JPS583223B2 - electrophotographic photoreceptor - Google Patents

Description

[Detailed description of the invention] The present invention relates to an electrophotographic photoreceptor.

Electrophotographic photoreceptors have various configurations in order to obtain predetermined characteristics or depending on the type of electrophotographic process to which they are applied.

As a typical electrophotographic photoreceptor, a photoreceptor having an insulating layer on its surface is widely used.

This insulating layer is used to protect the photoconductive layer, improve the mechanical strength of the photoreceptor, improve the dark decay characteristics, or be applied to certain electrophotographic processes (and for pollution-free purposes). It is established for a purpose.

Representative examples of photoreceptors having such insulating layers or electrophotographic processes using photoreceptors having insulating layers are, for example, U.S. Pat.
JP 16429, JP 38-15446, JP 46-3713, JP 42-23910, JP 43-24748, JP JP 1977-1
It is described in Japanese Patent Publication No. 9747, Japanese Patent Publication No. 36-4121, etc.

As a matter of course, electrophotographic photoreceptors are required to have predetermined sensitivity, electrical properties, and optical properties depending on the electrophotographic process to which they are applied.

However, the durability and cleanability of the photoreceptor are also important properties.

Durability is a property required when a photoreceptor is used repeatedly, and cleanability is a property that determines the ease with which residual toner that adheres to the surface of the photoreceptor can be removed. This significantly affects the prevention of damage to the cleaning means.

Originally, photoconductors equipped with an insulating layer have excellent durability, but it has been pointed out that there are still areas that can be improved in terms of toner transferability, cleaning performance, and surface smoothness. be done.

The main object of the present invention is to provide a photoreceptor having an insulating layer that has excellent surface lubricity and, as a result, excellent durability and cleanability.

The present invention is an electrophotographic photoreceptor characterized in that an insulating layer contains a silicate compound produced by hydrolyzing a silane coupling agent.

The silane coupling agent used in the present invention includes reactive groups that bind to inorganic substances, such as alkoxy groups and silanol groups, and reactive groups that bind to organic substances such as synthetic resins, such as vinyl groups and epoxy groups. It is a silane compound that has both a methacrylic group, an amino group, and an amino group in its molecule.

Examples of the silane cassopring agent include vinylchlorosilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinylroottris(β-methoxyethoxy)silane, γ-meccryloxypropyltrimethoxysilane, γ-meccryloxypropyltris( β-methoxyethoxy), silane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyl Triethoxysilane, N-β
-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N,N-bis(β-hydroxyethyl)-γ-aminopropyltriethoxysilane , γ-chloropropyltrimethoxysilane, and the like.

A hydrolysis product of a silane coupling agent is one in which part or all of the alkoxy group, halogen group, acyl group, etc. bonded to the silicon atom in the molecule of the silane coupling agent is replaced with acid or alcohol. It is.

Hydrolysis of the silane coupling agent can be accomplished by various methods.

For example, an inorganic acid can be added to a silane coupling agent to form a hydrolysis product.

Examples of hydrolysis products include silicate compounds such as methyl silicate, ethyl silicate, probyl silicate, butyl silicate, and phenyl silicate.

Furthermore, when using a silicate compound, it is also effective to use it together with a silane coupling agent.

It is also suitable to use hardening agents such as sodium acetate, ammonium acetate, sodium formate, and the like.

As the silane coupling agent, those having a vinyl group, an epoxy group, and a mono- or alkoxy group are suitable.

In particular, as a silane coupling agent, (CH3O-)3Si(CH2)3Cl, (CH3O)
3Si-(CH2)3SH, (CH3)2SiCl2, etc. are suitable.

The silane coupling agent may be hydrolyzed by the following method in addition to using an inorganic acid.

For example, it may be reacted with water brine in a heated state, irradiated with ultraviolet light in the presence of water, or reacted with an organic substance such as carboxylic acid or sulfonic acid.

A silicate compound produced by hydrolyzing a silane coupling agent forms an insulating layer with excellent surface lubricity, durability, cleanability, and surface hardness.

The insulating layer is usually formed by containing a silicate compound produced by hydrolyzing a silane coupling agent in a layer-forming resin.

The silicate compound produced by hydrolyzing the silane coupling agent is preferably contained in an amount of 10 to 70% by weight.

