JPH04186249A - Drum applying device - Google Patents

Abstract

PURPOSE:To eliminate mixing of bubbles in an application liquid and restrain the evaporation of a solvent by fixing and arranging dipping tanks, and reserving the overflowed application liquid in an overflow tank and then recovering and circulating it. CONSTITUTION:A chucking device 40, with which drums 70 are retained, is lowered to submerge them in dipping tank parts 12 where an application liquid is overflowed, and then the device 40 is raised to pull the drums up. The application liquid overflowed from the tanks 12 is reserved in an overflow tank part 11, is recovered in a stirring tank with a recovering pump 22 on reaching a given quantity, and is supplied to the tanks 12 with viscosity adjusted. A coating tank 10 of the device is nonelevating, consequently probable mixing of bubbles into the application liquid, due to a configuration change of piping circulating the application liquid, is eliminated. Also the evaporation of a solvent can be reduced because of the forced recovery of the application liquid with the pump 22.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is applicable to, for example, when manufacturing a photoreceptor drum used in an electrophotographic copying machine, etc. The present invention relates to a coating device for coating an industrial solution.

(Prior Art) Photoreceptor drums used in image forming apparatuses such as electrophotographic copying machines and printers are usually made by immersing an aluminum drum in a coating solution containing an organic photosensitive substance and an organic solvent. Manufactured by forming a photosensitive coating on the outer peripheral surface. When an aluminum drum is immersed in a coating solution in a coating tank, coating on the outer circumferential surface of the aluminum drum may be affected by the effects of organic solvent vapor contained in the coating solution and displacement of the coating solution surface. The coating tank is usually overflowed to prevent uneven coating thickness. The coating liquid overflowing from the coating tank is circulated to the coating tank.

The coating liquid used as the photosensitive layer of the photosensitive drum is a mixture of a photosensitive substance and an organic solvent. Therefore, since the organic solvent constantly evaporates from the coating liquid, the viscosity of the coating liquid gradually increases. When the viscosity of the coating liquid changes, the thickness of the applied coating liquid changes when an aluminum drum is immersed in the coating liquid and the coating liquid is applied to the outer peripheral surface of the drum.

Therefore, it is necessary to keep the viscosity of the coating liquid constant at all times.

FIG. 2 shows an example of a conventional drum coating device used when manufacturing photosensitive drums.

For example, a plurality of drums 70, whose outer peripheral surfaces are coated with a coating liquid, are held in a predetermined alignment state by a chucking device. A coating tank 51 is disposed below the chucking device so as to be movable up and down.

The coating tank 51 has a plurality of immersion tank parts 51b in which each drum 70 is immersed as it rises, and a coating liquid flows inside from the bottom to the top and overflows, and a plurality of immersion tank parts 51b in which the coating liquid overflows from each immersion tank part 51b It has an overflow tank section 51a to be accommodated, and both move up and down as one.

One end of a liquid feeding pipe 53 is connected to the lower end of each immersion tank portion 51b, and the other end of all the liquid feeding pipes 53 is connected to one liquid feeding block 55. . The liquid feeding block 55 moves up and down integrally with the coating tank 51.

The coating liquid stored in the overflow tank section 51a of the coating tank 51 is fed to the Knonyong tank 57 by gravity falling into a recovery pipe 56 whose upper end is attached to the bottom of the overflow tank section 51a. It looks like this. The coating tank 57 is fixedly arranged with respect to the coating tank 51 that moves up and down, and the recovery pipe 5
The lower end of the tank 5 is movable up and down.
It is located within 7.

The upper end of a pipe 58 is attached to the bottom of the cushion tank S7, and a recovery pump 54 is interposed in the middle of the pipe 58. The cushion tank 57 is provided with a level sensor 52 that detects that the coating liquid contained in the cushion tank 57 has reached a predetermined level.
If it is detected that the coating liquid in 7 has reached a predetermined level,
The recovery pump 54 is driven and the cushion tank 57
The coating liquid is collected via piping 58 into a stirring tank (not shown).

After the recovered coating liquid is adjusted to a predetermined viscosity in the stirring tank, it is fed to the liquid feeding block 55 to the flexible feeding pipe 59, and is then passed through the liquid feeding block 55 and each liquid feeding pipe 53. The water is then circulated to each immersion tank section 51b.

In such a drum coating device, the chucking device 80
The entire coating tank 51 is raised together with the liquid feeding block 55 with respect to the drum 70 held by the drum 70, with the coating liquid overflowing into each immersion tank portion 51b.

Then, the drum 70 is immersed in each immersion tank portion 51b. The coating liquid overflowing from each immersion tank section 51b is accommodated in the overflow tank section 51a, naturally falls through the recovery pipe 56, and is recovered into the cushion tank 57.

When the drum 70 is immersed in each immersion tank portion 51b, the entire coating tank 51 is lowered and the drum is removed from each immersion tank portion 51b.

