JP2005037480A - Electrophotographic photoreceptor, process cartridge, image forming apparatus, and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor capable of performing stable image formation over a prolonged period of time using a charging process which generates little ozone or NOx and uses low power, and further provide a process cartridge, an image forming apparatus, and an image forming method. <P>SOLUTION: The electrophotographic photoreceptor has at least an intermediate layer, a photosensitive layer and a charge injection layer on a conductive substrate, wherein the intermediate layer contains a compound formed from a composition comprising an inorganic oxide network forming compound, a metal-atom-containing organic network forming compound and a binder network forming compound. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００６１】
一般式（２）において、Ｒ^３は水素原子、炭素数１〜１０のアルキル基、炭素数１〜１０のアラルキル基、Ｒ^４は重合性二重結合を有する有機基、Ｘはハロゲン原子、アルコキシ基、アシロキシ基、アミノキシ基、フェノキシ基を示し、ｎは１〜３の整数である。
【００６２】
上記一般式（２）の重合性シラン化合物としては、シリル基、特に加水分解性を有するシリル基を有し、後述の各種連鎖重合性単量体と重合可能な化合物であれば特に制限されず、例えば、ＣＨ_２＝ＣＨＳｉ（ＣＨ_３）（ＯＣＨ_３）_２、ＣＨ_２＝ＣＨＳｉ（ＯＣＨ_３）_３、ＣＨ_２＝ＣＨＳｉ（ＣＨ_３）Ｃｌ_２、ＣＨ_２＝ＣＨＳｉＣｌ_３、ＣＨ_２＝ＣＨＣＯＯ（ＣＨ_２）_２Ｓｉ（ＣＨ_３）（ＯＣＨ_３）_２、ＣＨ_２＝ＣＨＣＯＯ（ＣＨ_２）_２Ｓｉ（ＯＣＨ_３）_３、ＣＨ_２＝ＣＨＣＯＯ（ＣＨ_２）_３Ｓｉ（ＣＨ_３）（ＯＣＨ_３）_２、ＣＨ_２＝ＣＨＣＯＯ（ＣＨ_２）_３Ｓｉ（ＯＣＨ_３）_３、ＣＨ_２＝ＣＨＣＯＯ（ＣＨ_２）_２Ｓｉ（ＣＨ_３）Ｃｌ_２、ＣＨ_２＝ＣＨＣＯＯ（ＣＨ_２）_２ＳｉＣｌ_３、ＣＨ_２＝ＣＨＣＯＯ（ＣＨ_２）_３Ｓｉ（ＣＨ_３）Ｃｌ_２、ＣＨ_２＝ＣＨＣＯＯ（ＣＨ_２）_３ＳｉＣｌ_３、ＣＨ_２＝Ｃ（ＣＨ_３）ＣＯＯ（ＣＨ_２）_２Ｓｉ（ＣＨ_３）（ＯＣＨ_３）_２、ＣＨ_２＝Ｃ（ＣＨ_３）ＣＯＯ（ＣＨ_２）_２Ｓｉ（ＯＣＨ_３）_３、ＣＨ_２＝Ｃ（ＣＨ_３）ＣＯＯ（ＣＨ_２）_３Ｓｉ（ＣＨ_３）（ＯＣＨ_３）_２、ＣＨ_２＝Ｃ（ＣＨ_３）ＣＯＯ（ＣＨ_２）_３Ｓｉ（ＯＣＨ_３）_３、ＣＨ_２＝Ｃ（ＣＨ_３）ＣＯＯ（ＣＨ_２）_２Ｓｉ（ＣＨ_３）Ｃｌ_２、ＣＨ_２＝Ｃ（ＣＨ_３）ＣＯＯ（ＣＨ_２）_２ＳｉＣｌ_３、ＣＨ_２＝Ｃ（ＣＨ_３）ＣＯＯ（ＣＨ_２）_３Ｓｉ（ＣＨ_３）Ｃ_ｌ２、ＣＨ_２＝Ｃ（ＣＨ_３）ＣＯＯ（ＣＨ_２）_３ＳｉＣｌ_３、
【００６３】
【化２】

【００６４】
等が挙げられる。これらの重合性シラン化合物は単独でまたは２種以上を混合して使用することができる。
【００６５】
上記一般式（２）の重合性シラン化合物と共にビニル系樹脂セグメントを形成する連鎖重合性単量体としては、例えば（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸ブチル、（メタ）アクリル酸２−エチルヘキシル、シクロヘキシル（メタ）アクリレートなどの（メタ）アクリル酸エステル；（メタ）アクリル酸、イタコン酸、フマル酸などのカルボン酸および無水マレイン酸などの酸無水物；グリシジル（メタ）アクリレートなどのエポキシ化合物；ジエチルアミノエチル（メタ）アクリレート、アミノエチルビニルエーテルなどのアミノ化合物；（メタ）アクリルアミド、イタコン酸ジアミド、α−エチルアクリルアミド、クロトンアミド、フマル酸ジアミド、マレイン酸ジアミド、Ｎ−ブトキシメチル（メタ）アクリルアミドなどのアミド化合物；アクリロニトリル、スチレン、α−メチルスチレン、塩化ビニル、酢酸ビニル、プロピオン酸ビニルなどからなるグループから選ばれる１またはそれ以上のビニル系連鎖重合性単量体を用いることが好ましい。又、水酸基を含むビニル系連鎖重合性単量体（モノマー）、例えば、２−ヒドロキシエチル（メタ）アクリレート、２−ヒドロキシプロピル（メタ）アクリレート、２−ヒドロキシビニルエーテル、Ｎ−メチロールアクリルアミドなども用いることができる。
【００６６】
又、本発明のＺ成分：バインダーネットワーク形成化合物としては、前記ビニル系樹脂セグメントを構成できるビニル系連鎖重合性単量体として、酸化防止サブユニット形成化合物を用いてもよい。
【００６７】
ここで、酸化防止サブユニットとはオゾン、ＮＯ_ｘ等の活性ガス、或いは紫外線等の光照射により引き起こされる酸化又は還元耐性を有する基を意味する。
【００６８】
バインダー樹脂に酸化防止機能を付与するには、樹脂構造の一部に、サブユニット（部分構造）としてヒンダードアミン、或いはヒンダードフェノール等の酸化防止サブユニットを取り込むことで達成される。
【００６９】
即ち、ビニル系樹脂セグメントを構成する前記一般式（２）の重合性シラン化合物、
ビニル系連鎖重合性単量体と共に、酸化防止サブユニット形成化合物を用いて重合反応を行ない、酸化防止サブユニットを有し且つシリル基を有するビニル系樹脂セグメントを形成し、その後該ビニル系樹脂セグメントのシリル基を介して、Ｘ成分：無機酸化物ネットワーク形成化合物やＹ成分：金属原子含有有機ネットワーク形成化合物、或いは前記したシロキサン縮合体と化学結合をすることが出来る。
【００７０】
ここで、ヒンダードアミン基とはアミン化合物のアミノ基のＮ原子近傍に立体障害性を有する基及びその誘導体を云う。立体障害性の基としては分岐状アルキル基、炭素数が３以上の基等が好ましい。
【００７１】
又、ヒンダードフェノール基とはフェノールの水酸基に対しオルト位置に立体障害性を有する基及びその誘導体を云う。（但し、水酸基がアルコキシに変成されていても良い）。立体障害性の基としては分岐アルキル基、或いは炭素数が３以上の基等が好ましい。
【００７２】
ビニル系樹脂セグメントにヒンダードアミン基、或いはヒンダードフェノール基をサブユニット（部分構造）として導入するには、前記一般式（２）の重合性シラン化合物、ビニル系連鎖重合性単量体と共に、酸化防止サブユニット形成化合物として、炭素−炭素不飽和結合の重合性不飽和基を有するヒンダードアミン化合物（単量体）或いはヒンダードフェノール化合物（単量体）を共存させ、これらの共存組成物の重合を行うことにより、ビニル系樹脂セグメント中にヒンダードアミン基或いはヒンダードフェノール基を導入することができる。
【００７３】
このような重合性不飽和基を有するヒンダードアミン化合物としては、重合性不飽和基を含有する立体障害アミン化合物が好ましく、なかでも重合性不飽和基を含有する立体障害ピペリジン化合物（以下、「ピペリジン系モノマー」ともいう。）が特に好ましい。ピペリジン系化合物の代表的なものとしては、例えば下記一般式（Ａ）で表される化合物を挙げることができる。
【００７４】
【化３】

【００７５】
一般式（Ａ）において、Ｒ^５は水素原子またはシアノ基を示し、Ｒ^６およびＲ^７は相互に同一でも異なってもよく、水素原子、メチル基またはエチル基を示し、Ｘは酸素原子またはイミノ基を示し、Ｙは水素原子、炭素数１〜１８のアルキル基または下記一般式（Ｂ）で表される重合性不飽和基を示す。
【００７６】
【化４】

