JPH07160015A - Coating liquid for electrophotographic photoreceptor and electrophotographic photoreceptor formed with the coating liquid - Google Patents

Abstract

PURPOSE:To provide an electrophotographic photoreceptor which can prolong the pot life up to a time for the practical use, has coating liquid for an elctrophotographic photoreceptor excellent in electrophotographic characteristics and stability of product quality, and has a layer formed by the use of the coating liquid. CONSTITUTION:Coating liquid containing hydrolysis condensation polymerized organic metal compound and an additive agent capable of improving stability of the coating liquid without spoiling the electrophotography characteristic is applied on a conductive supporting body, so as to form at least either of an under coat layer or a photosensitive layer. As for the organic metal compound, compound containing in its molecule silicon, zirconium, titanium, or aluminium, is favorably used. The additive agent is selected out of compound in which the same carbon having hydrogen atom is replaced with two electron attractive groups, hydrocarboxylic acid, its ester, ketoalcohol, aminoalcohol, and nitrogen compound containing N-replaced methylol.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a coating solution for electrophotographic photoconductors having high liquid stability and excellent manufacturing quality electrophotographic characteristics and stability, and a coating solution formed with high sensitivity. And an electrophotographic photosensitive member having a layer.

[0002]

2. Description of the Related Art Electrophotographic devices are used in the fields of copying machines, laser beam printers, etc., because of their high speed and high printing quality. As a photoconductor used in an electrophotographic apparatus, an organic photoconductor (OPC) using an organic photoconductive material has been developed and is becoming widespread. In addition, the structure of the photoconductor has changed from a single layer type in which a charge transfer type complex structure or a charge generating material is dispersed in a binder resin to a function separation type in which a charge generating layer and a charge transport layer are separated, Has improved. In this function-separated type photoreceptor, at present, a structure in which an undercoat layer is first formed on an aluminum substrate and then a charge generation layer and a charge transport layer are formed is becoming the mainstream. With the progress of electrophotographic apparatuses, higher quality image quality has been required for the performance of photoconductors. In order to improve the repetitive stability and environmental stability of the photoconductor, the charge generation layer, charge transport layer, and further the undercoat layer are important influences on electrophotographic characteristics such as sensitivity, image quality, and repetitive stability. Is giving. In view of this point, the present inventors have
We have previously investigated functional layers with excellent electrophotographic properties.
As a result, with respect to the undercoat layer, a film obtained by dry-curing a hydrolytic condensation-polymerizable organometallic compound typified by a zirconium alkoxide or a silane coupling agent was found to have excellent electrophotographic properties as the undercoat layer, It has been put to practical use.

[0003]

However, the hydrolytic condensation-polymerizable organometallic compound requires an appropriate amount of water during the curing reaction. Therefore, when water is mixed in the coating liquid due to moisture in the air or moisture adhering to the coating liquid circulator, the polymerization reaction of the hydrolytic polycondensable organometallic compound in the coating liquid proceeds, There may be a problem that the viscosity increases and, in some cases, changes such as gelation occur. Especially when the viscosity of the liquid increases in dip coating, if the pulling speed of the base material is set to the same speed and the base material is applied,
The film thickness of the photosensitive layer becomes thicker with the lapse of time, resulting in an increase in residual potential, image quality defects, and the like, so that sufficient electrophotographic characteristics cannot be obtained. Further, if the coating speed is slowed down in order to obtain an appropriate film thickness as the viscosity increases, the productivity will be significantly reduced. Furthermore, in the case of gelation, not only is it impossible to apply,
This will damage the circulator. Even in spray coating, as the viscosity increases, the coating liquid causes stringing and it becomes difficult to obtain a uniform coating film. In the case of a coating solution having a rapid hydrolysis reaction, the coating solution may cause gelation within one day. This tendency becomes more remarkable when the surrounding environment of the coating liquid is high in humidity. Therefore, the present invention is
It has been made in view of the above situation, and its purpose is high liquid stability, and a coating liquid for electrophotographic photoreceptor having excellent electrophotographic characteristics and stability of manufacturing quality, and high sensitivity. It is intended to provide an electrophotographic photoreceptor having a layer formed by using the coating solution.

