JP2004198483A

JP2004198483A - Apparatus and method for manufacturing electrophotographic photoreceptor

Info

Publication number: JP2004198483A
Application number: JP2002363709A
Authority: JP
Inventors: Akihiro Iiyama; 明宏飯山; Takeshi Egawa; 豪江川; Yoshihiro Yamaguchi; 芳広山口; Yoko Hirai; 陽子平井; Akira Okawa; 晃大川; Kifuku Takagi; 基福高木; Sakae Suzuki; 栄鈴木; Kenji Furuya; 賢二古屋
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2002-12-16
Filing date: 2002-12-16
Publication date: 2004-07-15

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and method for suppressing bubbles and manufacturing an electrophotographic photoreceptor without reducing the coating speed, to suppress the pulsation of a circulating pump without making the apparatus complicated, and to provide an electrophotographic photoreceptor having excellent coating quality. <P>SOLUTION: The apparatus for manufacturing an electrophotographic photoreceptor circulates at least coating liquid between a coating tank and a coating liquid reservoir, and coats a cylindrical substrate by dipping the substrate in the coating liquid in the coating tank. A barrier to the coating liquid is disposed at the outside of the cylindrical substrate and in a location higher than the liquid level of the coating liquid and not reaching the bottom face of the coating tank. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は浸漬塗工を行う電子写真感光体の製造装置および同装置を使用した電子写真感光体の製造方法に関する。
【０００２】
【従来の技術】
電子写真感光体は導電性の素管に感光層、下引き層、保護層など、多くの層を塗布することにより製造される。塗布方法としては、浸漬塗工、スプレー塗工、リング塗工等があるが、比較的簡易なことと、生産性の面から浸漬塗工がよく用いられる。一方、近年の複写機の多色化、高画質化に伴い電子写真感光体には高精度の品質が要求されるようになってきた。
【０００３】
浸漬塗工法では液物性変化の防止や液補充の容易さ等により塗工槽と塗工液貯蔵槽の二つの槽を具備し、この二つの槽間を塗工液を循環させておく方法が用いられ、その循環にはポンプを用いることが一般的である。しかしながら、ポンプの脈動により以下のような不具合が生じる。
【０００４】
即ち、ポンプの脈動により循環する際に塗工液中に気泡が入りこんでしまうことがあり、この気泡により電子写真感光体の膜が乱れて画像に悪影響を及ぼす危険がある。また、循環させる際、脈動の強いポンプを使用すると塗工槽内の液面までポンプの脈動の影響を受けてしまい、結果として電子写真感光体の塗膜乱れの原因となってしまう。このため、脈動の少ないポンプを使用する必要がある。
【０００５】
しかし、脈動の少ないポンプでは塗工液の十分な循環をすることが出来ない。また、気泡の発生を極力抑えるために浸漬状態からの引き上げ速度を落とすことにより対処できるが生産性が落ちるという問題がある。
【０００６】
このような問題を解決する方法として、特開平１０−３３９９６１号公報（特許文献１）では、循環順路途中にて塗工液を真空ポンプを使用して加圧することにより液中の気泡を溶解させているが、塗工液容器の密閉性や加圧装置などが必要となり、装置が複雑になってしまう。また、循環用ポンプより直接塗工槽へ液を供給しているため、塗工槽液面が循環用ポンプの脈動の影響を受けてしまう。特開平１１−０７２９３２号公報（特許文献２）には、オーバーフロー槽の戻り配管にバルブを設け、オーバーフロー槽液面高さを測定し、液面が低い時にはバルブを閉じ、液面が高いときはバルブを開くことで塗工液内への気泡の侵入を防止する方法が記載されているが、このような方法は、制御が複雑となり、液面検出のための機構も増えて装置も複雑となる。また、この場合も循環用ポンプと塗工槽が直結しているため、循環用ポンプの脈動が塗工槽液面に影響を及ぼしてしまう。このように上記公報記載の発明ではいずれも気泡の発生を防ぐのには十分とはいえない。
【０００７】
【特許文献１】
特開平１０−３３９９６１号公報
【特許文献２】
特開平１１−０７２９３２号公報
【０００８】
【発明が解決しようとする課題】
本発明の目的は、気泡の発生を抑え塗工速度を落とさずに電子写真感光体を製造することができる装置並びに製造方法を提供することである。また、装置を複雑にすることなく循環ポンプの脈動を抑え、塗膜品質の優れた電子写真感光体を提供することである。
