JPH04263266A - Substrate for electrophotographic sensitive body and its production - Google Patents

Abstract

PURPOSE:To ensure satisfactory appliability and to prevent the occurrence of fringes on an image due to the interference of light with an electrophotographic device using coherent light. CONSTITUTION:When an aluminum oxide film 3a is formed on the surface of an Al or Al alloy substrate 2 by anodic oxidation to obtain a substrate 1a for an electrophotographic sensitive body, a light absorbing material is incorporated into the surface part 5 of the film 3a so as to regulate the reflectance of the substrate 1a to coherent light to 50-80% and then the substrate 1a is subjected to a pore sealing treatment. An org. dye is suitable for use as the light absorbing material.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive substrate for an organic electrophotographic photoreceptor to be mounted on electrophotographic equipment that uses coherent light such as a laser beam for exposure, and a method for manufacturing the same.

0002

[Prior technology] PPC and non-impact printers (N
Electrophotographic application equipment, represented by IP), has undergone significant technological innovation supported by the expansion of the office automation equipment market. Regarding the photoreceptors used in these devices, those using organic materials are becoming mainstream instead of those using inorganic materials such as selenium and its alloys as photosensitive materials.

The conductive substrate on which the photosensitive material is laminated is often aluminum or aluminum alloy with a smooth machined surface in the case of selenium-based photoreceptors, but in the case of organic photoreceptors, selenium-based In addition to substrates equivalent to those used in the above, substrates with a thin insulating layer provided on the surface of the substrate to limit charge injection from the substrate are also often used. This largely depends on the conditions of the device in which the photoreceptor is installed, especially the method used in the developing section. It is indispensable for photoreceptors.

[0004] Various materials such as organic materials and inorganic materials are used for this insulating film. Aluminum or an aluminum alloy is often used as the substrate material, and in this case, it is known to use an anodic oxide film of aluminum as the insulating film, and various patents have been announced and published regarding the conditions for forming the film. For example, JP-A-62-4961
Publication No. 8, JP-A-58-44525, JP-A-58
-100138, JP 59-78354, JP 59-158, JP 59-15765
Publication No. 2, JP-A-61-140947, JP-A-6
1-198243, JP-A-61-198244, JP-A-61-198245, JP-A-61-1982-
198246, JP 63-116160, JP 61-116161, JP 63-11
6162, JP 63-116163, JP 63-116164, JP 63-1793
65, JP 63-214759, JP 63-298250, JP 63-311260
No. 63-311261, JP-A No. 63-1983
-311262, JP 63-314555, JP 63-316060, JP 1-29
No. 852, JP-A-1-79754, JP-A-1
-79755 publication, JP-A-1-108550 publication,
JP-A-1-108551, JP-A-1-11485
2 Publication, JP-A-1-114853, JP-A-1-
No. 114854, Japanese Patent Application Laid-open No. 114855,
JP-A-1-116557, JP-A-1-13157
1 Publication, JP-A-1-138564, JP-A-1-
No. 188860, Japanese Patent Application Laid-open No. 1-244469,
JP-A-1-274157, JP-A-1-27415
No. 7, JP-A-1-280768, JP-A-1-
Publication No. 288862, Japanese Unexamined Patent Publication No. 1-312553,
There are Japanese Patent Application Laid-open Nos. 1-312554, 2-5068, and 2-7070. All of these use an anodic oxide film formed under various film formation conditions either as is or with some layer laminated thereon.

[0005]

Problems to be Solved by the Invention Among the conditions for forming an anodic oxide film on aluminum, an anodic oxide film that is transparent to visible light can be produced by adjusting the liquid temperature and current during electrolysis and selecting a sealing agent. The outermost surface of such a membrane after sealing is microscopically very smooth. This is very advantageous for organic photoreceptors manufactured using coating methods. That is, the uniformity of the film formed by the dip coating method improves as the surface of the substrate becomes more uniform. However, this feature becomes an obstacle in photoreceptors for non-impact printers that use laser diodes (LDs) as light sources. Since the surface of the anodic oxide film is very smooth, the LD light, which is monochromatic light with a uniform wavelength, is reflected by the surface and bottom of the anodic oxide film, and the reflected light from each causes interference, causing shading on the image. A problem arises in that a pattern is repeated, resulting in striped unevenness of light and shade. As a result of the investigation, it was found that this unevenness corresponded to unevenness in the thickness of the anodic oxide film. Furthermore, it was also found that one repeating dark and light striped pattern occurs when the difference in film thickness of the anodic oxide film is about 0.4 μm. That is, in order to eliminate the dark and light striped pattern, it is sufficient to reduce the film thickness deviation of the anodic oxide film to 0.4 μm or less, but this far exceeds the process capability of forming the anodic oxide film.

