JP2576265B2 - Method for cleaning conductive substrate and method for manufacturing electrophotographic photoreceptor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for cleaning a conductive substrate and a method for producing an electrophotographic photoreceptor.

[Conventional technology]

The electrophotographic photosensitive member has a laminated 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, and the like. Examples of the conductive substrate used for the photoreceptor include a paper or plastic film subjected to conductive treatment, a plastic film in which a metal foil such as aluminum is laminated, a metal plate, and a metal drum. The most commonly used is a metal drum (hereinafter, abbreviated as a raw tube). The base tube is a metal formed into a drum shape by impact molding, extrusion, drawing or the like. If necessary, the tube may be mirror-finished by ironing or cutting the surface. The base tube is molded as described above,
Processing is performed by combining one or more processing methods.

Metal powder generated during the processing of the raw pipe, dust from the surrounding environment, oil used during processing, and protection of the surface of the raw pipe such as rust prevention when storing the raw pipe For example, oil to be applied has adhered. Since the above-mentioned deposits on the surface of the raw tube adversely affect the image characteristics and electrophotographic characteristics of the photoreceptor after the photosensitive layer is applied, the photosensitive layer is laminated to remove the surface deposits in the photoreceptor manufacturing process. Before that, the tube was cleaned.

[Problems to be solved by the invention]

2. Description of the Related Art Conventionally, in a process of manufacturing an electrophotographic photosensitive member, cleaning of a raw tube is generally performed in a non-contact manner such as ultrasonic cleaning or steam cleaning. The non-contact cleaning method has the advantage that it can be cleaned without damaging the surface of the tube, but on the other hand, so-called shavings and chips generated during processing of the tube (hereinafter abbreviated as processing powder).
In addition, dust adhering to the surface of the pipe during the process up to cleaning, oil used during processing and storage of the pipe, etc. may not be completely removed and remains on the pipe surface, resulting in poor cleaning. there were.

If the above-mentioned deposits remain on the raw tube, the image characteristics of the photoreceptor after the application of the photosensitive layer become blackish and deteriorate due to generation of fog.

In order to more reliably remove the deposits on the surface of the base tube than by the non-contact cleaning method, a member such as a brush or a rag is pressed against the surface of the base tube and the cleaning liquid is contained in the member or rubbed while being applied to the base tube, or There is a contact cleaning method such as rubbing a raw tube with a brush, a rag or the like in a bath filled with a cleaning liquid. But,
In these methods, the surface of the tube is damaged by rubbing,
If the conditions are bad, the surface may be shaved and a new surface of the tube will be attached to the powder, which may cause secondary surface contamination,
This adversely affected the image characteristics of the obtained photoreceptor.

The present invention provides a method for cleaning a conductive substrate which does not cause such poor cleaning and does not cause secondary surface contamination, and an electrophotograph which does not cause image defects such as black spots and fog using the cleaning method. An object of the present invention is to provide a method for manufacturing a photoconductor.

[Means for solving the problem]

The inventors of the present invention have conducted intensive studies to solve the above-described problems. As a result, the magnitude of the scraping of the pipe in the contact cleaning method depends on the solubility parameter value of oil used for processing and / or surface protection of the pipe, and the cleaning parameter. The present inventors have found that they depend on the difference from the solubility parameter value of the washing solution used sometimes, and have completed the present invention.

That is, in the present invention, the conductive substrate used in the production of the electrophotographic photoreceptor is represented by the formula (1) 15 ≧ | SP1−SP2 | ≧ 3 (1) [where SP1 represents a solubility parameter value of a cleaning liquid. , S
P2 represents the solubility parameter value of the oil used for forming, processing and / or protecting the surface of the conductive substrate], and is subjected to contact cleaning using a water-free cleaning solution selected to satisfy In a method for cleaning a conductive substrate and a method for manufacturing an electrophotographic photosensitive member having a photosensitive layer formed on the conductive substrate,
The present invention relates to a method for producing an electrophotographic photoreceptor, comprising washing a conductive substrate by the above-mentioned washing method before forming a photosensitive layer.