[0004]

Means for Solving the Problems The present inventors have improved the stability of a coating liquid to prevent gelation with respect to a coating liquid for an electrophotographic photoreceptor containing a hydrolytic polycondensable organometallic compound. In addition, we have investigated liquid stabilizers that do not impair electrophotographic properties. As a result, they have found that a certain compound is effective as an additive capable of improving the stability of the coating liquid without impairing the electrophotographic characteristics. Then, by adding these compounds, the life of the coating liquid can be significantly improved, and even when a hydrolytic polycondensable organometallic compound having an originally easy-to-cure composition is used, the coating is performed for a practical time. It is possible to extend the pot life of the liquid. Such a coating liquid for an electrophotographic photoreceptor of the present invention includes at least a hydrolytic condensation-polymerizable organometallic compound, a compound in which two electron-withdrawing groups are substituted on the same carbon having a hydrogen atom, a hydroxycarboxylic acid, And at least one compound selected from the group consisting of an ester, a keto alcohol, an amino alcohol, and an N-substituted methylol nitrogen-containing compound. Further, the electrophotographic photoreceptor of the present invention is one in which a conductive support is coated with an undercoat layer and a photosensitive layer, and the layer formed by applying the coating solution is at least the undercoat layer and the photosensitive layer. Characterized by being one of the layers. That is,
The coating liquid of the present invention can be applied to form any layer constituting an electrophotographic photoreceptor.

Next, the present invention will be described in detail. The electrophotographic photosensitive member of the present invention comprises a conductive support and an undercoat layer and a laminated photosensitive layer comprising a charge generation layer and a charge transport layer. However, the structure of the photoreceptor is not particularly limited, the photosensitive layer may be a single layer type, a surface protective layer may be formed if necessary, and further, an undercoat layer may not be provided. Good. Further, the coating liquid for electrophotographic photoreceptor of the present invention is effective in forming a layer having any photoreceptor constitution as described above, but the laminated type photoreceptor having a charge transport layer formed on the surface thereof exhibits repeated stability. Since it is excellent in performance such as and environmental fluctuation, the structure of the laminated type photoreceptor will be mainly described below. In the electrophotographic photoreceptor of the present invention,
As the conductive support, copper, aluminum, nickel,
In addition to metals such as iron, it is possible to use plastic, paper or the like that has been tube-shaped, belt-shaped or sheet-shaped conductiveized by depositing a metal on the surface or forming a coating film in which conductive powder is dispersed. it can. Further, in order to prevent the occurrence of interference fringes, by means of etching, anodizing, wet blasting, sand blasting, rough cutting, centerless grinding, etc.,
The surface of the support may be roughened.

An undercoat layer is formed on the surface of the conductive support for the purpose of preventing image quality defects, improving chargeability, and improving adhesion. As the material for forming the undercoat layer, silicon, zirconium, titanium, aluminum, manganese,
A hydrolytic condensation-polymerizable organometallic compound containing a metal atom such as iron, tin, cobalt, nickel, lead and molybdenum in the molecule (hereinafter referred to as a condensation-polymerizable organometallic compound) is used. Here, the polycondensable organometallic compound means an organometallic compound having a structure in which the central metal is substituted with one or more alkoxy groups such as methoxy group, ethoxy group, butoxy group, and the alkoxy group is formed by hydrolysis reaction. It has a reaction form in which the polycondensation reaction is carried out by elimination. These compounds can be used alone or as a mixture of two or more kinds or as a polycondensation product. Among the polycondensable organometallic compounds, the organometallic compound containing silicon, zirconium, titanium or aluminum has high film-forming property, low residual potential, little change due to environment, and further potential of repeated use. Excellent in performance such as little change. In addition, polyacetal such as polyvinyl butyral, polyvinyl alcohol, polyamide, cellulose resin, polyurethane, polyester, methacrylic resin, acrylic resin, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin One or more binder resins such as silicone-alkyd resin, phenol-formaldehyde resin, melamine resin, casein, and gelatin can be mixed with the above organometallic compound and used.