【００７７】
一般式（Ｂ）において、Ｒ^８およびＲ^９は相互に同一でも異なってもよく、水素原子、メチル基またはエチル基を示す。
【００７８】
一般式（Ａ）におけるＸのイミノ基中の水素原子は、置換されても置換されていなくてもよい。また、一般式（Ａ）におけるＹのうち、炭素数１〜１８のアルキル基の例としては、メチル基、エチル基、ｎ−プロピル基、イソプロピル基、ｎ−ブチル基、イソブチル基、ｓｅｃ−ブチル基、ｔ−ブチル基、ｎ−ペンチル基、ｎ−ヘキシル基、ｎ−ヘプチル基、ｎ−オクチル基、ｎ−ノニル基、ｎ−デシル基、ｎ−ウンデシル基、ｎ−ドデシル基、ｎ−トリデシル基、ｎ−テトラデシル基、ｎ−ペンタデシル基、ｎ−ヘキサデシル基、ｎ−ヘプタデシル基、ｎ−オクタデシル基等の直鎖または分岐鎖のアルキル基を挙げることができる。
【００７９】
上記、一般式（Ａ）のピペリジン系化合物のうち、好ましい化合物は、４−（メタ）アクリロイルオキシ−２，２，６，６−テトラメチルピペリジン、４−（メタ）アクリロイルアミノ−２，２，６，６−テトラメチルピペリジン、４−（メタ）アクリロイルオキシ−１，２，２，６，６−ペンタメチルピペリジン、４−（メタ）アクリロイルアミノ−１，２，２，６，６−ペンタメチルピペリジン、４−シアノ−４−（メタ）アクリロイルオキシ−２，２，６，６−テトラメチルピペリジン、４−シアノ−４−（メタ）アクリロイルアミノ−２，２，６，６−テトラメチルピペリジン、４−シアノ−４−（メタ）アクリロイルオキシ−１，２，２，６，６−ペンタメチルピペリジン、４−シアノ−４−（メタ）アクリロイルアミノ−１，２，２，６，６−ペンタメチルピペリジン、１−（メタ）アクリロイル−４−（メタ）アクリロイルオキシ−２，２，６，６−テトラメチルピペリジン、１−（メタ）アクリロイル−４−（メタ）アクリロイルアミノ−２，２，６，６−テトラメチルピペリジン、１−（メタ）アクリロイル−４−シアノ−４−（メタ）アクリロイルオキシ−２，２，６，６−テトラメチルピペリジン、１−（メタ）アクリロイル−４−シアノ−４−（メタ）アクリロイルアミノ−２，２，６，６−テトラメチルピペリジン、４−クロトノイルオキシ−２，２，６，６−テトラメチルピペリジン、４−クロトノイルアミノ−２，２，６，６−テトラメチルピペリジン、４−クロトノイルオキシ−１，２，２，６，６−ペンタメチルピペリジン、４−クロトノイルアミノ−１，２，２，６，６−ペンタメチルピペリジン、４−シアノ−４−クロトノイルオキシ−２，２，６，６−テトラメチルピペリジン、４−シアノ−４−クロトノイルアミノ−２，２，６，６−テトラメチルピペリジン、１−クロトノイル−４−クロトノイルオキシ−２，２，６，６−テトラメチルピペリジン、１−クロトノイル−４−クロトノイルアミノ−２，２，６，６−テトラメチルピペリジン、１−クロトノイル−４−シアノ−４−クロトノイルオキシ−２，２，６，６−テトラメチルピペリジン、１−クロトノイル−４−シアノ−４−クロトノイルアミノ−２，２，６，６−テトラメチルピペリジン等であり、なかでも４−（メタ）アクリロイルオキシ−２，２，６，６−テトラメチルピペリジン、４−（メタ）アクリロイルオキシ−１，２，２，６，６−ペンタメチルピペリジンが特に好ましい。
【００８０】
又、重合性不飽和基を有するヒンダードフェノール化合物としては、重合性不飽和基を含有するヒンダードフェノール化合物が好ましく、例えば下記のような化合物を挙げることができる。即ち、２−ｔ−ブチル−６−（３−ｔ−ブチル−２−ヒドロキシ−５−メチルベンジル）−４−メチルフェニルアクリレート、２−（３，５−ジ−ｔ−ブチル−４−ヒドロキシフェニル）エチルアクリレート、２−（３，５−ジ−ｓ−プロピル−４−ヒドロキシフェニル）エチルアクリレート、２−（３，５−ジ−ｔ−オクチル−４−ヒドロキシフェニル）エチルアクリレート、２−（３−ｔ−ブチル−５−（３−ｔ−ブチル−２−ヒドロキシ−５−メチルベンジル）４−ヒドロキシフェニル）エチルアクリレート、２−ｔ−ブチル−６−（３−ｔ−ブチル−２−ヒドロキシ−５−メチルベンジル）−４−メチルフェニル（メタ）アクリレート、２−（３，５−ジ−ｔ−ブチル−４−ヒドロキシフェニル）エチル（メタ）アクリレート、２−（３，５−ジ−ｓ−プロピル−４−ヒドロキシフェニル）エチル（メタ）アクリレート、２−（３，５−ジ−ｔ−オクチル−４−ヒドロキシフェニル）エチル（メタ）アクリレート、２−（３−ｔ−ブチル−５−（３−ｔ−ブチル−２−ヒドロキシ−５−メチルベンジル）４−ヒドロキシフェニル）エチル（メタ）アクリレート、３，５−ジ−ｔ−ブチル−４−ヒドロキシフェニルプロピオン酸ビニルエステル、３，５−ジ−ｔ−オクチル−４−ヒドロキシフェニルプロピオン酸ビニルエステル、３，５−ジ−ｔ−ブチル−４−ヒドロキシフェニルプロピオン酸−イソプロペニルエステル、３，５−ジ−ｔ−オクチル−４−ヒドロキシフェニルプロピオン酸−イソプロペニルエステル等が挙げられる。
【００８１】
又、前記ヒンダードアミン系或いはヒンダードフェノール系の酸化防止サブユニット形成化合物（重合性不飽和基を有する化合物）以外の化合物の例としては、フェニルサリチル酸（メタ）アクリレート、ｔ−ブチルフェニルサリチル酸（メタ）アクリレート等のサリチル酸化合物；２−（メタ）アクリロイルオキシ−４−メトキシベンゾフェノン、２−（メタ）アクリロイルオキシ−２’−ヒドロキシ−４−メトキシベンゾフェノン、２，２’−ジ（メタ）アクリロイルオキシ−４−メトキシベンゾフェノン、２，２’−ジ（メタ）アクリロイルオキシ−４，４’−ジメトキシベンゾフェノン、２−（メタ）アクリロイルオキシ−４−メトキシ−２’−カルボキシベンゾフェノン、２−ヒドロキシ−４−〔３−（メタ）アクリロイルオキシ−２−ヒドロキシプロポキシ〕ベンゾフェノン、２，２’−ジヒドロキシ−４−〔３−（メタ）アクリロイルオキシ−２−ヒドロキシプロポキシ〕ベンゾフェノン等のベンゾフェノン化合物；２−〔２’−（メタ）アクリロイルオキシ−５’−メチルフェニル〕ベンゾトリアゾール、２−〔２’−（メタ）アクリロイルオキシ−５’−ｔ−オクチルフェニル〕ベンゾトリアゾール、２−〔２’−（メタ）アクリロイルオキシ−３’，５’−ジ−ｔ−ブチルフェニル〕ベンゾトリアゾール等のベンゾトリアゾール化合物；２−エチルヘキシル−２−シアノ−３，３−ジフェニル（メタ）アクリレート、１，３−ビス（４−ベンゾイル−３−ヒドロキシフェノキシ）−２−プロピル（メタ）アクリレート、エチル−２−シアノ−３，３−ジフェニル（メタ）アクリレート等を挙げることができる。本発明において、前記酸化防止サブユニット形成化合物は、単独でまたは２種以上を混合して使用することができる。又、「ヒンダードアミン基或いはヒンダードフェノール基を有し」とはヒンダードアミン基或いはヒンダードフェノール基の少なくとも一方を有することを意味し、両方の基を有していても良い。
【００８２】
ここで、ヒンダードアミン基又はヒンダードフェノール基を有し且つシリル変性された（シリル基を有する）ビニル系樹脂セグメントの合成例を記載する。
【００８３】
（ビニル系樹脂セグメントＡ溶液の合成例：ヒンダードアミン基を有し且つシリル変性されたビニル系樹脂セグメントＡ溶液）
還流冷却器及び攪拌機を備えた反応容器に、モノマーとしてγ−メタクリロイルオキシプロピルトリメトキシシラン２５部、４−メタクロイルオキシ−１，２，２，６，６，−ペンタメチルピペリジン１部、メタクリル酸メチル８０部とメタクリル酸２−エチルヘキシル１５部、ｎ−ブチルアクリレート２９部、２−プロパノール１５０部、２−ブタノン５０部及びメタノール２５部を加えて混合した後、攪拌しながら８０℃に加温し、この混合物にアゾビスイソバレロニトリル４部をキシレン１０部に溶解した溶液を３０分間かけて滴下した後、８０℃で５時間反応させて固形分濃度４０％の側鎖にヒンダードアミン基を有し且つシリル基を有するビニル系樹脂セグメントＡ溶液を得た。
【００８４】
（ビニル系樹脂セグメントＢ溶液の合成例：ヒンダードフェノール基を有し且つシリル変性されたビニル系樹脂セグメントＢ溶液）
還流冷却器及び攪拌機を備えた反応容器に、モノマーとしてγ−メタクリロイルオキシプロピルトリメトキシシラン２０部、２−ｔ−ブチル−６−（３−ｔ−ブチル−２−ヒドロキシ−５−メチルベンジル）−４−メチルフェニルアクリレート２部、メタクリル酸メチル７０部、ｎ−ブチルアクリレート４０部、アクリル酸５部、２−ヒドロキシエチルメタクリレート１３部、１，１，１−トリメチルアミンメタクリルイミド１部、２−プロパノール１５０部、２−ブタノン５０部及びメタノール２５部を加えて混合した後、攪拌しながら８０℃に加温し、この混合物にアゾビスイソバレロニトリル４部をキシレン１０部に溶解した溶液を３０分間かけて滴下した後、８０℃で５時間反応させて固形分濃度４０％の側鎖にヒンダードフェノール基を有し且つシリル基を有するビニル系樹脂セグメントＢ溶液を得た。
【００８５】
（ビニル系樹脂セグメントＣ溶液の合成例：シリル変性されたビニル系樹脂セグメントＣ溶液）
還流冷却器及び攪拌機を備えた反応容器に、モノマーとしてγ−メタクリロイルオキシプロピルトリメトキシシラン２５部、メタクリル酸メチル８０部とメタクリル酸２−エチルヘキシル１５部、ｎ−ブチルアクリレート３０部、２−プロパノール１５０部、２−ブタノン５０部及びメタノール２５部を加えて混合した後、攪拌しながら８０℃に加温し、この混合物にアゾビスイソバレロニトリル４部をキシレン１０部に溶解した溶液を３０分間かけて滴下した後、８０℃で５時間反応させて固形分濃度４０％のシリル基を有するビニル系樹脂セグメントＣ溶液を得た。
【００８６】
上記合成例Ａ、Ｂに示したように重合性不飽和基を有するヒンダードアミン化合物、ヒンダードフェノール化合物、重合性シラン化合物及びビニル系連鎖重合性単量体を共存させ重合することにより、側鎖にヒンダードアミン基或いはヒンダードフェノール基を有し且つシリル基を有するビニル系樹脂セグメントを合成する事が出来る。
【００８７】
上記シリル基を有するビニル系樹脂セグメントの重合度は特に制限されないが、１０〜５００であることが望ましい。
【００８８】
次に、上記シリル基を有するビニル系樹脂セグメントＡ、Ｂ、Ｃにシロキサン縮合体成分を形成することにより、本発明の樹脂構造を有する中間層を形成できる。即ち、上記シリル基を有するビニル系樹脂セグメントと前記したような反応性有機ケイ素化合物を用いて、シリル基を有するビニル系樹脂セグメントのシリル基にシロキサン縮合体成分を形成する。このシロキサン縮合体成分の形成は中間層形成と同時に行ってもよいが、予め中間層溶液でシリル基末端にシロキサン縮合体成分を形成して、中間層形成を行ってもよい。
【００８９】
本発明の中間層はＸ成分、Ｙ成分、及びＺ成分を有する組成物から形成される化合物を含有するが、該化合物は中間層中で、各Ｘ成分、Ｙ成分、及びＺ成分が相互に化学結合により結合して形成されている。
【００９０】
前記化合物を構成するＸ成分、Ｙ成分、及びＺ成分の質量比はＸ成分１に対し、Ｙ成分０．００１〜０．５、Ｚ成分０．２５〜４の質量比で構成されていることが好ましい。Ｘ成分の質量比が少ないと、繰り返しの画像形成で、残留電位が増大しやすく、反転現像で画像濃度が低下しやすい。Ｘ成分が多すぎると、中間層の上に設置される電荷発生層の塗布性が劣化し、均一な膜形成ができない。又、Ｚ成分の質量比が多くても、少なくても繰り返し使用時の電子写真特性（帯電、感度、残留電位特性等）が劣化しやすい。
【００９１】
本発明の中間層の膜厚は、０．２〜２２μｍが好ましい。更に、４〜２０μｍがより好ましい。このような膜厚を持つことにより、絶縁破壊や黒ポチを防止でき且つ繰り返し使用時の良好な電子写真特性（帯電、感度、残留電位特性等）を得ることができる。
【００９２】
次に、本発明の中間層の製造方法について記載する。
本発明において中間層は上記のような中間層が形成されればいかなる方法によって形成されてよい。以下に、代表的な本発明の中間層の製造方法について記載する。
【００９３】
本発明の中間層はＸ成分、Ｙ成分、及びＺ成分を有する組成物を塗布液とし、該塗布液を導電性支持体上に塗布した後、硬化することにより形成することができる。
【００９４】
当該硬化によって、Ｘ成分、Ｙ成分、及びＺ成分を有する組成物から形成される化合物は各Ｘ成分、Ｙ成分、及びＺ成分のそれぞれの反応性基を介して、化学的に結合し、これによって導電性支持体からの電荷注入を良好に防止する整流性が良好な中間層を形成することができる。
【００９５】
上記塗布液中、或いは塗布液生成過程で金属キレート化合物を添加することが好ましい。ここで金属キレート化合物は、ジルコニウム、チタンおよびアルミニウムの群から選ばれる金属のキレート化合物である（以下、金属キレート化合物（ＩＩＩ）という）。金属キレート化合物（ＩＩＩ）は、前記の有機ケイ素化合物とシリル基を有するビニル系樹脂セグメントとの加水分解および／または部分縮合反応を促進し、３成分の共縮合物の形成を促進する作用をなすものと考えられる。
【００９６】
このような金属キレート化合物（ＩＩＩ）の例としては、一般式（３）、（４）、（５）で表される化合物、あるいはこれらの化合物の部分加水分解物が挙げられる。
【００９７】
一般式（３） Ｚｒ（ＯＲ_５）_ｐ（Ｒ_６ＣＯＣＨＣＯＲ_７）_４−ｐ
一般式（４） Ｔｉ（ＯＲ_５）_ｑ（Ｒ_６ＣＯＣＨＣＯＲ_７）_４−ｑ
一般式（５） Ａｌ（ＯＲ_５）_ｒ（Ｒ_６ＣＯＣＨＣＯＲ_７）_３−ｒ
一般式（３）、（４）、（５）におけるＲ_５およびＲ_６は、それぞれ独立に炭素数１〜６の１価の炭化水素基、具体的には、エチル基、ｎ−プロピル基、ｉ−プロピル基、ｎ−ブチル基、ｓｅｃ−ブチル基、ｔ−ブチル基、ｎ−ペンチル基、ｎ−ヘキシル基、シクロヘキシル基、フェニル基等を示し、Ｒ_７は、Ｒ_５およびＲ_６と同様の炭素数１〜６の１価の炭化水素基のほか、炭素数１〜１６のアルコキシ基、具体的には、メトキシ基、エトキシ基、ｎ−プロポキシ基、ｉ−プロポキシ基、ｎ−ブトキシ基、ｓｅｃ−ブトキシ基、ｔ−ブトキシ基、ラウリルオキシ基、ステアリルオキシ基等を示す。また、ｐおよびｑは０〜３の整数、ｒは０〜２の整数である。
【００９８】
このような金属キレート化合物（ＩＩＩ）の具体例としては、トリ−ｎ−ブトキシ・エチルアセトアセテートジルコニウム、ジ−ｎ−ブトキシ・ビス（エチルアセトアセテート）ジルコニウム、ｎ−ブトキシ・トリス（エチルアセトアセテート）ジルコニウム、テトラキス（ｎ−プロピルアセトアセテート）ジルコニウム、テトラキス（アセチルアセトアセテート）ジルコニウム、テトラキス（エチルアセトアセテート）ジルコニウム等のジルコニウムキレート化合物；ジ−ｉ−プロポキシ・ビス（エチルアセトアセテート）チタニウム、ジ−ｉ−プロポキシ・ビス（アセチルアセテート）チタニウム、ジ−ｉ−プロポキシ・ビス（アセチルアセトン）チタニウム等のチタンキレート化合物；ジ−ｉ−プロポキシ・エチルアセトアセテートアルミニウム、ジ−ｉ−プロポキシ・アセチルアセトナートアルミニウム、ｉ−プロポキシ・ビス（エチルアセトアセテート）アルミニウム、ｉ−プロポキシ・ビス（アセチルアセトナート）アルミニウム、トリス（エチルアセトアセテート）アルミニウム、トリス（エチルアセテート）アルミニウム、トリス（アセチルアセトナート）アルミニウム、モノアセチルアセトナート・ビス（エチルアセトアセテート）アルミニウム等のアルミニウムキレート化合物等が挙げられる。これらの化合物のうち、トリ−ｎ−ブトキシ・エチルアセトアセテートジルコニウム、ジ−ｉ−プロポキシ・ビス（アセチルアセトナート）チタニウム、ジ−ｉ−プロポキシ・エチルアセトアセテートアルミニウム、トリス（エチルアセトアセテート）アルミニウムが好ましい。これらの金属キレート化合物（ＩＩＩ）は、単独でまたは２種以上を混合して使用することができる。
【００９９】
金属キレート化合物（ＩＩＩ）の添加量は、Ｘ成分、Ｙ成分、及びＺ成分を含有する塗布液固形分（塗布液固形分とは塗布液を乾燥した後、残留する成分）の全質量に対する配合量が０．０１〜２０質量％、好ましくは０．５〜２０質量％となるような量である。金属キレート化合物（ＩＩＩ）の量が少なすぎると樹脂の３次元化が達成されないおそれがあり、一方、多すぎると塗液のポットライフが悪化する。
【０１００】
中間層の塗布液を塗布した後の硬化条件は、使用されるＸ成分、Ｙ成分、及びＺ成分の反応性に依存するが、６０〜１５０℃にて３０分〜６時間の乾燥を行わせるのが好ましい。
【０１０１】
これらの硬化反応を促進するためには有機溶媒が存在することが好ましい。ここで使用可能な有機溶媒としては、アルコール類、芳香族炭化水素類、エーテル類、ケトン類、エステル類などが好適である。有機溶媒の使用量は有機ケイ素化合物に対して限定されるものではなく、使用目的に応じて調製される。
【０１０２】
硬化反応促進させる溶媒としては有機ケイ素化合物、シリル基を有するビニル系樹脂セグメントを均一に溶解させる溶媒が好ましく用いられる。これらの溶媒としてはアルコール類、芳香族炭化水素類、エーテル類、ケトン類、エステル類などが用いられるが、特に下記に例示ような溶媒が好ましい。
【０１０３】
アルコール系溶媒としては炭素数１〜４のアルコール、即ちメタノール、エタノール、ｎ−プロパノール、ｉｓｏ−プロパノール、ｎ−ブタノール、ｉｓｏ−ブタノール、ｓｅｃ−ブタノール、ｔｅｒｔ−ブタノールが好ましく用いられる。
【０１０４】
非アルコール系溶媒としてはエチルメチルケトン、メチルイソプロピルケトン、メチルイソブチルケトン等のケトン系の溶媒が好ましく用いられる。
【０１０５】
上記中間層塗布液中には、更に、硬化促進剤必要により添加することができる。
【０１０６】
硬化促進剤としては、ナフテン酸、オクチル酸、亜硝酸、亜硫酸、アルミン酸、炭酸などのアルカリ金属塩；水酸化ナトリウム、水酸化カリウムなどのアルカリ性化合物；アルキルチタン酸、リン酸、ｐ−トルエンスルホン酸、フタル酸などの酸性化合物；エチレンジアミン、ヘキサンジアミン、ジエチレントリアミン、トリエチレンテトラミン、テトラエチレンペンタミン、ピペリジン、ピペラジン、メタフェニレンジアミン、エタノールアミン、トリエチルアミン、エポキシ樹脂の硬化剤として用いられる各種変性アミン、γ−アミノプロピルトリエトキシシラン、γ−（２−アミノエチル）−アミノプロピルトリメトキシシラン、γ−（２−アミノエチル）−アミノプロピルメチルジメトキシシラン、γ−アニリノプロピルトリメトキシシランなどのアミン系化合物、（Ｃ_４Ｈ_９）_２Ｓｎ（ＯＣＯＣ_１１Ｈ_２３）_２、（Ｃ_４Ｈ_９）_２Ｓｎ（ＯＣＯＣＨ＝ＣＨＣＯＯＣＨ_３）_２、（Ｃ_４Ｈ_９）_２Ｓｎ（ＯＣＯＣＨ＝ＣＨＣＯＯＣ_４Ｈ_９）_２、（Ｃ_８Ｈ_１７）_２Ｓｎ（ＯＣＯＣ_１１Ｈ_２３）_２、（Ｃ_８Ｈ_１７）_２Ｓｎ（ＯＣＯＣＨ＝ＣＨＣＯＯＣＨ_３）_２、（Ｃ_８Ｈ_１７）_２Ｓｎ（ＯＣＯＣＨ＝ＣＨＣＯＯＣ_４Ｈ_９）_２、（Ｃ_８Ｈ_１７）_２Ｓｎ（ＯＣＯＣＨ＝ＣＨＣＯＯＣ_８Ｈ_１７）_２、Ｓｎ（ＯＣＯＣＣ_８Ｈ_１７）_２、などのカルボン酸型有機スズ化合物；（Ｃ_４Ｈ_９）_２Ｓｎ（ＳＣＨ_２ＣＯＯ）_２、（Ｃ_４Ｈ_９）_２Ｓｎ（ＳＣＨ_２ＣＯＯＣ_８Ｈ_１７）_２、（Ｃ_８Ｈ_１７）_２Ｓｎ（ＳＣＨ_２ＣＯＯ）_２、（Ｃ_８Ｈ_１７）_２Ｓｎ（ＳＣＨ_２ＣＨ_２ＣＯＯ）_２、（Ｃ_８Ｈ_１７）_２Ｓｎ（ＳＣＨ_２ＣＯＯＣＨ_２ＣＨ_２ＯＣＯＣＨ_２Ｓ）_２、（Ｃ_８Ｈ_１７）_２Ｓｎ（ＳＣＨ_２ＣＯＯＣＨ_２ＣＨ_２ＣＨ_２ＣＨ_２ＯＣＯＣＨ_２Ｓ）_２、（Ｃ_８Ｈ_１７）_２Ｓｎ（ＳＣＨ_２ＣＯＯＣ_８Ｈ_１７）_２、（Ｃ_８Ｈ_１７）_２Ｓｎ（ＳＣＨ_２ＣＯＯＣ_１２Ｈ_２５）_２、（Ｃ_４Ｈ_９）_２ＳｎＯ、（Ｃ_８Ｈ_１７）_２ＳｎＯ、（Ｃ_４Ｈ_９）_２ＳｎＯ、（Ｃ_８Ｈ_１７）_２ＳｎＯなどの有機スズオキサイドとエチルシリケート、エチルシリケート４０、マレイン酸ジメチル、マレイン酸ジエチル、フタル酸ジオクチルなどのエステル化合物との反応生成物などの有機スズ化合物などが使用される。
【０１０７】
上記塗布液中の硬化促進剤の添加量は、塗布液固形分（固形分とは塗布液成分中の乾燥後に残留する成分を意味する）１００質量部に対して０．１〜２０質量部、好ましくは０．５〜１００質量部である。これらの量が少なすぎると膜の強度が低下するおそれがあり、一方、多すぎると塗液のポットライフが悪化する。
【０１０８】
本発明においては、中間層塗布液の全固形分濃度を調製し、併せて粘度も調製するために、有機溶媒を使用することができる。このような有機溶媒としては、アルコール類、芳香族炭化水素類、エーテル類、ケトン類、エステル類等の有機溶剤を使用することが好ましい。前記アルコール類としては、例えば１価または２価のアルコールを挙げることができ、具体的にはメタノール、エタノール、ｎ−プロピルアルコール、イソプロピルアルコール、ｎ−ブチルアルコール、ｓｅｃ−ブチルアルコール、ｔ−ブチルアルコール、ｎ−ヘキシルアルコール、ｎ−オクチルアルコール、エチレングリコール、ジエチレングリコール、トリエチレングリコール、エチレングリコールモノメチルエーテル、エチレングリコールモノエチルエーテル、エチレングリコールモノｎ−プロピルエーテル、エチレングリコールモノｎ−ブチルエーテル、酢酸エチレングリコールモノメチルエーテル、酢酸エチレングリコールモノエチルエーテル等を挙げることができる。これらのうち、炭素数１〜８の１価の飽和脂肪族アルコールが好ましい。また、前記芳香族炭化水素類の具体例としては、ベンゼン、トルエン、キシレン等を挙げることができ、前記エーテル類の具体例としては、テトラヒドロフラン、ジオキサン等を挙げることができ、前記エステル類の具体例としては、酢酸エチル、酢酸ｎ−プロピル、酢酸ｎ−ブチル、炭酸プロピレン等を挙げることができる。これらの有機溶媒は、単独または２種以上を混合して使用することができる。有機溶媒の添加方法は特に限定されるものではなく、本発明の表面保護液を調製する際および／または調製後の適宜の段階で添加することができる。
【０１０９】
又、本発明の中間層は実質的に絶縁層であることが好ましい。ここで絶縁層とは、体積抵抗が１×１０^８以上である。本発明の中間層の体積抵抗は１×１０^８〜１０^１５Ω・ｃｍが好ましく、１×１０^９〜１０^１４Ω・ｃｍがより好ましく、更に好ましくは、２×１０^９〜１×１０^１３Ω・ｃｍである。体積抵抗は下記のようにして測定できる。
【０１１０】
測定条件；ＪＩＳ：Ｃ２３１８−１９７５に準ずる。
測定器：三菱油化社製Ｈｉｒｅｓｔａ ＩＰ
測定条件：測定プローブ ＨＲＳ
印加電圧：５００Ｖ
測定環境：３０±２℃、８０±５ＲＨ％
体積抵抗が１×１０^８未満では中間層の電荷ブロッキング性が低下し、黒ポチの発生が増大し、電子写真感光体の電位保持性も劣化し、良好な画質が得られない。一方１０^１５Ω・ｃｍより大きいと繰り返し画像形成で残留電位が増大しやすく、良好な画質が得らにくい。
【０１１１】
尚、本発明のＸ成分、Ｙ成分、Ｚ成分を有する組成物から形成される化合物がＸ成分、Ｙ成分、Ｚ成分のそれぞれの化合物が相互に化学反応をして、三次元の結合形態を有する化合物（中間層の樹脂構造）を形成できていることの検証は、Ｘ成分、Ｙ成分、Ｚ成分を有する組成物の中間層或いは保護層の塗布液溶媒への溶媒溶解性や熱力学的検証、例えばガラス転移点（Ｔｇ）の消滅等で行なうことができる。
【０１１２】
次に、上記のような本発明の化合物を電荷輸送物質として用いた電子写真感光体、特に有機感光体の層構成について記載する。
【０１１３】
本発明の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。
【０１１４】
以下に本発明に用いられる有機感光体の構成について記載する。
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。
【０１１５】
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。
【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１０^３Ωｃｍ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、前記バリヤー機能を備えた中間層を設ける。
【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機能と電荷輸送機能を１つの層に持たせた単層構造の感光層構成でも良いが、より好ましくは感光層の機能を電荷発生層（ＣＧＬ）と電荷輸送層（ＣＴＬ）に分離した構成をとるのがよい。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。負帯電用の感光体では中間層の上に電荷発生層（ＣＧＬ）、その上に電荷輸送層（ＣＴＬ）の構成を取ることが好ましい。正帯電用の感光体では前記層構成の順が負帯電用感光体の場合の逆となる。本発明の最も好ましい感光層構成は前記機能分離構造を有する負帯電感光体構成である。
【０１２０】
以下に機能分離負帯電感光体の感光層構成について説明する。
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結晶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）としては公知の電荷輸送物質（ＣＴＭ）を用いることができる。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は高移動度で、且つ組み合わされるＣＧＭと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０．３０（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構造のうちの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。
【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電子写真感光体中ないしは電子写真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。
【０１２９】
電荷輸送層の膜厚は５〜４０μｍが好ましく、８〜３０μｍがより好ましい。電荷輸送層の合計膜厚が５μｍ未満だと帯電電位が不十分になりやすく、４０μｍを超えると、高速適応性が低下し、画像濃度が低下したり、鮮鋭性が劣化しやすい。高速適応性が十分で且つ良好な画像品質が得られる最も好ましい電荷輸送層の膜厚は１６〜２５μｍである。
【０１３０】
電荷注入層
本発明の電子写真感光体は、電荷輸送層上に電荷注入層を設けた構成を有するが、電荷注入層は基本的に導電性微粒子を分散したバインダー樹脂層から構成される。
【０１３１】
電荷注入層のバインダー樹脂としては、先に説明した電荷輸送層と同じ樹脂を使用する。
【０１３２】
電荷注入層の導電性微粒子としては、脂肪酸塩類、高級アルコール類、硫酸エステル類、脂肪酸アミン類、第四級アンモニウム塩類、アルキルピリジウム塩類、ポリオキシエチレンアルキルエーテル類、ポリオキシエチレンアルキルエステル類、ソルビタンアルキルエステル類、イミダゾリン誘導体等のアニオン系、カチオン系、又はノニオン系有機電解質；Ａｕ、Ａｇ、Ｃｕ、Ｎｉ、Ａｌ等の金属；ＺｎＯ、ＴｉＯ_２、ＳｎＯ_２、Ｉｎ_２Ｏ_３、Ｓｂ_２Ｏ_３含有ＳｎＯ_２、Ｉｎ_２Ｏ_３含有ＳｎＯ_２等の金属酸化物；ＭｇＦ_２、ＣａＦ_２、ＢｉＦ_２、ＡｌＦ_２、ＳｎＦ_２、ＳｎＦ_４、ＴｉＦ_４等の金属フッ化物；テトラインプロピルチタネート、テトラノルマルブチルチタネート、チタンアセチルアセトネート、チタンラクテートエチルエステル等の有機チタン化合物；及びそれらの混合物等が挙げられる。
【０１３３】
又、本発明の電荷注入層には、電荷輸送物質を含有させることが好ましい。電荷注入層に電荷輸送物質を含有させることにより、繰り返し使用に伴う感度の低下や残留電位の上昇も防止される。又、電荷注入層には前記した酸化防止機能を有する化合物を含有させることが好ましい。
【０１３４】
電荷注入層の膜厚は、０．３〜１０μｍが適当であり、好ましくは、１〜５μｍが良好である。
【０１３５】
又、電荷注入層の体積抵抗は１０^１０〜１０^１５Ω・ｃｍの範囲になるように設定するのが好ましく、特には１０^１０〜１０^１４Ω・ｃｍが好ましい。膜強度的には、導電性粒子の量が増えれば増えるほど弱くなるため、導電性粒子の量は、電荷注入層の抵抗及び残留電位が許容できる範囲において、少なくする方が好ましい。
【０１３６】
又、電荷注入層には、フッ素系樹脂粒子を含有させ、感光体表面の水に対する接触角を９０°以上にすることが好ましく、更に、９５°以上がより好ましい。即ち、接触角を大きくして、感光体の表面エネルギーを小さくすることにより、絶縁破壊や画像欠陥の原因となる感光体表面へのトナーや紙粉によるフィルミングの発生を防止することができる。該フッ素系樹脂粒子とはフッ素原子を含有した樹脂粒子を意味し、例えば、四フッ化エチレン樹脂、三フッ化塩化エチレン樹脂、六フッ化エチレンプロピレン樹脂、フッ化ビニル樹脂、フッ化ビニリデン樹脂、二フッ化二塩化エチレン樹脂及びこれらの共重合体のなかから１種あるいは２種以上を適宜選択するのが好ましいが、特に、四フッ化エチレン樹脂及びフッ化ビニリデン樹脂が好ましい。フッ素系樹脂粒子の分子量や粒子の粒径は、適宜選択することができ、特に制限されるものではないが、体積平均粒径が０．０５〜５μｍのものが好ましい。
【０１３７】
なお、上記フッ素系樹脂粒子の体積平均粒径はレーザ回折／散乱式粒度分布測定装置「ＬＡ−７００」（堀場製作所（株）社製）により測定される。又、感光体の表面接触角は、純水に対する接触角を接触角計（ＣＡ−ＤＴ−Ａ型：協和界面科学社製）を用いて２０℃５０％ＲＨの環境下で測定する。
【０１３８】
上記では本発明の最も好ましい感光体の層構成を例示したが、本発明では上記以外の感光体層構成でも良い。
【０１３９】
中間層、電荷発生層、電荷輸送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。
【０１４０】
又、これらの各層の塗布溶液は塗布工程に入る前に、塗布溶液中の異物や凝集物を除去するために、金属フィルター、メンブランフィルター等で濾過することが好ましい。例えば、日本ポール社製のプリーツタイプ（ＨＤＣ）、デプスタイプ（プロファイル）、セミデプスタイプ（プロファイルスター）等を塗布液の特性に応じて選択し、濾過をすることが好ましい。
【０１４１】
次に有機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。なお保護層は前記円形量規制型塗布加工方法を用いるのが最も好ましい。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。
【０１４２】
次に、本発明の接触帯電方式を用いた画像形成装置について説明する。
《帯電手段》
本発明は感光体に帯電部材を接触させて帯電する（以下、接触帯電部材を用いた帯電手段とも云う）。このような帯電部材としては、磁気ブラシ方式、帯電ローラ方式、ブレード方式等各種帯電部材を用いることができるが、これらの中でも帯電部材として帯電ローラ方式、或いは磁気ブラシ方式が最も好ましく本発明に用いられる。即ち、帯電の均一性が得られやすい帯電ローラ、或いは磁気ブラシが良い。以下、帯電ローラ方式、及び磁気ブラシ方式の帯電手段について記載する。
【０１４３】
本発明においては、導電性弾性部材により構成された帯電ローラを感光体（像担持体）に接触させ、該帯電ローラに電圧を印加して感光体（像担持体）を帯電することが出来る。
【０１４４】
このような帯電ローラ方式は、直流電圧をローラに印加する直流帯電方式、交流電圧をローラに印加する誘導帯電方式のいずれでもよい。
【０１４５】
又誘導帯電方式で印加される電圧の周波数ｆは任意のものが用いられるが、ストロービングすなわち縞模様を防止するために、導電性弾性ローラ及び像担持体部材の相対速度に応じて適当な周波数を選択できる。該相対速度は導電性弾性ローラと像担持体との接触領域の大きさによって決めることができる。
【０１４６】
導電性弾性ローラは芯金の外周に導電性弾性部材よりなる層（単に導電性弾性層又Ｈ、導電性ゴム層ともいう）を被覆したものである。
【０１４７】
前記導電性ゴム層に用いることのできるゴム組成物としては、ポリノルボルネンゴム、エチレン−プロピレンゴム、クロロプレンゴム、アクリロニトリルゴム、シリコーンゴム等が挙げられる。これらのゴムは、単独でまたは２種以上の混合ゴムとして使用することができる。
【０１４８】
導電性を付与するために、これらのゴム組成物に導電性付与剤を配合して使用する。適当な導電性付与剤としては、公知のカーボンブラック（ファーネス系カーボンブラックまたはケツチエンブラック）、酸化錫等の金属粉が挙げられる。導電性付与剤の使用量はゴム組成物全量に対して約５〜約５０質量部である。
【０１４９】
ゴム組成物には、ゴム基材、発泡剤、導電性付与剤以外に必要に応じて、ゴム用薬品、ゴム添加剤を配合して導電性発泡ゴム組成物とすることもできる。ゴム用薬品、ゴム添加剤としては、硫黄、パーオキサイド等の加硫剤、亜鉛華、ステアリン酸等の加硫促進助剤、スルフェンアミド系、チラウム系、チアゾール系、グラニジン系等の加硫促進剤、アミン系、フェノール系、硫黄系、リン系等の老化防止剤、または酸化防止剤、紫外線吸収剤、オゾン劣化防止剤、粘着付与剤等を使用することができ、さらに各種の補強剤、摩擦係数調整剤、シリカ、タルク、クレイ等の無機充填剤も任意に選択し使用し得る。これらの導電性ゴム層は１０^３〜１０^７Ωｃｍの範囲の直流体積抵抗率を有することが好ましい。
【０１５０】
更にこれら導電性弾性層の外側には、感光体表面に残留したトナー等の帯電部材への付着を防止する目的で、離型性被覆層を設けてもよい。該被覆層は又弾性層からのオイルの浸みだしの防止をはかると共に弾性層の抵抗ムラをキャンセルし、抵抗の均一化をはかる、帯電ローラの表面を保護する、帯電ローラの硬度を調整する、等の機能を果たしている。被覆層は上記物性を満足するものであれば、いずれのものでも良く、ひとつの層でも、複数の層でも良い。材料としてはヒドリンゴム、ウレタンゴム、ナイロン、ポリ弗化ビニリデン、ポリ塩化ビニリデン等の樹脂が挙げられる。また、被覆層の厚みは１００〜１０００μｍであることが好ましく、抵抗値は１０^５〜１０^９Ω・ｃｍであることが好ましい。また、表層に近づくにつれ抵抗値は大きくなっていることが好ましい。抵抗を調整する方法としては、被覆層にカーボンブラック、金属及び金属酸化物等の導電性物質を含有させること等が挙げられる。
【０１５１】
