JPH09218522A - Electrophotographic photoreceptor and its production - Google Patents
Electrophotographic photoreceptor and its productionInfo
- Publication number
- JPH09218522A JPH09218522A JP2492296A JP2492296A JPH09218522A JP H09218522 A JPH09218522 A JP H09218522A JP 2492296 A JP2492296 A JP 2492296A JP 2492296 A JP2492296 A JP 2492296A JP H09218522 A JPH09218522 A JP H09218522A
- Authority
- JP
- Japan
- Prior art keywords
- charge
- layer
- charge transport
- concentration
- photosensitive member
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Photoreceptors In Electrophotography (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、複写機、プリンタ及び
ファクシミリ等の装置に使用される電子写真感光体にお
いて、特にイオン化ポテンシャル値の異なる電荷発生材
料と電荷輸送材料を用いて形成される積層型の電子写真
感光体及びその製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member used in a device such as a copying machine, a printer or a facsimile, and in particular, a laminate formed by using a charge generating material and a charge transporting material having different ionization potential values. Type electrophotographic photoreceptor and a method for manufacturing the same.
【０００２】[0002]
【従来の技術】近年、電子写真感光体に使用される感光
体材料は、環境安定性やコストの面から無機系材料から
有機系材料へと移り変わってきた。この電子写真感光体
の構成としては、感光層が、電荷発生機能を有する電荷
発生層と電荷輸送機能を有する電荷輸送層とに機能分離
した積層型の感光体、および電荷発生と電荷輸送との両
機能を一層に兼ね備えた単層型の感光体が知られている
が、有機系感光体は、その特性から積層型の層構成を採
るものが多い。2. Description of the Related Art In recent years, photosensitive materials used for electrophotographic photosensitive members have been changed from inorganic materials to organic materials in view of environmental stability and cost. The structure of the electrophotographic photosensitive member includes a laminated type photosensitive member in which a photosensitive layer is functionally separated into a charge generating layer having a charge generating function and a charge transporting layer having a charge transporting function, and a charge generating and charge transporting layer. Although a single-layer type photoconductor having both functions as one layer is known, many organic photoconductors have a laminated type layer structure because of their characteristics.
【０００３】積層型の電子写真感光体では、異種の物質
および薄膜を積層構造に形成することになるため、感光
体の光導電機能である電荷発生機能及び電荷輸送機能に
加えて、電荷発生層と電荷輸送層との界面における電荷
注入機能が要求される。一般に、電荷注入の条件として
は、電荷が電子である場合には、電荷発生層と電荷輸送
層の伝導帯準位が一致することが理想的であり、一方、
電荷が正孔である場合には、電荷発生層と電荷輸送層の
価電子帯準位が一致することが理想的である。これらを
真空準位を基準にすると、伝導帯は電子親和力に対応
し、また価電子帯はイオン化ポテンシャルに対応する。
イオン化ポテンシャルとは、基底状態にある原子または
分子から１個の電子を無限遠に引き離して、１個の陽イ
オンと自由電子とに解離されるために要するエネルギー
をいう。In the multi-layer type electrophotographic photoconductor, since different kinds of materials and thin films are formed in a multi-layer structure, in addition to the charge generating function and the charge transporting function which are the photoconductive functions of the photoconductor, the charge generating layer. A charge injection function is required at the interface between the charge transport layer and the charge transport layer. In general, as a condition of charge injection, when the charge is an electron, it is ideal that the conduction band levels of the charge generation layer and the charge transport layer match.
When the charges are holes, it is ideal that the valence band levels of the charge generation layer and the charge transport layer match. Based on these vacuum levels, the conduction band corresponds to the electron affinity and the valence band corresponds to the ionization potential.
The ionization potential is the energy required to dissociate one electron from an atom or molecule in the ground state to infinity and dissociate it into one cation and a free electron.