【０００９】
【課題を解決するための手段】
上記本発明の目的は次の手段により達成される。
すなわち、本発明によれば、第一に、少なくとも塗工液を塗工槽と塗工液貯蔵槽間を循環させ、該塗工槽の塗工液中に円筒状基体を浸漬させて塗工を行う電子写真感光体の製造装置において、上記円筒状基体の外側で、かつ、塗工液の液面より高く塗工槽の底面まで至らない位置に塗工液の遮断壁を設けることを特徴とする電子写真感光体の製造装置が提供される。
【００１０】
第二に、請求項２では、上記請求項１記載の電子写真感光体の製造装置において、上記遮断壁の位置が、上記円筒状基体の表面から塗工槽の壁までの距離の１／１０〜４／５倍、該基体表面から離れた位置であることを特徴とする電子写真感光体の製造装置が提供される。
【００１１】
第三に、請求項３では、上記請求項１または２記載の電子写真感光体の製造装置において、上記遮断壁下面から塗工槽底面までの距離が、該塗工槽底面から塗工液液面までの距離の１０〜９０％であることを特徴とする電子写真感光体の製造装置が提供される。
【００１２】
第四に、請求項４では、上記請求項１乃至３のいずれかに記載の電子写真感光体の製造装置において、上記遮断壁外側の中間槽の周囲には液受け用皿を備え、該液受け用皿に液抜き可能な開口部を有することを特徴とする電子写真感光体の製造装置が提供される。
【００１３】
第五に、請求項５では、上記請求項１乃至４のいずれかに記載の電子写真感光体の製造装置において、上記中間槽の外壁上面が内側から外側に向かい傾斜を持っていることを特徴とする電子写真感光体の製造装置が提供される。
【００１４】
第六に、請求項６では、上記請求項１乃至５のいずれかに記載の電子写真感光体の製造装置において、液供給口が上記中間槽に設けられていることを特徴とする電子写真感光体の製造装置が提供される。
【００１５】
第七に、請求項７では、上記請求項１乃至６のいずれかに記載の電子写真感光体の製造装置において、液供給口が上記中間槽の上方に設けられていることを特徴とする電子写真感光体の製造装置が提供される。
【００１６】
第八に、請求項８では、上記請求項１乃至７のいずれかに記載の電子写真感光体の製造装置において、上記塗工槽内に液抜き可能な開口部を有することを特徴とする電子写真感光体の製造装置が提供される。
【００１７】
第九に、請求項９では、上記請求項１乃至８のいずれかに記載の電子写真感光体の製造装置において、上記塗工槽下部に円筒状基体が貫通可能な開口部を有し、該開口部に液漏れを防止するシール部材を有することを特徴とする電子写真感光体の製造装置が提供される。
【００１８】
第十に、請求項１０では、上記請求項９記載の電子写真感光体の製造装置において、上記液漏れを防止するシール部材が円筒状基体に接触することを特徴とする電子写真感光体の製造装置が提供される。
【００１９】
第十一に、請求項１１では、上記請求項１乃至１０のいずれかに記載の製造装置を用いて少なくとも感光層を塗工することを特徴とする電子写真感光体の製造方法が提供される。
【００２０】
第十二に、請求項１２では、上記請求項１１記載の電子写真感光体の製造方法において、塗工する際、上記中間槽内の液をオーバーフローさせて液面を常に一定の高さに保ち塗工を行うことを特徴とする電子写真感光体の製造方法が提供される。
【００２１】
第十三に、請求項１３では、上記請求項１１乃至１２のいずれかに記載の電子写真感光体の製造方法において、上記塗工槽の第一槽内の液を入れ替えることを特徴とする電子写真感光体の製造方法が提供される。
【００２２】
第十四に、請求項１４では、上記請求項１１乃至１３のいずれかに記載の電子写真感光体の製造方法において、円筒状基体を塗工槽と相対移動させて塗工を行う際、円筒状基体を塗工槽を貫通させて塗工を行うことを特徴とする電子写真感光体の製造方法が提供される。
【００２３】
第十五に、請求項１５では、上記請求項１４に記載の電子写真感光体の製造方法において、円筒状基体を塗工槽を貫通させる際、塗工液と円筒状基体間を密閉し液漏れを防止することを特徴とする電子写真感光体の製造方法が提供される。
【００２４】
【発明の実施の形態】
図１に本発明の構成の一例を示し、図２にその塗工部の拡大図を示す。これらに基づき本発明の説明を行うが、本発明はこれらに限定したものではない。
図１、２に示すように、被塗工体、即ち円筒状基体１は塗工槽２のほぼ中心に浸漬されるが、その円筒状基体１の外側で、かつ、塗工液の液面より高く塗工槽の底面まで至らない位置に塗工液の遮断壁１２を設けることで循環ポンプＰの脈動により生じる気泡を除去する効果がある。
【００２５】
液供給口１３が遮断壁１２よりも外側に位置していることで、送液中に気泡が混入していても、気泡は液よりも比重が軽いため、液供給口１３を出るとそのまま遮断壁１２の上方へ逃げていくため、遮断壁１２の内側への気泡の侵入を防止することが可能である。
遮断壁１２の位置は、前記円筒状基体１を基準として、該円筒状基体１の表面から塗工槽の壁までの距離の１／１０〜４／５倍、好ましくは１／５〜７／１０倍、更に好ましくは３／１０〜３／５倍、該円筒状基体表面から離れた位置にあることにより気泡除去効果が高い。
また、前記遮断壁の高さ、即ち前記遮断壁の下面と塗工槽底面との間隔は、該塗工槽底面から塗工液液面までの距離の１０〜９０％、好ましくは１０〜５０％、更に好ましくは１０〜２０％であれば気泡除去効果が高い。
遮断壁１２の固定の方法は特に規定はせず、上方より吊り下げるように固定しても、塗工槽の底に固定して、遮断壁１２に貫通口（図示なし）を設けてもよい。
【００２６】
また、使用する塗工液の粘度は３００ｃｐｓ以下が好ましい。本発明の装置であれば気泡が発生しないので従来よりも低い粘度のものも使用できる。また、リング塗工であれば使用する溶剤が少なくて済む。
【００２７】
