JPH0411861B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an electrophotographic photoreceptor that not only provides good image quality but also has less peeling of the photosensitive layer and is easy to peel and remove during reproduction. Photoreceptors for electrophotography, such as selenium photoreceptors, have a photosensitive layer mainly made of selenium formed by vapor deposition or plating on the surface of a cylindrical aluminum drum. In order to obtain a photoreceptor with good properties and whose characteristics do not change, the following conditions are required. In other words, the surface of the drum that serves as the base material must have a high level of flatness, be a mirror surface with high light reflectivity, have few deterioration layers due to damage to the crystals of the base material, and be finished with a surface that will not change over time. is well known. On the other hand, as is well known, the adhesion strength of the photosensitive layer to the drum surface is determined by the surface roughness of the drum surface. The impact caused by the photoreceptor may cause peeling damage to the photoreceptor layer, reducing the lifespan of the photoreceptor. Therefore, when finishing the drum surface, the above two contradictory
It is necessary to satisfy two requirements. Furthermore, the used photoreceptor is recycled by peeling the photoreceptor layer from the drum surface, but in this case, as shown in Figure 1a, the so-called high frequency component, a short period consisting of sharp protrusions, is removed. If such a surface finish is applied, the adhesion of the photosensitive layer will be improved, but peeling and removal will be difficult, resulting in difficulty in reproduction. In addition, if the processed surface has large periodic undulations as shown in Figure 1b, the gap length for feeding the copy paper changes, and the fed paper tends to jam and damage the photoreceptor surface, resulting in poor image quality. decrease. Therefore, when it comes to finishing the surface of the drum, it is required to have a surface roughness that is free from large waviness, high frequency components, and has strong adhesion to the photosensitive layer. is 0.1 to 0.1 when the photosensitive layer is selenium.
It is said to be 2.0μmRmax. Therefore, various finishing methods have been used to achieve such a surface finish, such as the so-called liquid honing method in which a liquid such as water in which carborundum is dispersed is injected onto the finished surface, and the superfinishing method. Mechanical grinding methods, such as a method in which a grindstone is brought into contact with the surface with a constant pressing pressure and fed while vibrating, and a method using a precision lathe using a diamond cutting tool, have been proposed and are being implemented in the production of photoreceptors. However, the surface finish roughness obtained by the liquid honing method is at best about 4 μm, which is insufficient. In addition, methods using super-finishing and ultra-precision lathes can obtain the required surface roughness in the range of 0.1 to 0.2 μm, but they cannot prevent large waviness on the finished surface due to the feed of the grindstone or external vibration. Not only is this difficult, but it also leaves behind high-frequency components that make playback difficult. In addition, the base metal crystals on the surface are damaged by the grindstone or cutter, and the formation of a degraded layer cannot be prevented, so deterioration over time is likely to occur. In addition, these mechanical grinding methods generally involve rough machining,
It requires preliminary processing such as intermediate processing, and is difficult to finish directly from the raw material. Therefore, the operation is troublesome and takes time. In addition, especially in the lathe method, the machining accuracy depends on the accuracy of the machining equipment, so not only does it require highly accurate machining equipment, but it also requires difficult management of the cutter tools in order to prevent loss of precision. Moreover, there are drawbacks such as difficulty in processing chips. Therefore, with the conventional surface finishing methods as described above, it is difficult to produce a photoreceptor that has a long life and is easy to recycle, realizing good image quality, and the production cost increases. The present invention aims to provide a photoreceptor that can satisfy the above requirements, and the details thereof will be explained below with reference to the drawings. The present invention involves grinding a passivation film using an abrasive material,
As a result of research, it has become clear that the so-called electrolytic composite processing method, which uses metal elution through electrolysis, is extremely effective in surface processing to create excellent photoreceptors.In short, electrolytic composite processing It is characterized by an electrophotographic photoreceptor that is formed by attaching a photosensitive layer to the surface of a substrate that is finished to have the required surface roughness and is free of high-frequency components and large-period waviness.Specifically, it is as follows: It is made by That is, as shown in the front view shown in FIG. 2, an electrode 1 and an abrasive material 2 attached to the tip thereof are formed by impregnating or adhering abrasive grains of a desired particle size to a viscoelastic material such as urethane sponge. Depending on the quality of the finished surface, a processing tool made of a hard abrasive material 2 made of abrasive grains hardened with a binder may be rotated at a constant speed in the direction of the arrow in the figure. Contact with the machined surface with a constant pressing pressure. Then, the electrode 1 is used as a cathode and the workpiece 3 is used as an anode, and the gap between them is adjusted to a specific optimum value according to the request so that the required current can be supplied, and an electrolytic solution such as sodium nitrate is supplied from the nozzle 4. A non-active electrolyte 5 such as (NaNO ₃ ) is supplied. First, a low voltage is applied to form an extremely thin passivation film 6 on the surface of the drum 3 as shown in FIG. As shown, the passivation film 6 is removed at the protrusion 7 to expose the metal surface into the electrolytic solution 5. Thereafter, the voltage is increased to concentrate the current on the exposed metal portion, and the operation of eluating the metal is repeated to smooth the surface as shown in FIG. 3c. Finally, a photosensitive layer is formed on the treated surface by vapor deposition or plating. As described above, electrochemical grinding performed on exposed metal protrusions has a large effect on smoothing by electrolytic composite machining. Therefore, there is no high frequency component with an acute angle with a small period that occurs in mechanical grinding as shown in Figure 1a, and it is possible to achieve a surface finish with the required surface roughness with less directionality, and it is also possible to achieve the required finish using the elution current. By setting the optimal value according to the surface, it becomes possible to quickly finish the surface by performing only one processing from the raw material. In addition, unlike grinding with a whetstone or edged tool, the crystals of the base material near the surface are less likely to be damaged and a degraded layer is less likely to occur, making it possible to finish the surface with less deterioration over time. In addition, by using a viscoelastic abrasive material, external vibrations and dynamic rigidity of the processing machine are absorbed by the viscoelasticity of the abrasive material, and the vibrations are prevented from reaching the finished surface. It is possible to prevent large periodic waviness from occurring. Therefore, by adhering a photosensitive layer to the surface of such a substrate, it is possible to provide a photoreceptor from which a good copy image can be obtained that satisfies the adhesion of the photosensitive layer and the ease of stripping and reproduction. Furthermore, a photoreceptor can be obtained in which the surface of the photoreceptor layer is less likely to be damaged due to paper jams. Next, an example will be described. Using an abrasive material containing abrasive grains in a urethane sponge, processing was carried out under the conditions shown in Table 1 below, and the state of surface roughness was measured using a roughness measuring device, and the following results were obtained. In other words, it is possible to easily obtain a processed surface with a roughness of 0.005 to 10 μm Rmax, which includes the necessary surface roughness to achieve a high-quality image and the required adhesion of the photosensitive layer, and is free of high-frequency components as shown in Figure 4. We were able to obtain a machined surface with uniform periodic roughness. In addition, the waviness can be reduced by more than two orders of magnitude compared to conventional mechanical grinding methods, and the photoreceptor with a photosensitive layer formed on the processed surface can be improved by mechanical grinding in terms of image quality, adhesion of the photosensitive layer, and reproducibility of the photosensitive layer. It has been confirmed that it has excellent properties that cannot be obtained by other methods.

