JP3694068B2 - Electrophotographic photoreceptor - Google Patents

Description

（式（Ｉ）において、Ｒ1 、Ｒ2 はシアノ、ニトロ、ハロゲン、非環式炭化水素又は非環式炭化水素のアルコキシ基で、シアノ、ニトロ、ハロゲン基以外は置換基があってもよく、しかもＲ1 、Ｒ2 は同じか異なっていてもよい。）
【０００９】
具体的に述べると、本発明者等は、着色性が分子内共役構造の大きさに関係あることに着目し、キノン骨格における検討結果より、ｐ−キノンの片側の置換基を、ジシアノメタン基とすることで電子受容性が高まり、しかも樹脂との相溶性が悪くならないことを見出した。さらに、ジシアノメタン基の反対側の酸素に対し、ｏ−置換基を導入することで、樹脂に対して格段に相溶性が良くなることを見出した。
【００１０】
本発明における新規なキノン誘導体は、次に述べるような特性を持つものである。
（１）高感度の正帯電型電子写真感光体を開発するためには、高移動度の電子移動物質が必要となる。電子移動性物質となるためには電子受容性が高くなければならないが、本発明のキノン誘導体は、電子受容性が極めて高い。
（２）本発明のキノン誘導体は、感光層のバインダとして用いる樹脂と相溶性が極めてよく、電荷移動層中に高濃度でしかも均一に含有させることができる。
（３）本発明のキノン誘導体は、着色性が弱く、そのため入射光に対し吸収が低いので、感度を低下させることがほとんどない。
また本発明のキノン誘導体は、負帯電型電子写真感光体に、正孔移動物質と共に添加すると、その電子移動作用によって感度を向上させ、残留電位を低下させる作用があるため、高感度負帯電型電子写真感光体にも使用できる。
【００１１】
【発明の実施の形態】
本発明におけるキノン誘導体は、正および負帯電型電子写真感光体において、電子移動物質として電荷移動作用をはたすものであり、感光体において、導電性基体の種類および形状、感光層の構成および膜厚、さらに感光層を構成する他の成分である樹脂、添加剤の種類と濃度に制限されるものではないが、好ましくは感光層中に０．１重量％から８０重量％の濃度で添加するのがよい。またキノン誘導体は１種単独で用いてもよいし、２種以上を混合して用いてもよい。
【００１２】
本発明の感光体の構成の例を図１及び図２に示す。図１は単層分散型感光体の断面図であり、符号１は導電性の基体、２は電荷移動物質の媒体中に電荷発生物質を分散させた感光層である。図２は機能分離型感光体の断面図であり、符号１は導電性基体、３は電荷発生層、４は電荷移動層であって、電荷発生層３と電荷移動層４とで感光層を形成している。
【００１３】
上記導電性基体１としては、導電性を有する種々の材料を使用することができ、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、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などがある。一般には円筒状のアルミニウム管単体、表面をアルマイトで処理した物、導電性樹脂を塗工した物などがよく用いられる。
【００１４】
電荷発生物質としては、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、フタロシアニン顔料、モノアゾ顔料、ビスアゾ顔料、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、ピリリウム塩等が例示され、これらは単体で用いられるばかりでなく、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る場合もある。
【００１５】
高感度化や残留電位の低下など電子写真特性の改良のため、公知の電荷移動物質を添加することもでき、例えば高分子化合物では、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や、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、ポリメタクリル酸などに、リチウム等の金属イオンをドープした高分子固体電解質等があげられる。さらに低分子化合物ではアントラセン、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、ヒドラゾン、トリフェニルメタン、トリフェニルアミン、エナミン、スチルベン化合物など公知のものならばいかなるものでも使用でき、さらに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化合物と電子受容化合物で形成された公知の有機電荷移動錯体等があり、これらを１種または２種以上混合して所望の感光体特性を得ることができる。
【００１６】
感光層を形成するために用いられるバインダ樹脂は、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、塩化ビニル−酢酸ビニル樹脂、ポリエステル樹脂、アルキッド樹脂、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、ポリスルホン樹脂、ジアリレート樹脂、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、フェノール樹脂等、エポキシアリレート等の光硬化性樹脂があり、これらを１種または２種以上を混合して使用する。また硬度や耐摩耗性を改善するため分子量の異なった樹脂を混合することもできる。
【００１７】
塗工液に使用する溶剤は、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、メトキシエタノール等のエーテル系類、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り、これらは１種または２種以上を混合して用いられる。塗工方法は公知の塗布手段によって行われる。
【００１８】
本発明の感光体を製造するための塗工液には、電子写真感光体特性を損なわない範囲で公知の物質、例えば、酸化防止剤、紫外線吸収剤、ラジカル捕捉剤、軟化剤、硬化剤、架橋剤等を添加することができ、これによって感光体の特性、耐久性、機械特性等が向上する。さらに分散安定剤、沈降防止剤、色分かれ防止剤、レベリング剤、消泡剤、増粘剤、艶消し剤等を添加することで、感光体の仕上がり外観、塗工液の寿命改善が図られる。
【００１９】
本発明の電子写真感光体では、導電性基体と感光層との間に接着機能、バリヤー機能、基体表面の欠陥被覆機能などを持つ下引層を設けてもよい。この下引層としては、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、ナイロン樹脂などを単独あるいは混合して用いることができる。また、樹脂中に金属酸化物やカーボンを分散した下引層も用いることができる。
【００２０】
また感光層の上に、感光体の耐久性の向上などを目的として表面保護層を設けることができ、その材料としては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、シリコン樹脂などがある。また、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なる表面保護層でもよい。
【００２１】
キノン誘導体の製造例
上記の式（Ｉ）のキノン誘導体は次の方法により製造される。
第１法は、ｐ−キノンの２，６位に目的の置換基が置換された物質が市販されている場合に用いられ、この反応はｐ−キノン化合物の片側の酸素原子をジシアノメタン化し、式（Ｉ）のキノン誘導体を得る方法である。
【００２２】
【化３】

【００２３】
〔製造例１〕
３，５−ジメチルベンゾキノン１０．０ｇとマロノニトリル５．０ｇとをジクロロメタン２４０ｍｌに溶解し、氷浴により撹拌した。温度を１０℃以下に保ちながら、四塩化チタン６．６ｍｌをゆっくり滴下した後、同様にピリジン２４．０ｍｌをゆっくり滴下し、撹拌しながら室温で５時間反応させた。減圧蒸留し、残留物に１０％塩酸２００ｍｌを加えて激しく撹拌し、ろ過後、数回水で洗浄し乾燥させた。これをヘキサンより再結晶して精製し、３，５−ジメチル−４−オキソ−１−ジシアノメチレンシクロヘキサジエン（Ｉ）ａの４．０ｇを収率３２％で得た。
【００２４】
〔製造例２〕
３，５−ジクロロベンゾキノン１０．０ｇとマロノニトリル４．０ｇとをジクロロメタン２４０ｍｌに溶解し、氷浴により撹拌した。温度を１０℃以下に保ちながら、四塩化チタン６．６ｍｌをゆっくり滴下した後、同様にピリジン２４．０ｍｌをゆっくり滴下し、撹拌しながら室温で５時間反応させた。減圧蒸留し、残留物に１０％塩酸２００ｍｌを加えて激しく撹拌し、ろ過後、数回水で洗浄し乾燥させた。これをヘキサンより再結晶して精製し、３，５−ジクロロ−４−オキソ−１−ジシアノメチレンシクロヘキサジエン（Ｉ）ｂの３．６ｇを収率２８％で得た。
【００２５】
第２法は、ｐ−キノンの２，６位に目的の置換基が置換された物質が市販されていない場合に用いられ、本法では先ず２，６位に置換基の付いたフェノール化合物よりｐ−キノン化合物とし、これを前記製造例１，２と同一の反応で式（Ｉ）のキノン誘導体とする。
【００２６】
【化４】

