JPH1165148A - Production of electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoreceptor drum having excellent performance such as printing performance which can largely decrease the cost by forming a photosensitive layer on the inner face of a cylindrical die and polymerizing monomers of a resin material for a transparent base body by centrifugal injection forming to form a cylindrical base body. SOLUTION: A charge transfer layer 5, charge generating layer 4, base coating layer 3 and conductive layer 2 are successively formed on the inner face of a cylindrical die 6 to form a photosensitive layer. Then a monomer material of a resin for a transparent base body 1 are polymerized by centrifugal injection forming. A release agent such as a Teflon-contg. nickel-plating film is preferably applied on the inner face of the die 6. As the monomer material of the resin for the transparent base body 1, methyl methacrylate which is the monomer for a polymethyl methacrylate resin is preferably used considering its polymn. characteristics. A transparent conductive coating material is used for the conductive layer and the conductive layer 2 is preferably formed to have 2×10<2> to 2×10<6> Ω/unit sq. surface resistance so as to obtain functions as an electrophotographic photoreceptor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a photosensitive member for electrophotography, and more particularly, to a method for producing an image recording substrate of an internally illuminated electrophotographic device such as a copying machine or a laser printer, that is, a photosensitive drum. The present invention relates to a method for manufacturing a photoconductor for internally illuminated electrophotography.

[0002]

2. Description of the Related Art Conventionally, in a recording apparatus such as a copying machine or a laser printer, an aluminum substrate is often used for a photosensitive drum. In an exposure process, a method of exposing from a surface of a photosensitive layer provided on the substrate is generally used. It is.

In this method, charging, exposure, development, transfer,
Since it is necessary to arrange the fixing, static elimination, and cleaning process devices around the photosensitive drum, there is a limit to the miniaturization of the recording device, and the scattering of the developer from the developing unit causes the optical system of the exposure device to There are drawbacks such as soiling and adversely affecting printing.

In order to solve such a problem, a photosensitive drum coated on a transparent substrate in the order of a conductive layer and a photosensitive layer is used, and a light source of an exposure device is installed inside the photosensitive member, so that the photosensitive member is exposed to light. An internally illuminated type device has been devised which aims at downsizing by a method of irradiating light from the inside and preventing contamination of an optical system due to scattering of a developer.

In a photosensitive drum used in such an internally illuminated electrophotographic apparatus, indium tin oxide (hereinafter abbreviated as "ITO") is used to form a transparent conductive layer on an inorganic glass or the like as a transparent substrate. A method of forming a film by sputtering or vacuum evaporation is known. In addition, Japanese Patent Application Laid-Open
In 319195 gazette (applicant: Fujitsu Limited),
A photosensitive drum in which doped polyaniline is laminated on a cylindrical glass substrate is shown.

[0006]

The problems of the prior art are that the use of a cylindrical inorganic glass substrate is expensive, has poor dimensional accuracy and is liable to be broken, and that the formation of a transparent conductive layer by sputtering or vacuum deposition is difficult. Poor film thickness uniformity and productivity,
That the step of forming the doped polyaniline layer is costly.

[0007] That is, as a characteristic of the support substrate used in the internally illuminated electrophotographic apparatus, the material used is inexpensive;
It has excellent dimensional accuracy, mechanical strength can withstand use as a photosensitive drum, and it has chemical stability that does not impair the quality as a photosensitive drum even in uncontrolled general air, It has transparency to transmit irradiation light without refraction at the time of exposure, good adhesion to the transparent conductive layer laminated on the support substrate, and has high productivity. Solvent resistance required when forming the photosensitive layer by dip coating. And heat resistance.

However, in the prior art, laminating a photosensitive layer on a transparent cylindrical substrate so as to satisfy all of these requirements is inevitably expensive in terms of manufacturing technology. There was a problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing a photosensitive drum having excellent printing performance and the like, which is used in an internally illuminated electrophotographic apparatus, very economically.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, after forming a photosensitive layer on the inner surface of a cylindrical mold, a monomer of a resin material for a transparent substrate is formed. By polymerizing by a centrifugal casting method to form a cylindrical substrate, the obtained photosensitive drum was found to be excellent in performance such as printing performance, and it was possible to greatly reduce the cost, and completed the present invention. Reached.

That is, in the method of manufacturing an electrophotographic photoreceptor of the present invention, a photosensitive layer is formed on the inner surface of a cylindrical mold, and then a monomer material of a resin for a transparent substrate is polymerized by a centrifugal casting method. Wherein the obtained resin is integrated with the photosensitive layer.

