JPH06313974A - Production of electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the electrophotographic sensitive body having high photosensitivity and excellent repeatable stability. CONSTITUTION:The method contains the stage applying the coating liq. for a charge generating layer containing the org. electron acceptor having >=-0.8V reduction potential Ered 1/2 basing on a saturated calomel electrode as a reference, a charge generating material and the first solvent on the conductive supporting body and applying the coating liq. for a charge transfer layer containing a charge transfer material and the second solvent thereon, the solubility of the org. electron acceptor to the second solvent is smaller than the solubility to the first solvent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electrophotographic photosensitive member, and more particularly to a method for manufacturing a novel electrophotographic photosensitive member in which the characteristics of the photosensitive member are improved by adding an organic electron acceptor.

[0002]

2. Description of the Related Art Conventionally, a polycyclic or heterocyclic ring such as trinitroanthracene or 2,4,7-trinitrofluorenone has been used in a photosensitive layer of a single-layer type electrophotographic photosensitive member using a hole transporting charge generating material. It is well known that chemical sensitization is performed by adding a ring nitro compound, an acid anhydride such as phthalic anhydride or trimellitic anhydride, a quinone such as anthraquinone, and an organic electron acceptor such as a nitrile compound such as tetracyanoethylene. ing. For example, JP-A-53-37424
No. 53-83745 and the like, by adding tetracyanoethylene or 2,4,7-trinitrofluorenone to the photosensitive layer of an electrophotographic photoreceptor using metal-free phthalocyanine or copper phthalocyanine, It is disclosed that the photosensitivity represented by the half-exposure amount of the photoconductor is improved, and further, the attenuation of the charging potential during repeated use can be reduced.

[0003]

In recent years, JP-A-57-5
No. 4942, No. 60-59355, No. 61-203461, No. 62-47054
No. 62-67094, etc., a laminated organic system having a layer structure in which two functions, that is, a charge transport layer and a charge generation layer, in which an organic photoconductive substance is bound with a resin or the like, are separated. Various proposals have been made regarding electrophotographic photoreceptors. Above all, an electrophotographic photoreceptor having a layer structure in which a charge transport layer is provided on a charge generation layer is excellent in durability and is currently the mainstream. However, the laminated organic electrophotographic photoreceptor of the prior art has been insufficient in terms of photosensitivity and repetitive stability. JP-A-61-2157 proposes to add an organic electron acceptor to the charge generation layer in a laminated organic electrophotographic photoreceptor.
Improvement of photosensitivity as seen in a single-layer electrophotographic photoreceptor (for example, J. Am. Chem. Soc. 102 (1980) 49
67-4970) is not seen. When the inventors of the present invention pursued this cause, the conventional organic electron acceptor has high solubility in the solvent of the charge transport layer coating liquid, so that the charge transport layer coating liquid is applied onto the charge generating layer to form the charge transport layer. It was found that the organic electron acceptor added to the charge generation layer during formation was eluted into the solvent of the charge transport layer coating solution and separated from the charge generation material, so that it did not work sufficiently as a sensitizer. . The present invention has been made in view of the above circumstances, and an object thereof is to have sufficient photosensitivity in practical use and to obtain a clear copy image even when repeatedly used. An object of the present invention is to provide a method for producing a laminated organic electrophotographic photosensitive member excellent in

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the reduction potential Ere based on a saturated calomel electrode is Ere.
A coating solution for a charge generation layer containing an organic electron acceptor having a d 1/2 of −0.8 V or more, a charge generation material, and a first solvent is coated on a conductive support, and the charge transport material and Including the step of applying a charge transport layer coating liquid containing two solvents,
However, the solubility of the organic electron acceptor in the second solvent is smaller than the solubility in the first solvent, by the method for manufacturing an electrophotographic photoreceptor,
The inventors have found that the above objects can be achieved and completed the present invention. In particular, in order to add an amount necessary to obtain a sufficient sensitizing effect, the organic electron acceptor has a solubility of 1.0 × 10 ⁻³ mol / l or more in the first solvent, It preferably has a solubility of 5.0 × 10 ⁻⁴ mol / l or less in the second solvent.

