JPH08101523A - Electrophotographic photoreceptor - Google Patents

Abstract

PURPOSE: To obtain a photoreceptor less liable to dark decay and the rise of residual potential even after repeated use while maintaining the adhesiveness of a photosensitive layer to the electrically conductive substrate and making the substrate free from defects. CONSTITUTION: When an undercoat layer and a photosensitive layer are successively formed on an electrically conductive substrate to obtain an electrophotographic photoreceptor, a high molecular electric charge transferring material and a low molecular electric charge transferring material are incorporated as effective components into the undercoat layer or a high molecular electric charge transferring material is incorporated as an effective component into the undercoat layer and the photosensitive layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having an undercoat layer containing a polymer charge transport material.

[0002]

2. Description of the Related Art Generally, an electrophotographic photosensitive member is composed of a conductive support and a photosensitive layer. However, the adhesion between the conductive support and the photosensitive layer is improved, the film forming property and coating property of the photosensitive layer are improved, For the purpose of covering defects in the conductive support, protecting the photosensitive layer against electrical breakdown, and improving dark decay due to charge injection from the conductive support to the photosensitive layer, a layer between the conductive support and the photosensitive layer is provided. A pull layer may be provided.

For the undercoat layer, SiO, Al ₂ is formed on the support.
A method of providing an inorganic material such as O ₃ or the like, particularly a metal oxide, by a method such as vapor deposition, sputtering, anodic oxidation, or a sol-gel method is known, and Al ₂ O ₃ is contained in the charge generation layer.
Or (Japanese Patent Application Laid-Open No. 55-142354),
Similarly, it is also known to incorporate a metal powder in the charge generation layer (Japanese Patent Laid-Open No. 60-21436).

Further, a polyamide resin is used as an undercoat layer (JP-A-58-30757 and JP-A-58-98739).
No.), alcohol-soluble nylon resin (JP-A-60
No. 196766), water-soluble polyvinyl butyral (JP-A-60-232553), polyvinyl butyral (JP-A-58-106549), and other resin layers have been proposed. On the other hand, JP-A-61-296362
The publication discloses an undercoat layer made of a charge transport material, a charge generating material, and a resin. However, even when these undercoat layers are used, none of them satisfy the above-mentioned characteristics, and further improvement has been desired.

That is, when the undercoat layer is an insulating material such as a resin or a metal oxide, a residual potential is likely to occur. On the other hand, when a conductive material is used as the undercoat layer, dark decay occurs due to charge injection from the substrate into the photosensitive layer. It has been proposed to use a low-molecular-weight charge transport material for the undercoat layer in order to compensate for such a defect in the electrostatic characteristics related to the undercoat layer, but unfortunately, the low-molecular charge transport material is not suitable for the photosensitive layer. It leached out to the photosensitive layer side when was applied and formed, and as a result, a remarkable effect could not be obtained. Here, it is conceivable to use a polymeric charge transport material instead of a low molecular charge transport material for the undercoat layer. However, the residual potential or surface potential of the photosensitive layer and the undercoat layer due to poor injection of charges may be used. Produces dark decay. On the other hand, regarding the adhesiveness, when a polymer charge transport material is used for the undercoat layer, in many cases, the adhesion between the undercoat layer and the photosensitive layer is not excellent, and peeling is likely to occur.

[0006]

SUMMARY OF THE INVENTION A first object of the present invention is to provide a photoreceptor having excellent adhesion between a conductive support and a photosensitive layer and eliminating defects of the conductive support. . A second object of the present invention is to provide a photoconductor in which the dark decay is small and the residual potential is small even when it is repeatedly used. A third object of the present invention is to provide an electrophotographic photosensitive member that does not generate a moire image even when image exposure is performed using coherent light.

[0007]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made extensive studies on the relationship between an undercoat layer material and a photosensitive layer material in order to solve these problems in electrical characteristics and adhesiveness at the same time. As a result, the above problems can be solved by including a polymer charge transporting material and a low molecular weight charge transporting material in the undercoat layer, or by incorporating a polymer charge transporting material in both the undercoat layer and the photosensitive layer. The present invention has been completed and the present invention has been completed.

