JP3587941B2 - Organic photoconductive material and electrophotographic photoreceptor using the same - Google Patents

Description

【００１４】
一般式（１）において、Ｒ₁、Ｒ₂は水素原子、置換基を有していてもよいアルキル基、アルケニル基を示し、Ｒ₃は置換基を有していてもよいアルキル基、アラルキル基、アリール基、複素環を示す。Ｒ₄は水素原子、ハロゲン原子、置換基を有していてもよいアルキル基、アルコキシ基を示し、ｎは０〜２までの整数を示す。Ｒ₆、Ｒ₇は、水素原子、置換基を有していてもよいアルキル基、アリール基、複素環基を示す。但し、Ｒ₆、Ｒ₇のどちらか一つに必ずアリール基、あるいは複素環を有する。Ｒ₅は置換基を有していてもよいビニル基、ブタジエニル基、１−シクロヘキセニル基を示す。但し、Ｒ ₁ ＝Ｒ ₂ ＝ＨでＲ ₅ がＣＨ ₂ ＝ＣＨ−の場合を除く。
【００１５】
ここでＲ_１、Ｒ_２の具体例としては、水素原子、メチル基、エチル基、ｎ−プロピル基、イソプロピル基などのアルキル基、アリル基、メタリル基などのアルケニル基を挙げることができる。また、Ｒ_１、Ｒ_２は置換基を有していてもよいが、その置換基の具体例としては、メトキシ基、エトキシ基などのアルコキシ基、弗素原子、塩素原子などのハロゲン原子などを挙げることができる。
【００１６】
また、Ｒ_３の具体例としては、メチル基、エチル基、ｎ−プロピル基、イソプロピル基などのアルキル基、ベンジル基、１−ナフチルメチル基などのアラルキル基、フェニル基、ナフチル基などのアリール基、フリル基、チエニル基などの複素環を挙げることができる。また、Ｒ_３は置換基を有していてもよいが、その置換基の具体例としては弗素原子、塩素原子などのハロゲン原子、メトキシ基、エトキシ基などのアルコキシ基、上述のアルキル基などを挙げることができる。
【００１７】
またＲ_６、Ｒ_７の具体例としては、水素原子、メチル基、エチル基、ｎ−プロピル基、イソプロピル基などのアルキル基、フェニル基、ナフチル基などのアリール基、あるいはフリル基、チエニル基の複素環などを挙げることができる。また、Ｒ_６、Ｒ_７は置換基を有していてもよく、その具体例としては、弗素原子、塩素原子などのハロゲン原子、上述のアルキル基、メトキシ基、エトキシ基などのアルコキシ基、そして上述のアリール基などを挙げることができる。
【００１８】
ここでＲ₅の具体例としては、ビニル基、１−シクロヘキセニル基を挙げることができる。但し、Ｒ₁＝Ｒ₂＝ＨのときはＲ₅は単なるビニル基（ＣＨ₂＝ＣＨ−）を除く。また、Ｒ₅は置換基を有していてもよいが、その置換基の具体例としてはメチル基、エチル基などのアルキル基、フェニル基、ナフチル基などのアリール基、チエニル基などの複素環基などを挙げることができる。
【００１９】
【発明の実施の形態】
本発明の有機光導電性材料は、適度な結晶性を有しているために精製が容易であり、かつ結着剤との相溶性もよい。従って、感光体作製後、感光体表面で結晶化することなく、安定した被膜を形成することが可能である。
【００２０】
本発明にかかわる一般式（１）で示される有機光導電性材料の具体例としては、以下に示すＣ−０１〜９５の構造を有するものが挙げられるが、これらに限定されるものではない。
【００２１】
【化３】

