｏ−、−ＣＯ−、−Ｓ−、−ＳＯ−、−ＳＯ₂−のいずれかを表し、ｉ及びｊは０〜４の整数である。〕
【００６７】
この場合、低摩擦係数化、高耐刷性、耐油性の観点からは、例えば、式〔Ｉａ〕、式〔ＩＩａ〕及び式〔ＩＩＩａ〕あるいは式〔Ｉａ〕、式〔ＩＩａ〕及び式〔ＩＩＩｂ〕で表される繰り返し単位からなるポリカーボネート共重合体を好適に用いることができる。
【００６８】
【化３９】

【００６９】
〔式中、ｄは０〜２００の整数を表し、好ましい範囲は１０〜１００である。〕
【００７０】
【化４０】

【００７１】
【化４１】

【００７２】
【化４２】

【００７３】
繰り返し単位を２種類以上有するポリカーボネート共重合体の場合、一般式〔Ｉ〕で表される繰り返し単位の含有割合が、一般式〔Ｉ〕で表される繰り返し単位のモル数と全ての繰り返し単位のモル数の合計に対するモル比で、０．０００１以上であることが望ましい。一般式〔Ｉ〕で表される繰り返し単位の含有割合が０．０００１以下の場合には耐フィルミング性向上の効果が十分に発揮されない。
【００７４】
また、前記ポリカーボネート共重合体は、塩化メチレンを溶媒とする濃度０．５ｇ／ｄｌの溶液の２０℃における還元粘度（ηＳＰ／ｃ）が０．５０ｄｌ／ｇ以上であると、成膜された感光層４の硬度が高くなり好ましい。
【００７５】
また、感光層４の構成を積層型あるいは逆積層型とした場合には、電荷発生層２及び電荷移動層３の片方あるいは両方に本発明の結着樹脂が用いられてもよいが、前記結着樹脂はその特性上、最表面層に含有されると、所望の特性が十分に発揮され好ましいものである。
【００７６】
一方、本発明の電子写真感光体においては、感光層４中に、上述した特定のポリカーボネート共重合体以外の結着樹脂を含有させることもできる。
【００７７】
感光層４を形成するために用いることができる結着樹脂としては、ポリカーボネート樹脂、スチレン樹脂、アクリル樹脂、スチレン−アクリル樹脂、エチレン−酢酸ビニル樹脂、ポリプロピレン樹脂、塩化ビニル樹脂、塩素化ポリエーテル、塩化ビニル−酢酸ビニル樹脂、ポリエステル樹脂、フラン樹脂、ニトリル樹脂、アルキッド樹脂、ポリアセタール樹脂、ポリメチルペンテン樹脂、ポリアミド樹脂、ポリウレタン樹脂、エポキシ樹脂、ポリアリレート樹脂、ジアリレート樹脂、ポリスルホン樹脂、ポリエーテルスルホン樹脂、ポリアリルスルホン樹脂、シリコーン樹脂、ケトン樹脂、ポリビニルブチラール樹脂、ポリエーテル樹脂、フェノール樹脂、ＥＶＡ（エチレン・酢酸ビニル・共重合体）樹脂、ＡＣＳ（アクリロニトリル・塩素化ポリエチレン・スチレン）樹脂、ＡＢＳ（アクリロニトリル・ブタジエン・スチレン）樹脂、エポキシアリレート等の光硬化樹脂等がある。これらは、１種でも２種以上混合して使用することも可能である。また、分子量の異なった樹脂を混合して用いれば、硬度や耐摩耗性を改善できるのでより好ましい。
【００７８】
本発明の電子写真感光体は、その感光層４中に電荷移動剤として一般式〔ＩＶ〕及び（又は）〔ＩＶ’〕で表される化合物を含有するものである。
【００７９】
【化４３】

【００８０】
〔式中、Ｒ₂₃は、水素原子又は炭素数１〜４のアルキル基のいずれかを表し、Ｒ₂₄〜Ｒ₂₆は、同一であっても異なっていてもよく、各々独立に水素原子、ハロゲン原子、置換基を有してもよい炭素数１〜４のアルキル基若しくはアルコキシ基、置換アミノ基又は炭素数６〜１２のアリール基のいずれかを表す。〕
【００８１】
【化４４】

【００８２】
〔式中、Ｒ_{23 ′}は、水素原子又は炭素数１〜４のアルキル基のいずれかを表し、Ｒ_{24 ′}〜Ｒ_{26 ′}は、同一であっても異なっていてもよく、各々独立に水素原子、ハロゲン原子、置換基を有してもよい炭素数１〜４のアルキル基若しくはアルコキシ基、置換アミノ基又は炭素数６〜１２のアリール基のいずれかを表す。〕
【００８３】
すなわち、本発明においては、一般式〔ＩＶ〕〔ＩＶ’〕で表される化合物のいずれか一方を含有する場合と、一般式〔ＩＶ〕〔ＩＶ’〕で表される化合物を両方を含有する場合が含まれる。
【００８４】
ここで、電荷移動層３中の一般式〔ＩＶ〕及び（又は）〔ＩＶ’〕で表される化合物の含有量は、結着樹脂１重量部に対し、０．５〜１．２重量部とすることが好ましい。
【００８５】
この化合物の含有量が０．５重量部より少ないと、残留電位が上昇するなど電気特性が悪化する。他方、１．２重量部より多いと、耐摩耗性等の機械特性が低下する。
【００８６】
一般式〔ＩＶ〕で表される化合物のうちでも、特に、式〔ＩＶａ〕で表される化合物、又は式〔ＩＶｂ〕で表される化合物を用いることが光疲労しない点で効果的である。
【００８７】
【化４５】

【００８８】
【化４６】

【００８９】
また、一般式〔ＩＶ'〕で表される化合物のうちでも、特に、式〔ＩＶａ'〕で表される化合物、又は式〔ＩＶｂ'〕で表される化合物を用いることが光疲労しない点で効果的である。
【００９０】
【化４７】

