JP3793035B2 - Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus having the electrophotographic photosensitive member, and method for producing the electrophotographic photosensitive member - Google Patents

Description

【００１４】
式中、Ａｒ^１〜Ａｒ^３は置換基を有していてもよいアルキル基、または置換基を有していてもよいアリール基を示す。ただし、Ａｒ^１〜Ａｒ^３のうちの少なくとも１つは、アリール基であり、Ａｒ ^１ 〜Ａｒ ^３ のうちの少なくとも１つは、ｔｅｒｔ−ブチル基である。
【００１５】
上記式中に含まれるアルキル基とは、メチル基、エチル基、プロピル基、ｎ−ブチル基、ｔｅｒｔ−ブチル基およびシクロヘキシル基などを示し、アリール基とは、縮合環式炭化水素基をも含み、例えば、フェニル基、ビフェニル基、ターフェニル基、ナフチル基、アンスリル基、フェナンスリル基およびピレニル基などを示す。
【００１６】
さらに、これらが有していてもよい置換基とは、メチル基、エチル基、プロピル基およびブチル基などのアルキル基、メトキシ基およびエトキシ基などのアルコキシ基、ジメチルアミノ基およびジエチルアミノ基などのアルキル置換アミノ基を示す。
【００１７】
また、本発明に従って、上記電子写真感光体を有するプロセスカートリッジおよび電子写真装置が提供される。
【００１８】
また、本発明にしたがって、上記電子写真感光体の製造方法が提供される。
【００１９】
【発明の実施の形態】
以下に、本発明の実施の形態を詳細に説明する。
【００２０】
本発明に用いられる電荷輸送材料は、アミン化合物とアリールハライドを原料として、下記式（１）で示されるホスフィン化合物とパラジウム化合物からなる触媒を用いて合成されたトリアリールアミン化合物である。
【００２１】
【外６】

【００２２】
式中、Ａｒ^１〜Ａｒ^３は置換基を有していてもよいアルキル基、または置換基を有していてもよいアリール基を示す。ただし、Ａｒ^１〜Ａｒ^３のうちの少なくとも１つは、アリール基であり、Ａｒ ^１ 〜Ａｒ ^３ のうちの少なくとも１つは、ｔｅｒｔ−ブチル基である。
【００２３】
本発明における上記触媒の作用機構は、詳細には解明できていないが、ホスフィン化合物が配位子としてパラジウム原子上に配位した状態で作用すると考えられる。すなわち、ホスフィン化合物が配位したパラジウム触媒は、まず、アリールハライドに酸化的に付加する。そして、ハロゲンが脱離すると同時に、今度はパラジウム原子上にアリールアミンが配位する。さらに、アミン上からパラジウム触媒が還元的に脱離してトリアリールアミンが形成されると考えられる。その際、塩基がハロゲンの脱離を促進していると考えている。
【００２４】
また、前記トリアリールアミン化合物は、トリフェニルアミンであることが好ましく、トリフェニルアミンの中でも、下記式（２）、式（３）または式（４）で示される化合物であることが好ましい。
【００２５】
【外７】

【００２６】
式中、Ｒ^１〜Ｒ^１５は、水素原子、置換基を有していてもよいアルキル基、アルコキシ基またはハロゲン原子を示す。ｎは０または１を示す。
【００２７】
前記式（２）、式（３）および式（４）中のＲ^１〜Ｒ^１５のアルキル基は、メチル基、エチル基、プロピル基、ｎ−ブチル基およびｔｅｒｔ−ブチル基などを示し、Ｒ^１〜Ｒ^１５のアルコキシ基とは、メトキシ基およびエトキシ基などを示し、Ｒ^１〜Ｒ^１５のハロゲン原子とは、フッ素原子、塩素原子および臭素原子を示す。
【００２８】
さらに、これらが有していてもよい置換基とは、メチル基、エチル基、プロピル基およびブチル基などのアルキル基を示す。
【００２９】
本発明に使用される上記式（１）に示されるホスフィン化合物は、少なくとも１つのアリール基を有しているため、トリアルキルアミン類に比べて、安定性が著しく向上している。例えば、トリ−ｔｅｒｔ−ブチルホスフィンが不活性なガスを封入した密閉容器中での保存が必要なのに対し、ジ−ｔｅｒｔ−ブチルフェニルホスフィンは、空気雰囲気下での保存が可能である。
【００３０】
また、本発明に使用される上記式（１）に示されるホスフィン化合物は、置換基を有していてもよいアルキル基を有するが、少なくとも１つはｔｅｒｔ−ブチル基である。
【００３１】
また、本発明に使用される上記式（１）に示されるホスフィン化合物は、置換基を有していてもよいアリール基を有するが、少なくとも１つは置換基を有していてもよいビフェニル基であることが好ましい。
【００３２】
以下に、本発明に用いられるホスフィン化合物の具体例を示すが、これに限定されるものではない。
【００３３】
【外８】

【００３４】
好ましい例としては、（Ｐ−５）および（Ｐ−６）が挙げられ、特に好ましい例としては、（Ｐ−５）のジ−ｔｅｒｔ−ブチルビフェニルホスフィンが挙げられる。
【００３５】
本発明で使用するパラジウム化合物としては、特に限定するものではないが、例えば、ヘキサクロルパラジウム（ＩＶ）酸ナトリウム四水和物およびヘキサクロルパラジウム（ＩＶ）酸カリウム四水和物などの四価パラジウム化合物類、塩化パラジウム（ＩＩ）、臭化パラジウム（ＩＩ）、酢酸パラジウム（ＩＩ）、パラジウムアセチルアセトナート（ＩＩ）、ジクロロビス（ベンゾニトリル）パラジウム（ＩＩ）、ジクロルビス（トリフェニルホスフィン）パラジウム（ＩＩ）、ジクロロテトラミンパラジウム（ＩＩ）およびジクロロ（シクロオクタ−１，５−ジエン）パラジウム（ＩＩ）などの二価パラジウム化合物類、トリス（ジベンジリデンアセトン）二パラジウム（０）、トリス（ジベンジリデンアセトン）二パラジウムクロロホルム錯体（０）およびテトラキス（トリフェニルホスフィン）パラジウム（０）などのパラジウム化合物類が挙げられる。
【００３６】
本発明においては、電荷輸送材料が塩基の存在下で合成されたものであることが好ましく、使用される塩基としては、無機塩基および／または有機塩基から選択すれば良く、特に限定するものではないが、ナトリウムメトキシド、ナトリウムエトキシド、カリウムメトキシド、カリウムエトキシド、リチウム−ｔｅｒｔ−ブトキシド、ナトリウム−ｔｅｒｔ−ブトキシドおよびカリウム−ｔｅｒｔ−ブトキシドなどのアルカリ金属アルコキシドが好ましく、特にはナトリウム−ｔｅｒｔ−ブトキシドが好ましい。また、リン酸三カリウムおよびフッ化セシウムなどの無機塩基も有効である。
【００３７】
本発明に使用される合成用溶媒としては、ハロゲン溶媒以外の一般的な不活性な有機溶媒であれば良く特に限定するものではないが、トルエンおよびキシレンなどの芳香族系溶媒やモノグライムなどのエーテル系溶媒が、原材料に対する溶解性の点で好ましい。
【００３８】
以下に、本発明に用いられる電荷輸送材料の具体例を示すが、これに限定されるものではない。
【外９】

