JPH04320268A - Washing method for base of electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To allow washing which does not adversely affects human bodies and local environment without decrease of the electrophotographic characteristic by washing a base with water specified in temp. and dissolved oxygen quantity. CONSTITUTION:A stage for washing the base with the water specified to at least >=40 deg.C and <=1ppm dissolved oxygen quantity is provided. Since the base is washed by mainly using the water in such a manner, the residues of halides by a hydrocarbon halide solvent are not generated and since the base is treated at >=40 deg.C warm water, the removal of the impurities sticking on the surface of the base is easy. Further, since the dissolved oxygen quantity participating in an oxidation reaction is confined to <=1ppm and the oxidation reaction does not nearly generates and the surface characteristic of the base is made uniform, therefore, the formation of the uniform photosensitive body is possible. Further, the adverse influence of the oxide films on electrophotographic characteristics is substantially eliminated. The washing water having <=10mus electrical conductivity is more effective. The surface of the base is thus washed without changing the properties thereof.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning conductive supports used in the production of electrophotographic photoreceptors.

0002

2. Description of the Related Art Electrophotographic photoreceptors are generally manufactured by forming a photosensitive layer on a conductive support (hereinafter referred to as support). Aluminum alloy is widely used as the material for this support, and is excellent in workability, dimensional stability, etc. of the support. When processing the support, oil-based substances such as cutting oil and antirust oil (kerosene, polybutene, etc.) are used. Furthermore, human fingerprints and the like may adhere to the support during transportation. Therefore, the support after processing always has residues of oil-based substances, and furthermore, there is adhesion of cutting powder during processing, dust in the air, and the like. If a photosensitive layer is formed using the support as it is, a uniform layer may not be formed and the photosensitive member may not function sufficiently, or even if a photosensitive layer is formed, an electrophotographic device using this photoreceptor may not be able to function properly. (copying machines, laser beam printers, LED printers, liquid crystal shutter printers, laser facsimiles, etc.) cannot perform adequately, and particularly causes image defects.

[0003] Therefore, when producing an electrophotographic photoreceptor, it is necessary to thoroughly wash the support. Conventionally,
In order to clean the support of electrophotographic photoreceptors (mainly made of aluminum alloy), halogenated hydrocarbons (trichloroethylene, trichloroethane, dichloromethane, or carbon tetrachloride, etc.) are required to clean the supports (mainly made of aluminum alloy). It has been used since. Furthermore, methods using acids or alkalis are also known. In addition, as a dry method, there is also a method of cleaning by irradiating ozone, ultraviolet rays, etc. to decompose deposits.

0004

[Problem to be solved by the invention] In the field that uses electrophotography technology, full-color copying machines, laser beam printers, etc. are being actively developed, and there is a particular demand for higher speed, higher image quality, and higher durability. It has been done. In order to meet these demands, it has been found that it is necessary to further improve the cleanliness of the support of the electrophotographic photoreceptor. The cleaning method using a halogenated hydrocarbon solvent, which is the current mainstream method for cleaning a support, has the above-mentioned characteristics, but leaves a trace amount of a halide on the support. Although this has not been a problem at the level of conventional electrophotography, even image defects caused by halides remaining on the support cannot be tolerated, particularly in order to achieve high image quality. Furthermore, organic solvents such as halogenated hydrocarbon solvents have a negative impact not only on the human body but also on the local environment. Furthermore, when acids or alkalis are used, corrosion of the neutralization process and the surface of the support may occur. In the method of using ozone, ozone itself has a negative effect on the human body, and not only this method but also requires large-scale equipment in order to take measures against the problem, and the installation location and cost thereof also require a lot of money.

[0005] Therefore, a cleaning method using water that does not have the above-mentioned problems is attracting attention. Further, in order to facilitate the removal of impurities and facilitate drying, it is conceivable to treat with hot water of about 40° C. or higher. However, when an aluminum alloy commonly used as a support is cleaned using this method, the surface of the aluminum alloy is highly active and the high temperature conditions cause an oxidation reaction on the surface, resulting in the formation of a very thick oxide film. This oxide film changes the surface characteristics of the aluminum alloy, and since this change is not uniform over the entire photoreceptor, it causes differences in paintability and electrophotographic characteristics depending on the part when making the photoreceptor. I'll let you.

