JP2510628B2 - Electrophotographic photoreceptor - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electrophotographic photoreceptor, and particularly to an electrophotographic photoreceptor having excellent production stability, image quality and durability of the electrophotographic photoreceptor. And an improved adhesive layer that enables

[Conventional technology]

Many organic photoconductors have been developed since the discovery that certain organic compounds exhibit photoconductivity. For example, organic photoconductive polymers such as poly-N-vinylcarbazole and polyvinylanthracene, low molecular weight organic photoconductors such as carbazole, anthracene, pyrazolines, oxadiazoles, hydrazones, and polyarylalkanes, and phthalocyanine pigments. , Azo pigments, cyanine dyes, polycyclic quinone pigments, perylene pigments, indigo dyes,
Organic pigments and dyes such as thioindigo dyes and methine squaric acid dyes are known. In particular, organic pigments and dyes that have photoconductivity are easier to synthesize than inorganic materials, and the variety that allows selection of compounds that exhibit photoconductivity in the appropriate wavelength range has been expanded. Conductive organic pigments and dyes have been proposed. For example, U.S. Pat.Nos. 4,123,270, 4,247,614 and 425,161.
No. 3, No. 4251614, No. 4256821, No. 4260672,
No. 4268596, No. 4278747, No. 4293628, and the like, a disazo pigment showing photoconductivity as a charge generating substance in a photosensitive layer functionally separated into a charge generating layer and a charge transporting layer as disclosed in The electrophotographic photoconductor used is known.

Since an electrophotographic photoreceptor using such an organic photoconductor can be produced by coating by appropriately selecting a binder, extremely high productivity, an inexpensive photoreceptor can be provided,
Moreover, it has an advantage that the photosensitive wavelength range can be freely controlled by selecting an organic pigment.

Among them, the laminated type photoreceptor obtained by laminating the charge transport layer and the charge generation layer containing a charge generation material as a main component is superior to other single layer type photoreceptors in residual potential, memory, repeating characteristics, There is an advantage in improving sensitivity. However, in recent years, it has been desired again to develop an organic photoconductor having sensitivity, memory, repeatability and durability equal to or higher than that of a highly sensitive inorganic photoconductor such as a-Se type, CdS type, and a-Si type. ing. However, there are still many unsolved problems in the development of such an organic photoconductor having high performance.

In particular, organic photoconductors have low mechanical strength, and when applied to copying machines, printers and the like, they cause pinholes, fine cracks, friction at the edges, peeling, etc., and cause image defects.

In addition, the organic photoreceptor is usually applied as a thin film of 10 to 40 μm on a conductive support, and the coating is likely to be disturbed due to defects such as impurities, scratches, dents, and bubbles on the support, It causes image defects.

In particular, in the case of a so-called function-separated type organic photoconductor in which a charge transport layer (CTL) is laminated on a charge generation layer (CGL), the sensitivity is very high and the residual potential is small, but it is dark. There is a drawback that attenuation and optical memory become large, and it is necessary to make the charge generation layer thinner for this measure (generally, 0.
01 μm to 6 μm). Therefore, under the present circumstances, it is more susceptible to defects such as protrusions, dents, scratches, and dents on the support, which causes various image defects, and high-quality images cannot be obtained.

In order to solve the mechanical strength of the organic photoreceptor, attempts have been made to improve the adhesive strength by roughening the support and the conductive layer.

The method of sandblasting the aluminum substrate of the support or performing the oxidation treatment may cause image defects even though the adhesive strength is improved.

Further, in the method of roughening the conductive layer by adding coarse irregular-shaped particles in the conductive layer, the production conditions are not destabilized, and a reproducible roughened coating film of the conductive layer is obtained. It was difficult.

Further, the conductive material used for the conductive layer is
Charge injection often occurs, and the presence of an adhesive layer is required to prevent charge injection between the conductive layer and the charge generation layer.

Further, it is known to provide an adhesive layer in order to improve the adhesive strength.

