JPH11327187A - Method for producing substrate for electrophotographic photoreceptor - Google Patents

Abstract

(57) Abstract: A surface of a cylindrical aluminum substrate of an electrophotographic organic photoreceptor is subjected to a surface roughening treatment. SOLUTION: A dry ice pellet of 0.3 to 1.0 mm is sprayed from a nozzle onto a surface of a substrate rotating at 300 to 1000 rpm at an injection rate of 0.5 to 4 kg / min, compressed air pressure × 3.
噴射 6 kg / cm ^{2 at} a flow rate of 0.5 to 2.5 m ³ / min, the nozzle is moved by moving the tool post, and dry ice pellets are sprayed at a nozzle moving speed of 2 to 15 mm per rotation of the substrate.

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 substrate used for an electrophotographic photosensitive member.

[0002]

2. Description of the Related Art An electrophotographic organic photoreceptor has a structure in which an organic photosensitive layer is provided on a substrate such as aluminum or an alloy thereof, directly or via an undercoat layer. Organic photoreceptors are excellent in terms of film-forming properties, light weight, low cost, and the like, and are increasingly used. As the organic photoreceptor, there are known a single layer type in which a photosensitive layer contains a charge generating material and a charge transfer material, and a layered type (separation type) of a charge generation layer and a charge transfer layer. However, the latter stacked organic photoreceptor is more advantageous because the range of material selectivity is widened.

In a copying machine or a printer that forms an image using an organic photoreceptor, light transmitted through a photosensitive layer on the surface of a substrate due to the coherence of monochromatic light for optical writing or semiconductor laser light. The reflected light and the reflected light on the surface of the photosensitive layer sometimes cause interference, and this has been a problem that this appears as interference fringe-like uneven shading on the image surface.

In order to solve such problems, conventionally, a light scattering agent is added to the undercoat layer to prevent interference, or the surface of the cylindrical aluminum substrate is formed by a cutting tool to form a continuous scattering surface with a cutting tool. The surface is roughened by liquid honing, superfinishing, wet or dry blasting, or formation of an anodic oxide film, and interference prevention treatment is performed as necessary.

[0005]

However, a method of preventing interference by adding a light scattering agent to the undercoat layer is to disperse titanium oxide powder in a thermoplastic resin, a thermosetting resin, or the like to form an insulating coating film. This coating film has a thickness of 5 μm or less in order to suppress a rise in residual potential in image formation, and light that has not been absorbed by the charge generation layer when performing optical writing with a semiconductor laser passes through the undercoat layer. There is a problem that image density unevenness due to transmission and reaching to the substrate surface and reflection is caused. Furthermore, it is extremely difficult to substantially uniformly roughen the surface of the substrate by simply cutting the surface of the substrate or by using liquid honing or the like, and large undulations and local irregularities are likely to occur. .

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to manufacture an electrophotographic organic photoreceptor in which the coherence of light is suppressed as much as possible and a good quality image can be obtained by treating a cylindrical aluminum substrate used in the organic photoreceptor. It provides the law.

[0007]

According to the present invention, firstly, the axis of the nozzle orifice is processed on the opposite side of the cutting tool on the tool post of the cutting machine or when the cutting tool is returned from the cutting position. A dry ice pellet injection blasting device is installed so as to be perpendicular to the axis of the workpiece, and the nozzle diameter is set to an opening of 40% or less on the outer diameter side of the workpiece, and a diameter of 0% is formed on the substrate surface after cutting. 0.3 to 1.0 mm dry ice pellets sprayed at 0.5 to 4 kg / min, compressed air pressure at 3 to 6 kg / c
m ² , a flow rate of 0.5 to 2.5 m ³ / min, and moving the nozzle by moving the tool post, spraying the nozzle at a nozzle moving distance of 2 to 15 mm per rotation of the substrate to roughen the surface of the substrate. The present invention provides a method for producing a substrate for an electrophotographic photoreceptor, characterized in that:

Secondly, there is provided the first method for producing a substrate for an electrophotographic photosensitive member, wherein the surface roughening is performed at a speed of 300 to 1,000 rotations / minute or less, which is lower than the substrate rotation speed, when the tool post is returned. Is done.

Third, the substrate before surface roughening is subjected to mirror finishing of 0.01 to 0.3 μm by cutting and then to random surface roughness of 0.5 to 2 μm by roughening. The first or second method for producing a substrate for an electrophotographic photosensitive member is provided.