[0006]

[Means for Solving the Problems] As a result of extensive studies in order to solve the above-mentioned problems, the present inventors have discovered that a photoreceptor can be cleaned by washing with water at 40° C. or higher and having a dissolved oxygen content of 1 ppm or less. It has been found that the support can be washed more effectively and that a support with uniform coating properties can be obtained, thus making it possible to create photosensitivity with uniform properties. That is, the present invention provides a method for cleaning a conductive support for an electrophotographic photoreceptor, comprising:
A method for cleaning a conductive support for an electrophotographic photoreceptor, comprising a step of cleaning with water at least 40° C. and having a dissolved oxygen amount of 1 ppm or less.

That is, in the present invention, since water is mainly used for cleaning, no halide residue is generated due to the halogenated hydrocarbon solvent, and furthermore, since the treatment is performed with hot water of 40° C. or higher, the surface of the support is It is easy to remove impurities attached to the surface. Conventionally, in this process, the aluminum alloy of the photoreceptor support undergoes an oxidation reaction due to the high temperature and dissolved oxygen in the water, resulting in the formation of an oxide film on the surface of the support. However, in the present invention, since the amount of dissolved oxygen involved in the oxidation reaction is set to 1 ppm or less, almost no oxidation reaction occurs and the surface characteristics of the support can be made uniform, making it possible to form a uniform photoreceptor.

Furthermore, the adverse effect of the oxide film on the electrophotographic properties is almost eliminated, and good properties are exhibited. Note that water used in the present invention is more effective if its conductivity is 10 μS or less.

The photosensitive layer provided on the cleaned support according to the present invention is not limited to inorganic photoreceptors, organic photoreceptors, etc., but organic photoreceptors can be coated by dip coating, spray coating, blade coating, etc. It is particularly effective in The photoreceptor may be a single-layer photoreceptor in which a charge-generating substance and a charge-transporting substance are mixed in a functionally separated manner, or a laminated layer in which a charge-generating layer containing a charge-generating substance and a charge-transporting layer containing a charge-transporting substance are laminated. It takes the form of a type photoreceptor, etc.

0010

[Examples] The present invention will be explained below with reference to Examples. [Example 1] Aluminum cylinder (30mm) after cutting
φ×260 mm) was prepared. A 1 wt % aqueous solution was prepared using Vanrise D-20 (Tokiwa Chemical Co., Ltd.) as a cleaning agent. The above-mentioned aluminum cylinder was immersed in this aqueous solution and treated with an ultrasonic oscillator (600 W, 28 kHz) for 1 minute.

[0011] Next, the water (dissolved oxygen 0.5 ppm,
The aluminum cylinder washed above was immersed in a drying tank to which water (temperature: 40°C) was continuously supplied (300 liters/hour), stopped for 10 seconds, and then pulled up (1 m/min) and air-dried on the tank.

Using this cleaned cylinder, an electrophotographic photoreceptor was prepared in which the following charge generation layer and charge transport layer were sequentially laminated.

[0013] Structural formula as a charge generating substance

[0014]

10 parts of the disazo pigment of formula 1, 6 parts of polyvinyl butyral resin (S-LEC BX-1, manufactured by Sekisui Chemical Co., Ltd.), and 50 parts of cyclohexanone were dispersed in a sand mill apparatus using glass beads. 100 parts of tetrahydrofuran was added to this dispersion and applied onto the previously cleaned cylinder to form a charge generation layer with a thickness of 0.2 μm.

Next, the structural formula

[0016]

10 parts of a stilbene compound represented by [Chemical formula 2] and 10 parts of a polycarbonate resin (Panlite L-1250, manufactured by Teijin Chemicals)
50 parts of dichloromethane and 10 parts of monochlorobenzene
It was dissolved in parts.

[0017] This was applied by dip coating on the above charge generation layer.
A charge transport layer having a thickness of 9 μm was formed.

[Example 2] A photoreceptor was prepared in exactly the same manner as in Example 1 except that the amount of dissolved oxygen was changed to 1 ppm.

[Comparative Example 1] A photoreceptor was prepared in exactly the same manner as in Example 1 except that the deoxidizing treatment was not performed. The amount of dissolved oxygen at this time was 9 ppm.