The present invention will be described in detail 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 undercoat layer 4 is provided on the conductive support 3.
Is provided, and in FIG. 3, the protective layer 5 is provided on the surface. Further, in FIG. 4, both the undercoat layer 4 and the protective layer 5 are provided. As the conductive support, metals such as aluminum, nickel, chromium and stainless steel; thin films of aluminum, titanium, nickel, chromium, stainless steel, gold, vanadium, tin oxide, indium oxide, indium tin oxide (ITO), etc. Examples thereof include a provided plastic film and the like; paper coated with or impregnated with a conductivity-imparting agent, and a plastic film. These conductive supports are used in an appropriate shape such as a drum shape, a sheet shape, and a plate shape, but are not limited to these shapes. Further, if necessary, the surface of the conductive support can be subjected to various treatments within a range that does not affect the image quality. For example, oxidation treatment, chemical treatment, and irregular reflection treatment such as coloring treatment or graining can be performed.

An undercoat layer may be provided between the conductive support and the charge generation layer. This undercoat layer prevents the injection of charges from the conductive support to the photosensitive layer at the time of charging the photoreceptor having a laminated structure and also serves as an adhesive that enhances the adhesion of the photosensitive layer to the conductive support. The action, and in some cases, the action of preventing reflection of light generated on the surface of the conductive support are shown. This undercoat layer can be formed by solution coating a binder resin on a conductive support. As the binder resin used for the undercoat layer, 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,
Known materials such as polyacrylic acid, polyacrylamide, zirconium chelate compounds, titanyl chelate compounds, titanyl alkoxide compounds, organic titanyl compounds, and silane coupling agents can be used. Examples of the coating method of the undercoat layer include blade coating method, Meyer bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain coating method and the like. The thickness of the undercoat layer is generally 0.
It is from 01 to 10 μm, preferably from 0.05 to 2 μm.

The charge generation layer contains an organic electron acceptor having an Ered 1/2 of -0.8 V or more based on a saturated calomel electrode and a charge generation material. The organic electron acceptor is 1. for the first solvent used in the charge generation layer coating solution.
It has a solubility of 0 × 10 ⁻³ mol / l or more and 5.0 × 10 ⁻⁴ mol / l for the second solvent used for the charge transport layer coating liquid.
It preferably has a solubility of 1 or less. Examples of the organic electron acceptor include the following general formula (I) or (II)
The compound represented by can be mentioned.

[0008]

[Chemical 3] [In the formula, Z is = C (CO ₂ R) ₂ (wherein R is a hydrogen atom or an alkyl group), = C (CN) ₂ , = O, or = N-CN,
R _{1 to} R ₄ are a hydrogen atom, a carboxyl group, an alkyl group, an alkoxycarbonyl group, an aryloxycarbonyl group,
A nitro group, a halogen atom, an alkylcarbonyl group, an arylcarbonyl group, or a vinyl group represented by the formula -CR ₅ = CR ₆ R ₇ (wherein, R ₅ is a hydrogen atom or an alkyl group, R ₆ and R ₇ are Hydrogen atom, or a substituted or unsubstituted phenyl group, provided that at least one of R ₆ and R ₇ is a substituted or unsubstituted phenyl group, and the other is a hydrogen atom), provided that R ₁ to At least one of R ₄ is a carboxyl group. ]

[0009]

[Chemical 4] [In the formula, Z is = C (CO ₂ R) ₂ (in the formula, R is a hydrogen atom or an alkyl group), = C (CN) ₂ , = O, or = N-CN. ]

General formula (I) or (I) in which Z is = C (CN) _2.
The compound represented by I) can be obtained by reacting a fluorenone compound or an anthraquinone compound with malononitrile by refluxing in pyridine or by refluxing in a solvent such as methylene chloride in the presence of a Lewis acid catalyst such as titanium tetrachloride. And the general formula (I) in which Z is = C (CO ₂ R) _2.
Alternatively, the compound represented by (II) is reacted with a fluorenone compound or anthraquinone compound and a malonic acid ester by refluxing in pyridine or in a solvent such as methylene chloride in the presence of a Lewis acid catalyst such as titanium tetrachloride. (See JP-A-63-70257 and JP-A-2-268146). The cyanimino compound represented by the general formula (I) or (II) in which Z is = N-CN is a fluorenone compound or anthraquinone compound and N, N'-bis (trimethylsilyl) carbodiimide in a solvent such as methylene chloride. Obtained by refluxing in the presence of a Lewis acid catalyst such as titanium tetrachloride (Ange
w. Chem. Int. Ed. Eugl., 23, 447 (1984)). Specific examples of the compound represented by the above general formula (I) or (II) include the following compounds. Table 1 shows the reduction potential Ered 1/2, the solubility in the charge generation layer coating solvent (first solvent), and the solubility in the charge transport layer coating solvent (second solvent).

