JPH0481861A - Manufacture of electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To manufacture a photosensitive body having an improved image characteristic without generating inferior image with lines or unevenness by forming an anodically oxidized coating on an Al base surface, subsequently washing with a cleaning solution incorporating alcohol or ketone and forming a photosensitive layer on the anodically oxydized coating after drying. CONSTITUTION:Any Al base body, in which Al is present as a major component, being capable of forming an anodically oxydized coating on the surface can be used. Formation of the anodically oxydized coating on the surface of such an Al base body is performed with an electrolysis by using the base body as an anode in an acidic aqueous solution such as oxalic acid and hydrosulfuric acid and after forming the coating, the acid is washed away and the impurity adhered on the surface is washed to remove it. The anodically oxydized coating film formed such a manner is porous and the sealing treatment may be required in some case. In order to seal efficiently, the Al base body may be treated to immerse it in an aqueous solution incorporating a metallic salt such as Ni acetate as a sealing treating agent. Thus by washing the Al base body with the cleaning solution incorporating alcohol or ketone, the image defects with lines or unevenness is efficiently prevented.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing an electrophotographic photoreceptor, and more specifically, an electrophotographic photoreceptor using an aluminum substrate on which an anodized film is formed. The present invention relates to a method of manufacturing a photoreceptor, and more specifically, to a method of preventing image defects specific to such an electrophotographic photoreceptor.

(Prior Art) Image forming systems using electrophotography have been widely applied in the field of copying, and recently, their use in optical printers is becoming widespread.

Most of the electrophotographic photoreceptors used in these applications have substrates made of aluminum or aluminum-based alloys (in this specification, both are collectively referred to as "aluminum substrates"). A photosensitive layer is formed on the substrate.

The photosensitive layer may have various forms and components, but in any case, the surface condition of the aluminum substrate has a large effect on the characteristics of the photoreceptor, and the stability of the characteristics of the photoreceptor may be impaired. There is. Therefore, in order to reduce the influence of the surface of the aluminum substrate on the photosensitive layer and to improve the adhesion between the two, aluminum substrates with an anodized film formed on the surface are used for electrophotographic photoreceptors, especially electrophotographic photoreceptors for optical printers. Used for body use.

In addition, such an anodic oxide film is often formed by electrolyzing a degreased aluminum substrate using it as an anode in an aqueous solution such as oxalic acid or sulfuric acid. After the substrate is sealed if necessary, it is usually washed with water to remove impurities adhering to the surface, and then subjected to the photosensitive layer forming step.

(Problems to be Solved by the Invention) However, electrophotographic photoreceptors using an aluminum substrate with an anodic oxide film formed on the surface have defects peculiar to the resulting images, such as streaks or uneven defects. Images may be visible.

As a result of intensive studies aimed at eliminating such image defects, the inventors of the present invention found that a trace amount of organic compounds were attached to the surface of the aluminum substrate where the image defects occurred in some way, such as by incorporating inorganic compounds. I found it. They also found that by cleaning the aluminum substrate with a cleaning solution containing alcohol or ketone, which is thought to be effective in dissolving and removing the deposits, before forming a photosensitive layer on the aluminum substrate, the image defects could be effectively prevented. , arrived at the present invention.

That is, an object of the present invention is to provide an image that does not cause image defects, particularly streaky or uneven images that are characteristic of the electrophotographic photoreceptor C2, which uses an aluminum substrate with an anodic oxide film formed on its surface. The object of the present invention is to manufacture an electrophotographic photoreceptor with good characteristics.

(Means for Solving the Problems) Therefore, the object of the present invention is to form an anodic oxide film on the surface of an aluminum substrate, wash it with a cleaning solution containing alcohol or ketone, and then dry the anodic oxide film on the surface of the aluminum substrate. This can be easily achieved by forming a photosensitive layer on.

(for production) The present invention will be explained in detail below.

Aluminum substrates for electrophotographic photoreceptors can have various types of aluminum or aluminum alloy components, manufacturing methods, etc., but in the method of the present invention, aluminum is the main component and an anodic oxide film can be formed on the surface. Any aluminum substrate can be used.

There are various methods for forming an anodic oxide film on the surface of such an aluminum substrate, all of which involve electrolysis using the substrate as an anode in an acidic aqueous solution such as oxalic acid or sulfuric acid. After formation, the acid is washed away,
Clean to remove impurities adhering to the surface.

Since the anodic oxide film thus formed is porous,
Pore sealing may be required. The pore sealing treatment is sometimes performed by treating the aluminum substrate with pressurized steam or boiling water, but in order to promote pore sealing efficiently, an aqueous solution containing a metal salt such as nickel acetate as a pore sealing agent is used. In some cases, the aluminum substrate is immersed in the process. Examples of the sealing agent include Top Seal DX, Tsubu Seal DX-200, and Top Seal Dx- manufactured by Okuno Seikagyo Co., Ltd.
300, Top Seal DX-500 or Nippon Kagaku Sangyo Co., Ltd.'s Alumite Sealer, Kuchizai Kagaku Co., Ltd.'s Hardware-3, and the like.

