JP2666395B2 - Electrophotographic photoreceptor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member having a photosensitive layer provided on a substrate subjected to a surface roughening treatment.

2. Description of the Related Art An electrophotographic photoreceptor has a structure in which a barrier layer is provided on a base, if necessary, and a photosensitive layer is formed. The surface of the substrate is usually mirror-finished to prevent image defects and to improve the coating properties of the photosensitive layer.

Japanese Patent Application Laid-Open No. 51-58954 discloses that the surface of a substrate is roughened by honing to improve the adhesion between the substrate and the photosensitive layer.
Japanese Patent Application Laid-Open Publication No. H11-157873 describes that the surface is roughened with a specific surface treatment material for the same purpose. Also, JP-A-58-162975,
60-79360, 60-112049, 61-42663 and 62-1862
No. 70 describes, for example, that when a laser beam is incident on the photosensitive layer, the substrate is roughened to scatter light in order to prevent interference fringes from occurring in the image due to multiple reflections. I have. As is apparent from these known techniques, it is not always preferable that the surface of the substrate is a mirror surface as long as the surface is uniformly roughened so that sudden image defects do not occur.

Problems to be Solved by the Invention By the way, when a photoconductor is used in an electrophotographic copying machine,
The distance between the photoreceptor and the developing roll must always be kept constant in order to improve the developing performance. For this reason, a method of contacting a roller with the end of the photoreceptor or holding it by coloring is usually adopted. In this case, the portion where the roller or the coloring contacts is rubbed, so that if the photosensitive layer is present on the substrate, the rubbed portion of the photosensitive layer may be unevenly peeled off or worn. There is a problem. Therefore, it is necessary to leave or remove the photosensitive layer in that portion.

However, when a substrate having a roughened surface is used,
If a roller or a color ring comes into contact with a part where the photosensitive layer is not provided, there is a problem that the roller or the color ring is inadvertently vibrated or abraded severely because the contact part is a rough surface. The present invention has been made in view of such problems.

Accordingly, an object of the present invention is to provide an electrophotographic photoreceptor which can prevent the vibration and abrasion of rollers and coloring even when a substrate having a roughened surface is used.

Means for Solving the Problems The electrophotographic photoreceptor of the present invention has, as its base, both ends having a smooth mirror surface corresponding to a contact portion of a roller and a coloring, and other portions roughened. It is characterized by using a thing. That is, the electrophotographic photoreceptor of the present invention roughens the surface of the cylindrical substrate, leaving at both ends a smaller area than the area corresponding to the non-image area,
The photosensitive layer is provided only on the roughened area.

FIG. 1 is a fragmentary sectional view of the electrophotographic photosensitive member of the present invention. 1 is a cylindrical substrate having a roughened surface 2 on which a photosensitive layer 3 is formed. Numeral 4 is a non-roughened portion at both ends.

In the present invention, the average roughness Ra of the roughened region is 0.
It is necessary that the thickness be 1 μm or more.

Methods for roughening the surface of the substrate include a method for adjusting the accuracy of surface cutting, a method for pressing a rotating grindstone, an anodizing method, an etching method, a sandpaper processing method, a wet honing method, a sandblasting method, and a buffing method. Processing methods and the like. Among these, the wet honing method is particularly advantageous because the processing time is short, the operation is simple, the desired surface roughness is easily obtained, and the stability is high. . The wet honing method is a method of suspending a powder of iron, glass, alumina, silicon carbide, epoxy resin, or the like in a liquid such as water, and spraying the powder at a high speed to roughen the surface of the substrate. In this case, the surface roughness can be appropriately controlled by spraying pressure, spraying speed, spraying amount, powder shape, size, hardness, specific gravity, suspension concentration, and the like.

Usually, the non-image area of the photoreceptor extends from the end of the cylindrical substrate.
Since it is in the range of 10 to 30 mm, the area left without roughening in the present invention is in the range of about 5 to 20 mm from the end.