【００３９】
好ましい例としては、（ＣＴ−５）、（ＣＴ−６）、（ＣＴ−７）、（ＣＴ−１０）、（ＣＴ−１１）および（ＣＴ−１２）が挙げられ、特に好ましい例としては、（ＣＴ−５）、（ＣＴ−６）および（ＣＴ−１１）が挙げられ、さらに好ましい例としては、（ＣＴ−６）が挙げられる。
【００４０】
本発明に使用するアリールハライドとは、アリールクロライド、アリールブロマイドおよびアリールアイオダイドなどを示す。
【００４１】
本発明に使用するアリールハライドおよびアミン化合物は、所望の電荷輸送材料の構造に対応した組み合わせのものであれば良く、特に限定されるものではないが、低分子の電荷輸送材料を合成する場合には、アリールモノハライドとモノアリールアミンまたはジアリールアミンの組み合わせ、もしくは、アリールジハライドとジアリールアミンの組み合わせが、高分子型の電荷輸送材料の場合は、アリールジハライドまたはアリールトリハライドとジアリールアミンの組み合わせが好ましい。
【００４２】
以下に、本発明に用いる電子写真感光体の構成について説明する。
【００４３】
本発明における電子写真感光体は、感光層が電荷輸送材料と電荷発生材料を同一の層に含有する単層型であっても、電荷輸送層と電荷発生層に分離した積層型でもよいが、電子写真特性的には積層型が好ましい。
【００４４】
使用する支持体は、導電性を有するものであればよく、アルミニウムやステンレスなどの金属、あるいは導電層を設けた金属、紙およびプラスチックなどが挙げられ、形状はシート状や円筒状などが挙げられる。
【００４５】
ＬＢＰなどの露光光がレーザー光の場合は、散乱による干渉縞防止または支持体の傷を被覆することを目的とした導電層を設けてもよい。これは、カーボンブラックや金属粒子などの導電性粉体をバインダー樹脂に分散させて形成することができる。導電層の膜厚は、５〜４０μｍが好ましく、特には１０〜３０μｍが好ましい。
【００４６】
その上に接着機能を有する中間層を設ける。中間層の材料としては、ポリアミド、ポリビニルアルコール、ポリエチレンオキシド、エチルセルロース、カゼイン、ポリウレタンおよびポリエーテルウレタンなどが挙げられる。これらは適当な溶剤に溶解して塗布される。中間層の膜厚は、０．０５〜５μｍが好ましく、特には０．３〜１μｍが好ましい。
【００４７】
中間層の上には電荷発生層が形成される。本発明に用いられる電荷発生材料としては、セレン−テルル、ピリリウム、チアピリリウム系染料、フタロシアニン、アントアントロン、ジベンズピレンキノン、トリスアゾ、シアニン、ジスアゾ、モノアゾ、インジゴ、キナクリドンおよび非対称キノシアニン系の各顔料が挙げられる。機能分離型の場合、電荷発生層は、前記電荷発生材料を０．３〜４倍量のバインダー樹脂および溶剤と共にホモジナイザー、超音波分散、ボールミル、振動ボールミル、サンドミル、アトライター、ロールミルおよび液衝突型高速分散機などの方法で十分に分散し、分散液を塗布、乾燥させて形成される。電荷発生層の膜厚は５μｍ以下が好ましく、特には０．１〜２μｍが好ましい。
【００４８】
電荷輸送層は、本発明からなる電荷輸送材料とバインダー樹脂とを溶剤中に溶解させた塗工液を塗工乾燥して形成する。用いられるバインダー樹脂としては、ポリカーボネート、ポリアリレート、ポリエステル、ポリスチレン、スチレン−アクリロニトリル共重合体、ポリスルホン、ポリメタクリル酸エステルおよびスチレン−メタクリル酸エステル共重合体などが挙げられる。
【００４９】
電荷輸送材料と０．５〜２倍量のバインダー樹脂と組み合わせ、塗工、乾燥し電荷輸送層を形成する。電荷輸送層の膜厚は、５〜４０μｍが好ましく、特には１５〜３０μｍが好ましい。
【００５０】
図１に本発明の電子写真感光体を有するプロセスカートリッジを用いた電子写真装置の概略構成を示す。
【００５１】
図において、１はドラム状の本発明の電子写真感光体であり、軸２を中心に矢印方向に所定の周速度で回転駆動される。電子写真感光体１は、回転過程において、一次帯電手段３によりその周面に正または負の所定電位の均一帯電を受け、ついで、スリット露光やレーザービーム走査露光などの露光手段（不図示）から出力される目的の画像情報の時系列電気デジタル画像信号に対応して強調変調された露光光４を受ける。こうして電子写真感光体１の周面に対し、目的の画像情報に対応した静電潜像が順次形成されていく。
【００５２】
形成された静電潜像は、ついで現像手段５によりトナー現像され、不図示の給紙部から電子写真感光体１と転写手段６との間に電子写真感光体１の回転と同期して取り出されて給紙された転写材７に、電子写真感光体１の表面に形成担持されているトナー画像が転写手段６により順次転写されていく。
【００５３】
トナー画像の転写を受けた転写材７は、電子写真感光体面から分離されて像定着手段８へ導入されて像定着を受けることにより画像形成物（プリント、コピー）として装置外へプリントアウトされる。
【００５４】
像転写後の電子写真感光体１の表面は、クリーニング手段９によって転写残りトナーの除去を受けて清浄面化され、さらに前露光手段（不図示）からの前露光光１０により除電処理された後、繰り返し画像形成に使用される。なお、一次帯電手段３が帯電ローラーなどを用いた接触帯電手段である場合は、前露光は必ずしも必要ではない。
【００５５】
本発明においては、上述の電子写真感光体１、一次帯電手段３、現像手段５およびクリーニング手段９などの構成要素のうち、複数のものを容器１１に納めてプロセスカートリッジとして一体に結合して構成し、このプロセスカートリッジを複写機やレーザービームプリンターなどの電子写真装置本体に対して着脱自在に構成してもよい。例えば、一次帯電手段３、現像手段５およびクリーニング手段９の少なくとも１つを電子写真感光体１と共に一体に支持してカートリッジ化して、装置本体のレールなどの案内手段１２を用いて装置本体に着脱自在なプロセスカートリッジとすることができる。
【００５６】
また、露光光４は、電子写真装置が複写機やプリンターである場合には、原稿からの反射光や透過光、あるいは、センサーで原稿を読取り、信号化し、この信号に従って行われるレーザービームの走査、ＬＥＤアレイの駆動および液晶シャッターアレイの駆動などにより照射される光である。
【００５７】
本発明の電子写真感光体は、電子写真複写機に利用するのみならず、レーザービームプリンター、ＣＲＴプリンター、ＬＥＤプリンター、ＦＡＸ、液晶プリンターおよびレーザー製版などの電子写真応用分野にも広く用いることができる。
【００５８】
【実施例】
以下、実施例に従って本発明をさらに詳細に説明する。なお、実施例中の「部」は質量部を表す。
【００５９】
＜合成例１＞
冷却管のついた１００ｍｌナスフラスコに４−ヨードトルエン４．３６ｇ（２０ｍｍｏｌ）、ジキシリルアミン４．９６ｇ（２２ｍｍｏｌ）およびトルエン２０ｍｌを入れ室温で５分間攪拌した。次に、ナトリウム−ｔｅｒｔ−ブトキシド２．６９ｇ（２８ｍｍｏｌ）、酢酸パラジウム１６０ｍｇ（０．７ｍｍｏｌ）およびジ−ｔｅｒｔ−ブチルビフェニルホスフィン（Ｐ−５）６４０ｍｇ（２．１ｍｍｏｌ）を加え、２０分間還流した。放冷後、トルエン８０ｍｌと水１００ｍｌを加え、１０分間攪拌した後、有機層を分取した。有機層を硫酸ナトリウムで乾燥した後、トルエンを留去した。
【００６０】
得られた粗成生物を、シリカゲルカラムを用いて精製し、５．６７ｇ（収率９０．０％、純度９９．９％）の電荷輸送材料（ＣＴ−１）を得た。純度は、ガスクロマトグラフィーの単純面積値から算出した。
【００６１】
＜合成例２〜８＞
表１に示した、アリールハライド、アミン化合物、リン化合物およびパラジウム化合物を用い、合成例１と同様な方法で電荷輸送材料を各々合成した。
【００６２】
【表１】

