JPH06175386A - Production of electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide an org. electrophotographic sensitive body excellent in high coating productivity at the time of forming a surface layer on a photosensitive layer formed on an electric conductive substrate and having superior uniformity in film thickness, ensuring high image quality and very excellent in durability. CONSTITUTION:When a surface layer is formed on a photosensitive layer formed on an electric conductive substrate by coating with a coating soln. contg. at least a resin binder and an org. solvent to produce an electrophotographic sensitive body, alkanol contg. a hydroxyl group and at least one among N, F and O excepting a hydroxyl group in one molecule and having <=185 deg.C b.p. is used as the org. solvent. The objective electrophotographic sensitive body is produced.

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 photoreceptor using a specific solution, and more particularly to a method for manufacturing an electrophotographic organic photoreceptor having excellent durability.

[0002]

2. Description of the Related Art Conventionally, inorganic photoconductive materials such as selenium, selenium-tellurium alloys, arsenic selenide, and cadmium sulfide have been widely used for electrophotographic photoreceptors. In recent years, research using organic photoconductive materials in the photosensitive layer has become popular, and it is suitable for mass production and has the possibility of being highly safe. Therefore, it absorbs light and generates charge carriers. The mainstream of research has been devised on a laminated-type photoreceptor having a charge generation layer and a charge transport layer, which separates the function of performing charge generation and the function of moving generated charge carriers. The multi-layered photoconductor has been put into practical use because a photoconductor with high sensitivity can be obtained by combining organic compounds having highly efficient charge generation and charge transport functions. In such a laminated electrophotographic photoreceptor, the charge transport layer is laminated on the charge generation layer, and since the charge transport layer usually has only a hole transport function, the sensitivity can be reduced only when negatively charged. And used under negative charge.

On the other hand, in the electrophotographic method, charging of the photosensitive member is usually carried out by corona discharge, but negative corona discharge is more difficult to discharge uniformly in the wire direction than positive corona discharge, and therefore the charging is uniform. Since it is difficult to obtain good performance, and the selenium-based photoconductor, which was the center of the prior art, was positively charged, I want to use the conventional technology for the developers and other peripheral processes used in this system. An organic photoconductor that can be used under positive charging is also under study. For example, a so-called inverse two-layer type photoconductor in which a charge transport layer and a charge generation layer are laminated in this order on a support, and a dispersion type photoconductor in which particles of a charge generation substance are dispersed in a charge transport medium have been proposed for positive charging. A study is underway. In the inverse two-layer type and dispersion type photoreceptor, incident light is absorbed near the surface of the photosensitive layer, and the region where the carrier is generated is near the surface, and is used under positive charging.

Organic photoconductors having several constitutions have been developed and have excellent chargeability and sensitivity. However, in terms of durability, the organic photoreceptor is inferior to the inorganic photoreceptor. Physical characteristics are one of the factors that determine durability. That is, since it has a defect in which abrasion and surface scratches are likely to occur due to a practical load from mechanical stress such as development with toner, friction with paper, friction with a cleaning member, etc., the durability performance is limited to the practical limit. Is the current situation.

[0005]

It is conceivable to provide a surface layer for protecting the surface of the photoconductor from the above-mentioned mechanical stress when the photoconductor is repeatedly used to improve the durability. However, there is a problem that when the surface layer is formed by coating, the photosensitive layer below the surface layer is dissolved, resulting in image defects and a phenomenon in which a high quality image cannot be obtained. Therefore, there has been a demand for a method capable of producing an organic photoreceptor having a surface layer formed of a coating solution which has good coating productivity and can maintain an appropriate layer structure.

[0006]

The inventors of the present invention have made extensive studies in view of the above problems, and as a result, at the time of coating a photoreceptor, use of a specific solvent as a solvent for a coating solution for forming a surface layer may cause image defects. It was found that high-quality images can be obtained by preventing unevenness of the photoconductor film thickness due to the dissolution of the other photosensitive layer, and completed the present invention.

