JPH07319175A - Electrophotographic photoreceptor - Google Patents

Abstract

PURPOSE:To provide an electrophotographic photoreceptor having good characteristics and little image defect in which an interference fringes pattern is not produced in an image even when the photoreceptor is used for an electrophotographic device using a coherent exposure light source, further performance can be stably maintained under any environments from low temp. low humidity to high temp. high humidity, and an image with little defect can be stably obtd. CONSTITUTION:This electrophotographic photoreceptor is produced by successively forming a charge producing layer 1 and a charge transfer layer 2 on a conductive supporting body 3. Thickness of the charge producing layer 1 is >=2mum. The charge producing layer contains a carrier in the same polarity as the electrification polarity of the photoreceptor and has >=0.2X10<-8>cm<2>/V carrier range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member used in copying machines, printers and the like. More specifically, the present invention relates to an electrophotographic photosensitive member suitable when coherent light such as laser light is used as an exposure light source.

[0002]

2. Description of the Related Art Conventionally, electrophotographic photoconductors have mainly been those using an inorganic photoconductive material such as selenium, selenium-tellurium alloy, selenium-arsenic alloy, and zinc oxide. An electrophotographic photoreceptor using an organic photoconductive material has been developed and put into practical use in view of its pollution-free property and film-forming property. In particular, the development of an organic electrophotographic photosensitive member having a layer structure in which a photosensitive layer is functionally separated into a charge transport layer and a charge generating layer has been actively pursued. Many of the function-separated organic electrophotographic photoconductors currently used are
It has a structure including a photosensitive layer in which a charge generation layer and a charge transport layer are sequentially laminated on a conductive substrate such as aluminum. As the charge generation layer becomes thicker, it becomes difficult for the charge having the same polarity as the charge polarity generated in the charge generation layer to be injected into the conductive substrate smoothly, resulting in the occurrence of memory, deterioration of chargeability during repeated use, and residual potential. Therefore, it is necessary to make the film extremely thin, and it is generally made to be a submicron order thin film. In order to sufficiently absorb the incident exposure light with such a thin film, the charge generation material is required to have a large absorption coefficient for the exposure light and high charge generation efficiency, and a pigment-based substance is mainly used. . Since the charge generation layer is formed as an extremely thin film on the conductive substrate as described above, if there are defects such as stains, scratches and irregularities on the surface of the substrate, the charge generation layer will be uneven in film thickness, This causes variations in the film quality and causes various defects such as white spots, black spots, uneven density, and fog on the image. In order to solve such a problem, improvement of a cleaning method for sufficiently removing dirt on the surface of the substrate and improvement of a finishing method for forming the substrate surface into a uniform shape without scratches have been advanced.

On the other hand, an electrophotographic apparatus using a coherent light such as a laser light as an exposure light has been developed, and a photosensitive member suitable for this has been developed. In such a device, due to the coherence of the exposure light, the reflected light of the incident exposure light on the substrate surface and the multiple reflected light in the photosensitive layer interfere with each other, resulting in an interference fringe pattern. Will appear in the image. In order to solve this problem, Japanese Patent Publication No. 2-60178 discloses a method of roughening the surface of the substrate to diffusely reflect the exposure light that has passed through the photosensitive layer and reached the surface of the substrate to prevent interference. There is. However, this method intentionally forms irregularities on the surface of the substrate, and has a problem that uneven film formation of the charge generation layer is likely to occur and image defects are likely to occur.
As a method of avoiding such problems and eliminating the need for roughening the surface of the substrate, a method of coloring the surface of the substrate with a dye capable of absorbing exposure light (Japanese Patent Laid-Open Nos. 58-100138 and 59-59). No. 158), a method of adding a pigment or a dye that absorbs exposure light into a charge generation layer, a charge generation material having a large absorption coefficient for exposure light is used, and a charge having a certain thickness or more is used. A method of providing a generating layer (Japanese Patent Publication No. 3-36220) has been proposed. However, these methods tend to cause charge traps in the charge generation layer or between the substrate and the charge generation layer, and cause problems such as reduction in sensitivity of the photoreceptor and deterioration in performance during long-term use. As a solution to this problem, a coating liquid in which titanium oxide, tin oxide, or carbon fine powder is dispersed in a binder is applied on a substrate to form an undercoat layer, which covers irregularities on the substrate surface, and A method of scattering exposure light is proposed in Japanese Examined Patent Publication No. 62-42498. However, this method does not always uniformly disperse the conductive fine particles in the binder as described above,
Local uneven distribution and particle aggregation often occur, and defects such as density unevenness, black spots, and white spots are likely to occur on the image.

