JPS62280753A - Reforming method for high-purity selenium - Google Patents

Abstract

PURPOSE:To improve conductivity while maintaining the transparency of a protective layer consisting of a binder resin having a substantially insulating characteristic by dispersing conductive or semi-conductive powder having <=0.3mu average grain size into said protective layer. CONSTITUTION:The protective layer of an electrophotographic sensitive body formed by successively laminating a photoconductive layer and the protective layer on a conductive base is formed by dispersing the powder essentially consisting of the group IVa element and having <=0.3mu average grain size into the binder resin. Vapor deposited films of Se, Se-Te alloy Se-As alloy, etc., org. photoconductor layers of PVK/TNF, etc., amorphous Si photosensitive layer, layers formed by dispersing inorg. photoconductors such as ZnO and CdS into the binder, etc., are usable as the photoconductive layer. The layer formed by laminating an electric charge generating layer and charge transfer layer is also usable. The group IVa element is exemplified by Si, C, and Ge.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Industrial Application Field The present invention relates to an electrophotographic photoreceptor, specifically, an electrophotographic photoreceptor used in an electrophotographic method known as the Carlson process.
The present invention relates to an electrophotographic photoreceptor in which a photoconductive layer and a surface protective layer are sequentially provided on a conductive support.

BACKGROUND OF THE INVENTION Conventionally used electrophotographic photoreceptors are those formed by vapor-depositing 3e, 5e-Te alloy, 3e-AS alloy, etc. as a photoreceptor layer on a conductive substrate, or PVK (polyvinylcarbazole TNF). A typical example is one coated with an organic photoconductor such as 2,4,7-dolinitrofluorenone (2,4,7-dolinitrofluorenone).However, when these are used repeatedly, the transfer paper peels off (A is The photoreceptor is easily damaged during cleaning of residual toner, and the photoreceptor layer is easily worn out, so the photoreceptor must be replaced relatively early before its characteristics deteriorate.

In order to improve this point, it is known to provide a surface layer on the surface of the photoreceptor. (Japanese Unexamined Patent Publication No. 57-30846, No. 55-134860, K, YaIIIamo
to et al:Photographic Sci
, Eng, 26 [4] 179 (1982)) Problems to be Solved by the Invention One of the problems to be solved by the invention is an insulating layer made of a material with relatively high electrical insulation properties. This insulating layer has the advantage that it can be made thicker and that it has higher mechanical strength. However, in order to repeatedly use this type of electrophotographic photoreceptor, for example, first long-term charging → secondary charging with opposite polarity → image exposure, or simultaneous image exposure with primary charger secondary charging → uniform exposure, etc. In addition, these processes require two or more charging steps in the second copying process, which increases the complexity of the device and the resulting unreliability of characteristics. This may result in poor quality or high costs. The other type is a protective layer that does not require the above-mentioned special latent image forming process and can be used in the so-called Carlson process of charged image exposure.

This protection III needs to have low insulation properties to prevent charge from accumulating on the surface or inside the protective layer.

The method that has been adopted so far is to add quaternary ammonium salts etc. to the protective layer, but the conductivity of these materials generally fluctuates widely due to moisture absorption, and the conductivity of the protective layer decreases when dry. The conductivity decreases and charge accumulates, causing fogging of the image. Also, in high humidity, the conductivity increases more than necessary, causing lateral charge migration and blurring of the image. Furthermore, in order to be used in the Carlson process, conventional protective layers must be relatively thin, with a thickness of several microns or less, and are difficult to satisfy in terms of mechanical strength. Furthermore, the protective layer is colored by the substance added to lower the insulation, which has an undesirable effect on the spectral sensitivity of the photoreceptor.

The present invention was made in order to eliminate the above-mentioned conventional drawbacks, and its object is to provide an electrophotographic photoreceptor having a protective layer that can be used in the Carlson process.

Therefore, an object of the present invention is to provide an electrophotographic photoreceptor that does not accumulate charge during repeated use, is stable under changing environmental conditions, has a relatively thick film thickness, and has favorable optical properties. shall be.

The present invention provides protection at a film thickness during use by dispersing conductive or semiconductive powder with an average particle size of 0.3μ or less in a protective layer made of a substantially insulating binder resin. It is based on the discovery that the electrical conductivity of a layer can be improved while keeping it substantially transparent.

Means for Solving the Problems The electrophotographic photoreceptor of the present invention is formed by sequentially laminating a photoconductive layer and a protective layer on a conductive support, and the protective layer has an average particle size of 0. It is characterized in that it is made by dispersing in a binder resin a powder whose main component is a Group 1 Va element having a particle diameter of .3μ or less.

The photoconductive layer in the electrophotographic photoreceptor of the present invention includes:
Vapor deposited films such as 3e, 3e-Te alloy, 3e-AS alloy, 5e-sb gold alloy, 3e-Bi gold alloy, organic photoconductor layer such as PVK/TNF, amorphous Si photoreceptor layer, zno
A material in which an inorganic photoconductor such as CdS or CdS is dispersed in a binder can be used, and a material in which a charge generation layer and a charge transport layer are laminated can also be used. In the present invention, the photoconductive layer can be used even if it has a weak mechanical strength and cannot be used in ordinary electrophotography.

The Group 1 Va elements used in the present invention include Si, C1, and Ge, and these are used alone or as a mixture or compound.

In the present invention, the powder containing the Group IVa element as a main component may contain a Group IIIa or Group Va element as an impurity. Examples of such impurities include boron, nitrogen, phosphorus, and aluminum.

The powder containing the Group 1Va element as a main component may contain the above elements in any proportion as long as the electrical resistance is 10 11 Ω·cm or less and the average particle size is 0.3 μm or less. When the average particle size is larger than 0.3μ, it becomes difficult to improve conductivity while maintaining transparency.

The powder containing the Group 1Va element as a main component can be produced by various methods. Typical production methods include hydrocarbon gases such as methane and ethylene, S i H4, S
! Examples include a glow discharge decomposition method using a silane gas such as 2H6 or a germane gas such as GeH4. By flowing a small amount of gas such as PH3, 82H6 together with these gases, it is possible to add P, B, etc. as impurities into the powder particles. By adding such impurities, the electrical resistance of the powder particles can be maintained at 10 11 Ω·cm or less. Furthermore, even without adding impurities, it is possible to obtain electrical conductivity higher than the above value by appropriately maintaining discharge conditions.

Furthermore, it is also possible to use commercially available powders containing Group 1 Va elements as their main components.

As the resin that can be used for the protective layer in the present invention,
It is desirable that the material be substantially transparent to visible light and have excellent electrical insulation, mechanical strength, and adhesive properties.

For example, polyester resin, polycarbonate resin, polyurethane resin, epoxy resin, acrylic resin, vinyl chloride-vinyl acetate copolymer, silicone resin, alkyd resin, polyvinyl chloride resin, cyclized butadiene rubber, fluororesin, etc. can be used. When solvent resistance of the protective layer is required, it is desirable to use a curable resin.

In the present invention, the binder resin provided in the protective layer and the first V a
Although the composition ratio of the powder to the powder whose main component is a group element varies depending on the combination of materials, the above powder is generally used in a range of 5 to 100 parts by weight per 100 parts by weight of the binder resin. Further, the thickness of the protective layer can be set in a range of 1 to 30 μm as necessary.

In the present invention, since photogeneration of charge carriers takes place in the photoconductive layer, the protective layer must be substantially transparent to the wavelength range of light to which the photoconductive layer is sensitive. Must not be.

Further, in the present invention, an intermediate layer may be provided between the protective layer and the photoconductive layer to improve adhesiveness, charge retention properties, etc., if necessary. In this case, the thickness of the intermediate layer is preferably 1 μm or less.

Function: In the electrophotographic photoreceptor of the present invention, the characteristics of the protective layer formed by dispersing the powder containing Group 1 Va elements as a main component are less affected by environmental changes, such as changes in temperature or humidity. Also, it has excellent durability.

In the electrophotographic photoreceptor of the present invention, the protective layer is the surface of a photoconductive layer in which a charge generation layer and a charge transport layer are laminated on a conductive substrate, which is known as a conventional laminated photoreceptor. The layers differ fundamentally in their functions and properties. That is, in the electrophotographic photoreceptor of the present invention, a charge pattern is formed between the interface between the protective layer and the photoconductive layer and the conductive substrate. In contrast, in conventional laminated electrophotographic photoreceptors, the charge pattern is formed between the surface of the charge generation layer and the conductive substrate. Further, in the present invention, charges are injected from the surface of the protective layer to the interface between the protective layer and the photoconductive layer, but in the case of a laminated type, the charges must remain on the surface of the charge transport layer. Furthermore, the protective layer in the present invention is thinner than the photoconductive layer so that a sufficient potential difference is generated between bright and dark areas, but the charge transport layer provided in the laminated type is thinner than the charge generation layer. Must be thick.

EXAMPLE Polyurethane resin (Rethane 4000, manufactured by Kansai Paint Co., Ltd. >100 parts by weight, 20 parts by weight of commercially available SiC powder with an average particle size of 0.28 μm, and 45 parts by weight of thinner were placed in a stainless steel ball mill, and dispersed and mixed for 160 hours. After dispersion was completed, 14.5 parts by weight of a curing agent was added to this, and the mixture was further stirred.
A spray liquid was obtained. This was spray coated to a thickness of 3μ on a 60μ thick Se vaporized film to obtain a photoreceptor having a protective layer on the surface. The protective layer formed was substantially transparent. (When the electrophotographic photoreceptor was placed in an electrophotographic copying machine (FX2300) and an image was formed,
I was able to obtain a good copy image. or. When 50,000 copies were made, no wear and tear deterioration was observed, indicating that the product had excellent durability.

Effects of the Invention The electrophotographic photoreceptor of the present invention has the following advantages over conventional ones. That is, (]) a latent image can be formed without using a special process, (2) there is almost no accumulation or increase in residual charge even if the electrophotographic photoreceptor is used repeatedly, and (3) there is no temperature fluctuation. (4) The thickness of the protective layer can be made relatively thick; (5) The protective layer does not substantially affect the photosensitivity of the photoconductive layer of the photosensitive layer. , and 6) have the effect of having a protective layer with high mechanical strength.

Claims (4)

[Claims] (1) In an electrophotographic photoreceptor formed by sequentially laminating a photoconductive layer and a protective layer on a conductive support, the protective layer contains a Group IVa element with an average particle size of 0.3 μ or less in a binder resin. An electrophotographic photoreceptor characterized in that it is made by dispersing a powder containing as a main component. (2) The electrophotographic photoreceptor according to claim 1, wherein the powder whose main component is a Group IVa element is composed of silicon and carbon. (3) The powder whose main component is a Group IVa element contains a Group IIIa or Group Va element as an impurity.
The electrophotographic photoreceptor described in . (4) The electrophotographic photoreceptor according to claim 3, wherein the impurity is boron, nitrogen, phosphorus, or aluminum.