JP4139196B2 - Intermediate transfer member and image forming apparatus - Google Patents

Description

（式中、Ｒは芳香族テトラカルボン酸残基、Ａｒは芳香族ジイソシアネート残基、Ｓiloxaneはジアミノシロキサン残基を表す）
一般的にポリアミドイミドは高強度で剛直な樹脂として知られるが、主鎖にシロキサン構造が導入されることで柔軟性が付与され、更に離型性も向上するという利点も生まれる。従って、上記材料を少なくとも表面に含むことで中間転写体の耐摩耗性、トナー離型性を満足することが可能になる。
【００２４】
このようなシリコーン変性ポリアミドイミドは、公知の製造方法により製造することが出来る。一般的にポリアミドイミドを製造する方法としては、イソシアネート法（特公昭４４−１９２７４、特公昭４５−２３９７等）、酸クロライド法（特公昭４２−１５６３７等）、直接重縮合法（特公昭４９−１０７７等）、溶液重縮合法（特公昭４０−８９１０等）等があるが何れの方法も用いることが出来る。
【００２５】
例えばイソシアネートを用いる方法としては、シロキサンジアミン、芳香族トリカルボン酸及びその誘導体、ジイソシアネートを原料として合成する方法がある。（特開２０００−１２２９６４等）
ここでシロキサンジアミン化合物としては、
【００２６】
【化２】