【００９１】
【化４８】

【００９２】
さらに、本発明の電子写真感光体の感光層４中には、他の電荷移動剤を添加することもできる。その場合には、感光層４の感度を高めたり、残留電位を低下させることができるので、本発明の電子写真感光体の特性を改良することができる。
【００９３】
そのような特性改良のために添加できる電荷移動剤としては、ポリビニルカルバゾール、ハロゲン化ポリビニルカルバゾール、ポリビニルピレン、ポリビニルインドロキノキサリン、ポリビニルベンゾチオフェン、ポリビニルアントラセン、ポリビニルアクリジン、ポリビニルピラゾリン、ポリアセチレン、ポリチオフェン、ポリピロール、ポリフェニレン、ポリフェニレンビニレン、ポリイソチアナフテン、ポリアニリン、ポリジアセチレン、ポリヘプタジイエン、ポリピリジンジイル、ポリキノリン、ポリフェニレンスルフィド、ポリフェロセニレン、ポリペリナフチレン、ポリフタロシアニン等の導電性高分子化合物を用いることができる。
【００９４】
また、低分子化合物として、トリニトロフルオレノン、テトラシアノエチレン、テトラシアノキノジメタン、キノン、ジフェノキノン、ナフトキノン、アントラキノン及びこれらの誘導体等、アントラセン、ピレン、フェナントレン等の多環芳香族化合物、インドール、カルバゾール、イミダゾール等の含窒素複素環化合物、フルオレノン、フルオレン、オキサジアゾール、オキサゾール、ピラゾリン、トリフェニルメタン、エナミン、スチルベン、ブタジエン、ヒドラゾン、トリフェニルアミン等を電荷移動剤として添加することができる。
【００９５】
また、同様の目的の電荷移動剤として、ポリエチレンオキシド、ポリプロピレンオキシド、ポリアクリロニトリル、ポリメタクリル酸等の高分子化合物にＬｉ（リチウム）イオン等の金属イオンをドープした高分子固体電解質等を添加することもできる。
【００９６】
さらに、同様の目的の電荷移動剤として、テトラチアフルバレン−テトラシアノキノジメタンで代表される電子供与性物質と電子受容性物質で形成された有機電荷移動錯体等も用いることができる。
【００９７】
なお、前記電荷移動剤は、１種だけ添加しても、２種以上の化合物を混合して添加しても所望の感光体特性を得ることができる。
【００９８】
本発明の電子写真感光体は、光導電材料や結着樹脂の酸化劣化による特性変化、クラックの防止、機械的強度の向上の目的で、その感光層４中に酸化防止剤や紫外線吸収剤を含有することが好ましい。
【００９９】
本発明に用いることができる酸化防止剤としては、2,6-ジ-tert-ブチルフェノール、2,6-ジ-tert-4-メトキシフェノール、2-tert-ブチル-4-メトキシフェノール、2,4-ジメチル-6-tert-ブチルフェノール、2,6-ジ-tert-ブチル-4-メチルフェノール、ブチル化ヒドロキシアニソール、プロピオン酸ステアリル-β-(3,5-ジ-tert-ブチル-4-ヒドロキシフェニル)、α-トコフェロール、β-トコフェロール、ｎ-オクタデシル-3-(3′-5′-ジ-tert-ブチル-4′-ヒドロキシフェニル)プロピオネート等のモノフェノール系、2,2′-メチレンビス(6-tert-ブチル-4-メチルフェノール）、4,4′-ブチリデン-ビス-(3-メチル-6-tert-ブチルフェノール)、4,4′-チオビス(6-tert-ブチル-3-メチルフェノール)、1,1,3-トリス(2-メチル-4-ヒドロキシ-5-tert-ブチルフェニル)ブタン、1,3,5-トリメチル-2,4,6-トリス(3,5-ジ-tert-ブチル-4-ヒドロキシベンジル)ベンゼン、テトラキス〔メチレン-3(3,5-ジ-tert-ブチル-4-ヒドロキシフェニル)プロピオネート〕メタン等のポリフェノール系等が好ましく、これらを１種若しくは２種以上を同時に感光層４中に含有することができる。
【０１００】
また、紫外線吸収剤としては、2-(5-メチル-2-ヒドロキシフェニル)ベンゾトリアゾール、2-〔2-ヒドロキシ-3,5-ビス(α,α-ジメチルベンジル)フェニル〕-2Ｈ-ベンゾトリアゾール、2-(3,5-ジ-tert-ブチル-2-ヒドロキシフェニル)ベンゾトリアゾール、2-(3-tert-ブチル-5-メチル-2-ヒドロキシフェニル)-5-クロロベンゾトリアゾール、2-(3,5-ジ-tert-ブチル-2-ヒドロキシフェニル)-5-クロロベンゾトリアゾール、2-(3,5-ジ-tert-アミル-2-ヒドロキシフェニル）ベンゾトリアゾール、2-(2′-ヒドロキシ-5′-tert-オクチルフェニル)ベンゾトリアゾール等のベンゾトリアゾール系、サリチル酸フェニル、サリチル酸-p-tert-ブチルフェニル、サリチル酸-p-オクチルフェニル等のサリチル酸系が好ましく、これらを１種若しくは２種以上を同時に感光層４に含有することができる。
【０１０１】
また、酸化防止剤と紫外線吸収剤を同時に添加することもできる。これらの添加は感光層４中であれば何れの層でもよいが、最表面の層、特に電荷移動層３に添加することが好ましい。
【０１０２】
なお、酸化防止剤の添加量は、結着樹脂に対して３〜２０重量％とすることが好ましく、紫外線吸収剤の添加量は、結着樹脂に対して３〜３０重量％とすることが好ましい。更に、酸化防止剤と紫外線吸収剤との両者を添加する場合には、両成分の添加量は、結着樹脂に対して５〜４０重量％とすることが好ましい。
【０１０３】
前記酸化防止剤、紫外線吸収剤以外にも、ヒンダードアミン、ヒンダードフェノール化合物等の光安定剤、ジフェニルアミン化合物等の老化防止剤、界面活性剤等を感光層４に添加することもできる。
【０１０４】
感光層４の形成方法としては、所定の感光材料と結着樹脂と共に溶媒に分散あるいは溶解して塗工液を作成し、所定の下地上に塗工する方法が一般的である。
【０１０５】
塗工方法としては、浸漬塗工、カーテンフロー、バーコート、ロールコート、リングコート、スピンコート、スプレーコート等、下地の形状や塗工液の状態に合わせて行うことができる。
【０１０６】
また、電荷発生層２は真空蒸着法により形成させることもできる。
【０１０７】
塗工液に使用する溶剤には、メタノール、エタノール、n-プロパノール、i-プロパノール、ブタノール等のアルコール類、ペンタン、ヘキサン、ヘプタン、オクタン、シクロヘキサン、シクロヘプタン等の飽和脂肪族炭化水素、トルエン、キシレン等の芳香族炭化水素、ジクロロメタン、ジクロロエタン、クロロホルム、クロロベンゼン等の塩素系炭化水素、ジメチルエーテル、ジエチルエーテル、テトラヒドロフラン（ＴＨＦ）、メトキシエタノール等のエーテル類、アセトン、メチルエチルケトン、メチルイソブチルケトン、シクロヘキサノン等のケトン類、ギ酸エチル、ギ酸プロピル、酢酸メチル、酢酸エチル、酢酸プロピル、酢酸ブチル、プロピオン酸メチル等のエステル類、Ｎ,Ｎ-ジメチルホルムアミド、ジメチルスルホキシド等がある。これらは単独で用いても、２種類以上の溶剤を混合して用いてもよい。
【０１０８】
本発明に係る電子写真感光体においては、導電性支持体１と感光層４との間に、接着機能、バリヤー機能、支持体表面の欠陥被覆機能などを持つ中間層を設けてもよい。この中間層としては、酸化アルミニウム、ポリエチレン樹脂、アクリル樹脂、エポキシ樹脂、ポリカーボネート樹脂、ポリウレタン樹脂、塩化ビニル樹脂、酢酸ビニル樹脂、ポリビニルブチラール樹脂、ポリアミド樹脂、ナイロン樹脂等を用いることができる。これらの中間層は、単独の樹脂で構成しても良く、２種類以上の樹脂を混合して構成しても良い。
【０１０９】
また、樹脂中に金属化合物、金属酸化物、カーボン、シリカ、樹脂粉体等を分散させた中間層を用いることもできる。更に、特性改善のために各種顔料、電子受容性物質や電子供与性物質等を含有させることもできる。
【０１１０】
加えて、感光層４の表面に、ポリビニルホルマール樹脂、ポリカーボネート樹脂、フッ素樹脂、ポリウレタン樹脂、シリコン樹脂等の有機薄膜や、シランカップリング剤の加水分解物で形成されるシロキサン構造体から成る薄膜を成膜して表面保護層を設けてもよく、その場合には、感光体の耐久性が向上するので好ましい。この表面保護層は、耐久性向上以外の他の機能を向上させるために設けてもよい。
【０１１１】
【実施例】
以下、本発明に係る電子写真感光体の実施例を比較例とともに詳細に説明する。
【０１１２】
〔実施例１〕
直径３０ｍｍのアルミニウムからなる円筒ドラム上に、電荷発生剤として式〔Ｖａ〕で表される化合物と結着樹脂としてポリビニルブチラールを、ジオキサンとアセトン８／２を溶媒とした分散液を調合し、浸漬塗工により０．１μｍ塗布し、電荷発生層を形成した。
【０１１３】
【化４９】

【０１１４】
次いで、結着樹脂として式〔Ｉａ〕、式〔ＩＩａ〕及び式〔ＩＩＩａ〕で表されるポリカーボネート共重合体と、電荷移動剤として式〔ＩＶａ〕〔ＩＶａ'〕で表される化合物の混合物と、酸化防止剤として2,6-ジ-tert-ブチル-4-メチルフェノールと、紫外線吸収剤として2-(5-メチル-2-ヒドロキシフェニル）ベンゾトリアゾ−ルをクロロホルムに溶解して塗工液を調製した。なお、この塗工液は電荷移動剤／結着樹脂＝０．８で調合されている。また、酸化防止剤／電荷移動剤＝０．０５、紫外線吸収剤／電荷移動剤＝０．１の重量比で調合されている。
【０１１５】
【化５０】

