JP2000047403A - Production of electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an electrophotographic photoreceptor capable of forming a uniform and clear image by providing an application method capable of uniformly applying an application solution for forming a bed layer and a charge generating layer to form an excellent paint film with both edges thereof being linear in a prescribed position. SOLUTION: In a method for producing a photoreceptor having a photoreceptor layer formed on a sheet-like conductive support 2, an application roller 6 having a number of recessed parts on the surface is brought into contact with the conductive support 2, and the application roller 6 is rotated in the direction reverse to the advancing direction of the conductive support 2 to apply the application solution supplied onto the application roll 6 to the conductive support 2.

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 photosensitive member for endless belts, and more particularly, to a method for uniformly applying a coating solution such as a coating solution for a charge generating layer and having few coating defects. It can form a coating film with excellent width regulation,
The present invention relates to a method for producing an endless belt-shaped electrophotographic photosensitive member having high working efficiency.

[0002]

2. Description of the Related Art In recent years, electrophotographic image forming methods have been widely used in copiers, printers and the like, since high quality images can be obtained immediately. As the core photoreceptor, an endless belt-shaped electrophotographic photoreceptor is widely used because it has a flexible property and a high degree of freedom in arrangement in an apparatus. Endless belt-shaped electrophotographic photoreceptor, a conductive layer obtained by forming a conductive layer on a flexible film, a coating solution is applied to the underlayer,
It is formed by laminating a charge generation layer, a charge transport layer, and the like.

[0003] A coating solution for an undercoat layer and a charge generation layer on a conductive support has been conventionally applied by a gravure coater method, a reverse coater method, a die coater method or the like. However, in the gravure coater method, the gravure cell pattern remains on the coated surface, it is difficult to obtain a uniform coating film, and when changing the film thickness of the coating film, replace with a gravure roll having a different size of the gravure cell. Work is required.

In the reverse coater method, a coating film having a constant thickness is formed uniformly because the thickness of the coating film varies depending on the gap between rolls, the peripheral speed ratio, the viscosity of the coating solution, the solid content ratio, and the like. In order to adjust the equipment and coating solution, skill is required,
Even after precise adjustment, a coating pattern called satin finish may remain on the coating surface. Further, the die coater has a problem that it is difficult to control the film thickness.

[0005]

SUMMARY OF THE INVENTION The present invention provides a coating solution for forming an underlayer, a charge generation layer, and the like, which is uniformly applied to form an excellent coating film, and which holds both side edges of the film at predetermined positions. Provided is a method for applying a coating solution that can be formed in a straight line, and a method for producing an electrophotographic photosensitive member that can produce an electrophotographic photosensitive member capable of forming a uniform and clear image. is there.

[0006]

SUMMARY OF THE INVENTION The present invention has been made as a result of intensive studies to achieve the above object, and a method of manufacturing a photoreceptor having a photoreceptor layer formed on a sheet-like conductive support. In, the application roller having a large number of recesses formed on the surface thereof is brought into contact with the conductive support and rotated and run in the direction opposite to the traveling direction of the conductive support to apply the coating liquid on the application roller onto the conductive support. An object of the present invention is to provide a method for producing an electrophotographic photosensitive member, which is characterized by being applied.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The electrophotographic photoreceptor of the present invention is shown in FIG.
The photosensitive member layer 3 is formed on the conductive support 2 as shown in FIG. The conductive support 2 is formed by laminating a synthetic resin film 2a and a metal layer 2b. In the present invention, a film and a sheet are used as synonyms, and identification by thickness is not performed.

Examples of the material of the synthetic resin film 2a include linear polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyolefin resins such as polyethylene and polypropylene, and polyvinyl chloride resins, and crystalline resins are preferred. Strength,
From the viewpoint of dimensional stability and the like, a linear polyester resin, particularly, polyethylene terephthalate is preferred.

The synthetic resin film 2a is usually used after being biaxially stretched. The stretching dimension is not particularly limited, and may be a sequential two-stage stretching method in which transverse stretching is performed after longitudinal stretching, or a simultaneous biaxial stretching method in which longitudinal and transverse stretching are simultaneously performed. The thickness of the resin film is usually about 50 to 150 μm. Also, a metal layer 2b for achieving the conductive support 2
Can be formed by metal vapor deposition. Examples of the vapor-deposited metal include copper, nickel, zinc, lead, and aluminum, and among them, aluminum is preferable.