Fourth, the first, second or third anodic oxide film having a thickness of 1 to 5 μm and a hardness of HV 350 to 600 is formed on the cylindrical aluminum substrate after surface roughening. The present invention also provides a method for producing an electrophotographic photoreceptor substrate.

According to the method of roughening the surface of a substrate by spraying the dry ice pellet of the present invention onto a cylindrical aluminum substrate, a desired surface of the substrate is formed. In the photographic organic photoreceptor, light interference is remarkably prevented.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. In the present invention, it is the cylindrical aluminum substrate of the organic photoreceptor whose outer peripheral surface is roughened by spraying dry ice pellets. The term “aluminum” as used herein includes not only aluminum but also an alloy of aluminum and another metal. This aluminum substrate is desirably cut before surface roughening.

FIG. 1 is a plan view of an apparatus useful for carrying out the present invention, which is provided with a cylindrical aluminum substrate outer diameter cutting machine and a dry ice pellet spray nozzle for roughening. Reference numeral 1 denotes a main shaft of an external machining machine, and a collet chuck 3 for clamping and holding an inner diameter of a cylindrical aluminum base is attached to a tip of a main spindle 2. 4
Is a tail shaft, and a collet chuck 6 similar to the above is attached to the tip of the tail shaft spindle 5 to clamp and hold the cylindrical aluminum base 7. The tail shaft spindle 5 is also a forward and backward shaft for attaching and detaching the base 7.

Reference numeral 8 denotes a cutting tool rest, on which one or a plurality of diamond cutting tools are mounted, the tool rest table 9 is advanced, and the outer diameter of the cylindrical aluminum base 7 is adjusted to the spindle rotational speed during the cutting forward step A. 3000-600
0 rpm, feed rate 0.05-0.5 mm / rev, cutting allowance 0.03-0.2 mm, surface roughness 0.01-
A mirror finish of 0.3 μm is applied. In the return step B, the tool post table 9 is returned by 5 to 15 mm, and in the return step C, the cylindrical aluminum substrate 7 is sprayed with dry ice pellets at a rotation speed of 300 to 1000 rpm from the nozzle 10 to roughen the surface.

A dry ice pellet supply hose 11 and a compressed air supply hose 12 are connected to the nozzle 10.
Dry ice pellets are constantly supplied from the pelletizer 13.

FIG. 2 is a side view of the arrangement of the nozzle 10 for spraying dry ice pellets. The nozzle 10 is arranged so that the axis of the nozzle orifice is perpendicular to the axis of the workpiece when the center of the horizontal axis of the cylindrical aluminum substrate 7 or the cutting tool is returned from the cutting position. 7 so as to be as perpendicular as possible. Reference numeral 8 denotes a cutting tool rest, reference numeral 14 denotes a return position of the diamond cutting tool at the time of returning, and reference numeral 15 denotes an aluminum chip suction port for cutting. Reference numeral 16 denotes a drive hydraulic cylinder for moving the tool rest table 9 forward and backward. The position of the outer diameter surface of the cylindrical aluminum base 7 and the position of the tip of the nozzle 10 are set by the screw knob 17 of the nozzle position adjusting table.

Unlike conventional surface-roughened materials (sand, plastic, water, etc.), dry ice pellets instantly sublimate (vaporize) without remaining or stagnation of the blasting material. It is suitable for chemical treatment. The diameter of the dry ice pellet is preferably 0.3 to 1.0 mm.
The injection amount of this is 0.5 to 4 kg / min.
A range of 6 kg / cm ² and a flow rate of 0.5 to 2.5 m ³ / min is appropriate. The nozzle is moved by moving the tool post, and dry ice pellets are sprayed at a nozzle moving distance of 2 to 15 mm per one rotation of the substrate. The surface of the cylindrical aluminum substrate is roughened.

This surface roughening method is desirably performed at a speed of 300 to 1000 rotations / minute or less, which is equal to or lower than the substrate rotation speed, when returning to the tool rest. Generally, in the processing method of finishing the substrate surface to a continuous surface roughness by cutting, a method of setting a plurality of cutting tools to improve the cutting efficiency and finishing to a predetermined continuous surface roughness on the outward path is adopted. Return the turret to the origin with. That is, in this return path, the photosensitive member does not have an effective substrate processing function. Therefore, in the present invention, it is advantageous to perform a roughening process by spraying dry ice pellets when returning to the tool rest.
Due to the surface roughening, the surface roughness of the cylindrical aluminum substrate becomes about 0.5 to 2 μm.

