JPH04233550A - Electrophotographic sensitive body and its production - Google Patents

Abstract

PURPOSE:To obtain excellent picture image characteristics with little fogging. CONSTITUTION:A charge generating layer is formed on a conductive substrate, on which a charge transfer layer is formed to constitute a function-separating type electrophotographic sensitive material. This conductive substrate is an aluminum substrate 1 obtd. by anodizing an aluminum plate and sealing the anodic oxide film with particles of <=0.5mum. max. particle diameter and >=400 particles/mum<2>. This electrophotographic sensitive material is produced by subjecting the conductive substrate to desmutting, anodic oxidation and sealing to remove coarse particles, and then forming a charge producing layer 3 and further a charge transfer layer 4.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly to a functionally separated electrophotographic photoreceptor.

0002

[Prior Art] Conventionally, in a functionally separated photoreceptor having a charge generation layer made of an organic pigment or organic dye, an anodized film is formed by anodizing an aluminum substrate, and a charge generation layer made of an organic pigment or dye is formed on the anodized film. An organic dye is formed to a thickness of about 0.1 μm by vacuum deposition or painting, and a charge transport layer made of an organic substance is further applied on this charge generation layer to a thickness of about 2 to 10 μm by coating.
It is formed to have a thickness of μm.

Conventionally, as a substrate for such a functionally separated photoreceptor, the surface of an aluminum tube manufactured by extrusion or drawing is smoothed by cutting, and then an anode is formed in a solution of sulfuric acid, oxalic acid, etc. An oxidized material is used, and the charge generation layer and charge transport layer are formed thereon. In addition, as a substrate, an aluminum plate was formed into a desired tube shape by drawing, and then anodized, and then a charge generation layer and a charge transport layer were formed, and then a pore sealing treatment was performed after the anodization. There are also those in which a charge generation layer and a charge transport layer are formed.

These functionally separated photoreceptors have charge retention properties, high sensitivity, repetition stability, dielectric breakdown resistance, abrasion resistance,
It is required to satisfy basic properties such as durability, moisture resistance, transferability, cleanability, and storage stability. Furthermore, the anodic oxide film that is the base of the charge generation layer is required to have adhesion to the charge generation layer, charge injection prevention properties, insulation properties, rectification properties, and the like.

[0005]

[Problems to be Solved by the Invention] As mentioned above, the charge generation layer is formed by vacuum depositing or painting an organic pigment or organic dye on the anodic oxide film. This may result in fogging during electrophotographic image formation. However, during manufacturing, there are variations in the thickness of the charge generation layer, such as when a predetermined thickness is obtained and when the thickness is increased, and the cause of this variation is unknown. On the other hand, there is an advantage that the thinner the charge generation layer is, the lower the residual potential and the less fogging, and it is desired to reduce the layer thickness of the charge generation layer. SUMMARY OF THE INVENTION An object of the present invention is to provide a photoreceptor and a method for manufacturing the same that eliminate the above-mentioned drawbacks.

[0006]

[Means for Solving the Problems] The present inventors have conducted various studies in order to overcome the above-mentioned difficulties in the conventional electrophotographic photoreceptor and its manufacturing method, and as a result have discovered the following fact. In other words, the charge generation layer becomes thicker than a predetermined thickness when the microscopic shape of the surface after the sealing treatment is rougher than usual. The charge generation layer is formed thicker than usual to increase the actual surface area and increase the anchoring effect. In addition, when forming a charge generation layer by vacuum evaporation, it was found that if the surface becomes rough after the sealing treatment, the charge generation layer is preferentially formed on the convex parts of the surface, resulting in locally thick parts. . The cause of this microscopic roughness is fine particles, and if these particles are large, the charge generation layer becomes thicker and fogging is likely to occur. It was also revealed that the smut generated during the sealing process remained until after the sealing process was completed, and that it was aluminum hydroxide that formed on the surface during the sealing process. The reason why the roughness of the surface of the anodic oxide film varies during production is that the liquid concentration, bath temperature, etc. of the entire anodizing process including pretreatment and sealing process vary during the process.

[0007] The present inventors have made this work based on these findings. That is, the present invention provides (1) a functionally separated electrophotographic photoreceptor in which a charge generation layer is formed on a conductive substrate and a charge transport layer is formed thereon, in which the conductive substrate is an anodized substrate; An electrophotographic photoreceptor, characterized in that the surface thereof is coated with particles having a maximum diameter of 0.5 μm or less and a number of particles of 400 particles/μm or more, which is anodized and then sealed. 2) A charge generation layer is formed on the conductive substrate after smut removal treatment, anodization treatment is performed, and coarse particles are removed by sealing treatment, and a charge transport layer is formed on this. (3) A method for producing an electrophotographic photoreceptor according to claim 2, wherein the surface after the sealing treatment has a particle layer with a maximum diameter of 0.5 μm or less and a number of particles of 400 particles/μm 2 or more. and (4) the method for producing an electrophotographic photoreceptor according to claim 2, characterized in that the sealing treatment is performed with a solution containing 0.01 g/l or more and 50 g/l or less of nickel acetate. It is something to do.

The electrophotographic photoreceptor of the present invention will be described according to one embodiment shown in the drawings. FIG. 1 is a sectional view of the electrophotographic photoreceptor, in which 1 is an aluminum substrate, 2 is an anodized film, and 2a is an anodized film. The maximum diameter formed on the surface is 0.5 μm
Hereinafter, a surface layer having particles of 400 particles/μm2 or more, 3 a charge generation layer, and 4 a charge transport layer are shown.