In order to solve the above-mentioned problems and prevent the occurrence of interference when coherent light is used as the exposure light, the charge generating layer is positively formed without hindering the function of the unevenness of the substrate surface. As a method of covering the defects that cause unevenness of film formation at the same time and at the same time preventing the occurrence of uneven film formation of the charge generation layer due to other defects on the surface of the substrate, an undercoating layer transparent to the coherent exposure light used is used. Methods have been proposed for coating substrates. For example, polyamide (JP-A-52-25638), nylon (JP-A-58-58).
15351), polyether (JP-A-2-242)
No. 265) or the like to form an undercoat layer with a resin having a relatively low resistance, or an organic conductive substance compatible with a binder resin, such as an organic carboxylate or a phosphate (JP-A-62-270962). JP-A-64-10259), a method of forming an undercoat layer with a chelate compound (JP-A-64-10259), and the like.

[0005]

As described above, the undercoating layer made of a material which is transparent to the coherent exposure light to be used can have a charge generating layer uniformly formed thereon, It is possible to obtain a photoconductor which has good characteristics and few image defects, and has no interference fringe pattern in an image even when used in an electrophotographic apparatus using coherent exposure light. However, since the resistance of the undercoat layer made of the above-mentioned materials changes with changes in temperature and humidity, it is difficult to stably maintain the performance of the photoconductor in each environment from low temperature low humidity to high temperature high humidity. There was a problem. The present invention has been made in view of the above circumstances, and an object thereof is to provide an image even when used in an electrophotographic apparatus that uses good coherent exposure light and has few image defects. To provide an electrophotographic photosensitive member that does not generate an interference fringe pattern, can stably maintain the performance in each environment from low temperature and low humidity to high temperature and high humidity, and can stably obtain an image with few defects. is there.

[0006]

As a result of studying various materials, the inventors of the present invention solve the above problems by setting the carrier range of the same polarity as the charge polarity in the charge generation layer to a specific value or more. It has been found that an electrophotographic photosensitive member can be obtained, and the present invention has been completed. That is,
The present invention relates to an electrophotographic photosensitive member comprising a conductive support, and at least a charge generation layer and a charge transport layer sequentially laminated on the conductive support, the charge generation layer having a thickness of 2 μm or more, and the charge polarity of the charge generation layer. And a carrier range of the same polarity as 0.2 × 10 ⁻⁸ cm ² / V or more.

Here, the carrier range is given by the product of the mobility (μ) in which the charge carriers move in the film and the life (τ) of the charge carriers. The method of obtaining the carrier range from the light decay rate of the surface potential by irradiating the pre-corona-charged photoconductor with light is the most convenient and excellent in reproducibility, and is therefore widely used in various studies. The measurement of the light attenuation curve can be performed by using a commercially available electrostatic copying paper tester or the like, and the carrier range can be calculated by the following equation (1).

[Equation 1] Here, E is the electric field, t is the time, Φ is the quantum efficiency of the photoconductor, e is the elementary charge, I is the number of incident photons, ε is the relative dielectric constant,
ε ₀ is the vacuum dielectric constant, L is the thickness of the photosensitive layer, μ is the mobility of charge carriers, and τ is the life of the charge carriers. The incident light at the time of measurement is used with a relatively weak exposure amount such that the monochromatic light having the wavelength in the region used for image exposure does not cause the carrier movement to be controlled. Although the upper limit of the film thickness depends on the relationship with the carrier range, it is preferable that the film thickness satisfy the relationship that the carrier range is three times or more of (film thickness / electric field).