さらに、上記遮断壁１２の外側の中間槽４へ塗工液を送液する際に、中間槽４の上部より流入させることで気泡の除去効果、脈動防止効果を高めることが可能である。そして、中間槽４を経て気泡、脈動共に除去された塗工液が塗工槽２内に流入する。
また、中間槽４の上方は開口しており、中間槽４内に充満した塗工液は上部より流出していく。中間槽４の周囲にはこの流出する塗工液の受け皿６が配設されており、この中間槽４上面高さが即ち塗工槽２の液面高さとなる。
この時、中間槽４の外壁１５上面１１は内側から外側へ傾斜を持っていることが好ましい。これにより、塗工液が中間槽４上部より流出する際の表面張力を抑制することができ、塗工液を均一に流出させることが可能である。
【００２８】
該液受け皿６には液抜き用の開口部１４を設けており、この開口部１４を通じて中間槽４から貯蔵槽３へ塗工液の戻り配管７が配設されており、これを通じて塗工液が貯蔵槽３へと回帰してくる。
また、この戻り配管７とは別に塗工槽２下部にも貯蔵槽３への戻り配管８（開口部１６）が配設されている。これは塗工槽２内の塗工液の物性変化を防止するためのものであり、塗工槽２内の塗工液を円滑に循環させることを目的としている。
さらに、中間槽４内に攪拌機構を設けることも塗工液の物性変化防止のためには効果的である。
【００２９】
上記戻り配管８の途中にはバルブ９が具備されており、任意に開閉が可能となっている。浸漬塗工法では塗工の際には極力塗工槽２内の塗工液の動きは無い方が均一な塗膜の形成が可能となるため、塗工中にはバルブ９を閉じて塗工槽２内の塗工液の流動を抑え、未塗工時にバルブ９を開放して塗工槽２内部の塗工液を循環させる（塗工液を入れ替える）。
以上により、塗膜欠陥の無い電子写真感光体の製造が可能となる。
【００３０】
以下本発明で用いられる導電性基体１、塗工槽２、貯蔵槽３、中間槽４について説明を補足する。
図中の１は塗布対象物である導電性基体であり、その構成物質としてはアルミ、黄銅、ステンレス、鋼鉄等の金属製円筒型基体、もしくはポリエチレン、ナイロン、ガラス等の絶縁体表面に金属を蒸着させたもの等が考えられるが、本発明はこの範囲に限定したものではない。
導電性基体１の外周面に感光層（主として下引き層、電荷発生層、電荷輸送層、保護層等の多層）を形成するための感光体材料を保持しておく塗工槽が２であり、この形状として淀みの発生しにくい円筒型が好ましい。
導電性基体１の外周面に感光層を形成するに当り、液物性の変化の防止、液補充の容易さを考慮すると塗工槽２とは別に塗工液の貯蔵槽があることが好ましい。本発明ではこの貯蔵槽が３となる。
まず貯蔵槽３内の塗工液が循環ポンプ５により中間槽４へと送液される。理想としては中間槽４は塗工槽２よりも容量が大きい方が良い。何故ならば、中間槽４は循環ポンプ５の脈動を吸収する役割があり、中間槽４の容量が大きいほど循環ポンプ５の脈動を中間槽４内にて吸収できる割合が大きくなるからである。
【００３１】
図３は本発明の製造装置の別の例を示すものである。内側に壁（遮断壁１２）を持ち、内部が２槽構造となっている塗工槽であり、外側の槽が中間槽４の役割を果たし、内側の槽が塗工槽２（塗工槽の第一槽というときもある）として機能する。内側の仕切り壁（遮断壁１２）には貫通口（図示なし）があり、塗工槽２と中間槽４を連通させている。
貯蔵槽３内に保持されている塗工液が循環ポンプ５によって外側の槽（中間槽４）へ送液される。循環ポンプ５の脈動を防止する意味では中間槽４の容量は塗工槽２の容量よりも大きいことが理想である。
また、塗工液中に混入した気泡を中間槽４内にて除去することも目的としているため、塗工槽２と中間槽４の仕切壁（遮断壁１２）の貫通口（図示なし）は下方に位置していることが望ましい。
【００３２】
また、中間槽４へ塗工液を送液する際に中間槽４の上部より流入させることにより塗工液内に混入した気泡の塗工槽２内への侵入を防止しやすくなる。
また、中間槽４の上面は開口しており、中間槽４内に充満した塗工液は上面より流出していき、中間槽４の上面高さが塗工槽２内の液面高さとなる。中間槽４の周囲上部にはこの流出した塗工液の受け皿６が設けられている。
中間槽４の壁上面は内側から外側へ傾斜部が設けられており、これにより塗工液が中間槽４上面より流出する際に表面張力の影響を抑制することができ、塗工液を均一に流出させることが可能である。
【００３３】
また、該液受け皿６には液抜き用の開口部１４が具備されており、該開口部１４より貯蔵槽３まで塗工液の戻り配管７が配設されていてこれを通じて塗工液が貯蔵槽３へと回帰していく。
塗工槽２下部にも貯蔵槽３への戻り配管８を配設することも効果的であり、該戻り配管８（開口部１６）を具備することで塗工槽２内の塗工液を円滑に循環させることができ、沈降性の高い塗工液を使用した際にも塗工槽２内の塗工液物性の変化を抑制することが可能となる。
該戻り配管８にはバルブ９を設け、未塗工時のみバルブ９を開放することで塗工中の塗工液の流動を抑制し、塗膜品質の向上を狙う。
以上により、塗膜欠陥の無い電子写真感光体の製造が可能となる。
【００３４】
図４は従来用いられている装置で、導電性基体を塗工槽下部を貫通させて塗工を行う装置であり、少量の塗工液にて塗工が可能となるが、気泡の発生を抑えるには十分ではない。
【００３５】
【実施例】
次に実施例によって本発明をさらに詳細に説明する。ただし、本発明は以下の実施例によって限定されるものではない。
【００３６】
実施例１〜４
図１に示す装置を用い、遮断壁の位置及び高さを変えて、４種類、それぞれ連続で１００本塗工を行い、膜厚を測定した。
導電性基体はアルミ製のφ３０とし、長さは３４０ｍｍのものを使用した。塗工液は粘度９６ｃｐｓであり、膜厚５μｍを狙って塗工を行った。塗工方式としては、円筒状基体を固定し、塗工槽を昇降させて塗工を行った。
【００３７】
比較例１
図４に示す装置を用いた以外は実施例と同様に行った。
【００３８】
実施例及び比較例によって得られた塗工後のドラムの膜厚を軸方向に６点、周方向に２点の計１２点について測定し、１００本のバラツキの平均値を調査した。結果を表１に示す。
【００３９】
【表１】

