JPH06202352A - Production of electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To produce an electrophotographic sensitive body in which the thick part of the photosensitive film due to the dripping of a photosensitive coating soln. at the lower end of the photosensitive body in treated (removed) without adversely affecting the photosensitive body and with no need for the device and tool and pretreatment and post treatment. CONSTITUTION:A cylindrical substrate 10 is dipped in a photosensitive coating soln. 15 and then pulled up in the axial direction to form a photosensitive layer on the surface to constitute a electrophotographic sensitive body, and then the thick part formed at the lower end of the substrate 10 and the deposit on the inner wall at the lower end are removed. In this case, the substrate 10 is relatively pulled up from the soln. 15 in the axial direction and allowed to stand for a certain time, the lower end of the substrate 10 is again dipped in the soln. 15 to allow the thick part 12 at the lower end of the substrate 10 to be absorbed in the soln 15 and to be removed.

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, and more particularly, to removal of a photosensitive coating liquid deposit after a photosensitive layer is formed on a cylindrical substrate constituting the electrophotographic photosensitive member by a dip coating method. The present invention relates to a method for manufacturing an electrophotographic photosensitive member with improved processes.

[0002]

2. Description of the Related Art Conventionally, electrophotographic photosensitive members have been manufactured by forming a photosensitive layer on the surface of a cylindrical substrate by a coating liquid method. Among such coating methods, the dip coating method in which a cylindrical substrate is dipped in a photosensitive coating solution and the cylindrical substrate is pulled up relative to the photosensitive coating solution to form a photosensitive layer is It has an advantage that a photosensitive layer having a constant film thickness can be efficiently formed. By the way, in the above-mentioned dip coating method, since the cylindrical substrate is pulled up relative to the photosensitive coating liquid, a thick portion due to the sagging of the photosensitive coating liquid is inevitably formed at the lower end of the cylindrical substrate. A large amount of residual solvent is present in such a thick portion even after natural drying, and if this is forcibly dried in a furnace at 80 ° C to 100 ° C, the outer portion of the thick portion is dried first and then the inner portion is dried. Since it is dried, the residual solvent inside the thick portion boils and expands the film formed outside, and many balloon-shaped defects occur.

Further, when the electrophotographic photosensitive member thus generated is incorporated in an electrophotographic apparatus, the positional accuracy of a member in the process of contacting the lower end of the photosensitive member is significantly lowered, and the blade cleans the toner on the photosensitive film. Sex is significantly impaired.

For this reason, the film thickness of the photosensitive film at the lower end of the cylindrical substrate must be around the average of the film thickness of the photosensitive film at the center of the photoconductor.

Regarding the removal of the thick portion of the photosensitive film, (1) after dip coating, the lower end of the photosensitive member is immersed in an ultrasonic cleaning tank containing a solvent and ultrasonic waves are applied (JP-A-59-59).
No. 142555) (2) A method of causing a flexible plate containing a solvent to act on the thick portion of the photosensitive film at the lower end of the photosensitive member (Japanese Patent Laid-Open No. 60-170858).
(3) A method in which a jig that causes a capillary phenomenon is caused to act on the thick portion of the photosensitive film at the lower end of the photoreceptor (JP-A-60-1462).
No. 45) (4) A method of applying a fluorine-based silane coupling agent to the lower end of the cylindrical substrate in advance before forming the photosensitive layer (JP-A-61-189555) (5) Applying a photosensitive coating solution Sometimes a method of fitting a spacer having an outer diameter different from the outer diameter of the cylindrical substrate (Japanese Patent Laid-Open Publication No. Sho 6-62).
No. 1-18964) and the like are disclosed.

[0006]

In the conventional methods (1) and (2) for causing a solvent to act on the lower end portion of the photoreceptor,
The solvent penetrates from the lower end of the photoconductor into the photosensitive layer, imparts fluidity to the photosensitive layer, and partially dissolves the photosensitive layer to deteriorate the state of the coating film.

Further, in the conventional methods (3), (4) and (5), a device for removing the thick portion of the photosensitive film, a jig and pre-processing are required. However, there is a drawback that the processing (processing) cost related to this is high.

