JPH0830004A - Production of aluminum pipe stock for electrophotographic photoreceptor - Google Patents

Abstract

PURPOSE:To improve the production efficiency of an aluminum pipe stock and the production efficiency of an electrophotographic photoreceptor by decreasing ranges where aluminum billets remain and include before defect parts are included, thereby effectively removing the defective parts. CONSTITUTION:This process for producing the aluminum pipe stock for the electrophotographic photoreceptor from the aluminum billet by an extrusion working method using a port hole die comprises using the port hole die of which the largest outside diameter of the port holes 4 therein is below 0.85 times the outside diameter of the billet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aluminum base material tube used as a conductive support for an electrophotographic photoreceptor.

[0002]

2. Description of the Related Art Conventionally, a cylindrical aluminum base made of aluminum or an aluminum alloy (hereinafter referred to as aluminum in the present invention) has been used as a conductive support for an electrophotographic photosensitive member. There are various methods for manufacturing the cylindrical aluminum substrate, and one of them is an aluminum billet, which is a cylindrical aluminum base material, is extruded using a porthole die to form a cylindrical aluminum tube. , Then, if necessary, squeeze processing on the aluminum tube,
There is a method for producing an electrophotographic photosensitive member by subjecting a conductive support to a treatment such as surface treatment, and then subjecting the surface of the conductive support to a photosensitive layer after performing a surface oxidation treatment if necessary. .

The extrusion method using this porthole die is known for general plastic molding and the like, but normally, a container (1) and a porthole die (2) as shown in FIG. 1 are used. Built-in die ring (3)
The aluminum billet, which is processed and processed by using the apparatus provided with, is transported in the container and pressed against the porthole die (2) under high temperature and high pressure.

A porthole die (2) is a short open porthole (4) having a large inlet portion and a small outlet portion as shown in the sectional view seen from above in FIG. 2 and the transverse sectional view in FIG. It is an axial cylinder, and the aluminum billet is once separated and flows in from this porthole inlet (5), then recombined through a small gap at the porthole outlet (6) and extruded as a thin-walled cylindrical aluminum tube. Be done. When one aluminum billet is extruded, the rear end is cut by a certain amount,
After that, the next aluminum billet is pushed out so as to connect to it.

[0005]

By the way, when an aluminum tube formed by such a processing method is used as a support for an electrophotographic photoreceptor, a small dot-like shape visible on the surface of the photoreceptor coated with a photosensitive layer is used. A defect has been found, and this problem has caused a problem that the defect is related to a high occurrence rate of image defects during image formation by an electrophotographic photosensitive member. Especially, the reason is about 20
It is conceivable that the paint does not deposit on the scratches of μ or more in the photosensitive layer coating process.

Further, such a defective portion is often found after the conventional photosensitive layer is formed, which is one of the causes for lowering manufacturing efficiency. Further, it is necessary to consider so as not to reduce the manufacturing efficiency of the aluminum base pipe even if the defective aluminum base pipe is removed. The present invention is intended to solve the above problems, and an object thereof is to provide an electrophotographic photoreceptor having reduced image defects, and an aluminum tube for the electrophotographic photoreceptor having the reduced defects. It is to provide a method of manufacturing. Further, by reducing the defective portions, the number of defective products found after the conventional photosensitive layer is formed is reduced. Another object is to improve the manufacturing efficiency of the aluminum tube by efficiently removing the defective product.

[0007]

In order to solve the above-mentioned problems, the inventors of the present invention have made diligent studies and as a result, found that the above-mentioned defects in the aluminum tube are due to impurities such as oxides present in the outer peripheral portion of the billet. Based on the hypothesis that it will occur, the shape of the porthole was examined, and as a result, by setting the ratio between the maximum outer diameter of the porthole and the outer diameter of the aluminum billet used to be below a certain level, the above defects were reduced and good electron It was discovered that an aluminum tube that can be used to manufacture a photographic photoreceptor is obtained, and furthermore, the efficiency of manufacturing the aluminum tube is high because the removal of the defective parts is minimized. The inventors have found that the efficiency of the photoconductor production is increased by decreasing the rate of defective products of (1), and have reached the present invention.

That is, the gist of the present invention is a method for producing an aluminum base pipe for an electrophotographic photosensitive member from an aluminum billet by an extrusion method using a porthole die, in which the maximum outer diameter of the porthole in the die is A method of manufacturing an aluminum base pipe for an electrophotographic photosensitive member is characterized in that a port hole die having an outer diameter of the aluminum billet of 0.85 times or less is used.

[0009]

The present invention will be described in detail below. 3 is a cross-sectional view showing an example of an extrusion processing apparatus used in the present invention, FIG. 4 is a cross-sectional view of the porthole die of the present invention seen from the inlet side, and FIG. 5 is a porthole die of the present invention. It is the sectional view which looked at from the side.

The extrusion apparatus illustrated in FIG. 3 is provided with a cylindrical container (1) and a die ring (3) incorporating a porthole die (2). The container is transported from the right side in the middle, passes through the porthole die under high temperature and high pressure, and then is transported to the left in the figure. FIG. 4 is a cross-sectional view of this porthole die (2) seen from the inlet side. A short-axis cylinder has several portholes (4) each having a substantially triangular inlet (5), preferably Three or more are provided, and a support portion (7) for partitioning each port hole is provided. The aluminum billet is separated and flows in through the port hole inlet (5), and is pressed and joined through a small gap at the port hole outlet (6) to be extruded as a thin-walled cylindrical aluminum tube.

