JP3876667B2 - Organic photoconductor, image forming apparatus, image forming method, and process cartridge - Google Patents

Description

【０１０１】
【化１１】

【０１０２】
【化１２】

【０１０３】
例示化合物の略記号は、以下の意味を示す。
４−Ｍｅ：フェニル基の４−位に置換するメチル基
３−Ｍｅ：フェニル基の３−位に置換するメチル基
４−Ｃｌ：フェニル基の４−位に置換する塩素原子
４−ＭｅＯ：フェニル基の４−位に置換するメトキシ基
４−Ｆ：フェニル基の４−位に置換するフッ素原子
一般式（３）の化合物例
【０１０４】
【化１３】

【０１０５】
【化１４】

【０１０６】
【化１５】

【０１０７】
例示化合物の略記号は、以下の意味を示す。
４−Ｍｅ：フェニル基の４−位に置換するメチル基
３−Ｍｅ：フェニル基の３−位に置換するメチル基
４−Ｃｌ：フェニル基の４−位に置換する塩素原子
４−ＭｅＯ：フェニル基の４−位に置換するメトキシ基
４−Ｆ：フェニル基の４−位に置換するフッ素原子
４−Ｂｒ：フェニル基の４−位に置換する臭素原子
一般式（４）の化合物例
【０１０８】
【化１６】

【０１０９】
【化１７】

【０１１０】
【化１８】

【０１１１】
【化１９】

【０１１２】
上記の一般式（４）の例示化合物の中で４−５、４−１５、４−１７、４−１８、４−１９、４−２２、４−２３、４−２９、４−３０が特に好ましい。
【０１１３】
次に上記中間層、電荷輸送層を含めて本発明の感光体の構成について記載する。
【０１１４】
導電性支持体
本発明の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。
【０１１５】
本発明の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。この真円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。
【０１１６】
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。
【０１１７】
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。
【０１１８】
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前記した中間層を設ける。
【０１１９】
感光層
本発明の感光体の感光層構成は前記中間層上に電荷発生層（ＣＧＬ）と電荷輸送層（ＣＴＬ）に分離した構成を有する。機能を分離した構成を取ることにより繰り返し使用に伴う残留電位増加を小さく制御でき、その他の電子写真特性を目的に合わせて制御しやすい。
【０１２０】
電荷発生層
電荷発生層には電荷発生物質（ＣＧＭ）を含有する。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。
【０１２１】
電荷発生物質（ＣＧＭ）としては公知の電荷発生物質（ＣＧＭ）を用いることができる。例えば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用いることができる。これらの中で繰り返し使用に伴う残留電位増加を最も小さくできるＣＧＭは複数の分子間で安定な凝集構造をとりうる立体、電位構造を有するものであり、具体的には特定の結晶構造を有するフタロシアニン顔料、ペリレン顔料のＣＧＭが挙げられる。例えばＣｕ−Ｋα線に対するブラッグ角２θが２７．２°に最大ピークを有するチタニルフタロシアニン、同２θが１２．４に最大ピークを有するベンズイミダゾールペリレン等のＣＧＭは繰り返し使用に伴う劣化がほとんどなく、残留電位増加小さくすることができる。
【０１２２】
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。
【０１２３】
電荷輸送層
電荷輸送層には電荷輸送物質（ＣＴＭ）及び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。
【０１２４】
電荷輸送物質（ＣＴＭ）としては前記の一般式（１）〜（４）の電荷輸送物質（ＣＴＭ）の他に感度等を調整するために、他の電荷輸送物質を併用しても良い。併用するＣＴＭとしては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。これらの中で繰り返し使用に伴う残留電位増加を最も小さくできるＣＴＭの併用は、相互のＣＴＭ間のイオン化ポテンシャル差が０．５（ｅＶ）以下の特性を有するものであり、好ましくは０．２５（ｅＶ）以下である。
【０１２５】
ＣＧＭ、ＣＴＭのイオン化ポテンシャルは表面分析装置ＡＣ−１（理研計器社製）で測定される。
【０１２６】
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。
【０１２７】
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。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１０〜５０μｍが好ましい。又、本発明の電荷輸送層は２層以上の多層構成とし、その最上層に保護層としての機能を持たせても良い。
【０１２８】
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。
【０１２９】
【化２０】

【０１３０】
【化２１】

【０１３１】
【化２２】

【０１３２】
【化２３】

【０１３３】
次に、本発明の画像形成装置について説明する。
図１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図である。
【０１３４】
図１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。
【０１３５】
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ー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。
【０１３６】
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。
【０１３７】
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。
【０１３８】
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１のように現像位置上部に設けて行う。
【０１３９】
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。
【０１４０】
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が圧接され、給紙された記録紙Ｐを挟着して転写される。
【０１４１】
次いで記録紙Ｐは転写ローラーとほぼ同時に圧接状態とされた分離電極（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の通過後感光体ドラム５０の周面より退避離間して次なるトナー像の形成に備える。図１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。
【０１４２】
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。
【０１４３】
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。
【０１４４】
本発明の有機電子写真感光体は電子写真複写機、レーザープリンター、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。
【０１４５】
【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。
【０１４６】
感光体１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。
【０１４７】

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。
【０１４８】
〈電荷輸送層〉
電荷輸送物質（例示化合物１−１） ２２５ｇ
ポリカーボネート（粘度平均分子量２０，０００） ３００ｇ
酸化防止剤（例示化合物６−３） ６ｇ
ジクロロメタン ２０００ｍｌ
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。
【０１４９】
感光体２〜２０の作製（感光体９、１０は比較例）
感光体１で用いた中間層の酸化チタン及びその表面処理と粒径、酸化チタン／バインダー樹脂質量比、溶剤及び乾燥膜厚と電荷輸送層の電荷輸送物質を表１、表２に示す様にした他は感光体１と同様にしてそれぞれ感光体２〜２０を作製した。
【０１５０】
感光体９、１０で用いた電荷輸送物質５−１及び５−２は下記構造の化合物である。
【０１５１】
【化２４】

【０１５２】
感光体２１の作製（比較例）
感光体１で用いた中間層の酸化チタンを除きポリアミド樹脂層の中間層を乾燥膜厚０．５μｍで形成した他は感光体１と同様にして感光体２１を作製した。
【０１５３】
感光体２２〜２５の作製（比較例）
感光体１の酸化チタンを数平均粒径１５μｍのオクチルシラン表面処理シリカ粒子に変更し、電荷輸送層中の電荷輸送物質を表２記載の化合物にした以外は感光体１と同様にして感光体２２〜２５を作製した。
【０１５４】
【表１】