[0011]

[Chemical 5]

[0012]

[Chemical 6]

[0013]

[Table 1] Table 1 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Solubility [mol / I] Organic electron Ered 1/2 (vsSCE) ━━━━━━━━━━━━━━━━━━━━━ Acceptor [V] n-Butyl acetate monochlorobenzene (charge generation layer coating solvent) (charge transport layer coating) Solvent) ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ I-1 -0.63 4.5 x 10 ^{-3 0.4 × 10 -3 I-2} -0.51 5.2 × 10 -3 0.4 × 10 -3 I-3 -0.68 5.4 × 10 -3 0.3 × 10 - ³ I-4-0.63 4.5 × 10 ⁻³ 0.3 × 10 ⁻³ I-5 −0.78 4.1 × 10 ⁻³ 0.4 × 10 ⁻³ I-6 −0.64 4.4 × 10 ⁻³ 0.5 × 10 ⁻³ I-7 −0.49 4.6 × 10 ⁻³ 0.4 × 10 ⁻³ I-8 −0.50 4.6 × 10 ⁻³ 0 ^{.5 × 10 -3 I-9 -0.64} 4.8 × 10 -3 0.3 × 1 ^{-3 II-1 -0.79 3.5 × 10} -3 0.4 × 10 -3 ━━━━━━━━━━━━━━━━━━━━━━━━━━━ ━━━━━━━━━━ 2,4,7-Trini −0.51 ＞ 1.0 × 10 ^-3 5.0 × 10 ^-1 Trofluorenone ━━━━━━━━━━━━━━ ━━━━━━━━━━━━━━━━━━━━━━━

The reduction potential is measured by a solution of an organic electron acceptor in acetonitrile (supporting electrolyte: 0.1M-TEA).
After degassing P) with argon, CV measurement (Yanako: Voltammetric analyzer P-1100, working electrode, counter electrode: platinum electrode, reference electrode: saturated calomel electrode) was performed. The solubility was determined from the ratio of the absorbance at the peak wavelength of the UV spectrum of the known concentration solution and the saturated solution at room temperature (20 ° C). Examples of the charge generation material include phthalocyanine pigments and squarylium pigments. Examples of phthalocyanine-based pigments include metal-free phthalocyanine crystals, oxytitanium phthalocyanine crystals, chlorogallium phthalocyanine crystals, dichlorotin phthalocyanine crystals, and hydroxygallium phthalocyanine crystals. The chlorogallium phthalocyanine crystal has a Bragg angle (2θ ± 0.2 °) of 7.4, 16.6 in an X-ray diffraction spectrum using CuKα as a radiation source.
Chlorogallium phthalocyanine crystal having strong diffraction peaks at 25.5 and 28.3 °, Bragg angle (2θ ± 0.2
), A chlorogallium phthalocyanine crystal having strong diffraction peaks at 6.8, 17.3, 23.6, and 26.9 °, and a Bragg angle (2θ ± 0.2 °) of 8.7 to 9.2, 17.6,
A chlorogallium phthalocyanine crystal having a strong diffraction peak at 24.0, 27.4 and 28.8 ° is preferable. The dichlorotin phthalocyanine crystal has a Bragg angle (2θ ± 2) in an X-ray diffraction spectrum using CuKα as a radiation source.
0.2 °) is 8.3, 12.2, 13.7, 15.9, 18.9, 2
Dichlorotin phthalocyanine crystal having a strong diffraction peak at 8.2 °, Bragg angle (2θ ± 0.2 °) of 8.5, 1
Dichlorotin phthalocyanine crystal having strong diffraction peaks at 1.2, 14.5 and 27.2 °, Bragg angle (2θ ± 0.
2 °) is 8.7, 9.9, 10.9, 13.1, 15.2, 16.
3, 17.4, 21.9, dichlorotin phthalocyanine crystals having strong diffraction peaks at 25.5 °, and Bragg angles (2θ ± 0.2 °) of 9.2, 12.2, 13.4, 14 .6,
Dichlorotin phthalocyanine crystals having strong diffraction peaks at 17.0 and 25.3 ° are preferred.