Examples of the silicon compound include, for example, vinyltrimethoxysilane, γ-methacryloxypropyl-
Tris (β-methoxyethoxy) silane, β- (3,4
-Epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ -Aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-
Examples thereof include silane compounds such as aminopropylmethyldimethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane and γ-chloropropyltrimethoxysilane. Particularly preferably used silane compounds are vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl). ) Ethyltrimethoxysilane, N- (β
-Aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, Examples include γ-mercaptopropyltrimethoxysilane and γ-chloropropyltrimethoxysilane.

Examples of zirconium compounds are, for example, zirconium methoxide, zirconium ethoxide, zirconium propoxide, zirconium butoxide, acetylacetonate zirconium butoxide, ethyl acetoacetate zirconium butoxide, zirconium acetate,
Examples include butoxy zirconium methacrylate, zirconium butoxide dimer and the like. Examples of titanium compounds include, for example, tetraisopropyl titanate and tetra n
-Butyl titanate, butyl titanate dimer, titanium octylene glycolate, titanium lactate, and the like. Examples of aluminum compounds include, for example, aluminum isopropylate, monobutoxyaluminum diisopropylate, aluminum butyrate, diethyl acetoacetic acid diisopropoxyaluminum and the like.

In the present invention, the stability of the coating liquid can be improved by adding the following stabilizers to the coating liquid for forming the undercoat layer containing these polycondensation-polymerizable organometallic compounds. As the stabilizer, β-diketones such as acetylacetone, dibenzoylmethane, benzoylacetone and fluorinated acetylacetone, acetoacetic acid,
Β-keto acids and their esters such as methyl acetoacetate, ethyl acetoacetate, butyl acetoacetate and ethyl propionyl acetate, gem-dibasic acids and their esters such as malonic acid, monoethyl malonate, diethyl malonate and diethyl isosuccinate. Hydrogen atoms such as gem-dinitriles such as malononitrile, α-cyanocarboxylic acids such as cyanoacetic acid and ethyl cyanoacetate and their esters, and α-nitrocarboxylic acids such as nitroacetic acid and ethyl nitroacetate and their esters. A compound having two electron-withdrawing groups substituted on the same carbon atom; lactic acid, methyl lactate, salicyl lactate, salicylic acid, methyl salicylate, ethyl salicylate, phenyl salicylate, malic acid, ethyl malate, tartaric acid,
Hydroxycarboxylic acids and their esters such as methyl tartrate and ethyl tartrate; 4-hydroxy-4-methyl-2
-Pentanone, 4-hydroxy-2-pentanone, 4-
Keto alcohols such as hydroxy-2-heptanone and 4-hydroxy-4-methyl-2-heptanone; monoethanolamine, diethanolamine, triethanolamine, N-methylmonoethanolamine, N-ethylmonoethanolamine, N, N Examples thereof include amino alcohols such as -dimethylethanolamine and N, N-diethylethanolamine; and N-substituted methylol-containing nitrogen compounds such as methylolmelamine, methylolurea and methylolacrylamide. Each of the above-mentioned carboxylic acids may be a salt thereof such as ammonium lactate salt. These compounds can be used alone or in combination of two or more.

These stabilizers are compounds used as reaction raw materials when synthesizing a metal chelate compound. However, with a coating solution containing a metal chelate compound corresponding to the amount added as a stabilizer of the coating solution, the stability of the solution against gelation is improved, but the chelate remains in the state of being incorporated into the coating film structure. By doing
This causes deterioration of electrical characteristics such as a large increase in residual potential of the photoconductor. On the other hand, when the stabilizer in the present invention is added to and mixed with the coating liquid, the stabilizing effect of the coating liquid is remarkably increased, and the amount of chelate produced in the coating film after drying and curing is slightly reduced. It can be suppressed, and the quality as an electrophotographic photoreceptor is not impaired. For example, the chelation reaction using acetylacetone is usually performed at a high temperature of about 100 ° C., and the chelation reaction hardly occurs simply by mixing the organometallic compound and the chelating agent at room temperature.
However, in the present invention in which the stabilizer is added to the coating solution containing the polycondensation-polymerizable organometallic compound, the stability of the solution against gelation is similar to that obtained by the chelation treatment. The solution stabilizing effect is most effective when β-diketones are used. Amino alcohols are also useful as a polymerization hardening agent for resins. These stabilizers are added in an amount of 0.001 per 1 metal atom in the polycondensable organometallic compound.
It is desirable to add it at a ratio of 10 mol. More preferably, it is desirable to add it in a ratio of 0.05 to 5 mol. If the addition amount is too small, sufficient effect cannot be obtained, and if the addition amount is too large, a precipitate is generated in the liquid due to the stabilizer itself or by-products with the polycondensable organometallic compound, increase in residual potential, etc. May cause deterioration of the photoconductor characteristics.