That is, according to the present invention, firstly, in an electrophotographic photosensitive member comprising a conductive support and an undercoat layer and a photosensitive layer provided in this order, a polymer charge transporting material is contained in the undercoat layer. Provided is an electrophotographic photoreceptor comprising a low-molecular charge transport material as an active ingredient.

Secondly, in an electrophotographic photosensitive member comprising a conductive support and an undercoat layer and a photosensitive layer sequentially provided thereon, the undercoat layer and the photosensitive layer contain a polymer charge transport material as an active ingredient. An electrophotographic photosensitive member characterized by the following is provided.

Further, according to the present invention, preferably, the photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer, and the charge generation layer contains a polymer charge transport material.
Alternatively, the photosensitive layer has a laminated structure of a charge generating layer and a charge transporting layer, and the charge transporting layer contains a polymer charge transporting material. Furthermore, the undercoat layer further contains metal oxide particles. There is provided the above electrophotographic photosensitive member characterized by containing the above.

The constitution of the electrophotographic photosensitive member of the present invention will be described below.
It will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an electrophotographic photosensitive member of the present invention, which has a structure in which an undercoat layer 13 and a photosensitive layer 15 are sequentially provided on a conductive support 11.
2 and 3, each of the photosensitive layers has a structure in which a charge generation layer 17 and a charge transport layer 19 are laminated.

As the conductive support 11, the volume resistance 10
Materials with conductivity of ¹⁰ Ωcm or less, such as metals such as aluminum, nickel, chromium, copper, silver, gold and platinum,
A film or cylindrical plastic or paper coated with a metal oxide such as tin oxide or indium oxide by vapor deposition or sputtering, or a plate made of aluminum, an aluminum alloy, nickel, stainless steel or the like, and D. I. , I. I. It is possible to use a tube or the like which is formed into a raw tube by a method such as extrusion or drawing and then surface-treated by cutting, superfinishing, polishing or the like.

Next, the undercoat layer 13 will be described. The undercoat layer of the electrophotographic photosensitive member according to claim 1 of the present invention contains a polymer charge transporting material and a low molecular charge transporting material as main components, and the electrophotographic photosensitive member according to claim 2 contains a polymer charge transporting material as a main component. To do.

The polymer charge-transporting material that can be used in the present invention is not particularly limited, but the following can be mentioned. (A) Polymer Having Carbazole Ring in Main Chain and / or Side Chain For example, JP-A-50-82056 and JP-A-54-
Examples thereof include the compounds described in 9632, JP-A-54-11737, and JP-A-4-183719. (B) Polymer having hydrazone structure in main chain and / or side chain For example, JP-A-57-78402 and JP-A-3-5
Examples thereof include the compounds described in Japanese Patent No. 0555. (C) Polysilylene polymer For example, JP-A-63-285552 and JP-A-5-
Examples thereof include the compounds described in 19497 and JP-A-5-70595. (D) Polymer having a tertiary amine structure in the main chain and / or side chain, for example, poly-p-vinyltriphenylamine, JP-A-1-17228, JP-A-1-13061, JP-A-1 -19049, Japanese Patent Application Laid-Open No. 1-105260, Japanese Patent Application Laid-Open No. 2-167335, Japanese Patent Application Laid-Open No. 5-40
Examples thereof include compounds described in JP-A No. 350 and JP-A No. 5-66598. (E) Other polymers For example, a formaldehyde condensation polymer of nitropyrene, JP-A-51-73888, JP-A-56-15074.
Examples thereof include the compounds described in JP-A-9.

