JP2000267303A - Electrophotographic photoreceptor and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the method for manufacturing the electrophotographic photoreceptor capable of reducing fluctuation of its quality and enhancing its electric characteristics and image characteristics and to provide the electrophotographic photoreceptor capable of forming high quality images stably for a long period. SOLUTION: This manufacturing method comprises at least the process for forming an undercoat layer containing a material capable of hydrolytic condensation and a process for forming a layer containing a charge generating material and a surfactant on a substrate. It is preferred that the above compound capable of hydrolytic condensation is an organic metal compound and or a silane coupling agent, and the organic metal compound is an organic titanium compound and the above surfactant is a nonionic surfactant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a conductive material on a conductive substrate.
More specifically, the present invention relates to an electrophotographic photosensitive member having excellent quality stability and capable of stably forming a high-quality image, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Electrophotographic apparatuses are widely used in fields such as copying machines and laser printers because of their high speed and high print quality. At present, an organic photoconductor (OPC) using an organic photoconductive material is widely used as a photoconductor used in these electrophotographic apparatuses. Also,
The structure of the photoconductor has changed from a single-layer photoconductor in which a charge transfer complex or charge generation material is dispersed in a binder resin to a function-separated photoconductor in which the charge generation layer and charge transport layer are separated. And
This greatly contributes to the improvement of the performance of the electrophotographic apparatus. At present, the photoreceptor having this function-separated structure has a structure in which an undercoat layer is first formed on an aluminum substrate, and a charge generation layer and a charge transport layer are further formed on the undercoat layer. However, with the development of electrophotographic technology,
Under the situation where higher quality image quality is required, there is a demand for further improvement of the performance of the photoconductor, which greatly affects the image quality.

Under these circumstances, the occurrence of interference fringes has recently been considered as a problem in photoreceptors for laser printers and the like, and various methods have been studied as methods for preventing interference fringes. A method of roughening the surface of a substrate is generally used. However, when the surface of the conductive substrate is roughened, application of a charge generation layer on the surface of the substrate may cause application defects such as repelling, bumping, or the like, and charges may be locally injected from the conductive substrate. There is a problem that black spots, white spots, etc. occur in the formed image.

As means for solving the above problems, generally,
An undercoat layer is provided between the conductive substrate and the charge generation layer. As a material for forming the undercoat layer, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl methyl ether, polyamide, thermoplastic polyester, phenoxy resin, casein, gelatin,
Thermosetting resins such as thermoplastic resins such as nitrocellulose, polyimides, polyethylene imines, epoxy resins, melamine resins, phenol resins and polyurethane resins are known. However, when the undercoat layer is formed using these resins, problems such as a decrease in sensitivity, an increase in residual potential upon repeated use, and other problems in electrical characteristics and image problems such as image defects are generally caused. Did not come to a solution.

On the other hand, a film obtained by drying and curing a hydrolytic condensation polymerizable compound such as a silane coupling agent as an electrophotographic photoreceptor having higher sensitivity and excellent image quality, repetition stability and environmental stability. It is known that it has excellent electrophotographic properties as an undercoat layer. By the way, this hydrolysis-condensation-polymerizable compound requires an appropriate amount of water at the time of a curing reaction. It has a reaction form that proceeds. Therefore, in order to efficiently cure the layer containing the hydrolytic condensation polymerizable compound, the presence of water is indispensable. This moisture
Usually, the water present in the undercoat layer coating solution is utilized, or supplied from the environmental air at the time of touch drying, or
During drying, it is supplied from the air contained in the dryer, and the curing reaction proceeds.

However, the amount of water present in the coating solution, the environmental air at the time of touch drying, and the air in the dryer is not necessarily sufficient to sufficiently promote the curing reaction of the hydrolytic condensation polymerizable compound. I can't say. In addition, since the amount of water contained varies depending on weather conditions such as season and weather, the cured state of the undercoat layer after the end of the effect reaction ends in an incomplete state, and the formed undercoat layer Has many variations. For this reason, the quality of the photoreceptor after the production has been largely varied. In particular, when the undercoat layer is formed using a hydrolytic polycondensable compound during the dry season in winter, the hydrolytic polycondensation reaction is not sufficiently promoted, so that the produced photoreceptor is poor in electrophotographic characteristics. Of the residual potential and defects in the formed image quality.

However, if the amount of water contained in the undercoat layer coating solution is increased in order to secure sufficient water, the hydrolysis reaction proceeds during storage of the undercoat layer coating solution, and the solution changes over time. Since it becomes extremely large, it becomes a factor for reducing the pot life of the coating liquid itself.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and achieve the following objects. That is, the present invention provides a method for manufacturing an electrophotographic photoreceptor capable of reducing quality variation of the electrophotographic photoreceptor and improving the electrical characteristics and image characteristics of the electrophotographic photoreceptor, and stably producing a high-quality image for a long period of time. An object is to provide an electrophotographic photosensitive member that can be formed.