【００２２】
【化４】

【００２３】
【化５】

【００２４】
【化６】

【００２５】
【化７】

【００２６】
【化８】

【００２７】
【化９】

【００２８】
【化１０】

【００２９】
【化１１】

【００３０】
【化１２】

【００３１】
【化１３】

【００３２】
【化１４】

【００３３】
【化１５】

【００３４】
本発明の電子写真感光体は、一般式（１）で示される有機光導電性材料及び電荷発生物質をそれぞれ１種類あるいは２種類以上含有することにより得られる。電荷発生物質には無機系電荷発生物質と有機系電荷発生物質があり、前者の例としては例えばセレン、セレン−テルル合金、セレン−ヒ素合金、硫化カドミウム、酸化亜鉛、アモルファスシリコンなどが挙げられる。有機系電荷発生物質の例としては、例えばメチルバイオレット、ブリリアントグリーン、クリスタルバイオレットなどのトリフェニルメタン系染料、メチレンブルーなどのチアジン染料、キニザリンなどのキノン染料、シアニン染料、アクリジン染料、ピリリウム色素、チアピリリウム色素、スクエアリウム色素、ペリノン系顔料、アントラキノン系顔料、金属含有あるいは無金属のフタロシアニン系顔料、ペリレン系顔料などが挙げられ、また、アゾ顔料も用いられる。
【００３５】
アゾ顔料としては、例えば特開昭４７−３７５４３号公報、特開昭５３−９５０３３号公報、特開昭５３−１３２３４７号公報、特開昭５３−１３３４４５号公報、特開昭５４−１２７４２号公報、特開昭５４−２０７３６号公報、特開昭５４−２０７３７号公報、特開昭５４−２１７２８号公報、特開昭５４−２２８３４号公報、特開昭５５−６９１４８号公報、特開昭５５−６９６５４号公報、特開昭５５−７９４４９号公報、特開昭５５−１１７１５１号公報、特開昭５６−４６２３７号公報、特開昭５６−１１６０３９号公報、特開昭５６−１１６０４０号公報、特開昭５６−１１９１３４号公報、特開昭５６−１４３４３７号公報、特開昭５７−６３５３７号公報、特開昭５７−６３５３８号公報、特開昭５７−６３５４１号公報、特開昭５７−６３５４２号公報、特開昭５７−６３５４９号公報、特開昭５７−６６４３８号公報、特開昭５７−７４７４６号公報、特開昭５７−７８５４２号公報、特開昭５７−７８５４３号公報、特開昭５７−９００５６号公報、特開昭５７−９００５７号公報、特開昭５７−９０６３２号公報、特開昭５７−１１６３４５号公報、特開昭５７−２０２３４９号公報、特開昭５８−４１５１号公報、特開昭５８−９０６４４号公報、特開昭５８−１４４３５８号公報、特開昭５８−１７７９５５号公報、特開昭５９−３１９６２号公報、特開昭５９−３３２５３号公報、特開昭５９−７１０５９号公報、特開昭５９−７２４４８号公報、特開昭５９−７８３５６号公報、特開昭５９−１３６３５１号公報、特開昭５９−２０１０６０号公報、特開昭６０−１５６４２号公報、特開昭６０−１４０３５１号公報、特開昭６０−１７９７４６号公報、特開昭６１−１１７５４号公報、特開昭６１−９０１６４号公報、特開昭６１−９０１６５号公報、特開昭６１−９０１６６号公報、特開昭６１−１１２１５４号公報、特開昭６１−２６９１６５号公報、特開昭６１−２８１２４５号公報、特開昭６１−５１０６３号公報、特開昭６２−２６７３６３号公報、特開昭６３−６８８４４号公報、特開昭６３−８９８６６号公報、特開昭６３−１３９３５５号公報、特開昭６３−１４２０６３号公報、特開昭６３−１８３４５０号公報、特開昭６３−２８２７４３号公報、特開昭６４−２１４５５号公報、特開昭６４−７８２５９号公報、特開平１−２００２６７号公報、特開平１−２０２７５７号公報、特開平１−３１９７５４号公報、特開平２−７２３７２号公報、特開平２−２５４４６７号公報、特開平３−９５５６１号公報、特開平３−２７８０６３号公報、特開平４−９６０６８号公報、特開平４−９６０６９号公報、特開平４−１４７２６５号公報、特開平５−１４２８４１号公報、特開平５−３０３２２６号公報、特開平６−３２４５０４号公報、特開平７−１６８３７９号公報などに記載の化合物が挙げられる。
【００３６】
また、これらのアゾ顔料に用いられるカプラー成分の構造は多岐に渡る。例えば特開昭５４−１７７３５号公報、特開昭５４−７９６３２号公報、特開昭５７−１７６０５５号公報、特開昭５９−１９７０４３号公報、特開昭６０−１３０７４６号公報、特開昭６０−１５３０５０号公報、特開昭６０−１０３０４８号公報、特開昭６０−１８９７５９号公報、特開昭６３−１３１１４６号公報、特開昭６３−１５５０５２号公報、特開平２−１１０５６９号公報、特開平４−１４９４４８号公報、特開平６−２７７０５号公報、特開平６−３４８０４７号公報などに記載の化合物が挙げられる。
【００３７】
上記アゾ顔料の具体例は以下に示すＢ−１〜４０に示す化合物と表１〜１４に示すカプラーとの組み合わせからなる全ての化合物を挙げることができるが、これらに限定されるものではない。また、これらの化合物と他の電荷発生物質を併用することも可能である。
【００３８】
【化１６】