【００２７】
〔製造例３〕
原料の３，５−ジ−ｔＢｕ−ヒドロキシルアニソール３３．０ｇをアセトニトリル３００ｍｌに溶解し、窒素ガス下で温度を０〜１０℃に保ち、臭素を７．８ｍｌ加えて撹拌した。温度を１０℃以下に保ちながら、ピリジン３４．８ｍｌとアセトニトリル６０ｍｌの混合溶液を滴下した。撹拌しながら１０℃以下で１時間、室温で２時間、さらに冷水４５０ｍｌを加えて３時間反応させた。これをヘキサンで抽出し、ヘキサン溶液を９０％メタノール水溶液で洗浄後、ヘキサンを減圧除去し、３，５−ジ−ｔＢｕ−ベンゾキノン２１．０ｇを収量８７％で褐色の液体として得た。
【００２８】
３，５−ジ−ｔＢｕ−ベンゾキノン１８．０ｇとマロノニトリル５．３ｇをジクロロメタン２４０ｍｌに溶解し氷浴上で撹拌した。温度を１０℃以下に保ちながら四塩化チタン８．８ｍｌをゆっくり滴下した後、同様にピリジン３２．２ｍｌをゆっくり滴下し、撹拌しながら室温で５時間反応させた。減圧濃縮によりジクロロメタンを除去し、残留物に１０％塩酸２００ｍｌを加えて激しく撹拌し、ろ過後残留物を水で数回洗浄してから乾燥させた。さらにヘキサンで再結晶操作し、３，５−ジ−ｔＢｕ−４−オキソ−１−ジシアノメチレンシクロヘキサジエン（Ｉ）ｃの３．８ｇを収率１７．３％で得た。
【００２９】
第３法は式（Ｉ）のキノン誘導体において、２，６位に任意に置換基を導入する方法であり、電子移動物質の製造法として有益である。本法ではニトロマロンアルデヒドとアルキルケトンを反応させ、２，６置換型ｐ−ニトロフェノール化合物を合成し、これをキノン化合物とした後、製造例１，２と同一の反応で式（Ｉ）のキノン誘導体とする。
【００３０】
【化５】

【００３１】
〔製造例４〕
水２４．３ｍｌと亜硝酸ナトリウム２５．０ｇを撹拌しながら温めて溶解した。ムコブロム酸２５．０ｇの９５％エタノール溶液２４．３ｍｌを温度５４±１℃に保ちながら滴下した。滴下後、５４±１℃に保ち１０分間撹拌した。０〜５℃に冷却し、沈澱をろ過後９５％エタノール８０ｍｌと水２０ｍｌの混合液に熱しながら溶解し、溶解後ろ過して液を０〜５℃に冷却し、ニトロマロンアルデヒドナトリウム・一水和物６．０ｇを収率３９％で得た。
【００３２】
１，３ジフェニル−２−プロパン８．８ｇのエタノール溶液４４ｍｌと水酸化ナトリウム３．３ｇの水溶液１５ｍｌとニトロマロンアルデヒドナトリウム・一水和物７．４ｇの水溶液６４ｍｌを２時間還流し、室温で２日間撹拌した。減圧蒸留により溶媒を除去し残渣に１０％塩酸を撹拌しながら加えてろ過した。１〜２滴の濃塩酸を含んだ酢酸／エタノールより再結晶させ、２，６−ジフェニル−４−ニトロフェノール８．９ｇを収率６５％で得た。
【００３３】
酢酸５０ｍｌに四酢酸鉛８．９ｇ、２，６−ジフェニル−４−ニトロフェノール６．７ｇを加え２４時間撹拌した。反応溶液をエーテルで抽出後に水で洗浄し、さらに５％水酸化ナトリウム水溶液、水の順で洗浄した。これを硫酸ナトリウムで脱水後、エーテルを除去してエタノールで再結晶し、２，６−ジフェニル−１，４−ベンゾキノン３．４ｇを収率５７％で得た。
【００３４】
ジクロロメタン１５０ｍｌに２，６−ジフェニル−１，４−ベンゾキノン５．７ｇ、マロノニトリル１．７ｇを加え、Ｎ₂ 下で撹拌した。温度を１０℃以下に保ち、四塩化チタン２．８ｍｌ、続いてピリジン１０．０ｍｌをゆっくり滴下し、室温で５時間撹拌後、減圧蒸留により溶媒を除去した。残渣を温ヘキサンで抽出後、１Ｎ塩酸、続いて水で洗浄し溶媒を除去した。シリカゲルを充填剤とし、溶離液はヘキサン／酢酸エチル＝２（体積比）を用いてカラムクロマトグラフィで精製し、３，５−ジフェニル−４−オキソ−１−ジシアノメチレンシクロヘキサジエン（Ｉ）ｄの０．８ｇを収率１１％で得た。
【００３５】
〔製造例５〕
製造例４の１，３ジフェニル−２−プロパンに代えて、３−ヘキサノン４．２ｇを用いて、３−エチル−５−メチル−４−オキソ−１−ジシアノメチレンシクロヘキサジエン（Ｉ）ｅの１．３ｇを収率１５％で得た。
【００３６】
上述した製造例１〜５で得られたキノン誘導体（Ｉ）ａ〜（Ｉ）ｅを次に示す。
【００３７】
【化６】

【００３８】
【化７】

【００３９】
【化８】

【００４０】
【化９】

【００４１】
【化１０】

【００４２】
【実施例】
以下本発明に係る電子写真感光体についての実施例を示す。なお、本発明はその要旨を越えない限りにおいて以下の実施例に限定されるものではない。
【００４３】
〔実施例１〕
電荷発生剤として式（II）に示すジスアゾ顔料１重量部、バインダとしてポリカーボネート１０重量部、溶媒としてＴＨＦ８０重量部を、サンドミルで１０時間混練分散し、更に式（III)のＴＰＤ誘導体９重量部と式（Ｉ）ａのキノン誘導体１重量部を加えて溶解した後この液を用いてアルミニウム製ドラム上に浸漬法で塗工し、厚さ２０μｍの電荷発生と電荷移動を兼ねた単層分散型の感光層２を形成し、８０℃で１時間乾燥して電子写真感光体を製造した。
【００４４】
【化１１】