【０００４】このエネルギー準位が電荷発生材料と電荷
輸送材料との間がに０．５ｅＶ以上離れていると、電荷
注入障壁が存在することになり、電荷は、電荷発生層か
ら電荷輸送層にスムーズに注入されず、電荷発生層と電
荷輸送層との界面に蓄積し、空間電荷を形成する。その
結果、繰り返し使用時に感度の低下を引き起こしてしま
うことになる。すなわち、電荷輸送層中において、電荷
輸送材料の濃度が不均一に分散されていると、電荷の輸
送が円滑に進行することができず、空間電荷が形成され
ることから、感光体を繰り返し使用すると感度が低下し
てしまうという問題があった。If this energy level is 0.5 eV or more between the charge generating material and the charge transporting material, a charge injection barrier will be present, and the charge will flow from the charge generating layer to the charge transporting layer. It is not injected smoothly, but accumulates at the interface between the charge generation layer and the charge transport layer to form space charges. As a result, the sensitivity will be lowered when it is repeatedly used. That is, if the concentration of the charge transport material is non-uniformly dispersed in the charge transport layer, charge transport cannot proceed smoothly and space charges are formed, so the photoreceptor is repeatedly used. Then, there was a problem that the sensitivity was lowered.
【０００５】[0005]
【発明が解決しようとする課題】本発明は、従来の技術
における上記した実情に鑑み、その問題点を解決するこ
とを目的としてなされたものである。すなわち、本発明
の目的は、電子写真感光体の電荷発生層と電荷輸送層に
それぞれ用いられている電荷発生材料と電荷輸送材料と
のイオン化ポテンシャル値が０．５ｅＶ以上離れている
場合において、繰り返し使用しても感度が安定した電子
写真感光体及びその製造方法を提供することにある。SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances in the prior art, and has been made to solve the problems. That is, the object of the present invention is to repeat when the charge generation material and the charge transport material used in the charge generation layer and the charge transport layer of the electrophotographic photoreceptor have ionization potential values of 0.5 eV or more, respectively. An object of the present invention is to provide an electrophotographic photoreceptor having stable sensitivity even when used and a method for producing the same.
【０００６】[0006]
【課題を解決するための手段】本発明者等は、鋭意検討
した結果、電荷発生材料と電荷輸送材料とのイオン化ポ
テンシャル値が０．５ｅＶ以上離れている場合、電荷が
電荷発生層から電荷輸送層にスムーズに注入されないこ
とは、電荷輸送層中の電荷輸送材料濃度が不均一である
ことに起因すること及びそれを解決する手段を見出し、
本発明を完成するに至った。Means for Solving the Problems As a result of intensive studies by the present inventors, when the charge generation material and the charge transport material have an ionization potential value of 0.5 eV or more, the charge is transported from the charge generation layer. The fact that the layer was not smoothly injected was found to be due to the non-uniform concentration of the charge transport material in the charge transport layer and a means for solving the problem.
The present invention has been completed.
【０００７】本発明の電子写真感光体は、イオン化ポテ
ンシャル値が０．５ｅＶ以上離れている電荷発生材料及
び電荷輸送材料をそれぞれ用いて形成される電荷発生層
及び電荷輸送層を有する電子写真感光体であって、該電
荷輸送層中の電荷輸送材料が、電荷発生層側の電荷輸送
材料濃度とその反対側の電荷輸送材料濃度との比が０．
８〜１．０の範囲であることを特徴とする。また、電子
写真感光体の製造方法は、イオン化ポテンシャル値が
０．５ｅＶ以上離れている電荷発生材料及び電荷輸送材
料をそれぞれ用いて形成される電荷発生層及び電荷輸送
層を有する電子写真感光体の製造方法において、電荷輸
送層の塗布液を塗布した後、１２５℃以上に加熱するこ
とを特徴とする。The electrophotographic photoconductor of the present invention has a charge generation layer and a charge transport layer which are formed by using a charge generation material and a charge transport material having an ionization potential value of 0.5 eV or more, respectively. The charge transport material in the charge transport layer has a ratio of the charge transport material concentration on the charge generation layer side to the charge transport material concentration on the opposite side of 0.
It is characterized in that it is in the range of 8 to 1.0. In addition, the method for producing an electrophotographic photosensitive member is a method for producing an electrophotographic photosensitive member having a charge generating layer and a charge transporting layer, which are formed by using a charge generating material and a charge transporting material having ionization potential values separated by 0.5 eV or more, respectively. In the manufacturing method, after the coating liquid for the charge transport layer is applied, it is heated to 125 ° C. or higher.