[0009]

Means for Solving the Problems The present inventors have conducted intensive studies on the components constituting the undercoat layer and the electron generating layer provided on the substrate of the electrophotographic photosensitive member.
Forming an undercoat layer containing a hydrolysis-condensable material, and applying a dispersion of a charge generation material in an aqueous solvent containing a surfactant to form a charge generation layer on the undercoat layer As a result, it has been found that variations in the production quality of the electrophotographic photosensitive member can be reduced and a high-quality image can be stably formed for a long period of time, and the present invention has been completed. The means for solving the above problems are as follows. That is,

<1> At least an undercoat layer forming step of forming an undercoat layer containing a hydrolysis-condensable material on a substrate, and a charge generation material and a surfactant are contained on the undercoat layer. And a charge generation layer forming step of forming a charge generation layer. <2> The hydrolysis-condensable material is an organometallic compound and / or
Or the method for producing an electrophotographic photosensitive member according to <1>, wherein the electrophotographic photosensitive member is a silane coupling agent. <3> The method according to <2>, wherein the organometallic compound is an organic zirconium compound or an organic titanium compound. <4> The method according to any one of <1> to <3>, wherein the surfactant is a nonionic surfactant.

<5> The method for producing an electrophotographic photosensitive member according to <4>, wherein the nonionic surfactant is a nonionic surfactant represented by the following general formula (1).

[0012]

Embedded image

[Wherein R ¹ is a hydrogen atom, an alkyl group,
Represents an alkylcarbonyl group. n and m are n = m = 0
And each independently represents an integer of 0 or more. ]

<6> The method for producing an electrophotographic photosensitive member according to <4>, wherein the nonionic surfactant is a nonionic surfactant represented by the following general formula (2).

[0015]

Embedded image

[Wherein R ² represents a hydrogen atom, an alkyl group,
Represents an alkylcarbonyl group, an alkoxy group, or an alkoxycarbonyl group. p and q each independently represent an integer of 0 or more, except when p = q = 0. ]

<7> The charge generating material is chlorogallium phthalocyanine crystal, metal-free phthalocyanine crystal,
The method for producing an electrophotographic photoreceptor according to any one of the above items <1> to <6>, which is a crystal of hydroxygallium phthalocyanine or a crystal of titanyl phthalocyanine.

<8> An electrophotographic photosensitive member obtained by the method for producing an electrophotographic photosensitive member according to any one of <1> to <7>.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the method for producing an electrophotographic photoreceptor of the present invention, at least a subbing layer containing a hydrolytic condensable material is formed on a substrate, and a surfactant is formed on the subbing layer. Is applied, and a charge generation layer is laminated by applying a dispersion in which the charge generation material is dispersed in an aqueous solvent containing. The electrophotographic photoreceptor of the present invention has at least an undercoat layer and a charge generation layer on a substrate, and has other layers as necessary. It is manufactured by a manufacturing method. Hereinafter, the method for producing the electrophotographic photoreceptor of the present invention will be described in detail, and the details of the electrophotographic photoreceptor of the present invention will be clarified through the description.

<Method for Producing Electrophotographic Photoreceptor> The method for producing an electrophotographic photoreceptor of the present invention comprises, at least, a step of forming an undercoat layer containing a hydrolysis-condensable material on a substrate; Forming a charge generation layer containing a charge generation material and a surfactant on the undercoat layer. That is, after the undercoat layer forming step, a charge generating layer forming step is provided. In the present invention, a charge transport layer forming step may be provided after the charge generating layer forming step, and a protective layer forming step may be further provided after the charge transport layer forming step.

In the undercoat layer forming step, an undercoat layer coating solution containing a hydrolysis-condensable material is prepared, and the coating solution is applied on a substrate to form an undercoat layer. The coating solution for the undercoat layer is obtained by adding a desired hydrolysis-condensable material to a solvent and, if necessary, a binder resin or conductive fine particles of tin oxide, titanium oxide, indium oxide, antimony oxide or oxidized oxide. It is prepared by adding tin oxide doped with antimony or the like.

Examples of the above-mentioned hydrolysis-condensable material include organometallic compounds and silane coupling agents. In the present invention, the undercoat layer is formed using at least one of the above-mentioned organometallic compound and silane coupling agent. In particular, it is preferable to use both an organometallic compound and a silane coupling agent in view of promoting a curing reaction by water supplied from the outside and forming an undercoat layer having a sufficient degree of polymerization curing.

Examples of the organometallic compound include organometallic compounds containing zirconium, titanium or aluminum, that is, organozirconium compounds, organotitanium compounds, and organoaluminum compounds. From the viewpoint of forming a layer, organic zirconium compounds and organic titanium compounds are preferred.

Examples of the organic zirconium compound include zirconium butoxide, zirconium triethanolamine, acetylacetone zirconium butoxide, ethyl zirconium butoxide acetoacetate, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium octoate, zirconium naphthenate, and lauric acid. Zirconium phosphate, zirconium stearate, zirconium isostearate,
Butoxyzirconium methacrylate, butoxyzirconium stearate, butoxyzirconium isostearate and the like.

Examples of the organic titanium compound include, for example,
Tetraisopropyl titanate, tetra n-butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium octylene glycolate, titanium lactate ammonium salt, titanium lactate, ethoxy titanium lactate, titanium triethanol aminate, polyhydroxytitanium stearate Rate and the like.

Examples of the organoaluminum compound include aluminum isopropylate, monobutoxyaluminum diisopropylate, aluminum butyrate, and ethyl acetoacetate aluminum diisopropylate.

Examples of the silane coupling agent include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β-
(3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- (β-amino Ethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl)
-Γ-aminopropylmethyldimethoxysilane, N, N
-Bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane and the like.