（Ｒ_１，Ｒ_６は２価の有機基、Ｒ_２〜Ｒ_５はアルキル基、フェニル基、又は置換フェニル基を示し、nは５〜５０の整数を示す)
が一般式として示され、具体的には、１，３−ビス（３−アミノプロピル）−１，１，３，３−テトラメチルジシロキサン、ビス（３−アミノプロピル）テトラメチルジシロキサン、ビス（１０−アミノデカメチレン）テトラメチルジシロキサン、アミノプロピル末端基を有するジメチルシロキサン４量体、８量体、ビス（３−アミノフェノキシメチル）テトラメチルジシロキサン等が挙げられる。
【００２７】
本発明の中間転写体に用いるシリコーン変性ポリアミドイミドの製造にはシロキサンジアミンの他に芳香族ジアミンを混合して用いることが出来る。例えば、（１）ビフェニル系ジアミン化合物、ジフェニルエーテル系ジアミン化合物、ベンゾフェノン系ジアミン化合物、ジフェニルスルホン系ジアミン化合物、ジフェニルメタン系ジアミン化合物、２，２−ビス（フェニル）プロパンなどのジフェニルアルカン系ジアミン化合物、２，２−ビス（フェニル）ヘキサフルオロプロパン系ジアミン系化合物、ジフェニレンスルホン系ジアミン化合物、（２）ジ（フェノキシ）ベンゼン系ジアミン化合物、ジ（フェニル）ベンゼン系ジアミン化合物、（３）ジ（フェノキシフェニル）ヘキサフルオロプロパン系ジアミン系化合物、ビス（フェノキシフェニル）プロパン系ジアミン系化合物物などの「芳香族環（ベンゼン環など）を２個以上、特に２〜５個有する芳香族ジアミン化合物」を主として含有する芳香族ジアミンを挙げることができ、それらを単独、あるいは、混合物として使用することができる。
【００２８】
前記芳香族ジアミンとしては、特に１，４−ジアミノジフェニルエーテル、１，３−ジアミノジフェニルエーテルなどのジフェニルエーテル系ジアミン化合物、１，３−ジ（４−アミノフェノキシ）ベンゼン、１，４−ビス（４−アミノフェノキシ）ベンゼンなどのジ（フェノキシ）ベンゼン系ジアミン化合物、２，２−ビス［４−（４−アミノフェノキシ）フェニル］プロパン、２，２−ビス［４−（３−アミノフェノキシ）フェニル］プロパン等のビス（フェノキシフェニル）プロパン系ジアミン系化合物を挙げることが出来る。
【００２９】
本発明の中間転写体に用いるシリコーン変性ポリアミドイミドの製造に用いる芳香族トリカルボン酸及びその誘導体を具体的に挙げると、トリメリット酸無水物、トリメリット酸無水物モノクロライド、１，４−ジカルボキシ−３−Ｎ，Ｎ−ジメチルカルバモイルベンゼン、１，４−ジカルボメトキシ−３−カルボキシベンゼン、１，４−ジカルボキシ−３−カルボフェノキシベンゼン、２，６−ジカルボキシ−３−カルボメトキシピリジン、１，６−ジカルボキシ−５−カルバモイルナフタリン、上記芳香族トリカルボン酸類とアンモニア、ジメチルアミン、トリエチルアミンなどからなるアンモニウム塩類などが挙げられる。これらのうちではトリメリット酸無水物、トリメリット酸無水物モノクロライドが好ましい。
【００３０】
本発明で用いる芳香族ジイソシアネートとして具体的には、４，４’−ジフェニルメタンジイソシアネート（以下ＭＤＩと略す）、２，４−トリレンジイソシアネート、２，６−トリレンジイソシアネート、ナフタレン−１，５−ジイソシアネート、ｏ−,ｍ−キシリレンジイソシアネート、２，４−トリレンダイマー等が例示できる。また、ヘキサメチレンジイソシアネート、４，４’−メチレンビス（シクロヘキシルイソシアネート）、イシホロンジイソシアネートなどのイソシアネートを単独でまたは組み合わせて用いることができる。
【００３１】
本発明の中間転写体に用いるシリコーン変性ポリアミドイミドの製造で使用する溶媒としては、生成した樹脂の溶解性に優れる非プロトン性極性溶媒が好ましい。このような非プロトン性極性溶媒として、ジメチルアセトアミド、ジメチルホルムアミド、ジメチルスルホキシド、Ｎ−メチル−２−ピロリドン、４−ブチロラクトン、スルホラン、シクロヘキサン等が例示できる。イミド化反応には、高温を有するため沸点の高い、Ｎ−メチル−２−ピロリドンが特に好ましい。
【００３２】
本発明の中間転写体は、少なくとも表面にシリコーン変性ポリアミドイミドを含有する事を特徴とするが、抵抗制御剤を添加することにより、前記シリコーン変性ポリアミドイミドを含む層の体積抵抗が１０^８Ω・ｃｍ以上１０^１２Ω・ｃｍ以下の範囲に制御することで、トナー転写率を改良することが出来る。転写率が悪いと感光体や中間転写体のクリーニングへの負担が増大したり、トナーのロスが多くなったりといった不具合がある。中間転写装置に要望されるトナー転写率は８０％以上で好ましくは９０％以上である。
【００３３】
本発明の中間転写体に用いる抵抗制御剤は通常の一般的なものが使用できる。具体的に挙げればケッチェンブラック、アセチレンブラック等のカーボンブラックやＮｉパウダー等の金属微粉末、酸化錫、酸化チタン、酸化亜鉛等の金属酸化物や異原子（例えばアンチモンなど）ドープ金属酸化物などの材料や第４級アンモニウム塩基、カルボン酸基、スルホン酸基、硫酸エステル基、リン酸エステル基などを含有する有機化合物もしくは重合体、エーテルエステルアミドもしくはエーテルアミドイミド重合体、エチレンオキサイド−エピハロヒドリン共重合体、メトキシポリエチレングリコールアクリレートなどで代表される導電性ユニットを有する化合物または高分子化合物などの有機帯電防止剤などの有機帯電防止剤等を用いることが出来る。
【００３４】
しかし、１０^８Ω・ｃｍ以上１０^１２Ω・ｃｍ以下の範囲で安定に体積抵抗を制御するためには酸化錫が好ましく、導電性に優れることからアンチモンなどの異原子をドープしたものが最も好ましい。これは例えば、球状粒子（Ｔ−１；三菱マテリアル社）や鱗片状粒子（ＥＬＣＯＭ−ＴＬ−２０；触媒化学工業社）のものなどがあり、何れのものも使用することが出来る。
【００３５】
更に発明者は上記酸化錫粒子をシランカップリング剤で表面処理することにより、転写時の画像チリを改善できることを見いだした。本発明の酸化錫の表面処理に使用できるシランカップリング剤としては、従来からある市販のものが使用できる。例えばＳＨ６０２０（γ−（２−アミノエチル）アミノプロピルトリメトキシシラン）、ＳＺ６０２３（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）、ＳＨ６０２６（アミノシラン）、ＳＺ６０３２（Ｎ−β−（Ｎ−ビニルベンジルアミノエチル）−γ−アミノプロピルトリメトキシシラン・塩酸塩）、ＳＺ６０５０（アミノシラン）、ＳＺ６０８３（γ−アニリノプロピルトリメトキシシラン）、ＡＹ４３−０２１（オクタデシルジメチル［３−（トリメトキシシリル）プロピル］アンモニウムクロライド）、ＡＹ４３−０３１（γ−ウレイドプロピルトリエトキシシラン）、ＳＺ６０３０（γ−メタクリロキシプロピルトリメトキシシラン）、ＳＨ６０４０（γ−グリシドキシプロピルトリメトキシシラン）等（いずれも東レ・ダウコーニング・シリコーン（株）製）を挙げることができる。
【００３６】
シランカップリング剤による酸化錫の表面処理は、例えば次のようにして行うことができる。酸化錫１００重量部に対してシランカップリング剤１重量部を添加し高速ミキサーにて５〜１０分間撹拌し、酸化錫の表面にシランカップリング剤を付着させる。次に高速ミキサーから取り出し１００〜１５０℃で１時間乾燥させる。
この表面処理品は本発明の中間転写体を製造時（後述する）、未処理品と全く同様に取り扱うことが可能である。
【００３７】
本発明の中間転写体は少なくとも表面がシリコーン変性ポリアミドイミドを含む材料から構成されることを特徴とするが、導電性のゴム層上にシリコーン変性ポリアミドイミドを含む層が設置されることは好ましい。これにより中間転写体に柔軟性が付与され、特にＯＨＰなどの硬質な転写材などにも安定な当接が確保されることで、トナーの中抜け現象等の発生が防止できる。
【００３８】
ゴム層に使用する材料は一般的なものを使用することが出来る。具体的に挙げるなら、ポリウレタン、ブチルゴム、ニトリルブタジエンゴム、エピクロルヒドリンゴム、ポリイソプレンゴム、ポリブタジエンゴム、シリコーンゴム、フッ素ゴム、スチレン−ブタジエンゴム、エチレン−プロピレンゴム、エチレン−プロピレン−ジエンゴム、クロロプレンゴム、アクリルゴム、及びこれらの混合物等を使用することが出来る。これらのゴム材料は一部を除き通常絶縁性であるが、トナー転写率を改善出来ることから、抵抗制御剤を添加して導電性にして使用することも可能である。その場合、ゴム層の体積抵抗は１０^１２Ω・ｃｍ以下が好ましく、更に１０^８Ω・ｃｍ以上１０^１２Ω・ｃｍ以下が最も好ましい。ゴム層の実効硬度はＪＩＳ Ａ９５度以下が良い。実効硬度とは中間転写体の硬度を直接硬度計で測定した値と定義され、実効硬度がＪＩＳ Ａ９５度を越えると十分な柔軟性が発現せずトナーの中抜け現象等が発生する。材料自体の抵抗が低く、抵抗制御剤を用いずに安定して導電性を確保できるという理由から、特に好ましくはニトリルブタジエンゴム、エピクロルヒドリンゴムである。これらのどちらか一方を用いても良いし、両者を混合して用いても構わない。
【００３９】
本発明の少なくともシリコーン変性ポリアミドイミドを含む層には抵抗制御剤の他に必要に応じて各種の有機・無機材料と混合し用いることが出来る。混合することの出来る他の有機樹脂材料としては、アルキド樹脂、塩素化ポリエーテル、塩素化ポリエチレン、エポキシ樹脂、フッ素樹脂、フェノール樹脂、ポリアミド、ポリカーボネート、ポリエチレン、メタクリル樹脂、ポリプロピレン、ポリスチレン系樹脂、ポリウレタン、ポリ塩化ビニル、ポリ塩化ビニリデン、シリコーン樹脂等が挙げられる。これらは溶剤に溶解して用いたり、どちらか一方を樹脂微粒子の状態で混合したりすることも可能である。