注１．表中、遮断壁の位置は、塗工槽に浸漬された円筒状基体の表面から塗工槽の内壁までの距離の１／１０〜４／５倍の範囲で変化させた。
注２．表中、遮断壁高さは、遮断壁下面から塗工槽底面までの距離を表し、該塗工槽底面から塗工液液面までの距離に対する％で示した。
注３．表中、液抜きは、塗工槽に設けた液抜き可能な開口部を表す。
【００４０】
【発明の効果】
以上のように、請求項１の製造装置によれば、塗工槽内の円筒状基体の外側で、かつ、塗工液の液面より高く塗工槽の底面まで至らない位置に塗工液の遮断壁を設けることから、遮断壁によって循環ポンプの脈動による気泡の侵入が阻止され、塗工速度を上げても、また、塗工槽を昇降させる塗工法の場合は昇降速度を上げても塗膜品質の優れた電子写真感光体を製造することができる。
【００４１】
請求項２の製造装置によれば、上記遮断壁の位置が上記円筒状基体の表面から塗工槽の壁までの距離の１／１０〜４／５倍、該基体表面から離れた位置であることから、上記気泡阻止効果が高い。
【００４２】
請求項３の製造装置によれば、上記遮断壁の高さが、該塗工槽底面から塗工液液面までの距離の１０〜９０％であることから、上記気泡阻止効果が高い。
【００４３】
請求項４の製造装置によれば、中間槽の周囲に液受け用皿を備え、該液受け用皿に液抜き可能な開口部を有することから、中間槽からオーバーフローした液を液受け用皿の開口部から貯蔵槽に戻すため塗工液を円滑に戻すことができる。
【００４４】
請求項５の製造装置によれば、上記中間槽の壁上面が内側から外側に向かい傾斜を持っていることから、塗工液が中間槽からオーバーフローするときの中間槽液面の表面張力を抑制することができ、塗工液を均一に流出させることができる。
【００４５】
請求項６の製造装置によれば、液供給口が上記中間槽、即ち遮断壁の外側に設けられていることから、気泡が遮断壁内側へ侵入するのが防止される。
【００４６】
請求項７の製造装置によれば、液供給口が上記中間槽の上方に設けられていることから、中間槽の上方より送液されるため気泡の除去効果と脈動防止効果を高めることができる。
【００４７】
請求項８の製造装置によれば、上記塗工槽内に液抜き可能な開口部を有することから、この開口部から貯蔵槽へ塗工液を戻すことができ、塗工槽内の塗工液の液物性変化を防止することができる。
【００４８】
請求項９の製造装置によれば、上記塗工槽下部に円筒状基体が貫通可能な開口部を有し、該開口部に液漏れを防止するシール部材を有することから、気泡が除去された少量の塗工液により円筒状基体を塗工槽下部を貫通させて塗工することができる。
【００４９】
請求項１０の製造装置によれば、上記シール部材が円筒状基体に接触することから、低粘度の塗工液でも液漏れなく塗工することができる。
【００５０】
請求項１１の製造方法によれば、上記製造装置により少なくとも感光層を形成することから、循環ポンプの脈動による気泡の侵入が阻止され、塗膜品質の優れた電子写真感光体を製造することができる。
【００５１】
請求項１２の製造方法によれば、塗工する際、上記中間槽内の液をオーバーフローさせて液面を常に一定の高さに保ち塗工を行うことから、均一な塗膜を形成することができる。
【００５２】
請求項１３の製造方法によれば、上記塗工槽の第一槽内の液を入れ替えることから、塗工槽内の塗工液の物性変化を防止することができる。
【００５３】
請求項１４の製造方法によれば、円筒状基体を塗工槽と相対移動させて塗工を行う際、円筒状基体を塗工槽を貫通させて塗工を行うことから、少量の塗工液により塗膜欠陥のない塗膜を形成することができる。
【００５４】
請求項１５の製造方法によれば、円筒状基体を塗工槽を貫通させる際、塗工液と円筒状基体間を密閉し液漏れを防止することから、低粘度の塗工液でも塗膜欠陥のない、安定した塗工を行うことができる。
【図面の簡単な説明】
【図１】本発明の塗工装置の一例を示す概略構成図。
【図２】図１の塗工槽の構成図。
【図３】本発明の塗工装置の別の例を示す概略構成図。
【図４】従来の塗工装置の概略構成図。
【符号の説明】
１円筒状基体
２塗工槽
３貯蔵槽
４中間槽
５循環ポンプ
６液受け皿
７戻り配管
８戻り配管
９バルブ
１０シール部材
１１中間槽の壁上面の傾斜
１２遮断壁
１３液供給口
１４液抜き用開口部
１５中間槽の壁
１６液抜き可能な開口部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electrophotographic photoreceptor manufacturing apparatus for performing dip coating and an electrophotographic photoreceptor manufacturing method using the same.
[0002]
[Prior art]
An electrophotographic photoreceptor is manufactured by applying a number of layers, such as a photosensitive layer, an undercoat layer, and a protective layer, to a conductive tube. Examples of the coating method include dip coating, spray coating, ring coating, and the like, but dip coating is often used from the viewpoint of relatively simplicity and productivity. On the other hand, with the recent increase in the number of colors and the high image quality of copiers, high-precision electrophotographic photosensitive members have been required.
[0003]
In the dip coating method, a method is provided in which two tanks, a coating tank and a coating liquid storage tank, are provided in order to prevent a change in physical properties of the liquid and to facilitate the replenishment of the liquid, and the coating liquid is circulated between the two tanks. In general, a pump is used for the circulation. However, the following problems occur due to the pulsation of the pump.
[0004]
That is, bubbles may enter into the coating liquid when circulating due to the pulsation of the pump, and there is a risk that the bubbles may disturb the film of the electrophotographic photosensitive member and adversely affect the image. When a circulating pump is used during circulation, the pulsation of the pump reaches the liquid level in the coating tank, and as a result, the coating film of the electrophotographic photosensitive member is disturbed. Therefore, it is necessary to use a pump with less pulsation.
[0005]
However, a pump with little pulsation cannot circulate the coating liquid sufficiently. Further, in order to suppress the generation of bubbles as much as possible, it is possible to cope with this by lowering the lifting speed from the immersion state, but there is a problem that productivity is reduced.
[0006]
As a method for solving such a problem, Japanese Patent Application Laid-Open No. 10-339961 (Patent Document 1) discloses a method in which bubbles in a liquid are dissolved by pressurizing a coating liquid using a vacuum pump in the middle of a circulation route. However, the hermeticity of the coating liquid container and a pressurizing device are required, and the device becomes complicated. Further, since the liquid is directly supplied from the circulation pump to the coating tank, the liquid level of the coating tank is affected by the pulsation of the circulation pump. Japanese Patent Application Laid-Open No. 11-072932 (Patent Document 2) discloses that a valve is provided in a return pipe of an overflow tank, a liquid level of the overflow tank is measured, the valve is closed when the liquid level is low, and the valve is closed when the liquid level is high. A method is described in which air bubbles are prevented from entering the coating liquid by opening a valve.However, such a method requires complicated control, a mechanism for detecting the liquid level increases, and the apparatus becomes complicated. Become. Also, in this case, since the circulation pump and the coating tank are directly connected, the pulsation of the circulation pump affects the coating tank liquid level. Thus, none of the inventions described in the above publications is sufficient to prevent the generation of bubbles.
[0007]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 10-339961 [Patent Document 2]
JP-A-11-072932
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus and a method for manufacturing an electrophotographic photoreceptor which suppresses the generation of bubbles and does not reduce the coating speed. Another object of the present invention is to provide an electrophotographic photoreceptor having excellent coating quality by suppressing pulsation of a circulation pump without complicating the apparatus.
[0009]
[Means for Solving the Problems]
The above object of the present invention is achieved by the following means.
That is, according to the present invention, first, at least the coating liquid is circulated between the coating tank and the coating liquid storage tank, and the cylindrical substrate is immersed in the coating liquid in the coating tank. In the electrophotographic photoreceptor manufacturing apparatus, a coating liquid blocking wall is provided outside the cylindrical substrate and at a position higher than the coating liquid level and not to the bottom of the coating tank. An electrophotographic photoreceptor manufacturing apparatus is provided.
[0010]
Secondly, according to a second aspect, in the apparatus for manufacturing an electrophotographic photosensitive member according to the first aspect, the position of the blocking wall is 1/10 of the distance from the surface of the cylindrical substrate to the wall of the coating tank. An apparatus for manufacturing an electrophotographic photoreceptor, characterized in that it is located at a position distant from the substrate surface by about 4/5 times.
[0011]
Thirdly, in a third aspect of the present invention, in the apparatus for manufacturing an electrophotographic photosensitive member according to the first or second aspect, the distance from the lower surface of the blocking wall to the bottom surface of the coating tank is changed from the bottom surface of the coating tank to the coating liquid. An apparatus for manufacturing an electrophotographic photoreceptor, wherein the distance to the surface is 10 to 90%.
[0012]