Of the above, 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 Methoxysilane, γ-lecaptopropyltrimethoxysilane and γ-chloropropyltrimethoxysilane are preferred.

When the coating solution for the undercoat layer is used, the solid concentration of the hydrolysis-condensable material in the coating solution is as follows:
It is preferably from 5 to 50% by weight, more preferably from 15 to 30% by weight. If the solid content is less than 5% by weight, it may be difficult to apply a thick film, and if it exceeds 50% by weight, the coating solution may be easily gelled.

When the organometallic compound and the silane coupling agent are used in combination, the ratio (organometallic compound: silane coupling agent) used is preferably from 99: 1 to 5:95, and from 95: 5 to 80: 20 is more preferred.

The solvent can be appropriately selected from known solvents, for example, n-butanol, is
Examples thereof include o-butanol, 1-propanol, and 2-propanol. As the amount of the solvent used,
50 to 95% by weight based on the total weight of the hydrolysis-condensable material
Is preferable, and 70 to 85% by weight is more preferable. If the amount is less than 50% by weight, the coating solution may be easily gelled, and if it exceeds 95% by weight, it may be difficult to apply a thick film.

As the binder resin, any binder resin having compatibility with the silane coupling agent and the organometallic compound can be appropriately selected from known polymer compounds, and examples thereof include polyvinyl butyral and the like. Acetal resin, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin,
Polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride
Examples include vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, and melamine resin. These resins can be used alone or as a mixture of a plurality of compounds or a condensation polymer thereof.

The amount of the binder resin used is preferably 1 to 50% by weight based on the total weight of the hydrolytic condensable material.
5 to 25% by weight is more preferred. When the use amount is less than 1% by weight, the film-forming property is reduced when trying to increase the film thickness, and cracks may easily occur in the undercoat layer. It may be easy to gel.

The coating method for applying the coating solution for the undercoat layer can be appropriately selected from known coating methods, for example, a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, and the like. Examples include a bead coating method, an air knife coating method, and a curtain coating method.

The thickness of the undercoat layer provided on the substrate is as follows:
0.1 to 10 μm is preferable, and 0.1 to 2 μm is more preferable. If the layer thickness is less than 0.1 μm, image defects such as black spots and white spots may occur, and
If it exceeds 300, cracks may easily occur in the undercoat layer.

In the step of forming the charge generation layer, a dispersion for the charge generation layer containing a charge generation material and a surfactant in an aqueous solvent is prepared, and the coating solution is laminated and applied on the undercoat layer. To form a charge generation layer. The dispersion for a charge generation layer is prepared by dispersing a charge generation material in an aqueous solvent in which a surfactant is dissolved, and adding a binder resin and the like as necessary.

An undercoat layer coating solution containing a hydrolysis-condensable material is applied on a substrate to form an undercoat layer. The undercoat layer is further coated with an aqueous solvent in which a surfactant is dissolved. By laminating and applying a charge generation layer dispersion prepared by dispersing a charge generation material to the undercoat layer from the charge generation layer dispersion, it is possible to efficiently and uniformly supply moisture, The curing reaction of the hydrolysis-condensable material contained in the undercoat layer is effectively promoted, and an undercoat layer having a sufficient degree of polymerization curing can be formed. That is, by using an aqueous solvent as the solvent in which the charge generating material is dispersed, the curing reaction can be effectively and stably promoted as described above.

In the curing reaction, as described above, by supplying water uniformly and stably, components having hydrolyzability such as alcohol component and carboxylic acid component in the hydrolytic condensation material are efficiently desorbed. , The condensation polymerization reaction is promoted. As a result, it is less susceptible to changes in the manufacturing environment and the like during the production of the photoreceptor, can reduce the variation in the production quality of the electrophotographic photoreceptor, has excellent charging characteristics, and stably removes image defects such as black spots for a long period of time. An electrophotographic photoreceptor capable of forming a high-quality image without generation can be stably manufactured.

The surfactant can be appropriately selected from known surfactants. In order to prevent an electrical disturbance in the charge generation layer, a nonionic surfactant is used. It is preferable to use

Examples of the nonionic surfactant include polyoxyalkene alkyl ether, polyoxyalkene alkylphenyl ether, polyoxyalkene sorbitan fatty acid ester, fatty acid monoglyceride, polyethylene glycol fatty acid ester, and polyoxyalkene alkylamine. Among them, a polyoxyalkene alkyl ether represented by the following general formula (1) or a polyoxyalkene alkyl phenyl ether represented by the following general formula (2) is preferable.

[0041]

Embedded image

Wherein R ¹ is a hydrogen atom, an alkyl group,
Represents an alkylcarbonyl group. m and n are m = n = 0
And each independently represents an integer of 0 or more. ]

[0043]

Embedded image

[Wherein R ² represents a hydrogen atom, an alkyl group,
Represents an alkylcarbonyl group, an alkoxy group, or an alkoxycarbonyl group. p and q each independently represent an integer of 0 or more, except when p = q = 0. ]

First, the polyoxyalkene alkyl ether represented by the general formula (1) will be described. In the general formula (1), R ¹ represents a hydrogen atom, an alkyl group, or an alkylcarbonyl group. m and n each independently represent an integer of 0 or more, except when m = n = 0. M and n are each independently preferably an integer of 0 to 50,
An integer from 0 to 20 is more preferred. Further, the m and n
Is preferably 2 to 50. The m
If + n is less than 2, cracks may be easily formed in the coating film, and if + n is more than 50, the coating solution may be easily repelled during coating.

