JP3551395B2 - Electrophotographic photoreceptor - Google Patents

Description

【００１２】
（各式中、Ｑ及びＱ′は酸素原子、＝C(CN)₂，＝C(CN)CO₂R′，＝C(CN)COR′，又は＝NCNを表す。Ａ₁，Ａ₂はアルキル基又はアリール基を表し、Ar及びAr′はアリール基を表し、Ｒはハロゲン原子、ニトロ基、シアノ基、又は各々置換、未置換のアルキル基、アルコキシ基、アリール基もしくはスチリル基、Ｙは＝C(R₁)R₂，＝C＝C(R₃)R₄を表し、Ｒ₁，Ｒ₂，Ｒ₃及びＲ′は各々置換、未置換のアルキル基又はアリール基を表し、Ｒ₄は水素原子、各々置換、未置換のアルキル基又はアリール基を表し、ｎは０又は１〜３の整数を表す。）
（２）導電性支持体上に感光層を設けた電子写真感光体において、該感光層が導電性支持体から電荷発生層、電荷輸送層の順に積層され、電荷輸送層に電荷輸送物質として前記一般式〔１〕、〔２〕又は〔４〕で表される化合物を含有することを特徴とする前記（１）記載の電子写真感光体。
【００１３】
本発明で言うアルキル基の例としてはメチル基、ブチル基、イソプロピル基、ヘンジル基などを挙げる事ができ、またアリール基の例としてはフェニル基、ナフチル基、チエニル基、ピリジル基などを挙げる事ができる。これらのアルキル基、アリール基はさらに置換基を含んでも良い。置換基としてはアルキル基、アルコキシル基、アリール基、スチリル基、ハロゲン原子、ニトロ基、シアノ基、アリールオキシカルボニル基、アルコキシカルボニル基、アリールカルボニル基、アルキルカルボニル基などを挙げる事ができる。
【００１４】
〔１〕一般式〔１〕に含まれる化合物の合成例
本発明の合成には色々な合成経路が考えられる。Ｍｏｕｂａｓｈｅｒの方法に従ってニンヒドリンからトリケトヒドロインデンを経て１，３−ジケト−２，２−ジフェニルインダンを合成し、これをマロノニトリルなどと反応させるのも一つの方法である。
一般式〔１〕に含まれる化合物の合成経路の例を示す。
【００１５】
【化３】

【００１６】
〈合成例１……化合物１−１の合成〉
（中間体 トリケトヒドロインデンの合成）
Ｊ．Ｃｈｅｍ．Ｓｏｃ．，７１，（１９４３）に従って合成した。
【００１７】
３００ｍｌの三頭フラスコにチオニルクロライド１１０ｍｌを取り、６０℃に加熱する。同温度にてニンヒドリン１７．５ｇを少しずつ１時間かけて加え、添加終了後さらに１時間加熱還流する。反応後、減圧下過剰のチオニルクロライドを留去し、さらにベンゼン１００ｍｌを加えて留去する。これにトルエン２００ｍｌを加えて加熱洗浄し熱時に濾過して赤色結晶１２．８ｇを得た。ｍｐ ２５１℃（文献．ｍｐ ２５５℃）収率８０％。
【００１８】
（中間体 １，３−ジケト−２，２−ジフェニルインダンの合成）
Ｊ．Ａｍｅｒ．Ｃｈｅｍ．Ｓｏｃ．，７３，３２４５（１９５１）に従って合成した。
【００１９】
上述のトリケトヒドロインデン１２．０ｇをベンゼン７５ｍｌに分散し１０℃以下にて発煙硫酸（２０％ ＳＯ_３）を添加する。添加終了後さらに室温にて３０分攪拌し氷水に注ぐ。有機層をトルエンで抽出しカラムにて精製した。ｎ−ヘキサンより再結晶してｍｐ
１２５℃の白色結晶 １３．９ｇを得た。収率 ６２％。
【００２０】
（化合物１−１の合成）
１，３−ジケト−２，２−ジフェニルインダン ３．０ｇとマロノニトリル２．１ｇをジクロルメタン ５０ｍｌに溶かす。氷冷下１０℃以下で四塩化チタン ４ｍｌを滴下する。滴下終了後、同温度にて１５分攪拌ついでピリジン ５ｍｌを滴下する。室温にて攪拌３時間、一夜放置後これに水を加えて反応を停止する。トルエンを加えて抽出、希塩酸ついで水で洗った後、シリカゲルカラムにてトルエンで展開しメタノールで結晶化させて目的とする化合物１−１を得る。淡黄色結晶 １．５０ｇ。
【００２１】
（化合物１−２、化合物１−３の合成）
１，３−ジケト−２，２−ジフェニルインダン ３．０ｇをジクロルメタン ５０ｍｌに溶かす。氷冷下１０℃以下で四塩化チタン ４ｍｌを滴下する。これに同温度にてビストリメチルシリルカルボジイミド ４ｍｌを滴下する。室温にて攪拌３時間、一夜放置後これに水を加えて反応を停止する。トルエンを加えて抽出、希塩酸ついで水で洗った後シリカゲルカラムにてトルエンで展開し第一留分より原料、第二留分より化合物１−２、第三留分より化合物１−３を得た。収量はそれぞれ１．２ｇ、０．６ｇであった。
【００２２】
次に本発明の化合物の具体例を示すがこれによって本発明の化合物が限定される物ではない。
【００２３】
【化４】

【００２４】
〔２〕一般式〔２〕に含まれる化合物の合成例
Ｏｒｇ．Ｓｙｎｔｈ．Ｃｏｌｌ．Ｖｏｌ．ＩＩ，６１（１９４１）及び、Ｃｏｌｌ．Ｖｏｌ．ＩＩＩ，３５３（１９５５）に記されているように無水フタル酸とフェニル酢酸からフタリドを合成し、ついでグリニヤ反応で２，３−ジフェニルインドンを作り、これとマロノニトリルなどを反応させるのも一つの方法である。
【００２５】
一般式〔２〕に含まれる化合物の合成経路の例を示す。
【００２６】
【化５】