The object of the present invention is to expose the lower end of the photosensitive member without any adverse effect on the photosensitive layer and without the need for a device, a jig and a pre-treatment for removing the thick portion of the photosensitive film. It is an object of the present invention to provide a method for manufacturing an electrophotographic photosensitive member, which treats (removes) a thick portion of a photosensitive film due to dripping of a photosensitive coating liquid.

[0009]

According to the present invention, the object is to immerse a cylindrical substrate in a photosensitive coating solution and pull the cylindrical substrate axially to form a photosensitive layer on its surface. ,
A method of removing thick parts formed at the lower end of the cylindrical substrate and deposits formed on the inner wall of the lower end of the electrophotographic photosensitive member, wherein the cylindrical substrate is removed from the photosensitive coating solution by a shaft. Direction relative to each other, a step of leaving the cylindrical substrate in a pulled-up state for a predetermined time, and a step of reimmersing the lower end of the installed cylindrical substrate in the photosensitive coating liquid. This is achieved by the method of manufacturing a photographic photoreceptor.

[0010]

According to the manufacturing method of the present invention, after pulling up the cylindrical substrate from the photosensitive coating liquid, the lower end of the cylindrical substrate is re-immersed in the photosensitive coating liquid, so that the film quality of the photosensitive film is deteriorated. Without doing so, it is possible to remove the thick portion formed by the photosensitive coating liquid at the lower end of the cylindrical substrate.

As a method of re-immersing the lower end of the cylindrical substrate in the photosensitive coating liquid, the lower end of the cylindrical substrate is lowered into the photosensitive coating liquid again, and the thick wall portion of the lower end portion of the cylindrical substrate is obtained. Is absorbed into the photosensitive coating solution, and this method is used to remove the thick portion of the photosensitive film from the lower end of the cylindrical substrate without the need for a device, a jig and a pre-treatment. It is possible to remove the thick portion due to the photosensitive coating liquid.

Further, as a method of reimmersing the lower end of the cylindrical substrate in the photosensitive coating solution, the cylindrical substrate is temporarily stopped near the height of the upper end of the coating tank wall, and the photosensitive coating solution is applied. It is preferable that the thick part at the lower end is absorbed into the coating liquid by filling or overflowing it, thereby eliminating the need for a device for removing the thick part of the photosensitive film, a jig, and pre-processing and post-processing. In addition, it is possible to remove the thick portion formed by the photosensitive coating liquid on the lower end of the cylindrical substrate.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the preferred embodiments shown in the drawings.

FIG. 3 shows a commonly used photoconductor coating device.

The cylindrical substrate 1 is held by a ball screw 2, and an elevating motor 3 is attached to the ball screw 2. A coating tank 4 is arranged below the cylindrical substrate 1, and the coating tank 4 is filled with a coating liquid 5.
The coating tank 4 usually has a cylindrical shape. A stirring tank 7 is arranged next to the coating tank 4, and the stirring tank 7 contains a coating solution 5 and a stirring blade 8. The coating tank 4 and the stirring tank 7 are connected via a pump 6 at the bottom. An overflow tank 9 is attached to the upper part of the coating tank 4, and the overflow tank 9 is connected to the agitation tank 7 by a recovery pipe 10. As the ball screw 2 is rotated by driving the lifting motor 3,
The cylindrical substrate 1 is immersed in the coating tank 4 or pulled up from the coating tank 4.

The coating liquid 5 is stirred in the stirring tank 7 by the stirring blades 8.
Is uniformly agitated by and is supplied from the bottom of the coating tank 4 by the pump 6. In the overflow tank 9, the cylindrical substrate 1 is applied to the coating tank 4 when the coating liquid 5 in the coating tank 4 is full.
It is for preventing the coating solution 5 that overflows from the coating tank 4 from spilling out from the coating tank 4 when it is immersed in the coating solution.
Is returned to the agitation tank 7 by the recovery pipe 10.

FIG. 1 is a process chart of a first embodiment of a method for manufacturing an electrophotographic photosensitive member according to the present invention. In FIG. 1, the coating tank 14 is filled with the coating liquid 15, and corresponds to the coating tank 4 of the apparatus of FIG. FIG. 1 shows a method of applying the coating liquid 15 to the cylindrical substrate 10 and then reimmersing only the lower end of the cylindrical substrate 10 in the coating liquid 15.

In FIG. 1A, a cylindrical substrate 10 is applied to a coating tank 1
4 is a view showing a process of pulling up from 4, and a photosensitive film 11 is formed on the cylindrical substrate 10. FIG.

