JP3952833B2 - Organic photoconductor, image forming method, image forming apparatus, and process cartridge - Google Patents

Description

【００５６】
【化９】

【００５７】
【化１０】

【００５８】
【化１１】

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【化１２】

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【化１７】

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【化１８】

【００６６】
又、立体異性体構造を有する電荷輸送物質の分子量は５００以上、１５００以下が好ましい。このような高分子量の電荷輸送物質を用いることにより、電荷輸送層の膜質の向上を図ることができ、前記した本発明の効果をより顕著にすることができる。
【００６７】
本発明のガラス転移点の測定方法について記載する
本発明のガラス転移点の測定は、測定試料を約１．０ｍｇをアルミパンに入れ、蓋をして秤量を行う。これを熱流束示差走査熱量計ＤＳＣ−５０（島津製作所社製）にて、２０℃からスタート、３℃／分の昇温温度で２２０℃まで測定を行った。
【００６８】
測定試料としては、電荷輸送層のバインダー樹脂のガラス転移点をＴｇｂはバインダー樹脂そのものを試料として用い、電荷輸送層のガラス転移点Ｔｇｌは感光体から電荷輸送層を剥離した試料を用いて測定する。
【００６９】
次に、本発明の有機感光体の層構成について記載する。
本発明において、有機感光体とは電子写真感光体の構成に必要不可欠な電荷発生機能及び電荷輸送機能の少なくとも一方の機能を有機化合物に持たせて構成された電子写真感光体を意味し、公知の有機電荷発生物質又は有機電荷輸送物質から構成された感光体、電荷発生機能と電荷輸送機能を高分子錯体で構成した感光体等公知の有機電子写真感光体を全て含有する。
【００７０】
本発明の有機感光体は電荷発生物質として、前記Ｂ型チタニルフタロシアニン顔料を用いることを特徴とする。該Ｂ型チタニルフタロシアニン顔料はオキシチタニウムフタロシアニンとも云われ、化学式としては下記構造式で表される。
【００７１】
【化１９】

【００７２】
（式中、Ｘはハロゲン原子を表し、ｎは０〜１の数を示す。前記Ｘが塩素原子の場合ｎは０〜０．５が好ましく、０〜０．１がより好ましい。）
前記ブラッグ角（２θ±０．２°）７．５°、２８．７°に顕著な回折ピークを有するチタニルフタロシアニン顔料（且つ、７．５°又は２８．７°が最大ピークである）の製造方法は特開平１−２３９２４８号、同１−２１７０５０号等に開示されており、これらの開示された製造方法を用いて作製することができ、これらの製造方法で作製したチタニルフタロシアニン顔料は、例えば図１に示したようなブラッグ角（２θ±０．２°）７．５°、２８．７°に顕著な回折ピークを有するＸ線回折スペクトルを示す。図１のチタニルフタロシアニン顔料のＸ線回折スペクトルは上記７．５°に最大回折ピークを有し、他に、ブラッグ角（２θ±０．２°）１０．３°、１２．３°、１６．３°、１８．４°、２２．６°、２４．５°、２５．４°、２８．７°にも明瞭な回折ピークを示している。尚、該チタニルフタロシアニン顔料の分散粒径を小さくしていくと、低角度の７．５°のピークは小さくなり、最大回折ピークが２８．７°になる。
【００７３】
上記の電荷発生物質を含有する有機感光体の層構成は、導電性支持体上に電荷発生層及び電荷輸送層の感光層等から構成される。導電性支持体と電荷発生層の間に中間層を設ける方がより好ましい。又、これらの各層は１層がら構成されてもよいし、２層以上から構成されてもよい。
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導電性支持体
感光体に用いられる導電性支持体としてはシート状、円筒状のどちらを用いても良いが、画像形成装置をコンパクトに設計するためには円筒状導電性支持体の方が好ましい。
【００７５】
円筒状導電性支持体とは回転することによりエンドレスに画像を形成できるに必要な円筒状の支持体を意味し、真直度で０．１ｍｍ以下、振れ０．１ｍｍ以下の範囲にある導電性の支持体が好ましい。この真直度及び振れの範囲を超えると、良好な画像形成が困難になる。
【００７６】
導電性の材料としてはアルミニウム、ニッケルなどの金属ドラム、又はアルミニウム、酸化錫、酸化インジュウムなどを蒸着したプラスチックドラム、又は導電性物質を塗布した紙・プラスチックドラムを使用することができる。導電性支持体としては常温で比抵抗１０³Ωｃｍ以下が好ましい。
【００７７】
本発明で用いられる導電性支持体は、その表面に封孔処理されたアルマイト膜が形成されたものを用いても良い。アルマイト処理は、通常例えばクロム酸、硫酸、シュウ酸、リン酸、硼酸、スルファミン酸等の酸性浴中で行われるが、硫酸中での陽極酸化処理が最も好ましい結果を与える。硫酸中での陽極酸化処理の場合、硫酸濃度は１００〜２００ｇ／Ｌ、アルミニウムイオン濃度は１〜１０ｇ／Ｌ、液温は２０℃前後、印加電圧は約２０Ｖで行うのが好ましいが、これに限定されるものではない。又、陽極酸化被膜の平均膜厚は、通常２０μｍ以下、特に１０μｍ以下が好ましい。
【００７８】
中間層
本発明においては導電性支持体と感光層の間に、バリヤー機能を備えた中間層を設けることもできる。
【００７９】
本発明においては導電性支持体と前記感光層のとの接着性改良、或いは該支持体からの電荷注入を防止するために、該支持体と前記感光層の間に中間層（下引層も含む）を設けることもできる。該中間層の材料としては、ポリアミド樹脂、塩化ビニル樹脂、酢酸ビニル樹脂並びに、これらの樹脂の繰り返し単位のうちの２つ以上を含む共重合体樹脂が挙げられる。これら下引き樹脂の中で繰り返し使用に伴う残留電位増加を小さくできる樹脂としてはポリアミド樹脂が好ましい。又、これら樹脂を用いた中間層の膜厚は０．０１〜０．５μｍが好ましい。
【００８０】
又、本発明に好ましく用いられる中間層はシランカップリング剤、チタンカップリング剤等の有機金属化合物を熱硬化させた硬化性金属樹脂を用いた中間層が挙げられる。硬化性金属樹脂を用いた中間層の膜厚は、０．１〜２μｍが好ましい。
【００８１】
又、本発明に好ましく用いられる中間層は疎水化表面処理をしたＮ型半導性微粒子をバインダー中に分散した中間層が挙げられる。例えばシリカ・アルミナ処理及びシラン化合物で表面処理した平均粒径が０．０１〜１μｍの酸化チタンをポリアミド樹脂中に分散した中間層が挙げられる。このような中間層の膜厚は、１〜２０μｍが好ましい。
【００８２】
Ｎ型半導性微粒子とは、導電性キャリアを電子とする性質をもつ微粒子を示す。すなわち、導電性キャリアを電子とする性質とは、該Ｎ型半導性微粒子を絶縁性バインダーに含有させることにより、基体からのホール注入を効率的にブロックし、また、感光層からの電子に対してはブロッキング性を示さない性質を有するものをいう。
【００８３】
前記Ｎ型半導性微粒子は、具体的には酸化チタン（ＴｉＯ₂）、酸化亜鉛（ＺｎＯ）、酸化スズ（ＳｎＯ₂）等の微粒子が挙げられるが、本発明では、特に酸化チタンが好ましく用いられる。
【００８４】
本発明に用いられるＮ型半導性微粒子の平均粒径は、数平均一次粒径において１０ｎｍ以上５００ｎｍ以下の範囲のものが好ましく、より好ましくは１０ｎｍ〜２００ｎｍ、特に好ましくは、１５ｎｍ〜５０ｎｍである。
【００８５】
数平均一次粒径の値が前記範囲内にあるＮ型半導性微粒子を用いた中間層は層内での分散を緻密なものとすることができ、十分な電位安定性、及び黒ポチ発生防止機能を有する。
【００８６】
前記Ｎ型半導性微粒子の数平均一次粒径は、例えば酸化チタンの場合、透過型電子顕微鏡観察によって１００００倍に拡大し、ランダムに１００個の粒子を一次粒子として観察し、画像解析によりフェレ径の数平均径として測定される。
【００８７】
本発明に用いられるＮ型半導性微粒子の形状は、樹枝状、針状および粒状等の形状があり、このような形状のＮ型半導性微粒子は、例えば酸化チタン粒子では、結晶型としては、アナターゼ型、ルチル型及びアモルファス型等があるが、いずれの結晶型のものを用いてもよく、また２種以上の結晶型を混合して用いてもよい。その中でもルチル型のものが最も良い。
【００８８】
本発明のＮ型半導性微粒子に行われる疎水化表面処理の１つは、複数回の表面処理を行い、かつ該複数回の表面処理の中で、最後の表面処理が反応性有機ケイ素化合物による表面処理を行うものである。また、該複数回の表面処理の中で、少なくとも１回の表面処理がアルミナ、シリカ、及びジルコニアから選ばれる少なくとも１種類以上の表面処理であり、最後に反応性有機ケイ素化合物の表面処理を行うことが好ましい。
【００８９】
尚、アルミナ処理、シリカ処理、ジルコニア処理とはＮ型半導性微粒子表面にアルミナ、シリカ、或いはジルコニアを析出させる処理を云い、これらの表面に析出したアルミナ、シリカ、ジルコニアにはアルミナ、シリカ、ジルコニアの水和物も含まれる。又、反応性有機ケイ素化合物の表面処理とは、処理液に反応性有機ケイ素化合物を用いることを意味する。
【００９０】
この様に、酸化チタン粒子の様なＮ型半導性微粒子の表面処理を少なくとも２回以上行うことにより、Ｎ型半導性微粒子表面が均一に表面被覆（処理）され、該表面処理されたＮ型半導性微粒子を中間層に用いると、中間層内における酸化チタン粒子等のＮ型半導性微粒子の分散性が良好となり、電子写真特性、特に繰り返し使用時の残留電位の安定性、更に黒ポチ、環境メモリ等の改善効果を増大させることができる。
【００９１】
電荷発生層
電荷発生層には前記したＢ型チタニルフタロシアニン顔料を電荷発生物質（ＣＧＭ）として含有する。このＢ型チタニルフタロシアニン顔料以外にも、必要により他の電荷発生物質を用いてもよい。例えば他のフタロシアニン顔料、アゾ顔料、ペリレン顔料、アズレニウム顔料などを併用いることができが、本発明の効果を十分に確保するためには、Ｂ型チタニルフタロシアニン顔料を電荷発生物質全体の５０質量％以上とすることが好ましい。
【００９２】
その他の物質としては必要によりバインダー樹脂、その他添加剤を含有しても良い。電荷発生層にＣＧＭの分散媒としてバインダーを用いる場合、バインダーとしては公知の樹脂を用いることができるが、最も好ましい樹脂としてはホルマール樹脂、ブチラール樹脂、シリコーン樹脂、シリコーン変性ブチラール樹脂、フェノキシ樹脂等が挙げられる。バインダー樹脂と電荷発生物質との割合は、バインダー樹脂１００質量部に対し２０〜６００質量部が好ましい。これらの樹脂を用いることにより、繰り返し使用に伴う残留電位増加を最も小さくできる。電荷発生層の膜厚は０．０１μｍ〜２μｍが好ましい。
【００９３】
電荷輸送層
電荷輸送層には電荷輸送物質（ＣＴＭ）として立体異性体混合物を用い、且つＣＴＭを分散し製膜するバインダー樹脂を含有する。その他の物質としては必要により酸化防止剤等の添加剤を含有しても良い。
【００９４】
電荷輸送物質（ＣＴＭ）としては前記した立体異性体混合物の電荷輸送物質の他に公知の電荷輸送物質を併用して用いることもできる。例えばトリフェニルアミン誘導体、ヒドラゾン化合物、スチリル化合物、ベンジジン化合物、ブタジエン化合物などを併用して、用いることができる。これら電荷輸送物質は通常、適当なバインダー樹脂中に溶解して層形成が行われる。
【００９５】
電荷輸送層（ＣＴＬ）に用いられる樹脂としては、例えばポリスチレン、アクリル樹脂、メタクリル樹脂、塩化ビニル樹脂、酢酸ビニル樹脂、ポリビニルブチラール樹脂、エポキシ樹脂、ポリウレタン樹脂、フェノール樹脂、ポリエステル樹脂、アルキッド樹脂、ポリカーボネート樹脂、シリコーン樹脂、メラミン樹脂並びに、これらの樹脂の繰り返し単位のうちの２つ以上を含む共重合体樹脂、又これらの絶縁性樹脂の他、ポリ−Ｎ−ビニルカルバゾール等の高分子有機半導体が挙げられる。
【００９６】
これらＣＴＬのバインダーとして最も好ましいものはポリカーボネート樹脂である。ポリカーボネート樹脂はＣＴＭの分散性、電子写真特性を良好にすることにおいて、最も好ましい。又電荷輸送層が表面層となる感光体の場合は、機械的摩耗に強いポリカーボネートが好ましく、このようなポリカーボネートとしては平均分子量が２，０００，０００〜２５，０００のポリカーボネートが好ましい。ここで平均分子量は数平均分子量、重量平均分子量、及び粘度平均分子量のいずれのものでもよい。バインダー樹脂と電荷輸送物質との割合は、バインダー樹脂１００質量部に対し１０〜２００質量部が好ましい。又、電荷輸送層の膜厚は１０〜４０μｍが好ましい。
【００９７】
又、電荷輸送層には酸化防止剤を含有させることが好ましい。該酸化防止剤とは、その代表的なものは有機感光体中ないしは有機感光体表面に存在する自動酸化性物質に対して、光、熱、放電等の条件下で酸素の作用を防止ないし、抑制する性質を有する物質である。代表的には下記の化合物群が挙げられる。
【００９８】
【化２０】