Therefore, the surface property of the adhesive layer has a great influence on image characteristics and durability characteristics. In particular, when sufficient adhesive strength cannot be obtained between the conductive layer and the adhesive layer, or between the adhesive layer and the photosensitive layer, pinholes, cracks and peeling from the edge of the photosensitive layer during durable use of the photoreceptor , Cracks, image characteristics,
This will cause the durability characteristics to deteriorate significantly.

In recent years, printers using laser beams (LB
P), LEDs, printers using liquid crystal shutters, etc. are being actively developed, but in the case of LBP in particular, a phenomenon called laser light interference occurs and so-called interference fringes occur on the image.

Various techniques have been studied in order to prevent the interference fringes, but as one of the most effective techniques, a method of roughening the support is already known. Chemical methods (such as etching) and mechanical methods (such as sandgrass and grinding with a cutting tool) are known as methods for roughening the surface of the support, but they are difficult in terms of pollution problems, production stability, and production costs, respectively. Perhaps there is a large variation in surface roughness, and it is difficult to control the characteristics.

When the surface becomes irregularly rough, charge injection, pinholes, etc. are partially generated, causing image defects such as black spots, white spots, and fog, which is still an unsatisfactory stage for practical use.

Also, a method of utilizing an adhesive layer is being studied. There is a method of adding coarse irregularly-shaped particles to the adhesive layer, and adding irregularly-shaped fine particles having high cohesiveness.

However, although the addition of these particles makes it relatively easy to control the surface roughness, it also causes irregular coarse defects on the surface, and black spots on the image, and major problems such as fog occur. The current situation.

[Problems to be solved by the invention]

An object of the present invention is to provide an electrophotographic photosensitive member which maintains high image quality even during durable use and has excellent adhesiveness against cracking and peeling of the photosensitive layer, that is, high image quality and high durability.

Another object of the present invention is to provide an electrophotographic photosensitive member free from image defects caused by protrusions, dents, scratches, dents, etc. on the support.

It is another object of the present invention to provide an electrophotographic photosensitive member that prevents interference fringes from occurring when a laser beam is used as a light source without causing a harmful effect on image defects.

[Means for solving problems]

That is, the present invention is an electrophotographic photosensitive member having an adhesive layer between the support and the photosensitive layer, the adhesive layer is substantially casein, gelatin, polyamide, polyurethane,
At least one binder selected from the group consisting of polyvinyl alcohol, nitrocellulose resin, ethylene-acrylic acid copolymer resin, phenol resin, acrylic resin, polyester and polyether, and spherical resin fine powder excluding silicone resin fine powder And the spherical degree of the spherical resin fine powder is 0.5 or more.

FIG. 1 shows an embodiment of the present invention in which an adhesive layer 3 and a photosensitive layer 4 are laminated on a support 1, and spherical resin fine powder 5 is uniformly dispersed and contained in the adhesive layer 3.

FIG. 2 is also one form of the present invention, in which a conductive layer 2, an adhesive layer 3 and a photosensitive layer 4 are laminated on a support 1, and a spherical resin fine powder 5 is uniformly dispersed and contained in the adhesive layer 3. Has been done.

In the present invention, by containing the spherical resin fine powder in the intermediate layer, it is possible to impart appropriate unevenness to the surface of the adhesive layer and enhance the adhesiveness between the adhesive layer and the layer laminated thereon.

However, when irregularly shaped particles are added,
Since the surface of the adhesive layer is irregularly roughened, good adhesion cannot be obtained, which causes image defects. Due to the triboelectrification that occurs when the irregularly shaped particles are dispersed in the organic binder and the solvent, the electric charge is localized on a part of the particle surface, and as a result, aggregates of the particles are formed and the coated surface is It is unevenly textured.

As a result, in the layer coating laminated on the adhesive layer,
Repelling, agglomeration, etc. occur and cause partial image defects. In addition, minute spots (white spots and black spots on the image) are produced as a whole, and the image quality is degraded.

However, in the case of spherical particles, electric charges are not localized on a part of the particle surface, and the particles do not aggregate with each other, so that a uniform coated surface without local defects can be obtained.

Furthermore, being a resin powder, it has a better affinity with organic binders than inorganic powders, and has a relatively low specific gravity, so the dispersion is uniform, the dispersion is stable, and the coating film is uniform. Has the effect of further improving.