The photosensitive layer includes a charge transport layer, a charge generation layer,
A layer can be formed on the inner surface of the cylindrical mold in the order of the undercoat layer and the conductive layer.

As the monomer material of the resin for the transparent substrate, it is preferable to use methyl methacrylate, which is a monomer of polymethyl methacrylate resin (PMMA), due to its polymerization characteristics.

Further, a transparent conductive paint is used as the conductive layer, and the conductive layer has a surface resistance of 2 × 10 ² to 2 × 10 ^6.
Ω / □ is preferred for obtaining the function as an electrophotographic photosensitive member.

In the present invention, a monomer such as PMMA used as a substrate material is polymerized by a centrifugal casting method to obtain a cylindrical substrate. Therefore, a photosensitive layer is sequentially coated and formed on the inner surface of a cylindrical mold. After forming a conductive layer thereon,
A monomer such as PMMA, which is a base material, is cast, a polymerization reaction is advanced while applying a centrifugal force by rotation, and the resin is cured. Then, a photosensitive drum integrated with a photosensitive layer can be obtained. Such an approach enables a significant cost reduction. In addition, since the organic photosensitive drum can be integrally manufactured, defects such as coating unevenness due to uneven drying speed and coating unevenness due to vibration, which have occurred in a drum manufacturing process using a conventional dip coating method, are eliminated. It is possible to manufacture high-quality products, and a large economical effect can be obtained from this aspect.

[0016]

FIG. 1 is a sectional view of a photosensitive drum.
The cross-sectional structure of a transparent conductive layer 2 formed on the outer surface of a photosensitive drum substrate 1 made of a transparent synthetic resin, and an undercoat layer 3, a charge generation layer 4, and a charge transport layer 5 respectively laminated thereon are shown.
FIG. 2 is a partially cutaway perspective view schematically illustrating a process of manufacturing the photosensitive drum using the mold 6.

In a preferred embodiment of the present invention, a photosensitive layer is obtained by forming a charge transport layer 5, a charge generation layer 4, an undercoat layer 3, and a conductive layer 2 in this order on the inner surface of a cylindrical mold 6. The monomer material of the resin for the transparent substrate is polymerized by a centrifugal casting method. On the inner surface of the mold 6, as a release agent,
For example, nickel plating containing Teflon may be applied. The formation of each layer of the photosensitive layer can be performed by applying a centrifugal force while rotating the mold with a roller, and drying the solvent while blowing air heated to a predetermined temperature. Further, in order to polymerize the monomer material of the resin for the transparent substrate by a centrifugal casting method, after sufficiently drying the photosensitive layer with hot air, a mixture of the monomer material and the polymerization catalyst is applied to a substrate having a thickness of about 1 to 1. The fixed amount is set to 5 mm, and the mold is
What is necessary is just to rotate while heating to 0-80 degreeC.

In the present invention, as the transparent support substrate 1 for the photosensitive drum used in the internally illuminated electrophotographic apparatus, a synthetic resin having transparency and suitable for the production method of the present invention, preferably P
MMA can be mentioned.

The transparent conductive layer 2 is preferably formed by using indium tin oxide (ITO) or a SnO ₂ -based transparent conductive coating solution, and the thickness of the conductive layer is generally Is 0.5 to 5 μm, preferably 1
３3 μm. When the thickness of the conductive layer is larger than 5 μm, the transparency is deteriorated. When the thickness is smaller than 0.5 μm, the surface resistance is 2 × 1.
0 ⁶ Ω / □ larger.

For the undercoat layer 3, an alcohol-soluble polyamide, a solvent-soluble aromatic polyamide, a thermosetting urethane resin, a melamine resin, or the like can be used. As the alcohol-soluble polyamide, nylon 6, nylon 8,
Copolymers such as nylon 12, nylon 66, nylon 610, and nylon 612, and N-alkyl-modified or N-alkoxyalkyl-modified nylon are preferred. These specific compounds include Alamine CM80
00 (manufactured by Toray Industries, Inc., 6/66/610/12 copolymerized nylon), Elbamide 9061 (manufactured by Dupont Japan Co., Ltd., 6/66/612 copolymerized nylon), Daiamide T-170 (Daicel-Hurz ( Co., Ltd., nylon 12-based copolymer nylon).

Further, TiO ₂ , alumina,
Inorganic fine powder such as calcium carbonate and silica can be added. The thickness of the undercoat layer 3 is 0.05 to 20 μm.
And it is preferably 0.05 to 10 μm.