Various organic or inorganic fine powders can be mixed in the undercoat layer for the purpose of preventing the generation of interference fringes and improving the electrical characteristics. In particular, white pigments such as titanium oxide, zinc oxide, zinc white, zinc sulfide, lead white, and lithopone,
Inorganic pigments such as alumina, calcium carbonate and barium sulfate as extender pigments, tetrafluoroethylene resin, benzoguanamine resin and styrene resin are effective.
The fine powder is added as needed, but when it is added, 10 to 80% by weight, more preferably 30 to 70% by weight, based on the solid content of the undercoat layer, is appropriate. The added fine powder has a particle size of 0.01 to 2 μm. If the particle size is too large, the undercoat layer becomes highly uneven, and electrical non-uniformity increases, and image quality defects are likely to occur. If the particle size is too small, a sufficient light scattering effect cannot be obtained. In the preparation of the coating liquid for forming the undercoat layer, the fine powder is added to the solution in which the resin component is dissolved and the dispersion treatment is performed. As a method for dispersing the fine powder in the resin, roll mill, ball mill, vibrating ball mill, attritor,
Means such as a sand mill, a colloid mill, a paint shaker, etc. can be adopted. By increasing the film thickness of the subbing layer, the concealment of irregularities of the base material is improved, so generally, if the film thickness is increased, the image quality defect tends to be reduced, but the electrical repeatability also deteriorates, The film thickness is 0.1
It is preferably in the range of 5 μm.

As described above, the photosensitive layer formed on the undercoat layer may basically have a single-layer structure or a laminated structure in which the charge-generating layer and the charge-transporting layer are functionally separated. Good. In the case of a laminated structure, the charge generation layer and the charge transport layer may be laminated in either order. The charge generation layer is formed by forming a charge generation material by vacuum vapor deposition, or by dispersing and applying it in an organic solvent and a binder resin.
As the charge generation material, amorphous selenium, crystalline selenium,
Selenium-tellurium alloys, selenium-arsenic alloys, other selenium compounds and selenium alloys, inorganic photoconductors such as zinc oxide and titanium oxide, metal-free phthalocyanines, titanyl phthalocyanines, copper phthalocyanines, tin phthalocyanines, and various phthalocyanines such as gallium phthalocyanines. Various organic pigments and dyes such as pigments, squarylium-based, anthanthrone-based, perylene-based, azo-based, anthraquinone-based, pyrene-based, pyrylium salts and thiapyrylium salts are used. In addition, these organic pigments generally have several types of crystal, and in particular, various crystal types such as α and β are known for phthalocyanine pigments, but pigments that provide sensitivity suitable for the purpose. Any of these crystal forms may be used.

Examples of the binder resin in the charge generation layer include bisphenol A type and bisphenol Z type polycarbonates, polyesters, methacrylic resins, acrylic resins, polyvinyl chloride, polystyrenes, polyvinyl acetates, styrene-butadiene copolymers, and chlorides. Examples thereof include vinylidene-acrylonitrile copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, and poly N-vinylcarbazole. . These binder resins may be used alone or in combination of two or more.
The mixing ratio of the charge generating material and the binder resin is 10: by weight.
The range of 1 to 1:10 is desirable. As a method for dispersing the charge generating material in the binder resin, a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, or the like can be used. The film thickness of the charge generation layer is generally set in the range of 0.01 to 5 μm, preferably 0.05 to 2.0 μm. In the present invention, a silane coupling agent or an organic metal alkoxide can be used for various purposes such as prevention of aggregation of the charge generating material, improvement of dispersibility, and improvement of electric characteristics. Furthermore, these polycondensation-polymerizable organometallic compounds and the above-mentioned stabilizer can be added to the charge generating material and the binder resin to form the charge generating layer. That is, the coating liquid for an electrophotographic photoreceptor of the present invention can be used as a coating liquid for forming a charge generation layer in addition to forming an undercoat layer, and in that case, it is possible to extend the pot life. it can.