[Actual Machine Test-1] Examples 1 and 2, Comparative Example 1
The electrophotographic properties of the photoreceptor prepared in the above were evaluated using a laser beam printer (LBP-SX) manufactured by Canon Inc. in the following manner. First, a standard drum wrapped with a Mylar sheet (25 μm) was set to be charged to -800V. The charging ability of each photoreceptor was measured under these conditions. Next, the surface potential of each photoreceptor was adjusted to -700V, and then the amount of light (E200) required to lower the surface potential to -200V was measured. Furthermore, after strong exposure, the residual potential (Vr) without charging was measured. Thereafter, the amount of change in chargeability ΔVd and the amount of change in residual potential (ΔVr) after 3000 sheets of printing were repeated on these photoreceptors were measured. The results are summarized in Table 1.

[0021]

[Table 1] In Comparative Example 1, which contained a large amount of dissolved oxygen, the sensitivity (required light amount for E200) was almost the same as in Examples 1 and 2, but the charging ability was significantly lowered. Furthermore, the absolute values of the change in chargeability (ΔVd) and the change in residual potential (ΔVr) due to continuous printing were large, and the so-called potential stability was low.

[Example 3] Using a detergent cylinder obtained in exactly the same manner as in Example 1, an electrophotographic photoreceptor was prepared in which the following charge generation layer and charge transport layer were successively laminated.

As a charge generating substance, structural formula:

[0024]

10 parts of the disazo pigment of formula 3, 6 parts of polyvinyl butyral resin (S-LEC BX-1, manufactured by Sekisui Chemical Co., Ltd.), and 50 parts of cyclohexanone were dispersed in a sand mill apparatus using glass beads. 100 parts of tetrahydrofuran was added to this dispersion, and the mixture was coated on the cylinder cleaned by the method of Example 1 to form a charge generation layer with a thickness of 0.2 μm.

Next, a charge transport layer identical to that shown in Example 1 was coated on the charge generation layer to form a charge transport layer having a thickness of 19 μm, thereby producing a photoreceptor.

[Example 4] In Example 1, the water temperature was set to 50
A cleaned aluminum cylinder was obtained in exactly the same manner except that the temperature was changed to ℃. The charge generation layer and charge transport layer shown in Example 3 were sequentially provided on this cylinder to form a photoreceptor. [Comparative Example 2] The same cleaning and drying methods as those shown in Comparative Example 1 were carried out, and the charge generation layer and charge transport layer shown in Example 3 were sequentially provided to prepare a photoreceptor.

[Actual machine test-2] Example 3 created here
, 4 and Comparative Example 2 were installed in a Canon copier FC-5.

First, a standard drum wrapped with a Mylar sheet (25 μm) was set to be charged to -800V. The charging ability of each photoreceptor was measured under these conditions. Next, adjust the surface potential of each photoreceptor to -700V, and then calculate the amount of light E2 required to lower the surface potential to -200V.
00 was measured. Furthermore, after strong exposure, the residual potential (Vr) without charging was measured. Thereafter, the amount of change in chargeability ΔVd and the amount of change in residual potential (ΔVr) after 2000 continuous sheets of printing were repeated on these photoreceptors were measured. The results are summarized in Table 2.

[0029]

[Table 2] In Examples 3 and 4, high charging ability was obtained, whereas
In Comparative Example 2, only low values were obtained. Furthermore, Examples 3 and 4 exhibited stable potential characteristics even after continuous copying.

[0030] When we measure the thickness of the oxide film on the aluminum cylinder that has been washed and dried, it is 25 Å for the aluminum cylinder treated with deoxidized water, whereas it is 25 Å for the aluminum cylinder treated with deoxidized water. In the aluminum cylinder, it was 80 Å.

[0031]

Effects of the Invention As described above, according to the method for cleaning an electrophotographic photoreceptor support of the present invention, it is possible to clean the support without deforming its surface properties, and it is possible to clean the electrophotographic photoreceptor support by carrier injection from the support. Does not cause deterioration of properties. Furthermore, since it is a water-based cleaning method, it does not have any negative impact on the human body or the local environment.

Claims (2)

[Claims] 1. A method for cleaning a conductive support for an electrophotographic photoreceptor, comprising the step of washing with water at least 40° C. and having a dissolved oxygen content of 1 ppm or less. How to clean the support. 2. The method for cleaning a conductive support for an electrophotographic photoreceptor according to claim 1, wherein the conductivity of the cleaning water is 10 μS or less.