【００４０】
次に本発明の中間転写体の形態について説明する。これまで説明上中間転写ドラムを用いてきたが、本発明はこれに制約されるものではなく、どのような形態も使用することが可能だが、ドラム形状以外に好適に用いられる形態としてはベルト形状が挙げられる。
【００４１】
図２に中間転写ベルトを画像形成装置に装着した代表的な例を挙げた。
像担持体としての感光体ドラム１１は、図示しないモータ等の駆動手段によって、複写時には矢印方向に回転駆動される。この感光体ドラム１１の周囲には、回転方向に沿ってクリーニング前除電器１２、クリーニング装置１３、除電ランプ１４、帯電器１５、露光装置１６、電位センサ１７、黒現像ユニット（Ｋ）、シアン現像ユニット（Ｃ）、マゼンタ現像ユニット（Ｍ）、イエロー現像ユニット（Ｙ）からなる現像部１８、現像濃度パターン検出用の光学センサ１９、中間転写体としての中間転写ベルト２０などが配置されている。
【００４２】
中間転写ベルト２０は、バックアップローラ２１、バイアスローラ２２ａ、アースローラ２２ｂ及び駆動ローラ２３に張架されており、図示しないモータ等の駆動手段により矢印方向に無端状に走行するように構成されている。バイアスローラ２２ａとアースローラ２２ｂとの間には、一次転写時に転写バイアス電圧が印加され、一次転写領域の転写ニップ部に転写電界を発生させている。また、バイアスローラ２２ａには、感光体ドラム１１との離接機構（図示せず）が設けられており、一次転写時には感光体ドラム１１と接触するが、二次転写時には感光体ドラム１１から離間する。なお、図２は二次転写時の状態を示したもので、感光体ドラム１１とバイアスローラ２２ａは所定距離だけ離間している。一方、中間転写ベルト２０の下端には、図示しない離接機構を備えた転写ローラ２４がバックアップローラ２１と対向配置されている。この転写ローラ２４は、通常は中間転写ベルト２０と離間しているが、二次転写時には、ベルト２０面に形成された４色の重ね画像を転写材としての転写紙２５に一括転写するタイミングで離接機構により中間転写ベルト２０側へ押圧される。なお、転写ローラ２４には、二次転写領域の転写ニップ部に転写電界を発生するための転写バイアス電圧が印加されており、この転写電界の作用によってトナー像は転写紙２５へ転写される。ベルトクリーニングユニット２６は、ブラシローラ２６ａ、ゴムブレード２６ｂ及び中間転写ベルト２０との離接機構（図示せず）等により構成されており、１色目の画像をベルト転写した後の２、３、４色目をベルト転写している間は、中間転写ベルト２０面から離間している。
【００４３】
以上のような構成において、複写動作が開始されると、露光装置１６により感光体ドラム１１上に画像データによる光像の書き込みが行われ、感光体ドラム１１の外周表面に潜像が形成される。この潜像は、現像部１８の特定色の現像ユニットにより現像されてトナー像となり、感光体ドラム１１と等速移動している中間転写ベルト２０との当接部（一次転写領域）にて中間転写ベルト２０の表面に転写される（一次転写）。フルカラーの場合は、この行程を３色あるいは４色分繰り返し、中間転写ベルト２０にフルカラー画像を形成する。中間転写ベルト２０に転写されたトナー像は、中間転写ベルト２０と転写紙２５との当接部（二次転写領域）にて転写紙２５上に一括転写される（二次転写）。この後、転写紙２５は図示しない定着行程を経てフルカラー画像として出力される。なお、転写紙２５は、図示しない給紙ローラ、レジストローラにより、中間転写ベルト２０上のフルカラー画像の先端部が二次転写領域の紙転写位置に到達するタイミングに合わせて給紙される。
【００４４】
中間転写ベルト形状ではレイアウトの自由度が大きく、装置の小型化が図れるという長所がある。ベルト形状の場合、本発明の少なくともシリコーン変性ポリアミドイミドを含む層単独で用いても構わないし、ゴムや樹脂で構成されるベルト基材の表面に本発明の少なくともシリコーン変性ポリアミドイミドを含む層を設置しても構わない。
【００４５】
本発明の中間転写体の製造方法について説明する。
（１）シリコーン変性ポリアミドイミドを溶剤に溶解して塗工成型する方法
シリコーン変性ポリアミドイミドを溶剤に溶解後中間転写体を作成する場合は、常法に従って行うことができ、例えば、前述した各成分を溶媒に溶解または分散させた液状組成物を、適当なキャリアー（支持体）上に流延し、次いで、溶剤を乾燥除去することで行うことができる。キャリアーとしては、格別制限はなく、一般的な溶液流延法で用いられるものが使用され、例えば、ＳＵＳ、Ａｌ等の金属製、導電性樹脂製、ゴム製のローラやベルトなどを挙げることができる。溶剤としては、例えば、Ｎ−メチル−２−ピロリドン、Ｎ，Ｎ−ジメチルアセトアミド、Ｎ，Ｎ−ジメチルホルムアミド、ジメチルスルホキシド、スルホラン、ヘキサメチルリン酸トリアミド、１，３−ジメチル−２−イミダゾリドン、ヘキサン、ベンゼン、トルエン、キシレン、メチルエチルケトン、アセトン、ジエチルエーテル、テトラヒドロフラン、ジオキサン、１,２−ジメトキシメタン、ジエチレングリコールジメチルエーテル、メチルセロソルブ、セロソルブアセテート、メタノール、エタノール、プロパノール、イソプロパノール、酢酸メチル、酢酸エチル、アセトニトリル、塩化メチレン、クロロホルム、四塩化炭素、クロロベンゼン、ジクロロベンゼン、ジクロロエタン、トリクロロエタン等が挙げられ、これらの中から、各成分が溶解・分散するように種類と量を適宜選択して使用する。溶剤中のシリコーン変性ポリアミドイミドの濃度は、製造する膜厚に応じて適宜選択されるが、通常０．１〜６０重量％、好ましくは１〜５０重量％、より好ましくは５〜４５重量％の範囲である。環状オレフィン系ポリマーの濃度がこの範囲にあるときに、膜厚調整が容易でかつ製膜性にも優れ好適である。
【００４６】
液状組成物をキャリアー上に流延する方法としては、格別制限されないが、例えば、ドクターナイフ、メイア・バー、ロール・コートなどを用いて行うことができる。液状組成物の流延は、スプレー、ハケ、ロール、スピンコート、ディッピングなどで塗布することにより行える。１回の塗布で所望の膜厚が得られない場合は、繰り返し塗布することができる。
【００４７】
（２）ベルトの成型方法
本発明のシリコーン変性ポリアミドイミドを用いてベルト基体を作製する代表的な方法として遠心成型法がある。これは、溶剤に溶解した樹脂溶液を回転する円筒形状の成形型内部にスプレーやノズルからベルト素材としての原料溶液（以下塗布液ということがある。）を流し込んで、この成形型を高速回転させながらその遠心力により塗布液を拡げて均一な膜としてこの膜を固化させることにより無端状成形体を成形する方法（いわゆる遠心成形法）により無端ベルトを製造する方法で、この方法に従えば、塗布された塗布液は遠心力により拡げられるので、比較的均一な厚みの塗布層が得られやすい。
【００４８】
この遠心成形によるベルト作製は、筒状の成形型の内面に流動性の塗布液を塗布した後、膜厚を均一にするために高速の遠心力で回転して塗布液の凝集の表面エネルギーに打ち勝つ力で塗布膜を押し広げて膜の均一化を行うものである。そして、その塗布液には原料ワニスを溶剤で希釈したものが成形型に塗布される。そのため、この塗布液は、高速回転しているときは、型の内面に均一に塗布されているが、回転を止めたり、回転数を緩くするとだんだん成形型の底部に溜まってくる。したがって、この遠心成形法によれば、一定の均一な溶液膜になった状態を保ちつつ、溶剤を除去して固化させなければならない。
次に実施例について説明する。
【００４９】
実施例１及び比較例１〜４
アルミニウムシート（１ｍｍ厚）に表１に示したシリコーン変性ポリアミドイミド及びフッ素樹脂、ポリイミド樹脂、シリコーン樹脂を塗布して所定の温度、時間加熱した後、サンプルシートとした。
【００５０】
下記の方法により、摩耗試験及びトナー離型試験を行った。
（１）耐摩耗性…テーバー摩耗試験（摩耗輪ＣＳ５、１ｋｇ荷重で３０００回転後試験前後の重量差）
摩耗の許容重量は３ｍｇ以下である。
【００５１】
（２）離型性…対トナーランク試験
図３は、対トナーランク試験の概要を示した図である。試験はトナー３１、トナー転写Ａｌマイラー３２、樹脂塗布マイラー３３、Ｓｉゴム４４及びＳＵＳ３５等を有する実験室用簡易プレス成型機を使用して行った。
図３に示す如く試料板３２，３３をトナー３１（リコーシアントナー タイプ４１００）と接触し、実験室用簡易プレス成型機を用い１０ｋｇ／ｃｍ^２，５０℃，１ｈｒの条件で加熱、加圧した。試験後、３ｋｇ／ｃｍ^２のエアーでトナー３１をブローオフし、トナー残留状態を下記のように目視ランク評価した。
【００５２】
離型性ランク
ランク８ 極めて容易にトナーが除去される
７ 若干時間を要するが完全にトナーが除去される
６ 僅かに（数％以下）トナーが残留する
５ 数％〜１／３程度のトナーが残留する
４ １／３〜２／３程度のトナーが残留する
３ ２／３以上トナーが残留する
２ 全面にトナーが残留する（トナー粒子として存在）
１ 全面にトナーが残留する(トナー粒子として存在せず、粒子同士融着)
離型の許容はランク７以上である。
上記の試験結果を表１に示す。
【００５３】
【表１】