【００３９】
【化１７】

【００４０】
【化１８】

【００４１】
【化１９】

【００４２】
【化２０】

【００４３】
【化２１】

【００４４】
【化２２】

【００４５】
【表１】

【００４６】
【表２】

【００４７】
【表３】

【００４８】
【表４】

【００４９】
【表５】

【００５０】
【表６】

【００５１】
【表７】

【００５２】
【表８】

【００５３】
【表９】

【００５４】
【表１０】

【００５５】
【表１１】

【００５６】
【表１２】

【００５７】
【表１３】

【００５８】
【表１４】

【００５９】
感光体の形態としては種々のものが知られているが、そのいずれにも用いることができる。例えば、導電性支持体上に電荷発生物質、電荷輸送物質、およびフィルム形成性結着剤樹脂からなる感光層を設けたものがある。また、導電性支持体上に、電荷発生物質と結着剤樹脂からなる電荷発生層と、電荷輸送物質と結着剤樹脂からなる電荷輸送層を設けた積層型の感光体も知られている。電荷発生層と電荷輸送層はどちらが上層となっても構わない。また、必要に応じて導電性支持体と感光層の間に下引き層を、感光体表面にオーバーコート層を、積層型感光体の場合は電荷発生層と電荷輸送層との間に中間層を設けることもできる。本発明の化合物を用いて感光体を作製する支持体としては、金属製ドラム、金属板、導電性加工を施した紙やプラスチックフィルムのシート状、ドラム状あるいはベルト状の支持体などが使用される。
【００６０】
それらの支持体上へ感光層を形成するために用いるフィルム形成性結着剤樹脂としては利用分野に応じて種々のものがあげられる。例えば複写用感光体の用途ではポリスチレン樹脂、ポリビニルアセタール樹脂、ポリスルホン樹脂、ポリカーボネート樹脂、酢ビ・クロトン酸共重合体樹脂、ポリエステル樹脂、ポリフェニレンオキサイド樹脂、ポリアリレート樹脂、アルキッド樹脂、アクリル樹脂、メタクリル樹脂、フェノキシ樹脂などが挙げられる。これらの中でも、ポリスチレン樹脂、ポリビニルアセタール樹脂、ポリカーボネート樹脂、ポリエステル樹脂、ポリアリレート樹脂などは感光体としての電位特性に優れている。また、これらの樹脂は、単独あるいは共重合体のいずれでもよく、またこれらを１種または２種以上を混合して用いることができる。これら結着剤樹脂の光導電性化合物に対して加える量は、２０〜１０００重量％が好ましく、５０〜５００重量％がより好ましい。
【００６１】
積層型感光体の場合、電荷発生層に含有されるこれらの樹脂は、電荷発生物質に対して１０〜５００重量％が好ましく、５０〜１５０重量％がより好ましい。樹脂の比率が高くなりすぎると電荷発生効率が低下し、また樹脂の比率が低くなりすぎると成膜性に問題が生じる。また、電荷輸送層に含有されるこれらの樹脂は、電荷輸送物質に対して２０〜１０００重量％が好ましく、５０〜５００重量％がより好ましい。樹脂の比率が高すぎると感度が低下し、また、樹脂の比率が低くなりすぎると繰り返し特性の悪化や塗膜の欠損を招くおそれがある。
【００６２】
これらの樹脂の中には、引っ張り、曲げ、圧縮などの機械的強度に弱いものがある。この性質を改良するために、可塑性を与える物質を加えることができる。具体的には、フタル酸エステル（例えばＤＯＰ、ＤＢＰなど）、リン酸エステル（例えばＴＣＰ、ＴＯＰなど）、セバシン酸エステル、アジピン酸エステル、ニトリルゴム、塩素化炭化水素などが挙げられる。これらの物質は、必要以上に添加すると電子写真特性の悪影響を及ぼすので、その割合は結着剤樹脂に対し２０重量％以下が好ましい。
【００６３】
その他、感光体中への添加物として酸化防止剤やカール防止剤など、塗工性の改良のためレベリング剤などを必要に応じて添加することができる。
【００６４】
一般式（１）で示されるスチルベン化合物は更に他の電荷輸送物質と組み合わせて用いることができる。電荷輸送物質には正孔輸送物質と電子輸送物質がある。前者の例としては、例えば特公昭３４−５４６６号公報などに示されているオキサジアゾール類、特公昭４５−５５５号公報などに示されているトリフェニルメタン類、特公昭５２−４１８８号公報などに示されているピラゾリン類、特公昭５５−４２３８０号公報などに示されているヒドラゾン類、特開昭５６−１２３５４４号公報などに示されているオキサジアゾール類などを挙げることができる。一方、電子輸送物質としては、例えばクロラニル、テトラシアノエチレン、テトラシアノキノジメタン、２，４，７−トリニトロ−９−フルオレノン、２，４，５，７−テトラニトロ−９−フルオレノン、２，４，５，７−テトラニトロキサントン、２，４，８−トリニトロチオキサントン、１，３，７−トリニトロジベンゾチオフェン、１，３，７−トリニトロジベンゾチオフェン−５，５−ジオキシドなどがある。これらの電荷輸送物質は単独または２種以上組み合わせて用いることができる。
【００６５】
また、一般式（１）で示されるスチルベン化合物と電荷移動錯体を形成し、更に増感効果を増大させる増感剤として、ある種の電子吸引性化合物を添加することもできる。この電子吸引性化合物としては例えば、２，３−ジクロロ−１，４−ナフトキノン、１−ニトロアントラキノン、１−クロロ−５−ニトロアントラキノン、２−クロロアントラキノン、フェナントレンキノンなどのキノン類、４−ニトロベンズアルデヒドなどのアルデヒド類、９−ベンゾイルアントラセン、インダンジオン、３，５−ジニトロベンゾフェノン、３，３′，５，５′−テトラニトロベンゾフェノンなどのケトン類、無水フタル酸、４−クロロナフタル酸無水物などの酸無水物、テレフタラルマロノニトリル、９−アントリルメチリデンマロノニトリル、４−ニトロベンザルマロノニトリル、４−（ｐ−ニトロベンゾイルオキシ）ベンザルマロノニトリルなどのシアノ化合物、３−ベンザルフタリド、３−（α−シアノ−ｐ−ニトロベンザル）フタリド、３−（α−シアノ−ｐ−ニトロベンザル）−４，５，６，７−テトラクロロフタリドなどのフタリド類などを挙げることができる。
【００６６】
本発明の有機光導電性材料は、感光体の形態に応じて上記の種々の添加物質と共に適当な溶剤中に溶解または分散し、その塗布液を先に述べた導電性支持体上に塗布し、乾燥して感光体を製造することができる。
【００６７】
塗布溶剤としてはクロロホルム、ジクロロエタン、ジクロロメタン、トリクロロエタン、トリクロロエチレン、クロロベンゼン、ジクロロベンゼンなどのハロゲン化炭化水素、ベンゼン、トルエン、キシレンなどの芳香族炭化水素、ジオキサン、テトラヒドロフラン、メチルセロソルブ、エチルセロソルブ、エチレングリコールジメチルエーテルなどのエーテル系溶剤、メチルエチルケトン、メチルイソブチルケトン、メチルイソプロピルケトン、シクロヘキサノンなどのケトン系溶剤、酢酸エチル、ギ酸メチル、メチルセロソルブアセテートなどのエステル系溶剤、Ｎ，Ｎ−ジメチルホルムアミド、アセトニトリル、Ｎ−メチルピロリドン、ジメチルスルホキシドなどの非プロトン性極性溶剤及びｎ−ブタノール、２−プロパノールなどのアルコール系溶剤などを挙げることができる。これらの溶剤は単独または２種以上の混合溶剤として使用することができる。
【００６８】
【実施例】
次に本発明を実施例により更に詳細に説明するが、本発明はこれらに何ら限定されるものではない。
【００６９】
【化２３】

【００７０】
合成例１ 例示化合物Ｃ−１１の合成
上記（２）で示されるアルデヒド体２．０２ｇ、及びジエチルシンナミルフォスフォネート２．７２ｇを溶かした１，２−ジメトキシエタン８０ｍｌ溶液に、室温で撹拌下、カリウムｔ−ブトキシド１．４１ｇをゆっくりと加えた。３０分撹拌を続けた後、反応液を５００ｍｌの氷水に注ぎ込んで反応を停止し、酢酸エチルで有機成分を抽出した。分離した有機層を無水硫酸ナトリウムで乾燥し、減圧下溶媒を留去した。得られたオイル状物質をシリカゲルカラムクロマトグラフィーで精製して化合物Ｃ−１１を２．１０ｇ得た。収率７３％。融点１１２．６℃。
【００７１】
【化２４】