Other components may be added as necessary to form the insulating layer.

Typical such other components include various isocyanates, fatty acid amides, fatty acid metal salts, wax, and the like.

Fatty acid amide or fatty acid metal salt contributes to improving image density.

These compounds include, for example, stearamide,
Examples include oleic acid amide, stearic acid metal salt, oleic acid metal salt, and the like.

Further, the wax further improves the moisture resistance of the layer, and as the wax, ordinary waxes such as ethylene wax and paraffin wax are appropriately used.

As the resin used for forming the insulating layer, various ordinary resins can be used as appropriate.

For example, organic insulating materials such as polyethylene, polyester, polypropylene, polystyrene, polyvinyl chloride, polyvinyl acetate, acrylic resin, polycarbonate, silicone resin, fluororesin, epoxy resin, and solvent-based and heat-treated copolymers and mixtures thereof. Materials such as polymers and photopolymer types may be used.

Furthermore, in forming the insulating layer more easily, forming the insulating layer by coating is superior to forming the insulating layer by adhering an insulating film.

Furthermore, in the case of coating, a seamless insulating layer can be formed on a drum-shaped photoreceptor.

In this respect, using a curable resin is a more effective mode than other resins.

Curable resin is a resin that is cured by heat, light, electron beam, etc.

In the case of thermosetting, room temperature is sufficient depending on the type of resin.

Particularly suitable curable resins include acrylic resins, urethane resins, polyester resins, epoxy resins, melamine resins, silicone resins, etc. These resins are silicate compounds produced by hydrolyzing silane coupling agents. It has excellent chemical affinity with

Note that the thickness of the insulating layer is set according to desired characteristics.

In general, when an insulating layer is added for the main purpose of protecting the photoreceptor, improving its durability, dark decay characteristics, etc., the insulating layer is set relatively thin, and when the photoreceptor is used for a specific electrophotographic process, The insulating layer is set to be relatively thick.

Usually, the thickness of the insulating layer is 0.1 to 100μ, especially 0.
．． It is set to 1 to 50μ.

The most typical structure of the photoreceptor of the present invention is a laminate in which the photoconductive layer is between a support and an insulating layer.

The support can be any metal plate such as stainless steel, copper, aluminum, or tin, paper, sheet, or resin film. Formed from material.

The support may be omitted if necessary.

The photoconductive layer includes S, Se, Pbo, and S, Se, Te,
It is formed by vacuum deposition of an inorganic photoconductive material such as an alloy or intermetallic compound containing As, Sb, Pb, etc.

In addition, when using the sputtering method, ZnO, CdS, C
A photoconductive layer can also be formed by depositing a photoconductive material with a high melting point, such as dSe or TiO2, on the support.

In addition, when forming a photoconductive layer by coating, organic photoconductive materials such as polyvinylcarbazole, anthracene, phthalocyaninine, dye-sensitized or Lewis acid-sensitized products, and combinations of these with insulating binders may be used. Mixtures may be used.

Also suitable are mixtures of inorganic photoconductors such as ZnO, CdS, TiO2, PbO, etc. with insulating binders.

Note that various resins such as the above-mentioned resin for forming an insulating layer are used as the insulating binder.

Although the thickness of the photoconductive layer depends on the type and characteristics of the photoconductive material used, it is generally 5 to 100 μm, particularly 10 to 50 μm.
degree is suitable.

Alternatively, an insulating layer not containing a silicate compound may be interposed between the insulating layer and the photoconductive layer.

Example 1 200 g of 59 Se was weighed out in an evaporating dish, the evaporation source temperature was 300°C, the substrate (Al drum) temperature was 68°C, and the system vacuum degree was 1.
Vapor deposition was carried out at ×10 −5 torr for 35 minutes to form two photoconductive layers with a thickness of 60 μm.

A photocurable urethane resin (trade name: Sonne, manufactured by Kansai Paint) with a viscosity of 90CP was placed on one of the obtained photoconductive layers.
After soaking in a solution diluted with methyl ethyl ketone solvent so that it becomes S, and pulling it up at a speed of 30 mm/min,
It was cured by irradiation with a mercury lamp for 5 minutes to form an insulating layer of 10 μm.