In electrophotography that uses laser light as a light source, line scanning with laser light produces an image, but line images such as characters do not pose a problem, but in the case of solid images, interference fringe-like density unevenness occurs. However, the interference fringes can be prevented by including the spherical resin fine powder in the adhesive layer as in the present invention.

The average particle size of the spherical resin fine powder contained in the adhesive layer is 0.
6 to 2 μm is preferable. If the average particle size is smaller than 0.6 μm, the effect of roughening the coated surface cannot be obtained when the affinity between the fine particles and the binder is good. When the affinity between the fine particles and the binder is poor, the stability and productivity of the coating liquid is significantly reduced due to the agglomeration between the fine particles, and the coating surface also has many irregular irregularities, which significantly reduces the image quality. Cause On the other hand, when the average particle size exceeds 2 μm, the roughness of the coated surface becomes large, and fine cissing and lumps are generated in the layer coating film to be laminated thereon, and white spots on the image,
This causes defects such as black dots.

The average particle size can be measured by the following method. The spherical resin fine powder is observed with a scanning electron microscope, the diameter of each particle is measured, and an average value of 20 points is taken. This operation is repeated three times, and the average value is used as the average particle diameter. However, when the particle size distribution of the powder is large, it is necessary to shake well in advance to make it uniform.

The spherical resin fine powder in the present invention has a sphericity of 0.5 or more, preferably 0.8 or more, where the ratio of the diameter of the minimum circumscribed circle to the diameter of the maximum inscribed circle of the particles is 1. is there. Therefore, true spheres and ellipsoidal spheres are preferable, and irregularly shaped particles are inappropriate.

Further, the specific gravity of the dispersion medium in which the organic binder is dissolved in the solvent is almost in the range of 0.8 to 1.5. Therefore, the specific gravity of the dispersoid (fine spherical resin powder) dispersed in the dispersion medium is 0.7.
It is preferably in the range of 1.7 to 1.7, particularly 0.9 to 1.5.

If the specific gravity is less than 0.7 or greater than 1.7, the uniformity and stability of the dispersion liquid cannot be sufficiently obtained in any case.
This causes the coating film to be irregularly roughened and deteriorate the image quality.
According to the method of the present invention, the surface of the adhesive layer can be uniformly controlled to a target surface roughness without degrading the image quality, and the organic material has high sensitivity, high image quality, and high durability. A photoreceptor can be provided.

It is premised that the spherical resin fine powder does not dissolve in the solvent. For example, when a ketone or ester solvent is used, it is necessary to combine polyamide and polyolefin resin powders.

If the spherical resin fine powder is a curable resin, it is often insoluble in the solvent, and the above-mentioned restrictions can be avoided.

The spherical resin fine powder of the present invention is a fine powder made of a thermoplastic resin or a curable resin.

Examples of the thermoplastic resin include acrylic resin, styrene resin, polycarbonate resin, polyester resin, polyamide resin and the like. As the acrylic resin, a polymer of monomers such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, phenyl methacrylate, methyl acrylate, and ethyl acrylate, or a copolymer of these monomers and another monofunctional monomer is used. Used.

As the styrene resin, a polymer of monomers such as styrene, methylstyrene and chlorostyrene, or a copolymer of these monomers and another monofunctional monomer is used.

As the polycarbonate resin, a polycondensate of bisphenol A and phosgene or a polycondensate of bisphenol Z and phosgene is used.

As the polyester resin, a polycondensate of a dicarboxylic acid such as terephthalic acid, isophthalic acid, orthophthalic acid and ethylene glycol, propylene glycol or glycerin, or a copolycondensate thereof is used.

As the polyamide resin, a polycondensate of ε-aminocaproic acid, ω-aminoundecanoic acid, a polycondensate of hexamethylenediamine and adipic acid, or the like is used.

As the curable resin, for example, melamine resin, urea resin,
Acrylic resin, styrene resin, etc. are mentioned.

As the silicone resin, a heat vulcanizing type silicone rubber, a room temperature curing type silicone rubber, a silicone resin or a modified silicone resin is used.

