JPH03188451A - Surface roughening method for organic electrophotographic photoreceptor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an organic electrophotographic photoreceptor, and more particularly, to an organic electrophotographic photoreceptor for obtaining an organic electrophotographic photoreceptor with good cleaning properties and image characteristics. Concerning body surface roughening methods.

[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. Especially after the transfer process.

The cleaning step for removing residual toner on the photoreceptor is an essential step in order to always obtain clear copy images.

As a method for this cleaning, the following two-stage method is usually used. The first method is to press a rubber plate-shaped member called a cleaning blade onto the photoconductor to eliminate the gap between the photoconductor and the cleaning blade, prevent toner from falling through, and scrape off the remaining toner. This is the way to take it. FIGS. 1 and 2 are schematic cross-sectional views showing typical examples of cleaning devices that utilize such a leaning blade. placed close together.

Apply one edge of one end of the cleaning blade 3 attached to the cleaning device to the surface of the photoreceptor 20, as shown in FIG. As shown in FIG. 2, the remaining toner is scraped off by applying pressure in the forward direction (it is known that the cleaning performance is better in one direction of the counter).

In this method, the roller of the fur brush is rotated so as to come into contact with the surface of the photoreceptor to wipe or knock off the remaining toner. Of these two methods.

Since rubber blades are cheaper and easier to design, cleaning using cleaning blades is currently the mainstream. In particular, when performing natural color development, natural colors are produced by layering the three primary colors of magenta, cyan, and yellow, or four additional colors including black, so the amount of toner used is less than the usual amount for one color. The amount of cleaning required is far greater than that of development, so it is best to use a cleaning method in which a rubber blade is pressed against the photoreceptor.

However, the counter-unidirectional cleaning blade, which exhibits excellent cleaning performance, has a drawback in that the cleaning blade tends to reverse due to the large frictional force with the photoreceptor. This reversal of the cleaning blade r is a phenomenon in which the cleaning blade 3, which is oriented in one counter direction shown in FIG.

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 easily reversed.

In addition, when performing a natural color phenomenon, toners of three colors magenta, cyan, and yellow, or four colors including black are used three or four times to produce one image.
Since development is performed twice, the load on the cleaning blade becomes large, which tends to cause the cleaning blade to reverse or even cause damage to the edge portion.

Additionally, when the surface layer of the photoreceptor is made of organic matter, the frictional resistance between the cleaning blade and the photoreceptor surface increases compared to an inorganic surface, making it particularly likely that the cleaning blade will flip over and the edges will be damaged. .

Therefore, the present applicant previously proposed in Japanese Patent Application No. 62-256769 that the surface of the photoreceptor be roughened in advance.
Therefore, we have proposed a method for preventing cleaning failures due to inversion of the cleaning blade, loss of play edges, etc., without causing deterioration in image quality. The roughening state of the photoreceptor surface is determined by the 10-point average roughness (
R,)O measurement method, the maximum value, average value and minimum value are all preferably within the range of 0.3 to 5.0, more preferably 0.3 to 2.0 #I is within the range of

When the maximum value is larger than 5.0 μm, streak-like defects tend to appear in the image. Furthermore, if the minimum value is as small as 0.34i, the friction between the cleaning blade and the surface of the photoreceptor is hardly alleviated in some areas, and the effect of roughening the surface of the photoreceptor is not recognized. The maximum value, average value and minimum value above are 0.3 to 5.0
If it is within the μm range, the contact area between the photoreceptor surface and the cleaning blade is reduced.

In addition, small particles (
(115 μm or less) or the shavings (less than 1 #1) on the surface of the photoconductor that have been scraped off due to use and seep into the gap between the photoconductor surface and the cleaning plate r. Since lubricity is easily imparted, cleaning failures due to reversal LK of the cleaning blade can be prevented.

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 preferred 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 the 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 material is easily embedded in the organic electrophotographic photoreceptor, causing pinholes and deteriorating the electrophotographic properties, whereas film-like abrasive material This is because in the case of , there is almost no embedding.

[Problem to be solved by the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an organic electrophotographic photoreceptor that can prevent cleaning failures and scratch patterns on images due to reversal of the cleaning blade, loss of edges, and the like.

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 extensive studies on roughening the surface of a photoreceptor, the present inventors have found that when roughening the surface of an organic electrophotographic photoreceptor using an abrasive, the surface roughening can be achieved in a clean environment. By carrying out processing.

10-point average roughness (R
2) and its maximum value, average value, and minimum value (
In this specification, these are respectively referred to as maximum surface roughness, average surface roughness, and minimum surface roughness) are all 0.3 to 5.
．． It has been found that a uniform rough surface condition within the range of 0 thickness 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 an abrasive.
It is characterized by surface roughening treatment under an environment of 0,000 or less (American Federal Standard 209B).

In other words, by roughening the surface of the photoreceptor outside the above cleanliness range, coarse dust in the air adheres to the surface of the photoreceptor and the abrasive material during polishing, and this dust is the cause. This prevents deep scratches from occurring on the photoreceptor.

Further, by using a film-like abrasive material, the device can be designed compactly, and there are advantages in that the polishing effect can be maintained stably. Furthermore, organic electrophotographic photoreceptors that act as photoconductors are often unstable when exposed to strong light; therefore, when roughening the surface, they are processed in the dark or under light of a wavelength that the photoreceptor does not absorb. This is desirable.