帯電ローラの表面粗さＲｚを調整するには帯電ローラの表面層（導電性弾性層又は被覆層）に粉体を含有させることが好ましい。本発明に用いられる粒体は、無機物あるいは有機物のいずれでもよいが、無機物の場合、シリカ粉末が特に好ましい。有機物の場合、たとえばウレタン樹脂粒子、ナイロン粒子、シリコーンゴム粒子、エポキシ樹脂粒子等が挙げられる。これらの粒子は単独でまたは２種以上混合して用いられる。適当な粒体は表面層の表面粗度Ｒｚを０．０５〜１０．０μｍの範囲に調整できる物質を選べばよいが、粒体の粒子径が１〜２０μｍの範囲にあると所望の表面粗度範囲が達成されやすい。粒子径が２０μｍを超すと、表面粗度Ｒｚも１０．０μｍを超し、所期の目的を果さない。逆に、粒子径が１μｍ未満であると、表面粗度Ｒｚが０．０５μｍ未満となりやすくこれも所期の目的を果さない。
【０１５２】
表面粗度Ｒｚを０．０５〜１０．０μｍの範囲に設定する理由は、１０．０μｍを超すとローラ表面に対するトナーのフィルミングが顕著になるからであり、０．０５μｍ未満であると帯電ローラと感光体ドラムの密着性が高まり、すなわち接触面積が大きくなるので帯電音の抑制ができなくなるからである。
【０１５３】
粉体の表面層中の配合割合は、樹脂１００質量部に対して約５〜約２０質量部の割合で配合し、分散することが好ましい。
【０１５４】
帯電ローラは、たとえば次のようにして製造することができる。すなわち、まず円筒状成形空間を有する成形型内に、金属製の回転軸（芯金）を入れ成形型内に導電性弾性体層形成材料を充填し、加硫を行うことにより回転軸の外周面に導電性弾性体層を形成する。次いで、導電性弾性体層の形成された回転軸を成形型から取出す。一方、ウレタン樹脂等の材と、粒体、導電付与剤その他の添加剤を配合し、この配合物をボールミル等を用いて混合、撹拌し表面層形成材料混合物を調製する。そしてこの混合物をディップ法、ロールコート法、スプレーコーティング法等によって前記導電性弾性体層の形成された回転軸表面に均一な厚みに塗工して乾燥し、加熱硬化することにより２層構造の帯電ローラを製造することができる。このようにして得られる帯電ローラは、その最外層である表面層の表面の粗度Ｒｚが０．０５〜１０．０μｍに形成される。
【０１５５】
次に本発明の画像形成装置について述べる。
図１は帯電ローラ帯電を用いた画像形成装置の１例を示す図である。この画像形成装置は本発明を実施するためのものであり、静電潜像形成のための帯電手段として、帯電ローラを感光体ドラムに接触させて帯電せしめ（帯電工程）、又トナーを転写紙へ転写するための転写極（転写手段）に転写ローラを用いている（転写工程）。この転写ローラを直接或いは転写紙を挟んで感光体ドラムに接触させることによりオゾンの発生を回避させた態様のものでいわゆる接触帯電方式を採用しており、そして非接触現像により静電潜像を現像するものである。
【０１５６】
図１（ａ）において帯電ローラ１によって帯電された感光体ドラム２上にレーザを用いた像露光により静電潜像が形成される（像露光工程）。そして、この静電潜像は、感光体ドラム２に近接して配置された現像装置（現像手段）３の現像剤担持体である現像スリーブ４によってトナー像に現像される（現像工程）。そして、転写前の除電ランプ５によって感光体ドラム２の電荷が除電された後、トナー像は、給紙カセットから搬送ローラ８によって搬送されてきた転写紙Ｐに、転写ローラ６によりトナーと逆極性の電荷が付与され、この逆極性の電荷の静電気力により転写紙Ｐにトナーが転写される。トナー転写後の転写紙Ｐは、感光体ドラム２から分離された後、搬送ベルト７によって定着装置へ送られ、加熱ローラと押圧ローラによってトナー像が転写紙Ｐに定着される（定着工程）。
【０１５７】
前記帯電ローラ１（及び転写ローラ６）には電源９（１０）からＤＣ及びＡＣ成分から成るバイアス電圧が印加され、オゾン発生量が極めて少い状態で感光体ドラム２への帯電及びトナー像の転写紙Ｐへの帯電が行なわれる。前記電圧は通常±３００〜１０００ＶのＤＣバイアスとこれに重畳して１００Ｈｚ〜１０ＫＨｚ、２００〜３５００Ｖ（ｐ−ｐ）のＡＣバイアスを付加することが好ましい。
【０１５８】
前記帯電ローラ１及び転写ローラ６は感光体ドラム２への圧接下に従動又は強制回転される。
【０１５９】
前記感光体ドラム２への圧接は１０〜１００ｇ／ｃｍとされローラの回転は感光体ドラム２の周速の１〜８倍とされる。
【０１６０】
図１（ｂ）に示すように前記帯電ローラ１（及び転写ローラ６）は芯金２０と、その外周に設けられた導電性弾性部材であるクロルプレンゴム、ウレタンゴム、シリコーンゴム等のゴム層又はそれらのスポンジ層２１から成り、好ましくは最外層に０．０１〜１μｍ厚の離型性弗素系樹脂又はシリコーン樹脂層から成る保護層２２を設けて構成される。
【０１６１】
転写後の感光体ドラム２はクリーニング器（クリーニング手段）１１のクリーニングブレード１２の圧接によりクリーニングされ次の画像形成に供えられる。
【０１６２】
電子写真方式の画像形成装置としては、感光体と、帯電手段、現像手段、クリーニング手段等の構成要素をプロセスカートリッジとして一体に結合して構成し、このユニットを装置本体に対して着脱自在に構成しても良い。又像露光手段、現像手段、転写又は分離器、クリーニング手段の少なくとも１つを感光体とともに一体に支持してプロセスカートリッジを形成し、画像形成装置本体に着脱自在の単一ユニットとし、装置本体のレールなどの案内手段を用いて着脱自在の構成としても良い。
【０１６３】
尚、前記図１においては、帯電器、及び転写極ともローラ帯電器を用いているが、本発明においては、本発明は帯電器に接触帯電部材（帯電ローラ等）を用いることであり、転写極には転写ローラ以外の転写手段を用いても良い。
【０１６４】
次に、帯電部材に磁気ブラシを用いる磁気ブラシ帯電装置について説明する。図２は接触式の磁気ブラシ帯電装置の図、図３は図２の帯電装置による交流バイアス電圧と帯電電位との関係を示す図である。
【０１６５】
一般に帯電用磁気ブラシを形成する磁気粒子の体積平均粒径が大きいと、帯電用磁気粒子搬送体（搬送担体）上に形成される磁気ブラシの穂の状態が粗いために、電界による振動を与えながら帯電しても、磁気ブラシにムラが現れ易く、帯電ムラの問題が起こる。この問題を解消するには、磁気粒子の体積平均粒径を小さくすればよく、実験の結果、体積平均粒径が２００μｍ以下でその効果が現れ始め、特に１５０μｍ以下になると、実質的に磁気ブラシの穂の粗に伴う問題が生じなくなる。しかし、粒子が細か過ぎると帯電時に感光体ドラム５０面に付着するようになったり、飛散し易くなったりする。これらの現象は、粒子に作用する磁界の強さ、それによる粒子の磁化の強さにも関係するが、一般的には、粒子の体積平均粒径が２０μｍ以下に顕著に現れるようになる。
【０１６６】
以上から、磁気粒子の粒径は体積平均粒径が２００μｍ以下、２０μｍ以上であり、且つ該磁気粒子の個数平均粒径の１／２倍以下の粒径を有する磁気粒子を３０個数％以下とすることが必要である。なお、磁化の強さは３０〜１００ｅｍｕ／ｇのものが好ましく用いられる。
【０１６７】
このような磁気粒子は、磁性体として前述した従来の二成分現像剤の磁性キャリヤ粒子におけると同様の、鉄、クロム、ニッケル、コバルト等の金属、あるいはそれらの化合物や合金、例えば四三酸化鉄、γ−酸化第二鉄、二酸化クロム、酸化マンガン、フェライト、マンガン−銅系合金、と云った強磁性体の粒子、又はそれら磁性体粒子の表面をスチレン系樹脂、ビニル系樹脂、エチレン系樹脂、ロジン変性樹脂、アクリル系樹脂、ポリアミド樹脂、エポキシ樹脂、ポリエステル樹脂等の樹脂で被覆するか、あるいは、磁性体微粒子を分散して含有した樹脂で作るかして得られた粒子を従来公知の平均粒径選別手段で粒径選別することによって得られる。
【０１６８】
なお、磁気粒子を球状に形成することは、搬送担体に形成される粒子層が均一となり、また搬送担体に高いバイアス電圧を均一に印加することが可能となると云う効果も与える。即ち、磁気粒子が球形化されていることは、（１）一般に、磁気粒子は長軸方向に磁化吸着され易いが、球形化によってその方向性がなくなり、従って、磁気粒子層が均一に形成され、局所的に抵抗の低い領域や層厚のムラの発生を防止する、（２）磁気粒子の高抵抗化と共に、従来の粒子に見られるようなエッジ部が無くなって、エッジ部への電界の集中が起こらなくなり、その結果、帯電用磁気粒子の搬送担体に高いバイアス電圧を印加しても、感光体ドラム５０面に均一に放電して帯電ムラが起こらない、という効果を与える。
【０１６９】
以上のような効果を奏する球形粒子には磁気粒子の抵抗率が１０^５〜１０^１０Ωｃｍであるように導電性の磁気粒子を形成したものが好ましい。この抵抗率は、粒子を０．５０ｃｍ^２の断面積を有する容器に入れてタッピングした後、詰められた粒子上に１ｋｇ／ｃｍ^２の荷重を掛け、荷重と底面電極との間に１０００Ｖ／ｃｍの電界が生ずる電圧を印加したときの電流値を読み取ることで得られる値であり、この抵抗率が低いと、搬送担体にバイアス電圧を印加した場合に、磁気粒子に電荷が注入されて、感光体ドラム５０面に磁気粒子が付着し易くなったり、あるいはバイアス電圧による感光体ドラム５０の絶縁破壊が起こり易くなったりする。また、抵抗率が高いと電荷注入が行われず帯電が行われない。
【０１７０】
さらに、接触式の磁気ブラシ帯電装置１２０に用いられる磁気粒子は、それにより構成される磁気ブラシが振動電界により軽快に動き、しかも外部飛散が起きないように、比重が小さく、且つ適度の最大磁化を有するものが望ましい。具体的には真比重が６以下で最大磁化が３０〜１００ｅｍｕ／ｇのもの、特に４０〜８０ｅｍｕ／ｇを用いると好結果が得られることが判明した。
【０１７１】
以上を総合して、磁気粒子は、少なくとも長軸と短軸の比が３倍以下であるように球形化されており、針状部やエッジ部等の突起が無く、抵抗率は好ましくは１０^５〜１０^１０Ωｃｍの範囲にあることが望まれる。そして、このような球状の磁気粒子は、磁性体粒子にできるだけ球形のものを選ぶこと、磁性体微粒子分散系の粒子では、できるだけ磁性体の微粒子を用いて、分散樹脂粒子形成後に球形化処理を施すこと、あるいはスプレードライの方法によって分散樹脂粒子を形成すること等によって製造される。
【０１７２】
図２又は図３によれば、帯電装置としての磁気ブラシ帯電装置１２０は回転する感光体ドラム５０と対向し、感光体ドラム５０との近接部（帯電部Ｔ）において同方向（反時計方向）に回転される帯電用磁気粒子搬送体としての、例えばアルミ材やステンレス材を用いた円筒状の帯電スリーブ１２０ａと、該帯電スリーブ１２０ａの内部に設けられるＮ、Ｓ極よりなる磁石体１２１と、該磁石体１２１により帯電スリーブ１２０ａの外周面上に形成され感光体ドラム５０を帯電する磁気粒子からなる磁気ブラシと、磁石体１２１のＮ−Ｎ磁極部において該帯電スリーブ１２０ａ上の磁気ブラシを掻取るスクレーパ１２３と、磁気ブラシ帯電装置１２０内の磁気粒子を撹拌或いは磁気粒子供給時に使用済み磁気粒子を磁気ブラシ帯電装置１２０の排出口１２５より溢れさせて排出する撹拌スクリュウ１２４と、磁気ブラシの穂立ち規制板１２６とにより構成される。帯電スリーブ１２０ａは磁石体１２１に対し回動可能になっていて、感光体ドラム５０との対向位置で感光体ドラム５０の移動方向と同方向（反時計方向）に０．１〜１．０倍の周速度で回転させられるのが好ましい。また帯電スリーブ１２０ａは、帯電バイアス電圧を印加し得る導電性の搬送担体が用いられるが、特に、表面に粒子層が形成される導電性の帯電スリーブ１２０ａの内部に複数の磁極を有する磁石体１２１が設けられている構造のものが好ましく用いられる。このような搬送担体においては、磁石体１２１との相対的な回転によって、導電性の帯電スリーブ１２０ａの表面に形成される磁気粒子層が波状に起伏して移動するようになるから、新しい磁気粒子が次々と供給され、帯電スリーブ１２０ａ表面の磁気粒子層に多少の層厚の不均一があっても、その影響は上記波状の起伏によって実際上問題とならないように十分カバーされる。帯電スリーブ１２０ａの表面は磁気粒子の安定な均一搬送のために表面の平均粗さを５．０〜３０μｍとすることが好ましい、平滑であると搬送は十分に行えなく、粗すぎると表面の凸部から過電流が流れ、どちらにしても帯電ムラが生じ易い。上記の表面粗さとするにはサンドブラスト処理が好ましく用いられる。また、帯電スリーブ１２０ａの外径は５．０〜２０ｍｍが好ましい。これにより、帯電に必要な接触領域を確保する。接触領域が必要以上に大きいと帯電電流が過大となるし、小さいと帯電ムラが生じ易い。また上記のように小径とした場合、遠心力により磁気粒子が飛散あるいは感光体ドラム５０に付着し易いために、帯電スリーブ１２０ａの線速度は感光体ドラム５０の移動速度と殆ど同じか、それよりも遅いことが好ましい。
【０１７３】
また、帯電スリーブ１２０ａ上に形成する磁気粒子層の厚さは、規制手段によって十分に掻き落されて均一な層となる厚さであることが好ましい。帯電領域において帯電スリーブ１２０ａの表面上の磁気粒子の存在量が多すぎると磁気粒子の振動が十分に行われず感光体の摩耗や帯電ムラを起こすとともに過電流が流れ易く、帯電スリーブ１２０ａの駆動トルクが大きくなるという欠点がある。反対に磁気粒子の帯電領域における帯電スリーブ１２０ａ上の存在量が少な過ぎると感光体ドラム５０への接触に不完全な部分を生じ磁気粒子の感光体ドラム５０上への付着や帯電ムラを起こすことになる。実験を重ねた結果、帯電領域における磁気粒子の好ましい付着量は１００〜４００ｍｇ／ｃｍ^２であり、特に好ましくは２００〜３００ｍｇ／ｃｍ^２であることが判明している。なお、この付着量は、磁気ブラシの帯電領域における平均値である。
【０１７４】
帯電装置としての磁気ブラシ帯電装置１２０には、直流（ＤＣ）バイアスＥ３に必要により交流（ＡＣ）バイアスＡＣ３が重畳される帯電バイアス、例えば直流バイアスＥ３としてトナーと同極性（本実施形態においてはマイナス極性）の−１００〜−５００Ｖが、また交流バイアスＡＣ３として周波数１〜５ｋＨｚ、電圧３００〜５００Ｖ_Ｐ−Ｐの帯電バイアスが印加される帯電スリーブ１２０ａにより、感光体ドラム５０の周面が接触、摺擦されて感光体ドラム５０が帯電される。帯電スリーブ１２０ａと感光体ドラム５０との間には前記交流バイアスＡＣ３の電圧印加による振動電界が形成されているので、磁気ブラシを経て感光体層１０ａ上への電荷の注入が円滑に行われて一様に高速な帯電が行われる。
【０１７５】
感光体ドラム５０を帯電した帯電スリーブ１２０ａ上の磁気ブラシは、磁石体１２１に設けられるＮ−Ｎ磁極部において、スクレーパ１２３により帯電スリーブ１２０ａ上より落下され帯電スリーブ１２０ａとの近接部において帯電スリーブ１２０ａと逆方向（反時計方向）に回転する撹拌スクリュウ１２４により撹拌された後、再度磁気ブラシ形成され帯電部Ｔに搬送される。
【０１７６】
図３に示すように、帯電バイアスの交流バイアスＡＣ３のピーク・ピーク電圧（Ｖ_Ｐ−Ｐ）と帯電電位との関係は、ピーク・ピーク電圧Ｖ_Ｐ−Ｐが大きくなるに従い帯電電位が大きくなり、帯電電位はピーク・ピーク電圧が一定のＶ１で帯電バイアスの直流バイアスＥ３の値ＶＳとほぼ等しい値で飽和し、それ以上ピーク・ピーク電圧Ｖ_Ｐ−Ｐを大きくしても帯電電位は殆ど変化しないという特性がある。磁気粒子の電気抵抗は環境条件によっても変化するが、また使用するに従い磁気粒子の表面にトナーが融着するなどして電気抵抗は高くなる。このため、特性曲線は使用初期の新しい磁気粒子の場合は実線で示す（ａ）のように左側に、長期間使用した磁気粒子の場合は前記特性曲線は点線で示す（ｂ）のように右側に位置することになる。
【０１７７】
本発明の画像形成装置の接触方式による帯電装置では、装着電源のｏｎ時或いはプリント開始前に帯電電位に相当する直流バイアスＥ３の電圧値を所定値とし、交流バイアスＡＣ３のピーク・ピーク電圧（Ｖ_Ｐ−Ｐ）を低い値から次第に大きくした帯電バイアスを印加してその時変化する感光体ドラム５０の帯電電位を電位計ＥＳによって検出する。検出される帯電電位はＡ／Ｄ変換器によってディジタル値に変換されたのち制御部（ＣＰＵ）に入力される。制御部ではこの帯電電位が所定値ＶＳの飽和点に達した時のＶ_Ｐ−Ｐの値を適正バイアス値Ｖ１と規定してプリント動作とする。
【０１７８】
即ち、プリントが行われる時交流バイアスＡＣ３を低い値から次第に大きくして（スイープして）交流バイアスＡＣ３のＶ_Ｐ−Ｐの値Ｖ１を求め、制御部からバイアス信号が出力される。この制御信号はＤ／Ａ変換器によってアナログ値に変換された後交流バイアスＡＣ３に送出され、交流バイアスＡＣ３は決定されたピーク・ピーク電圧Ｖ１を出力する。その際のピーク・ピーク電圧Ｖ１の値とメモリに格納された磁気粒子の劣化により交換すべき規定値Ｖ２を読み出しこれと比較する。磁気粒子はトナーの混入により抵抗が増加するので、プリントの使用に従い適正バイアス値Ｖ１が増加する。これに伴い印加するＶ_Ｐ−Ｐが増加し帯電不能な状態が生じることになる。測定した電圧値が帯電不能を示す規定値Ｖ２より小さい間は画像形成を続けるが、規定値Ｖ２より大きくなると、制御部より画像形成動作停止信号が送出され画像形成動作を停止し、不図示の操作部の表示部に帯電装置異常の表示を行う。この表示に基づき、帯電用の磁気粒子の供給ボトル２２０を磁気ブラシ帯電装置１２０にセットし、供給ボトル２２０底面の不図示の開閉蓋を開口して磁気粒子を磁気ブラシ帯電装置１２０に落下、供給する。上記において感光体ドラム５０の電位の測定に電位計ＥＳを用いたが、バイアス電源に直流電流計を繋いで用いて交流バイアスＶ_Ｐ−Ｐを変化させ、この電流値が飽和点に達した時のＶ_Ｐ−Ｐを適正バイアス値Ｖ１と設定し、規定値Ｖ２との比較を行いＶ１を越えた時磁気粒子の供給を行うようにしてもよい。
【０１７９】
またメンテナンス時或いは例えば５万プリント等の定期時に、帯電用の磁気粒子の交換が行われる。メモリに記憶されたメンテナンスプリント毎や例えば５万プリント毎の定期時に、制御部を通して交換信号が出され、不図示の駆動モータの駆動により予めセットされた帯電用の磁気粒子の供給ボトル２２０の供給ローラ２２１が回転され、供給ボトル２２０内の磁気粒子が磁気ブラシ帯電装置１２０内に全量が１回で落下される。供給後空の供給ボトル２２０を外し、新たな供給ボトル２２０をセットすることにより画像形成装置が作動状態となるように制御することも可能である。また、定期時に制御部より不図示の操作部に例えばランプの点滅等による供給信号を表示し、供給ボトル２２０を磁気ブラシ帯電装置１２０にセットし、供給ボトル２２０底面の不図示の開閉蓋を開口して磁気粒子を供給するようにしてもよい。
【０１８０】
落下された磁気粒子は回転される帯電スリーブ１２０ａにより搬送され、スクレーパ１２３により帯電スリーブ１２０ａ表面より掻落とされて磁気ブラシ帯電装置１２０の底部に補給される。これに伴い、反時計方向に回転される撹拌スクリュウ１２４により磁気ブラシ帯電装置１２０内部に収納されている使用済みの磁気粒子が排出口１２５より溢れ出され、ダクトＤＢを通して共通の磁気粒子回収容器３００に回収される。この際、供給ボトル２２０より磁気ブラシ帯電装置１２０内に供給される１回の磁気粒子供給量は磁気ブラシ帯電装置１２０内に収納される全磁気粒子に対して、２０〜５０質量％が好ましい。２０質量％未満では新規に供給される磁気粒子量が少な過ぎ交換効果がなく良好な帯電が行われず、５０質量％を越えると新規の磁気粒子が溢れ出てしまう。
【０１８１】
上記により、帯電装置内の磁気粒子が劣化されることなく良好な帯電性能が長期に維持される。
【０１８２】
図４は磁気ブラシ帯電器を有する画像形成装置の１例を示す断面図である。図４において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、その上に本発明の構成を有する感光体で、接地されて時計方向に駆動回転される。５２は磁気ブラシ帯電器で、感光体ドラム５０周面に対し一様な帯電を与えられる（帯電工程）。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。
【０１８３】
感光体への一様帯電ののち像露光器５３により画像信号に基づいた像露光が行われる（像露光工程）。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。
【０１８４】
その静電潜像は次いで現像器５４で現像される（現像工程）。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、現像剤は図示していない層形成手段によって現像スリーブ５４１上に１００〜６００μｍの層厚に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。
【０１８５】
転写材（記録紙とも云う）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５７の回転作動により転写域へと給紙される。
【０１８６】
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の周面に転写ローラ（転写器）５８が圧接され、給紙された転写材Ｐを挟着して転写される（転写工程）。
【０１８７】
次いで転写材Ｐは転写ローラとほぼ同時に圧接状態とされた分離ブラシ（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６０１と圧着ローラ６０２の加熱、加圧によってトナーを溶着したのち（定着工程）排紙ローラ６１を介して装置外部に排出される。なお前記の転写ローラ５８及び分離ブラシ５９は転写材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。
【０１８８】
一方転写材Ｐを分離した後の感光体ドラム５０は、クリーニング器６２のクリーニングブレード６２１の圧接により残留トナーを除去・清掃し、再び露光部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。
【０１８９】
尚、７０は感光体、帯電器、転写器・分離器及びクリーニング器を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。
【０１９０】
画像形成装置としては、上述の感光体と、現像器、クリーニング器等の構成要素をプロセスカートリッジとして一体に結合して構成し、このユニットを装置本体に対して着脱自在に構成しても良い。又、帯電器、像露光器、現像器、転写又は分離器、及びクリーニング器の少なくとも１つを感光体とともに一体に支持してプロセスカートリッジを形成し、装置本体に着脱自在の単一ユニットとし、装置本体のレールなどの案内手段を用いて着脱自在の構成としても良い。
【０１９１】
像露光は、画像形成装置を複写機やプリンターとして使用する場合には、原稿からの反射光や透過光を感光体に照射すること、或いはセンサーで原稿を読み取り信号化し、この信号に従ってレーザビームの走査、ＬＥＤアレイの駆動、又は液晶シャッターアレイの駆動を行い感光体に光を照射することなどにより行われる。
【０１９２】
尚、ファクシミリのプリンターとして使用する場合には、像露光器１３は受信データをプリントするための露光を行うことになる。
【０１９３】
本発明の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。
【０１９４】
【実施例】
以下、実施例を挙げて本発明を詳細に説明するが、本発明の態様はこれに限定されない。但し、下記文中の「部」は「質量部」を示す。
【０１９５】
下記のごとくして、感光体を作製した。
感光体１の作製
〈中間層（ＵＣＬ）〉
下記中間層塗布液を調製し、洗浄済みの円筒状アルミニウム基体上に浸漬塗布法で塗布し、中間層を形成した。
【０１９６】
Ｘ成分：酸化チタン（数平均一次粒子径：３５ｎｍのアナターゼ形酸化チタン顔料） １００部
Ｙ成分：イソプロピルトリイソステアロイルチタネート １０部
Ｚ成分−１：ビニル系樹脂セグメントＡ溶液（ヒンダードアミン基を有し且つシリル変性されたビニル系樹脂樹脂成分Ａ溶液） １００部
Ｚ成分−２：メチルトリメトキシシラン ７０部
Ｚ成分−３：ジメチルジメトキシシラン ３０部
溶媒１：ｉ−ブチルアルコール １００部
溶媒２：ブチルセロソルブ ７５部
ジ−ｉ−プロポキシエチルアセトアセテートアルミニウム １０部
上記Ｘ成分、Ｙ成分、溶媒１、５０部を混合し、該混合液を一昼夜かけてメディア分散した。該メディア分散液に上記した残りの成分を添加し、よく攪拌した後、攪拌下、純水３０部を滴下し、６０℃で４時間反応させた。次いで室温まで冷却してジオクチルスズジマレエートエステルのｉ−プロピルアルコール溶液（固形分１５％）を１０部添加、攪拌して、その後濾過してメディアを除去し、中間層塗布液を調製した。この塗布液を前記円筒状アルミニウム基体上に円形量規制型塗布装置により塗布し、１２０℃、１時間の加熱硬化を行い、乾燥膜厚１０μｍの本発明のＸ成分、Ｙ成分、及びＺ成分を有する組成物（中間層塗布液）から形成される化合物を含有する中間層を形成した。
【０１９７】
〈電荷発生層（ＣＧＬ）〉
オキシチタニルフタロシアニン（Ｃｕ−Ｋα特性Ｘ線によるＸ線回折の最大ピーク角度がブラッグ２θで２７．３） ２０部
ポリビニルブチラール（＃６０００−Ｃ、電気化学工業社製） １０部
酢酸ｔ−ブチル ７００部
４−メトキシ−４−メチル−２−ペンタノン ３００部
上記組成物を混合し、サンドミルを用いて分散し、電荷発生層塗布液を調製した。この塗布液を浸漬塗布法で塗布し、前記中間層の上に乾燥膜厚０．３μｍの電荷発生層を形成した。
【０１９８】
〈電荷輸送層（ＣＴＬ）〉
電荷輸送剤（〔４−（２，２−ジフェニルビニル）フェニル〕−ジ−ｐ−トリルアミン） ７５部
ポリカーボネート樹脂（ユーピロンＺ３００：三菱ガス化学社製）１００部
塩化メチレン ７５０部
上記組成物を混合し、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た。
【０１９９】
〈電荷注入層〉
電荷輸送物質（〔４−（２，２−ジフェニルビニル）フェニル〕−ジ−ｐ−トリルアミン） ２００部
ビスフェノールＺ型ポリカーボネート
（ユーピロンＺ３００：三菱ガス化学社製） ３００部
下記化合物Ａで表面処理した（処理量７％）
アンチモンドープ酸化スズ超微粒子 ２５０部
メチルハイドロジェンシリコーンオイル（商品名：ＫＦ９９、信越シリコーン（株）製）で表面処理した（処理量２０％）アンチモンドープ酸化スズ微粒子２５０部
ヒンダードアミン（サノールＬＳ２６２６：三共社製） ３部
ポリテトラフルオロエチレン樹脂粒子（平均粒径０．５μｍ） １５０部
１−ブタノール ２０００部
を混合し、溶解して表面保護層塗布液を調製した。この塗布液を前記感光体１の電荷輸送層の上に浸漬塗布法で塗布し、１００℃、４０分の加熱硬化を行い乾燥膜厚２．０μｍの電荷注入層を形成し、感光体２を作製した。該感光体１の表面の水に対する接触角は１１６°であった。
【０２００】
感光体２の作製
感光体１の作製において、中間層塗布液の酸化チタンの粒径を３５ｎｍから１５ｎｍのアナターゼ形酸化チタン顔料に代えた他は同様にして、本発明のＸ成分、Ｙ成分、及びＺ成分を有する組成物から形成される化合物を含有する中間層を有する感光体２を作製した。
【０２０１】
感光体３の作製
感光体１の作製において、中間層塗布液の酸化チタンの粒径を３５ｎｍから１８０ｎｍのアナターゼ形酸化チタン顔料に代えた他は同様にして、本発明のＸ成分、Ｙ成分、及びＺ成分を有する組成物から形成される化合物を含有する中間層を有する感光体３を作製した。
【０２０２】
感光体４の作製
感光体１の作製において、中間層塗布液のビニル系樹脂セグメントＡ溶液をビニル系樹脂セグメントＢ溶液（ヒンダードフェノール基を有し且つシリル変性されたビニル系セグメントＢ溶液）に代えた以外は感光体１と同様にして、本発明のＸ成分、Ｙ成分、及びＺ成分を有する組成物から形成される化合物を含有する中間層を含有する感光体４を作製した。
【０２０３】
感光体５の作製
感光体１の作製において、中間層を下記の中間層に代え、乾燥膜厚を４μｍにした以外は同様にして、本発明のＸ成分、Ｙ成分、及びＺ成分を有する組成物から形成される化合物を含有する中間層を有する感光体５を作製した。
【０２０４】
〈中間層（ＵＣＬ）〉
下記中間層塗布液を調製し、洗浄済みの円筒状アルミニウム基体上に塗布し、中間層を形成した。
【０２０５】
Ｘ成分：酸化チタン（数平均一次粒子径：３５ｎｍのアナターゼ形酸化チタン顔料） １００部
Ｙ成分：γ−グリシドキシプロピルトリメトキシシラン １０部
Ｚ成分−１：ビニル系樹脂セグメントＡ溶液（ヒンダードアミン基を有し且つシリル変性されたビニル系樹脂セグメントＡ溶液） １００部
Ｚ成分−２：メチルトリメトキシシラン １００部
溶媒１：ｉ−ブチルアルコール １００部
溶媒２：ブチルセロソルブ ７５部
ジ−ｉ−プロポキシエチルアセトアセテートアルミニウム １０部
上記Ｘ成分、Ｙ成分、溶媒１、５０部を混合し、該混合液を一昼夜かけてメディア分散した。該メディア分散液に上記した残りの成分を添加し、よく攪拌した後、攪拌下、純水３０部を滴下し、６０℃で４時間反応させた。次いで室温まで冷却してジオクチルスズジマレエートエステルのｉ−プロピルアルコール溶液（固形分１５％）を１０部を添加、攪拌して、その後濾過してメディアを除去し、中間層塗布液を調製した。この塗布液を円筒状アルミニウム基体上に円形量規制型塗布装置により塗布し、１２０℃、１時間の加熱硬化を行い、乾燥膜厚４μｍの本発明のＸ成分、Ｙ成分、及びＺ成分を有する組成物（中間層塗布液）から形成される化合物を含有する中間層を形成した。
【０２０６】
感光体６の作製
感光体１の作製において、中間層を下記の中間層に代え、乾燥膜厚を２０μｍにした以外は同様にして、本発明のＸ成分、Ｙ成分、及びＺ成分を有する組成物から形成される化合物を含有する中間層を有する感光体６を作製した。
【０２０７】
〈中間層（ＵＣＬ）〉
下記中間層塗布液を調製し、洗浄済みの円筒状アルミニウム基体上に塗布し、中間層を形成した。
【０２０８】
Ｘ成分：酸化チタン（数平均一次粒子径：３５ｎｍのアナターゼ形酸化チタン顔料） １００部
Ｙ成分：γ−グリシドキシプロピルトリメトキシシラン ２０部
Ｚ成分−１：ビニル系樹脂セグメントＢ溶液（ヒンダードフェノール基を有し且つシリル変性されたビニル系樹脂セグメントＢ溶液） １００部
Ｚ成分−２：メチルトリメトキシシラン ８０部
溶媒１：ｉ−ブチルアルコール １００部
溶媒２：ブチルセロソルブ ７５部
ジ−ｉ−プロポキシエチルアセトアセテートアルミニウム １０部
上記Ｘ成分、Ｙ成分、溶媒１、５０部を混合し、該混合液を一昼夜かけてメディア分散した。該メディア分散液に上記した残りの成分を添加し、よく攪拌した後、攪拌下、純水３０部を滴下し、６０℃で４時間反応させた。次いで室温まで冷却してジオクチルスズジマレエートエステルのｉ−プロピルアルコール溶液（固形分１５％）を１０部を添加、攪拌して、その後濾過してメディアを除去し、中間層塗布液を調製した。この塗布液を円筒状アルミニウム基体上に円形量規制型塗布装置により塗布し、１２０℃、１時間の加熱硬化を行い、乾燥膜厚２０μｍのＸ成分、Ｙ成分、及びＺ成分を有する組成物（中間層塗布液）から形成される化合物を含有する中間層を形成した。
【０２０９】
感光体７の作製
感光体１の作製において、中間層塗布液のＸ成分の酸化チタンをアナターゼ形酸化チタンからルチル形酸化チタン（数平均一次粒子径：３５ｎｍ）に代え、Ｚ成分のビニル系樹脂セグメントＡ溶液をビニル系樹脂セグメントＣ溶液（シリル変性されたビニル系樹脂セグメントＣ溶液）に代えた以外は感光体１と同様にして、本発明のＸ成分、Ｙ成分、及びＺ成分を有する組成物から形成される化合物を含有する中間層を有する感光体７を作製した。
【０２１０】
感光体８
感光体１の作製において、中間層塗布液のＸ成分を酸化チタンから酸化亜鉛（数平均一次粒子径：１００ｎｍ）に変更した以外は同様にして、本発明のＸ成分、Ｙ成分、及びＺ成分を有する組成物から形成される化合物を含有する中間層を有する感光体８を作製した。
【０２１１】
感光体９
感光体１の作製において、中間層塗布液のＸ成分を酸化チタンから酸化ジルコニウム（数平均一次粒子径：３５０ｎｍ）に変更した以外は同様にして、本発明のＸ成分、Ｙ成分、及びＺ成分を有する組成物から形成される化合物を含有する中間層を有する感光体９を作製した。
【０２１２】
感光体１０
感光体１の作製において、中間層塗布液のＸ成分を酸化チタンから酸化アルミニウムＡｌ_２Ｏ_３（数平均一次粒子径：３５ｎｍ）に変更した以外は同様にして、本発明のＸ成分、Ｙ成分、及びＺ成分を有する組成物から形成される化合物を含有する中間層を有する感光体９を作製した。
【０２１３】
感光体１１
感光体１の作製において、中間層塗布液のＺ成分−１を除去し、Ｚ成分−２を７０部から１４０部に、Ｚ成分−３を３０部から６０部にに変更した以外は同様にして、本発明のＸ成分、Ｙ成分、及びＺ成分を有する組成物（中間層塗布液）から形成される化合物を含有する中間層を有する感光体９を作製した。
【０２１４】
感光体１２〜１５
感光体１の作製において、電荷注入層のポリテトラフルオロエチレン樹脂粒子の種類、量及び膜厚を表１のように代え、感光体の接触角を変化させた以外は感光体１と同様にして感光体１２〜１５を作製した。
【０２１５】
感光体１６（比較用感光体）
感光体１の作製において、中間層を下記の中間層に代えた以外は同様にして、比較用の感光体１６を作製した。
【０２１６】
中間層塗布液の作製
Ｘ成分：酸化チタン（数平均一次粒子径：３５ｎｍのアナターゼ形酸化チタン顔料） １００部
Ｙ成分：イソプロピルトリイソステアロイルチタネート １０部
Ｚ成分：ポリアミド樹脂（メトキシメチル化ナイロン６（メトキシメチル化度は２５％）） １５０部
イソプロピルアルコール ５００部
ポリアミドをイソプロピルアルコールで加温溶解後、酸化チタンを混合、該混合液を分散部分の構造がセラミックで表面加工されたサンドミル分散機で、分散時間１０時間、バッチ式にて分散し中間層塗布液を作製した。該中間層塗布液を円筒状アルミニウム基体上に円形量規制型塗布装置により塗布し、乾燥膜厚１０μｍの中間層を形成した。
【０２１７】
感光体１７（比較用感光体）
感光体１の作製において、中間層塗布液のＸ成分：酸化チタンを除いた以外は感光体１と同様にして、比較用の感光体１７を作製した。
【０２１８】
感光体１８（比較用感光体）
感光体１の作製において、電荷注入層を除いた以外は感光体１と同様にして、比較用の感光体１８を作製した。
【０２１９】
表１中に、感光体１〜１８の中間層、電荷注入層の相違点と前記した感光体表面の水に対する接触角の測定結果を示した。
【０２２０】
【化５】