【００６３】
＜比較合成例１＞
合成例１に用いたアリールハライドおよびアミン化合物から、アリールアミン化合物の一般的な合成方法であるＵｌｌｍａｎｎ反応を用いて、電荷輸送材料（ＣＴ−１）の合成を行った。
【００６４】
すなわち、合成例１のナトリウム−ｔｅｒｔ−ブトキシド２．６９ｇ（２８ｍｍｏｌ）、酢酸パラジウム１６０ｍｇ（０．７ｍｍｏｌ）およびジ−ｔｅｒｔ−ブチルビフェニルホスフィンに代えて、銅粉３．８１ｇ（６０ｍｍｏｌ）、炭酸カリウム５．５３ｇ（４０ｍｍｏｌ）を用い、さらにトルエンをｏ−ジクロルベンゼンに代えて、４−ヨードトルエンがなくなるまで還流下で反応を行った。４−ヨードトルエンがなくなるのに６時間を要した。
【００６５】
得られた粗生成物は、合成例１と同じ方法で精製を行い、４．１０ｇ（収率６５．０％、純度９９．５％）の電荷輸送材料（ＣＴ−１）を得た。純度は、ガスクロマトグラフィーの単純面積値から算出した。
【００６６】
＜比較合成例２〜８＞
表２に示した合成例２〜８の合成条件を、比較合成例１と同様にして触媒、溶媒および反応時間を代えた以外は、合成例２〜８と同様にして、電荷輸送材料を合成した。純度は、表２の通りであった。
【００６７】
【表２】

【００６８】
＜比較合成例９〜１６＞
合成例１〜８の各リン化合物に代えて、トリ−ｔｅｒｔ−ブチルホスフィン４２５ｍｇ（２．１ｍｍｏｌ）を用いた以外は、合成例１〜８と同様にして、電荷輸送材料の合成および精製を行った。純度、収量および収率は、表３の通りであった。純度は、ガスクロマトグラフィーの単純面積値から算出した。
【００６９】
【表３】

