JPS60179171A - Coating device - Google Patents

Abstract

PURPOSE:To coat continuously the outer peripheral surface of a cylindrical base material to be coated by providing a means for moving up and down the surface of a coating liquid in a ring painting method. CONSTITUTION:When the beam of light from a light source 4 is interrupted by a cylindrical body 5 in process of coating, a detector 3 is operated, and a lift 6 and a liquid surface changing member connected to the lift is operated and elevated. The outer peripheral surface of a base material to be coated such as a cylindrical body can be continuously painted in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating device, and more particularly to a coating device suitable for coating an electrophotographic photoreceptor on the outer circumference 1i of a cylindrical body.

Methods for coating the outer peripheral surface of a coated substrate such as a 1'-1 cylindrical body include a spray method, a dipping method, a vertical coating method using a ring-shaped liquid container, a curtain coating method, Single methods such as blade coating method, roll coating method, and extrusion method are known.

However, although the spray method is excellent in mass production, it has the disadvantages of a small amount of coating per application and poor surface smoothness, and it has a wide range of film thickness from 1 μm to several tens of μm and extremely high surface roughness. It is not suitable as a coating method for electrophotographic photoreceptors that require a durable coating layer.

The dipping method is a relatively simple method, but there is a large difference in film thickness between the upper and lower parts of the cylindrical object, and when applying two or more layers, each layer must be applied using the same solvent system. The disadvantage is that the lower layer is easily damaged (and it is also poor in mass production).

The ring coating method disclosed in JP-A-53-22544, JP-A-56-101149, JP-A-58-11064, and JP-A-58-180261 has excellent surface smoothness of the coating layer, and also shortens the contact time with the coating liquid. It has the advantage of being suitable for multilayer coating because of its short length. In the ring coating method, an elastic ring with an inner diameter slightly smaller than the outer diameter of the cylindrical body and a liquid container outer cylinder are integrated, and the cylindrical body is passed through the ring to form either the cylindrical body or the ring. The coating is applied to the outer surface of the cylindrical body by moving one or both of them. However, in this ring coating method, it is difficult to continuously coat a large number of circles with irregular shapes due to the structure of the apparatus. For example, the first circle 13-shaped body and the second circle? , ``If the i-shaped body is not completely joined without any gaps and passed through the ring, the coating chamber will not be formed and the coating liquid will leak out and stain the second cylindrical body. In the case where the cylindrical body is fed by the lower lifting means and passed through the application ring and discharged by the upper lifting means, the speed of both lifting means is set to full speed during the transfer from the lower lifting means to the upper lifting means. Also, when the first cylindrical body and the second cylindrical body are joined, the speeds of the circumferential circles 11] must match completely, otherwise the This is because the joint will form and become the first cause of disturbance on the coating surface.Also, if the J&joint is not accurate enough to be considered as an integral cylindrical body, liquid will accumulate in the mismatched part of the joint. The liquid pools may sag on the outer surface of the second cylindrical body and disturb the coating surface, or may penetrate into the inner surface of the joint and stain the inner surface of the second cylindrical body.

An object of the present invention is to solve the problems of the ring coating method as described above, and to provide a coating device that can continuously coat the outer circumferential surface of a substrate to be coated, such as a cylindrical body. be.

Other objects and advantages of the present invention will be understood from the following description.

The above-mentioned object of the present invention is an apparatus for applying a coating liquid onto a circular outer circumferential surface of a substrate to be coated using a ring-shaped liquid container, characterized by having means for vertically varying the level of the coating liquid. This was achieved using a coating device that

Hereinafter, the present invention will be explained in more detail using the drawings.

FIG. 1 is a schematic view of the main parts showing the process of continuously coating a cylindrical body using the coating apparatus of the present invention. 2 and 3 show the ring-shaped liquid container 7 in FIG.
FIG. 2 is a sectional view showing an example, and FIG. 2 shows the state immediately before the coating of the cylindrical body is finished, and FIG. 3 shows the state immediately before the coating starts. FIG. 4 is a sectional view showing another example of a ring-shaped liquid container.