【００４５】
【化１２】

【００４６】
〔実施例２〕
実施例１の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｂのキノン誘導体を用いて感光体を製造した。
【００４７】
〔実施例３〕
実施例１の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｃのキノン誘導体を用いて感光体を製造した。
【００４８】
〔実施例４〕
実施例１の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｄのキノン誘導体を用いて感光体を製造した。
【００４９】
〔実施例５〕
実施例１の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｅのキノン誘導体を用いて感光体を製造した。
【００５０】
〔比較例１〕
実施例１の式（Ｉ）ａのキノン誘導体に代えて、３，５−ジクロロキノンを用いて感光体を製造した。
【００５１】
〔比較例２〕
実施例１の式（Ｉ）ａのキノン誘導体に代えて、３，５−ジフェニルキノンを用いて感光体を製造した。
【００５２】
〔比較例３〕
実施例１の式（Ｉ）ａのキノン誘導体に代えて、テトラシアノキノジメタンを用いて感光体を製造した。
【００５３】
〔実施例６〕
電荷発生剤として高純度オキシチタニルフタロシアニン１重量部、バインダとしてポリカーボネート１０重量部、溶媒としてＴＨＦ８０重量部を、サンドミルで１０時間混練分散し、更に式（III)のＴＰＤ誘導体９重量部と式（Ｉ）ａのキノン誘導体１重量部を加えて溶解した後この液を用いてアルミニウム製ドラム上に浸漬法で塗工し、厚さ２０μｍの電荷発生と電荷移動を兼ねた単層分散型の感光層２を形成し、８０℃で１時間乾燥して電子写真感光体を製造した。
【００５４】
〔実施例７〕
実施例６の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｂのキノン誘導体を用いて感光体を製造した。
【００５５】
〔実施例８〕
実施例６の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｃのキノン誘導体を用いて感光体を製造した。
【００５６】
〔実施例９〕
実施例６の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｄのキノン誘導体を用いて感光体を製造した。
【００５７】
〔実施例１０〕
実施例６の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｅのキノン誘導体を用いて感光体を製造した。
【００５８】
〔比較例４〕
実施例６の式（Ｉ）ａのキノン誘導体に代えて、３，５−ジクロロキノンを用いて感光体を製造した。
【００５９】
〔比較例５〕
実施例６の式（Ｉ）ａのキノン誘導体に代えて、３，５−ジフェニルキノンを用いて感光体を製造した。
【００６０】
〔比較例６〕
実施例６の式（Ｉ）ａのキノン誘導体に代えて、テトラシアノキノジメタンを用いて感光体を製造した。
【００６１】
〔実施例１１〕
上記式（II）に示したジスアゾ顔料２重量部と、バインダとしてポリビニルブチラール１重量部とを乾式混練した後、溶媒として１，４−ジオキサン１６重量部とアセトン４重量部とを加えサンドミルにて２時間分散し、これを塗工液としてアルミニウム製ドラム上に浸漬塗布したのち乾燥させて厚さ０．５μｍの電荷発生層３を形成した。次いで、式（Ｉ）ａのキノン誘導体１０重量部に対しポリカーボネート１０重量部とＴＨＦ１００重量部とを加え溶解した塗工液を電荷発生層３の表面に浸漬塗布して厚さ２０μｍの電荷移動層４を形成し、８０℃で１時間乾燥して機能分離型の電子写真感光体を製造した。
【００６２】
〔実施例１２〕
実施例１１の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｂのキノン誘導体を用いて感光体を製造した。
【００６３】
〔実施例１３〕
実施例１１の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｃのキノン誘導体を用いて感光体を製造した。
【００６４】
〔実施例１４〕
実施例１１の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｄのキノン誘導体を用いて感光体を製造した。
【００６５】
〔実施例１５〕
実施例１１の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｅのキノン誘導体を用いて感光体を製造した。
【００６６】
〔比較例７〕
実施例１１の式（Ｉ）ａのキノン誘導体に代えて、３，５−ジクロロキノンを用いて感光体を製造した。
【００６７】
〔比較例８〕
実施例１１の式（Ｉ）ａのキノン誘導体に代えて、３，５−ジフェニルキノンを用いて感光体を製造した。
【００６８】
〔比較例９〕
実施例１１の式（Ｉ）ａのキノン誘導体に代えて、テトラシアノキノジメタンを用いて感光体を製造した。
【００６９】
〔実施例１６〕
導電性基体であるアルミニウム製ドラム上に圧力１０^-5torr、加熱温度５００℃で膜厚５００オングストロームになるように、高純度オキシチタニルフタロシアニンを蒸着して図２に示したような電荷発生層３を形成した。次いで、式（Ｉ）ａのキノン誘導体１０重量部に対しポリカーボネート１０重量部とＴＨＦ１００重量部とを加え溶解した塗工液を電荷発生層３の表面に浸漬塗布して厚さ２０μｍの電荷移動層４を形成し、８０℃で１時間乾燥して機能分離型の電子写真感光体を製造した。
【００７０】
〔実施例１７〕
実施例１６の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｂのキノン誘導体を用いて感光体を製造した。
【００７１】
〔実施例１８〕
実施例１６の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｃのキノン誘導体を用いて感光体を製造した。
【００７２】
〔実施例１９〕
実施例１６の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｄのキノン誘導体を用いて感光体を製造した。
【００７３】
〔実施例２０〕
実施例１６の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｅのキノン誘導体を用いて感光体を製造した。
【００７４】
〔比較例１０〕
実施例１６の式（Ｉ）ａのキノン誘導体に代えて、３，５−ジクロロキノンを用いて感光体を製造した。
【００７５】
〔比較例１１〕
実施例１６の式（Ｉ）ａのキノン誘導体に代えて、３，５−ジフェニルキノンを用いて感光体を製造した。
【００７６】
〔比較例１２〕
実施例１６の式（Ｉ）ａのキノン誘導体に代えて、テトラシアノキノジメタンを用いて感光体を製造した。
【００７７】
〔実施例２１〕
高純度オキシチタニルフタロシアニン５ｇをガラスビーズ５０ｍｌと共にペイントシェイカで１００時間乾式粉砕する。次に、ｎ−プロパノール５０ｍｌと、ポリビニルブチラール５ｇを加え、１時間湿式ミリングする。更に、メチルエチルケトン１００ｍｌを加えて１０時間分散する。分散して得られた溶液をアルミニウム製ドラム上に浸漬塗布し、乾燥させて厚さ０．２μｍの電荷発生層３を形成した。次いで、式（Ｉ）ａのキノン誘導体１０重量部に対しポリカーボネート１０重量部とＴＨＦ１００重量部とを加え溶解した塗工液を電荷発生層３の表面に浸漬塗布して厚さ２０μｍの電荷移動層４を形成し、８０℃で１時間乾燥して機能分離型の電子写真感光体を製造した。
【００７８】
〔実施例２２〕
実施例２１の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｂのキノン誘導体を用いて感光体を製造した。
【００７９】
〔実施例２３〕
実施例２１の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｃのキノン誘導体を用いて感光体を製造した。
【００８０】
〔実施例２４〕
実施例２１の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｄのキノン誘導体を用いて感光体を製造した。
【００８１】
〔実施例２５〕
実施例２１の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｅのキノン誘導体を用いて感光体を製造した。
【００８２】
〔比較例１３〕
実施例２１の式（Ｉ）ａのキノン誘導体に代えて、３，５−ジクロロキノンを用いて感光体を製造した。
【００８３】
〔比較例１４〕
実施例２１の式（Ｉ）ａのキノン誘導体に代えて、３，５−ジフェニルキノンを用いて感光体を製造した。
【００８４】
〔比較例１５〕
実施例２１の式（Ｉ）ａのキノン誘導体に代えて、テトラシアノキノジメタンを用いて感光体を製造した。
【００８５】
〔実施例２６〕
上記式（II）に示すジスアゾ顔料２重量部と、バインダとしてポリビニルブチラール１重量部を乾式混練した後、溶媒として１，４−ジオキサン１６重量部とアセトン４重量部とを加えサンドミルにて２時間分散し、これを塗工液としてアルミニウム製ドラム上に浸漬塗布したのち乾燥させて厚さ０．５μｍの電荷発生層３を形成した。次いで、式（III)のＴＰＤ誘導体１０重量部に対しポリカーボネート１０重量部とＴＨＦ１００重量部、更に式（Ｉ）ａのキノン誘導体１重量部を加え溶解した塗工液を電荷発生層３の表面に浸漬塗布し、厚さ２０μｍの電荷移動層４を形成したのち、８０℃で１時間乾燥して機能分離型の電子写真感光体を製造した。
【００８６】
〔実施例２７〕
実施例２６の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｂのキノン誘導体を用いて感光体を製造した。
【００８７】
〔実施例２８〕
実施例２６の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｃのキノン誘導体を用いて感光体を製造した。
【００８８】
〔実施例２９〕
実施例２６の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｄのキノン誘導体を用いて感光体を製造した。
【００８９】
〔実施例３０〕
実施例２６の式（Ｉ）ａのキノン誘導体に代えて、式（Ｉ）ｅのキノン誘導体を用いて感光体を製造した。
【００９０】
〔比較例１６〕
実施例２６の式（Ｉ）ａのキノン誘導体に代えて、３，５−ジクロロキノンを用いて感光体を製造した。
【００９１】
〔比較例１７〕
実施例２６の式（Ｉ）ａのキノン誘導体に代えて、３，５−ジフェニルキノンを用いて感光体を製造した。
【００９２】
〔比較例１８〕
実施例２６の式（Ｉ）ａのキノン誘導体に代えて、テトラシアノキノジメタンを用いて感光体を製造した。
【００９３】
実施例１〜２５および比較例１〜１５において、電子写真感光体の感度である半減露光エネルギ（ｌｕｘ＊ｓｅｃ）の測定を以下の方法で行った。先ずコロナ放電電流が１７μＡとなるように電圧設定された印加電圧によって暗所でコロナ放電を行い、感光体を正帯電させた後、白色光で露光し、表面電位が７００Ｖから３５０Ｖに半減する露光エネルギを求めた。
【００９４】
表１に示す実施例１〜５の本発明の結果において、式（II）のジスアゾ顔料を電荷発生剤とした単層分散型正帯電感光体は、比較例１〜３の感光体に比べて明らかに高感度である。
【００９５】
【表１】