The hydroxygallium phthalocyanine crystal has a Bragg angle (2θ ± 0.2 °) of 7.7, 16.5 in an X-ray diffraction spectrum using CuKα as a radiation source.
Hydroxygallium phthalocyanine crystal having strong diffraction peaks at 25.1 and 26.6 °, Bragg angle (2θ ± 0.
Hydroxygallium phthalocyanine crystal having a strong diffraction peak at 7.9, 16.5, 24.4 and 27.6 degrees,
Bragg angle (2θ ± 0.2 °) is 7.0, 7.5, 10.5,
11.7, 12.7, 17.3, 18.1, 24.5, 26.2, 2
7. Hydroxygallium phthalocyanine crystal with strong diffraction peak at 7.1 °, Bragg angle (2θ ± 0.2 °) is 7.
5, 9.9, 12.5, 16.3, 18.6, 25.1, 28.3 °
Hydroxygallium phthalocyanine crystal having a strong diffraction peak at 6, and Bragg angle (2θ ± 0.2 °) of 6.
Hydroxygallium phthalocyanine crystals having strong diffraction peaks at 8, 12.8, 15.8 and 26.0 ° are preferred.
As the metal-free phthalocyanine crystal, an X-type metal-free phthalocyanine crystal is preferable. The oxytitanium phthalocyanine crystal has a Bragg angle (2θ ± 0.2 °) of 9. in the X-ray diffraction spectrum using CuKα as a radiation source.
3, 10.6, 13.2, 15.1, 15.7, 16.1, 20.
Oxytitanium phthalocyanine crystal having strong diffraction peaks at 8, 23.3 and 26.3 °, Bragg angle (2θ ±
0.2 °) is 7.6, 100.2, 12.6, 13.2, 15.1, 1
6.3, 17.3, 18.3, 22.5, 24.2, 25.3, 28.
An oxytitanium phthalocyanine crystal having a strong diffraction peak at 6 °, and a Bragg angle (2θ ± 0.2 °)
Oxytitanium phthalocyanine crystals having strong diffraction peaks at 9.7, 11.7, 15.0, 23.5 and 27.3 ° are preferred. The compounding amount of the organic electron acceptor in the charge generation layer is from 0.001 part by weight to 1 part by weight of the charge generation material.
It is preferably 0.1 part by weight.

In the charge generation layer, the charge generation material and the organic electron acceptor are preferably dispersed in the binder resin. The binder resin can be selected from a wide range of insulating resins, and can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, and 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, polyamide resins, acrylic resins. Insulating resins such as, but not limited to, polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, and polyvinyl pyrrolidone resin can be used. These binder resins may be used alone or in combination of two or more. The compounding ratio (weight ratio) of the charge generating material and the binder resin is preferably in the range of 10: 1 to 1:10.

The first solvent used for the charge generation layer coating liquid is methanol, ethanol, n-poupanol, n.
-Butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate,
Usual organic solvents such as dioxane, tetrahydrofuran, methylene chloride, chloroform and the like can be mentioned, and these solvents may be used alone or in combination of two or more kinds. The above material components can be dispersed in the above solvent and coated on a conductive support to form a charge generation layer. As the dispersion method, a usual method such as a ball mill dispersion method, an attritor dispersion method, or a sand mill dispersion method can be used. During this dispersion, the particles of the charge generation material were adjusted to 0.5
μm or less, preferably 0.3 μm or less, more preferably
A particle size of 0.15 μm or less is desirable. Further, as a method for applying the coating liquid for the charge generating layer, 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, a curtain coating method or the like is used. be able to. The thickness of the charge generation layer is generally 0.1 to 5 μm, preferably 0.2 to 2.0 μm.