【００５４】
実施例２及び比較例５，６
温度計，撹拌機，冷却管を取り付けたセパラブルの３つ口フラスコに、４，４’−ジフエニルメタンジイソシアネート（ＭＤＩ）７７．６４ｇと、１，３−ビス（３−アミノプロピル）−１，１，３，３−テトラメチルジシロキサン２．６１ｇと、Ｎ−メチル−２−ピロリドン２１５．６１ｇを配合し、撹拌溶解させながら４０℃で２時間かけて充分反応させた。ついで、これに無水トリメリツト酸（ＴＭＡ）を５７．６ｇ添加し、３０分間で１４０℃まで温度を上げてこの状態で６時間反応を続けた。その後、このＮ−メチル−２−ピロリドンを加えて温度を５０℃まで下げ反応を終了し、シリコーン変性ポリアミドイミドのＮ−メチル−２−ピロリドン溶液（固形分濃度１２重量％）を得た。
【００５５】
この樹脂１００重量部を溶剤（Ｎ−メチル−２−ピロリドン溶液）で希釈、アルミニウム素管（８０φ）にスプレー塗工し、１５０℃／３０分、２５０℃／３０分、３５０℃／５分加熱乾燥した後、シリコーン変性ポリアミドイミド表面層を有する中間転写体とした。（１０μm膜厚）（実施例２）
同様の方法で比較例１及び２で用いた樹脂を用いて中間転写体を作製した。（それぞれ比較例５，６）
これらの転写体を図１に示した装置に装着して１０万枚の通紙試験を行った後、表面トナーをテープで転写し、リコー製ＰＰＣペーパータイプ６０００に貼り付けその画像濃度を測定した。又、テープを直接ペーパーに貼り付け同様に画像濃度を測定し、その差をトナーフィルミングΔＩＤとした。又、試験前後の径差より表面層の摩耗量も測定した。尚、通紙試験に用いた図１の装置には下記の部材を使用した。
【００５６】
感光体；ベルトＯＰＣ感光体
トナー；リコーシアントナー タイプ４１００
転写材；リコー製ＰＰＣペーパータイプ６０００
二次転写ローラ；導電性ウレタンスポンジローラ（１０^９Ω）
上記の結果を表２に示す。
【００５７】
【表２】

【００５８】
実施例３，４
実施例１のシリコーン変性ポリアミドイミド１００重量部にカーボンブラック（Printex９０；デグサ社）をそれぞれ０，１５，２２，３０，４５重量部添加し、７２時間ボールミル分散した。これを実施例２と同様にスプレー塗工し、実施例２と同様に中間転写体を得た（実施例３）。表面層の膜厚は１０μｍである。
【００５９】
実施例３で使用したカーボンブラックの代わりに導電性酸化錫（Ｔ１；三菱マテリアル社製）４０，６０，８０，１００重量部添加して、実施例３と同様の方法で中間転写体を得た。（実施例４）。
これらの中間転写体の体積抵抗をＤＣ１００Ｖで１分後の抵抗値から次式を用いて算出した。
【００６０】
体積抵抗Ｒ（Ω・cm）＝（抵抗測定値Ｒ)×ｌｎ｛(２πＬ)／(ａ／ｂ)｝
Ｌ；主電極巾（ｃｍ）、ａ；中間転写体径、ｂ；素管径
体積抵抗は長さ方向に７ヶ所測定しその平均値を算出した。又、それら７カ所の測定値の最大値と最小値の対数値の差（バラツキ）を求めた。ｌｏｇ（Ｍａｘ）−ｌｏｇ（Ｍｉｎ）の許容は１．２以下で好ましくは０．８以下である。
【００６１】
次にこの中間転写体を図１に実施例２と同様の装置に装着した。転写率の測定は、ベタ画像の一次転写前のＯＰＣ上トナー付着量（ｍｇ／ｃｍ^２）及び二次転写後未定着トナー（ｍｇ／ｃｍ^２）を吸引法で測定し、次式で算出した。
転写率（％）＝（二次転写後未定着トナー／一次転写前のＯＰＣ上トナー付着量）×１００
【００６２】
上記の結果を表３に示す。
【表３】

【００６３】
実施例５
実施例４で使用した導電性酸化錫１００重量部に対してシランカップリング剤（表中に記載）１重量部を添加し高速ミキサーにて５分間撹拌し、酸化錫の表面にシランカップリング剤を付着させる。次に高速ミキサーから取り出し１５０℃で１時間乾燥させた。
シリコーン変性ポリアミドイミド（HR14ET；東洋紡績）１００重量部に対してこの表面処理酸化錫４０，６０，８０，１００重量部を添加して、実施例４と同様の方法で中間転写体を作製し、体積抵抗を測定した。
【００６４】
転写チリ評価方法
この中間転写ドラムを図１に示した画像形成装置に装着して、テスト画像を出力したときの１ドット黒ラインを２００倍レンズを搭載したマイクロスコープＶＨ５９１０（キーエンス社製）にて観察し、その視野中における１ラインのチリトナーの個数をカウントした。その個数により、下記のようなランク分けを行なった。
体積抵抗と転写チリの結果を実施例４と併せて表４に示す。
【００６５】
【表４】

◎；チリトナーなし、○；チリトナー１０個未満、△；チリトナー１０〜１００個、×；チリトナー１００個以上
【００６６】
実施例６〜１０
ゴム層の作製
ゴム層Ａ形成成分
シリコーンゴム（ＳＨ８３１Ｕ；トーレシリコーン） １００重量部
カーボンブラック・サーマルブラック（旭カーボン社製） ２５重量部
加硫剤（Ｃ８；信越化学） ２重量部
ゴム層Ｂ形成成分
ブチルゴム(日本合成ゴム製Ｂｕｔｙｌ２６８（商品名）) １００重量部
カーボンブラック・サーマルブラック（旭カーボン社製） ３５重量部
亜鉛華 ５重量部
ステアリン酸 １重量部
加硫用添加剤（硫黄を含む） ７．５重量部
ゴム層Ｃ形成成分
ＥＰＤＭ［日本合成ゴム製ＥＰ２１（商品名）］ １００重量部
カーボンブラック・サーマルブラック（旭カーボン社製） ３５重量部
亜鉛華 ５重量部
ステアリン酸 １重量部
加硫用添加剤（硫黄を含む） ７．５重量部
ゴム層Ｄ形成成分
ニトリルブタジエンゴム
［（日本合成ゴム製Ｎ２２０Ｓ（商品名）］ １００重量部
亜鉛華 ５重量部
ステアリン酸 １重量部
加硫用添加剤（硫黄を含む） ７．５重量部
ゴム層Ｅ形成成分
エピクロルヒドリンゴム(ダイソー製エピクロマーＣＧ) １００重量部
亜鉛華 ５重量部
ステアリン酸 １重量部
加硫用添加剤（硫黄を含む） ７．５重量部
【００６７】
これらのゴム層成分を所定の方法で混練したのち、アルミニウム素管上にゴム層を所定の方法により成型した。（蒸気加硫法、ゴム層厚は表中に記載）
次にゴム層上に表面層成分として実施例５の表面処理導電性酸化錫６０重量部添加品を用いて、加熱硬化条件を１５０℃／１時間、表面層膜厚を３μmとした以外は実施例５と同様に中間転写体を作製した。
【００６８】
これらの中間転写体の実効硬度、体積抵抗（７ヶ所の平均値）、体積抵抗の最大値−最小値を測定した。
これらの中間転写ドラムを図１に示した画像形成装置に装着し、ＯＨＰシート（リコー製ＯＨＰフィルムタイプ２）を用いて画像出力試験を行い、１ドット黒ライン中抜け画像の有無を評価した。
上記の結果を表５に示す。
【００６９】
【表５】