The charge generation layer 4 receives light and generates charges. In addition, it is important that the charge generation efficiency is high, and at the same time, the injected property of the generated charge into the charge transporting layer 5 is important. As the charge generating substance, metal-free phthalocyanine, phthalocyanine compounds such as titanyl phthalocyanine, various azo, quinone, indigo, cyanine, squarylium, azulhenium, pigments or dyes such as pyrylium compounds, and selenium or selenium compounds are used. A suitable substance can be selected according to the light wavelength region of the exposure light source used for the formation. Since the charge generation layer only needs to have a charge generation function, its film thickness depends on the light absorption coefficient and the amount of the charge generation substance in the film, and is generally 5 μm or less, preferably 0.1 μm or less. 1 to 1 μm. The charge generation layer may be mainly composed of a charge generation substance, to which a charge transport substance or the like is added. As the resin binder, polycarbonate, polyester, polyamide, polyurethane, vinyl chloride resin, phenoxy resin, polyvinyl butyral, diallyl phthalate resin, methacrylic acid ester polymers and copolymers, and the like can be used in appropriate combination. .

The charge transport layer 5 is a coating film in which various hydrazone-based compounds, styryl-based compounds, amine-based compounds, and derivatives thereof are used alone or in combination as a charge-transporting substance in a resin binder. In some places, the insulator layer retains the charge of the photosensitive layer, and has the function of transporting the charge injected from the charge generation layer when receiving light. The thickness of the charge transport layer is preferably 10 to 40.
μm. Polycarbonate as a resin binder,
Polymers and copolymers of polyester, polystyrene and methacrylate can be used. In order to prevent deterioration of the charge transport layer due to ozone, which is a problem due to corona discharge, when the obtained photoreceptor is repeatedly used, an amine-based, phenol-based, sulfur-based, and zinc-based An antioxidant such as a phosphate ester or a phosphorous ester can be contained.

As described above, the photosensitive drum having the structure including the transparent synthetic resin substrate and the photosensitive layer containing the organic photoconductive substance is used during the processes of transferring the toner to the recording paper after the exposure and development, and removing the static electricity. Since the surface charges are released by grounding through the base, if the electric resistance of the base is high, formation of an electrostatic latent image and elimination of static electricity cannot be performed smoothly. for that reason,
The surface resistance of the transparent conductive layer laminated on the resin substrate is 2 ×
It is preferable to set the resistance to 10 ⁶ Ω / □ or less, but 2 × 10 ²
Making the surface resistance smaller than Ω / □ is not preferable because the transparency becomes low.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described. Example 1 A hydrazone-based compound (manufactured by Fuji Electric Co., Ltd.) 10 as a fixed amount of charge transport material was placed inside a cylindrical mold having both ends closed.
0 parts by weight and 100 parts by weight of a polycarbonate resin (Iupilon PCZ manufactured by Mitsubishi Engineering-Plastics Co., Ltd.) are mixed with 800 parts by weight of dichloromethane, and a coating solution obtained by mixing and dissolving is added.
(0 rpm), a centrifugal force was applied, and the solvent was dried while blowing air heated to 50 to 60 ° C. to form a charge transporting material to a thickness of about 20 μm on the mold wall surface. At this time, a Teflon-containing nickel plating (Nimflon manufactured by Uemura Kogyo Co., Ltd.) was coated on the inner surface of the mold as a release agent with a film thickness of about 10 μm.
m.

Next, an X-type inorganic metal phthalocyanine (FAS manufactured by Dainippon Ink and Chemicals, Inc.) was used as a charge generating material.
A coating solution obtained by mixing and dissolving 10 parts by weight of TGEN BLUE 8120) and 10 parts by weight of a vinyl chloride resin (MR-110 manufactured by Zeon Corporation) with 686 parts by weight of dichloromethane and 294 parts by weight of 1,2-dichloroethane. And a film was formed in a thickness of about 0.5 μm in the same manner.

Further, as an undercoat layer material, an alcohol-soluble polyamide resin (Amilan CM8 manufactured by Toray Industries, Inc.) was used.
000) was mixed with 5 parts by weight of methanol and 95 parts by weight of methanol to form a coating solution having a thickness of about 0.5 μm.
Transparent conductive material (ITO-based paint: E manufactured by Catalyst Chemical Industry Co., Ltd.)
LCOM P-1202: Surface resistance 1.3 × 10 ³ Ω /
□) was formed to a thickness of about 1 μm.