That is, the gist of the present invention is to provide an electrophotographic photoreceptor in which a surface layer is formed by applying a coating solution containing at least a binder resin and an organic solvent onto a photosensitive layer provided on a conductive support. In the manufacturing method, as the organic solvent,
Use of an alkanol having a boiling point of 185 ° C. or lower, which contains a hydroxyl group and any atom other than the hydroxyl group containing at least one of an oxygen atom, a nitrogen atom and a fluorine atom in the molecule, and is used for producing an electrophotographic photoreceptor. In the way.

The present invention will be described in detail below. The photosensitive layer of the present invention contains at least a charge generating substance and a charge transporting substance. As a specific structure of the photosensitive layer containing the charge generating substance and the charge transporting substance, a charge generating layer containing the charge generating substance as a main component on a conductive support, a charge transporting substance containing the charge transporting substance and a binder resin as a main component A laminated structure in which layers are laminated in this order. An inverse two-layer structure in which a charge transporting layer containing a charge transporting substance and a binder resin as main components and a charge generating layer containing a charge generating substance as a main component are laminated in this order on a conductive support. A dispersion type structure in which a charge generating substance is dispersed in a layer containing a charge transporting substance and a binder resin on a conductive support. An example of the basic form is such a configuration.

A surface layer is formed on these photosensitive layers. Particularly, when the surface layer is formed on the photosensitive layer having an inverse two-layer structure,
Since the charge generation layer immediately below the surface layer is usually relatively thin, it is easily affected by the nonuniformity of the photosensitive layer thickness due to dissolution. Therefore, the method of the present invention is significantly effective in the case of a photosensitive layer having an inverted two-layer structure. These photosensitive layer and surface layer are formed on the conductive support by a known method such as roll coating, dip coating or spray coating.

Various known supports can be used as the conductive support. For example, aluminum, copper, nickel,
Metal drum such as stainless steel; metal foil laminated, metal or conductive oxide deposited or sputtered, and metal fine powder, carbon black, copper iodide, tin oxide, titanium oxide, indium oxide, alumina, etc. conductive A plastic film that has been subjected to a conductive treatment, such as applying a conductive substance together with a binder if necessary,
Examples include plastic drums, glass drums, and paper.

A known barrier layer or organic layer which is commonly used may be provided between the conductive support and the photosensitive layer provided on the support. Examples of the barrier layer include an anodized aluminum film, an inorganic layer such as aluminum oxide and aluminum hydroxide, an organic layer such as polyvinyl alcohol, casein, polyvinylpyrrolidone, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide and polyamide. Is used.

As the charge generating substance used in the photosensitive layer, various inorganic and organic charge generating substances can be used. For example, as an inorganic charge generating substance, various selenium-based alloy materials such as amorphous selenium, selenium-tellurium alloys, trigonal selenium, and arsenic triselenide; cadmium sulfide, cadmium selenide, etc. II to VI Group compound semiconductor materials; known materials such as amorphous silicon and silicon hydride are used in the form of fine particles. Further, phthalocyanine pigments, perylene pigments, polycyclic quinones known as organic charge generating substances,
Quinacridone pigment, indigo pigment, squarylium salt,
Azo pigments and the like can be used.

Of these, phthalocyanine pigments and azo pigments can be used as more preferable materials. Examples of the phthalocyanine pigment include those described by the following general formula.

[0014]

[Chemical 1]

Cu, Fe, M as the metal component of the above M
g, Si, Ge, Sn, Pb, In, Ga, Al, Ti
And phthalocyanine containing atoms such as, and metal-free phthalocyanine to which two hydrogen atoms are added. X is a hydrogen atom, a lower alkyl group, a lower alkoxy group,
Examples include nitro group, cyano group, halogen atom, m
Represents an integer from 0 to 4.

As the above-mentioned azo pigment, various ones can be mentioned, but an azo pigment having an aromatic condensed ring such as a naphthalene ring as a coupler component is preferable, and a more preferable material is at least one coupler component represented by the following general formula. Examples thereof include monoazo pigments, bisazo pigments, trisazo pigments and other polyazo pigments.

