JPH05204172A - Method for manufacturing electrophotographic photoreceptor - Google Patents

Abstract

PURPOSE:To enable the production of a uniform photosensitive film in a short period of time by subjecting a conductive base body to spray coating with a photosensitive coating liquid from a spray ejecting port which is disposed to face the conductive base body and has a continuous groove shape. CONSTITUTION:The conductive base body 1 descends in an annular nozzle 12 having the annular spray ejecting port 11 of the groove shape continuing to the inner side. The conductive base body 1 is stopped when the top end thereof to be coated arrives at a prescribed position. The coating liquid is passed through a coating liquid transporting pipe 13 by a pump from a coating liquid stirring tank and arrives at the annular spray ejecting port 11, from which the coating liquid is ejected as the conductive base body 1 ascends. The angle (a) of the annular spray ejecting port 11 is preferably set at 40 to 50 deg. as splashing back is intensive if the angle is large and as the coating liquid hardly sticks to the surface of the base body 1 and the loss of the coating liquid increases if the angle is small. The coating may also be executed by the moving of the annular nozzle 12 on the surface of the conductive base body 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an electrophotographic photoreceptor having stable image characteristics by a spray coating method in continuous production of electrophotographic photoreceptors for copying machines, printers and the like.

[0002]

2. Description of the Related Art Electrophotographic photoreceptors for copying machines, printers, etc., include a charge generating layer containing a condensed polycyclic pigment or an azo pigment on the surface of a conductive substrate such as aluminum and a hydrazone,
It is formed by laminating and coating a charge transport layer containing a material such as an arylamine-based material.

Coating of electrophotographic photoreceptors and the like is mainly carried out by a dip coating method. For example, a conductive cylindrical substrate is dipped in the coating solution in the coating layer and pulled up to form a photosensitive layer having a constant film thickness on the surface of the substrate. However, this dip coating method has a remarkably poor use efficiency of the coating solution, which is one of the causes of increasing the cost of the product.

There is a ring method as a coating method for increasing the use efficiency of the coating liquid. In this method, a resin molded product (blade) with a thickness of about 0.1 mm is hollowed out to be slightly smaller than the conductive cylindrical substrate (a concentric outer diameter is preferable), and the coating solution is placed in the holder (blade). Is in close contact with the cylindrical substrate, so the coating liquid does not leak), and the coating film is formed by pushing up the cylindrical substrate. In the case of this ring-type coating method, the use efficiency of the coating solution is improved as compared with the dip coating method, but the apparatus becomes large and a spacer is required, and the coating solution is applied from the fitting portion between the cylindrical substrate and the spacer. There is a drawback of sagging. Furthermore, since streaks due to contact with the blade enter the surface of the cylindrical substrate, there are problems such as causing image defects, and there are few cases in which the film is actually used.

Generally, in a method of manufacturing a photoconductor using such a coating technique, in order to improve image quality and reduce image defects in image formation using the photoconductor,
It is desired to reduce the manufacturing cost by forming a uniform photosensitive layer, improving the use efficiency of the coating liquid, and reducing the manufacturing process and the manufacturing time.

However, in recent years, the photosensitive member is not limited to a cylindrical one, and a conductive member is vapor-deposited on a belt-shaped substrate such as a metal or polyester film and both ends thereof are joined.

In such a photoreceptor, the thickness of the substrate is thin and soft as compared with the cylindrical photoreceptor, and since the length in the circumferential direction is long, the above-mentioned dip coating method and ring type coating method are used. When manufactured, the coating tank and the entire device become large, which is not practical. The spray coating method is suitable for producing such a belt-shaped photoreceptor, and has an advantage that the thickness and quality of the photosensitive layer can be made relatively uniform. Furthermore,
Such a spray-type coating method can improve the use efficiency of the coating liquid to, for example, 90% or more, and is therefore advantageous in terms of manufacturing cost. In particular, the spray coating method makes it possible to easily stack the coating films, and from the viewpoint of improving the characteristics of the photoconductor, the importance of the ease of stacking the coating films is emphasized.