The polymer charge-transporting material used in the present invention is not limited to the above-mentioned polymers, but also copolymers of known monomers,
Block polymer, graft polymer, star polymer,
Further, for example, a cross-linked polymer having an electron donating group as disclosed in JP-A-3-109406 can be used. The polymeric charge transport material used in the present invention is, among other materials listed above,
The use of those belonging to (b), (c), and (d) can give preferable effects. The polymer charge transport material used in the present invention does not necessarily have a high molecular weight and may be a so-called oligomer. Therefore, the weight average molecular weight of the polymer is preferably 1000 or more, and more preferably 2000 to 2000000.

If desired, an electrically inactive binder resin may be used in combination with the undercoat layer 13 of the present invention. As the binder resin, polyvinyl alcohol, casein, copolymerized nylon, methoxymethylated nylon, polyurethane, polyester, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polyacrylamide , Melamine resin, phenol resin, alkyd-melamine resin, epoxy resin and the like are used.

As described above, in the electrophotographic photosensitive member according to the first aspect, the low molecular charge transport material is used as the main component of the undercoat layer 13 together with the high molecular charge transport material.

The low molecular charge transport material used for the undercoat layer 13 includes a hole transport material and an electron transport material.
Examples of the low molecular weight electron transport substance include chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone,
2,4,5,7-tetranitroxanthone, 2,4,8
-Trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5.
Known electron-accepting substances such as 5-dioxide and 3,5-dimethyl-3 ′, 5′-ditertiarybutyl-4,4′-diphenoquinone can be mentioned. As the low-molecular-weight hole transport material, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives,
Diarylamine derivative, triarylamine derivative,
Other known materials such as stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives and butadiene derivatives are mentioned. Used. These low molecular weight charge transport materials may be used alone or in combination of two or more.

The undercoat layer 13 of the present invention includes metal oxides such as aluminum oxide, tin oxide, indium oxide, titanium oxide, zirconium oxide, zinc oxide, silicon oxide, tantalum oxide, molybdenum oxide and tungsten oxide. It is also possible to use a mixture thereof, a mixed crystal thereof, or the like in a fine powder state, whereby the moire image can be eliminated. Here, the moire image will be slightly described. In image exposure, when light is coherent such as LD, LED, etc., and when light reflection occurs at the lower end of the photosensitive layer, a moire image is generated in the halftone portion. However, by adding the metal oxide fine powder to the undercoat layer according to the present invention, it is possible to eliminate the moire image by irregularly reflecting or refracting the coherent light.

For the undercoat layer 13, a polymer charge transport material and / or a low molecular charge transport material is used as an active ingredient, and metal oxide particles and, if necessary, an electrically inactive binder resin are used together. It is possible to form these by dispersing these with a ball mill, attritor, sand mill, etc. using an appropriate solvent such as tetrahydrofuran, cyclohexanone, dioxane, 2-butanone, dichloroethane, etc., and diluting the dispersion appropriately. it can.
The coating can be performed by a dip coating method, a spray coating method, a bead coating method, or the like. The thickness of the undercoat layer 13 used in the present invention is 0.1 to 10 μm, preferably 0.2 to 5 μm.

Next, the photosensitive layer 15 will be described. First,
The photosensitive layer of the electrophotographic photosensitive member of claim 1 will be described. The photosensitive layer may be a single layer or a laminated layer, but for convenience of description, the case where the photosensitive layer is composed of the charge generation layer 17 and the charge transport layer 19 will be described first.

The charge generation layer 17 is a layer containing a charge generation material as a main component. As the charge generation material, inorganic and organic materials are used, and representative examples thereof include monoazo pigments, disazo pigments, trisazo pigments, perylene pigments, perinone pigments, quinacridone pigments, quinone condensed polycyclic compounds,
Examples thereof include squaric acid type dyes, phthalocyanine type pigments, naphthalocyanine type pigments, azurenium salt type dyes, selenium, selenium-tellurium, selenium-arsenic compounds, and amorphous silicon. Among these, azo pigments, perylene pigments, perinone pigments, quinacridone pigments, quinone condensed polycyclic compounds, squalic acid dyes, phthalocyanine pigments, naphthalocyanine pigments,
Good results are obtained when an organic material typified by an azurenium salt dye is used. The charge generating materials may be used alone or in combination of two or more.