【０１５５】
【表２】

【０１５６】
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１〜２５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（３０℃、８０％ＲＨ）と低温低湿環境（１０℃、３０％ＲＨ）の両方で、それぞれ連続１万枚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。
【０１５７】
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
解像度（文字画像の判別容易性で判定）
○：初期と１万枚コピー後の解像度に差がない
△：ハーフトーン画像で１万枚コピー後の解像度に軽微な低下有り
×：１万枚コピー後の解像度に顕著な低下有り
黒ポチ（初期及び１万枚コピー後のベタ白画像で評価）
黒ポチの評価は、長径が０．４ｍｍ以上の黒ポチがＡ４紙当たり何個あるかで判定した。尚、黒ポチ長径はビデオプリンター付き顕微鏡等で測定できる。黒ポチ評価の判定基準は、下記に示す通りである。
【０１５８】
Ａ：０．４ｍｍ以上の黒ポチ頻度：全ての複写画像が３個／Ａ４以下
Ｂ：０．４ｍｍ以上の黒ポチ頻度：４個／Ａ４以上、１９個／Ａ４以下
が１枚以上発生
Ｃ：０．４ｍｍ以上の黒ポチ頻度：２０個／Ａ４以上が１枚以上発生
白抜け（初期及び１万枚コピー後のハーフトーン画像で評価）
白抜けの評価は、長径が０．４ｍｍ以上の白抜けがＡ４紙当たり何個あるかで判定した。尚、白抜け長径はビデオプリンター付き顕微鏡等で測定できる。白抜け評価の判定基準は、下記に示す通りである。
【０１５９】
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
ΔＶ₁₂の評価（高温高湿環境で評価）
上記各１万枚コピー後、１時間の休止をはさんでΔＶ₁₂の評価を行った。現像位置に電位センサーを設置し、感光体の１回転目と２回転目の黒べた部電位を測定し、その差の絶対値をΔＶ₁₂とした。
【０１６０】
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。
【０１６１】
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。
【０１６２】
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
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（ｇ／ｃｍ）となるように重り荷重方式で当接した。
【０１６３】
評価結果を表３に示した。
【０１６４】
【表３】