This operation was repeated three times to form a 30 μm insulating layer on the photoconductive layer.

This sample is referred to as (A). On the other photoconductive layer, (A
) was repeated twice to form a 20μ thick urethane insulating layer.

Furthermore, on this layer, a photocurable urethane resin, vinyltriacetoxylan and butyl silicate (86:12:2
), then added 1 part by weight of sodium acetate per 100 parts by weight of the mixture as a hardening agent, and immersed it in a solution diluted with ethyl alcohol to give a viscosity of 90 CPS.
After pulling up at a speed of m/min, heating at 75°C for 15 minutes, irradiating with a 4Kw mercury lamp for 5 minutes to harden,
A 0μ insulating layer was laminated.

This sample is designated as (B). Obtained samples (A), (B)
On the other hand, primary DC charging, secondary AC static neutralization simultaneous exposure, whole surface irradiation, dry development with toner, urethane cleaning blade (hardness 70°, angle to the insulating layer surface 30°,
As a result of testing the lubricity, image quality, and durability of the sample through a cleaning process using a blade load of 20 kg, it was found that sample (A) had a friction coefficient of 270 and produced severe sliding noise (frictional noise between the blade and the insulating layer). At 50 revolutions of the drum, wear on the blade edge and cleaning scratches on the insulating layer were observed, but on the other hand, for sample (B),
With a coefficient of friction of 1.06, the photosensitive drum rotates smoothly and the image is good, and even after 36,500 rotations of the photosensitive drum, there are no abrasion breaks on the blade edge, cleaning scratches on the insulating layer, or defects caused by fusion development of the developer. Membrane properties could not be confirmed.

Example 2 200 g of 5-nine Se-Te (10 wt%) alloy was weighed into an evaporating dish, and the temperature was 40° C. at an evaporation source temperature of 320° C., a substrate (Al drum) temperature of 69° C., and an internal vacuum of 1×10 −5 torr.
Deposition was carried out for minutes to form two photoconductive layers with a thickness of 65 microns.

One of the two types of photoconductive layers obtained was immersed in a solution diluted with methyl ethyl ketone so that the viscosity of the photocurable unsaturated polyester resin (product name: UV-CM-103-manufactured by Cashew KK) was 90 CPS. , at a speed of 30 mm/min, and then irradiated with a 4 Kw mercury lamp for 5 minutes to cure.

This operation was repeated three times to form an insulating layer of 30 μm.

This sample is designated as (C). On the other photoconductive layer (C)
The photocurable unsaturated polyester used in , γ-methacryloxypropyltrimethoxysilane and probyl silicate (70:25:5) were mixed, and ammonium acetate and acetic acid were added as curing agents to 100 parts by weight of the mixture, respectively. Add 1 part by weight, dilute with methyl alcohol to have a viscosity of 90CPS, pull it up at a speed of 30mm/min, heat it at 80℃ for 15 minutes, and then irradiate it with a 4Kw mercury lamp for 5 minutes to harden it to 10μ. The film thickness was obtained.

This operation was repeated three times to form a 30 μm insulating layer on the photoconductive layer.

This sample is designated as (D).

The obtained samples (C) and (D) were subjected to the same test as in Example 1. As a result, the blade edge of sample (C) was worn out and damaged by 50 rotations of the photosensitive drum, and the sliding noise was severe and cleaning was difficult. However, for sample (D), the photosensitive drum rotated smoothly, the image and cleaning performance were good, and no abnormalities were observed on the blade edge or insulating layer even after the drum rotated 39,000 times. There wasn't.

Example 3 200 g of 59 Se-As (1.0 wt%) alloy was weighed into an evaporating dish, and the temperature was 40° C. at an evaporation source temperature of 315° C., a substrate (Al drum) temperature of 68° C., and an internal vacuum of 1×10 −5 torr. Deposition was carried out for minutes to form two 68μ photoconductive layers.

One side of the resulting two photoconductive layers was immersed in a solution prepared by diluting a thermosetting acrylic resin (trade name: Pulse Lac no 2000, manufactured by China Paint Co., Ltd.) with methyl ethyl ketone to a viscosity of 90 CPS, and dipping it at 30 mm/min. After pulling it up at a speed of , it was cured by heating at 60° C. for 30 minutes.