After the photosensitive layers laminated as described above are sufficiently dried with hot air, an appropriate amount of a polymerization catalyst is added to methyl methacrylate (acrylic resin monomer) and mixed to obtain a material having a thickness of about 2 mm. Put in, mold 40 ~ 5
The polymerization was carried out by rotating while heating to 0 ° C. After the polymerization and curing, both ends of the mold were opened, and the cylindrical substrate integrated with the photosensitive layer was carefully taken out.

Example 2 In the same manner as in Example 1, after forming the coating films of the charge transport layer, the charge generation layer and the undercoat layer, the transparent conductive material (Sn
O-based paint: ELCOMP-353 manufactured by Catalyst Chemicals, Inc.
0: surface resistance 3.4 × 10 ⁵ Ω / □), and then methyl methacrylate was subjected to centrifugal polymerization in the same manner as in Example 1 to obtain an integrated photosensitive drum.

With respect to the photosensitive drums manufactured in Examples 1 and 2, the moldability and the total light transmittance in the state without the photosensitive layer (the state of the acrylic resin tube obtained by centrifugally polymerizing methyl methacrylate monomer directly) were used. , Surface roughness, roundness and dimensional accuracy were measured, and the results are shown in Table 1 below.
Further, the measurement of the initial electrical characteristics as a photoreceptor was evaluated by a tester shown in FIG. 3 and the print characteristics were evaluated by a tester of the type shown in FIG. 4, and the obtained results are shown in Table 2 below.

The principle of measurement by the tester shown in FIG.
The photoreceptor 7 is charged to -600V by the scorotron charger 8 while rotating in the arrow direction at a peripheral speed 60 mm / sec, and the dark potential V _o with the potential at no exposure of the probe 9 having an exposure light source 10. The rotation was stopped and the potential holding ratio V _k5 (%) when left in a dark place for 5 seconds was determined.
A light having a wavelength of 660 nm and an irradiance of ² μw / cm ² was exposed, and the potential after 0.2 seconds was set to a bright portion potential V _i , which was 5
The dark portion potential after the second is Vr. However, because of the surface exposure machine, a light-shielding member was attached to the inner surface of the photoreceptor, and measurement was performed.
In FIG. 3, reference numeral 11 denotes an infrared filter, and reference numeral 12 denotes a static elimination light source.

In the tester shown in FIG. 4, 7 is a photoreceptor, 13 is an exposure light source, 14 is a charge eliminating light source, 15 a developing unit, and 1
6 is a charging machine, 17 is a transfer machine, and 18 is a cleaning blade.

[0033]

[Table 1]

[0034]

[Table 2] As is clear from the above table, good electrical characteristics and good printing performance were obtained in the photosensitive drums of Example 1 and Example 2.

[0035]

According to the present invention, a photosensitive drum is obtained by integral casting with a photosensitive layer by a centrifugal casting method using PMMA or the like as an image recording substrate of a photosensitive member for an internally illuminated electrophotographic apparatus. This makes it possible to obtain a photosensitive drum excellent in printing performance and economically excellent.

[Brief description of the drawings]

FIG. 1 is a sectional view of a photosensitive drum.

FIG. 2 is a partially cutaway perspective view schematically illustrating a process of manufacturing a photosensitive drum using a mold.

FIG. 3 is a schematic diagram showing the measurement principle of the electric property tester.

FIG. 4 is a process layout diagram of a testing machine used for a printing characteristic testing machine.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transparent drum substrate 2 transparent conductive layer 3 undercoat layer 4 charge generation layer 5 charge transport layer 6 casting mold 7 photoconductor 8 corotron charger 9 probe 10 exposure light source 11 infrared filter 12 static elimination light source 13 exposure light source 14 Static elimination light source 15 Developing device 16 Charging machine 17 Transfer machine 18 Cleaning blade

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G03G 5/14 102 G03G 5/14 102 // B29L 31:00

Claims (4)

[Claims] After a photosensitive layer is formed on the inner surface of a cylindrical mold, a monomer material of a resin for a transparent substrate is polymerized by a centrifugal casting method, and the obtained resin is integrated with the photosensitive layer. A method for producing an electrophotographic photoreceptor, comprising: 2. The method according to claim 1, wherein the photosensitive layer is formed on the inner surface of a cylindrical mold in the order of a charge transport layer, a charge generation layer, an undercoat layer, and a conductive layer. 3. The method according to claim 1, wherein methyl methacrylate, which is a monomer of polymethyl methacrylate resin, is used as a monomer material of the resin for the transparent substrate. 4. A transparent conductive paint is used for the conductive layer, and the conductive layer has a surface resistance of 2 × 10 ² to 2 × 10 ⁶ Ω /.
3. The method according to claim 2, which is □.