FIG. 3 is a view of a conventional spray coating apparatus, in which the support 17 supports the conductive cylindrical substrate 1 and the rotary shaft 18 is rotated to atomize the coating liquid from the tip of the spray nozzle 19. To form a film by spraying on the substrate 1. The spray nozzle 19 moves from the left end to the right end of the base 1.

In such a conventional spray type coating apparatus, various measures are required to uniformly coat the coating liquid. For example, the spray nozzle may be reciprocated from end to end of the substrate several times. As a result, the spray time is lengthened, which contributes to the high manufacturing cost.

[0010]

In the spray coating method, it is desired to provide a method for manufacturing an electrophotographic photosensitive member which can reduce the time required for spray coating and can form a uniform coating layer at low manufacturing cost. ing.

[0011]

Means for Solving the Problems As a result of earnest studies by the present inventors, by spray-coating a photoreceptor coating liquid from a continuous groove-shaped spray injection port arranged so as to face a conductive substrate, It has been found that a uniform photosensitive film can be produced in a short time, and the present invention has been completed based on this finding.

[0012]

1 is a cross-sectional view of a spray-applying device of the present invention, and FIG. 2 is a ring-shaped nozzle having a continuous groove-shaped annular spray injection port.

The conductive substrate 1 descends inside a ring-shaped nozzle 12 having a groove-shaped annular spray injection port 11 continuous inside, and stops when the upper end of the conductive substrate 1 to be coated reaches a predetermined position. The coating liquid reaches the annular spray injection port 11 from the coating liquid agitation tank via the coating liquid transport pipe 13 by a pump, and is jetted as the conductive substrate 1 rises.

The angle a of the annular spray injection port 11 is not particularly limited, but if the angle is large, the splashing of the coating liquid is strong,
On the other hand, if it is small, the coating liquid is unlikely to adhere to the surface of the substrate 1 and the loss of the coating liquid increases, so that it is preferably 30 to 60 °, more preferably 40 to 50 °. The application is not limited to the above, and the ring-shaped nozzle 12 may move on the surface of the conductive substrate 1.

The distance between the annular spray injection port 11 and the surface of the conductive substrate 1 varies depending on the viscosity of the coating liquid, the type of solvent, the slit width of the injection port, etc., but is preferably 3 to 50 mm, more preferably 8 to 12 mm. preferable. If the slit width of the annular spray injection port 11 is too wide, it will be difficult to form a uniform and stable photoconductor layer because a large amount of the coating liquid will be jetted out.If it is too narrow, the amount of the coating liquid jetted out will be small. There is a risk that the object of the invention will not be achieved and the injection port will be clogged with the binder contained in the coating liquid, which is 0.05 to 2 mm, more preferably 0.
1 to 0.5 mm is preferable. The flow rate of the coating solution blown out is not particularly limited, but is preferably 0.05 to 5 gal / min.

FIG. 4 shows another embodiment of the spray coating apparatus of the present invention. The conductive substrate 1 is held by a holder 15, and the ring-shaped nozzle 12 moves up and down while being rotated by a rotating shaft 16, so that the surface of the substrate 1 is coated. Further, the application is not limited to the above, and the ring-shaped nozzle 12 may be fixed and the conductive substrate 1 may move up and down while rotating. The rotating speed of the conductive substrate is not particularly limited, but is preferably 50 to 300 rpm.

As the conductive substrate of the electrophotographic photosensitive member used in the present invention, a cylindrical substrate or a thin film sheet of a metal such as aluminum, copper, nickel, stainless steel or brass, or a polyester film of aluminum, tin alloy, indium oxide or the like is used. Alternatively, it may be vapor-deposited on paper or a cylindrical substrate of a metal film.

An undercoat layer may be provided for the purpose of improving the adhesion of the photoreceptor layer, improving the coatability, improving the coating of defects on the substrate, and improving the injection of charges from the substrate to the charge generating layer. As the material of the undercoat layer, polyamide, copolymer nylon,
Resins such as casein, polyvinyl alcohol, cellulose and gelatin are known. These are dissolved in various organic solvents and coated on a conductive cylindrical substrate so that the film thickness is about 0.1 to 5 μm.