【０２２１】
【表１】

【０２２２】
【表２】

【０２２３】
Ｇ、Ｈは下記のフッ素系樹脂微粒子を示す。
Ｇ：四フッ化エチレン樹脂粒子（ルブロンＬ−２、ダイキン工業（株）製）
Ｈ：三フッ化エチレン樹脂粒子（ダイフロン、ダイキン工業（株）製）
尚、前記感光体１〜１８の作製と同時に、各感光体の中間層塗布液を用いて、アルミ蒸着したポリエチレンテレフタレート支持体上に各中間層塗布液を塗布し、前記感光体の乾燥条件と同じ条件で乾燥膜厚１０μｍの中間層を形成して体積抵抗測定用試料を作製し、各中間層の体積抵抗を測定した。その結果、感光体１〜１８の中間層の体積抵抗は全て１×１０^８以上であった。又、同時に各中間層の塗布液溶媒への溶媒溶解性を検証したが、感光体１６の中間層を除く全ての中間層が塗布液溶媒へ溶解せず、これらの中間層が三次元構造の架橋構造を有していることが示された。一方、感光体１６の中間層は、塗布液溶媒への溶解性を示し、中間層形態が徐々に溶解していった。
【０２２４】
評価１（帯電ローラを用いた評価）
以上のようにして得た感光体１〜１８を下記構成の帯電ローラを組み込んだコニカ（株）製の反転現像方式デジタル複写機「Ｋｏｎｉｃａ７０５０」の改造機に各々装着し、高温高湿（３０℃８０％ＲＨ）と低温低湿（１０℃２０％ＲＨ）の環境下で、それぞれ評価項目を変えて評価した。評価結果を表３に示す。
【０２２５】
帯電ローラ
導電性弾性体層の材料として、ポリノルボルネンゴム／カーボンブラック／ナフテン系オイル及び必要に応じて加硫剤、加硫促進剤、添加剤等を混合、調製し、金型充填し、導電性弾性体層を形成した。この層の上に、被覆層形成材料としてポリエステルウレタン、粒径約０．５μｍの樹脂粉体、カーボンブラック、溶剤（ＭＥＫ／ジメチルホルムアミド）から成る組成物液中に浸漬し、コーティング、乾燥、加熱処理し、ウレタン層からなる被覆層を形成し、帯電ローラＮｏ．１を得た。導電性弾性層の抵抗は３．２×１０^４Ωｃｍ、被覆層の抵抗は５．２×１０^５Ωｃｍであり、帯電ローラの表面粗さは十点平均粗さＲｚが０．１であった。
【０２２６】
感光体の線速：２８０ｍｍ／ｓｅｃ
露光条件
露光部電位目標：−５０Ｖ未満にする露光量に設定。
【０２２７】
露光ビーム：ドット密度８００ｄｐｉ（ｄｐｉとは２．５４ｃｍ当たりのドット数）の像露光を行った。レーザビームスポット面積：０．８×１０^−９ｍ^２、レーザは７８０ｎｍの半導体レーザを使用
転写条件：コロトロン電極を用いた静電転写
分離条件：交流バイアスを印加した分離電極の分離手段を用いた
クリーニング：ゴム弾性ブレードを用い、感光体への当接角度：２０°、当接荷重：２０（ｇ／ｃｍ）になるように調整した。
【０２２８】
評価項目及び評価方法
評価項目及び評価基準
残留電位の評価（べた黒画像の電位変化）
低温低湿（１０℃２０％ＲＨ）、高温高湿（ＨＨ：３０℃８０％ＲＨ）環境下で、画素率が７％の文字画像、ハーフトーン画像、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で１枚間欠モードにて１万枚の複写を行い、初期と１万枚後の現像位置でのべた黒画像部の電位変化（｜ΔＶ｜）を評価した。｜ΔＶ｜が小さい方が繰り返し残留電位の上昇が小さい。
【０２２９】
◎；べた黒画像部の電位変化｜ΔＶ｜が５０Ｖ未満（良好）
○；べた黒画像部の電位変化｜ΔＶ｜が５０Ｖ以上、１５０Ｖ以下（実用上問題なし）
×；べた黒画像部の電位変化｜ΔＶ｜が１５０Ｖより大きい（実用上問題有り）
帯電電位の評価（べた白画像の電位変化）
低温低湿（１０℃２０％ＲＨ）、高温高湿（ＨＨ：３０℃８０％ＲＨ）環境下で、画素率が７％の文字画像、ハーフトーン画像、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で１枚間欠モードにて１万枚の複写を行い、初期と１万枚後の現像位置でのべた白画像部の電位変化（｜ΔＶ｜）を評価した。｜ΔＶ｜が小さい方が繰り返し帯電電位の変化が小さい。
【０２３０】
◎；べた白画像部の電位変化｜ΔＶ｜が５０Ｖ未満（良好）
○；べた白画像部の電位変化｜ΔＶ｜が５０Ｖ以上、１５０Ｖ以下（実用上問題なし）
×；べた白画像部の電位変化｜ΔＶ｜が１５０Ｖより大きい（実用上問題有り）
画像濃度；低温低湿（ＬＬ：１０℃２０％ＲＨ）、高温高湿（ＨＨ：３０℃８０％ＲＨ）で評価
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。多数枚のコピーで残留電位が増加すると、画像濃度が低下する。各１万枚コピー後のべた黒画像部で測定した。
【０２３１】
◎：低温低湿、高温高湿とも黒ベタ画像が１．２より高い（良好）
○：低温低湿、高温高湿とも黒ベタ画像が１．０以上、１．２以下（実用上問題なし）
×：低温低湿、高温高湿の何れかで黒ベタ画像が１．０未満（実用上問題あり）
カブリ；低温低湿（ＬＬ：１０℃２０％ＲＨ）、高温高湿（ＨＨ：３０℃８０％ＲＨ）で評価
カブリ濃度はべた白画像をマクベス社製ＲＤ−９１８を使用し反射濃度で測定した。該反射濃度は相対濃度（複写していないＡ４紙の濃度を０．０００とする）で評価した。各１万枚コピー後のべた黒画像部で測定した。
【０２３２】
◎；低温低湿、高温高湿とも濃度が０．０１０未満（良好）
○；低温低湿、高温高湿とも濃度が０．０１０以上、０．０２０以下（実用上問題ないレベル）
×；低温低湿、高温高湿の何れかで濃度が０．０２０より高い（実用上問題となるレベル）
絶縁破壊；低温低湿（ＬＬ：１０℃２０％ＲＨ）、高温高湿（３０℃８０％ＲＨ）で評価
○；ＬＬ又はＨＨで電荷リークによる感光体の絶縁破壊が発生なし。
【０２３３】
×；ＬＬ又はＨＨで電荷リークによる感光体の絶縁破壊が発生した。
周期性の画像欠陥（高温高湿（３０℃８０％ＲＨ））
周期性が感光体の周期と一致し、目視できる黒ポチ、黒筋状の画像欠陥が、Ａ４サイズ当たり何個あるかで判定した。
【０２３４】
◎；０．４ｍｍ以上の画像欠陥の頻度：全ての複写画像が５個／Ａ４以下（良好）
○；０．４ｍｍ以上の画像欠陥の頻度：６個／Ａ４以上、１０個／Ａ４以下が１枚以上発生（実用上問題なし）
×；０．４ｍｍ以上の画像欠陥の頻度：１１個／Ａ４以上が１枚以上発生（実用上問題有り）
鮮鋭性
画像の鮮鋭性は、低温低湿（１０℃２０％ＲＨ）、高温高湿（３０℃８０％ＲＨ）の両環境において画像を出し、文字潰れで評価した。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。
【０２３５】
◎；画像ボケの発生がなく、３ポイント、５ポイントとも明瞭であり、容易に判読可能
○；画像ボケの発生が軽微であり、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
×；画像ボケが発生し、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
【０２３６】
【表３】