[0017]

[Chemical 2]

Where A is a divalent aromatic hydrocarbon group,
Alternatively, it represents a divalent heterocyclic group containing a nitrogen atom in the ring. In the case of a laminated structure, the charge generating substance is used as a main component constituting the charge generating layer, and may be used as a uniform layer formed by a method such as vapor deposition or sputtering, or a binder in the form of fine particles. It may be used in a form dispersed in a resin. In this case, as the binder resin, polyvinyl acetate, polyacrylic ester, methacrylate resin,
Various binder resins such as polyester resin, polycarbonate resin, polyvinyl acetal resin such as polyvinyl butyral and polyvinyl formal, phenoxy resin, cellulose ester, cellulose ether, urethane resin and epoxy resin can be used. The composition ratio of the charge generating substance and the binder resin is usually preferably in the range of 100: 10 to 5: 100 by weight.

Further, the charge generation layer is, for example, 2, 4, 7
Electron-accepting substances such as trinitrofluorenone and tetracyanoquinodimethane, heterocyclic compounds such as carbazole, indole, imidazole, oxazole, pyrazole, oxadiazole, pyrazoline and thiadiazole, aniline derivatives, hydrazone compounds, aromatic amine derivatives An electron-donating substance such as a stilbene derivative or a polymer having a group composed of these compounds in the main chain or side chain may be mixed. The weight ratio of these electron accepting substance or electron donating substance to the charge generating substance is preferably in the range of 50: 1 to 1: 100. The charge generation layer is usually formed to have a thickness of 0.1 to 10 μm.

Further, in the case of the dispersion type photosensitive layer structure as described above, the charge generating substance is dispersed in the form of fine particles in the matrix having the charge transporting substance and the binder resin. Examples of the charge transport material used in the photosensitive layer include various known materials used in electrophotographic photoreceptors. Compounds having a heterocycle such as carbazole, indole, imidazole, thiazole, oxadiazole, pyrazole and pyrazoline; aniline derivatives such as phenylamine, diphenylamine, triphenylamine; hydrazone derivatives;
Examples thereof include stilbene derivatives; and electron-donating substances such as polymers having a group composed of these compounds in the main chain or side chain. Particularly preferred substances include hydrazone derivatives, aniline derivatives and stilbene derivatives.

As the binder resin used together with the charge transport material, various known resins can be used. Thermoplastic resins and curable resins such as polycarbonate resins, polyester resins, polyarylate resins, acrylic resins, methacrylate resins, styrene resins, and silicone resins can be used. Particularly preferred are polycarbonate resins, polyacrylate resins, and polyester resins that are less likely to cause wear and scratches. As the bisphenol component of the polycarbonate resin, various known components such as bisphenol A, bisphenol C and bisphenol Z can be used.

The charge transporting material and the binder resin are mixed in a proportion of, for example, 20 to 200 parts by weight, preferably 40 to 150 parts by weight, based on 100 parts by weight of the resin. In the case of a laminated structure, the charge transport layer is formed mainly with the above components, but the thickness of the charge transport layer is usually 5
In the case of the dispersion type photosensitive layer used in an amount of ˜50 μm, preferably 10 to 40 μm, the charge generating substance is dispersed as fine particles in the matrix containing the charge transporting substance and the binder resin as the main components in the above mixing ratio. However, the particle size is required to be sufficiently small, and the particle size is preferably 1 μm or less, more preferably 0.5 μm or less. If the amount of the charge generating substance dispersed in the photosensitive layer is too small, sufficient sensitivity cannot be obtained, and if it is too large, there are adverse effects such as a decrease in charging property and a decrease in sensitivity. For example, preferably 0.5 to 50. It is used in the range of wt%, more preferably in the range of 1 to 20 wt%. The thickness of the photosensitive layer is usually 5 to 50 μm, more preferably 10 to 40 μm.

Further, the photosensitive layer of the present invention has film-forming property, flexibility,
Known plasticizers for improving mechanical strength, additives for suppressing accumulation of residual potential, dispersion aids for improving dispersion stability, leveling agents for improving coating properties, such as silicone oil. , And other additives may be added. The photosensitive layer of the present invention is prepared by dissolving a charge generating substance and / or a charge transporting substance in a suitable solvent according to a conventional method, and if necessary, a binder resin sensitizing agent, an electron donating compound, an electron absorbing compound or a plasticizer, Antioxidant,
A coating solution obtained by adding additives such as an ultraviolet absorber and a leveling agent is applied on a conductive support and dried to form a photosensitive layer having a film thickness of usually about 0.1 μm to 50 μm. be able to. In the case of a photosensitive layer comprising two layers of a charge generating layer and a charge transporting layer, the coating solution is applied on the charge generating layer, or the charge generating layer is formed on the charge transporting layer obtained by applying the coating solution. It can be manufactured by forming.