In the charge generation layer 17 of the present invention, an electrically inactive binder resin may be used in combination if necessary. As the binder resin, polyamide, polyurethane, polyester, epoxy resin, holyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, holyvinyl formal, polyvinyl ketone, polystyrene, polyacrylamide or the like is used.

In the charge generation layer 17, the charge generation substance is dispersed together with a binder resin if necessary using a suitable solvent such as tetrahydrofuran, cyclohexanone, dioxane, 2-butanone, dichloroethane, etc. by a ball mill, attritor, sand mill or the like, It can be formed by appropriately diluting the dispersion liquid and applying it. The coating can be performed by using a dip coating method, a spray coating method, a roller coating method, or the like. The thickness of the charge generation layer 17 is 0.01
About 5 μm is suitable, and preferably 0.1 to 2 μm
Is.

The charge transport layer 19 can be formed by dissolving or dispersing a charge transport material and a binder resin in an appropriate solvent, applying the solution, and drying the solution. If necessary, a plasticizer or a leveling agent can be added. The charge transport layer 19 is composed of a charge transport material and a binder resin. As the charge transport material, the above-mentioned low molecular charge transport material and / or polymer charge transport material can be used as they are. As the binder resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinyl Vinylidene chloride, polyarylate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene,
Examples thereof include thermoplastic or thermosetting resins such as acrylic resins, silicone resins, epoxy resins, melamine resins, urethane resins, phenol resins, and alkyd resins. As the solvent, tetrahydrofuran, dioxane, toluene, 2-butanone, monochlorobenzene, dichloroethane, methylene chloride and the like are used. The appropriate thickness of the charge transport layer 19 is 5 to 100 μm.

In the present invention, a plasticizer or a leveling agent may be added to the charge transport layer 19. As a plasticizer,
Dibutyl phthalate, dioctyl phthalate, and other resins used as plasticizers for general resins can be used as they are, and the amount used is 0 to 30 relative to the binder resin.
About wt% is appropriate. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain are used, and the amount thereof is 0 to 1 weight with respect to the binder resin. % Is appropriate.

Next, the case where the photosensitive layer 15 has a single layer structure will be described. In this case as well, in most cases, a function-separated type of charge-generating substance and charge-transporting substance is used. That is, it can be formed by dissolving or decomposing the charge-generating substance, the charge-transporting substance and the binder resin in a suitable solvent, and coating and drying them. Further, if necessary, a plasticizer, a leveling agent, etc. can be added. As the binder resin, the binder resin described above in the charge transport layer 19 may be used as it is, or the binder resin described in the charge generation layer 17 may be mixed. A photosensitive layer obtained by adding a hole-transporting substance to a eutectic complex formed of a pyrylium-based dye or bisphenol A-based polycarbonate can also be used as the single-layer photosensitive layer 15. The thickness of the single photosensitive layer 15 is 5 to 1
00 μm is suitable.

Next, the photosensitive layer of the electrophotographic photosensitive member of claim 2 will be described. The basic structure of the photosensitive layer according to claim 2 is the same as that of claim 1, but the photosensitive layer according to claim 2 contains the polymer charge transporting material as described above.

As the polymer charge transporting material used here, the polymer charge transporting material used for the undercoat layer can be used as it is. In the case of a laminated structure, the polymer charge transport material can be contained in the charge generation layer or the charge transport layer. In this case, the polymer charge transporting material used in the charge generating layer has an ionization potential (Ip) of 0.2e to the Ip value of the charge generating material.
When the value is smaller than the value obtained by adding V, good photosensitivity is exhibited. The amount of the polymer charge transport material used in the charge generation layer is 0.
1 to 10 parts by weight is preferable, and 0.2 to 5 is more preferable.
Parts by weight. A constituent material of another photosensitive layer of the electrophotographic photosensitive member according to claim 2, for example, a charge generating substance, a charge transporting substance,
The binder, auxiliary additive components and the like are the same as those described in the section of the photosensitive layer of claim 1.