【００７０】
（実施例１）
直径３０ｍｍ×長さ３５７ｍｍのアルミニウムシリンダーを支持体とし、それに、以下の材料より構成される塗工液を支持体上に浸漬法で塗布し、１４０℃で３０分間熱硬化することによって、膜厚が１５μｍの導電層を形成した。
導電性顔料：ＳｎＯ_２コート処理硫酸バリウム１０部
抵抗調節用顔料：酸化チタン２部
バインダー樹脂：フェノール樹脂６部
レベリング材：シリコーンオイル０．００１部
溶剤：メタノール／メトキシプロパノール（混合比０．２／０．８）２０部
次に、この上にＮ−メトキシメチル化ナイロン３部および共重合ナイロン３部をメタノール６５部／ｎ−ブタノール３０部の混合溶媒に溶解した溶液を浸漬法で塗布し、膜厚が０．７μｍの中間層を形成した。
【００７１】
次に、ＣｕＫαの特性Ｘ線回折におけるブラッグ角（２θ±０．２°）の９．０°、１４．２°、２３．９°および２７．１°に強いピークを有するオキシチタニウムフタロシアニン４部とポリビニルブチラール樹脂（エスレックＢＸ−１、積水化学社製）２部およびシクロヘキサノン６０部を直径０．５ｍｍガラスビーズを用いたサンドミル装置で３時間分散した後、エチルアセテート１００部を加えて電荷発生層用分散液を調製した。これを浸漬法で塗布し、膜厚が０．２μｍの電荷発生層を形成した。
【００７２】
次に、合成例１で合成した電荷輸送材料（ＣＴ−１）８部とポリカーボネート樹脂｛ユーピロンＺ２００；三菱エンジニアリングプラスチックス（株）｝１０部をモノクロロベンゼン４０部／ジクロロメタン４０部の混合溶媒に溶解した。この塗工液を浸漬法で塗布し、１１０℃で１時間乾燥し、膜厚が２６μｍの電荷輸送層を形成した。
【００７３】
作製した電子写真感光体をキヤノン（株）製ＬＢＰ−９５０に取り付け、３０℃／湿度８５％ＲＨの高温高湿の環境下で暗部電位Ｖｄ、明部電位Ｖｌおよび残留電位Ｖｒを測定した。ＬＢＰ−９５０には、電子写真感光体の電子写真特性を測定するための改造を施した。
【００７４】
さらに、高温高湿の環境下で３万枚の通紙耐久を行い、初期と３万枚後の暗部電位Ｖｄ、明部電位および残留電位Ｖｒを測定した。結果を表３に示す。
【００７５】
（実施例２〜８）
実施例１の電荷輸送材料に代えて、合成例２〜８で合成した電荷輸送材料を用いた以外は、実施例１と同様にして電子写真感光体を作製し、評価を行った。結果を表３に示す。
【００７６】
（比較例１〜１６）
実施例１の電荷輸送材料に代えて、比較合成例１〜１６で示した電荷輸送材料を用いた以外は、実施例１と同様にして電子写真感光体を作製し、評価を行った。結果を表４に示す。
【００７７】
【表４】

【００７８】
実施例の電子写真感光体は、比較例に比べ、いずれも耐久安定性に優れていることがわかる。これは、本発明に示されるホスフィン化合物とパラジウム化合物を用いた合成法により電荷輸送材料を製造することで、電位変動の原因となる不純物の生成が抑えられ、より高純度な電荷輸送材料が得られたためと考えられる。
【００７９】
また、比較例９〜１６に示したトリアルキルホスフィンを用いた場合にも、純度が高いにもかかわらず、電位変動が大きいが、これは、トリアルキルホスフィンを用いた場合、理由はわからないが、ごく微量の触媒起因の不純物が電荷輸送材料中に残り、悪影響を与えたものと考えている。
【００８０】
【発明の効果】
以上のように、本発明によれば、高感度で、耐久安定に優れ、製造が容易で、かつ比較的安価な電子写真感光体を有するプロセスカートリッジおよび電子写真装置を提供することが可能となった。
【図面の簡単な説明】
【図１】 本発明の電子写真感光体を有するプロセスカートリッジを用いる電子写真装置の概略構成の例を示す図である。
【符号の説明】
１ 電子写真感光体
２ 軸
３ 帯電手段
４ 露光光
５ 現像手段
６ 転写手段
７ 転写材
８ 定着手段
９ クリーニング手段
１０ 前露光光
１１ プロセスカートリッジ容器
１２ 案内手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus. More specifically, the present invention relates to an electrophotographic photosensitive member using a charge transport material synthesized using a specific synthesis method, and a process cartridge having the electrophotographic photosensitive member. And an electrophotographic apparatus.
[0002]
[Prior art]
In recent years, a multi-layer electrophotographic photosensitive member in which a photosensitive layer is functionally separated into a charge generation layer and a charge transport layer has been proposed. The electrophotographic photosensitive member having this laminated structure can be improved in terms of sensitivity to visible light, charge retention and surface strength. Many organic compounds have been proposed as charge transport materials. For example, JP-A-52-72231 discloses pyrazoline compounds, JP-A-55-52063 discloses hydrazone compounds, JP-A-54-58445 and JP-A-57-195254 discloses A phenylamine compound is disclosed in Japanese Patent Laid-Open Nos. 54-151955 and 58-198043, and stilbene compounds are disclosed. In particular, many triarylamine compounds having a triphenylamine structure have excellent electrophotographic characteristics compared to other compounds, such as easy molecular design and high hole mobility. Has been.
[0003]
However, even in electrophotographic photoreceptors using these triarylamine compounds as charge transport materials, the sensitivity characteristics are not always sufficient, potential fluctuations during repeated use, and image defects under low or high humidity. There are still points to be improved.
[0004]
The characteristics of the electrophotographic photoreceptor are affected not only by the charge transport material structure but also by its purity. In particular, it has been found that the influence of impurities in the charge transport material appears strongly with respect to fluctuations in the residual potential. Therefore, it is preferable that the charge transporting material used in the electrophotographic photosensitive member has a high purity and a small amount of impurities. In other words, the impurities trap holes, which are carriers, in the charge transport layer, hindering the movement of carriers, and the accumulated holes form space charges, which causes fluctuations in the residual potential. Therefore, a smaller amount is preferable.
[0005]
Conventionally, in the manufacture of charge transport materials, purification processes such as recrystallization and column chromatography are performed at the end of the manufacturing process. However, recrystallization does not remove impurities sufficiently, In column chromatography, there are problems in terms of cost and safety, such as using expensive silica gel and alumina for chromatography, and using a large amount of flammable and dangerous organic solvents. was there.
[0006]
The amine compound used for the charge transport material is usually synthesized by a condensation reaction between a corresponding aryl halide and an amine compound.
[0007]
For example, a method (Ullmann reaction) of synthesizing from a corresponding iodobenzene and an amine compound using a copper catalyst is known {Dai Organic Chemistry, vol. 16, 52 (1959) Asakura Shoten, Organic Chemistry Course 3, 66 (1983), Maruzen, etc. However, in the reaction using these copper catalysts, a large amount of copper catalyst is used, a high reaction temperature is required, and the reaction time is long. Since coloring impurities and decomposition products that adversely affect photographic characteristics are by-produced, it is difficult to purify arylamines from the reaction system, and there is a problem that high cost is required for purification.
[0008]
Recently, Stephan L. Buchwald et al. Reported a method for synthesizing amines from aryl halides and amine compounds using phosphines and palladium compounds as catalysts in the presence of a base {Tetrahedron Letters, Vol. 36, no. 21, 3609 (1955); Am. Chem. Soc. Vol 120, 9722 (1998)}. Since this reaction proceeds under relatively mild conditions, it is considered that the amount of impurities generated is significantly reduced compared to the Ullmann reaction. John. F. A similar method has been reported by Hartwig et al. {J. Org. Chem. 61, 1133 (1996)}.
[0009]
Furthermore, as a method for synthesizing triarylamines using these, a synthesis method using a trialkylphosphine and a palladium compound as a catalyst is disclosed in Japanese Patent Laid-Open Nos. 10-139742 and 10-310561. . However, although these methods have advantages such as cost-effective aryl bromide being used as a raw material and a relatively low reaction temperature and a short reaction time, the production cost is low because the trialkylphosphine used is expensive. Not only did it increase, but there were new problems such as insufficient storage stability of the catalyst and danger of spontaneous ignition.
[0010]
As a result of intensive studies to improve the above problems, the present inventors have found that Stephen L. Of the phosphine compounds that can be used in the synthesis method of triarylamine using the reaction of Buchwald et al., Compounds having a specific structure are not only excellent in cost, storage stability and safety, but also obtained by it. When the obtained triarylamine compound is used for an electrophotographic photosensitive member, it has been found that it exhibits excellent characteristics of potential stability and environmental stability during durability.
[0011]
[Problems to be solved by the invention]
The present invention has been made to improve the above problems. That is, an object of the present invention is to provide an electrophotographic photoreceptor excellent in durability stability, easy to manufacture and relatively inexpensive, a process cartridge and an electrophotographic apparatus having the electrophotographic photoreceptor.
[0012]
[Means for Solving the Problems]
In accordance with the present invention, in an electrophotographic photoreceptor comprising a charge generation material and a charge transport material, the charge transport material comprises a amine compound and an aryl halide as raw materials, and a catalyst comprising a phosphine compound and a palladium compound represented by the following formula (1) An electrophotographic photoreceptor characterized in that it is a triarylamine compound synthesized using
[0013]
[Outside 5]