The alkyl group has 6 to 14 carbon atoms.
Is preferred, and an alkyl group having 8 to 12 carbon atoms is more preferred. The alkyl group may have not only a linear structure but also a branched structure. In particular,
Examples thereof include an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. Among them, a nonyl group is preferable.

The alkylcarbonyl group is preferably an alkylcarbonyl group having 6 to 14 carbon atoms, and more preferably an alkylcarbonyl group having 8 to 12 carbon atoms. The alkylcarbonyl group may have not only a linear structure but also a branched structure. Specific examples include an octylcarbonyl group, a nonylcarbonyl group, a decylcarbonyl group, an undecylcarbonyl group, and a dodecylcarbonyl group. Among them, a nonylcarbonyl group is preferable.

The polyoxyalkene alkyl ether represented by the general formula (1) has a molecular weight of 1
Those having 70 to 3300 are preferable, and those having 400 to 900 are more preferable.

Hereinafter, specific examples of the polyoxyalkene alkyl ether represented by the general formula (1) will be shown, but the present invention is not limited thereto.

[0050]

Embedded image

Next, the polyoxyalkene alkyl phenyl ether represented by the general formula (2) will be described. In the general formula (2), R ² represents a hydrogen atom, an alkyl group,
Represents an alkylcarbonyl group, an alkoxy group, or an alkoxycarbonyl group. p and q each independently represent an integer of 0 or more, except when p = q = 0. Each of p and q is preferably independently an integer of 0 to 50,
An integer from 0 to 20 is more preferred. Further, the p and q
Is preferably 2 to 50. The p
If + q is less than 2, cracks may be easily formed in the coating film, and if it is more than 50, the coating solution may be easily repelled during coating.

The alkyl group has 6 to 14 carbon atoms.
Is preferred, and an alkyl group having 8 to 12 carbon atoms is more preferred. The alkyl group may have not only a linear structure but also a branched structure. In particular,
Examples thereof include an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. Among them, a nonyl group is preferable.

The alkylcarbonyl group is preferably an alkylcarbonyl group having 6 to 14 carbon atoms, more preferably an alkylcarbonyl group having 8 to 12 carbon atoms. The alkylcarbonyl group may have not only a linear structure but also a branched structure. Specific examples include an octylcarbonyl group, a nonylcarbonyl group, a decylcarbonyl group, an undecylcarbonyl group, and a dodecylcarbonyl group. Among them, a nonylcarbonyl group is preferable.

The alkoxy group has 6 to 1 carbon atoms.
An alkoxy group having 4 carbon atoms is preferable, and an alkoxy group having 8 to 12 carbon atoms is more preferable. Specific examples include an octoxy group, a nonoxy group, a decoroxy group, an undecoxy group, and a dodecoxy group, and among them, a nonoxy group is preferable.

The alkoxycarbonyl group is preferably an alkoxycarbonyl group having 6 to 14 carbon atoms, and more preferably an alkoxycarbonyl group having 8 to 12 carbon atoms. Specific examples include an octoxycarbonyl group, a nonoxycarbonyl group, a deoxycarbonyl group, an undecoxycarbonyl group, and a dodecoxycarbonyl group. Among them, a nonoxycarbonyl group is preferable.

The polyoxyalkene alkyl phenyl ether represented by the general formula (2) preferably has a molecular weight of 250 to 3400, more preferably 480 to 1400.
000 is more preferred.

Hereinafter, specific examples of the polyoxyalkene alkyl phenyl ether represented by the general formula (2) will be shown, but the present invention is not limited thereto.

[0058]

Embedded image

As described above, in the present invention, an aqueous solvent is used as a solvent for dispersing the charge generating material, and in this case, a surfactant is used in combination to form a charge in the prepared dispersion for a charge generating layer. Sufficient dispersion stability with respect to the generated material can be obtained. Therefore, even if a solvent in which a polymer binder material is dissolved in a solvent is not used as a conventional dispersion medium, sufficient dispersion stability can be ensured and aggregation of the charge generation material can be avoided. Can prevent image defects and improve the pot life of the dispersion for the charge generation layer. In this case, the nonionic surfactant represented by the general formula (1) or (2) is particularly useful.

Examples of the charge generating material include phthalocyanine pigments such as metal-free phthalocyanine, chlorogallium phthalocyanine, hydroxygallium phthalocyanine, dichlorotin phthalocyanine, titanyl phthalocyanine, etc., clidon pigments, quinone pigments, perylene pigments, indigo pigments, benzimidazolones Pigments, anthrone pigments,
Squarium pigments and the like can be mentioned, and among them, phthalocyanine pigments are preferable in that they are excellent in dispersion stability at the time of dispersion and good film formability is obtained.