In the electrophotographic photoreceptor of the present invention, a protective layer may be provided on the photosensitive layer for the purpose of protecting the photosensitive layer. Materials used for this are ABS resin, AC
S resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallyl sulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyether sulfone, polyethylene, polyethylene terephthalate,
Ponoimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide, polysulfone,
Examples thereof include resins such as AS resin, AB resin, BS resin, polyurethane, polyvinyl chloride, polyvinylidene chloride, and epoxy resin. In addition, for the purpose of improving wear resistance, the protective layer may be made of a fluororesin such as polytetrafluoroethylene, a silicone resin, and a dispersion of an inorganic material such as titanium oxide, tin oxide or potassium titanate in these resins. It can be added. As a method of forming the protective layer,
The usual coating method is adopted. The thickness of the protective layer is
About 0.5 to 10 μm is suitable. In addition to the above, known materials such as i-C and a-SiC formed by the vacuum thin film manufacturing method can also be used as the protective layer.

In the present invention, it is possible to provide another intermediate layer between the photosensitive layer 15 and the protective layer. A binder resin is generally used as a main component in the intermediate layer. Examples of these resins include polyamide, alcohol-soluble nylon, water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. As a method of forming the intermediate layer, a usual coating method is adopted as described above. The thickness of the intermediate layer is preferably about 0.05 to 2 μm.

[0032]

EXAMPLES Examples will be shown below, but the examples explain the present invention in detail, and the present invention is not limited to the examples. All parts are parts by weight.

Example 1 An undercoat layer coating solution and a eutectic complex photoconductive layer coating solution having the following compositions were successively coated and dried on a polyethylene terephthalate film having an aluminum conductive layer to a thickness of 1 μm.
An undercoat layer and a eutectic complex photoconductive layer having a thickness of 20 μm were formed. [Undercoat layer coating liquid] 11 parts of a polymeric charge transport material having the following structural formula

Embedded image 8 parts low molecular weight charge transport material with the following structural formula

Embedded image 2-butanone 50 parts [eutectic complex photoconductive layer coating liquid] 4- (4-dimethylaminophenyl) -2,6-di 1.5 parts phenylthiapyrylium tetrafluoroborate polycarbonate 24 parts (Teijin Kasei: Panlite L-1225) 20 parts of a hole transport material having the following structural formula

Embedded image 620 parts of methylene chloride

Comparative Example-1 A photoconductor of Comparative Example-1 was prepared in the same manner as in Example-1, except that the coating liquid for undercoat layer was changed to the following liquid. [Undercoat layer coating liquid] Water-soluble polyvinyl acetal 15 parts (Sekisui Chemical Co., Ltd .: W-101 10% aqueous solution) Water 20 parts Methanol 50 parts

Example-2 Thickness 45 produced by electroforming
An undercoat layer coating solution having the following composition, a charge generation layer coating solution and a charge transport layer coating solution are sequentially applied and dried on a nickel endless belt having a thickness of 0.7 μm.
A charge generation layer having a thickness of 0.3 μm and a charge transport layer having a thickness of 18 μm were formed. [Undercoat layer coating liquid] 10 parts of a polymer charge transport material having the following structural formula

[Chemical 4] 5 parts of low molecular charge transport material with the following structural formula

Embedded image Toluene 50 parts [Charge generating layer coating liquid] 5 parts of charge generating substance having the following structure

[Chemical 6] Polyvinyl butyral 3 parts (Sekisui Chemical Co., Ltd .: S-REC BL-S) Cyclohexanone 200 parts 4-Methyl-2-pentanone 90 parts [Charge transport layer coating liquid] Polycarbonate 11 parts (Teijin Kasei: Panlite K-1300) Structural formula charge transport material 8 parts

[Chemical 7] Tetrahydrofuran 80 parts

Comparative Example-2 A photoconductor of Comparative Example-2 was prepared in the same manner as in Example-2 except that the undercoat layer was not provided.

