JPS61209457A - Method for processing conductive substrate surface of electrophotographic sensitizing material - Google Patents

Abstract

PURPOSE:To attain a uniform surface roughness ensuring an appropriate adhesive strength between a surface and a photosensitive layer and to insure a harmful substance developing a critical partial picture defect against leaving by executing grinding and making the surface into a coarse surface with a grinding tape available from bonding a flexible base material to abrasive grains. CONSTITUTION:An aluminum circular substrate 1 having 0.6-0.8mum in surface roughness R2 (JIS + peak average roughness), whose outer surface is machined and ground, is set to a lathe. A grinding device 2 equipped with a grinding tape supply roller 4, a grinding tape winding roller 5, a motor 6 rotating and driving these rollers, a tension roller 7 and a torque motor 8 for rotating and driving said roller 7 is similarly fitted to the lathe, and moreover the grinding tape 3 available from adhering securely the abrasive grain to the flexible base material with an adhesive is set. The circular substrate 1 is rotated in the prescribed direction, and the grinding tape 3 is pressed on the outer surface of the substrate with the prescribed pressure. While the tape 3 is traveling in the direction reverse to the rotating one of the circular substrate 1 and is moving slowly in the axial direction of the circular substrate 1, the surface is ground and made into a roughness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field to which the Invention Pertains] The present invention 4 relates to a method for surface processing a conductive substrate of an electrophotographic photoreceptor in which a photosensitive layer is provided on a conductive substrate.

[Prior art and its problems]

2. Description of the Related Art Electrophotographic photoreceptors (hereinafter also simply referred to as photoreceptors) are used in so-called electrophotographic devices, such as electrophotographic copying machines and printers. At that time, for example, in a dry copying machine using the Carlson method, which is a typical electrophotographic method,
First, the surface of the photoreceptor is uniformly charged with an electrostatic charge by corona discharge or the like. Thereafter, by exposing this surface to imagewise light, the electrostatic charge in the exposed area disappears, and an electrostatic latent image corresponding to the light gRK is formed on the surface of the photoreceptor. Next, toner is applied to this electrostatic latent image to form a toner image, and the toner image is transferred and fixed onto paper or the like to obtain a copy. On the other hand, the photoreceptor removes any static charge remaining on its surface electrically.

The static electricity is removed optically, and any remaining toner is mechanically removed using a brush or blade, thereby cleaning the surface and preparing it for repeated use.

In a so-called cleaning process in which the residual toner is mechanically removed, a considerable load is applied to the surface of the photosensitive layer of the photoreceptor. Therefore, adhesion between the photosensitive layer and the substrate is required to the extent that the photosensitive layer does not peel off due to this force.

The surface of the conductive substrate (hereinafter simply referred to as the substrate) of the photoreceptor is preferably a smooth mirror surface with as few irregularities as possible from the viewpoint of uniformity of its electrophotographic characteristics and copying characteristics. Finishing K causes problems with respect to the adhesion of the photosensitive layer mentioned above.

An interlayer of organic adhesive was provided between the mirror-finished substrate surface and the photosensitive layer to improve adhesion, but this resulted in drawbacks such as contamination of impurities and deterioration of electrophotographic properties such as an increase in residual potential. was there.

An effective method is to roughen the surface of the substrate to improve the adhesion of the photosensitive layer and to reduce adhesion. However, roughening the surface of the substrate itself is unfavorable in terms of the electrophotographic characteristics of the photoreceptor and the uniformity of the copied image characteristics.
Therefore, it is desirable to have a method of uniformly roughening the surface with the minimum necessary roughness in order to obtain suitable adhesion, and a method that minimizes the mixing and adhesion of harmful impurities, and various surface roughening methods have been proposed.

The method of chemically etching the surface of a mirror-finished substrate is an effective method in terms of obtaining a uniformly rough surface, but it does not provide sufficient adhesive strength between the substrate and the photosensitive layer. Another drawback is that the processing steps before and after etching are complicated.

Further, surface roughening by liquid honing causes long-period waviness and non-uniform surface roughness, resulting in non-uniformity and deterioration of the electrophotographic characteristics of the photoreceptor.

Although the grinding method and superfinishing method are considered to be considerably more effective methods than the above-mentioned methods, uneven surface roughness occurs due to partial clogging of the grindstone. Further, as a self-generating action of the cutting edge during grinding, the abrasive grains are crushed and fallen off, and it is unavoidable that these fallen and crushed abrasive grains bite into the surface of the substrate and remain. Sara K.