【０１１６】
【化５１】

【０１１７】
【化５２】

【０１１８】
【化５３】

【０１１９】
【化５４】

【０１２０】
ここで、ポリカーボネート共重合体の繰り返し単位のモル比は式〔Ｉｂ〕／式〔ＩＩａ〕／式〔ＩＩＩａ〕＝０．１／８２／１８とし、その場合の還元粘度は１．７ｄｌ／ｇであった。
【０１２１】
そして、浸漬塗工によりこの塗工液を塗布した後、１００℃の温度下で１時間乾燥し、２０μｍの膜厚の電荷移動層を形成した。以上のような方法で電子写真感光体を作製した。
【０１２２】
〔実施例２〕
実施例１において、電荷移動剤／結着樹脂＝０．５とした以外は同様の条件で電子写真感光体を作製した。
【０１２３】
〔実施例３〕
実施例１において、電荷移動剤／結着樹脂＝１．２とした以外は同様の条件で電子写真感光体を作製した。
【０１２４】
〔実施例４〕
実施例１の電荷移動剤に代えて、式〔ＩＶｂ〕〔ＩＶｂ'〕で表される化合物の混合物を用いた以外は実施例１と同様の条件で電子写真感光体を作製した。
【０１２５】
【化５５】

【０１２６】
【化５６】

【０１２７】
〔実施例５〕
電荷移動層形成用の塗工液において、結着樹脂を、式〔Ｉｂ〕、式〔ＩＩａ〕及び式〔ＩＩＩｂ〕で表されるポリカーボネート共重合体に代えた以外は実施例１と同様の条件で電荷発生層を形成する。
【０１２８】
【化５７】

【０１２９】
【化５８】

【０１３０】
【化５９】

ここで、ポリカーボネート共重合体の繰り返し単位のモル比は式〔Ｉｂ〕／式〔ＩＩａ〕／式〔ＩＩＩｂ〕＝０．１／８２／１８とし、その場合の還元粘度は１．７ｄｌ／ｇであった。
【０１３１】
その後、実施例１と同様の条件で電荷移動層を形成し、電子写真感光体を作製した。
【０１３２】
〔実施例６〕
実施例５の電荷移動剤に代えて、式〔ＩＶｂ〕〔ＩＶｂ'〕で表される化合物の混合物を用いた以外は実施例５と同様の条件で電子写真感光体を作製した。
【０１３３】
【化６０】

【０１３４】
【化６１】

【０１３５】
〔実施例７〕
電荷発生剤として式〔Ｖｂ〕で表される化合物と、電荷移動剤として式〔ＩＶａ〕〔ＩＶａ'〕〔Ｖｃ〕で表される化合物の混合物と、結着樹脂として式〔Ｉｂ〕、式〔ＩＩａ〕及び式〔ＩＩＩａ〕で表されるポリカーボネート共重合体と、酸化防止剤として2,6-ジ-tert-ブチル-4-メチルフェノールと、紫外線吸収剤として2-(5-メチル-2-ヒドロキシフェニル）ベンゾトリアゾ−ルをクロロホルムを溶媒とした分散液を調合した。
【０１３６】
なお、この塗工液は電荷移動剤(式〔ＩＶａ〕＋式〔ＩＶａ'〕＋式〔Ｖｃ〕）／結着樹脂＝０．８に調整されている。
【０１３７】
【化６２】

【０１３８】
【化６３】

【０１３９】
【化６４】

【０１４０】
【化６５】

【０１４１】
【化６６】

【０１４２】
【化６７】

【０１４３】
【化６８】

ここで、ポリカーボネート共重合体の繰り返し単位のモル比は式〔Ｉｂ〕／式〔ＩＩａ〕／式〔ＩＩＩａ〕＝０．１／８２／１８とし、その場合の還元粘度は１．７ｄｌ／ｇであった。
【０１４４】
そして、浸漬塗工によりこの塗工液を直径３０ｍｍのアルミニウムからなる円筒ドラム上に塗布した後、１００℃の温度下で１時間乾燥し、２０μｍの膜厚の感光層を形成した。以上のような方法で電子写真感光体を作製した。
【０１４５】
〔実施例８〕
実施例７の結着樹脂に代えて、式〔Ｉｂ〕、式〔ＩＩａ〕及び式〔ＩＩＩｃ〕で表されるポリカーボネート共重合体を用いた以外は実施例１と同様の条件で電子写真感光体を作製した。
【０１４６】
【化６９】

【０１４７】
【化７０】

【０１４８】
【化７１】

ここで、ポリカーボネート共重合体の繰り返し単位のモル比は式〔Ｉｂ〕／式〔ＩＩａ〕／式〔ＩＩＩｃ〕＝０．１／８２／１８とし、その場合の還元粘度は１．７ｄｌ／ｇであった。
【０１４９】
なお、摩擦係数評価用として、１００ｍｍ×１００ｍｍのアルミニウムを蒸着したＰＥＴ（ポリエチレンテレフタレート）フィルム上に実施例１〜８の感光層を塗布し、シート状電子写真感光体を作製した。
【０１５０】
評価方法
〔静電特性の測定〕
電子写真感光体評価装置（ダイナミックモード測定）を用い、実施例１〜８によって作製された円筒状電子写真感光体の初期の表面電位、感度、残留電位、暗減衰率等の静電特性を測定したところ、表１に示すように、いずれも良好な特性であった。
【０１５１】
〔光疲労試験〕
常温常湿(２４℃、４０％ＲＨ)の環境下にて、電子写真感光体評価装置を用い、実施例１〜８によって作製された円筒状電子写真感光体を印加電圧−５ＫＶで帯電させ、波長７８０ｎｍ、露光光量２０ｅｒｇ／ｃｍ２ の光を用いて電子写真感光体を露光したときの残留電位ＶＲ(−Ｖ)を測定した。
【０１５２】
一方、前記電子写真感光体に照度８００ｌｕｘの蛍光灯光を１０分間照射し、その後、前記電子写真感光体評価装置により残留電位ＶＲ１(−Ｖ)を測定し、蛍光灯光を照射する前後の残留電位の差(｜ＶＲ−ＶＲ１｜)をΔＶＲ(Ｖ)とした。その結果を表１に示す。
【０１５３】
〔摩擦係数の測定〕
摩擦係数評価用に作製された前記シート状電子写真感光体を平面上に固定し、摩擦係数測定装置(ＨＥＩＤＯＮ社製 トライボギア ミューズ ＴＹＰＥ９４Ｂ)を用いて静摩擦係数を測定した。その結果を表１に示す。
【０１５４】
〔画像試験〕
ブラシ帯電方式によって負に帯電させた実施例１〜８の円筒状電子写真感光体を、ＬＥＤ露光、非磁性一成分現像方式、ブレードクリーニング方式により画像形成を行う電子写真装置に装着し、Ａ４用紙を５，０００枚連続印字させ、連続印字後の画像を評価した。その結果を表１に示す。
【０１５５】
他方、実施例１〜８の円筒状電子写真感光体を、前記光疲労試験を行った後に前記電子写真装置に装着し、画像印字を行い評価した。
【０１５６】
〔ブレードの捲れ及び異音の発生の評価〕
画像試験における５，０００枚連続印字の際にブレード捲れの有無及びブレードの異音の発生有無を観測した。その結果を表１に示す。
【０１５７】
〔クラック発生の評価〕
前記電子写真感光体表面に指紋を付着させ２４時間常温常湿下に放置し、指紋の付いた部分についてクラック発生の有無を目視で観察した。その結果を表１に示す。
【０１５８】
【表１】

