JPH03197952A - Manufacture of electrophotographic sensitive material - Google Patents

Abstract

PURPOSE:To reduce friction force with a cleaning blade without staining an operation space and deteriorating the environment and to prevent stripping of the blade by dispersing a fine lubricative powder into a solvent and spraying this dispersion on the surface of the photosensitive body. CONSTITUTION:The fine lubricative powder, such as that of a fluororesin, is dispersed into a fluorocarbon solvent or the like, and sprayed on the surface of the photosensitive layer to attach it, thus permitting this attached powder to be freed of most of the solvent by evaporation at the time of coating, not to affect electrophotographic characteristics and to be uniformly attached, therefore, friction with the cleaning blade to be reduced without spoiling the operation and space and the environment, and to prevent stripping of the blade.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method for producing an electrophotographic photoreceptor, and in particular an organic photoreceptor that can be produced without contaminating the working environment and has good cleaning properties and image characteristics. The present invention relates to a method for manufacturing an electrophotographic photoreceptor.

[Prior Art] Generally, in an electrophotographic process, an electrophotographic photoreceptor is repeatedly subjected to a cycle consisting of at least the steps of charging, image exposure, development, transfer, and cleaning. 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.

Two conventional methods are used for this cleaning. 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, thereby preventing toner from slipping through and scraping off the remaining toner. be. FIG. 1 is a schematic cross-sectional view showing a typical example of a cleaning device using such a leaning blade, in which a cleaning device 1 is placed close to a cylindrical photoreceptor 2 rotating in the direction of arrow A. , one edge of one end of the cleaning blade 3 attached to the cleaning device is applied to the surface of the photoreceptor 2 in a counter direction relative to the rotational direction of the photoreceptor as shown in the figure, or in a direction not shown in the figure. Scrape off the remaining toner by applying pressure in the forward direction (it is known that the cleaning performance is better in one direction of the counter). The second method is to rotate the roller of the fur brush so that it touches the surface of the photoreceptor to wipe away the remaining toner.
Or you can knock it off. Of these two methods, the comb blade is cheaper and easier to design, so cleaning using a cleaning blade is currently the mainstream.

However, since a large frictional force is likely to be generated between the cleaning blade, which exhibits excellent cleaning performance, and the photoreceptor, there remains room for improvement in that the cleaning blade is likely to turn over. Here, the state in which the cleaning blade is curled means that the edge 3b of the cleaning blade 3 is in contact with the photoreceptor, as shown in FIG. 1(b). Yes, when using the cleaning blade (see Figure 1)
As shown in a), it is necessary to keep the edge 3a of the cleaning blade 3 in contact with the photoreceptor.

Furthermore, when the surface layer of the photoreceptor is made of an organic substance, 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 turn over and the edges will be damaged. .

[Problems to be Solved by the Invention] In order to solve these problems, conventional methods have been taken to prevent initial curling by applying lubricating fine powder to the tip of the blade or the surface of the photoreceptor. However, when applying methods such as rubbing fine powder on the tip of the blade or on the surface of the photoreceptor, there are hygiene problems as the fine powder dust is thrown up, and there are also problems such as the work space being contaminated by the dust thrown up during coating. Ta. Furthermore, since the applied amount was more than necessary, the fine powder was often blown away by vibrations caused by driving the electrophotographic apparatus main body, staining the inside of the electrophotographic apparatus main body, for example, corona discharge wires, etc.

Therefore, an object of the present invention is to provide an electrophotographic method that can manufacture a photoreceptor without deteriorating the working space or environment, and can significantly reduce the frictional force between the photoreceptor and the cleaning blade, thereby preventing the blade from slipping. An object of the present invention is to provide a method for manufacturing a photoreceptor.

[Means for Solving the Problems] That is, the present invention is characterized in that the lubricating fine powder is attached to the surface of the electrophotographic photoreceptor by spraying an organic solvent dispersion of the lubricating fine powder. This is a method for manufacturing an electrophotographic photoreceptor.

The present invention will be explained in more detail below.

Specific examples of the lubricating fine powder that can be used in the present invention include fine fluororesin powder (including spherical bodies), fine silicone resin powder (including spherical bodies), and the like. The average particle size of these fine powders is 20 LLm or less, especially O,lum or more, 8 g in order not to impair toner cleaning.
A range of m or less is preferable.

As shown in FIG. 2, the organic electrophotographic photoreceptor produced according to the present invention has an organic photosensitive layer 5 laminated on a conductive support 4, and this photosensitive layer 5 preferably includes a charge generation layer. This is a laminated photosensitive layer functionally separated into a charge transport layer 6 and a charge transport layer 7.

The conductive support 4 is made of 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 in the form of a drum or sheet. Any conventionally known materials, such as those molded into shapes, can be used.

