JPS6356975B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a cylinder for an electrophotographic photoreceptor, which is characterized in that it is made into a tubular product by rolling up cellulose fiber paper impregnated with a thermosetting synthetic resin and then forming it under heat and pressure. The present invention relates to a method for manufacturing a shaped substrate.

The present invention relates to a copying method using a conventionally known electrophotographic process. For example, using a photoreceptor in which an insulating layer, a photoconductive insulating layer, and a conductive layer are sequentially formed on a cylindrical substrate from the outermost layer, first, the surface of the insulating layer is uniformly coated in a positive or negative direction with an electrode or corona discharge. The surface of the insulating layer to be charged is then irradiated with an original image to be copied, and at the same time an alternating current corona discharge is applied to the surface of the insulating layer to generate an electrostatic image due to the difference in surface potential that occurs according to the light and dark pattern of the original image. After forming the electrostatic image on the surface and visualizing the electrostatic image using a developer mainly composed of charged colored particles, the visible image is transferred to a transfer material such as paper using an internal or external electric field. An electrophotographic copy image is obtained by thermally fixing the image.

If the electrophotographic photoreceptor mentioned above is repeatedly used, its surface is likely to be damaged and deteriorated, and the quality of the copied images deteriorates due to fatigue of the photoconductive insulating layer over time. It is generally said that there are limits.

Therefore, in order to obtain high-quality copied images at all times, it is necessary to replace and update the electrophotographic photoreceptor at regular intervals, such as when 50,000 copies have been completed.

Conventionally, a metal cylinder made of aluminum or the like has been generally used as the cylindrical substrate of an electrophotographic photoreceptor, and although this has the advantage that the substrate itself can be used as a conductor (the above-mentioned conductive layer), On the other hand, it is relatively expensive and, as mentioned above, has the disadvantage that it cannot be easily incinerated or otherwise disposed of after updating at regular intervals in order to obtain high quality copies.

Therefore, the inventors of the present invention sought to obtain a cylindrical substrate that was inexpensive, had a surface smoothness and roundness comparable to that of a metal cylinder, and could be easily disposed of by incineration, and as a result of various studies, the present invention was developed. It has arrived.

That is, the present invention involves rolling up cellulose fiber paper impregnated with a thermosetting synthetic resin to a desired thickness, and molding this by heating and pressing from the circumferential direction to form a tubular article having a desired outer diameter. A method of manufacturing a cylindrical substrate for an electrophotographic photoreceptor is provided.

Recently, examples of cutting cellulose fiber paper impregnated with thermosetting synthetic resin into appropriate dimensions, stacking them, and forming them into a plate shape by applying pressure under heating are often seen in wall materials, flooring materials, etc. By the way.

The substrate of the present invention is similar to the above, that is, cellulose fiber paper impregnated with a thermosetting synthetic resin is rolled up to the required thickness on a cylindrical core material that is configured to be splittable, and this is rolled up from the circumferential direction. A cylindrical molded product is obtained by uniformly heating and pressurizing, and then dividing and removing the cylindrical core material.

In this way, a cylinder can be obtained that has strength and surface smoothness comparable to cylinders made of metal such as aluminum conventionally used for the substrate of electrophotographic photoreceptors, and has a high degree of roundness. However, it cannot be denied that some unevenness occurs on the cylindrical surface at the end edge of the cellulose fiber paper after winding.
This is finished by polishing by an appropriate method after hot molding.

Examples of thermosetting synthetic resins include phenol resins, melamine resins, guanamine resins, aniline resins, and epoxy resins, and any of them may of course be used.

Next, fine carbon powder is dispersed in a vinyl chloride-vinyl acetate binder and applied onto the substrate to form a conductive layer. Since fine carbon powder is well dispersed in the vinyl chloride-vinyl acetate binder, a uniform conductive layer can be obtained.

Next, a photoconductive fine powder such as CdS or CdSe ZnO is dispersed in a thermoplastic or thermosetting resin, or
Alternatively, a photoconductive insulating layer is formed by dispersing it in a binder of a thermosetting synthetic resin (e.g., epoxy resin, polyester resin) that is solvent-free and liquid at room temperature, and coating it on the conductive layer to form a photoconductive insulating layer. Use as a photographic photoreceptor.

Alternatively, a synthetic resin such as polyethylene, polypropylene, polystyrene, or the like is selected and coated on the photoconductive insulating layer to obtain an electrophotographic photoreceptor having a light-transmitting organic insulating layer.

According to the method of manufacturing a cylindrical substrate for an electrophotographic photoreceptor of the present invention, effects completely equivalent to those of the conventional photoreceptor having a metal cylinder as a base can be obtained, and in addition, all materials are combustible. Because of this structure, the photoreceptor can be easily disposed of by incineration and is extremely advantageous in terms of cost.

Examples are shown below.

Example: Base paper for decorative laminates with a weight of 150 g and a density of 0.6 was impregnated with a phenolic resin liquid, air-dried and then dried at 100°C for 2 minutes to produce impregnated paper with a resin content of 150 g/m ² in terms of solid content. did.

The impregnated paper was conveyed on iron rolls heated to 120°C, softening the impregnated resin while rolling it to a diameter of 78 m.
Wrap it around a cylindrical core of 4 m/m under normal pressure.
Roll it up until it is as thick as . Next, this was put into a mold and heat treated at a temperature of 160°C and a pressure of 150 kg/m ² for 60 minutes to harden it. Thereafter, this was cooled and the mold and iron core were removed to obtain a tubular laminate (referred to as a laminate tube).

The surface of the obtained laminated tube has high hardness and is smooth, but the end of the winding of the impregnated paper that makes up the laminated tube has a step in a straight line, so this part was polished uniformly with a polishing machine. Wall thickness 2m/m, outer diameter 78m/
A laminated pipe with an inner diameter of 74 m/m was produced.

The laminated tube was cut into a length of 272 m/m to obtain a cylindrical substrate for an electrophotographic photoreceptor. When the physical properties of the cylindrical substrate were measured, the roundness was within 0.2 m/m, which was comparable to that of an aluminum drum commonly used as a cylindrical substrate for electrophotographic photoreceptors. Furthermore, the cylindrical substrate was lighter than an aluminum drum, resistant to physical impact, and had excellent chemical resistance.

Next, 10 parts by weight of carbon black and 8 parts by weight of vinyl chloride-maleic anhydride copolymer resin were placed in a ball mill and dispersed for 2 hours. A coating liquid was then applied to the surface and both end faces of the above-mentioned cylindrical substrate, and heated at 100°C for 30 minutes. It was dried for minutes to provide a 30μ thick conductive layer.

80 parts by weight of Cds and epoxy resin on the top surface of the conductive layer.
18 parts by weight of epoxy curing agent amine and 1.8 parts by weight of epoxy curing agent amine were mixed to form a 45μ thick photoconductive layer, and a 20μ thick polyester tube was further placed on top of the photoconductive layer.95
The material was heated at .degree. C. for 15 minutes and shrink-wrapped to produce an electrophotographic photoreceptor using this as an insulating layer.

The electrophotographic photoreceptor obtained in the above manner exhibited exactly the same performance as a conventional electrophotographic photoreceptor using a metal cylinder such as aluminum.

Claims (1)

[Claims] 1. Cellulose fiber paper impregnated with a thermosetting synthetic resin is rolled up to a desired thickness and then heated and pressed from the circumferential direction to form a tubular product having a desired outer diameter. A method for manufacturing a cylindrical substrate for an electrophotographic photoreceptor.