JPH0217020B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a method for manufacturing an electrophotographic photoreceptor in which the surface of a photosensitive layer is roughened.

[Prior art and its problems]

Conventionally, electrophotographic photoreceptors have been required to have a smooth surface in view of image formation, reliability, and the like. For example, this type of photoreceptor generally uses a photoreceptor using Se alloy, in which an amorphous Se alloy is deposited on a conductive substrate by vacuum evaporation method or the like.
It is used as a photoconductive layer, and its surface is a glossy smooth surface (mirror surface). If the surface of the photoconductive layer is smooth, the adhesion with the toner increases, resulting in a disadvantage that the transferability, cleaning performance, and separation of the transfer paper are impaired. Furthermore, an excessive amount of cleaning equipment is required to remove residual toner, which damages the surface of the photoreceptor, which shortens the life of the photoreceptor and causes deterioration in image quality due to poor cleaning.

Recently, it has been found that it is more effective for the surface of the photoreceptor to be roughened to some extent in order to overcome the above-mentioned drawbacks. Although there are several proposals for roughening the surface of the photoconductive layer by adding fine irregularities to the surface, none of them have been put to practical use due to industrial difficulties. Particularly in the process of forming a photoconductive layer, it is difficult with conventional vapor deposition methods to moderately roughen the surface of the photoconductive layer made of a fluid photoconductive material such as Se-based material. It has been believed that surface roughening due to adhesion of foreign matter or contact with foreign matter during or after the formation of the photoconductive layer causes surface crystallization, which impairs reliability, but As ₂ Se ₃ photoreceptors have a high glass transition point. Since it is resistant to foreign matter contact, the surface of the photoconductive layer can be roughened by direct surface processing, for example, by cylindrical grinding, superfinishing, or the like. However, the method of directly processing the surface of the photoconductive layer is unfavorable in terms of electrostatic properties, such as changes in the surface structure resulting in poor charge retention and no charge being carried. In addition, the surface of the conductive substrate is made rough by cylindrical grinding, liquid honing, etc., and the conditions for the photoconductive layer formation process are adjusted such that the temperature of the substrate during vapor deposition is below the glass transition point for Se-based photoreceptors. There is a method of roughening the surface of the photoconductive layer by making appropriate settings. Although this method has no problem in terms of electrostatic properties, it is difficult to form a stable rough surface on the surface of the photoconductive layer because it does not provide a stable rough surface on the surface of the substrate.

[Purpose of the invention]

In order to improve toner transfer performance, transfer paper separation performance, and cleaning performance, the present invention can stably form a photoreceptor with a roughened photoconductive layer surface without impairing electrostatic properties. An object of the present invention is to provide a method for manufacturing an electrophotographic photoreceptor that can be produced.

[Key points of the invention]

The present invention comprises a step of vapor depositing a first photoconductive layer made of a selenium-based material on the surface of a conductive substrate, a step of roughening the surface of the first photoconductive layer formed by this step, and a step of roughening the surface of the first photoconductive layer formed by this step. A photoreceptor is manufactured by a step of similarly vapor depositing a second photoconductive layer made of a selenium-based material on the surface of the first photoconductive layer.

Generally, the viscosity of Se or Se alloy changes suddenly near the glass transition point Tg, and the fluidity fluctuates. In other words, at temperatures near or above Tg, fluidity increases,
Below Tg, fluidity decreases. Amorphous Se or
Formation of the photoconductive layer using the Se alloy is carried out by a vacuum evaporation method, and the fluidity of the Se or Se alloy on the substrate can be changed by the substrate temperature set at the time of vapor deposition.

The present invention utilizes the above-mentioned properties to form a first photoconductive layer by vapor deposition using a conventional method, and roughens the surface of this first photoconductive layer so that the rough surface appears on the layer surface. The second photoconductive layer is formed by vapor deposition at a temperature below Tg.

[Embodiments of the invention]

FIG. 1 shows a cross section of a photoreceptor according to an embodiment of the present invention. Reference numeral 1 denotes a conductive substrate made of metal or alloy such as Al, Fe, Cu, etc., and its surface is processed by cylindrical grinding, liquid honing, etc., but it is not necessary to have a limited roughness. A first photoconductive layer 2 made of selenium or a selenium alloy is deposited on this substrate 1, and its surface is roughened by surface processing such as cylindrical grinding or liquid honing. Furthermore, a second photoconductive layer 3 made of As ₂ Se ₃ is deposited thereon at a temperature below the glass transition point of As ₂ Se ₃ to form a rough surface 4 on its surface.