The phthalocyanine pigments described below include, but are not limited to, the following in the present invention. For example, in the X-ray diffraction spectrum, the Bragg angle (2θ ±
0.2 °), at least 7.4 °, 16.6 °, 2
A chlorogallium phthalocyanine crystal having strong diffraction peaks at 5.5 ° and 28.3 °; a Bragg angle (2θ) with respect to CuKα characteristic X-rays in an X-ray diffraction spectrum.
± 0.2 °), at least 7.7 °, 9.3 °, 1
Metal-free phthalocyanine crystals having strong diffraction peaks at 6.9 °, 17.5 °, 22.4 ° and 28.8 °;

In the X-ray diffraction spectrum, the Bragg angles (2θ ± 0.2 °) with respect to the CuKα characteristic X-rays are at least 7.5 °, 9.9 °, 12.5 °, 16.3 °.
ヒ ド ロ キ シ, 18.6 ゜, 25.1 ゜ and 28.3 ゜ hydroxygallium phthalocyanine crystals having strong diffraction peaks; in the X-ray diffraction spectrum, the Bragg angle (2θ ± 0.2 ゜) with respect to CuKα characteristic X-rays ,at least,
And titanyl phthalocyanine crystals having strong diffraction peaks at 9.6 °, 24.1 ° and 27.2 °.

Among them, chlorogallium phthalocyanine crystals, metal-free phthalocyanine crystals, hydroxygallium phthalocyanine crystals, or titanyl phthalocyanine crystals are preferred from the viewpoints of dispersion stability and electrophotographic properties when used as a coating solution. These charge generation materials can be used alone or in combination of two or more.

When the dispersion for the charge generation layer is used, the solid concentration of the charge generation material in the coating solution is preferably 1 to 3.
It is preferably 50% by weight, more preferably 1 to 10% by weight. If the solid content is less than 1% by weight, it may be difficult to increase the film thickness, and if it exceeds 50% by weight, the pot life may be reduced.

The mixing ratio (weight) of the surfactant and the charge generating material is preferably from 1:10 to 10: 1, and more preferably from 1: 5.
~ 5: 1 is more preferred. If the compounding ratio is less than 1:10, that is, if the amount of the surfactant is too small, the dispersion stability of the dispersion for a charge generation layer is reduced, and aggregation of a large number of charge generation materials in the formed charge generation layer. Not only may it form and cause image quality defects such as black spots and white spots, but it may also reduce the pot life of the dispersion and may exceed 10: 1, ie, a surfactant If the amount is too large, the residual potential may increase and the sensitivity may decrease.

The water-based solvent is preferably purified water such as ion-exchanged water or distilled water. As long as the surfactant is dissolved, a polar solvent other than water can be used as a mixture. Examples of the polar solvent include methanol, ethanol, propanol, butanol, dimethyl sulfoxide, dimethylformamide, ethylene glycol and the like.

The amount of the aqueous solvent to be used is preferably 100 to 10000% by weight, more preferably 200 to 1000% by weight, based on the total weight of the charge generation layer. If the amount used is less than 100% by weight, dispersion may not be possible, and if it exceeds 10,000% by weight, it may be difficult to increase the film thickness.

Examples of the binder resin usable for the charge generation layer include natural resins such as vegetable gums such as gum arabic, gum tragan, guar gum, karaya gum, locust bean gum, arabinogalactone, pectin, and quince seed starch. Macromolecules; alginic acid, carrageenan,
Seaweed-based polymers such as agar; animal-based polymers such as gelatin, casein, albumin, and collagen; microbial polymers such as xanthene gum and dextran; and semi-synthetic ones include methylcellulose, ethylcellulose, and hydroxyethylcellulose. And fibrous polymers such as hydroxypropylcellulose and carboxymethylcellulose. In addition, in the case of a pure synthetic system, vinyl polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, and polyvinyl methyl ether; and acrylic resins such as non-cross-linked polyacrylamide and water-soluble styrene acrylic resin are exemplified.

When a charge generating material, a surfactant, a binder resin and the like are added and dispersed in the aqueous solvent to prepare a liquid dispersion for a charge generating layer in a coating liquid, the dispersing means includes: It can be appropriately selected from known dispersing machines,
For example, a sand mill, a colloid mill, an attritor, a ball mill, a dyno mill, a high-pressure homogenizer, an ultrasonic disperser, a coball mill, a roll mill and the like can be mentioned.

The coating method for applying the charge generation layer dispersion can be appropriately selected from known coating methods, for example, a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, and the like. Examples include a bead coating method, an air knife coating method, and a curtain coating method.

The thickness of the charge generation layer is 0.01 to 5
μm is preferable, and 0.03 to 2 μm is more preferable. If the layer thickness is less than 0.01 μm, the sensitivity is reduced,
Density unevenness may occur, and if it exceeds 5 μm, cracks may easily occur in the coating film during coating.

In the electrophotographic photoreceptor of the present invention, the undercoat layer and the charge generation layer are provided on the substrate in this order, and after the charge generation layer formation step, the charge transport layer formation is further performed. A step is provided to form a charge transport layer. In the charge transport layer forming step, a charge transport layer-containing coating solution containing a charge transport material is prepared, and the coating solution is applied on the charge generation layer to form a charge transport layer. The charge transport layer coating solution is prepared by adding a charge transport material, a binder resin, and the like to a solvent.

The charge transporting material can be appropriately selected from known materials, and includes amino compounds, hydrazone compounds, pyrazoline compounds, oxazole compounds, oxadiaol compounds, stilbene compounds, carbazole compounds, benzidine compounds and the like. Is mentioned. These charge transport materials can be used alone or in combination of two or more.

When the coating solution for the charge transport layer is used, the solid content concentration of the charge transport material in the coating solution is preferably 5 to 5.
It is preferably 40% by weight, more preferably 10 to 30% by weight. If the solid content is less than 5% by weight, it may be difficult to increase the film thickness, and if it exceeds 40% by weight, the coating speed may be reduced and productivity may be poor.