【００２７】
原料となる無水フタル酸誘導体の合成には例えば次ぎのような経路もある。
【００２８】
【化６】

【００２９】
〈合成例１……化合物２−１の合成〉
２，３−ジフェニルインドン ２．８ｇをジクロルメタン５０ｍｌに溶かす。これにマロノニトリル １．３ｇを加え氷冷する。１０℃以下にて四塩化チタン ４ｍｌを滴下する。滴下終了後、同温度にて１５分攪拌ついでピリジン ５ｍｌを滴下する。室温にて攪拌３時間、一夜放置後これに水を加えて反応を停止する。トルエンを加えて抽出、希塩酸ついで水で洗った後シリカゲルカラムにてトルエンで展開しメタノールで結晶化させて目的とする化合物２−１を得る。赤紫色結晶 ３．０ｇ 収率 ９２％。
【００３０】
〈合成例２−２……化合物２の合成〉
Ｄｏｋｌａｄｙ Ａｋａｄ．Ｎａｕｋ Ｓ．Ｓ．Ｓ．Ｒ．，９４， ５７−６０（１９５４）＝Ｃｈｅｍｉｃａｌ Ａｂｓｔｒａｃｔ，Ｖｏｌ ４９，３９２０ｇに準じて合成した。２，３−ジフェニルインドン ４．０ｇを酢酸２５ｍｌに溶かし９０℃まで加熱する。これに発煙硝酸（ｄ＝１．５０）２．０ｍｌを加えただちに室温まで冷却、同温度にて６時間攪拌する。水に注ぎトルエンで抽出、カラムにて分離し ｍｐ１６５℃のオレンジ色結晶１．２ｇを得た（文献．ｍｐ １６４℃…文献の記載と異なり、収率は低いものの一段で目的とする２−フェニル−３−（４−ニトロフェニル）インドンを得た。）。
【００３１】
ついで、この物 ０．８ｇをジクロルメタン３０ｍｌに溶かす。これにビストリメチルシリルカルボジイミド １．２ｇを加え氷冷する。１０℃以下にて四塩化チタン ６ｍｌを滴下する。室温にて２４時間攪拌、ついで水を加え反応を停止する。有機層をトルエンで抽出、希塩酸ついで水で洗った後シリカゲルカラムにてトルエンで展開し目的とする化合物２−２を得た。
【００３２】
〈化合物２−１０の合成〉
【００３３】
【化７】

【００３４】
（中間体アンヒドラアセトンベンジル（中間体２−１）の合成）
Ｓｏｃ．，８７，６７９を参考にして行った。６ｇの水酸化カリウムを２０ｍｌのエタノールに溶かす。これをアセトン５８ｇ、ベンジル１００ｇの混合液に水冷しながら加える。ついで室温で６時間放置反応させた。反応後、黒色物よりトルエン可溶分を抽出、トルエン液をエバポレートし、得られた固体をエーテルで洗浄する。粗結晶８０ｇ。
【００３５】
（中間体２−２の合成（中間体２−１の脱水２量化））
ＪＡＣＳ．，５５，３７７３（１９３３）に従って合成した。上述の（中間体２−１）５０ｇを酢酸６０ｍｌに分散し、濃硫酸１０ｍｌを加える。加熱還流（１１０℃）２時間、放冷後、結晶が析出する。濾過し、酢酸で洗浄する。３２ｇ灰色（文献と異なり、異性体は得られなかった）。
【００３６】
（中間体２−３の合成（中間体２−２の脱ＣＯ熱転移））
ＪＡＣＳ．，５５，３７７３（１９３３）に従い、（中間体２−２）３５ｇを窒素気流下２１０℃に加熱（２０分）転移させた。反応後、トルエンに溶かし、シリカゲルカラムに分離する。
【００３７】
単黄色部分を分離、オイルをエタノールで結晶化させる。３２ｇ。
【００３８】
（２，３，５，６−テトラフェニルインデン−１−オンの合成）
ＪＡＣＳ．，５５，３７７３（１９３３）に従い、１０ｇの上記中間体と，０．６ｇの硫黄をフラスコに取り、マントルヒーターで加熱、内温を３００〜３２５℃に３０分保つ、硫化水素の発生が認められる。
【００３９】
放冷後、トルエンに溶かし、カラム分離し、赤色結晶６．０ｇを得た。
【００４０】
（化合物２−１０の合成）
上記の２，３，５，６−テトラフェニルインデン−１−オン ２．２ｇとマロノニトリル ０．７ｇをジクロロメタン ４０ｍｌに溶かす。これに氷冷下、四塩化チタン ３ｍｌとピリジン ４ｍｌを加え室温で一夜放置する。反応後、水を注ぎ、トルエンで抽出し、トルエン層を弱塩酸で洗浄後カラム精製する。赤黒色結晶１．７ｇ。
【００４１】
以下、本発明の一般式〔２〕で示される化合物の具体例を示すがこれによって本発明の化合物が限定される物ではない。
【００４２】
【化８】

【００５０】
〔４〕一般式〔４〕に含まれる化合物の合成例
これらの物の合成には幾つかの経路が考えられる。Ｋｏｅｌｓｈ等（Ｊ．Ｏｒｇ．Ｃｈｅｍ．６，６８４（１９４１））が行ったようにフェニル酢酸とベンゾイル蟻酸からジフェニルマレイン酸無水物を作り、この誘導体から合成していくのも一つの方法である。
【００５１】
下記に一般式〔４〕で示される化合物の合成経路を示す。
【００５２】
【化１１】