The charge transport layer can be formed by applying a solution prepared by dissolving the charge transport material and the binder resin in a suitable solvent and drying the solution. As the charge transport material, 2,5-bis (p-diethylaminophenyl)-
Oxadiazole derivatives such as 1,3,4-oxadiazole, 1,3,5-triphenylpyrazoline, 1- [pyridyl- (2)]-3,5-di (p-diethylaminostyryl) pyrazoline, etc. Such as pyrazoline derivatives, triphenylamine, tri (p-tolyl) amine, aromatic tertiary amino compounds such as dibenzylaniline, N, N′-diphenyl-N, N′-bis (m-tolyl) benzidine, etc. Aromatic tertiary diamino compound, 3- (p-dimethylaminophenyl) -5,6-di (p-methoxyphenyl)-
1,2,4-Triazine derivatives such as 1,2,4-triazine, hydrazone derivatives such as p-diethylaminobenzaldehyde 2,2-diphenylhydrazone, 2-phenyl-
Quinazoline derivatives such as 4-styrylquinazoline, benzofuran derivatives such as 6-hydroxy-2,3-di (p-methoxyphenyl) benzofuran, α-stilbene derivatives such as p- (2,2-diphenylvinyl) triphenylamine, Enamine derivatives, carbazole derivatives such as N-ethylcarbazole, hole-transporting substances such as poly N-vinylcarbazole and its derivatives, quinone compounds such as chloranil, bromoanil, anthraquinone, tetracyanoquinodimethane compounds, 2,4,4 Fluorenone compounds such as 7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone, xanthone compounds, thiophene compounds, etc., or a heavy chain having a group consisting of the compounds exemplified above in the main chain or side chain. Coalescence or the like is used. These charge transport materials can be used alone or in combination of two or more.

Examples of the binder resin in the charge transport layer include acrylic resins, polyarylate, polyesters, polycarbonates such as bisphenol A type and bisphenol Z type, polystyrene, acrylonitrile-styrene copolymers, acrylonitrile-butadiene copolymers, polyvinyl butyral. Examples thereof include insulating resins such as polyvinyl formal, polysulfone, polyacrylamide, polyamide, and chlorinated rubber, and organic photoconductive polymers such as polyvinylcarbazole, polyvinylanthracene, and polyvinylpyrene. The compounding ratio of the charge transport material and the binder resin is 10: 1 to 1: 5 by weight.
Is desirable. Examples of the solvent used when forming the charge transport layer include benzene, aromatic hydrocarbons such as toluene, halogenated aromatic hydrocarbons such as chlorobenzene, and the like.
Acetone, ketones such as 2-butanone, methylene chloride,
Halogenated aliphatic hydrocarbons such as chloroform and ethylene chloride, cyclic or linear ethers such as tetrahydrofuran, dioxane and ethylene glycol diethyl ether, or mixed solvents thereof can be used. The thickness of the charge transport layer is generally 5 to 50 μm,
It is preferably set in the range of 10 to 40 μm.