【０１６５】
表３から明らかなように本発明の中間層が、複数回の表面処理を施され且つ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であるＮ型半導性微粒子と、バインダー樹脂を含有しており、電荷輸送層が前記一般式（２）、（３）、（４）で表される化合物を含有する感光体２〜８、１１〜１３、１６〜１８は、画像濃度、カブリ、解像度等の画像特性が良好であり、電位変動特性（ΔＶ₁₂）及び黒ポチ、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て、対応する比較例の感光体９、１０、１４（感光体１３の比較例）、感光体２３〜２５に対して優れた改善効果を示している。
【０１６６】
即ち、中間層は本発明の構成でも電荷輸送層の電荷輸送物質が本発明外の感光体９，１０では白抜け発生が著しく、カブリも発生している。又、中間層が本発明外の感光体２３〜２５では黒ポチ発生が著しく、解像度、カブリの評価も悪い。又、フッ素原子を有する有機ケイ素化合物の表面処理を受けている酸化チタンを含有する中間層の感光体１、感光体１４も、本願発明の感光体１３に比しカブリの改善効果が劣っている。
【０１６７】
【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、黒ポチや白ヌケが発生せず又初期の電位変動が小さい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】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図。
【符号の説明】
５０ 感光体ドラム（又は感光体）
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 photoreceptors (hereinafter also simply referred to as photoreceptors) are mainly organic photoreceptors that are excellent in advantages such as pollution and ease of manufacture, from inorganic photoreceptors such as Se, arsenic, arsenic / Se alloys, CdS, and ZnO. On the other hand, organic photoreceptors using various materials 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 formation using a halogen lamp as a light source and digital image formation 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 photoreceptor.
[0006]
Also, in digital writing, the writing speed is slow because the exposure beam diameter is small. For this reason, a combination with reversal development is mainly used as a developing method for the exposed portion. However, as a problem specific to an image forming method using this reversal development, the toner should be formed at a place where an image should be originally formed as a white background portion. It is known that the phenomenon of fogging due to adhesion of the toner, that is, the occurrence of black spots due to local defects of the photoreceptor.
[0007]
In order to solve these problems, a technique using an intermediate layer for an organic photoreceptor has been developed. For example, an electrophotographic photoreceptor having a structure in which an intermediate layer is provided between a conductive support and a photosensitive layer, and titanium oxide particles are dispersed in a resin in the intermediate layer is known. In addition, a technique for an intermediate layer containing titanium oxide subjected to surface treatment is also known. For example, iron oxide disclosed in JP-A-4-303846, titanium oxide surface-treated with tungsten oxide, titanium oxide surface-treated with an amino group-containing coupling agent disclosed in JP-A-9-96916, and JP-A-9-258469. Titanium oxide surface-treated with an organosilicon compound, titanium oxide surface-treated with methyl hydrogen polysiloxane disclosed in JP-A-8-328283, metal oxide disclosed in JP-A-11-344826, or surface-treated with an organic compound An organic photoreceptor having an intermediate layer using dendritic titanium oxide has been proposed.
[0008]
However, even under these harsh environments such as high temperature and high humidity using these technologies, the prevention of black spots is not sufficient, or the residual potential rises due to repeated use, and the exposure portion potential rises. There is a problem that the image density cannot be obtained sufficiently.
[0009]
Furthermore, if the insulation of the intermediate layer is increased to reduce free carriers from the conductive support to the photosensitive layer and the black spots are reduced, image defects called “white spots” opposite to black spots occur. The problem of being easy to do is found. 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 solid black image. This phenomenon does not cause charge to disappear at the image exposure portion when forming a latent image on an organic photoreceptor. This is probably because a minute portion is generated, and is considered to be a phenomenon opposite to the black spot. In this way, in an image forming apparatus using an organic photoreceptor, conflicting image defects such as black black spots on a white background and white white spots on a black background or halftone occur, and an organic photoreceptor that has solved both of these image defects. Development is needed.
[0010]
On the other hand, laser light and LED light are mainly used as an image exposure light source for forming a latent image. Currently, the oscillation wavelength of input light that is most often used is near-infrared light of 780 nm or 660 nm and 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 compounds are relatively easy to synthesize and many exhibit high sensitivity to long-wavelength light, so that organic photoreceptors using phthalocyanine compounds have been widely studied and put into practical use. .
[0011]
For example, JP-B-5-55860 discloses a photoreceptor using titanyl phthalocyanine, JP-A-59-155551 discloses a photoreceptor using β-type indium phthalocyanine, and JP-A-2-233769 discloses a photoreceptor. A photoreceptor using χ-type metal-free phthalocyanine and an organic photoreceptor using vanadyloxyphthalocyanine are disclosed in JP-A No. 61-28557, respectively.
[0012]
In the organophotoreceptor using the phthalocyanine pigment, the charging potential immediately after the image formation is paused for a certain period of time and then restarted is lower than the second and subsequent charging potentials (hereinafter referred to as initial potential fluctuation). ) Have a problem. This phenomenon causes the copy image formed at the first rotation of the photosensitive member to be clearly inferior to that after the second rotation, particularly in the reverse development. As an image defect, it appears as a toner fog on a white background, so it is conspicuous and serious.
[0013]
Also, an image forming apparatus using a transfer electrode for a transfer device for transferring toner to recording paper has a band electrode having a polarity opposite to that of charging when the toner image is transferred to the recording paper by the reversal development process as described above. The layered organic photoconductor used and containing the phthalocyanine compound in the charge generation layer is strongly affected by the reverse charge during transfer, and the image deterioration at the first rotation of the organic photoconductor tends to be noticeable.
[0014]
[Problems to be solved by the invention]
The present invention has been made in view of the above-mentioned problems of the prior art, and provides an organic photoreceptor having good potential stability and free from image defects such as black spots and white spots, and more specifically, black spots and white spots. It is an object of the present invention to provide a good organic photoconductor that does not cause image defects such as missing and has a small initial potential fluctuation, and an image forming method, an image forming apparatus, and a process cartridge using the organic photoconductor.
[0015]
[Means for Solving the Problems]
The object of the present invention has been achieved by adopting the following photoconductor structure as a result of studying each layer constituting the photoconductor.
[0017]
  1. In an organic photoreceptor having a laminated structure of a charge generation layer and a charge transport layer via an intermediate layer on a conductive support, the intermediate layer comprisesN-type semiconductive fine particles that have been subjected to a plurality of surface treatments and the final surface treatment is a surface treatment with a reactive organosilicon compound;An organic photoreceptor comprising a binder resin, wherein the charge transport layer contains a compound represented by the general formula (2).
[0018]
  2. In an organic photoreceptor having a laminated structure of a charge generation layer and a charge transport layer via an intermediate layer on a conductive support, the intermediate layer comprisesN-type semiconductive fine particles that have been subjected to a plurality of surface treatments and the final surface treatment is a surface treatment with a reactive organosilicon compound;An organic photoreceptor comprising a binder resin, wherein the charge transport layer contains a compound represented by the general formula (3).
[0019]
  3. In an organic photoreceptor having a laminated structure of a charge generation layer and a charge transport layer via an intermediate layer on a conductive support, the intermediate layer comprisesN-type semiconductive fine particles that have been subjected to a plurality of surface treatments and the final surface treatment is a surface treatment with a reactive organosilicon compound;An organic photoreceptor comprising a binder resin, wherein the charge transport layer contains a compound represented by the general formula (4).
[0021]
  4. The reactive organosilicon compound is methyl hydrogen polysiloxaneAny one of 1-3The organic photoreceptor described in 1.
[0022]
  5. The reactive organosilicon compound is a compound represented by the general formula (6),Any one of 1-3The organic photoreceptor described in 1.
[0023]
  6. R in the general formula (6) is an alkyl group having 4 to 8 carbon atoms,5The organic photoreceptor described in 1.
[0024]
  7. Of the plurality of surface treatments, at least one surface treatment is at least one kind of surface treatment of alumina, silica and zirconia.1-6The organophotoreceptor according to any one of the above.
[0025]
  8. The N-type semiconductor fine particles are subjected to a surface treatment of either or both of alumina and silica, and then a surface treatment of a reactive organosilicon compound.1-7The organophotoreceptor according to any one of the above.
[0026]
  9. The N-type semiconductive fine particles are subjected to a surface treatment of a reactive organosilicon compound having a fluorine atom.3The organophotoreceptor according to any one of the above.
[0027]
  10. The N-type semiconductive fine particles are subjected to a surface treatment with at least silica or alumina, and then a surface treatment using a reactive organotitanium compound.3The organophotoreceptor according to any one of the above.
[0028]
  11. The N-type semiconductive fine particles are subjected to a surface treatment with at least silica or alumina, and then a surface treatment using a reactive organozirconium compound.3The organophotoreceptor according to any one of the above.
[0029]
  12. The N-type semiconductive fine particles are metal oxide particles,11The organophotoreceptor according to any one of the above.
[0030]
  13. The number average primary particle size of the N-type semiconductive fine particles is 10 nm or more and 200 nm or less.12The organophotoreceptor according to any one of the above.
[0031]
  14. The N-type semiconductive fine particles are titanium oxide particles,13The organophotoreceptor according to any one of the above.
[0032]
  15. 1 to 3 above, wherein the binder of the intermediate layer is polyamide.14The organophotoreceptor according to any one of the above.
[0033]
  16. 1 to15An image forming method comprising forming an electrophotographic image using the organophotoreceptor according to any one of the above.
[0034]
  17. Said16An image forming apparatus that forms an electrophotographic image using the image forming method described in 1.
[0035]
  18. At least said 115The 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.
[0036]
  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 having a laminated structure of a charge generation layer and a charge transport layer via an intermediate layer on a conductive support. Type semiconductive fine particles and a binder resin, and the charge transport layer has the general formula (2It contains one or more compounds selected from the compounds represented by (4) to (4).
[0037]
That is, when an electrophotographic image is formed by reversal development using the organic photoreceptor having the above structure, it is possible to prevent the occurrence of both black spots and white defects and to form a large number of images continuously. The initial potential fluctuation is suppressed to a small level, the fluctuation of the image density of the first image and the second image of the recording paper can be prevented, and a good image can be created from the start.
[0038]
The intermediate layer and photosensitive layer of the present invention will be described below.
The N-type semiconducting fine particles used in the intermediate layer of the present invention 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.
[0039]
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.
[0040]
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 200 nm in the number average primary particle diameter, more preferably 10 nm to 100 nm, and particularly preferably 15 nm to 50 nm. .
[0041]
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.
[0042]
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.
[0043]
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.
[0044]
One of the surface treatments performed on the N-type semiconducting fine particles of the present invention is a plurality of surface treatments, and the last surface treatment is a surface made of a reactive organosilicon compound. The processing 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.
[0045]
Alumina treatment, silica treatment, and zirconia treatment are treatments for precipitating alumina, silica, or zirconia on the surface of the N-type semiconductive fine particles. Alumina, silica, and zirconia deposited on these surfaces include alumina, silica, Zirconia hydrates are also included. The surface treatment of the reactive organosilicon compound means using a reactive organosilicon compound in the treatment liquid.
[0046]
In addition, as another method of the surface treatment performed on the N-type semiconducting fine particles of the present invention, a plurality of surface treatments are performed, and among the plurality of surface treatments, the last surface treatment is reactive organic. Surface treatment is performed using a titanium compound or a reactive organic zirconium compound. Further, in the plurality of surface treatments, at least one surface treatment is performed by at least one kind of surface treatment selected from alumina, silica, and zirconia, and finally the reactive organic titanium compound or reaction It is preferable to perform surface treatment with a conductive organic zirconium compound.
[0047]
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 semiconducting fine particles are used in the intermediate layer, a good photoconductor having good dispersibility of N-type semiconductive fine particles such as titanium oxide particles in the intermediate layer and causing no image defects such as black spots. You can get it.
[0048]
In addition, the surface treatment of alumina and silica is performed multiple times, followed by surface treatment with a reactive organosilicon compound, and a reactive organotitanium compound or reactive organozirconium after the surface treatment of alumina and silica. What performs the surface treatment using a compound is particularly preferable.
[0049]
In addition, although the above-mentioned treatment of alumina and silica may be performed simultaneously, it is preferable to perform the alumina treatment first and then the silica treatment. Further, the amount of treatment of alumina and silica when treating alumina and silica is preferably higher than that of alumina.
[0050]
The surface treatment of the N-type semiconductive fine particles such as titanium oxide with a metal oxide such as alumina, silica, and zirconia can be performed by a wet method. For example, N-type semiconducting fine particles subjected to surface treatment of silica or alumina can be produced as follows.
[0051]
When titanium oxide particles are used as the N-type semiconductive fine particles, titanium oxide particles (number average primary particle size: 50 nm) are dispersed in water at a concentration of 50 to 350 g / L to form an aqueous slurry. Add acid salt or water-soluble aluminum compound. Thereafter, alkali or acid is added for neutralization, and silica or alumina is precipitated on the surface of the titanium oxide particles. Subsequently, filtration, washing, and drying are performed to obtain the target surface-treated titanium oxide. When sodium silicate is used as the water-soluble silicate, it can be neutralized with an acid such as sulfuric acid, nitric acid or hydrochloric acid. On the other hand, when aluminum sulfate is used as the water-soluble aluminum compound, it can be neutralized with an alkali such as sodium hydroxide or potassium hydroxide.
[0052]
In addition, the amount of the metal oxide used for the surface treatment is 0.1 to 50 parts by mass with respect to 100 parts by mass of the N-type semiconductive fine particles such as titanium oxide particles in the charged amount during the surface treatment. More preferably, 1 to 10 parts by mass of a metal oxide is used. In the case of using alumina and silica as described above, for example, in the case of titanium oxide particles, it is preferable to use 1 to 10 parts by mass with respect to 100 parts by mass of titanium oxide particles, and it is preferable that the amount of silica is larger than that of alumina. .
[0053]
The surface treatment with the reactive organosilicon compound performed after the surface treatment with the metal oxide is preferably performed by the following wet method.
[0054]
That is, titanium oxide treated with the metal oxide is added to a solution obtained by dissolving or suspending the reactive organosilicon compound in an organic solvent or water, and the solution is stirred for several minutes to 1 hour. And depending on the case, after heat-processing this liquid, it passes through processes, such as filtration, and is dried, The titanium oxide particle which coat | covered the surface with the organosilicon compound is obtained. Note that the reactive organosilicon compound may be added to a suspension in which titanium oxide is dispersed in an organic solvent or water.
[0055]
In the present invention, the surface of the titanium oxide particles is coated with a reactive organosilicon compound because photoelectron spectroscopy (ESCA), Auger electron spectroscopy (Auger), secondary ion mass spectrometry (SIMS), and diffuse reflection. This is confirmed by combining surface analysis techniques such as FI-IR.
[0056]
The amount of the reactive organosilicon compound used for the surface treatment is 0.1 to 10 parts by weight of the reactive organosilicon compound with respect to 100 parts by mass of titanium oxide treated with the metal oxide in the charge amount during the surface treatment. 50 mass parts, More preferably, 1-10 mass parts is preferable. When the surface treatment amount is less than the above range, the surface treatment effect is not sufficiently imparted, and the dispersibility of the titanium oxide particles in the intermediate layer is deteriorated. Further, when the above range is exceeded, the electrophotographic characteristics are deteriorated, and as a result, the residual potential is increased and the charged potential is decreased.
[0057]
Examples of the reactive organosilicon compound used in the present invention include compounds represented by the following general formula (5). If the compound has a condensation reaction with a reactive group such as a hydroxyl group on the titanium oxide surface, the following compound is used. It is not limited to.
[0058]
General formula (5)
(R)_n-Si- (X)_4-n
(In the formula, Si represents a silicon atom, R represents an organic group in which carbon is directly bonded to the silicon atom, X represents a hydrolyzable group, and n represents an integer of 0 to 3.)
In the organosilicon compound represented by the general formula (5), an organic group in which carbon is directly bonded to silicon represented by R includes alkyl such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, and dodecyl. Group, aryl group such as phenyl, tolyl, naphthyl, biphenyl, epoxy-containing group such as γ-glycidoxypropyl, β- (3,4-epoxycyclohexyl) ethyl, γ-acryloxypropyl, γ-methacryloxypropyl (Meth) acryloyl group, hydroxyl group such as γ-hydroxypropyl and 2,3-dihydroxypropyloxypropyl, vinyl group such as vinyl and propenyl, mercapto group such as γ-mercaptopropyl, γ-aminopropyl, Amino-containing groups such as N-β (aminoethyl) -γ-aminopropyl, γ-chloropropyl, , 1,1-tri fluoroalkyl propyl, nonafluorohexyl, halogen-containing groups such as perfluorooctylethyl, other nitro, and cyano-substituted alkyl group. Examples of the hydrolyzable group for X include alkoxy groups such as methoxy and ethoxy, halogen groups, and acyloxy groups.
[0059]
Moreover, the organosilicon compound represented by General formula (5) may be individual, and may be used in combination of 2 or more type.
[0060]
Moreover, in the specific compound of the organosilicon compound represented by the general formula (5), when n is 2 or more, a plurality of R may be the same or different. Similarly, when n is 2 or less, the plurality of Xs may be the same or different. Moreover, when using 2 or more types of organosilicon compounds represented by General formula (5), R and X may be the same between each compound, and may differ.
[0061]
Examples of compounds in which n is 0 include the following compounds.
Tetrachlorosilane, diethoxydichlorosilane, tetramethoxysilane, phenoxytrichlorosilane, tetraacetoxysilane, tetraethoxysilane, tetraallyloxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetrakis (2-methoxyethoxy) silane, tetrabutoxysilane , Tetraphenoxysilane, tetrakis (2-ethylbutoxy) silane, tetrakis (2-ethylhexyloxy) silane, and the like.
[0062]
Examples of the compound in which n is 1 include the following compounds.