【００５３】
〈合成例４−１……化合物４−１の合成〉
（中間体 ２，３−ジフェニルマレイン酸無水物の合成）
Ｏｒｇ．Ｓｙｎｔｈ．，Ｃｏｌｌ．Ｖｏｌ．Ｉ，４３６に従ってフェニルアセトニトリルを酸加水分解してフェニル酢酸を作った。ついでＪ．Ｏｒｇ．Ｃｈｅｍ．６，６８４（１９４１）を参考にしてベンゾイル蟻酸 ３５．０ｇと炭酸ナトリウム １．３０ｇを無水酢酸１３０ｍｌに溶かし、これに上述のフェニル酢酸 ３２．７ｇを加え、加熱還流した。６時間後、水４０ｍｌを加え、放冷後、折出した結晶を濾過した。酢酸／水（１／１）の混液１５０ｍｌで洗って、淡黄色結晶 ｍｐ１４８〜１４９℃（文献値 １５７〜１５８℃）４３．０ｇを得た。収率７４％。
【００５４】
（中間体 ２，４，５−トリフェニル−４−シクロペンテン−１，３−ジオンの合成）
上述の２，３−ジフェニルマレイン酸無水物 ３５．０ｇ、フェニル酢酸 ２８．０ｇ、酢酸カリウム ０．３ｇ、酢酸ナトリウム １．１ｇを混合し、２２０〜２３０℃で１．５時間溶融反応させる。
【００５５】
反応後、溶融したままメタノール５００ｍｌに注ぎ析出した結晶を濾過する。淡黄色のベンザルジフェニルマレイド ４３．５ｇを得た。ｍｐ１７５℃。
【００５６】
上述のベンザルジフェニルマレイド ３８．９ｇをメタノール２５０ｍｌに分散する。これにナトリウムメチラート ７．２ｇを加えて２時間加熱還流した。その後薄層クロマトグラフＣをチェックして、反応の進行を確認しながらナトリウムメチラートを少しずつ加えていく（１０分おきに１．０ｇずつ添加する。）。５．０ｇ加えた時点で反応終了を確認した。
【００５７】
ついで氷水 ５００ｍｌ，酢酸 ５０ｍｌの混合液に注ぎ、析出した黄色結晶を濾取する。３２．６ｇ。熱トルエン ５００ｍｌに溶かし熱時濾過して微量の不溶分を除き、減圧下に溶媒を留去、酢酸より再結晶してｍｐ１６６℃の黄色結晶２７ｇを得た（文献値．ｍｐ １６８℃）。
【００５８】
（化合物４−１ ２，４，５−トリフェニル−２−ベンジル−４−シクロペンテン−１，３−ジオンの合成）
上述のトリフェニルシクロペンテンジオン ６．５ｇをメタノール ５０ｍｌに分散し、カリウムｔ−ブトキシド ３．５ｇを加え、１０分攪拌、ついでベンジルクロライド ５．０ｇを滴下し、室温で１０時間攪拌した。一夜放置後、濾過し、水で洗浄する。エタノールにより再結晶して目的とする黄色結晶を得る。３．２ｇ ｍｐ１８８℃。
【００５９】
（化合物４−２、４−３の合成）
上述のトリフェニルベンジルシクロペンテンジオン ３．０ｇを５０ｍｌのジクロルメタンに溶かし、１０℃以下で四塩化チタン ６ｍｌを加える。１０分攪拌の後ビストリメチルシリルカルボジイミド ５ｍｌを滴下する。室温にて攪拌３時間、一夜放置後これに水を加えて反応を停止する。トルエンを加えて抽出、希塩酸ついで水で洗浄した後シリカゲルカラムにてトルエンで展開し第一留分より化合物４−２、第二留分より化合物４−３を単離した。化合物４−２ １．０ｇ，ｍｐ１８９℃ 化合物４−３ ０．７ｇ，ｍｐ２２０℃ 。
【００６０】
次に本発明の一般式〔４〕で示される化合物の具体例を示すがこれによって本発明の化合物が限定される物ではない。
【００６１】
【化１２】

【００６２】
【化１３】

【００６３】
本発明の物質は優れた電子輸送性を有しており、これをバインダー中に分子分散して様々な層に添加することにより電子写真感光体にその性質を利用する事ができる。
【００６４】
例えば通常の機能分離型負帯電感光体の電荷輸送層に添加することで正帯電電子写真感光体とする事ができる。また単層型の正帯電感光体に顔料と混合して使うことで顔料濃度を減らす事もできる。また正帯電感光体に保護層を設ける場合、そこに添加することもできる。さらに通常の負帯電感光体においても本発明の化合物を電荷発生層や下引き層に添加することで感度向上を計る事ができる。
【００６５】
本発明の化合物を分子分散するバインダーとしては例えばポリカーボネート樹脂、ポリスチレン樹脂、アクリル樹脂、メタアクリル樹脂、塩化ビニル樹脂、酢酸ビニル樹脂、フェノール樹脂、エポキシ樹脂、シリコン樹脂、ポリエステル樹脂、エポキシ樹脂およびこれらの共重合体などを挙げる事ができる。
【００６６】
本発明の化合物を機能分離型の電荷輸送層に用いる場合、その量はバインダー樹脂１００重量部あたり２０〜２００重量部が好ましい。形成される電荷輸送層の厚さは好ましくは５〜３０μｍである。また単層型感光体の場合のバインダー：電荷輸送物質：電荷発生物質の割合は１００：１〜２００：１〜２００が好ましく、形成される感光層の膜厚は５〜４０μｍが好ましい。また本発明の感光体には電荷発生物質として公知のものをすべて使用できる、例えばセレン系の無機半導体、種々のフタロシアニン化合物、アゾ化合物、ピリリウム化合物、ペリレン化合物、スクアリウム化合物、多環キノン化合物を挙げる事ができる。また本発明の感光層においてはオゾン劣化防止の目的で様々な酸化防止剤を添加することができる。たとえばヒンダードフェノール類、ヒンダードアミン類、ハイドロキノン類、有機燐化合物などを挙げる事ができる。
【００６７】
【実施例】
以下、実施例を挙げて本発明を詳細に説明するが、本発明の態様はこれに限定されない。尚、「部」とは「重量部」を表す。
【００６８】
実施例１−１
アルミニウムを蒸着したポリエステルフィルム上にＹ型チタニルフタロシアニン（特開昭６４−１７０６６号記載）１部、シリコーン−ブチラール樹脂０．５部、分散媒として酢酸ｔ−ブチル５０部をサンドミルを使用して分散した液をワイヤーバーを使って塗布し厚さ０．３μｍの電荷発生層を形成した。ついで下表に示す例示化合物（１−１，１−２，１−３）１部とポリカーボネート樹脂『ユーピロンＺ２００』（三菱瓦斯化学）２．０部を１．２−ジクロルエタン１０部に溶解し、電荷発生層上にドクターブレードを使用して塗布し膜厚２０μｍの電荷輸送層を形成し本発明の感光体サンプルとした。
【００６９】
比較例１−１
実施例における本発明の化合物の代わりに比較化合物（Ｃ_１−１）を用いた以外は実施例と同様にして比較サンプルを作製した。
【００７０】
【化１４】

【００７１】
評価１
実施例および比較例で得たサンプルについて静電紙試験装置ＥＰＡ−８１００（川口電機）を用いて評価した。＋６ｋｖのコロナ帯電を５秒間行い帯電能を見る（受容電位Ｖａ）、つぎに５秒間暗所に放置する（初期電位Ｖｉ）。ついで８ｌｕｘの白色光を照射し表面電位が初期電位Ｖｉの半分になるまでの露光量Ｅ１／２（ｌｕｘ．ｓｅｃ）を求め感度とし、１０秒間露光後の表面電位を残留電位Ｖｒとした。
【００７２】
結果１
【００７３】
【表１】

【００７４】
本発明の化合物はいずれも高い受容電位、優れた感度特性、そして低い残留電位を示す。これに対して対応する比較サンプルは残留電位は高く感度が低い。２位のアリール基の効果と思われる。
【００７５】
実施例２−１
アルミニウムを蒸着したポリエステルフィルム上に前記Ｙ型チタニルフタロシアニン１部、シリコーン−ブチラール樹脂０．５部、分散媒として酢酸ｔ−ブチル５０部をサンドミルを使用して分散した液をワイヤーバーを使って塗布し厚さ０．３μｍの電荷発生層を形成した。ついで下表に示す例示化合物１部とポリカーボネート樹脂『ユーピロンＺ２００』（三菱瓦斯化学）２．０部を１，２−ジクロルエタン１０部に溶解し、電荷発生層上にドクターブレードを使用して塗布し膜厚２０μｍの電荷輸送層を形成し本発明の感光体サンプルとした。
【００７６】
比較例２−１
実施例における本発明の化合物の代わりに比較化合物（Ｃ_２−１）を用いた以外は実施例と同様にして比較サンプルを作製した。
【００７７】
【化１５】