【００７２】
合成例２ 例示化合物Ｃ−２６の合成
上記（３）で示されるアルデヒド体３．３４ｇ、及びジエチルシンナミルフォスフォネート４．１２ｇを溶かした１，２−ジメトキシエタン８０ｍｌ溶液に、室温で撹拌下、カリウムｔ−ブトキシド３．０１ｇをゆっくりと加えた。３０分撹拌を続けた後、反応液を５００ｍｌの氷水に注ぎ込んで反応を停止し、酢酸エチルで有機成分を抽出した。分離した有機層を無水硫酸ナトリウムで乾燥し、減圧下溶媒を留去した。得られたオイル状物質をシリカゲルカラムクロマトグラフィーで精製して化合物Ｃ−２６を４．０３ｇ得た。収率８６％。融点９９．５℃。
【００７３】
実施例１
アゾ顔料（Ｂ−１、Ｃｐ＝Ａ−２１）１重量部及びポリエステル樹脂（東洋紡製バイロン２００）１重量部をテトラヒドロフラン１００重量部と混合し、ペイントコンディショナー装置でガラスビーズと共に２時間分散した。こうして得た分散液を、アプリケーターにてアルミ蒸着ポリエステル上に塗布して乾燥し、膜厚約０．２μｍの電荷発生層を形成した。次にスチルベン化合物（例示化合物Ｃ−０１）を、ポリアリレート樹脂（ユニチカ製Ｕ−ポリマー）と１：１の重量比で混合し、ジクロロエタンを溶媒として１０重量％の溶液を作り、上記の電荷発生層の上にアプリケーターで塗布して膜厚約２０μｍの電荷輸送層を形成した。乾燥後にこの層を観察したところ、スチルベン化合物の結晶析出は全く見られなかった。
【００７４】
この様にして作製した積層型感光体について、静電記録試験装置（川口電機製ＳＰ−４２８）を用いて電子写真特性の評価を行なった。
測定条件：印加電圧−６ｋＶ、スタティックＮｏ． ３（ターンテーブルの回転スピードモード：１０ｍ／ｍｉｎ ）。その結果、帯電電位（Ｖ０）が−７９５Ｖ、半減露光量（Ｅ１／２）が１．２ルックス・秒と高感度の値を示した。
【００７５】
更に同装置を用いて、帯電−除電（除電光：白色光で４００ルックス×１秒照射）を１サイクルとする繰返し使用に対する特性評価を行った。５０００回での繰返しによる帯電電位の変化を求めたところ、１回目の帯電電位（Ｖ０）−７９５Ｖに対し、５０００回目の帯電電位（Ｖ０）は−７７５Ｖであり、繰返しによる電位の低下がほとんどなく安定した特性を示した。また、１回目の半減露光量（Ｅ１／２）１．２ルックス・秒に対して５０００回目の半減露光量（Ｅ１／２）は１．２ルックス・秒と変化がなく優れた特性を示した。
【００７６】
実施例２〜４８
実施例１のアゾ顔料（Ｂ−１、Ｃｐ＝Ａ−２１）及び例示化合物Ｃ−０１の代わりに、それぞれ表１５、表１６に示すアゾ顔料及びスチルベン化合物を用いた他は、実施例１と同様にして感光体を作製してその特性を評価した。結果を表１５、表１６に示す。なおこれらの感光体においても実施例１と同様に、乾燥後にスチルベン化合物の結晶析出は全く認められなかった。
【００７７】
【表１５】

【００７８】
【表１６】

【００７９】
実施例４９
アゾ顔料（Ｂ−１、Ｃｐ＝Ａ−２１）１重量部とテトラヒドロフラン４０重量部を、ペイントコンディショナー装置でガラスビーズと共に８時間分散処理した。こうして得た分散液に、スチルベン化合物（例示化合物Ｃ−０１）を２．５重量部、ポリカーボネート樹脂（三菱ガス化学製ＰＣＺ−２００）１０重量部、テトラヒドロフラン６０重量部を加え、更にペイントコンディショナー装置で３０分間分散処理を行った後、アプリケーターにてアルミ蒸着ポリエステル上に塗布し、膜厚約１５μｍの感光層を形成した。乾燥後、この層を観察したところ、サウチルベン化合物の結晶析出は全く認められなかった。この感光体の電子写真特性を、実施例１と同様にして評価した。ただし、印加電圧のみ＋５ｋＶに変更した。その結果、１回目の帯電電位（Ｖ０）＋４１０Ｖ、半減露光量（Ｅ１／２）１．４ルックス・秒、５０００回繰り返し後の帯電電位（Ｖ０）＋３９０Ｖ、半減露光量（Ｅ１／２）１．４ルックス・秒と、高感度でしかも変化の少ない、優れた特性を示した。
【００８０】
実施例５０〜９６
実施例４９のアゾ顔料（Ｂ−１２、Ｃｐ＝Ａ−２１）及び例示化合物Ｃ−０１の代わりに、それぞれ表１７、表１８に示すアゾ顔料及びスチルベン化合物を用いた他は、実施例４９と同様にして感光体を作製してその特性を評価した。結果を表１７、表１８に示す。なお、これらの感光体においても、実施例４９と同様に、スチルベン化合物の結晶析出は全く認められなかった。
【００８１】
【表１７】

【００８２】
【表１８】

【００８３】
実施例９７〜１０７
実施例１のアゾ顔料の代わりにτ型無金属フタロシアニンを、例示化合物Ｃ−０１の代わりにそれぞれ表１９に示すスチルベン化合物を用いた他は、実施例１と同様にして感光体を作製してその特性を評価した。結果を表１９に示す。また、これらの感光体においても実施例１と同様、スチルベン化合物の結晶析出は全く認められなかった。
【００８４】
【表１９】

【００８５】
実施例１０８〜１１８
実施例４９のアゾ顔料の代わりにＹ型チタニルオキシフタロシアニンを、例示化合物Ｃ−０１の代わりにそれぞれ表２０に示すスチルベン化合物を用いた他は、実施例１と同様にして感光体を作製してその特性を評価した。結果を表２０に示す。また、これらの感光体においても、実施例４９と同様、スチルベン化合物の結晶析出は全く認められなかった。
【００８６】
【表２０】

【００８７】
【化２５】

【００８８】
比較例１
電荷輸送物質として例示化合物Ｃ−０１の代わりに上記に示す比較化合物（４）を用いた他は、実施例１と同様に感光体を作製した。しかし、比較化合物（４）は結晶性が高く、作製した感光体表面で結晶化してしまった。その感光体の特性を評価した結果、帯電電位は（Ｖ０）−２８０Ｖ、 半減露光量（Ｅ１／２）は３．７ルックス・秒と帯電電位の低下、並びに感度の低下がみられた。
【００８９】
【化２６】