【００９９】
【化２１】

【０１００】
【化２２】

【０１０１】
【化２３】

【０１０２】
電荷輸送層は２層以上の層構成にしてもよい。この場合は表面の電荷輸送層に保護層として機能を付加し、クリーニングブレード等との耐摩耗特性を強化した層構成が好ましい。
【０１０３】
中間層、感光層、保護層等の層形成に用いられる溶媒又は分散媒としては、ｎ−ブチルアミン、ジエチルアミン、エチレンジアミン、イソプロパノールアミン、トリエタノールアミン、トリエチレンジアミン、Ｎ，Ｎ−ジメチルホルムアミド、アセトン、メチルエチルケトン、メチルイソプロピルケトン、シクロヘキサノン、ベンゼン、トルエン、キシレン、クロロホルム、ジクロロメタン、１，２−ジクロロエタン、１，２−ジクロロプロパン、１，１，２−トリクロロエタン、１，１，１−トリクロロエタン、トリクロロエチレン、テトラクロロエタン、テトラヒドロフラン、ジオキソラン、ジオキサン、メタノール、エタノール、ブタノール、イソプロパノール、酢酸エチル、酢酸ブチル、ジメチルスルホキシド、メチルセロソルブ等が挙げられる。本発明はこれらに限定されるものではないが、ジクロロメタン、１，２−ジクロロエタン、メチルエチルケトン等が好ましく用いられる。また、これらの溶媒は単独或いは２種以上の混合溶媒として用いることもできる。
【０１０４】
本発明の電子写真感光体を製造するための塗布加工方法としては、浸漬塗布、スプレー塗布、円形量規制型塗布等の塗布加工法が用いられるが、感光層の上層側の塗布加工は下層の膜を極力溶解させないため、又、均一塗布加工を達成するためスプレー塗布又は円形量規制型（円形スライドホッパ型がその代表例）塗布等の塗布加工方法を用いるのが好ましい。なお前記スプレー塗布については例えば特開平３−９０２５０号及び特開平３−２６９２３８号公報に詳細に記載され、前記円形量規制型塗布については例えば特開昭５８−１８９０６１号公報に詳細に記載されている。
【０１０５】
次に、本発明の画像形成装置について説明する。
図３は本発明の画像形成方法の１例としての画像形成装置の断面構成図である。
【０１０６】
図３に於いて５０は像担持体である感光体ドラム（感光体）で、有機感光層をドラム上に塗布し、その上に本発明の樹脂層を塗設した感光体で、接地されて時計方向に駆動回転される。５２はスコロトロンの帯電器（帯電手段）で、感光体ドラム５０周面に対し一様な帯電をコロナ放電によって与えられる。この帯電器５２による帯電に先だって、前画像形成での感光体の履歴をなくすために発光ダイオード等を用いた帯電前露光部５１による露光を行って感光体周面の除電をしてもよい。
【０１０７】
感光体への一様帯電の後、像露光手段としての像露光器５３により画像信号に基づいた像露光が行われる。この図の像露光器５３は図示しないレーザダイオードを露光光源とする。回転するポリゴンミラー５３１、ｆθレンズ等を経て反射ミラー５３２により光路を曲げられた光により感光体ドラム上の走査がなされ、静電潜像が形成される。
【０１０８】
ここで本発明の反転現像プロセスとは帯電器５２により、感光体表面を一様に帯電し、像露光が行われた領域、即ち感光体の露光部電位（露光部領域）を現像工程（手段）により、顕像化する画像形成方法である。一方未露光部電位は現像スリーブ５４１に印加される現像バイアス電位により現像されない。
【０１０９】
その静電潜像は次いで現像手段としての現像器５４で現像される。感光体ドラム５０周縁にはトナーとキャリアとから成る現像剤を内蔵した現像器５４が設けられていて、マグネットを内蔵し現像剤を保持して回転する現像スリーブ５４１によって現像が行われる。現像器５４内部は現像剤攪拌搬送部材５４４、５４３、搬送量規制部材５４２等から構成されており、現像剤は攪拌、搬送されて現像スリーブに供給されるが、その供給量は該搬送量規制部材５４２により制御される。該現像剤の搬送量は適用される有機電子写真感光体の線速及び現像剤比重によっても異なるが、一般的には２０〜２００ｍｇ／ｃｍ²の範囲である。
【０１１０】
現像剤は、例えば前述のフェライトをコアとしてそのまわりに絶縁性樹脂をコーティングしたキャリアと、前述のスチレンアクリル系樹脂を主材料としてカーボンブラック等の着色剤と荷電制御剤と低分子量ポリオレフィンからなる着色粒子に、シリカ、酸化チタン等を外添したトナーとからなるもので、現像剤は搬送量規制部材によって層厚を規制されて現像域へと搬送され、現像が行われる。この時通常は感光体ドラム５０と現像スリーブ５４１の間に直流バイアス、必要に応じて交流バイアス電圧をかけて現像が行われる。また、現像剤は感光体に対して接触あるいは非接触の状態で現像される。感光体の電位測定は電位センサー５４７を図３のように現像位置上部に設けて行う。
【０１１１】
記録紙Ｐは画像形成後、転写のタイミングの整った時点で給紙ローラー５７の回転作動により転写域へと給紙される。
【０１１２】
転写域においては転写のタイミングに同期して感光体ドラム５０の周面に転写電極（転写手段：転写器）５８が作動し、給紙された記録紙Ｐにトナーと反対極性の帯電を与えてトナーを転写する。
【０１１３】
次いで記録紙Ｐは分離電極（分離器）５９によって除電がなされ、感光体ドラム５０の周面により分離して定着装置６０に搬送され、熱ローラー６０１と圧着ローラー６０２の加熱、加圧によってトナーを溶着したのち排紙ローラー６１を介して装置外部に排出される。なお前記の転写電極５８及び分離電極５９は記録紙Ｐの通過後、一次作動を中止し、次なるトナー像の形成に備える。図３では転写電極５８にコロトロンの転写帯電極を用いている。転写電極の設定条件としては、感光体のプロセススピード（周速）等により異なり一概に規定することはできないが、例えば、転写電流としては＋１００〜＋４００μＡ、転写電圧としては＋５００〜＋２０００Ｖを設定値とすることができる。
【０１１４】
一方記録紙Ｐを分離した後の感光体ドラム５０は、クリーニング器（クリーニング手段）６２のブレード６２１の圧接により残留トナーを除去・清掃し、再び帯電前露光部５１による除電と帯電器５２による帯電を受けて次なる画像形成のプロセスに入る。
【０１１５】
尚、７０は感光体、帯電器、転写器、分離器及びクリーニング器が一体化されている着脱可能なプロセスカートリッジである。
【０１１６】
本発明の有機電子写真感光体は電子写真複写機、レーザプリンター、ＬＥＤプリンター及び液晶シャッター式プリンター等の電子写真装置一般に適応するが、更に、電子写真技術を応用したディスプレー、記録、軽印刷、製版及びファクシミリ等の装置にも幅広く適用することができる。
【０１１７】
【実施例】
以下、実施例をあげて本発明を詳細に説明するが、本発明の様態はこれに限定されない。文中の「部」は質量部を表す。
【０１１８】
実施例１（参考例）
合成例１（例示化合物Ｔ２０の合成例）
【０１１９】
【化２４】

【０１２０】
上記式で表される化合物１０ｇをオキシ塩化リン３２ｇに溶解させ、５０℃まで加熱しジメチルホルムアミド２２ｍｌを少しずつ滴下した（発熱し４０〜７０℃になる）。反応液を９０℃前後にコントロールしながら、１５時間撹拌した。４０℃まで放冷した後、余分なオキシ塩化リンを十分に加水分解し析出した結晶をろ別し、水で懸濁して洗浄し、洗液が中性になるまで洗浄を繰り返し下記構造式で表されるビスホルミル化合物９．２５ｇ（７７％）を得た。
【０１２１】
【化２５】

【０１２２】
上記得られたビスホルミル化合物２ｇと、下記構造式で表されるホスホネート化合物４．３ｇをジメチルホルムアミド２０ｍｌに溶解した。反応液を２０℃前後に保ちながら、ナトリウムメトキシド１．０ｇを少しずつ添加した（発熱有り）。４時間撹拌後、水３０ｍｌを加え常法により精製処理を行って黄色結晶３．３ｇ（８１％）を得た。この黄色結晶を、元素分析及び質量分析を行ったところ、下記表１のような結果となり例示化合物Ｔ２０であることが確認された。
【０１２３】
【化２６】

【０１２４】
元素分析（Ｃ₅₃Ｈ₄₉Ｎ）
【０１２５】
【表１】

【０１２６】
質量分析（Ｃ₅₃Ｈ₄₉Ｎ）
Ｍｗ（計算値）＝６９９
Ｍｗ⁺（実測値）＝６９９
上記の合成で得られたＴ２０の化合物をＴ２０−１とする。このＴ２０−１は下記液体クロマトグラフィ（ＨＰＣＬ）の測定結果ｃｉｓ−ｃｉｓ／ｃｉｓ−ｔｒａｎｓ／ｔｒａｎｓ−ｔｒａｎｓ混合比が１．１／２．２／１．０であった。尚、Ｔ２０ｃｉｓ−ｃｉｓ、Ｔ２０ｔｒａｎｓ−ｔｒａｎｓ、Ｔ２０ｃｉｓ−ｔｒａｎｓの構造式を下記に示す。
【０１２７】
液体クロマトグラフィの測定条件
測定機：島津ＬＣ６Ａ（島津製作所製）
カラム：ＣＬＣ−ＳＩＬ（島津製作所製）
検出波長：２９０ｎｍ
移動相：ｎ−ヘキサン／ジオキサン＝１０〜５００／１
移動相の流速：約１ｍｌ／ｍｉｎ
サンプル（Ｔ２０）溶媒：ｎ−ヘキサン／ジオキサン＝１０／１
サンプル（Ｔ２０）：３ｍｇ／溶媒１０ｍｌ
【０１２８】
【化２７】

【０１２９】
上記で得られたＴ２０−１を液体クロマトグラフィを用いてｃｉｓ−ｃｉｓ体、ｃｉｓ−ｔｒａｎｓ体、ｔｒａｎｓ−ｔｒａｎｓ体に分離した化合物も得た。これらｃｉｓ−ｃｉｓ体のＴ２０をＴ２０ｃ−ｃ、ｃｉｓ−ｔｒａｎｓ体のＴ２０をＴ２０ｃ−ｔ、ｔｒａｎｓ−ｔｒａｎｓ体のＴ２０をＴ２０ｔ−ｔとする。Ｔ２０−１とＴ２０ｃ−ｃ、Ｔ２０ｃ−ｔ、Ｔ２０ｔ−ｔの４つの化合物を用い、混合比を変えて、表２に示す如くｃｉｓ−ｃｉｓ／ｃｉｓ−ｔｒａｎｓ／ｔｒａｎｓ−ｔｒａｎｓの混合比を持つＴ２０−２〜Ｔ２０−６の化合物を作製した。
【０１３０】

酸化チタン、ポリアミド樹脂、メタノールを同一容器中に加え超音波ホモジナイザーを用いて分散し、中間層用の塗布液を調製した。この塗布液を円筒状アルミニウム基体上に浸漬塗布し、１１０℃、１時間の加熱硬化を行い、４μｍの乾燥膜厚で中間層を設けた。
【０１３１】

を混合し、サンドミルを用いて１０時間分散し、電荷発生層塗布液を調製した。この塗布液を前記中間層の上に浸漬塗布法で塗布し、乾燥膜厚０．２μｍの電荷発生層を形成した。
【０１３２】
〈電荷輸送層〉
電荷輸送物質（Ｔ２０−１） ２２５部
ポリカーボネート（粘度平均分子量：２０，０００） ３００部
酸化防止剤（例示化合物１−３） ６部
ジクロロメタン ２０００部
を混合し、溶解して電荷輸送層塗布液を調製した。この塗布液を前記電荷発生層の上に浸漬塗布法で塗布し、乾燥膜厚２４μｍの電荷輸送層を形成し、感光体１を作製した。
【０１３３】
感光体２〜９の作製
感光体１で用いた電荷輸送物質（Ｔ２０−１）をＴ２０−２〜Ｔ２０−６、Ｔ２０ｃ−ｃ、Ｔ２０ｃ−ｔ、Ｔ２０ｔ−ｔに代え、異性体混合比を表２のように変えた以外は感光体１と同様にして感光体２〜９を作製した。
【０１３４】
感光体１０の作製
感光体１で用いた電荷輸送物質（Ｔ２０−１）を下記化学構造の電荷輸送物質Ｔ１０１に代えた以外は同様にして感光体１０を作製した。
【０１３５】
【化２８】