Fourthly, according to a fourth aspect, in the electrophotographic photosensitive member manufacturing apparatus according to any one of the first to third aspects, a liquid receiving tray is provided around the intermediate tank outside the blocking wall, and the liquid receiving tray is provided. An apparatus for manufacturing an electrophotographic photosensitive member, characterized in that the receiving plate has an opening through which liquid can be drained.
[0013]
Fifth, a fifth aspect of the present invention is the electrophotographic photoreceptor manufacturing apparatus according to any one of the first to fourth aspects, wherein the upper surface of the outer wall of the intermediate tank has a slope from the inside to the outside. An electrophotographic photoreceptor manufacturing apparatus is provided.
[0014]
Sixthly, according to a sixth aspect, in the electrophotographic photosensitive member manufacturing apparatus according to any one of the first to fifth aspects, a liquid supply port is provided in the intermediate tank. An apparatus for manufacturing a body is provided.
[0015]
Seventhly, according to a seventh aspect of the invention, in the electrophotographic photosensitive member manufacturing apparatus according to any one of the first to sixth aspects, a liquid supply port is provided above the intermediate tank. An apparatus for manufacturing a photoreceptor is provided.
[0016]
Eighthly, according to an eighth aspect, in the electrophotographic photoreceptor manufacturing apparatus according to any one of the first to seventh aspects, the coating device has an opening through which liquid can be drained. An apparatus for manufacturing a photoreceptor is provided.
[0017]
Ninthly, in the ninth aspect, the apparatus for manufacturing an electrophotographic photoreceptor according to any one of the first to eighth aspects, further comprising an opening through which a cylindrical substrate can penetrate at a lower portion of the coating tank. An apparatus for manufacturing an electrophotographic photoreceptor, characterized in that the opening has a seal member for preventing liquid leakage.
[0018]
Tenthly, according to a tenth aspect of the present invention, in the electrophotographic photosensitive member manufacturing apparatus according to the ninth aspect, the sealing member for preventing the liquid leakage comes into contact with the cylindrical substrate. An apparatus is provided.
[0019]
Eleventh, an eleventh aspect provides a method for manufacturing an electrophotographic photoreceptor, wherein at least a photosensitive layer is coated using the manufacturing apparatus according to any one of the first to tenth aspects. .
[0020]
Twelfthly, in the twelfth aspect, in the method of manufacturing an electrophotographic photosensitive member according to the eleventh aspect, at the time of coating, the liquid in the intermediate tank overflows to keep the liquid level at a constant level. There is provided a method for producing an electrophotographic photosensitive member, which comprises performing coating.
[0021]
Thirteenthly, according to a thirteenth aspect, in the method of manufacturing an electrophotographic photosensitive member according to any one of the eleventh and twelfth aspects, the liquid in the first tank of the coating tank is replaced. A method for manufacturing a photographic photoreceptor is provided.
[0022]
Fourteenthly, according to a fourteenth aspect, in the method of manufacturing an electrophotographic photosensitive member according to any one of the eleventh to thirteenth aspects, when the coating is performed by moving the cylindrical substrate relative to the coating tank, The present invention provides a method for producing an electrophotographic photoreceptor, in which coating is performed by passing a glass substrate through a coating tank.
[0023]
Fifteenthly, in the fifteenth aspect, in the method for manufacturing an electrophotographic photoreceptor according to the fourteenth aspect, when the cylindrical substrate is made to penetrate the coating tank, the coating liquid and the cylindrical substrate are hermetically sealed. There is provided a method of manufacturing an electrophotographic photoreceptor, which prevents leakage.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows an example of the configuration of the present invention, and FIG. 2 shows an enlarged view of the coating portion. The present invention will be described based on these, but the present invention is not limited to these.
As shown in FIGS. 1 and 2, an object to be coated, that is, a cylindrical substrate 1 is immersed substantially in the center of a coating tank 2, but outside the cylindrical substrate 1 and at a liquid level of a coating liquid. Providing the coating liquid blocking wall 12 at a position higher than the bottom surface of the coating tank has an effect of removing bubbles generated by pulsation of the circulation pump P.
[0025]
Since the liquid supply port 13 is located outside the shut-off wall 12, even if bubbles are mixed in the liquid being sent, the bubbles have a lower specific gravity than the liquid, so the bubbles are shut off as they exit the liquid supply port 13. Since the air escapes above the wall 12, it is possible to prevent air bubbles from entering the inside of the blocking wall 12.
The position of the blocking wall 12 is 1/10 to 4/5 times the distance from the surface of the cylindrical substrate 1 to the wall of the coating tank, preferably 1/5 to 7 / A bubble removal effect is high by being 10 times, more preferably 3/10 to 3/5 times, away from the surface of the cylindrical substrate.
The height of the blocking wall, that is, the distance between the lower surface of the blocking wall and the bottom surface of the coating tank is 10 to 90%, preferably 10 to 50% of the distance from the bottom surface of the coating tank to the liquid surface of the coating liquid. %, More preferably 10 to 20%, the effect of removing bubbles is high.
The method of fixing the blocking wall 12 is not particularly limited, and the blocking wall 12 may be fixed to be suspended from above or may be fixed to the bottom of the coating tank, and a through hole (not shown) may be provided in the blocking wall 12. .
[0026]
The viscosity of the coating solution used is preferably 300 cps or less. The apparatus of the present invention does not generate air bubbles, and therefore can use one having a lower viscosity than the conventional one. Also, the ring coating requires less solvent to be used.
[0027]
Further, when the coating liquid is sent to the intermediate tank 4 outside the blocking wall 12, by flowing the coating liquid from above the intermediate tank 4, it is possible to enhance the air bubble removing effect and the pulsation preventing effect. Then, the coating liquid from which both air bubbles and pulsations have been removed flows through the intermediate tank 4 into the coating tank 2.
The upper part of the intermediate tank 4 is open, and the coating liquid filled in the intermediate tank 4 flows out from the upper part. A tray 6 for the flowing coating liquid is disposed around the intermediate tank 4, and the height of the upper surface of the intermediate tank 4 is the liquid level of the coating tank 2.
At this time, it is preferable that the upper surface 11 of the outer wall 15 of the intermediate tank 4 has a slope from the inside to the outside. Thereby, the surface tension when the coating liquid flows out from the upper portion of the intermediate tank 4 can be suppressed, and the coating liquid can be uniformly discharged.