【０１５９】
表１から明らかなように、本実施例１〜８の電子写真感光体は摩擦係数が小さく、ブレードの捲れや異音の発生が全くないため、連続印字後の画像においても欠陥が全く発生しなかった。
【０１６０】
また、指紋によるクラックの発生もなく、光疲労もほとんどないため、熟練したサービスマンでなくとも容易にメンテナンスをすることが可能である。
【０１６１】
【発明の効果】
以上述べたように、本発明の電子写真感光体は、表面電位や感度等の静電特性に影響されることなく、摩擦係数が非常に小さく、ブレードの捲れや異音が全く発生せず、しかも指紋の付着に対しても強い耐久性を示し、更に光疲労にも強いものである。
よって、本発明によれば、優れた電子写真特性、クリーニング性、耐油性を有し、かつ、メンテナンスの簡略化が図れる電子写真感光体を提供することができるものである。
【図面の簡単な説明】
【図１】本発明に係る電子写真感光体の一例の構成を示す断面図
【図２】本発明に係る電子写真感光体の他の例の構成を示す断面図
【符号の説明】
１…導電性支持体 ２…電荷発生層 ３…電荷移動層 ４…感光層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic photosensitive member used for an electrophotographic apparatus such as a copying machine or a laser beam printer, and more particularly to an electrophotographic photosensitive member using an organic photoconductive material.
[0002]
[Prior art]
In general, inorganic materials such as selenium (Se), cadmium sulfide (CdS), zinc oxide (ZnO), and amorphous silicon (a-Si) are used as the photoconductive material of the electrophotographic photosensitive member. A photoreceptor using such an inorganic material is charged with, for example, a charging roller in a dark place, and then image exposure is performed to selectively eliminate the charge of only the exposed portion to form an electrostatic latent image. It is used every time it is visualized and imaged. The basic characteristics required for such an electrophotographic photosensitive member are (1) being able to be charged to an appropriate potential in a dark place, and (2) having a function of being able to eliminate surface charges by light irradiation. However, each of the inorganic materials has advantages and disadvantages. For example, selenium (Se) is satisfactory in the characteristics (1) and (2), but is not flexible and difficult to process into a film, and is sensitive to heat and mechanical shock. There are drawbacks such as requiring care in handling. Furthermore, amorphous silicon (a-Si) has the disadvantages that the manufacturing conditions are difficult and the manufacturing cost is high.
[0003]
Therefore, in recent years, as an electrophotographic photosensitive member, a phthalocyanine or azo compound, which is known as an organic photoconductive substance, is used as a charge generation layer, and a function-separated type constituted by stacking a charge transfer layer made of a hydrazone compound or the like Organic photoreceptors are the mainstream.
[0004]
[Problems to be solved by the invention]
By the way, conventionally, bisphenol A-type polycarbonate resin is most commonly used as a binder resin for organic photoreceptors.
[0005]
However, when a photosensitive layer is formed using a bisphenol A type polycarbonate resin as a binder resin, there are disadvantages such as the coating solution for the photosensitive layer being unstable. Therefore, there is a demand for a charge transfer layer material that does not have such a drawback.
[0006]
In addition, since the photosensitive layer using this polycarbonate resin has a large coefficient of friction on the surface, when the electrophotographic photosensitive member is mounted on an electrophotographic apparatus and the electrophotographic process is repeated, the residual toner on the surface of the photosensitive layer is cleaned. There have been problems such as a commonly used cleaning blade reversing or generating abnormal noise.
[0007]
Furthermore, since this polycarbonate resin has poor oil resistance, it may accidentally touch the surface of the photosensitive layer during maintenance of the electrophotographic apparatus, etc., and fingerprints may be attached. In many cases, cracks occur and the electrophotographic photosensitive member becomes unusable.
[0008]
On the other hand, in consideration of the stability of the coating solution, it has also been proposed to use a bisphenol Z-type polycarbonate resin as a material for the photosensitive layer of the electrophotographic photosensitive member. However, even when this bisphenol Z-type polycarbonate resin is used, it has not been able to solve problems such as blade cracking due to a large friction coefficient, generation of abnormal noise and cracks.
[0009]
Thereafter, polycarbonate resins and polycarbonate copolymers having various structures other than the bisphenol A type and Z type have been developed, as described in, for example, Japanese Patent Application Laid-Open No. 4-179961, but all the above problems have been solved. We haven't found what we can do yet.
[0010]
On the other hand, the electrophotographic photosensitive member may be exposed to room light during maintenance or replacement of the electrophotographic photosensitive member. However, if the electrophotographic photosensitive member is exposed to light for a long time, the charge transfer agent deteriorates. As a result, the residual potential of the electrophotographic photosensitive member increases. Such a situation is a major obstacle to simplifying maintenance. For this reason, maintenance must be performed by skilled service personnel, and the service personnel must also pay close attention.
[0011]
The present invention has been made in order to solve such problems of the prior art, and reduces the coefficient of friction of the surface of the photosensitive layer without impairing the excellent electrophotographic characteristics, improves oil resistance, and reduces light resistance. An object of the present invention is to provide an electrophotographic photoreceptor free from fatigue.
[0012]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have made an electrophotographic photoreceptor using a polycarbonate copolymer having a specific structure and a charge transfer agent having a specific structure as a binder resin in the photosensitive layer. However, it has been found that there is no problem with the conventional technique and that excellent electrostatic characteristics are maintained over a long period of time, and the present invention has been completed.
[0013]
The invention according to claim 1 made on the basis of such a viewpoint is an electrophotographic photosensitive member in which a photosensitive layer having at least a charge generating agent, a charge transfer agent, and a binder resin is formed on a conductive support. And a polycarbonate copolymer containing a repeating unit represented by the general formula [I] as a binder resin, and a compound represented by the general formula [IV] and / or [IV ′] as a charge transfer agent. The weight ratio of the charge transfer agent to the binder resin is charge transfer agent / binder resin = 0.5 to 1.2.
[0014]
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[0015]
[Wherein, R _{1 to} R ₁₂ each independently represents an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and a to c represent an integer of 2 to 6; D represents an integer of 0 to 200. ]
[0016]
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[0017]
[Wherein R ₂₃ represents either a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R _{24 to} R ₂₆ may be the same or different, and each independently represents a hydrogen atom, a halogen atom, It represents either an atom, an alkyl group having 1 to 4 carbon atoms which may have a substituent or an alkoxy group, a substituted amino group, or an aryl group having 6 to 12 carbon atoms. ]
[0018]
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[0019]
[Wherein R _{23 ′} represents either a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R _{24 ′ to} R _{26 ′} may be the same or different, and each independently represents a hydrogen atom. An atom, a halogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms or an alkoxy group, a substituted amino group, or an aryl group having 6 to 12 carbon atoms is represented. ]
[0020]
In the invention of claim 1 having such a structure, by containing a polycarbonate copolymer containing a repeating unit consisting of a siloxane structure represented by the general formula [I] as a binder resin in the photosensitive layer, Since the releasability and lubricity are improved, the friction coefficient of the photosensitive layer is reduced.
[0021]
Moreover, it becomes difficult to be light-fatigue by containing the compound represented by general formula [IV] and / or [IV '] as a charge transfer agent.
[0022]
In this case, as in the invention described in claim 2, in the invention described in claim 1, the binder resin in the photosensitive layer is represented by general formula [I], general formula [II] and general formula [III]. A polycarbonate copolymer comprising repeating units can also be contained.
[0023]
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[0024]
[Wherein, R _{1 to} R ₁₂ each independently represents an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and a to c represent an integer of 2 to 6; D represents an integer of 0 to 200. ]
[0025]
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[0026]
[Wherein, A represents a single bond, —O—, —CO—, —S—, —SO—, —SO ₂ —,
—CR ₁₅ R ₁₆ — (wherein R ₁₅ and R ₁₆ are each independently a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a substituted aryl group. Or a 1,5-cycloalkylidene group having 5 to 8 carbon atoms, a 9,9-fluorenylidene group, or an α, ω-alkylene group having 2 to 12 carbon atoms.
R ₁₃ and R ₁₄ each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a substituted aryl group, and e and f are each independently Represents an integer of 0 to 4; ]
[0027]
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[0028]
[Wherein, B represents a single bond, —O—, —CO—, —S—, —SO—, —SO ₂ —,
—CR ₁₉ R ₂₀ — (wherein R ₁₉ and R ₂₀ are each independently a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a substituted aryl group. Or a 1,5-cycloalkylidene group having 5 to 8 carbon atoms, an α, ω-alkylene group having 2 to 12 carbon atoms, or a functional group represented by the general formula [III ′]. .
R ₁₇ and R ₁₈ each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a substituted aryl group.
Here, B is —O—, —CO—, —S—, —SO—, —SO ₂ —, —CR ₁₉ R ₂₀ —, a 1,1-cycloalkylidene group having 5 to 8 carbon atoms, or 2 carbon atoms. In the case of any of ˜12 α, ω-alkylene groups, g and h each independently represents an integer of 1 to 4.
When B is a single bond or general formula [III ′], g and h each independently represent an integer of 0 to 4. ]
[0029]
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[0030]
[Wherein, R ₂₁ and R ₂₂ each independently represent a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclohexyl group, an aryl group having 6 to 12 carbon atoms, or a substituted aryl group; It represents any of a bond, —O—, —CO—, —S—, —SO—, —SO ₂ —, and i and j are integers of 0 to 4. ]
[0031]
In the case of the invention described in claim 2, in addition to the repeating unit represented by the general formula [I] as the binder resin, the repeating unit represented by the general formula [II] and the general formula [III] is used in the photosensitive layer. By containing a polymerized polycarbonate copolymer, the toner filming resistance is improved.
[0032]
In particular, as in the invention described in claim 3, in the invention described in claim 2, the photosensitive layer comprises a repeating unit represented by the formula [Ia], the formula [IIa] and the formula [IIIa] as the binder resin. A polycarbonate copolymer can also be contained.
[0033]
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[0034]
[In formula, d represents the integer of 0-200, and a preferable range is 10-100. ]
[0035]
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[0036]
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[0037]
The invention described in claim 3 has a small friction coefficient and is preferable in terms of high printing durability and oil resistance.
[0038]
Further, as in the invention described in claim 4, in the invention described in claim 2, the photosensitive layer comprises a repeating unit represented by the formula [Ia], the formula [IIa] and the formula [IIIb] as a binder resin. A polycarbonate copolymer can also be contained.
[0039]
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[0040]
[In formula, d represents the integer of 0-200, and a preferable range is 10-100. ]
[0041]
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[0042]
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The invention according to claim 4 also has a small friction coefficient and is preferable in terms of high printing durability and oil resistance.
[0043]
Further, as in the invention described in claim 5, in the invention described in any one of claims 1 to 4, a compound represented by the formula [IVa] and / or [IVa ′] is used as a charge transfer agent. You can also.
[0044]
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[0045]
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[0046]
The invention described in claim 5 is also preferable in that the sensitivity of the photosensitive member becomes high and the light fatigue is also enhanced.
[0047]
Further, as in the invention described in claim 6, in the invention described in any one of claims 1 to 5, a compound represented by the formula [IVb] and / or [IVb ′] is used as a charge transfer agent. You can also.
[0048]
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[0049]
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[0050]
The invention described in claim 6 is also preferable in that the sensitivity of the photosensitive member becomes high and it is strong against light fatigue.
[0051]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the electrophotographic photosensitive member according to the present invention will be described in detail. 1 and 2 are cross-sectional views showing the structure of a preferred embodiment of the electrophotographic photosensitive member according to the present invention.
FIG. 1 shows an example of the structure of a function-separated type electrophotographic photosensitive member applicable to the present invention. On a cylindrical conductive support 1, a charge generation layer 2, a charge transfer layer 3, and Are formed in this order, and the charge generation layer 2 and the charge transfer layer 3 constitute a photosensitive layer 4.
[0052]
FIG. 2 shows an example of the structure of a single layer type electrophotographic photosensitive member applicable to the present invention, and a charge generating agent and a charge transfer agent are contained on the conductive support 1. A photosensitive layer 4 is formed.
[0053]
Examples of the conductive support 1 that can be used in the present invention include processing of simple metals such as aluminum, brass, stainless steel, nickel, chromium, titanium, gold, silver, copper, tin, platinum, molybdenum, indium, and alloys thereof. And conductive glass coated with tin oxide, indium oxide, and aluminum iodide, and a conductive plate such as metal or carbon treated with a method such as vapor deposition or plating to provide conductivity. The conductive support 1 can be configured using various materials having conductivity without being limited by the type or shape. Moreover, about the shape of the electroconductive support body 1, the thing of drum shape, rod shape, plate shape, sheet shape, and belt shape can be used.
[0054]
As the charge generating agent that can be used in the present invention, a disazo pigment or oxytitanium phthalocyanine is desirable in terms of good sensitivity compatibility, but is not limited thereto. Others such as selenium, selenium-tellurium, selenium-arsenic, amorphous silicon, metal-free phthalocyanine, other metal phthalocyanine pigments, monoazo pigments, trisazo pigments, polyazo pigments, indigo pigments, selenium pigments, toluidine pigments, pyrazoline pigments, perylene pigments Quinacridone pigments, polycyclic quinone pigments, pyrylium salts, and the like can be used.
[0055]
These charge generating agents may be used alone or in combination of two or more in order to obtain an appropriate photosensitivity wavelength and sensitizing action.
[0056]
The electrophotographic photoreceptor of the present invention contains a polycarbonate copolymer containing a repeating unit having a siloxane structure represented by the general formula [I] as a binder resin in the photosensitive layer 4.
[0057]
Embedded image