Condensation product of melamine and cyanuric acid as melamine resin,
A polycondensation product of memine and formaldehyde is used.

A polycondensate of methyl roll urea is used as the urea resin.

Acrylic resin: Copolymer of monofunctional monomer such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, phenyl methacrylate, methyl acrylate, ethyl acrylate and polyfunctional monomer such as divinylbenzene and trivinylbenzene Is used.

As the styrene resin, a copolymer of a monofunctional monomer such as styrene, methylstyrene and chlorostyrene and a polyfunctional monomer such as divinylbenzene and trivinylbenzene is used.

The resins used for the spherical resin fine powder have been exemplified above, but among these, melamine resin, polyamide, acrylic resin and styrene resin are preferable. Silicone resins are particularly preferred from the viewpoints of dispersion stability, mechanical strength, solvent resistance and the like.

The surface roughness of the adhesive layer targeted by the present invention is 0.5 to 4 μ.
m, particularly 0.7 to 2 μm is suitable. Further, it is important that the maximum height (maximum roughness) is 6 μm or less.

All-round surface shape measuring instrument (made by Kosaka Laboratory)
Model SE-3C) and is expressed by 10-point average roughness (JISB0601). In addition, the maximum height (JISB0601) is expressed as a value excluding abnormal values that are particularly rare.

In the present invention, the amount of the spherical resin fine powder added is 0.5 to 30% by weight, preferably 2 to 10% by weight, based on the total weight of the adhesive layer. If the amount added is less than 0.5% by weight, the durability and mechanical strength of the photoreceptor will be insufficient, and if it exceeds 30% by weight, image defects will occur.

The structure of the electrophotographic photosensitive member of the present invention is basically composed of a support, a conductive layer, an adhesive layer, and a photosensitive layer in this order from the lower layer. The photosensitive layer is composed of a charge generation layer (CGL) and a charge transport layer (CTL). )
In the so-called function-separated type photoreceptor, which is composed of CGL and CTL, the effect is most remarkable in the structure in which the layers are laminated in this order.
However, when the photosensitive layer is laminated in the order of CTL and CGL,
The present invention can be an effective technique even when the adhesion between the CTL and the adhesive layer is poor.

As the support used in the present invention, various materials such as metal, plastic, sheet such as paper, belt, and cylindrical may be considered, and the following conductive supports are generally used. is there.

For example, aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold, platinum, or the like can be used. In addition, aluminum, aluminum alloy indium monoxide, tin oxide, indium oxide can be used. , Plastics with a layer formed by vacuum deposition of tin oxide alloy, etc., a support with conductive particles coated on a plastic with a suitable binder, a support or conductive material impregnated with plastic or paper with conductive particles. It is possible to use a plastic or the like having a hydrophilic polymer.

Next, most of the layers after the conductive layer are coated with a liquid dissolved or dispersed in a solvent. When forming a layer by coating, use a coating method such as a dip coating method, a spray coating method, a spinner coating method, a peat coating method, a Meyer bar coating method, a blade coating method, a roller coating method, or a curtain coating method. It can be carried out.

The conductive layer has at least a binder and a conductive substance. The thickness of the conductive layer depends on the surface condition of the support (scratches, unevenness,
It should be set to the optimum value depending on the dent, etc.), and 0.5 to 1
The width can be set as wide as 00 μm, but usually 10 to 50 μm
It is a degree.

As the conductive layer binder used in the present invention, polyarylate resin, polysulfone resin, polyamide resin,
Acrylic resin, acrylonitrile resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, phenol resin, epoxy resin, polyester resin, alkyd resin,
Examples thereof include polycarbonate, polyurethane, and copolymer resins containing two or more repeating units of these resins, such as styrene-butadiene copolymer, styrene-acrylonitrile copolymer, and styrene-maleic acid copolymer.