【００７０】
実施例１１
図４は本実施の形態の一例に係るシームレスベルトを形成するための遠心成形装置を示したものである。図４（ａ）は遠心成形装置の側断面図を、図４（ｂ）は（ａ）のＡ−Ａ断面図である。図４に示す遠心成形装置４１に内径φが１８０ｍｍ、長さが３６０ｍｍの円筒型の成形型４２を装着した。水平方向に成形型４２の回転軸をセットし、成形型４２を５００ｒｐｍの高速回転させた。これにより、キャビティ４２ａの全面に満遍なく離型液が塗布され、約５０μｍの均一厚みのベルト素材層４５が形成された。
ベルト素材液としては、実施例３のカーボンブラック２２重量部分散液を用いた。
【００７１】
成形型の回転速度を１００ｒｐｍに減速し、ベルト素材液をスプレー塗布にて塗布した。その後、回転数を５００ｒｐｍに上げて塗布液膜を均一にしてベルト素材層４５を形成した。さらに、ドライエアーを流してこのベルト素材層４５が指触で乾燥された程度に自然乾燥させた。
成形型４２を取り外し、縦に立てて、このベルト素材層４５をゆっくりと上方に向けて引き出したところ、環状のベルト素材層４５をスムースに成形型４２から取り外すことができた。
【００７２】
このベルト素材層４５の環内に別の型を挿入して形態を保った状態で、約１２０℃で２０分加熱して、溶媒の乾燥と共に予備的にイミド化を行った。さらに、３００℃に加熱してイミド化を行い、膜厚約１００μｍの平滑なシームレスベルトが形成された。
この中間転写ベルトを図２に示した画像形成装置に装着して、１０万枚の通紙試験を行った。試験後、膜厚とトナーフィルミングΔＩＤを測定したところ、それぞれ９８．４μｍ（膜厚）及び０．０２（ΔＩＤ）であった。
【００７３】
【発明の効果】
本発明によれば、中間転写体の少なくとも表面に少なくともシリコーン変性ポリアミドイミドを用いることにより、離型性と耐摩耗性が伴った中間転写体を提供することが出来る。又、転写チリや中抜け等の異常画像が解消された画像形成装置を提供することが出来る。
【図面の簡単な説明】
【図１】発明の実施の形態において使用した中間転写ドラムを装着した画像形成装置の一例を示す図である。
【図２】発明の実施の形態のおいて使用した中間転写ベルトを装着した画像形成装置の一例を示す図である。
【図３】対トナーランク試験を示す図である。
【図４】シームレスベルトの形成に使用した遠心成形装置の一例を示す図である。（ａ）は装置の側断面図であり、（ｂ）は（ａ）のＡ−Ａ断面図である。
【符号の説明】
１ 中間転写ドラム
２ 感光体
３ 二次転写ローラ
４ 除電
５ クリーニング
６ 転写材
７ トナー
Ａ 一次転写部
Ｂ 二次転写部
１１ 感光体ドラム
１３ クリーニング装置
２０ 中間転写ベルト
２５ 転写紙[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrophotographic system such as a copying machine, a printer, a facsimile, and the like, and more specifically, an intermediate transfer member such as an intermediate transfer drum and a belt and a primary and secondary transfer process with these interposed. The present invention relates to an image forming apparatus using an intermediate transfer method.
[0002]
[Prior art]
In recent years, electrophotographic image forming apparatuses capable of copying and printing full-color images have been put into practical use. As a transfer method for transferring a full-color image to a transfer material, an intermediate transfer member double transfer method [image of a photoconductor, etc.] Each color image of yellow (Y), magenta (M), cyan (C), and black (Bk) formed for each color on the support is sequentially superimposed and transferred onto the intermediate transfer member, and the transferred full color In general, the toner image is transferred onto a transfer material in a batch (also referred to as an intermediate transfer method) because it is excellent in terms of paper-free properties and full-surface copying.
[0003]
In such an intermediate transfer type image forming apparatus, various components are brought into contact with the surface of the intermediate transfer member. They are, for example, so-called secondary transfer rollers that are in contact with the intermediate transfer member when the toner is (secondary) transferred to the transfer material in addition to the above-described photoreceptor, toner, transfer material, A cleaning member such as a blade, a roller, or a brush that cleans toner remaining on the intermediate transfer member after the secondary transfer. Therefore, various mechanical and electrical external forces are constantly applied to the intermediate transfer member due to the rubbing action and electrical action with these parts, and durability against these external forces is required. In particular, various surface properties such as surface wear resistance, releasability to toner, and low friction coefficient to reduce frictional force with each component are the most important. Several materials used for the intermediate transfer member have been studied.
[0004]
For example, there is an example in which a fluorine-based resin or elastomer is used for the surface layer of the intermediate transfer member. (For example, see Patent Documents 1 to 5.)
Fluororesin is known as a material having very good releasability, but conversely, when used as a surface layer material, there is a drawback such as poor adhesion to the substrate and peeling, and the mechanical properties of the film are also particularly Since it was not excellent, it had problems such as surface wear and scratch resistance. Other high mold release materials include silicone resins and elastomers (see, for example, Patent Documents 6 to 10) and polyolefin-based materials (see Patent Documents 11 and 12). was there.
[0005]
Conversely, materials having excellent mechanical properties include polycarbonate (see Patent Documents 13 to 17), polyimide (see Patent Documents 18 to 22), polyamideimide (see Patent Documents 23 and 24), and the like. On the other hand, the material is not sufficiently releasable, and there is a problem that toner particles and additives thereof adhere to the surface. Other than these, there are proposals such as polyester materials (see Patent Documents 25 and 26) and polyurethane materials (see Patent Documents 27 and 28), but none of them satisfy wear resistance and releasability at the same time. It was.
[0006]
Further, there are problems such as image quality related to the intermediate transfer device using the intermediate transfer member. These include, for example, increasing the toner transfer rate as much as possible in the process of transferring a toner image from a photosensitive member to an intermediate transfer member (primary transfer) and in the step of transferring from an intermediate transfer member to a transfer material such as paper (secondary transfer). In addition to the necessity of reducing the residual toner as much as possible, it is also important to reduce abnormal images as much as possible. The present invention improves and improves the transfer rate, and in particular, improves an abnormal image related to a system using an intermediate transfer member, so-called “toner scattering during transfer” (hereinafter referred to as transfer dust).
[0007]
Here, transfer dust means that a visible image formed on an image carrier during primary transfer is not transferred to a position where it should originally be transferred but is diffused and transferred to the periphery thereof, resulting in an image being transferred. This is a phenomenon of blurring, and particularly impairs the sharpness of an image at a thin line portion. In the above intermediate transfer method, as a typical conventional technique for improving the image quality, a high resistance toner is non-electrostatically transferred to an intermediate transfer medium, and then press-transfer-fixed with a heating roll through a recording sheet ( For example, see Patent Document 29), and after non-electrostatic transfer of conductive toner to an intermediate transfer medium, press-transfer fixing with a heating roll with a recording sheet interposed (see, for example, Patent Document 30), Each time the toner image is transferred to the intermediate transfer medium, the toner image transferred by the sheet peeling charger is neutralized (see, for example, Patent Document 31), and the transfer potential at the final transfer stage is larger than the transfer potential immediately before. In addition, the intermediate transfer medium that applies a predetermined voltage to the intermediate transfer medium while moving to each transfer stage (see, for example, Patent Document 32), the intermediate transfer before reaching the means for transferring the visible image from the intermediate transfer body to the paper Which provided a means for neutralizing the above charge (for example, see Patent Document 33.), And the like.
[0008]
However, among these conventional techniques, Patent Documents 29 and 30 require a recording sheet that can be pressed and fixed by a heating roll, and cannot take advantage of the paper-free property that is an advantage of the intermediate transfer member transfer method. In Patent Documents 31, 32, and 33, in any case, it is necessary to provide a means for removing static electricity and / or applying a voltage and / or a control means thereof, which not only complicates the machine control mechanism but also reduces the size of the machine. Hinder.
[0009]
Another abnormal image is “missing”. This is because the toner to be transferred originally remains without being pinpointed and is seen on the image as a part of the toner missing.
As a typical conventional technique for improving the void, an organic fluorine-based compound is supplied to the surface of the intermediate transfer member (see, for example, Patent Document 34), and a wettability control agent is added to the intermediate transfer member material ( For example, refer to Patent Document 35.), which forms a protective film having lubricity such as zinc stearate on the surface of an intermediate transfer member (for example, refer to Patent Document 36), and uses silicone rubber as an intermediate transfer material, and its surface Those for controlling the roughness (for example, see Patent Document 37), those for providing a peripheral speed difference to the contact member of the intermediate transfer body and polishing the surface of the intermediate transfer body (for example, see Patent Document 38), and intermediate transfer. When the toner filming occurs on the surface of the body, the surface is polished (for example, see Patent Document 39), the surface after the intermediate transfer body surface roughness is detected (for example, see Patent Document 40), or constant. Polishing the intermediate transfer member for each copy number (e.g., see Patent Document 41.), And the like.
However, these techniques have not been able to sufficiently improve the void.
[0010]
[Patent Document 1]
JP-A-5-40417
[Patent Document 2]
JP-A-6-234903
[Patent Document 3]
JP-A-7-92825
[Patent Document 4]
JP-A-8-267605
[Patent Document 5]
JP-A-10-166508
[Patent Document 6]
Japanese Patent Laid-Open No. 5-46035
[Patent Document 7]
JP-A-8-30117
[Patent Document 8]
JP-A-9-269676
[Patent Document 9]
Japanese Patent Laid-Open No. 10-20538
[Patent Document 10]
Japanese Patent Laid-Open No. 11-231678
[Patent Document 11]
JP-A-5-311016
[Patent Document 12]
JP 7-24912 A
[Patent Document 13]
JP-A-6-93175
[Patent Document 14]
Japanese Patent Laid-Open No. 6-149081
[Patent Document 15]
Japanese Patent Laid-Open No. 6-149083
[Patent Document 16]
Japanese Patent Laid-Open No. 10-10880
[Patent Document 17]
JP-A-13-31849
[Patent Document 18]
JP 7-156287 A
[Patent Document 19]
JP-A-8-176319
[Patent Document 20]
Japanese Patent Laid-Open No. 11-24427
[Patent Document 21]
JP-A-11-170389
[Patent Document 22]
Japanese Patent Application Laid-Open No. 12-172085
[Patent Document 23]
JP-A-5-77252
[Patent Document 24]
Japanese Patent Laid-Open No. 10-226028
[Patent Document 25]
Japanese Patent Laid-Open No. 13-13801
[Patent Document 26]
Japanese Patent Laid-Open No. 13-18284
[Patent Document 27]
Japanese Patent Laid-Open No. 10-319727
[Patent Document 28]
Japanese Patent Laid-Open No. 11-30915
[Patent Document 29]
JP 63-34570 A
[Patent Document 30]
JP-A-63-34571
[Patent Document 31]
JP-A-1-282571
[Patent Document 32]
JP-A-2-183276
[Patent Document 33]
JP-A-4-147170
[Patent Document 34]
JP 58-187968 A
[Patent Document 35]
Japanese Patent Laid-Open No. 2-198476
[Patent Document 36]
JP-A-2-238881
[Patent Document 37]
JP-A-3-242667
[Patent Document 38]
JP-A-4-305666
[Patent Document 39]
JP-A-5-307344
[Patent Document 40]
JP-A-5-313526
[Patent Document 41]
JP-A-5-323802
[0011]
[Problems to be solved by the invention]
An object of the present invention is to improve the above-described prior art, and more specifically, to provide an intermediate transfer body having improved surface characteristics such as wear resistance and releasability. An object of the present invention is to provide an intermediate transfer member that does not cause side effects such as other abnormal images. Furthermore, another object of the present invention is to provide a high-quality image forming apparatus using the intermediate transfer member of the present invention.
[0012]
[Means for Solving the Problems]
In order to solve the above problems, the present invention employs the following configuration.
[0013]
(1) The intermediate transfer member according to claim 1 is primarily transferred by superimposing a plurality of visible color development images sequentially formed on the image carrier with toner on the intermediate transfer member running endlessly, In the intermediate transfer apparatus that collectively transfers the primary transfer image on the intermediate transfer body onto a transfer material, at least the surface of the intermediate transfer body is made of a material containing silicone-modified polyamideimide.
[0014]
(2) The intermediate transfer member according to claim 2 has a volume resistance of 10 composed of a material containing silicone-modified polyamideimide.⁸Ω · cm or more 10¹²It is characterized by being in the range of Ω · cm or less.
[0015]
(3) The intermediate transfer member according to (3), wherein conductive tin oxide is added to a layer composed of a material containing silicone-modified polyamideimide. It is described in either.
[0016]
(4) The intermediate transfer member according to (4) is characterized in that the conductive tin oxide is surface-treated with a silane coupling agent.
[0017]
(5) The intermediate transfer member according to claim 5 is composed of a plurality of layers, and a surface layer composed of a material containing at least silicone-modified polyamideimide and 10 layers below the surface layer.¹²It is described in any one of the above (1) to (4), characterized by having a rubber substrate having a volume resistance of Ω · cm or less and an effective hardness of JIS A 95 degrees or less.
[0018]
(6) The intermediate transfer member according to (6) is characterized in that the rubber substrate contains nitrile-butadiene rubber and / or epichlorohydrin rubber.
[0019]
(7) An image forming apparatus according to claim 7 is an image forming layer apparatus comprising at least charging, exposure, development, intermediate transfer, cleaning, static elimination devices and an electrophotographic photosensitive member, wherein the intermediate transfer device Is mounted with the intermediate transfer member described in any one of (1) to (6) above.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
An apparatus including the intermediate transfer member of the present invention will be described with reference to the drawings. FIG. 1 shows an example in which a drum is used as an intermediate transfer member as a representative example of an apparatus having the intermediate transfer member of the present invention. An outline of primary transfer and secondary transfer will be described.
Primary transfer
The toner 7 developed on the photosensitive member 2 by the developing device shown in FIG. 1 is brought into contact with the intermediate transfer drum 1 that rotates in synchronization with the photosensitive member 2 in the primary transfer portion A, and is given a predetermined bias potential to be transferred to the intermediate transfer drum. 1 is transferred. The toner developed in each color (black, yellow, magenta, cyan) is transferred from the photoreceptor 2 to the intermediate transfer drum 1 and the toner image is superimposed on the intermediate transfer drum 1.
[0021]
Secondary transfer
The secondary transfer roller 3 is usually separated from the intermediate transfer drum 1 but is in close contact with the intermediate transfer drum 1 during the secondary transfer. The transfer material 6 is conveyed in synchronization with the intermediate transfer drum 1 and passes between the intermediate transfer drum 1 and the secondary transfer roller 3. At this time, a bias voltage having a polarity opposite to the charging polarity of the toner is applied to the secondary transfer roller 3, and the toner 7 is secondarily transferred to the transfer material 6. Thereafter, the transfer material 6 is given a predetermined charge by the sheet neutralization 8 to remove the staying charge, and is easily peeled off from the intermediate transfer drum 1. Thereafter, the transfer material 6 moves to the fixing step. Further, the toner 7 remaining on the intermediate transfer drum 1 is removed and initialized by a predetermined cleaning component 5 (for example, a brush, a roller, etc.) in contact with the intermediate transfer drum 1.
For example, the intermediate transfer drum 1 is coated with various materials as described above in order to improve surface characteristics and the like on a cylindrical aluminum base tube.
[0022]
The present invention is characterized in that at least the surface of the intermediate transfer member is made of a material containing silicone-modified polyamideimide. Next, the silicone-modified polyamideimide used in the present invention will be described.
The silicone-modified polyamideimide used on at least the surface of the present invention can be represented by the following general formula.
[0023]
[Chemical 1]