【０１３６】
感光体１１の作製
感光体１で用いた電荷発生層のＢ型チタニルフタロシアニン顔料をＹ型チタニルフタロシアニン顔料（Ｃｕ−Ｋα特性Ｘ線によるＸ線回折スペクトルにてブラッグ角２θで、２７．２±０．２°に最大ピークを有するチタニルフタロシアニン顔料：図２）に代えた以外は感光体１と同様にして感光体１１を作製した。
【０１３７】
【表２】

【０１３８】
評価
評価機としてコニカ社製デジタル複写機Ｋｏｎｉｃａ７０７５（コロナ帯電、レーザ露光、反転現像、静電転写、爪分離、ブレードクリーニング、クリーニング補助ブラシローラー採用プロセスを有する）を用い、該複写機に感光体１〜１１を搭載し評価した。クリーニング性及び画像評価は、画素率が７％の文字画像、人物顔写真、ベタ白画像、ベタ黒画像がそれぞれ１／４等分にあるオリジナル画像をＡ４中性紙にコピーして行った。環境条件は厳しい条件の高温高湿環境：ＨＨ環境（３０℃、８０％ＲＨ）と低温低湿環境：ＬＬ環境（１０℃、２０％ＲＨ）の両方で、それぞれ連続１万枚コピー、計２万枚のコピーを行いハーフトーン、ベタ白画像、ベタ黒画像を作製し下記の評価を行った。
【０１３９】
評価基準
画像濃度（マクベス社製ＲＤ−９１８を使用して測定。紙の反射濃度を「０」とした相対反射濃度で測定した。初期及び各１万枚コピー後の画像で評価した。）
◎：黒ベタ画像が１．２以上
○：黒ベタ画像が１．２未満〜１．０
×：黒ベタ画像が１．０未満
カブリ（初期及び各１万枚コピー後のベタ白画像を目視で判定）
◎：両方の環境条件下のコピーを通してカブリの発生なし
○：どちらか一方の環境下で濃度０．０１〜０．０２のカブリが発生
×：どちらか一方の環境下で濃度０．０３以上のカブリが発生
画像欠陥評価
環境メモリ：上記高温高湿環境（３０℃、８０％ＲＨ）で１万枚コピー後、上記Ｋｏｎｉｃａ ７０７５複写機を同条件下に２４ｈｒ放置し、その後低湿低温下（ＬＬ：１０℃、２０％ＲＨ）に置き、３０分後、コピーした。オリジナル画像で０．４の濃度のハーフトーン画像を０．４の濃度にコピー、コピー画像の濃度差（ΔＨＤ＝最大濃度−最小濃度）で判定
Ａ：ΔＨＤが０．０５以下（良好）
Ｂ：ΔＨＤが０．０５より大で０．１未満（実用上問題なし）
Ｃ：ΔＨＤが０．１以上（実用上問題あり）
黒ポチ（上記各１万枚コピー後、更にベタ白のコピー画像１００枚を作製して評価）
黒ポチについては、周期性が感光体の周期と一致し、目視できる黒ポチが、Ａ４サイズ当たり何個あるかで判定した。
【０１４０】
Ａ：０．４ｍｍ以上の黒ポチ頻度：全ての複写画像が３個／Ａ４以下（良好）Ｂ：０．４ｍｍ以上の黒ポチ頻度：４個／Ａ４以上、１０個／Ａ４以下が１枚以上発生（実用上問題なし）
Ｃ：０．４ｍｍ以上の黒ポチ頻度：１１個／Ａ４以上が１枚以上発生（実用上問題有り）
白抜け（上記各１万枚コピー後、更にハーフトーン画像１００枚を作製して評価）
白抜けの評価は、周期性が感光体の周期と一致し、目視できる白抜けが、Ａ４サイズ当たり何個あるかで判定した。
【０１４１】
Ａ：０．４ｍｍ以上の白抜け頻度：全ての複写画像が３個／Ａ４以下
Ｂ：０．４ｍｍ以上の白抜け頻度：４個／Ａ４以上、１９個／Ａ４以下
が１枚以上発生
Ｃ：０．４ｍｍ以上の白抜け頻度：２０個／Ａ４以上が１枚以上発生
解像度（文字画像の判別容易性で判定）
上記各１万枚のコピー後に、３ポイント、５ポイントの文字画像を形成し、下記の判断基準で評価した。
【０１４２】
◎：３ポイント、５ポイントとも明瞭であり、容易に判読可能
○：３ポイントは一部判読不能、５ポイントは明瞭であり、容易に判読可能
×：３ポイントは殆ど判読不能、５ポイントも一部あるいは全部が判読不能
その他評価条件
尚、上記デジタル複写機Ｋｏｎｉｃａ７０７５を用いたその他の評価条件は下記の条件に設定した。
【０１４３】
帯電条件
帯電器；スコロトロン帯電器、初期帯電電位を−７５０Ｖ
露光条件
露光部電位を−５０Ｖにする露光量に設定。
【０１４４】
現像条件
ＤＣバイアス；−５５０Ｖ
現像剤は、フェライトをコアとして絶縁性樹脂をコーティングしたキャリアとスチレンアクリル系樹脂を主材料としてカーボンブラック等の着色剤と荷電制御剤と本発明の低分子量ポリオレフィンからなる着色粒子に、シリカ、酸化チタン等を外添したトナーの現像剤を使用。
【０１４５】
転写条件
転写極；コロナ帯電方式
クリーニング条件
クリーニング部に硬度７０°、反発弾性３４％、厚さ２（ｍｍ）、自由長９ｍｍのクリーニングブレードをカウンター方向に線圧２０（Ｎ／ｍ）となるように重り荷重方式で当接した。
【０１４６】
評価結果を表３に示した。
【０１４７】
【表３】

【０１４９】
実施例２（参考例）
合成例２（例示化合物Ｔ５０の合成例）
【０１５０】
【化２９】

【０１５１】
上記式で表される化合物１０ｇをオキシ塩化リン３４ｇに溶解させ、５０℃まで加熱しジメチルホルムアミド２３ｍｌを少しずつ滴下した（発熱し４０〜７０℃になる）。反応液を９０℃前後にコントロールしながら、１５時間撹拌した。４０℃まで放冷した後、余分なオキシ塩化リンを十分に加水分解し析出した結晶をろ別し、水で懸濁して洗浄し、洗液が中性になるまで洗浄を繰り返し下記構造式で表されるビスホルミル化合物９．４３ｇ（７８％）を得た。
【０１５２】
【化３０】

【０１５３】
上記得られたビスホルミル化合物２ｇと、下記構造式で表されるホスホネート化合物４．３ｇをジメチルホルムアミド２０ｍｌに溶解した。反応液を２０℃前後に保ちながら、ナトリウムメトキシド１．０ｇを少しずつ添加した（発熱有り）。４時間撹拌後、水３０ｍｌを加え常法により精製処理を行って黄色結晶３．３ｇ（８１％）を得た。この黄色結晶を、元素分析及び質量分析を行ったところ、下記表４のような結果となり例示化合物Ｔ５０であることが確認された。
【０１５４】
【化３１】

【０１５５】
元素分析（Ｃ₄₀Ｈ₃₉Ｎ）
【０１５６】
【表４】

【０１５７】
質量分析（Ｃ₄₀Ｈ₃₉Ｎ）
Ｍｗ（計算値）＝５３３
Ｍｗ⁺（実測値）＝５３３
上記の合成で得られたＴ５０の化合物をＴ５０−１とする。このＴ５０−１は前記液体クロマトグラフィ（ＨＰＣＬ）の測定結果ｃｉｓ−ｃｉｓ／ｃｉｓ−ｔｒａｎｓ／ｔｒａｎｓ−ｔｒａｎｓ混合比が１．２／２．０／１．０であった。尚、Ｔ５０ｃｉｓ−ｃｉｓ、Ｔ５０ｔｒａｎｓ−ｔｒａｎｓ、Ｔ５０ｃｉｓ−ｔｒａｎｓの構造式を下記に示す。
【０１５８】
【化３２】

【０１５９】
上記で得られたＴ５０−１を液体クロマトグラフィを用いてｃｉｓ−ｃｉｓ体、ｃｉｓ−ｔｒａｎｓ体、ｔｒａｎｓ−ｔｒａｎｓ体に分離した化合物も得た。これらｃｉｓ−ｃｉｓ体のＴ５０をＴ５０ｃ−ｃ、ｃｉｓ−ｔｒａｎｓ体のＴ５０をＴ５０ｃ−ｔ、ｔｒａｎｓ−ｔｒａｎｓ体のＴ５０をＴ５０ｔ−ｔとする。Ｔ５０−１とＴ５０ｃ−ｃ、Ｔ５０ｃ−ｔ、Ｔ５０ｔ−ｔの４つの化合物を用い、混合比を変えて、表５に示す如くｃｉｓ−ｃｉｓ／ｃｉｓ−ｔｒａｎｓ／ｔｒａｎｓ−ｔｒａｎｓの混合比を持つＴ５０−２〜５０−６の化合物を作製した。
【０１６０】
感光体１２〜２０の作製
感光体１で用いた電荷輸送物質（Ｔ２０−１）をＴ５０−１〜Ｔ５０−６、Ｔ５０ｃ−ｃ、Ｔ５０ｃ−ｔ、Ｔ５０ｔ−ｔに代え、異性体混合比を表５のように変えた以外は感光体１と同様にして感光体１２〜２０を作製した。
【０１６１】
感光体２１の作製
感光体１で用いた電荷発生層のＢ型チタニルフタロシアニン顔料をＹ型チタニルフタロシアニン顔料（Ｃｕ−Ｋα特性Ｘ線によるＸ線回折スペクトルにてブラッグ角２θで、２７．２±０．２°に最大ピークを有するチタニルフタロシアニン顔料）に、電荷輸送物質（Ｔ２０−１）をＴ５０−１代えた以外は感光体１と同様にして感光体２１を作製した。
【０１６２】
【表５】

【０１６３】
上記感光体１２〜２１を用いて、実施例１と同様の評価を行った。結果を表６に示す。
【０１６４】
【表６】

【０１６６】
実施例３（請求項１に対応した実施例）
感光体２２の作製
〈中間層〉
酸化チタンＳＭＴ５００ＳＡＳ（１回目：シリカ・アルミナ処理、２回目：
メチルハイドロジェンポリシロキサン処理：テイカ社製） ３００ｇ
ポリアミド樹脂 ＣＭ８０００（東レ社製） １００ｇ
メタノール １０００ｇ
酸化チタン、ポリアミド樹脂、メタノールを同一容器中に加え超音波ホモジナイザーを用いて分散し、中間層用の塗布液を調製した。この塗布液を円筒状アルミニウム基体上に浸漬塗布し、１１０℃、１時間の加熱硬化を行い、４μｍの乾燥膜厚で中間層を設けた。
【０１６７】

を混合し、サンドミルを用いて１０時間分散し、電荷発生層塗布液を調製した。この塗布液を前記中間層の上に浸漬塗布法で塗布し、乾燥膜厚０．２μｍの電荷発生層を形成した。
【０１６８】

を混合し、溶解して電荷輸送層塗布液を調製した。この塗布液を前記電荷発生層の上に浸漬塗布法で塗布し、その後１００℃、６０分間の乾燥を行い、残留溶媒量を０．１質量％以下にし、乾燥膜厚２４μｍの電荷輸送層を形成して感光体２２を作製した。尚、感光体２２の電荷輸送層の固形分は電荷輸送物質、ポリカーボネートＺ、及び酸化防止剤の合計量：５３６ｇであり、電荷輸送物質２３０ｇのモル数は０．３２９ｍｏｌであるので、単位質量当たりの電荷輸送物質のモル数は６．１×１０^-4ｍｏｌ／ｇである。
【０１６９】
【化３３】

【０１７０】
感光体２３〜２７の作製
感光体２２で用いた電荷輸送物質（Ｔ２０−１）の量を表７のように変えた以外は感光体２２と同様にして感光体２３〜２７を作製した。
【０１７１】
感光体２８の作製
感光体２２で用いた電荷発生層のＢ型チタニルフタロシアニン顔料をＹ型チタニルフタロシアニン顔料（Ｃｕ−Ｋα特性Ｘ線によるＸ線回折スペクトルにてブラッグ角２θで、２７．２±０．２°に最大ピークを有するチタニルフタロシアニン顔料）に代えた以外は感光体２２と同様にして感光体２８を作製した。
【０１７２】
【表７】