In particular, acrylic resin, methacrylic resin, phenol resin, styrene resin, polyurethane resin, epoxy resin,
Thermosetting resins and curable rubbers such as alkyd resins, polyester resins, silicone resins, melamine resins and copolymers thereof are suitable. As the conductive substance dispersed in the conductive layer, metal powder such as aluminum, tin and silver,
Carbon powder and titanium oxide, conductive pigments mainly composed of metal oxides such as barium sulfate, zinc oxide and tin oxide, polyacetylene, polyphenylene oxide, polypyrrole, polythioquen and substances doped with LiClO4 or the like, Metal phthalocyanine (M-PC), polymers containing M-PC in the main chain, and substances obtained by doping these with I ₂ , TCNQ (tetracyanoquinodimethane), -NH ₂ , -COO
Examples include substances (polymeric metal complexes) quaternary ammonium salts, quaternary chlorinated polymers, and various ionic substances in which a metal ion is coordinated to a polymer having H and —OH.
Further, a light absorber may be contained in this conductive layer.

Further, the conductive layer may contain a surface energy lowering agent such as silicone oil or various surfactants,
As a result, it is possible to obtain a uniform coating surface with a small coating defect. As a method of dispersing the conductive powder in the resin,
A conventional method such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill or a colloid mill can be used.

The adhesive layer is a resin layer capable of blocking the injection of carriers (charges) from the support or the conductive layer to the photosensitive layer, and is required to have an electric resistance of 1/50 or less as compared with the photosensitive layer. In general, many have high electric resistance, and therefore the film thickness is appropriately 5 μm or less, preferably 0.1 μm to 3 μm.

Examples of the material used as the binder of the adhesive layer include casein, gelatin, polyamide, (nylon 6, nylon 66, nylon 610, copolymer nylon, alkoxymethylated nylon) polyurethane, polyvinyl alcohol, nitrocellulose resin, ethylene-acrylic acid copolymer. Polymer resins, phenol resins, acrylic resins, polyesters and polyethers.

The charge generation layer is formed by applying and drying a coating liquid in which a charge generation substance as described below is dispersed in a suitable binder resin.

The charge generating substance used in the present invention is a pigment, but a dye soluble in a solvent can also be used by selecting a solvent and forming particles.

As the charge generating substance, a phthalocyanine pigment, anthanthrone pigment, dibenzpyrene pigment, pyrantrone pigment, azo pigment, indigo pigment, quinacridone pigment,
Examples thereof include cyanine dyes, squavarylium dyes, azurenium salt compounds, pyrylium, thiopyrylium dyes, xanthene dyes, quinoneimine dyes, triphenylmethane dyes, and styryl dyes.

