JPH04265979A - Base for electrophotographic sensitive body and production thereof - Google Patents

Abstract

PURPOSE:To provide the base from which an electrophotographic sensitive body which does not generate the unequal image densities occurring in interference is obtainable even when used for an electrophotograph applying device using LD light or LED light as exposing light and the process for producing this base. CONSTITUTION:This base 1 is constituted by forming an anodized Al film 12 having the film thickness within a 4 to 20mum range on the surface of a tubular base body 11 consisting of an Al alloy and has 20% ratio of the reflected light to the incident light of the coherent LD light or LED light. Such base 1 is produced by adequately roughening the surface of the base body surface by taking the content of the impurity and more particularly Mg in the Al alloy and the method for working the alloy to the tube into consideration, then forming the anodized Al film 12 having an adequate film thickness under adequate conditions.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support for an electrophotographic photoreceptor used in an electrophotographic printer or copying machine using a laser diode (LD) or a light emitting diode (LED) as an exposure source.

0002

[Prior Art] Electrophotographic photoreceptors used in electrophotographic printers and copiers that use monochromatic and coherent light exposure sources such as LDs and LEDs generally use Al as a support. It is obtained by using an alloy tube and laminating a charge generation layer and a charge transport layer thereon by vapor deposition or coating to form a photosensitive layer. A thin layer is often provided on the surface of the support to suppress charge injection from the support and improve image quality. Various materials such as organic materials and inorganic materials are used for this charge injection suppression layer, but the material for the support is A
When an Al alloy is used, an anodized Al layer (hereinafter also simply referred to as an alumite layer) obtained by anodizing its surface is often used.

0003

However, the alumite layer described above is transparent to LD light and LED light. For this reason, in the case of an electrophotographic photoreceptor using an Al alloy support provided with an alumite layer on the surface, the reflected light from the support of the LD light or LED light incident as exposure light is reflected from the surface of the alumite layer. These reflected lights cause interference, and if there are variations in the thickness of the alumite layer, there will be areas where they strengthen and areas where they weaken, and accordingly, Carrier generation occurs unevenly in the charge generation layer stacked on the alumite layer. For this reason, image density unevenness corresponding to variations in the thickness of the alumite layer occurs on the image.

The present invention solves the above-mentioned problems and does not cause image density unevenness due to interference even when used in an electrophotographic application device that uses coherent light such as LD light or LED light as exposure light. The object of the present invention is to provide a support for an electrophotographic photoreceptor that can form good images and a suitable method for producing the same.

[0005]

[Means for Solving the Problems] According to the present invention, the support for an electrophotographic photoreceptor is coated on the surface of a tubular substrate made of an aluminum alloy with anodized aluminum having a film thickness of 4 μm or more and 20 μm or less. This problem can be solved by using a support on which a film is formed and the ratio of reflected light to incident light of coherent light such as LD light or LED light is 20% or more.

[0006] When the above-mentioned support is an aluminum (Al) alloy drawn tube containing magnesium (Mg) in a range of 0.8% by weight or more and 2.8% by weight or less, The surface roughness is R by cutting the surface.
After finishing the surface so that the maximum diameter is within the range of 0.1 μm or more and 1.5 μm or less, the surface is coated with a sulfuric acid electrolyte with a liquid temperature of 14° C. or more and 16° C. or less and a concentration of 20% by weight at a current density of 1.
Perform anodizing treatment using a direct current method within a range of 3A/dm2 or more and 1.7A/dm2 or less, followed by sealing treatment using a nickel acetate solution, and anodize the film thickness within a range of 4μm or more and 20μm or less. It can be produced by forming an Al film.

[0007] In addition, when using an Al alloy drawn pipe containing Mg in the range of 0.45% by weight to 1.2% by weight as a material, its surface is roughened by rough cutting followed by SF processing. Surface roughness Rmax is 0.2μm or more1
．． After finishing it so that it is within the range of 0 μm or less, it is preferable to form an anodized Al film on the surface in the same manner as described above.

Furthermore, when using an Al alloy cold forged pipe containing Mg in the range of 0.45% by weight or more and 1.2% by weight or less, the surface is roughened by liquid honing. Rmax: 0.2μm or more 1.0μ
After finishing it so that it is within the range of m or less, it is preferable to form an anodic oxide film on the surface in the same manner as described above.

[0009]

[Function] Using a support made of an Al alloy substrate with an alumite layer provided on the surface, it can be mounted on an electrophotographic application device that uses LD light or LED light as exposure light to prevent image density unevenness caused by interference. To get the body, use LD light or L
It is only necessary to reduce the ratio of reflected light to the incident light of the ED light, and by setting this ratio to 20% or less, it is possible to prevent the occurrence of image density unevenness.