The present invention has been made in view of the above points, and can be installed in electrophotographic application equipment that uses coherent light such as LD light for exposure without impairing coating properties. An object of the present invention is to provide a substrate for an electrophotographic photoreceptor that can prevent a pattern of dark and light stripes caused by light interference even when used in an electrophotographic photoreceptor, and a suitable manufacturing method thereof.

[0007]

[Means for Solving the Problems] According to the present invention, the above-mentioned problem is solved by providing a substrate for an electrophotographic photoreceptor comprising an anodized aluminum film on the surface of the substrate made of aluminum or an aluminum alloy. The surface of the film contains a light-absorbing substance, and the reflectance of this substrate for coherent light is 50% or more8
This problem can be solved by making the substrate for an electrophotographic photoreceptor within the range of 0% or less.

[0008] The above-mentioned substrate is produced by forming an aluminum oxide film on the surface of the substrate made of aluminum or an aluminum alloy by anodic oxidation, incorporating a light-absorbing substance into the aluminum oxide film, and then subjecting it to a sealing treatment. It can be made by

[0009] It is preferable to use an organic dye as the light absorbing substance.

0010

[Operation] FIG. 1 is an explanatory diagram showing the state of reflection on the substrate when coherent light, such as LD light, is incident on a photoreceptor using the substrate according to the present invention, and FIG. FIG. 2 is an explanatory diagram showing a state of reflection on a base when coherent light is incident on a photoreceptor.

In the conventional photoreceptor, as shown in FIG. 2, a transparent anodic oxide film 3 is formed on the surface of an aluminum base 2.
A photosensitive layer 4 provided on the substrate 1b formed by forming b.
Incident light 100, 20 that passes through and enters the base 1b
0 is reflected by the smooth surface of the anodic oxide film 3b and the surface of the aluminum base 2, resulting in reflected lights 101 and 102, respectively.
and 201, 202. The thickness of the anodic oxide film 3b at the incident position of the incident light 100 and 200 is d1, respectively.
d2, there is an optical path difference of 2d1 between the reflected light 101 and the reflected light 102, and an optical path difference of 2d2 between the reflected light 201 and the reflected light 202, resulting in a phase difference.
1 and the reflected light 102, and the reflected light 201 and the reflected light 202 will interfere with each other, and these reflected lights will strengthen or weaken each other depending on the optical path difference. Therefore, if there is a thickness deviation in the anodic oxide film 3b, there will be areas where the reflected light strengthens each other and areas where it weakens each other, and as these reflected lights enter the photosensitive layer, carrier generation in the photosensitive layer becomes stronger or weaker. This causes striped unevenness in density on the image.

On the other hand, in the photoreceptor according to the present invention,
As shown in FIG. 1, a substrate 1a is used, in which an anodic oxide film 3a containing a light-absorbing substance is formed on the surface portion 5 of an aluminum substrate 2. For this reason, the reflected lights 11 and 12 on the surface of the anodic oxide film 3a and the reflected light on the surface of the aluminum base 2 of the incident lights 10 and 20 that pass through the photosensitive layer 4 and enter the base 1a are weakened. , the respective interferences are reduced, and the anodic oxide film 3 of FIG.
Even if there is a film thickness deviation similar to that in b, it is possible to prevent the occurrence of striped density unevenness on the image. At this time, the reflectance of the base 1a for the coherent incident light [reflected light on the surface of the anodic oxide film 3a for the incident light (10, 11) (reflected light 11
, 21) and the reflected light (reflected light 12, 22) that is reflected on the surface of the aluminum substrate 2 and transmitted through the anodic oxide film 3a.
) is preferably in the range of 50% or more and 80% or less. This reflectance can be controlled by the material and content of the light absorbing substance contained in the surface of the anodic oxide film.

The substrate for an electrophotographic photoreceptor of the present invention is obtained by forming an aluminum oxide film on the surface of the substrate made of aluminum or an aluminum alloy by anodizing, incorporating a light-absorbing substance into this film, and then subjecting it to a sealing treatment. It can be suitably manufactured. Since the surface of the anodic aluminum oxide film before sealing treatment is porous, a light-absorbing substance can be easily contained therein, and can be fixed by subsequent sealing treatment. It is preferable to use an organic dye as the light-absorbing substance, and in this case, the dye can be absorbed by controlling the type of dye, the concentration of the dye when dissolved in a solvent such as water, and the immersion time of the film in the dye solution. , a substrate with appropriate reflectance can be obtained.

[0014]

[Embodiments] Examples of the present invention will be described in detail below.