That is, trichlorosilane, methyltrichlorosilane, vinyltrichlorosilane, ethyltrichlorosilane, allyltrichlorosilane, n-propyltrichlorosilane, n-butyltrichlorosilane, chloromethyltriethoxysilane, methyltrimethoxysilane, mercaptomethyltrimethoxysilane, Trimethoxyvinylsilane, ethyltrimethoxysilane, 3,3,4,4,5,5,6,6,6-nonafluorohexyltrichlorosilane, phenyltrichlorosilane, 3,3,3-trifluoropropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, triethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 2-aminoethylaminomethyltrimethoxysilane, benzene Rutrichlorosilane, methyltriacetoxysilane, chloromethyltriethoxysilane, ethyltriacetoxysilane, phenyltrimethoxysilane, 3-allylthiopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-bromopropyltriethoxysilane 3-allylaminopropyltrimethoxysilane, propyltriethoxysilane, hexyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, bis (ethylmethylketoxime) methoxymethylsilane, pentyltri Examples include ethoxysilane, octyltriethoxysilane, dodecyltriethoxysilane, and the like.
[0063]
Examples of compounds in which n is 2 include the following compounds.
Dimethyldichlorosilane, dimethoxymethylsilane, dimethoxydimethylsilane, methyl-3,3,3-trifluoropropyldichlorosilane, diethoxysilane, diethoxymethylsilane, dimethoxymethyl-3,3,3-trifluoropropylsilane, 3 -Chloropropyldimethoxymethylsilane, chloromethyldiethoxysilane, diethoxydimethylsilane, dimethoxy-3-mercaptopropylmethylsilane, 3,3,4,4,5,5,6,6,6-nonafluorohexylmethyldi Chlorosilane, methylphenyldichlorosilane, diacetoxymethylvinylsilane, diethoxymethylvinylsilane, 3-methacryloxypropylmethyldichlorosilane, 3-aminopropyldiethoxymethylsilane, 3- (2-aminoethylaminopropyl) Pill) dimethoxymethylsilane, t-butylphenyldichlorosilane, 3-methacryloxypropyldimethoxymethylsilane, 3- (3-cyanopropylthiopropyl) dimethoxymethylsilane, 3- (2-acetoxyethylthiopropyl) dimethoxymethylsilane, Dimethoxymethyl-2-piperidinoethylsilane, dibutoxydimethylsilane, 3-dimethylaminopropyldiethoxymethylsilane, diethoxymethylphenylsilane, diethoxy-3-glycidoxypropylmethylsilane, 3- (3-acetoxypropyl) And thio) propyldimethoxymethylsilane, dimethoxymethyl-3-piperidinopropylsilane, and diethoxymethyloctadecylsilane.
[0064]
Examples of compounds in which n is 3 include the following compounds.
Examples include trimethylchlorosilane, methoxytrimethylsilane, ethoxytrimethylsilane, methoxydimethyl-3,3,3-trifluoropropylsilane, 3-chloropropylmethoxydimethylsilane, and methoxy-3-mercaptopropylmethylmethylsilane.
[0065]
The organosilicon compound represented by the general formula (5) is preferably an organosilicon compound represented by the following general formula (6).
[0066]
General formula (6)
R-Si- (X)_Three
In the formula, R represents an alkyl group, an aryl group, and X represents a methoxy group, an ethoxy group, or a halogen atom.
[0067]
In the organosilicon compound represented by the general formula (6), an organosilicon compound in which R is an alkyl group having 4 to 8 carbon atoms is more preferred, and specific examples of preferred compounds include trimethoxy n-butylsilane. , Trimethoxy i-butylsilane, trimethoxyhexylsilane, and trimethoxyoctylsilane.
[0068]
Moreover, a hydrogen reactive polysilicon compound is mentioned as a preferable reactive organosilicon compound used for the last surface treatment. The hydrogen polysiloxane compound having a molecular weight of 1000 to 20000 is generally easily available, and has a good function to prevent the occurrence of black spots.
In particular, when methylhydrogenpolysiloxane is used for the final surface treatment, a good effect can be obtained.
[0069]
Another surface treatment of the titanium oxide of the present invention is titanium oxide particles that have been surface treated with an organosilicon compound having a fluorine atom. It is preferable to perform the surface treatment with the organosilicon compound having a fluorine atom and the wet method described above.
[0070]
That is, an organic silicon compound having a fluorine atom is dissolved or suspended in an organic solvent or water, untreated titanium oxide is added thereto, and such a solution is stirred and mixed for several minutes to 1 hour. In some cases, after heat treatment, the film is dried through a process such as filtration, and the titanium oxide surface is coated with an organosilicon compound having a fluorine atom. Note that the organosilicon compound having a fluorine atom may be added to a suspension in which titanium oxide is dispersed in an organic solvent or water.
[0071]
The titanium oxide surface is covered with an organosilicon compound having a fluorine atom because photoelectron spectroscopy (ESCA), Auger electron spectroscopy (Auger), secondary ion mass spectrometry (SIMS), and diffuse reflection FI. It can be confirmed in a composite manner using a surface analyzer such as -IR.
[0072]
Examples of the organosilicon compound having a fluorine atom used in the present invention include 3,3,4,4,5,5,6,6,6-nonafluorohexyltrichlorosilane, 3,3,3-trifluoropropyltrimethoxy. Silane, methyl-3,3,3-trifluoropropyldichlorosilane, dimethoxymethyl-3,3,3-trifluoropropylsilane, 3,3,4,4,5,5,6,6,6-nonafluoro Examples include hexylmethyldichlorosilane.
[0073]
In the present invention, the final surface treatment performed on the above-mentioned N-type semiconducting fine particles may be performed using a reactive organic titanium compound or a reactive organic zirconium compound. Is performed by a method according to the surface treatment method using the reactive organosilicon compound.
[0074]
The surface of the N-type semiconducting fine particles is coated with a reactive organic titanium compound or a reactive organic zirconium compound. This is because photoelectron spectroscopy (ESCA), Auger electron spectroscopy (Auger), and secondary ion mass spectrometry. This method can be confirmed with high accuracy by using a combination of surface analysis methods such as SIMS and diffuse reflection FI-IR.
[0075]
Specific reactive organic titanium compounds used for the surface treatment of the N-type semiconductor fine particles include metal alkoxide compounds such as tetrapropoxy titanium and tetrabutoxy titanium, diisopropoxytitanium bis (acetylacetate), and diisopropoxy. Examples thereof include metal chelate compounds such as titanium bis (ethyl acetoacetate), diisopropoxytitanium bis (lactate), dibutoxytitanium bis (octylene glycolate), and diisopropoxytitanium bis (triethanolaminate). Examples of the reactive organic zirconium compound include metal alkoxide compounds and metal chelate compounds such as tetrabutoxyzirconium and butoxyzirconium tri (acetyl acetate).
[0076]
Next, N-type semiconducting fine particles (hereinafter also referred to as surface-treated N-type semiconducting fine particles) such as titanium oxide particles subjected to the surface treatment. The structure of the intermediate layer using the treated titanium oxide) will be described.
[0077]
The intermediate layer according to the present invention comprises a liquid obtained by dispersing surface-treated N-type semiconductive fine particles such as surface-treated titanium oxide obtained by performing the surface treatment a plurality of times in a solvent together with a binder resin on a conductive support. It is produced by applying to.
[0078]
The intermediate layer of the present invention is provided between the conductive support and the photosensitive layer, and has a barrier function for improving adhesion between the conductive support and the photosensitive layer and preventing charge injection from the support. Examples of the binder resin for the intermediate layer include polyamide resins, vinyl chloride resins, vinyl acetate resins, polyvinyl acetal resins, polyvinyl butyral resins, polyvinyl alcohol resins, melamine resins, epoxy resins, alkyd resins, and other thermosetting resins. And a copolymer resin containing two or more of the repeating units. Among these binder resins, polyamide resins are particularly preferable, and alcohol-soluble polyamides such as copolymerization and methoxymethylolation are particularly preferable.
[0079]
The amount of the surface-treated N-type semiconductive fine particles of the present invention dispersed in the binder resin is, for example, in the case of surface-treated titanium oxide, 10 to 10,000 parts by weight, preferably 100 parts by weight of the binder resin. Is 50 to 1,000 parts by mass. By using the surface-treated titanium oxide within this range, the dispersibility of the titanium oxide can be kept good, black spots are not generated, and a good intermediate layer with little initial potential fluctuation can be formed.
[0080]
The thickness of the intermediate layer of the present invention is preferably 0.5 to 15 μm. By using the film thickness within the above range, it is possible to form an intermediate layer having good electrophotographic characteristics in which black spots do not occur and initial potential fluctuation is small.
[0081]
The intermediate layer coating solution prepared for forming the intermediate layer of the present invention is composed of the surface-treated N-type semiconductive fine particles such as surface-treated titanium oxide, a binder resin, a dispersion solvent, and the like. The same solvent as that used for the production of the photosensitive layer is appropriately used.
[0082]
That is, the solvent or dispersion medium used for forming the intermediate layer, photosensitive layer, and other resin layers of the present invention includes n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N, N-dimethylformamide. , Acetone, 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, Ruserosorubu, and the like.
[0083]
The intermediate layer coating solution solvent is not limited to these, but methanol, ethanol, butanol, 1-propanol, isopropanol, and the like are preferably used. These solvents may be used alone or as a mixed solvent of two or more.
[0084]
Further, as the intermediate layer coating solvent, it is preferable to use a mixed solvent of methanol and linear alcohol having high resin solubility in order to prevent the occurrence of drying unevenness during the intermediate layer coating, and the preferred solvent ratio is What mixed linear alcohol with the ratio of 0.05-0.6 with respect to methanol 1 by volume ratio is good. Thus, by using a coating solvent as a mixed solvent, the evaporation rate of the solvent can be maintained appropriately, and the occurrence of image defects due to drying unevenness during coating can be suppressed.
[0085]
As a means for dispersing the surface-treated titanium oxide used for the preparation of the intermediate layer coating solution, any means such as a sand mill, a ball mill, or an ultrasonic dispersion may be used.
[0086]
As the coating processing method for producing the electrophotographic photosensitive member of the present invention including the intermediate layer, coating processing methods such as dip coating, spray coating, and circular amount regulation type coating are used. In order to achieve a uniform coating process, it is preferable to use a coating process method such as spray coating or circular amount regulation type (a typical example is a circular slide hopper type). . 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.
[0087]
Next, the photosensitive layer laminated on the intermediate layer 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.
[0088]
The layer structure of the organic photoreceptor has a structure in which a charge generation layer and a charge transport layer are coated on the intermediate layer.
[0089]
  If necessary, the charge transport layer may be composed of two or more layers.
  In the present invention, the general formula (2) To (4) are contained as a charge transport material.
[0090]
That is, the organophotoreceptor of the present invention comprises the above-described intermediate layer on a conductive support, and a charge generation layer and a charge transport layer as described above on the conductive support. As a result, it is possible to prevent both image defects and white image defects, and to obtain a clear electrophotographic image in which the initial potential fluctuation is small and the initial image density fluctuation is prevented.
[0091]
  The general formula (2) To (4) are shown as specific compound examples, but the present invention can be used effectively with compounds other than these specific examples.
[0099]
Example of compound of general formula (2)
[0100]
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[0101]
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[0102]
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[0103]
The abbreviations of the exemplified compounds have the following meanings.
4-Me: methyl group substituted at the 4-position of the phenyl group
3-Me: methyl group substituted at the 3-position of the phenyl group
4-Cl: Chlorine atom substituted at the 4-position of the phenyl group
4-MeO: a methoxy group substituted at the 4-position of the phenyl group
4-F: a fluorine atom substituted at the 4-position of the phenyl group
Example of compound of general formula (3)
[0104]
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[0105]
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[0106]
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[0107]
The abbreviations of the exemplified compounds have the following meanings.
4-Me: methyl group substituted at the 4-position of the phenyl group
3-Me: methyl group substituted at the 3-position of the phenyl group
4-Cl: Chlorine atom substituted at the 4-position of the phenyl group
4-MeO: a methoxy group substituted at the 4-position of the phenyl group
4-F: a fluorine atom substituted at the 4-position of the phenyl group
4-Br: Bromine atom substituted at the 4-position of the phenyl group
Example of compound of general formula (4)
[0108]
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[0109]
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[0110]
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[0111]
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[0112]
Among the exemplified compounds of the general formula (4), 4-5, 4-15, 4-17, 4-18, 4-19, 4-22, 4-23, 4-29, and 4-30 are particularly preferable. preferable.
[0113]
Next, the structure of the photoreceptor of the invention including the intermediate layer and the charge transport layer will be described.
[0114]
Conductive support
The conductive support used in the photoreceptor of the present invention may be either a sheet or a cylinder, but a cylindrical conductive support is more preferable for designing an image forming apparatus in a compact manner.
[0115]
The cylindrical conductive support of the present invention means a cylindrical support necessary for forming an endless image by rotating, and the straightness is in the range of 0.1 mm or less and the deflection is 0.1 mm or less. A conductive support is preferred. Exceeding the roundness and shake range makes it difficult to form a good image.
[0116]
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.
[0117]
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 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.
[0118]
Middle class
In the present invention, the intermediate layer having a barrier function is provided between the conductive support and the photosensitive layer.
[0119]
Photosensitive layer
The photosensitive layer structure of the photoreceptor of the present invention has a structure in which a charge generation layer (CGL) and a charge transport layer (CTL) are separated on the intermediate layer. By adopting a configuration in which the functions are separated, an increase in the residual potential due to repeated use can be controlled to be small, and other electrophotographic characteristics can be easily controlled according to the purpose.
[0120]
Charge generation layer
The charge generation layer contains a charge generation material (CGM). Other substances may contain a binder resin and other additives as necessary.
[0121]
A known charge generation material (CGM) can be used as the charge generation material (CGM). For example, a phthalocyanine pigment, an azo pigment, a perylene pigment, an azulenium pigment, or the like can be used. Among these, the CGM that can minimize the increase in residual potential due to repeated use has a three-dimensional and potential structure that can form a stable aggregate structure among a plurality of molecules. Specifically, a phthalocyanine having a specific crystal structure. CGM of pigments and perylene pigments. For example, CGM such as titanyl phthalocyanine having a maximum peak at a Bragg angle 2θ of 27.2 ° with respect to Cu-Kα ray and benzimidazole perylene having a maximum peak at 2θ of 12.4 has little deterioration due to repeated use. Potential increase can be reduced.
[0122]
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.
[0123]
Charge transport layer
The charge transport layer contains a charge transport material (CTM) and a binder resin that disperses and forms a CTM. Other substances may contain additives such as antioxidants as necessary.
[0124]
As the charge transport material (CTM), in addition to the charge transport materials (CTM) represented by the general formulas (1) to (4), other charge transport materials may be used in combination. Examples of CTM used in combination include triphenylamine derivatives, hydrazone compounds, styryl compounds, benzidine compounds, butadiene compounds, and the like. These charge transport materials are usually dissolved in a suitable binder resin to form a layer. Among these, the combined use of CTM capable of minimizing the increase in residual potential due to repeated use has a characteristic that the difference in ionization potential between the CTMs is 0.5 (eV) or less, preferably 0.25 ( eV) or less.
[0125]
The ionization potential of CGM and CTM is measured with a surface analyzer AC-1 (manufactured by Riken Keiki Co., Ltd.).
[0126]
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, and copolymer resin containing two or more of repeating units of these resins. In addition to these insulating resins, high molecular organic semiconductors such as poly-N-vinylcarbazole can be used.
[0127]
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. 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 50 μm. The charge transport layer of the present invention may have a multilayer structure of two or more layers, and the uppermost layer may have a function as a protective layer.
[0128]
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 organic photoreceptor or on the surface of the organic photoreceptor, It is a substance that has the property of inhibiting. Typical examples include the following compound groups.
[0129]
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[0130]
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[0131]
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[0132]
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[0133]
Next, the image forming apparatus of the present invention will be described.
FIG. 1 is a cross-sectional view of an image forming apparatus as an example of the image forming method of the present invention.
[0134]
In FIG. 1, reference numeral 50 denotes a photosensitive drum (photosensitive member) which is an image bearing member, which is a photosensitive member coated with an organic photosensitive layer on the drum and coated with the resin layer of the present invention, 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.
[0135]
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.
[0136]
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.
[0137]
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.
[0138]
The developer includes, for example, a carrier in which the above ferrite is used as a core and an insulating resin is coated around the carrier, a colorant such as carbon black, a charge control agent, and the low molecular weight polyolefin of the present invention, which is mainly composed of the above styrene acrylic resin. The developer is made up of a toner obtained by externally adding silica, titanium oxide or the like to the colored particles, and the developer is transported to the development zone 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.
[0139]
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.
[0140]
In the transfer area, a transfer electrode (transfer means: transfer device) 58 is pressed against the peripheral surface of the photosensitive drum 50 in synchronization with the transfer timing, and the fed recording paper P is sandwiched and transferred.
[0141]
Next, the recording paper P is neutralized by a separation electrode (separator) 59 brought into a pressure contact state almost simultaneously with the transfer roller, separated by the peripheral surface of the photosensitive drum 50, conveyed to the fixing device 60, and pressure-bonded to the heat roller 601. After the toner is welded by heating and pressurizing the roller 602, the toner is discharged to the outside of the apparatus via the discharge roller 61. The transfer electrode 58 and the separation electrode 59 are retracted away from the peripheral surface of the photosensitive drum 50 after the recording paper P has passed to prepare for the next toner image formation. In FIG. 1, 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.
[0142]
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.
[0143]
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.
[0144]
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, but also displays, recordings, light printing, and plate making using electrophotographic technology. It can also be widely applied to apparatuses such as facsimiles.
[0145]
【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.
[0146]
Production of photoreceptor 1
<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.
[0147]