【００９０】
比較例２
電荷輸送物質として例示化合物Ｃ−０１の代わりに上記に示す比較化合物（５）を用いた他は、実施例１と同様に感光体を作製した。比較例１と同様に、比較化合物（５）も結晶性が高く、作製した感光体の表面で結晶化してしまった。その感光体の特性を評価した結果、帯電電位（Ｖ０）は−３００Ｖ、半減露光量（Ｅ１／２）は２．９ルックス・秒と帯電電位の低下、並びに感度の低下がみられた。
【００９１】
【発明の効果】
以上から明らかなように、本発明の有機光導電性材料を用いれば高感度で高耐久性を有し、安定した被膜を形成することが可能な優れた電子写真感光体を提供することができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an organic photoconductive material and an electrophotographic photosensitive member using the same, and more particularly, to an electrophotographic photosensitive member containing a specific organic photoconductive material.
[0002]
[Prior art]
In recent years, the use of electrophotography has spread not only in the field of copiers but also in fields where photographic technology has been conventionally used, such as printing plate materials, slide films, and microfilms. Application to printers is also being considered. Recently, the use of a photoconductive material for applications other than the electrophotographic photoreceptor, for example, an electrostatic recording element, a sensor material, an EL element, and the like has been studied. Accordingly, demands for photoconductive materials and electrophotographic photoreceptors using the same are becoming higher and wider. Heretofore, inorganic photoconductive materials such as selenium, cadmium sulfide, zinc oxide, and silicon have been known as electrophotographic photoconductors, and have been widely studied and put to practical use. While these inorganic materials have many advantages, they also have various disadvantages. For example, selenium has drawbacks in that production conditions are difficult and crystallization is easily caused by heat and mechanical shock, and cadmium sulfide and zinc oxide have poor moisture resistance and durability. It has been pointed out that silicon is insufficient in chargeability and difficult to manufacture. In addition, selenium and cadmium sulfide have toxicity problems.
[0003]
On the other hand, organic photoconductive materials have good film-forming properties, excellent flexibility, light weight, good transparency, and the design of photoreceptors over a wide wavelength range by an appropriate sensitization method. Because of its advantages such as ease of use, its practical use is gradually attracting attention.
[0004]
By the way, a photoreceptor used in the electrophotographic technology is generally required to have the following basic properties. That is, (1) high chargeability against corona discharge in a dark place, (2) little leakage (dark decay) of the obtained charge in a dark place, and (3) charge charge by light irradiation. (4) The residual charge after light irradiation is small.
[0005]
However, to date, much research has been conducted on photoconductive polymers such as polyvinyl carbazole as organic photoconductive materials, but these have not always had sufficient film properties, flexibility, and adhesiveness. It is difficult to say that the toner has sufficient basic properties as a photoreceptor.
[0006]
On the other hand, for organic low-molecular-weight photoconductive compounds, it is possible to obtain a photoreceptor having excellent mechanical strength such as film properties, adhesiveness, and flexibility by selecting a binder and the like used for photoreceptor formation. However, it is difficult to find a compound suitable for maintaining high sensitivity characteristics.
[0007]
In order to improve such a point, an organic photoreceptor having higher sensitivity characteristics has been developed in which the charge generation function and the charge transport function are shared by different substances. The feature of such a photoconductor, which is called a function-separated type, is that a material suitable for each function can be selected from a wide range, and a photoconductor with arbitrary performance can be easily manufactured. Has been advanced.
[0008]
Among them, as the substance in charge of the charge generation function, various kinds of substances such as phthalocyanine pigment, squarium dye, azo pigment, and perylene pigment have been studied, and among them, azo pigments can have various molecular structures, Since charge generation efficiency can be expected, it has been widely studied and its practical use has been advanced. However, in this azo pigment, the relationship between the molecular structure and the charge generation efficiency has not yet been clarified. The fact is that we are searching for the optimal structure through extensive synthesis research, but it fully satisfies the basic properties and high durability required for the photoreceptors listed above. Things have not yet been obtained.
[0009]
On the other hand, the substances in charge of the charge transport function include a hole transport substance and an electron transport substance. A wide variety of materials such as hydrazone compounds and stilbene compounds have been studied as hole transport materials, and 2,4,7-trinitro-9-fluorenone and diphenoquinone derivatives have been studied as electron transport materials. The fact is that we are searching for the optimal structure through extensive synthesis research. In fact, many improvements have been made so far, but none of the above-mentioned photoconductors sufficiently satisfy the basic properties and high durability demands of the photoconductors.
[0010]
As described above, various improvements have been made in the production of electrophotographic photoreceptors, but those which sufficiently satisfy the basic properties and high durability required for the photoreceptors listed above. Has not yet been obtained.
[0011]
[Problems to be solved by the invention]
It is an object of the present invention to use in electrophotographic photosensitive members and sensor materials, EL elements, electrostatic recording elements, and the like, which have a high charged potential, high sensitivity, and exhibit stable performance without changing various characteristics even when used repeatedly. It is to provide a possible organic photoconductive material. Further, another object of the present invention is to provide an electrophotographic photoreceptor which is easy to produce and has excellent compatibility with a binder.
[0012]
[Means for Solving the Problems]
The present inventors have conducted research on a photoconductive material to achieve the above object, and as a result, have found that an organic photoconductive material having a specific structure is effective, and reached the present invention. The organic photoconductive material having a specific structure as described above is a compound represented by the following general formula (1).
[0013]
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[0014]
In the general formula (1), R ₁ and R ₂ represent a hydrogen atom, an alkyl group or an alkenyl group which may have a substituent, and R ₃ represents an alkyl group or an aralkyl group which may have a substituent. , An aryl group, and a heterocyclic ring. R ₄ represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group which may have a substituent, and n represents an integer of 0 to 2. R ₆ and R ₇ represent a hydrogen atom, an alkyl group which may have a substituent, an aryl group, or a heterocyclic group. However, one of R ₆ and R ₇ always has an aryl group or a heterocyclic ring. R ₅ represents optionally vinyl group which may have a substituent group, butadienyl group, a 1-cyclohexenyl group. However, this excludes the case where R ₁ = R ₂ = H and R ₅ is CH ₂ = CH-.