In the present invention, an antioxidant is added to the photosensitive layer for the purpose of preventing the deterioration of the photoreceptor due to ozone or other oxidizing gas generated in the electrophotographic apparatus, or light or heat.
Additives such as a light stabilizer and a heat stabilizer can be added. For example, as the antioxidant, hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirocumalone, spiroindanone and their derivatives, organic sulfur compounds,
Examples thereof include organic phosphorus compounds. Examples of the light stabilizer include derivatives such as benzophenone, benzotriazole, dithiocarbamate and tetramethylpiperidine.
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. As usable electron accepting substances, for example, succinic anhydride, maleic anhydride,
Dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid Acid, p
Examples thereof include nitrobenzoic acid and phthalic acid.
Among these, fluorenone type, quinone type, and benzene derivatives having an electron-withdrawing substituent such as chlorine atom, cyano group, nitro group are particularly preferable. As a coating method for forming the photosensitive layer, a dip coating method, a spray coating method, a bead coating method, a blade coating method, a roller coating method and the like can be adopted. It is preferable that the drying is performed by touch-drying at room temperature and then heat-drying at a temperature of 30 to 200 ° C. for 5 minutes to 2 hours.

In the electrophotographic photoreceptor of the present invention, a surface protective layer may be formed on the single-layer type photosensitive layer or the charge transport layer, if necessary. The surface protective layer may be either an insulating resin protective layer or a low resistance protective layer in which a resistance adjusting agent is added to the insulating resin. In the case of the low resistance protective layer, for example, a layer in which conductive fine particles are dispersed in an insulating resin can be used. As the insulating resin, polycondensation resins such as polyamide, polyurethane, polyester, epoxy resin, polyketone, and polycarbonate, and vinyl polymers such as polyvinyl ketone, polystyrene, and polyacrylamide are used. As the conductive fine particles, fine particles having an electrical resistance of 10 ⁹ Ω · cm or less and an average particle diameter of 0.3 μm or less, preferably 0.1 μm or less and exhibiting white, gray or bluish white are suitable. Examples of the conductive material include molybdenum oxide, tungsten oxide, antimony oxide, tin oxide, titanium oxide, indium oxide, a solid solution of tin oxide and antimony or antimony oxide, or a mixture thereof, or these in a single particle. The metal oxide of the above may be mixed or coated. Among them, tin oxide, and a solid solution of tin oxide and antimony or antimony oxide are preferably used because they can appropriately adjust the electric resistance and can make the protective layer substantially transparent ( JP-A-57-30847
No. 57-128344). A silane coupling agent or an alkoxide can be used for various purposes such as prevention of aggregation of conductive fine particles, improvement of dispersibility, and improvement of electric characteristics. These polycondensation-polymerizable organometallic compounds may be subjected to a surface treatment with the conductive fine particles and then subjected to a dispersion preparation treatment, or may be added to a coating solution for forming a surface protective layer for coating / drying treatment. It is also possible to do Furthermore, when a polycondensable organometallic compound is used, it is also effective to add the stabilizer to improve the stability of the liquid.

As described in detail above, in the constitution of the photoconductor of the present invention, when a plurality of layers contain a polycondensable organometallic compound, each layer is formed in order to extend the spot life. It is possible to add said stabilizer to the liquid. The electrophotographic photoreceptor of the present invention can be used in electrophotographic apparatuses such as light lens type copying machines, laser beam printers that emit light in the near-infrared light or visible light range, digital copying machines, LED printers and laser facsimiles. The photoreceptor of the present invention can be used in combination with a one-component or two-component regular developer or reversal developer.

[0019]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. The following "parts" mean "parts by weight". Example 1 170 parts of n-butanol in which 4 parts of polyvinyl butyral resin (S-REC BM-S: manufactured by Sekisui Chemical Co., Ltd.) was dissolved and 36 parts of zirconium butyrate were mixed and stirred. Acetylacetone was added to and mixed with this solution at a ratio of 0.5 mol with respect to 1 mol of zirconium butyrate to prepare a coating liquid for forming an undercoat layer. This coating solution was applied onto a 40 mmφ aluminum support, air-dried at room temperature for 10 minutes, and then 1
A heat-curing treatment was performed at 70 ° C. for 10 minutes to form an undercoat layer. It should be noted that the coating liquid did not deteriorate such as gelation of the liquid even in the circulation test in the circulation coating device for 10 days. Then, x-type metal-free phthalocyanine 1 as a charge generating material
5 parts, polyvinyl butyral resin (S-REC BM-
A mixture consisting of 10 parts of S) and 300 parts of n-butanol was dispersed in a sand mill for 4 hours. The obtained dispersion is dip-coated on the undercoat layer and dried to a film thickness of 0.
A 2 μm charge generation layer was formed. Next, 4 parts of N, N'-diphenyl-N, N'-bis (m-tolyl) benzidine and 6 parts of bisphenol Z polycarbonate resin having a molecular weight of 40,000 were added to 80 parts of chlorobenzene and dissolved. The obtained solution was applied onto the above charge generation layer and dried to form a charge transport layer having a film thickness of 20 μm, whereby an electrophotographic photoreceptor having a three-layer structure was manufactured.

Comparative Example 1 An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that acetylacetone was not added. In addition, when the coating solution for forming the undercoat layer obtained on the way was subjected to a circulation test in a circulation coating apparatus, generation of a gelled product was observed on the second day, and the amount thereof tended to increase. Stopped. Comparative Example 2 A coating liquid for forming an undercoat layer was prepared in the same manner as in Example 1 except that 2-pentanone was added instead of acetylacetone. When the obtained coating liquid was subjected to the above circulation test, gelation occurred on the second day. An electrophotographic photosensitive member was manufactured in the same manner as in Example 1 using the solution prepared on the first day of preparation of this coating solution. Comparative Example 3 A coating liquid for forming an undercoat layer was prepared in the same manner as in Example 1 except that acetylacetone zirconium butyrate was used instead of zirconium butyrate and acetylacetone was not added. When the obtained coating liquid was subjected to the above circulation test, gelation did not occur even after 10 days.
An electrophotographic photosensitive member was manufactured in the same manner as in Example 1 using the solution prepared on the first day of preparation of this coating solution.

Each manufactured electrophotographic photosensitive member was mounted on a laser beam printer (XP-11: manufactured by Fuji Xerox Co., Ltd.), charged at -700 V, and then exposed at a predetermined light intensity to measure residual potential. And low temperature and low humidity (1
The image quality was examined after running test of 10,000 copies at 0 ° C., 15% RH). The results are shown in Table 1. The number of black dots in the image quality column indicates the number of black dots in one B4 sheet.

[Table 1] The photoconductor of Example 1 had good light attenuation characteristics, and had few image quality defects due to repeated use. On the other hand, the photoconductors of Comparative Examples 1 and 2 have good light attenuation characteristics and image quality characteristics, but are poor in stability of the coating liquid for forming the undercoat layer. Further, the photoconductor of Comparative Example 3 exhibited high stability of the coating liquid for forming the undercoat layer, but exhibited a high residual potential, and many image defects (black spots) occurred due to repeated use.

Examples 2 to 22 In a solution of 190 parts of ethanol in which 3 parts of polyvinyl butyral resin (S-REC BX-1, manufactured by Sekisui Chemical Co., Ltd.) was dissolved, 30 parts of various polycondensable organometallic compounds shown in Table 2 and A stabilizer was added and mixed at a predetermined molar ratio with respect to the organometallic compound, and the mixture was stirred to prepare a coating liquid for forming an undercoat layer.
This coating solution was coated on an aluminum support having a diameter of 40 mm and heat-cured at 170 ° C. for 10 minutes to form an undercoat layer having a film thickness of 1 μm. Next, a mixture of 15 parts of titanyl phthalocyanine as a charge generating material, 10 parts of vinyl chloride-vinyl acetate copolymer resin (VMCH: manufactured by Nippon Unicar Co., Ltd.) and 300 parts of n-butanol was subjected to dispersion treatment for 4 hours by a sand mill. The resulting dispersion was applied onto the undercoat layer and dried to form a charge generation layer having a thickness of 0.2 μm. Next, a charge transport layer was formed in the same manner as in Example 1 to manufacture an electrophotographic photosensitive member having a three-layer structure.

Comparative Examples 4 to 11 Electrophotographic photoreceptors were manufactured in the same manner as in Example 2 except that the material composition of the undercoat layer was changed to the composition shown in Table 3.