[0015] A 10% H2SO4 solution is used as an electrolyte solution, and a cleaned aluminum alloy cylindrical base body processed into a desired shape is immersed in the electrolyte solution, and a current density of 1A/dm is applied.
2 for 10 minutes. The substrate on which the anodic oxide film is formed is immersed in an aqueous solution of an organic dye for 1 minute to impregnate the surface of the anodic oxide film with the organic solvent. As an organic dye, TAC manufactured by Okuno Pharmaceutical Co., Ltd.
Using BLUE-SLH, the dye concentration of the aqueous solution was changed to 6 types as shown in Table 1, and 6 types of No. 1 were immersed in each aqueous solution. 1~No. No. 6 substrates were prepared. These substrates were immersed in a nickel acetate solution at a temperature of 90° C. for 20 minutes to seal the holes, and dried at a temperature of 150° C. for 3 hours to obtain substrates for electrophotographic photoreceptors. When we measured the reflectance of the surfaces of these substrates for LD light, the results are shown in Table 1.
The value was as shown in

A coating solution containing a phthalocyanine pigment as a charge generating substance and a binder such as a vinyl chloride resin dispersed and dissolved in an organic solvent is applied onto these substrates by dip coating to generate a charge in a film thickness of 0.5 μm. form a layer and then on top of that,
A charge transport layer with a thickness of 20 μm was formed by dip coating a coating solution containing a hydrazone compound as a charge transport material and a binder, such as polycarbonate, dissolved in an organic solvent. A photographic photoreceptor was produced.

Images were printed on these photoreceptors using a commercially available semiconductor laser printer, and the occurrence of striped density unevenness caused by interference was investigated. The results are shown in Table 1 in correspondence with the dye concentration of the aqueous solution used to impregnate the surface of the anodic oxide film of the substrate and the reflectance of the substrate to LD light. Table 1 also shows the applicability of the charge generation layer to the surface of the substrate.

[0018]

[Table 1]

From Table 1, it can be seen that an organic photoreceptor manufactured using a substrate whose reflectance to LD light is within the range of 50% to 80% can be used in a semiconductor laser printer that uses LD light as exposure light. It can be seen that a good image without striped density unevenness caused by interference can be obtained. In the case of the organic dye of the example, such a reflectance can be obtained by immersing the substrate after forming the anodized aluminum film in an aqueous solution with a dye concentration of 2% or less for 1 minute to impregnate the surface of the film with the dye. can get. Since the reflectance is determined by the dye content on the surface of the film, the immersion time may be varied while keeping the dye concentration constant.

The substance contained in the surface of the anodic aluminum oxide film of the substrate is not limited to the organic dyes of the embodiments, but may be other dyes or even light-absorbing substances other than dyes. It is necessary to contain it so that the reflectance of the substrate is within the range of 50% or more and 80% or less.

[0021]

According to the present invention, in a substrate for an electrophotographic photoreceptor comprising an anodized aluminum film on the surface of a substrate made of aluminum or an aluminum alloy, a light-absorbing substance is provided on the surface of the anodized aluminum film. The reflectance of this substrate for coherent light is 5.
It should be within the range of 0% or more and 80% or less. By using such a substrate, an organic photosensitive layer can be formed on it with good coating properties to produce an electrophotographic photoreceptor, and the resulting photoreceptor can be used in electrophotographic applications that use coherent light for exposure. When installed in a device, it is possible to obtain good images without striped unevenness caused by optical interference.

In order to incorporate a light-absorbing substance into the surface of the anodized aluminum film of the substrate, an aluminum oxide film is formed on the surface of the substrate made of aluminum or aluminum alloy by anodizing, and the surface of the film contains a light-absorbing substance. It is preferable to perform a sealing treatment after incorporating the substance. The surface of the anodized aluminum film is porous and can easily contain light-absorbing substances.
Thereafter, by performing a sealing treatment, the light-absorbing substance can be fixed, and a substrate for an electrophotographic photoreceptor having stable reflectance can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the state of reflection of coherent light on the substrate of a photoreceptor using the substrate according to the present invention.

[Fig. 2] An explanatory diagram showing the state of reflection of coherent light on the base of a photoreceptor using a conventional base.

[Explanation of symbols]

1a Base 2 Aluminum base 3a Anodic oxide film 4 Photosensitive layer 5　　　　　　　　Anodic oxide film surface part

Claims (4)

[Claims] 1. A substrate for an electrophotographic photoreceptor comprising an anodized aluminum film on the surface of a substrate made of aluminum or an aluminum alloy, the surface of the anodized aluminum film containing a light-absorbing substance, and A substrate for an electrophotographic photoreceptor, characterized in that the substrate has a reflectance of coherent light in a range of 50% or more and 80% or less. 2. The substrate for an electrophotographic photoreceptor according to claim 1, wherein the light absorbing substance is an organic dye. 3. A method for producing a substrate for an electrophotographic photoreceptor comprising an anodized aluminum film on the surface of a substrate made of aluminum or an aluminum alloy, wherein an aluminum oxide film is formed on the surface of the substrate made of aluminum or an aluminum alloy by anodizing. 1. A method for producing a substrate for an electrophotographic photoreceptor, comprising the steps of: forming an anodized aluminum film, incorporating a light-absorbing substance into the anodized aluminum film, and then subjecting the film to a sealing treatment. 4. The method for producing a substrate for an electrophotographic photoreceptor according to claim 3, wherein an organic dye is used as the light-absorbing substance.