[0015]
Here, specific examples of R ₁ and R ₂ include a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, an n-propyl group and an isopropyl group, and an alkenyl group such as an allyl group and a methallyl group. R ₁ and R ₂ may have a substituent. Specific examples of the substituent include an alkoxy group such as a methoxy group and an ethoxy group, and a halogen atom such as a fluorine atom and a chlorine atom. be able to.
[0016]
Specific examples of R ₃ include alkyl groups such as methyl group, ethyl group, n-propyl group and isopropyl group, aralkyl groups such as benzyl group and 1-naphthylmethyl group, and aryl groups such as phenyl group and naphthyl group. , A furyl group, a thienyl group and the like. R ₃ may have a substituent. Specific examples of the substituent include a halogen atom such as a fluorine atom and a chlorine atom, an alkoxy group such as a methoxy group and an ethoxy group, and the above-described alkyl group. Can be mentioned.
[0017]
Specific examples of R ₆ and R ₇ include a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, an n-propyl group and an isopropyl group, an aryl group such as a phenyl group and a naphthyl group, and a furyl group and a thienyl group. Heterocycles and the like can be mentioned. Further, R ₆ and R ₇ may have a substituent, and specific examples thereof include a halogen atom such as a fluorine atom and a chlorine atom, the above-described alkyl group, an alkoxy group such as a methoxy group and an ethoxy group, and The above-mentioned aryl groups can be exemplified.
[0018]
Here, specific examples of R ₅ include a vinyl group and a 1 -cyclohexenyl group. However, when _{R 1 = R 2 = H R} 5 except a simple vinyl groups (CH ₂ = CH-). R ₅ may have a substituent. Specific examples of the substituent include an alkyl group such as a methyl group and an ethyl group, an aryl group such as a phenyl group and a naphthyl group, and a heterocyclic group such as a thienyl group. And the like.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Since the organic photoconductive material of the present invention has appropriate crystallinity, it can be easily purified and has good compatibility with a binder. Therefore, it is possible to form a stable film without crystallization on the surface of the photoconductor after the photoconductor is manufactured.
[0020]
Specific examples of the organic photoconductive material represented by the general formula (1) according to the present invention include those having the structures of C-01 to 95 shown below, but are not limited thereto.
[0021]
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[0022]
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[0023]
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[0024]
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[0025]
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[0026]
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[0027]
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[0028]
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[0029]
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[0030]
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[0031]
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[0032]
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[0033]
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[0034]
The electrophotographic photoreceptor of the present invention can be obtained by containing one or more of the organic photoconductive material represented by the general formula (1) and the charge generating substance. The charge generating material includes an inorganic charge generating material and an organic charge generating material. Examples of the former include selenium, selenium-tellurium alloy, selenium-arsenic alloy, cadmium sulfide, zinc oxide, amorphous silicon, and the like. Examples of organic charge generating substances include, for example, triphenylmethane dyes such as methyl violet, brilliant green and crystal violet, thiazine dyes such as methylene blue, quinone dyes such as quinizarin, cyanine dyes, acridine dyes, pyrylium dyes, and thiapyrylium dyes And squarium dyes, perinone pigments, anthraquinone pigments, metal-containing or metal-free phthalocyanine pigments, perylene pigments, and the like, and azo pigments are also used.
[0035]
Examples of azo pigments include JP-A-47-37543, JP-A-53-95033, JP-A-53-132347, JP-A-53-133445, and JP-A-54-12742. JP-A-54-20736, JP-A-54-20737, JP-A-54-21728, JP-A-54-22834, JP-A-55-69148, JP-A-55-69148 JP-A-69654, JP-A-55-79449, JP-A-55-117151, JP-A-56-46237, JP-A-56-116039, JP-A-56-116040, JP-A-56-119134, JP-A-56-143439, JP-A-57-63537, JP-A-57-63538, JP-A-57-63541 JP-A-57-63542, JP-A-57-63549, JP-A-57-66438, JP-A-57-74746, JP-A-57-78542, and JP-A-57-64542. JP-A-78543, JP-A-57-90056, JP-A-57-90057, JP-A-57-90632, JP-A-57-116345, JP-A-57-202349, JP-A-58-4151, JP-A-58-90644, JP-A-58-144358, JP-A-58-177555, JP-A-59-31962, JP-A-59-33253. JP-A-59-71059, JP-A-59-72448, JP-A-59-78356, JP-A-59-136351, and JP-A-59-201060. Japanese Patent Application Laid-Open Nos. Sho 60-15642, 60-140351, 60-179746, 61-11754, 61-90164, and 61-90164. 61-90165, JP-A-61-90166, JP-A-61-112154, JP-A-61-269165, JP-A-61-281245, and JP-A-61-51063. JP-A-62-267363, JP-A-63-68844, JP-A-63-89866, JP-A-63-139355, JP-A-63-142063, -183450, JP-A-63-282743, JP-A-64-21455, JP-A-64-78259, JP-A-1-200267, JP-A-1-2-2 JP-A-027557, JP-A-1-319754, JP-A-2-72372, JP-A-2-254467, JP-A-3-95561, JP-A-3-278806, and JP-A-4-96068 JP-A-4-96069, JP-A-4-147265, JP-A-5-142841, JP-A-5-303226, JP-A-6-324504, JP-A-7-168379, etc. And the compounds described in the above.
[0036]
The structure of the coupler component used in these azo pigments is various. For example, JP-A-54-17735, JP-A-54-79632, JP-A-57-176055, JP-A-59-197043, JP-A-60-130746 and JP-A-60-130746. JP-A-153050, JP-A-60-103048, JP-A-60-189759, JP-A-63-131146, JP-A-63-155052, JP-A-2-110569, Compounds described in JP-A-4-149448, JP-A-6-27705, JP-A-6-348047 and the like can be mentioned.
[0037]
Specific examples of the azo pigment include, but are not limited to, all compounds composed of combinations of the compounds shown in B-1 to 40 shown below and the couplers shown in Tables 1 to 14. Further, these compounds can be used in combination with other charge generating substances.
[0038]
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[0039]
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[0040]
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[0041]
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[0042]
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[0043]
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[0044]
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[0045]
[Table 1]