Cutting agents such as water and oil are used to prevent clogging of the grinding wheel and promote self-growth of the cutting edge of the abrasive grains. Cleaning requires a complicated process, and even if ultrasonic cleaning is performed, it is difficult to completely remove residual abrasive grains and cutting agents.

Uneven surface roughness due to clogging of the grinding wheel and residual abrasive grains and cutting agents can cause unevenness and deterioration of electrophotographic characteristics of the photoreceptor, and unevenness of copied images, especially fatal localized images. It had the disadvantage of causing defects.

[Purpose of the invention]

The purpose of the present invention is to eliminate the drawbacks of the various surface finishing methods described above, and to uniformly improve the surface roughness of the photoreceptor substrate to a surface roughness that can change the adhesion strength to the photosensitive layer. It is an object of the present invention to provide a surface finishing method that roughens the surface so that harmful substances that cause image defects do not remain and provides good electrophotographic characteristics and image characteristic sound.

[Key points of the invention]

The object of the present invention is achieved by polishing and roughening the surface of the photoreceptor using an abrasive tape containing abrasive grains attached to a flexible base material as a final finishing process on the surface of the photoreceptor.

The abrasive tape described above is a thin sheet tape-like material in which abrasive grains are fixed to a flexible base material, such as a polyester film, with an adhesive. When polishing by pressing the abrasive-fixed surface of this abrasive tape against the surface of the substrate to be polished, the flexibility of the abrasive tape does not apply enough force to cause the abrasive grains to break or fall off. Polishing is performed without causing any scratches, and moreover, this polishing can remove abrasive grains and other foreign matter that have bitten into the substrate surface during previous processing and remain. However, if the same polishing surface of this polishing tape is repeatedly used, abnormal surface roughening occurs due to clogging, so it is necessary to polish the same polishing surface only once.

Furthermore, the grinding force of surface roughening using this abrasive tape is weaker than that of the conventional grinding method. Therefore, when processing the substrate, it is recommended to roughen the surface using an abrasive tape and remove remaining abrasive grains and other foreign matter as a finishing step after cutting and grinding with a whetstone. This will shorten the processing time of the substrate. This is valid.

[Embodiments of the invention]

The present invention will be described below with reference to embodiments and the drawings.

Example 1. ~3゜ Fig. 1 is a block diagram conceptually showing an embodiment of the present invention, in which Fig. 1(a) is a side view of the base body viewed from the direction of the cylinder axis, and Fig. 1(b) is a side view of the base body as seen from the direction of the cylinder axis. ) is a side view seen from a direction perpendicular to the cylinder axis.

The outer surface is cut and ground with a whetstone to achieve a surface roughness of RS (JI
An aluminum cylindrical substrate 1 having a ten-point average roughness of 0.6 to 0.8 μm is mounted on a lathe (not shown). Also, a polishing tape supply roller 4, a polishing tape take-up row 25. A polishing device 2, which is equipped with a motor 6 for rotationally driving these rollers, a tension roller 7, and a torque motor 8 for rotationally driving these rollers, is also attached to the lathe, and a polishing tape 3 is set thereon. The cylindrical base 1 is rotated in a predetermined direction, and the polishing tape 3 is pressed against its outer surface with a predetermined pressure, and is gradually moved in the axial direction of the cylindrical base 1 while running in the opposite direction to the rotation direction of the cylindrical base 1. Polish and roughen the surface while moving. The pressing pressure of the polishing tape 3 is adjusted by the relative position between the base 1 and the polishing device 2 and the tension roller 7 connected to the torque motor 8, and the running speed of the polishing tape 3 is adjusted by the polishing tape supply roller connected to the motor 6. 54 and the abrasive tape take-up roller 5. The axial movement of the polishing tape 30 and the cylindrical base unit is performed by moving the entire polishing device 2 in the axial direction.

Using the polishing method described above, using three types of polishing tape manufactured by Nitto Electric Industry ■, the outer diameter was 80m+ under the following conditions.
An aluminum cylindrical substrate having a wall thickness of 3 m and a length of 328 mm was surface-treated to obtain the substrates of Examples 1 to 3. The type of abrasive tape and the roughness of the substrate surface observed in each example are shown in Part 1.

