JPH046849Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The invention is a chucking device used when coating the outer circumferential surface of a hollow substrate to be coated by dipping, and more specifically, when coating an organic photoreceptor drum for electrophotography. Regarding the chucking device used.

(Prior art) Organic photoconductor drums for electrophotography (hereinafter referred to as OPC drums) are coated substrates of cylindrical drums made of aluminum, etc., and coated with an organic photoconductive material mixed and dispersed in an organic solvent, a binder, etc., on the outer circumferential surface of a coated substrate. It is made by coating a coating liquid containing other additives to form a photosensitive layer. One of the coating methods for such OPC drums is the immersion method, in which the cylindrical drum that is the substrate to be coated is immersed in the coating liquid, and then the substrate to be coated is pulled up from the coating liquid. be. In such a coating method, since the substrate to be coated is immersed in the coating liquid, the coating liquid is applied even to the inner surface of the substrate to be coated, which does not need to be coated. For this reason, there is a lot of loss of the coating liquid, and the yield of the coating liquid is poor, which increases the manufacturing cost.

As a method for preventing such coating on the inner surface of a cylindrical coated substrate, Japanese Utility Model Application Publication No. 147192/1989 discloses a pressure means 1 as shown in FIGS. 4 and 5.
5 and an elastic member 12 which is elastically deformed in the circumferential direction by the pressure means 15 and held in close contact with the inner surface 20 of the cylindrical coating substrate in an airtight manner.

By using such a chucking device 5, the substrate 2 to be coated is chucked by being held in close contact with the inner surface 20 of the entire circumference by the elastic member 12 during coating. The coated substrate 2
Even when the substrate 2 is immersed in the coating liquid 30, the lower part of the substrate 2 to be coated is kept airtight by the elastic member 12, thereby preventing the coating liquid 30 from entering from the lower part of the substrate 2 to be coated. As a result, the coating can be prevented from being applied to the inner surface 20 of the substrate 2 to be coated, and only the outer surface 21 can be coated. In other words, it is a chucking device of a coating machine that serves both to hold the substrate to be coated and to prevent coating on the inner surface of the substrate to be coated.

(Problems to be Solved) When coating an OPC drum using the chucking device 5 described above, the elastic member 12 made of rubber packing deteriorated and became unusable. The reason for this is thought to be as follows. That is, rubber materials used for rubber packing include butyl rubber, urethane rubber, neoprene rubber, silicone rubber, nitrile rubber, sulfurized rubber, and natural rubber. These rubber materials are OPC
It was found that the solvent vapor 31 of tetrahydrolane (THF) as an organic solvent used in the drum coating liquid 30 causes deterioration. as an organic solvent
THF is commonly used as a coating solution for OPC drums. As a result of testing the durability against THF using various rubber materials, no rubber material was found that was durable against THF. Most rubber materials expand 1.2 to 2 times. Butyl rubber and urethane rubber have become brittle, and neoprene, silicone rubber, and sulfurized rubber have decreased strength and become easier to break.

Since the rubber material is thus altered by the THF solvent, it becomes impossible to repeatedly chuck the coated substrate 2, and it is necessary to frequently replace the elastic member 12. For example, when the rubber material expands, the rubber packing becomes so large that it becomes impossible to insert the chucking device 5 into the hollow shell of the substrate 2 to be coated.

The purpose of the present invention is to prevent organic solvents from deteriorating elastic members made of rubber packing as described above, and furthermore, to make it possible to use rubber materials with excellent elasticity as elastic members. An object of the present invention is to provide a chucking device for a coating machine that can more reliably hold a substrate to be coated by eliminating the need to replace an elastic member due to deterioration due to the influence of steam.

Another object of the present invention is to provide a chucking device for a coating machine that can prevent a coating liquid from adhering to the inner surface of a substrate to be coated and uniformly coat the outer surface thereof.

(Means for Solving the Problem) The chucking device of the coating machine of the present invention includes a pressurizing means and an elastic member that is elastically deformed in the circumferential direction by the pressurizing means and held in close contact with the inner surface of a cylindrical coating base in an airtight manner. The support member of the pressure means is circular, and the difference between its outer diameter and the inner diameter of the cylindrical application base is within 3 mm, and the support member of the elastic member has a length l.
By using a chucking device having a diameter of 50 mm or more, the vapor of the organic solvent is blocked and does not come into contact with the rubber material, thereby preventing deterioration of the rubber material and solving the above problem.

Furthermore, the lower part of the support member is tapered to facilitate insertion of the chucking device into the cylindrical application base.

(Example) The present invention will be explained below based on an example of coating on an OPC drum.

As shown in FIGS. 1 and 2, the chucking device 1 of the present invention includes, for example, a pressure means 11 and an elastic member 12 that is elastically deformed in the circumferential direction by the pressure means 11. This chucking device is arranged in the hollow shell of the cylindrical drum 2 to be chucked.

The pressurizing means 11 includes a support member 111 that supports the elastic member 12 in the circumferential direction of the drum;
and an elastic member pressing member 112 that is slidably disposed in the direction of the drum axis. The shapes of the support member 111 and the pressing member 112 are not particularly limited, and may be any shape that can sandwich the elastic member 12 and press the elastic member 12 evenly. The pressurizing means 11 is
Further, a pressing means 113 presses the pressing member 112 relative to the supporting member 111 in the drum axial direction and elastically deforms the elastic member 12 in the drum circumferential direction.
has. As the pressing means 113, the elastic member 1
Any material that can press 2 and impart a desired amount of elastic deformation may be used. Examples include hydraulic or pneumatic cylinders, spring means, a prime mover and rack-and-pinion combination, or compressed air.

The elastic member 12 has a ring shape, for example, and is held between the support member 111 and the pressing member 112. The elastic member 12 is elastically deformed in the circumferential direction by being pressed by the pressing means 113, and is brought into airtight contact along the inner surface 20 of the drum. In this way, the drum 2 is connected to the support member 11 via the elastic member 12.
1, it is held securely. Moreover, the drum 2 will not be deformed. Further, since the support is based on elastic deformation, high precision is not required for attaching the elastic member 12. As the elastic member 12, the pressure means 1
A material having strength and elasticity sufficient to withstand the pressing force of 1 and the frictional force with the drum 2 is appropriately used. Examples include butyl rubber, urethane rubber, neoprene rubber, silicone rubber, nitrile rubber, sulfurized rubber, and natural rubber. Further, the support member 111 has the same circular shape as the cylindrical drum, the difference 2t between its outer diameter and the inner diameter of the cylindrical drum is within 3 mm, and its length l is 50 mm or more. By using such a support member, the ascending passage for organic solvent vapor can be made narrow and
By increasing the length, a blocking effect is created, in effect,
Since the organic solvent vapor does not come into contact with the rubber material, deterioration of the rubber material is prevented, and the above problem can be solved. Preferably, when the inner diameter difference 2t is 1 mm, the length l is 50 mm or more, and when the inner diameter difference 2t is 3 mm, the length l is
It is desirable to make it 100mm or more.

Further, by providing a tapered portion 115 at the lower part of the support member 111, the chucking device 1
can be easily inserted into the hollow body of the cylindrical drum 2.

In the chucking device of the present invention, as shown in FIG.
Similarly, by making it circular and long, the chucking device 4 can further prevent the drum from wobbling due to buoyancy when the drum 2 is immersed in the coating liquid 30.

The chucking device of the present invention is suitably used in fields such as coating on OPC drums, which require extremely high precision and use organic solvents, but can of course be applied to other fields as well.

(Operation) A cylindrical drum, which is a substrate to be coated, is coated by dip coating as shown in FIGS. 2 and 3 using the chucking device of the present invention. First, drum 2
The chucking devices 1 and 4 are inserted into the hollow shell of the chucking device. Then, pressure is applied to the pressing means 113 and the pressing means 11 presses the elastic member 12 . The elastic member 12 is elastically deformed in the circumferential direction, and the drum inner surface 20
to be airtightly adhered to. Thereby, the chucking devices 1 and 4 reliably connect and support the drum 2. Next, the drum 2 is immersed in the coating liquid 30 in the coating liquid storage tank 3 by lowering the chucking device. Since the drum 2 is circumferentially supported by the elastic member 12, it is held and chucked in a stable state. Furthermore, there is less wobbling due to buoyancy. Since it is chucked in this state, the elastic member 12 airtightly seals the inner surface 20 of the drum, and as a result, the coating liquid 30 is prevented from entering into the drum 2. At this time, drum 2
Since air is retained inside, the drum 2 is not deformed by the hydraulic pressure of the coating liquid 30. Further, since the upward passage of the organic solvent vapor 31 generated in the air within the drum 2 is blocked by the support member 111, the organic solvent vapor 31 cannot rise above the support member 111. Therefore, the organic solvent vapor 31 does not come into contact with the elastic member 12 made of rubber packing, so that the elastic member 12 does not change in quality.

Next, the drum 2 is taken out from the coating liquid 30 by pulling up the chucking devices 1 and 4 upward. Then, the drum 2 with a predetermined coating layer formed on the outer surface 21 is released from the close contact of the elastic member 12 by releasing the pressure of the pressing means 113. Next, the drum 2 is removed from the chucking devices 1 and 4 by withdrawing the chucking device 1 from the hollow body of the drum 2.

Thereafter, the drum with the coating layer formed on its outer surface is sent to the next step, for example, to be dried and become an OPC drum.

(Effects of the invention) According to the invention, by preventing the elastic member from being altered by solvent vapor, the chucking device of the coating machine that does not require replacement of the elastic member, and furthermore, the inside of the substrate to be coated can be coated. By providing a chucking device for a coating machine that can coat while preventing liquid from being coated, long-term continuous operation and inexpensive coating become possible.

[Brief explanation of the drawing]

FIGS. 1 and 2 are front sectional views of main parts showing one embodiment of the chucking device of the present invention, respectively. FIG. 3 is a front sectional view of a main part showing another embodiment of the chucking device of the present invention, and FIGS. 4 and 5 are front sectional views of main parts of a conventional chucking device. 1, 4, 5... Chucking device, 2... Drum, 3... Coating liquid storage tank, 11... Pressurizing means, 1
2... Elastic member, 30... Coating liquid, 31... Solvent vapor.

Claims (1)

[Claims for Utility Model Registration] (1) Comprising a pressure means and an elastic member that is elastically deformed in the circumferential direction by the pressure means and held in airtight contact with the inner surface of the cylindrical application base, and the pressure is applied. The supporting member of the means is circular, and the difference between its outer diameter and the inner diameter of the cylindrical application base is within 3 mm, and the length l of the supporting member of the elastic member is 50 mm.
The above is the chucking device. (2) The chucking device according to claim 1, wherein the lower part of the support member is tapered.