JPH03184053A - Surface roughening method for organic electrophotographic photoreceptor - Google Patents

Abstract

PURPOSE:To prevent a cleaning defect by executing surface roughening in a manner as to prevent the contact of both the transverse ends of a film-like polishing material with a photosensitive body at the time of roughening the surface of the photosensitive body by using the polishing material. CONSTITUTION:The surface roughening is executed in a manner as to prevent the contact of both the transverse ends of the film-like polishing material 2 with the photosensitive body 1 at the time of roughening the surface of the photosensitive body 1 by using the polishing material. For example, the surface roughening is executed by using a lifting member 4 in order to prevent the contact of both the transverse ends the polishing material 2 with the photosensitive body 1 at the time of moving the film-like polishing material 2 from a delivery roller 5 in an arrow direction toward a take-up roller 6 via a press roller 3 made of rubber in pressurized contact with the electrophotographic sensitive body 1. The surface roughening of the org. electrophtographic sensitive body is uniformly executed within the prescribed range in this way and the cleaning defect and image defect are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an organic electrophotographic photoreceptor, and more specifically, an organic electrophotographic photoreceptor for obtaining an organic electrophotographic photoreceptor with good cleaning properties and image characteristics. This paper relates to a surface roughening method.

[Conventional technology]

Generally, in an electrophotographic process, an electrophotographic photoreceptor is subjected to at least charging, image exposure, and development.

A cycle consisting of transfer and cleaning steps is repeated. In particular, the cleaning process for removing residual toner on the photoreceptor after the transfer process is an important process in order to always obtain clear copy images.

The following two methods are generally used for this cleaning. The first method is to press a rubber plate-shaped part called a cleaning blade onto the photoconductor to eliminate the gap between the photoconductor and the cleaning blade, thereby preventing toner from slipping through. This method involves scraping off the remaining toner. The second method is to wipe or knock off the remaining toner by rotating the roller of the fur brush so that it comes into contact with the surface of the photoreceptor. Of these two methods, since the rubber blade is cheaper and easier to design, cleaning using a cleaning blade is currently the mainstream. In particular, when performing natural color development, natural colors are produced by overlapping the three primary colors of magenta, cyan, and yellow, or even four colors including black, so the amount of toner used is 1/2 of the normal amount.
color development, and therefore it is best to use a cleaning method in which a rubber blade is pressed against the photoreceptor.

However, the cleaning blade that exhibits excellent cleaning properties has a drawback in that the cleaning blade tends to flip over because of the large frictional force with the photoreceptor. This reversal of the cleaning blade is a phenomenon in which the cleaning blade in one direction of the counter is warped in the direction of movement of the photoreceptor, that is, in the opposite direction to the one direction of the counter.

What is the phenomenon of this cleaning blade turning over?

If the surface of the photoreceptor is made hard, that is, less likely to be scraped, in order to extend the life of the photoreceptor, this problem becomes even more likely to occur. or.

When toner particle size is made uniform and minute toner particles are removed to improve image quality, the lubricity caused by toner entering the gap between the cleaning blade and the photoreceptor surface is weakened. , the cleaning blade is more likely to turn over.

In addition, when performing natural color development, toner of magenta, cyan, and yellow or four colors including black is used three or four times to produce one image.
Since development is carried out twice, the load on the cleaning blade is large, making it more likely that the cleaning blade will flip over or that the edge portion will be damaged.

It was a cabinet. When the surface layer of the photoreceptor is made of an organic material, the frictional resistance between the cleaning blade and the photoreceptor surface is increased compared to an inorganic surface, and the IJ-ning blade is particularly likely to reverse or damage the edges. Become.