[0058]
[Wherein, R _{1 to} R ₁₂ each independently represents an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and a to c represent an integer of 2 to 6; D represents an integer of 0 to 200. ]
[0059]
And in this invention, since the mold release property and lubricity improve by containing the polycarbonate copolymer containing the repeating unit which consists of siloxane structures, the friction coefficient of a photosensitive layer can be reduced.
[0060]
Moreover, the polycarbonate copolymer of this invention can make the polycarbonate structural unit represented by general formula [II] and general formula [III] into a repeating unit other than the said siloxane structural unit. These polycarbonate structural units can be appropriately selected depending on the characteristics, ease of synthesis, use of the resin, and the like.
[0061]
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[0062]
[Wherein, A represents a single bond, —O—, —CO—, —S—, —SO—, —SO ₂ —,
-CR ₁₅ R ₁₆ - (where the R15 and R16, each independently represent a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 6 carbon atoms, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms And a 1,5-cycloalkylidene group having 5 to 8 carbon atoms, a 9,9-fluorenylidene group, or an α, ω-alkylene group having 2 to 12 carbon atoms.
R ₁₃ and R ₁₄ each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a substituted aryl group, and e and f are each independently Represents an integer of 0 to 4; ]
[0063]
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[0064]
[Wherein, B represents a single bond, —O—, —CO—, —S—, —SO—, —SO ₂ —,
—CR ₁₉ R ₂₀ — (wherein R ₁₉ and R ₂₀ are each independently a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a substituted aryl group. Or a 1,5-cycloalkylidene group having 5 to 8 carbon atoms, an α, ω-alkylene group having 2 to 12 carbon atoms, or a functional group represented by the general formula [III ′]. .
R ₁₇ and R ₁₈ each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a substituted aryl group.
Here, B is —O—, —CO—, —S—, —SO—, —SO ₂ —, —CR ₁₉ R ₂₀ —, a 1,1-cycloalkylidene group having 5 to 8 carbon atoms, or 2 carbon atoms. In the case of any of ˜12 α, ω-alkylene groups, g and h each independently represents an integer of 1 to 4.
When B is a single bond or general formula [III ′], g and h each independently represent an integer of 0 to 4. ]
[0065]
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[0066]
[Wherein, R ₂₁ and R ₂₂ each independently represent a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclohexyl group, an aryl group having 6 to 12 carbon atoms, or a substituted aryl group; It represents any of a bond, —O—, —CO—, —S—, —SO—, —SO ₂ —, and i and j are integers of 0 to 4. ]
[0067]
In this case, from the viewpoint of low friction coefficient, high printing durability, and oil resistance, for example, the formula [Ia], the formula [IIa] and the formula [IIIa] or the formula [Ia], the formula [IIa] and the formula [IIIb A polycarbonate copolymer comprising a repeating unit represented by the formula can be suitably used.
[0068]
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[0069]
[In formula, d represents the integer of 0-200, and a preferable range is 10-100. ]
[0070]
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[0071]
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[0072]
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[0073]
In the case of a polycarbonate copolymer having two or more types of repeating units, the content ratio of the repeating units represented by the general formula [I] is the number of moles of the repeating units represented by the general formula [I] and all the repeating units. The molar ratio with respect to the total number of moles is preferably 0.0001 or more. When the content ratio of the repeating unit represented by the general formula [I] is 0.0001 or less, the effect of improving the filming resistance is not sufficiently exhibited.
[0074]
The polycarbonate copolymer has a reduced viscosity (ηSP / c) at 20 ° C. of a solution having a concentration of 0.5 g / dl in methylene chloride as a solvent of 0.50 dl / g or more. The hardness of the layer 4 is preferably increased.
[0075]
In addition, when the photosensitive layer 4 has a laminated type or a reverse laminated type, the binder resin of the present invention may be used for one or both of the charge generation layer 2 and the charge transfer layer 3. In view of the characteristics of the resin, when it is contained in the outermost surface layer, the desired characteristics are sufficiently exhibited, which is preferable.
[0076]
On the other hand, in the electrophotographic photoreceptor of the present invention, the photosensitive layer 4 can contain a binder resin other than the specific polycarbonate copolymer described above.
[0077]
Examples of the binder resin that can be used to form the photosensitive layer 4 include polycarbonate resin, styrene resin, acrylic resin, styrene-acrylic resin, ethylene-vinyl acetate resin, polypropylene resin, vinyl chloride resin, chlorinated polyether, Vinyl chloride-vinyl acetate resin, polyester resin, furan resin, nitrile resin, alkyd resin, polyacetal resin, polymethylpentene resin, polyamide resin, polyurethane resin, epoxy resin, polyarylate resin, diarylate resin, polysulfone resin, polyethersulfone resin , Polyallylsulfone resin, silicone resin, ketone resin, polyvinyl butyral resin, polyether resin, phenol resin, EVA (ethylene / vinyl acetate / copolymer) resin, ACS (acrylonitrile / chlorine) Polyethylene-styrene) resin, ABS (acrylonitrile butadiene styrene) resins, photocurable resins such as epoxy arylate. These may be used alone or in combination of two or more. In addition, it is more preferable to use a mixture of resins having different molecular weights because the hardness and wear resistance can be improved.
[0078]
The electrophotographic photoreceptor of the present invention contains a compound represented by the general formulas [IV] and / or [IV ′] as a charge transfer agent in the photosensitive layer 4.
[0079]
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[0080]
[Wherein R ₂₃ represents either a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R _{24 to} R ₂₆ may be the same or different, and each independently represents a hydrogen atom, a halogen atom, It represents either an atom, an alkyl group having 1 to 4 carbon atoms which may have a substituent or an alkoxy group, a substituted amino group, or an aryl group having 6 to 12 carbon atoms. ]
[0081]
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[0082]
[Wherein R _{23 ′} represents either a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R _{24 ′ to} R _{26 ′} may be the same or different, and each independently represents a hydrogen atom. An atom, a halogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms or an alkoxy group, a substituted amino group, or an aryl group having 6 to 12 carbon atoms is represented. ]
[0083]
That is, in the present invention, both the compound represented by the general formula [IV] [IV ′] and the compound represented by the general formula [IV] [IV ′] are contained. Includes cases.
[0084]
Here, the content of the compound represented by the general formulas [IV] and / or [IV ′] in the charge transfer layer 3 is 0.5 to 1.2 parts by weight with respect to 1 part by weight of the binder resin. It is preferable that
[0085]
If the content of this compound is less than 0.5 parts by weight, the electrical characteristics deteriorate, for example, the residual potential increases. On the other hand, when the amount is more than 1.2 parts by weight, mechanical properties such as wear resistance are lowered.
[0086]
Among the compounds represented by the general formula [IV], it is particularly effective to use a compound represented by the formula [IVa] or a compound represented by the formula [IVb] from the viewpoint of light fatigue.
[0087]
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[0088]
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[0089]
Further, among the compounds represented by the general formula [IV ′], in particular, the use of the compound represented by the formula [IVa ′] or the compound represented by the formula [IVb ′] does not cause light fatigue. It is effective.
[0090]
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[0091]
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[0092]