Examples of the solvent for preparing the coating solution include aromatic hydrocarbons such as benzene, toluene and xylene; ketones such as acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, cyclohexanone and cyclopentanone; methyl acetate and acetic acid. Esters such as ethyl, methyl propionate, methyl cellosolve, ethyl cellosolve; alcohols such as methanol, ethanol, propanol, butanol; ethers such as tetrahydrofuran, dioxane, dimethoxymethane, dimethoxyethane, diglyme; carbon tetrachloride, chloroform, Halogenated hydrocarbons such as methylene chloride, dichloroethane, trichloroethylene, chlorobenzene; amides such as N, N-dimethylformamide, N, N-dimethylacetamide; dimethylsulfate Kishido; 4-methoxy-4-methyl-pentanone -2, as well as alkanol and the like used in the surface layer formed of the present invention method. These solvents alone,
Alternatively, they may be mixed and used.

A surface layer is provided on these photosensitive layers.
It is important to use a solvent for dissolving the binder resin of the surface layer used in the present invention, which does not dissolve these photosensitive layers, particularly the charge transport layer, and does not make the film thickness uneven. If a solvent that dissolves the photosensitive layer is used, during the coating step or during drying after the coating step, the photosensitive layer is dissolved and eroded by the solvent of the coating solution for the surface layer, resulting in a significantly uneven film thickness, This non-uniformity of film thickness appears as an image defect. In extreme cases, the photosensitive layer may disappear and the conductive support may be exposed.

Therefore, in the present invention, as a solvent which does not dissolve the photosensitive layer and does not make the film thickness nonuniform, a boiling point containing hydroxyl group and at least one of oxygen atom, nitrogen atom and fluorine atom other than the hydroxyl group in the molecule is used. An alkanol having a temperature of 185 ° C. or lower is used as a solvent for forming the surface layer. Here, examples of the functional group containing an oxygen atom in the molecule include an ether group, a carbonyl group and an ester group, and examples of the alkanol containing an oxygen atom include 2-methoxyethanol, 2-ethoxyethanol and 2- Ethylene glycol monoalkyl ethers such as butoxyethanol and tetrahydrofurfuryl alcohol, 2-hydroxyethyl acetate, 2-hydroxyethyl propionate, methyl hydroxyacetate, methyl lactate, ethyl lactate and other esters, diacetone alcohol, 3-hydroxy Examples thereof include ketone alcohol such as -3-methyl-2-butanone.

The functional group containing a nitrogen atom in the molecule includes an amino group, and examples of the alkanol containing a nitrogen atom include dimethylaminoethanol and diethylaminoethanol. Examples of the group containing a fluorine atom in the molecule include various fluoroalkyl groups, and examples of the alkanol containing a fluorine atom include CF ₃ C.
F ₂ CH ₂ OH, F (CF ₂ ) ₄ CH ₂ CH ₂ OH, H
(CF ₂ ) ₄ CH ₂ OH, H (CF ₂ ) ₂ CH ₂ OH,
F (CF ₂ ) ₅ CH ₂ OH, F (CF ₂ ) ₃ CH ₂ O
H, F (CF ₂ ) ₄ CH ₂ OH and the like can be mentioned. Further, the above-mentioned hydroxyl group and alkanol having two or more of oxygen atom, nitrogen atom and fluorine atom other than the hydroxyl group can be used. Examples of these are methoxyethyl lactate, trifluoromethoxyethyl lactate, H (C
_{F 2) 4 CH 2 OCH 2} CH 2 OH , and the like.

The boiling point of the hydroxyl group and the alkanol containing at least one of oxygen atom, nitrogen atom and fluorine atom other than the hydroxyl group is preferably 185 ° C. or lower, more preferably 165 ° C. or lower. .
Therefore, the boiling point of the alkanol having a large molecular weight is higher than the above value, which is not preferable in terms of coating and drying. The above alkanols can be used alone or in combination. It may be mixed with various alcohols, and the weight ratio of alcohol to alkanol is from 5 to 100 to 1.
A range of 00: 5 is preferred.