【０２３７】
表３より、本発明のＸ成分、Ｙ成分、Ｚ成分を有する組成物から形成される化合物を含有する中間層、該中間層上に感光層、電荷注入層を有する感光体１〜１５は高温高湿、低温低湿での残留電位、帯電電位の安定性に優れており、このことから画像濃度が十分で且つカブリ濃度が小さい。しかも絶縁破壊も発生せず、黒ポチ等の改良効果が顕著であり、その結果鮮鋭性が良好な電子写真画像を得ている。特に、Ｘ成分にアナターゼ形酸化チタンを用い、Ｚ成分にビニル系樹脂セグメント（Ｚ成分−１）と反応性有機ケイ素化合物（Ｚ成分−２、Ｚ成分−３）を用い、且つ電荷注入層の接触角が９５°以上の感光体１〜６、１２、１３は各評価項目の改良効果が他の感光体７〜１１、１４、１５に比し顕著である。一方、中間層のバインダー樹脂にポリアミド樹脂を用いＺ成分を用いていない本発明外の感光体１６は残留電位上昇が大きく、画像濃度が低下し、絶縁破壊も発生し、鮮鋭性も低下している。又、中間層にＸ成分を用いていない本発明外の感光体１７は残留電位上昇、帯電電位の変動が大きく、画像濃度の低下、カブリの発生、絶縁破壊やモアレも発生し、その結果鮮鋭性も低下している。又、電荷注入層を持たない感光体１８は帯電電位の変動が大きく、カブリが発生し、その結果鮮鋭性も低下している。又、絶縁破壊、黒ポチも発生している。
【０２３８】
評価２（磁気ブラシを用いた評価）
〈評価条件〉
評価１で用いた帯電ローラを磁気ブラシ帯電器に変更し、更に、感光体の線速：１４０ｍｍ／ｓｅｃに改造した以外は評価１と同様にして、感光体１〜１５を評価した。
【０２３９】
（磁気ブラシ帯電器）
図２の構造を有す。
【０２４０】
磁気粒子の作製
帯電用磁気ブラシを形成する磁気粒子を下記のように作製した。
【０２４１】
Ｆｅ_２Ｏ_３：５０モル％
ＣｕＯ：２４モル％
ＺｎＯ：２４モル％
以上を粉砕、混合し分散剤およびバインダーと水を加えスラリーとした後、スプレードライヤーで造粒操作を行い、分級した後１１２５℃にて焼成を行った。得られた磁気粒子を解砕処理の後、分級を行い、体積平均粒径が２７μｍである磁気粒子１を得た。磁気粒子の抵抗率は２×１０^７Ωｃｍ、磁化の強さは６５ｅｍｕ／ｇであった。
【０２４２】
磁気粒子の体積平均粒径の測定方法
キャリアの体積平均粒径の測定は、代表的には湿式分散機を備えたレーザ回折式粒度分布測定装置「ヘロス（ＨＥＬＯＳ）」（シンパティック（ＳＹＭＰＡＴＥＣ）社製）により測定することができる。
【０２４３】
抵抗率（Ωｃｍ）の測定法
磁気粒子を０．５０ｃｍ^２の断面積を有する容器に入れてタッピングした後、詰められた粒子上に１ｋｇ／ｃｍ^２の荷重を掛け、荷重と底面電極との間に１０００Ｖ／ｃｍの電界が生ずる電圧を印加したときの電流値を読み取ることで得られる値。
【０２４４】
帯電条件
帯電スリーブ；１０ｍｍφのステンレス鋼
帯電スリーブに印加される電圧；直流電圧４５０Ｖに交流電圧を重畳
帯電領域の磁性粒子量；２５０ｍｇ／ｃｍ^２
帯電スリーブ／感光体の線速比；０．８
〈評価〉
磁気ブラシを用いた接触帯電方式の画像形成方法においても、本発明の感光体１〜１５は帯電ローラによる接触帯電の場合とほぼ同等の効果が得られている。
【０２４５】
【発明の効果】
本発明の電子写真感光体、プロセスカートリッジ及び画像形成装置を用いることにより、接触帯電方式で発生しやすい低温低湿、高温高湿での残留電位の上昇や帯電電位の変動を防止し、又絶縁破壊や画像欠陥を防止し、画像濃度、カブリ、モアレ、鮮鋭性が良好な電子写真画像を提供することができる。
【図面の簡単な説明】
【図１】帯電ローラ帯電を用いた画像形成装置の１例を示す図である。
【図２】接触式の磁気ブラシ帯電装置の図である。
【図３】図２の帯電装置による交流バイアス電圧と帯電電位との関係を示す図である。
【図４】磁気ブラシ帯電器を有する画像形成装置の１例を示す断面図である。
【符号の説明】
１ 帯電ローラ
２ 感光体ドラム
３ 現像装置
４ 現像スリーブ
５ 除電ランプ
６ 転写ローラ
７ 搬送ベルト
８ 搬送ローラ
２０ 芯金
５０ 感光体ドラム
５１ 露光部
５２ 磁気ブラシ帯電器
５３ 像露光器
５４ 現像器
１２０ 磁気ブラシ帯電装置
１２０ａ 帯電スリーブ
２２０ 供給ボトル
３００ 磁気粒子回収容器[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic photosensitive member, a process cartridge, an image forming apparatus, and an image forming method used for electrophotographic image formation, and more specifically, to electrophotographic image formation used in the field of copying machines and printers. The present invention relates to an electrophotographic photosensitive member, a process cartridge, an image forming apparatus, and an image forming method.
[0002]
[Prior art]
Organic photoconductors have great advantages such as wide selection of materials, excellent environmental suitability and low production costs compared to inorganic photoconductors such as selenium photoconductors and amorphous silicon photoconductors. In recent years, electrophotographic photoreceptors have become the mainstream in place of inorganic photoreceptors.
[0003]
On the other hand, in the image forming method based on the Carlson method, a charged, electrostatic latent image is formed on an electrophotographic photosensitive member, and a toner image is formed. Then, the toner image is transferred to a transfer paper, fixed, and finally processed. An image is formed.
[0004]
A corona discharger is the best known charging member that has been used as a member of the charging means. The corona discharger has an advantage that stable charging can be performed. However, since a high voltage must be applied to the corona discharger, a large amount of ionized oxygen, ozone, moisture, nitric oxide compound, etc. is generated, leading to deterioration of the organic photoreceptor (hereinafter also referred to as a photoreceptor). Or have problems such as adversely affecting the human body.
[0005]
Therefore, in recent years, use of a contact charging method that does not use a corona discharger has been studied. Specifically, a voltage is applied to a magnetic brush or a conductive roller that is a charging member to bring it into contact with a photosensitive member that is a member to be charged, and the surface of the photosensitive member is charged to a predetermined potential. If such a contact charging method is used, the voltage can be lowered and the amount of ozone generated can be reduced as compared with a non-contact charging method using a corona discharger.
[0006]
The contact charging method is applied to the photoconductor.²-10¹⁰In this method, a direct current voltage or a direct current voltage superimposed on an alternating current is applied to a charging member having a resistance of about Ω · cm, and is brought into pressure contact with the photosensitive member to give an electric charge. Since this charging method is performed by discharging from the charging member to the member to be charged in accordance with Paschen's law, charging is started by applying a voltage equal to or higher than a certain threshold value. In this contact charging method, compared with the corona charging method, the voltage applied to the charging member is low, but since discharge is accompanied, a small amount of ozone and nitrogen oxides are generated.
[0007]
For this reason, as a new charging method, a charging method by directly injecting charges into the photosensitive member is disclosed (Patent Document 1). This charging method is a method in which a charge injection layer is provided on the surface of a photoconductor, a voltage is applied to a contact conductive member such as a charging roller, a charging brush, a charging magnetic brush, etc., and injection charging is performed by contacting the charge. In this charging method, almost one-to-one charging is possible with respect to the applied voltage with almost no discharge phenomenon. Therefore, compared with the conventional contact charging method, the amount of ozone and NOx generated is very small. It is an excellent charging method with low power.
[0008]
As the injection charging method, an electrophotographic photosensitive member having a structure in which a charge injection layer is provided on the surface layer (mostly on a charge transport layer) of the electrophotographic photosensitive member for injection charging is known. That is, an electrophotographic photosensitive member has been proposed in which a charge injection layer containing a binder resin and conductive fine particles or a charge transport material is used as a surface layer (Patent Document 2). However, when the surface of the electrophotographic photosensitive member is repeatedly charged through the charge injection layer by direct contact with a charging roller or the like, cracks, contamination, or the like generated in the charge injection layer occurs. Charges are concentrated in such areas as causing breakdowns and image defects such as black spots and image blurring. In particular, these problems are likely to occur under severe conditions such as high temperature and high humidity and low temperature and low humidity.
[0009]
In order to prevent the occurrence of image defects such as dielectric breakdown and black spots as described above, the surface of the aluminum substrate of the conductive support is anodized to increase the resistance to charge leakage of the electrophotographic photosensitive member. It has been proposed to prevent charge leakage from the conductive support even if cracks, contamination, etc. occur in the substrate (Patent Document 3).
[0010]
However, an electrophotographic photosensitive member having a charge injection layer using an anodized aluminum substrate has an alumite layer altered by slight changes in anodized processing and subsequent aging conditions, and the effect of preventing the above-described charge leakage is stable. In addition to the problem that it is difficult to obtain, it tends to be a charge trap site between the alumite layer and the photosensitive layer, and a residual potential tends to be gradually accumulated with long-term use.
[0011]
[Patent Document 1]
Japanese Patent Laid-Open No. 6-3921
[0012]
[Patent Document 2]
JP 2002-31911 A
[0013]
[Patent Document 3]
Japanese Patent Laid-Open No. 5-80567
[0014]
[Problems to be solved by the invention]
The present invention uses an electrification method that generates less ozone and nitrogen oxides and has low power, and further has low dependence on temperature and humidity environment, and can perform long-term stable image formation. And a process cartridge and an image forming apparatus.
[0015]
Another object of the present invention is to prevent deterioration of electrophotographic characteristics (sensitivity, residual potential, etc.) that are likely to occur during repeated use in an electrophotographic photoreceptor used in contact charging type image forming methods, An object of the present invention is to provide an electrophotographic photosensitive member, a process cartridge, and an image forming apparatus that can prevent image defects such as black spots from occurring and can perform stable long-term image formation with good sharpness.
[0016]
[Means for Solving the Problems]
As a result of intensive studies, the present inventors have studied in detail about the conductive support, intermediate layer, photosensitive layer and charge injection layer of the electrophotographic photosensitive member used in the contact charging method in order to solve the above-described problems of the present invention. As a result of the extensive investigation, by installing an intermediate layer that can prevent charge leakage and has stable potential characteristics for repeated use on the conductive support, image defects such as dielectric breakdown and black spots and image blurring can be obtained. The electrophotographic photosensitive member having a long-term stable performance by preventing deterioration of electrophotographic characteristics (sensitivity, residual potential, etc.) that are likely to occur during repeated use. It has been found that a clear electrophotographic image having a high density and a high resolving power can be stably obtained by using an electrophotographic photoreceptor, and the present invention has been completed.
[0017]
The object of the present invention is achieved by adopting one of the following configurations.
1. In an electrophotographic photosensitive member used in an image forming apparatus having a charging means for charging by bringing a charging member into contact with the electrophotographic photosensitive member, the electrophotographic photosensitive member has at least an intermediate layer, a photosensitive layer and a conductive layer on a conductive support. An electrophotographic photoreceptor comprising a charge injection layer, wherein the intermediate layer contains a compound formed from a composition having the following X component, Y component, and Z component.
[0018]
X component: Inorganic oxide network forming compound
Y component: Metal atom-containing organic network forming compound
Z component: Binder network forming compound
2. In an electrophotographic photosensitive member used in an image forming apparatus having a charging means for charging by bringing a charging member into contact with the electrophotographic photosensitive member, the electrophotographic photosensitive member has at least an intermediate layer, a charge generation layer, and a conductive support. An electrophotographic photoreceptor comprising a charge transport layer and a charge injection layer, wherein the intermediate layer contains a compound formed from a composition having the X component, the Y component and the Z component.
[0019]
3. 3. The electrophotographic photosensitive member according to 1 or 2, wherein the X component is an inorganic oxide particle having a reactive group on its surface.
[0020]
4). The inorganic oxide particles are TiO₂, ZrO₂, ZnO, Al₂O₃4. The electrophotographic photosensitive member as described in 3 above, which is any one of the particles.
[0021]
5. TiO₂5. The electrophotographic photosensitive member as described in 4 above, wherein the particles are anatase type titanium oxide.
[0022]
6). The electrophotographic photosensitive member according to any one of 3 to 5, wherein the number average primary particles of the inorganic oxide particles are 5 to 400 nm.
[0023]
7). The electrophotographic photosensitive member according to any one of 1 to 6, wherein the Y component is a coupling agent.
[0024]
8). 8. The electrophotographic photosensitive member according to 7, wherein the coupling agent is a titanium coupling agent or a silane coupling agent.
[0025]
9. 9. The electrophotographic photosensitive member according to any one of 1 to 8, wherein the Z component is a reactive organosilicon compound.
[0026]
10. 9. The electrophotographic photosensitive member according to any one of 1 to 8, wherein the Z component is a reactive segment.
[0027]
11. 11. The electrophotographic photosensitive member as described in 10 above, wherein the reactive segment is a vinyl resin having a low polymerization degree.
[0028]
12 12. The electrophotographic photoreceptor according to any one of 1 to 11, wherein the Z component is a combination of a reactive organosilicon compound and a reactive segment.
[0029]
13. 13. The electrophotographic photosensitive member according to any one of 1 to 12, wherein the intermediate layer has a thickness of 4 to 20 μm.
[0030]
14 14. The electrophotographic photosensitive member according to any one of items 1 to 13, wherein the charge injection layer contains conductive particles.
[0031]
15. In a process cartridge used in an image forming apparatus having a charging means for charging by bringing a charging member into contact with an electrophotographic photosensitive member, the electrophotographic photosensitive member has at least an intermediate layer, a photosensitive layer, and a charge injection layer on the conductive support. An electrophotographic photosensitive member containing a compound formed of a composition having the X component, the Y component, and the Z component, and a charging means for uniformly charging the electrophotographic photosensitive member, on the electrophotographic photosensitive member An image forming apparatus is integrally supported by at least one of a developing unit that visualizes an electrostatic latent image of the toner and a transfer unit that transfers a toner image visualized on the electrophotographic photosensitive member onto a transfer material. A process cartridge which is detachably attached to a main body.
[0032]
16. In an image forming apparatus having a charging means for charging by bringing a charging member into contact with an electrophotographic photosensitive member, the electrophotographic photosensitive member has at least an intermediate layer, a photosensitive layer and a charge injection layer on a conductive support, An image forming apparatus, wherein the intermediate layer contains a compound formed from a composition having the X component, the Y component, and the Z component.
[0033]
17. An image forming method comprising a charging means for charging by bringing a charging member into contact with an electrophotographic photosensitive member, wherein an electrophotographic image is formed using the image forming apparatus described in 16 above.
[0034]
Hereinafter, the present invention will be described in detail.
Structure of electrophotographic photoreceptor
The electrophotographic photosensitive member of the present invention has at least an intermediate layer, a photosensitive layer and a charge injection layer on a conductive support, and the intermediate layer is formed from a composition having the following X component, Y component and Z component. It is characterized by containing a compound.
[0035]
X component: Inorganic oxide network forming compound
Y component: Metal atom-containing organic network forming compound
Z component: Binder network forming compound
The electrophotographic photoreceptor of the present invention has at least an intermediate layer, a charge generation layer, a charge transport layer and a charge injection layer on a conductive support, and the intermediate layer comprises the X component, the Y component, and the Z component. It contains the compound formed from the composition which has this.
[0036]
Since the electrophotographic photosensitive member of the present invention has the above-described configuration, it is likely to occur in an image forming apparatus having a charging unit that contacts and charges a charging member on the electrophotographic photosensitive member. Defects can be prevented and electrophotographic characteristics (sensitivity, residual potential, etc.) can be prevented from deteriorating, and stable image formation can be performed over a long period of time.
[0037]
The network-forming compound common to the X component, Y component, and Z component of the present invention is a compound having a three-dimensional bond form by the chemical reaction of the respective compounds of the X component, Y component, and Z component ( It means a compound capable of forming an intermediate layer or a protective layer resin structure).
[0038]
As the X component of the present invention, that is, the inorganic oxide network forming compound, a hydroxyl group or an amino group capable of chemically reacting with the metal atom-containing organic network forming compound of the Y component or the binder network forming compound of the Z component is formed on the surface. Inorganic oxide particles having are preferable. Examples of such inorganic oxides include oxide particles such as cerium oxide, chromium oxide, aluminum oxide, magnesium oxide, silicon oxide, tin oxide, zirconium oxide, iron oxide, and titanium oxide that are not surface-treated. It is done. Among these, titanium oxide (TiO₂), Zinc oxide (ZnO), aluminum oxide (Al₂O₃), Zirconium oxide (ZrO)₂And titanium oxide is particularly preferably used.
[0039]
The inorganic oxide particles are preferably fine particles having a number average primary particle size in the range of 5 to 400 nm. In particular, 10 nm to 200 nm is preferable. The number average primary particle diameter is a measured value as an average diameter in the ferret direction by image analysis by magnifying fine particles 10,000 times by transmission electron microscope observation, observing 100 particles randomly as primary particles.
[0040]
In the titanium oxide particles, there are anatase type, rutile type, brookite type, amorphous type and the like as crystal types, among which the anatase type titanium oxide pigment is most preferable as the inorganic oxide particles of the present invention.
[0041]
As the Y component of the present invention, that is, the metal atom-containing organic network forming compound, a coupling agent that reacts with a reactive group such as a hydroxyl group present on the surface of the inorganic oxide particles or a binder network forming compound of the Z component is preferable. Among these, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent, or the like is preferable.
[0042]
Titanium coupling agents include isopropyl triisostearoyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, isopropyl tri (N-aminoethyl-aminoethyl) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, tetra (2, 2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylisostearoyl titanate, Isopropyltridodecylbenzenesulfonyl titanate, isopropylisostearoyl diacryl titanate, Sopuropirutori (dioctyl phosphate) titanate, isopropyl tri acyl phenyl titanate, tetraisopropyl bis (dioctyl phosphate) titanate and the like are used.
[0043]
As the aluminum coupling agent, acetoalkoxyaluminum diisopropylate or the like is used.
[0044]
As the silane coupling agent, vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyl Trimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β- (aminoethyl) γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) γ -Aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropylmethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane and the like are used.
[0045]
The X component inorganic oxide network-forming compound is previously treated with the Y component metal atom-containing organic network forming compound, and the surface-treated X component inorganic oxide network forming compound is used to form a Z component, which will be described later. You may make it react. In this case, the surface treatment of the inorganic oxide network forming compound of the X component can be performed by the following wet method.
[0046]
That is, an X component inorganic oxide network forming compound is added to a solution obtained by dissolving or suspending the Y component metal atom-containing organic network forming compound in an organic solvent or water. It is also possible to obtain a dispersion of an X-component inorganic oxide network-forming compound having a surface dispersed with a medium and, if necessary, subjecting the mixed solution to a heat treatment to coat the surface with a Y-component metal atom-containing organic network-forming compound. The Y component metal atom-containing organic network forming compound may be added to a suspension in which the X component inorganic oxide network forming compound is dispersed in an organic solvent or water.
[0047]
The amount of the Y component metal atom-containing organic network forming compound used for the surface treatment is the amount of the Y component metal with respect to 100 parts by mass of the X component inorganic oxide network forming compound in the charged amount during the surface treatment. It is preferable to use 0.1 to 50 parts by mass, more preferably 0.1 to 40 parts by mass of the atom-containing organic network forming compound. When the surface treatment amount is less than the above range, the surface treatment effect is not sufficiently imparted, and the rectifying action and dispersibility of the X component inorganic oxide network forming compound in the intermediate layer are deteriorated. Further, when the surface treatment amount exceeds the above range, the electrophotographic characteristics are deteriorated, and as a result, the residual potential is increased and the charged potential is decreased.
[0048]
The Z component of the present invention, that is, the binder network forming compound has a reactive group capable of reacting with the inorganic oxide particles of the X component and the coupling agent of the Y component, and can be converted into a resin capable of functioning as a binder component. , Oligomers, segment components and the like are used.
[0049]
Z component of the present invention: Reactive organosilicon represented by the following general formula (1) capable of forming a siloxane condensate (condensate having a structure in which a plurality of siloxane bonds are three-dimensionally linked) as a binder network forming compound Compounds are preferred.
[0050]
General formula (1) R_nSi (Z)_4-n
(In the formula, R represents an organic group in which carbon is directly bonded to silicon in the formula, Z represents a hydroxyl group or a hydrolyzable group, and n is an integer of 0 to 3).
Z in the general formula (1) is a hydrolyzable group, and examples thereof include a methoxy group, an ethoxy group, a methylethylketoxime group, a diethylamino group, an acetoxy group, a propenoxy group, a propoxy group, a butoxy group, and a methoxyethoxy group. Examples of organic groups in which carbon is directly bonded to silicon represented by R include alkyl groups such as methyl, ethyl, propyl and butyl, aryl groups such as phenyl, tolyl, naphthyl and biphenyl, γ-glycidoxypropyl, β -Epoxy-containing groups such as (3,4-epoxycyclohexyl) ethyl, γ-acryloxypropyl, (meth) acryloyl groups of γ-methacryloxypropyl, γ-hydroxypropyl, 2,3-dihydroxypropyloxypropyl, etc. Hydroxyl-containing groups, vinyl-containing groups such as vinyl and propenyl, mercapto-containing groups such as γ-mercaptopropyl, amino-containing groups such as γ-aminopropyl and N-β (aminoethyl) -γ-aminopropyl, γ-chloropropyl 1,1,1-trifluoropropyl, nonafluorohexyl, perfluorooctylethyl, etc. Androgenic group, other nitro, and a cyano-substituted alkyl group. R_nWhen n is 2 or 3, the plurality of organic groups bonded to the same silicon atom may be the same or different.
[0051]
In the production of the siloxane condensate component of the present invention, when two or more reactive organosilicon compounds represented by the general formula (1) are used, the R of each reactive organosilicon compound may be the same or different. It may be.
[0052]
Specific examples of the reactive organosilicon compound represented by the general formula (1) include the following compounds.
[0053]
That is, examples of compounds in which n is 0 include 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 can be given.
[0054]
Examples of compounds in which n is 1 include trichlorosilane, chloromethyltrichlorosilane, methyltrichlorosilane, 1,2-dibromoethyltrichlorosilane, vinyltrichlorosilane, 1,2-dichloroethyltrichlorosilane, 1-chloroethyltrichlorosilane, 2-chloroethyltrichlorosilane, ethyltrichlorosilane, 3,3,3-trifluoropropyltrichlorosilane, 2-cyanoethyltrichlorosilane, allyltrichlorosilane, 3-bromopropyltrichlorosilane, chloromethyltrimethoxysilane, 3-chloropropyl Trichlorosilane, n-propyltrichlorosilane, ethoxymethyldichlorosilane, dimethoxymethylchlorosilane, trimethoxysilane, 3-cyanopropyltrichlorosilane, n-butyltri Lolosilane, isobutyltrichlorosilane, chloromethyltriethoxysilane, methyltrimethoxysilane, mercaptomethyltrimethoxysilane, pentyltrichlorosilane, trimethoxyvinylsilane, ethyltrimethoxysilane, 3,3,4,4,5,5,6 6,6-nonafluorohexyltrichlorosilane, 4-chlorophenylchlorosilane, phenyltrichlorosilane, cyclohexyltrichlorosilane, hexyltrichlorosilane, tris (2-chloroethoxy) silane, 3,3,3-trifluoropropyltrimethoxysilane, 2 -Cyanoethyltrimethoxysilane, triethoxychlorosilane, 3-chloropropyltrimethoxysilane, triethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyl Pyrtrimethoxysilane, 2-aminoethylaminomethyltrimethoxysilane, benzyltrichlorosilane, p-tolyltrichlorosilane, 6-trichlorosilyl-2-norbornene, 2-trichlorosilylnorbornene, methyltriacetoxysilane, heptyltrichlorosilane, chloro Methyltriethoxysilane, butyltrimethoxysilane, methyltriethoxysilane, methyltris (2-aminoethoxy) silane, β-phenethyltrichlorosilane, triacetoxyvinylsilane, 2- (4-cyclohexylethyl) trichlorosilane, ethyltriacetoxysilane, 3-trifluoroacetoxypropyltrimethoxysilane, octyltrichlorosilane, triethoxyvinylsilane, ethyltriethoxysilane, 3- (2-amino Tilaminopropyl) trimethoxysilane, chloromethylphenylethyltrichlorosilane, 2-phenylpropyltrichlorosilane, 4-chlorophenyltrimethoxysilane, phenyltrimethoxysilane, nonyltrichlorosilane, 2-cyanoethyltriethoxysilane, allyltriethoxysilane, 3 -Allylthiopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-bromopropyltriethoxysilane, 3-chloropropyltriethoxysilane, 3-allylaminopropyltrimethoxysilane, propyltriethoxysilane, hexyltri Methoxysilane, 3-aminopropyltriethoxysilane, methyltriisopropenoxysilane, 3-methacryloxypropyltrimethoxysilane, decyltri Lorosilane, bis (ethylmethylketoxime) methoxymethylsilane, 3-morpholinopropyltrimethoxysilane, 3-piperazinopropyltrimethoxysilane, methyltripropoxysilane, methyltris (2-methoxyethoxysilane), 2- (2 -Aminoethylthioethyl) triethoxysilane, 3- [2- (2-aminoethylaminoethylamino) propyl] triethoxysilane, tris (1-methylvinyloxy) vinylsilane, 2- (3,4-epoxycyclohexylethyl) ) Trimethoxysilane, triisopropoxyvinylsilane, tris (2-methoxyethoxy) vinylsilane, diisopropoxyethylmethylketoximemethylsilane, 3-piperidinopropyltrimethoxysilane, pentyltriethoxysilane, 4 -Chlorophenyltriethoxysilane, phenyltriethoxysilane, bis (ethylmethylketoxime) methylisopropoxysilane, bis (ethylmethylketoxime) -2-methoxyethoxymethylsilane, 3- (2-methylpiperidinopropyl) tri Methoxysilane, 3-cyclohexylaminopropyltrimethoxysilane, O, O'-diethyl-S- (2-triethoxysilylethyl) dithiophosphate, benzyltriethoxysilane, 6-triethoxysilyl-2-norbornene, 3- Benzylaminopropyltrimethoxysilane, methyltris (ethylmethylketoxime) silane, bis (ethylmethylketoxime) butoxymethylsilane, methyltris (N, N-diethylaminoxy) silane, tetradecyltrichloro Silane, octyltriethoxysilane, phenyltris (2-methoxyethoxy) silane, 3- (vinylbenzylaminopropyl) trimethoxysilane, N- (3-triethoxysilylpropyl) -p-nitrobenzamide, 3- (vinylbenzyl Aminopropyl) triethoxysilane, octadecyltrichlorosilane, dodecyltriethoxysilane, docosyltrichlorosilane, octadecyltriethoxysilane, dimethyloctadecyl-3-trimethoxylsilylpropylammonium chloride, 1,2-bis (methyldichlorosilyl) ethane, etc. Is mentioned.
[0055]
Examples of compounds in which n is 2 include chloromethylmethyldichlorosilane, dimethyldichlorosilane, ethyldichlorosilane, methylvinyldichlorosilane, ethylmethyldichlorosilane, dimethoxymethylsilane, dimethoxydimethylsilane, divinyldichlorosilane, methyl-3,3 , 3-trifluoropropyldichlorosilane, allylmethyldichlorosilane, 3-chloropropylmethyldichlorosilane, diethyldichlorosilane, methylpropyldichlorosilane, diethoxysilane, 3-cyanopropylmethyldichlorosilane, butylmethyldichlorosilane, bis ( 2-chloroethoxy) methylsilane, diethoxymethylsilane, phenyldichlorosilane, diallyldichlorosilane, dimethoxymethyl-3,3,3-trifluoropropylsila , Methylpentyldichlorosilane, 3-chloropropyldimethoxymethylsilane, chloromethyldiethoxysilane, diethoxydimethylsilane, dimethoxy-3-mercaptopropylmethylsilane, 3,3,4,4,5,5,6,6 6-nonafluorohexylmethyldichlorosilane, methylphenyldichlorosilane, diacetoxymethylvinylsilane, cyclohexylmethyldichlorosilane, hexylmethyldichlorosilane, diethoxymethylvinylsilane, hexylmethyldichlorosilane, diethoxymethylvinylsilane, phenylvinyldichlorosilane, 6 -Methyldichlorosilyl-2-norbornene, 2-methyldichlorosilylnorbornene, 3-methacryloxypropylmethyldichlorosilane, diethoxydivinylsilane, hep Rumethyldichlorosilane, dibutyldichlorosilane, diethoxydiethylsilane, dimethyldipropoxysilane, 3-aminopropyldiethoxymethylsilane, 3- (2-aminoethylaminopropyl) dimethoxymethylsilane, allylphenyldichlorosilane, 3-chloro Propylphenyldichlorosilane, methyl-β-phenethyldichlorosilane, dimethoxymethylphenylsilane, 2- (4-cyclohexenylethyl) methyldichlorosilane, methyloctyldichlorosilane, diethoxyethylmethylketoxime methylsilane, 2- (2- Aminoethylthioethyl) diethoxymethylsilane, O, O'-diethyl-S- (2-trimethylsilylethyl) dithiophosphate, O, O'-diethyl-S- (2-trimethoxysilyl ester) D) Dithiophosphate, t-butylphenyldichlorosilane, 3-methacryloxypropyldimethoxymethylsilane, 3- (3-cyanopropylthiopropyl) dimethoxymethylsilane, 3- (2-acetoxyethylthiopropyl) dimethoxymethylsilane, Dimethoxymethyl-2-piperidinoethylsilane, dimethoxymethyl-3-piperazinopropylsilane, dibutoxydimethylsilane, dimethoxy-3- (2-ethoxyethylthiopropyl) methylsilane, 3-dimethylaminopropyldiethoxymethylsilane , Diethyl-2-trimethylsilylmethylthioethyl phosphite, diethoxymethylphenylsilane, decylmethyldichlorosilane, bis (ethylmethylketoxime) ethoxymethylsilane, diethoxy-3-g Sidoxypropylmethylsilane, 3- (3-acetoxypropylthio) propyldimethoxymethylsilane, dimethoxymethyl-3-piperidinopropylsilane, dipropoxyethylmethylketoximemethylsilane, diphenyldichlorosilane, diphenyldifluorosilane, diphenylsilane Diol, Dihexyldichlorosilane, Bis (ethylmethylketoxime) methylpropoxysilane, Dimethoxymethyl-3- (4-methylpiperidinopropyl) silane, Dodecylmethyldichlorosilane, Dimethoxydiphenylsilane, Dimethoxyphenyl-2-piperidino Ethoxysilane, dimethoxymethyl-3- (3-phenoxypropylthiopropyl) silane, diacetoxydiphenylsilane, diethoxydiphenylsilane, diethoxide Examples include silmethylsilane, methyloctadecyldichlorosilane, diphenylmethoxy-2-piperidinoethoxysilane, docosylmethyldichlorosilane, and diethoxymethyloctadecylsilane.
[0056]
In general, the reactive organosilicon compound used as a raw material of the siloxane condensate component having a three-dimensional cross-linked structure generally has a hydrolyzable group number (4-n) n of 3 bonded to a silicon atom. Sometimes, the polymerization reaction of the reactive organosilicon compound is suppressed. When n is 0, 1 or 2, a polymerizing reaction is likely to occur. In particular, when 1 or 0, the crosslinking reaction can be advanced to a high degree. Therefore, by controlling these, the storage stability of the coating layer solution obtained, the hardness of the coating film, and the like can be controlled.
[0057]
In addition, as another example of the Z component: binder network forming compound of the present invention, it can react with the X component: inorganic oxide network forming compound and Y component: metal atom-containing organic network forming compound, and can form a resin structure. A reactive segment. Here, the segment refers to a polymer having a low polymerization degree used to form the final resin structure of the intermediate layer of the present invention.
[0058]
As the reactive segment, for example, a polymerizable silane compound that undergoes a polymerization reaction with the chain polymerizable monomer is allowed to coexist in the chain polymerizable monomer, and the X component: the inorganic oxide network forming compound or the Y component. : A vinyl resin segment having a silyl group capable of reacting with a metal atom-containing organic network forming compound and capable of forming a resin structure.
[0059]
That is, a silyl group-containing vinyl resin in which a silyl group is introduced into a chain polymerization component can be formed by coexisting a polymerizable silane compound of the following general formula (2) together with a chain polymerizable monomer to advance the polymerization. The silyl group introduced into the vinyl resin enables chemical reaction with the X component: inorganic oxide network forming compound and the Y component: metal atom-containing organic network forming compound. In particular, when the silyl group-containing vinyl resin is used together with the reactive organosilicon compound represented by the general formula (1) capable of forming the siloxane condensate, the binder component formed from these two Z components is a vinyl resin. A resin structure in which the organic segment (segment containing a carbon atom in the chain structure) and the inorganic segment of the siloxane condensate component (having a chain structure of silicon and oxygen) coexist, and adhesion to the substrate and the above-described inorganic An intermediate layer binder resin having excellent dispersibility of oxide particles and excellent repetition characteristics and black spot prevention characteristics can be formed. In addition, the intermediate layer photoconductor having the binder resin formed from the two Z components has a stable residual potential and charging potential even when the intermediate layer is thickened. Even if the thickness is in the range of several μm, the surface of the conductive support can be sufficiently covered, and dielectric breakdown or black spots can be sufficiently prevented.
[0060]
[Chemical 1]

[0061]
In the general formula (2), R³Is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aralkyl group having 1 to 10 carbon atoms, R⁴Represents an organic group having a polymerizable double bond, X represents a halogen atom, an alkoxy group, an acyloxy group, an aminoxy group, or a phenoxy group, and n is an integer of 1 to 3.
[0062]
The polymerizable silane compound of the general formula (2) is not particularly limited as long as it is a compound having a silyl group, particularly a hydrolyzable silyl group, and capable of polymerizing with various chain polymerizable monomers described below. , For example, CH₂= CHSi (CH₃) (OCH₃)₂, CH₂= CHSi (OCH₃)₃, CH₂= CHSi (CH₃) Cl₂, CH₂= CHSiCl₃, CH₂= CHCOO (CH₂)₂Si (CH₃) (OCH₃)₂, CH₂= CHCOO (CH₂)₂Si (OCH₃)₃, CH₂= CHCOO (CH₂)₃Si (CH₃) (OCH₃)₂, CH₂= CHCOO (CH₂)₃Si (OCH₃)₃, CH₂= CHCOO (CH₂)₂Si (CH₃) Cl₂, CH₂= CHCOO (CH₂)₂SiCl₃, CH₂= CHCOO (CH₂)₃Si (CH₃) Cl₂, CH₂= CHCOO (CH₂)₃SiCl₃, CH₂= C (CH₃) COO (CH₂)₂Si (CH₃) (OCH₃)₂, CH₂= C (CH₃) COO (CH₂)₂Si (OCH₃)₃, CH₂= C (CH₃) COO (CH₂)₃Si (CH₃) (OCH₃)₂, CH₂= C (CH₃) COO (CH₂)₃Si (OCH₃)₃, CH₂= C (CH₃) COO (CH₂)₂Si (CH₃) Cl₂, CH₂= C (CH₃) COO (CH₂)₂SiCl₃, CH₂= C (CH₃) COO (CH₂)₃Si (CH₃) C_l2, CH₂= C (CH₃) COO (CH₂)₃SiCl₃,
[0063]
[Chemical formula 2]

[0064]
Etc. These polymerizable silane compounds can be used alone or in admixture of two or more.
[0065]
Examples of the chain polymerizable monomer that forms a vinyl resin segment together with the polymerizable silane compound of the general formula (2) include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, (Meth) acrylic acid esters such as 2-ethylhexyl (meth) acrylate and cyclohexyl (meth) acrylate; carboxylic acids such as (meth) acrylic acid, itaconic acid and fumaric acid, and acid anhydrides such as maleic anhydride; glycidyl ( Epoxy compounds such as meth) acrylate; amino compounds such as diethylaminoethyl (meth) acrylate and aminoethyl vinyl ether; (meth) acrylamide, itaconic acid diamide, α-ethylacrylamide, crotonamide, fumaric acid diamide, maleic acid diamide, N- Butoxymethyl ( (C) Amide compounds such as acrylamide; use of one or more vinyl chain polymerizable monomers selected from the group consisting of acrylonitrile, styrene, α-methylstyrene, vinyl chloride, vinyl acetate, vinyl propionate, etc. preferable. In addition, a vinyl chain polymerizable monomer (monomer) containing a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxyvinyl ether, N-methylol acrylamide, etc. may be used. Can do.
[0066]
Further, as the Z component: binder network forming compound of the present invention, an antioxidant subunit forming compound may be used as the vinyl chain polymerizable monomer capable of constituting the vinyl resin segment.
[0067]
Here, the antioxidant subunits are ozone and NO._xIt means a group having resistance to oxidation or reduction caused by irradiation with an active gas such as ultraviolet light or light such as ultraviolet rays.
[0068]
To impart an antioxidant function to the binder resin, it is achieved by incorporating an antioxidant subunit such as a hindered amine or a hindered phenol as a subunit (partial structure) into a part of the resin structure.
[0069]
That is, the polymerizable silane compound of the general formula (2) constituting the vinyl resin segment,
A polymerization reaction is performed using an antioxidant subunit-forming compound together with a vinyl chain polymerizable monomer to form a vinyl resin segment having an antioxidant subunit and a silyl group, and then the vinyl resin segment. Through the silyl group, X component: inorganic oxide network forming compound, Y component: metal atom-containing organic network forming compound, or the aforementioned siloxane condensate can be chemically bonded.
[0070]
Here, the hindered amine group refers to a group having steric hindrance in the vicinity of the N atom of the amino group of the amine compound and a derivative thereof. As the steric hindrance group, a branched alkyl group, a group having 3 or more carbon atoms, and the like are preferable.
[0071]
The hindered phenol group refers to a group having a steric hindrance at the ortho position with respect to the hydroxyl group of phenol and a derivative thereof. (However, the hydroxyl group may be converted to alkoxy). The sterically hindering group is preferably a branched alkyl group or a group having 3 or more carbon atoms.
[0072]
In order to introduce a hindered amine group or hindered phenol group as a subunit (partial structure) into the vinyl resin segment, together with the polymerizable silane compound of the above general formula (2) and the vinyl chain polymerizable monomer, antioxidant is introduced. As a subunit-forming compound, a hindered amine compound (monomer) or a hindered phenol compound (monomer) having a polymerizable unsaturated group having a carbon-carbon unsaturated bond is allowed to coexist and polymerization of these coexisting compositions is performed. Thus, a hindered amine group or a hindered phenol group can be introduced into the vinyl resin segment.
[0073]
As such a hindered amine compound having a polymerizable unsaturated group, a sterically hindered amine compound containing a polymerizable unsaturated group is preferable, and among them, a sterically hindered piperidine compound containing a polymerizable unsaturated group (hereinafter referred to as “piperidine-based compound”). Also referred to as “monomer”) is particularly preferred. Typical examples of the piperidine compounds include compounds represented by the following general formula (A).
[0074]
[Chemical Formula 3]

[0075]
In the general formula (A), R⁵Represents a hydrogen atom or a cyano group, R⁶And R⁷May be the same or different and each represents a hydrogen atom, a methyl group or an ethyl group, X represents an oxygen atom or an imino group, Y represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or the following general formula (B ) Represents a polymerizable unsaturated group.
[0076]
[Formula 4]