【０１７３】
評価
評価は実施例１と同じ方法で行った。
【０１７４】
評価結果を表８に示した。
【０１７５】
【表８】

【０１７６】
表８から明らかなように電荷輸送層に立体異性体混合物の最大異性体成分の含有率が４０〜９０質量％の範囲にある電荷輸送物質を含有し、電荷輸送層のＴｇｌが１００℃より高い１２２〜１６１℃の感光体２４〜２７は、環境メモリ、黒ポチ及び白抜け等の画像欠陥の発生も少なく、感光体２７（電荷輸送物質の濃度が低く、画像濃度が低下している）を除いて、画像濃度、カブリ、解像度等の画像特性が良好であり、全ての特性がバランスを持って改善されている。一方、電荷輸送層のＴｇｌが７５℃、８９℃の本発明外の感光体２２及び２３では白抜け発生が増加し、解像力も低下している。又、Ｙ型チタニルフタロシアニン顔料を電荷発生物質として用いた感光体２８は環境メモリ、解像度の劣化が著しい。
【０１７７】
実施例４（請求項１に対応した実施例）
感光体２９〜４１の作製
感光体２２で用いた電荷輸送物質の種類とその量を表９のように変えた以外は感光体２２と同様にして感光体２９〜４１を作製した。
【０１７８】
感光体４２の作製
感光体２２で用いた電荷発生層のＢ型チタニルフタロシアニン顔料をＹ型チタニルフタロシアニン顔料（Ｃｕ−Ｋα特性Ｘ線によるＸ線回折スペクトルにてブラッグ角２θで、２７．２±０．２°に最大ピークを有するチタニルフタロシアニン顔料）に代え、電荷輸送物質の種類とその量を表９のようにした以外は感光体２２と同様にして感光体４２を作製した。
【０１７９】
【表９】

【０１８０】
上記感光体２９〜４２を用いて、実施例１と同様の評価を行った。結果を表１０に示す。
【０１８１】
【表１０】

【０１８２】
表１０から明らかなように、電荷輸送層に立体異性体混合物のの最大異性体成分の含有率が４０〜９０質量％の範囲にある電荷輸送物質を含有し、電荷輸送層のＴｇｌが１００℃より高い感光体２９〜３３は、画像濃度、カブリ、解像度等の画像特性が良好であり、環境メモリ、黒ポチ及び白抜け等の画像欠陥の発生も少なく全ての特性がバランスを持って改善されている。一方、電荷輸送層のＴｇｌは１１５℃、１１３℃、１１７℃と１００℃より高くても、電荷輸送物質が立体異性体混合物ではない感光体３４、３５、３６は画像濃度の低下が大きく、解像度が劣化している。又、電荷輸送物質が立体異性体混合物であっても、電荷輸送層のＴｇｌが１００℃より低い感光体３７〜４１も白抜け発生が増加し、解像度が劣化している。又、Ｙ型チタニルフタロシアニン顔料を電荷発生物質として用いた感光体４２は環境メモリ、解像度の劣化が著しい。
【０１８３】
【発明の効果】
実施例からも明らかなように、本発明の構成を有する有機感光体を用いることにより、環境メモリ、白抜けや黒ポチが発生せず、鮮鋭な電子写真画像を得ることができる。又該有機感光体を用いた良好な電子写真画像を達成できる画像形成方法、画像形成装置及びプロセスカートリッジを提供する事が出来る。
【図面の簡単な説明】
【図１】７．５°、２８．７°に顕著な回折ピークを有するチタニルフタロシアニン顔料のＸ線回折スペクトルを示す。
【図２】２７．２±０．２°に最大ピークを有するチタニルフタロシアニン顔料のＸ線回折スペクトルを示す。
【図３】本発明の画像形成方法の１例としての画像形成装置の断面構成図である。
【符号の説明】
５０ 感光体ドラム（感光体）
５１ 帯電前露光部
５２ 帯電器
５３ 像露光器
５４ 現像器
５４１ 現像スリーブ
５４３，５４４ 現像剤攪拌搬送部材
５４７ 電位センサー
５７ 給紙ローラー
５８ 転写電極
５９ 分離電極（分離器）
６０ 定着装置
６１ 排紙ローラー
６２ クリーニング器
７０ プロセスカートリッジ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an organic photoreceptor used in the field of copying machines and printers, and an image forming method, an image forming apparatus, and a process cartridge using the organic photoreceptor.
[0002]
[Prior art]
Electrophotographic photoconductors have moved from inorganic photoconductors such as Se, arsenic, arsenic / Se alloys, CdS, ZnO, etc. to organic photoconductors that are superior in terms of pollution and ease of manufacturing, and various materials have been used. Organic photoreceptors have been developed.
[0003]
In recent years, function-separated type photoconductors in which charge generation and charge transport functions are assigned to different materials have become the mainstream, and in particular, stacked organic photoconductors with a charge generation layer and a charge transport layer are widely used. It has been.
[0004]
Turning to the electrophotographic process, latent image forming methods are roughly classified into analog image forming using a halogen lamp as a light source and digital image forming using an LED or laser as a light source. Recently, as a hard copy printer for a personal computer, and in an ordinary copying machine, a digital latent image forming method has been rapidly becoming mainstream because of the ease of image processing and the development of a multifunction device.
[0005]
In digital image formation, a laser, particularly a semiconductor laser or an LED, is used as a light source for writing image information converted into a digital electrical signal as an electrostatic latent image on a photoconductor.
[0006]
The oscillation wavelength of these laser light and LED light is 780 nm or 660 nm near infrared light or long wavelength light close thereto. For organic photoreceptors used for digital image formation, the first required characteristic is high sensitivity to these long-wavelength light. It has been studied whether or not it has such characteristics. Among them, phthalocyanine pigments are relatively easy to synthesize and many exhibit high sensitivity to long-wavelength light, and organic photoreceptors using phthalocyanine pigments have been widely studied and put into practical use. .
[0007]
Among these, titanyl phthalocyanine pigments (hereinafter simply referred to as Y-type titanyl phthalocyanine pigments or Y-types) having a maximum peak at a Bragg angle 2θ of 27.2 ± 0.2 ° in a powder X-ray diffraction spectrum are highly sensitive materials. It is also known as an academic society report (Oda et al., Electrophotographic Society Journal, 29 (3), 250 (1990), etc.).
[0008]
When this Y-type titanyl phthalocyanine pigment is used as a carrier generating substance, charging characteristics and sensitivity characteristics change due to environmental fluctuations, particularly humidity fluctuations, and environmental memory tends to be generated. The environmental memory refers to a phenomenon in which a black belt-like image defect occurs in reversal development in which an exposed portion is a toner image when temperature and humidity fluctuate greatly. As countermeasures against humidity fluctuations, alkylene diols, polyalkylene glycols, antistatic agents, and the like have been proposed as moisturizing agents in the charge generation layer of the photoreceptor (Japanese Patent Laid-Open Nos. 5-313389, 5-333777, and 6-118675). ). However, these mere moisturizing agents are difficult to answer in recent years to pursue higher image quality, and if added in large amounts, even humectants, such as diol compounds, can easily act as organic insulators and increase the residual potential. Defects are likely to occur. In addition, side effects such as a decrease in charging potential are observed with antistatic agents and the like.
[0009]
On the other hand, a titanyl phthalocyanine pigment having a prominent peak at a Bragg angle 2θ of 7.5 ° or 28.7 ° in a powder X-ray diffraction spectrum, and one of them is the maximum peak (hereinafter referred to as B-type titanyl phthalocyanine pigment) (Also referred to as a B-type pigment) is known as a charge generating substance that exhibits stable sensitivity and is easy to synthesize (Japanese Patent Laid-Open No. 61-239248, etc.).
[0010]
However, when an organic photoreceptor is produced using this B-type pigment charge generation material, the black belt-like image defect of the environmental memory is improved, but the residual potential increases with repeated use. Therefore, in order to prevent the increase in the residual power, if the concentration of the charge transport material in the charge transport layer is increased at the same time as using the B-type pigment, the increase in the residual power is improved, but an image defect called “white spot” is caused. A problem has been found that is likely to occur. This white spot is a halftone image of reversal development or a dot-like or line-like image defect that is not developed into a black solid image. This phenomenon does not cause the charge to be lost in the image exposure portion when forming a latent image on the organic photoreceptor. This is thought to be due to the occurrence of minute portions, and is considered to be an image defect opposite to “black spots” well known for reversal development.
[0011]
Further, it has been found that the influence of the intermediate layer adjacent to the charge generation layer is large in order to improve the above-described increase in residual power and increase the sensitivity of the photoreceptor using the B-type pigment.
[0012]
For example, a method of forming an intermediate layer by dispersing titanium oxide particles or the like in a copolymerized polyamide resin or a methoxymethylated polyamide resin composed of a chemical structure having few carbon chains between amide bonds such as 6-nylon is widely known. It has been. However, if such an intermediate layer is used to improve the residual potential, a “black spot” image defect is likely to occur under high temperature and high humidity, and a black belt-like image defect of the environmental memory is also likely to occur.
[0013]
In order to obtain an electrophotographic photosensitive member that simultaneously improves image defects such as black belts, white spots, black spots, and the like and prevents an increase in residual potential due to repeated use, the present inventors have integrated conventional photosensitive member technologies. To the present invention.
[0014]
[Problems to be solved by the invention]
An object of the present invention is to provide an organic photoreceptor that has good potential stability and does not generate image defects such as black belts, white spots, and black spots in view of the above-described problems of the prior art. Does not cause image defects such as black belts, white spots, black spots, etc., and the potential fluctuation that prevents the increase in residual potential due to repeated use is an organic photoreceptor, and an image forming method and an image forming method using the organic photoreceptor It is to provide an apparatus and a process cartridge.
[0015]
[Means for Solving the Problems]
That is, the object of the present invention is achieved by using an organic photoreceptor having the following constitution.
[0016]
  1. X-ray diffraction by a Cu-Kα characteristic X-ray in an organic photoreceptor in which a charge generation layer containing a charge generation material on a conductive support and a charge transport layer having a charge transport material thereon are laminated. It contains a titanyl phthalocyanine pigment having a prominent diffraction peak at a Bragg angle (2θ ± 0.2 °) of 7.5 ° and 28.7 ° in the spectrum, and the charge transport layer is a bis (arylethenylphenyl) aniline system Containing a charge transport material having a stereoisomer mixture of compounds and a content of a maximum isomer component in the stereoisomer mixture of 40 to 90% by massAn organic photoreceptor, wherein the glass transition point Tgb of the binder resin of the charge transport layer and the glass transition point Tgl of the charge transport layer satisfy the following relationship.
  100 ° C. <Tgl <Tgb (both Tgb and Tgl, the unit is ° C.)
[0017]
2.The titanyl phthalocyanine pigment isX-ray diffraction spectrum by Cu-Kα characteristic X-ray, showing Bragg angles (2θ ± 0.2 °) of 7.5 °, 22.6 °, 24.5 °, 25.4 °, 28.7 ° Has a diffraction peak and the maximum diffraction peak is 7.5 ° or 28.7 °IsAn organic photoreceptor characterized by the above.
[0020]
  3. The bis (arylethenylphenyl) aniline compound is a compound represented by the general formula (1)1 or 2The organic photoreceptor described in 1.
[0021]
  4. The bis (arylethenylphenyl) aniline compound is a compound represented by the general formula (2).Or 2The organic photoreceptor described in 1.
[0022]
  5. The bis (arylethenylphenyl) aniline compound is a compound represented by the general formula (3).Or 2The organic photoreceptor described in 1.
[0023]
  6. The bis (arylethenylphenyl) aniline compound is a compound represented by the general formula (4).Or 2The organic photoreceptor described in 1.
[0024]
  7. The bis (arylethenylphenyl) aniline compound is a compound represented by the general formula (5).Or 2The organic photoreceptor described in 1.
[0025]
  8. The bis (arylethenylphenyl) aniline compound is a compound represented by the general formula (6).Or 2The organic photoreceptor described in 1.
[0026]
  9. The bis (arylethenylphenyl) aniline-based compound is a compound represented by the general formula (7).Or 2The organic photoreceptor described in 1.
[0027]
  10. The main binder resin of the charge transport layer is polycarbonate,9The organophotoreceptor according to any one of the above.
[0028]
  11. The above 1 to 3 characterized by having an intermediate layer between the conductive support and the charge generation layer.10The organophotoreceptor according to any one of the above.
[0029]
  12. The intermediate layer contains N-type semiconductive fine particles and a binder resin.11The organophotoreceptor described.
[0030]
  13. 1 to12An image forming method comprising forming an electrophotographic image using the organophotoreceptor according to any one of the above.
[0031]
  14. Said13An image forming apparatus that forms an electrophotographic image using the image forming method described in 1.
[0032]
  15. At least said 112The organic photoreceptor according to any one of the above and at least one of a charger, an image exposure device, a developing device, a transfer device, and a cleaning device are integrated, and can be inserted into and removed from the image forming apparatus. Process cartridge characterized by.
[0033]
Hereinafter, the present invention will be described in detail.
The organic photoreceptor of the present invention (hereinafter also simply referred to as a photoreceptor) is an organic photoreceptor in which a charge generating layer containing a charge generating material is laminated on a conductive support, and a charge transporting layer having a charge transporting material is laminated thereon. , A titanyl phthalocyanine pigment (B) in which the charge generation substance has an X-ray diffraction spectrum by Cu-Kα characteristic X-rays and has remarkable diffraction peaks at Bragg angles (2θ ± 0.2 °) of 7.5 ° and 28.7 ° Type titanyl phthalocyanine pigment), the charge transport layer is a stereoisomer mixture of a bis (arylethenylphenyl) aniline compound, and the content of the maximum isomer component in the stereoisomer mixture is 40 to 90 It is characterized in that it contains a charge transport material that is mass%.
[0034]
The organophotoreceptor of the present invention is an organophotoreceptor in which a charge generating layer containing a charge generating material is laminated on a conductive support, and a charge transporting layer having a charge transporting material is laminated thereon. X-ray diffraction spectrum by Kα characteristic X-ray, remarkable diffraction peaks at Bragg angles (2θ ± 0.2 °) of 7.5 °, 22.6 °, 24.5 °, 25.4 °, 28.7 ° And a titanyl phthalocyanine pigment (the pigment also belongs to B-type titanyl phthalocyanine pigment) having a maximum diffraction peak at 7.5 ° or 28.7 °, and the charge transport layer is bis (arylethenylphenyl) ) It is a stereoisomer mixture of aniline compounds, and contains a charge transport material having a content of the largest isomer component in the stereoisomer mixture of 40 to 90% by mass.
[0035]
The photoreceptor of the present invention has the above-described configuration, thereby preventing the occurrence of the above-described conflicting image defects, that is, black belt-like, white spots and black defects, and increasing the residual potential due to repeated use. It is possible to produce a sharp electrophotographic image without causing any problems.
[0036]
That is, a charge transporting material having a charge transporting property, which is a stereoisomer mixture of bis (arylethenylphenyl) aniline compounds, is used as the charge transporting material of the charge transporting layer, and the charge transporting layer has a Bragg angle (2θ ± 0. 2 °) 7.5 °, titanyl phthalocyanine pigment having a prominent diffraction peak at 28.7 °, or Bragg angle (2θ ± 0.2 °) 7.5 °, 22.6 °, 24.5 °, 25 By laminating on a charge generating layer containing a titanyl phthalocyanine pigment having a pronounced diffraction peak at .4 °, 28.7 ° and a maximum diffraction peak at 7.5 ° or 28.7 °, A photoconductor capable of preventing sharp image defects such as black belt-like image defects, white spots and black spots in an environmental memory, and generating a sharp electrophotographic image by preventing a residual potential increase due to repeated use. It is done. And the content rate of the largest component of this stereoisomer mixture needs to be 40-90 mass%. When the content of the maximum component is larger than 90% by mass, the dispersibility of the charge transport material is deteriorated, causing fogging and a decrease in image density, and easily causing a decrease in sharpness. On the other hand, if it is less than 40% by mass, the occurrence of white spots increases, the resolution decreases, and the stability of the electrophotographic characteristics is also impaired. In particular, the content of the maximum component is preferably 45 to 80% by mass.
[0037]
By using the charge transport material of the stereoisomer mixture of the bis (arylethenylphenyl) aniline compound as described above, the compatibility between the photosensitive layer, for example, the binder of the charge transport layer and the charge transport material is improved. This is thought to be due to the improvement in film quality and electrophotographic characteristics of the charge transport layer.
[0038]
In addition, the organic photoreceptor of the present invention is an organic photoreceptor in which a charge generation layer containing a charge generation material on a conductive support and a charge transport layer having a charge transport material thereon are laminated. A charge transport layer comprising a titanyl phthalocyanine pigment having a diffraction peak at a Bragg angle (2θ ± 0.2 °) of 7.5 ° and 28.7 ° in an X-ray diffraction spectrum by Cu-Kα characteristic X-rays; Contains a bis (arylethenylphenyl) aniline-based compound, and the glass transition point Tgb of the binder resin of the charge transport layer and the glass transition point Tgl of the charge transport layer satisfy the following relationship.
[0039]
100 ° C. <Tgl <Tgb (both Tgb and Tgl, the unit is ° C.)
In addition, the organic photoreceptor of the present invention is an organic photoreceptor in which a charge generation layer containing a charge generation material on a conductive support and a charge transport layer having a charge transport material thereon are laminated. X-ray diffraction spectrum by Cu-Kα characteristic X-ray, showing Bragg angles (2θ ± 0.2 °) of 7.5 °, 22.6 °, 24.5 °, 25.4 °, 28.7 ° Contains a titanyl phthalocyanine pigment having a diffraction peak and a maximum diffraction peak at 7.5 ° or 28.7 °, the charge transport layer contains a bis (arylethenylphenyl) aniline compound, and charge transport The glass transition point Tgb of the binder resin of the layer and the glass transition point Tgl of the charge transport layer satisfy the following relationship.
[0040]
100 ° C. <Tgl <Tgb (both Tgb and Tgl, the unit is ° C.)
The photoreceptor of the present invention has the above-described configuration, thereby preventing the occurrence of the above-described conflicting image defects, that is, black belt-like, white spots and black defects, and increasing the residual potential due to repeated use. It is possible to produce a sharp electrophotographic image without causing any problems.
[0041]
The glass transition point Tgl of the charge transport layer is governed by the binder resin, the charge transport material, and the additives other than the charge transport material, which are the main components of the charge transport layer. Of course, in addition to this, there is an influence of the residual solvent concentration, but the residual solvent often has an adverse effect on the electrophotographic characteristics such as charging characteristics and sensitivity of the organic photoreceptor and film physical properties, and it is generally preferable to remove as much as possible. . Further, since additives other than the charge transport material are added in a smaller amount than the charge transport material, the influence on the glass transition point Tgl is limited by that amount, but in order not to deteriorate the film physical properties of the charge transport layer. It is necessary to use the quantity and quality (a compound that does not lower the glass transition point Tgl).
[0042]
The charge transport material of the present invention is a compound having the property of drift mobility of electrons or holes, and as another definition, the charge transport material can be used for charge transport by a known method capable of detecting the charge transport ability such as Time-Of-Flight method. This refers to a compound that can provide the resulting detection current.
[0043]
By the way, the conventional charge transport layer contains a large amount of a charge transport material in the charge transport layer in order to transport the charge generated in the charge generation layer to the surface of the photoreceptor. Therefore, even if the amount of residual solvent and the amount and quality of other additives are selected and used, it is extremely difficult for the glass transition point Tgl of the charge transport layer to exceed 100 ° C.
[0044]
In the present invention, a bis (arylethenylphenyl) aniline-based compound is used as at least one of the charge transport materials, the total molar amount of the charge transport material in the charge transport layer is set to a low molar amount, and the glass transition point of the charge transport layer The present invention has been achieved by developing a charge transport layer technique that does not reduce Tgl and that does not lower the charge transport ability, and is combined with a charge generation layer using a B-type titanyl phthalocyanine pigment.
[0045]
That is, the present invention is configured such that the glass transition point Tgl of the charge transport layer is 100 ° C. or more, and the charge transport layer is disposed on the charge generation layer containing the B-type titanyl phthalocyanine pigment, It is possible to obtain a photoconductor that prevents image defects such as black spots and prevents a residual potential from increasing due to repeated use, and enables production of sharp electrophotographic images. The physical properties of such a charge transport layer include a charge transport material of a bis (arylethenylphenyl) aniline compound composed of a stereoisomer mixture as a charge transport material in the charge transport layer, and a low mole number in the charge transport layer. For example, 2.0 × 10 5 per unit mass of the charge transport layer^-Four(Mol / g) to 6.0 × 10^-FourBy containing a (mol / g) charge transport material, this is achieved by reducing the degree of decrease in the glass transition point Tgl of the charge transport layer (the degree of decrease from the glass transition point Tgb of the binder resin). In addition, the total number of moles of the charge transport material per unit mass of the charge transport layer is 2.0 × 10^-FourIf it is less than (mol / g), the sensitivity tends to be lowered, and the image density is likely to decrease and the fog is likely to increase. On the other hand, 6.0 × 10^-FourIf it exceeds (mol / g), it tends to be difficult to set the glass transition point Tgl of the charge transport layer to 100 ° C. or higher, although it depends on the type of the charge transport material.
[0046]
That is, by using a stereoisomer mixture of a bis (arylethenylphenyl) aniline compound as a charge transport material and using the charge transport material in a low molar amount, the film physical properties of the charge transport layer are not deteriorated. It is possible to achieve an organic photoreceptor that prevents the occurrence of image defects such as black spots and has good electrophotographic characteristics.
[0047]
The stereoisomer mixture of the bis (arylethenylphenyl) aniline compound preferably has a content of the largest isomer component in the isomer mixture of 40 to 90% by mass. When the content of the maximum component is larger than 90% by mass, the dispersibility of the charge transport material is deteriorated, causing fogging and a decrease in image density, and easily causing a decrease in sharpness. On the other hand, if it is less than 40% by mass, the occurrence of white spots increases, the resolution decreases, and the stability of the electrophotographic characteristics is also impaired. In particular, the content of the maximum component is preferably 45 to 80% by mass.
[0048]
Further, it is preferable to use a compound having a molecular weight of 500 or more and 1500 or less of the charge transport material of the stereoisomer. If the molecular weight is less than 500, the electrophotographic characteristics are liable to deteriorate, and if it is more than 1500, the compatibility with the binder resin tends to be lowered, and image defects such as white spots and black spots are likely to occur.
[0049]
The binder resin for the charge transport layer is preferably a polycarbonate resin excellent in both electrophotographic characteristics and film properties. Here, the polycarbonate is a polymer having a carbonate structure (—OCOO—).
[0050]
The polycarbonate resin has a glass transition point Tgb that varies depending on the resin structure, molecular weight, etc., but in the case of a commercially available polycarbonate resin, it is in the range of about 160 to 200 ° C. Therefore, when polycarbonate is used as the binder resin for the charge transport layer, the degree of decrease in the glass transition point of the charge transport layer (from the binder resin) by the charge transport material or other additives should be 60-100 ° C. or less. is necessary.
[0051]
The main binder resin of the present invention means a content of 50% by mass or more based on the total binder resin in the charge transport layer.
[0052]
The bis (arylethenylphenyl) aniline-based compound of the present invention refers to a group of compounds having two arylethenylphenyl groups having the same chemical structure on the nitrogen atom of aniline, preferably represented by the general formula (1). It is a compound, and preferably a compound having an alkyl group or an alkoxy group at the ortho or para position of the aniline group as in the general formulas (2) to (6).
[0053]
Further, the charge transport material of the stereoisomer mixture refers to a charge transport material compound having the same chemical structural formula and having an isomeric structure which is caused by different configuration of atoms or atomic groups therein.
[0054]
Examples of preferred bis (arylethenylphenyl) aniline compounds of the present invention will be given below, but the present invention is not limited to the following compound examples. In addition, any of these compounds can have a stereoisomer structure.
[0055]
[Chemical 8]