The thickness of the metal deposition layer is usually 400 to 10
The metal is deposited on the resin film by a known deposition method such as an electrothermal melting deposition method, an ion beam deposition method, or an ion plating method. In addition, as the metal layer, a metal foil such as an aluminum foil and a nickel foil, or a laminated film in which these metals are laminated can be used. In this case, the metal foil is preferably 5 μm or less.

A known barrier layer, which is generally used, can be provided as an underlayer 4 between the conductive support 2 and the photosensitive layer 3. As the barrier layer, for example, polyvinyl alcohol, casein, polyvinylpyrrolidone,
Polyacrylic acid, celluloses, gelatin, starch,
An organic layer of polyurethane, polyimide, polyamide or the like is used, and if necessary, inorganic particles such as titanium oxide or aluminum oxide may be added.

The photoreceptor layer 3 may be a single layer containing a charge generating substance and a charge transporting substance, or may be of a function separated type in which a charge generating layer and a charge transporting layer are laminated. Describing the function-separated type photoreceptor, as the charge generation material used in the charge generation layer, any of known charge generation materials can be used, and phthalocyanine, azo dye, quinacridone,
Polycyclic quinone, pyrylium salt, thiapyrylium salt, indigo, thioindigo, anthantrone, pyranthrone,
Examples include various organic pigments such as cyanine, dyes, and the like. Of these, phthalocyanines in which a metal such as metal-free phthalocyanine, copper indium chloride, gallium chloride, tin, oxytitanium, zinc, and vanadium, or an oxide or chloride thereof is coordinated are preferable.

As the binder for the charge generation layer, resins such as polyacetal such as polyvinyl butyral, polyvinyl acetate, and phenoxy resin can be used. The thickness of the charge generation layer is usually 0.1 μm to 1 μm, preferably 0.15 μm to 0.6 μm. The content of the charge generating substance used here is in the range of 20 to 300 parts by weight, preferably 50 to 200 parts by weight, based on 100 parts by weight of the binder resin.

As the charge transporting material in the charge transporting layer, various low molecular compounds such as pyrazoline derivatives, oxazole derivatives, hydrazone derivatives, stilbene derivatives, and arylamines can be used. A binder resin is blended with these charge transport materials. Preferred binder resins include, for example, polymethyl methacrylate, polystyrene, vinyl polymers such as polyvinyl chloride, and copolymers thereof, polycarbonate, polyester, polysulfone, polyether, polyketone, phenoxy, epoxy, silicone resin, and the like. These partially crosslinked cured products are also used.

Further, the charge transport layer may contain various additives such as an antioxidant and a sensitizer. The thickness of the charge transport layer is 10 to 40 μm, preferably 10 to 30 μm. The photoreceptor sheet thus obtained is usually cut into a sheet having a predetermined size, as shown in FIG. 1, an endless belt having both ends joined by fusion or bonding with an adhesive, or on a cylindrical body. Used in the form of a coated roll.

According to the present invention, in the formation of the underlayer and the photoreceptor layer, the application of the coating liquid is performed by a coating roller having a large number of minute concave portions formed on the surface.
If the coating method is described for the case where the underlayer 4 is formed on the conductive support 2, as shown in FIG.
Denotes two guide rolls 5 arranged at a predetermined interval.
a, 5b, and the conductive support 2 travels in the direction of the arrow and is supplied by the rotation of the guide rolls 5a, 5b.

An application roll 6 is provided below the middle of the guide rolls 5a and 5b, and the application roll 6 is disposed such that the conductive support 2 is in contact with the surface opposite to the surface in contact with the guide rolls 5a and 5b. Is done. On the outer surface of the application roll 5, a large number of minute concave portions, so-called gravure cells, are provided. There are no restrictions on the shape of the gravure cell, the cross section is conical,
It may be either a pyramid type or a trapezoid type, may be provided in an independent dot shape, or may have a spiral groove structure.

The diameter of the coating roll 6 is preferably 10 to 80 mm, particularly preferably 20 to 50 mm. By reducing the diameter of the application roll 6, the contact area between the conductive support 2 and the application roll 6 is reduced, and the ink pool is reduced, so that the ink does not swim and the application is stabilized. Further, it is desirable that the application roll 6 is positioned at an intermediate portion between the guide rolls 5a and 5b, and that no backup roll is provided on the back surface of the application roll 6. The application roll 6 is brought into contact with the conductive support 2 by bringing the application roll 6 into contact between the guide rolls.
The state of light contact with the so-called kiss state,
The generation of wrinkles on the conductive support 2 can be prevented.