FIG. 1 (b) shows that the coating is completed. When the cylindrical substrate 10 is pulled out of the coating tank 14 and left as it is to dry the photosensitive film 11, a thick portion 12 of the photosensitive film 11 is formed at the lower end of the cylindrical substrate 10 due to dripping. To be done.

FIG. 1C shows that the cylindrical substrate 10 is re-immersed in the coating liquid 15 in order to remove the thick portion 12 due to the liquid dripping generated at the lower end of the cylindrical substrate 10. There is. The timing of this re-immersion is the viscosity of the coating liquid, the type of solvent, the surface of the cylindrical substrate 10 and the coating tank 14.
Although the condition varies depending on the distance from the inner wall of the cylindrical substrate, etc., when the thickened portion 12 becomes the largest, the lower end of the cylindrical substrate 10 becomes 0.
1 mm to 5 mm, preferably about 0.3 mm to 2 mm, is dipped in the coating liquid 15.

If the timing of this re-immersion is too early, even if the thick portion 12 due to dripping is absorbed in the coating liquid 15,
Further, the drips flow from above, and the thick portion 12 is formed again, and the effect cannot be expected.

If the re-immersion timing is too late,
The thick portion 12 due to the liquid dripping is dried and the coating liquid 15
Instead of being absorbed into the inside, it becomes a state of being applied twice, and the thick portion 12 becomes thicker.

Further, the immersion time is preferably 0.1 seconds to 10 seconds, and more preferably 0.2 seconds to 1 second is most efficient and has good workability.

FIG. 1 (d) shows the thick portion 1 by the above method.
After absorbing 2 into the coating liquid 15, the cylindrical substrate 10
Is pulled up from the coating tank 14 and the formation of the photosensitive film 11 is completed.

FIG. 2 is a process chart of a second embodiment of the method for manufacturing an electrophotographic photosensitive member according to the present invention. In FIG. 2, the coating tank 24 is filled with the coating liquid 25, and an overflow tank 29 is provided above the coating tank 24.
The coating tank 24 and the overflow tank 29 correspond to the coating tank 4 and the overflow tank 9 of the apparatus shown in FIG. This second
The above method utilizes a step of circulating and stirring the coating liquid 25 after coating the photosensitive film 22 in order to absorb the thick portion 22 at the lower end due to the liquid dripping into the coating liquid.

In FIG. 2A, the cylindrical substrate 20 is applied to the coating tank 2
4 is a view showing a process of pulling up from 4, and a photosensitive film 21 is formed on the cylindrical substrate 20. FIG.

In FIG. 2B, the coating liquid 25 is applied to the cylindrical substrate 2
After coating to 0, the lower end of the cylindrical substrate 20 is stopped at a height substantially equal to the upper height of the coating tank 24. The position where the cylindrical substrate 20 is stopped is 0.1 mm at the lower end of the cylindrical substrate 20 when the coating liquid 25 overflows in the coating tank 24 in consideration of the rise due to the surface tension of the coating liquid. ~ 5 mm, preferably 0.3 mm to 2 mm
It is better to be immersed in the coating liquid 25.

FIG. 2 (c) shows a process in which the coating liquid 24 is circulated for the purpose of filtration and stirring. It is a process drawing which absorbs and is processed. The cylindrical substrate 20 is held at the position shown in FIG. 2B, the photosensitive film 21 is dried to some extent, and drops due to liquid dripping are applied to the coating tank 2.
4, the coating liquid 25 is circulated from the lower part of the coating tank 24 by the circulation pump 6 of FIG. 3 and the coating liquid 25 overflows into the overflow tank 29 when the thick portion 22 becomes the largest. By the cylindrical substrate 20
Has a lower end of 0.1 mm to 5 mm, preferably 0.3 mm to 2
The thickness of about 22 mm is soaked in the coating liquid 25 so that the thick portion 22 due to the liquid dripping is absorbed in the coating liquid 25.

FIG. 2D shows the thick portion 2 formed by the above method.
2 is absorbed in the coating liquid 25, and then the cylindrical substrate 20
Is pulled up from the coating tank 24 and the formation of the photosensitive film 21 is completed.

Hereinafter, the present invention will be specifically described with reference to experimental examples, but the present invention is not limited to these experimental examples.