【００７８】
評価２
実施例および比較例で得たサンプルについて静電紙試験装置ＥＰＡ−８１００（川口電機）を用いて評価した。＋６ｋｖのコロナ帯電を５秒間行い帯電能を見る（受容電位Ｖａ）、つぎに５秒間暗所に放置する（初期電位Ｖｉ）。ついで８ｌｕｘの白色光を照射し表面電位が初期電位Ｖｉの半分になるまでの露光量Ｅ１／２（ｌｕｘ．ｓｅｃ）を求め感度とし、１０秒間露光後の表面電位を残留電位Ｖｒとした。
【００７９】
結果２
【００８０】
【表２】

【００８１】
本発明の化合物はいずれも高い受容電位、優れた感度特性、そして低い残留電位を示すが、これは４，５位の縮合した芳香環の作用に基づくものと思われる。これに対して対応する比較サンプルは残留電位は高く感度が悪い。
【００９１】
実施例４−１
アルミニウムを蒸着したポリエステルフィルム上にＹ型チタニルフタロシアニン１部、シリコーン−ブチラール樹脂０．５部、分散媒として酢酸ｔ−ブチル５０部をサンドミルを使用して分散した液をワイヤーバーを使って塗布し厚さ０．３μｍの電荷発生層を形成した。ついで下表に示す例示化合物１部とポリカーボネート樹脂『ユーピロンＺ２００』（三菱瓦斯化学）３．０部を１．２−ジクロルエタン１３部に溶解し、電荷発生層上にドクターブレードを使用して塗布し膜厚２５μｍの電荷輸送層を形成し本発明の感光体サンプルとした。
【００９２】
比較例４−１
実施例における本発明の化合物の代わりに比較化合物Ｃ_３−１を用いた以外は実施例と同様にして比較サンプルを作製した。
【００９３】
実施例４−２
アルミニウムを蒸着したポリエステルフィルム上にジブロムアンスアンスロン１部、ポリカーボネート樹脂 ０．５部、分散媒として酢酸ｔ−ブチル５０部をサンドミルを使用して分散した液をワイヤーバーを使って塗布し厚さ０．９μｍの電荷発生層を形成した。ついで下表に示す例示化合物１部とポリカーボネート樹脂『ユーピロンＺ２００』（三菱瓦斯化学）３．０部を１．２−ジクロルエタン１３部に溶解し、電荷発生層上にドクターブレードを使用して塗布し膜厚２５μｍの電荷輸送層を形成し本発明の感光体サンプルとした。
【００９４】
比較例４−２
実施例における本発明の化合物の代わりに比較化合物を用いた以外は実施例と同様にして比較サンプルを作製した。
【００９５】
評価４
実施例および比較例で得たサンプルについて静電紙試験装置ＥＰＡ−８１００（川口電機）を用いて評価した。＋６ｋｖのコロナ帯電を５秒間行い帯電能を見る（受容電位Ｖａ）、つぎに５秒間暗所に放置する（初期電位Ｖｉ）。ついで８ｌｕｘの白色光を照射し表面電位が初期電位Ｖｉの半分になるまでの露光量Ｅ１／２（ｌｕｘ．ｓｅｃ）を求め感度とした。
【００９６】
結果４
【００９７】
【表４】

【００９８】
本発明の化合物はいずれも高い受容電位、優れた感度特性を示す。この感度特性は比較にあげたジフェノキノン誘導体と比較して優れ、かつ感光体の色がジフェノキノンの赤紫に比して黄色〜無色となっている。これは近赤外光ばかりでなく可視光も充分に電荷発生層に到達することを意味し、レーザープリンター以外の可視光を使用した複写機への応用を容易にするものである。この事はチタニルフタロシアニンの代わりに可視光にのみ吸収をもつジブロムアンスアンスロンでは感度が比較サンプルと極端に違う事からも理解される。
【００９９】
【発明の効果】
本発明により、下記効果が得られる。
【０１００】
（１）電子輸送能を有する電荷輸送物質を用いて高感度でかつ残留電位が小さく、更に繰り返し使用してもそれらの特性が変化しない耐久性の優れた電子写真感光体を提供する。
【０１０１】
（２）電子輸送能を有する電荷輸送物質を用いて高感度でかつ残留電位が小さく、更に可視領域に強烈な色がなく近赤外光を使ったデジタル複写機、プリンターばかりでなく可視光を使用したアナログ複写機にも使用可能な感光体を提供することが出来る。[0001]
[Industrial applications]
The present invention relates to an electrophotographic photosensitive member for forming an electrostatic latent image. More specifically, the present invention relates to an electrophotographic photosensitive member having a layer containing a compound having an electron transporting ability.
[0002]
[Prior art]
Conventionally, as an electrophotographic photoreceptor, an inorganic photoreceptor containing an inorganic photoconductive substance such as selenium, zinc oxide, or silicon as a main component has been widely used. However, these are not always satisfactory in sensitivity, heat stability, moisture resistance, and durability, and some inorganic photoreceptors contain substances harmful to the human body, and thus have a problem in disposal.
[0003]
In order to overcome the drawbacks of the inorganic photoreceptors, research and development of organic photoreceptors having a photosensitive layer containing various organic photoconductive compounds as main components have been actively conducted in recent years.
[0004]
Most of these practically used organic photoreceptors have a function-separated laminated structure, that is, a charge generation layer (CGL) composed of azo, phthalocyanine, and a condensed polycyclic pigment, and a charge transport layer (CTL) composed of a charge transport material (CTM). ). As charge transport substances, pyrazoline, hydrazone, triphenylamine compounds and styryl derivatives thereof are well known. However, these known substances are all substances having a hole transporting ability. In the case of a function-separated type photoreceptor having CGL as a lower layer and CTL as an upper layer, it is necessary to negatively charge the surface of the photoreceptor. For this reason, there are drawbacks that the developer used for the conventional inorganic photoreceptor cannot be used, and that the amount of ozone generated when the photoreceptor is charged by corona discharge is larger than that of positive charging. Also, a photoreceptor having a reverse layer structure in which CTL is a lower layer and a CGL as an upper layer, and a single-layer photoreceptor containing a charge generation material (CGM) and a charge transport material in the same layer are positively charged but have high durability and sensitivity. Not enough performance has been obtained.
[0005]
In order to solve the above problems, it is necessary to develop a substance having an electron transporting ability as a charge transporting substance. As such an electron transporting substance, 2,4,6-trinitrofluorenone is known, but this substance has poor solubility and compatibility with a solvent and a polymer used as a binder, and constitutes an actual photosensitive layer. It does not have sufficient properties to be used, and its use has been discontinued due to its carcinogenicity.
[0006]
In recent years, some electron transporting substances having a soluble group introduced into an electron accepting structure have been reported. For example, JP-A-2-135362, JP-A-2-214866, JP-A-3-290666 and the like can be mentioned. In particular, the fluorenone compounds described in JP-A-5-279582, Japan Hard Copy '92 ”, p. 173, are excellent in sensitivity with low residual potential, but are not denitrified, and are not carcinogenic. The quinone compounds described in JP-A-1-206349 are excellent electron-transporting substances that do not have a plurality of nitro groups, which are said to induce carcinogenicity. (Red-purple), and cannot provide a sufficient amount of light to the charge generating substance.
[0007]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a highly durable electrophotographic photosensitive material that has high sensitivity and a small residual potential by using a charge transporting substance having an electron transporting ability, and that does not change its properties even when used repeatedly. Is to provide the body.
[0008]
Still another object of the present invention is to provide a digital copying machine using a near-infrared light without a strong color in the visible region with high sensitivity and a small residual potential using a charge transport material having an electron transport ability. An object of the present invention is to provide a photosensitive member that can be used not only for a printer but also for an analog copying machine using visible light.
[0009]
[Means for Solving the Problems]
The object of the present invention is achieved by the following electrophotographic photosensitive member.
[0010]
(1) the following general formula [1], [2] or an electrophotographic photosensitive member characterized by having a photosensitive layer containing a compound represented by [4].
[0011]
Embedded image