[0077]
In the general formula (B), R⁸And R⁹May be the same or different and each represents a hydrogen atom, a methyl group or an ethyl group.
[0078]
The hydrogen atom in the imino group of X in the general formula (A) may be substituted or unsubstituted. Examples of the alkyl group having 1 to 18 carbon atoms in Y in the general formula (A) include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl. Group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group And linear or branched alkyl groups such as a group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group and n-octadecyl group.
[0079]
Among the piperidine compounds of the general formula (A), preferred compounds are 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloylamino-2,2, 6,6-tetramethylpiperidine, 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloylamino-1,2,2,6,6-pentamethyl Piperidine, 4-cyano-4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-cyano-4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4-cyano-4- (meth) acryloylamino-1,2 2,6,6-pentamethylpiperidine, 1- (meth) acryloyl-4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4- (meth) acryloyl Amino-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano-4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 1- (meth) Acryloyl-4-cyano-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 4-crotonoylamino- 2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-1,2,2,6,6-pentamethylpiperidine, 4-crotonoyl Mino-1,2,2,6,6-pentamethylpiperidine, 4-cyano-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 4-cyano-4-crotonoylamino-2, 2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoylamino-2,2,6,6- Tetramethylpiperidine, 1-crotonoyl-4-cyano-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-cyano-4-crotonoylamino-2,2,6 6-tetramethylpiperidine, among others 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloyl Oxy-1,2,2,6,6-pentamethylpiperidine is particularly preferred.
[0080]
Moreover, as a hindered phenol compound which has a polymerizable unsaturated group, the hindered phenol compound which contains a polymerizable unsaturated group is preferable, for example, the following compounds can be mentioned. That is, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2- (3,5-di-t-butyl-4-hydroxyphenyl) ) Ethyl acrylate, 2- (3,5-di-s-propyl-4-hydroxyphenyl) ethyl acrylate, 2- (3,5-di-t-octyl-4-hydroxyphenyl) ethyl acrylate, 2- (3 -T-butyl-5- (3-t-butyl-2-hydroxy-5-methylbenzyl) 4-hydroxyphenyl) ethyl acrylate, 2-t-butyl-6- (3-t-butyl-2-hydroxy- 5-methylbenzyl) -4-methylphenyl (meth) acrylate, 2- (3,5-di-t-butyl-4-hydroxyphenyl) ethyl (meth) acrylate, 2- 3,5-di-s-propyl-4-hydroxyphenyl) ethyl (meth) acrylate, 2- (3,5-di-t-octyl-4-hydroxyphenyl) ethyl (meth) acrylate, 2- (3- t-butyl-5- (3-t-butyl-2-hydroxy-5-methylbenzyl) 4-hydroxyphenyl) ethyl (meth) acrylate, vinyl 3,5-di-t-butyl-4-hydroxyphenylpropionate Ester, 3,5-di-t-octyl-4-hydroxyphenylpropionic acid vinyl ester, 3,5-di-t-butyl-4-hydroxyphenylpropionic acid-isopropenyl ester, 3,5-di-t- And octyl-4-hydroxyphenylpropionic acid-isopropenyl ester.
[0081]
Examples of compounds other than the hindered amine-based or hindered phenol-based antioxidant subunit-forming compound (compound having a polymerizable unsaturated group) include phenyl salicylic acid (meth) acrylate and t-butylphenyl salicylic acid (meth). Salicylic acid compounds such as acrylate; 2- (meth) acryloyloxy-4-methoxybenzophenone, 2- (meth) acryloyloxy-2′-hydroxy-4-methoxybenzophenone, 2,2′-di (meth) acryloyloxy-4 -Methoxybenzophenone, 2,2'-di (meth) acryloyloxy-4,4'-dimethoxybenzophenone, 2- (meth) acryloyloxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4- [3 -(Meth) acryloyloxy Benzophenone compounds such as 2-hydroxypropoxy] benzophenone and 2,2′-dihydroxy-4- [3- (meth) acryloyloxy-2-hydroxypropoxy] benzophenone; 2- [2 ′-(meth) acryloyloxy-5 ′ -Methylphenyl] benzotriazole, 2- [2 '-(meth) acryloyloxy-5'-t-octylphenyl] benzotriazole, 2- [2'-(meth) acryloyloxy-3 ', 5'-di- benzotriazole compounds such as t-butylphenyl] benzotriazole; 2-ethylhexyl-2-cyano-3,3-diphenyl (meth) acrylate, 1,3-bis (4-benzoyl-3-hydroxyphenoxy) -2-propyl (Meth) acrylate, ethyl-2-cyano-3,3-dipheny (Meth) acrylate, and the like. In this invention, the said antioxidant subunit formation compound can be used individually or in mixture of 2 or more types. Further, “having a hindered amine group or hindered phenol group” means having at least one of a hindered amine group or a hindered phenol group, and may have both groups.
[0082]
Here, a synthesis example of a vinyl resin segment having a hindered amine group or a hindered phenol group and silyl-modified (having a silyl group) will be described.
[0083]
(Synthesis example of vinyl resin segment A solution: vinyl resin segment A solution having a hindered amine group and modified with silyl)
In a reaction vessel equipped with a reflux condenser and a stirrer, 25 parts of γ-methacryloyloxypropyltrimethoxysilane, 1 part of 4-methacryloyloxy-1,2,2,6,6, -pentamethylpiperidine as monomers, methacrylic acid After adding 80 parts of methyl, 15 parts of 2-ethylhexyl methacrylate, 29 parts of n-butyl acrylate, 150 parts of 2-propanol, 50 parts of 2-butanone and 25 parts of methanol, the mixture was heated to 80 ° C. with stirring. To this mixture, a solution of 4 parts of azobisisovaleronitrile dissolved in 10 parts of xylene was added dropwise over 30 minutes, followed by reaction at 80 ° C. for 5 hours to have a hindered amine group in the side chain with a solid content concentration of 40%. And the vinyl-type resin segment A solution which has a silyl group was obtained.
[0084]
(Synthesis example of vinyl resin segment B solution: vinyl resin segment B solution having a hindered phenol group and modified with silyl)
In a reaction vessel equipped with a reflux condenser and a stirrer, 20 parts of γ-methacryloyloxypropyltrimethoxysilane as a monomer, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl)- 2-methylphenyl acrylate 2 parts, methyl methacrylate 70 parts, n-butyl acrylate 40 parts, acrylic acid 5 parts, 2-hydroxyethyl methacrylate 13 parts, 1,1,1-trimethylamine methacrylamide 1 part, 2-propanol 150 1 part, 50 parts of 2-butanone and 25 parts of methanol were added and mixed, and then heated to 80 ° C. with stirring, and a solution of 4 parts of azobisisovaleronitrile in 10 parts of xylene was added to this mixture over 30 minutes. After adding dropwise, the reaction is carried out at 80 ° C. for 5 hours to form a hindered phenol on the side chain with a solid content of 40%. To obtain a vinyl resin segment B solution and having a silyl group having a group.
[0085]
(Synthesis example of vinyl resin segment C solution: silyl-modified vinyl resin segment C solution)
In a reaction vessel equipped with a reflux condenser and a stirrer, 25 parts of γ-methacryloyloxypropyltrimethoxysilane, 80 parts of methyl methacrylate and 15 parts of 2-ethylhexyl methacrylate, 30 parts of n-butyl acrylate, 150 of 2-propanol 1 part, 50 parts of 2-butanone and 25 parts of methanol were added and mixed, and then heated to 80 ° C. with stirring, and a solution of 4 parts of azobisisovaleronitrile in 10 parts of xylene was added to this mixture over 30 minutes. After dropping, the reaction was carried out at 80 ° C. for 5 hours to obtain a vinyl resin segment C solution having a silyl group with a solid concentration of 40%.
[0086]
As shown in the above synthesis examples A and B, a hindered amine compound having a polymerizable unsaturated group, a hindered phenol compound, a polymerizable silane compound, and a vinyl chain polymerizable monomer are allowed to coexist and polymerize on the side chain. A vinyl resin segment having a hindered amine group or a hindered phenol group and having a silyl group can be synthesized.
[0087]
The degree of polymerization of the vinyl resin segment having a silyl group is not particularly limited, but is preferably 10 to 500.
[0088]
Next, an intermediate layer having the resin structure of the present invention can be formed by forming a siloxane condensate component on the vinyl resin segments A, B, and C having the silyl group. That is, the siloxane condensate component is formed on the silyl group of the vinyl resin segment having a silyl group using the vinyl resin segment having the silyl group and the reactive organic silicon compound as described above. The formation of the siloxane condensate component may be performed simultaneously with the formation of the intermediate layer, or the intermediate layer may be formed by previously forming the siloxane condensate component at the silyl group terminal in the intermediate layer solution.
[0089]
The intermediate layer of the present invention contains a compound formed from a composition having an X component, a Y component, and a Z component, and the compound contains each of the X component, the Y component, and the Z component in the intermediate layer. They are formed by chemical bonds.
[0090]
The mass ratio of the X component, the Y component, and the Z component constituting the compound is composed of the mass ratio of the Y component of 0.001 to 0.5 and the Z component of 0.25 to 4 with respect to the X component 1. Is preferred. If the mass ratio of the X component is small, the residual potential tends to increase during repeated image formation, and the image density tends to decrease during reversal development. When there are too many X components, the applicability | paintability of the charge generation layer installed on an intermediate | middle layer will deteriorate, and uniform film formation cannot be performed. Further, even if the mass ratio of the Z component is large or small, the electrophotographic characteristics (charging, sensitivity, residual potential characteristics, etc.) during repeated use are likely to deteriorate.
[0091]
As for the film thickness of the intermediate | middle layer of this invention, 0.2-22 micrometers is preferable. Furthermore, 4-20 micrometers is more preferable. By having such a film thickness, dielectric breakdown and black spots can be prevented, and good electrophotographic characteristics (charging, sensitivity, residual potential characteristics, etc.) during repeated use can be obtained.
[0092]
Next, the method for producing the intermediate layer of the present invention will be described.
In the present invention, the intermediate layer may be formed by any method as long as the above intermediate layer is formed. Below, the manufacturing method of the typical intermediate | middle layer of this invention is described.
[0093]
The intermediate layer of the present invention can be formed by using a composition having an X component, a Y component, and a Z component as a coating solution, coating the coating solution on a conductive support, and then curing.
[0094]
By the curing, the compound formed from the composition having the X component, the Y component, and the Z component is chemically bonded through the respective reactive groups of the X component, the Y component, and the Z component. As a result, it is possible to form an intermediate layer with good rectification property that well prevents charge injection from the conductive support.
[0095]
It is preferable to add a metal chelate compound in the coating liquid or in the process of forming the coating liquid. Here, the metal chelate compound is a metal chelate compound selected from the group consisting of zirconium, titanium and aluminum (hereinafter referred to as metal chelate compound (III)). The metal chelate compound (III) promotes the hydrolysis and / or partial condensation reaction between the organosilicon compound and the vinyl resin segment having a silyl group, and promotes the formation of a three-component cocondensate. It is considered a thing.
[0096]
Examples of such metal chelate compound (III) include compounds represented by general formulas (3), (4), and (5), or partial hydrolysates of these compounds.
[0097]
General formula (3) Zr (OR₅)_p(R₆COCHCOR₇)_4-p
General formula (4) Ti (OR₅)_q(R₆COCHCOR₇)_4-q
Formula (5) Al (OR₅)_r(R₆COCHCOR₇)_3-r
R in the general formulas (3), (4), (5)₅And R₆Are each independently a monovalent hydrocarbon group having 1 to 6 carbon atoms, specifically, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, or a t-butyl group. N-pentyl group, n-hexyl group, cyclohexyl group, phenyl group and the like, and R₇Is R₅And R₆In addition to the monovalent hydrocarbon group having 1 to 6 carbon atoms, as well as the alkoxy group having 1 to 16 carbon atoms, specifically, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, n- A butoxy group, a sec-butoxy group, a t-butoxy group, a lauryloxy group, a stearyloxy group and the like are shown. P and q are integers of 0 to 3, and r is an integer of 0 to 2.
[0098]
Specific examples of such metal chelate compound (III) include tri-n-butoxy ethylacetoacetate zirconium, di-n-butoxy bis (ethylacetoacetate) zirconium, n-butoxy tris (ethylacetoacetate). Zirconium chelate compounds such as zirconium, tetrakis (n-propylacetoacetate) zirconium, tetrakis (acetylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium; di-i-propoxy bis (ethylacetoacetate) titanium, di-i -Titanium chelate compounds such as propoxy bis (acetylacetate) titanium and di-i-propoxy bis (acetylacetone) titanium; di-i-propoxy ethylacetoacetate Minium, di-i-propoxy acetylacetonate aluminum, i-propoxy bis (ethylacetoacetate) aluminum, i-propoxy bis (acetylacetonato) aluminum, tris (ethylacetoacetate) aluminum, tris (ethyl acetate) Examples thereof include aluminum chelate compounds such as aluminum, tris (acetylacetonato) aluminum, monoacetylacetonate-bis (ethylacetoacetate) aluminum, and the like. Among these compounds, tri-n-butoxy ethyl acetoacetate zirconium, di-i-propoxy bis (acetylacetonate) titanium, di-i-propoxy ethyl acetoacetate aluminum, tris (ethyl acetoacetate) aluminum preferable. These metal chelate compounds (III) can be used alone or in admixture of two or more.
[0099]
The amount of the metal chelate compound (III) added is the total amount of coating solution solids containing the X component, Y component, and Z component (the coating solution solids are components remaining after the coating solution is dried). The amount is 0.01 to 20% by mass, preferably 0.5 to 20% by mass. If the amount of the metal chelate compound (III) is too small, the three-dimensional resin may not be achieved. On the other hand, if the amount is too large, the pot life of the coating liquid is deteriorated.
[0100]
The curing conditions after applying the coating solution for the intermediate layer depend on the reactivity of the X component, Y component, and Z component used, but drying is performed at 60 to 150 ° C. for 30 minutes to 6 hours. Is preferred.
[0101]
In order to accelerate these curing reactions, an organic solvent is preferably present. As the organic solvent usable here, alcohols, aromatic hydrocarbons, ethers, ketones, esters and the like are suitable. The amount of the organic solvent used is not limited to the organosilicon compound, and is prepared according to the purpose of use.
[0102]
As the solvent for promoting the curing reaction, a solvent that uniformly dissolves the organosilicon compound and the vinyl resin segment having a silyl group is preferably used. As these solvents, alcohols, aromatic hydrocarbons, ethers, ketones, esters and the like are used, and the solvents exemplified below are particularly preferable.
[0103]
As the alcohol solvent, alcohol having 1 to 4 carbon atoms, that is, methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, and tert-butanol are preferably used.
[0104]
As the non-alcohol solvent, ketone solvents such as ethyl methyl ketone, methyl isopropyl ketone, and methyl isobutyl ketone are preferably used.
[0105]
In the said intermediate | middle layer coating liquid, a hardening accelerator can be further added as needed.
[0106]
Curing accelerators include alkali metal salts such as naphthenic acid, octylic acid, nitrous acid, sulfurous acid, aluminate and carbonic acid; alkaline compounds such as sodium hydroxide and potassium hydroxide; alkyltitanic acid, phosphoric acid and p-toluenesulfone Acid, phthalic acid and other acidic compounds; ethylenediamine, hexanediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, piperidine, piperazine, metaphenylenediamine, ethanolamine, triethylamine, various modified amines used as curing agents for epoxy resins, γ-aminopropyltriethoxysilane, γ- (2-aminoethyl) -aminopropyltrimethoxysilane, γ- (2-aminoethyl) -aminopropylmethyldimethoxysilane, γ-anilinopropyltrimethoxy Amine compounds, such as orchids, (C₄H₉)₂Sn (OCOC₁₁H₂₃)₂, (C₄H₉)₂Sn (OCOCH = CHCOOCH₃)₂, (C₄H₉)₂Sn (OCOCH = CHCOOC₄H₉)₂, (C₈H₁₇)₂Sn (OCOC₁₁H₂₃)₂, (C₈H₁₇)₂Sn (OCOCH = CHCOOCH₃)₂, (C₈H₁₇)₂Sn (OCOCH = CHCOOC₄H₉)₂, (C₈H₁₇)₂Sn (OCOCH = CHCOOC₈H₁₇)₂, Sn (OCOCC₈H₁₇)₂Carboxylic acid type organotin compounds such as₄H₉)₂Sn (SCH₂COO)₂, (C₄H₉)₂Sn (SCH₂COOC₈H₁₇)₂, (C₈H₁₇)₂Sn (SCH₂COO)₂, (C₈H₁₇)₂Sn (SCH₂CH₂COO)₂, (C₈H₁₇)₂Sn (SCH₂COOCH₂CH₂OCOCH₂S)₂, (C₈H₁₇)₂Sn (SCH₂COOCH₂CH₂CH₂CH₂OCOCH₂S)₂, (C₈H₁₇)₂Sn (SCH₂COOC₈H₁₇)₂, (C₈H₁₇)₂Sn (SCH₂COOC₁₂H₂₅)₂, (C₄H₉)₂SnO, (C₈H₁₇)₂SnO, (C₄H₉)₂SnO, (C₈H₁₇)₂An organic tin compound such as a reaction product of an organic tin oxide such as SnO and an ester compound such as ethyl silicate, ethyl silicate 40, dimethyl maleate, diethyl maleate, dioctyl phthalate, or the like is used.
[0107]
The addition amount of the curing accelerator in the coating liquid is 0.1 to 20 parts by mass with respect to 100 parts by mass of the coating liquid solid content (the solid content means a component remaining after drying in the coating liquid component), Preferably it is 0.5-100 mass parts. If the amount is too small, the strength of the film may be reduced. On the other hand, if the amount is too large, the pot life of the coating liquid deteriorates.
[0108]
In the present invention, an organic solvent can be used in order to adjust the total solid concentration of the intermediate layer coating solution and also adjust the viscosity. As such an organic solvent, it is preferable to use organic solvents such as alcohols, aromatic hydrocarbons, ethers, ketones and esters. Examples of the alcohols include monovalent or divalent alcohols, and specifically include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, and t-butyl alcohol. , N-hexyl alcohol, n-octyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono n-propyl ether, ethylene glycol mono n-butyl ether, ethylene glycol monomethyl acetate Examples include ether and ethylene glycol monoethyl ether acetate. Of these, monovalent saturated aliphatic alcohols having 1 to 8 carbon atoms are preferred. Specific examples of the aromatic hydrocarbons include benzene, toluene, xylene, and the like. Specific examples of the ethers include tetrahydrofuran, dioxane, and the like. Examples include ethyl acetate, n-propyl acetate, n-butyl acetate, propylene carbonate and the like. These organic solvents can be used individually or in mixture of 2 or more types. The method for adding the organic solvent is not particularly limited, and the organic solvent can be added at the time of preparing the surface protection liquid of the present invention and / or at an appropriate stage after the preparation.
[0109]
Moreover, it is preferable that the intermediate layer of the present invention is an insulating layer substantially. Here, the insulating layer has a volume resistance of 1 × 10.⁸That's it. The volume resistance of the intermediate layer of the present invention is 1 × 10⁸-10¹⁵Ω · cm is preferred, 1 × 10⁹-10¹⁴Ω · cm is more preferable, and 2 × 10 is more preferable.⁹~ 1x10¹³Ω · cm. The volume resistance can be measured as follows.
[0110]
Measurement conditions: According to JIS: C2318-1975.
Measuring instrument: Hiresta IP manufactured by Mitsubishi Yuka
Measurement conditions: Measurement probe HRS
Applied voltage: 500V
Measurement environment: 30 ± 2 ℃, 80 ± 5RH%
Volume resistance is 1 × 10⁸If it is less than 1, the charge blocking property of the intermediate layer is lowered, the occurrence of black spots increases, the potential holding property of the electrophotographic photosensitive member is deteriorated, and good image quality cannot be obtained. Meanwhile 10¹⁵If it is greater than Ω · cm, the residual potential tends to increase in repeated image formation, and it is difficult to obtain good image quality.
[0111]
In addition, the compound formed from the composition having the X component, the Y component, and the Z component of the present invention causes the respective compounds of the X component, the Y component, and the Z component to react with each other to form a three-dimensional bonding form. The verification that the compound (resin structure of the intermediate layer) can be formed is based on the solvent solubility and thermodynamics of the composition containing the X component, Y component and Z component in the coating solution solvent of the intermediate layer or protective layer Verification can be performed by, for example, disappearance of the glass transition point (Tg).
[0112]
Next, the layer structure of an electrophotographic photoreceptor using the compound of the present invention as described above as a charge transport material, particularly an organic photoreceptor will be described.
[0113]
The organic photoconductor of the present invention means an electrophotographic photoconductor constituted by giving an organic compound at least one of a charge generation function and a charge transport function indispensable for the constitution of the electrophotographic photoconductor. It contains all known organic electrophotographic photoreceptors such as a photoreceptor composed of an organic charge generating material or an organic charge transport material, a photoreceptor composed of a polymer complex with a charge generating function and a charge transport function.
[0114]
The constitution of the organic photoreceptor used in the present invention is described below.
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.
[0115]
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 straightness 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 resistivity is 10 at room temperature.³Ωcm 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 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.
[0118]
Middle class
In the present invention, an intermediate layer having the barrier function is provided between the conductive support and the photosensitive layer.
[0119]
Photosensitive layer
The photosensitive layer configuration of the photoreceptor of the present invention may be a single layer photosensitive layer configuration in which a charge generation function and a charge transport function are provided on one layer on the intermediate layer. It is preferable that the generation layer (CGL) and the charge transport layer (CTL) be separated. 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. In the negatively charged photoconductor, it is preferable that a charge generation layer (CGL) is formed on the intermediate layer, and a charge transport layer (CTL) is formed thereon. In the positively charged photoconductor, the order of the layer configuration is the reverse of that in the negatively charged photoconductor. The most preferred photosensitive layer structure of the present invention is a negatively charged photoreceptor structure having the function separation structure.
[0120]
The structure of the photosensitive layer of the function-separated negatively charged photoreceptor will be described below.
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, CGM which can minimize the increase in residual potential due to repeated use has a crystal structure capable of taking a stable aggregate structure among a plurality of molecules, specifically, a phthalocyanine pigment having a specific crystal structure, CGM of a perylene pigment is mentioned. For example, CGMs such as titanyl phthalocyanine having a maximum peak at a Bragg angle 2θ of 27.2 ° with respect to Cu—Kα rays and benzimidazole perylene having a maximum peak at 2θ of 12.4 have little deterioration due to repeated use. Potential increase can be reduced.
[0122]
When a binder is used as a 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]
A known charge transport material (CTM) can be used as the charge transport material (CTM). For example, a triphenylamine derivative, a hydrazone compound, a styryl compound, a benzidine compound, a butadiene compound, or the like can be used. These charge transport materials are usually dissolved in a suitable binder resin to form a layer. Among these, the CTM capable of minimizing the increase in the residual potential due to repeated use has a high mobility and an ionization potential difference with the combined CGM of 0.5 (eV) or less, preferably 0 .30 (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 the repeating unit structures 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.
[0128]
The charge transport layer preferably contains an antioxidant. Typical examples of the antioxidants prevent the action of oxygen on auto-oxidizing substances existing in the electrophotographic photosensitive member or on the surface of the electrophotographic photosensitive member under conditions of light, heat, and discharge. It is also a substance having a suppressing property.
[0129]
The thickness of the charge transport layer is preferably 5 to 40 μm, more preferably 8 to 30 μm. When the total thickness of the charge transport layer is less than 5 μm, the charging potential tends to be insufficient, and when it exceeds 40 μm, the high-speed adaptability is lowered, the image density is lowered, and the sharpness is liable to be deteriorated. The most preferable thickness of the charge transport layer that can provide high-speed adaptability and good image quality is 16 to 25 μm.
[0130]
Charge injection layer
The electrophotographic photoreceptor of the present invention has a structure in which a charge injection layer is provided on a charge transport layer, and the charge injection layer is basically composed of a binder resin layer in which conductive fine particles are dispersed.
[0131]
As the binder resin for the charge injection layer, the same resin as the charge transport layer described above is used.
[0132]
As the conductive fine particles of the charge injection layer, fatty acid salts, higher alcohols, sulfate esters, fatty acid amines, quaternary ammonium salts, alkyl pyridium salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl esters, Anionic, cationic or nonionic organic electrolytes such as sorbitan alkyl esters and imidazoline derivatives; metals such as Au, Ag, Cu, Ni and Al; ZnO and TiO₂, SnO₂, In₂O₃, Sb₂O₃Contained SnO₂, In₂O₃Contained SnO₂Metal oxide such as MgF₂, CaF₂, BiF₂, AlF₂, SnF₂, SnF₄TiF₄Metal fluorides such as tetrainpropyl titanate, tetranormal butyl titanate, titanium acetylacetonate, titanium lactate ethyl ester and the like; and mixtures thereof.
[0133]
The charge injection layer of the present invention preferably contains a charge transport material. By including a charge transport material in the charge injection layer, a decrease in sensitivity and an increase in residual potential due to repeated use can be prevented. The charge injection layer preferably contains a compound having the above-described antioxidant function.
[0134]
The thickness of the charge injection layer is suitably from 0.3 to 10 μm, preferably from 1 to 5 μm.
[0135]
The volume resistance of the charge injection layer is 10¹⁰-10¹⁵It is preferable to set so as to be in the range of Ω · cm.¹⁰-10¹⁴Ω · cm is preferred. Since the film strength becomes weaker as the amount of conductive particles increases, it is preferable to reduce the amount of conductive particles within a range where the resistance and residual potential of the charge injection layer are acceptable.
[0136]
Further, the charge injection layer contains fluorine resin particles, and the contact angle of the photoreceptor surface with water is preferably 90 ° or more, and more preferably 95 ° or more. That is, by increasing the contact angle and reducing the surface energy of the photoreceptor, it is possible to prevent filming due to toner or paper dust on the surface of the photoreceptor, which causes dielectric breakdown and image defects. The fluorine-based resin particles mean resin particles containing fluorine atoms. For example, tetrafluoroethylene resin, trifluoroethylene chloride resin, hexafluoroethylenepropylene resin, vinyl fluoride resin, vinylidene fluoride resin, It is preferable to appropriately select one or two or more of ethylene difluoride dichloride resin and copolymers thereof, and particularly, tetrafluoroethylene resin and vinylidene fluoride resin are preferable. The molecular weight of the fluororesin particles and the particle diameter of the particles can be appropriately selected and are not particularly limited, but those having a volume average particle diameter of 0.05 to 5 μm are preferable.
[0137]
The volume average particle diameter of the fluororesin particles is measured by a laser diffraction / scattering particle size distribution measuring apparatus “LA-700” (manufactured by Horiba, Ltd.). The surface contact angle of the photosensitive member is measured by using a contact angle meter (CA-DT-A type: manufactured by Kyowa Interface Science Co., Ltd.) in an environment of 20 ° C. and 50% RH.
[0138]
In the above, the most preferable layer structure of the photoreceptor of the present invention is exemplified, but in the present invention, a photoreceptor layer structure other than the above may be used.
[0139]
Solvents or dispersion media used to form layers such as intermediate layers, charge generation layers, and charge transport layers include n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N, N-dimethylformamide, and 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, methyl cello Lube, 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.
[0140]
The coating solution for each layer is preferably filtered with a metal filter, a membrane filter or the like in order to remove foreign matters and aggregates in the coating solution before entering the coating step. For example, it is preferable to select a pleated type (HDC), a depth type (profile), a semi-depth type (profile star), etc., manufactured by Nippon Pole Co., Ltd. according to the characteristics of the coating solution and perform filtration.
[0141]
Next, as a coating processing method for producing an organic electrophotographic photosensitive member, a coating processing method such as dip coating, spray coating, circular amount regulation type coating, etc. is 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). It is most preferable to use the circular amount regulation type coating method for the protective layer. The circular amount regulation type coating is described in detail in, for example, Japanese Patent Application Laid-Open No. 58-189061.
[0142]
Next, an image forming apparatus using the contact charging method of the present invention will be described.
<Charging means>
In the present invention, charging is performed by bringing a charging member into contact with the photoreceptor (hereinafter also referred to as charging means using the contact charging member). As such a charging member, various charging members such as a magnetic brush method, a charging roller method, and a blade method can be used. Among these, a charging roller method or a magnetic brush method is most preferable as the charging member and used in the present invention. It is done. That is, a charging roller or a magnetic brush that is easy to obtain charging uniformity is preferable. The charging roller type and magnetic brush type charging means will be described below.
[0143]
In the present invention, a charging roller composed of a conductive elastic member can be brought into contact with a photosensitive member (image carrier), and a voltage can be applied to the charging roller to charge the photosensitive member (image carrier).
[0144]
Such a charging roller system may be either a DC charging system in which a DC voltage is applied to the roller or an induction charging system in which an AC voltage is applied to the roller.
[0145]
In addition, the frequency f of the voltage applied by the induction charging method is arbitrary, but an appropriate frequency is selected according to the relative speed of the conductive elastic roller and the image carrier member in order to prevent strobing, that is, a stripe pattern. Can be selected. The relative speed can be determined by the size of the contact area between the conductive elastic roller and the image carrier.
[0146]
The conductive elastic roller is formed by coating the outer periphery of a metal core with a layer made of a conductive elastic member (also simply referred to as a conductive elastic layer or H or a conductive rubber layer).
[0147]
Examples of the rubber composition that can be used for the conductive rubber layer include polynorbornene rubber, ethylene-propylene rubber, chloroprene rubber, acrylonitrile rubber, and silicone rubber. These rubber | gum can be used individually or as 2 or more types of mixed rubbers.
[0148]
In order to impart conductivity, a conductivity imparting agent is blended with these rubber compositions. Examples of suitable conductivity imparting agents include known carbon black (furnace carbon black or ketien black), metal powder such as tin oxide. The usage-amount of an electroconductivity imparting agent is about 5 to about 50 mass parts with respect to the rubber composition whole quantity.
[0149]
In addition to the rubber base material, the foaming agent, and the conductivity imparting agent, the rubber composition may be blended with a rubber chemical and a rubber additive as necessary to obtain a conductive foamed rubber composition. Rubber chemicals and rubber additives include vulcanizing agents such as sulfur and peroxide, vulcanization accelerators such as zinc white and stearic acid, vulcanized sulfenamide, thyrium, thiazole and granidine Accelerators, amine-based, phenol-based, sulfur-based, phosphorus-based anti-aging agents, antioxidants, UV absorbers, ozone degradation inhibitors, tackifiers, etc. can be used, and various reinforcing agents In addition, an inorganic filler such as a friction coefficient modifier, silica, talc, clay and the like can be arbitrarily selected and used. These conductive rubber layers are 10³-10⁷It preferably has a direct current volume resistivity in the range of Ωcm.
[0150]
Further, on the outside of these conductive elastic layers, a releasable coating layer may be provided for the purpose of preventing the toner remaining on the surface of the photoreceptor from adhering to the charging member. The coating layer also prevents oil seepage from the elastic layer and cancels the resistance unevenness of the elastic layer, uniforms the resistance, protects the surface of the charging roller, and adjusts the hardness of the charging roller. Etc. The covering layer may be any layer as long as it satisfies the above physical properties, and may be a single layer or a plurality of layers. Examples of the material include resins such as hydrin rubber, urethane rubber, nylon, polyvinylidene fluoride, and polyvinylidene chloride. Moreover, it is preferable that the thickness of a coating layer is 100-1000 micrometers, and resistance value is 10⁵-10⁹It is preferably Ω · cm. Moreover, it is preferable that resistance value becomes large as it approaches the surface layer. Examples of the method for adjusting the resistance include adding a conductive material such as carbon black, metal, and metal oxide to the coating layer.
[0151]
In order to adjust the surface roughness Rz of the charging roller, it is preferable to include powder in the surface layer (conductive elastic layer or coating layer) of the charging roller. The granular material used in the present invention may be either an inorganic substance or an organic substance, but in the case of an inorganic substance, silica powder is particularly preferable. In the case of organic substances, for example, urethane resin particles, nylon particles, silicone rubber particles, epoxy resin particles and the like can be mentioned. These particles are used alone or in combination of two or more. A suitable particle may be selected from a material that can adjust the surface roughness Rz of the surface layer to a range of 0.05 to 10.0 μm, but if the particle diameter of the particle is in the range of 1 to 20 μm, the desired surface roughness is selected. The degree range is easy to achieve. If the particle diameter exceeds 20 μm, the surface roughness Rz also exceeds 10.0 μm, which does not fulfill the intended purpose. Conversely, if the particle size is less than 1 μm, the surface roughness Rz tends to be less than 0.05 μm, which also does not fulfill the intended purpose.
[0152]
The reason why the surface roughness Rz is set in the range of 0.05 to 10.0 μm is that if it exceeds 10.0 μm, filming of the toner on the roller surface becomes remarkable, and if it is less than 0.05 μm, the charging roller This is because the adhesion between the photosensitive drum and the photosensitive drum is increased, that is, the contact area is increased, so that charging noise cannot be suppressed.
[0153]
It is preferable to mix and disperse | distribute the mixture ratio in the surface layer of a powder in the ratio of about 5 to about 20 mass parts with respect to 100 mass parts of resin.
[0154]
The charging roller can be manufactured as follows, for example. That is, first, a metal rotating shaft (core metal) is placed in a forming die having a cylindrical forming space, a conductive elastic layer forming material is filled in the forming die, and vulcanization is performed, whereby the outer periphery of the rotating shaft is filled. A conductive elastic layer is formed on the surface. Next, the rotating shaft on which the conductive elastic layer is formed is taken out from the mold. On the other hand, a material such as a urethane resin and granules, a conductivity-imparting agent and other additives are blended, and this blend is mixed and stirred using a ball mill or the like to prepare a surface layer forming material mixture. Then, the mixture is applied to the surface of the rotating shaft on which the conductive elastic layer is formed by a dip method, a roll coating method, a spray coating method, etc., dried to a uniform thickness, and heat-cured to form a two-layer structure. A charging roller can be manufactured. The charging roller thus obtained is formed so that the surface roughness Rz of the outermost surface layer is 0.05 to 10.0 μm.
[0155]
Next, the image forming apparatus of the present invention will be described.
FIG. 1 is a diagram showing an example of an image forming apparatus using charging roller charging. This image forming apparatus is for carrying out the present invention. As a charging means for forming an electrostatic latent image, a charging roller is brought into contact with a photosensitive drum for charging (charging process), and toner is transferred to a transfer paper. A transfer roller is used as a transfer pole (transfer means) for transferring to (transfer process). The transfer roller is in contact with the photosensitive drum directly or with the transfer paper interposed therebetween to avoid the generation of ozone. The so-called contact charging method is adopted, and the electrostatic latent image is formed by non-contact development. Develop.