The following liquids A and B were used as the charge-generating coating liquid and the charge-transporting coating liquid for manufacturing the electrophotographic photosensitive member.

(Liquid A) 2 parts by weight of dibromoanthanthrone, 2 parts by weight of butyral resin (S-REC BM-2, manufactured by Sekisui Chemical Co., Ltd.), and 230 parts by weight of cyclohexanone 8 in a ball mill.
Time dispersed.

(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.

By the coating method for removing the thick portion at the lower end according to the present invention, A
After drying the solution, apply it to a film thickness of 0.5 μm and
After drying at 10 ° C. for 10 minutes, the solution B was dried so as to have a thickness of 20 μm, and dried at 80 ° C. for 60 minutes to prepare 50 photoconductors.

As a comparative example, 50 photoconductors having the same conditions and the same film thickness as those of the experimental example according to the present invention were produced by a conventional coating method in which the lower thick portion was not processed.

Repeating copying was carried out by a copying machine SF-8100 manufactured by Sharp Co., Ltd., with the external appearances of the lower ends of both of them, the amounts of the respective coating liquids used, and rotation flanges attached to both ends of the substrate. The results are shown in Table 1.

[0037]

[Table 1]

According to Table 1, the appearance condition of the lower end of the experimental example according to the present invention was not abnormal in all 50 pieces, whereas in the comparative example in which the conventional thick portion at the lower end was not treated, all 50 pieces were found. Blistering of the coating film was observed at the lower end of the.

The amount of the coating liquid used was slightly smaller in the experimental example according to the present invention than in the comparative example.

As a result of repeatedly copying 5,000 sheets, the experimental example according to the present invention showed no particular abnormality, whereas the comparative example caused a phenomenon in which black spots increased after the 3,000th sheet. After the 4000th sheet, a phenomenon was observed in which toner leakage increased.

From the above experimental results, it is possible to provide a high-quality and inexpensive photoreceptor by treating the thick portion by the method for producing an electrophotographic photoreceptor of the present invention.

[0042]

【The invention's effect】

(1) Since other devices and jigs are unnecessary, it is possible to reduce the cost of the product.

(2) Since the thick portion at the lower end is absorbed in the coating liquid, the portion can be reused as a material, so that the amount of coating liquid used can be reduced, leading to cost reduction.

[Brief description of drawings]

FIG. 1 is a process drawing showing a first embodiment according to the present invention.

FIG. 2 is a process drawing showing a second embodiment according to the present invention.

FIG. 3 is a configuration diagram of an electrophotographic photoreceptor manufacturing apparatus.

[Explanation of symbols]

 1 10 20 Cylindrical Substrate 2 Ball Screw 3 Lifting Motor 4 14 24 Coating Tank 5 15 25 Coating Liquid 6 Pump 7 Stirring Tank 8 Stirring Blade 9 Overflow Tank 10 Recovery Pipe 11 21 Photosensitive Film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayuki Sakamoto 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Inventor Hiroshi Matsumoto 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka (72) Inventor Makoto Kurokawa 22-22 Nagaike-cho, Abeno-ku, Osaka City, Osaka Prefecture

Claims (3)

[Claims] 1. A cylindrical substrate is dipped in a photosensitive coating solution, the cylindrical substrate is pulled up in the axial direction to form a photosensitive layer on the surface of the cylindrical substrate, and an electrophotographic photoreceptor is formed. A treatment method for removing a thick portion formed at a lower end portion and an adhered substance generated at an inner wall of the lower end portion, the step of relatively pulling up the cylindrical substrate in the photosensitive coating liquid in an axial direction, and the cylindrical substrate. And a step of allowing the lower end of the left cylindrical substrate to be re-immersed in the photosensitive coating liquid, the method for manufacturing an electrophotographic photosensitive member. 2. The method for producing an electrophotographic photosensitive member according to claim 1, wherein the re-immersing step comprises the step of re-immersing the lower end of the left cylindrical substrate into the photosensitive coating solution. 3. The reimmersing step causes the left-standing cylindrical substrate to be temporarily stopped near the height of the upper end of the coating tank wall to fill or overflow the photosensitive coating liquid into the coating tank. The method for producing an electrophotographic photosensitive member according to claim 1, comprising the step of immersing the lower end of the cylindrical substrate in a coating liquid.