(Wherein R represents an aromatic tetracarboxylic acid residue, Ar represents an aromatic diisocyanate residue, and Siloxane represents a diaminosiloxane residue)
Polyamideimide is generally known as a high-strength and rigid resin. However, the introduction of a siloxane structure in the main chain provides flexibility and further improves the releasability. Accordingly, it is possible to satisfy the wear resistance and toner releasability of the intermediate transfer member by including the above material on at least the surface.
[0024]
Such a silicone-modified polyamideimide can be produced by a known production method. In general, as a method for producing polyamideimide, an isocyanate method (Japanese Examined Patent Publication No. 44-19274, Japanese Examined Publication No. 45-2397, etc.), an acid chloride method (Japanese Examined Patent Publication No. Sho 42-15637), a direct polycondensation method (Japanese Examined Patent Publication No. 49-49) 1077, etc.) and solution polycondensation methods (Japanese Examined Patent Publication No. 40-8910, etc.), but any method can be used.
[0025]
For example, as a method using isocyanate, there is a method in which siloxane diamine, aromatic tricarboxylic acid and derivatives thereof, and diisocyanate are used as raw materials. (JP 2000-122964, etc.)
Here, as the siloxane diamine compound,
[0026]
[Chemical 2]

(R₁, R₆Is a divalent organic group, R₂~ R₅Represents an alkyl group, a phenyl group, or a substituted phenyl group, and n represents an integer of 5 to 50)
Is represented as a general formula, specifically, 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane, bis (3-aminopropyl) tetramethyldisiloxane, bis (10-aminodecamethylene) tetramethyldisiloxane, dimethylsiloxane tetramer having an aminopropyl end group, octamer, bis (3-aminophenoxymethyl) tetramethyldisiloxane, and the like.
[0027]
In the production of the silicone-modified polyamideimide used for the intermediate transfer member of the present invention, an aromatic diamine can be mixed and used in addition to the siloxane diamine. For example, (1) biphenyl diamine compounds, diphenyl ether diamine compounds, benzophenone diamine compounds, diphenyl sulfone diamine compounds, diphenylmethane diamine compounds, diphenylalkane diamine compounds such as 2,2-bis (phenyl) propane, 2-bis (phenyl) hexafluoropropane diamine compound, diphenylene sulfone diamine compound, (2) di (phenoxy) benzene diamine compound, di (phenyl) benzene diamine compound, (3) di (phenoxyphenyl) Mainly “aromatic diamine compounds having 2 or more, especially 2 to 5 aromatic rings (benzene rings)” such as hexafluoropropane diamine compounds and bis (phenoxyphenyl) propane diamine compounds. It can be mentioned aromatic diamine containing them alone or can be used as a mixture.
[0028]
Examples of the aromatic diamine include diphenyl ether diamine compounds such as 1,4-diaminodiphenyl ether and 1,3-diaminodiphenyl ether, 1,3-di (4-aminophenoxy) benzene, and 1,4-bis (4-amino). Di (phenoxy) benzene-based diamine compounds such as phenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, and the like And bis (phenoxyphenyl) propane-based diamine compounds.
[0029]
Specific examples of the aromatic tricarboxylic acid and its derivatives used in the production of the silicone-modified polyamideimide used in the intermediate transfer member of the present invention include trimellitic anhydride, trimellitic anhydride monochloride, 1,4-dicarboxyl. -3-N, N-dimethylcarbamoylbenzene, 1,4-dicarbomethoxy-3-carboxybenzene, 1,4-dicarboxy-3-carbophenoxybenzene, 2,6-dicarboxy-3-carbomethoxypyridine, Examples include 1,6-dicarboxy-5-carbamoylnaphthalene, ammonium salts composed of the above aromatic tricarboxylic acids and ammonia, dimethylamine, triethylamine, and the like. Of these, trimellitic anhydride and trimellitic anhydride monochloride are preferred.
[0030]
Specific examples of the aromatic diisocyanate used in the present invention include 4,4′-diphenylmethane diisocyanate (hereinafter abbreviated as MDI), 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, and naphthalene-1,5-diisocyanate. O-, m-xylylene diisocyanate, 2,4-tolylene dimer, and the like. In addition, isocyanates such as hexamethylene diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate) and isifolone diisocyanate can be used alone or in combination.
[0031]
As the solvent used in the production of the silicone-modified polyamideimide used for the intermediate transfer member of the present invention, an aprotic polar solvent excellent in solubility of the produced resin is preferable. Examples of such aprotic polar solvents include dimethylacetamide, dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, 4-butyrolactone, sulfolane, and cyclohexane. For the imidization reaction, N-methyl-2-pyrrolidone having a high boiling point and a high boiling point is particularly preferable.
[0032]
The intermediate transfer member of the present invention is characterized by containing at least a silicone-modified polyamideimide on the surface, but the volume resistance of the layer containing the silicone-modified polyamideimide is 10 by adding a resistance control agent.⁸Ω · cm or more 10¹²By controlling in the range of Ω · cm or less, the toner transfer rate can be improved. When the transfer rate is low, there are problems such as an increased burden on cleaning of the photosensitive member and the intermediate transfer member and an increase in toner loss. The toner transfer rate required for the intermediate transfer device is 80% or more, preferably 90% or more.
[0033]
As the resistance control agent used in the intermediate transfer member of the present invention, a usual general agent can be used. Specifically, carbon black such as ketjen black and acetylene black, metal fine powder such as Ni powder, metal oxide such as tin oxide, titanium oxide and zinc oxide, and metal oxide such as antimony doped Organic compounds or polymers containing quaternary ammonium bases, carboxylic acid groups, sulfonic acid groups, sulfate ester groups, phosphate ester groups, ether ester amide or ether amide imide polymers, ethylene oxide-epihalohydrin An organic antistatic agent such as an organic antistatic agent such as a polymer, a compound having a conductive unit represented by methoxypolyethylene glycol acrylate, or a polymer compound can be used.
[0034]
But 10⁸Ω · cm or more 10¹²In order to control the volume resistance stably in the range of Ω · cm or less, tin oxide is preferable, and since it is excellent in conductivity, the one doped with a different atom such as antimony is most preferable. This includes, for example, spherical particles (T-1; Mitsubishi Materials Corporation) and scaly particles (ELCOM-TL-20; Catalyst Chemical Industry Co., Ltd.), and any of them can be used.
[0035]
Furthermore, the inventor has found that image dust during transfer can be improved by surface-treating the tin oxide particles with a silane coupling agent. As a silane coupling agent that can be used for the surface treatment of the tin oxide of the present invention, conventional commercially available silane coupling agents can be used. For example, SH6020 (γ- (2-aminoethyl) aminopropyltrimethoxysilane), SZ6023 (γ- (2-aminoethyl) aminopropylmethyldimethoxysilane), SH6026 (aminosilane), SZ6032 (N-β- (N-vinyl) Benzylaminoethyl) -γ-aminopropyltrimethoxysilane / hydrochloride), SZ6050 (aminosilane), SZ6083 (γ-anilinopropyltrimethoxysilane), AY43-021 (octadecyldimethyl [3- (trimethoxysilyl) propyl] Ammonium chloride), AY43-031 (γ-ureidopropyltriethoxysilane), SZ6030 (γ-methacryloxypropyltrimethoxysilane), SH6040 (γ-glycidoxypropyltrimethoxysilane), etc. As well as Toray Dow Corning Silicone Co., Ltd.).
[0036]
Surface treatment of tin oxide with a silane coupling agent can be performed, for example, as follows. 1 part by weight of a silane coupling agent is added to 100 parts by weight of tin oxide, and the mixture is stirred for 5 to 10 minutes with a high-speed mixer to adhere the silane coupling agent to the surface of tin oxide. Next, it is taken out from the high speed mixer and dried at 100 to 150 ° C. for 1 hour.
This surface-treated product can be handled in the same manner as an untreated product when the intermediate transfer member of the present invention is manufactured (described later).
[0037]
The intermediate transfer member of the present invention is characterized in that at least the surface is composed of a material containing a silicone-modified polyamideimide, but it is preferable that a layer containing a silicone-modified polyamideimide is placed on a conductive rubber layer. As a result, flexibility is imparted to the intermediate transfer member, and particularly stable contact with a hard transfer material such as OHP is ensured, thereby preventing the occurrence of a toner dropout phenomenon.
[0038]
A general material can be used for the rubber layer. Specific examples include polyurethane, butyl rubber, nitrile butadiene rubber, epichlorohydrin rubber, polyisoprene rubber, polybutadiene rubber, silicone rubber, fluorine rubber, styrene-butadiene rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, chloroprene rubber, acrylic. Rubber, a mixture thereof, and the like can be used. These rubber materials are usually insulative except for a part, but since the toner transfer rate can be improved, a resistance control agent can be added to make them conductive. In that case, the volume resistance of the rubber layer is 10¹²Ω · cm or less is preferable, and further 10⁸Ω · cm or more 10¹²Most preferred is Ω · cm or less. The effective hardness of the rubber layer is preferably JIS A95 degrees or less. The effective hardness is defined as a value obtained by directly measuring the hardness of the intermediate transfer member with a hardness meter. When the effective hardness exceeds JIS A 95 degrees, sufficient flexibility does not appear and a toner dropout phenomenon or the like occurs. Nitrile butadiene rubber and epichlorohydrin rubber are particularly preferred because the resistance of the material itself is low and the conductivity can be secured stably without using a resistance control agent. Either one of these may be used, or a mixture of both may be used.
[0039]
The layer containing at least the silicone-modified polyamideimide of the present invention can be used by mixing with various organic / inorganic materials as required in addition to the resistance control agent. Other organic resin materials that can be mixed include alkyd resin, chlorinated polyether, chlorinated polyethylene, epoxy resin, fluororesin, phenol resin, polyamide, polycarbonate, polyethylene, methacrylic resin, polypropylene, polystyrene resin, polyurethane , Polyvinyl chloride, polyvinylidene chloride, silicone resin and the like. These can be used by dissolving in a solvent, or one of them can be mixed in the form of resin fine particles.
[0040]
Next, the form of the intermediate transfer member of the present invention will be described. Although the intermediate transfer drum has been used in the description so far, the present invention is not limited to this, and any form can be used. However, as a form suitably used other than the drum form, a belt form is preferable. Is mentioned.
[0041]
FIG. 2 shows a typical example in which the intermediate transfer belt is mounted on the image forming apparatus.
The photosensitive drum 11 as an image carrier is rotationally driven in the direction of an arrow during copying by a driving unit such as a motor (not shown). Around the photosensitive drum 11, a pre-cleaning static eliminator 12, a cleaning device 13, a static elimination lamp 14, a charger 15, an exposure device 16, a potential sensor 17, a black developing unit (K), and cyan development are arranged along the rotation direction. A developing unit 18 including a unit (C), a magenta developing unit (M), a yellow developing unit (Y), an optical sensor 19 for detecting a development density pattern, an intermediate transfer belt 20 as an intermediate transfer member, and the like are arranged.
[0042]
The intermediate transfer belt 20 is stretched around a backup roller 21, a bias roller 22a, an earth roller 22b, and a driving roller 23, and is configured to run endlessly in a direction indicated by an arrow by driving means such as a motor (not shown). . A transfer bias voltage is applied between the bias roller 22a and the earth roller 22b at the time of primary transfer, and a transfer electric field is generated in the transfer nip portion of the primary transfer region. The bias roller 22a is provided with a separation mechanism (not shown) for contact with the photosensitive drum 11, and contacts the photosensitive drum 11 during primary transfer, but is separated from the photosensitive drum 11 during secondary transfer. To do. FIG. 2 shows a state at the time of secondary transfer. The photosensitive drum 11 and the bias roller 22a are separated by a predetermined distance. On the other hand, at the lower end of the intermediate transfer belt 20, a transfer roller 24 having a separation / contact mechanism (not shown) is disposed to face the backup roller 21. The transfer roller 24 is usually separated from the intermediate transfer belt 20, but at the time of secondary transfer, the four-color superimposed image formed on the surface of the belt 20 is collectively transferred to a transfer sheet 25 as a transfer material. It is pressed toward the intermediate transfer belt 20 by the separation / contact mechanism. A transfer bias voltage for generating a transfer electric field is applied to the transfer roller 24 at the transfer nip portion of the secondary transfer region, and the toner image is transferred to the transfer paper 25 by the action of the transfer electric field. The belt cleaning unit 26 is composed of a brush roller 26a, a rubber blade 26b, a separation / contact mechanism (not shown) with the intermediate transfer belt 20, and the like, 2, 3, 4 after the first color image is transferred to the belt. While the color is being transferred to the belt, it is separated from the surface of the intermediate transfer belt 20.
[0043]
In the above configuration, when the copying operation is started, the exposure device 16 writes an optical image based on the image data on the photosensitive drum 11, and a latent image is formed on the outer peripheral surface of the photosensitive drum 11. . The latent image is developed by a developing unit of a specific color of the developing unit 18 to become a toner image, and is intermediate at a contact portion (primary transfer region) between the photosensitive drum 11 and the intermediate transfer belt 20 moving at a constant speed. Transfer is performed on the surface of the transfer belt 20 (primary transfer). In the case of full color, this process is repeated for three colors or four colors to form a full color image on the intermediate transfer belt 20. The toner image transferred to the intermediate transfer belt 20 is collectively transferred onto the transfer paper 25 (secondary transfer) at a contact portion (secondary transfer region) between the intermediate transfer belt 20 and the transfer paper 25. Thereafter, the transfer paper 25 is output as a full-color image through a fixing process (not shown). The transfer paper 25 is fed by a paper feed roller and a registration roller (not shown) at the timing when the leading end of the full color image on the intermediate transfer belt 20 reaches the paper transfer position in the secondary transfer area.
[0044]
The intermediate transfer belt shape has advantages in that the degree of freedom in layout is large and the apparatus can be miniaturized. In the case of a belt shape, the layer containing at least the silicone-modified polyamideimide of the present invention may be used alone, or the layer containing at least the silicone-modified polyamideimide of the present invention is installed on the surface of the belt substrate composed of rubber or resin. It doesn't matter.
[0045]
The method for producing the intermediate transfer member of the present invention will be described.
(1) A method in which a silicone-modified polyamideimide is dissolved in a solvent and coated and molded
When preparing an intermediate transfer body after dissolving the silicone-modified polyamideimide in a solvent, it can be carried out according to a conventional method. For example, a liquid composition in which each of the above-described components is dissolved or dispersed in a solvent can be prepared with an appropriate carrier (support Body) and then the solvent is removed by drying. There are no particular restrictions on the carrier, and those used in general solution casting methods are used. For example, a metal roller such as SUS or Al, a conductive resin, or a rubber roller or belt may be used. it can. Examples of the solvent include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, sulfolane, hexamethylphosphoric triamide, 1,3-dimethyl-2-imidazolidone, and hexane. , Benzene, toluene, xylene, methyl ethyl ketone, acetone, diethyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxymethane, diethylene glycol dimethyl ether, methyl cellosolve, cellosolve acetate, methanol, ethanol, propanol, isopropanol, methyl acetate, ethyl acetate, acetonitrile, Examples include methylene chloride, chloroform, carbon tetrachloride, chlorobenzene, dichlorobenzene, dichloroethane, and trichloroethane. The type and amount are appropriately selected and used so that each component is dissolved and dispersed. The concentration of the silicone-modified polyamideimide in the solvent is appropriately selected according to the film thickness to be produced, but is usually 0.1 to 60% by weight, preferably 1 to 50% by weight, more preferably 5 to 45% by weight. It is a range. When the concentration of the cyclic olefin polymer is in this range, the film thickness can be easily adjusted and the film forming property is excellent and suitable.
[0046]
The method of casting the liquid composition on the carrier is not particularly limited, but can be performed using, for example, a doctor knife, Meir bar, roll coat or the like. The liquid composition can be cast by spraying, brushing, rolling, spin coating, dipping or the like. When a desired film thickness cannot be obtained by a single application, it can be applied repeatedly.
[0047]
(2) Belt molding method
A typical method for producing a belt substrate using the silicone-modified polyamideimide of the present invention is a centrifugal molding method. This is because a raw material solution (hereinafter sometimes referred to as coating solution) as a belt material is poured from a spray or nozzle into a cylindrical mold that rotates a resin solution dissolved in a solvent, and this mold is rotated at high speed. However, the method of producing an endless belt by a method of forming an endless shaped body by expanding the coating liquid by the centrifugal force and solidifying the film as a uniform film (so-called centrifugal molding method), according to this method, Since the applied coating solution is expanded by centrifugal force, a coating layer having a relatively uniform thickness is easily obtained.
[0048]
In this belt formation by centrifugal molding, after applying a fluid coating solution to the inner surface of a cylindrical mold, it is rotated by a high-speed centrifugal force to make the film thickness uniform, and the surface energy of aggregation of the coating solution is obtained. The coating film is spread and spread with a force to overcome, and the film is made uniform. The coating solution is prepared by diluting the raw material varnish with a solvent to the mold. Therefore, this coating solution is uniformly applied to the inner surface of the mold when rotating at high speed, but gradually accumulates at the bottom of the mold when the rotation is stopped or the number of rotations is reduced. Therefore, according to this centrifugal molding method, the solvent must be removed and solidified while maintaining the state of a uniform solution film.
Next, examples will be described.
[0049]
Example 1 and Comparative Examples 1 to 4
A silicone-modified polyamideimide, a fluororesin, a polyimide resin, and a silicone resin shown in Table 1 were applied to an aluminum sheet (1 mm thick), heated at a predetermined temperature for a predetermined time, and used as a sample sheet.
[0050]
An abrasion test and a toner release test were performed by the following methods.
(1) Abrasion resistance: Taber abrasion test (wear wheel CS5, weight difference before and after the test after 3000 revolutions with 1 kg load)
The allowable weight for wear is 3 mg or less.
[0051]
(2) Releasability: Toner rank test
FIG. 3 is a view showing an outline of the toner rank test. The test was performed using a simple laboratory press molding machine having toner 31, toner transfer Al mylar 32, resin-coated mylar 33, Si rubber 44, SUS35, and the like.
As shown in FIG. 3, the sample plates 32 and 33 are brought into contact with the toner 31 (Ricohian toner type 4100), and 10 kg / cm is used using a simple laboratory press molding machine.², 50 ° C., 1 hr. 3kg / cm after the test²The toner 31 was blown off with air, and the residual toner state was evaluated by visual rank as follows.
[0052]
Releasability rank
Rank 8 Toner is removed very easily
7 It takes some time but the toner is completely removed
6 Slightly (less than several percent) of toner remains
5 About several to 1/3 of toner remains
4 About 1/3 to 2/3 of toner remains
3 2/3 or more toner remains
2 Toner remains on the entire surface (present as toner particles)
1 Toner remains on the entire surface (no toner particles exist, particles are fused)
The mold release tolerance is rank 7 or higher.
The test results are shown in Table 1.
[0053]
[Table 1]