In FIG. 1, the lifting devices 1 and 13 are provided with means for lifting and lowering at a constant speed. The means for raising and lowering may be any known method, such as a motor, a hydraulic cylinder, a pneumatic cylinder, etc.

Rods 2 and 12 are connected to the lifting devices 1 and 13, respectively, and the tips of the rods 2 and 12 are connected to holders (not shown) that can hold the first cylindrical body 5 and the second cylindrical body 9 from inside. ) and holds a circular fJ-shaped body. The retainer may be of a known type, for example an expandable three-claw retainer. The detection device 3 and the light source 4 include a cylindrical body 5
This is the position where the detection device 3 is activated when the light beam is interrupted by the detection device 3, and this position is installed at a position corresponding to the position immediately before the completion of coating the circular 1"1" shaped body 5. There are no particular restrictions on the detection device (limit switches, metal detection proximity switches, electrostatic switches, etc. are used.

The cylindrical body 5 passes through the ring-shaped liquid container 7 and is applied while being raised at a constant speed by the lifting device 1. During coating, a coating liquid is supplied from the coating liquid supply pipe 8 in an amount equal to the amount consumed by coating. As the coating progresses, when the cylindrical body 5 eventually blocks the light beam emitted from the light source 4, the detection device 3 is activated. FIG. 2 shows the state of the coating device immediately before the detection device 3 operates. When the detection device 3 operates, the elevating device 6 and the liquid level changing member 73 connected thereto operate and rise.

The lifting device 6 and the liquid level changing member 73 are connected by a connecting rod 72. At the same time, it is preferable to cut off the supply of the coating liquid from the coating liquid supply pipe 8.

The lifting distance of the lifting device 6 is from the height at which the liquid level of the coating liquid 74 exceeds the elastic ring 71 (see FIG. 2) to the liquid level changing member 7.
3), it is necessary to at least reach a height below the elastic ring 71 (FIG. 3).

Preferably, as shown in FIG. 3, the operation of the lifting device 6 is stopped with the liquid level changing member 73 not being pulled out from the liquid level and with a portion of its tip remaining in the liquid. This can prevent the liquid surface from undulating, but since both ends of the cylindrical body are generally not used as photoreceptors, the member 73 may be removed from the liquid surface.

First circle 1. ) The shaped body 5 continues to rise and passes through the elastic ring 71, completing the application.

Since the liquid level of the coating liquid is lower than the tip of the elastic ring 71 due to the rise of the liquid level changing member, the coating liquid 74 does not leak out from the liquid container 7.

'The cylindrical body 5 that has been coated is then subjected to the next process (for example, drying).
It is discharged into 1 plant (1 not shown). After being discharged, the rod 2 raises the second cylindrical body 9 by the lifting device 1 and returns to the position where it should be applied. The cylindrical body 9 held by a holder (not shown) at the tip is ready for the next application.

Lift f? At t13, the cylindrical body 9 rises and stops when its tip reaches the elastic ring 71. In detecting this stop position, the detection device 10 operates when the cylindrical body 9 no longer blocks the light emitted from the light source 11, and the lifting operation of the lifting device 13 is stopped. This state is shown in FIG. At the same time, the holder at the tip of the rod 2, which had finished discharging and descended, holds the cylindrical body 9 (not shown), and the detection device 10 operates, causing the lifting device 6 to lower the liquid level changing member 73. , the liquid level of the coating liquid is the elastic ring 71
As a result, the coating liquid 74 comes into contact with the outer peripheral surface of the cylindrical body 9 and becomes ready for coating.

At the same time as the lifting device 1 starts to rise at a constant speed, the coating liquid is supplied from the coating liquid supply pipe 8 and coating starts. The lifting device 13 is lowered in preparation for the feeding of the next cylindrical body.