The charge generation layer contains a charge generation material which generates a charge upon irradiation with light as a main component, and if necessary, a known binder, plasticizer and sensitizer, and these components are dispersed in a solvent. It is coated on the conductive cylindrical substrate or the undercoat layer so that the film thickness is 1 μm or less (dry film thickness).

As the charge generating material, a perylene pigment,
Polycyclic quinone pigments, phthalocyanine pigments, metal phthalocyanine pigments, squarylium dyes, azurenium dyes, thiapyrylium dyes, and carbazole skeletons, styrylstilbene skeletons, triphenylamine skeletons, dibenzothiophene skeletons, oxadiazole skeletons, fluorenone skeletons, bis Examples thereof include azo pigments having a stilbene skeleton, a distyryl oxadiazole skeleton, or a distyryl carbazole skeleton.

The charge-transporting layer contains a charge-transporting material capable of receiving and transporting charges generated by the charge-generating material and a binder as essential components, and if necessary, known leveling agents, plasticizers and sensitizers. Agent, etc., these ingredients are dissolved in a solvent to give a dry film thickness of 5 to 70 μm.
It is coated on the charge generation layer.

As the charge transport material, poly-N-vinylcarbazole and its derivative, poly-γ-carbazolylethylglutamate and its derivative, pyrene-formaldehyde condensate and its derivative, polyvinylpyrene, polyvinylphenanthrene, oxazole derivative and oxo. Electron donating property of diazole derivative, imidazole derivative, 9- (p-diethylaminostyryl) anthracene, 1,1-bis (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, hydrazone derivatives, etc. Substances, fluorenone derivatives, dibenzothiophene derivatives, indenothiophene derivatives, phenanthrenequinone derivatives, indenopyridine derivatives, thioxanthone derivatives, benzo [c] cinnoline derivatives Body, phenazine oxide derivatives, tetracyanoethylene, tetracyanoquinodimethane, Puromaniru, chloranil, and electron accepting substance benzoquinone and the like.

The binder constituting the charge transport layer may be any binder that is compatible with the charge transport material, and examples thereof include polycarbonate, polyvinyl butyral, polyamide, polyester, polyketone, epoxy resin, polyurethane, polyvinyl ketone, Examples thereof include polystyrene, polyacrylamide, phenol resin, and phenoxy resin.

Examples of the solvent for the charge generating layer coating liquid and the charge transporting layer coating liquid include dichloroethane, benzene, chloroform, cyclohexanone, ethyl ether, acetone, ethanol, dichlorobenzene and methyl ethyl ketone.

According to the method of the present invention, an electrophotographic photosensitive member having a uniform photosensitive member film can be manufactured at a low cost because the time required for spraying can be greatly shortened.

[0026]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

The following liquids A and B are used as the charge generating coating liquid and the charge transporting coating liquid for the electrophotographic photosensitive member structure, respectively.
The liquid was used.

(A liquid) 2 parts by weight of dibromoanthanthrone, 2 parts by weight of butaral resin (Eslec BM-2, manufactured by Sekisui Chemical Co., Ltd.), and 230 parts by weight of cyclohexanone were dispersed in a ball mill for 8 hours. thing.

(B liquid) 1 part by weight of hydrazone type charge transport material [Nippon Kayaku Co., Ltd., trade name-ABPH], and polycarbonate resin [Teijin Kasei Co., Ltd. trade name-
Panlite L-1250] 1 part by weight dissolved in 8 parts by weight of dichloroethane.

Example 1 Using the spray coating apparatus shown in FIG. 1, the solution A was spray coated under the following conditions so that the dry film thickness would be 0.5 μm.
Dry for 10 minutes, and then dry solution B under the following conditions to a film thickness of 20
It was applied by spraying so as to have a thickness of μm and dried at 70 ° C. for 1 hour.