[0156]
In FIG. 1A, an electrostatic latent image is formed on a photosensitive drum 2 charged by a charging roller 1 by image exposure using a laser (image exposure process). The electrostatic latent image is developed into a toner image by a developing sleeve 4 which is a developer carrying member of a developing device (developing means) 3 disposed in the vicinity of the photosensitive drum 2 (developing step). Then, after the charge of the photosensitive drum 2 is discharged by the discharging lamp 5 before transfer, the toner image is transferred to the transfer paper P transported by the transporting roller 8 from the paper feed cassette and transferred to the transfer paper 6 by the reverse polarity of the toner. The toner is transferred onto the transfer paper P by the electrostatic force of the reverse polarity charge. After the toner transfer, the transfer paper P is separated from the photosensitive drum 2 and then sent to the fixing device by the conveying belt 7, and the toner image is fixed to the transfer paper P by the heating roller and the pressing roller (fixing step).
[0157]
A bias voltage composed of DC and AC components is applied to the charging roller 1 (and transfer roller 6) from a power source 9 (10), and the charging of the photosensitive drum 2 and the toner image are generated in a state where the amount of ozone generation is extremely small. The transfer paper P is charged. The voltage is preferably a DC bias of ± 300 to 1000 V and an AC bias of 100 to 10 KHz and 200 to 3500 V (pp) superimposed on the DC bias.
[0158]
The charging roller 1 and the transfer roller 6 are driven or forcibly rotated under pressure contact with the photosensitive drum 2.
[0159]
The pressure contact with the photosensitive drum 2 is 10 to 100 g / cm, and the rotation of the roller is 1 to 8 times the peripheral speed of the photosensitive drum 2.
[0160]
As shown in FIG. 1B, the charging roller 1 (and the transfer roller 6) includes a cored bar 20 and a rubber layer such as chlorprene rubber, urethane rubber, and silicone rubber that are conductive elastic members provided on the outer periphery thereof. Or it consists of those sponge layers 21, Preferably it is comprised by providing the protective layer 22 which consists of a mold release fluorine-type resin or silicone resin layer of 0.01-1 micrometer thickness in the outermost layer.
[0161]
After the transfer, the photosensitive drum 2 is cleaned by the pressure contact of the cleaning blade 12 of the cleaning device (cleaning means) 11 and used for the next image formation.
[0162]
As an electrophotographic image forming apparatus, a photosensitive member and components such as a charging unit, a developing unit, and a cleaning unit are integrally combined as a process cartridge, and this unit is configured to be detachable from the apparatus main body. You may do it. Further, at least one of the image exposure means, the developing means, the transfer or separator, and the cleaning means is integrally supported together with the photosensitive member to form a process cartridge, and is a single unit that is detachable from the main body of the image forming apparatus. It is good also as a structure which can be attached or detached using guide means, such as a rail.
[0163]
In FIG. 1, a roller charger is used for both the charger and the transfer electrode. However, in the present invention, the present invention is to use a contact charging member (charging roller or the like) for the charger. Transfer means other than the transfer roller may be used for the poles.
[0164]
Next, a magnetic brush charging device using a magnetic brush as the charging member will be described. FIG. 2 is a diagram of a contact-type magnetic brush charging device, and FIG. 3 is a diagram showing a relationship between an AC bias voltage and a charging potential by the charging device of FIG.
[0165]
In general, if the volume average particle size of the magnetic particles forming the charging magnetic brush is large, the ears of the magnetic brush formed on the charging magnetic particle carrier (conveyance carrier) are rough. However, even when charged, unevenness is likely to appear on the magnetic brush, resulting in a problem of uneven charging. In order to solve this problem, the volume average particle diameter of the magnetic particles may be reduced. As a result of the experiment, the effect starts to appear when the volume average particle diameter is 200 μm or less. The problems associated with the coarseness of the ears are eliminated. However, if the particles are too fine, they will adhere to the surface of the photosensitive drum 50 during charging, or may be easily scattered. These phenomena relate to the strength of the magnetic field acting on the particles and the magnetization strength of the particles, but generally, the volume average particle diameter of the particles becomes noticeable at 20 μm or less.
[0166]
From the above, the magnetic particles have a volume average particle size of 200 μm or less, 20 μm or more, and 30% by number or less of magnetic particles having a particle size of 1/2 or less of the number average particle size of the magnetic particles. It is necessary to. The magnetization strength is preferably 30 to 100 emu / g.
[0167]
Such magnetic particles are the same as the magnetic carrier particles of the conventional two-component developer described above as the magnetic material, such as metals such as iron, chromium, nickel and cobalt, or their compounds and alloys, such as iron tetroxide. , Γ-ferric oxide, chromium dioxide, manganese oxide, ferrite, manganese-copper alloy, ferromagnetic particles, or the surface of these magnetic particles is made of styrene resin, vinyl resin, ethylene resin Particles obtained by coating with a resin such as rosin-modified resin, acrylic resin, polyamide resin, epoxy resin, polyester resin, or made of resin containing dispersed magnetic fine particles are conventionally known. It can be obtained by selecting the particle size with an average particle size selecting means.
[0168]
In addition, forming the magnetic particles in a spherical shape has an effect that the particle layer formed on the carrier is uniform, and a high bias voltage can be uniformly applied to the carrier. That is, the magnetic particles are spherical. (1) Generally, magnetic particles are easily magnetized and adsorbed in the long axis direction, but the directionality is lost by the spherical shape, and therefore the magnetic particle layer is formed uniformly. (2) With the increase in resistance of magnetic particles, the edge portion as found in conventional particles is eliminated, and the electric field to the edge portion is prevented. Concentration does not occur, and as a result, even when a high bias voltage is applied to the carrier for charging magnetic particles, the surface of the photosensitive drum 50 is uniformly discharged and charging unevenness does not occur.
[0169]
The spherical particles having the above effects have a magnetic particle resistivity of 10⁵-10¹⁰What formed the electroconductive magnetic particle so that it is (omega | ohm) cm is preferable. This resistivity is 0.50 cm for particles.²1 kg / cm on the packed particles after tapping in a container having a cross-sectional area of²And a value obtained by reading a current value when a voltage generating an electric field of 1000 V / cm is applied between the load and the bottom electrode. If this resistivity is low, a bias voltage is applied to the carrier. Is applied to the magnetic particles, the magnetic particles are likely to adhere to the surface of the photosensitive drum 50, or the dielectric breakdown of the photosensitive drum 50 due to the bias voltage is likely to occur. If the resistivity is high, charge injection is not performed and charging is not performed.
[0170]
Furthermore, the magnetic particles used in the contact-type magnetic brush charging device 120 have a small specific gravity and an appropriate maximum magnetization so that the magnetic brush formed by the magnetic brush is moved easily by an oscillating electric field and no external scattering occurs. It is desirable to have Specifically, it has been found that good results can be obtained when the true specific gravity is 6 or less and the maximum magnetization is 30 to 100 emu / g, particularly 40 to 80 emu / g.
[0171]
In summary, the magnetic particles are spheroidized so that the ratio of the major axis to the minor axis is 3 times or less, there are no protrusions such as needles and edges, and the resistivity is preferably 10⁵-10¹⁰It is desired to be in the range of Ωcm. For such spherical magnetic particles, select spherical particles as much as possible for magnetic particles, and for magnetic particles dispersed particles, use magnetic particles as much as possible, and perform spheronization after forming dispersed resin particles. Or by forming dispersed resin particles by a spray drying method.
[0172]
According to FIG. 2 or FIG. 3, the magnetic brush charging device 120 as a charging device faces the rotating photoconductor drum 50 and is in the same direction (counterclockwise) at a proximity portion (charging unit T) with the photoconductor drum 50. A cylindrical charging sleeve 120a using, for example, an aluminum material or a stainless material, and a magnet body 121 made of N and S poles provided inside the charging sleeve 120a, A magnetic brush made of magnetic particles formed on the outer peripheral surface of the charging sleeve 120 a by the magnet body 121 and charging the photosensitive drum 50, and a magnetic brush on the charging sleeve 120 a at the NN magnetic pole portion of the magnet body 121 are scraped. The scraper 123 to be taken and the magnetic particles in the magnetic brush charging device 120 are stirred or supplied to the magnetic brush charging device 120 when the magnetic particles are supplied. And stirring screw 124 to discharge overflowing from the discharge port 125, constituted by the bristles regulating plate 126 of the magnetic brush. The charging sleeve 120a is rotatable with respect to the magnet body 121, and is 0.1 to 1.0 times in the same direction (counterclockwise) as the movement direction of the photosensitive drum 50 at a position facing the photosensitive drum 50. It is preferably rotated at a peripheral speed. As the charging sleeve 120a, a conductive carrier capable of applying a charging bias voltage is used. In particular, the magnet body 121 having a plurality of magnetic poles inside the conductive charging sleeve 120a having a particle layer formed on the surface thereof. Those having a structure provided with are preferably used. In such a carrier, the magnetic particle layer formed on the surface of the conductive charging sleeve 120a moves up and down in a wave shape due to the relative rotation with the magnet body 121. Even if the magnetic particle layer on the surface of the charging sleeve 120a is somewhat uneven in thickness, the influence is sufficiently covered so as not to cause a problem due to the wavy undulations. The surface of the charging sleeve 120a preferably has an average surface roughness of 5.0 to 30 [mu] m for stable and uniform transfer of magnetic particles. If the surface is smooth, the surface cannot be sufficiently transported. Overcurrent flows from the part, and in any case, uneven charging tends to occur. Sand blasting is preferably used to achieve the above surface roughness. Further, the outer diameter of the charging sleeve 120a is preferably 5.0 to 20 mm. This ensures a contact area necessary for charging. If the contact area is larger than necessary, the charging current becomes excessive, and if it is small, charging unevenness is likely to occur. When the diameter is small as described above, magnetic particles are likely to be scattered or adhere to the photosensitive drum 50 due to centrifugal force. Therefore, the linear velocity of the charging sleeve 120a is almost the same as the moving velocity of the photosensitive drum 50, or more It is also preferable that it is slow.
[0173]
Further, the thickness of the magnetic particle layer formed on the charging sleeve 120a is preferably a thickness that is sufficiently scraped off by the regulating means to form a uniform layer. If there is too much magnetic particles on the surface of the charging sleeve 120a in the charging region, the magnetic particles will not vibrate sufficiently, causing photoconductor wear and charging unevenness and overcurrent easily flowing, and driving torque of the charging sleeve 120a. Has the disadvantage of becoming larger. On the other hand, if the amount of the magnetic particles on the charging sleeve 120a in the charged region of the magnetic particles is too small, an incomplete portion is formed in contact with the photosensitive drum 50, and adhesion of the magnetic particles on the photosensitive drum 50 or uneven charging occurs. become. As a result of repeated experiments, the preferable adhesion amount of magnetic particles in the charged region is 100 to 400 mg / cm.²And particularly preferably 200 to 300 mg / cm.²It has been found that This adhesion amount is an average value in the charging region of the magnetic brush.
[0174]
The magnetic brush charging device 120 serving as a charging device includes a charging bias in which an alternating current (AC) bias AC3 is superimposed on a direct current (DC) bias E3 as necessary, for example, a direct current bias E3 having the same polarity as the toner (in this embodiment, minus). Polarity) of -100 to -500V, and frequency of 1 to 5kHz and voltage of 300 to 500V as AC bias AC3_PPThe peripheral surface of the photosensitive drum 50 is contacted and rubbed by the charging sleeve 120a to which the charging bias is applied, and the photosensitive drum 50 is charged. Since an oscillating electric field is formed between the charging sleeve 120a and the photosensitive drum 50 by applying the voltage of the AC bias AC3, the electric charge is smoothly injected onto the photosensitive layer 10a through the magnetic brush. High-speed charging is performed uniformly.
[0175]
The magnetic brush on the charging sleeve 120a charged with the photosensitive drum 50 is dropped from the charging sleeve 120a by the scraper 123 at the NN magnetic pole portion provided in the magnet body 121, and the charging sleeve 120a in the vicinity of the charging sleeve 120a. Then, the magnetic brush is formed again and conveyed to the charging unit T after being stirred by the stirring screw 124 rotating in the opposite direction (counterclockwise).
[0176]
As shown in FIG. 3, the peak-to-peak voltage (V_PP) And the charging potential, the peak-to-peak voltage V_PPThe charging potential increases as the voltage increases, and the charging potential saturates when the peak-to-peak voltage is constant V1 and is substantially equal to the value VS of the DC bias E3 of the charging bias._PPThere is a characteristic that the charging potential hardly changes even when the value is increased. Although the electric resistance of the magnetic particles varies depending on the environmental conditions, the electric resistance increases as the toner is fused to the surface of the magnetic particles as it is used. For this reason, the characteristic curve is shown on the left side as shown by a solid line in the case of new magnetic particles in the initial stage of use, and the characteristic curve is shown on the right side as shown in FIG. Will be located.
[0177]
In the charging device using the contact method of the image forming apparatus of the present invention, the voltage value of the DC bias E3 corresponding to the charging potential is set to a predetermined value when the mounted power source is turned on or before printing is started, and the peak-to-peak voltage (V_PP) Is gradually increased from a low value, and the charging potential of the photosensitive drum 50 that changes at that time is detected by the electrometer ES. The detected charging potential is converted into a digital value by an A / D converter and then input to a control unit (CPU). In the control unit, V when the charged potential reaches the saturation point of the predetermined value VS._PPIs defined as an appropriate bias value V1, and a printing operation is performed.
[0178]
That is, when printing is performed, the AC bias AC3 is gradually increased from a low value (swept) to the V of the AC bias AC3._PPAnd a bias signal is output from the control unit. This control signal is converted to an analog value by the D / A converter and then sent to the AC bias AC3. The AC bias AC3 outputs the determined peak-to-peak voltage V1. At this time, the value of the peak-to-peak voltage V1 and the specified value V2 to be exchanged due to the deterioration of the magnetic particles stored in the memory are read and compared. Since the resistance of the magnetic particles increases due to toner mixing, the proper bias value V1 increases as the print is used. V applied as a result_PPWill increase and an unchargeable state will occur. The image formation is continued while the measured voltage value is smaller than the prescribed value V2 indicating that charging is not possible. However, when the measured voltage value is larger than the prescribed value V2, an image forming operation stop signal is sent from the control unit to stop the image forming operation. The charging unit abnormality is displayed on the display unit of the operation unit. Based on this display, the charging magnetic particle supply bottle 220 is set in the magnetic brush charging device 120, and an opening / closing lid (not shown) on the bottom of the supply bottle 220 is opened to drop and supply the magnetic particles to the magnetic brush charging device 120. To do. In the above description, the electrometer ES is used to measure the potential of the photosensitive drum 50. However, an AC bias V is obtained by connecting a DC ammeter to a bias power source._PPAnd when this current value reaches the saturation point, V_PPMay be set to an appropriate bias value V1, and compared with a specified value V2, and when V1 is exceeded, magnetic particles may be supplied.
[0179]
In addition, the magnetic particles for charging are exchanged during maintenance or at regular intervals such as 50,000 prints. At each maintenance print stored in the memory or at regular intervals of, for example, 50,000 prints, an exchange signal is output through the control unit, and supply of the charging magnetic particle supply bottle 220 set in advance by driving a drive motor (not shown) The roller 221 is rotated, and the magnetic particles in the supply bottle 220 are dropped into the magnetic brush charging device 120 in one time. It is also possible to control the image forming apparatus to be in an operating state by removing the empty supply bottle 220 after supply and setting a new supply bottle 220. In addition, a supply signal such as blinking of a lamp is displayed on the operation unit (not shown) from the control unit at regular intervals, the supply bottle 220 is set on the magnetic brush charging device 120, and an open / close lid (not shown) on the bottom of the supply bottle 220 is opened. Then, magnetic particles may be supplied.
[0180]
The dropped magnetic particles are conveyed by the rotating charging sleeve 120a, scraped off from the surface of the charging sleeve 120a by the scraper 123, and replenished to the bottom of the magnetic brush charging device 120. Accordingly, the used magnetic particles stored in the magnetic brush charging device 120 are overflowed from the discharge port 125 by the stirring screw 124 rotated counterclockwise, and the common magnetic particle recovery container 300 is passed through the duct DB. To be recovered. At this time, the supply amount of the magnetic particles supplied from the supply bottle 220 into the magnetic brush charging device 120 is preferably 20 to 50% by mass with respect to all the magnetic particles stored in the magnetic brush charging device 120. If the amount is less than 20% by mass, the amount of newly supplied magnetic particles is so small that there is no exchange effect and good charging is not performed. If the amount exceeds 50% by mass, new magnetic particles overflow.
[0181]
As described above, good charging performance is maintained for a long time without deterioration of the magnetic particles in the charging device.
[0182]
FIG. 4 is a cross-sectional view showing an example of an image forming apparatus having a magnetic brush charger. In FIG. 4, reference numeral 50 denotes a photosensitive drum (photosensitive member) which is an image bearing member. An organic photosensitive layer is applied on the drum, and a photosensitive member having the structure of the present invention is applied to the photosensitive drum. Is done. Reference numeral 52 denotes a magnetic brush charger, which can uniformly charge the circumferential surface of the photosensitive drum 50 (charging process). Prior to charging by the charger 52, the peripheral surface of the photosensitive member may be discharged by performing exposure by the 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.
[0183]
After uniform charging of the photoreceptor, image exposure based on the image signal is performed by the image exposure unit 53 (image exposure process). 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.
[0184]
The electrostatic latent image is then developed by the developing device 54 (development process). 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 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. It consists of toner with silica, titanium oxide, etc. added externally to the particles. The developer is regulated to a layer thickness of 100 to 600 μm on the developing sleeve 541 by a layer forming means (not shown) and conveyed to the developing area. Then, 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.
[0185]
The transfer material (also referred to as recording paper) P is fed to the transfer area by the rotation operation of the paper feed roller 57 at the time when the transfer timing is ready after image formation.
[0186]
In the transfer area, a transfer roller (transfer device) 58 is pressed against the peripheral surface of the photosensitive drum 50 in synchronization with the transfer timing, and the transferred transfer material P is sandwiched and transferred (transfer process).
[0187]
Next, the transfer material P is neutralized by a separation brush (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 pressed against the heat roller 601. After the toner is welded by heating and pressurizing the roller 602 (fixing step), the toner is discharged to the outside of the apparatus via the discharge roller 61. The transfer roller 58 and the separation brush 59 are separated from the peripheral surface of the photosensitive drum 50 after the transfer material P has passed, and prepare for the formation of the next toner image.
[0188]
On the other hand, after the transfer material P is separated, the photosensitive drum 50 is subjected to removal and cleaning of residual toner by pressure contact of the cleaning blade 621 of the cleaning device 62, and again after being subjected to charge removal by the exposure unit 51 and charging by the charger 52. Enter the image forming process.
[0189]
Reference numeral 70 denotes a detachable process cartridge in which a photoconductor, a charger, a transfer device / separator, and a cleaning device are integrated.
[0190]
As the image forming apparatus, the above-described photosensitive member and components such as a developing device and a cleaning device may be integrally coupled as a process cartridge, and this unit may be configured to be detachable from the apparatus main body. In addition, a process cartridge is formed by integrally supporting at least one of a charger, an image exposure device, a developing device, a transfer or separation device, and a cleaning device together with a photosensitive member, and a single unit that is detachable from the apparatus main body. It is good also as a structure which can be attached or detached using guide means, such as a rail of an apparatus main body.
[0191]
When the image forming apparatus is used as a copying machine or a printer, image exposure is performed by irradiating a photosensitive member with reflected light or transmitted light from a document, or by reading a document with a sensor and generating a laser beam according to this signal. Scanning, driving the LED array, or driving the liquid crystal shutter array and irradiating the photosensitive member with light are performed.
[0192]
When used as a facsimile printer, the image exposure unit 13 performs exposure for printing received data.
[0193]
The 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. It can be widely applied to apparatuses such as facsimiles.
[0194]
【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. However, “part” in the following text indicates “part by mass”.
[0195]
A photoreceptor was prepared as follows.
Production of photoreceptor 1
<Intermediate layer (UCL)>
The following intermediate layer coating solution was prepared and applied on a washed cylindrical aluminum substrate by a dip coating method to form an intermediate layer.
[0196]
X component: Titanium oxide (number average primary particle size: 35 nm anatase type titanium oxide pigment) 100 parts
Y component: 10 parts isopropyl triisostearoyl titanate
Z component-1: Vinyl resin segment A solution (hindered amine group-containing silyl-modified vinyl resin resin component A solution) 100 parts
Z component-2: 70 parts of methyltrimethoxysilane
Z component-3: 30 parts of dimethyldimethoxysilane
Solvent 1: 100 parts of i-butyl alcohol
Solvent 2: 75 parts of butyl cellosolve
Di-i-propoxyethyl acetoacetate aluminum 10 parts
The X component, Y component, and 1, 50 parts of the solvent were mixed, and the mixture was dispersed in media over a whole day and night. The remaining components described above were added to the media dispersion and stirred well, and then 30 parts of pure water was added dropwise with stirring and reacted at 60 ° C. for 4 hours. Subsequently, the mixture was cooled to room temperature, 10 parts of an i-propyl alcohol solution of dioctyltin dimaleate ester (solid content 15%) was added and stirred, and then filtered to remove the media to prepare an intermediate layer coating solution. This coating solution is applied onto the cylindrical aluminum substrate with a circular amount-regulating coating device, and heated and cured at 120 ° C. for 1 hour, and the X component, Y component, and Z component of the present invention having a dry film thickness of 10 μm are applied. An intermediate layer containing a compound formed from the composition (intermediate layer coating solution) was formed.
[0197]
<Charge generation layer (CGL)>
Oxytitanyl phthalocyanine (Maximum peak angle of X-ray diffraction by Cu-Kα characteristic X-ray is 27.3 in Bragg 2θ) 20 parts
Polyvinyl butyral (# 6000-C, manufactured by Denki Kagaku Kogyo) 10 parts
700 parts of t-butyl acetate
300 parts of 4-methoxy-4-methyl-2-pentanone
The above composition was mixed and dispersed using a sand mill to prepare a charge generation layer coating solution. This coating solution was applied by a dip coating method to form a charge generation layer having a dry film thickness of 0.3 μm on the intermediate layer.
[0198]
<Charge transport layer (CTL)>
Charge transfer agent ([4- (2,2-diphenylvinyl) phenyl] -di-p-tolylamine) 75 parts
100 parts of polycarbonate resin (Iupilon Z300: manufactured by Mitsubishi Gas Chemical Company)
750 parts of methylene chloride
The above composition was 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.
[0199]
<Charge injection layer>
Charge transport material ([4- (2,2-diphenylvinyl) phenyl] -di-p-tolylamine) 200 parts
Bisphenol Z-type polycarbonate
(Iupilon Z300: manufactured by Mitsubishi Gas Chemical Company) 300 parts
Surface treatment with the following compound A (treatment amount 7%)
Antimony-doped tin oxide ultrafine particles 250 parts
250 parts of antimony-doped tin oxide fine particles surface-treated with methyl hydrogen silicone oil (trade name: KF99, manufactured by Shin-Etsu Silicone Co., Ltd.)
Hindered amine (Sanol LS2626: Sankyosha) 3 parts
150 parts of polytetrafluoroethylene resin particles (average particle size 0.5 μm)
1-butanol 2000 parts
Were mixed and dissolved to prepare a surface protective layer coating solution. This coating solution is applied onto the charge transport layer of the photoreceptor 1 by a dip coating method, and heat cured at 100 ° C. for 40 minutes to form a charge injection layer having a dry film thickness of 2.0 μm. Produced. The contact angle of the surface of the photoreceptor 1 with respect to water was 116 °.
[0200]
Production of photoconductor 2
In the production of the photoreceptor 1, the X component, the Y component, and the Z component of the present invention are similarly used except that the particle size of the titanium oxide in the intermediate layer coating solution is changed to an anatase type titanium oxide pigment of 35 nm to 15 nm. Photoreceptor 2 having an intermediate layer containing a compound formed from the composition was produced.
[0201]
Production of photoconductor 3
In the production of the photoreceptor 1, the X component, the Y component, and the Z component of the present invention are similarly used except that the particle size of titanium oxide in the intermediate layer coating solution is changed to an anatase type titanium oxide pigment of 35 nm to 180 nm. Photoreceptor 3 having an intermediate layer containing a compound formed from the composition was produced.
[0202]
Production of photoconductor 4
Photosensitive material 1 was prepared except that the vinyl resin segment A solution of the intermediate layer coating solution was replaced with a vinyl resin segment B solution (a vinyl segment B solution having a hindered phenol group and silyl-modified). In the same manner as the body 1, a photoreceptor 4 containing an intermediate layer containing a compound formed from the composition having the X component, the Y component, and the Z component of the present invention was produced.
[0203]
Production of photoreceptor 5
In the production of the photoreceptor 1, the intermediate layer is replaced with the following intermediate layer, and is formed from the composition having the X component, the Y component, and the Z component of the present invention except that the dry film thickness is 4 μm. Photoconductor 5 having an intermediate layer containing a compound was produced.
[0204]
<Intermediate layer (UCL)>
The following intermediate layer coating solution was prepared and applied onto a washed cylindrical aluminum substrate to form an intermediate layer.
[0205]
X component: Titanium oxide (number average primary particle size: 35 nm anatase type titanium oxide pigment) 100 parts
Y component: γ-glycidoxypropyltrimethoxysilane 10 parts
Z component-1: 100 parts of vinyl resin segment A solution (vinyl resin segment A solution having a hindered amine group and modified with silyl)
Z component-2: 100 parts of methyltrimethoxysilane
Solvent 1: 100 parts of i-butyl alcohol
Solvent 2: 75 parts of butyl cellosolve
Di-i-propoxyethyl acetoacetate aluminum 10 parts
The X component, Y component, and 1, 50 parts of the solvent were mixed, and the mixture was dispersed in media over a whole day and night. The remaining components described above were added to the media dispersion and stirred well, and then 30 parts of pure water was added dropwise with stirring and reacted at 60 ° C. for 4 hours. Next, after cooling to room temperature, 10 parts of i-propyl alcohol solution of dioctyltin dimaleate ester (solid content 15%) was added and stirred, and then filtered to remove the media to prepare an intermediate layer coating solution. . This coating solution is applied onto a cylindrical aluminum substrate with a circular amount-regulating coating device, heat-cured at 120 ° C. for 1 hour, and has the X component, Y component, and Z component of the present invention having a dry film thickness of 4 μm. An intermediate layer containing a compound formed from the composition (intermediate layer coating solution) was formed.
[0206]
Production of photoreceptor 6
In the production of the photoreceptor 1, the intermediate layer is replaced with the following intermediate layer, and is formed from the composition having the X component, the Y component, and the Z component of the present invention except that the dry film thickness is 20 μm. A photoreceptor 6 having an intermediate layer containing a compound was produced.
[0207]
<Intermediate layer (UCL)>
The following intermediate layer coating solution was prepared and applied onto a washed cylindrical aluminum substrate to form an intermediate layer.
[0208]
X component: Titanium oxide (number average primary particle size: 35 nm anatase type titanium oxide pigment) 100 parts
Y component: 20 parts of γ-glycidoxypropyltrimethoxysilane
Z component-1: vinyl resin segment B solution (hindered phenol group-containing silyl-modified vinyl resin segment B solution) 100 parts
Z component-2: 80 parts of methyltrimethoxysilane
Solvent 1: 100 parts of i-butyl alcohol
Solvent 2: 75 parts of butyl cellosolve
Di-i-propoxyethyl acetoacetate aluminum 10 parts
The X component, Y component, and 1, 50 parts of the solvent were mixed, and the mixture was dispersed in media over a whole day and night. The remaining components described above were added to the media dispersion and stirred well, and then 30 parts of pure water was added dropwise with stirring and reacted at 60 ° C. for 4 hours. Next, after cooling to room temperature, 10 parts of i-propyl alcohol solution of dioctyltin dimaleate ester (solid content 15%) was added and stirred, and then filtered to remove the media to prepare an intermediate layer coating solution. . This coating solution is applied onto a cylindrical aluminum substrate by a circular amount-regulating coating device, and heat-cured at 120 ° C. for 1 hour, and a composition having an X component, a Y component, and a Z component with a dry film thickness of 20 μm ( An intermediate layer containing a compound formed from (intermediate layer coating solution) was formed.
[0209]
Production of photoconductor 7
In preparation of the photoreceptor 1, the X component titanium oxide of the intermediate layer coating solution is changed from anatase type titanium oxide to rutile type titanium oxide (number average primary particle size: 35 nm), and the Z component vinyl resin segment A solution is vinyl. It is formed from the composition having the X component, the Y component, and the Z component of the present invention in the same manner as the photoreceptor 1 except that the resin-based resin segment C solution (silyl-modified vinyl-based resin segment C solution) is used. Photoreceptor 7 having an intermediate layer containing the compound was produced.
[0210]
Photoconductor 8
In the production of the photoreceptor 1, the X component, the Y component, and the Z component of the present invention were similarly performed except that the X component of the intermediate layer coating solution was changed from titanium oxide to zinc oxide (number average primary particle size: 100 nm). Photoreceptor 8 having an intermediate layer containing a compound formed from a composition having the above was produced.
[0211]
Photoconductor 9
In the production of the photoreceptor 1, the X component, the Y component, and the Z component of the present invention were similarly performed except that the X component of the intermediate layer coating solution was changed from titanium oxide to zirconium oxide (number average primary particle size: 350 nm). A photoreceptor 9 having an intermediate layer containing a compound formed from a composition having the above was prepared.
[0212]
Photoconductor 10
In the production of the photoreceptor 1, the X component of the intermediate layer coating solution is changed from titanium oxide to aluminum oxide Al.₂O₃A photoconductor 9 having an intermediate layer containing a compound formed from a composition having an X component, a Y component, and a Z component of the present invention except that the number average primary particle size is changed to 35 nm. Produced.
[0213]
Photoconductor 11
In the production of the photoreceptor 1, the Z component-1 of the intermediate layer coating solution was removed, and the Z component-2 was changed from 70 parts to 140 parts, and the Z component-3 was changed from 30 parts to 60 parts. Thus, a photoreceptor 9 having an intermediate layer containing a compound formed from a composition (intermediate layer coating solution) having an X component, a Y component, and a Z component of the present invention was produced.
[0214]
Photoconductor 12-15
In the production of the photoconductor 1, the type, amount, and film thickness of the polytetrafluoroethylene resin particles in the charge injection layer were changed as shown in Table 1, and the same as the photoconductor 1 except that the contact angle of the photoconductor was changed. Photoconductors 12 to 15 were produced.
[0215]
Photoconductor 16 (Comparative photoconductor)
A photoconductor 16 for comparison was produced in the same manner as the photoconductor 1 except that the intermediate layer was replaced with the following intermediate layer.
[0216]
Preparation of intermediate layer coating solution
X component: Titanium oxide (number average primary particle size: 35 nm anatase type titanium oxide pigment) 100 parts
Y component: 10 parts isopropyl triisostearoyl titanate
Z component: 150 parts of polyamide resin (methoxymethylated nylon 6 (degree of methoxymethylation is 25%))
Isopropyl alcohol 500 parts
Polyamide is heated and dissolved in isopropyl alcohol, and then titanium oxide is mixed. The mixture is dispersed in a batch system for 10 hours with a sand mill disperser in which the structure of the dispersed part is surface-treated with ceramic. Was made. The intermediate layer coating solution was applied onto a cylindrical aluminum substrate by a circular amount regulating type coating device to form an intermediate layer having a dry film thickness of 10 μm.
[0217]
Photoconductor 17 (Comparative photoconductor)
In the production of the photoreceptor 1, a comparative photoreceptor 17 was produced in the same manner as the photoreceptor 1 except that the X component of the intermediate layer coating solution: titanium oxide was removed.
[0218]
Photoconductor 18 (Comparative photoconductor)
In the production of the photoconductor 1, a comparative photoconductor 18 was produced in the same manner as the photoconductor 1 except that the charge injection layer was removed.
[0219]
Table 1 shows the difference between the intermediate layers and the charge injection layers of the photoreceptors 1 to 18 and the measurement results of the contact angle of the photoreceptor surface with water.
[0220]
[Chemical formula 5]