Examples of the binder resin usable for the charge transport layer include polycarbonate, polyarylate, polystyrene, polyester, styrene-acrylonitrile copolymer, polysulfone, polymethacrylic acetate,
Styrene-methacryl acetate copolymers, polyolefins, and the like.

The compounding ratio (weight) of the charge transporting material to the binder resin is preferably from 1: 5 to 5: 1, more preferably from 1: 3 to 5: 1.
3: 1 is more preferred. If the mixing ratio is less than 1: 5, that is, the charge transporting material content ratio is too low, the sensitivity may decrease. If the mixing ratio exceeds 5: 1, that is, if the charge transporting material content ratio is too high, the charge The mechanical strength of the transport material may decrease. When the charge transporting material has a film-forming property by itself, the binder resin can be omitted.

Examples of the solvent include monochlorobenzene, tetrahydrofuran, methyl ethyl ketone, cyclohexane, methylene chloride, chloroform and the like.

The coating method for applying the coating solution for the charge transport layer can be appropriately selected from known coating methods, and examples thereof include a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, and a bead coating method. And a curtain coating method.

Further, after the charge transport layer forming step,
A protective layer forming step may be provided. In the protective layer forming step, the protective layer can be formed by preparing a coating liquid for the protective layer and applying the coating liquid onto a substrate, or by attaching a sheet-like film. The coating liquid for the protective layer is prepared by adding a conductive material, a binder resin and the like to a solvent. As the conductive material, tin oxide, titanium oxide,
Conductive fine particles such as antimony oxide and tin oxide doped with antimony oxide can be used.

As described above, the method for producing an electrophotographic photoreceptor of the present invention makes it possible to improve the curing reactivity of an undercoat layer formed on a substrate, and the product quality of the produced electrophotographic photoreceptor varies. And image characteristics can be improved. In addition, the dispersion stability of the dispersion for the charge generation layer is improved, and the aggregation of the charge generation material is suppressed, so that the pot life during storage of the dispersion is extended and the occurrence of image defects is prevented. be able to.

<Electrophotographic Photoreceptor> The electrophotographic photoreceptor of the present invention is manufactured by the above-described method of manufacturing an electrophotographic photoreceptor of the present invention, and at least an undercoat layer and a charge generation layer are laminated on a substrate in this order. It is composed. Further, a charge transport layer may be provided on the charge generation layer, and another layer may be provided on the charge transport layer.

The undercoat layer is formed on a substrate by the method for producing an electrophotographic photoreceptor of the present invention and contains a hydrolytic condensable material. Further, the charge generation layer is formed on the undercoat layer by the method for producing an electrophotographic photoreceptor of the present invention, and includes a charge generation material and a surfactant.

The substrate can be selected from known substrates. Among them, a substrate having conductivity is preferable, and a substrate having conductivity and conventionally used as a substrate of an electrophotographic photosensitive member is used. (Hereinafter, "conductive substrate"
That. ) Can be appropriately selected. Examples of the material of the base include aluminum, nickel, chromium, and stainless steel. In addition, the surface of the conductive substrate can be subjected to various treatments as necessary within a range that does not affect the image quality. For example, surface anodization,
Chemical treatment, coloring treatment, and the like can be performed.

In the case of a function-separated structure in which a charge generation layer is provided on an undercoat layer as in the electrophotographic photosensitive member of the present invention,
A charge transport layer is further formed on the charge generation layer.

A protective layer may be provided on the charge transport layer for the purpose of improving printing durability. The thickness of the protective layer is preferably from 0.5 to 20 μm, more preferably from 1 to 10 μm. If the layer thickness is less than 0.5 μm, it may be difficult to improve printing durability,
When the value exceeds, the residual potential increases, and the fog density in the non-image area may increase.

In the present invention, in order to prevent the deterioration of the photoreceptor due to ozone, oxidizing gas, light, or heat generated in the electrophotographic apparatus, the charge generation layer and / or the charge transport layer are provided with an antioxidant. Additives such as agents, light stabilizers and heat stabilizers can be added. As an antioxidant, for example,
Hindered phenols, hindered amines, p-phenylenediamines, arylalkanes, hydroquinones, spirocoumarone, spiroidanone and derivatives thereof,
Organic sulfur compounds, organic phosphorus compounds and the like can be mentioned. Examples of the light stabilizer include derivatives such as benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine.

For the purpose of improving the sensitivity of the electrophotographic photoreceptor, reducing the residual potential, and reducing the fatigue when repeatedly used, at least one kind of electron accepting substance can be contained. Examples of the electron accepting substance include succinic anhydride, maleic anhydride, dibromomaleic anhydride,
Phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitro Examples thereof include benzoic acid and phthalic acid. Among them, fluorenone-based, quinone-based, and benzene derivatives substituted with an electron-withdrawing group such as a chlorine atom, a cyano group, and a nitro group are particularly preferable.

The electrophotographic photoreceptor of the present invention can be applied to electrophotographic devices such as light lens type copiers, laser printers that emit near-infrared light or visible light, digital copiers, LED printers, and laser facsimile machines. it can. Further, the electrophotographic photoreceptor can be used in combination with a one-component or two-component regular developer or a reversal developer.