[Table] As is clear from the above description, according to the present invention, it is possible to obtain an electrophotographic photoreceptor that can produce high-quality images and has excellent adhesion and peel reproducibility of the photosensitive layer. , the practical effect is great.

[Brief explanation of drawings]

Fig. 1 is an example diagram showing the condition of a machined surface by mechanical grinding, Fig. 2 is an explanatory diagram of the electrolytic composite machining device used in the present invention, and Fig. 3 is a diagram of the machining process.
FIG. 4 is a diagram showing the roughness of the processed surface according to the present invention. DESCRIPTION OF SYMBOLS 1... Electrode, 2... Abrasive grain material, 3... Conductive workpiece, 4... Nozzle, 5... Electrolyte, 6... Passivation film, 7... Projection.

Claims (1)

[Claims] 1. A processing tool consisting of an electrode and a viscoelastic abrasive material is brought into contact with the surface of the substrate under constant pressing pressure to supply an inactive electrolyte, and the current is adjusted to the optimum value with the electrode as a cathode and the substrate as an anode. First, a low voltage is applied to form a thin passivation film on the substrate surface, and then the substrate surface is scraped with the abrasive grain material to remove the passivation film at the convex portions, and then the voltage is increased. Through electrolytic composite processing, which smoothes the surface of the substrate by repeating operations to elute metal from exposed metal parts, the surface of the substrate is finished with a surface roughness of 0.1 to 2.0 μm without high frequency components or large periodic waviness. A photoreceptor for electrophotography, characterized in that it is formed by adhering a photosensitive layer mainly composed of selenium.