Even when sealing treatment is performed, in most cases the surface is washed with water to clean it after the treatment.

However, the above-mentioned pore-sealing agent contains a small amount of surfactant in addition to the metal salt as the main component, and the present inventors believe that the organic compound that is thought to be derived from the surfactant is
It was discovered that inorganic compounds incorporated into the material remained on the surface of the substrate even after washing with water. Furthermore, even when the above-mentioned sealing agent is not used, it has been found that a small amount of organic or inorganic compounds, which are thought to have entered the air or from the equipment, adhere to the surface of the substrate.

Organic compounds that exist on the substrate surface as impurities include:
Examples of inorganic compounds include organic carboxylates and nonionic or anionic surfactants in sealing agents, and polymeric lubricants used in processing equipment.On the other hand, inorganic compounds include metals in sealing agents. Inorganic metal salts such as nickel acetate, nickel hydroxide, sodium acetate, and nickel sulfate derived from salts, and aluminum hydroxide, aluminum oxide, and aluminum sulfate derived from aluminum eluted from the substrate into the anodizing treatment solution or sealing treatment solution. Examples include sand dust whose main component is a silicate compound such as Mg or ACCa, which is contained as an impurity in the air or in the processing liquid.

The method of the present invention is characterized in that the aluminum substrate on which the anodic oxide film is formed is cleaned with a cleaning solution containing alcohol or ketone. It is believed that the reason why image defects can be effectively prevented is that the above-mentioned impurities on the surface of the substrate can be almost completely removed.

In addition, as described above in detail the origin of impurities that cause image defects, when sealing using a sealing agent, compared to when not using a sealing agent, water washing removes them more easily. I can't do it,
This is because many impurities remain on the substrate surface, which can only be removed using a cleaning solution containing alcohol or ketone.
The effect of applying the method of the present invention is particularly large.

In the method of the present invention, a cleaning solution containing alcohol or ketone can be used to clean the aluminum substrate after the anodic oxide film is formed, and the type of alcohol or ketone and other components of the cleaning solution are not particularly limited, but depending on the impurities. A cleaning solution containing a relatively low molecular weight alcohol or ketone is used because it dissolves a large amount of organic compounds well, is easily dissolved in water, is easy to use as an aqueous solution, and is easy to dry after cleaning. is preferable. in particular,
Cleaning liquids containing methanol, ethanol, isopropanol or n-propanol or acetone, methylacetone or methylethylketone are preferred.

Moreover, two or more kinds of alcohols may contain a ketone.

The cleaning liquid may be made of 100% alcohol or ketone, or may be a solution of a high boiling point hydrocarbon solvent such as kerosene, but it is easy to handle and can meet the objectives of the present invention. Industrially, it is most preferable to use an aqueous solution in terms of achieving sufficient effects.

The concentration of alcohol or ketone in the cleaning solution: If it is too small, the cleaning effect will be reduced, so in the case of an alcohol aqueous solution, it is 3 to 100 vcf%, and in the case of a 7 volume solution of ketone water, it is 3 to 100
vof2% is preferred. On the other hand, if the concentration of alcohol or ketone is too high, the cleaning effect will not be much improved, and it will only increase the concentration of vapor in the working environment and waste unnecessary effort to ensure safety. An aqueous solution having an alcohol or ketone concentration of about 4 to 50 voj 2% is most preferable as the cleaning liquid.

Good results can be obtained by common cleaning methods such as immersion, showering, brushing, jetting, or ultrasonic cleaning.

In addition, in the method of the present invention, the inorganic compound and organic compound that adhere to the surface of the aluminum substrate are not always included in the organic compound and may be attached individually. In such cases, better results can be obtained by combining cleaning with a cleaning solution containing alcohol or ketone and cleaning with an aqueous nitric acid solution. In this case, particularly good results are obtained when the concentration of nitric acid is 0.3% or more and 10% or less. When the nitric acid concentration exceeds 10%, while it is highly effective in removing impurities that cause defective images, it may have an adverse effect on electrical properties, which are required properties of an electrophotographic photoreceptor.

As mentioned above, the aluminum substrate whose surface has been cleaned by washing with a cleaning solution containing alcohol or ketone is subjected to the irradiation layer forming process after drying. It is applicable to the production of electrophotographic photoreceptors having any type of photoreceptor layer, regardless of the type of photoreceptor.

The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to the following Examples unless it exceeds the gist thereof.