[0012]
(Wherein, Q and Q 'is an oxygen _{atom, = C (CN) 2,} = C (CN) CO 2 R', = C (CN) COR ', or = .A _1, A ₂ representing a NCN is Represents an alkyl group or an aryl group, Ar and Ar ′ represent an aryl group, R represents a halogen atom, a nitro group, a cyano group, or a substituted or unsubstituted alkyl group, an alkoxy group, an aryl group or a styryl group , and Y represents _{= C (R 1) R 2} , = C = C (R 3) represents _{R 4, R 1, R 2} , R 3 and R 'represents respectively substituted, an unsubstituted alkyl group or aryl group, R ₄ Represents a hydrogen atom, a substituted or unsubstituted alkyl group or an aryl group, and n represents an integer of 0 or 1 to 3.)
(2) In an electrophotographic photoreceptor in which a photosensitive layer is provided on a conductive support, the photosensitive layer is laminated on the conductive support in the order of a charge generation layer and a charge transport layer. formula [1], [2] or the (1) electrophotographic photosensitive member, wherein the containing the compound represented by [4].
[0013]
Examples of the alkyl group referred to in the present invention include a methyl group, a butyl group, an isopropyl group, and a henzyl group. Examples of the aryl group include a phenyl group, a naphthyl group, a thienyl group, and a pyridyl group. Can be. These alkyl groups and aryl groups may further contain a substituent. Examples of the substituent include an alkyl group, an alkoxyl group, an aryl group, a styryl group, a halogen atom, a nitro group, a cyano group, an aryloxycarbonyl group, an alkoxycarbonyl group, an arylcarbonyl group, and an alkylcarbonyl group.
[0014]
[1] Synthetic Examples of Compounds Contained in General Formula [1] Various synthetic routes are conceivable for the synthesis of the present invention. One method is to synthesize 1,3-diketo-2,2-diphenylindane from ninhydrin via triketohydroindene according to Moubasher's method and react it with malononitrile or the like.
The example of the synthesis route of the compound included in the general formula [1] is shown.
[0015]
Embedded image

[0016]
<Synthesis Example 1 Synthesis of Compound 1-1>
(Synthesis of Intermediate Triketohydroindene)
J. Chem. Soc. , 71, (1943).
[0017]
110 ml of thionyl chloride is placed in a 300 ml three-necked flask and heated to 60 ° C. At the same temperature, 17.5 g of ninhydrin is added little by little over 1 hour, and after the addition is completed, the mixture is refluxed for 1 hour. After the reaction, excess thionyl chloride is distilled off under reduced pressure, and 100 ml of benzene is further added and distilled off. To this, 200 ml of toluene was added, washed with heating, and filtered while hot to obtain 12.8 g of red crystals. mp 251 ° C (Reference. mp 255 ° C) Yield 80%.
[0018]
(Synthesis of Intermediate 1,3-Diketo-2,2-diphenylindane)
J. Amer. Chem. Soc. , 73, 3245 (1951).
[0019]
12.0 g of the above-mentioned triketohydroindene is dispersed in 75 ml of benzene, and fuming sulfuric acid (20% SO ₃ ) is added at 10 ° C or less. After the addition is completed, the mixture is further stirred at room temperature for 30 minutes and poured into ice water. The organic layer was extracted with toluene and purified with a column. Recrystallized from n-hexane and mp
13.9 g of 125 ° C. white crystals were obtained. Yield 62%.
[0020]
(Synthesis of Compound 1-1)
Dissolve 3.0 g of 1,3-diketo-2,2-diphenylindane and 2.1 g of malononitrile in 50 ml of dichloromethane. 4 ml of titanium tetrachloride is added dropwise at 10 ° C. or less under ice cooling. After completion of the dropwise addition, the mixture was stirred at the same temperature for 15 minutes, and then 5 ml of pyridine was added dropwise. After stirring at room temperature for 3 hours and leaving overnight, water was added thereto to stop the reaction. Toluene is added and extracted, washed with dilute hydrochloric acid and then with water, developed with toluene on a silica gel column, and crystallized with methanol to obtain the desired compound 1-1. 1.50 g of pale yellow crystals.
[0021]
(Synthesis of Compound 1-2 and Compound 1-3)
Dissolve 3.0 g of 1,3-diketo-2,2-diphenylindane in 50 ml of dichloromethane. 4 ml of titanium tetrachloride is added dropwise at 10 ° C. or less under ice cooling. At the same temperature, 4 ml of bistrimethylsilylcarbodiimide is added dropwise. After stirring at room temperature for 3 hours and leaving overnight, water was added thereto to stop the reaction. Toluene was added for extraction, washed with diluted hydrochloric acid and then with water, and then developed with toluene on a silica gel column to obtain a raw material from the first fraction, a compound 1-2 from the second fraction, and a compound 1-3 from the third fraction. . The yields were 1.2 g and 0.6 g, respectively.
[0022]
Next, specific examples of the compound of the present invention will be shown, but the compound of the present invention is not limited thereto.
[0023]
Embedded image