Application of liquid A- Distance between substrate surface and injection port: 10 mm-Moving speed of substrate: 8 mm / sec-Blowout flow rate: 0.1 gal / min-Application time: 70 sec Application of liquid B -Substrate surface and injection port Distance: 8mm ・ Movement speed of substrate: 6mm / sec ・ Blowout flow rate: 1.2gal / min ・ Coating time: 194sec Each of the obtained electrophotographic photosensitive members (20 pieces) is attached with a flange for rotating and grounding. It was mounted on a copying machine SF-7750 manufactured by Sharp Corporation, and a copy was taken and image evaluation was carried out. As a result, the non-defective rate was 90%.

Comparative Example Using the spray coating apparatus of FIG. 3, under the following conditions, the solution A was spray coated so that the dry film thickness would be 0.5 μm, and then at 80 ° C.
Dry for 10 minutes, and then dry solution B under the following conditions to a dry film thickness of 20
It was applied by spraying so as to have a thickness of μm and dried at 70 ° C. for 1 hour.

Application of liquid A- Distance between substrate surface and nozzle: 10 mm-Movement speed of nozzle: 2 mm / sec-Blowout flow rate: 0.015 gal / min-Number of rotations of substrate: 200 rpm-Application time: 170 sec Application of liquid B- Distance between the surface of the body and the nozzle: 8 mm-Movement speed of the nozzle: 1 mm / sec-Blowout flow rate: 0.2 gal / min-Number of revolutions of the substrate: 150 rpm-Coating time: 340 sec Obtained electrophotographic photoreceptor (20 pieces) As a result of image evaluation in the same manner as in Example 1, the non-defective rate was 60%.

From the comparison of the coating time between Example 1 and Comparative Example, the coating time in Example 1 was shortened to about 1/4 for the solution A and about 1/6 for the solution B.

Example 2 An electrophotographic photosensitive member was manufactured in the same manner as in Example 1 except that the solutions A and B were applied under the following conditions in the spray coating apparatus shown in FIG.

Application of liquid A- Distance between substrate surface and injection port: 10 mm-Movement speed of substrate: 5 mm / sec-Blowout flow rate: 0.1 gal / min-Number of rotations of substrate: 200 rpm-Application time: 70 sec Liquid B Coating・ The distance between the surface of the substrate and the injection port: 8 mm ・ Movement speed of the substrate: 2.5 mm / sec ・ Blowout flow rate: 1.2 gal / min ・ Number of revolutions of the substrate: 150 rpm ・ Coating time: 136 sec Obtained electrophotographic exposure As a result of image evaluation of the body (20 pieces) by the same method as in Example 1, the non-defective rate was 90%.

From the comparison of the coating times of Example 2 and the comparative example, it can be seen that the coating time of the method of Example 2 is greatly shortened.

[0038]

According to the method of the present invention, since the spray coating is performed by the continuous groove-shaped spray jet ports facing the substrate, the time required for the spray coating can be greatly shortened and the production of the electrophotographic photosensitive member can be performed. Cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic view of a spray coating device of the present invention.

2 is a cross-sectional view of the ring nozzle of FIG. 1 of the present invention.

FIG. 3 is a schematic view of a conventional spray coating device.

FIG. 4 is a schematic view of a spray coating device with a rotary jig of the present invention.

[Explanation of symbols]

 1 Conductive Substrate 11 Annular Spray Jet 12 Ring Nozzle 15 Holder 16 Rotating Shaft

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masanori Matsumoto 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Hiroshi Matsumoto 22-22 Nagaike-cho, Abeno-ku, Osaka, Osaka Co., Ltd. (72) Inventor Mitsuhiro Shinobu 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Prefecture

Claims (1)

[Claims] 1. A method for producing an electrophotographic photosensitive member, which comprises applying a coating liquid for a photosensitive member onto a conductive substrate by a spray method.
A method for producing an electrophotographic photosensitive member, which comprises spray-applying a coating liquid for a photosensitive member from a continuous groove-shaped ejection port facing the surface of the conductive substrate.