[0046]
[Table 2]

[0047]
[Table 3]

[0048]
[Table 4]

[0049]
[Table 5]

[0050]
[Table 6]

[0051]
[Table 7]

[0052]
[Table 8]

[0053]
[Table 9]

[0054]
[Table 10]

[0055]
[Table 11]

[0056]
[Table 12]

[0057]
[Table 13]

[0058]
[Table 14]

[0059]
Various types of photoreceptors are known, and any of them can be used. For example, there is one in which a photosensitive layer comprising a charge generating substance, a charge transporting substance, and a film-forming binder resin is provided on a conductive support. Further, a laminated photoreceptor in which a charge generation layer composed of a charge generation substance and a binder resin and a charge transport layer composed of a charge transport substance and a binder resin are provided on a conductive support is also known. . Either of the charge generation layer and the charge transport layer may be an upper layer. In addition, if necessary, an undercoat layer is provided between the conductive support and the photosensitive layer, an overcoat layer is provided on the surface of the photosensitive member, and in the case of a laminated photosensitive member, an intermediate layer is provided between the charge generation layer and the charge transport layer. Can also be provided. As a support for preparing a photoreceptor using the compound of the present invention, a metal drum, a metal plate, a sheet-like or drum-like or belt-like support of paper or plastic film subjected to conductive processing, and the like are used. You.
[0060]
As the film-forming binder resin used for forming a photosensitive layer on such a support, various resins can be used depending on the field of use. For example, for photoreceptors for copying, polystyrene resin, polyvinyl acetal resin, polysulfone resin, polycarbonate resin, vinyl acetate / crotonic acid copolymer resin, polyester resin, polyphenylene oxide resin, polyarylate resin, alkyd resin, acrylic resin, methacrylic resin And phenoxy resins. Among them, polystyrene resin, polyvinyl acetal resin, polycarbonate resin, polyester resin, polyarylate resin, and the like have excellent potential characteristics as a photoconductor. These resins may be used alone or as a copolymer, and they may be used alone or in combination of two or more. The amount of the binder resin added to the photoconductive compound is preferably 20 to 1000% by weight, and more preferably 50 to 500% by weight.
[0061]
In the case of a laminated photoreceptor, these resins contained in the charge generation layer are preferably from 10 to 500% by weight, more preferably from 50 to 150% by weight, based on the charge generation substance. If the ratio of the resin is too high, the charge generation efficiency is reduced, and if the ratio of the resin is too low, there is a problem in film formability. Further, these resins contained in the charge transporting layer are preferably 20 to 1000% by weight, more preferably 50 to 500% by weight, based on the charge transporting substance. If the ratio of the resin is too high, the sensitivity is lowered, and if the ratio of the resin is too low, the repetition characteristics may be deteriorated or the coating may be damaged.
[0062]
Some of these resins have low mechanical strength such as tension, bending, and compression. In order to improve this property, substances which impart plasticity can be added. Specific examples include phthalic acid esters (eg, DOP, DBP, etc.), phosphoric acid esters (eg, TCP, TOP, etc.), sebacic acid esters, adipic acid esters, nitrile rubber, chlorinated hydrocarbons, and the like. If these substances are added unnecessarily, they adversely affect the electrophotographic properties. Therefore, the proportion is preferably 20% by weight or less based on the binder resin.
[0063]
In addition, as an additive to the photoreceptor, a leveling agent or the like for improving coating properties, such as an antioxidant or an anti-curl agent, can be added as needed.
[0064]
The stilbene compound represented by the general formula (1) can be used in combination with another charge transport substance. The charge transport materials include a hole transport material and an electron transport material. Examples of the former include, for example, oxadiazoles disclosed in JP-B-34-5466, triphenylmethanes disclosed in JP-B-45-5555, and JP-B-52-4188. And the like, hydrazones disclosed in JP-B-55-42380, oxadiazoles disclosed in JP-A-56-123544 and the like. On the other hand, examples of the electron transport material include chloranil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 1,3,7-trinitrodibenzothiophene, 1,3,7-trinitrodibenzothiophene-5,5-dioxide and the like. These charge transport materials can be used alone or in combination of two or more.
[0065]
In addition, a certain kind of electron-withdrawing compound can be added as a sensitizer that forms a charge transfer complex with the stilbene compound represented by the general formula (1) and further increases the sensitizing effect. Examples of the electron-withdrawing compound include quinones such as 2,3-dichloro-1,4-naphthoquinone, 1-nitroanthraquinone, 1-chloro-5-nitroanthraquinone, 2-chloroanthraquinone, and phenanthrenequinone; Aldehydes such as benzaldehyde, ketones such as 9-benzoylanthracene, indandione, 3,5-dinitrobenzophenone, 3,3 ', 5,5'-tetranitrobenzophenone, phthalic anhydride, 4-chloronaphthalic anhydride and the like Acid anhydrides, cyano compounds such as terephthalalmalononitrile, 9-anthrylmethylidene malononitrile, 4-nitrobenzalmalonenitrile, 4- (p-nitrobenzoyloxy) benzalmalononitrile, 3-benzalphthalide, 3 -(Α-cyano-p-ni Robenzaru) phthalide, 3- (alpha-cyano -p- Nitorobenzaru) -4,5,6,7 such phthalides such as tetrachloro phthalide can be cited.
[0066]
The organic photoconductive material of the present invention is dissolved or dispersed in an appropriate solvent together with the various additives described above depending on the form of the photoreceptor, and the coating solution is coated on the conductive support described above. After drying, a photoreceptor can be manufactured.
[0067]
As a coating solvent, halogenated hydrocarbons such as chloroform, dichloroethane, dichloromethane, trichloroethane, trichloroethylene, chlorobenzene, dichlorobenzene, aromatic hydrocarbons such as benzene, toluene, xylene, dioxane, tetrahydrofuran, methyl cellosolve, ethyl cellosolve, ethylene glycol dimethyl ether Ether solvents such as methyl ethyl ketone, methyl isobutyl ketone, methyl isopropyl ketone, and cyclohexanone; ester solvents such as ethyl acetate, methyl formate and methyl cellosolve acetate; N, N-dimethylformamide, acetonitrile and N-methyl Aprotic polar solvents such as pyrrolidone and dimethyl sulfoxide and n-butanol and 2-propanol; Or the like can be mentioned alcohol-based solvent. These solvents can be used alone or as a mixed solvent of two or more.
[0068]
【Example】
Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.
[0069]
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[0070]
Synthesis Example 1 Synthesis of Exemplified Compound C-11 A solution of 2.02 g of the aldehyde shown in the above (2) and 2.72 g of diethylcinnamylphosphonate in 80 ml of 1,2-dimethoxyethane was stirred at room temperature. And 1.41 g of potassium t-butoxide were slowly added. After stirring was continued for 30 minutes, the reaction solution was poured into 500 ml of ice water to stop the reaction, and an organic component was extracted with ethyl acetate. The separated organic layer was dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The obtained oily substance was purified by silica gel column chromatography to obtain 2.10 g of compound C-11. 73% yield. 112.6 ° C.
[0071]
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[0072]
Synthesis Example 2 Synthesis of Exemplified Compound C-26 A solution of 3.34 g of the aldehyde compound shown in the above (3) and 4.12 g of diethylcinnamylphosphonate in 80 ml of 1,2-dimethoxyethane was stirred at room temperature. And 3.01 g of potassium t-butoxide were slowly added. After stirring was continued for 30 minutes, the reaction solution was poured into 500 ml of ice water to stop the reaction, and an organic component was extracted with ethyl acetate. The separated organic layer was dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The obtained oily substance was purified by silica gel column chromatography to obtain 4.03 g of compound C-26. 86% yield. Melting point 99.5 ° C.
[0073]
Example 1
1 part by weight of an azo pigment (B-1, Cp = A-21) and 1 part by weight of a polyester resin (Vylon 200 manufactured by Toyobo) were mixed with 100 parts by weight of tetrahydrofuran, and dispersed together with glass beads by a paint conditioner for 2 hours. The dispersion thus obtained was applied on an aluminum-evaporated polyester using an applicator and dried to form a charge generation layer having a thickness of about 0.2 μm. Next, a stilbene compound (exemplified compound C-01) was mixed with a polyarylate resin (U-Polymer manufactured by Unitika) at a weight ratio of 1: 1 to prepare a 10% by weight solution using dichloroethane as a solvent. A charge transport layer having a thickness of about 20 μm was formed on the layer by coating with an applicator. When this layer was observed after drying, no crystal precipitation of the stilbene compound was observed.
[0074]
The electrophotographic characteristics of the laminated photoreceptor thus manufactured were evaluated using an electrostatic recording tester (SP-428 manufactured by Kawaguchi Electric).
Measurement conditions: applied voltage -6 kV, static No. 3 (turntable rotation speed mode: 10 m / min). As a result, the charged potential (V0) was −795 V, and the half-life exposure amount (E1 / 2) was 1.2 lux · sec, which was a high sensitivity value.
[0075]
Further, by using the same apparatus, the characteristic evaluation for repeated use with one cycle of charging-discharging (discharging light: irradiation with white light at 400 lux × 1 second) was performed. When the change of the charging potential due to the repetition of 5000 times was obtained, the charging potential (V0) of the 5000th time was -775 V with respect to the charging potential (V0) of -795 V of the first time, and the potential was hardly reduced by the repetition. It showed stable characteristics. The half-exposure dose (E1 / 2) of the 5000th time was 1.2 lux / sec, which was excellent at 1.2 lux / sec. .
[0076]
Examples 2 to 48
Example 1 was repeated except that the azo pigment of Example 1 (B-1, Cp = A-21) and the exemplified compound C-01 were replaced with azo pigments and stilbene compounds shown in Tables 15 and 16, respectively. Similarly, a photoreceptor was prepared and its characteristics were evaluated. The results are shown in Tables 15 and 16. As in Example 1, no crystal precipitation of the stilbene compound was observed on these photoconductors after drying.
[0077]
[Table 15]