The photosensitive layer of the present invention will be described below.
1 to 4 are schematic views showing a cross section of the electrophotographic photosensitive member of the present invention. In FIG. 1, the charge generation layer 1 is provided on the conductive support 3, and the charge transport layer 2 is provided thereon. In FIG. 2, the conductive support 3 is further added.
An undercoat layer 4 is provided on the upper side, and in FIG. 3, a protective layer 5 is provided on the surface. Further, in FIG. 4, both the undercoat layer 4 and the protective layer 5 are provided.

Examples of the conductive support include metals such as aluminum, nickel, chromium and stainless steel, and aluminum, titanium, nickel, chromium, stainless steel, gold, vanadium, tin oxide, indium oxide and ITO.
Examples thereof include a plastic film or the like provided with a thin film such as the above, paper coated with or impregnated with a conductivity-imparting agent, and a plastic film. These conductive supports are used in a suitable shape such as a drum shape, a sheet shape, and a plate shape, but are not limited thereto. Further, the surface of the conductive support has a center line average roughness R
It is preferable that a is 0.10 μm or more and the maximum width of the recess is 10 μm or less. If Ra is less than 0.10 μm, interference fringes are likely to occur, and the range is preferably 0.14 to 1.0 μm, more preferably 0.14 to 0.2 μm.

As a method of roughening the surface of the conductive support, a method of adjusting the precision of surface cutting by cutting,
There are a method of pressing a rotary grindstone, an etching method, a sandpaper processing method, a dry honing processing method, a wet honing processing method, a sandblast processing method, a buff processing method, and the like. Among them, a cutting method, a dry method or a wet method. The honing method requires a short processing time, the work is easy, and the desired surface roughness is easily obtained.
It is a preferable method because of its stability. When adjusting the precision of surface cutting by cutting, for example, a tool having a V-shaped cutting edge is regularly rotated by a cutting machine such as a milling machine or a lathe while rotating the cylindrical conductive support. By pressing and moving in a predetermined direction, it is possible to form desired flat groove-shaped irregularities. The wet honing treatment is a method of suspending a powdery abrasive in a liquid such as water and spraying it on the surface of the substrate at a high speed to roughen the surface. It can be controlled by speed, amount of abrasive, type, shape, size, hardness, specific gravity, suspension temperature and the like. Similarly, the dry honing treatment is a method of spraying an abrasive with air at a high speed on the surface of the conductive support to roughen the surface, and the surface roughness can be controlled in the same manner as the wet honing treatment. As the abrasive used in these wet or dry honing treatments, silicon carbide,
Examples thereof include particles of alumina, iron, glass beads and the like. In the wet or dry honing process, in order to reduce the formation of a locally locally roughened portion that causes an interference fringe pattern that appears at the time of image formation, for example, the spraying speed of the polishing agent may be decreased to reduce the unit surface treatment. Increasing the processing time per area is a very preferred method. That is, by increasing the roughening treatment time and decreasing the spraying speed of the polishing agent, it is possible to reduce the variation in the collision energy of the polishing agent on the substrate to be processed. As a result, it is possible to reduce the locally locally roughened portion as compared with the normal roughness portion. According to this method, the desired surface roughness can be easily obtained, the stability is obtained, and it is not necessary to introduce new process equipment. The spraying speed is defined by the distance between the spray gun and the substrate surface, compressed air, nozzle diameter, etc., and the spraying speed can be controlled by adjusting them.