[0054]
Example 2 and Comparative Examples 5 and 6
In a separable three-necked flask equipped with a thermometer, a stirrer, and a condenser, 77.64 g of 4,4′-diphenylmethane diisocyanate (MDI), 1,3-bis (3-aminopropyl) -1, 2.61 g of 1,3,3-tetramethyldisiloxane and 215.61 g of N-methyl-2-pyrrolidone were blended and reacted sufficiently at 40 ° C. for 2 hours while being dissolved by stirring. Next, 57.6 g of trimellitic anhydride (TMA) was added thereto, the temperature was raised to 140 ° C. over 30 minutes, and the reaction was continued in this state for 6 hours. Thereafter, this N-methyl-2-pyrrolidone was added to lower the temperature to 50 ° C. to complete the reaction, whereby an N-methyl-2-pyrrolidone solution of silicone-modified polyamideimide (solid content concentration 12% by weight) was obtained.
[0055]
100 parts by weight of this resin is diluted with a solvent (N-methyl-2-pyrrolidone solution), spray-coated on an aluminum tube (80φ), heated at 150 ° C./30 minutes, 250 ° C./30 minutes, 350 ° C./5 minutes After drying, an intermediate transfer body having a silicone-modified polyamideimide surface layer was obtained. (10 μm film thickness) (Example 2)
In the same manner, an intermediate transfer member was produced using the resins used in Comparative Examples 1 and 2. (Comparative Examples 5 and 6 respectively)
These transfer bodies were mounted on the apparatus shown in FIG. 1 and a 100,000 sheet passing test was conducted. Then, the surface toner was transferred with a tape and attached to a Ricoh PPC paper type 6000, and the image density was measured. . Further, the image density was measured in the same manner as when the tape was directly attached to paper, and the difference was defined as toner filming ΔID. Further, the wear amount of the surface layer was also measured from the diameter difference before and after the test. In addition, the following members were used for the apparatus of FIG. 1 used for the paper passing test.
[0056]
Photoconductor; belt OPC photoconductor
Toner: Ricoh cyan toner type 4100
Transfer material: Ricoh PPC paper type 6000
Secondary transfer roller; conductive urethane sponge roller (10⁹Ω)
The results are shown in Table 2.
[0057]
[Table 2]