The charge transport layer is chloranil, bromoanil, tetracyanoethylene, tetracyanoquinomedimethane, 2,4,7-
Trinitro-9-fluoreno, 2,4,5,7-tetranitro-9-fluorene, 2,4,7-trinitro-9-dicyanomethylenefluorenone, 2,4,5,7-tetranitroxanthone, 2,4, Electron withdrawing substances such as 8-trinitrothioxanthone and those obtained by molecularizing these electron withdrawing substances, pyrene, N-ethylcarbazole, N-isopropylcarbazole, N-methyl-N-phenylhydrazino-3-methylidene -9-ethylcarbazole, N, N-diphenylhydrazino-3-methylidene-9-ethylcarbazole, N, N-diphenylhydrazino-3-methylidene-10-ethylphenothiazine, N, N-diph Enylhydrazino-3-methylidene-10-ethylphenoxazine,
p-diethylaminobenzaldehyde-N, N-diphenylhydrazone, p-diethylaminobenzaldehyde-
N-α-naphthyl-N-phenylhydrazone, p-pyrrolidinobenzaldehyde-N, N-diphenylhydrazone, 1,3,3-trimethylindolenine-ω-aldehyde-N, N-diphenylhydrazone, p- Hydrazones such as diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone, 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1-phenyl-3- (p -Diethylaminostyryl) -5- (p-
Diethylaminophenyl) pyrazolin, 1- [quinolyl (2)] 3- (p-diethylaminostyryl) -5-
(P-Diethylaminophenyl) pyrazoline, 1- [pyridyl (2)]-3- (p-diethylaminostyryl)
-5- (p-diethylaminophenyl) pyrazoline, 1
-[6 (methoxy-pyridyl (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1- [pyridyl (3)]-3- (p
-Diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1- [lepidil (2)]-3
-(P-Diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1- [pyridyl (2)]-3- (p-diethylaminostyryl) -4-
Methyl-5- (p-diethylaminophenyl) pyrazoline, 1- [pyridyl (2)]-3- (α-methyl-p-
Diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1-phenyl-3- (p-diethylaminostyryl) -4-methyl-5- (p-diethylaminophenyl) pyrazoline, 1-phenyl-3- (α
-Benzyl-p-diethylaminostyryl) -5- (p
-Diethylaminophenyl) pyrazoline, pyrazolines such as spiropyrazolin, 2- (p-diethylaminostyryl) -6-diethylaminobenzoxazole, 2
Oxazole compounds such as-(p-dimethylaminophenyl) -4- (p-dimethylaminophenyl) -5- (2-chlorophenyl) oxazole, 2- (p-diethylaminostyryl) -6-diethylaminobenzothiazole, etc. Compounds, triarylmethane compounds such as bis (4-diethylamino-2-methylphenyl) -phenylmethane, 1,1-bis (4-N, N-diethylamino-2-methylphenyl) heptane, 1,1,2 Polyarylalkanes such as 2,2, -tetrakis (4-N, N-dimethylamino-2-methylphenyl) ethane, α-phenyl-4-N, N'diphenylaminostyrylbenes, N-ethyl-3 (α-phenylstyryl) Carbazole 4-N, N'-dibenzylamino-9-fluorenylidene and other styryl compounds, triphenylamine, Li -N- vinylcarbazole, polyvinyl pyrene, polyvinyl anthracene,
Formed by applying and drying a coating solution of a hole-transporting substance such as polyvinyl acridine, poly-9-vinylphenylanthracene, pyrene-formaldehyde resin, ethylcarbazole formaldehyde resin dissolved in a film-forming resin. To be done.

Further, these charge transport materials can be used in combination of two or more kinds.

As the binder, polyarylate resin, polysulfone resin, polyamide resin, acrylic resin, acrylonitrile resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, phenol resin, epoxy resin, polyester resin, alkyd resin, polycarbonate, polyurethane, or these A copolymer resin containing two or more of the resin repeating units, such as a styrene-butadiene copolymer, a styrene-acrylonitrile copolymer, a styrene-maleic acid copolymer, can be used.

The film thickness of the photosensitive layer is 5 to 50 μm, preferably 10 to 30 μm, but in the case of a function-separated type in which CGL and CTL are laminated in this order, CGL is used.
Is 0.01-5 μm, preferably 0.05-3 μm, and CTL is 5-5
0 μm, preferably 10 to 30 μm is suitable.

If necessary, add a protective layer containing an organic binder as a main component.
It may be provided in the uppermost layer with a film thickness of 5 to 10 μm.

Further, the uppermost layer may contain a lubricating substance, an ultraviolet absorber and an antioxidant.

The electrophotographic photoreceptor of the present invention can be applied to electrophotographic apparatuses in general such as a copying machine, an LBP (laser beam printer), an LED printer, an LCD printer (liquid crystal shutter printer), and a micro reader printer. Applied day spray, recording, light printing, plate making,
It can be widely applied to devices such as Facsimile.

Example-1 100 parts of conductive titanium oxide powder (manufactured by Titanium Industry Co., Ltd.) (parts by weight, the same applies hereinafter) Titanium oxide powder (Sakai Industry Co., Ltd.)
100 parts of phenol resin and 125 parts of phenol resin (trade name: Briofuen, manufactured by Toyo Ink Co., Ltd.) were mixed in a solvent of 50 parts of methanol and 50 parts of methyl cellosolve, and then dispersed by a ball mill for 6 hours. This dispersion is 60φ x 26
It was coated on a 0 mm aluminum cylinder by a dip coating method and heat-cured at 150 ° C. for 30 minutes to form a conductive layer having a film thickness of 20 μm.