Further, the surface of the conductive support is preferably a metal subjected to anodizing treatment. The anodizing process is
For example, in the case of aluminum, it is carried out in an acidic liquid such as chromic acid, sulfuric acid, oxalic acid and phosphoric acid. The anodic oxide film thus formed acts as a chemical non-conducting substance, and the ionic substance in the photosensitive layer is moved, so that a local charge injection part due to a chemical reaction with the support metal is generated. It is considered to prevent. The thickness of the anodized film is 0.01
It must be at least μm. Thickness is 0.01 μm
If the thickness is smaller than this, the effect of improving the image quality becomes insufficient and white spots and black spots occur. The anodic oxide coating formed as described above is, for example, a sealing material such as a high temperature sealing treatment or a boiling water sealing treatment in which it is immersed in an aqueous solution containing nickel acetate as a main component in order to enhance the stability of the coating. Pore treatment is desirable.

An undercoat layer may be further provided between the conductive support and the charge generation layer. The undercoat layer is an adhesive layer that prevents the injection of charges from the conductive support to the photosensitive layer during charging of the photosensitive layer having a laminated structure, and also integrally holds the photosensitive layer to the conductive support. And the like. The binder resin used for the undercoat layer includes polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate resin, polyurethane resin, polyimide resin, vinylidene chloride resin. , Polyvinyl acetal resin, vinyl chloride-
Vinyl acetate copolymer, polyvinyl alcohol resin, water-soluble polyester resin, nitrocellulose, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, polyacrylic acid, polyacrylamide, zirconium chelate compound, titanyl chelate compound, titanyl alkoxide Known materials such as compounds, organic titanyl compounds, and silane coupling agents can be used. The thickness of the undercoat layer is 0.01 to 10 μm.
m, preferably 0.05-2 μm. Further, as a coating method used when providing the undercoat layer,
Conventional methods such as a blade coating method, a Mayer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method and a curtain coating method can be used.

The charge generation layer is formed by dispersing a charge generation material in a binder resin, and as the charge generation material, there are phthalocyanine type, squarylium type, anthanthrone type, perylene type, azo type, anthraquinone type, and pyrene type. , Organic pigments and dyes such as pyrylium salts are used. Examples of the phthalocyanine-based pigment include metal-free phthalocyanine, oxytitanium phthalocyanine, chlorogallium phthalocyanine, dichlorotin phthalocyanine, and hydroxygallium phthalocyanine. The binder resin can be selected from a wide range of insulating resins. It can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, polysilane. Preferred binder resins include polyvinyl butyral resins, polyarylate resins (polycondensates of bisphenol A and phthalic acid, etc.), polycarbonate resins, polyester resins, phenoxy resins, vinyl chloride-vinyl acetate copolymers, vinylidene chloride resins, polyamides. Resin, acrylic resin, polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinylpyrrolidone resin, and other insulating resins can be mentioned, but are not limited to these. Absent. These binder resins may be used alone or in combination of two or more.

The compounding ratio (weight ratio) is 10: 1 to
A range of 1:10 is preferred. As a method for dispersing these, a usual method such as a ball mill dispersion method, an attritor dispersion method, or a sand mill dispersion method can be used.
Further, during this dispersion, it is effective that the particles have a particle size of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less. Further, as a solvent used for dispersing these, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, Ordinary organic solvents such as tetrahydrofuran, methylene chloride and chloroform may be used alone or in combination of two or more.

The carrier range of electrons in the charge generation layer is 0.2 × 10 ^-8 cm ² / V or more, preferably,
An electron-transporting material can be added in order to obtain 0.5 × 10 ⁻⁸ cm ² / V or more. As an electron transport material, p
-Quinone compounds such as benzoquinone, chloranil, bromoanil, anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, xanthone compounds, benzophenone compounds, cyanovinyl compounds, ethylene Examples thereof include a system compound and the like, or a polymer having a group composed of these compounds in a main chain or a side chain. These charge transport materials may be used alone or in combination of two or more. Similarly, in order to increase the carrier range of holes, a hole transport material may be added.

The thickness of the charge generation layer used in the present invention is 2.0 μm or more. As a coating method for providing the charge generation layer, a usual method such as a blade coating method, a Mayer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method and a curtain coating method is used. be able to.