[0024]
[2] Synthesis example of compound included in general formula [2] Org. Synth. Coll. Vol. II, 61 (1941) and Coll. Vol. III, 353 (1955), phthalide is synthesized from phthalic anhydride and phenylacetic acid, and then 2,3-diphenylindone is produced by a Grignard reaction, and this is reacted with malononitrile or the like. Is the way.
[0025]
The example of the synthesis route of the compound included in the general formula [2] is shown.
[0026]
Embedded image

[0027]
The synthesis of the phthalic anhydride derivative as a raw material includes, for example, the following route.
[0028]
Embedded image

[0029]
<Synthesis Example 1 Synthesis of Compound 2-1>
Dissolve 2.8 g of 2,3-diphenylindone in 50 ml of dichloromethane. 1.3 g of malononitrile is added to this and cooled with ice. At 10 ° C. or lower, 4 ml of titanium tetrachloride is added dropwise. After completion of the dropwise addition, the mixture was stirred at the same temperature for 15 minutes, and then 5 ml of pyridine was added dropwise. After stirring at room temperature for 3 hours and leaving overnight, water was added thereto to stop the reaction. Toluene is added and extracted, washed with diluted hydrochloric acid and then with water, developed with a silica gel column with toluene, and crystallized with methanol to obtain the desired compound 2-1. Red purple crystals 3.0 g Yield 92%.
[0030]
<Synthesis Example 2-2: Synthesis of Compound 2>
Doklady Akad. Nauk S.A. S. S. R. , 94, 57-60 (1954) = Chemical Abstract, Vol 49, 3920 g. Dissolve 4.0 g of 2,3-diphenylindone in 25 ml of acetic acid and heat to 90 ° C. 2.0 ml of fuming nitric acid (d = 1.50) is added thereto, and the mixture is immediately cooled to room temperature and stirred at the same temperature for 6 hours. The mixture was poured into water, extracted with toluene, and separated by a column to obtain 1.2 g of orange crystals having an mp of 165 ° C. (Reference. Mp 164 ° C .: unlike the description in the literature, the yield was low but the desired 2-phenyl was obtained in one step) -3- (4-Nitrophenyl) indone was obtained.).
[0031]
Then, 0.8 g of this product is dissolved in 30 ml of dichloromethane. To this is added 1.2 g of bistrimethylsilylcarbodiimide and cooled with ice. At 10 ° C. or lower, 6 ml of titanium tetrachloride is added dropwise. Stir at room temperature for 24 hours, then add water to stop the reaction. The organic layer was extracted with toluene, washed with dilute hydrochloric acid and then with water, and developed with a silica gel column with toluene to obtain the desired compound 2-2.
[0032]
<Synthesis of Compound 2-10>
[0033]
Embedded image

[0034]
(Synthesis of Intermediate Anhydraacetone Benzil (Intermediate 2-1))
Soc. , 87, 679. Dissolve 6 g of potassium hydroxide in 20 ml of ethanol. This is added to a mixture of 58 g of acetone and 100 g of benzyl while cooling with water. Then, the reaction was allowed to stand at room temperature for 6 hours. After the reaction, toluene-soluble matter is extracted from the black matter, the toluene solution is evaporated, and the obtained solid is washed with ether. 80 g of crude crystals.
[0035]
(Synthesis of Intermediate 2-2 (Dehydration and Dimerization of Intermediate 2-1))
JACS. , 55, 3773 (1933). 50 g of the above (intermediate 2-1) is dispersed in 60 ml of acetic acid, and 10 ml of concentrated sulfuric acid is added. After cooling under heating to reflux (110 ° C.) for 2 hours, crystals precipitate. Filter and wash with acetic acid. 32 g gray (unlike the literature, no isomers were obtained).
[0036]
(Synthesis of Intermediate 2-3 (De-CO thermal transition of Intermediate 2-2))
JACS. , 55, 3773 (1933), 35 g of (Intermediate 2-2) was transferred to 210 ° C. under a nitrogen stream by heating (20 minutes). After the reaction, the product is dissolved in toluene and separated on a silica gel column.
[0037]
Separate the single yellow part and crystallize the oil with ethanol. 32g.
[0038]
(Synthesis of 2,3,5,6-tetraphenylinden-1-one)
JACS. , 55, 3773 (1933), 10 g of the above intermediate and 0.6 g of sulfur were placed in a flask, heated with a mantle heater, and the internal temperature was maintained at 300 to 325 ° C. for 30 minutes. Generation of hydrogen sulfide was observed. .
[0039]
After standing to cool, the residue was dissolved in toluene and subjected to column separation to obtain 6.0 g of red crystals.
[0040]
(Synthesis of Compound 2-10)
2.2 g of the above 2,3,5,6-tetraphenylinden-1-one and 0.7 g of malononitrile are dissolved in 40 ml of dichloromethane. Under ice-cooling, 3 ml of titanium tetrachloride and 4 ml of pyridine are added, and the mixture is left overnight at room temperature. After the reaction, water is poured, extracted with toluene, the toluene layer is washed with weak hydrochloric acid, and then purified by column. 1.7 g of red-black crystals.
[0041]
Hereinafter, specific examples of the compound represented by the general formula [2] of the present invention are shown, but the compound of the present invention is not limited thereto.
[0042]
Embedded image

[0050]
[4] Synthetic examples of compounds contained in general formula [4] Several routes are considered for synthesizing these compounds. As described by Koelsh et al. (J. Org. Chem. 6, 684 (1941)), one method is to make diphenylmaleic anhydride from phenylacetic acid and benzoylformic acid and synthesize from this derivative.
[0051]
The synthetic route of the compound represented by the general formula [4] is shown below.
[0052]
Embedded image