According to the present invention, by setting the difference between the solubility parameter value of the oil and the solubility parameter value of the cleaning solution to 3 or more, preferably 5 or more, the surface of the base tube is markedly damaged even by the contact cleaning, Can be prevented and new metal powder can be prevented from adhering to the surface. The error is usually 15 or less.

Hot water means the oil used in the processing of the final step of processing the raw tube before forming the photoreceptor and / or the oil used for surface protection such as rust prevention.

In the present invention, the material of the raw tube is aluminum, iron,
Any material may be used as long as it is copper, other metals and / or alloys thereof, but aluminum and its alloys are generally used in terms of weight, price, and workability.

As the base tube, a tube made into a drum shape by impact molding, extrusion, drawing, or the like is used. However, if necessary, a tube whose surface is mirror-finished by ironing or cutting may be used. The raw pipe is processed by one or a combination of the above-described forming and processing methods. For example,
When performing cutting (hereinafter, abbreviated as "cutting"), it is common to apply cutting oil, and after cutting, protect the pipe by applying rust-preventive oil to prevent corrosion of the surface of the pipe. Therefore, metal powder of the raw material of the raw tube, that is, so-called swarf, adheres to the surface of the raw tube, and dust in the surrounding environment adheres during cutting and storage. Therefore, in the manufacturing process of the photoreceptor, it is necessary to clean the tube in order to remove the deposits on the surface of the tube as described above.

The cleaning method of the present invention is not limited to the raw tube, but is also applicable to the above-described conductive-treated paper or plastic film, a plastic film in which a metal foil such as aluminum is laminated, a metal plate, and the like.

In the present invention, the contact cleaning is performed, but the contact cleaning and the non-contact cleaning method such as the ultrasonic cleaning method can be performed simultaneously or in parallel. As a cleaning member, a brush, sponge, chamois, gauze, rag, etc. is a soft material that does not damage the raw tube as much as possible, and is not attacked by the cleaning liquid, and does not elute any components,
Use a material that has such a strength that it does not wear out during cleaning. As such a cleaning member, a member commercially available for use in a clean room where dust is suppressed can be used.However, even if the member is not used for a clean room, it can be washed with a cleaning liquid or pure water to remove dust and dirt. Any material can be used as long as it does not generate much dust thereafter.

The cleaning solution used in the contact cleaning in the present invention,
It must have specific solubility parameter values as described above. That is, by setting the difference between the solubility parameter value of the oil and the solubility parameter value of the cleaning liquid to 3 or more, desirably 5 or more, the surface of the raw tube is markedly damaged or the surface of the raw tube is scraped even by contact cleaning. New metal powder can be prevented from adhering to the surface. On the other hand, if the difference between the solubility parameter values is less than 3, the surface is shaved during contact cleaning, and secondary surface contamination occurs.

In the present invention, the mechanism by which a cleaning solution having a specific solubility parameter value can be used to prevent damage to the tube surface and new deposits even by contact cleaning has not yet been sufficiently elucidated. By using a cleaning solution that does not dissolve the oil adhering to the tube surface, the oil is not removed at once in the initial stage, and the oil contacts the tube while chips and dust are being removed. It is expected that it functions as a cushion with the cleaning member and prevents the occurrence of secondary surface contamination.

The solubility parameter value in the present invention is RF
Required by the Fedors method. Formula (2) shows a specific calculation formula.

δ = (ΔE / V) ^1/2 = (ΣΔei / ΣΔvi) ^1/2 (2) wherein δ represents a solubility parameter value, ΔE and V represent an aggregation energy density and a molar volume, respectively. Δei,
Δvi indicates the evaporation energy and molar volume of an atom or atomic group, respectively. For details, see Polym. Eng. Sci., Vol. 14, No. 2, p. 147 (1
974).