Example-3 A photoconductor was prepared in the same manner as in Example-2, except that the coating liquid for undercoat layer was changed to the following liquid. [Undercoat layer coating liquid] 8 parts of polymer charge transport material having the following structural formula

Embedded image Low molecular weight charge transport material with the following structural formula 7 parts

[Chemical 9] Titanium dioxide powder 15 parts (Ishihara Sangyo: Taipaque R-670) Polyvinyl butyral 2 parts (Sekisui Chemical: S-REC BL-1) 4-Methyl-2-pentanone 50 parts

Comparative Example-3 A photoconductor of Comparative Example-3 was prepared in the same manner as in Example-3, except that the coating liquid for undercoat layer was changed to the following liquid. [Undercoat layer coating liquid] Alcohol-soluble polyamide 7 parts (Toray: Amilan CM-4000) Titanium dioxide powder 15 parts (Ishihara Sangyo: Taipaque R-670) Isopropyl alcohol 20 parts Methanol 50 parts

Example 4 An undercoat layer coating solution, a charge transport layer coating solution, and a charge generating layer coating solution having the following compositions were sequentially applied on an aluminum plate having a thickness of 0.2 mm and dried to give a thickness. An undercoat layer having a thickness of 2.5 μm, a charge transport layer having a thickness of 21 μm, and a charge generating layer having a thickness of 0.3 μm were formed. [Undercoat layer coating liquid] 10 parts of a polymer charge transport material having the following structural formula

[Chemical 10] 9 parts low molecular weight charge transport material with the following structural formula

[Chemical 11] Tetrahydrofuran 50 parts [Charge transport layer coating liquid] Polycarbonate 8 parts (Teijin Kasei: Panlite L-1250) 8 parts of the charge transport substance having the following structural formula

[Chemical 11] Methylene chloride 80 parts [Charge generating layer coating liquid] 5 parts of charge generating substance having the following structure

[Chemical 12] Polyvinyl butyral 3 parts (Denka Butyral # 5000-1 manufactured by Denki Kagaku Kogyo) Tetrahydrofuran 200 parts 4-Methyl-2-pentanone 90 parts

Comparative Example-4 A photoconductor of Comparative Example-4 was prepared in the same manner as in Example-4 except that the coating liquid for undercoat layer was changed to the following liquid. [Undercoat layer coating liquid] Vinyl chloride-vinyl acetate-maleic anhydride copolymer resin 15 parts (Sekisui Chemical Co., Ltd .: S-REC MF-10) Isopropyl alcohol 20 parts Methanol 50 parts

Example-5 A photoconductor was prepared in the same manner as in Example-4, except that the coating liquid for undercoat layer was changed to the following liquid. [Undercoat layer coating liquid] 10 parts of a polymer charge transport material having the following structural formula

[Chemical 13] 5 parts of low molecular charge transport material with the following structural formula

Embedded image Aluminum oxide powder 30 parts 4-Methyl-2-pentanone 50 parts

Comparative Example-5 A photoconductor of Comparative Example-5 was prepared in the same manner as in Example-5, except that the coating liquid for undercoat layer was changed to the following liquid. [Undercoat layer coating liquid] Polyarylate (U polymer U-100, made by Unitika) 15 parts Tetrahydrofuran 20 parts 2-Butanone 50 parts

Example 6 An undercoat layer coating solution and a photosensitive layer coating solution having the following compositions were successively applied and dried on a polyethylene terephthalate film having an aluminum conductive layer, and the undercoat layer and the thickness of 2 μm were formed. A photosensitive layer having a thickness of 19 μm was formed. Polymer charge transport material having the following structural formula 10 parts

Embedded image 2-Butanone 50 parts [Photosensitive layer coating liquid] Charge-generating material having the following structural formula 1.5 parts

