JPS5990662A - Coating device - Google Patents

Abstract

PURPOSE:To improve coating efficiency by installing a hood which has openings on a wall surface and is provided internally and intermittently with shielding plates on the circumference above a paint tank to constitute a painting device thereby eliminating uneven coating and increasing the speed of painting. CONSTITUTION:A paint 5 is contained in a paint tank 6, and a member 4 to be coated is supported by a coating arm 1 and is dipped and pulled into and from the paint. A hood 7 is installed above the paint tank 1, which hood is internally and intermittently partitioned by shielding plates 2 from the lower to the upper part. The vapor pressure in each stage wherein the solvent vapor evaporating from the coated film on the member pulled up after the coating and the paint is filled is regulated by the hole diameter in the openings 3 provided on the side face of the hood so that the inside of the hood is filled with the vapor pressure higher than the atm. pressure. The hood is so designed that the vapor pressure decreases successively from the lower stage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating device, particularly to a coating device that does not cause uneven coating.

Conventionally, a method in which a member to be coated is immersed in a coating material and then pulled up in a direction perpendicular to the liquid surface for coating is well known as a dip coating method.

In such dip coating methods, coating unevenness is a very serious problem. If there is any unevenness, for example, in the case of a photosensitive layer of an electrophotographic photoreceptor, unevenness in reception potential or sensitivity will occur in the electrophotographic characteristics, causing image disturbance.Z).

Conventionally, when coating by dipping, the pulling speed had to be as slow as possible in order to obtain a uniform film thickness, resulting in extremely low work efficiency. That is, when coating with a high vapor pressure solvent, if the pulling speed is increased, the solvent evaporates rapidly immediately after coating, resulting in an uneven phenomenon (a phenomenon in which the coating surface becomes cloudy due to absorption of moisture). ,
Causes paint film defects inside.

SUMMARY OF THE INVENTION The main object of the present invention is to provide a coating device that can increase coating speed and coating efficiency without causing uneven coating.

The present invention provides a coating device that forms a coating film by immersing a member to be coated in a coating material and pulling it up to form a coating film. It is characterized by the fact that it has been installed. In other words, by installing a hood over the paint tank that has shielding plates intermittently placed inside and has open walls, the concentration of solvent vapor in the paint gradually decreases in the space above the paint tank. Therefore, even if the coating speed becomes slow, rapid drying of the coating film applied to the member to be coated can be avoided, and uneven coating and short-lived phenomena can be prevented.

The number of stages of shielding plates formed inside the hood is determined as appropriate, but usually two or more stages, particularly three or more stages is preferred.

Incidentally, the part to be coated may be immersed in the paint and then relatively lifted up by lowering the paint tank.

FIG. 1 shows one typical embodiment of the coating apparatus according to the present invention. A member 4 to be coated, which is housed in a paint tank 6, is immersed in the paint while being supported by the coating arm 1, and then pulled up. A hood 7 is installed above the paint tank, and the interior of the hood is intermittently partitioned from the bottom to the top by a partition plate 2. After application, the solvent vapor volatilized from the coating film of the workpiece and the paint fills each stage.The vapor pressure of each stage is determined by the opening 3 on the side of the hood.
The hood is designed so that the inside of the hood is filled with a higher steam pressure than the outside world, and the steam pressure gradually decreases from the bottom. As a result, a uniform coating film can be efficiently obtained even though the coating speed is higher than that of the paint tank.

Coating device d according to the present invention: Effective in applications requiring high coating film accuracy, for example, in the production of electrophotographic photoreceptors. Electrophotographic photoreceptors have various configurations depending on the type of electrophotographic process to which they are applied, but generally include a photosensitive layer containing a photoconductive material on a substrate, and if necessary, an insulating layer on top of the photosensitive layer. It is made up of layers.

By forming such a photosensitive layer or insulating layer using the coating apparatus according to the present invention, a high-quality electrophotographic photoreceptor without image unevenness can be manufactured.

Example 1 The following photosensitive layer forming paint was filled to a depth of 300 mm, and a hood as shown in the figure (with 4 tiers of plates) was attached to the top of a stainless steel paint tank with an inner diameter of 70 mm and a height of 350 mm, and an outer diameter of 50 mm. An aluminum drum with a length of 260 fl m and a length of
After drying for 1.0 minutes at 100°C at a speed of wpn10, the center of the drum (at 130M) in the circumferential direction 90 degrees, 4 points every 4 points in total, 4
The film thickness was measured at point 0 using an eddy current film thickness meter. For comparison, the same coating was performed on a system using a shielding plate and a hood without openings, and the film thickness was measured. The results are shown in Table 1.

(Photosensitive layer forming paint) PolyN vinyl carbazole 2.6 Kp2.
4.7 Trinitrofluorenone 4.4 Kq Monochlorobenzene 40. OKr Table 1 Example 2 Using the same equipment as in Example 1, the number of plates inside the hood was raised by 3 steps, the speed was 110rn1R/min, and the photosensitive forming paint was 1-[pyridyl-(2)]-]3- 14-N, N-
Diethylaminostyryl -5,-(4-N,N,diethylaminophenyl)pyrazoline 2.6 Kfl Polysulfonic acid resin (trade name: Newdel P-1700;
Made by U-C1C) 4. , 4 Kg, monochlorobenzene 40. Coating was performed instead of OKz, and the adjacent thickness was measured under the same conditions as in Example 1.

For comparison, a system using a hood without a strainer plate was coated. Table 2 shows the results.

From Table 2, it was confirmed that the coating film was formed uniformly by the hood equipped with the shielding plate.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a coating device according to the present invention. 2: Shielding plate, 3: Opening, 4: Part to be coated, 5: Paint, 6: IJ tank for coating, 7: Hood. Applicant Canon Co., Ltd. No. 1 M325-

Claims (1)

[Claims] 1. In a coating device that forms a coating film by immersing a member to be coated in a paint and pulling it up, a seven-door with an opening in the wall and intermittent shielding plates around the inside is placed above the paint tank. A coating device characterized by being installed.