JPH03215869A - Base body cleaning method - Google Patents

Abstract

PURPOSE:To prevent a defect in coating such as liquid repellence from being caused by rubbing the entire coated surface of the base body by a mark forming means such as a brush before base body is coated, and thus forming uniform and fine marks. CONSTITUTION:The base body is made of aluminum alloy and its surface roughness Rmax is 0.2mum. The base body 1 and rotary brush 2 while brought into contact with each other rotate in the same direction so that their rotary shafts 1a and 2a are held in parallel to each other. At this time, a cleaning solvent 3 is jetted from a shower nozzle 4. Thus, while cleaning is carried out with the cleaning solvent, the rotary brush 2 is rubbed against the surface of the base body 1 to form the uniform and fine brush marks over the entire surface. The rotary brush 2 is made of resin (nylon) and the diameter of brush hairs is preferably <=0.1mm. The surface of the base body is coated with coating liquid consisting of 2pts.wt. dibromo anthanthrone, 2pts.wt. butyral resin, and 230pts.wt. cyclohexanone to form a film which is 0.5mum in dry film thickness. Thus, the coated surface free from a defect such as coating liquid repellence is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a method for cleaning a substrate before coating the substrate to be coated.

(b) Prior Art When a coating liquid is applied to a certain substrate, the substrate is cleaned before coating. This is done to remove oil, dust, etc. that cause coating defects such as liquid repellency. Generally, cleaning methods include ultrasonic cleaning, jesotho cleaning, steam cleaning, etc., and oil, dust, etc. are completely removed.

For example, in the case of a photoreceptor substrate, it is first subjected to ultrasonic cleaning, then cooled, steam cleaned, dried, and sent to the next coating process.

(C) Problems to be Solved by the Invention However, according to the above-mentioned method, although oil, dust, etc. can be completely cleaned, problems such as liquid repellency may occur. This is especially true for surfaces with low surface free energy (wettability), such as mirror-finished surfaces, and conventional cleaning methods have the problem of not being able to improve surface free energy, no matter how thoroughly they are cleaned. there were.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a substrate cleaning method that improves surface free energy at the same time as cleaning.

(d) Means for Solving the Problems In the substrate cleaning method of the present invention, the coating surface of the substrate to be coated is rubbed with a scratch forming means such as a brush before coating, and the entire coating surface is coated. It is characterized by uniformly creating scratches that are smaller than the surface roughness of .

tel action In the method for cleaning a substrate according to the present invention, in cleaning the substrate to be coated before coating, the entire coated surface of the substrate is rubbed at the same time with a scratch forming means such as a brush, thereby cleaning the coated surface of the substrate. Scratches smaller than the surface roughness of the coated surface are uniformly made over the entire surface. As a result, minute irregularities are formed all over the coated surface, and since the irregularities are smaller than the surface roughness, they do not affect the functionality of the finished product of the substrate. Prevent occurrence.

(fl Example) FIG. 3 is a process diagram of a substrate cleaning method according to an example of the present invention. In this example, a case will be explained in which scratches are formed on the substrate of a photoreceptor using a brush. The material of the substrate is aluminum. It is made of an alloy and has a surface roughness of 0.2 μmRmax.

First, the rotating brush and the substrate are rotated in the same direction while in contact with each other, and the brush is cleaned using a cleaning solvent.

Next, take a 60° hot bath, then a cold bath, wash with Fuji air, and dry. The conditions for these steps are as follows.

Brush cleaning Cleaning liquid - 1.1.1 Trichloroethane Brush rotation speed - 90 ~ l O O rpm Substrate rotation speed -
20~60 r p rn hot bath cleaning? &-1
．． 1.1. 1- +J Ku Roeta: / Temperature -60
Immersion time - 30 seconds Cold bath Cleaning solution - 1.1.1. }Lichloroethane immersion time - 30 seconds steam cleaning Cleaning liquid - 1.11. I-Licroethane and drying time - 30 seconds FIG. 1 is an enlarged view of the coated surface of the substrate after being scratched with a brush. The surface roughness of the aluminum alloy substrate is usually 0.05 to 0.2 μm Rmax, and the depth of the groove is also 0.05 to 0.2 μm, depending on the surface roughness. The deep grooves 10 in the figure are caused by drum cutting, and the surface roughness is usually 0.05 to 0.2 μm, which is included in RrnaX, and the minute a11 is a brush scratch, which is 0.05 to 0.2 μm.
It is attached shallower than m.