As described above, in the present invention, the surface of the cylindrical aluminum substrate is mirror-finished to 0.01 to 0.3 μm by cutting as a pre-surface roughening process, and the random surface roughness is obtained by the above-mentioned surface roughening method. It is preferable to apply 0.5 to 2 μm. Surface roughening by cutting is to form a continuous roughness that intersects the axial direction of the substrate, and in the dip coating method in photoconductor manufacturing, which is currently the mainstream of production, when the coating liquid is dried, There is a problem that uneven coating is formed due to the continuous roughness and undulation. Therefore, continuous roughness due to cutting and undulations resulting therefrom can be removed by mirror finishing and roughening methods.

In the image forming process of the function-separated type organic photoreceptor for electrophotography, charging and exposure at 600 to 1000 V are repeated. It is the photoreceptor film that takes charge of the electrostatic capacitance C in the dark.
And the resistance R is determined. When the aluminum substrate surface is a natural oxide film, it hardly contributes to the charging. Therefore, it is effective to perform the anodic oxide film treatment to add the resistance R and the capacitance C to the aluminum substrate surface. It is. When a general anodic oxide film is used for the image formation process on the high charge side, the volume resistivity is about 5 × 10 ¹² Ω · cm, and the withstand voltage tends to be slightly low. Requires a high withstand voltage.

Therefore, as shown in FIG. 3, in the function-separated type organic photoreceptor for electrophotography of the present invention, the surface 19 of the substrate 18 is roughened to a surface roughness of 0.5 to 2 μm by spraying dry ice pellets. After cleaning, the anodic oxide film 20 is formed on the surface with a hardness of HV 350-600 and 1-5.
It is formed to a thickness of μm. This anodized film can be formed by performing anodization in an electrolytic solution such as sulfuric acid, phosphoric acid, nitric acid, or a mixture thereof.

In the function-separated type organic photoreceptor, the undercoat layer 21
A light scattering agent is dispersed to form a coating film of 3 to 5 μm or 10 to 15 μm to smooth the surface of the substrate 18, and the coating unevenness of the charge generation layer 22 as thin as 0.1 to 0.5 μm. Suppress the occurrence. Reference numeral 23 denotes a charge transport layer, which determines the film thickness in accordance with the charge amount. 1 for normal function-separated organic photoreceptor
5 to 30 μm.

In the charge exposure process of the photowriting photosensitive member by the semiconductor laser light 24, the charge amount is determined by the charge transport layer 2
3. Determined by the electric capacity C and the resistance R of the charge generation layer 22, the undercoat layer 21, and the surface layer of the substrate 18. When the surface of the substrate 18 is untreated, charge injection is facilitated and dark decay after charging is performed. Is increased, or a high charge causes a partial leak to cause defects such as black spots and white spots on an image. Therefore, the anodic oxide coating 20 is applied. With this coating, the surface area is further increased, the capacitance C is increased, and the anodic oxide coating 20 is formed.
The volume resistivity of the coating is 1 × 10 ¹³ Ω
The stability at the time of charging is further increased by increasing the value to cm.

When optical writing for image formation is performed after charging, most of the light absorbed by the charge generation layer 22 generates photocarriers. However, 5 to 10% of the light passes through the undercoat layer 21 which is a light scattering surface and is reflected on the surface of the base 18. When the surface of the substrate 18 is a mirror surface or when a regular reflection surface is partially formed, the transmitted light is regularly reflected and re-enters the charge generation layer and is absorbed, thereby causing density unevenness and moire on an image. However, these defects can be prevented on the roughened surface where the anodic oxide film is formed.

[0025]

(1) According to the first aspect of the present invention, by attaching the dry ice pellet injection blasting device to the cylindrical aluminum substrate cutting machine, it is possible to spray the pellet without removing the cylindrical aluminum substrate immediately after cutting. Compared to the case of removing and roughening in a separate process by removing the surface, it is possible to share the drive mechanism and control such as holding, rotation and nozzle feed of the cylindrical aluminum substrate with the substrate cutting machine, and manufacture Processing can be performed without extending the process.

(2) According to the second aspect of the present invention, in the cutting of the cylindrical aluminum substrate, a cutting origin is set on the spindle side of the spindle to facilitate attachment and detachment of the workpiece, and the starting point is set from the cutting start point. The cutting tool is arranged 5 to 10 mm before and the cutting process is performed in the forward process, and the tool is pulled back in the returning process to return the tool post to the cutting origin. The return time in the return step takes about 3 to 5 seconds for a normal cylindrical aluminum substrate, and the above-described roughening step is performed at a substrate rotation of 300 to 1000 rpm.
By doing so, processing can be performed without prolonging the cutting time.