By repeating the above operations, it becomes possible to perform continuous application by supplying cylindrical bodies at intervals.

The coating device of the present invention is characterized by having means for varying the level of the coating liquid above and below the tip of the elastic ring, respectively, at the start and end of coating on one cylindrical body.

One such means is to raise and lower the level of the coating liquid at the tip of the elastic ring by dipping it in the coating liquid 74 and pulling it out of the coating liquid, as described above with reference to FIGS. 2 and 3. Volume body (liquid level fluctuation part 4) J'73)
This method uses

Another preferable means is as shown in FIG.
This is a method of providing a coating liquid discharge pipe 82 equipped with a valve 81 that opens and closes according to the operation of the detection devices 3 and 10. This method has the advantage that it can be applied continuously by simply opening and closing the valve 81 without having to stop the liquid supply from the coating liquid supply pipe 8.Other explanations refer to the explanations in FIGS. 1 to 3. I can do it.

The coating liquid discharge pipe 82 has an elastic ring tip ζ as shown in FIG.
It is preferable that the liquid level is slightly lower than 111 because the liquid level can be quickly secured until the start of the next coating.

In the coating device of the present invention, continuous coating of a cylindrical body can be performed more efficiently by installing several lifting devices 1 or 13. Furthermore, a plurality of coating liquid supply pipes 8, coating liquid discharge pipes 82, etc. can be provided.

The viscosity of the liquid applied using the coating device of the present invention can be selected over a wide range, but is usually 0.5 to
About 1,000 centipoise (cp), preferably 1~
It is 500CP.

The coating device of the present invention is suitable for manufacturing electrophotographic photoreceptors that require a thin and highly uniform coated surface, but it can be applied to other substrates as long as the substrate is coated on a circular outer circumferential surface. It can also be used for.

Examples are shown below.

Example 1 A fourth ring-shaped liquid container 7 of the coating device shown in FIG.
Use the one shown in the figure and use a 116φ aluminum tube (
Apply the following treatment onto the outer circumferential surface of the length (33℃) at the coating speed IQ *m
/ = yx, was applied continuously to 30 aluminum tubes by the method described above and dried.

The coating film thickness was 20 μm. When the potential was measured after drying, it was confirmed that there was only a fluctuation in the potential within 596 points in the circumferential direction and the length direction, and it was confirmed that the same quality could be ensured with good reproducibility for a large number of cylindrical bodies.

Example 2 In the coating solution of Example 1, the total amount of xylene was 1. 00
Example 1 was repeated except that the distance was adjusted to 0 m.

This coating layer had a thickness of about 0.3 μm and was a uniform thin film layer that could be sufficiently used as a charge generation layer.

[Brief explanation of drawings]

FIG. 1 is a schematic view of the main parts of the process of coating a cylindrical body using the coating apparatus of the present invention. 2 and 3 are cross-sectional views showing one example of the coating device of the present invention, and FIG. 4 is a cross-sectional view showing another example.1, 6.13...
・・・・・・Lifting device 5.9・・・・・・・・・・・・・・・
・・・・・・Cylindrical body 3.10・・・・・・・・・・・・
・・・・・・Detection device 4.11・・・・・・・・・・
......Light source 71...
......Elastic ring 73...
.........Curved/liquid level fluctuation member 75...
・・・・・・・・・・・・・・・・・・Bent liquid container outer cylinder 8
・・・・・・・・・・・・・・・Curved application liquid supply pipe 8
1・・・・・・・・・・・・・・・・・・・・・・・・
Valve 82・・・・・・・・・・・・・・・・・・
Curved coating liquid discharge pipe 76...
Curved coating layer 2, 12.72... and rod Fig. 1 Fig. 2 @ Fig. 3

Claims (1)

[Claims] (A device for applying a coating liquid to the circular outer circumferential surface of a substrate to be coated using a ring-shaped liquid container, characterized by having a means for varying the level of the coating liquid downward by 2) Device.