Therefore, the applicant of the present invention previously applied for Japanese Patent Application No. 62-256769 to roughen the surface of the photoreceptor in advance. We proposed a method to prevent cleaning defects caused by such problems. The roughening state of the photoreceptor surface is determined by the 10-point average roughness (
Preferably, the maximum value, average value, and minimum value are all within the range of 0.3 to 50 μm, which is even more preferable! Preferably, it is within the range of 0.3 to 2.0 μm. When the maximum value is larger than 5.0 μm, streak-like defects tend to appear in the image. Further, when the minimum value is as small as 0.3 μm, the friction between the cleaning blade and the photoreceptor surface is hardly alleviated partially, and the effect of roughening the rich photoreceptor surface is not recognized. The maximum value, average value and minimum value above are 03~5゜0μ
If it is within the range of m, the contact area between the photoreceptor surface and the cleaning blade is reduced.

In addition, those with a minute particle size that are contained in a small amount in the toner (
The cleaning blade has lubricity that is generated by moderately getting into the gap between the photoreceptor surface and the cleaning blade, as well as the shavings of the surface of the photoreceptor (1μm or less) that have been scraped off during use. Since it slides easily, it is possible to prevent cleaning failures due to the cleaning blade being reversed, etc.

On the other hand, as a method for roughening the surface of a photoreceptor.

JP-A-53-92133 and JP-A-57-9477
A mechanical polishing method such as a sandblasting method using a brush or an abrasive material as described in Publication No. 2, and drying conditions during coating as described in Japanese Patent Application Laid-open No. 53-92133. The surface can be roughened by adding powder particles to the surface layer in advance and coating it as described in JP-A No. 52-26226. There are ways to do this. Among these methods, the mechanical polishing method is the most preferable in that it increases the lubricity between the cleaning blade and the surface of the photoreceptor. This is because the shavings on the surface of the photoreceptor generated by mechanical polishing act as a lubricant. Among mechanical polishing methods, a method using a film-like abrasive material is more preferable. The reason for this is that in the case of sandblasting, etc., the abrasive is embedded in the organic electrophotographic photoreceptor.
This is because film-like abrasives have almost no embedding, whereas they tend to smear, causing pinholes and deteriorating electrophotographic properties.

[Problem to be solved by the invention]

However, in the conventional mechanical polishing method, in which the surface of a photoreceptor is polished by pressure contact with an abrasive material to make the surface rough, the roughening state may vary even on the same photoreceptor due to differences in the contact state of the abrasive material, the contact pressure, and the polishing speed. It is very difficult to control the roughened surface, and in areas where the roughened surface is shallow, the friction between the cleaning blade and the photoconductor is not alleviated, causing the cleaning blade to become uneven. There have been disadvantages such as inversion and loss of edge parts, and image defects as scratch patterns on one image in deep roughened areas. It is an object of the present invention to provide an organic electrophotographic photoreceptor that can prevent poor cleaning due to loss of edge portions and the like and scratch patterns on images.

Another object of the present invention is to uniformly roughen the surface of an organic electrophotographic photoreceptor within a predetermined range in order to prevent this cleaning failure.

An object of the present invention is to provide a surface roughening method.

[Means to solve the problem]

As a result of intensive studies on roughening the surface of a photoreceptor, the present inventors have developed a method for roughening the surface of an organic electrophotographic photoreceptor using a film-like abrasive material, as shown in FIG. According to JIS, by roughening the abrasive material so that both end portions in the width direction do not come into contact with the photoreceptor,
The maximum value, average value, and minimum value (in this specification, these are referred to as maximum surface roughness and average surface roughness, respectively) as defined by the 10-point average roughness (R2) measurement method defined in standard BO601. and minimum surface roughness) are both O13~5.0μ
It has been found that a uniform rough surface condition falling within the range of m can be obtained and that poor cleaning can be prevented.

That is, 1 the present invention provides a method for roughening the surface of an organic electrophotographic photoreceptor using a film-like abrasive, in which the surface of the photoreceptor is roughened with the abrasive in the width direction of the abrasive. It is characterized in that it is carried out so that both end portions do not come into contact with the photoreceptor.