[0053]
<Synthesis Example 4-1 Synthesis of Compound 4-1>
(Synthesis of Intermediate 2,3-Diphenylmaleic Anhydride)
Org. Synth. , Coll. Vol. The acid hydrolysis of phenylacetonitrile according to I.436 produced phenylacetic acid. Then J. Org. Chem. With reference to 6,684 (1941), 35.0 g of benzoyl formic acid and 1.30 g of sodium carbonate were dissolved in 130 ml of acetic anhydride, and 32.7 g of the above-mentioned phenylacetic acid was added thereto, followed by heating under reflux. After 6 hours, 40 ml of water was added, and after standing to cool, the precipitated crystals were filtered. The crystals were washed with 150 ml of a mixed solution of acetic acid / water (1/1) to obtain 43.0 g of pale yellow crystals, mp 148 to 149 ° C (literature 157 to 158 ° C). Yield 74%.
[0054]
(Synthesis of Intermediate 2,4,5-Triphenyl-4-cyclopentene-1,3-dione)
35.0 g of the above-mentioned 2,3-diphenylmaleic anhydride, 28.0 g of phenylacetic acid, 0.3 g of potassium acetate, and 1.1 g of sodium acetate are mixed, and a melt reaction is performed at 220 to 230 ° C. for 1.5 hours.
[0055]
After the reaction, the mixture is poured into 500 ml of methanol while being molten, and the precipitated crystals are filtered. 43.5 g of pale yellow benzaldiphenylmaleide were obtained. mp 175 ° C.
[0056]
38.9 g of the above-mentioned benzaldiphenylmaleide are dispersed in 250 ml of methanol. 7.2 g of sodium methylate was added thereto, and the mixture was heated under reflux for 2 hours. Then, while checking the progress of the reaction by checking the thin layer chromatography C, sodium methylate is added little by little (1.0 g is added every 10 minutes). When 5.0 g was added, completion of the reaction was confirmed.
[0057]
Then, the mixture is poured into a mixture of 500 ml of ice water and 50 ml of acetic acid, and the precipitated yellow crystals are collected by filtration. 32.6 g. The residue was dissolved in 500 ml of hot toluene and filtered while hot to remove a small amount of insoluble components. The solvent was distilled off under reduced pressure, and the residue was recrystallized from acetic acid to obtain 27 g of yellow crystals having an mp of 166 ° C (literature value: mp 168 ° C).
[0058]
(Synthesis of Compound 4-1 2,4,5-triphenyl-2-benzyl-4-cyclopentene-1,3-dione)
6.5 g of the above-mentioned triphenylcyclopentenedione was dispersed in 50 ml of methanol, 3.5 g of potassium t-butoxide was added, stirred for 10 minutes, then 5.0 g of benzyl chloride was added dropwise, and the mixture was stirred at room temperature for 10 hours. After standing overnight, filter and wash with water. Recrystallization from ethanol gives the desired yellow crystals. 3.2 g mp 188 ° C.
[0059]
(Synthesis of Compounds 4-2 and 4-3)
3.0 g of the above-mentioned triphenylbenzylcyclopentenedione is dissolved in 50 ml of dichloromethane, and 6 ml of titanium tetrachloride is added at 10 ° C. or lower. After stirring for 10 minutes, 5 ml of bistrimethylsilylcarbodiimide is added dropwise. After stirring at room temperature for 3 hours and leaving overnight, water was added thereto to stop the reaction. Toluene was added for extraction, washed with diluted hydrochloric acid and then with water, and then developed with a silica gel column with toluene to isolate Compound 4-2 from the first fraction and Compound 4-3 from the second fraction. Compound 4-2 1.0 g, mp 189 ° C Compound 4-3 0.7 g, mp 220 ° C.
[0060]
Next, specific examples of the compound represented by the general formula [4] of the present invention are shown, but the compounds of the present invention are not limited thereto.
[0061]
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[0062]
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[0063]
The substance of the present invention has an excellent electron-transporting property, and its properties can be utilized in an electrophotographic photosensitive member by dispersing the molecule in a binder and adding it to various layers.
[0064]
For example, a positively charged electrophotographic photosensitive member can be obtained by adding it to a charge transport layer of a normal function-separated negatively charged photosensitive member. The pigment concentration can also be reduced by using a single-layer type positively charged photoconductor mixed with a pigment. When a protective layer is provided on the positively charged photoreceptor, it can be added thereto. Further, even in a usual negatively charged photoreceptor, the sensitivity can be improved by adding the compound of the present invention to the charge generation layer or the undercoat layer.
[0065]
As the binder for molecularly dispersing the compound of the present invention, for example, polycarbonate resin, polystyrene resin, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, phenol resin, epoxy resin, silicone resin, polyester resin, epoxy resin and these Copolymers and the like can be mentioned.
[0066]
When the compound of the present invention is used in a charge transporting layer of a function separation type, its amount is preferably 20 to 200 parts by weight per 100 parts by weight of the binder resin. The thickness of the formed charge transport layer is preferably 5 to 30 μm. In the case of a single-layer type photoreceptor, the ratio of binder: charge transporting substance: charge generating substance is preferably from 100: 1 to 200: 1 to 200, and the thickness of the formed photosensitive layer is preferably from 5 to 40 μm. The photoreceptor of the present invention can use all known charge generating substances, such as selenium-based inorganic semiconductors, various phthalocyanine compounds, azo compounds, pyrylium compounds, perylene compounds, squarium compounds, and polycyclic quinone compounds. Can do things. Further, in the photosensitive layer of the present invention, various antioxidants can be added for the purpose of preventing ozone deterioration. For example, hindered phenols, hindered amines, hydroquinones, organic phosphorus compounds and the like can be mentioned.
[0067]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples, but embodiments of the present invention are not limited thereto. Here, “parts” means “parts by weight”.
[0068]
Example 1-1
1 part of Y-type titanyl phthalocyanine (described in JP-A-64-17066), 0.5 part of silicone-butyral resin, and 50 parts of t-butyl acetate as a dispersion medium were dispersed on a polyester film on which aluminum was deposited by using a sand mill. The solution was applied using a wire bar to form a charge generation layer having a thickness of 0.3 μm. Then, 1 part of the exemplified compound (1-1, 1-2, 1-3) shown in the following table and 2.0 parts of a polycarbonate resin "Iupilon Z200" (Mitsubishi Gas Chemical) were dissolved in 10 parts of 1.2-dichloroethane, A 20 μm-thick charge transporting layer was formed on the charge generating layer by using a doctor blade to obtain a photoreceptor sample of the present invention.
[0069]
Comparative Example 1-1
Except for comparative compound instead of the compound of the present invention (C 1 _-1) using the example was fabricated comparative samples in the same manner as in Example.
[0070]
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[0071]
Evaluation 1
The samples obtained in Examples and Comparative Examples were evaluated using an electrostatic paper tester EPA-8100 (Kawaguchi Electric). +6 kv corona charging is performed for 5 seconds to check the charging ability (acceptance potential Va), and then left in a dark place for 5 seconds (initial potential Vi). Then, 8 lux white light was irradiated to determine the exposure amount E1 / 2 (lux.sec) until the surface potential became half of the initial potential Vi, and the sensitivity was determined. The surface potential after exposure for 10 seconds was defined as the residual potential Vr.
[0072]
Result 1
[0073]
[Table 1]