[0014]
In the formula, Ar ^{1 to} Ar ³ represent an alkyl group which may have a substituent, or an aryl group which may have a substituent. Provided ^that at least one of Ar 1 to Ar ³ is an aryl group der ^is, at least one of Ar 1 to Ar ³ is Ru der tert- butyl group.
[0015]
The alkyl group contained in the above formula represents a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, a cyclohexyl group, and the like, and the aryl group includes a condensed cyclic hydrocarbon group. For example, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group, and the like are shown.
[0016]
Furthermore, the substituents which they may have are alkyl groups such as methyl group, ethyl group, propyl group and butyl group, alkoxy groups such as methoxy group and ethoxy group, alkyl groups such as dimethylamino group and diethylamino group. A substituted amino group is shown.
[0017]
Further, according to the present invention, a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member are provided.
[0018]
According to the present invention, there is also provided a method for producing the above electrophotographic photosensitive member.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0020]
The charge transport material used in the present invention is a triarylamine compound synthesized using an amine compound and an aryl halide as raw materials and a catalyst composed of a phosphine compound and a palladium compound represented by the following formula (1).
[0021]
[Outside 6]

[0022]
In the formula, Ar ^{1 to} Ar ³ represent an alkyl group which may have a substituent, or an aryl group which may have a substituent. Provided ^that at least one of Ar 1 to Ar ³ is an aryl group der ^is, at least one of Ar 1 to Ar ³ is Ru der tert- butyl group.
[0023]
Although the mechanism of action of the catalyst in the present invention has not been elucidated in detail, it is considered that the catalyst functions in a state in which the phosphine compound is coordinated on the palladium atom as a ligand. That is, a palladium catalyst coordinated with a phosphine compound is first oxidatively added to an aryl halide. At the same time as the elimination of the halogen, an arylamine is coordinated on the palladium atom. Furthermore, it is considered that the palladium catalyst is reductively eliminated from the amine to form a triarylamine. At that time, it is considered that the base promotes elimination of the halogen.
[0024]
The triarylamine compound is preferably triphenylamine, and among the triphenylamines, a compound represented by the following formula (2), formula (3) or formula (4) is preferable.
[0025]
[Outside 7]

[0026]
In the formula, R ^{1 to} R ¹⁵ represent a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group, or a halogen atom. n represents 0 or 1.
[0027]
The alkyl groups of R ^{1 to} R ^{15 in} the formula (2), the formula (3), and the formula (4) represent a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, and the like, and R ¹ and alkoxy groups to R ^15, indicates as methoxy and ethoxy ^groups, and halogen atoms R 1 ^{to R 15,} a fluorine atom, a chlorine atom and a bromine atom.
[0028]
Furthermore, the substituent which these may have shows alkyl groups, such as a methyl group, an ethyl group, a propyl group, and a butyl group.
[0029]
Since the phosphine compound represented by the above formula (1) used in the present invention has at least one aryl group, the stability is remarkably improved as compared with trialkylamines. For example, while tri-tert-butylphosphine needs to be stored in a sealed container filled with an inert gas, di-tert-butylphenylphosphine can be stored in an air atmosphere.
[0030]
The phosphine compound represented by the above formula used in the present invention (1) has an alkyl group which may have a substituent, at least one Ru der tert- butyl group.
[0031]
The phosphine compound represented by the above formula used in the present invention (1) has an aryl group which may have a substituent, at least one good biphenyl group which may have a substituent It is preferable that
[0032]
Although the specific example of the phosphine compound used for this invention below is shown, it is not limited to this.
[0033]
[Outside 8]

[0034]
Preferable examples include (P-5) and (P-6) , and particularly preferable examples include di-tert-butylbiphenylphosphine of (P-5) .
[0035]
Although it does not specifically limit as a palladium compound used by this invention, For example, tetravalent palladium, such as sodium hexachloro palladium (IV) acid tetrahydrate and hexachloro palladium (IV) potassium tetrahydrate, Compounds, palladium (II) chloride, palladium (II) bromide, palladium (II) acetate, palladium acetylacetonate (II), dichlorobis (benzonitrile) palladium (II), dichlorobis (triphenylphosphine) palladium (II) , Divalent palladium compounds such as dichlorotetramine palladium (II) and dichloro (cycloocta-1,5-diene) palladium (II), tris (dibenzylideneacetone) dipalladium (0), tris (dibenzylideneacetone) dipalladium Chlorojo Arm complex (0) and tetrakis (triphenylphosphine) palladium (0) a palladium compound such as and the like.
[0036]
In the present invention, the charge transport material is preferably synthesized in the presence of a base, and the base used may be selected from an inorganic base and / or an organic base, and is not particularly limited. Are preferably alkali metal alkoxides such as sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, lithium-tert-butoxide, sodium-tert-butoxide and potassium-tert-butoxide, especially sodium-tert-butoxide. Is preferred. In addition, inorganic bases such as tripotassium phosphate and cesium fluoride are also effective.
[0037]
The synthesis solvent used in the present invention is not particularly limited as long as it is a general inert organic solvent other than a halogen solvent, but is not limited to aromatic solvents such as toluene and xylene, and ethers such as monoglyme. A system solvent is preferable in terms of solubility in raw materials.
[0038]
Specific examples of the charge transport material used in the present invention are shown below, but are not limited thereto.
[Outside 9]

[0039]
Preferred examples include (CT-5), (CT-6), (CT-7), (CT-10), (CT-11) and (CT-12), and particularly preferred examples include (CT-5), (CT-6) and (CT-11) are mentioned, and (CT-6) is mentioned as a more preferable example.
[0040]
The aryl halide used in the present invention includes aryl chloride, aryl bromide and aryl iodide.
[0041]
The aryl halide and amine compound used in the present invention are not particularly limited as long as the aryl halide and the amine compound are in a combination corresponding to the structure of the desired charge transport material, but when synthesizing a low molecular charge transport material. Is a combination of aryl monohalide and monoarylamine or diarylamine, or a combination of aryl dihalide and diarylamine is a polymer type charge transport material, a combination of aryl dihalide or aryltrihalide and diarylamine Is preferred.
[0042]
Hereinafter, the configuration of the electrophotographic photoreceptor used in the present invention will be described.
[0043]
In the electrophotographic photoreceptor of the present invention, the photosensitive layer may be a single layer type in which the charge transport material and the charge generation material are contained in the same layer, or may be a stacked type in which the charge transport layer and the charge generation layer are separated, From the viewpoint of electrophotographic characteristics, a laminated type is preferable.
[0044]
The support to be used may be any material having conductivity, and examples thereof include metals such as aluminum and stainless steel, metals provided with a conductive layer, paper, plastics, and the like, and examples of the shape include sheets and cylinders. .
[0045]
When exposure light such as LBP is laser light, a conductive layer may be provided for the purpose of preventing interference fringes due to scattering or covering scratches on the support. This can be formed by dispersing conductive powder such as carbon black or metal particles in a binder resin. The thickness of the conductive layer is preferably 5 to 40 μm, and particularly preferably 10 to 30 μm.
[0046]
An intermediate layer having an adhesive function is provided thereon. Examples of the material for the intermediate layer include polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane, and polyether urethane. These are dissolved in an appropriate solvent and applied. The thickness of the intermediate layer is preferably 0.05 to 5 μm, particularly preferably 0.3 to 1 μm.
[0047]
A charge generation layer is formed on the intermediate layer. Examples of the charge generating material used in the present invention include selenium-tellurium, pyrylium, thiapyrylium dyes, phthalocyanine, anthanthrone, dibenzpyrenequinone, trisazo, cyanine, disazo, monoazo, indigo, quinacridone, and asymmetric quinocyanine pigments. Can be mentioned. In the case of the functional separation type, the charge generation layer is composed of a homogenizer, ultrasonic dispersion, ball mill, vibration ball mill, sand mill, attritor, roll mill, and liquid collision type with the charge generation material 0.3 to 4 times the binder resin and solvent. It is sufficiently dispersed by a method such as a high-speed disperser, and the dispersion is applied and dried. The thickness of the charge generation layer is preferably 5 μm or less, particularly preferably 0.1 to 2 μm.
[0048]
The charge transport layer is formed by coating and drying a coating solution in which the charge transport material according to the present invention and a binder resin are dissolved in a solvent. Examples of the binder resin used include polycarbonate, polyarylate, polyester, polystyrene, styrene-acrylonitrile copolymer, polysulfone, polymethacrylic acid ester, and styrene-methacrylic acid ester copolymer.
[0049]
A charge transporting material and 0.5 to 2 times the amount of binder resin are combined, coated and dried to form a charge transporting layer. The thickness of the charge transport layer is preferably 5 to 40 μm, particularly preferably 15 to 30 μm.
[0050]
FIG. 1 shows a schematic configuration of an electrophotographic apparatus using a process cartridge having the electrophotographic photosensitive member of the present invention.
[0051]
In the figure, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is rotated about a shaft 2 in the direction of an arrow at a predetermined peripheral speed. In the rotation process, the electrophotographic photosensitive member 1 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by the primary charging unit 3, and then from an exposure unit (not shown) such as slit exposure or laser beam scanning exposure. The exposure light 4 that is enhanced and modulated corresponding to the time-series electric digital image signal of the target image information to be output is received. In this way, electrostatic latent images corresponding to the target image information are sequentially formed on the peripheral surface of the electrophotographic photoreceptor 1.
[0052]
The formed electrostatic latent image is then developed with toner by the developing means 5 and taken out from a sheet feeding unit (not shown) between the electrophotographic photoreceptor 1 and the transfer means 6 in synchronization with the rotation of the electrophotographic photoreceptor 1. The toner image formed and supported on the surface of the electrophotographic photosensitive member 1 is sequentially transferred by the transfer means 6 onto the transferred transfer material 7.
[0053]
The transfer material 7 that has received the transfer of the toner image is separated from the surface of the electrophotographic photosensitive member, introduced into the image fixing means 8, and subjected to image fixing to be printed out as an image formed product (print, copy). .
[0054]
After the image transfer, the surface of the electrophotographic photosensitive member 1 is cleaned by the removal of the toner remaining after the transfer by the cleaning unit 9, and is further subjected to charge removal processing by the pre-exposure light 10 from the pre-exposure unit (not shown). Used repeatedly for image formation. When the primary charging unit 3 is a contact charging unit using a charging roller or the like, pre-exposure is not always necessary.
[0055]
In the present invention, a plurality of components such as the above-described electrophotographic photosensitive member 1, primary charging unit 3, developing unit 5, and cleaning unit 9 are housed in a container 11 and integrally combined as a process cartridge. The process cartridge may be configured to be detachable from an electrophotographic apparatus main body such as a copying machine or a laser beam printer. For example, at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported with the electrophotographic photosensitive member 1 to form a cartridge, and is attached to and detached from the apparatus main body using a guide unit 12 such as a rail of the apparatus main body. A flexible process cartridge can be obtained.
[0056]
Further, when the electrophotographic apparatus is a copying machine or a printer, the exposure light 4 is reflected or transmitted light from the original, or the original is read by a sensor and converted into a signal, and a laser beam scanning performed according to this signal is performed. The light emitted by driving the LED array and the liquid crystal shutter array.
[0057]
The electrophotographic photosensitive member of the present invention can be used not only in electrophotographic copying machines but also widely in electrophotographic application fields such as laser beam printers, CRT printers, LED printers, FAX, liquid crystal printers, and laser plate making. .
[0058]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples. In addition, "part" in an Example represents a mass part.
[0059]
<Synthesis Example 1>
4-Iodotoluene 4.36 g (20 mmol), dixylylamine 4.96 g (22 mmol) and toluene 20 ml were placed in a 100 ml eggplant flask equipped with a condenser, and stirred at room temperature for 5 minutes. Next, 2.69 g (28 mmol) of sodium-tert-butoxide, 160 mg (0.7 mmol) of palladium acetate and 640 mg (2.1 mmol) of di-tert-butylbiphenylphosphine ( P-5 ) were added and refluxed for 20 minutes. After allowing to cool, 80 ml of toluene and 100 ml of water were added and stirred for 10 minutes, and then the organic layer was separated. After drying the organic layer with sodium sulfate, toluene was distilled off.
[0060]
The resulting crude product was purified using a silica gel column to obtain 5.67 g (yield 90.0%, purity 99.9%) of a charge transport material (CT-1). The purity was calculated from the simple area value of gas chromatography.
[0061]
<Synthesis Examples 2 to 8 >
Using the aryl halide, amine compound, phosphorus compound and palladium compound shown in Table 1, charge transport materials were synthesized in the same manner as in Synthesis Example 1.
[0062]
[Table 1]

[0063]
<Comparative Synthesis Example 1>
The charge transport material (CT-1) was synthesized from the aryl halide and amine compound used in Synthesis Example 1 using the Ullmann reaction, which is a general method for synthesizing arylamine compounds.
[0064]
That is, instead of 2.69 g (28 mmol) of sodium-tert-butoxide, 160 mg (0.7 mmol) of palladium acetate and di-tert-butylbiphenylphosphine in Synthesis Example 1, 3.81 g (60 mmol) of copper powder, potassium carbonate 5 .53 g (40 mmol) was used, and toluene was replaced with o-dichlorobenzene, and the reaction was carried out under reflux until 4-iodotoluene disappeared. It took 6 hours for 4-iodotoluene to run out.
[0065]
The obtained crude product was purified by the same method as in Synthesis Example 1 to obtain 4.10 g (yield 65.0%, purity 99.5%) of charge transport material (CT-1) . The purity was calculated from the simple area value of gas chromatography.
[0066]
<Comparative Synthesis Examples 2 to 8 >
The synthesis conditions of Synthesis Example 2-8 shown in Table 2, the catalyst in the same manner as in Comparative Synthesis Example 1, except for changing the solvent and the reaction time, in the same manner as in Synthesis Example 2-8, combining a charge transporting material did. The purity was as shown in Table 2.
[0067]
[Table 2]

[0068]
<Comparative Synthesis Examples 9 to 16 >
Instead of the phosphorus compound of Synthesis Example 1-8, except for using tri -tert- butylphosphine 425 mg (2.1 mmol), in the same manner as in Synthesis Example 1-8, was synthesized and purified in the charge transporting material It was. The purity, yield, and yield were as shown in Table 3. The purity was calculated from the simple area value of gas chromatography.
[0069]
[Table 3]

[0070]
Example 1
The film thickness is obtained by using an aluminum cylinder having a diameter of 30 mm × length of 357 mm as a support, applying a coating liquid composed of the following materials onto the support by a dipping method, and thermosetting at 140 ° C. for 30 minutes. Formed a conductive layer of 15 μm.
Conductive pigment: SnO ₂ coated barium sulfate 10 parts Resistance adjusting pigment: Titanium oxide 2 parts Binder resin: Phenol resin 6 parts Leveling material: Silicone oil 0.001 part Solvent: Methanol / methoxypropanol (mixing ratio 0.2 / 0.8) 20 parts Next, a solution prepared by dissolving 3 parts of N-methoxymethylated nylon and 3 parts of copolymer nylon in a mixed solvent of 65 parts of methanol / 30 parts of n-butanol was applied by a dipping method. An intermediate layer having a thickness of 0.7 μm was formed.
[0071]
Next, 4 parts of oxytitanium phthalocyanine having strong peaks at 9.0 °, 14.2 °, 23.9 ° and 27.1 ° of the Bragg angles (2θ ± 0.2 °) in the characteristic X-ray diffraction of CuKα And 2 parts of polyvinyl butyral resin (ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 60 parts of cyclohexanone were dispersed for 3 hours in a sand mill apparatus using glass beads having a diameter of 0.5 mm, and then 100 parts of ethyl acetate was added to the charge generation layer. A dispersion was prepared. This was applied by an immersion method to form a charge generation layer having a thickness of 0.2 μm.
[0072]
Next, 8 parts of the charge transport material (CT-1) synthesized in Synthesis Example 1 and 10 parts of polycarbonate resin {Iupilon Z200; Mitsubishi Engineering Plastics Co., Ltd.} are dissolved in a mixed solvent of 40 parts monochlorobenzene / 40 parts dichloromethane. did. This coating solution was applied by an immersion method and dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 26 μm.
[0073]
The produced electrophotographic photosensitive member was attached to an LBP-950 manufactured by Canon Inc., and the dark portion potential Vd, the light portion potential Vl, and the residual potential Vr were measured in a high temperature and high humidity environment of 30 ° C./humidity 85% RH. The LBP-950 was modified to measure the electrophotographic characteristics of the electrophotographic photoreceptor.
[0074]
Further, 30,000 sheets were passed through in an environment of high temperature and high humidity, and the dark part potential Vd, the bright part potential, and the residual potential Vr after the initial and 30,000 sheets were measured. The results are shown in Table 3.
[0075]
(Examples 2 to 8 )
An electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the charge transport material synthesized in Synthesis Examples 2 to 8 was used in place of the charge transport material in Example 1. The results are shown in Table 3.
[0076]
(Comparative Examples 1 to 16 )
An electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the charge transporting materials shown in Comparative Synthesis Examples 1 to 16 were used in place of the charge transporting material of Example 1. The results are shown in Table 4.
[0077]
[Table 4]