When the surface of an organic electrophotographic photoreceptor is roughened using a film-like abrasive, uniform pressure is applied at both ends of the abrasive in the width direction. This resulted in non-uniform surface conditions. In contrast, in the present invention, when roughening the surface of a patterned photoreceptor with the abrasive material, both end portions in the width direction of the abrasive material are separated from the photoreceptor, and the other portions are polished to obtain a uniform rough surface. This made it possible to

In carrying out the surface roughening method of the present invention, an apparatus schematically shown in cross section in FIG. 2 can be used as an example. The organic electrophotographic photoreceptor 1 is rotated clockwise or counterclockwise. On the other hand, the film-like abrasive material 2 is moved in the direction of the arrow from the delivery roller 5 to the take-up roller 6 via the rubber surface pressing roller 3 that is in pressure contact with the electrophotographic photoreceptor. At this time, the film-like abrasive material 2 rubs the surface of the electrophotographic photoreceptor 1 at the position of the pressing roller 3. In the present invention, as shown in FIG. 1, a lifting member 4 is used to roughen the surface of the abrasive so that both end portions in the width direction do not come into contact with the photoreceptor.

Film-like abrasives used in the practice of the present invention include those in which fine particles of aluminum oxide, silicon carbide, chromium oxide, diamond, etc. are coated and fixed on a film of polyester or the like.

The organic electrophotographic photoreceptor treated by the surface roughening method of the present invention has an organic photosensitive layer laminated on a conductive support, and this photosensitive layer preferably has a charge generation layer and a charge transport layer. This is a laminated photosensitive layer with functionally separated layers.

As a conductive support, metal such as aluminum, aluminum alloy, stainless steel, metal coated with a conductive substance alone or with a suitable binder to provide a conductive layer, or conductive treated plastic or paper can be used in the form of a drum or sheet. Any conventionally known material can be used, such as one molded into.

The charge generation layer combines a charge generation substance such as an azo pigment, a quinone pigment, a quinocyanine pigment, a perylene pigment, an indigo pigment, or a phthalocyanino pigment with a composite material such as polyvinyl butyral, polystyrene, acrylic resin, polyester, polyvinyl acetate, or polycarbonate. It can be formed by being dispersed in an adhesive resin, and it can also be formed as a vapor deposited film using a vacuum evaporation device. Favorable film thickness is 0.0
It is 1 to 3 μm.

The charge transport layer is made of styryl compounds, hydrazone compounds,
Triarylamine compounds, carbazole compounds,
Charge transport substances such as oxazole compounds and pyrazoline compounds, polyarylates, polystyrene, acrylic resins, and polyesters.

It can be formed by being dispersed in a binder resin such as polycarbonate. Preferred film thickness: 10 to 30 Itm
It is. It was. As a structure of the photosensitive layer, a charge generation layer may be formed on the charge transport layer, and furthermore, the photosensitive layer may be a single layer type in which the above-mentioned charge generation substance and charge transport substance are contained in the same layer. good.

Furthermore, an intermediate layer such as a subbing layer may be provided between the conductive support and the photosensitive layer in order to improve adhesiveness and barrier properties.

The organic electrophotographic photoreceptor whose surface has been roughened by the method of the present invention is used in an electrophotographic process having a cleaning means using a rubber blade brought into contact with the photoreceptor in one counter direction.

Example 1 An 80 φ
A 1 μm thick undercoat layer was provided by dip coating a 5% methanol solution of 2 quaternary nylon copolymer.

Next, 10 parts (parts by weight, the same applies hereinafter) of the disazo pigment of the structural formula, polyvinyl butyral (degree of butyralization 68%, number average molecular weight 82
0000) and 50 parts of cyclohexanone were dispersed for 20 hours in a sand mill using a Raspize. 70 to 120 (appropriate) parts of methyl ethyl ketone were added to this dispersion and coated on the undercoat layer to form a charge generation layer with a thickness of 0.1 μm.

Next, 10 parts of bisphenol type 2 polycarbonate (viscosity average molecule [30000) and 10 parts of a hydrazone compound of the structural formula are dissolved in monochlorobenzene 65FIA,
This solution was dip coated onto the charge generation layer to form a charge transport layer with a thickness of 18 μm.

The average surface roughness of this photoreceptor was 0.0 μm.