In order to obtain the above-described support, the light reflected on the surface of the alumite layer of the support and the light reflected on the surface of the Al alloy substrate are respectively scattered, and the light incident on the alumite layer and the light reflected on the Al alloy substrate are scattered. It is preferable to scatter the reflected light on the substrate surface within the alumite layer.

[0011] In the present invention, the surface of the Al alloy substrate is finished to have an appropriate surface roughness, thereby scattering reflected light on the surface. The surface of the alumite layer formed on the thus roughened surface of the Al alloy substrate becomes a rough surface corresponding to the surface roughness of the substrate, and the reflected light on the surface of the alumite layer is also scattered. Furthermore, by appropriately selecting the conditions for forming the alumite layer, impurities contained in the Al alloy, particularly Mg, are oxidized within the alumite layer to develop a white color, thereby causing light scattering within the alumite layer. Al
The degree of color development of the alumite layer differs depending on the impurity content of the alloy, and furthermore, even if the same Al alloy is used, the degree of color development of the alumite layer will differ depending on the method of processing it into a tube, and the degree of light scattering within the alumite layer will also differ. It's coming. Therefore, depending on the Al alloy impurity content and the processing method for the pipe,
The ratio of reflected light to incident light on the support as a whole is 2
It is necessary to select the method of roughening the surface of the Al alloy substrate and the surface roughness so that the roughness is 0% or less.

[0012] The alumite layer is prepared by coating the surface of the Al alloy substrate with a sulfuric acid electrolyte having a concentration of 20% by weight, and controlling the liquid temperature to 14°C or higher to 16°C.
Within the following range, the current density is 1.3A/dm2 or more1
．． It is preferable to perform anodization using a direct current method at 7 A/dm2 or less and perform sealing treatment using a nickel acetate solution, since impurities are appropriately oxidized. When an Al alloy drawn tube containing Mg in the range of 0.8% by weight or more and 2.8% by weight or less is used as the base of the support, the surface roughness of the base is reduced by cutting. Rmax
If the alumite layer is formed in the above-described manner after finishing the support to have a thickness in the range of 0.1 μm or more and 1.5 μm or less, the total reflected light of the support becomes 20% or less, which is suitable. In addition, when an Al alloy drawn tube containing Mg in the range of 0.4% by weight or more and 1.2% by weight or less is used as the base of the support, the surface of the base is rough cut and then SF processing is performed. By doing this, the surface roughness is reduced to 0.2 at Rmax.
It is preferable to finish the thickness within the range of 1.0 μm or more. Furthermore, when an Al alloy cold forged tube containing Mg in the range of 0.4% by weight or more and 1.2% by weight or less is used as the base of the support, the surface of the base is roughened by liquid honing. Rmax: 0.2μm or more 1.0μm
It is preferable to finish within the following range.

[0013] If the thickness of the alumite layer is less than 4 μm, the uniformity of the layer will be poor, and if it exceeds 20 μm, cracks will occur in the alumite layer, which is not preferable. In addition, from the viewpoint of the function as a charge injection suppressing layer, the film thickness is 4 μm.
It is preferable that the thickness be within a range of not less than m and not more than 20 μm.

[0014]

[Example] FIG. 1 is a schematic cross-sectional view of an embodiment of an electrophotographic photoreceptor using a support according to the present invention. A photosensitive layer 2 is formed on which a charge generation layer 21 and a charge transport layer 22 are sequentially laminated.

Example 1-1 A drawn Al alloy tube containing 0.8% by weight of Mg was used as the Al alloy substrate, and its surface was finished by cutting to a mirror surface with a surface roughness of 0.1 μm at Rmax. The surface was anodized using a sulfuric acid electrolyte with a concentration of 20% by weight at a temperature of 15°C and a direct current method at a current density of 1.5A/dm2, followed by sealing using a nickel acetate solution. was applied to form an alumite layer with a thickness of 8 μm, which was used as a support. The ratio of the reflected light to the incident light of the LD light on this support was about 20%.

Comparative Example 1-1 In Example 1-1, the liquid temperature in the anodizing treatment was changed to 2.
A support was produced in the same manner as in Example 1-1 except that the temperature was changed to 2° C. and the current density was changed to 0.8 A/dm 2 . The ratio of the reflected light to the incident light of the LD light on this support was about 60%.