FIG. 2 is an explanatory diagram of brush cleaning in the same cleaning method. The base body 1 and the rotating brush 2 are rotated in the same direction with their rotating shafts 1a and 2a parallel to each other while in contact with each other. At this time, the cleaning solvent 3 is spouted from the shower nozzle 4. In this way, at the same time as cleaning with the cleaning solvent, the rotating brush 2 is removed from the base 1.
Rub the surface to form small, uniform scratches on the entire surface.

The rotating brush 2 is made of resin (nylon), and the diameter of the bristles is preferably 1 mm or less, preferably 0.1 mm or less. However, if the brush becomes too thin, the elasticity of the brush becomes weak and the rotation speed needs to be increased.

The substrate with brush scratches that was cleaned as described above and the substrate without brush scratches that had been cleaned by the conventional method of ultrasonic cleaning, cold bath, steam cleaning and drying described above were washed with a wettability indicator (
Comparing the surface free energy using Wako Pure Chemical Industries),
The substrate with brush scratches by the method of the present invention is 38dy
It was found that the surface free energy was 34 dyne/cm for the substrate without brush scratches obtained by the conventional method, and that the surface free energy was larger for the substrate with brush scratches.

In addition, 2 parts by weight of dibrom anthron and butyral resin (S-LEC BM2
, Sekisui Science) 2 parts by weight, cyclohexanone 230
Apply a coating liquid consisting of parts by weight to achieve a dry film thickness of 0.5
A coating film of μm was formed.

The rate of good coatings without defects such as repelling of the coating liquid was 70% for the substrates without brush scratches, and 95% for the substrates with brush scratches, which was a significant improvement.

Furthermore, 1 part by weight of a hydrazone-based charge transport agent (trade name: rABPFLJ, manufactured by Anan Kosha Co., Ltd.) and a polycarbonate resin (manufactured by Teijin Kasei Co., Ltd.) were applied to the surface of the coating film of the substrate having brush scratches obtained by the method of the present invention. , Panlight L-
1250) A coating solution prepared by dissolving 1 part by weight in 8 parts by weight of dichloroethane was applied, and a dry film w. After coating to a thickness of 15 μm and drying at 70 L for 1 hour to form a charge transport layer, an electrophotographic photoreceptor was prepared. Then, the electrophotographic photoreceptor was attached to an image forming apparatus (Sharp Corporation SF
8100) to form an image and evaluate the image.As a result, it was possible to obtain a high-quality image with no brush scratches appearing on the image. As a result, it was found that fine scratches, which were smaller than the surface roughness, were evenly formed on the surface of the substrate and did not adversely affect the image.

Note that the rotating direction of the rotating brush and the base body may be the same direction or opposite directions, but it is possible to make more uniform and minute scratches by rotating the rotating brush in the same direction.

In this embodiment, a rotating brush is used as the scratch forming means, but any means may be used as long as it can create uniform and minute scratches. Further, the present invention is not limited to coating the substrate of a photoreceptor.

(Effects of the Invention As described above, according to the present invention, before coating the substrate to be coated, a scratch forming means such as a brush is used to rub the entire surface of the substrate to be coated, thereby creating uniform and minute scratches. Due to these scratches, minute irregularities are formed all over the coated surface, increasing the surface free energy. Therefore, the occurrence of coating defects such as liquid repellency can be prevented.

[Brief explanation of drawings]

FIG. 1 is an enlarged view of the coated surface of a substrate with brush scratches caused by a substrate cleaning method according to an embodiment of the present invention. FIG. 2 is an explanatory diagram of brush cleaning in the same substrate cleaning method. Third
The figure is a process diagram of the same substrate cleaning method. 1-Base, 2-Rotating brush (flaw forming means of this example), 11-Brush scratches (C minute scratches of this example).

Claims (1)

[Claims] (1) The coating surface of the substrate to be coated is rubbed with a scratch-forming means such as a brush before coating, and scratches smaller than the surface roughness of the coating surface are uniformly created over the entire coating surface. Substrate cleaning method.