【０００８】[0008]
【発明の実施の形態】以下、本発明の実施の形態につい
て詳細に説明する。本発明は、電荷発生材料を用いて形
成される電荷発生層及び電荷輸送材料を用いて形成され
る電荷輸送層を機能分離して設けた積層型の電子写真感
光体において、使用される電荷発生材料と電荷輸送材料
との間に、イオン化ポテンシャル値に０．５ｅＶ以上の
差異がある場合に、電荷輸送層中に分散されている電荷
輸送材料が特定の濃度範囲で分布して存在していること
を要件としているものである。本発明においては、具体
的には、電荷輸送層中の電荷輸送材料について、電荷発
生層側の電荷輸送材料濃度とその反対側の電荷輸送材料
濃度との比が０．８〜１．０の範囲であることが必要で
ある。Embodiments of the present invention will be described below in detail. The present invention relates to a charge generation layer used in a laminated electrophotographic photosensitive member provided with a charge generation layer formed of a charge generation material and a charge transport layer formed of a charge transport material by functional separation. When there is a difference of 0.5 eV or more in the ionization potential value between the material and the charge transport material, the charge transport material dispersed in the charge transport layer exists in a specific concentration range. Is a requirement. In the present invention, specifically, in the charge transport material in the charge transport layer, the ratio of the concentration of the charge transport material on the side of the charge generation layer to the concentration of the charge transport material on the opposite side is 0.8 to 1.0. Must be in range.
【０００９】一般に、電子写真感光体における電荷輸送
層中の電荷輸送材料は、分子分散により均一に分散され
ていると考えられるが、実際には不均一に分散されてい
る。この事実は、電荷輸送層中の電荷輸送材料を染色
し、これを電子顕微鏡により観察する方法等により確認
することができるし、また、定量的には、ＩＲ／ＡＴＲ
測定によるピーク強度比から判断することができる。Generally, the charge-transporting material in the charge-transporting layer of the electrophotographic photosensitive member is considered to be uniformly dispersed by molecular dispersion, but actually it is non-uniformly dispersed. This fact can be confirmed by, for example, a method of dyeing the charge transport material in the charge transport layer and observing it with an electron microscope, and quantitatively, IR / ATR
It can be determined from the measured peak intensity ratio.
【００１０】上記した電荷輸送層中における電荷輸送材
料が不均一に分散されているのは、電荷輸送層を形成す
る際の乾燥時の加熱温度が低いこと等により、電荷輸送
層の内部で対流が生じて電荷輸送材料が移動してしまう
ことに起因するものと考えられる。このように、電荷輸
送層中において、電荷輸送材料の濃度が不均一に分散さ
れていると、電荷の輸送がスムーズに行われず、空間電
荷が形成されて、繰り返し使用時に感度の低下を引き起
こすことになる。The charge transporting material in the charge transporting layer is non-uniformly dispersed because convection occurs inside the charge transporting layer due to a low heating temperature during drying when the charge transporting layer is formed. It is considered that this is caused by the fact that the charge transport material moves due to the occurrence of the phenomenon. As described above, when the concentration of the charge transport material is non-uniformly dispersed in the charge transport layer, the charge is not transported smoothly, space charges are formed, and the sensitivity is lowered during repeated use. become.
【００１１】電荷輸送材料の濃度は、電荷発生層と電荷
輸送層との界面における電荷注入を制限する作用をして
いるものと考えられる。この電荷注入過程は、異種分子
間のホッピング移動とすると、電荷注入は分子間距離に
依存し、電荷輸送材料の電荷数が小さ過ぎると電荷は注
入されない。その結果として、上記したように、電荷発
生層と電荷輸送層との界面に蓄積して空間電荷を形成
し、繰り返し使用時に感度の低下が発生する。このこと
は、電荷輸送層内においても生じると考えられるため、
電荷輸送層内の電荷輸送材料の濃度分布について充分考
慮しなければならない。It is considered that the concentration of the charge transport material has a function of limiting charge injection at the interface between the charge generation layer and the charge transport layer. If this charge injection process is hopping transfer between different molecules, the charge injection depends on the intermolecular distance, and if the number of charges in the charge transport material is too small, no charges are injected. As a result, as described above, the charge is accumulated at the interface between the charge generation layer and the charge transport layer to form space charge, and the sensitivity is lowered during repeated use. Since this is considered to occur in the charge transport layer,
The concentration distribution of the charge transport material in the charge transport layer must be carefully considered.
【００１２】本発明は、イオン化ポテンシャル値が０．
５ｅＶ以上離れている電荷発生材料と電荷輸送材料とを
用いて形成されている積層型の電子写真感光体におい
て、電荷輸送層中の電荷輸送材料について、電荷発生層
側に存在する電荷輸送材料濃度とその反対側に存在する
電荷輸送材料濃度との濃度分布比を０．８〜１．０の範
囲に保持させることにより、電荷発生層から電荷輸送層
への電荷注入を円滑に行うことができるようにするもの
である。The present invention has an ionization potential value of 0.