As the binder resin for the surface layer soluble in a solvent containing an alkanol, polyvinyl acetal resins such as polyvinyl acetoacetal, polyvinyl propional, polyvinyl butyral, and polyvinyl pentanal, and their copolymers and phenoxy resins are used. , Polyamide resin, phenol resin, urethane resin, cellulose ester, cellulose ether, epoxy resin and the like, and copolymers and mixtures thereof. In this case, the composition ratio of the binder resin and the solvent is usually 1: 1 by weight.
The range of 000 to 100: 10 is preferred. Further, the surface layer is, for example, 2,4,7-trinitrofluorenone,
Electron-accepting substances such as tetracyanoquinodimethane, carbazole, indole, imidazole, oxazole,
Heterocyclic compounds such as pyrazole, oxadiazole, pyrazoline, and thiadiazole, aniline derivatives, hydrazone compounds, aromatic amine derivatives, stilbene derivatives, or electron donors such as polymers having groups of these compounds in the main chain or side chain The substance may be mixed.

Further, inorganic particles such as alumina, titania and silica, metal particles such as copper, iron and aluminum and oxide particles thereof, fibers or particles containing carbon as a main component, lithium salt, quaternary ammonium salt compound and the like. Ion conductive material, particles of alloy containing selenium as a main component, particles of II-VI group compound semiconductors such as cadmium sulfide, particles of amorphous silicon hydride, and other conductive or semiconductive particles It may be done.

Further, phthalocyanine, perylene, polycyclic quinones, quinacridone, indigo, squarylium salt,
Various pigments such as azo may be mixed. Furthermore, if necessary, various additives such as antioxidants and sensitizers, known plasticizers for improving film-forming property, flexibility and mechanical strength, additives for suppressing residual potential A dispersion aid for improving dispersion stability, a leveling agent for improving coating properties, and a surfactant such as silicone oil, fluorine-based oil and other additives may be contained. The thickness of the surface layer is usually 0.1 to 10 μm, preferably 0.1 to 5 μm
Used in.

[0032]

According to the present invention, when the surface layer is formed on the photosensitive layer provided on the conductive support, the coating productivity is good, the uniformity of the film thickness is excellent, and the image quality is high. It is possible to provide an organic photoreceptor having excellent durability.

[0033]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example 1 An extruded aluminum tube was ironed to a thickness of 0.
An aluminum cylinder having a diameter of 75 mm, an outer diameter of 30 mm and a length of 246 mm was produced. After forming an anodized film having an average film thickness of 10 μm on this aluminum cylinder, it was subjected to a sealing treatment, washed with water and dried.

Next, 70 parts by weight of the hydrazone compound represented by the following formula (1) and the following formula (2) were used in the aluminum cylinder.
1.5 parts by weight of the cyano compound shown in

[0036]

[Chemical 3]

And 100 parts by weight of a polycarbonate resin (Novalex 7030A manufactured by Mitsubishi Kasei Co., Ltd.)
A charge transport layer was provided so that the film thickness after dried coating was 17 μm by dipping and coating in a solution dissolved in 1000 parts by weight of 1,4-dioxane. On the other hand, 2 in the X-ray diffraction spectrum
200 parts by weight of n-propanol was added to 10 parts by weight of oxytitanium phthalocyanine having a main peak at 7.3 ° (± 0.2 °), and the liquid temperature was cooled to 5 ° C. or lower by cooling with ice water, followed by 10 with a sand grind mill. Time pulverization and atomization dispersion treatment were performed. Next, polyvinyl butyral (Denka Butyral # -600, manufactured by Denki Kagaku Kogyo KK)
0) was mixed with a 10% n-propanol solution containing 5 parts by weight to prepare a coating solution.