In the present invention, various means are applied to roughen the surface while leaving predetermined regions at both ends of the cylindrical substrate. For example, a portion that is not to be roughened may be coated with an appropriate material to roughen the surface. In the case of adjusting the accuracy of surface cutting, when cutting both ends, the surface roughness Ra0.1.
The surface may be cut with high precision so as to be less than μm.

The entire surface of the substrate before roughening was Ra0.1μ.
It is preferable that the surface is previously treated by a method such as surface cutting so as to be less than m. It is also effective for improving dimensional accuracy. Alternatively, a substrate prepared by DI processing as described in JP-A-58-202454 may be used, in which case a surface roughness of Ra 0.01 μm is obtained.

Next, a photosensitive layer is formed on the cylindrical substrate, and the photosensitive layer needs to be provided only in the roughened area. For this purpose, the non-roughened area is covered with an appropriate material so that the photosensitive layer is not formed, or the photosensitive layer is formed on the entire surface of the cylindrical substrate, and then the non-roughened area at the end is formed. And the like.

The layer structure of the photosensitive layer may be a single layer structure or a laminated structure including a charge generation layer and a charge transport layer. As a material constituting them, any conventionally known material can be used. For example, as photosensitive materials, Se-based materials,
Conventionally known materials such as amorphous silicon materials, ZnO, CdS, and various organic materials can be used.

The electrophotographic photoreceptor of the present invention has portions that are not roughened at both ends of the cylindrical substrate. Therefore, when the electrophotographic photoreceptor is mounted on a copying machine and a copying operation is performed, a roller or Even if the coloring abuts, it does not cause vibration or wear. In addition, since the portion where the photosensitive layer is provided is roughened, laser light applied to the photosensitive layer does not cause interference.

Examples Hereinafter, the present invention will be described with reference to examples.

Example 1 An aluminum pipe of 1 mm × 40 mmφ × 310 mm was prepared,
Cutting was performed by a mirror lathe using a diamond tool, and the surface was finished to a smooth surface of Ra0.04 μm.

This aluminum pipe was treated by the liquid honing apparatus shown in FIG. In FIG. 2, 1 is an aluminum pipe, 5 is a pump, 6 is a gun, 7 is air,
8 is a booth and 9 is a flange.

Honing conditions include an alundum abrasive (# 30
0) 10 kg was suspended in water 40 and sprayed onto aluminum pipe 1 with 4 kg / cm ² of air 7 while pumping it to gun 6 at a flow rate of 6 / min. The gun was moved at a speed of 40 cm / min in the axial direction of the aluminum pipe, and the aluminum pipe was rotated at 100 rpm. The upper and lower ends of the aluminum pipe were fixed by flanges 9 each of which entered only 10 mm from the edge, and were held so that the both ends were not honed. The surface roughness after the honing treatment was Ra 0.18 μm.

A methanol / butanol solution of a copolymerized nylon resin (trade name: CM8000, manufactured by Toray Industries, Inc.) was applied to the honed aluminum pipe with a ring coater to form a 0.7 μm-thick barrier layer. .

Next, 3 parts of vanadyl phthalocyanine was added to 10 parts of polyester resin (product side: PE100, manufactured by Goodyear Chemical Company).
% Cyclohexanone solution. The distributed operation is
Using a 10 mmφ ball, the mixture was mixed by a ball mill for 2 hours. Add 2-butanone 10
The coating solution was added to the coating solution, and the solution was applied onto the barrier layer by a ring coating machine to form a charge generating layer having a thickness of 0.4 μm.

A charge transport layer was formed on the charge generation layer. That is, 4 parts of N, N'-diphenyl-N, N'-bis (3-methylphenyl) [1,1-biphenyl] -4,4-diamine is used as a charge transporting material, and 6 parts of polycarbonate Z resin is used together with monochlorobenzene. The solution was dissolved in 40 parts, and the obtained solution was applied by a dip coating apparatus at a pulling rate of 11 cm / min. 110 ℃
For 1 hour to form a charge transport layer having a thickness of 20 μm.

Thereafter, the layer applied by 10 mm was peeled off from both upper and lower ends of the aluminum pipe.