[0221]
[Table 1]

[0222]
[Table 2]

[0223]
G and H represent the following fluororesin fine particles.
G: Tetrafluoroethylene resin particles (Lublon L-2, manufactured by Daikin Industries, Ltd.)
H: Ethylene trifluoride resin particles (Daifuron, manufactured by Daikin Industries, Ltd.)
At the same time as the production of the photoconductors 1 to 18, the intermediate layer coating solution was applied onto an aluminum-deposited polyethylene terephthalate support using the intermediate layer coating solution of each photoconductor. An intermediate layer having a dry film thickness of 10 μm was formed under the same conditions to prepare a volume resistance measurement sample, and the volume resistance of each intermediate layer was measured. As a result, the volume resistances of the intermediate layers of the photoreceptors 1 to 18 are all 1 × 10.⁸That was all. At the same time, the solvent solubility of each intermediate layer in the coating solution solvent was verified. However, all the intermediate layers except the intermediate layer of the photoreceptor 16 were not dissolved in the coating solution solvent, and these intermediate layers had a three-dimensional structure. It was shown to have a crosslinked structure. On the other hand, the intermediate layer of the photoreceptor 16 showed solubility in the coating solution solvent, and the intermediate layer form gradually dissolved.
[0224]
Evaluation 1 (Evaluation using a charging roller)
The photoconductors 1 to 18 obtained as described above were respectively mounted on a remodeling machine of a reverse development type digital copying machine “Konica 7050” manufactured by Konica Co., Ltd. in which a charging roller having the following configuration was incorporated. 80% RH) and low-temperature and low-humidity (10 ° C., 20% RH) environments were evaluated with different evaluation items. The evaluation results are shown in Table 3.
[0225]
Charging roller
As the material for the conductive elastic layer, polynorbornene rubber / carbon black / naphthenic oil and, if necessary, vulcanizing agent, vulcanization accelerator, additive, etc. are mixed and prepared, filled in the mold, and conductive elastic A body layer was formed. On this layer, it is immersed in a composition liquid consisting of polyester urethane as a coating layer forming material, resin powder having a particle diameter of about 0.5 μm, carbon black, and a solvent (MEK / dimethylformamide), coating, drying and heating. Treatment to form a coating layer composed of a urethane layer. 1 was obtained. The resistance of the conductive elastic layer is 3.2 × 10⁴Ωcm, resistance of the coating layer is 5.2 × 10⁵The surface roughness of the charging roller was 10 point average roughness Rz of 0.1.
[0226]
Photoconductor linear velocity: 280 mm / sec
Exposure conditions
Exposure portion potential target: set to an exposure amount to be less than −50V.
[0227]
Exposure beam: Image exposure was performed with a dot density of 800 dpi (dpi is the number of dots per 2.54 cm). Laser beam spot area: 0.8 × 10^-9m²The laser uses a 780nm semiconductor laser
Transfer conditions: electrostatic transfer using corotron electrodes
Separation condition: Using separation means of separation electrode with AC bias applied
Cleaning: A rubber elastic blade was used to adjust the contact angle to the photosensitive member: 20 ° and the contact load: 20 (g / cm).
[0228]
Evaluation items and evaluation methods
Evaluation items and evaluation criteria
Evaluation of residual potential (change in potential of solid black image)
Under low-temperature and low-humidity (10 ° C., 20% RH) and high-temperature, high-humidity (HH: 30 ° C., 80% RH) environments, the character image, halftone image, solid white image, and solid black image with a pixel rate of 7% are each 1 / The original image in four equal parts was copied at 10,000 sheets in the single sheet intermittent mode at A4, and the potential change (| ΔV |) of the solid black image portion at the development position after the initial and 10,000 sheets was evaluated. . The smaller the | ΔV |, the smaller the increase in the residual potential.
[0229]
A: Potential change in solid black image portion | ΔV | is less than 50 V (good)
○: Potential change | ΔV | of solid black image portion is 50 V or more and 150 V or less (no problem in practical use)
×: The potential change | ΔV | of the solid black image portion is larger than 150 V (practically problematic)
Evaluation of charging potential (change in potential of solid white image)
Under low-temperature and low-humidity (10 ° C, 20% RH) and high-temperature, high-humidity (HH: 30 ° C, 80% RH) environments, a character image with a pixel rate of 7%, a halftone image, a solid white image, and a solid black image are each 1 / The original image in four equal parts was copied in 10,000 sheets in the single sheet intermittent mode at A4, and the potential change (| ΔV |) of the solid white image portion at the development position after the initial and 10,000 sheets was evaluated. . The smaller | ΔV | is, the smaller the change in charging potential is.
[0230]
A: Potential change | ΔV | of solid white image portion is less than 50 V (good)
○: Potential change of solid white image portion | ΔV | is 50 V or more and 150 V or less (no problem in practical use)
×: The potential change | ΔV | of the solid white image portion is larger than 150 V (practically problematic)
Image density: evaluated at low temperature and low humidity (LL: 10 ° C, 20% RH), high temperature and high humidity (HH: 30 ° C, 80% RH)
Measured using Macbeth RD-918. The relative reflection density was measured with the paper reflection density set to “0”. As the residual potential increases on multiple copies, the image density decreases. Measurements were taken at the solid black image portion after 10,000 copies each.
[0231]
A: Black solid image is higher than 1.2 for both low temperature and low humidity and high temperature and high humidity (good)
○: Black solid image of 1.0 to 1.2 in both low temperature and low humidity and high temperature and high humidity (no problem in practical use)
×: Black solid image is less than 1.0 in either low temperature and low humidity or high temperature and high humidity (practical problem)
Fog; evaluated at low temperature and low humidity (LL: 10 ° C, 20% RH), high temperature and high humidity (HH: 30 ° C, 80% RH)
The fog density was measured by reflection density of a solid white image using RD-918 manufactured by Macbeth. The reflection density was evaluated by a relative density (the density of A4 paper not copied is 0.000). Measurements were taken at the solid black image portion after 10,000 copies each.
[0232]
A: Concentration is less than 0.010 (good) for both low temperature and low humidity and high temperature and high humidity
○: Concentration of 0.010 or more and 0.020 or less for both low temperature and low humidity and high temperature and high humidity (a level that causes no practical problems)
X: Concentration is higher than 0.020 at either low temperature and low humidity or high temperature and high humidity
Dielectric breakdown; evaluated at low temperature and low humidity (LL: 10 ° C, 20% RH), high temperature and high humidity (30 ° C, 80% RH)
◯: No dielectric breakdown of the photoreceptor due to charge leakage in LL or HH.
[0233]
X: Dielectric breakdown of the photoreceptor due to charge leakage occurred at LL or HH.
Periodic image defects (high temperature and high humidity (30 ° C, 80% RH))
The periodicity coincided with the period of the photoconductor, and the number of visible black spots and black streak-like image defects per A4 size was determined.
[0234]
A: Frequency of image defects of 0.4 mm or more: All copy images are 5 / A4 or less (good)
○: Frequency of image defects of 0.4 mm or more: 1 or more of 6 / A4 or more and 10 / A4 or less (no problem in practical use)
X: Frequency of image defects of 0.4 mm or more: 11 or more A4 or more occurred (practical problem)
Sharpness
The sharpness of the image was evaluated by squeezing the characters in both low temperature and low humidity (10 ° C., 20% RH) and high temperature, high humidity (30 ° C., 80% RH) environments. 3-point and 5-point character images were formed and evaluated according to the following criteria.
[0235]
◎: There is no image blur, and 3 and 5 points are clear and easy to read.
○: Image blurring is minor, 3 points are partially unreadable, 5 points are clear, and easy to read
×: Image blur occurs, 3 points are almost unreadable, 5 points are partially or completely unreadable
[0236]
[Table 3]

[0237]
According to Table 3, the intermediate layer containing the compound formed from the composition having the X component, the Y component, and the Z component of the present invention, and the photoreceptors 1 to 15 having the photosensitive layer and the charge injection layer on the intermediate layer have a high temperature. It is excellent in stability of residual potential and charging potential at high humidity, low temperature and low humidity, and from this, the image density is sufficient and the fog density is small. In addition, dielectric breakdown does not occur, and the improvement effect of black spots etc. is remarkable, and as a result, an electrophotographic image with good sharpness is obtained. In particular, anatase-type titanium oxide is used for the X component, a vinyl resin segment (Z component-1) and a reactive organosilicon compound (Z component-2, Z component-3) are used for the Z component, and the charge injection layer The photoreceptors 1 to 6, 12, and 13 having a contact angle of 95 ° or more have a remarkable improvement effect of each evaluation item as compared with the other photoreceptors 7 to 11, 14, and 15. On the other hand, the photoreceptor 16 outside the present invention that uses polyamide resin as the binder resin of the intermediate layer and does not use the Z component has a large residual potential increase, image density decreases, dielectric breakdown also occurs, and sharpness also decreases. Yes. Further, the non-inventive photoconductor 17 which does not use the X component in the intermediate layer has a large residual potential, large fluctuations in the charged potential, image density lowering, fogging, dielectric breakdown and moire. The nature has also declined. Further, the photosensitive member 18 having no charge injection layer has a large variation in charging potential, fogging occurs, and as a result, sharpness is also lowered. Moreover, dielectric breakdown and black spots have also occurred.
[0238]
Evaluation 2 (Evaluation using a magnetic brush)
<Evaluation conditions>
The photoconductors 1 to 15 were evaluated in the same manner as in Evaluation 1 except that the charging roller used in Evaluation 1 was changed to a magnetic brush charger and the linear velocity of the photoconductor was modified to 140 mm / sec.
[0239]
(Magnetic brush charger)
It has the structure of FIG.
[0240]
Production of magnetic particles
Magnetic particles forming a charging magnetic brush were prepared as follows.
[0241]
Fe₂O₃: 50 mol%
CuO: 24 mol%
ZnO: 24 mol%
The above was pulverized and mixed to form a slurry by adding a dispersant, a binder and water, followed by granulation with a spray dryer, classification, and firing at 1125 ° C. The obtained magnetic particles were crushed and then classified to obtain magnetic particles 1 having a volume average particle size of 27 μm. Magnetic particle resistivity is 2 × 10⁷The Ωcm and the strength of magnetization were 65 emu / g.
[0242]
Method for measuring volume average particle diameter of magnetic particles
The volume average particle diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.
[0243]
Measuring method of resistivity (Ωcm)
Magnetic particles 0.50cm²1 kg / cm on the packed particles after tapping in a container having a cross-sectional area of²A value obtained by reading the current value when a voltage generating an electric field of 1000 V / cm is applied between the load and the bottom electrode.
[0244]
Charging conditions
Charging sleeve; 10mmφ stainless steel
Voltage applied to charging sleeve; AC voltage superimposed on DC voltage 450V
Amount of magnetic particles in the charged region: 250 mg / cm²
Charge sleeve / photoconductor linear velocity ratio; 0.8
<Evaluation>
Also in the contact charging type image forming method using a magnetic brush, the photoreceptors 1 to 15 of the present invention have almost the same effect as the contact charging by the charging roller.
[0245]
【The invention's effect】
By using the electrophotographic photosensitive member, the process cartridge and the image forming apparatus of the present invention, it is possible to prevent the increase in the residual potential and the fluctuation of the charged potential at low temperature and low humidity and high temperature and high humidity, which are likely to occur in the contact charging method, and the dielectric breakdown. And image defects can be prevented, and an electrophotographic image with good image density, fogging, moire and sharpness can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an example of an image forming apparatus using charging roller charging.
FIG. 2 is a diagram of a contact-type magnetic brush charging device.
FIG. 3 is a diagram illustrating a relationship between an AC bias voltage and a charging potential by the charging device of FIG. 2;
FIG. 4 is a cross-sectional view showing an example of an image forming apparatus having a magnetic brush charger.
[Explanation of symbols]
1 Charging roller
2 Photosensitive drum
3 Development device
4 Development sleeve
5 Static elimination lamp
6 Transfer roller
7 Conveyor belt
8 Transport roller
20 cored bar
50 Photosensitive drum
51 Exposure section
52 Magnetic brush charger
53 Image exposure unit
54 Developer
120 Magnetic brush charging device
120a Charging sleeve
220 supply bottle
300 Magnetic particle collection container

Claims (17)

In an electrophotographic photosensitive member used in an image forming apparatus having a charging means for charging by bringing a charging member into contact with the electrophotographic photosensitive member, the electrophotographic photosensitive member has at least an intermediate layer, a photosensitive layer and a conductive layer on a conductive support. An electrophotographic photoreceptor comprising a charge injection layer, wherein the intermediate layer contains a compound formed from a composition having the following X component, Y component, and Z component.
X component: inorganic oxide network forming compound Y component: metal atom-containing organic network forming compound Z component: binder network forming compound In an electrophotographic photosensitive member used in an image forming apparatus having a charging means for charging by bringing a charging member into contact with the electrophotographic photosensitive member, the electrophotographic photosensitive member has at least an intermediate layer, a charge generation layer, and a conductive support. An electrophotographic photoreceptor comprising a charge transport layer and a charge injection layer, wherein the intermediate layer contains a compound formed from a composition having the X component, the Y component and the Z component. The electrophotographic photosensitive member according to claim 1, wherein the X component is an inorganic oxide particle having a reactive group on the surface. The electrophotographic photosensitive member according to claim 3, wherein the inorganic oxide particles are any one of TiO ₂ , ZrO ₂ , ZnO, and Al ₂ O ₃ . The electrophotographic photosensitive member according to claim 4, wherein the TiO ₂ particles are anatase-type titanium oxide. 6. The electrophotographic photosensitive member according to claim 3, wherein the number average primary particles of the inorganic oxide particles are 5 to 400 nm. The electrophotographic photosensitive member according to claim 1, wherein the Y component is a coupling agent. The electrophotographic photosensitive member according to claim 7, wherein the coupling agent is a titanium coupling agent or a silane coupling agent. The electrophotographic photosensitive member according to claim 1, wherein the Z component is a reactive organosilicon compound. The electrophotographic photosensitive member according to claim 1, wherein the Z component is a reactive segment. The electrophotographic photosensitive member according to claim 10, wherein the reactive segment is a vinyl resin having a low polymerization degree. The electrophotographic photoreceptor according to any one of claims 1 to 11, wherein the Z component is a combination of a reactive organosilicon compound and a reactive segment. The electrophotographic photosensitive member according to claim 1, wherein the intermediate layer has a thickness of 4 to 20 μm. The electrophotographic photosensitive member according to claim 1, wherein the charge injection layer contains conductive particles. In a process cartridge used in an image forming apparatus having a charging means for charging by bringing a charging member into contact with an electrophotographic photosensitive member, the electrophotographic photosensitive member has at least an intermediate layer, a photosensitive layer, and a charge injection layer on the conductive support. An electrophotographic photosensitive member containing a compound formed of a composition having the X component, the Y component, and the Z component, and a charging means for uniformly charging the electrophotographic photosensitive member, on the electrophotographic photosensitive member An image forming apparatus is integrally supported by at least one of a developing unit that visualizes an electrostatic latent image of the toner and a transfer unit that transfers a toner image visualized on the electrophotographic photosensitive member onto a transfer material. A process cartridge which is detachably attached to a main body. In an image forming apparatus having a charging means for charging by bringing a charging member into contact with an electrophotographic photosensitive member, the electrophotographic photosensitive member has at least an intermediate layer, a photosensitive layer and a charge injection layer on a conductive support, An image forming apparatus, wherein the intermediate layer contains a compound formed from a composition having the X component, the Y component, and the Z component. 17. An image forming method comprising a charging means for charging by bringing a charging member into contact with an electrophotographic photosensitive member, wherein an electrophotographic image is formed using the image forming apparatus of claim 16.

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