When one aluminum billet is extruded,
The rear end portion is usually cut within a range of about 20 mm or less, and then the next aluminum billet is extruded so as to be connected to it. A feature of the present invention is that, as such a porthole die, the maximum outer diameter (B in FIG. 4) of the entrance portion of the porthole is 0.85 times or less, preferably 0.8 times or less, preferably 0.8 times or less the outer diameter of the aluminum billet. It consists in using a porthole die that is 0.78 times or less. Alternatively, the maximum outer diameter of the inlet portion of the port hole is 0.8 times or less, preferably 0.75 times or less, the inner diameter of the container (a in the figure). If the maximum outer diameter of the inlet portion of the port hole is too smaller than the outer diameter of the aluminum billet, the extrusion pressure will increase, which is not preferable. Therefore, the outer diameter of the inlet part of the port hole is 0.5 with respect to the outer diameter of the aluminum billet.
It is 5 times or more, preferably 0.6 times or more.

According to the features of the present invention, the inflow of impurities such as oxides, which are considered to be present on the outer peripheral surface of the aluminum billet, is slowed by the presence of the shoulder portion of the porthole die, so that the aluminum base tube as a product is supplied. The contamination of is reduced. Further, by cutting and removing the rear end portion of the aluminum billet which remains at a fixed amount at the end of the extrusion of one billet, it is possible to extremely efficiently collectively remove the portion where the impurities are accumulated.

As the aluminum billet used in the present invention, various known aluminum alloys other than simple substance of aluminum are usually used.

[0014]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. [Example 1 and Comparative Example 1] As Example 1, the port hole inlet inner diameter (B in the figure) 0.75 times the outer diameter of aluminum billet and 0.7 times the inner diameter of the container (A in the figure).
An extrusion apparatus as shown in FIGS. 3 to 5 using a porthole die having (The outer diameter of the aluminum billet used is 178 mm, the inner diameter of the container is 185 mm, and the outer diameter of the inlet of the port hole of the die is 130 m.
m, the outer diameter of the die ring (c in the figure) was 330 mm. On the other hand, as Comparative Example 1 which is a conventional example, a porthole die having a porthole inlet inner diameter of 0.90 times the outer diameter of aluminum billet and 0.86 times the inner diameter of the container is used in FIGS. 1 and 2. An extruding device as shown in FIG.
(The outer diameter of the entrance of the port hole of the die is 160 mm.
Except for the above, the same as in Example 1) An aluminum billet made of an alloy of aluminum and manganese was extruded by each of these devices. 1
The rear end portion of the aluminum billet extruded was cut by about 20 mm and the next aluminum billet was extruded to manufacture an aluminum tube.

Electric charge generation containing oxytitanium phthalocyanine and polyvinyl butyral resin is carried out on the surface of a conductive support after ironing the aluminum tube to form a thin long-axis cylinder. A layer and a charge transport layer containing a hydrazone compound and a polycarbonate resin were laminated by a dip coating method to produce an electrophotographic photoreceptor.

A small dot defect rate was evaluated by visual inspection. As a result, in Comparative Example 1 which is a conventional method, 10 to 20% of defects were generated in the portion using the raw tube between the billet seam portion and the front 8 m after extrusion of the next billet, and other than that. Whereas 1% of defects were generated in the portion, in Example 1 using the porthole die of the present invention, the next billet was 8 m from the billet joint portion.
It was confirmed that the defects between 2 to 5% and the other portions were reduced to 0.5%.

[0017]

As described in detail above, according to the present invention, an aluminum photographic tube having an extremely low defect rate can be obtained, so that an electrophotographic photosensitive member having excellent characteristics with few image defects can be obtained.
Further, since the portion of the blank pipe having the defect is reduced, the number of defective products is small and the manufacturing efficiency of the aluminum blank pipe is improved. In addition, since the defective aluminum tube is reduced, the number of defective products conventionally found after forming the photosensitive layer is reduced, and the production efficiency of the electrophotographic photoreceptor is improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a conventional extrusion machine using a porthole die.

FIG. 2 is a cross-sectional view of a conventional porthole die seen from above.

FIG. 3 is a cross-sectional view of a conventional porthole die.

FIG. 4 is a cross-sectional view of an extrusion processing apparatus using the porthole die of the present invention.

FIG. 5 is a sectional view of the porthole die of the present invention viewed from the inlet side.

FIG. 6 is a cross-sectional view of the porthole die of the present invention viewed from the side.

[Description of sign]

 1: Container 2: Porthole die 3: Die ring 4: Porthole 5: Porthole inlet 6: Porthole outlet 7: Partition support

Claims (1)

[Claims] 1. A method for manufacturing an aluminum base pipe for an electrophotographic photosensitive member from an aluminum billet by an extrusion method using a porthole die, wherein the maximum outer diameter of the porthole in the die is the outer diameter of the aluminum billet. A method of manufacturing an aluminum base tube for an electrophotographic photosensitive member, characterized in that a porthole die having a size of 0.85 times or less of the above is used.