The charge transport layer usually contains a charge transport material dispersed in a binder resin. As the charge transport material, 2,
5-bis (p-diethylaminophenyl) -1,3,4
-Oxadiazole derivatives such as oxadiazole, 1,
3,5-triphenyl-pyrazoline, 1- [pyridyl-
(2)]-3- (p-Diethylaminostyryl) -5-
Pyrazoline derivatives such as (p-diethylaminophenyl) pyrazoline, aromatic tertiary amino compounds such as triphenylamine and dibenzylaniline, N, N'-diphenyl-N, N'-bis- (3-methylphenyl)- [1,
1'-biphenyl] -4,4'-diamine and other aromatic tertiary diamino compounds, 3- (4'-diethylaminophenyl) -5,6-di- (4'-methoxyphenyl)-
1,2,4-Triazine derivatives such as 1,2,4-triazine, 4-diethylaminobenzaldehyde-1,1 '
Hydrazone derivatives such as diphenylhydrazone, quinazoline derivatives such as 2-phenyl-4-styrylquinazoline, benzofuran derivatives such as 6-hydroxy-2,3-di (p-methoxyphenyl) benzofuran, p- (2,
Α-stilbene derivatives such as 2'-diphenylvinyl) -N, N-diphenylaniline, "Journal of Imaging S"
cience "29: 7-10 (1985), enamine derivatives, poly-N such as N-ethylcarbazole.
-Vinylcarbazole and its derivatives, poly-γ-carbazole ethylglutamate and its derivatives, and further pyrene, polyvinylpyrene, polyvinylanthracene, polyvinylacridine, poly-9-biphenylanthracene, pyrene-formaldehyde resin, ethylcarbazole-formaldehyde resin, etc. Known charge transport materials can be used, but are not limited to these. In addition, these charge transport materials are used alone or
A mixture of two or more species can be used.

As the binder resin that can be used in the charge transport layer, 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, silicon Known resins such as resins, silicone-alkyd resins, phenol-formaldehyde resins, styrene-alkyd resins, and poly-N-vinylcarbazole can be mentioned, but not limited to these. 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 second solvent used for the charge transport layer coating liquid,
Aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, ketones such as acetone and 2-butanone, halogenated aliphatic hydrocarbons such as methylene chloride, chloroform and ethylene, cyclic hydrocarbons such as tetrahydrofuran and ethyl ether, or Ordinary organic solvents such as linear ethers may be used alone or in combination of two or more.

The above material components are dissolved in the above solvent,
This coating solution can be coated on the charge generation layer to form the charge transport layer. As a method for applying the coating liquid for the charge transport layer, it is possible to use 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. it can. The thickness of the charge transport layer is generally 5 to 50 μm.
m, preferably 10 to 30 μm. In addition, additives such as antioxidants, light stabilizers, and heat stabilizers are added to the photosensitive layer for the purpose of preventing deterioration of the photoreceptor due to ozone or oxidizing gas generated in the copying machine, or light or heat. You may. Examples of antioxidants include hindered phenols,
Examples thereof include hindered amines, paraphenylenediamines, aryl alkanes, hydroquinones, spirochromans, spiroindanones and their derivatives, organic sulfur compounds and organic phosphorus compounds. Further, examples of the light stabilizer include derivatives such as benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine.

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 photoconductor and to improve the mechanical strength of the photoconductor. This protective layer contains a conductive material dispersed in a binder resin. As the conductive material, a metallocene compound such as N, N'-dimethylferrocene, N, N'-diphenyl-N, N'-
Aromatic amine compounds such as bis (3-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine, metals such as antimony oxide, tin oxide, titanium oxide, indium oxide, tin oxide-antimony oxide Materials such as oxides can be used, but are not limited to these. Further, as the binder resin used for this protective layer, polyamide resin, polyurethane resin, polyester resin,
Known resins such as an epoxy resin, a polyketone resin, a polycarbonate resin, a polyvinyl ketone resin, a polystyrene resin, and a polyacrylamide resin can be mentioned. The protective layer is formed on the charge transport layer using a conventional coating 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. be able to. It is preferable that the protective layer has an electric resistance of 10 ⁹ to 10 ¹⁴ Ω · cm. Electric resistance is 10 ¹⁴ Ω
When it is more than 10 cm, the residual potential is increased and the fog of the copy is increased, and when it is less than 10 ⁹ Ω · cm, the image becomes blurred and the resolution is deteriorated. Also, the protective layer should be constructed so as not to substantially impede the penetration of the light used for imagewise exposure. The thickness of the protective layer is 0.5 to 20 μm
Is suitable, and preferably 1 to 10 μm.