[0028]
The liquid receiving tray 6 is provided with an opening 14 for draining the liquid, and a return pipe 7 for the coating liquid from the intermediate tank 4 to the storage tank 3 is provided through the opening 14. Returns to the storage tank 3.
In addition to the return pipe 7, a return pipe 8 (opening 16) to the storage tank 3 is provided below the coating tank 2. This is for preventing a change in the physical properties of the coating liquid in the coating tank 2 and is intended to smoothly circulate the coating liquid in the coating tank 2.
Further, providing a stirring mechanism in the intermediate tank 4 is also effective for preventing a change in the physical properties of the coating liquid.
[0029]
A valve 9 is provided in the middle of the return pipe 8, and can be freely opened and closed. In the dip coating method, it is possible to form a uniform coating film when the coating liquid in the coating tank 2 does not move as much as possible during coating. The flow of the coating liquid in the tank 2 is suppressed, and the valve 9 is opened when the coating is not performed to circulate the coating liquid in the coating tank 2 (replace the coating liquid).
As described above, it is possible to manufacture an electrophotographic photosensitive member having no coating film defects.
[0030]
Hereinafter, the description of the conductive substrate 1, the coating tank 2, the storage tank 3, and the intermediate tank 4 used in the present invention will be supplemented.
In the figure, reference numeral 1 denotes a conductive substrate which is an object to be coated, and a constituent material thereof is a metal cylindrical substrate such as aluminum, brass, stainless steel, steel or the like, or a metal on an insulator surface such as polyethylene, nylon, glass or the like. Although it is conceivable that the film is deposited, the present invention is not limited to this range.
The coating tank 2 holds a photosensitive material for forming a photosensitive layer (mainly a multilayer such as an undercoat layer, a charge generation layer, a charge transport layer, and a protective layer) on the outer peripheral surface of the conductive substrate 1. Preferably, the shape is a cylindrical shape in which stagnation hardly occurs.
In forming the photosensitive layer on the outer peripheral surface of the conductive substrate 1, it is preferable to provide a coating liquid storage tank separately from the coating tank 2 in consideration of prevention of change in liquid physical properties and ease of replenishment of the liquid. In the present invention, this storage tank is 3.
First, the coating liquid in the storage tank 3 is sent to the intermediate tank 4 by the circulation pump 5. Ideally, the capacity of the intermediate tank 4 should be larger than that of the coating tank 2. This is because the intermediate tank 4 has a role of absorbing the pulsation of the circulation pump 5, and the larger the capacity of the intermediate tank 4, the larger the ratio of the pulsation of the circulation pump 5 that can be absorbed in the intermediate tank 4.
[0031]
FIG. 3 shows another example of the manufacturing apparatus of the present invention. This is a coating tank having a wall (blocking wall 12) on the inside and a two-tank structure inside, the outer tank serving as the intermediate tank 4, and the inner tank serving as the coating tank 2 (coating tank). Of the first tank). The inner partition wall (blocking wall 12) has a through-hole (not shown), and connects the coating tank 2 and the intermediate tank 4.
The coating liquid held in the storage tank 3 is sent to the outer tank (intermediate tank 4) by the circulation pump 5. Ideally, the capacity of the intermediate tank 4 is larger than the capacity of the coating tank 2 in order to prevent pulsation of the circulation pump 5.
In addition, since the purpose is to remove air bubbles mixed in the coating liquid in the intermediate tank 4, a through hole (not shown) of a partition wall (blocking wall 12) between the coating tank 2 and the intermediate tank 4 is provided. It is desirable to be located below.
[0032]
In addition, when the coating liquid is sent to the intermediate tank 4, by flowing the coating liquid from the upper part of the intermediate tank 4, it is easy to prevent bubbles mixed in the coating liquid from entering the coating tank 2.
The upper surface of the intermediate tank 4 is open, and the coating liquid filled in the intermediate tank 4 flows out from the upper surface, so that the height of the upper surface of the intermediate tank 4 becomes the liquid level in the coating tank 2. . A tray 6 for the coating liquid that has flowed out is provided in an upper part around the intermediate tank 4.
The upper surface of the wall of the intermediate tank 4 is provided with a slope from the inside to the outside, so that the influence of surface tension when the coating liquid flows out from the upper surface of the intermediate tank 4 can be suppressed, and the coating liquid can be evenly distributed. It is possible to spill.
[0033]
The liquid receiving tray 6 is provided with an opening 14 for draining the liquid, and a return pipe 7 for the coating liquid is provided from the opening 14 to the storage tank 3, through which the coating liquid is stored. Return to tank 3.
It is also effective to provide a return pipe 8 to the storage tank 3 below the coating tank 2, and by providing the return pipe 8 (opening 16), the coating liquid in the coating tank 2 can be removed. The coating liquid can be smoothly circulated, and even when a coating liquid having a high sedimentation property is used, it is possible to suppress a change in physical properties of the coating liquid in the coating tank 2.
A valve 9 is provided in the return pipe 8, and the valve 9 is opened only when the coating is not performed, thereby suppressing the flow of the coating liquid during coating and aiming at improving the quality of the coating film.
As described above, it is possible to manufacture an electrophotographic photosensitive member having no coating film defects.
[0034]
FIG. 4 shows a conventional apparatus in which a conductive substrate is penetrated through a lower portion of a coating tank to perform coating. The coating can be performed with a small amount of a coating liquid. Not enough to suppress.
[0035]
【Example】
Next, the present invention will be described in more detail by way of examples. However, the present invention is not limited by the following examples.
[0036]
Examples 1-4
Using the apparatus shown in FIG. 1, 100 coatings were continuously performed on four types of the barrier walls while changing the position and height thereof, and the film thickness was measured.
The conductive substrate used was φ30 made of aluminum and had a length of 340 mm. The coating liquid had a viscosity of 96 cps, and was applied with a film thickness of 5 μm. As a coating method, a cylindrical substrate was fixed, and a coating tank was moved up and down to perform coating.
[0037]
Comparative Example 1
The procedure was performed in the same manner as in the example except that the apparatus shown in FIG. 4 was used.
[0038]
The film thickness of the coated drums obtained in the examples and comparative examples was measured at a total of 12 points, 6 points in the axial direction and 2 points in the circumferential direction, and the average value of 100 variations was investigated. Table 1 shows the results.
[0039]
[Table 1]