Example 1-2 In Example 1-1, the Mg content of the Al alloy was set to 2.8.
% by weight, and the surface roughness of the Al alloy substrate is Rmax = 1
．． A support was produced in the same manner as in Example 1-1 except that the thickness was 5 μm. The ratio of the reflected light to the incident light of the LD light on this support was about 10%.

Comparative Example 1-2 In Example 1-2, the conditions for anodizing treatment were changed to Comparative Example 1.
A support was produced in the same manner as in Example 1-2 except for the same changes as in Example 1-1. The ratio of the reflected light to the incident light of the LD light on this support was about 65%.

Example 2-1 Al containing 0.45% by weight of Mg as an Al alloy substrate
Using a drawn alloy tube, the surface was rough cut using a Compax tool, then SF processing was performed using a #4000 grindstone to give a surface roughness of Rmax of 0.2 μm, and then the surface was A support was produced by forming an alumite layer in the same manner as in Example 1-1. The ratio of the reflected light to the incident light of the LD light on this support was about 20%.

Comparative Example 2-1 In Example 2-1, the conditions for anodizing treatment were changed to Comparative Example 1.
A support was produced in the same manner as in Example 2-1 except for the same changes as in Example 2-1. The ratio of the reflected light to the incident light of the LD light on this support was about 70%.

Example 2-2 In Example 2-1, the Mg content of the Al alloy was set to 1.2.
% by weight, and the surface roughness of the Al alloy substrate is Rmax = 1
．． A support was produced in the same manner as in Example 2-1 except that the thickness was finished to 0 μm. The ratio of the reflected light to the incident light of the LD light on this support was about 10%.

Comparative Example 2-2 In Example 2-2, the conditions for anodizing treatment were changed to Comparative Example 1.
A support was produced in the same manner as in Example 2-2 except for the same changes as in Example 2-1. The ratio of the reflected light to the incident light of the LD light on this support was about 65%.

Example 3-1 Al containing 0.45% by weight of Mg as an Al alloy substrate
Using a cold forged alloy pipe, the surface was finished to a surface roughness of Rmax of 0.2 μm by liquid honing, and then an alumite layer was formed on the surface in the same manner as in Example 1-1 to form a support. Created. The ratio of the reflected light to the incident light of the LD light on this support was about 20%.

Comparative Example 3-1 In Example 3-1, the conditions for anodizing treatment were changed to Comparative Example 1.
A support was produced in the same manner as in Example 3-1 except for the same changes as in Example 3-1. The ratio of the reflected light to the incident light of the LD light on this support was about 70%.

Example 3-2 In Example 3-1, the Mg content of the Al alloy was set to 1.2.
% by weight, and the surface roughness of the Al alloy substrate is Rmax = 1
．． A support was produced in the same manner as in Example 3-1 except that the thickness was finished to 0 μm. The ratio of the reflected light to the incident light of the LD light on this support was about 10%.

Comparative Example 3-2 In Example 3-2, the anodizing treatment conditions were changed to Comparative Example 1-
A support was produced in the same manner as in Example 3-2 except that the same changes as in Example 1 were made. The ratio of the reflected light to the incident light of the LD light on this support was about 65%.

A photosensitive layer was formed by sequentially laminating a charge generation layer and a charge transport layer on each of the supports of Examples and Comparative Examples thus obtained, and Example 1-- having the structure shown in FIG. 1~
Twelve types of electrophotographic photoreceptors were produced, including Example 3-2 and Comparative Examples 1-1 to 3-2.

These photoreceptors were mounted on a commercially available semiconductor laser printer, an image with a 50% halftone dot pattern was printed out, and the occurrence of image density unevenness due to interference was investigated. The results are shown in Table 1 along with the ratio of the reflected light to the incident light of the LD light of the support used.

[0029]

[Table 1]

From Table 1, it can be seen that the photoreceptor using the support of the example in which the ratio of reflected light to the incident LD light is 20% or less does not cause image density unevenness due to interference, but the ratio of reflected light to the incident LD light does not occur. The photoreceptor using the support of the comparative example in which the proportion of reflected light was as large as 60% or more had uneven image density due to interference, and the superiority of the support according to the present invention is clear.

[0031] In addition, under the conditions of anodizing the surface of the Al alloy substrate, the liquid temperature is in the range of 14°C or more and 16°C or less, and the current density is 1.3A/dm2 or more and 1.7A/dm2.
It was found that a good support similar to that of the example can be obtained within the following range.

Furthermore, when the Mg content in the Al alloy decreases, the amount of Mg oxidized during surface anodization decreases, so the light scattering effect within the alumite layer disappears, and conversely, the Mg content decreases. It has been found that as the number increases, the amount of defects in the Al alloy substrate increases, making it unsuitable as a support.