The charge generation layer 6 contains charge generation substances such as azo pigments, quinone pigments, quinocyanine pigments, perylene pigments, indigo pigments, and phthalocyanine pigments, and binders such as polyvinyl butyral, polystyrene, acrylic resin, polyester, polyvinyl acetate, and polycarbonate. It can be formed by being dispersed in a resin, or it can also be formed as a vapor deposited film using a vacuum evaporation device. The preferred film thickness is 0.
01-3 μm.

The charge transport layer 7 contains a charge transport material such as a styryl compound, a hydrazone compound, a triarylamine compound, a carbazole compound, an oxazole compound, or a pyrazoline compound, or a charge transport material such as a polyarylate, polystyrene, acrylic resin, polyester, or polycarbonate. It can be formed by being dispersed in a binder resin. The preferred film thickness is 10 to 30 μm. Further, as a structure of the photosensitive layer 5, a charge generation layer 6 may be formed on the charge transport layer 7 (
Furthermore, the photosensitive layer 5 may be of a single layer type in which the above-mentioned charge generating substance and charge transporting substance are contained in the same layer.

Furthermore, an intermediate layer such as an undercoat layer may be provided between the conductive support 4 and the photosensitive layer 5 in order to improve adhesiveness and barrier properties.

The production of the organic electrophotographic photoreceptor according to the present invention is carried out by dispersing lubricating fine powder in a suitable solvent and spraying it on the surface of the photoreceptor on which each of the above layers is formed. Any material may be used as long as it can uniformly disperse the lubricating fine powder and almost evaporates during application, such as a fluorocarbon solvent.

The lubricating fine powder applied by this method does not affect the electrophotographic properties because the solvent has almost evaporated by the time it is applied to the photoreceptor, and the fine powder adheres uniformly to the photoreceptor surface. Because of this, it does not cause blade fraying etc.

However, if this lubricating fine powder coating solvent is applied to the surface of the photoreceptor in a liquid state, such as by dipping or brushing, the surface of the photoreceptor will be attacked by the solvent, causing image unevenness and other problems. It will cause problems.

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

[Example] The present invention will be explained below using examples.

Example 1 An aluminum cylinder of 80φ x 360mm was used as a support, and soluble nylon (6-66-slo-t2
A 5% methanol solution of nylon copolymer) was applied by dip coating to provide a Lum-thick undercoat layer.

Next, 10 parts of a disazo pigment with the following structural formula (parts by weight, the same applies hereinafter), polyvinyl butyral (butyralization degree 6),
8%, number average molecular weight 20,000') and 50 parts of cyclohexanone were dispersed for 20 hours in a sand mill using 1φ glass beads. 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 Z-type polycarbonate (viscosity average molecular weight 30,000') and IO part of a hydrazone compound having the following structural formula were dissolved in 65 parts of monochlorobenzene, and this solution was dip-coated onto the above charge generation layer to form a layer with a thickness of 18 μm. A charge transport layer was formed. Photoconductor 1
shall be.

Next, a fluororesin fine powder (trade name Lublon LA, manufactured by Daikin Industries, Ltd., manufactured by Daikin Industries, Ltd.) dispersed in a fluorocarbon solvent (trade name Guiflon S3, manufactured by Daikin Industries, Ltd.) or the like was applied to the surface of the photoreceptor 1 prepared by the above method. A photoreceptor of the present invention was manufactured by spraying and coating a photoreceptor of the present invention. This will be referred to as photoreceptor 2.

This photoreceptor 2 was incorporated into an electrophotographic device (NP-3525, manufactured by Canon) having a charging, image exposure, development, transfer, and comb blade cleaning mechanism (linear pressure 11 g/cm), and repeated image output evaluations were performed. Tokoro, 10
No problems occurred until 10,000 copies were printed. This is Example 1 and the results are shown in Table 1.

Examples 2 and 3.4 In Example 1, a fine fluororesin powder (trade name Kynar #461, manufactured by Pennwalt) dispersed in a fluorocarbon solvent (trade name Guiflon S3, manufactured by Daikin Industries, Ltd.) was applied to the surface of the photoreceptor 1. A photoreceptor was manufactured in the same manner as in Example 1, except that a vinylidene fluoride resin (manufactured by Polymer, Co., Ltd.) was applied by spraying. This will be referred to as a photoreceptor 3.

On the other hand, a photoreceptor was produced in the same manner as in Example 1, except that iron stearate (reagent, manufactured by Kishida Chemical Co., Ltd.) dispersed in benzene was sprayed onto the surface of photoreceptor 1. This will be referred to as a photoreceptor 4.

Furthermore, a photoreceptor was produced in the same manner as in Example 1, except that magnesium stearate (reagent, manufactured by Kishida Chemical Co., Ltd.) dispersed in benzene was applied by spraying onto the surface of photoreceptor 1. This will be referred to as the photoreceptor 5.