[0078]
[Table 16]

[0079]
Example 49
1 part by weight of an azo pigment (B-1, Cp = A-21) and 40 parts by weight of tetrahydrofuran were dispersed together with glass beads for 8 hours using a paint conditioner. To the dispersion thus obtained, 2.5 parts by weight of a stilbene compound (exemplified compound C-01), 10 parts by weight of a polycarbonate resin (PCZ-200 manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 60 parts by weight of tetrahydrofuran were added. After a dispersion treatment for 30 minutes, the dispersion was applied on an aluminum vapor-deposited polyester with an applicator to form a photosensitive layer having a thickness of about 15 μm. After drying, this layer was observed, and no crystal precipitation of the sautylben compound was observed at all. The electrophotographic characteristics of this photoreceptor were evaluated in the same manner as in Example 1. However, only the applied voltage was changed to +5 kV. As a result, the first charging potential (V0) +410 V, half-exposure amount (E1 / 2) 1.4 lux / sec, and the charging potential (V0) +390 V after 5,000 repetitions, half-exposure amount (E1 / 2) 1. It showed excellent characteristics with high sensitivity and little change of 4 looks / sec.
[0080]
Examples 50 to 96
Example 49 was repeated except that the azo pigment and the stilbene compound shown in Tables 17 and 18 were used instead of the azo pigment (B-12, Cp = A-21) and Exemplified Compound C-01 of Example 49, respectively. Similarly, a photoreceptor was prepared and its characteristics were evaluated. The results are shown in Tables 17 and 18. In addition, also in these photoconductors, as in Example 49, no stilbene compound was crystallized.
[0081]
[Table 17]

[0082]
[Table 18]

[0083]
Examples 97 to 107
A photoconductor was prepared in the same manner as in Example 1, except that the azo pigment of Example 1 was replaced with a τ-type metal-free phthalocyanine, and the stilbene compounds shown in Table 19 were used instead of Exemplified Compound C-01. Its properties were evaluated. The results are shown in Table 19. Also, as in Example 1, no stilbene compound crystals were precipitated on these photosensitive members.
[0084]
[Table 19]

[0085]
Examples 108 to 118
A photoconductor was prepared by the same way as that of Example 1 except that Y-type titanyloxyphthalocyanine was used instead of the azo pigment of Example 49 and stilbene compounds shown in Table 20 instead of Exemplified Compound C-01, respectively. Its properties were evaluated. The results are shown in Table 20. Also, in these photoreceptors, crystal precipitation of the stilbene compound was not observed at all, as in Example 49.
[0086]
[Table 20]

[0087]
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[0088]
Comparative Example 1
A photoconductor was prepared by the same way as that of Example 1 except that the comparative compound (4) shown above was used instead of the exemplary compound C-01 as the charge transporting substance. However, Comparative Compound (4) had high crystallinity and crystallized on the surface of the produced photoreceptor. As a result of evaluating the characteristics of the photoreceptor, the charging potential was (V0) -280 V, the half-life exposure amount (E1 / 2) was 3.7 lux / sec, and the charging potential was lowered and the sensitivity was lowered.
[0089]
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[0090]
Comparative Example 2
A photoconductor was prepared by the same way as that of Example 1 except that Comparative Compound (5) shown above was used instead of Exemplified Compound C-01 as a charge transporting substance. As in Comparative Example 1, Comparative Compound (5) also had high crystallinity and crystallized on the surface of the produced photoreceptor. As a result of evaluating the characteristics of the photoreceptor, the charging potential (V0) was -300 V, and the half-life exposure amount (E1 / 2) was 2.9 lux · sec.
[0091]
【The invention's effect】
As is clear from the above, the use of the organic photoconductive material of the present invention can provide an excellent electrophotographic photoreceptor having high sensitivity and high durability and capable of forming a stable film. .

Claims (3)

An organic photoconductive material represented by the following general formula (1).

(In the general formula (1), R ₁ and R _{2 each} represent a hydrogen atom, an optionally substituted alkyl group or an alkenyl group, and R ₃ represents an optionally substituted alkyl group or aralkyl. R ₄ represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group which may have a substituent, and n represents an integer of 0 to 2. R ₆ , R ₇ represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group, or a heterocyclic group, provided that at least one of R ₆ and R _{7 has} an aryl group or a heterocyclic group. .R ₅ good vinyl group which may have a substituent, 1 - shows a cyclohexenyl group, however, R ₅ in R ₁ = R ₂ = H is excluded the case of CH ₂ = CH-).. An electrophotographic photoreceptor comprising a photosensitive layer containing an organic photoconductive material represented by the general formula (1) on a conductive support. 3. The electrophotographic photoreceptor according to claim 2, wherein the photosensitive layer contains a charge generating substance and a charge transporting substance, and the charge transporting substance is an organic photoconductive material represented by the general formula (1). .