As the above-mentioned film-like abrasive materials that can be used in the practice of the present invention, there are 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 includes a charge generation layer and a charge transport layer. It is a laminated photosensitive layer with separated functions.

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 contains a charge generation substance such as an azo pigment, a quino/pigment, a quinocyanine pigment, a perylene pigment, an indigo pigment, or a 7-talocyanine pigment, and a charge generation substance such as a polyvinyl butyral, polystyrene, acrylic resin, polyester, polyvinyl acetate, polycarbonate, etc. It can be formed by being dispersed in a binding resin. It can also be formed as a vapor deposited film using a vacuum evaporation apparatus. The preferred film thickness is 0
．． 01-3 μm.

The charge transport layer is a styrene compound, a hirrazo/type compound 2
- Charge transport substances such as triarylamine compounds, carbazole compounds, oxazole compounds, and pyrazoline compounds are added to 7t? Really related, f! Listyrene,
Acrylic resin, polyester.

It can be formed by being dispersed in a binder resin such as polycargonate. The preferred film thickness is 10 to 30 μm. Further, 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. You can.

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 brake Y brought into contact with the photoreceptor in one counter direction.

Example 1 An aluminum cylinder of 80φ x 360 parts m was used as a support, and soluble nylon (6-66-610-1
A 1 μm-thick undercoat layer was provided by dip coating a 5-timethanol 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 2
0000) and 50 parts of cyclohexanone were dispersed for 20 hours in a sand mill using 1φ glass beads. 7O-120 (appropriate) parts of methyl ethyl ketone were added to this dispersion and coated on the undercoat layer to form a charge generation layer having a thickness of Q, 1/a.

Next, 10 parts of bisphenol type 2 polycarbonate (viscosity average molecular weight 3000) and 10 parts of a hydrazone compound having the structural formula were dissolved in 65 parts of monochlorobenzene, and this solution was dip coated onto the above charge generation layer to form a 18#l thick layer. A charge transport layer was formed.

The average surface roughness of this photoreceptor was 0.0 prr1.

The photoreceptor made by the above method is cleanliness class GO.
, ooo (American Federal Standard 209B) environment, the average surface roughness (R,') u 1 was obtained by polishing with a film polishing material (wrapping film manufactured by Jumin 3M Co., Ltd.) with a film grain size of 6.0 parts m. The minimum surface roughness was 0.6 μm, and the maximum surface roughness was 1.51 trn.

This photoreceptor was charged, image exposed, developed, transferred, and cleaned with a polyurethane rubber sprayer (linear pressure 1197 cm).
) was installed in an electrophotographic apparatus (NP-3525, manufactured by Canon) and repeated image output evaluations were performed, and no problems occurred up to 100,000 copies.

Comparative Example 1 When surface roughening was carried out using the same equipment as in Example 1 in a processing environment of cleanliness class 120.000 (US Federal Standard 209B), the average surface roughness (R2) was 1.0 μm.
, the minimum surface roughness was 0.6 μm, and the same results as in Example 1 were obtained, but the maximum surface roughness was 6.0 μm, which was a considerably larger value compared to Example 1. It became. When this photoreceptor was incorporated into the electrophotographic apparatus used in Example 1 and image output was evaluated, scratches on the photoreceptor with a surface roughness of 5.0 parts or more appeared as streaks on the image. Examples 2 and 3 Using the same apparatus as in Example 1, an abrasive material with a film particle size of 9 μm was used on an abrasive material with a film particle size of 6 μm to obtain the cleanliness shown in Table 1 (American Federal Standard 209B). Surface roughening treatment was performed under environmental conditions.

Average surface roughness (P, ) of the obtained surface, minimum surface roughness.

Maximum surface roughness and 10 tests conducted by incorporating it into an electrophotographic device
Table 1 shows the results of durability evaluation of 10,000 sheets.

Table 1 Table 2 Comparative examples 2 and 3 Instead of the environment treated in Examples 2 and 3.

The surface roughening treatment was performed in the same manner as in Examples 2 and 3 with the cleanliness shown in Table 2. The results are shown in Table 2.

As shown in Examples 1 and 2.3 and Comparative Examples 1 and 2.3 above, a uniform and high-quality rough surface is obtained by processing the photoreceptor in an environment of cleanliness class 100.000 or less. I was able to obtain high-quality images without streaks.

〔Effect of the invention〕

As explained above, by performing surface roughening treatment in an environment of cleanliness class 100.000 or less according to the present invention, a uniform and stable roughened surface can be obtained, and it can be used by incorporating it into an electrophotographic copying device. You can obtain high-quality images without streaks.

This also has the effect of preventing the Shikamo cleaning blade from turning over.

[Brief explanation of drawings]

1 and 2 are schematic diagrams illustrating a known cleaning device, with FIG. 1 showing a cleaning blade arrangement in one direction of the counter, and FIG. 2 showing a cleaning blade arrangement in a forward direction. In the figure, 1 is a cleaning device, 2 is a photoreceptor, 3 is a cleaning blade, and 3-1 is an inverted state of the cleaning blade.

Claims (1)

[Claims] 1. In a method of roughening the surface of an organic electrophotographic photoreceptor using an abrasive, the surface roughening treatment is performed in an environment of cleanliness class 100,000 or less (American Federal Standard 209B). A method for roughening the surface of an organic electrophotographic photoreceptor, characterized by: 2. The method for roughening the surface of an organic electrophotographic photoreceptor according to claim 1, wherein the abrasive material is a film-like abrasive material.