(Example 1) A JIS6063 alloy aluminum pipe with a mirror finish on the surface was heated at 65°C in a 40 g/j2 aqueous solution of the degreaser Fine Cleaner 315 (manufactured by Nippon Barker Rising Co., Ltd.).
After degreasing for 10 minutes and washing with water, it was immersed in 7% nitric acid at 25°C for 1 minute. After washing with water, 1.0 A/N in 180 g/β sulfuric acid electrolyte (dissolved aluminum concentration 7 g/n)
d m 2 (D) Electron oxidation was performed to form an anodic oxide film with an average thickness of 7 μm.Furthermore, after washing with water, a metal salt sealant alumite sealer (Nippon Kagaku Sangyo) containing nickel acetate as a main component was applied. IOg/f at 94°C
After being immersed in a water solution for 30 minutes, it was pulled out, washed with a 100% methanol solution, finished washed with pure water, and then dried.

The aluminum pipe, which had an anodized film formed on its surface and which had been sealed, was mixed with 10 parts by weight of oxytitanium phthalocyanine and 5 parts by weight of polyvinyl butyral (Suresoku BH-3 manufactured by Block Chemical Co., Ltd.), and 1,2-dimethoxyethane. A charge generating layer was formed by adding 500 parts by weight, pulverizing with a sand grind mill, and applying a dispersion treatment by dip coating so that the film thickness after drying was 0.4 μm.

Next, this aluminum pipe was mixed with 56 parts by weight of a hydrazone compound having the structural formula, 14 parts by weight of a hydrazone compound having the structural formula, 1.5 parts by weight of a cyanide compound having the structural formula, and 100 parts by weight of polycarbonate resin (Tubalex 7030A manufactured by Mitsubishi Kasei Corporation) was mixed with 1.4-dioxane 1,0
A charge transfer layer was formed by dip coating in a solution dissolved in 0.00 parts by weight so that the film thickness after drying was 17 μm.

The drum-type electrophotographic photoreceptor thus obtained was installed in a commercially available copying machine modified for reversal development, and the image characteristics were evaluated. As a result, good images were obtained.

(Example 2) JIS1 instead of JIS6063 alloy aluminum pipe
An anodic oxide film was formed in the same manner as in Example 1, except that an aluminum pipe made of 050 alloy was used. After further washing with water,
5 g of metal salt sealant Hardwall-3 (manufactured by Kuchizai Kagaku Co., Ltd.) containing nickel fluoride as the main component at 33°C
After being immersed in an aqueous solution for 10 ml, it was pulled out, washed with an aqueous solution with an ethanol concentration of 20 vol, washed again with pure water, and then dried. A drum-type electrophotographic photoreceptor was manufactured using the aluminum pipe, which had been sealed with an anodic oxide film formed on its surface, in exactly the same manner as in Example 1, and its image characteristics were evaluated. As a result, good images were obtained. Ta.

(Example 3) Instead of a JIS6063 alloy aluminum pipe with a mirror finish on the surface, JI with a mirror finish by ironing the surface.
The methyl ethyl ketone concentration was 20 after the sealing treatment in the same manner as in Example 1 except that an aluminum pipe made of S3003 alloy was used.
After washing with a 2% vOj aqueous solution, it was further washed with a 5% nitric acid aqueous solution, and after final washing with pure water, it was dried. A drum-type electrophotographic photoreceptor was manufactured using the thus sealed aluminum pipe in exactly the same manner as in Example 1, and the image characteristics were evaluated. As a result, a good image was obtained.

(Comparative Example 1) A drum-shaped electrophotographic photoreceptor was manufactured in exactly the same manner as in Example 1, except that only pure water was used to wash the aluminum pipe pulled up from the metal salt sealant aqueous solution. When the characteristics were evaluated, many streaky and uneven images were observed in the obtained images.

(Comparative Example 2) A drum-shaped electrophotographic photoreceptor was manufactured in exactly the same manner as in Example 1, except that a 7% nitric acid aqueous solution was used to clean the aluminum pipe pulled up from the metal salt sealant aqueous solution. When the characteristics were evaluated, many streaky and uneven images were observed in the obtained images.

(Effects of the Invention) According to the method of the present invention, there are few image defects, and in particular, the peculiar streaky defective image that has been a problem with electrophotographic photoreceptors using an aluminum substrate on which an anodic oxide film is formed is produced. It is possible to easily produce an electrophotographic photoreceptor with excellent image characteristics, which provides great industrial benefits.

Claims (1)

[Claims] (1) An electrophotographic photoreceptor characterized in that an anodic oxide film is formed on the surface of an aluminum substrate, then washed with a cleaning solution containing alcohol or ketone, and after drying, a photosensitive layer is formed on the anodic oxide film. Production method.