Note 1. In the table, the position of the blocking wall was changed in a range of 1/10 to 4/5 times the distance from the surface of the cylindrical substrate immersed in the coating tank to the inner wall of the coating tank.
Note2. In the table, the height of the blocking wall represents the distance from the lower surface of the blocking wall to the bottom surface of the coating tank, and is represented by% with respect to the distance from the bottom surface of the coating tank to the liquid surface of the coating liquid.
Note3. In the table, "liquid drainage" represents an opening provided in the coating tank and capable of draining liquid.
[0040]
【The invention's effect】
As described above, according to the manufacturing apparatus of claim 1, the coating liquid is located outside the cylindrical substrate in the coating tank and at a position higher than the liquid level of the coating liquid and not reaching the bottom of the coating tank. Since the blocking wall is provided, the blocking wall prevents bubbles from entering due to the pulsation of the circulation pump, so that even if the coating speed is increased, or in the case of the coating method of raising and lowering the coating tank, the lifting speed is increased. An electrophotographic photosensitive member having excellent coating film quality can be manufactured.
[0041]
According to the manufacturing apparatus of the second aspect, the position of the blocking wall is a position 1/10 to 4/5 times the distance from the surface of the cylindrical substrate to the wall of the coating tank, away from the substrate surface. Therefore, the above-described bubble blocking effect is high.
[0042]
According to the manufacturing apparatus of the third aspect, since the height of the blocking wall is 10 to 90% of the distance from the bottom surface of the coating tank to the liquid surface of the coating liquid, the bubble blocking effect is high.
[0043]
According to the manufacturing apparatus of the fourth aspect, since the liquid receiving plate is provided around the intermediate tank, and the liquid receiving plate has an opening through which the liquid can be drained, the liquid overflowing from the intermediate tank is supplied to the liquid receiving plate. The coating liquid can be returned smoothly to return to the storage tank from the opening.
[0044]
According to the manufacturing apparatus of the fifth aspect, since the upper surface of the wall of the intermediate tank is inclined from the inside to the outside, the surface tension of the liquid surface of the intermediate tank when the coating liquid overflows from the intermediate tank is suppressed. And the coating liquid can be uniformly discharged.
[0045]
According to the manufacturing apparatus of claim 6, since the liquid supply port is provided outside the intermediate tank, that is, outside the blocking wall, bubbles are prevented from entering the inside of the blocking wall.
[0046]
According to the manufacturing apparatus of the seventh aspect, since the liquid supply port is provided above the intermediate tank, the liquid is sent from above the intermediate tank, so that the bubble removing effect and the pulsation preventing effect can be enhanced. .
[0047]
According to the manufacturing apparatus of the eighth aspect, since the coating tank has an opening through which liquid can be drained, the coating liquid can be returned from the opening to the storage tank, and the coating liquid in the coating tank can be removed. It is possible to prevent a change in liquid physical properties of the liquid.
[0048]
According to the manufacturing apparatus of the ninth aspect, since the lower portion of the coating tank has an opening through which the cylindrical base can penetrate, and the opening has a sealing member for preventing liquid leakage, bubbles are removed. The coating can be performed by passing the cylindrical substrate through the lower part of the coating tank with a small amount of the coating liquid.
[0049]
According to the manufacturing apparatus of the tenth aspect, since the sealing member comes into contact with the cylindrical substrate, it is possible to apply even a low-viscosity coating liquid without liquid leakage.
[0050]
According to the manufacturing method of the eleventh aspect, since at least the photosensitive layer is formed by the manufacturing apparatus, the invasion of bubbles due to the pulsation of the circulating pump is prevented, and an electrophotographic photosensitive member having excellent coating film quality can be manufactured. it can.
[0051]
According to the manufacturing method of the twelfth aspect, at the time of coating, since the liquid in the intermediate tank overflows and the liquid level is always maintained at a constant height and the coating is performed, a uniform coating film is formed. Can be.
[0052]
According to the manufacturing method of the thirteenth aspect, since the liquid in the first tank of the coating tank is exchanged, it is possible to prevent a change in physical properties of the coating liquid in the coating tank.
[0053]
According to the manufacturing method of claim 14, when the coating is performed by moving the cylindrical base relative to the coating tank, the coating is performed by passing the cylindrical base through the coating tank. A coating film having no coating film defects can be formed by the liquid.
[0054]
According to the production method of claim 15, when the cylindrical substrate is passed through the coating tank, the coating liquid and the cylindrical substrate are sealed to prevent liquid leakage. Defect-free and stable coating can be performed.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an example of a coating apparatus of the present invention.
FIG. 2 is a configuration diagram of a coating tank of FIG.
FIG. 3 is a schematic configuration diagram showing another example of the coating apparatus of the present invention.
FIG. 4 is a schematic configuration diagram of a conventional coating apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cylindrical base body 2 Coating tank 3 Storage tank 4 Intermediate tank 5 Circulation pump 6 Liquid receiving tray 7 Return pipe 8 Return pipe 9 Valve 10 Seal member 11 Inclination of upper surface of intermediate tank wall 12 Blocking wall 13 Liquid supply port 14 For drainage Opening 15 Wall of intermediate tank 16 Opening from which liquid can be drained