[0056]
[Chemical 9]

[0057]
[Chemical Formula 10]

[0058]
Embedded image

[0059]
Embedded image

[0060]
Embedded image

[0061]
Embedded image

[0062]
Embedded image

[0063]
Embedded image

[0064]
Embedded image

[0065]
Embedded image

[0066]
The molecular weight of the charge transport material having a stereoisomer structure is preferably 500 or more and 1500 or less. By using such a high molecular weight charge transport material, the film quality of the charge transport layer can be improved, and the effects of the present invention described above can be made more remarkable.
[0067]
It describes about the measuring method of the glass transition point of this invention.
In the measurement of the glass transition point of the present invention, about 1.0 mg of a measurement sample is placed in an aluminum pan, and the lid is covered and weighed. This was measured with a heat flux differential scanning calorimeter DSC-50 (manufactured by Shimadzu Corporation) from 20 ° C. to a temperature of 3 ° C./min up to 220 ° C.
[0068]
As a measurement sample, the glass transition point of the binder resin of the charge transport layer is measured using Tgb as the sample of the binder resin itself, and the glass transition point Tgl of the charge transport layer is measured using a sample obtained by peeling the charge transport layer from the photoreceptor. .
[0069]
Next, the layer structure of the organic photoreceptor of the present invention will be described.
In the present invention, the organic photoconductor means an electrophotographic photoconductor formed by giving an organic compound at least one of a charge generation function and a charge transport function indispensable for the configuration of the electrophotographic photoconductor. All known organic electrophotographic photoreceptors such as a photoreceptor composed of the above organic charge generating substance or organic charge transporting substance, a photoreceptor composed of a polymer complex with charge generating function and charge transporting function are contained.
[0070]
The organophotoreceptor of the present invention is characterized by using the B-type titanyl phthalocyanine pigment as a charge generating substance. The B-type titanyl phthalocyanine pigment is also called oxytitanium phthalocyanine and is represented by the following structural formula as a chemical formula.
[0071]
Embedded image