When the coating liquid stored in the tank 57 reaches the level at which the level sensor 52 is attached, the recovery pump 54 is driven, and the coating liquid passes through the pipe 58 and is recovered to the stirring tank.

(Problem to be Solved by the Invention) In this way, since the coating tank 51 itself moves up and down, the liquid feeding block 5 moves up and down together with the coating tank 51.
The curvature of the flexible feed pipe 59 connected to the pipe 5 changes as it moves up and down. With such a change in the curvature of the feed pipe 59, there is a possibility that air bubbles may be mixed into the coating liquid flowing inside. The air bubbles mixed into the coating liquid adhere to the outer circumferential surface of the drum, so that the coating liquid is not applied to that area, and the drum cannot be used as a photoreceptor drum.

In addition, an overflow tank portion 51a of the coating tank 51
The coating liquid contained in the container falls naturally within the collection pipe 56, and
It is stored in the Kunongyong tank 57. For this reason, it is necessary to replace the coating liquid with air in the vertical recovery pipe 56, and the coating liquid contacts the air in the recovery pipe 56 to promote evaporation of the solvent. As a result, the viscosity of the coating liquid increases in a short period of time, making it difficult to adjust the viscosity and furthermore requiring a large amount of solvent to adjust the viscosity.

The present invention is intended to solve the above-mentioned conventional problems, and its purpose is to eliminate the risk of air bubbles being mixed into the circulating coating solution, to easily adjust the viscosity of the coating solution, and to improve the coating process. The object of the present invention is to provide a drum coating device that requires only a small amount of solvent for the viscosity gW of the liquid.

(Means for Solving the Problems) The drum coating device of the present invention includes a chucking device that lifts and lowers the drum while holding it in a vertical state, and a chucking device that allows the coating liquid to flow from below and overflow.
The drum held by the chucking device has a dipping tank portion in which the drum is immersed in the coating liquid as the chucking device descends, and an overflow tank portion in which the coating liquid overflowing from the dipping tank portion is stored. A coating tank fixedly disposed below the chucking device, a recovery pump for forcibly recovering the coating solution stored in the overflow tank of the coating tank, and a recovery pump that forcibly recovers the coating solution collected by the recovery means. means for circulating the coating liquid into the dipping tank section, thereby achieving the above object.

(Function) In the drum coating device of the present invention, the drum held by the chucking device is immersed in the overflowing coating liquid in the dipping tank portion of the coating tank by raising and lowering the chucking device. The coating liquid overflowing from the immersion tank is first stored in the overflow tank of the coating tank, and then forcibly recovered by the recovery pump. Then, it is circulated to the immersion tank section by a predetermined circulation means.

(Example) FIG. 1 is a schematic diagram showing an example of the drum coating device of the present invention. This circulation system is used in a coating film forming process in which an aluminum drum 70 is immersed in a coating solution containing a photosensitive substance and an organic solvent to form a photosensitive layer on its outer peripheral surface.

In this drum coating device, a predetermined chucking device 40
The coating tank 10 is disposed below an aluminum drum 70 that is held in a vertical position. The chucking device 40 includes, for example, six drums arranged in three rows and two columns? 0.70. It is designed to move up and down while holding the... in a vertical position. The coating tank 10 disposed below the chucking device 40
The drums 70 are arranged in three rows and two columns so that each drum 70 held by the chucking device 40 is accommodated as the chucking device 40 descends. It has six immersion tank parts 12. A liquid feed pipe 13 is connected to the lower end of each immersion tank portion 12, and the coating liquid flowing through each liquid feed pipe 13 is
The water flows through each immersion tank section 12 from the bottom to the top and overflows. Each immersion tank section 12 is held within the overflow tank 11 so as to be in a vertical state. Then, the overflowing coating liquid is stored in the overflow tank section 11.

The overflow tank section 11 is in a fixed state with respect to the chucking device 40 that is raised and lowered.

A partition plate 14 is installed horizontally within the overflow tank section ll. The partition plate 14 is provided with six circular through holes 14a through which the upper part of each immersion tank part 12 is inserted with a slight gap between them.

Furthermore, a pair of upper and lower upper limit level sensors 16 and lower limit level sensors 17 are attached to the overflow tank section 11 to detect when the coating liquid stored in the overflow tank section 11 has reached a predetermined level.

The bottom surface of the overflow tank portion 11 is inclined, and the upper end portion of the recovery pipe 21 communicates with the bottom surface of the bottom surface. The other end of the recovery pump 22 is connected to, for example, a stirring tank (not shown), and the recovery pump 22 is interposed in the middle. The coating liquid stored in the overflow tank section 11 is then transferred to the upper limit level sensor 1.
A collection pump 22 driven by the detection by the pump 6 forces the water to flow through the collection pipe 21 and is collected in a stirring tank (not shown).