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.
[0148]
<Charge transport layer>
225 g of charge transport material (Exemplary Compound 1-1)
Polycarbonate (viscosity average molecular weight 20,000) 300 g
Antioxidant (Exemplary Compound 6-3) 6 g
Dichloromethane 2000ml
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.
[0149]
Production of photoconductors 2 to 20 (photoconductors 9 and 10 are comparative examples)
As shown in Tables 1 and 2, the titanium oxide of the intermediate layer used in the photoreceptor 1 and its surface treatment and particle size, titanium oxide / binder resin mass ratio, solvent and dry film thickness, and the charge transport material of the charge transport layer are shown in Tables 1 and 2. Otherwise, Photoconductors 2 to 20 were prepared in the same manner as Photoconductor 1.
[0150]
The charge transport materials 5-1 and 5-2 used in the photoreceptors 9 and 10 are compounds having the following structures.
[0151]
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[0152]
Preparation of photoconductor 21 (comparative example)
Photosensitive member 21 was prepared in the same manner as photosensitive member 1, except that the intermediate layer of the polyamide resin layer was formed with a dry film thickness of 0.5 μm except for the titanium oxide of the intermediate layer used in photosensitive member 1.
[0153]
Production of photoconductors 22 to 25 (comparative example)
Photoreceptor 1 is the same as Photoreceptor 1 except that the titanium oxide of Photoreceptor 1 is changed to octylsilane surface-treated silica particles having a number average particle size of 15 μm, and the charge transport material in the charge transport layer is changed to the compounds shown in Table 2. 22-25 were produced.
[0154]
[Table 1]