[0072]
(In the formula, X represents a halogen atom, and n represents a number of 0 to 1. When X is a chlorine atom, n is preferably 0 to 0.5, and more preferably 0 to 0.1.)
Production of titanyl phthalocyanine pigment having a remarkable diffraction peak at the Bragg angle (2θ ± 0.2 °) of 7.5 ° and 28.7 ° (and 7.5 ° or 28.7 ° is the maximum peak) The methods are disclosed in JP-A-1-239248, 1-271050 and the like, and can be prepared using these disclosed production methods. The titanyl phthalocyanine pigment produced by these production methods is, for example, X-ray diffraction spectra having remarkable diffraction peaks at Bragg angles (2θ ± 0.2 °) of 7.5 ° and 28.7 ° as shown in FIG. The X-ray diffraction spectrum of the titanyl phthalocyanine pigment in FIG. 1 has a maximum diffraction peak at 7.5 °, and the Bragg angles (2θ ± 0.2 °) are 10.3 °, 12.3 °, 16. Clear diffraction peaks are also shown at 3 °, 18.4 °, 22.6 °, 24.5 °, 25.4 °, and 28.7 °. As the dispersed particle diameter of the titanyl phthalocyanine pigment is reduced, the low angle 7.5 ° peak becomes smaller and the maximum diffraction peak becomes 28.7 °.
[0073]
The layer structure of the organic photoreceptor containing the charge generation material is composed of a charge generation layer, a charge transport layer photosensitive layer, and the like on a conductive support. It is more preferable to provide an intermediate layer between the conductive support and the charge generation layer. Each of these layers may be composed of one layer, or may be composed of two or more layers.
[0074]
Conductive support
The conductive support used for the photosensitive member may be either a sheet or a cylinder, but a cylindrical conductive support is more preferable for designing an image forming apparatus compactly.
[0075]
Cylindrical conductive support means a cylindrical support necessary for forming an endless image by rotating. Conductivity is within a range of 0.1 mm or less in straightness and 0.1 mm or less in deflection. A support is preferred. Exceeding the range of straightness and shake makes it difficult to form a good image.
[0076]
As the conductive material, a metal drum such as aluminum or nickel, a plastic drum deposited with aluminum, tin oxide, indium oxide or the like, or a paper / plastic drum coated with a conductive substance can be used. As a conductive support, the specific resistance is 10 at room temperature.^ThreeΩcm or less is preferable.
[0077]
As the conductive support used in the present invention, one having an alumite film that has been sealed on the surface thereof may be used. The alumite treatment is usually performed in an acidic bath such as chromic acid, sulfuric acid, oxalic acid, phosphoric acid, boric acid, sulfamic acid, etc., but anodizing treatment in sulfuric acid gives the most preferable result. In the case of anodizing treatment in sulfuric acid, the sulfuric acid concentration is preferably 100 to 200 g / L, the aluminum ion concentration is 1 to 10 g / L, the liquid temperature is about 20 ° C., and the applied voltage is preferably about 20 V. It is not limited. The average film thickness of the anodized film is usually 20 μm or less, particularly preferably 10 μm or less.
[0078]
Middle class
In the present invention, an intermediate layer having a barrier function may be provided between the conductive support and the photosensitive layer.
[0079]
In the present invention, in order to improve the adhesion between the conductive support and the photosensitive layer, or to prevent charge injection from the support, an intermediate layer (including an undercoat layer) is provided between the support and the photosensitive layer. Including) can also be provided. Examples of the material for the intermediate layer include polyamide resins, vinyl chloride resins, vinyl acetate resins, and copolymer resins containing two or more of these resin repeating units. Of these subbing resins, a polyamide resin is preferable as a resin capable of reducing the increase in residual potential due to repeated use. The film thickness of the intermediate layer using these resins is preferably 0.01 to 0.5 μm.
[0080]
Examples of the intermediate layer preferably used in the present invention include an intermediate layer using a curable metal resin obtained by thermosetting an organic metal compound such as a silane coupling agent or a titanium coupling agent. As for the film thickness of the intermediate | middle layer using curable metal resin, 0.1-2 micrometers is preferable.
[0081]
Further, the intermediate layer preferably used in the present invention includes an intermediate layer in which N-type semiconductive fine particles subjected to a hydrophobic surface treatment are dispersed in a binder. For example, an intermediate layer in which titanium oxide having an average particle size of 0.01 to 1 μm, which has been surface-treated with silica / alumina treatment and silane compound, is dispersed in a polyamide resin. The film thickness of such an intermediate layer is preferably 1 to 20 μm.
[0082]
The N-type semiconducting fine particles are fine particles having the property of using conductive carriers as electrons. That is, the property that the conductive carrier is an electron is that the N-type semiconducting fine particles are contained in an insulating binder to effectively block hole injection from the substrate, and to convert electrons from the photosensitive layer into electrons. On the other hand, it has the property which does not show blocking property.
[0083]
Specifically, the N-type semiconductive fine particles are composed of titanium oxide (TiO 2).₂), Zinc oxide (ZnO), tin oxide (SnO)₂In particular, titanium oxide is preferably used in the present invention.
[0084]
The average particle diameter of the N-type semiconducting fine particles used in the present invention is preferably in the range of 10 nm to 500 nm in the number average primary particle diameter, more preferably 10 nm to 200 nm, and particularly preferably 15 nm to 50 nm. .
[0085]
The intermediate layer using N-type semiconducting fine particles whose number average primary particle size is within the above range can be finely dispersed in the layer, has sufficient potential stability, and generates black spots. Has a prevention function.
[0086]
For example, in the case of titanium oxide, the number-average primary particle size of the N-type semiconducting fine particles is magnified 10,000 times by observation with a transmission electron microscope, and 100 particles are randomly observed as primary particles. It is measured as the number average diameter.
[0087]
The shape of the N-type semiconducting fine particles used in the present invention includes dendritic, needle-like, and granular shapes. For example, in the case of titanium oxide particles, the N-type semiconductive fine particles have a crystalline form. There are anatase type, rutile type and amorphous type, but any crystal type may be used, or two or more crystal types may be mixed and used. Of these, the rutile type is the best.
[0088]
One of the hydrophobizing surface treatments performed on the N-type semiconductive fine particles of the present invention is a plurality of surface treatments, and the last surface treatment is a reactive organosilicon compound among the plurality of surface treatments. The surface treatment is performed. In addition, at least one of the surface treatments is at least one surface treatment selected from alumina, silica, and zirconia, and finally the surface treatment of the reactive organosilicon compound is performed. It is preferable.
[0089]
Alumina treatment, silica treatment, and zirconia treatment are treatments for precipitating alumina, silica, or zirconia on the surface of the N-type semiconducting fine particles. Zirconia hydrates are also included. The surface treatment of the reactive organosilicon compound means using a reactive organosilicon compound in the treatment liquid.
[0090]
In this way, the surface treatment of the N-type semiconductive fine particles such as titanium oxide particles was performed at least twice, so that the surface of the N-type semiconductive fine particles was uniformly coated (treated), and the surface treatment was performed. When N-type semiconductive fine particles are used in the intermediate layer, the dispersibility of the N-type semiconductive fine particles such as titanium oxide particles in the intermediate layer is improved, and the electrophotographic characteristics, particularly the stability of the residual potential during repeated use, Furthermore, the improvement effect of black spots, environmental memory, etc. can be increased.
[0091]
Charge generation layer
The charge generation layer contains the B-type titanyl phthalocyanine pigment as a charge generation material (CGM). In addition to the B-type titanyl phthalocyanine pigment, other charge generating materials may be used as necessary. For example, other phthalocyanine pigments, azo pigments, perylene pigments, azurenium pigments, and the like can be used in combination. The above is preferable.
[0092]
Other substances may contain a binder resin and other additives as necessary. When a binder is used as the CGM dispersion medium in the charge generation layer, a known resin can be used as the binder, but the most preferred resins include formal resin, butyral resin, silicone resin, silicone-modified butyral resin, phenoxy resin, and the like. Can be mentioned. The ratio of the binder resin to the charge generating material is preferably 20 to 600 parts by mass with respect to 100 parts by mass of the binder resin. By using these resins, the increase in residual potential associated with repeated use can be minimized. The thickness of the charge generation layer is preferably 0.01 μm to 2 μm.
[0093]
Charge transport layer
The charge transport layer contains a binder resin that uses a stereoisomer mixture as a charge transport material (CTM) and forms a film by dispersing CTM. Other substances may contain additives such as antioxidants as necessary.
[0094]
As the charge transport material (CTM), a known charge transport material can be used in combination with the charge transport material of the stereoisomer mixture described above. For example, a triphenylamine derivative, a hydrazone compound, a styryl compound, a benzidine compound, a butadiene compound, or the like can be used in combination. These charge transport materials are usually dissolved in a suitable binder resin to form a layer.
[0095]
Examples of the resin used for the charge transport layer (CTL) include polystyrene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, and polycarbonate. Resin, silicone resin, melamine resin, copolymer resin containing two or more of these resin repeating units, and high molecular organic semiconductors such as poly-N-vinylcarbazole in addition to these insulating resins Can be mentioned.
[0096]
Most preferred as a binder for these CTLs is a polycarbonate resin. The polycarbonate resin is most preferable in improving the dispersibility and electrophotographic characteristics of CTM. In the case of a photoreceptor having a charge transport layer as a surface layer, a polycarbonate resistant to mechanical abrasion is preferable. As such a polycarbonate, a polycarbonate having an average molecular weight of 2,000,000 to 25,000 is preferable. Here, the average molecular weight may be any of a number average molecular weight, a weight average molecular weight, and a viscosity average molecular weight. The ratio of the binder resin to the charge transport material is preferably 10 to 200 parts by mass with respect to 100 parts by mass of the binder resin. The thickness of the charge transport layer is preferably 10 to 40 μm.
[0097]
The charge transport layer preferably contains an antioxidant. Typical examples of the antioxidants are those that prevent the action of oxygen under conditions of light, heat, discharge, etc., on auto-oxidizing substances present in the organophotoreceptor or on the organophotoreceptor surface, It is a substance that has the property of inhibiting. Typical examples include the following compound groups.
[0098]
Embedded image