[Chemical 15] Polymer charge transport material having the following structural formula 24 parts

Embedded image Tetrahydrofuran 650 parts

Comparative Example-6 A photoconductor of Comparative Example-6 was prepared in the same manner as in Example-6, except that the coating liquid for undercoat layer was changed to the one described below. [Undercoat layer coating liquid] Water-soluble polyvinyl acetal 10 parts (Sekisui Chemical Co., Ltd .: W-201 25% aqueous solution) Water 30 parts Methanol 30 parts

Example 7 An undercoat layer coating solution, a charge generating layer coating solution and a charge transporting layer coating solution having the following compositions were sequentially formed on a nickel endless belt having a thickness of 50 μm prepared by electroforming. After coating and drying, an undercoat layer having a thickness of 0.5 μm, a charge generating layer having a thickness of 0.2 μm, and a charge transporting layer having a thickness of 23 μm were formed. [Undercoat layer coating liquid] 10 parts of a polymer charge transport material having the following structural formula

Embedded image Toluene 50 parts [Charge generating layer coating liquid] 5 parts of charge generating substance having the following structure

[Chemical 17] Polymer charge transport material with the following structural formula 4 parts

Embedded image Cyclohexanone 200 parts 4-Methyl-2-pentanone 90 parts [Charge Transport Layer Coating Liquid] Polycarbonate 11 parts (Mitsubishi Gas Chemical Co., Ltd .: Iupilon Z-300) 8 parts charge transport material of the following structural formula

Embedded image Tetrahydrofuran 80 parts

Comparative Example-7 Comparative Example-7 was carried out in the same manner as in Example-2 except that polyvinyl butyral (Sekisui Chemical Co., Ltd .: S-REC BL-1) was used as the subbing layer in Example-7. The body was made.

Example-8 A photoconductor was prepared in the same manner as in Example-7 except that the coating liquid for charge generating layer in Example-7 was changed to the following liquid. [Charge generating layer coating liquid] 5 parts of the charge generating substance having the following structure

[Chemical 19] Polymer charge transport material with the following structural formula 2 parts

Embedded image Polyester 1 part (Toyobo: Byron 200) Cyclohexanone 200 parts Tetrahydrofuran 90 parts

Comparative Example-8 A photoconductor of Comparative Example-8 was prepared in the same manner as in Example-8 except that the coating liquid for undercoat layer was changed to the following liquid. [Undercoat layer coating liquid] Vinyl chloride-vinyl acetate-maleic anhydride copolymer resin 15 parts (Sekisui Chemical Co., Ltd .: S-REC MF-10) Isopropyl alcohol 20 parts Methanol 50 parts

Example 9 An undercoat layer coating liquid, a charge transport layer coating liquid, a charge generating layer coating liquid, and a protective layer coating liquid having the following compositions were sequentially coated on an aluminum cylinder having an outer diameter of 80 mm.・ Dry, thickness 3
.mu.m undercoat layer, 23 .mu.m thick charge transport layer, 0.
A charge generation layer having a thickness of 4 μm and a protective layer having a thickness of 5 μm were formed. [Undercoat layer coating liquid] 10 parts of a polymer charge transport material having the following structural formula

[Chemical 21] Methylene chloride 50 parts [Charge transport layer coating liquid] Polymer charge transport material having the following structural formula 10 parts

[Chemical 10] Tetrahydrofuran 80 parts [Charge generation layer coating liquid] x-type metal-free phthalocyanine 5 parts Polyvinyl butyral 3 parts (Denka Butyral # 4000-1 manufactured by Denki Kagaku Kogyo) Tetrahydrofuran 200 parts 4-Methyl-2-pentanone 90 parts [Protective layer Coating liquid] Tin oxide containing 10% antimony oxide 30 parts Styrene-methacrylic acid-N-methylol methacrylamide resin 10 parts Toluene 80 parts n-Butanol 70 parts