Example 1: The surface of the conductive substrate 1 was processed by cylindrical grinding,
The temperature of substrate 1 was kept at 230℃ and the thickness was 60μm.
_{Deposit As2Se3} . The surface of the first photoconductive layer 2 of the photoreceptor thus obtained is roughened by superfinishing. The surface of the photoconductive layer 2 was roughened to a roughness of 0.1 to 0.5 μm using a #2000 grindstone. In this state, due to electrostatic properties, the charge retention rate is less than 50% compared to conventional products, and it is not practical to carry charge. Furthermore, using the same evaporation source, the substrate 1
When the second photoconductive layer 3 was formed by vapor deposition to a thickness of 1 to 5 .mu.m while maintaining the temperature at 150.degree. C., a rough surface with a roughness of 0.1 to 0.4 .mu.m could be obtained on the surface.

Example 2: The surface of the conductive substrate 1 was processed by cylindrical grinding, the temperature of the substrate 1 was maintained at 150°C, and the thickness of the As ₂ Se ₃ layer 1 was
The photoconductive layer was deposited to a thickness of 60 μm, and the surface of the resulting photoconductive layer was roughened by superfinishing. The surface of the photoconductive layer 1 was roughened to a roughness of 0.1 to 0.5 μm using a #2000 grindstone.
Furthermore, As ₂ Se ₃ was added to substrate 1 while keeping the temperature of substrate 1 at 150℃.
When ~5μm was deposited, the surface was 0.1~0.4μm
It was possible to obtain a second photoconductive layer 3 roughened to a roughness of .

The electrostatic properties of the photoreceptors obtained in Examples 1 and 2 were comparable to those of conventional products, the image quality was good, and no defects such as white streaks occurred on the images. Since a photosensitive layer with a roughened surface was obtained, toner transfer properties, transfer paper separation properties, and cleaning properties were improved.

Methods for roughening the first layer include super finishing (SF) using a grindstone, polishing by rotating a drum while rotating the grindstone, and using emery paper, polishing cloth, etc. in place of the grindstone. You can read it. Liquid honing is also effective because it can provide a matte finish that does not easily leave processing marks on the image.

The irregularities appearing on the surface of the photosensitive layer (second photoconductive layer) have a roughness in the range of 0.1 to 2 μm, particularly 0.1 to 2 μm.
A range of 1 μm is desirable, and it is effective that the width of the unevenness in the surface direction is smaller than the particle size of the toner used. If the unevenness is larger than this, spot-like charging unevenness will occur, resulting in a defect on the image. Also, the cleaning blade gets scratched, shortening its lifespan. If the unevenness is small, desired cleaning performance cannot be obtained.

In the process of forming the second photoconductive layer, the temperature of the substrate greatly influences the surface of the photosensitive layer, as described above, and therefore needs to be set within an appropriate range. The temperature of the substrate that makes it possible to roughen the surface of the photosensitive layer is As ₂ Se ₃
When used as a photoconductive material, the temperature is usually 180°C or lower, particularly 100 to 170°C. Also, the second
If the deposition thickness of the photoconductive layer is selected to be too large, the surface will be smoothed, and if it is selected to be too small, the roughness of the surface will become large, so it is necessary to adjust the roughness so that it falls within the above range. There is.

〔Effect of the invention〕

The present invention involves mechanically processing the surface of a first photoconductive layer formed on a conductive substrate to make it rough, and depositing the substrate temperature on the roughened photoconductive layer to achieve a glass transition of the photoconductive material. A second photoconductive layer is formed by vapor deposition to obtain a photoreceptor for electrophotography having a rough surface. Moreover, it has become possible to stably produce an electrophotographic photoreceptor with good image quality, so the effects obtained are extremely large.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of an electrophotographic photoreceptor according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Conductive substrate, 2... First photoconductive layer, 3...
As ₂ Se ₃ layers, 4...Rough surface.

Claims (1)

[Claims] 1. A first photoconductive layer made of a selenium-arsenic alloy is deposited on the surface of a conductive substrate, and then this surface is roughened, and then a second photoconductive layer is placed on top of it, with a surface roughness of 0.1. A method for producing an electrophotographic photoreceptor, which comprises depositing the substrate to a thickness of 1 to 5 μm while maintaining the substrate at a predetermined temperature below the glass transition temperature of a selenium-arsenic alloy such that the thickness of the selenium-arsenic alloy becomes 2.0 μm.