The coating roll 6 is rotated in a direction in which the contacting peripheral surface rotates and runs in a direction opposite to the running direction of the conductive support 2, that is, in a counterclockwise direction in the figure. Rotational speed relative to the running speed V _B of the conductive substrate 2, the ratio V _R / V _B of the rotational speed V _R of the peripheral surface of the coating roll is preferably in the range of 0.6 to 3.0 . If the ratio V _R / V _B is less than 0.6, the application of the coating liquid cannot keep up and the coating cannot be performed. If the ratio exceeds 3.0, the conductive liquid is transferred to the conductive support 2 before the transfer to the conductive support 2. Since it passes through the point of contact with the body 2, the application amount decreases and becomes unstable. V _R / V
_{The B} ratio is preferably in the range of 1.2 to 2.0.
Thickness of the coating film according to _R / V _B ratio is increased becomes larger. Therefore, in the present invention, the thickness of the coating film can be adjusted by adjusting the rotation speed of the coating roll 6 and the traveling speed of the conductive support 2.

Reference numeral 7 denotes a coating liquid storage tank, and reference numeral 8 denotes a doctor blade for adjusting the amount of the coating liquid on the coating roll surface. It is desirable that the doctor blade 8 is disposed at an angle close to the tangential direction of the coating roll 6 to soften the contact with the coating roll 6. Conductive support 2 using the apparatus of FIG.
When the coating liquid is applied to the guide rolls 5a and 5b, the conductive support 2 is wound around the guide rolls 5a and 5b with the surface to be coated facing downward, and the guide rolls 5a and 5b rotate counterclockwise. By doing so, the conductive support 2 travels in the direction of the arrow. The application roll 6 disposed below the intermediate portion between the guide rolls 5a and 5b rotates counterclockwise to apply the coating liquid in the storage tank 7 to the surface and rises, and the amount of the coating liquid is regulated by the doctor knife 8. After that, the coating is performed in contact with the conductive support 2.

[0021]

According to the present invention having such a constitution, a uniform coating film can be formed without generating a gravure cell pattern or a matte pattern in a conventional coating method. A uniform coating film can be obtained as a whole without causing repelling due to dirt or foreign matter.
Further, the coating width of the coating liquid can be sharply regulated, and a ground layer can be easily and stably formed when forming the ground layers on both sides of the coating film in a later step.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of an electrophotographic photosensitive member obtained by the present invention.

FIG. 2 is a side view showing a coating method.

[Explanation of symbols]

 Reference Signs List 1 electrophotographic photoreceptor 2 conductive support 2a resin film 2b metal layer 3 photoreceptor layer 4 underlayer 5a, 5b guide roll 6 application roll 7 storage tank 8 doctor knife

Claims (6)

[Claims] 1. A method for manufacturing a photoconductor in which a photoconductor layer is formed on a sheet-shaped conductive support, wherein an application roller having a plurality of concave portions formed on a surface thereof is brought into contact with the conductive support and the conductive roller is electrically conductive. A method for producing a photoconductor for electrophotography, comprising applying a coating solution on an application roll onto a conductive support by rotating and traveling in a direction opposite to a traveling direction of the support. 2. The method for producing an electrophotographic photosensitive member according to claim 1, wherein the coating roller has a diameter of 10 to 80 mm. 3. The conductive support is caused to run between two guide rollers disposed at a predetermined interval, and an application roll is disposed at an intermediate portion of the guide roll to guide the conductive support. 3. The method for producing an electrophotographic photoreceptor according to claim 1, wherein the coating liquid is applied by contacting the opposite side of the roll contact surface. 4. The ratio V _R / V _B of the running speed V _B of the conductive support to the running speed V _R of the peripheral surface of the coating roll is 0.6.
The method for producing an electrophotographic photoreceptor according to claim 1, wherein 5. The electrophotographic photosensitive member according to claim 1, wherein the conductive support is a flexible sheet in which a metal layer is laminated on a synthetic resin film, and the electrophotographic photosensitive member is an endless belt-shaped photosensitive member. The method for producing the electrophotographic photosensitive member according to the above. 6. The method for producing an electrophotographic photoreceptor according to claim 1, wherein the coating liquid is a coating liquid for forming an underlayer or a coating liquid for forming a charge generation layer.