[0155]
[Table 2]

[0156]
Evaluation
As an evaluation machine, a digital copying machine Konica 7075 manufactured by Konica (corona charging, laser exposure, reverse development, electrostatic transfer, nail separation, blade cleaning, cleaning auxiliary brush roller adoption process) is used. 25 was mounted 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 harsh, high-temperature and high-humidity environment (30 ° C, 80% RH) and low-temperature and low-humidity environment (10 ° C, 30% RH). A black image was prepared and evaluated as follows.
[0157]
Evaluation criteria
Image density (measured using Macbeth RD-918. Measured with a relative reflection density of “0” as the paper reflection density. Evaluated with initial and 10,000-copy images.)
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 solid white image after initial and 10,000 copies)
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
Resolution (determined by ease of distinguishing character images)
○: There is no difference in the resolution after the initial copy and 10,000 copies
Δ: There is a slight decrease in the resolution after copying 10,000 copies in a halftone image.
×: Significant reduction in resolution after 10,000 copies
Black spot (Evaluated with solid white image after initial and 10,000 copies)
The evaluation of black spots was determined by how many black spots with a major axis of 0.4 mm or more per A4 paper. The major diameter of black spots can be measured with a microscope with a video printer. The criteria for black spot evaluation are as shown below.
[0158]
A: Black spot size of 0.4 mm or more Frequency: All 3 copies / A4 or less
B: Black spot frequency of 0.4 mm or more Frequency: 4 / A4 or more, 19 / A4 or less
1 or more occurrences
C: Black spot frequency of 0.4 mm or more Frequency: 20 / A4 or more occurs 1 or more
White spots (evaluated with halftone images after initial and 10,000 copies)
The evaluation of white spots was determined by the number of white spots having a major axis of 0.4 mm or more per A4 paper. In addition, the hollow long diameter can be measured with a microscope with a video printer. The criteria for the white spot evaluation are as follows.
[0159]
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
ΔV₁₂Evaluation (Evaluated in high temperature and high humidity environment)
ΔV across the 1 hour pause after each 10,000 copies₁₂Was evaluated. A potential sensor is installed at the development position, and the black spot potential at the first and second rotations of the photoconductor is measured, and the absolute value of the difference is ΔV.₁₂It was.
[0160]
Other evaluation conditions
The other evaluation conditions using the digital copying machine Konica 7075 were set to the following conditions.
[0161]
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.
[0162]
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 external addition of titanium, etc.
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 (g / cm) in the counter direction.
[0163]
The evaluation results are shown in Table 3.
[0164]
[Table 3]