As described above, the cleaning liquid used in the present invention is determined by the combination with the processing oil for the raw tube. For example, when the processing oil is an aliphatic hydrocarbon, methanol, ethanol, ethylene glycol, 1,3-butanediol , and so on. Further, the components of the cleaning liquid may be composed of a single substance or a mixture of two or more substances. For example, even if a component having the same value as the solubility parameter value of the oil is contained in the cleaning solution, the solubility parameter value of the entire cleaning solution may satisfy the conditions of the present invention.

〔Example〕

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. In the examples, "parts" means "parts by weight", and "SP value" means "solubility parameter value".

All the raw tubes used in the examples and comparative examples are mirror-finished aluminum alloy drums by cutting, and the raw tubes have an outer diameter of 120 mm and a pipe length of 373 mm. Rolling oil D110 (manufactured by Exxon Chemical) (SP value = 8.5).

Example 1 Freon TF (manufactured by DuPont-Mitsui Fluorochemicals) (SP value = 16.7) was used as a contact-cleaning liquid, and Casebencott (made by Asahi Kasei) was used as a contact-cleaning member. After the contact pipe was manually washed with a Bencott containing Freon TF, it was ultrasonically washed in methylene chloride, and the surface of the pipe was observed with a metallographic microscope. The surface roughness was measured with Talysurf 6) manufactured by Hobson.

Next, a metal-free phthalocyanine (hereinafter, τ =
1 part of H ₂ Pc), 1 part of silicone resin KR214 (manufactured by Shin-Etsu Chemical) and 9 parts of tetrahydrofuran (hereinafter abbreviated as THF) 9
Eight parts of the mixed solution was kneaded for 8 hours using a ball mill, the resulting dispersion was applied by dip coating, and dried at 140 ° C. for 60 minutes to form a 0.5 μm-thick charge generating layer.

Next, bis (p-diethylaminophenyl) -4,4-
3.5 parts of diphenyl-1,3-butadiene and 10.5 parts of polycarbonate resin Iupilon S2000 (manufactured by Mitsubishi Gas Chemical) were completely dissolved in 86 parts of a 1: 1 (weight ratio) mixed solvent of methylene chloride and 1,1,2-trichloroethane. The dissolved solution was applied by dip coating, and dried at 120 ° C. for 60 minutes to form a charge transport layer having a thickness of 18 μm.

Example 2 Using methanol (SP value = 14.3) as a cleaning solution for contact cleaning, cleaning, surface observation, surface roughness measurement, and formation of a photosensitive layer were performed in the same manner as in Example 1.

Comparative Example 1 After performing only ultrasonic cleaning in methylene chloride without performing contact cleaning, cleaning, surface observation, surface roughness measurement, and formation of a photosensitive layer were performed in the same manner as in Example 1.

Comparative Example 2 Methylene chloride (SP value = 9.1) as a cleaning solution for contact cleaning
And cleaning, surface observation, surface roughness measurement, and formation of a photosensitive layer were performed in the same manner as in Example 1.

Comparative Example 3 Cleaning, surface observation, surface roughness measurement, and formation of a photosensitive layer were performed in the same manner as in Example 1 by using rolling oil for aluminum D110 (the same as cutting oil) as a cleaning liquid for contact cleaning.

Example 3 A cleaning solution and a photosensitive layer were formed in the same manner as in Example 1, except that a mixture of Freon TF and methylene chloride (8: 2, SP value: 15.1) was used as a cleaning solution for contact cleaning.

Example 4 After washing and surface observation of the base tube under the same conditions as in Example 1, 3.5 parts of polyamide resin M1276 (manufactured by Nippon Rilsan) and 3.5 parts of melamine resin M2000 (manufactured by Hitachi Chemical) were mixed with methanol and methylene chloride. A liquid completely dissolved in 93 parts of a 1: 1 mixed solvent was applied by dip coating and dried at 120 ° C. for 60 minutes to form a 0.5 μm-thick undercoat layer. Next, a charge generation layer and a charge transport layer were formed in the same manner as in Example 1.

Example 5 The tube was washed under the same conditions as in Example 1. Next, after forming an undercoat layer in the same manner as in Example 4, 2.5 parts of τ-H ₂ Pc,
0.5 part of a phenoxy resin YP-50 (manufactured by Toto Kasei) and 97 parts of cyclohexane are kneaded for 8 hours using a ball mill, and the obtained coating solution is applied by dip coating, dried at 120 ° C. for 60 minutes and dried to a thickness of 0.5 μm. A charge generation layer was formed. Next, Example 1
A charge transport layer was formed in the same manner as in Example 1.

The electrophotographic photoreceptors obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were subjected to a printing test to examine image characteristics.

FIGS. 1 to 5 show the observation results of the tube surface with a microscope. In Comparative Example 1, the cutting chips at the time of cutting could not be removed and remained on the surface (FIG. 3). Comparative Examples 2 and 3 (FIG. 4, FIG.
In Fig.), Metal powder whose surface was shaved although cutting chips were removed during cutting was observed, and it was found that secondary surface contamination had occurred. In contrast, Example 1 (FIG. 1)
And in Example 2 (FIG. 2), although the streak due to the contact cleaning is seen, the cutting chips at the time of cutting have been removed, and no secondary surface contamination has occurred. It can be said that there is.

Table 1 shows the measurement results of the surface roughness. from this result,
It can be seen that the closer the SP value of the cleaning liquid is to the SP value of the processing oil, the greater the surface roughness is, and the easier the surface is shaved. The surface roughness is indicated by the maximum value of peaks and valleys on the surface.

Table 2 shows the results of the printing test. Example 1
No black spots and fogging were observed in the photoconductors of Nos. 1 to 5, whereas black spots and fogging were observed in Comparative Examples 1 to 3.

[Effects of the Invention] The method for cleaning a conductive substrate for an electrophotographic photoreceptor of the present invention reliably removes dirt from the surface of a raw tube and does not cause secondary contamination due to cleaning. An electrophotographic photosensitive member that does not generate image defects such as fog can be manufactured.

[Brief description of the drawings]

FIG. 1 is a micrograph (500 ×) showing the metal structure on the surface of the tube washed in Example 1, and FIG. 2 is a micrograph (500 ×) showing the metal structure on the surface of the tube washed in Example 2. ), FIG. 3 is a micrograph (× 500) showing the metal structure on the surface of the tube washed in Comparative Example 1, and FIG. 4 is a micrograph showing the metal structure on the surface of the tube washed in Comparative Example 2 (× 500). FIG. 5 is a micrograph (× 500) showing the metal structure on the surface of the tube washed in Comparative Example 3.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuo Katsutani 4-13-1, Higashicho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Chemical Co., Ltd. Yamazaki Plant (72) Inventor Kei Kei Kasutani 4-13-1, Higashicho, Hitachi City, Ibaraki Prefecture No. Hitachi Chemical Co., Ltd. Yamazaki Factory (56) References JP-A-1-130160 (JP, A) JP-A-3-61390 (JP, A) JP-A-2-13960 (JP, A)

Claims (2)

(57) [Claims] A conductive substrate used in the production of an electrophotographic photoreceptor is represented by the following formula (1): 15 ≧ | SP1−SP2 | ≧ 3 (1) [where SP1 represents a solubility parameter value of a cleaning solution; S
P2 represents the solubility parameter value of the oil used for forming, processing and / or protecting the surface of the conductive substrate], and is subjected to contact cleaning using a water-free cleaning solution selected to satisfy A method for cleaning a conductive substrate. 2. A method for producing an electrophotographic photosensitive member having a photosensitive layer formed on a conductive substrate, wherein the conductive substrate is washed by the method according to claim 1 before forming the photosensitive layer. Manufacturing method of electrophotographic photoreceptor.