In a laminated electrophotographic photosensitive member formed by using a charge generating material and a charge transporting material that are separated by 5 eV or more, with respect to the charge transporting material in the charge transporting layer, the concentration of the charge transporting material existing on the charge generating layer side By maintaining the concentration distribution ratio between the concentration of the charge transporting material and the concentration of the charge transporting material on the opposite side to 0.8 to 1.0, the charge injection from the charge generating layer to the charge transporting layer can be smoothly performed. To do so.
【００１３】本発明において、上記した電荷輸送層にお
ける電荷輸送材料の濃度分布比が０．８〜１．０の範囲
にある電子写真感光体を製造するためには、電荷輸送層
の形成に用いる塗布液を塗布した後、その塗布層を１２
５℃以上で加熱処理することが必要であり、好ましくは
１３５℃以上で加熱処理を行う。このようにして作製さ
れた電子写真感光体は、繰り返し使用後においても感度
が非常に安定したものとなっている。In the present invention, in order to produce an electrophotographic photosensitive member in which the concentration distribution ratio of the charge transport material in the above charge transport layer is in the range of 0.8 to 1.0, it is used for forming the charge transport layer. After applying the coating solution, apply the coating layer 12
It is necessary to perform heat treatment at 5 ° C. or higher, preferably 135 ° C. or higher. The electrophotographic photosensitive member produced in this manner has very stable sensitivity even after repeated use.
【００１４】本発明において、電子写真感光体の作製に
用いられる導電性支持体、感光層の結着樹脂、感光材料
及びその他の添加剤等、および必要に応じて設けられる
下引き層、保護層等の各層における材料は、いずれも従
来公知のものから適宜選択することができる。In the present invention, a conductive support used for producing an electrophotographic photosensitive member, a binder resin for the photosensitive layer, a photosensitive material and other additives, and an undercoat layer and a protective layer, which are provided as necessary. The material of each layer such as can be appropriately selected from conventionally known materials.
【００１５】[0015]
【実施例】以下、実施例により本発明を具体的に説明す
る。 実施例１ 円筒状導電性支持体として、３０ｍｍφのアルミニウム
製パイプを使用し、その上にジルコニウム化合物を混合
したポリビニルブチラール樹脂のブチルアルコール溶液
を浸漬塗布法により塗布し、乾燥させて膜厚約１μｍの
下引き層を形成した。次に、Ｘ型無金属フタロシアニン
顔料（イオン化ポテンシャル値＝４．９８ｅＶ）１．２
５ｇとポリビニルブチラール樹脂１．２５ｇとを、シク
ロヘキサノン９７．５ｇ中の固形分濃度が２．５重量％
となるように分散させた溶液を、上記支持体の下引き層
上に浸漬塗工し、オーブン乾燥器を用いて１００℃で１
０分間乾燥させて、膜厚０．２５μｍの電荷発生層を形
成した。The present invention will be described below in detail with reference to examples. Example 1 A 30 mmφ aluminum pipe was used as a cylindrical conductive support, and a butyl alcohol solution of polyvinyl butyral resin mixed with a zirconium compound was applied thereon by a dip coating method and dried to a film thickness of about 1 μm. To form an undercoat layer. Next, an X-type metal-free phthalocyanine pigment (ionization potential value = 4.98 eV) 1.2
5 g of polyvinyl butyral resin and 1.25 g of polyvinyl butyral resin having a solid content concentration of 2.5% by weight in 97.5 g of cyclohexanone.
The thus-dispersed solution is applied onto the undercoat layer of the support by dip coating, and the solution is dried at 100 ° C. for 1 hour using an oven dryer.
It was dried for 0 minutes to form a charge generation layer having a film thickness of 0.25 μm.