Claims

An apparatus for manufacturing an electrophotographic photoreceptor, in which at least a coating liquid is circulated between a coating tank and a coating liquid storage tank, and a cylindrical substrate is immersed in the coating liquid of the coating tank to perform coating. An electrophotographic photoreceptor manufacturing apparatus, characterized in that a coating liquid blocking wall is provided outside the cylindrical substrate and at a position higher than the coating liquid level and not to the bottom of the coating tank.

2. The apparatus for manufacturing an electrophotographic photoreceptor according to claim 1, wherein the position of the blocking wall is 1/10 to 4/5 times the distance from the surface of the cylindrical substrate to the wall of the coating tank, from the surface of the substrate. An apparatus for manufacturing an electrophotographic photosensitive member, which is located at a remote position.

3. The apparatus for manufacturing an electrophotographic photosensitive member according to claim 1, wherein a distance from a lower surface of the blocking wall to a coating tank bottom is 10 to 90% of a distance from the coating tank bottom to a coating liquid level. An apparatus for manufacturing an electrophotographic photosensitive member, comprising:

4. An electrophotographic photoreceptor manufacturing apparatus according to claim 1, wherein a liquid receiving tray is provided around the intermediate tank outside the blocking wall, and the liquid receiving tray can be drained. An apparatus for manufacturing an electrophotographic photoreceptor, comprising:

The apparatus for manufacturing an electrophotographic photosensitive member according to claim 1, wherein an upper surface of an outer wall of the intermediate tank is inclined from inside to outside.

The apparatus for manufacturing an electrophotographic photosensitive member according to claim 1, wherein a liquid supply port is provided in the intermediate tank.

The apparatus for manufacturing an electrophotographic photosensitive member according to claim 1, wherein a liquid supply port is provided above the intermediate tank.

The apparatus for manufacturing an electrophotographic photosensitive member according to any one of claims 1 to 7, wherein the coating tank has an opening through which liquid can be drained.

9. The apparatus for manufacturing an electrophotographic photosensitive member according to claim 1, further comprising: an opening through which a cylindrical substrate can penetrate at a lower portion of the coating tank, wherein the opening prevents leakage of the liquid. An apparatus for manufacturing an electrophotographic photoreceptor, comprising:

10. The apparatus for manufacturing an electrophotographic photoconductor according to claim 9, wherein the seal member for preventing the liquid leakage contacts a cylindrical base.

A method for producing an electrophotographic photoreceptor, comprising applying at least a photosensitive layer using the production apparatus according to claim 1.

12. The electrophotographic photoreceptor manufacturing method according to claim 11, wherein, when coating, the liquid in the intermediate tank is overflowed so that the liquid level is always kept at a constant height, and the electrophotography is performed. Manufacturing method of photoreceptor.

The method for manufacturing an electrophotographic photosensitive member according to claim 11, wherein the liquid in the first tank of the coating tank is replaced.

14. The method of manufacturing an electrophotographic photoreceptor according to claim 11, wherein the coating is performed by moving the cylindrical base relative to the coating tank and performing the coating by passing the cylindrical base through the coating tank. A method for producing an electrophotographic photoreceptor, comprising:

15. The electrophotographic photoreceptor manufacturing method according to claim 14, wherein when the cylindrical substrate is passed through the coating tank, the coating liquid and the cylindrical substrate are sealed to prevent liquid leakage. Manufacturing method of photoreceptor.