The charge transport layer is formed by containing the charge transport layer material in a suitable binder resin. As the hole transport material, a triarylamine-based compound, a benzidine-based compound, an arylalkane-based compound, an aryl-substituted ethyl-based compound, a stilbene-based compound, an anthracene-based compound, a hydrazone-based compound, or a group composed of these compounds is a main chain. Alternatively, a polymer having a side chain may be used. These charge transport materials may be used alone or in combination of two or more. Among these hole transport materials, benzidine compounds, triarylamine compounds, and mixtures of these compounds are preferably used. Further, the binder resin used for the charge transport layer is a polycarbonate resin,
Polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, Vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-
A known resin such as vinylcarbazole can be used, but the resin is not limited to these. Among these binder resins, particularly good properties are exhibited when the polycarbonate resin represented by the following structural formulas (I) to (V) is used.

[0018]

[Chemical 1] These binder resins may be used alone or in combination of two or more.

The compounding ratio (weight ratio) of the charge transport material and the binder resin is preferably 10: 1 to 1: 5. The thickness of the charge transport layer used in the present invention is generally 5 to 50 μm, preferably 10 to 30 μm. As a coating method,
Usual methods such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method and a curtain coating method can be used. Further, as the solvent used in providing the charge transport layer, aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, ketones such as acetone and 2-butanone, halogens such as methylene chloride, chloroform and ethylene chloride. Cycloaliphatic hydrocarbons, tetrahydrofuran,
Ordinary organic solvents such as cyclic or linear ethers such as ethyl ether may be used alone or in combination of two or more.

Additives such as antioxidants and light stabilizers are added to the photosensitive layer for the purpose of preventing the deterioration of the photoreceptor due to ozone or oxidizing gas generated in the copying machine, or light or heat. be able to. For example, as the antioxidant, hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroindanone and their derivatives,
Examples thereof include organic sulfur compounds and organic phosphorus compounds. Examples of the light stabilizer include benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine derivatives. Further, at least one electron-accepting substance can be contained for the purpose of improving sensitivity, reducing residual potential, and reducing fatigue during repeated use.
The electron accepting substance that can be used in the photoreceptor of the present invention includes
For example, succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, chloranil, dinitroanthraquinone, trinitrate. Examples thereof include nitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid and phthalic acid. Of these, fluorenone type, quinone type, Cl, CN, NO ₂
Particularly preferred are benzene derivatives having electron-withdrawing substituents such as

If necessary, a protective layer may be provided on the charge transport layer. This protective layer is used to prevent chemical deterioration of the charge transport layer during charging of the photosensitive layer having a laminated structure and to improve the mechanical strength of the photosensitive layer. This protective layer is formed by containing a conductive material in a suitable binder. As the conductive material, N,
Metallocene compounds such as N'-dimethylferrocene, N,
Aromatic amine compounds such as N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine, antimony oxide, tin oxide,
Materials such as titanium oxide, indium oxide, and metal oxides such as tin oxide-antimony oxide can be used, but are not limited thereto. As the binder resin used for this protective layer, known resins such as polyamide resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinylketone resin, polystyrene resin, polyacrylamide resin and the like can be used. it can. Further, it is preferable that this protective layer is configured to have an electric resistance of 10 ⁹ to 10 ¹⁴ Ω · cm. When the electric resistance is 10 ¹⁴ Ω · cm or more, the residual potential rises to give a copy with a lot of fog, and when it is 10 ⁹ Ω · cm or less, the image becomes blurred and the resolution is lowered. Also, the protective layer should be constructed so as not to substantially interfere with the transmission of light used for imagewise exposure. The thickness of the protective layer used in the present invention is 0.5 to 20 μm.
m, preferably 1-10 μm. As a coating method, a usual method such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method and a curtain coating method can be used.