[0165]
  As is apparent from Table 3, the intermediate layer of the present inventionHowever, it contains N-type semiconductive fine particles that have been subjected to a plurality of surface treatments and the final surface treatment is a surface treatment with a reactive organosilicon compound, and a binder resin, and the charge transporting layer has the general formula ( Photoreceptor 2 containing compounds represented by 2), (3) and (4)-8, 11-13, 16-18Have good image characteristics such as image density, fog, and resolution, and potential fluctuation characteristics (ΔV₁₂) And image defects such as black spots and white spots are few, and all characteristics have been improved in a balanced manner.Thus, the improvement effect is excellent with respect to the corresponding photoreceptors 9, 10, 14 (comparative example of the photoreceptor 13) and the photoreceptors 23 to 25 of the corresponding comparative example.
[0166]
  That isEven in the structure of the present invention, the intermediate layer has white spots on the photoconductors 9 and 10 other than the present invention, and fog is also generated. Further, the intermediate layer is a photoreceptor 2 outside the present invention.3On the other hand, the occurrence of black spots is remarkable, and the evaluation of resolution and fog is poor.Further, the intermediate layer photoreceptor 1 and photoreceptor 14 containing titanium oxide that has been subjected to a surface treatment of an organosilicon compound having fluorine atoms are also inferior in fogging effect as compared with the photoreceptor 13 of the present invention. .
[0167]
【The invention's effect】
As is clear from the examples, by using the organic photoreceptor having the structure of the present invention, it is possible to obtain a sharp electrophotographic image in which black spots and white spots are not generated and initial potential fluctuation is small. 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 is a cross-sectional view of an image forming apparatus as an example of an image forming method of the present invention.
[Explanation of symbols]
50 photoconductor drum (or photoconductor)
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 (18)