[0058]
Examples 3 and 4
Carbon black (Printex 90; Degussa Co., Ltd.) was added to 100 parts by weight of the silicone-modified polyamideimide in Example 1, respectively, and dispersed by ball mill for 72 hours. This was spray coated in the same manner as in Example 2 to obtain an intermediate transfer member as in Example 2 (Example 3). The film thickness of the surface layer is 10 μm.
[0059]
Instead of the carbon black used in Example 3, 40, 60, 80, 100 parts by weight of conductive tin oxide (T1; manufactured by Mitsubishi Materials Corporation) was added to obtain an intermediate transfer member by the same method as in Example 3. . (Example 4).
The volume resistance of these intermediate transfer members was calculated from the resistance value after 1 minute at 100 VDC using the following equation.
[0060]
Volume resistance R (Ω · cm) = (Measured resistance value R) × ln {(2πL) / (a / b)}
L: Main electrode width (cm), a: Intermediate transfer member diameter, b: Elementary tube diameter
The volume resistance was measured at seven locations in the length direction, and the average value was calculated. Further, the difference (variation) between the logarithmic values of the maximum value and the minimum value of the measured values at these seven locations was obtained. The tolerance of log (Max) -log (Min) is 1.2 or less, preferably 0.8 or less.
[0061]
Next, this intermediate transfer member was mounted in the same apparatus as in Example 2 in FIG. The transfer rate is measured by the amount of toner adhering to the OPC before the primary transfer of the solid image (mg / cm²) And unfixed toner after secondary transfer (mg / cm²) Was measured by the suction method and calculated by the following formula.
Transfer rate (%) = (unfixed toner after secondary transfer / toner adhesion amount on OPC before primary transfer) × 100
[0062]
The results are shown in Table 3.
[Table 3]

[0063]
Example 5
1 part by weight of a silane coupling agent (described in the table) is added to 100 parts by weight of the conductive tin oxide used in Example 4, and the mixture is stirred for 5 minutes with a high-speed mixer. To attach. Next, it was taken out from the high speed mixer and dried at 150 ° C. for 1 hour.
By adding 40, 60, 80, 100 parts by weight of this surface-treated tin oxide to 100 parts by weight of silicone-modified polyamideimide (HR14ET; Toyobo), an intermediate transfer member was produced in the same manner as in Example 4. Volume resistance was measured.
[0064]
Transcript evaluation method
This intermediate transfer drum is mounted on the image forming apparatus shown in FIG. 1, and a one-dot black line when a test image is output is observed with a microscope VH5910 (manufactured by Keyence Corporation) equipped with a 200 × lens. The number of dust toner in one line in the field of view was counted. According to the number, the following ranking was performed.
The results of volume resistance and transfer dust are shown in Table 4 together with Example 4.
[0065]
[Table 4]

◎: No dust toner, ○: Less than 10 dust toners, Δ: 10 to 100 dust toners, ×: 100 or more dust toners
[0066]
Examples 6-10
Fabrication of rubber layer
Rubber layer A forming component
100 parts by weight of silicone rubber (SH831U; Torre Silicone)
Carbon black thermal black (Asahi Carbon Co., Ltd.) 25 parts by weight
Vulcanizing agent (C8; Shin-Etsu Chemical) 2 parts by weight
Rubber layer B forming component
Butyl rubber (Japan Synthetic Rubber Butyl 268 (trade name)) 100 parts by weight
Carbon black and thermal black (Asahi Carbon Co., Ltd.) 35 parts by weight
5 parts by weight of zinc white
1 part by weight of stearic acid
Vulcanizing additive (including sulfur) 7.5 parts by weight
Rubber layer C forming component
EPDM [Japan synthetic rubber EP21 (trade name)] 100 parts by weight
Carbon black and thermal black (Asahi Carbon Co., Ltd.) 35 parts by weight
5 parts by weight of zinc white
1 part by weight of stearic acid
Vulcanizing additive (including sulfur) 7.5 parts by weight
Rubber layer D forming component
Nitrile butadiene rubber
[(Japan Synthetic Rubber N220S (trade name)] 100 parts by weight
5 parts by weight of zinc white
1 part by weight of stearic acid
Vulcanizing additive (including sulfur) 7.5 parts by weight
Rubber layer E forming component
Epichlorohydrin rubber (Daiso Epichromer CG) 100 parts by weight
5 parts by weight of zinc white
1 part by weight of stearic acid
Vulcanizing additive (including sulfur) 7.5 parts by weight
[0067]
After kneading these rubber layer components by a predetermined method, a rubber layer was molded on the aluminum base tube by a predetermined method. (Steam vulcanization method, rubber layer thickness listed in the table)
Next, 60 parts by weight of the surface-treated conductive tin oxide of Example 5 was used as a surface layer component on the rubber layer, except that the heat curing conditions were 150 ° C./1 hour and the surface layer thickness was 3 μm. An intermediate transfer member was prepared in the same manner as in Example 5.
[0068]
The effective hardness, volume resistance (average value of 7 locations), and volume resistance maximum value-minimum value of these intermediate transfer members were measured.
These intermediate transfer drums were mounted on the image forming apparatus shown in FIG. 1, and an image output test was performed using an OHP sheet (OHP film type 2 manufactured by Ricoh) to evaluate the presence or absence of a one-dot black line missing image.
The results are shown in Table 5.
[0069]
[Table 5]

[0070]
Example 11
FIG. 4 shows a centrifugal molding apparatus for forming a seamless belt according to an example of the present embodiment. 4A is a side sectional view of the centrifugal molding apparatus, and FIG. 4B is a sectional view taken along the line AA in FIG. A cylindrical molding die 42 having an inner diameter φ of 180 mm and a length of 360 mm was attached to the centrifugal molding apparatus 41 shown in FIG. The rotating shaft of the mold 42 was set in the horizontal direction, and the mold 42 was rotated at a high speed of 500 rpm. As a result, the release liquid was uniformly applied to the entire surface of the cavity 42a, and the belt material layer 45 having a uniform thickness of about 50 μm was formed.
As the belt material liquid, the dispersion of 22 parts by weight of carbon black of Example 3 was used.
[0071]
The rotational speed of the mold was reduced to 100 rpm, and the belt material liquid was applied by spray coating. Thereafter, the rotational speed was increased to 500 rpm, the coating liquid film was made uniform, and the belt material layer 45 was formed. Further, the belt material layer 45 was naturally dried to such an extent that the belt material layer 45 was dried by touch with dry air.
When the molding die 42 was removed, and the belt material layer 45 was pulled out upwards while standing vertically, the annular belt material layer 45 could be smoothly removed from the molding die 42.
[0072]
In a state where another form was inserted into the ring of the belt material layer 45 and the form was maintained, the belt material layer 45 was heated at about 120 ° C. for 20 minutes, and preliminarily imidized with drying of the solvent. Furthermore, imidation was performed by heating to 300 ° C., and a smooth seamless belt having a film thickness of about 100 μm was formed.
This intermediate transfer belt was mounted on the image forming apparatus shown in FIG. 2, and 100,000 sheets were tested. After the test, the film thickness and toner filming ΔID were measured and found to be 98.4 μm (film thickness) and 0.02 (ΔID), respectively.
[0073]
【The invention's effect】
According to the present invention, by using at least silicone-modified polyamideimide on at least the surface of the intermediate transfer member, an intermediate transfer member with releasability and wear resistance can be provided. Further, it is possible to provide an image forming apparatus in which abnormal images such as transfer dust and voids are eliminated.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of an image forming apparatus equipped with an intermediate transfer drum used in an embodiment of the invention.
FIG. 2 is a diagram showing an example of an image forming apparatus equipped with an intermediate transfer belt used in the embodiment of the invention.
FIG. 3 is a diagram illustrating a toner rank test.
FIG. 4 is a view showing an example of a centrifugal molding apparatus used for forming a seamless belt. (A) is side sectional drawing of an apparatus, (b) is AA sectional drawing of (a).
[Explanation of symbols]
1 Intermediate transfer drum
2 Photoconductor
3 Secondary transfer roller
4 Static neutralization
5 Cleaning
6 Transfer material
7 Toner
A Primary transfer section
B Secondary transfer section
11 Photosensitive drum
13 Cleaning device
20 Intermediate transfer belt
25 Transfer paper

Claims (7)

A plurality of visible color development images sequentially formed on the image carrier with toner are sequentially superimposed and primarily transferred onto an endless intermediate transfer member, and the primary transfer image on the intermediate transfer member is used as a transfer material. In the intermediate transfer apparatus that performs secondary transfer in a lump, at least the surface of the intermediate transfer member is made of a material containing silicone-modified polyamideimide. 2. The intermediate transfer member according to claim 1, wherein the volume resistance of the layer composed of the material containing the silicone-modified polyamideimide is in the range of 10 ⁸ Ω · cm to 10 ¹² Ω · cm. The intermediate transfer member according to claim 1, wherein conductive tin oxide is added to a layer composed of a material containing a silicone-modified polyamideimide. The intermediate transfer member according to claim 3, wherein the conductive tin oxide is surface-treated with a silane coupling agent. The intermediate transfer member is composed of a plurality of layers, and has a surface layer composed of a material containing at least a silicone-modified polyamideimide and a lower layer having a volume resistance of 10 ¹² Ω · cm or less and an effective hardness of JIS A of 95 degrees or less. The intermediate transfer member according to any one of claims 1 to 4, further comprising a rubber substrate. 6. The intermediate transfer member according to claim 5, wherein the rubber base material contains nitrile-butadiene rubber and / or epichlorohydrin rubber. 7. An image forming layer apparatus comprising at least charging, exposure, development, intermediate transfer, cleaning, static elimination devices, and an electrophotographic photosensitive member, wherein the intermediate transfer device is any one of claims 1 to 6. An image forming apparatus having the intermediate transfer member mounted thereon.

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