[0074]
All of the compounds of the present invention exhibit high receptive potential, excellent sensitivity properties, and low residual potential. On the other hand, the corresponding comparative sample has a high residual potential and low sensitivity. This is probably due to the effect of the aryl group at the 2-position.
[0075]
Example 2-1
Using a wire bar, apply a liquid obtained by dispersing 1 part of the Y-type titanyl phthalocyanine, 0.5 part of silicone-butyral resin, and 50 parts of t-butyl acetate as a dispersion medium using a sand mill on a polyester film on which aluminum is deposited. Then, a charge generation layer having a thickness of 0.3 μm was formed. Next, 1 part of the exemplified compound shown in the following table and 2.0 parts of a polycarbonate resin “Iupilon Z200” (Mitsubishi Gas Chemical) were dissolved in 10 parts of 1,2-dichloroethane, and the solution was applied on the charge generation layer using a doctor blade. A charge transport layer having a thickness of 20 μm was formed to obtain a photoconductor sample of the present invention.
[0076]
Comparative Example 2-1
Except for comparative compound instead of the compound of the present invention (C 2 _-1) using the example was fabricated comparative samples in the same manner as in Example.
[0077]
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[0078]
Evaluation 2
The samples obtained in Examples and Comparative Examples were evaluated using an electrostatic paper tester EPA-8100 (Kawaguchi Electric). +6 kv corona charging is performed for 5 seconds to check the charging ability (acceptance potential Va), and then left in a dark place for 5 seconds (initial potential Vi). Then, 8 lux white light was irradiated to determine the exposure amount E1 / 2 (lux.sec) until the surface potential became half of the initial potential Vi, and the sensitivity was determined. The surface potential after exposure for 10 seconds was defined as the residual potential Vr.
[0079]
Result 2
[0080]
[Table 2]

[0081]
All of the compounds of the present invention show a high acceptance potential, excellent sensitivity properties, and a low residual potential, presumably due to the action of the fused aromatic ring at the 4,5 position. On the other hand, the corresponding comparative sample has a high residual potential and low sensitivity.
[0091]
Example 4-1
A liquid obtained by dispersing 1 part of Y-type titanyl phthalocyanine, 0.5 part of silicone-butyral resin, and 50 parts of t-butyl acetate as a dispersion medium using a sand mill on a polyester film on which aluminum is deposited is applied using a wire bar. A charge generation layer having a thickness of 0.3 μm was formed. Next, 1 part of the exemplified compound shown in the following table and 3.0 parts of a polycarbonate resin "Iupilon Z200" (Mitsubishi Gas Chemical) were dissolved in 13 parts of 1.2-dichloroethane, and the solution was applied on the charge generation layer using a doctor blade. A charge transport layer having a thickness of 25 μm was formed to obtain a photoconductor sample of the present invention.
[0092]
Comparative Example 4-1
Except for using the comparative compound C ₃ -1 instead of the compound of the present invention in Examples was prepared comparative sample in the same manner as in Example.
[0093]
Example 4-2
A liquid obtained by dispersing 1 part of dibromance anthuron, 0.5 part of a polycarbonate resin, and 50 parts of t-butyl acetate as a dispersion medium using a sand mill on a polyester film on which aluminum is vapor-deposited is applied using a wire bar. A charge generation layer of 0.9 μm was formed. Next, 1 part of the exemplified compound shown in the following table and 3.0 parts of a polycarbonate resin "Iupilon Z200" (Mitsubishi Gas Chemical) were dissolved in 13 parts of 1.2-dichloroethane, and the solution was applied on the charge generation layer using a doctor blade. A charge transport layer having a thickness of 25 μm was formed to obtain a photoconductor sample of the present invention.
[0094]
Comparative Example 4-2
Comparative samples were prepared in the same manner as in the examples except that comparative compounds were used instead of the compounds of the present invention in the examples.
[0095]
Evaluation 4
The samples obtained in Examples and Comparative Examples were evaluated using an electrostatic paper tester EPA-8100 (Kawaguchi Electric). +6 kv corona charging is performed for 5 seconds to check the charging ability (acceptance potential Va), and then left in a dark place for 5 seconds (initial potential Vi). Then, 8 lux of white light was irradiated to determine the exposure E1 / 2 (lux.sec) until the surface potential became half of the initial potential Vi, and the sensitivity was determined.
[0096]
Result 4
[0097]
[Table 4]

[0098]
All of the compounds of the present invention show high accepting potential and excellent sensitivity characteristics. This sensitivity characteristic is superior to the diphenoquinone derivative described above, and the color of the photoreceptor is yellow to colorless as compared with the reddish purple of diphenoquinone. This means that not only near-infrared light but also visible light can sufficiently reach the charge generation layer, which facilitates application to a copier using visible light other than a laser printer. This can be understood from the fact that the sensitivity is extremely different from that of the comparative sample in the case of dibromoanthanethrone, which absorbs only visible light instead of titanyl phthalocyanine.
[0099]
【The invention's effect】
According to the present invention, the following effects can be obtained.
[0100]
(1) To provide an electrophotographic photoreceptor having high sensitivity and low residual potential using a charge transporting substance having an electron transporting ability, and having excellent durability in which the characteristics thereof do not change even when repeatedly used.
[0101]
(2) Using a charge transporting substance having electron transporting ability, it has high sensitivity and small residual potential, has no intense color in the visible region, and uses not only digital copying machines and printers using near-infrared light but also visible light. It is possible to provide a photoreceptor that can be used in the used analog copying machine.

Claims (2)

The following general formula [1], [2] or an electrophotographic photosensitive member characterized by having a photosensitive layer containing a compound represented by [4].

(Wherein, Q and Q 'is an oxygen _{atom, = C (CN) 2,} = C (CN) CO 2 R', = C (CN) COR ', or = .A _1, A ₂ representing a NCN is Represents an alkyl group or an aryl group, Ar and Ar ′ represent an aryl group, R represents a halogen atom, a nitro group, a cyano group, or a substituted or unsubstituted alkyl group, an alkoxy group, an aryl group or a styryl group , and Y represents _{= C (R 1) R 2} , = C = C (R 3) represents _{R 4, R 1, R 2} , R 3 and R 'represents respectively substituted, an unsubstituted alkyl group or aryl group, R ₄ Represents a hydrogen atom, a substituted or unsubstituted alkyl group or an aryl group, and n represents an integer of 0 or 1 to 3.) In an electrophotographic photoreceptor having a photosensitive layer provided on a conductive support, the photosensitive layer is laminated from the conductive support to a charge generation layer and a charge transport layer in this order, and the charge transport layer has the general formula [ 1], [2] or the electrophotographic photosensitive member according to claim 1, characterized by containing a compound represented by [4].