In an organophotoreceptor having a laminated structure of a charge generation layer and a charge transport layer on an electrically conductive support via an intermediate layer, the intermediate layer is subjected to multiple surface treatments and the final surface treatment is reactive. Organic photosensitivity characterized in that it contains N-type semiconducting fine particles, which are surface treated with an organosilicon compound, and a binder resin, and the charge transport layer contains a compound represented by the following general formula ( 2 ) body.

(In the formula, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ may be the same or different, and each represents a hydrogen atom, an alkyl group, an alkoxy group, an aryloxy group, a halogen atom or An aryl group which may have a substituent, and m2 and n2 each represent 0 or 1) In an organophotoreceptor having a laminated structure of a charge generation layer and a charge transport layer on an electrically conductive support via an intermediate layer, the intermediate layer is subjected to multiple surface treatments and the final surface treatment is reactive. Organic photosensitivity characterized in that it contains N-type semiconducting fine particles that are a surface treatment with an organosilicon compound and a binder resin, and the charge transport layer contains a compound represented by the following general formula ( 3 ) body.

(Wherein R _{7 to} R ₁₃ may be the same or different and each represents a hydrogen atom, a lower alkyl group, an alkoxy group, an aryloxy group, a halogen atom or an optionally substituted aryl group; m3 And n3 represents 0 or 1.) In an organophotoreceptor having a laminated structure of a charge generation layer and a charge transport layer on an electrically conductive support via an intermediate layer, the intermediate layer is subjected to multiple surface treatments and the final surface treatment is reactive. Organic photosensitivity characterized in that it contains N-type semiconducting fine particles that are a surface treatment with an organosilicon compound, and a binder resin, and the charge transport layer contains a compound represented by the following general formula ( 4 ) body.

(In the formula, Ar ₅ represents an aromatic monocyclic hydrocarbon, a condensed polycyclic hydrocarbon or a heterocyclic compound residue, and R _{14 to} R ₁₆ each independently represents a hydrogen atom, a hydroxyl group, an alkyl group, or an aralkyl group. Represents a phenyl group or an alkoxy group, R ₁₇ and R ₁₈ each represent an alkoxy group, a dialkylamino group, a diaralkylamino group, and a piperidino group, and m4 and n4 represent 1 or 2, provided that m4 and n4 are 2 In this case, R ₁₇ and R ₁₈ may be bonded to each other to form a ring.) The organophotoreceptor according to claim 1, wherein the reactive organosilicon compound is methylhydrogenpolysiloxane. The organophotoreceptor according to claim 1, wherein the reactive organosilicon compound is a compound represented by the following general formula (6).
General formula (6) R-Si- (X) _Three
[Wherein, R represents an alkyl group, an aryl group, X represents a methoxy group, an ethoxy group, or a halogen atom. ] 6. The organic photoreceptor according to claim 5, wherein R in the general formula (6) is an alkyl group having 4 to 8 carbon atoms. The organic according to any one of claims 1 to 6, wherein at least one of the plurality of surface treatments is at least one kind of surface treatment of alumina, silica and zirconia. Photoconductor. The N-type semiconductive fine particles are subjected to a surface treatment of either or both of alumina and silica, and then a surface treatment of a reactive organosilicon compound. The organophotoreceptor according to any one of the above. The organophotoreceptor according to claim 1, wherein the N-type semiconductive fine particles are subjected to a surface treatment of a reactive organosilicon compound having a fluorine atom. The N-type semiconducting fine particles are subjected to a surface treatment with at least silica or alumina, and then a surface treatment using a reactive organotitanium compound. The organic photoreceptor described in 1. The N-type semiconductive fine particles are subjected to a surface treatment with at least silica or alumina, and then a surface treatment using a reactive organozirconium compound. The organic photoreceptor described in 1. The organophotoreceptor according to claim 1, wherein the N-type semiconductive fine particles are metal oxide particles. The organophotoreceptor according to claim 1, wherein the N-type semiconductive fine particles have a number average primary particle size of 10 nm to 200 nm. The organophotoreceptor according to claim 1, wherein the N-type semiconductive fine particles are titanium oxide particles. The organic photoreceptor according to claim 1, wherein the binder of the intermediate layer is polyamide. An image forming method comprising forming an electrophotographic image using the organic photoreceptor according to claim 1. An electrophotographic image is formed using the image forming method according to claim 16. An image forming apparatus. The organic photoreceptor according to any one of claims 1 to 15 and at least one of a charger, an image exposure device, a developing device, a transfer device, and a cleaning device are integrally incorporated into and removed from the image forming apparatus. A process cartridge configured to be capable of being used.

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