【００９６】
表２に示す実施例６〜１０の本発明の結果において、オキシチタニルフタロシアニンを電荷発生剤とした単層分散型正帯電感光体は比較例４〜６の感光体と比べて明らかに高感度である。
【００９７】
【表２】

【００９８】
表３に示す実施例１１〜１５の本発明の結果において、式（II）のジスアゾ顔料を樹脂と共に分散後塗工して電荷発生層を形成した機能分離型正帯電感光体は、感度特性を示しているが、比較例７〜９は感度をまったく示していない。
【００９９】
【表３】

【０１００】
表４に示す実施例１６〜２０の本発明の結果において、オキシチタニルフタロシアニンを真空蒸着により電荷発生層を形成した機能分離型正帯電感光体は、感度特性を示しているが、比較例１０〜１２は感度をまったく示していない。
【０１０１】
【表４】

【０１０２】
表５に示す実施例２１〜２５の本発明の結果において、オキシチタニルフタロシアニンを樹脂と共に分散後塗工して電荷発生層を形成した機能分離型正帯電感光体は、感度特性を示しているが、比較例１３〜１５は感度をまったく示していない。
【０１０３】
【表５】

【０１０４】
実施例２６〜３０および比較例１６〜１８において、電子写真感光体の感度である半減露光エネルギ（ｌｕｘ＊ｓｅｃ）の測定を以下の方法で行った。先ずコロナ放電電流が１７μＡとなるよう電圧設定された印加電圧によって暗所でコロナ放電を行い、感光体を負帯電させた後、白色光で露光し、表面電位が−７００Ｖから−３５０Ｖに半減する露光エネルギを求めた。
【０１０５】
表６に示す実施例２６〜３０の本発明の結果において、上記式（II）のジスアゾ顔料を樹脂と共に分散後塗工して電荷発生層を形成した機能分離型正帯電感光体は、比較例１６〜１８に比べて明らかに高感度である。
【０１０６】
【表６】

【０１０７】
【発明の効果】
以上説明したように、本発明に係る電子写真感光体によれば、バインダ樹脂との相溶性が良く、着色性が弱く、また高移動度の電子移動物質であるキノン誘導体を感光層として用いたので、耐久性があり実用に耐える高感度の電子写真感光体を得ることができた。
【図面の簡単な説明】
【図１】本発明の単層分散型感光体の構成図である。
【図２】本発明の機能分離型感光体の構成図である。
【符号の説明】
１ 導電性基体
２ 感光層
３ 電荷発生層
４ 電荷移動層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic photosensitive member used for a copying machine, a laser printer, and the like.
[0002]
[Prior art]
Conventionally, selenium, selenium-tellurium, selenium-arsenic, amorphous-silicon, and the like have been used for photoconductors such as copying machines and laser printers. However, in recent years, organic photoreceptors that are inexpensive and have low environmental pollution are becoming mainstream. Known organic photoreceptors include a functional separation type photoreceptor in which a charge generation layer (CGL) and a charge transfer layer (CTL) are laminated, and a single layer dispersion type photoreceptor in which a charge generation substance is dispersed in a medium of a charge transfer substance. It has been.
[0003]
As a charge transfer material for these photoconductors, a material with high mobility is required, but since most materials have hole mobility, practically available organic photoconductors are limited to negatively charged types. Yes. However, since charging of the photoreceptor uses corona discharge, the negatively charged electrophotographic method generates a lot of ozone, and has problems such as contamination of the indoor environment and deterioration of the photoreceptor. In order to prevent these problems, a special charging method that does not generate ozone, a filter that filters generated ozone, and the like are required, and there are disadvantages such as an electrophotographic process and apparatus becoming complicated and expensive.
[0004]
In order to reduce the generation of ozone, the market demand for positively charged photoconductors increases, and high-mobility electron transfer materials are required for developing the photoconductors. Examples of the electron transfer material include trinitrofluorenone (TNF), tetracyanoethylene, tetracyanoquinodimethane (TCNQ), quinone, diphenoquinone, naphthoquinone, anthraquinone, and derivatives thereof, but are compatible with the binder resin. Many substances are bad, and cannot be uniformly dispersed at a high concentration in the charge transfer layer of the photosensitive layer. When these substances are described in detail, for example, TNF having a high electron accepting property has a drawback that it is highly toxic and is not suitable for practical use. TCNQ exhibits extremely high electron acceptability, but has poor compatibility with the binder resin, and cannot be uniformly dispersed at a high concentration in the charge transfer layer. Further, since TCNQ is strongly colored, when the photosensitive layer is formed, there is a disadvantage that the light that should originally reach the charge generating material is absorbed and the sensitivity is lowered.
[0005]
The diphenoquinone derivative has relatively good compatibility with the binder resin, but has a large molecule and thus becomes highly colored, and lowers the sensitivity for the same reason as TCNQ. Further, although an asymmetric substitution type derivative has been proposed for the diphenoquinone skeleton, it is not satisfactory as an electron transfer material to provide a highly sensitive positively charged electrophotographic photoreceptor. As described above, at present, satisfactory high-sensitivity positively charged electrophotographic photosensitive members have not been obtained.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a high-sensitivity electrophotographic photosensitive member using a high-mobility electron-transfer material having good compatibility with a binder resin and low colorability.
[0007]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors have found that the difficulty of compatibility with the binder resin is related to the asymmetry of the molecule of the electron transfer material, and the strength of the color is related to the size of the molecule of the electron transfer material. Focusing on this fact, the present inventors have found a novel quinone derivative capable of obtaining highly sensitive electrophotographic characteristics.
[0008]
      That is, the present invention is an electrophotographic photosensitive member having a photosensitive layer containing a novel quinone derivative represented by the following general formula (I) on a conductive substrate.
◎
[Chemical 2]