[0022]

The present invention will be described in more detail with reference to the following examples. The scope of the invention is not limited to the examples below. (Synthesis example) 9-fluorein-4-carboxylic acid 3.0 g (13.3 mmol), malonnitrile 2 g (30.5 mmol), piperidine 0.3 ml and pyridine 45 ml were put into a 100 ml three-necked flask, and nitrogen was added. The mixture was refluxed under an air stream for 8 hours. After cooling to room temperature, the precipitated crystals were filtered off and washed with water,
Recrystallized from methanol solvent to give compound (I-1) 1.7 g
Was obtained as orange needle crystals. Melting point: 296 ℃ (decomp.)
The infrared absorption spectrum is shown in FIG.

(Example 1) 10 parts of a zirconium compound (trade name: Organix ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.) and a silane compound (trade name: A1) on an aluminum substrate.
110, made by Japan Junker Co., Ltd.) 1 part, i-propanol 4
A solution consisting of 0 part and 20 parts butanol was applied by a dip coating method and dried by heating at 150 ° C. for 10 minutes to form an undercoat layer having a thickness of 0.5 μm. Next, 1 part of X-type metal-free phthalocyanine crystal and the above compound (I-1) 0.
05 parts were mixed with 1 part of polyvinyl butyral resin (trade name: S-REC BM-S, manufactured by Sekisui Chemical Co., Ltd.) and 100 parts of n-butyl acetate, and treated with a glass shaker for 1 hour on a paint shaker to be dispersed, and then obtained. The obtained dispersion is applied onto the above-mentioned undercoat layer by a dip coating method,
It was heated and dried at 0 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.15 μm. Next, 2 parts of the compound represented by the following structural formula (III) and poly (4, represented by the following structural formula (IV)
4'-cyclohexylidene diphenylene carbonate)
3 parts was dissolved in 20 parts monochlorobenzene, and the obtained coating solution was applied on an aluminum substrate having a charge generation layer formed thereon by a dip coating method, and dried by heating at 120 ° C. for 1 hour to give a film thickness of 20 μm. Was formed on the charge transport layer.

[Chemical 7] The electrophotographic characteristics of the electrophotographic photosensitive member thus obtained were measured as follows using an electrostatic copying paper test apparatus (Kawaguchi Electric: Electrostatic Analyzer EPA-8100). The electrophotographic photoconductor is charged by corona discharge of -6 kV in an environment of normal temperature and humidity (20 ° C, 40% RH), and then the light of a tungsten lamp is converted into a monochromatic light of 800 nm by using a monochromator. The surface was exposed with light adjusted to have a light amount of 1 μW / cm ² . Surface potential V ₀ (volt), half exposure amount E _1/2 (erg
/ Cm ² ) was measured, and then 10 lux of white light was irradiated for 1 second to measure the residual potential V _R (volt). After repeating the above charging and exposure 1000 times, V ₀ , E
_1/2 and V _R were measured. The variation amounts of V ₀ , E _1/2 , and V _R due to 1000 times of charging and exposure are ΔV ₀ , Δ
It is represented by E _1/2 and ΔV _R , and the results are shown in Tables 2 and 3.

Example 2 The compound (I
Except that compound (II-1) was used instead of -1).
A photoconductor was prepared in the same manner as in Example 1, and the same measurement was performed. The results are shown in Tables 2 and 3. (Comparative Example 1) A photoconductor was prepared in the same manner as in Example 1 except that 2,4,7-trinitrofluorenone was used instead of the compound (I-1) in Example 1, and the same measurement was carried out. I went. The results are shown in Tables 2 and 3. (Comparative Example 2) A photoconductor was prepared in the same manner as in Example 1 except that the compound (I-1) was not used, and the same measurement was carried out. The results are shown in Tables 2 and 3. (Example 3) A photoconductor was prepared in the same manner as in Example 1 except that a chlorogallium phthalocyanine crystal was used instead of the X-type metal-free phthalocyanine crystal, and the same measurement was performed. The results are shown in Tables 2 and 3. (Example 4) A photoconductor was prepared in the same manner as in Example 2 except that a chlorogallium phthalocyanine crystal was used instead of the X-type metal-free phthalocyanine crystal, and the same measurement was performed. The results are shown in Tables 2 and 3. (Comparative Example 3) A photoreceptor was prepared in the same manner as in Example 3 except that 2,4,7-trinitrofluorenone was used instead of the compound (I-1) in Example 3, and the same measurement was carried out. I went. The results are shown in Tables 2 and 3. (Comparative Example 4) A photoconductor was prepared in the same manner as in Example 3 except that the compound (I-1) was not used, and the same measurement was carried out. The results are shown in Tables 2 and 3.

