JPS6356977B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a substrate constituting an electrophotographic photoreceptor that can be copied multiple times by electrostatic latent image transfer or toner image transfer. Provided is a method for manufacturing a cylindrical substrate for an electrophotographic photoreceptor that is used in a copying method (so-called TESI method or PPC method) in which a latent image or unfixed toner image is formed and then transferred to coated paper or plain paper. That is.

Conventionally, metal cylinders such as aluminum have been widely used as cylindrical substrates for electrophotographic photoreceptors that are used repeatedly. Since the metal substrate itself is a conductor, it has the advantage of being able to be used as a conductive layer of a photoreceptor, but it has the disadvantage that it is relatively expensive and it is not always easy to dispose of the photoreceptor after use. .

In view of the above-mentioned circumstances, the present inventors sought to obtain a cylindrical substrate that is inexpensive, has surface smoothness and roundness comparable to metal cylinders, and can be easily disposed of by incineration. As a result of various studies, it was found that the master base material for printing etc. proposed by the applicant in JP-A No. 53-29802 can be used as the material for the above-mentioned cylindrical base body, as it is capable of thermal fusion between constituent fibers. The inventors have found that the present invention is useful and have completed the present invention.

That is, the present invention involves rolling a sheet made from a mixture of raw materials mainly consisting of 90 to 0% by weight of wood pulp and 10 to 100% by weight of polyolefin synthetic pulp while or after rolling the sheet to a desired thickness. ,
This method of manufacturing a cylindrical substrate for an electrophotographic photoreceptor is characterized in that the material is heated and pressurized from the circumferential direction to thermally fuse the pulp fibers to form a tubular product having a desired outer diameter.

The polyolefin-based synthetic pulp referred to in the present invention refers to ethylene homopolymers such as high-pressure polyethylene and medium-low-pressure polyethylene resins, copolymers with other monomers that can be copolymerized with ethylene, polypropylene that is a propylene homopolymer, and It contains a copolymer of propylene and other copolymerizable monomers. Among these, the medium and low pressure ethylene homopolymer provided the best characteristics.

In addition, most wood pulps can be used for mixing with synthetic pulp, regardless of the raw material tree species or cooking conditions, but among them, NUKP, which is advantageous in strength properties, can be used.
Alternatively, it is preferable to use NBKP as the main component.

The above-mentioned polyolefin synthetic pulp and wood pulp are mixed, and paper is made using commonly known papermaking raw material preparation equipment and a paper machine, aiming at a basis weight of 60 to 150 g/m ² . obtain a sheet that is . This sheet is rolled or layered to the desired thickness on a cylindrical core material that is configured to be splittable, and then heated from the circumferential direction at a temperature near the melting point of polyolefin synthetic pulp (approximately 110 to 170°C). Heat and pressurize to partially melt the synthetic pulp in the sheet and fuse the synthetic pulp to the wood pulp, or
Alternatively, after fusing the synthetic pulps together, the cylindrical core material is divided and removed to obtain a cylindrical molded product that serves as the base of the present invention.

In this way, a cylinder is obtained which 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, since it is undeniable that some unevenness occurs on the cylindrical surface at the end of the winding of the sheet, this is finished by polishing by an appropriate method after hot molding.

Since the present invention uses the thermal meltability of synthetic pulp as a means for smoothing the surface of a substrate, the main part of the present invention is to obtain a sheet as a material by mixing synthetic pulp. As a result of experiments, it was confirmed that a substrate having a sufficiently smooth surface could be obtained if the mixing ratio of synthetic pulp was 10% by weight or more.

In addition, in order to fully exhibit the electrophotographic performance of the photosensitive layer, which is mainly a photoconductive layer, provided on the substrate obtained by the manufacturing method of the present invention, various conductive materials may be added internally to the material sheet. Alternatively, it is preferable to impregnate the material so that its volume resistivity is 10 ⁹ Ω·cm or less.

In this case, the conductive agent may be an inorganic conductive substance such as sodium chloride, sodium aluminate, sodium phosphate, barium iodide, carbon black, metal powder, etc. alone or a mixture of two or more thereof, or vinylbenzyltrimethylammonium salt. Examples include organic conductive substances such as polymers of 1, polystyrene sulfonate, and the like. These conductive substances may be added internally to papermaking raw materials in advance, or impregnated after papermaking.