Processing conditions Polishing tape tension 5 kg Polishing speed (substrate outer peripheral surface speed) 6 m/min Polishing tape running speed
0.5m/min Abrasive tape axial movement speed 6w/rotation (base) Daphne cut abrasive (Product name) MS-5 (
(manufactured by Idemitsu Kosan) Table 1 Comparative Example 1 An aluminum cylindrical substrate having the same dimensions as Examples 1 to 3 was cut and then ground with a whetstone under the following conditions to obtain a substrate of Comparative Example 1. The JIS ten point average roughness 1 of the surface is 0.
It was 6 μm.

Processing conditions: Grindstone used: FBB Gos100
0 (manufactured by Japan Special Abrasive) Grinding wheel pressure 0.8 kg/cj Polishing speed (polishing outer surface speed) 1 U Om/min Grinding wheel pressure
1.5■/rotation Example 4゜Examples 1 to 3 Comparative Example 10 After washing the cloth,
A selenium-tellurium alloy was vacuum-deposited to a thickness of 60 μm at a substrate temperature of 70° C. to obtain an electrophotographic photoreceptor. For these photoreceptors, the adhesion of the Cere/tellurium layer to the substrate is related to the surface roughness, the halftone image uniformity is related to the uniformity of the surface roughness, and the abrasive grain.

Halftone white spots related to residual foreign matter such as abrasives on the substrate surface were investigated for defects.

Adhesion was determined by dropping a steel ball f 1 m in weight and 8 m in diameter onto the surface of the photoconductor, and then applying cellophane tape (Ml 405, manufactured by Nippon Pan) to the selenium and
The selenium-tellurium layer (7) was adhered to the surface of the tellurium photosensitive layer, and then the seven-layer tape was forcibly peeled off, and the evaluation was based on the surface area of the substrate from which the selenium-tellurium layer (7) was peeled off.

○ mark: Peeling only at the steel ball falling area △ mark: Peeling area 1- or less Attach a photoreceptor to a dry copying machine and use the standard chart (Electrophotography Society 1982111L)
After making 20,000 copies of 3 charts), a halftone original of the size of A3 paper is copied, and the uniformity of the image quality of the copied halftone images is visually evaluated.

O mark... Image quality is uniform across the entire surface Δ mark...
...White spots in halftones where streaks are partially seen are defects.White spots that occur in the area (824-) corresponding to one rotation of the photoreceptor in the halftone image mentioned above are evaluated by the number of defects. .

The evaluation results are shown in Table 2.

Table 2 also shows Examples 1 to 3. Regarding the substrates processed under the respective conditions of Comparative Example 1, the residual status of abrasive grains on the substrate surface was examined using a microscope.
There were residual abrasive grains (area of i x 45 μm), but no residual abrasive grains were observed in Examples 1 to 3. From these evaluation results, each example is an excellent method for preventing the residue of abrasive grains and other foreign substances compared to the comparative example, and in particular, Example 1
．． It can be seen that method 3 is a very effective method for roughening the surface of a substrate, which uniformly roughens the surface of the substrate with good adhesion and leaves no residue of abrasive particles.

Embodiments 5 and 6 Fig. 2 is a conceptual diagram showing another embodiment of the present invention. Fig. 2 (a) is a side view of the base body as seen from the direction of the cylinder axis, and b) The figure is a side view seen from a direction perpendicular to the cylinder axis.

An aluminum cylindrical base 1 whose outer surface has been subjected to cutting and grinding is attached to a lathe (not shown). Also, the polishing tape supply row 24°, the polishing tape take-up roller 5°, and the motor 6 that rotates these rollers.
Tension roller roller, torque motor that rotationally drives it 8. Polishing tape 3t - A polishing device 2 equipped with an air cylinder 9 whose shaft is equipped with a contact roller 10 for pressing against the surface of the substrate is also attached to the lathe, and the polishing tape 3 is set therein. The cylindrical base 1 is rotated in a predetermined direction, and the polishing tape 3 is applied to the outer surface of the contact roller 10. It is pressed at a predetermined pressure by air pressure via an air cylinder 9, and is polished and polished on the surface while running in the direction opposite to the direction of rotation of the cylindrical base 10 and gradually moving in the axial direction of the cylindrical base l. Perform surface roughening. To prevent the polishing tape 3 from bending, a tension roller 7 connected to a torque motor 8 applies the required tension to the polishing tape 3.
The running speed of the polishing tape 30 is adjusted by a polishing tape supply roller 4 and a polishing tape take-up roller 5 connected to a motor 6. The axial movement of the cylindrical base 1 of the polishing tape 3 is performed by moving the entire polishing device 2 in the axial direction.