Furthermore, it has been found that it is effective if the thickness of the alumite layer is within the range of 4 μm or more and 20 μm or less. If the film thickness is less than 4 μm, a uniform alumite layer cannot be obtained, and if it exceeds 20 μm, cracks will occur, which is not preferable.

[0034]

According to the present invention, an alumite layer having a thickness of 4 μm to 20 μm is formed on the surface of a substrate made of an Al alloy, and the ratio of reflected light to incident light of LD light or LED light is reduced. is 20% or less. By using such a support, it is possible to form a good image that does not cause image density unevenness due to interference even when mounted in an electrophotographic application device that uses coherent light such as LD light or LED light as exposure light. An electrophotographic photoreceptor can be obtained.

Such a support is provided in claims 2, 3 and 4.
Impurities in Al alloys, especially Mg, as described in
It is produced by appropriately roughening the surface of the substrate in consideration of the content of and the method of processing into a tube, and then forming an alumite layer of an appropriate thickness under appropriate conditions on the surface. In the support produced by this method, the surface of the base is roughened and the surface of the alumite layer is also roughened accordingly, so the reflected light on the base surface and the surface of the alumite layer is is scattered. Further, Mg in the alumite layer is oxidized and colored white, and light passing through the alumite layer is scattered. Therefore, the LD light or LE light of the support as a whole
It becomes possible to reduce the ratio of reflected light to incident D light to 20% or less.

[Brief explanation of the drawing]

[Fig. 1] A schematic cross-sectional view of an example of a photoreceptor using the support of the present invention.

[Explanation of symbols]

1 Support 2 Photosensitive layer 11 Al alloy base 12 Alumite layer 21 Charge generation layer 22 Charge transport layer

Claims (4)

[Claims] Claim 1: An anodized aluminum film having a thickness of 4 μm or more and 20 μm or less is formed on the surface of a tubular substrate made of an aluminum alloy, upon which coherent light such as semiconductor laser diode light or light emitting diode light is incident. A support for an electrophotographic photoreceptor, characterized in that the ratio of reflected light to light is 20% or less. [Claim 2] The surface of a drawn aluminum alloy tube containing magnesium in a range of 0.8% by weight or more and 2.8% by weight or less is cut so that the surface roughness is 0 at the maximum height Rmax.
．． After finishing it so that it is within the range of 1μm or more and 1.5μm or less, the surface is coated with a liquid temperature of 14℃ or more and 16℃ or less and a concentration of 2.
Current density 1.3A/dm using 0% by weight sulfuric acid electrolyte
2 Anodized aluminum film with a thickness of 4 μm or more and 20 μm or less by performing anodizing treatment using a direct current method within a range of 2 or more and 1.7 A/dm2 or less, followed by sealing treatment using a nickel acetate solution. 1. A method for producing a support for an electrophotographic photoreceptor, the method comprising: forming a support for an electrophotographic photoreceptor; Claim 3: Magnesium 0.45% by weight or more 1.2% by weight
The surface roughness of the aluminum alloy drawn tube containing the aluminum alloy in the range of 0.2 μm or more and 1.0 μm or less at the maximum height Rmax is roughened by rough cutting and subsequent super finishing (SF processing). After finishing the surface, a current density of 1.3 A/dm2 or more is applied to the surface using a sulfuric acid electrolyte with a liquid temperature of 14°C or more and 16°C or less and a concentration of 20% by weight.
．． Anodizing with a direct current method within a range of 7A/dm2 or less, followed by sealing using a nickel acetate solution to form an anodized aluminum film with a thickness of 4 μm or more and 20 μm or less. A method for producing a support for an electrophotographic photoreceptor, characterized by: Claim 4: Magnesium 0.45% by weight or more 1.2% by weight
After finishing the surface of the cold-forged aluminum alloy pipe containing the aluminum alloy in the range of 0.2 μm or more and 1.0 μm or less at the maximum height Rmax by liquid honing, Liquid temperature on the surface is 14℃ or higher and 16℃
Below, using a sulfuric acid electrolyte with a concentration of 20% by weight, a current density of 1
．． Anodic oxidation treatment is performed using a direct current method within a range of 3A/dm2 or more and 1.7A/dm2 or less, followed by sealing treatment using a nickel acetate solution to form a film with a thickness of 4μm or more and 20μm.
A method for producing a support for an electrophotographic photoreceptor, which comprises forming an anodized aluminum film within the following range.