[0099]
Embedded image

[0100]
Embedded image

[0101]
Embedded image

[0102]
The charge transport layer may be composed of two or more layers. In this case, a layer structure in which a function as a protective layer is added to the charge transport layer on the surface and the wear resistance with the cleaning blade or the like is enhanced is preferable.
[0103]
Solvents or dispersion media used for forming layers such as intermediate layers, photosensitive layers and protective layers include n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N, N-dimethylformamide, acetone, and methyl ethyl ketone. , Methyl isopropyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, dichloromethane, 1,2-dichloroethane, 1,2-dichloropropane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethane , Tetrahydrofuran, dioxolane, dioxane, methanol, ethanol, butanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, methyl cellosolve, etc. And the like. Although this invention is not limited to these, Dichloromethane, 1, 2- dichloroethane, methyl ethyl ketone, etc. are used preferably. These solvents may be used alone or as a mixed solvent of two or more.
[0104]
As the coating processing method for producing the electrophotographic photosensitive member of the present invention, coating processing methods such as dip coating, spray coating, and circular amount regulation type coating are used. In order to prevent the film from being dissolved as much as possible, and in order to achieve uniform coating processing, it is preferable to use a coating processing method such as spray coating or circular amount regulation type (circular slide hopper type is a typical example). The spray coating is described in detail in, for example, JP-A-3-90250 and JP-A-3-269238, and the circular amount-regulating coating is described in detail in, for example, JP-A-58-189061. Yes.
[0105]
Next, the image forming apparatus of the present invention will be described.
FIG. 3 is a cross-sectional configuration diagram of an image forming apparatus as an example of the image forming method of the present invention.
[0106]
In FIG. 3, reference numeral 50 denotes a photosensitive drum (photosensitive member) which is an image bearing member. An organic photosensitive layer is coated on the drum and a resin layer of the present invention is coated thereon, and is grounded. Driven and rotated clockwise. Reference numeral 52 denotes a scorotron charger (charging means) for uniformly charging the circumferential surface of the photosensitive drum 50 by corona discharge. Prior to the charging by the charger 52, the peripheral surface of the photosensitive member may be discharged by performing exposure by the pre-charging exposure unit 51 using a light emitting diode or the like in order to eliminate the history of the photosensitive member in the previous image formation.
[0107]
After uniform charging of the photoreceptor, image exposure based on the image signal is performed by an image exposure unit 53 as an image exposure unit. The image exposure unit 53 in this figure uses a laser diode (not shown) as an exposure light source. Scanning on the photosensitive drum is performed by the light whose optical path is bent by the reflection mirror 532 through the rotating polygon mirror 531 and the fθ lens, and an electrostatic latent image is formed.
[0108]
Here, the reversal development process of the present invention means that the surface of the photoconductor is uniformly charged by the charger 52 and the image-exposed area, that is, the exposed area potential (exposed area) of the photoconductor is developed. ) To form an image. On the other hand, the unexposed portion potential is not developed by the developing bias potential applied to the developing sleeve 541.
[0109]
The electrostatic latent image is then developed by a developing device 54 as developing means. A developing device 54 containing a developer composed of toner and carrier is provided on the periphery of the photosensitive drum 50, and development is performed by a developing sleeve 541 that contains a magnet and rotates while holding the developer. The inside of the developing device 54 is composed of developer agitating / conveying members 544 and 543, a conveying amount regulating member 542 and the like, and the developer is agitated and conveyed and supplied to the developing sleeve. Controlled by member 542. The amount of the developer transported varies depending on the linear velocity and the specific gravity of the applied organic electrophotographic photoreceptor, but is generally 20 to 200 mg / cm.²Range.
[0110]
The developer is, for example, a carrier composed of the above-mentioned ferrite as a core and coated with an insulating resin around it, and a coloring material such as carbon black, a charge control agent, and a low molecular weight polyolefin mainly composed of the above-mentioned styrene acrylic resin. The toner is composed of toner in which silica, titanium oxide or the like is externally added to the particles, and the developer is transported to the development area with the layer thickness regulated by the transport amount regulating member, and development is performed. At this time, usually, development is performed by applying a DC bias between the photosensitive drum 50 and the developing sleeve 541 and, if necessary, an AC bias voltage. Further, the developer is developed in contact with or not in contact with the photoreceptor. The potential of the photoconductor is measured by providing a potential sensor 547 above the development position as shown in FIG.
[0111]
The recording paper P is fed to the transfer area by the rotation operation of the paper feed roller 57 when the transfer timing is ready after the image formation.
[0112]
In the transfer area, a transfer electrode (transfer means: transfer device) 58 operates on the peripheral surface of the photosensitive drum 50 in synchronization with the transfer timing, and the charged recording paper P is charged with a polarity opposite to that of the toner. Transfer the toner.
[0113]
Next, the recording paper P is neutralized by a separation electrode (separator) 59, separated by the peripheral surface of the photosensitive drum 50 and conveyed to the fixing device 60, and the toner is removed by heating and pressurization of the heat roller 601 and the pressure roller 602. After the welding, the sheet is discharged to the outside of the apparatus via the sheet discharge roller 61. The transfer electrode 58 and the separation electrode 59 stop the primary operation after passing through the recording paper P, and prepare for the next toner image formation. In FIG. 3, a transfer band electrode of corotron is used as the transfer electrode 58. The transfer electrode setting conditions vary depending on the process speed (peripheral speed) of the photosensitive member and cannot be specified. For example, the transfer current is set to +100 to +400 μA, and the transfer voltage is set to +500 to +2000 V. can do.
[0114]
On the other hand, after the recording paper P is separated, the photosensitive drum 50 removes and cleans residual toner by pressure contact of the blade 621 of the cleaning device (cleaning means) 62, and again performs charge removal by the pre-charge exposure unit 51 and charging by the charger 52. Then, the next image forming process is started.
[0115]
Reference numeral 70 denotes a detachable process cartridge in which a photoconductor, a charger, a transfer device, a separator, and a cleaning device are integrated.
[0116]
The organic electrophotographic photosensitive member of the present invention is generally applicable to electrophotographic apparatuses such as electrophotographic copying machines, laser printers, LED printers, and liquid crystal shutter printers, and further displays, recordings, light printing, plate making using electrophotographic technology. It can also be widely applied to apparatuses such as facsimiles.
[0117]
【Example】
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the aspect of this invention is not limited to this. “Part” in the sentence represents part by mass.
[0118]
  Example 1 (Reference example)
  Synthesis Example 1 (Synthesis Example of Exemplary Compound T20)
[0119]
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[0120]
10 g of the compound represented by the above formula was dissolved in 32 g of phosphorus oxychloride, heated to 50 ° C., and 22 ml of dimethylformamide was added dropwise little by little (heated to 40 to 70 ° C.). The reaction solution was stirred for 15 hours while controlling at around 90 ° C. After allowing to cool to 40 ° C., excess phosphorus oxychloride is sufficiently hydrolyzed and the precipitated crystals are filtered off, suspended in water and washed, and washing is repeated until the washing solution becomes neutral. 9.25 g (77%) of the bisformyl compound represented were obtained.
[0121]
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[0122]
2 g of the obtained bisformyl compound and 4.3 g of a phosphonate compound represented by the following structural formula were dissolved in 20 ml of dimethylformamide. While maintaining the reaction solution at around 20 ° C., 1.0 g of sodium methoxide was added little by little (exothermic). After stirring for 4 hours, 30 ml of water was added and purification was performed by a conventional method to obtain 3.3 g (81%) of yellow crystals. When this yellow crystal was subjected to elemental analysis and mass spectrometry, the results shown in Table 1 below were obtained, and it was confirmed that the compound was Exemplified Compound T20.
[0123]
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[0124]
Elemental analysis (C₅₃H₄₉N)
[0125]
[Table 1]

[0126]
Mass spectrometry (C₅₃H₄₉N)
Mw (calculated value) = 699
Mw⁺(Actual measurement value) = 699
The T20 compound obtained by the above synthesis is referred to as T20-1. As for this T20-1, the measurement result of the following liquid chromatography (HPCL) had a cis-cis / cis-trans / trans-trans mixing ratio of 1.1 / 2.2 / 1.0. The structural formulas of T20cis-cis, T20trans-trans, and T20cis-trans are shown below.
[0127]
Measurement conditions for liquid chromatography
Measuring machine: Shimadzu LC6A (manufactured by Shimadzu Corporation)
Column: CLC-SIL (manufactured by Shimadzu Corporation)
Detection wavelength: 290 nm
Mobile phase: n-hexane / dioxane = 10-500 / 1
Mobile phase flow rate: about 1 ml / min
Sample (T20) Solvent: n-hexane / dioxane = 10/1
Sample (T20): 3 mg / solvent 10 ml
[0128]
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[0129]
The compound which isolate | separated T20-1 obtained above into the cis-cis body, cis-trans body, and trans-trans body using the liquid chromatography was also obtained. T20 of these cis-cis bodies is T20c-c, T20 of cis-trans bodies is T20c-t, and T20 of trans-trans bodies is T20t-t. T20-1 and T20c-c, T20c-t, T20t-t were used, and the mixing ratio was changed, and T20 having a mixing ratio of cis-cis / cis-trans / trans-trans as shown in Table 2 A compound of −2 to T20-6 was prepared.
[0130]

Titanium oxide, polyamide resin, and methanol were added to the same container and dispersed using an ultrasonic homogenizer to prepare a coating solution for the intermediate layer. This coating solution was dip-coated on a cylindrical aluminum substrate, heat-cured at 110 ° C. for 1 hour, and an intermediate layer was provided with a dry film thickness of 4 μm.
[0131]

Were mixed for 10 hours using a sand mill to prepare a charge generation layer coating solution. This coating solution was applied onto the intermediate layer by a dip coating method to form a charge generation layer having a dry film thickness of 0.2 μm.
[0132]
<Charge transport layer>
225 parts of charge transport material (T20-1)
300 parts of polycarbonate (viscosity average molecular weight: 20,000)
Antioxidant (Exemplary Compound 1-3) 6 parts
2000 parts of dichloromethane
Were mixed and dissolved to prepare a charge transport layer coating solution. This coating solution was applied onto the charge generation layer by a dip coating method to form a charge transport layer having a dry film thickness of 24 μm.
[0133]
Preparation of photoreceptors 2-9
The charge transport material (T20-1) used in Photoreceptor 1 was replaced with T20-2 to T20-6, T20c-c, T20c-t, and T20t-t, except that the isomer mixture ratio was changed as shown in Table 2. Were prepared in the same manner as Photoreceptor 1.
[0134]
Production of photoconductor 10
Photoconductor 10 was prepared in the same manner except that charge transport material (T20-1) used in photoconductor 1 was replaced with charge transport material T101 having the following chemical structure.
[0135]
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[0136]
Production of photoconductor 11
The B-type titanyl phthalocyanine pigment of the charge generation layer used in the photoreceptor 1 was changed to a Y-type titanyl phthalocyanine pigment (X-ray diffraction spectrum by Cu-Kα characteristic X-ray with a Bragg angle 2θ and a maximum of 27.2 ± 0.2 °). Photoreceptor 11 was produced in the same manner as Photoreceptor 1 except that the titanyl phthalocyanine pigment having a peak: FIG.
[0137]
[Table 2]

[0138]
Evaluation
As an evaluation machine, a digital copying machine Konica 7075 manufactured by Konica (corona charging, laser exposure, reversal development, electrostatic transfer, nail separation, blade cleaning, cleaning auxiliary brush roller adoption process) is used. 11 was installed and evaluated. The cleaning performance and image evaluation were performed by copying an original image in which a character image having a pixel ratio of 7%, a human face photo, a solid white image, and a solid black image are equally divided into A4 neutral paper. Environmental conditions are severe, high temperature and high humidity environment: HH environment (30 ° C, 80% RH) and low temperature low humidity environment: LL environment (10 ° C, 20% RH). A halftone image, a solid white image, and a solid black image were prepared by copying a sheet, and the following evaluation was performed.
[0139]
Evaluation criteria
Image density (measured using Macbeth RD-918. Measured by relative reflection density with paper reflection density set to “0”. Evaluated with initial and 10,000 copies of each image.)
A: Black solid image is 1.2 or more
○: Black solid image is less than 1.2 to 1.0
X: Black solid image is less than 1.0
Fog (visually determine the solid white image after initial and 10,000 copies each)
A: No fogging occurs through copying under both environmental conditions
○: fogging with a concentration of 0.01 to 0.02 occurs in either environment
×: fogging with a concentration of 0.03 or more occurs in either environment
Image defect evaluation
Environmental memory: After copying 10,000 sheets in the above high temperature and high humidity environment (30 ° C., 80% RH), the Konica 7075 copier is left under the same conditions for 24 hours, and then at low humidity and low temperature (LL: 10 ° C., 20% RH). ) And copied after 30 minutes. Copy halftone image of 0.4 density in original image to 0.4 density, and judge by density difference of copy image (ΔHD = maximum density – minimum density)
A: ΔHD is 0.05 or less (good)
B: ΔHD is larger than 0.05 and smaller than 0.1 (no practical problem)
C: ΔHD is 0.1 or more (practical problem)
Black Potty (After making 10,000 copies of each, make and evaluate 100 more solid white copy images)
For black spots, the periodicity coincided with the period of the photoreceptor, and it was determined how many black spots per A4 size were visible.
[0140]
A: Black spot frequency of 0.4 mm or more: All copy images are 3 / A4 or less (good) B: Black spot frequency of 0.4 mm or more: 4 / A4 or more, 10 / A4 or less is 1 or more Occurrence (no problem in practical use)
C: Black spot frequency of 0.4 mm or more Frequency: 11 / A4 or more occurs (practically problematic)
White spots (After each 10,000 copies, 100 halftone images are produced and evaluated)
The evaluation of white spots was made by determining how many white spots per A4 size were observed, with the periodicity matching the period of the photoreceptor.
[0141]
A: White spot frequency of 0.4 mm or more: All copied images are 3 / A4 or less
B: White spot frequency of 0.4 mm or more: 4 / A4 or more, 19 / A4 or less
1 or more occurrences
C: White spot frequency of 0.4 mm or more: 20 or more A4 or more occur
Resolution (determined by ease of distinguishing character images)
After each 10,000 copies, a 3 point, 5 point character image was formed and evaluated according to the following criteria.
[0142]
◎: 3 points and 5 points are clear and easy to read
○: 3 points are partially unreadable, 5 points are clear and easily readable
×: 3 points are almost unreadable 5 points are partially or completely unreadable
Other evaluation conditions
The other evaluation conditions using the digital copying machine Konica 7075 were set to the following conditions.
[0143]
Charging conditions
Charger: Scorotron charger, initial charge potential of -750V
Exposure conditions
Set the exposure amount so that the potential of the exposed area is -50V.
[0144]
Development conditions
DC bias; -550V
The developer consists of a carrier coated with an insulating resin with ferrite as the core, a styrene acrylic resin as a main material, a coloring agent such as carbon black, a charge control agent, and colored particles comprising the low molecular weight polyolefin of the present invention, silica, oxidation Uses toner developer with titanium added externally.
[0145]
Transcription conditions
Transfer pole; corona charging method
Cleaning conditions
A cleaning blade having a hardness of 70 °, a rebound resilience of 34%, a thickness of 2 (mm), and a free length of 9 mm was brought into contact with the cleaning portion by a weight load method so that the linear pressure was 20 (N / m) in the counter direction.
[0146]
The evaluation results are shown in Table 3.
[0147]
[Table 3]

[0149]
  Example 2 (Reference example)
  Synthesis Example 2 (Synthesis Example of Exemplified Compound T50)
[0150]
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[0151]
10 g of the compound represented by the above formula was dissolved in 34 g of phosphorus oxychloride, heated to 50 ° C., and 23 ml of dimethylformamide was added dropwise little by little (heated to 40 to 70 ° C.). The reaction solution was stirred for 15 hours while controlling at around 90 ° C. After allowing to cool to 40 ° C., excess phosphorus oxychloride is sufficiently hydrolyzed and the precipitated crystals are filtered off, suspended in water and washed, and washing is repeated until the washing solution becomes neutral. 9.43 g (78%) of the bisformyl compound represented were obtained.
[0152]
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[0153]
2 g of the obtained bisformyl compound and 4.3 g of a phosphonate compound represented by the following structural formula were dissolved in 20 ml of dimethylformamide. While maintaining the reaction solution at around 20 ° C., 1.0 g of sodium methoxide was added little by little (exothermic). After stirring for 4 hours, 30 ml of water was added and purification was performed by a conventional method to obtain 3.3 g (81%) of yellow crystals. When this yellow crystal was subjected to elemental analysis and mass spectrometry, the results shown in Table 4 below were obtained, and it was confirmed that the compound was Exemplified Compound T50.
[0154]
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[0155]
Elemental analysis (C₄₀H₃₉N)
[0156]
[Table 4]