Next, an aluminum cylinder coated with the charge-transporting layer prepared above was dip-coated with this dispersion liquid, and a charge-generating layer was provided so that the film thickness after drying was 0.2 μm. Furthermore, 9.5 parts by weight of polyvinyl butyral and 0.5 part by weight of a quaternary ammonium salt compound were added to a methyl lactate solvent 10
The surface layer coating liquid was prepared by stirring and mixing with 100 parts by weight, and the surface layer was provided on the aluminum cylinder coated with the charge transport layer and the charge generating layer so that the film thickness after drying was 0.4 μm.

The thus prepared photoconductor is mounted on a photoconductor characteristic measuring machine and charged to 700 V at an initial stage, and then 780
The half-exposure sensitivity and residual potential when an exposure of nm was given were measured. The results are shown in Table 1 together with the values of the subsequent examples. Both the sensitivity and the residual potential were good. A commercially available laser printer-PC in which this photoreceptor is modified for positive charging.
As a result of evaluation by attaching to -406LM (manufactured by NEC Corporation), a good image without defects was obtained.

Example 2 A photoreceptor was prepared in the same manner as in Example 1 except that H (CF ₂ ) ₄ CH ₂ OH was used in place of methyl lactate as a solvent for the surface layer coating solution used in Example 1. As a result of fabrication and evaluation in the same manner, a good image without defects was obtained.

Example 3 A photoreceptor was prepared in the same manner as in Example 1 except that H (CF ₂ ) ₂ CH ₂ OH was used in place of methyl lactate as a solvent for the surface layer coating solution used in Example 1. As a result of fabrication and evaluation in the same manner, a good image without defects was obtained.

Example 4 A photoreceptor was prepared in the same manner as in Example 1 except that 2-methoxyethanol was used in place of methyl lactate as a solvent for the surface layer coating solution used in Example 1. As a result of evaluation, a good image without defects was obtained.

Example 5 A photoreceptor was prepared in the same manner as in Example 1 except that 3-hydroxy-3-methyl-2butanone was used in place of methyl lactate as a solvent for the surface layer coating solution used in Example 1. Was prepared and evaluated in the same manner, and a good image free from defects was obtained.

Examples 6 to 10 As an alternative to polyvinyl butyral in the surface layer coating solution used in Examples 1 to 5, an epoxy resin (YD-0 manufactured by Tohto Kasei Co., Ltd.) was used.
Photosensitive members were produced in the same manner as in Examples 1 to 5 except that 14) was used and evaluated in the same manner. As a result, good images without defects were obtained on the respective photosensitive members.

Example 11 Instead of the oxytitanium phthalocyanine used in Example 1, 10 parts by weight of the azo compound represented by the formula (3) and 10 parts by weight of the hydrazone compound represented by the formula (1) were used. Atomization dispersion treatment was carried out in the same manner as in Example 1 to prepare a photoconductor in the same manner as in Example 1, and the photoconductor characteristics were evaluated by exposure to white light. As a result, both white light sensitivity and residual potential were good.
As a result of image evaluation in the same manner as in Example 1, a good image without defects was obtained.

[0046]

[Chemical 4]

Example 12 In place of the oxytitanium phthalocyanine used in Example 1, 10 parts by weight of the azo compound represented by the formula (4) and 10 parts by weight of the hydrazone compound represented by the formula (1) were used. Atomization dispersion treatment was carried out in the same manner as in Example 1 to prepare a photoconductor in the same manner as in Example 1, and the photoconductor characteristics were evaluated by exposure to white light. As a result, both the half-exposure sensitivity and the residual potential were good. As a result of image evaluation in the same manner as in Example 1, a good image without defects was obtained.

[0048]

[Chemical 5]

Example 13 Example 1 was repeated except that the charge generation layer, the charge transport layer and the surface layer were provided in this order on the aluminum cylinder.
A photoconductor was prepared in the same manner as described above, and the photoconductor prepared in this manner was mounted on a photoconductor characteristic measuring machine, initially charged to −700 V, and the half-exposure sensitivity and residual when exposed at 780 nm were given. As a result of measuring the potential, both the sensitivity and the residual potential were good. A commercially available laser printer-PC-406LM (NEC Corp.) obtained by modifying this photoconductor for negative charging.
As a result of installation and evaluation, a good image without defects was obtained.