Comparative Example-9 Comparative Example-9 was carried out in the same manner as in Example-9, except that the coating liquid for charge transport layer was changed to the following liquid.
A photoconductor was manufactured. [Charge Transport Layer Coating Liquid] 10 parts of a low molecular charge transport material having the following structural formula

[Chemical formula 22] Polycarbonate (A2700, manufactured by Idemitsu Petrochemical) 10 parts Tetrahydrofuran 80 parts

Example-10 A photoconductor was prepared in the same manner as in Example-9, except that the coating liquid for undercoat layer was changed to the following liquid. [Undercoat layer coating liquid] 10 parts of a polymer charge transport material having the following structural formula

[Chemical 10] Aluminum oxide powder 30 parts 4-Methyl-2-pentanone 50 parts

Each of the above photoconductors was attached to an electrostatic paper analyzer [SP-428: Kawaguchi Denki Seisakusho], and the following measurements were carried out. Charged at corona discharge voltage + 6.0kV (or -5.5kV) 2
Potential Vm (V) after 0 seconds, potential Vo after 20 seconds of dark decay
(V), the residual potential of the exposed 20 seconds by the white light of intensity 61ux V _R (V), was further measured [lux · sec] exposure amount E1 / 2 required to attenuate the potential Vo to 1/2 . The potential holding ratio is defined as follows. Potential holding ratio = Vo / Vm Further, charging and exposure under the above conditions were continuously performed for 1 hour at the same time to fatigue the photoconductor, and then the photoconductor characteristics were measured in the same manner as above. The results are shown in Table 1. (Below margin)

[0053]

[Table 1]

Each of the photoconductors of Examples 1 to 10 was mounted on a laser printer SP2000 manufactured by Ricoh Co., Ltd., and when images were printed, clear images were obtained. Further, when the photoconductors of Examples-1 to 10 and Comparative Examples 1 to 9 were mounted on the same laser printer and repeatedly printed, the photoconductors of Comparative Examples 1 to 9 showed a conductive support and a photosensitive layer. Peeling occurred between the photoconductors, but no peeling of the photoconductors was observed in the photoconductors of Examples 1 to 10 after printing 1000 sheets. Further, in particular, in the photoreceptor of Example 3 in which the metal oxide particles were contained in the undercoat layer, a clear image without moire was obtained.

[0055]

EFFECTS OF THE INVENTION According to the present invention, the dark decay is small even after repeated use, and the residual potential of the residual potential is reduced without losing the effects of adhesion between the conductive support and the photosensitive layer and elimination of defects of the conductive support. It is possible to obtain a photosensitive member with a small rise. According to the invention, by further containing metal oxide particles in the undercoat layer, in addition to the above effects,
Even when image exposure is performed using coherent light, a photoconductor that does not produce a moire image can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an electrophotographic photosensitive member of the present invention.

FIG. 2 is a schematic sectional view of an electrophotographic photosensitive member of the present invention.

FIG. 3 is a schematic sectional view of an electrophotographic photosensitive member of the present invention.

Claims (5)

[Claims] 1. An electrophotographic photosensitive member comprising a conductive support and an undercoat layer and a photosensitive layer sequentially provided on the conductive support, wherein the undercoat layer contains a polymer charge transport material and a low molecular charge transport material as active ingredients. An electrophotographic photosensitive member characterized by being formed. 2. An electrophotographic photosensitive member comprising a conductive support and an undercoat layer and a photosensitive layer provided in this order, wherein the undercoat layer and the photosensitive layer contain a polymer charge transport material as an active ingredient. An electrophotographic photoreceptor characterized by the above. 3. The electrophotography according to claim 2, wherein the photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer, and the charge generation layer contains a polymer charge transport material. Photoconductor. 4. The electrophotography according to claim 2, wherein the photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer, and the charge transport layer contains a polymer charge transport material. Photoconductor. 5. The electrophotographic photosensitive member according to claim 1, wherein the undercoat layer further contains metal oxide particles.