An aluminum cylindrical substrate having an outer diameter of 80 aa, a wall thickness of 3 cm, and a length of 328 cm was surface-processed using the above-mentioned polishing method under the following conditions. At that time, the material of the contact roller was changed to obtain the substrates of Examples 5 and 6. The material of the contact roller used in each example and the roughness of the substrate surface observed were
Shown in the table.

Processing conditions Polishing tape GO+ 2000 (manufactured by Nitto Electric Industry ■) Polishing tape tension 5 kg Polishing speed (substrate outer peripheral surface speed) 5 m/min Contact roller pressure 5 to 10 kg / 25 wa Polishing tape running speed 0.5 m/min Polishing tape axial direction Movement speed: 6 doves/rotation (substrate) Daphne cut (Product abrasive name) Ha-5 (manufactured by Idemitsu Kosan) After cleaning the substrate of Example 5.6 after 2 years and 3 years, the selenium-tellurium alloy was heated at 70°C. were vacuum-deposited to a thickness of 60 μm to produce electrophotographic photoreceptors, and the characteristics of these photoreceptors were evaluated according to Example 4. The results are shown in Table 4. was not observed as in Examples 1 to 3. It can be seen that Examples 5 and 6 are excellent substrate surface processing methods as well as Examples 1 and 3, but in addition, the provision of the contact roller 10 increases the pressing force of the abrasive tape against the substrate surface. Since the grinding force can be increased, it is also possible to omit the preliminary grinding process.

Furthermore, if the shape of the contact roller is such that both ends of the roller 10 are chamfered with an inclined t as shown in the front view of FIG. 3, both sides of the polishing tape 3 will follow the shape of the contact roller. The edge of the abrasive tape will no longer touch the substrate surface as it will curl toward the contact roller side. Thus, in the polishing operations of Examples 1 to 3, it is possible to prevent "feed marks" (partial deep scratches) that may occur due to the edges of the polishing tape when the polishing tape moves in the axial direction of the substrate. The abstract is valid.

The surface roughness of the substrate obtained by the polishing method of the present invention can be set to any desired value by appropriately selecting the type of polishing tape, processing conditions, number of times of polishing, etc.

〔Effect of the invention〕

As described above, the method of the present invention, in which the final surface treatment of the conductive substrate of an electrophotographic photoreceptor is polished with a flexible abrasive tape, allows the substrate to be polished uniformly over the entire surface and in appropriate contact with the photosensitive layer. This is a very effective surface roughening method that can roughen the surface of the substrate to a degree that increases adhesive strength, and can also remove abrasive grains and other harmful foreign substances that can cause fatal defects in reproduced images. . When a photoreceptor is manufactured using a substrate that has been processed in this way, it has excellent electrophotographic properties and durability, and has good image characteristics, and in particular, there is no white spot in the image, which is a fatal defect in reproduced images. An extremely excellent electrophotographic photoreceptor can be obtained.

[Brief explanation of drawings]

1(a) is a side view of a cylindrical conductive substrate viewed from the axial direction, and FIG. 1(b) is a cylindrical 4 [ FIG. Fig. 2 is a conceptual configuration diagram showing another embodiment of the present invention, in which Fig. 2(a) is a side view of a cylindrical conductive substrate viewed from the axial direction, and Fig. 2(b) is a cylindrical conductive substrate. This is a side view of the electrically conductive substrate viewed from a direction perpendicular to its axis. FIG. 3 is a front view showing one shape of the contact roller shown in FIG. 2. FIG. DESCRIPTION OF SYMBOLS 1... Conductive substrate, 2... Polishing device, 3... Polishing tape. 2. L Rosi M1 Figure 2 Figure 3

Claims (1)

[Claims] 1) In a method for processing the surface of a conductive substrate of an electrophotographic photoreceptor, the surface is polished and roughened using an abrasive tape in which abrasive grains are bonded to a flexible substrate as the final finishing treatment of the surface. 1. A method of processing a surface of a conductive substrate of an electrophotographic photoreceptor, the method comprising: