JPH06138685A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To prevent production of interference fringes without deteriorating picture images by specifying the surface roughness of both of conductive supporting body and surface protective layer. CONSTITUTION:A photosensitive layer containing an org. photoconductive material and a surface protective layer are formed on a conductive supporting body. The surface of the conductive supporting body has 0.01-0.5mum 10-point average surface roughness Rz (JIS B0601), and the surface protective layer has 0.2-1.2mum surface roughness Rz. By specifying surface roughness of the surface protective layer, the incident angle of the laser light on the surface of the protective layer varies, which suppresses interference between the reflected light from the surface of the photosensitive body and from the supporting body. By roughening the surface of the conductive supporting body to have 0.01-0.5mum 10-point average roughness, adhesion property with a cleaning blade is decreased and peeling of the blade can be decreased. In this process, it is preferable that the surface protective layer contains a charge transfer material and that the surface protective layer contains fluorine-contg. org. resin fine particles to decrease frictional resistance of the charge transfer material and the surface.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor,
More specifically, it relates to an electrophotographic photoreceptor having high image uniformity, high reproducibility and high durability.

[0002]

2. Description of the Related Art In recent years, organic photoconductors having a photosensitive layer made of an organic photoconductor have been widely used as electrophotographic photoconductors. Conventionally, there have been problems with respect to sensitivity, durability, ozone resistance, NOx resistance and the like. However, in recent years, charge generation materials,
The above drawbacks have been overcome by improving and optimizing the charge transport material and the binder resin.

Further, a laser has recently been used as a light source of a copying machine equipped with an organic photoconductor. Since the laser is a coherent light, the light reflected by the surface of the photosensitive layer and the light reflected by the support surface interfere with each other unless the light is completely absorbed in the photosensitive layer, and in particular, there is a problem called moire or interference fringes on a halftone image. Occurs.

Therefore, it is possible to suppress the interference with the reflected light on the surface of the photosensitive member by absorbing or scattering the reflected light of the support.

[0005]

As a method of absorbing the reflected light of the above support, a blackening method can be considered, but it has conductivity and is excellent in environment resistance, electric resistance characteristics and the like. No substance found.

Next, as a method of scattering the reflected light, it is considered that the surface is disordered or grooves are regularly formed. However, in the former case, the surface-roughening substance is embedded in the surface of the photoconductor, and even if it is washed, it will not easily fall and become an image defect, resulting in an image. In the latter case, it is difficult to obtain the effect unless the groove is deep. Therefore, there are problems such as deterioration of coverage of the photosensitive layer and appearance of grooves in the image.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electrophotographic photosensitive member capable of preventing the generation of interference fringes without degrading an image.

[0008]

The electrophotographic photoreceptor of the present invention comprises at least a photosensitive layer containing an organic photoconductor and a surface protective layer on a conductive support, and the surface of the conductive support is roughened. The surface roughness Rz is 0.01 μm or more and 0.5 μm or less, and the surface roughness Rz of the surface protective layer is 0.2 μm or more and 1.2 μm or less.

The surface of the surface protective layer has an average roughness Rz of 10 points.
(JIS B 0601) 0.2 μm or more 1.2 μm
By the following, the incident angle on the surface of the protective layer of the laser is different, and as a result, interference between the reflected light of the laser on the surface of the photoreceptor and the reflected light of the surface of the support is suppressed. When roughening only the support as in the past, it is necessary to scatter the reflection of the support, so it is more effective to roughen the surface, but the spot size of the laser also spreads and the image quality deteriorates. To do. In the present invention, the direction of the reflected light on the surface of the surface protective layer also changes, and the optical path of the laser light is changed twice when it is incident and when it is reflected by the support, so the surface roughness is small. But the effect is great. In the present invention, the 10-point average roughness Rz of the conductive support is 0.01 μm.
m or more and 0.5 μm or less. By roughening the surface as described above, as another effect, the adhesiveness with the cleaning blade is reduced and the blade turning is reduced. It is possible to make the roughness of the protective layer further rough, but the scattering of the laser light becomes large, and as a result, the spot expands and the image quality falls. In addition, cleaning failure occurs, which is not preferable.

The surface roughening of the conductive support and the surface protective layer can be carried out by a known means such as polishing tape, buffing, sandblasting and the like.

The photosensitive layer of the electrophotographic photosensitive member of the present invention contains at least a charge generating material and a charge transporting material. Examples of the charge generating material include phthalocyanine pigments, polycyclic quinone pigments,
Trisazo pigment, disazo pigment, azo pigment, perylene pigment, indigo pigment, quinacridone pigment, azurenium salt dye, squalium dye, cyanine dye, pyrylium dye, thiopyrylium dye, xanthene dye, quinoneimine dye, triphenylmethane dye, styryl dye, etc. To be

Examples of charge transport materials include pyrene compounds,
N-alkylcarbazole compound, hydrazone compound,
N, N-dialkylaniline compounds, diphenylamine compounds, triphenylamine compounds, triphenylmethane compounds, pyrazoline compounds, styryl compounds, stilbene compounds, polynitro compounds, polycyano compounds, and pendant polymers in which these compounds are fixed on a polymer, etc. Is mentioned.

In many cases, the above-mentioned charge generating material, charge transporting material and the like are dispersed and contained in a binder resin binder having film forming properties to form a photosensitive layer and the like. As such a binder resin binder, polyester, polyurethane, polyarylate, polyethylene, polystyrene,
Polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, phenol resin, acrylic resin, silicone resin, epoxy resin, urea resin, allyl resin, alkyd resin, polyamide-imide, nylon, polysulfone, polyallyl ether, polyacetal, butyral resin and the like. To be

Next, the layer structure of the electrophotographic photosensitive member of the present invention will be described. Conductive substrates are iron, copper, gold, silver, aluminum,
Metals and alloys such as zinc, titanium, lead, nickel, tin, antimony and indium, or oxides of the above metals,
Carbon, a conductive polymer, etc. can be used. There are a drum shape such as a cylindrical shape and a cylindrical shape, and a belt shape and a sheet shape. The conductive material may be molded and processed as it is, used as a paint, vapor-deposited, or processed by etching or plasma treatment. In the case of paint, not only the above-mentioned metals and alloys but also paper, plastic, etc. are used as the substrate.

The photosensitive layer in the photoreceptor of the present invention may have a single layer structure or a laminated structure.

The thickness of the photosensitive layer is preferably 10 to 50 μm.

In the case of a laminated structure, it is composed of at least a charge generation layer and a charge transport layer, but the charge polarity is used depending on whether the charge generation layer is provided on the conductive substrate side or the charge transport layer is provided. Toner polarity is different. The film thickness of the charge generation layer can be 0.001 μm to 6 μm, and more preferably 0/01 μm to 2 μm. The content ratio of the charge generating material contained in the charge generating layer is 10 to 10
It can be 0% by weight, more preferably 5
It is 0 to 100% by weight. The thickness of the charge transport layer is the thickness of the photosensitive layer minus the thickness of the charge generation layer. The content of the charge transport material contained in the charge transport layer is 20 to 80% by weight, more preferably 30.
Is about 70% by weight.

An undercoat layer may be provided between the conductive substrate and the photosensitive layer. The undercoat layer functions as a charge injection control at the interface and as an adhesive layer. The undercoat layer is mainly composed of a binder resin, but may contain the above-mentioned metal or alloy, or an oxide, salt or surfactant thereof. Specific examples of the binder resin forming the undercoat layer include polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide,
Polypropylene, polyimide, phenol resin, acrylic resin, silicone resin, epoxy resin, area resin,
Examples thereof include allyl resin, alkyd resin, polyamide-imide, nylon, polysulfone, polyallyl ether, polyacetal, butyral resin and the like. The thickness of the undercoat layer is 0.05 μ to 7 μ, and more preferably 0.1 μ to 2 μ.

The protective layer is always provided on the photosensitive layer. The protective layer is mainly made of resin, and examples thereof include polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, phenol resin, acrylic resin, silicone resin, epoxy resin, area resin, and allyl. Resin, alkyd resin, polyamide-
Examples thereof include imide, nylon, polysulfone, polyallyl ether, polyacetal and butyral resin.

The thickness of the protective layer is preferably 0.05 to 15 μm, more preferably 1.5 to 10 μm.

Further, in order to maintain the charge transporting property, a charge transporting material may be added to the protective layer, and in order to reduce frictional resistance of the surface, fluorine atom-containing resin fine particles and the like may be added.

Examples of the charge transport material contained in the protective layer include pyrene compounds, N-alkylcarbazole compounds,
Hydrazone compounds, N, N-dialkylaniline compounds, diphenylamine compounds, triphenylamine compounds, triphenylmethane compounds, pyrazoline compounds, styryl compounds, stilbene compounds, polynitro compounds,
Examples thereof include polycyano compounds, and pendant polymers in which these compounds are fixed on a polymer.

Examples of the fluorine atom-containing resin fine particles contained in the surface protective layer include polytetrafluoroethylene,
Polychlorotrifluoroethylene, polyvinylidene fluoride, polydichlorofluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexalfluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, and tetrafluoro It is composed of one or more selected from the group consisting of ethylene-hexafluoropropylene-perfluoroalkylvinyl ether copolymer.

The fluorine atom-containing resin fine particles are contained in the surface protective layer in an amount of 5 to 70% by weight, preferably 5 to 50% by weight.

An example of an electrophotographic apparatus using the electrophotographic photosensitive member of the present invention will be described with reference to FIG.

The drum 7 is rotated in the direction of the arrow by a drive system (not shown), and the surface of the drum 7 is negatively charged by the charger 6. Next, the light of the semiconductor laser reaches the surface through an optical system such as the polygon mirror 9, the fθ lens, and the mirror 4, and an electrostatic latent image is formed. Next, the latent image is developed and visualized by the negatively charged powder called toner in the developing device 3 which is rotated by the developing rotator 1 and faces the drum 7.

On the other hand, on the transfer drum 23 that rotates in synchronization with the photosensitive drum 7, the transfer paper that has passed through the paper transport section from the cassette 17 is electrostatically adsorbed. Then, the developed toner image is transferred onto the transfer paper by the output of the transfer charger 25.

The untransferred toner remaining on the drum 7 is scraped off by the cleaning blade of the cleaner section 8. Then, the charges remaining on the surface of the drum are removed by the removing light.

The above is the one-color process. After the above process is performed four times, the transfer charge is removed by the paper static eliminator 22, and the transfer paper is separated from the transfer drum 23 by the separation charger 21. The toner on the transfer paper is fixed by the fixing device 14 after passing through the transport unit 10.

[0030]

Example: A methoxymethylated nylon resin (number average molecular weight 32000) was placed on a φ80 × 360 aluminum cylinder.
30 parts by weight and 10 parts by weight of alcohol-soluble copolymer nylon resin (number average molecular weight 29000) are methanol 26
A liquid dissolved in a mixed solvent of 0 part by weight and 40 parts by weight of butanol was applied by a dipping coating machine to form an undercoat layer having a film thickness after drying of 1 μm.

Next, the disazo pigment represented by the following structural formula [1]

[0032]

[Outer 1] 4 parts by weight, 2 parts by weight of benzal resin, and 40 parts by weight of tetrahydrofuran were dispersed for 60 hours in a sand mill apparatus using φ1 mm glass beads, and then diluted with a cyclohexanone / tetrahydrofuran mixed solvent to obtain a charge generation layer coating material. It was This coating solution is applied on the above-mentioned undercoat layer by a dipping coating machine, and the film thickness after drying is 0.1 μm.
Of the charge generation layer.

Next, the following structural formula [2]

[0034]

[Outside 2] 10 parts by weight of the charge transport material and 10 parts by weight of a polycarbonate resin (number average molecular weight 25000) are dissolved in a mixed solvent of 20 parts by weight of dichloromethane and 40 parts by weight of monochlorobenzene, and this solution is dip-coated on the charge generation layer. And dried at 120 ° C for 60 minutes to obtain a film thickness of 20 μm
Was formed on the charge transport layer.

Next, 2 parts by weight of polytetrafluoroethylene fine particles (Lubron L-5, manufactured by Daikin Industries, Ltd.),
4 parts by weight of a polycarbonate resin (bisphenol Z type, number average molecular weight of 40,000), 4 parts by weight of the charge transport material of structural formula [2], 250 parts by weight of monochlorobenzene, and 250 parts by weight of dichloromethane are dispersed in a sand mill to form a protective layer coating. Obtained. Apply this paint by spray coating and
It was dried at 20 ° C. for 60 minutes to form a 30 μm protective layer.

The electrophotographic photoconductors having the above-mentioned constitutions, in which the surface roughness of the cylinder and the surface roughness of the surface protective layer are changed as shown in Table 1, are mounted on the electrophotographic apparatus shown in FIG. 1 to form an image. went. The results are shown in Table 1.

[0037]

[Table 1]

Comparative Example 1 Cylinder surface roughness Rz is 0.
Image formation was performed using a photoreceptor having a thickness of 05 μm and having no protective layer. As a result, interference fringes were generated in the image.

[Comparative Example 2] The cylinder surface roughness Rz is 0.
Image formation was performed using a photoreceptor having a thickness of 15 μm and having no protective layer. As a result, interference fringes were generated in the image.

[0040]

As described above, an excellent image without interference fringes can be formed by the electrophotographic photosensitive member according to the present invention.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of the schematic configuration of an electrophotographic apparatus having an electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

 1 Developing Device Rotating Body 3 Developing Device 4 Mirror 6 Primary Charging Device 7 Photosensitive Drum 8 Drum Cleaner Section 9 Polygon Scanner Motor 10 Conveying Section 14 Fixing Device 17 Cassette 18 Feeding Roller 21 Separation Charging Device 22 Paper Eliminating Device 23 Transfer Drum 25 Transfer charger

Front page continued (72) Inventor Shoji Amamiya 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Masaaki Yamagami 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor ▲ Yoshi ▼ Kimihiro Mura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (3)

[Claims] 1. An electrophotographic photoreceptor having at least a photosensitive layer containing an organic photoconductor and a surface protective layer on a conductive support, wherein the surface roughness Rz of the conductive support is 0.0.
An electrophotographic photosensitive member characterized by having a surface roughness Rz of 1 μm or more and 0.5 μm or less and a surface roughness Rz of the surface protective layer of 0.2 μm or more and 1.2 μm or less. 2. The electrophotographic photosensitive member according to claim 1, wherein the surface protective layer contains fluorine atom-containing resin fine particles. 3. The electrophotographic photosensitive member according to claim 1, wherein the surface protective layer contains a charge transport material.