[0022]

EXAMPLES The present invention will be described below with reference to examples.
The examples are for explaining the present invention in detail, and the present invention is not limited to the examples. In addition,
In the examples and comparative examples, all "parts" are "parts by weight". Example 1 An aluminum pipe whose surface has a centerline average roughness Ra of 0.14 μm and which is roughened so that the maximum width of the recess is 1.8 μm is anodized to form an oxide film having a thickness of 5 μm. Zirconium compound (trade name: Organix ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.) on the formed aluminum substrate 1
A solution consisting of 0 part and 1 part of a silane compound (trade name: A1110, manufactured by Nippon Unicar Co., Ltd.) and 40 parts of i-propanol and 20 parts of butanol was applied by a dip coating method, and dried by heating at 150 ° C. for 10 minutes to give a film thickness. 0.1
An undercoat layer of μm was formed. Next, a powder X-ray diffraction pattern using CuKα as a radiation source is shown in FIG. 5, 1 part of dichlorotin phthalocyanine crystal, 1 part of polyvinyl butyral resin (trade name: S-REC BM-S, manufactured by Sekisui Chemical Co., Ltd.) and a predetermined amount of acetic acid n. -Butyl was treated with a glass bead with a paint shaker for 1 hour to be dispersed, and then the obtained coating liquid was applied onto the undercoat layer to form a charge generation layer having a thickness of about 5.0 µm. Next, 2 parts of the compound represented by the following structural formula (VI) and the following structural formula (I)

[Chemical 2] 3 parts of poly (4,4′-cyclohexylidenediphenylene carbonate) represented by Mw = 39000 (viscosity average molecular weight) was dissolved in 20 parts of monochlorobenzene, and the resulting coating liquid was used to form a charge generation layer. It was applied on an aluminum substrate by a dip coating method and dried by heating at 120 ° C. for 1 hour to form a charge transport layer having a film thickness of 20 μm.

The electrophotographic photosensitive member thus obtained was used as a laser printer XP- manufactured by Fuji Xerox Co., Ltd.
The No. 11 was mounted in a modified evaluation apparatus, and the electrical characteristics and image quality characteristics were evaluated. The electrical characteristics are evaluated at room temperature and normal humidity (20 ° C, 40% RH) and low temperature and low humidity (10 ° C, 15%).
% RH) by measuring the potential at the development position in the above device. Here, the potential when the laser light is not irradiated after charging is VH, the potential when the laser light of 12 mJ / m ² is irradiated is VL, and the potential when the laser light of about 30 mJ / m ² is irradiated is VR. Further, in the same evaluation device, prints were actually output to evaluate defects on the image. The results are shown in Table 1. In addition, an optical attenuation curve of a sample in which only a charge generation layer under the same conditions is provided on an aluminum substrate is measured by an electrostatic copying paper test apparatus (Kawaguchi Electric Co., Ltd .: Electrostatic Analyzer EPA-
8100) to determine the carrier range. The value of the carrier range was 0.6 × 10 ^-8 cm ² / V.

Example 2 In place of the dichlorotin phthalocyanine crystal in Example 1, a powder X-ray diffraction diagram using CuKα as a radiation source is shown in FIG. 6 except that the dichlorotin phthalocyanine crystal was used.
A photoconductor was prepared in the same manner as in Example 1, and the same measurement was performed. The results are shown in Table 1. The value of the carrier range of this charge generation layer was 1.0 × 10 ⁻⁸ cm ² / V. Example 3 In place of the dichlorotin phthalocyanine crystal in Example 1, a dichlorotin phthalocyanine crystal whose powder X-ray diffraction diagram using CuKα as a radiation source is shown in FIG. 7 was used, except that
A photoconductor was prepared in the same manner as in Example 1, and the same measurement was performed. The results are shown in Table 1. The value of the carrier range of this charge generation layer was 1.0 × 10 ⁻⁸ cm ² / V. Example 4 Instead of the charge generation layer in Example 1, 1 part of X-type metal-free phthalocyanine crystal, polyvinyl butyral resin (trade name: S-REC BM-S, manufactured by Sekisui Chemical Co., Ltd.) 1
Parts, 3,5-dimethyl-3 ', 5'-di-ter-butyl-4,4'-diphenoquinone and 1 part of a predetermined amount of n-butyl acetate were treated with a glass bead on a paint shaker for 1 hour to be dispersed. Thereafter, a photoreceptor was prepared in the same manner as in Example 1 except that the obtained coating liquid was applied onto the above-mentioned undercoat layer to form and use a charge generation layer having a thickness of about 3.0 μm. The measurement was performed. The results are shown in Table 1. The value of the carrier range of this charge generation layer is 0.5 × 1.
It was 0 ^-8 cm ² / V.