This operation was repeated three times to form an insulating layer with a thickness of 30 μm.

This sample is designated as (E). On the other photoconductive layer, (E
) The mixture of thermosetting acrylic resin, vinylchlorosilane, and phenyl silicate (91:6:31) used in ) was immersed in a solution prepared with ethyl alcohol so that the viscosity was 90 CPS, and the mixture was pulled up at a speed of 30 mm/min. After that, 7
It was cured by heating at 5° C. for 30 minutes.

This operation was repeated three times to form an insulating layer with a thickness of 30 μm.

This sample is designated as (F).

The obtained samples (E) and (F) were tested in the same manner as in Example 1. As a result, the blade edge of sample (E) was worn and damaged at 40 rotations of the photosensitive drum, and there was no sliding noise. violently,
A phenomenon of poor cleaning was observed, but on the other hand, the sample (F
), the photosensitive drum rotated smoothly, the image quality and cleaning performance were good, and even when the photosensitive drum was rotated at 17,500 rpm, there was hardly any wear on the blade edge or cleaning scratches on the insulating layer.

Examples 4 to 14 In the production of sample (A) of Example 1, a mixture of components shown in the following examples was used instead of the photocurable urethane resin, and the necessary heating and/or light irradiation curing was performed. A sample was prepared by processing.

As a result, the samples manufactured for each of Examples 4 to 14 also had excellent surface lubricity, similar to sample (B).

Example mixture components 4 Urethane resin (trade name: Toa Urethane 500 manufactured by Toa Urethane) (90) Vinylchlorosilane (7) Phenyl silicate (3) 5 Polyester resin (trade name: Pulslac 1000,
Made by China Paint) (40) Vinyl acetoxysilane (14) Butyl silicate (3) Sodium acetate (3) Urethane resin (Product name: Tourethane 500) (40) 6 Polyester resin (Product name: Burnok D-160,
(manufactured by Nippon Reich) (30) Epoxy resin (product name: Epicote 828, manufactured by Shell)
(34) γ-methacryloxypropyltrimethoxysilane (3
0) Methyl ethyl silicate (6) 7 Acrylic urethane resin (Product name: Lastrazol A-
803, manufactured by Nippon Reich) (40) Epoxy resin (trade name: Epicote 1001, manufactured by Shell) (40) Ethyl silicate (2) Vinyl-tris (β-methoxyethoxy) silane (17
) Ammonium acetate (0.5) Acetic acid (0.5) 8 Urethane resin (Product name: Sonne, manufactured by Kansai Paint) (
30) Polyester resin (trade name: Desmohen 800, manufactured by Nippon Reich) (40) Vinylchlorosilane (25) Butyl silicate (5) 9 Polyester resin (trade name: ODX-105 manufactured by Nippon Reich) (90) N-bis ( β-Hydroxyethyl)-γ-aminopropyltriethoxysilane (8) Ethyl silicate (2) 10 Polyester resin (Product name: Burnok D-220
, manufactured by Nippon Reich) (80) Vinyltriethoxysilane (16) Butyl silicate (3) Sodium acetate (1) 11 Photocurable epoxy resin (Product name: Epicote 828
) (90) Vinyltriacetoxysilane (8) Ethyl silicate (2) 12 Photocurable unbonded polyester (Product name: U■-CM
-102, made by Cashew) (80) γ-glycidoxypropyltrimethoxysilane (17
) Butyl silicate (3) 13 Melamine resin (Product name: D-100-2 manufactured by Nippon Paint) (70) Vinyltrimethoxysilane (25) Phenyl silicate (5) 14 Silicone resin (Product name: X-12-917) (manufactured by Shin-Etsu Chemical) (60) Vinylchlorosilane (32) Methyl ethyl silicate (7) Sodium acetate and acetic acid (0.5 each) In addition, - in 4 to 14 above, the numbers in brackets indicate the weight composition ratio.

Claims (1)

[Scope of Claims] 1. An electrophotographic photoreceptor having an insulating layer on a photoconductive layer, wherein the insulating layer contains a silicate compound produced by hydrolyzing a silane coupling agent. body. 2. The electrophotographic photoreceptor according to claim 1, wherein the insulating layer contains a silicate compound produced by hydrolyzing a silane coupling agent and a curable resin.