Example 5 A photoconductor was prepared in the same manner as in Example 1 except that a hydroxygallium phthalocyanine crystal was used instead of the X-type metal-free phthalocyanine crystal in Example 1, and the same measurement was carried out. It was The results are shown in Tables 2 and 3. (Example 6) A photoconductor was prepared in the same manner as in Example 2 except that a hydroxygallium phthalocyanine crystal was used instead of the X-type metal-free phthalocyanine crystal, and the same measurement was performed. The results are shown in Tables 2 and 3. (Comparative Example 5) A photoconductor was prepared in the same manner as in Example 5 except that 2,4,7-trinitrofluorenone was used in place of the compound of the structural formula (I-1) in Example 5.
The same measurement was performed. The results are shown in Tables 2 and 3. (Comparative Example 6) A photoconductor was prepared in the same manner as in Example 5 except that the compound of structural formula (I-1) was not used, and the same measurement was carried out. The results are shown in Tables 2 and 3
Shown in.

[0026]

[Table 2] Table 2 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Initial characteristics (once) Maintenance characteristics ( 1000 times) Organic Electronics ━━━━━━━━━━━━━━━━━━━━━━━ Acceptor Vo E _1/2 V _RP Vo E _1/2 V _RP (V) (erg / cm ² (V) (V) (erg / cm ² (V) ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example 1 ( I-1) -790 3.7 -31 -780 3.8 -27 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ━━━ Example 2 (II-1) -795 4.1 -33 -790 3.9 -29 ━━━━━━━━━━━━━━━━━━━━━━━━━ ━━━━━━━━━━━ 2,4,7-Trini Comparative Example 1 Trofluore -805 6.7 -45 -780 6.4 -40 Non ━━━━━━━━━━━━━━ ━━━━━━━━━━━━━━━━━━━━━ Comparative example 2 ────── -820 6.8 -40 -790 6.6 -45 ━━━━━━ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Embodiment 3 (I-1 -795 1.4 -3 -790 1.5 -4 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Implementation Example 4 (II-1) -800 1.5 -3 -795 1.6 -5 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ━━━━━━ 2,4,7-Trini Comparative Example 3 Trofluore -800 2.0 -4 -795 2.2 -6 Non Non ━━━━━━━━━━━━━━━━━━ ━━━━━━━━━━━━━━━━━ Comparative example 4 ─────── -810 2.0 -4 -805 2.1 -5 ━━━━━━━━━━━ Example 5 (I-1) -795 1.0 -20 -790 1.1 -18 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example 6 (II-1) -800 1.1 -22 -790 1 .2 -20 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 2,4,7-Trini Comparative Example 5 Trofluore -800 2.0 -20 -770 2.4 -29 Non Non ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ━━━━ Comparative example 6 ─────── -800 2.1 -22 -775 2.4 -27 ━━━━━━━━━━━━━━━━━━━━━━━━ ━━━━━━━━━━━━

[0027]