Furthermore, other charge transfer agents can be added to the photosensitive layer 4 of the electrophotographic photoreceptor of the present invention. In that case, since the sensitivity of the photosensitive layer 4 can be increased and the residual potential can be lowered, the characteristics of the electrophotographic photosensitive member of the present invention can be improved.
[0093]
Examples of charge transfer agents that can be added to improve such properties include polyvinyl carbazole, halogenated polyvinyl carbazole, polyvinyl pyrene, polyvinyl indoloquinoxaline, polyvinyl benzothiophene, polyvinyl anthracene, polyvinyl acridine, polyvinyl pyrazoline, polyacetylene, polythiophene, Conductive polymer compounds such as polypyrrole, polyphenylene, polyphenylene vinylene, polyisothianaphthene, polyaniline, polydiacetylene, polyheptadiene, polypyridinediyl, polyquinoline, polyphenylene sulfide, polyferrocenylene, polyperinaphthylene, polyphthalocyanine, etc. Can be used.
[0094]
In addition, as low molecular weight compounds, trinitrofluorenone, tetracyanoethylene, tetracyanoquinodimethane, quinone, diphenoquinone, naphthoquinone, anthraquinone and derivatives thereof, polycyclic aromatic compounds such as anthracene, pyrene, phenanthrene, indole, carbazole Nitrogen-containing heterocyclic compounds such as imidazole, fluorenone, fluorene, oxadiazole, oxazole, pyrazoline, triphenylmethane, enamine, stilbene, butadiene, hydrazone, triphenylamine and the like can be added as a charge transfer agent.
[0095]
Also, as a charge transfer agent for the same purpose, a polymer solid electrolyte doped with a metal ion such as Li (lithium) ion to a polymer compound such as polyethylene oxide, polypropylene oxide, polyacrylonitrile, polymethacrylic acid or the like is added. You can also.
[0096]
Further, as a charge transfer agent for the same purpose, an organic charge transfer complex formed of an electron donating substance typified by tetrathiafulvalene-tetracyanoquinodimethane and an electron accepting substance can be used.
[0097]
The charge transfer agent can obtain desired photoreceptor characteristics even when it is added alone or in a mixture of two or more compounds.
[0098]
The electrophotographic photosensitive member of the present invention contains an antioxidant or an ultraviolet absorber in the photosensitive layer 4 for the purpose of preventing characteristic changes due to oxidative degradation of the photoconductive material or binder resin, preventing cracks, and improving mechanical strength. It is preferable to contain.
[0099]
Antioxidants that can be used in the present invention include 2,6-di-tert-butylphenol, 2,6-di-tert-4-methoxyphenol, 2-tert-butyl-4-methoxyphenol, 2,4 -Dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, butylated hydroxyanisole, stearyl propionate-β- (3,5-di-tert-butyl-4-hydroxyphenyl ), Α-tocopherol, β-tocopherol, monophenols such as n-octadecyl-3- (3′-5′-di-tert-butyl-4′-hydroxyphenyl) propionate, 2,2′-methylenebis (6 -tert-butyl-4-methylphenol), 4,4'-butylidene-bis- (3-methyl-6-tert-butylphenol), 4,4'-thiobis (6-tert-butyl-3-methylphenol) 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert- Preferred are polyphenols such as til-4-hydroxybenzyl) benzene, tetrakis [methylene-3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, and these are used as one kind or two or more kinds. At the same time, it can be contained in the photosensitive layer 4.
[0100]
Examples of the ultraviolet absorber include 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole. 2- (3,5-di-tert-butyl-2-hydroxyphenyl) benzotriazole, 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- ( 3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-tert-amyl-2-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy -5'-tert-octylphenyl) benzotriazoles such as benzotriazole, salicylic acid phenyl, salicylic acid-p-tert-butylphenyl, salicylic acid-p-octylphenyl, etc. Can be simultaneously contained in the photosensitive layer 4.
[0101]
Further, the antioxidant and the ultraviolet absorber can be added simultaneously. These may be added to any layer in the photosensitive layer 4, but are preferably added to the outermost layer, particularly the charge transfer layer 3.
[0102]
The addition amount of the antioxidant is preferably 3 to 20% by weight with respect to the binder resin, and the addition amount of the ultraviolet absorber is preferably 3 to 30% by weight with respect to the binder resin. preferable. Furthermore, when adding both an antioxidant and an ultraviolet absorber, it is preferable that the addition amount of both components shall be 5 to 40 weight% with respect to binder resin.
[0103]
In addition to the antioxidant and the ultraviolet absorber, a light stabilizer such as a hindered amine or a hindered phenol compound, an anti-aging agent such as a diphenylamine compound, a surfactant, or the like may be added to the photosensitive layer 4.
[0104]
As a method for forming the photosensitive layer 4, a method is generally used in which a coating solution is prepared by dispersing or dissolving in a solvent together with a predetermined photosensitive material and a binder resin, and coating is performed on a predetermined surface.
[0105]
As a coating method, dip coating, curtain flow, bar coating, roll coating, ring coating, spin coating, spray coating, and the like can be performed according to the shape of the base and the state of the coating liquid.
[0106]
The charge generation layer 2 can also be formed by a vacuum deposition method.
[0107]
Solvents used in the coating solution include alcohols such as methanol, ethanol, n-propanol, i-propanol and butanol, saturated aliphatic hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane and cycloheptane, toluene, Aromatic hydrocarbons such as xylene, chlorinated hydrocarbons such as dichloromethane, dichloroethane, chloroform, chlorobenzene, ethers such as dimethyl ether, diethyl ether, tetrahydrofuran (THF), methoxyethanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc. Esters such as ketones, ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, N, N-dimethylformamide, dimethyl sulfoxide, etc. That. These may be used alone or as a mixture of two or more solvents.
[0108]
In the electrophotographic photoreceptor according to the present invention, an intermediate layer having an adhesive function, a barrier function, a defect covering function on the support surface, and the like may be provided between the conductive support 1 and the photosensitive layer 4. As the intermediate layer, aluminum oxide, polyethylene resin, acrylic resin, epoxy resin, polycarbonate resin, polyurethane resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, polyamide resin, nylon resin, or the like can be used. These intermediate layers may be composed of a single resin or a mixture of two or more kinds of resins.
[0109]
An intermediate layer in which a metal compound, metal oxide, carbon, silica, resin powder, or the like is dispersed in the resin can also be used. Furthermore, various pigments, electron accepting substances, electron donating substances and the like can be contained for improving the characteristics.
[0110]
In addition, a thin film made of an organic thin film such as polyvinyl formal resin, polycarbonate resin, fluororesin, polyurethane resin, or silicon resin, or a siloxane structure formed from a hydrolyzate of a silane coupling agent is formed on the surface of the photosensitive layer 4. A surface protective layer may be provided by film formation, which is preferable because the durability of the photoreceptor is improved. This surface protective layer may be provided in order to improve functions other than the durability improvement.
[0111]
【Example】
Hereinafter, examples of the electrophotographic photosensitive member according to the present invention will be described in detail together with comparative examples.
[0112]
[Example 1]
On a cylindrical drum made of aluminum having a diameter of 30 mm, a dispersion represented by the formula [Va] as a charge generating agent and polyvinyl butyral as a binder resin and a solvent containing dioxane and acetone 8/2 as a solvent is prepared and immersed. A 0.1 μm coating was applied to form a charge generation layer.
[0113]
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[0114]
Next, a polycarbonate copolymer represented by the formulas [Ia], [IIa] and [IIIa] as a binder resin, and a mixture of compounds represented by the formula [IVa] [IVa ′] as a charge transfer agent; Dissolve 2,6-di-tert-butyl-4-methylphenol as an antioxidant and 2- (5-methyl-2-hydroxyphenyl) benzotriazole as an ultraviolet absorber in chloroform to prepare a coating solution. Prepared. In addition, this coating liquid is prepared by charge transfer agent / binder resin = 0.8. Moreover, it is prepared in a weight ratio of antioxidant / charge transfer agent = 0.05 and ultraviolet absorber / charge transfer agent = 0.1.