Using the apparatus and method shown in FIGS. 1 and 2.

Both ends in the width direction of the film-like abrasive material1. The film-like abrasive material was brought into contact with the photoconductor and polished without contacting the photoconductor prepared by the above method.

The average surface roughness of this photoreceptor surface (R, B 1.0 μm, minimum and maximum surface roughness are 0.811 m and 1, respectively)
．． It was 2 μm. This photoreceptor is charged, exposed to light, and developed.

Electrophotographic device (NP-3) with transfer and cleaning with a polyurethane rubber blade (linear pressure 11 N/m)
525 (manufactured by Canon) and repeated image output evaluations showed no problems at 100,000 copies. The results are shown in Table 1.

Comparative Example 1 When an experiment was conducted in the same manner as in Example 1 using the same apparatus and photoreceptor except that the photoreceptor was not polished by pressing the button, the cleaning blade reversed after about 10 images were repeatedly produced. The device has stopped working. The results are shown in Table 1.

Comparative Example 2 In accordance with Example 1, polishing was carried out by bringing the film-like abrasive into contact with the photoreceptor so that only one end of the film-like abrasive material was separated from the photoreceptor by 1.0 m. The average surface roughness of the surface of this photoreceptor (R) is 1.4 μm, and the minimum and maximum surface roughness are 02 μm and 5.5 μm, respectively.
Met. When this photoreceptor was installed in the same apparatus as in Example 1 and the same experiment was conducted, image defects appeared from the initial stage of repeated image production, and after about 500 copies, surface roughness was observed. The cleaning blade reversed from a shallow depth and the device stopped working.

Comparative Example 3 Similar to Example 1, the photoreceptor was polished by bringing the entire surface of the photoreceptor into contact with a film-like abrasive material. The average surface roughness (R2
) is 1.5 μm, and the minimum and maximum surface roughness are 0, respectively.
．． They were 2 μm and 7.0 μm. Example 1
When I installed it in a similar device and conducted the same experiment, it turned out to be the end! Image defects appear from the beginning of image output>
6. After repeating this for a while, the cleaning blade reversed from a shallow surface roughness.

device stops working Ta.

table As described above, as shown in Example 1 and Comparative Examples 1 to 3.

By roughening the surface by preventing both ends of the film-like abrasive material from coming into contact with the photoconductor, an excellent image without image defects due to scratches can be obtained, and the gap between the cleaning blade and the photoconductor surface can be roughened. It can be seen that the lubrication durability is improved.

〔Effect of the invention〕

As explained above, the surface of the photoreceptor is cleaned in order to prevent the cleaning blade from flipping over and the edges from being damaged due to friction between the cleaning blade and the surface of the photoreceptor, which occurs in the electrophotographic process using a cleaning means using a rubber blade. Although a method of pre-polishing has been proposed, it is difficult to control the roughened state of the photoreceptor surface, and in shallowly roughened areas, the cleaning blade may flip over or the edges and edges may be damaged, resulting in However, according to the present invention, the surface of the organic electrophotographic photoreceptor can be uniformly roughened within a predetermined range. Accordingly, it is possible to provide an organic electrophotographic photoreceptor that can prevent cleaning defects and image defects.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a portion in contact with a photoreceptor when the surface roughening method of the present invention is carried out. FIG. 2 is a schematic cross-sectional view of an apparatus that can be used in the surface roughening method of the present invention. In the figure, 1 is an organic electrophotographic photoreceptor, 2 is a film-like abrasive material, 3 is a pressing roller, 4 is a lifting member, 5 is a feed roller, and 6 is a winding roller.

Claims (1)

[Claims] In a method of roughening the surface of an organic electrophotographic photoreceptor using a film-like abrasive material, when the surface of the photoreceptor is roughened with the abrasive material, both widthwise end portions of the abrasive material are A method for roughening the surface of an organic electrophotographic photoreceptor, characterized in that the method is carried out in such a manner that the surface does not come into contact with the surface of an organic electrophotographic photoreceptor.