(3) According to the third aspect of the present invention, the function of the surface of the cylindrical aluminum substrate by cutting is to incorporate a rough surface for preventing unevenness in image formation and moire, etc. into a constant flattening. If the surface is roughened by the above method, the cutting process only needs to be flattened, the feed radius is increased by increasing the cutting edge radius of the cutting tool, cutting can be done close to mirror finishing, and cutting efficiency can be increased, and cutting Processing time in the process can be taken. When the substrate before surface roughening is cut to a surface roughness of 0.1 to 0.3 μm, the surface becomes a regular reflection surface, and subsequently, when the surface is roughened by spraying the dry ice pellet, the regular reflection surface becomes Since this disappears, if this specular reflection component is detected, it is possible to determine whether or not the roughening is appropriate. The surface roughening by spraying of the dry ice pellets is a random rough surface unlike the continuous roughness of the cutting process. 2
If the roughness exceeds μm, burrs and the like are likely to occur and image defects are likely to occur.

(4) According to the fourth aspect of the present invention, the surface of the cylindrical aluminum substrate roughened by spraying the dry ice pellets is washed and then subjected to an anodic oxidation treatment, whereby the undercoating layer is coated. And the defect size of the coating film becomes finer and disappears. Also, since the surface area increases, the capacitance C component increases, and if the anodized film is hard, the volume specific resistance can be increased as compared with a general anodized film, and the minute partial discharge during charging can be reduced.
White spots and black spots can be reduced as image defects.

[Brief description of the drawings]

FIG. 1 is a diagram showing a substrate outer diameter cutting machine and a dry ice pellet spraying nozzle mounting position for roughening.

FIG. 2 is a diagram illustrating an arrangement of a nozzle for spraying dry ice pellets.

FIG. 3 is a schematic sectional view of a function-separated organic photoconductor for electrophotography.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer diameter cutting machine main spindle 2 Spindle spindle 3 Collet chuck 4 Tail axis 5 Tail axis spindle 6 Collet chuck 7 Cylindrical aluminum base 8 Cutting tool post 9 Tool post table 10 Dry ice pellet spray nozzle 11 Dry ice pellet supply hose Reference Signs List 12 compressed air supply hose 13 pelletizer 14 return position of diamond cutting tool at return path 15 aluminum chip suction port 16 tool post table table drive forward / backward hydraulic cylinder 17 nozzle position adjustment stand screw knob 18 base 19 base surface 20 anodic oxide film 21 undercoat layer Reference Signs List 22 charge generation layer 23 charge transfer layer 24 semiconductor laser light

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Terushima Tateshima Ricoh Co., Ltd. 1-3-6 Nakamagome, Ota-ku, Tokyo

Claims (4)

[Claims] Dry ice pellets such that the axis of a nozzle orifice is at right angles to the axis of a workpiece when the tool is returned from the cutting position to the opposite side of the tool on the tool rest of the cutting machine. An injection blasting device is installed, and the diameter of the nozzle is set to an opening of 40% or less on the outer diameter side of the workpiece. 0.5 to 4 kg / min, compressed air pressure 3 to
The nozzle is moved by 6 kg / cm ² , the flow rate is 0.5 to 2.5 m ³ / min, and the tool post is moved, and the nozzle is sprayed at a nozzle moving distance of 2 to 15 mm per rotation of the substrate to roughen the surface of the substrate. A method for producing a substrate for an electrophotographic photoreceptor. 2. The method for manufacturing a substrate for an electrophotographic photosensitive member according to claim 1, wherein said surface roughening is performed at a speed of 300 to 1000 revolutions / minute or less, which is equal to or lower than the substrate cutting speed, when the tool post is returned. 3. The substrate before surface roughening is subjected to mirror finishing of 0.01 to 0.3 μm by cutting, and then to random surface roughness of 0.5 to 2 μm by roughening. The method for producing a substrate for an electrophotographic photoreceptor according to claim 1 or 2, wherein 4. The electrophotograph according to claim 1, wherein an anode strengthening film having a thickness of 1 to 5 μm and a hardness of HV 350 to 600 is formed on the cylindrical aluminum substrate after the surface roughening. A method for manufacturing a photoreceptor substrate.