The residual potential of each of the manufactured electrophotographic photosensitive members was measured in the same manner as in Example 1. The results are shown in Tables 2 and 3. The pot life in the table is
10 g of each coating liquid for forming the undercoat layer was collected in a 30 cc glass container, transferred into a deep dish filled with water, and left in a high humidity state formed by covering the dish (deterioration accelerating method). ) Investigated the stability of the solution.

[Table 2]

[0025]

[Table 3]

Example 23 23 parts of alkyd resin (M-6406-50: manufactured by Dainippon Ink and Chemicals), melamine resin (Super Beckamine L-1)
17-60: manufactured by Dainippon Ink and Chemicals, Inc.) 5 parts and a mixture of 41 parts of methyl ethyl ketone was applied on an 84 mmφ aluminum pipe and dried to form an undercoat layer having a film thickness of 1.5 μm. Then, a mixture of 25 parts of trigonal selenium, 3 parts of butyral resin (XYHL: UCL) and 190 parts of n-butanol was placed in a ball pot,
After ball milling with SUS balls (10 mmφ) for 48 hours, 7 parts of tetraethoxysilane, 1 part of acetylacetone and 200 parts of n-butanol were added and stirred for 1 hour. After stirring, the mill base was taken out, and n-butanol was added so that the solid content concentration became 2.8 wt% and the mixture was stirred for dilution to prepare a coating solution for forming a charge generation layer. This coating solution is applied onto the base material coated with the above-mentioned undercoat layer,
It was dried at 0 ° C. for 10 minutes to form a charge generation layer having a film thickness of about 0.2 μm. This coating solution did not gel even after 2 weeks, and showed stable liquid properties. Subsequently, 90 parts of tri (p-tolyl) amine as a charge transport material, a polycarbonate resin (C-1400: manufactured by Teijin Chemicals Ltd.) 1
A coating solution was prepared from 00 parts, 0.002 parts of silicone oil (KF-54: manufactured by Shin-Etsu Chemical Co., Ltd.) and 870 parts of tetrahydrofuran. The resulting coating liquid was applied onto the charge generation layer and dried to form a charge transport layer having a film thickness of 24 μm, thereby producing an electrophotographic photoreceptor having a three-layer structure.

Comparative Example 12 Example 23 except that no acetylacetone was added.
An electrophotographic photosensitive member was manufactured in the same manner as. The charge generation layer-forming coating liquid containing no acetylacetone was about 1
The liquid viscosity increased with the lapse of weeks, and gelation was observed.

Each of the electrophotographic photosensitive members produced is transferred to a copying machine (V
ivace500: manufactured by Fuji Xerox Co., Ltd.) and examined for potential change and image quality after exposure. The results are shown in Table 4.

[Table 4]

[0029]

INDUSTRIAL APPLICABILITY According to the present invention, a coating solution containing a condensation-polymerizable organometallic compound such as zirconium alkoxide is used to prepare a compound in which two electron-withdrawing groups are substituted on the same carbon atom having a hydrogen atom, hydroxycarboxylic acid. , Its ester,
By containing a compound selected from keto alcohol, amino alcohol and N-substituted methylol nitrogen-containing compound, it is possible to obtain a coating solution for an electrophotographic photosensitive member which satisfies stable solution quality and electrophotographic characteristics.

Claims (4)

[Claims] 1. At least a hydrolytic condensation-polymerizable organometallic compound, a compound in which two electron-withdrawing groups are substituted on the same carbon having a hydrogen atom, hydroxycarboxylic acid, its ester, keto alcohol, amino alcohol and N-. A coating liquid for an electrophotographic photoreceptor, which comprises one or more compounds selected from substituted methylol nitrogen-containing compounds. 2. The coating liquid for an electrophotographic photoreceptor according to claim 1, which is a coating liquid for forming an undercoat layer. 3. The coating liquid for an electrophotographic photoreceptor according to claim 2, wherein the hydrolytic condensation-polymerizable organometallic compound is an organozirconium compound. 4. An electrophotographic photosensitive member comprising a conductive support coated with an undercoat layer and a photosensitive layer, wherein the layer formed by applying the coating solution according to claim 1 is at least the undercoat layer and the photosensitive layer. An electrophotographic photosensitive member characterized by being any one of: