JP2001154376A - Method of cleaning conductive substrate and method of producing electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of cleaning a conductive substrate by which the surface of a conductive substrate is not damaged but contamination on the surface of the conductive substrate can be easily and surely removed without carrying out a complicated process such as precision cleaning by ultrasonic waves, the deposited foreign matter is easily removed and secondary contamination by cleaning is not caused, and to provide a method of producing an electrophotographic photoreceptor having excellent image quality by which the surface of a conductive substrate is not damaged but contamination on the surface of the conductive substrate can be easily and surely removed without carrying out a complicated process such as precision cleaning by ultrasonic waves, the deposited foreign matter is easily removed, secondary contamination by cleaning is not caused, and image defects such as black spots and fog are not produced. SOLUTION: In the method of cleaning a conductive substrate by cleaning the surface of a conductive substrate by using a cleaning liquid containing a fluorine-based solvent, and in the method of producing an electrophotographic photoreceptor by forming a photosensitive layer on the conductive substrate, the surface of the conductive substrate is cleaned by using a cleaning liquid containing a fluorine-based solvent before the photosensitive layer is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for cleaning a conductive substrate and a method for manufacturing an electrophotographic photosensitive member.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member has a structure in which a photosensitive layer is applied or deposited on a conductive substrate, and is mounted on a copying machine, a laser beam printer, or the like. Examples of the conductive substrate used for the photoreceptor include a paper or plastic film, a metal plate, and a metal drum that have been subjected to conductive treatment. The most commonly used is a metal drum (hereinafter, abbreviated as a raw tube). The base tube is a metal formed into a drum by impact molding, extrusion, drawing or the like. The surface of the raw tube may be mirror-finished by ironing or cutting, if necessary. Further, the surface of the raw tube may be subjected to anodizing treatment. The base tube is manufactured by combining one or more of the above-described molding and processing methods.

[0003] On the surface of such a raw pipe, metal powder generated in the processing step of the raw pipe, dust from the surrounding environment, oil used at the time of processing, dust protection on the surface for storing the processed raw pipe, and the like. Oil applied to protect the product has adhered. The deposits on the surface of the base tube adversely affect the image characteristics of the photoreceptor after applying the photosensitive layer and the electrophotographic characteristics.
In the manufacturing process of the photoreceptor, the element pipe is washed before the photosensitive layer is laminated in order to remove the surface deposits.

[0004] Solvents such as methylene chloride, chlorofluorocarbon and 1,1,1-trichloroethane have generally been used as cleaning agents. However, these solvents have problems such as destruction of stratospheric ozone when released into the atmosphere, and their use is being regulated internationally as harmful to the global environment. Research and development have been conducted on a method of cleaning a conductive substrate without using a suitable solvent, and the above-described conductive substrate has been cleaned with an aqueous cleaning solution.

[0005] When the conductive substrate is washed with an aqueous cleaning solution as described above, the conductive substrate is generally led to a plurality of cleaning tanks in order, and the conductive substrate is placed in the aqueous cleaning solution in each cleaning tank. By immersion, the above-mentioned foreign substances adhering to the surface of the conductive substrate are removed from the surface of the conductive substrate by ultrasonic waves, brushes, etc. Foreign substances adhering to the surface of the conductive substrate have been removed from the surface of the conductive substrate by the aqueous cleaning liquid sprayed in this manner.

However, when cleaning is performed by sequentially guiding the conductive substrate to the plurality of cleaning tanks as described above, the conductive substrate adheres to the conductive substrate during transfer between the cleaning tanks. The water-based cleaning solution that has been dried is partially dried, and a film of a detergent such as a surfactant contained in the water-based cleaning solution is partially formed on the surface of the conductive substrate, or the conductive substrate is cleaned in a cleaning tank. During the transfer, the aqueous cleaning liquid adhering to the conductive substrate is dried from the upper end side of the conductive substrate sequentially, and also from the lower end side due to the influence of steam or heat from the cleaning tank. Drying was performed in sequence, and drying was performed from the upper end side and the drying from the lower end side under different drying conditions, thereby forming a boundary on the surface of the conductive substrate.

In the case where a film of a detergent such as a surfactant is partially formed as described above, or a photosensitive layer is formed on the surface of a conductive substrate having a boundary formed by drying,
When the formation of the photosensitive layer is not successfully performed, particularly when the photosensitive layer is formed by applying a coating solution for a photosensitive layer in which a binder resin or a photosensitive material is dissolved or dispersed in a solvent to the surface of the conductive substrate, In the portion where the detergent film such as the surfactant is formed as described above, or in the boundary portion due to drying, uneven coating or aggregation occurs on the photosensitive layer, or the adhesiveness of the photosensitive layer to the conductive substrate is deteriorated. However, when an image is formed using the photoreceptor thus obtained, there is a problem that the formed image has black spots, fog, etc., and the image quality is degraded.

[0008]

SUMMARY OF THE INVENTION The invention according to claims 1 to 4 removes dirt on the surface of the conductive substrate without damaging the surface of the conductive substrate and performing complicated operations such as precision cleaning by ultrasonic waves. It is an object of the present invention to provide a method of cleaning a conductive substrate which can be easily and surely removed, and a foreign substance adhered can be easily removed and secondary contamination due to cleaning is not generated. The invention according to claims 5 to 8 easily and reliably removes and adheres dirt on the surface of the conductive substrate without damaging the conductive substrate and performing complicated operations such as ultrasonic precision cleaning. An object of the present invention is to provide a method of manufacturing an electrophotographic photoreceptor excellent in image quality, in which foreign matter is easily removed and secondary contamination due to washing is not generated, and image defects such as black spots and fog do not occur.

[0009]

The present invention relates to a method for cleaning a conductive substrate, comprising cleaning the surface of the conductive substrate using a cleaning solution containing a fluorine-based solvent. The present invention also relates to the above-described method for cleaning a conductive substrate, which cleans the surface of the conductive substrate while rubbing the surface of the conductive substrate with a contact member. Also, the present invention
The present invention relates to the above method for cleaning a conductive substrate, wherein the cleaning liquid further contains an alcohol-based solvent in addition to the fluorine-based solvent. Also,
In the present invention, the fluorinated solvent is 1,1,1,2,3,4,
It relates to the above-mentioned washing method, which is 4,5,5,5-decafluoropentane.

Further, according to the present invention, in a method of manufacturing an electrophotographic photoreceptor for forming a photosensitive layer on a conductive substrate, the surface of the conductive substrate is cleaned with a cleaning liquid containing a fluorine-based solvent before forming the photosensitive layer. And a method for producing an electrophotographic photoreceptor. The present invention also relates to the above-described method for producing an electrophotographic photoreceptor, in which a surface of a conductive substrate is cleaned while being rubbed with a contact member. The present invention also relates to the above-mentioned method for producing an electrophotographic photoreceptor, wherein the cleaning liquid further contains an alcohol-based solvent in addition to the fluorine-based solvent. The present invention also relates to the above-mentioned method for producing an electrophotographic photosensitive member, wherein the fluorine-based solvent is 1,1,1,2,3,4,4,5,5,5-decafluoropentane.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below.
The conductive substrate in the present invention is made of aluminum,
Examples thereof include iron, copper, and other metals and / or alloys thereof. In the case of electrophotography, aluminum and its alloys are preferably used in view of weight, price, and workability.
The shape of the conductive substrate is not particularly limited, but in the case of electrophotography, a cylindrical shape is preferable, and such a conductive substrate having a cylindrical shape is called a base tube. As the material, a drum-shaped material obtained by impact molding, extrusion, drawing, or the like is used, and then, if necessary, a material obtained by mirror-finishing the base tube surface by ironing, cutting, or the like may be used. Further, a material obtained by anodizing the surface of the base tube may be used.

The raw pipe is processed by one or a combination of the above-mentioned forming and processing methods. For example, when performing a cutting process (hereinafter, abbreviated as “cutting”), it is common to apply a cutting oil, and after the cutting, a dustproof oil is applied to prevent corrosion of the surface of the raw pipe. For this reason, metal powder of the raw material of the raw tube generated by cutting, so-called swarf, adheres to the surface of the raw tube, and dust in the surrounding environment adheres during cutting and storage. Wash the tube.

The cleaning solution used in the present invention contains a fluorine-based solvent as an essential component. As the fluorine-based solvent, a conventionally known fluorine-based solvent can be used. Is preferred. As a fluorinated solvent,
1,1,1,2,3,4,4,5,5,5-decafluoropentane is preferred from the viewpoints of detergency, damage prevention, adhesion of shavings, workability and the like.

It is preferable that the cleaning liquid further contains an alcohol-based solvent in addition to the fluorine-based solvent from the viewpoints of detergency, prevention of scratches, prevention of adhesion of shavings, and the like. As the alcohol-based solvent, conventionally known ones can be used, but from the viewpoint of detergency, prevention of scratches, prevention of adhesion of shavings, etc.
Ethanol is preferred. In this case, the fluorinated solvent is 90 to
The mixing ratio is preferably 99% by weight, desirably 94 to 99% by weight, and the alcoholic solvent is 1 to 10% by weight, desirably 1 to 6% by weight. In addition, 1,1,1,2,3,4,
4,5,5,5-decafluoropentane and 1,1,2,2
The mixed solvent of 3,4,4,5,5,5-decafluoropentane and ethanol is Bertrel XF and Bertrel XE
Commercially available from Mitsui-Dupont Fluorochemicals, Inc.

In the cleaning, a cleaning step using a cleaning liquid mainly containing a fluorine-based solvent and a cleaning step using a cleaning liquid mainly containing a mixed solvent of a fluorine-based solvent / alcohol-based solvent are combined. It is preferable from the viewpoints of force, scratch prevention, adhesion of shavings and the like.

The cleaning method of the present invention can be applied not only to the raw tube but also to the above-mentioned conductive-treated paper or plastic film, a metal plate of aluminum or the like.

In the present invention, the cleaning is performed while rubbing the surface of the conductive substrate by using a contact member (contact cleaning). Examples of the contact member include a brush, a sponge, and the like.
A soft material such as chamois, gauze, waste cloth, etc. that does not damage the surface of the conductive substrate as much as possible, and is not attacked by the cleaning solution, does not elute any components, and does not generate dust due to wear during cleaning Use the one with the strength of

In the present invention, in addition to the cleaning step using a cleaning solution containing a fluorine-based solvent, it is possible to immerse the substrate in another solvent and carry out ultrasonic cleaning, or to carry out contact cleaning of the surface with another solvent. By doing so, an electrophotographic photosensitive member excellent in image quality can be obtained. Preferred examples of the other solvent include solvents containing no halogen atom, such as acetone, tetrahydrofuran, and methanol.

[0019]

Next, the present invention will be described in detail with reference to examples. All the raw tubes used in the examples and comparative examples are made of an aluminum alloy drum and mirror-finished by cutting, and the dimensions of the raw tube are 120 mm in outer diameter and 373 mm in tube length.

Example 1 Bertrel XF (manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) was used as a cleaning solution, and Bencott (a gauze manufactured by Asahi Kasei Corporation) was used as a contact member. The bencot containing Vertrel XF was brought into contact with the tube and washed, and then immersed in acetone for 3 minutes, and then the surface of the tube was washed with tetrahydrofuran soaked in the bencot. After observing the surface of the tube after washing with a metallographic microscope, the surface roughness of the tube was measured with Talysurf 6 (a surface roughness meter manufactured by Rank Taylor Hobson).

Example 2 Metal-free phthalocyanine (manufactured by Toyo Ink Mfg. Co., Ltd .; hereafter referred to as τ-H ₂ P) was placed on a base tube washed in the same manner as in Example 1.
c) and a mixture of 1 part by weight of silicone resin KR214 (manufactured by Shin-Etsu Chemical Co., Ltd.) and 98 parts by weight of tetrahydrofuran (hereinafter abbreviated as THF) is kneaded for 8 hours using a ball mill. The dispersion was applied by dipping and dried at 140 ° C. for 60 minutes to form a film having a thickness of 0.5 μm.
Was formed. Next, 3.5 parts by weight of bis (p-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene and Tufet B were placed on the charge generating layer.
10.5 parts by weight of 500 (made by Idemitsu Kosan Co., Ltd.) in THF86
The solution dissolved in parts by weight is applied by dipping and coating.
The resultant was dried at 0 ° C. for 60 minutes to form a charge transport layer having a thickness of 20 μm, thereby obtaining an electrophotographic photosensitive member.

Example 3 Vertrel XF (manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) was used as a cleaning solution, and Bencott (Asahi Kasei Corporation) was used as a contact cleaning member.
Gauze). After washing the Bencott containing Vertrel XF by contacting the tube, ultrasonic cleaning was performed in methylene chloride. After observing the surface of the tube after washing with a metallographic microscope, the surface roughness of the tube was measured with Talysurf 6 (a surface roughness meter manufactured by Rank Taylor Hobson).

Example 4 A charge generation layer and a charge transport layer were formed on a raw tube cleaned in the same manner as in Example 3 in the same manner as in Example 2 to obtain an electrophotographic photosensitive member.

Example 5 The procedure of Example 1 was repeated except that Bertrel XE (manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) was used as the cleaning solution.

Example 6 A charge generating layer and a charge transport layer were formed on a raw tube cleaned in the same manner as in Example 5 in the same manner as in Example 2, to obtain an electrophotographic photosensitive member.

Example 7 The procedure of Example 3 was repeated except that Vertrel XE was used as the cleaning solution.

Example 8 A charge generating layer and a charge transport layer were formed on a raw tube cleaned in the same manner as in Example 6 in the same manner as in Example 2 to obtain an electrophotographic photosensitive member.

Example 9 A bencott containing vertrel XF was brought into contact with a base tube for washing, a bencot containing vertrel XE was brought into contact with the base tube, washed, and immersed in acetone for 3 minutes. Thereafter, the surface of the base tube was contact-washed with tetrahydrofuran contained in Bencott. After observing the surface of the tube after washing with a metallographic microscope, the surface roughness of the tube is measured with a Talysurf 6 surface roughness meter (a surface roughness meter manufactured by Rank Taylor Hobson).
Was measured.

Example 10 A charge generating layer and a charge transport layer were formed on a raw tube cleaned in the same manner as in Example 8 in the same manner as in Example 2 to obtain an electrophotographic photosensitive member.

COMPARATIVE EXAMPLE 1 For cleaning the tube, only ultrasonic cleaning was performed in methylene chloride, the surface of the tube was observed with a metallographic microscope, and the surface roughness of the tube was measured using Talysurf 6 (manufactured by Rank Taylor Hobson).
Surface roughness meter).

Comparative Example 2 A charge generating layer and a charge transporting layer were formed on a base tube washed in the same manner as in Comparative Example 1 in the same manner as in Example 2 to obtain an electrophotographic photosensitive member.

Comparative Example 3 The procedure of Example 1 was repeated, except that methylene chloride was used as the washing liquid.

Comparative Example 4 A charge generating layer and a charge transporting layer were formed on a base tube washed in the same manner as in Comparative Example 3 in the same manner as in Example 2 to obtain an electrophotographic photosensitive member.

Comparative Example 5 THF was used as a cleaning solution, and gauze bencot was used as a contact member. After washing the bencot containing THF in contact with the surface of the tube, the substrate was immersed in acetone for 3 minutes, and then the surface of the tube was washed with Bertrel XF containing the bencot. After observing the surface of the tube after washing with a metallographic microscope, the surface roughness of the tube was measured with Talysurf 6 (a surface roughness meter manufactured by Rank Taylor Hobson).

Comparative Example 6 A charge generating layer and a charge transporting layer were formed on a base tube washed in the same manner as in Comparative Example 5 in the same manner as in Example 2 to obtain an electrophotographic photosensitive member.

Table 1 shows the results of microscopic observation of the surface condition of the tube after cleaning in Examples 1, 3, 5, 7, 9 and Comparative Examples 1, 3, and 5.

[0037]

[Table 1]

In Comparative Example 1, the cutting chips during cutting were not removed and remained on the surface. In Comparative Examples 3 and 5, although metal chips at the time of cutting could be removed, metal powder whose surface was newly shaved was observed, and it was found that secondary surface contamination had occurred. On the other hand, in Examples 1, 3, 5, 7, and 9, although the streak due to the contact cleaning was seen, the swarf at the time of cutting was removed, and secondary surface contamination occurred. It can be said that it is in a good surface condition. Further, Example 1,
In Nos. 5 and 9, the cutting chips at the time of cutting were completely removed without performing ultrasonic cleaning.

In Examples 1, 3, 5, 7, 9 and Comparative Examples 1, 3, and 5, the measurement results of the surface roughness of the blank tube and the results of Examples 2, 4, 6, 8, 10, and Comparative Examples Example 2,
Table 2 shows the printing test results of the electrophotographic photosensitive members obtained in 4 and 6.
Shown in

[0040]

[Table 2]

Examples 1 to 10 in which the contact cleaning of the present invention was performed
In Comparative Example 1, the surface roughness was larger than Comparative Examples 1 and 2 of the products not subjected to contact cleaning, but did not affect the image and showed good image characteristics without black spots and fogging. In Comparative Examples 3 to 6 in which contact cleaning was performed with a solvent other than the solvent of the present invention, black spots, fogging, and streaks occurred on the image. Since the surface roughness is also larger than that of Examples 1 to 10, it can be seen that the solvent and the process of the contact cleaning greatly affect the surface condition and image characteristics of the raw tube.

[0042]

The method for cleaning a conductive substrate according to any one of claims 1 to 4 does not damage the surface of the conductive substrate and does not perform complicated operations such as precision cleaning with ultrasonic waves. Is easily and surely removed, and adhered foreign matter is easily removed so that secondary contamination due to washing is not generated. The method for producing an electrophotographic photoreceptor according to any one of claims 5 to 8, can easily and reliably remove stains on the surface of the conductive substrate without damaging the conductive substrate and performing complicated operations such as precision cleaning by ultrasonic waves. It is excellent in image quality which does not cause secondary contamination due to cleaning by easily removing adhering foreign matter and does not cause image defects such as black spots and fogging.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takao Ochiai 4-3-1-1, Higashicho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Chemical Co., Ltd. Yamazaki Office (72) Inventor Kazuhiro Hanada 4--13 Higashicho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi Chemical Co., Ltd. Yamazaki Office F-term (reference) 2H068 AA54 EA05

Claims (8)

[Claims] 1. A method for cleaning a conductive substrate, comprising cleaning the surface of the conductive substrate using a cleaning solution containing a fluorine-based solvent. 2. The method for cleaning a conductive substrate according to claim 1, wherein the cleaning is performed while rubbing the surface of the conductive substrate with a contact member. 3. The method for cleaning a conductive substrate according to claim 1, wherein the cleaning liquid further contains an alcohol-based solvent in addition to the fluorine-based solvent. 4. The method according to claim 1, wherein the fluorinated solvent is 1,1,1,2,3,
4. The method for cleaning a conductive substrate according to claim 1, wherein the conductive substrate is 4,4,5,5,5-decafluoropentane. 5. A method for producing an electrophotographic photoreceptor in which a photosensitive layer is formed on a conductive substrate, wherein the surface of the conductive substrate is cleaned using a cleaning solution containing a fluorine-based solvent before forming the photosensitive layer. A method for producing an electrophotographic photoreceptor. 6. The method for producing an electrophotographic photoreceptor according to claim 5, wherein the surface of the conductive substrate is cleaned while being rubbed with a contact member. 7. The method for producing an electrophotographic photosensitive member according to claim 5, wherein the cleaning liquid further contains an alcohol solvent in addition to the fluorine solvent. 8. The method according to claim 1, wherein the fluorinated solvent is 1,1,1,2,3,
The method for producing an electrophotographic photoreceptor according to claim 5, 6 or 7, which is 4,4,5,5,5-decafluoropentane.