The present invention is basically the same as the conventional method except that a specific surface layer 2a is formed on the surface of the anodic oxide film 2, and the thickness of each constituent layer is also set according to the conventional method. I can do it. Further, in the present invention, the charge generation layer 3 is formed by vacuum deposition or painting using an organic pigment or an organic dye.

In the present invention, there is no particular restriction on the thickness of the surface layer 2a, and the particles of the surface layer 2a may be formed in either a single layer or a multilayer structure, but they are usually formed in a multilayer structure.

However, the particles may be within the above range for particles exposed on the surface. On the other hand, if the number of particles covering the surface exceeds 0.5μm or the number of particles is 400/μm.
If it is less than m2, the surface becomes rough and fogging is likely to occur during photographic image formation.

Next, the method for manufacturing the electrophotographic photoreceptor of the present invention will be explained. The aluminum used as the substrate may be either aluminum or an aluminum alloy, and there are no particular restrictions on the type of alloy or the method for manufacturing it. Furthermore, the pretreatment degreasing may be acidic, alkaline, or neutral, and the etching may be acidic or alkaline.

[0013] The anodic oxidation treatment can be carried out according to a conventional method, and there are no particular restrictions, but the so-called sulfuric acid method is preferred because it uses inexpensive chemicals, is economically superior, and has a fast film formation rate and excellent productivity. Basically, it is not limited to the sulfuric acid method, but may also be a single or mixed solution of oxalic acid, phosphoric acid, chromic acid, etc., and the electrolysis method is particularly limited, such as constant current, constant voltage, pulse method, two-stage electrolysis method, etc. It's not a thing.

[0014] Smut (insoluble residue) removal treatment is performed before anodizing, but this is to prevent smut generated during pretreatment degreasing and etching from remaining until after the sealing treatment and forming coarse particles. It's for a reason. As a smut removal method, acidic solutions such as nitric acid and hydrofluoric acid can be used alone or as a mixed solution of two or more.

Furthermore, using a sealing solution containing 0.01 g/l or more and 50 g/l or less of nickel acetate is because nickel acetate has traditionally been used as a sealing accelerator (sealing aid). This is because when added in an appropriate amount, it has the effect of making the surface particles finer. However, 0.01g/
If it is less than 1, the particles of aluminum hydroxide generated during sealing will become coarse and roughen the surface, and if it is more than 50 g/l, a powdery state will occur, so it is preferably 0.01 g/l or more and 50 g/l or less. The sealing solution contains 0.01g of nickel acetate.
There is no problem even if other ions such as fluorine compounds, Co, and Si are contained as long as they are contained in an amount of at least /l and at most 50g/l.

[0016]

EXAMPLES Examples of the present invention are shown below, but it goes without saying that the present invention is not limited in any way by the description of these examples. Example 1 JIS A5052 material was extruded to an inner diameter of 30 mm.
A tube with an outer diameter of 32 mm and a length of 300 mm was manufactured, the surface was polished to a mirror finish, and then washed with a commercially available neutral degreaser.
Perform etching treatment by dipping for seconds, and after washing with water, 30wt%H
Smut was removed by immersing it in a NO3 solution for 1 minute at room temperature. After that, it was washed with water and anodized. The anodic oxidation treatment was performed using a 15 wt % sulfuric acid solution at a bath temperature of 20° C. and a current density of 1 A/dm 2 to form a film of 6 μm. After the anodic oxidation, it was washed with water, and then sealed by immersion in a nickel acetate solution having the concentration shown in Table 1 at 50° C. for 10 minutes. The sample is immersed in a charge generator material solution containing an azo organic pigment to form a charge generation layer on the surface, and then a 15 μm thick charge transport layer containing a hydrazone derivative is formed to produce a photoreceptor. did.

The resulting photoreceptor was subjected to reversal development using a powder image transfer type copying machine, and the occurrence of fog and black spots on the image was examined. The fine particles on the surface were measured by taking a photograph with a scanning electron microscope at a magnification of 50,000 times. The results are shown in Table 1.

[0018]

[Table 1]

[0019]

According to the electrophotographic photoreceptor of the present invention, excellent image characteristics with less fog can be obtained. Moreover, the method of the present invention can be easily implemented industrially to produce electrophotographic photoreceptors with such excellent performance.

[Brief explanation of the drawing]

FIG. 1 shows a cross-sectional view of one embodiment of the electrophotographic photoreceptor of the present invention.

[Explanation of symbols]

1 Aluminum substrate 2 Anodic oxide film 2a Surface layer 3 Charge generation layer 4 Charge transport layer

Claims (4)

[Claims] Claim 1: Forming a charge generation layer on a conductive substrate,
In the functionally separated electrophotographic photoreceptor on which a charge transport layer is formed, the conductive substrate is an anodized substrate, the surface of which has a maximum diameter of 0.5 μm or less;
An electrophotographic photoreceptor characterized by using an aluminum substrate coated with particles having a number of 400 particles/μm2 or more and subjected to an anodizing treatment and a sealing treatment. 2. After smut removal treatment, anodizing treatment is performed, and after sealing treatment is performed to remove coarse particles, a charge generation layer is formed on this conductive substrate, and a charge transport layer is formed on this. A method for manufacturing an electrophotographic photoreceptor, characterized by: [Claim 3] The surface after sealing treatment has a maximum diameter of 0.5 μm.
The method for producing an electrophotographic photoreceptor according to claim 2, wherein the electrophotographic photoreceptor has a layer of particles of 400 particles/μm2 or more. Claim 4: The pore sealing treatment was performed using 0.01 nickel acetate.
3. The method for producing an electrophotographic photoreceptor according to claim 2, wherein the method is carried out using a solution containing at least 50 g/l.