[0157]
  Mass spectrometry (C₄₀H₃₉N)
  Mw (calculated value) = 533
  Mw⁺(Actual measurement value) = 533
  The T50 compound obtained by the above synthesis is designated as T50-1. This T50-1 isin frontMeasurement result of liquid chromatography (HPCL) The cis-cis / cis-trans / trans-trans mixing ratio was 1.2 / 2.0 / 1.0. The structural formulas of T50cis-cis, T50trans-trans, and T50cis-trans are shown below.
[0158]
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[0159]
The compound which isolate | separated T50-1 obtained above into the cis-cis body, cis-trans body, and trans-trans body using the liquid chromatography was also obtained. T50 of these cis-cis bodies is T50c-c, T50 of cis-trans bodies is T50c-t, and T50 of trans-trans bodies is T50t-t. T50-1 and T50c-c, T50c-t, T50t-t were used, and the mixing ratio was changed, and T50 having a mixing ratio of cis-cis / cis-trans / trans-trans as shown in Table 5 Compounds of −2 to 50-6 were prepared.
[0160]
Preparation of photoreceptors 12-20
The charge transport material (T20-1) used in the photoreceptor 1 was changed to T50-1 to T50-6, T50c-c, T50c-t, T50t-t, and the isomer mixture ratio was changed as shown in Table 5 Were produced in the same manner as Photoreceptor 1.
[0161]
Production of photoconductor 21
The B-type titanyl phthalocyanine pigment of the charge generation layer used in the photoreceptor 1 was changed to a Y-type titanyl phthalocyanine pigment (X-ray diffraction spectrum by Cu-Kα characteristic X-ray with a Bragg angle 2θ and a maximum of 27.2 ± 0.2 °). A photoconductor 21 was produced in the same manner as the photoconductor 1 except that the charge transport material (T20-1) was replaced with T50-1 in a titanyl phthalocyanine pigment having a peak.
[0162]
[Table 5]

[0163]
Evaluations similar to those in Example 1 were performed using the photoconductors 12 to 21. The results are shown in Table 6.
[0164]
[Table 6]

[0166]
  Example 3 (claims)1Example corresponding to
  Production of photoconductor 22
  <Intermediate layer>
  Titanium oxide SMT500SAS (first time: silica / alumina treatment, second time:
  Methyl hydrogen polysiloxane treatment: manufactured by Teika) 300 g
  Polyamide resin CM8000 (Toray Industries, Inc.) 100g
  Methanol 1000g
  Titanium oxide, polyamide resin, and methanol were added to the same container and dispersed using an ultrasonic homogenizer to prepare a coating solution for the intermediate layer. This coating solution was dip-coated on a cylindrical aluminum substrate, heat-cured at 110 ° C. for 1 hour, and an intermediate layer was provided with a dry film thickness of 4 μm.
[0167]

Were mixed for 10 hours using a sand mill to prepare a charge generation layer coating solution. This coating solution was applied onto the intermediate layer by a dip coating method to form a charge generation layer having a dry film thickness of 0.2 μm.
[0168]

Were mixed and dissolved to prepare a charge transport layer coating solution. This coating solution is applied onto the charge generation layer by a dip coating method, followed by drying at 100 ° C. for 60 minutes to reduce the residual solvent amount to 0.1% by mass or less, and a charge transport layer having a dry film thickness of 24 μm. Thus, a photoreceptor 22 was produced. The solid content of the charge transport layer of the photoreceptor 22 is 536 g of the total amount of the charge transport material, polycarbonate Z, and antioxidant, and the number of moles of the charge transport material 230 g is 0.329 mol. The number of moles of the charge transport material is 6.1 × 10^-Fourmol / g.
[0169]
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[0170]
Preparation of photoreceptors 23-27
Photoconductors 23 to 27 were produced in the same manner as the photoconductor 22 except that the amount of the charge transport material (T20-1) used in the photoconductor 22 was changed as shown in Table 7.
[0171]
Production of photoconductor 28
The B-type titanyl phthalocyanine pigment of the charge generation layer used in the photoreceptor 22 was changed to a Y-type titanyl phthalocyanine pigment (X-ray diffraction spectrum by Cu-Kα characteristic X-ray with a Bragg angle 2θ, maximum at 27.2 ± 0.2 ° A photoconductor 28 was produced in the same manner as the photoconductor 22 except that it was replaced with a titanyl phthalocyanine pigment having a peak.
[0172]
[Table 7]

[0173]
Evaluation
Evaluation was performed in the same manner as in Example 1.
[0174]
The evaluation results are shown in Table 8.
[0175]
[Table 8]

[0176]
  As is clear from Table 8, the charge transport layer contains the stereoisomer mixture.The content of the maximum isomer component is in the range of 40 to 90% by mass.The photoconductors 24 to 27 having a charge transport material and having a Tgl of the charge transport layer higher than 100 ° C. and having a temperature of 122 to 161 ° C. are less likely to cause image defects such as environmental memory, black spots, and white spots. Image characteristics such as image density, fogging, and resolution are good and all characteristics are improved in a balanced manner (except that the density of the charge transport material is low and the image density is low). On the other hand, in the photoreceptors 22 and 23 outside the present invention having Tgl of 75 ° C. and 89 ° C., the occurrence of white spots is increased and the resolving power is also decreased. In addition, the photoreceptor 28 using the Y-type titanyl phthalocyanine pigment as a charge generating material has a significant deterioration in environmental memory and resolution.
[0177]
  Example 4 (claims)1Example corresponding to
  Production of photoconductors 29 to 41
  Photoconductors 29 to 41 were produced in the same manner as the photoconductor 22 except that the type and amount of the charge transport material used in the photoconductor 22 were changed as shown in Table 9.
[0178]
Production of photoconductor 42
The B-type titanyl phthalocyanine pigment of the charge generation layer used in the photoreceptor 22 was changed to a Y-type titanyl phthalocyanine pigment (X-ray diffraction spectrum by Cu-Kα characteristic X-ray with a Bragg angle 2θ, maximum at 27.2 ± 0.2 ° Instead of the titanyl phthalocyanine pigment having a peak), a photoconductor 42 was prepared in the same manner as the photoconductor 22 except that the types and amounts of charge transport materials were as shown in Table 9.
[0179]
[Table 9]

[0180]
The same evaluation as in Example 1 was performed using the photosensitive members 29 to 42 described above. The results are shown in Table 10.
[0181]
[Table 10]

[0182]
  As is clear from Table 10, the charge transport layer contains a mixture of stereoisomers.The content of the maximum isomer component is in the range of 40 to 90% by mass.The photoconductors 29 to 33 containing a charge transport material and having a charge transport layer having a Tgl higher than 100 ° C. have good image characteristics such as image density, fog, and resolution, and images such as environmental memory, black spots, and white spots. There are few defects and all characteristics are improved in a balanced manner. On the other hand, even if the Tgl of the charge transport layer is higher than 115 ° C., 113 ° C., 117 ° C. and 100 ° C., the photoreceptors 34, 35 and 36 in which the charge transport material is not a stereoisomer mixture have a large decrease in image density. Has deteriorated. Further, even if the charge transport material is a stereoisomer mixture, the occurrence of white spots on the photoconductors 37 to 41 having a Tgl of the charge transport layer lower than 100 ° C. is increased and the resolution is deteriorated. In addition, the photoreceptor 42 using the Y-type titanyl phthalocyanine pigment as a charge generating substance has a significant deterioration in environmental memory and resolution.
[0183]
【The invention's effect】
As is clear from the examples, by using the organic photoreceptor having the configuration of the present invention, a sharp electrophotographic image can be obtained without generating environmental memory, white spots or black spots. Further, it is possible to provide an image forming method, an image forming apparatus and a process cartridge capable of achieving a good electrophotographic image using the organic photoreceptor.
[Brief description of the drawings]
FIG. 1 shows an X-ray diffraction spectrum of a titanyl phthalocyanine pigment having remarkable diffraction peaks at 7.5 ° and 28.7 °.
FIG. 2 shows an X-ray diffraction spectrum of a titanyl phthalocyanine pigment having a maximum peak at 27.2 ± 0.2 °.
FIG. 3 is a cross-sectional configuration diagram of an image forming apparatus as an example of the image forming method of the present invention.
[Explanation of symbols]
50 Photosensitive drum (photosensitive member)
51 Pre-charge exposure section
52 Charger
53 Image exposure unit
54 Developer
541 Development Sleeve
543,544 Developer stirring and conveying member
547 Potential sensor
57 Feed roller
58 Transfer electrode
59 Separation electrode (separator)
60 Fixing device
61 Paper discharge roller
62 Cleaning device
70 Process cartridge

Claims (15)

X-ray diffraction by Cu-Kα characteristic X-rays in an organic photoreceptor in which a charge generation layer containing a charge generation material on a conductive support and a charge transport layer having a charge transport material thereon are laminated. It contains a titanyl phthalocyanine pigment having a prominent diffraction peak at a Bragg angle (2θ ± 0.2 °) of 7.5 ° and 28.7 ° in the spectrum, and the charge transport layer is a bis (arylethenylphenyl) aniline system A mixture of stereoisomers of the compound and a charge transport material having a content of the largest isomer component in the stereoisomer mixture of 40 to 90% by mass, and a glass transition point Tgb of the binder resin of the charge transport layer; An organic photoreceptor, wherein a glass transition point Tgl of the charge transport layer satisfies the following relationship.
100 ° C. <Tgl <Tgb (both Tgb and Tgl, the unit is ° C.) The titanyl phthalocyanine pigment is an X-ray diffraction spectrum by Cu-Kα characteristic X-ray, and Bragg angles (2θ ± 0.2 °) of 7.5 °, 22.6 °, 24.5 °, 25.4 °, 28. 7 ° to have a significant diffraction peaks, and photoreceptors maximum diffraction peak is characterized by a 7.5 ° or 28.7 °. The organophotoreceptor according to claim 1 or 2, wherein the bis (arylethenylphenyl) aniline compound is a compound represented by the following general formula (1).

[In general formula (1), R ¹ , R ² , R ^Three , R ^Four , R ^Five Are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group. Ar ¹ Is a hydrogen atom or a substituted or unsubstituted aromatic group, Ar ² Represents a substituted or unsubstituted aromatic group. ] The organophotoreceptor according to claim 1, wherein the bis (arylethenylphenyl) aniline compound is a compound represented by the following general formula (2).

[In general formula (2), R ¹ , R ² , R ^Three , R ^Four Are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group. Ar ¹ Is a hydrogen atom or a substituted or unsubstituted aromatic group, Ar ² Represents a substituted or unsubstituted aromatic group. ] The organophotoreceptor according to claim 1 or 2, wherein the bis (arylethenylphenyl) aniline compound is a compound represented by the following general formula (3).

[In general formula (3), R ¹ , R ² , R ^Three , R ^Four Are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group. Ar ¹ Is a hydrogen atom or a substituted or unsubstituted aromatic group, Ar ² Represents a substituted or unsubstituted aromatic group. ] The organophotoreceptor according to claim 1 or 2, wherein the bis (arylethenylphenyl) aniline compound is a compound represented by the following general formula (4).

[In general formula (4), R ¹ , R ² , R ^Three Are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group. Ar ¹ Is a hydrogen atom or a substituted or unsubstituted aromatic group, Ar ² Represents a substituted or unsubstituted aromatic group. ] The organophotoreceptor according to claim 1 or 2, wherein the bis (arylethenylphenyl) aniline compound is a compound represented by the following general formula (5).

[In general formula (5), R ¹ , R ² , R ^Three Are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group. Ar ¹ Is a hydrogen atom or a substituted or unsubstituted aromatic group, Ar ² Represents a substituted or unsubstituted aromatic group. ] The organophotoreceptor according to claim 1, wherein the bis (arylethenylphenyl) aniline compound is a compound represented by the following general formula (6).

[In general formula (6), R ¹ , R ² Are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group. Ar ¹ Is a hydrogen atom or a substituted or unsubstituted aromatic group, Ar ² Represents a substituted or unsubstituted aromatic group. ] Ar ¹ , Ar ² The organic photoreceptor of any one of claims 3 to 8, wherein the substituted or unsubstituted aromatic group is represented by the following general formula (7).

[In general formula (7), R ⁶ ~ R ¹⁷ Are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, a halogenated alkyl group having 1 to 4 carbon atoms, a halogen atom or an alkoxy group having 1 to 4 carbon atoms. ] The organic photoreceptor according to claim 1, wherein the main binder resin of the charge transport layer is polycarbonate. The organic photoreceptor according to claim 1, further comprising an intermediate layer between the conductive support and the charge generation layer. 12. The organic photoreceptor according to claim 11, wherein the intermediate layer contains N-type semiconductive fine particles and a binder resin. An image forming method comprising forming an electrophotographic image using the organophotoreceptor according to claim 1. An image forming apparatus that forms an electrophotographic image using the image forming method according to claim 13. It has at least one of the organic photoreceptor according to any one of claims 1 to 12 and a charger, an image exposure device, a developing device, a transfer device, and a cleaning device as one body, and is taken in and out of the image forming apparatus. A process cartridge configured to be capable of being configured.

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