[0078]
It can be seen that the electrophotographic photoreceptors of the examples are all superior in durability stability as compared with the comparative examples. This is because a charge transport material is produced by a synthesis method using a phosphine compound and a palladium compound shown in the present invention, so that generation of impurities that cause potential fluctuations can be suppressed and a charge transport material with higher purity can be obtained. It is thought that it was because
[0079]
Moreover, even when the trialkylphosphine shown in Comparative Examples 9 to 16 is used, although the purity is high, the potential fluctuation is large, but when using the trialkylphosphine, the reason is not known. It is considered that a very small amount of impurities derived from the catalyst remained in the charge transport material and had an adverse effect.
[0080]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a process cartridge and an electrophotographic apparatus having an electrophotographic photosensitive member having high sensitivity, excellent durability and stability, easy to manufacture, and relatively inexpensive. It was.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus using a process cartridge having the electrophotographic photosensitive member of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 2 Axis 3 Charging means 4 Exposure light 5 Developing means 6 Transfer means 7 Transfer material 8 Fixing means 9 Cleaning means 10 Pre-exposure light 11 Process cartridge container 12 Guide means

Claims (18)

In an electrophotographic photoreceptor including a charge generation material and a charge transport material, the charge transport material is synthesized using an amine compound and an aryl halide as raw materials and a catalyst composed of a phosphine compound and a palladium compound represented by the following formula (1). An electrophotographic photosensitive member, characterized in that the electrophotographic photosensitive member is a prepared triarylamine compound.
[Outside 1]

(In the formula, Ar ^{1 to} Ar ³ represent an alkyl group which may have a substituent, or an aryl group which may have a substituent. However, at least one of Ar ^{1 to} Ar ³ is aryl der ^is, at least one of Ar 1 to Ar ³ is Ru der tert- butyl group.)   The electrophotographic photosensitive member according to claim 1, wherein the triarylamine compound is synthesized in the presence of a base.   The electrophotographic photosensitive member according to claim 2, wherein the base is an alkali metal alkoxide.   The electrophotographic photosensitive member according to claim 3, wherein the alkali metal alkoxide is sodium-tert-butoxide.   The electrophotographic photosensitive member according to claim 1, wherein the triarylamine compound is a triphenylamine compound. The electrophotographic photosensitive member according to claim 5, wherein the triphenylamine compound is a compound represented by a formula selected from the group consisting of the following formulas (2), (3), and (4).
[Outside 2]

(In the formula, R ^{1 to} R ¹⁵ represent a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group or a halogen atom. N represents 0 or 1.) The phosphine compound, an electrophotographic photosensitive member according to any one of claims 1 to 6 having at least one substituent which may biphenyl group optionally having. The phosphine compound, an electrophotographic photosensitive member according to any one of claims 1 to 7, which is a di -tert- butyl biphenyl phosphine. The electrophotographic photosensitive member according to any one of claims 1-8, charging means for charging the electrophotographic photosensitive member, a developing means for developing an electrophotographic photosensitive member which is formed of an electrostatic latent image with toner, and transfer Process cartridge characterized in that it is integrally supported with at least one means selected from the group consisting of cleaning means for collecting toner remaining on the electrophotographic photosensitive member after the process, and is detachable from the electrophotographic apparatus main body. . The electrophotographic photosensitive member according to any one of claims 1-8, charging means for charging the electrophotographic photoreceptor, exposing means for forming an electrostatic latent image was exposed to the charged electrophotographic photosensitive member, electrostatic An electrophotographic apparatus comprising: a developing unit that develops toner on an electrophotographic photosensitive member on which a latent image is formed; and a transfer unit that transfers a toner image on the electrophotographic photosensitive member onto a transfer material. In a method for producing an electrophotographic photoreceptor including a charge generation material and a charge transport material,
A step of synthesizing a triarylamine compound using an amine compound and an aryl halide as raw materials using a catalyst comprising a phosphine compound and a palladium compound represented by the following formula (1):
Dissolving the triarylamine compound in a solvent to prepare a photosensitive layer coating solution; and
Applying and drying the coating solution to form a photosensitive layer;
A process for producing an electrophotographic photosensitive member, comprising:
[Outside 3]

(In the formula, Ar ^{1 to} Ar ³ represent an alkyl group which may have a substituent, or an aryl group which may have a substituent. However, at least one of Ar ^{1 to} Ar ³ is aryl der ^is, at least one of Ar 1 to Ar ³ is Ru der tert- butyl group.) The method for producing an electrophotographic photosensitive member according to claim 11 , wherein the step of synthesizing the triarylamine compound is performed in the presence of a base. The method for producing an electrophotographic photosensitive member according to claim 12 , wherein the base is an alkali metal alkoxide. The method for producing an electrophotographic photosensitive member according to claim 13 , wherein the alkali metal alkoxide is sodium-tert-butoxide. The method for producing an electrophotographic photosensitive member according to any one of claims 11 to 14 , wherein the triarylamine compound is a triphenylamine compound. The method for producing an electrophotographic photoreceptor according to claim 15 , wherein the triphenylamine compound is a compound represented by a formula selected from the group consisting of the following formulas (2), (3), and (4).
[Outside 4]

(In the formula, R ^{1 to} R ¹⁵ represent a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group or a halogen atom. N represents 0 or 1.) The method for producing an electrophotographic photoreceptor according to any one of claims 11 to 16 , wherein the phosphine compound has a biphenyl group which may have at least one substituent. The method for producing an electrophotographic photosensitive member according to any one of claims 11 to 17 , wherein the phosphine compound is di-tert-butylbiphenylphosphine.

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