The obtained electrophotographic photosensitive member was attached to a laser beam printer (LBP) having a dot density of 400 dpi. The developing machine is a roller made of polyacetal resin having a width of 4 mm, so that the distance between the electrophotographic photosensitive member and the developing roll is 200 μm.
It was designed to contact both ends of the electrophotographic photosensitive member.
Looking at the obtained LBP output image, no image defects such as interference fringes occurred. No abnormalities were observed in the output test of 2,000 sheets continuously.

Comparative Example 1 An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the coating layers at both ends of the electrophotographic photosensitive member were not removed.

When this electrophotographic photoreceptor was mounted on an LBP and subjected to an output test, a normal image was obtained initially, but 2,000
After the sheet, the coating layer at the end was peeled off in some places, and the peeled small pieces fell into the developing roll, causing uneven development.

Comparative Example 2 An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that an aluminum pipe not subjected to any surface roughening treatment by a honing treatment was used.

When the electrophotographic photoreceptor was attached to the LBP and a copy image was viewed, a grain pattern was generated due to interference, and the image quality was poor.

Comparative Example 3 At the time of honing treatment in Example 1, an aluminum pipe was attached to a flange fixed from the inside thereof,
A roughening treatment was performed on the entire surface. An electrophotographic photoreceptor was produced in the same manner as in Example 1 except that this aluminum pipe was used. However, when the coating layer at the end is peeled, the surface of the end is also roughened, so that it takes time to peel and the workability is poor. Also, the peeled surface was not clean.

When this electrophotographic photoreceptor was mounted on an LBP and subjected to an output test, a normal image was obtained initially, but 2,000
After the printing, the gap between the electrophotographic photosensitive member and the developing roll was changed due to friction or deformation of the rollers, and a low-quality image in which the image density fluctuated in one printing was obtained.

Example 2 At the time of the honing treatment in Example 1, the air pressure was 3 k
Two types of aluminum pipes were produced in place of g / cm ² and 2.5 kg / cm ² . As for each surface roughness, Ra was 0.13 μm and 0.10 μm, respectively.

An electrophotographic photosensitive member was produced in the same manner as in Example 1 using each aluminum pipe. When this electrophotographic photoreceptor was attached to the LBP and tested for image quality, Ra0.1
The electrophotographic photosensitive member using the 3 μm pipe had no problem as in Example 1. On the other hand, in the case of an electrophotographic photosensitive member using an aluminum pipe having a Ra of 0.10 μm, interference fringes were slightly generated. However, when attached to an LBP having a dot density of 300 dpi, no interference fringes were generated.

Effect of the Invention In the electrophotographic photoreceptor of the present invention, the surface of the substrate where the photosensitive layer is present is roughened, so that the adhesion of the photosensitive layer is improved, and the output image is formed by irradiating a laser beam. Even if you get
No interference fringes occur in the image. On the other hand, both ends of the cylindrical substrate where the photosensitive layer does not exist are not roughened, so that even if rollers or colorings are brought into contact therewith, no troubles such as vibration and wear occur.

[Brief description of the drawings]

FIG. 1 is a fragmentary sectional view of the electrophotographic photosensitive member of the present invention, and FIG. 2 is a schematic configuration diagram of a liquid honing apparatus for performing a roughening process. DESCRIPTION OF SYMBOLS 1 ... Cylindrical substrate, 2 ... Roughened surface, 3 ... Photosensitive layer, 4 ... End part, 5 ... Pump, 6 ... Gun, 7 ... Air, 8 ... Booth, 9 …… Flange.

Claims (3)

(57) [Claims] 1. The surface of a cylindrical substrate is roughened, leaving a smaller area at both ends than an area corresponding to a non-image area,
An electrophotographic photoreceptor comprising a photosensitive layer provided only in a roughened area. 2. The electrophotographic photosensitive member according to claim 1, wherein the surface roughening treatment is performed by honing. 3. The electrophotographic photosensitive member according to claim 1, wherein the average roughness of the roughened region on the surface of the cylindrical substrate is 0.1 μm or more.