(In the formula (I), R1 and R2 are cyano, nitro, halogen, acyclic hydrocarbon.Or acyclic hydrocarbonIn addition to cyano, nitro, and halogen groups, there may be substituents, and R1 and R2 may be the same or different.. )
[0009]
Specifically, the inventors focused on the fact that the colorability is related to the size of the intramolecular conjugated structure, and based on the results of studies on the quinone skeleton, the substituent on one side of p-quinone was converted to a dicyanomethane group. As a result, it was found that the electron acceptability is increased and the compatibility with the resin is not deteriorated. Furthermore, it discovered that compatibility was improved remarkably with respect to resin by introduce | transducing o-substituent with respect to the oxygen of the other side of a dicyanomethane group.
[0010]
The novel quinone derivative in the present invention has the following characteristics.
(1) In order to develop a highly sensitive positively charged electrophotographic photosensitive member, a high mobility electron transfer material is required. In order to become an electron transfer substance, electron acceptability must be high, but the quinone derivative of the present invention has extremely high electron acceptability.
(2) The quinone derivative of the present invention has extremely good compatibility with the resin used as the binder for the photosensitive layer, and can be uniformly contained in the charge transfer layer at a high concentration.
(3) The quinone derivative of the present invention has low colorability, and therefore has low absorption with respect to incident light, so that the sensitivity is hardly lowered.
Further, the quinone derivative of the present invention, when added together with a hole transfer substance to a negatively charged electrophotographic photosensitive member, has the effect of improving sensitivity and lowering the residual potential due to its electron transfer action, so that it has a high sensitivity negative charge type. It can also be used for electrophotographic photoreceptors.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The quinone derivative in the present invention has a charge transfer action as an electron transfer substance in positive and negative charge type electrophotographic photosensitive members. In the photosensitive member, the type and shape of the conductive substrate, the structure and the film thickness of the photosensitive layer. Further, it is not limited to the type and concentration of the resin and additives which are other components constituting the photosensitive layer, but preferably it is added to the photosensitive layer at a concentration of 0.1 wt% to 80 wt%. Is good. Moreover, a quinone derivative may be used individually by 1 type, and 2 or more types may be mixed and used for it.
[0012]
Examples of the structure of the photoreceptor of the present invention are shown in FIGS. FIG. 1 is a cross-sectional view of a single-layer dispersion type photoconductor, where reference numeral 1 is a conductive substrate, and 2 is a photosensitive layer in which a charge generating material is dispersed in a medium of a charge transfer material. FIG. 2 is a cross-sectional view of the function-separated type photoconductor. Reference numeral 1 denotes a conductive substrate, 3 denotes a charge generation layer, 4 denotes a charge transfer layer, and the charge generation layer 3 and the charge transfer layer 4 form a photosensitive layer. Forming.
[0013]
As the conductive substrate 1, various materials having conductivity can be used, such as aluminum, brass, stainless steel, nickel, chromium, titanium, gold, silver, copper, tin, platinum, molybdenum, and indium. Conductive substances such as metal simple substance and alloys thereof, conductive metals such as the above metals and carbon are deposited and plated, and coated with conductive plastic plates and films, and further coated with tin oxide, indium oxide, and aluminum iodide. Examples include conductive glass. Generally, a cylindrical aluminum tube alone, a surface treated with alumite, a material coated with a conductive resin, etc. are often used.
[0014]
Examples of the charge generating substance include selenium, selenium-tellurium, selenium-arsenic, amorphous-silicon, phthalocyanine pigment, monoazo pigment, bisazo pigment, trisazo pigment, polyazo pigment, indigo pigment, selenium pigment, toluidine pigment, pyrazoline pigment, perylene. Examples thereof include pigments, quinacridone pigments, pyrylium salts and the like, and these are not only used alone, but may be used in combination of two or more in order to obtain an appropriate photosensitivity wavelength and sensitizing action.
[0015]
In order to improve electrophotographic characteristics such as higher sensitivity and lower residual potential, a known charge transfer material can be added. For example, as a polymer compound, polyvinyl carbazole, halogenated polyvinyl carbazole, polyvinyl pyrene, polyvinyl indoloquinoxaline , Polyvinylbenzothiophene, polyvinylanthracene, polyvinylacridine, polyvinylpyrazoline, polyacetylene, polythiophene, polypyrrole, polyphenylene, polyphenylenevinylene, polyisothianaphthene, polyaniline, polydiacetylene, polyheptadiene, polypyridinediyl, polyquinoline, polyphenylene sulfide, Conductive polymer compounds such as polyferrocenylene, polyperinaphthylene, polyphthalocyanine, polyethylene oxide, polypropylene oxide De, polyacrylonitrile, etc. polymethacrylic acid, solid polymer electrolyte, etc. doped with metal ions of lithium, and the like. In addition, low molecular weight compounds include polycyclic aromatic compounds such as anthracene, pyrene, phenanthrene, nitrogen-containing heterocyclic compounds such as indole, carbazole, imidazole, fluorenone, fluorene, oxadiazole, oxazole, pyrazoline, hydrazone, triphenylmethane, triphenylmethane, Any known compounds such as phenylamine, enamine and stilbene compounds can be used, and further known organic charge transfer complexes formed by electron donating compounds and electron accepting compounds represented by tetrathiafulvalene-tetracyanoquinodimethane The desired photoreceptor characteristics can be obtained by mixing one or more of them.
[0016]
The binder resin used to form the photosensitive layer is polycarbonate resin, styrene resin, acrylic resin, styrene-acrylic resin, ethylene-vinyl acetate resin, polypropylene resin, vinyl chloride resin, vinyl chloride-vinyl acetate resin, polyester resin, Photocurable resins such as alkyd resin, polyamide resin, polyurethane resin, epoxy resin, polyarylate resin, polysulfone resin, diarylate resin, silicone resin, ketone resin, polyvinyl butyral resin, polyether resin, phenol resin, epoxy arylate, etc. These are used singly or in combination of two or more. In addition, resins having different molecular weights can be mixed in order to improve hardness and wear resistance.
[0017]
Solvents used in the coating solution are alcohols such as methanol, ethanol, n-propanol, i-propanol and butanol, saturated aliphatic hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane and cycloheptane, toluene and xylene. Aromatic hydrocarbons such as dichloromethane, chlorinated hydrocarbons such as dichloromethane, dichloroethane, chloroform, chlorobenzene, ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, methoxyethanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, Esters such as ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, N, N-dimethylformamide, dimethyl sulfoxide, etc. , Which may be used alone or in combination. The coating method is performed by a known coating means.
[0018]
In the coating liquid for producing the photoreceptor of the present invention, a known substance, for example, an antioxidant, an ultraviolet absorber, a radical scavenger, a softener, a curing agent, as long as the electrophotographic photoreceptor characteristics are not impaired. A crosslinking agent or the like can be added, which improves the characteristics, durability, mechanical characteristics and the like of the photoreceptor. Furthermore, by adding dispersion stabilizers, anti-settling agents, anti-color separation agents, leveling agents, antifoaming agents, thickeners, matting agents, etc., the finished appearance of the photoreceptor and the life of the coating solution can be improved. .
[0019]
In the electrophotographic photoreceptor of the present invention, an undercoat layer having an adhesion function, a barrier function, a defect covering function on the surface of the substrate, and the like may be provided between the conductive substrate and the photosensitive layer. As the undercoat 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, etc. are used alone or in combination. be able to. An undercoat layer in which a metal oxide or carbon is dispersed in a resin can also be used.
[0020]
Further, a surface protective layer can be provided on the photosensitive layer for the purpose of improving the durability of the photoreceptor, and examples thereof include polyvinyl formal resin, polycarbonate resin, fluorine resin, polyurethane resin, and silicon resin. Moreover, the surface protective layer which consists of a siloxane structure formed with the hydrolyzate of a silane coupling agent may be sufficient.
[0021]
Production examples of quinone derivatives
The quinone derivative of the above formula (I) is produced by the following method.
The first method is used when a substance in which the target substituent is substituted at positions 2 and 6 of p-quinone is commercially available, and this reaction dicyanomethanates the oxygen atom on one side of the p-quinone compound, This is a method for obtaining a quinone derivative of formula (I).
[0022]
[Chemical 3]