Next, 20 parts of copolymerized nylon (trade name: Amilan CM-8000, manufactured by Toray Industries, Inc.) was dissolved in a mixed solution of 60 parts of methanol and 40 parts of butanol. In the liquid in which this copolymerized nylon was dissolved, the spherical degree was 0.7 and the average particle size was 2.0μ with respect to the copolymerized nylon.
15% by weight of spherical acrylic resin fine powder of m was mixed and dispersed for 2 hours with a propeller stirrer. This liquid was applied onto the conductive layer and dried with hot air at 50 ° C. for 20 minutes to form an adhesive layer having a thickness of 3 μm.

Next, type ε copper phthalocyanine (manufactured by Toyo Ink Co., Ltd.)
100 parts, butyral resin (manufactured by Sekisui Chemical Co., Ltd.) 50 parts and cyclohexane 1350 parts were dispersed for 20 hours in a sand mill using 1φ glass beads. To this dispersion was added 2700 parts of methyl ethyl ketone, and dip-coated on the adhesive layer.
After heating and drying at 10 ° C. for 10 minutes, a charge generation layer having a coating amount of 0.15 g / m ² was provided.

Then p-diethylaminobenzaldehyde-N-β
10 parts naphthyl-N-phenylhydrazone and styrene-methyl methacrylate copolymer (trade name MS200,
15 parts of Iron Manufacturing Chemical Co., Ltd. was dissolved in 80 parts of toluene. This solution was applied on the charge generation layer and dried with hot air at 100 ° C. for 1 hour to form a charge transport layer having a thickness of 16 μm.

Laser printer experiment with photoconductor No. 1 manufactured in this way having a gallium-aluminum-arsenic semiconductor laser (oscillation wavelength 780 nm output 5 mW), corona charger (negative charging) developing device, transfer charger and cleaner I put it on the machine and displayed the image. As a result, the image density of the solid image portion was uniform and the line image was sharp.

The dark potential and the exposure potential of this photosensitive member were measured at the initial stage and after the endurance of 50,000 images, and the stability of the potential is shown in Table 1.

The exposure dose is 9 μJ / cm ² .

Further, the surface roughness of the adhesive layer and the uniformity of the coating film surface were observed and shown in Table 1.

Comparative Example-1 A conductive layer, an adhesive layer, a charge generation layer, and a charge transport layer were applied in the same manner as in Example 1 except that the spherical acrylic resin fine powder was removed from the adhesive layer in Example 1, and an electrophotographic photoreceptor was prepared. No. 2 was manufactured.

When this photoconductor No. 2 was placed in the same laser printer experimental machine as described above and an image was produced, there was no problem with the line image, but uneven density occurred due to interference in the solid image portion.

Comparative Example-2 In the adhesive layer of Example 1, 10% by weight of zinc oxide powder (average particle size 2 μm) was mixed in the resin used in Example 1 instead of the spherical acrylic resin fine powder, and after coating, 20 at 5 ° C
After hot-air drying for 5 minutes, a 5 μm thick adhesive layer was provided on the same conductive layer as in Example 1. Further, a charge generation layer and a charge transport layer were provided on this adhesive layer in the same manner as in Example 1 to manufacture electrophotographic photosensitive member No. 3.

Image formation was performed on this photoconductor No. 3 in the same manner as in Example 1. As a result, no density unevenness due to interference is observed in the solid image portion, but continuous photofinishing durability of 500 sheets is continuously obtained by this photoconductor. When I went there, a black hole appeared due to a pinhole.

The evaluation of the photosensitive member was performed in the same manner as in Example 1 and shown in Table 1.

Comparative Example-3 In the adhesive layer of Example 1, instead of the spherical acrylic resin fine powder, a silicone resin fine powder having a sphericity of 0.3 (average particle size)
Electrophotographic photosensitive member No. 4 was manufactured in the same manner as in Example 1 except that 0.8 μm) was used.

Evaluation of the photoconductor was performed in the same manner as in Example 1 and shown in Table 1.

Example-2 Copolymerized nylon (trade name: Amilan CM-8000, Toray Industries, Inc.)
20 parts) were dissolved in a mixed solution of 60 parts of methanol and 40 parts of butanol. 10% by weight of spherical acrylic resin fine powder having an average particle size of 2.0 μm was mixed in the solution in which the copolymerized nylon was dissolved, and dispersed with a propeller stirrer for 2 hours. This solution was applied onto an aluminum cylinder of 60φ × 260 mm and dried in hot air at 50 ° C. for 20 minutes to form a 2 μm thick adhesive layer.