[0089]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. still,
Hereinafter, “parts” and “%” in the examples represent “parts by weight” and “% by weight”, respectively. Example 1 First, to 152 parts of n-butyl alcohol, 8 parts of polyvinyl butyral (trade name: Esrec BM-1, manufactured by Sekisui Chemical Co., Ltd.) was added and dissolved by stirring to prepare a 5% polyvinyl butyral solution. . Next, a 50% toluene solution of tributoxy zirconium acetylacetonate (trade name: ZC540, manufactured by Matsumoto Kosho Co., Ltd.) 10
0 parts, 10 parts of γ-aminopropyltriethoxysilane (trade name: A1100, manufactured by Nippon Unicar Co., Ltd.) and n
A solution obtained by mixing 130 parts of -butyl alcohol was added to the polyvinyl butyral solution, and the mixture was stirred with a stirrer to prepare a coating liquid for an undercoat layer.

The coating solution for undercoat layer obtained above was applied to 30
It is applied on a mirror-finished aluminum pipe of φ × 340 mm using a dip coating device, and is dried by heating at 150 ° C. to give a layer thickness of 1.
An undercoat layer of 15 μm was formed.

On the other hand, a 2% aqueous solution of a surfactant in which 3 parts of polyoxyethylene octyl ether (Exemplified Compound 1-1) was dissolved in 150 parts of purified water was added to a Bragg angle (2θ ± 0.2) for CuKα characteristic X-ray. °) 7.4 °, 1
3 parts of a chlorogallium phthalocyanine crystal having strong diffraction peaks at 6.6 °, 25.5 ° and 28.3 ° were added, and the mixture was dispersed with a sand mill for 24 hours to obtain a charge generation layer dispersion having a solid content of 4%. Prepared.

The dispersion for a charge generation layer obtained above was applied onto the undercoat layer by lamination using a dip coating apparatus.
The resultant was dried by heating at 00 ° C. to form a charge generation layer having a thickness of 0.15 μm.

Further, in 40 parts of monochlorobenzene, 4 parts of N, N-bis (3,4-dimethylphenyl) biphenyl-4-amine as a charge transporting material were dissolved together with 6 parts of a polycarbonate Z resin, and the solid content concentration was 20%. Was prepared. The obtained coating solution for a charge transport layer was further laminated and applied on the charge generation layer using a dip coating apparatus, and dried by heating at 115 ° C. to form a film having a thickness of 24 μm.
m of the charge transport layer was formed, whereby an electrophotographic photoreceptor (1) of the present invention was produced.

<Measurement of Charge Amount> The electrophotographic photoreceptor (1) obtained above was applied to a laser printer (trade name: XP-1).
1, manufactured by Fuji Xerox Co., Ltd.), and the charge amount on the surface of the electrophotographic photosensitive member (1) was measured as follows.
Under an environment of 20 ° C. and 50% RH, the grid applied voltage is −60.
The surface of the electrophotographic photoreceptor (1) was charged by a scorotron charger of 0 V (VH).
6. Irradiation energy using an 80 nm semiconductor laser.
Discharge was performed by irradiating a laser beam of 0 mJ / m ² (V
L). Then, after a lapse of 3 seconds, a red LED was used to irradiate red light with an irradiation energy of 50 mJ / m ² to perform static elimination (VR). The potentials (VH, V
L, VRP). Further, after 10,000 times of repeated charging and exposure, each potential (ΔVH,
ΔVL, ΔVRP) were measured. The measured results are shown in Table 1 below.

<Evaluation of Image> Using the electrophotographic photoreceptor (1), the amount of black spots (the number of black spots) in the image was evaluated for the print image after the repetitive charging and exposure of 10,000 times. The results of the evaluation are shown in Table 1 below.

Example 2 The n-butyl alcohol (total 282 parts) used for the undercoat layer in Example 1 was replaced with isopropyl alcohol (total 282 parts), and 50% toluene of tributoxy zirconium acetylacetonate was used. The solution was replaced with 50 parts of titanium acetylacetonate (trade name: Organix TC100, manufactured by Matsumoto Kosho Co., Ltd.) and γ-
Aminopropyltriethoxysilane was replaced with γ- (2-aminoethyl) aminopropyltrimethoxysilane (trade name:
A1120, manufactured by Nippon Unicar Co., Ltd.) An electrophotographic photoreceptor (2) of the present invention was produced in the same manner as in Example 1 except that the thickness of the undercoat layer was changed to 0.5 μm. . The measurement of the charge amount and the image evaluation were performed in the same manner as in Example 1. The results are shown in Table 1 below.

Example 3 Example 1 was repeated except that the polyoxyethylene octyl ether (Exemplified Compound 1-1) used in Example 1 was replaced with a polyoxyalkene alkylphenyl ether (Exemplified Compound 2-9). Similarly, an electrophotographic photoreceptor (3) of the present invention was produced. Example 1
The measurement of the charge amount and the image evaluation were performed in the same manner as described above, and the results are shown in Table 1 below.