The photoconductive layer provided on the substrate obtained by the present invention includes inorganic light such as zinc oxide, titanium dioxide, indium oxide, tungsten trioxide, zinc sulfide, cadmium sulfide, cadmium selenide, arsenic trisulfide, and antimony trisulfide. Known materials can be used, such as a photosensitive layer containing a conductive material or an organic photoconductive material such as polyvinylcarbazole or anthracene as a main component, and a laminated photoreceptor comprising a charge generation layer and a charge transport layer. Further, the present invention can also be applied to a photoreceptor having an insulating layer provided on its surface.

According to the method for manufacturing a cylindrical substrate of the present invention, an electrophotographic photoreceptor formed thereby can obtain exactly the same effect as a photoreceptor having a conventional metallic cylinder as a base, and furthermore, Since it is made entirely of combustible materials, it can be easily incinerated and is extremely advantageous in terms of cost.

Examples are shown below.

Example (1) Polyethylene synthetic pulp (SWP, manufactured by Mitsui Zerapack Co., Ltd.) 50 parts by weight NUKP (unbleached kraft pulp, manufactured by Tomoekawa Paper Mills)
50 parts by weight Urea resin (Euramin P-1510, manufactured by Mitsui Toatsu Co., Ltd.) (solid content) 2 parts by weight Sizing agent (Size Pine, manufactured by Arakawa Forestry Co., Ltd.) (solid content) 2 parts by weight Sulfuric acid band 4 parts by weight Carbon black ( Mitsubishi Carbon No. 40, manufactured by Mitsubishi Kasei Corporation) 6 parts by weight
The sheet was formed to have a specific resistance of 127.3 g/m ² and a volume resistivity of 2×10 ³ Ω·cm. Next, this sheet was wound around a cylindrical iron core having a diameter of 38 mm, and the sheets were rolled up to a thickness of 4 mm under normal pressure.

This was then placed in a mold and heat treated at a temperature of 120 to 135°C and a pressure of 10 kg/cm ² for 30 minutes to fuse.

Thereafter, this was cooled, and the mold and iron core were removed to obtain a tubular laminate (hereinafter referred to as a laminate tube).

The surface of the obtained laminated tube is high in hardness and smooth, but since the end edge of the rolled sheet forming the laminated tube has a linear step, this part was polished uniformly using a polishing machine. Wall thickness: 2mm, outer diameter: 78
A laminated tube with an inner diameter of 74 mm was fabricated.

This laminated tube was cut into a length of 272 mm to obtain a cylindrical substrate for an electrophotographic photoreceptor. When this cylindrical substrate was measured, the circularity was within 0.2 mm, which was comparable to that of the currently commonly used aluminum cylindrical substrate. Furthermore, this cylindrical substrate was lighter than an aluminum cylindrical substrate, resistant to physical impact, and had excellent chemical resistance.

Next, 100 parts by weight of ZnO (#4000 manufactured by Sakai Chemical Co., Ltd.), 30 parts by weight of a 1% methanol solution of rose bengal, 65 parts by weight of acrylic resin (LR472 manufactured by Mitsubishi Rayon Co., Ltd.), and 80 parts by weight of toluene were then placed on the upper surface of this cylindrical substrate. was placed in a ball mill for 1 hour, and a coating solution was applied and dried to prepare an electrophotographic photosensitive layer with a thickness of 20 μm.

The electrophotographic photoreceptor obtained in the above manner exhibited exactly the same performance as a conventional electrophotographic photoreceptor having a cylindrical base made of metal such as aluminum.

Example (2) 80 parts by weight of cadmium sulfide, 18 parts by weight of epoxy resin, and 18 parts by weight of epoxy curing agent amine were mixed on the upper surface of the cylindrical substrate prepared as in Example (1) to form a photoconductive material with a thickness of 45 μm. layer, and then add thickness on top of that
Cover a 20 μm polyester tube and heat at 95℃.
The material was heated 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 having a cylindrical base made of metal such as aluminum.

Claims (1)

[Claims] 1 A sheet made by mixing raw materials mainly consisting of 90 to 0% by weight of wood pulp and 10 to 100% by weight of synthetic pulp with a polyolefin diameter is rolled up to the required thickness, or after being rolled up, it is rolled into a circle. 1. A method for manufacturing a cylindrical substrate for an electrophotographic photoreceptor, which comprises heating and pressurizing from the circumferential direction to thermally fuse pulp fibers to form a tubular body having a desired outer diameter.