JPH0256944B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating device, and more particularly, to a coating device that can efficiently and continuously form a coating film of uniform thickness on the outer peripheral surface of a substrate to be coated. It is.

Conventionally, spray methods, dipping methods, ring methods, and the like have been proposed as methods for forming a uniform coating film on the outer surface of a cylindrical body such as an electrophotographic photoreceptor.

Although the spray method is a simple coating method and is used in a wide range of fields, the smoothness of the coating film is poor, so it is not suitable for applications that require a uniform surface, such as electrophotographic photoreceptors.

Although the dipping method produces a relatively uniform coating film, it is complicated to control the concentration and temperature of the coating solution, and when two or more layers are coated, the problem arises that the lower layer may be damaged if the same solvent system is used.

Compared to the above two methods, the ring method has the advantage that the surface smoothness of the coating film is excellent and the contact time with the coating liquid is short, making it suitable for multilayer coating.

These prior art include JP-A-53-22544 and JP-A-56-
There are 101149, 58-180261, etc. The conventional ring coating method integrates a flexible ring with a diameter slightly smaller than that of the cylindrical body and an outer cylinder of the coating chamber.The cylindrical body is passed through this ring, and the outer surface of the cylindrical body and the ring are A coating film is obtained on the outer surface of the cylindrical body by filling the coating liquid into the coating chamber formed by the cylindrical body and moving either the cylindrical body or the ring, or both. However, in this coating method, due to the structure of the coating section, when trying to coat individual cylindrical bodies in succession, there is a gap between the first cylindrical body and the second cylindrical body. Must not be.

When the first cylindrical body and the second cylindrical body are supplied discontinuously, in the discontinuous gap,
A coating chamber is no longer formed, and the coating liquid leaks out and contaminates the second cylindrical body. Therefore, it is essential to supply the cylindrical body seamlessly and continuously.

Considering the case where the cylindrical body is supplied by the lower lifting means, passes through the application ring, and is discharged by the upper lifting means, at least during the transfer from the lower lifting means to the upper lifting means. teeth,
The speeds of both lifting means must match completely. Also, when joining the first cylindrical body and the second cylindrical body, the speeds of the two cylindrical bodies must completely match. This is because if they do not match, an impact will occur during bonding and the coated surface will be disturbed. In addition, if the joint is not precise enough to be considered as a single cylindrical body, the mismatch in the joint will cause a pool of liquid, which will sag on the outer surface of the cylindrical body below, disturbing the coated surface. or penetrate the inner surface of the joint and contaminate the inner surface of the underlying cylindrical body.

An object of the present invention is to provide a coating device that is simple and has excellent mass productivity.

Another object of the present invention is to provide an apparatus for efficiently applying coating liquid without wasting it.

The present inventors have made extensive studies to solve these problems and have completed the present invention. That is, in an apparatus for coating the outer circumferential surface of a substrate to be coated using a flexible coating ring, the flexible coating ring 21 and ring support 22 are integrated (hereinafter simply referred to as the coating ring). The coating ring can be moved up and down within the outer cylinder 23 of the coating chamber, and while the coating liquid is being applied to the cylindrical body, the coating ring is located at the lower part, so that the coating liquid can come into contact with the outer surface of the cylindrical body. When the coating is finished, the coating ring moves upward and acts as a weir for the coating liquid, preventing the coating liquid from leaking and falling. By doing this, even if the cylindrical bodies are spaced apart, the coating can be performed while being continuously supplied, which solves the conventional problems. The operating accuracy of this device needs to be considered only when the lifting device 8 is raised.

An example of an embodiment of the present invention will be described in detail using the drawings.

FIG. 1 is a schematic overall view of the present invention, and FIG.
Figures 3, 4, and 5 show the coating chamber 2 in Figure 1.
2 is a detailed enlarged cross-sectional view illustrating the start of coating of the second cylindrical body 1' immediately before the end of coating of the first cylindrical body 1.

In the figure, the lifting device 8 is provided with means for lifting at a constant speed. The raising means may be any known method, such as a motor, a hydraulic cylinder, a pneumatic cylinder, etc. It is important to raise at a constant speed, and the lowering does not need to be at a constant speed. The lifting device 8 includes
A rod 7 is connected, and the tip of the rod 7 has a holder (not shown) capable of holding the cylindrical body 1 from inside, and holds the cylindrical body 1.