Examples 4 to 6 Each of the chlorogallium phthalocyanine crystals used in the charge generation layer of Example 1 had a Bragg angle (2θ ± 0.2 °) with respect to CuKα characteristic X-rays in the X-ray diffraction spectrum. ,at least,
7.7, 9.3, 16.9, 17.5, 22.
A metal-free phthalocyanine crystal having a strong diffraction peak at 4 ° and 28.8 ° [Example 4], and a Bragg angle (2θ ±
0.2 °), at least 7.5 °, 9.9 °, 1
2.5, 16.3, 18.6, 25.1, and 2
A hydroxygallium phthalocyanine crystal having a strong diffraction peak at 8.3 ° [Example 5] or a CuKα characteristic X-ray Bragg angle (2θ) in an X-ray diffraction spectrum
Example 1 except that the titanyl phthalocyanine crystal [Example 6] having strong diffraction peaks at least at 9.6 °, 24.1 ° and 27.2 ° of ± 0.2 °) was used.
In the same manner as in the above, electrophotographic photoreceptors (4) to (6) of the present invention were produced. The measurement of the charge amount and the image evaluation were performed in the same manner as in Example 1, and the results are shown in Table 1 below.

(Comparative Examples 1 and 2) The dispersion for the charge generation layer using the aqueous surfactant solution in Examples 1 and 2 was
In a solution in which 3 parts of a vinyl chloride-vinyl acetate copolymer resin (trade name: VMCH, manufactured by Union Carbide Co.) was previously dissolved in 100 parts of (n-) butyl acetate, the Bragg angle (2θ ± 0. 2 °) 7.4 °, 16.
3 parts of chlorogallium phthalocyanine crystals having strong diffraction peaks at 6 °, 25.5 ° and 28.3 ° were added,
After dispersing in a sand mill for 24 hours, the electrophotographic photoreceptors (7) and (7) were prepared in the same manner as in Example 1 except that the dispersion was diluted with n-butyl acetate and replaced with a dispersion for charge generation layer having a solid concentration of 4%. 8) was produced. The measurement of the charge amount and the image evaluation were performed in the same manner as in Example 1. The results are shown in Table 1 below.

Comparative Example 3 The polyoxyethylene octyl ether (exemplary compound 1-1) used in the charge generation layer dispersion of Example 1 was replaced with stearyltrimethylammonium chloride as an ionic surfactant. An electrophotographic photosensitive member (9) was produced in the same manner as in Example 1 except for the above. The measurement of the charge amount and the image evaluation were performed in the same manner as in Example 1. The results are shown in Table 1 below.

[0101]

[Table 1]

As is clear from Table 1, after the undercoat layer containing the hydrolytic condensable material was provided on the substrate, the charge generating material was dispersed in the surfactant-containing aqueous solvent on the undercoat layer. In Examples 1 to 6 using the method for producing an electrophotographic photoreceptor of the present invention, in which the dispersion for a charge generation layer is applied, the charge characteristics are excellent, and a long-term stable image formation without image defects such as black spots is obtained. An electrophotographic photoreceptor capable of forming a high-quality image was produced. On the other hand, in Comparative Examples 1 and 2 in which a surfactant-containing aqueous solvent was not used in the dispersion for the charge generation layer laminated and applied on the undercoat layer, the charging potential on the surface of the obtained electrophotographic photosensitive member was reduced by the number of prints. It greatly fluctuated with the increase, and there were many occurrences of image defects such as black spots in the formed image, and a high-quality image could not be obtained stably. In Comparative Example 3 using an ionic surfactant as the surfactant, a printed image could not be obtained due to poor charging.

[0103]

According to the present invention, it is possible to provide a method of manufacturing an electrophotographic photoreceptor which has less variation in quality and can improve electrical characteristics and image characteristics of the electrophotographic photoreceptor.
According to the electrophotographic photoreceptor of the present invention, a high-quality image can be stably formed for a long period of time.

Claims (8)

[Claims] At least an undercoat layer forming step of forming an undercoat layer containing a hydrolysis-condensable material on a substrate,
Forming a charge generation layer containing a charge generation material and a surfactant on the undercoat layer. A method for manufacturing an electrophotographic photoreceptor, comprising: 2. The method according to claim 1, wherein the hydrolysis-condensable material is an organometallic compound and / or a silane coupling agent. 3. The method according to claim 2, wherein the organometallic compound is an organic zirconium compound or an organic titanium compound. 4. The method for producing an electrophotographic photoreceptor according to claim 1, wherein the surfactant is a nonionic surfactant. 5. The non-ionic surfactant is a non-ionic surfactant represented by the following general formula (1).
3. The method for producing an electrophotographic photoreceptor according to 1. Embedded image [In the formula, R ¹ represents a hydrogen atom, an alkyl group, or an alkylcarbonyl group. n and m each independently represent an integer of 0 or more, except when n = m = 0. ] 6. The nonionic surfactant according to claim 4, wherein the nonionic surfactant is a nonionic surfactant represented by the following general formula (2).
3. The method for producing an electrophotographic photoreceptor according to 1. Embedded image [In the formula, R ² represents a hydrogen atom, an alkyl group, an alkylcarbonyl group, an alkoxy group, or an alkoxycarbonyl group. p and q each independently represent an integer of 0 or more, except when p = q = 0. ] 7. The electrophotographic photoreceptor according to claim 1, wherein the charge generation material is a chlorogallium phthalocyanine crystal, a metal-free phthalocyanine crystal, a hydroxygallium phthalocyanine crystal, or a titanyl phthalocyanine crystal. Production method. 8. An electrophotographic photosensitive member obtained by the method for producing an electrophotographic photosensitive member according to claim 1.