[0023]
[Production Example 1]
10.0 g of 3,5-dimethylbenzoquinone and 5.0 g of malononitrile were dissolved in 240 ml of dichloromethane and stirred in an ice bath. While keeping the temperature at 10 ° C. or less, 6.6 ml of titanium tetrachloride was slowly added dropwise, and then 24.0 ml of pyridine was slowly added dropwise and reacted at room temperature for 5 hours with stirring. The residue was distilled under reduced pressure, 200 ml of 10% hydrochloric acid was added to the residue, stirred vigorously, filtered, washed several times with water and dried. This was purified by recrystallization from hexane to obtain 4.0 g of 3,5-dimethyl-4-oxo-1-dicyanomethylenecyclohexadiene (I) a in a yield of 32%.
[0024]
[Production Example 2]
10.0 g of 3,5-dichlorobenzoquinone and 4.0 g of malononitrile were dissolved in 240 ml of dichloromethane and stirred in an ice bath. While keeping the temperature at 10 ° C. or less, 6.6 ml of titanium tetrachloride was slowly added dropwise, and then 24.0 ml of pyridine was slowly added dropwise and reacted at room temperature for 5 hours with stirring. The residue was distilled under reduced pressure, 200 ml of 10% hydrochloric acid was added to the residue, stirred vigorously, filtered, washed several times with water and dried. This was purified by recrystallization from hexane to obtain 3.6 g of 3,5-dichloro-4-oxo-1-dicyanomethylenecyclohexadiene (I) b in a yield of 28%.
[0025]
The second method is used when a substance in which the target substituent is substituted at positions 2 and 6 of p-quinone is not commercially available. In this method, first, a phenol compound having a substituent at positions 2 and 6 is used. This is a p-quinone compound, which is converted into a quinone derivative of the formula (I) by the same reaction as in Production Examples 1 and 2.
[0026]
[Formula 4]

[0027]
[Production Example 3]
33.0 g of 3,5-di-tBu-hydroxylanisole as a raw material was dissolved in 300 ml of acetonitrile, the temperature was kept at 0 to 10 ° C. under nitrogen gas, and 7.8 ml of bromine was added and stirred. While maintaining the temperature at 10 ° C. or lower, a mixed solution of 34.8 ml of pyridine and 60 ml of acetonitrile was added dropwise. While stirring, the reaction was carried out at 10 ° C. or lower for 1 hour, at room temperature for 2 hours, and 450 ml of cold water was further added and reacted for 3 hours. This was extracted with hexane, the hexane solution was washed with 90% aqueous methanol solution, and then hexane was removed under reduced pressure to obtain 21.0 g of 3,5-di-tBu-benzoquinone as a brown liquid with a yield of 87%.
[0028]
18.0 g of 3,5-di-tBu-benzoquinone and 5.3 g of malononitrile were dissolved in 240 ml of dichloromethane and stirred on an ice bath. While maintaining the temperature at 10 ° C. or lower, 8.8 ml of titanium tetrachloride was slowly dropped, and similarly, 32.2 ml of pyridine was slowly dropped and reacted at room temperature for 5 hours with stirring. Dichloromethane was removed by concentration under reduced pressure, 200 ml of 10% hydrochloric acid was added to the residue and stirred vigorously. After filtration, the residue was washed several times with water and dried. Furthermore, recrystallization operation was performed with hexane to obtain 3.8 g of 3,5-di-tBu-4-oxo-1-dicyanomethylenecyclohexadiene (I) c in a yield of 17.3%.
[0029]
The third method is a method in which a substituent is introduced arbitrarily at the 2,6-positions in the quinone derivative of the formula (I), and is useful as a method for producing an electron transfer substance. In this method, a nitromalonaldehyde and an alkyl ketone are reacted to synthesize a 2,6-substituted p-nitrophenol compound, which is converted into a quinone compound, and then the same reaction as in Production Examples 1 and 2 is performed. A quinone derivative is used.
[0030]
[Chemical formula 5]

[0031]
[Production Example 4]
24.3 ml of water and 25.0 g of sodium nitrite were dissolved while warming with stirring. 24.3 ml of 95% ethanol solution of 25.0 g of mucobromic acid was added dropwise while maintaining the temperature at 54 ± 1 ° C. After dropping, the mixture was kept at 54 ± 1 ° C. and stirred for 10 minutes. Cool to 0-5 ° C, filter the precipitate and dissolve it in a mixture of 80% 95% ethanol and 20 ml of water with heating, dissolve and filter to cool the solution to 0-5 ° C. 6.0 g of the Japanese product was obtained with a yield of 39%.
[0032]
44 ml of an ethanol solution of 8.8 g of 1,3 diphenyl-2-propane, 15 ml of an aqueous solution of 3.3 g of sodium hydroxide and 64 ml of an aqueous solution of 7.4 g of nitromalonaldehyde sodium monohydrate were refluxed for 2 hours, Stir for days. The solvent was removed by distillation under reduced pressure, and 10% hydrochloric acid was added to the residue with stirring, followed by filtration. Recrystallization from acetic acid / ethanol containing 1 to 2 drops of concentrated hydrochloric acid gave 8.9 g of 2,6-diphenyl-4-nitrophenol in a yield of 65%.
[0033]
To 50 ml of acetic acid, 8.9 g of lead tetraacetate and 6.7 g of 2,6-diphenyl-4-nitrophenol were added and stirred for 24 hours. The reaction solution was extracted with ether and then washed with water, and further washed with a 5% aqueous sodium hydroxide solution and water in this order. This was dehydrated with sodium sulfate, ether was removed and recrystallized with ethanol to obtain 3.4 g of 2,6-diphenyl-1,4-benzoquinone in a yield of 57%.
[0034]
To 150 ml of dichloromethane were added 5.7 g of 2,6-diphenyl-1,4-benzoquinone and 1.7 g of malononitrile.₂Stirred under. While maintaining the temperature at 10 ° C. or lower, 2.8 ml of titanium tetrachloride and then 10.0 ml of pyridine were slowly added dropwise, stirred for 5 hours at room temperature, and then the solvent was removed by distillation under reduced pressure. The residue was extracted with warm hexane, washed with 1N hydrochloric acid and then with water to remove the solvent. Purified by column chromatography using silica gel as the packing material and hexane / ethyl acetate = 2 (volume ratio) as the eluent, and 3,5-diphenyl-4-oxo-1-dicyanomethylenecyclohexadiene (I) d 0 0.8 g was obtained with a yield of 11%.
[0035]
[Production Example 5]
Instead of 1,3diphenyl-2-propane of Production Example 4, 4.2 g of 3-hexanone was used, and 1 of 3-ethyl-5-methyl-4-oxo-1-dicyanomethylenecyclohexadiene (I) e was used. .3 g was obtained with a yield of 15%.
[0036]
The quinone derivatives (I) a to (I) e obtained in Production Examples 1 to 5 described above are shown below.
[0037]
[Chemical 6]

[0038]
[Chemical 7]

[0039]
[Chemical 8]

[0040]
[Chemical 9]

[0041]
[Chemical Formula 10]

[0042]
【Example】
Examples of the electrophotographic photoreceptor according to the present invention will be described below. In addition, this invention is not limited to a following example, unless the summary is exceeded.
[0043]
[Example 1]
1 part by weight of a disazo pigment represented by formula (II) as a charge generator, 10 parts by weight of polycarbonate as a binder, 80 parts by weight of THF as a solvent were kneaded and dispersed in a sand mill for 10 hours, and further 9 parts by weight of a TPD derivative of formula (III) After adding 1 part by weight of the quinone derivative of the formula (I) a and dissolving, this solution is applied onto an aluminum drum by a dipping method, and a single-layer dispersion type having a thickness of 20 μm that serves both as charge generation and charge transfer The photosensitive layer 2 was formed and dried at 80 ° C. for 1 hour to produce an electrophotographic photoreceptor.
[0044]
Embedded image

[0045]
Embedded image

[0046]
[Example 2]
Instead of the quinone derivative of the formula (I) a in Example 1, a photoreceptor was produced using the quinone derivative of the formula (I) b.
[0047]
Example 3
Instead of the quinone derivative of the formula (I) a in Example 1, a photoreceptor was produced using the quinone derivative of the formula (I) c.
[0048]
Example 4
Instead of the quinone derivative of the formula (I) a in Example 1, a photoreceptor was produced using the quinone derivative of the formula (I) d.
[0049]
Example 5
In place of the quinone derivative of the formula (I) a in Example 1, a photoreceptor was produced using the quinone derivative of the formula (I) e.
[0050]
[Comparative Example 1]
A photoconductor was produced using 3,5-dichloroquinone instead of the quinone derivative of formula (I) a in Example 1.
[0051]
[Comparative Example 2]
In place of the quinone derivative of the formula (I) a in Example 1, 3,5-diphenylquinone was used to produce a photoreceptor.
[0052]
[Comparative Example 3]
A photoconductor was produced using tetracyanoquinodimethane instead of the quinone derivative of the formula (I) a of Example 1.
[0053]
Example 6
1 part by weight of high-purity oxytitanyl phthalocyanine as a charge generating agent, 10 parts by weight of polycarbonate as a binder, and 80 parts by weight of THF as a solvent are kneaded and dispersed in a sand mill for 10 hours. 1) 1 part by weight of the quinone derivative of a was added and dissolved, and then this solution was applied onto an aluminum drum by a dipping method, and a monolayer dispersion type photosensitive layer having a thickness of 20 μm and both charge generation and charge transfer. 2 was formed and dried at 80 ° C. for 1 hour to produce an electrophotographic photosensitive member.
[0054]
Example 7
In place of the quinone derivative of the formula (I) a in Example 6, a photoreceptor was produced using the quinone derivative of the formula (I) b.
[0055]
Example 8
In place of the quinone derivative of formula (I) a in Example 6, a photoreceptor was produced using the quinone derivative of formula (I) c.
[0056]
Example 9
In place of the quinone derivative of the formula (I) a in Example 6, a photoreceptor was produced using the quinone derivative of the formula (I) d.
[0057]
Example 10
Instead of the quinone derivative of the formula (I) a in Example 6, a photoreceptor was produced using the quinone derivative of the formula (I) e.
[0058]
[Comparative Example 4]
A photoconductor was produced using 3,5-dichloroquinone instead of the quinone derivative of formula (I) a in Example 6.
[0059]
[Comparative Example 5]
A photoconductor was produced using 3,5-diphenylquinone instead of the quinone derivative of formula (I) a in Example 6.
[0060]
[Comparative Example 6]
A photoconductor was produced using tetracyanoquinodimethane instead of the quinone derivative of formula (I) a in Example 6.
[0061]
Example 11
After dry kneading 2 parts by weight of the disazo pigment represented by the above formula (II) and 1 part by weight of polyvinyl butyral as a binder, 16 parts by weight of 1,4-dioxane and 4 parts by weight of acetone are added as a solvent in a sand mill. This was dispersed for 2 hours, dip coated on an aluminum drum as a coating solution, and then dried to form a charge generation layer 3 having a thickness of 0.5 μm. Next, a coating solution prepared by adding 10 parts by weight of polycarbonate and 100 parts by weight of THF to 10 parts by weight of the quinone derivative of formula (I) a is dip-coated on the surface of the charge generation layer 3 to form a charge transfer layer having a thickness of 20 μm. 4 was dried at 80 ° C. for 1 hour to produce a function-separated electrophotographic photosensitive member.
[0062]
Example 12
In place of the quinone derivative of the formula (I) a in Example 11, a photoreceptor was produced using the quinone derivative of the formula (I) b.
[0063]
Example 13
In place of the quinone derivative of formula (I) a in Example 11, a photoreceptor was produced using the quinone derivative of formula (I) c.
[0064]
Example 14
In place of the quinone derivative of the formula (I) a in Example 11, a photoreceptor was produced using the quinone derivative of the formula (I) d.
[0065]
Example 15
In place of the quinone derivative of formula (I) a in Example 11, a photoreceptor was produced using the quinone derivative of formula (I) e.
[0066]
[Comparative Example 7]
A photoconductor was produced using 3,5-dichloroquinone instead of the quinone derivative of formula (I) a in Example 11.
[0067]
[Comparative Example 8]
A photoconductor was produced using 3,5-diphenylquinone instead of the quinone derivative of formula (I) a in Example 11.
[0068]
[Comparative Example 9]
A photoconductor was produced using tetracyanoquinodimethane instead of the quinone derivative of formula (I) a in Example 11.
[0069]
Example 16
A pressure of 10 on an aluminum drum as a conductive substrate.^-FiveA high-purity oxytitanyl phthalocyanine was vapor-deposited so as to have a film thickness of 500 angstroms at a heating temperature of 500 ° C. to form the charge generation layer 3 as shown in FIG. Next, a coating solution prepared by adding 10 parts by weight of polycarbonate and 100 parts by weight of THF to 10 parts by weight of the quinone derivative of formula (I) a is dip-coated on the surface of the charge generation layer 3 to form a charge transfer layer having a thickness of 20 μm. 4 was dried at 80 ° C. for 1 hour to produce a function-separated electrophotographic photosensitive member.
[0070]
Example 17
In place of the quinone derivative of formula (I) a in Example 16, a photoreceptor was produced using the quinone derivative of formula (I) b.
[0071]
Example 18
In place of the quinone derivative of formula (I) a in Example 16, a photoreceptor was produced using the quinone derivative of formula (I) c.
[0072]
Example 19
In place of the quinone derivative of formula (I) a in Example 16, a quinone derivative of formula (I) d was used to produce a photoreceptor.
[0073]
Example 20
In place of the quinone derivative of formula (I) a in Example 16, a photoreceptor was produced using the quinone derivative of formula (I) e.
[0074]
[Comparative Example 10]
A photoconductor was produced using 3,5-dichloroquinone instead of the quinone derivative of formula (I) a in Example 16.
[0075]
[Comparative Example 11]
A photoconductor was produced using 3,5-diphenylquinone instead of the quinone derivative of the formula (I) a of Example 16.
[0076]
[Comparative Example 12]
A photoconductor was produced using tetracyanoquinodimethane instead of the quinone derivative of formula (I) a in Example 16.
[0077]
Example 21
5 g of high-purity oxytitanyl phthalocyanine is dry-pulverized for 100 hours with a paint shaker along with 50 ml of glass beads. Next, 50 ml of n-propanol and 5 g of polyvinyl butyral are added and wet milled for 1 hour. Further, 100 ml of methyl ethyl ketone is added and dispersed for 10 hours. The solution obtained by dispersion was dip-coated on an aluminum drum and dried to form a charge generation layer 3 having a thickness of 0.2 μm. Next, a coating solution prepared by adding 10 parts by weight of polycarbonate and 100 parts by weight of THF to 10 parts by weight of the quinone derivative of formula (I) a is dip-coated on the surface of the charge generation layer 3 to form a charge transfer layer having a thickness of 20 μm. 4 was dried at 80 ° C. for 1 hour to produce a function-separated electrophotographic photosensitive member.
[0078]
[Example 22]
In place of the quinone derivative of the formula (I) a in Example 21, a photoreceptor was produced using the quinone derivative of the formula (I) b.
[0079]
Example 23
In place of the quinone derivative of formula (I) a in Example 21, a photoreceptor was produced using the quinone derivative of formula (I) c.
[0080]
Example 24
In place of the quinone derivative of formula (I) a in Example 21, a photoreceptor was produced using a quinone derivative of formula (I) d.
[0081]
Example 25
In place of the quinone derivative of formula (I) a in Example 21, a photoreceptor was produced using the quinone derivative of formula (I) e.
[0082]
[Comparative Example 13]
A photoconductor was produced using 3,5-dichloroquinone instead of the quinone derivative of formula (I) a in Example 21.
[0083]
[Comparative Example 14]
A photoconductor was produced using 3,5-diphenylquinone instead of the quinone derivative of formula (I) a in Example 21.
[0084]
[Comparative Example 15]
A photoconductor was produced using tetracyanoquinodimethane instead of the quinone derivative of the formula (I) a in Example 21.
[0085]
Example 26
After dry kneading 2 parts by weight of the disazo pigment represented by the above formula (II) and 1 part by weight of polyvinyl butyral as a binder, 16 parts by weight of 1,4-dioxane and 4 parts by weight of acetone are added as a solvent for 2 hours in a sand mill. This was dispersed, applied as an application liquid onto an aluminum drum, and then dried to form a charge generation layer 3 having a thickness of 0.5 μm. Subsequently, 10 parts by weight of polycarbonate and 100 parts by weight of THF with respect to 10 parts by weight of the TPD derivative of formula (III) and further 1 part by weight of the quinone derivative of formula (I) a were added and dissolved on the surface of the charge generation layer 3. After dipping and forming the charge transfer layer 4 having a thickness of 20 μm, it was dried at 80 ° C. for 1 hour to produce a function-separated electrophotographic photosensitive member.
[0086]
Example 27
Instead of the quinone derivative of formula (I) a in Example 26, a quinone derivative of formula (I) b was used to produce a photoreceptor.
[0087]
Example 28
In place of the quinone derivative of formula (I) a in Example 26, a quinone derivative of formula (I) c was used to produce a photoreceptor.
[0088]
Example 29
Instead of the quinone derivative of formula (I) a in Example 26, a quinone derivative of formula (I) d was used to produce a photoreceptor.
[0089]
Example 30
Instead of the quinone derivative of formula (I) a in Example 26, a quinone derivative of formula (I) e was used to produce a photoreceptor.
[0090]
[Comparative Example 16]
A photoconductor was produced using 3,5-dichloroquinone instead of the quinone derivative of the formula (I) a in Example 26.
[0091]
[Comparative Example 17]
Instead of the quinone derivative of formula (I) a in Example 26, 3,5-diphenylquinone was used to produce a photoreceptor.
[0092]
[Comparative Example 18]
A photoconductor was produced using tetracyanoquinodimethane instead of the quinone derivative of formula (I) a in Example 26.
[0093]
In Examples 1 to 25 and Comparative Examples 1 to 15, the half exposure energy (lux * sec), which is the sensitivity of the electrophotographic photosensitive member, was measured by the following method. First, corona discharge is performed in the dark with an applied voltage set so that the corona discharge current is 17 μA, the photosensitive member is positively charged, then exposed to white light, and the surface potential is reduced to half from 700 V to 350 V. I asked for energy.
[0094]
In the results of the present invention of Examples 1 to 5 shown in Table 1, the monolayer dispersion type positively charged photoreceptor using the disazo pigment of the formula (II) as a charge generating agent is compared with the photoreceptors of Comparative Examples 1 to 3. Clearly high sensitivity.
[0095]
[Table 1]

[0096]
In the results of the present invention of Examples 6 to 10 shown in Table 2, the single-layer dispersed positively charged photoreceptor using oxytitanyl phthalocyanine as a charge generator is clearly more sensitive than the photoreceptors of Comparative Examples 4 to 6. is there.
[0097]
[Table 2]

[0098]
In the results of the present invention of Examples 11 to 15 shown in Table 3, the function-separated positively charged photoreceptor formed by dispersing the disazo pigment of the formula (II) together with the resin and coating it to form a charge generation layer has a sensitivity characteristic. Although shown, Comparative Examples 7-9 do not show any sensitivity.
[0099]
[Table 3]

[0100]
In the results of the present invention of Examples 16 to 20 shown in Table 4, the function-separated positively charged photoreceptor in which the charge generation layer is formed by vacuum deposition of oxytitanyl phthalocyanine shows sensitivity characteristics. 12 shows no sensitivity at all.
[0101]
[Table 4]

[0102]
In the results of Examples 21 to 25 of the present invention shown in Table 5, the function-separated positively charged photoreceptor in which the charge generation layer is formed by dispersing and coating oxytitanyl phthalocyanine together with the resin exhibits sensitivity characteristics. Comparative Examples 13 to 15 do not show any sensitivity.
[0103]
[Table 5]

[0104]
In Examples 26-30 and Comparative Examples 16-18, the half exposure energy (lux * sec), which is the sensitivity of the electrophotographic photosensitive member, was measured by the following method. First, corona discharge is performed in the dark with an applied voltage set so that the corona discharge current is 17 μA, the photosensitive member is negatively charged and then exposed to white light, and the surface potential is halved from −700 V to −350 V. The exposure energy was determined.
[0105]
In the results of the present invention of Examples 26 to 30 shown in Table 6, the function-separated positively charged photoreceptor in which the charge generation layer is formed by dispersing the disazo pigment of the above formula (II) together with the resin and coating it is a comparative example. It is clearly more sensitive than 16-18.
[0106]
[Table 6]

[0107]
【The invention's effect】
As described above, according to the electrophotographic photoreceptor of the present invention, a quinone derivative, which is a high mobility electron transfer material, has good compatibility with the binder resin, low colorability, and is used as the photosensitive layer. Therefore, it was possible to obtain a highly sensitive electrophotographic photosensitive member that is durable and practical.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a single-layer dispersion type photoreceptor of the present invention.
FIG. 2 is a configuration diagram of a function-separated type photoreceptor of the present invention.
[Explanation of symbols]
1 Conductive substrate
2 Photosensitive layer
3 Charge generation layer
4 Charge transfer layer

Claims (1)

An electrophotographic photoreceptor comprising a photosensitive layer containing a quinone derivative represented by the following general formula (I) on a conductive substrate.
◎

(In the formula (I), R1 and R2 are cyano, nitro, halogen, acyclic hydrocarbon or an acyclic hydrocarbon alkoxy group, and there may be substituents other than cyano, nitro and halogen groups; R1 and R2 may be the same or different .)

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