[Table 3] Table 3 ━━━━━━━━━━━━━━━━━━━━━━━━━━ Stability No. Organic electron ━━━━━━━━━━━━━ Acceptor △ Vo △ E _1/2 △ V _RP (V) (erg / cm ² (V) ━━━━━━━━━━━━━ ━━━━━━━━━━━━━ Example 1 (I-1) 10 0.1 4 ━━━━━━━━━━━━━━━━━━━━━━━━━━ ━━ Example 2 (II-1) 5 0.2 4 ━━━━━━━━━━━━━━━━━━━━━━━━━━ ━ 2,4,7-Trini Comparative Example 1 Trofluole 25 0.3 5 Non ━━━━━━━━━━━━━━━━━━━━━━━━━━ Comparative example 2 ─────── 30 0.2 5 ━━ ━━━━━━━━━━━━━━━━━━━━━━━━━ Embodiment 3 (I-1) 5 0.1 1 ━━━━━━━━━━━━━━ ━━━━━━━━━━━━━ Example 4 (II-1) 5 0.1 2 ━━━━━━━━━━━━━━━━━━━━━━━━━ ━━ 2,4,7-Trini Comparative Example 3 Troff Luore 5 0.2 2 Non Non ━━━━━━━━━━━━━━━━━━━━━━━━━━ Comparative Example 4 ────── 5 0.1 1 ━━━ ━━━━━━━━━━━━━━━━━━━━━━━━ Embodiment 5 (I-1) 5 0.1 2 ━━━━━━━━━━━━━━━ ━━━━━━━━━━━━ Example 6 (II-1) 10 0.1 2 ━━━━━━━━━━━━━━━━━━━━━━━━━━ ━ 2,4,7-Trini Comparative Example 5 Trofluore 30 0.4 9 Non ━━━━━━━━━━━━━━━━━━━━━━━━━━ Comparative Example 6 ─── ─── 25 0.3 5 ━━━━━━━━━━━━━━━━━━━━━━━━━━

[0028]

The electrophotographic photosensitive member of the present invention has high photosensitivity and excellent repetitive stability, as is clear from the results of the above examples.

[Brief description of drawings]

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

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

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

FIG. 4 is a schematic cross-sectional view of an example of the electrophotographic photosensitive member of the present invention.

FIG. 5 is an infrared absorption spectrum diagram of compound (I-1) produced in Synthesis Example.

[Explanation of symbols]

 1 Charge Generation Layer 2 Charge Transport Layer 3 Conductive Support 4 Undercoat Layer 5 Protective Layer

Claims (5)

[Claims] 1. A reduction potential based on a saturated calomel electrode.
A coating solution for a charge generation layer containing an organic electron acceptor having an Ered 1/2 of −0.8 V or more, a charge generation material, and a first solvent is coated on a conductive support, and the charge transport material and An electrophotographic photoreceptor comprising a step of applying a charge transport layer coating solution containing two solvents, provided that the solubility of the organic electron acceptor in the second solvent is smaller than the solubility in the first solvent. Manufacturing method. 2. The organic electron acceptor has a solubility of 1.0 × 10 ⁻³ mol / l or more in the first solvent and 5.0 × 10 ⁻⁴ mol / l in the second solvent. The method for producing an electrophotographic photosensitive member according to claim 1, which has a solubility of 1 or less. 3. The method for producing an electrophotographic photosensitive member according to claim 1, wherein the organic electron acceptor is a compound represented by the following general formula (I). [Chemical 1] [In the formula, Z is = C (CO ₂ R) ₂ (wherein R is a hydrogen atom or an alkyl group), = C (CN) ₂ , = O, or = N-CN,
R _{1 to} R ₄ are a hydrogen atom, a carboxyl group, an alkyl group, an alkoxycarbonyl group, an aryloxycarbonyl group,
A nitro group, a halogen atom, an alkylcarbonyl group, an arylcarbonyl group, or a vinyl group represented by the formula -CR ₅ = CR ₆ R ₇ (wherein, R ₅ is a hydrogen atom or an alkyl group, R ₆ and R ₇ are Hydrogen atom, or a substituted or unsubstituted phenyl group, provided that at least one of R ₆ and R ₇ is a substituted or unsubstituted phenyl group, and the other is a hydrogen atom), provided that R ₁ to At least one of R ₄ is a carboxyl group. ] 4. The organic electron acceptor has the following general formula (I
The method for producing an electrophotographic photosensitive member according to claim 1, which is a compound represented by I). [Chemical 2] [In the formula, Z is = C (CO ₂ R) ₂ (in the formula, R is a hydrogen atom or an alkyl group), = C (CN) ₂ , = O, or = N-CN. ] 5. The method for producing an electrophotographic photosensitive member according to claim 1, wherein the charge generating material is a phthalocyanine pigment.