[0115]
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[0116]
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[0117]
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[0118]
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[0119]
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[0120]
Here, the molar ratio of the repeating unit of the polycarbonate copolymer is formula [Ib] / formula [IIa] / formula [IIIa] = 0.1 / 82/18, and the reduced viscosity in that case is 1.7 dl / g. there were.
[0121]
And after apply | coating this coating liquid by dip coating, it dried at the temperature of 100 degreeC for 1 hour, and formed the charge transfer layer with a film thickness of 20 micrometers. An electrophotographic photosensitive member was produced by the method described above.
[0122]
[Example 2]
An electrophotographic photosensitive member was produced under the same conditions as in Example 1 except that charge transfer agent / binder resin = 0.5.
[0123]
Example 3
An electrophotographic photosensitive member was produced under the same conditions as in Example 1, except that the charge transfer agent / binder resin was 1.2.
[0124]
Example 4
Instead of the charge transfer agent of Example 1, an electrophotographic photosensitive member was produced under the same conditions as in Example 1 except that a mixture of compounds represented by the formula [IVb] [IVb ′] was used.
[0125]
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[0126]
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[0127]
Example 5
In the coating solution for forming the charge transfer layer, the same conditions as in Example 1 except that the binder resin was replaced with a polycarbonate copolymer represented by the formula [Ib], formula [IIa] and formula [IIIb]. To form a charge generation layer.
[0128]
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[0129]
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[0130]
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Here, the molar ratio of the repeating unit of the polycarbonate copolymer is formula [Ib] / formula [IIa] / formula [IIIb] = 0.1 / 82/18, and the reduced viscosity in that case is 1.7 dl / g. there were.
[0131]
Thereafter, a charge transfer layer was formed under the same conditions as in Example 1 to produce an electrophotographic photoreceptor.
[0132]
Example 6
Instead of the charge transfer agent of Example 5, an electrophotographic photoreceptor was produced under the same conditions as in Example 5 except that a mixture of compounds represented by the formulas [IVb] and [IVb ′] was used.
[0133]
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[0134]
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[0135]
Example 7
A compound represented by the formula [Vb] as the charge generating agent, a mixture of the compounds represented by the formula [IVa] [IVa ′] [Vc] as the charge transfer agent, and the formula [Ib], the formula [ IIa] and a polycarbonate copolymer represented by the formula [IIIa], 2,6-di-tert-butyl-4-methylphenol as an antioxidant, and 2- (5-methyl-2- A dispersion of hydroxyphenyl) benzotriazole in chloroform as a solvent was prepared.
[0136]
The coating liquid was adjusted to charge transfer agent (formula [IVa] + formula [IVa ′] + formula [Vc]) / binder resin = 0.8.
[0137]
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[0138]
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[0139]
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[0140]
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[0141]
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[0142]
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[0143]
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Here, the molar ratio of the repeating unit of the polycarbonate copolymer is formula [Ib] / formula [IIa] / formula [IIIa] = 0.1 / 82/18, and the reduced viscosity in that case is 1.7 dl / g. there were.
[0144]
Then, this coating solution was applied on a cylindrical drum made of aluminum having a diameter of 30 mm by dip coating, and then dried at a temperature of 100 ° C. for 1 hour to form a photosensitive layer having a thickness of 20 μm. An electrophotographic photosensitive member was produced by the method described above.
[0145]
Example 8
Instead of the binder resin of Example 7, an electrophotographic photosensitive member under the same conditions as in Example 1 except that a polycarbonate copolymer represented by the formula [Ib], formula [IIa] and formula [IIIc] was used. Was made.
[0146]
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[0147]
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[0148]
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Here, the molar ratio of the repeating units of the polycarbonate copolymer is formula [Ib] / formula [IIa] / formula [IIIc] = 0.1 / 82/18, and the reduced viscosity in that case is 1.7 dl / g. there were.
[0149]
For evaluation of the friction coefficient, the photosensitive layers of Examples 1 to 8 were applied on a PET (polyethylene terephthalate) film on which 100 mm × 100 mm of aluminum was vapor-deposited to prepare a sheet-like electrophotographic photosensitive member.
[0150]
Evaluation method (measurement of electrostatic characteristics)
Using an electrophotographic photosensitive member evaluation apparatus (dynamic mode measurement), the electrostatic characteristics such as the initial surface potential, sensitivity, residual potential, dark decay rate, etc. of the cylindrical electrophotographic photosensitive member produced according to Examples 1 to 8 are measured. As a result, as shown in Table 1, all had good characteristics.
[0151]
(Light fatigue test)
Under an environment of normal temperature and normal humidity (24 ° C., 40% RH), the electrophotographic photosensitive member evaluation apparatus was used to charge the cylindrical electrophotographic photosensitive member produced according to Examples 1 to 8 at an applied voltage of −5 KV. The residual potential VR (−V) when the electrophotographic photosensitive member was exposed using light having a wavelength of 780 nm and an exposure light amount of 20 erg / cm 2 was measured.
[0152]
On the other hand, the electrophotographic photosensitive member is irradiated with fluorescent lamp light having an illuminance of 800 lux for 10 minutes, and then the residual potential VR1 (−V) is measured by the electrophotographic photosensitive member evaluation apparatus, and the residual potential before and after the fluorescent lamp light irradiation is measured. The difference (| VR−VR1 |) was taken as ΔVR (V). The results are shown in Table 1.
[0153]
[Measurement of friction coefficient]
The sheet-like electrophotographic photosensitive member produced for evaluating the friction coefficient was fixed on a flat surface, and the static friction coefficient was measured using a friction coefficient measuring device (Tribogear Muse TYPE 94B manufactured by HEIDON). The results are shown in Table 1.
[0154]
[Image test]
The cylindrical electrophotographic photosensitive member of Examples 1 to 8, which is negatively charged by a brush charging method, is mounted on an electrophotographic apparatus that forms an image by LED exposure, a non-magnetic one-component development method, and a blade cleaning method. 5,000 sheets were continuously printed, and the image after continuous printing was evaluated. The results are shown in Table 1.
[0155]
On the other hand, the cylindrical electrophotographic photoreceptors of Examples 1 to 8 were mounted on the electrophotographic apparatus after performing the light fatigue test, and image printing was performed for evaluation.
[0156]
[Evaluation of blade stagnation and abnormal noise]
During continuous printing of 5,000 sheets in the image test, the presence or absence of blade curl and the occurrence of abnormal noise on the blade were observed. The results are shown in Table 1.
[0157]
[Evaluation of crack occurrence]
Fingerprints were attached to the surface of the electrophotographic photosensitive member and allowed to stand at room temperature and humidity for 24 hours, and the presence or absence of cracks was visually observed on the fingerprinted portions. The results are shown in Table 1.
[0158]
[Table 1]