【００１６】次に、Ｎ，Ｎ−ビス（３，４−ジメチルフ
ェニル）ビフェニル−４−アミン（イオン化ポテンシャ
ル値＝５．５２ｅＶ）１１．２５ｇとポリカーボネート
樹脂１１．２５ｇとを、モノクロルベンゼンとテトラヒ
ドロフラン（重量比１：３）との混合溶媒７７．５ｇ中
の固形分濃度が２２．５重量％となるように分散させた
溶液を、電荷発生層の上に浸漬塗工し、オーブン乾燥器
を用いて１２５℃で４０分間乾燥させて膜厚２４μｍの
電荷輸送層を形成することにより、電子写真感光体を作
製した。Next, 11.25 g of N, N-bis (3,4-dimethylphenyl) biphenyl-4-amine (ionization potential value = 5.52 eV) and polycarbonate resin 11.25 g were mixed with monochlorobenzene and tetrahydrofuran ( A solution having a solid content concentration of 22.5% by weight in a mixed solvent of 77.5 g with a weight ratio of 1: 3) was applied by dip coating on the charge generation layer, and an oven dryer was used. And dried at 125 ° C. for 40 minutes to form a charge transport layer having a film thickness of 24 μm, thereby preparing an electrophotographic photosensitive member.
【００１７】実施例２ 実施例１と同様にして、円筒状導電性支持体上に、電荷
発生層まで形成した。次に、電荷輸送層は、Ｎ，Ｎ−ビ
ス（３，４−ジメチルフェニル）ビフェニル−４−アミ
ン１１．２５ｇとポリカーボネート樹脂１１．２５ｇと
を、モノクロルベンゼンとテトラヒドロフラン（重量比
１：３）との混合溶媒７７．５ｇ中の固形分濃度が２
２．５重量％となるように分散させた溶液を、電荷発生
層の上に浸漬塗工し、オーブン乾燥器を用いて１５５℃
で４０分間乾燥させて膜厚２４μｍの電荷輸送層を形成
することにより、電子写真感光体を作製した。Example 2 In the same manner as in Example 1, a charge generating layer was formed on a cylindrical conductive support. Next, for the charge transport layer, N, N-bis (3,4-dimethylphenyl) biphenyl-4-amine (11.25 g) and polycarbonate resin (11.25 g) were mixed with monochlorobenzene and tetrahydrofuran (weight ratio 1: 3). The solid content concentration in the mixed solvent of 77.5 g is 2
The solution dispersed so as to be 2.5% by weight is applied by dip coating on the charge generation layer, and then 155 ° C. using an oven dryer.
And dried for 40 minutes to form a charge transport layer having a film thickness of 24 μm, thereby preparing an electrophotographic photoreceptor.
【００１８】比較例１ 実施例１と同様にして、円筒状導電性支持体上に、電荷
発生層まで形成した。次に、電荷輸送層は、Ｎ，Ｎ−ビ
ス（３，４−ジメチルフェニル）ビフェニル−４−アミ
ン１１．２５ｇとポリカーボネート樹脂１１．２５ｇと
を、モノクロルベンゼンとテトラヒドロフラン（重量比
１：３）との混合溶媒７７．５中の固形分濃度が２２．
５重量％となるように分散させた溶液を、電荷発生層の
上に浸漬塗工し、オーブン乾燥器を用いて１１５℃で４
０分間乾燥させて膜厚２４μｍの電荷輸送層を形成する
ことにより、電子写真感光体を作製した。Comparative Example 1 In the same manner as in Example 1, a charge generating layer was formed on a cylindrical conductive support. Next, for the charge transport layer, N, N-bis (3,4-dimethylphenyl) biphenyl-4-amine (11.25 g) and polycarbonate resin (11.25 g) were mixed with monochlorobenzene and tetrahydrofuran (weight ratio 1: 3). Solid solvent concentration in the mixed solvent 77.5 of 22.
The solution dispersed so as to be 5% by weight was applied onto the charge generation layer by dip coating, and the solution was dried at 115 ° C. for 4 hours using an oven dryer.
An electrophotographic photosensitive member was produced by drying for 0 minutes to form a charge transport layer having a film thickness of 24 μm.