The holding device may be of a known type, for example, an expandable three-claw holding method may be used. The detection device 5 and the light source 6 are located at a position where the detection device 5 operates when the cylindrical body 1 intercepts the light beam 9, and these devices are installed at coincident positions just before the coating of the cylindrical body 1 is completed. There are no particular limitations on the detection device, and limit switches, metal detection proximity switches, electrostatic switches, etc. may be used.

The cylindrical body 1 passes through the coating chamber 2 and is connected to the lifting device 8.
The coating film 25 is formed while rising at a constant speed. During coating, the coating liquid supply pipe 3 supplies an amount of coating liquid 24 equal to the amount of coating liquid consumed by coating. When the coating progresses and the cylindrical body 1 eventually blocks the light beam 9 emitted from the light source 6, the detection device 5 is activated. FIG. 2 shows the state of the detection device 5 on the verge of operation. When the detection device 5 operates, the coating ring lifting device 4 operates and raises the coating ring in synchronization with the rising speed of the cylindrical body 1. At the same time, the supply of the coating liquid from the coating liquid supply pipe 3 is cut off.

The rising position of the coating ring is the point where the tip of the flexible coating ring 21 passes over the coating liquid level 26 of the coating liquid 24, at which point the coating ring lifting device 4 stops operating and the coating ring also stops.

The applicator ring lifting device 4 may be a motor, or a known device such as a hydraulic, pneumatic, cylinder, or electromagnetic solenoid, and is connected to and interlocks with the applicator ring.

The cylindrical body 1 continues to rise, passing the tip of the flexible coating ring 21 and passing through the coating chamber 2 as well. This state is shown in FIG.

Since the coating liquid level 26 is lower than the tip of the flexible coating ring 21, the coating liquid 24 does not leak out of the flexible coating ring 21.

A packing material may be inserted into the sliding surfaces of the ring support 22 and the coating chamber outer cylinder 23 to prevent the coating liquid 24 from leaking.

The cylindrical body 1 that has been coated is discharged to the next process, for example, a drying process (not shown). After being discharged, the rod 7 is lifted up and returned to its position by the elevating device 8 in order to apply the next cylindrical body 1'.

On the other hand, the lifting device 8', the rod 7' connected to the lifting device 8', and the cylindrical body 1' held by a holder (not shown) at the tip of the rod 7' are ready for the next application. are doing.

The cylindrical body 1' is raised by the lifting device 8' and stopped when its tip reaches the flexible applicator ring 21.

This position is detected when the cylindrical body 1' no longer blocks the light emitted from the light source 6', so that the detection device 5' is activated and the lifting operation of the lifting device 8' is stopped.

This state is shown in FIG.

At the same time, the holder at the tip of the rod 7, which had finished discharging and descended, holds the cylindrical body 1' (not shown), and the detection device 5' operates.
The coating ring lifting device 4 lowers the coating ring,
The coating liquid level 26 is above the tip of the flexible coating ring 21, and the coating liquid 24 comes into contact with the outer surface of the cylindrical body 1' and becomes ready for coating. This state is shown in FIG. At the same time as the lifting device 8 starts to rise at a constant speed, the coating liquid 24 starts to be supplied from the coating liquid supply pipe 3, and coating starts. The lifting device 8' allows the feeding of the next cylindrical body.
descend.

By repeating the above operations, continuous coating becomes possible even though the cylindrical bodies are supplied at intervals. In order to achieve even greater efficiency, multiple lifting devices 8 may be installed and used alternately, thereby saving time required for discharging the cylindrical body.

[Brief explanation of drawings]

Figure 1 is a schematic overall view of the present invention, Figures 2 and 3.
4 and 5 are detailed enlarged sectional views of FIG. 1 and 2. In the figure, 1 and 1' are cylindrical bodies to be coated, and 2
is a coating chamber, 3 is a coating liquid supply pipe, 4 is a coating ring lifting device, 5, 5' is a detection device, 6, 6' is a light source,
7, 7' are rods, 8, 8' are lifting devices, 9, 9'
21 is a light beam, 21 is a flexible coating ring, 22 is a ring support tool 23 is a coating chamber outer cylinder, 24 is a coating liquid, 25
2 is a coating film, and 26 is a coating liquid level.

Claims (1)

[Claims] 1. An apparatus for applying a coating onto the outer peripheral surface of a substrate to be coated using a flexible coating ring, the apparatus includes a flexible coating ring 21, a ring support 22, and a coating chamber outer cylinder 23, and the flexible coating ring 21 The coating device is characterized in that the ring support 22 is integrated with the ring support member 22 and is movable upward and downward within the outer cylinder of the coating chamber.