[0159]
As is apparent from Table 1, the electrophotographic photoreceptors of Examples 1 to 8 have a small coefficient of friction, and there is no occurrence of blade bending or abnormal noise. Therefore, no defects are generated even in images after continuous printing. There wasn't.
[0160]
In addition, since there is no generation of cracks due to fingerprints and almost no light fatigue, it is possible to easily perform maintenance even without a skilled service person.
[0161]
【The invention's effect】
As described above, the electrophotographic photosensitive member of the present invention is not affected by electrostatic characteristics such as surface potential and sensitivity, has a very small coefficient of friction, and does not generate blade stagnation or abnormal noise. Moreover, it is highly durable against fingerprints and is also resistant to light fatigue.
Therefore, according to the present invention, it is possible to provide an electrophotographic photosensitive member having excellent electrophotographic characteristics, cleaning properties, and oil resistance and capable of simplifying maintenance.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the structure of an example of an electrophotographic photosensitive member according to the present invention. FIG. 2 is a cross-sectional view showing the structure of another example of an electrophotographic photosensitive member according to the present invention.
DESCRIPTION OF SYMBOLS 1 ... Conductive support body 2 ... Charge generation layer 3 ... Charge transfer layer 4 ... Photosensitive layer

Claims (6)

In an electrophotographic photosensitive member in which a photosensitive layer having at least a charge generating agent, a charge transfer agent, and a binder resin is formed on a conductive support, a repetition represented by the general formula [I] as a binder resin in the photosensitive layer A polycarbonate copolymer containing units and a compound represented by the general formula [IV] and / or [IV ′] as a charge transfer agent, and the weight ratio of the charge transfer agent and the binder resin is Charge transfer agent / binder resin = 0.5 to 1.2.

[Wherein, R _{1 to} R ₁₂ each independently represents an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and a to c represent an integer of 2 to 6; D represents an integer of 0 to 200. ]

[Wherein R ₂₃ represents either a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R _{24 to} R ₂₆ may be the same or different, and each independently represents a hydrogen atom, a halogen atom, It represents either an atom, an alkyl group having 1 to 4 carbon atoms which may have a substituent or an alkoxy group, a substituted amino group, or an aryl group having 6 to 12 carbon atoms. ]

[Wherein R _{23 ′} represents either a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R _{24 ′ to} R _{26 ′} may be the same or different, and each independently represents a hydrogen atom. An atom, a halogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms or an alkoxy group, a substituted amino group, or an aryl group having 6 to 12 carbon atoms is represented. ] 2. The polycarbonate copolymer comprising a repeating unit represented by the general formula [I], the general formula [II] and the general formula [III] as a binder resin in the photosensitive layer. Electrophotographic photoreceptor.

[Wherein, R _{1 to} R ₁₂ each independently represents an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and a to c represent an integer of 2 to 6; D represents an integer of 0 to 200. ]

[Wherein, A represents a single bond, —O—, —CO—, —S—, —SO—, —SO ₂ —,
-CR ₁₅ R ₁₆ - (where the R15 and R16, each independently represent a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 6 carbon atoms, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms And a 1,5-cycloalkylidene group having 5 to 8 carbon atoms, a 9,9-fluorenylidene group, or an α, ω-alkylene group having 2 to 12 carbon atoms.
R ₁₃ and R ₁₄ each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a substituted aryl group, and e and f are each independently Represents an integer of 0 to 4; ]

[Wherein, B represents a single bond, —O—, —CO—, —S—, —SO—, —SO ₂ —,
—CR ₁₉ R ₂₀ — (wherein R ₁₉ and R ₂₀ are each independently a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a substituted aryl group. Or a 1,5-cycloalkylidene group having 5 to 8 carbon atoms, an α, ω-alkylene group having 2 to 12 carbon atoms, or a functional group represented by the general formula [III ′]. .
R ₁₇ and R ₁₈ each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a substituted aryl group.
Here, B is —O—, —CO—, —S—, —SO—, —SO ₂ —, —CR ₁₉ R ₂₀ —, a 1,1-cycloalkylidene group having 5 to 8 carbon atoms, or 2 carbon atoms. In the case of any of ˜12 α, ω-alkylene groups, g and h each independently represents an integer of 1 to 4.
When B is a single bond or general formula [III ′], g and h each independently represent an integer of 0 to 4. ]

[Wherein, R ₂₁ and R ₂₂ each independently represent a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclohexyl group, an aryl group having 6 to 12 carbon atoms, or a substituted aryl group; It represents any of a bond, —O—, —CO—, —S—, —SO—, —SO ₂ —, and i and j are integers of 0 to 4. ] 3. The electrophotographic photosensitive material according to claim 2, wherein the photosensitive layer contains a polycarbonate copolymer comprising repeating units represented by the formula [Ia], the formula [IIa] and the formula [IIIa] as a binder resin. body.

[In formula, d represents the integer of 0-200, and a preferable range is 10-100. ]

3. The electrophotographic photosensitive material according to claim 2, wherein the photosensitive layer contains a polycarbonate copolymer comprising repeating units represented by the formulas [Ia], [IIa] and [IIIb] as a binder resin. body.

[In formula, d represents the integer of 0-200, and a preferable range is 10-100. ]

5. The electrophotographic photosensitive member according to claim 1, wherein the charge transfer agent is a compound represented by the formula [IVa] and / or [IVa ′].

The electrophotographic photosensitive member according to any one of claims 1 to 5, wherein the charge transfer agent is a compound represented by the formula [IVb] and / or [IVb '].

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