In the stirring tank, the recovered coating liquid is adjusted to have a predetermined viscosity. The coating liquid adjusted to a predetermined viscosity in the stirring tank is then fed to the liquid feeding block 30.

One end of a feed pipe 31 is connected to the bottom surface of the liquid feed block 30, and the coating liquid is fed from the stirring tank through the feed pipe 31. Inside the liquid feeding block 30, the coating liquid fed from the feeding pipe 31 is distributed into six equal amounts. The respective liquid sending pipes 13 connected to are connected to each other. Therefore, the coating liquid distributed in equal amounts inside the liquid feeding block 30 flows into each liquid feeding pipe 13 and is circulated into each immersion tank 12. The liquid feeding block 30, like the coating tank 10, is fixed to a chucking device that is moved up and down. In addition, the liquid feeding block 3
0 is connected to a suitable air vent pipe 32.

In the drum coating device having such a configuration, when a predetermined number of drums 70 are held vertically in the chucking device 40, the coating liquid is fed to each dipping tank portion 12 via each liquid feeding pipe 13. , overflows from each immersion tank section 12. In this state, the entire chucking device 40 is lowered, and each drum 70 is immersed in the overflowing coating liquid in each immersion tank section 12. Then, when each drum 70 is almost entirely immersed, the chucking device 40 is raised, and each drum 70 is removed from the coating liquid in each immersion tank section 12.

The coating liquid overflowing from each immersion tank section 12 is
The overflow tank portion 1 passes through the gap between each through hole 14a of the partition plate 14 and each immersion tank portion 12.
It is accommodated within 1. The coating liquid contained in the overflow tank section 11 is stored within the overflow tank section 11. When the stored coating liquid reaches a level detected by the upper limit level sensor 16, the recovery pump 22 installed in the recovery pipe 21 is driven, and the recovery pump 22 forcibly removes the coating liquid. is collected in a stirring tank. Recovery of the coating liquid by the recovery pump 22 is continued until the coating liquid in the autocooler flow tank section 11 reaches the mounting position of the lower limit level sensor 17.

In this manner, the coating liquid in the overflow tank section 11 is forcibly recovered within the recovery tube 21 by the recovery pump 22, so there is no risk of it coming into contact with air within the recovery tube 21. Further, since the overflow tank section 11 is covered by the partition plate 14, evaporation of the solvent in the coating liquid is significantly suppressed in the overflow tank section 11 and the recovery pipe 21.

In the stirring/stirring tank where the coating liquid is collected, the coating liquid is adjusted to have a predetermined viscosity. Then, the coating liquid adjusted to a predetermined viscosity is fed from the feeding pipe 31 to the liquid feeding block 30, and divided into six equal parts in the liquid feeding block 30.
The liquid is circulated from each liquid sending pipe 32 to each immersion tank section 12 .

Since the coating tank 10 does not go up and down, the liquid feeding block 30 does not need to be raised and lowered in the same manner as the coating tank 10. Therefore, the feeding pipe 31 attached to the liquid feeding block 30
is in a fixed state. As a result, there is no fear that air bubbles will be mixed into the coating liquid flowing inside due to a change in the curvature of the feed pipe 31.

(Effects of the Invention) As described above, in the drum coating device of the present invention, the coating tank does not move up and down, so there is no fear that the shape of the piping that circulates the coating liquid in the coating tank will change, and the inside of the piping There is no risk of air bubbles being mixed into the flowing coating liquid due to changes in the curvature of the pipe. In addition, the coating liquid that overflows from the immersion tank section of the coating tank is temporarily stored in the overflow tank section of the coating tank and then forcibly recovered by the recovery pump. Evaporation of the solvent due to contact with air is suppressed. As a result, it becomes easy to adjust the viscosity of the recovered coating liquid, and moreover, the amount of solvent for adjusting the viscosity can be significantly reduced.

4. Figure 1 is a schematic diagram showing an example of the drum coating device of the present invention;
FIG. 2 is a schematic diagram of a conventional drum coating device.

DESCRIPTION OF SYMBOLS 10... Coating tank, 11... Overflow tank part, 12... Immersion tank part, 13... Liquid feeding pipe, 1
4... Partition plate, 16... Upper limit level sensor, 17
...lower limit level sensor, 21...recovery pipe, 22...
・Recovery pump, 30...To liquid feeding brochure 31...Feeding pipe, 40...Chucking device, 70...Drum.

that's all

Claims (1)

[Claims] 1. A chucking device that raises and lowers the drum while holding it in a vertical state;
The drum held by the chucking device has a dipping tank portion in which the drum is immersed in the coating liquid as the chucking device descends, and an overflow tank portion in which the coating liquid overflowing from the dipping tank portion is stored. A coating tank fixedly disposed below the chucking device, a recovery pump for forcibly recovering the coating solution stored in the overflow tank of the coating tank, and a recovery pump that forcibly recovers the coating solution collected by the recovery means. A drum coating device comprising: means for circulating a coating liquid into the dipping tank section.