【００１９】上記実施例及び比較例において作製した電
子写真感光体について、下記の方法により感光体の電気
特性及び電荷輸送材料の濃度を測定した。 ［感光体の電気特性］電子写真感光体の電気特性は、円
筒状感光体を、一定速度で回転させる手段、帯電させる
手段、露光させる手段及び表面電位を測定する手段とを
備えている装置を用いて測定した。感光体試料は、ＶGR
ID＝５００Ｖに設定したスコロトロンにより帯電され、
ハロゲンランプ光を干渉フィルターに通して７８０ｎｍ
にした光を用いて７ｍＪ／ｍ2 の露光を行って測定し
た。上記した方法において、帯電後電位及び露光後電位
について、それぞれ１０サイクル目及び２００サイクル
目の値を測定した。With respect to the electrophotographic photosensitive members produced in the above Examples and Comparative Examples, the electrical characteristics of the photosensitive members and the concentration of the charge transport material were measured by the following methods. [Electrical Characteristics of Photoreceptor] The electrical characteristics of the electrophotographic photoreceptor are as follows: a device having a means for rotating a cylindrical photoreceptor at a constant speed, a means for charging, a means for exposing, and a means for measuring surface potential. It was measured using. Photoconductor sample is VGR
Charged by a scorotron set to ID = 500V,
780nm through the halogen filter light through the interference filter
The light was exposed to 7 mJ / m @ 2 and measured. In the above-mentioned method, the value at the 10th cycle and the value at the 200th cycle were measured for the potential after charging and the potential after exposure.
【００２０】［電荷輸送材料の濃度測定］電荷輸送層中
の電荷輸送材料の濃度測定には、ＩＲ／ＡＴＲ法を用い
た。円筒状導電性支持体上に形成されている電荷輸送層
のみを剥離し、ＺｎＳｅ４５°結晶板に挟んで電荷輸送
層の電荷発生層側とその反対側の電荷輸送材料の濃度測
定を行った。電荷輸送材料の濃度は、結着樹脂として使
用しているポリカーボネート樹脂の１７７４ｃｍ-1のピ
ーク強度に対するＮ，Ｎ−ビス（３，４−ジメチルフェ
ニル）ビフェニル−４−アミンの１６００ｃｍ-1のピー
ク強度比から半定量した。なお、このときの電荷輸送層
の測定深さは、表面から１μｍ程度である。[Measurement of Concentration of Charge Transport Material] The IR / ATR method was used to measure the concentration of the charge transport material in the charge transport layer. Only the charge transport layer formed on the cylindrical conductive support was peeled off, sandwiched between the ZnSe 45 ° crystal plates, and the concentration of the charge transport material on the charge generation layer side of the charge transport layer and on the opposite side was measured. The concentration of the charge transporting material is such that the peak intensity of N, N-bis (3,4-dimethylphenyl) biphenyl-4-amine at 1600 cm -1 with respect to the peak intensity of 1774 cm -1 of the polycarbonate resin used as the binder resin. Semi-quantitative from the ratio. The measurement depth of the charge transport layer at this time is about 1 μm from the surface.
【００２１】以上により、電子写真感光体の電気特性お
よび電荷輸送層中の電荷輸送材料濃度比について測定し
た結果を表１に示す。Table 1 shows the results obtained by measuring the electrical characteristics of the electrophotographic photosensitive member and the concentration ratio of the charge transport material in the charge transport layer.
【表１】 [Table 1]
【００２２】表１によれば、実施例１〜２では、電荷輸
送材料の濃度比が０．８〜１．０の範囲にあるため、露
光後電位は１０〜２００サイクルの間で安定している。
これに対して、比較例１では、その濃度比が０．８以下
であるため、露光後電位は１０〜２００サイクルの間で
大きく変化していて不安定であることを示し、電荷輸送
層中の電荷輸送材料の分布状態の不均一性が大きく、繰
り返し使用時の露光後電位は悪化する傾向が見られる。According to Table 1, in Examples 1 and 2, since the concentration ratio of the charge transport material is in the range of 0.8 to 1.0, the potential after exposure is stable during 10 to 200 cycles. There is.
On the other hand, in Comparative Example 1, since the concentration ratio was 0.8 or less, the post-exposure potential changed significantly during 10 to 200 cycles and was unstable. There is a large non-uniformity in the distribution state of the charge transport material, and the potential after exposure during repeated use tends to deteriorate.
【００２３】従って、繰り返し使用時の露光後電位の増
加量を抑制するため、換言すると、繰り返し使用時の感
度を安定させるためには、電荷輸送材料濃度の偏析は
０．８〜１．０の範囲であることを必要とすることは明
らかである。また、その濃度の制御方法としては、加熱
処理温度であることが理解できる。また、この系の場
合、１３５℃以上で加熱処理を行うことにより、特に望
ましい感光層を有する電子写真感光体を得ることが可能
である。Therefore, in order to suppress the amount of increase in potential after exposure during repeated use, in other words, in order to stabilize the sensitivity during repeated use, the segregation of the charge transport material concentration is 0.8 to 1.0. It is clear that it needs to be in range. Further, it can be understood that the method of controlling the concentration is the heat treatment temperature. Further, in the case of this system, it is possible to obtain an electrophotographic photosensitive member having a particularly desirable photosensitive layer by performing heat treatment at 135 ° C. or higher.