Comparative Examples 1 to 4 1,4-dioxane, 1,2-dimethoxyethane, 1,2-dichloroethane or tetrahydrofuran was used instead of methyl lactate as a solvent for the surface layer coating solution used in Example 1, respectively. Except for the above, a photoconductor was prepared in the same manner as in Example 1 and evaluated in the same manner. As a result, turtle shell coating unevenness was visually observed on each photoconductor drum surface, and the film thickness was remarkably uneven. The defect was reflected on the image as it was, resulting in a remarkable image defect.

Comparative Examples 5 to 8 Instead of methyl lactate as the solvent for the surface layer coating solution used in Example 6, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-dichloroethane or tetrahydrofuran was used, respectively. Except for the above, a photoconductor was prepared in the same manner as in Example 6 and evaluated in the same manner. As a result, coating unevenness in the shape of a turtle shell was visually observed on each photoconductor drum surface, and the film thickness was remarkably uneven. The defect was reflected on the image as it was, resulting in a remarkable image defect.

Comparative Examples 9 to 12, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-dichloroethane or tetrahydrofuran were used instead of methyl lactate as a solvent for the surface layer coating solution used in Example 11, respectively. A photosensitive member was prepared in the same manner as in Example 11 except for the above conditions, and evaluated in the same manner. As a result, turtle shell coating unevenness was visually observed on the surface of each photosensitive drum, and the film thickness was remarkably uneven. The defect was reflected on the image as it was, resulting in a remarkable image defect.

Comparative Examples 13 to 16 1,4-Dioxane, 1,2-dimethoxyethane, 1,2-dichloroethane or tetrahydrofuran was used instead of methyl lactate as a solvent for the surface layer coating solution used in Example 12, respectively. A photoreceptor was prepared in the same manner as in Example 12 except for the above, and evaluated in the same manner. As a result, turtle shell coating unevenness was visually observed on the surface of each photoreceptor drum, and the film thickness was remarkably uneven. The defect was reflected on the image as it was, resulting in a remarkable image defect.

Comparative Examples 17 to 20 1,4-dioxane, 1,2-dimethoxyethane, 1,2-dichloroethane or tetrahydrofuran were used instead of methyl lactate as a solvent for the surface layer coating solution used in Example 13, respectively. A photoreceptor was prepared in the same manner as in Example 13 except for the above conditions, and evaluated in the same manner. As a result, turtle shell coating unevenness was visually observed on each photoreceptor drum surface, and the film thickness was remarkably uneven. The defect was reflected on the image as it was, resulting in a remarkable image defect.

[0055]

[Table 1] Table 1 Examples Dark potential Sensitivity Residual potential Image evaluation 1 700V 0.40 μJ / cm ² 190V No defect ² 700V 0.44 μJ / cm ² 200V No defect 3 700V 0.42 μJ / cm ² 180V No defect 4 700V 0.49μJ / cm ² 230V No defect 5 700V 0.46μJ / cm ² 200V No defect 6 700V 0.38μJ / cm ² 160V No defect 7 700V 0.39μJ / cm ² 170V No defect 8 700V 0.38μJ / cm ² 190V No defect 9 700V 0.37 μJ / cm ² 165V No defect 10 700V 0.39 μJ / cm ² 170V No defect 11 700V 2.4 lux · sec 150V No defect 12 700V 1.8 lux · sec 160V No defect 13 −700V 0.41μJ / cm ² 180V No defect

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuyuki Mito 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryo Kasei Co., Ltd. (72) Inventor Atsuro Saida 1000 Kamoshida-cho, Midori-ku, Yokohama, Kanagawa (72) Inventor Kaname Makino, 1000, Kamoshida-cho, Midori-ku, Yokohama, Kanagawa Sanryo Kasei Co., Ltd.

Claims (1)

[Claims] 1. A method for producing an electrophotographic photosensitive member, which comprises forming a surface layer by applying a coating liquid containing at least a binder resin and an organic solvent on a photosensitive layer provided on a conductive support. A method for producing an electrophotographic photosensitive member, characterized in that, as an organic solvent, an alkanol having a boiling point of 185 ° C. or lower, which contains a hydroxyl group and at least one of an oxygen atom, a nitrogen atom and a fluorine atom other than the hydroxyl group in the molecule is used.