These photoreceptors 3, 4. , 5 were incorporated into the same electrophotographic apparatus as in Example 1, and repeated image output evaluations were performed, and no problems occurred in either case up to 100,000 copies. These are referred to as Examples 2 and 3.4, and the results are shown in Table 1.

Comparative Example 1 A photoreceptor was manufactured in the same manner as in Example 1 except that nothing was applied to the surface of the photoreceptor 1 in Example 1.

This will be referred to as the photoreceptor 6. When this photoreceptor 6 was installed in the same apparatus as in Example 1 and repeated image output evaluations were performed, the cleaning blade reversed after about 10 sheets.
The device has stopped working. This was taken as Comparative Example 1, and the results are shown in Table 1.

Comparative Example 2.3 In Example 1, fluororesin fine powder (
A photoreceptor was produced in the same manner as in Example 1, except that a vinylidene fluoride resin (trade name Kynar #461, manufactured by Pennwalt Co., Ltd.) was rubbed on the photoreceptor. This will be referred to as photoreceptor 7.

Further, a photoreceptor was manufactured in the same manner as in Example 1 except that iron stearate (reagent, manufactured by Daikin Chemical Co., Ltd.) was rubbed on the surface of photoreceptor 1 in Example 1. This will be referred to as a photoreceptor 8.

When these photoreceptors 7.8 were incorporated into the same electrophotographic apparatus as in Example 1 and repeatedly evaluated for image production, no cleaning defects such as reversal of the cleaning blade occurred in any of the photoreceptors up to 100,000 sheets. However, the working space during the production of photoreceptors 7 and 8 (during powder application) was extremely contaminated due to powder scattering, etc., and cleaning was required after the work was completed.

In addition, for both photoreceptors 7 and 8, part of the fine powder rubbed on the photoreceptor during repeated image output evaluations (the part where more than necessary was applied because it could not be applied uniformly) contaminated the inside of the electrophotographic apparatus body. In particular, contamination of the corona discharge wire for secondary charging had a significant effect on the image and had to be cleaned.

These are referred to as Comparative Examples 2 and 3, and the results are shown in Table 1.

Comparative Examples 4 and 5 In Example 1, fluororesin fine powder (trade name Lublon LA, manufactured by Daikin Industries, Ltd.) dispersed in a fluorocarbon solvent (trade name Daiflon S3, manufactured by Daikin Industries, Ltd.) was applied to the surface of the photoreceptor 1. A photoreceptor was produced in the same manner as in Example 1, except that fluorinated ethylene resin) was applied by dipping. This will be referred to as photoreceptor 9.

In addition, in Example 1, fluororesin fine powder (trade name Lublon LA, manufactured by Daikin Industries, Ltd., tetrafluoroethylene, dispersed in a fluorocarbon solvent (trade name Guiflon S3, manufactured by Daikin Industries), A photoreceptor was manufactured in the same manner as in Example 1, except that the resin) was applied by brushing. This is referred to as a photoreceptor 10.

Both photoreceptors 9 and 10 had their surface layers attacked by the fine powder coating solvent, and were incorporated into the same electrophotographic apparatus as in Example 1 and repeatedly evaluated for image production. Repeated imaging evaluation was discontinued because upper unevenness occurred. These are used as Comparative Examples 4 and 5 and the results are shown in Table 1.

As shown in Examples 1 to 4, the electrophotographic photoreceptor obtained according to the present invention does not cause blade curling and can produce good images.

On the other hand, the electrophotographic photoreceptor of Comparative Example 1 has a high coefficient of friction and causes blade slippage. Comparative Example 2.3
In this case, the blade does not turn over, but the work space is unavoidably contaminated during coating, and the inside of the electrophotographic equipment body,
In particular, image defects occur due to contamination of the corona discharge wire for secondary charging. Furthermore, in the case of Comparative Examples 4 and 5, the surface layer of the photoreceptor was eroded by the fine powder coating solvent, resulting in unevenness in the surface layer of the photoreceptor, resulting in image defects.

[Effects of the Invention] According to the method for manufacturing an electrophotographic photoreceptor of the present invention, it is possible to manufacture the electrophotographic photoreceptor without degrading the work space or environment, and the friction between the obtained photoreceptor and the cleaning blade is significantly reduced. This eliminates blade sagging, and provides a good image with no streaks or other unevenness.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of a cleaning device that uses a cleaning blade to explain its operation. FIG. 2 is a sectional view showing an example of an organic electrophotographic photoreceptor manufactured by the method of the present invention. 1 is a cleaning device, 2 is a photoreceptor, 3 is a cleaning blade, 4 is a conductive support, 5 is a photosensitive layer, 6 is a charge generation layer, and 7 is a charge transport layer.

Claims (1)

[Claims] 1. A method for producing an electrophotographic photoreceptor, which comprises adhering the lubricant fine powder to the surface of the electrophotographic photoreceptor by spraying a dispersion of the lubricant fine powder in an organic solvent.