【００２４】[0024]
【発明の効果】本発明の電子写真感光体は、電荷発生材
料と電荷輸送材料とのイオン化ポテンシャル値が０．５
ｅＶ以上離れていても、電荷輸送層中の電荷輸送材料の
濃度分布を一定の範囲で均一に保持することにより、繰
り返し使用しても感度が極めて安定している。また、電
子写真感光体の製造方法は、電荷輸送層を形成する塗布
液を一定以上の温度で加熱処理するという簡単な操作に
より、電荷輸送層中の電荷輸送材料の濃度分布を一定の
範囲に保持することができる。The electrophotographic photoreceptor of the present invention has an ionization potential value of 0.5 between the charge generating material and the charge transporting material.
Even if the distance is eV or more, by keeping the concentration distribution of the charge transport material in the charge transport layer uniform within a certain range, the sensitivity is extremely stable even after repeated use. In addition, the method for producing an electrophotographic photosensitive member is such that the concentration distribution of the charge transporting material in the charge transporting layer is kept within a certain range by a simple operation of heating the coating solution for forming the charge transporting layer at a certain temperature or higher. Can be held.
Claims (2)
上離れている電荷発生材料及び電荷輸送材料をそれぞれ
用いて形成される電荷発生層及び電荷輸送層を有する電
子写真感光体において、該電荷輸送層中の電荷輸送材料
が、電荷発生層側の電荷輸送材料濃度とその反対側の電
荷輸送材料濃度との比が０．８〜１．０の範囲であるこ
とを特徴とする電子写真感光体。1. An electrophotographic photosensitive member having a charge generation layer and a charge transport layer, which are formed by using a charge generation material and a charge transport material having ionization potential values separated by 0.5 eV or more, respectively, in the charge transport layer. 2. The electrophotographic photoreceptor, wherein the ratio of the charge transport material concentration on the charge generation layer side to the charge transport material concentration on the opposite side is in the range of 0.8 to 1.0.
上離れている電荷発生材料及び電荷輸送材料をそれぞれ
用いて形成される電荷発生層及び電荷輸送層を有する電
子写真感光体の製造方法において、電荷輸送層の塗布液
を塗布した後、１２５℃以上に加熱することを特徴とす
る電子写真感光体の製造方法。2. A method for producing an electrophotographic photosensitive member having a charge generating layer and a charge transporting layer, which are formed by using a charge generating material and a charge transporting material having ionization potential values separated by 0.5 eV or more, respectively. A method for producing an electrophotographic photosensitive member, which comprises applying a layer coating solution and then heating the layer at 125 ° C. or higher.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2492296A JPH09218522A (en) | 1996-02-13 | 1996-02-13 | Electrophotographic photoreceptor and its production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2492296A JPH09218522A (en) | 1996-02-13 | 1996-02-13 | Electrophotographic photoreceptor and its production |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09218522A true JPH09218522A (en) | 1997-08-19 |
Family
ID=12151639
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2492296A Pending JPH09218522A (en) | 1996-02-13 | 1996-02-13 | Electrophotographic photoreceptor and its production |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09218522A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008158456A (en) * | 2006-12-26 | 2008-07-10 | Ricoh Co Ltd | Method for manufacturing electrophotographic photoreceptor, and electrophotographic photoreceptor and image forming apparatus obtained by method |
| JP2011022425A (en) * | 2009-07-16 | 2011-02-03 | Fuji Xerox Co Ltd | Electrophotographic photoreceptor, process cartridge, and image forming apparatus |
-
1996
- 1996-02-13 JP JP2492296A patent/JPH09218522A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008158456A (en) * | 2006-12-26 | 2008-07-10 | Ricoh Co Ltd | Method for manufacturing electrophotographic photoreceptor, and electrophotographic photoreceptor and image forming apparatus obtained by method |
| JP2011022425A (en) * | 2009-07-16 | 2011-02-03 | Fuji Xerox Co Ltd | Electrophotographic photoreceptor, process cartridge, and image forming apparatus |
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