JP2679196B2 - Hollow substrate coating device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus for hollow substrates, and more particularly to a coating apparatus for hollow substrates that coats the outer surface of a hollow substrate without coating the inner surface.

[Conventional technology]

The electrophotographic photoreceptor is formed, for example, by laminating a photosensitive layer on the outer surface of a hollow cylindrical substrate. In recent years, electrophotographic photoreceptors using organic materials have been put into practical use because of their advantages such as flexibility, thermal stability, and film forming properties. For example, there are phthalocyanine compounds and various azo compounds as charge generating substances,
Hydrazone, pyrazoline, oxadiazole, etc. are used as the charge transport material. These charge generating substances and charge transporting substances are separately or mixed and laminated on a substrate to form a photosensitive layer. A so-called dipping method in which a substrate is immersed in a coating solution and pulled up is preferably used for forming a photosensitive layer using an organic material. However, the method of simply immersing the hollow substrate has a drawback that a photosensitive layer is formed on the inner surface of the hollow substrate and the photosensitive materials such as the charge generating substance and the charge transporting substance are wasted. Conventionally, as a method for overcoming this drawback, a method of closing the lower open end of the hollow substrate, as disclosed in Japanese Patent Laid-Open No. 59-80363, the jig for holding the hollow substrate is made airtight and the coating liquid is applied by residual air pressure. There is known a method of preventing the invasion of the above, and a method of forming the holding jig with an elastic body and a material that presses the holding jig as disclosed in JP-A-62-65763.

[Problems to be solved by the invention]

However, in the method of closing the lower open end of the hollow substrate, there is a problem that the jig needs to be attached and detached and the jig to which the coating liquid adheres needs to be cleaned. Further, in the method of preventing the coating liquid from entering due to residual air pressure, the hollow substrate However, there is a problem that the inner surface of the resin cannot be completely shielded from the coating liquid, and each method requires a jig having a complicated structure.

The present invention has been made in view of the above points, and an object thereof is to apply the outer surface of a hollow substrate by blocking the open end of the hollow substrate by an elastic action so as to be easily attached and detached and without requiring jig cleaning. An object of the present invention is to provide a coating device for a hollow substrate that can be used.

[Means for solving the problem]

According to the present invention, the above object is to provide a coating apparatus for a hollow substrate in which a hollow substrate is immersed in a coating solution and then pulled up to coat the outer surface of the substrate, and a coating tank for filling the coating solution and holding the hollow substrate from below. The coating tank is provided with a bellows-shaped inner cylinder that expands and contracts as the hollow base moves up and down. The lower end of the inner cylinder is fixed to the bottom of the coating tank and the upper end is fitted to the open lower end of the hollow base. This is achieved by further comprising an elastic strengthening means that exerts a pressing force in a direction that enhances the liquid tightness of the fitting portion, inside the inner cylinder.

[Action]

The elastic strengthening means enhances the adhesion between the hollow base and the bellows-shaped inner cylinder to prevent the coating liquid from entering. Since the bellows-shaped inner cylinder is fixed and integrated with the bottom of the coating tank, it is always in contact with the coating liquid and does not need to be washed after each coating. Further, since the bellows-shaped inner cylinder fits with the lower opening end of the hollow substrate, it can be easily attached and detached.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of a coating apparatus according to an embodiment of the present invention, wherein the lower end of a bellows-shaped inner cylinder 2 made of polyethylene is provided with a flange-shaped projecting portion 21, and the bottom side wall of the coating tank 1 and a bottom plate 7 are used for liquid It is attached so that it will not leak. Hollow substrate 3
The straight portion 22 at the upper end of the bellows-shaped inner cylinder 2 is liquid-tightly fitted through the packing 5 to the lower open end of the. A spring 6 is provided inside the bellows-shaped inner cylinder 2, and sealing is performed by tightening the packing 5 with the hollow base body 3. A spring fixing plate 31 having a hole 32 at the center is provided below the hollow substrate 3. 100 parts by weight of the following hydrazone derivative as the coating liquid 4A Is mixed with 700 parts by weight of tetrahydrofuran and 100 parts by weight of polymethylmethacrylate polymer is mixed with 700 parts by weight of toluene to prepare a mixture. The hollow substrate 3 is dipped in this coating solution and then pulled up at a rate of 3 mm / sec to apply the charge transport layer. 50 parts by weight of metal-free phthalocyanine, polyester resin on the charge transport layer obtained by drying
A coating solution prepared by kneading 50 parts by weight, 50 parts by weight of polymethyl methacrylate polymer, and 800 parts by weight of tetrahydrofuran.
Apply B using the ironing method. Lifting speed is 10 mm /
Seconds. In this way, the charge transport layer and the charge generation layer can be laminated on the hollow substrate 3.

In addition, after applying the coating liquid 4B by the dipping method, the coating liquid 4A
It can also be applied by a method of ironing.

In the above process, the bellows made of polyethylene will not be attacked by the coating liquids 4A and 4B.

It suffices that the upper end of the inner cylinder 2 can be fitted, and it may be tapered depending on the shape of the lower opening of the hollow substrate. Although the upper end of the inner cylinder 2 is open in this embodiment, it may be closed.

〔The invention's effect〕

According to the present invention, in a coating apparatus for a hollow substrate in which a hollow substrate is dipped in a coating solution and then pulled up to coat the outer surface of the substrate, a coating tank for filling the coating solution and the hollow substrate holding the hollow substrate from below are provided. The coating tank is provided with a bellows-shaped inner cylinder that expands and contracts as the container is moved up and down, the lower end of the inner cylinder is fixed to the bottom of the coating tank, and the upper end is fitted to the opening lower end of the hollow substrate. Since the elastic strengthening means for exerting a pressing force in the direction of increasing the liquid tightness of the fitting portion is inserted inside the inner cylinder, it is possible to apply it by the cooperation work of the bellows-shaped inner cylinder and the elastic strengthening means. Since the invasion of the liquid is prevented and the hollow base and the bellows-shaped inner cylinder are brought into close contact with each other by the elastic action of the elastic reinforcing means, the hollow base can be easily attached and detached. Further, since the bellows-shaped inner cylinder is fixed to the bottom of the coating tank, the bellows-shaped inner cylinder is always in contact with the coating solution inside the coating tank, and it is not necessary to wash it after the coating is completed.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a coating apparatus according to an embodiment of the present invention. 1 ... Coating tank, 2 ... Bellows-shaped inner cylinder, 3 ... Hollow substrate, 4
A, 4B: coating liquid, 5: packing.

Claims (1)

(57) [Claims] 1. A hollow substrate coating apparatus in which a hollow substrate is dipped in a coating liquid and then pulled up to coat the outer surface of the substrate, and a coating tank for filling the coating liquid and the hollow substrate are held from below. The coating tank is provided with a bellows-shaped inner cylinder that expands and contracts as the container is moved up and down, the lower end of the inner cylinder is fixed to the bottom of the coating tank, and the upper end is fitted to the opening lower end of the hollow substrate. An apparatus for coating a hollow substrate, characterized in that an elastic strengthening means for exerting a pressing force in a direction to enhance the liquid tightness of the fitting portion is inserted inside the inner cylinder.