Comparative Examples 1 to 3 In Examples 1 to 3, the charge generation layer has a thickness of 0.15 μm.
A photoconductor was prepared in the same manner as in Example 1 except that m was set, and the same measurement was performed. The results are shown in Table 1. Comparative Example 4 A photoconductor was prepared in the same manner as in Example 1 except that an X-type metal-free phthalocyanine crystal was used instead of the dichlorotin phthalocyanine crystal in Example 1, and the same measurement was performed. The results are shown in Table 1. The carrier range of this charge generation layer is 0.1 × 10 ^-9 cm ² / V.
Met. Comparative Example 5 Except that the undercoat layer was a copolymerized nylon (trade name: CM8000, manufactured by Toray Industries, Inc.) having a thickness of about 1.0 μm and the thickness of the charge generation layer was 0.15 μm in Example 1. A photoconductor was prepared in the same manner as in Example 1, and the same measurement was performed. The results are shown in Table 1. Comparative Example 6 Al pipe not subjected to surface roughening treatment (Ra = 0.08μ)
m) was used and a photoreceptor was prepared in the same manner as in Example 1 except that the charge generation layer had a thickness of 0.15 μm, and the same measurement was performed. The results are shown in Table 1.

[0026]

[Table 1]

[0027]

Since the electrophotographic photoreceptor of the present invention is used under the above conditions for the film thickness and carrier range of the charge generation layer, it has good characteristics, few image defects, and coherent exposure light. No interference fringe pattern is generated in the image even when used in an electrophotographic device that uses, and the performance can be stably maintained in each environment from low temperature low humidity to high temperature high humidity.
An image with few defects can be stably obtained.

[Brief description of drawings]

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

FIG. 2 shows a schematic sectional view of another example of the electrophotographic photosensitive member of the present invention.

FIG. 3 shows a schematic sectional view of another example of the electrophotographic photosensitive member of the present invention.

FIG. 4 is a schematic sectional view showing still another example of the electrophotographic photosensitive member of the present invention.

5 shows a powder X-ray diffraction pattern of the dichlorotin phthalocyanine crystal used in Example 1. FIG.

FIG. 6 shows a powder X-ray diffraction pattern of the dichlorotin phthalocyanine crystal used in Example 2.

FIG. 7 shows a powder X-ray diffraction pattern of the dichlorotin phthalocyanine crystal used in Example 3.

[Explanation of symbols]

1 ... Charge generating layer, 2 ... Charge transporting layer, 3 ... Conductive support,
4 ... Undercoat layer, 5 ... Protective layer.

Claims (2)

[Claims] 1. An electrophotographic photosensitive member comprising a conductive support and a charge generation layer and a charge transport layer sequentially laminated on the conductive support, wherein the thickness of the charge generation layer is 2 μm or more, and the charge polarity of the photosensitive member is An electrophotographic photosensitive member characterized by having a carrier range of carriers of the same polarity in a charge generation layer of 0.2 × 10 ⁻⁸ cm ² / V or more. 2. The conductive support has a center line average roughness Ra.
Is 0.10 μm or more and the concave portion has a maximum width of 10 μm or less, and the electrophotographic photosensitive member according to claim 1.