Next, type ε copper phthalocyanine (manufactured by Toyo Ink Co., Ltd.)
100 parts, butyral resin (manufactured by Sekisui Chemical Co., Ltd.) 50 parts and cyclohexane 1350 parts were dispersed for 20 hours by a sand mill using 1φ glass beads. To this dispersion was added 2700 parts of methyl ethyl ketone, and dip-coated on the adhesive layer.
After heating and drying at 100 ° C. for 100 minutes, a charge generation layer having a coating amount of 0.15 g / m ² was provided.

Then, 10 parts of a hydrazone compound having the following structural formula And polycarbonate resin (Product name: Panlite L-12
50: Teijin Kasei Co., Ltd. 15 parts was dissolved in 80 parts dichloromethane. This solution is applied on the charge generation layer and the temperature is 100 ° C.
Hot air drying was performed for a period of time to form a 20 μm thick charge transport layer.

The photoconductor No. 5 manufactured in this manner was placed in a laser printer experimental machine and evaluated in the same manner as in Example 1.
Shown in the table.

Example-3 An electrophotographic photosensitive member No. 6 was produced in the same manner as in Example-2 except that spherical melamine resin fine powder was used in place of the spherical acrylic resin fine powder in the adhesive layer of Example-2. Further, this photosensitive member was evaluated in the same manner as in Example 1 and shown in Table 2.

Example-4 An electrophotographic photosensitive member No. 7 was produced in the same manner as in Example-2 except that spherical styrene resin fine powder was used in place of the spherical acrylic resin fine powder in the adhesive layer of Example-2. Further, this photosensitive member was evaluated in the same manner as in Example 1 and shown in Table 2.

Comparative Example-4 An electrophotographic photosensitive member No. 8 was produced in the same manner as in Example-2 except that zinc oxide particles (non-spherical) were used in place of the spherical acrylic resin fine powder in the adhesive layer of Example-2. . Further, this photosensitive member was evaluated in the same manner as in Example 1 and shown in Table 2.

[Advantages of the Invention] According to the present invention, it is possible to obtain an electrophotographic photosensitive member that does not cause image defects even when repeatedly used repeatedly, maintains high image quality, and has good adhesion and adhesive strength. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and FIG. 2 are schematic views of an electrophotographic photosensitive member of the present invention. 1 ... Support 2 ... Conductive layer 3 ... Adhesive layer 4 ... Photosensitive layer 5 ... Spherical resin fine powder 6 ... Charge generation layer 7 ... Charge transport layer

Claims (7)

(57) [Claims] 1. An electrophotographic photoreceptor having an adhesive layer between a support and a photosensitive layer, the adhesive layer being substantially casein, gelatin, polyamide, polyurethane, polyvinyl alcohol, nitrocellulose resin, ethylene-acrylic acid. At least one binder selected from the group consisting of copolymer resin, phenol resin, acrylic resin, polyester and polyether, and spherical resin fine powder excluding silicone resin fine powder, and the spherical degree of the spherical resin powder is 0.5. An electrophotographic photosensitive member characterized by the above. 2. The spherical resin fine powder has an average particle diameter of 0.6 to 2 μm.
The electrophotographic photosensitive member according to claim 1, wherein 3. The electrophotographic photosensitive member according to claim 1, wherein the spherical resin fine powder has a sphericity of 0.8 or more. 4. A spherical resin fine powder is acrylic resin, styrene resin, polycarbonate, polyester, polyamide,
The electrophotographic photoreceptor according to claim 1, which is selected from a melamine resin and a urea resin. 5. The electrophotographic photoreceptor according to claim 4, wherein the spherical resin fine powder is selected from melamine resin, polyamide, acrylic resin and styrene resin. 6. The electrophotographic photoreceptor according to claim 1, which has a laminated structure of an adhesive layer and a photosensitive layer on a support. 7. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer.