JPH0811209B2 - Continuous production method of photoreceptor drum - Google Patents

Description

The present invention relates to a method for continuously manufacturing a photosensitive drum. More specifically, the present invention relates to a method of continuously applying a photoconductor coating liquid to a tube to manufacture a photoconductor drum so as to form a coating film having a uniform thickness.

[Conventional technology]

Conventionally, the photosensitive drum has a short tube having the same length as the shape of the final photosensitive drum, and then has a high accuracy such as the smoothness of the surface and the straightness of the drum. It has been manufactured by providing a photoreceptor layer thereon after performing a process for making the same.

On the other hand, as a photosensitive material, the progress of organic photosensitive material, which is inexpensive and safe, is remarkable, and excellent performance can be obtained simply by coating a coating solution in which an organic photosensitive material is dissolved or dispersed with an appropriate binder as needed. It is possible to make a photoconductor drum of.

Also, a long (substantially infinite length) resin material tube having sufficient surface smoothness, straightness, etc. as a material tube for a photosensitive drum can be obtained (for example, JP-A-59-178235). This resin-made tube can be made conductive by kneading the resin itself with carbon or the like, and it is expected that a photoreceptor drum can be manufactured at low cost by combining it with the above-mentioned organic photoreceptor material.

[Problems to be solved by the invention]

However, if the coating liquid is simply applied using a relatively long tube, the coating apparatus becomes large in size and the operation becomes difficult, and there is a problem in that it is not very effective even if implemented industrially. is there. In addition, if an attempt is made to apply the coating at the same time as the production of the raw pipe, the film thickness is determined by the pulling-up speed of the raw pipe in a commonly used dipping method, so that the thickness of the photoreceptor layer also changes when the production speed of the raw pipe changes. There is.

A method of utilizing surface tension is known as a method of controlling the film thickness (Japanese Patent Laid-Open No. 61-20044), but this method has a problem that it cannot be applied to continuous coating.

[Means for solving problems]

As a result of intensive studies on a method for solving the above problems, the present inventors have found that a uniform photoconductor layer can be formed by using an immersion tank having a specific structure, and have completed the present invention.

That is, in the present invention, the photoreceptor coating liquid is placed in a dip tank having a through hole having a diameter slightly larger than the outer diameter of the cylindrical photoconductor drum tube at the bottom, and the photoconductor drum tube is placed at the bottom of the dip tank. In the method for continuously manufacturing a photosensitive drum by moving vertically upward through a through hole, the dipping tank has a truncated cone shape in which a cone is cut parallel to the bottom side, and By providing a means capable of controlling the liquid level of the coating liquid, the coating liquid level of the dipping tank is raised or lowered according to the change in the moving speed of the photoconductor drum tube to continuously form a coating film of uniform thickness. It is a continuous manufacturing method of a photosensitive drum, which is characterized in that it is formed in a uniform manner.

The present invention corresponds to the conventionally known so-called dip coating method in that the photosensitive material coating liquid is applied by moving the drum tube relative to the dipping tank that penetrates the photosensitive drum.

In the present invention, the shape of the dipping tank, that is, the dipping tank is a truncated cone shape in which a cone is cut parallel to the bottom side, and further, means for controlling the liquid level of the coating liquid in the dipping tank is provided. Is important. Here, it is preferable that the bottom of the dipping tank has a through hole having a diameter slightly larger than the outer diameter of the cylindrical photosensitive drum element tube and that the coating liquid does not leak.

The structure of the immersion tank, which is important in the present invention, will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of a state in which a dipping bath and a drum base pipe are applied, where 1 is a drum base pipe and 2 is a truncated cone-shaped dipping bath important in the present invention. 3 is a means for controlling the liquid level of the coating liquid in the dipping tank, is a container connected to the dipping tank 2 at the bottom, and 4 is a liquid level detector (for example, the distance to the liquid surface using laser light). Is a detector capable of detecting the change in the liquid level) and the liquid level of the connected dipping tank 2 can be known by knowing the liquid level of the container 3.
Reference numeral 5 denotes a coating liquid, and the liquid level of the container of 3 is changed by letting the coating liquid flow in and out through the pipe of 7. Reference numeral 6 is, for example, an O-ring provided so that the coating liquid does not leak.

Here, it is preferable that the size of the dipping tank is about 10 to 20 mm larger than the outer diameter of the photoreceptor drum tube at the opening, and about 0.2 to 1 mm at the smallest conical portion. By moving the liquid level of the coating liquid and changing the distance between the wall of the dipping tank and the wall of the drum tube at the liquid level, the thickness of the coating film is controlled as a result. That is, it is possible to compensate for the change in the thickness of the coating film caused by the change in the relative moving speed of the photoconductor drum tube to the dipping tank.

In the present invention, preferably, a thermosetting resin is continuously molded using an extrusion molding machine having a screw having a tip portion and a smooth portion, and the molded product is used as a raw tube to continuously apply a photoreceptor. .

At this time, in order to have the surface smoothness of the molded product, or the straightness, which has important accuracy as a raw tube for the photosensitive drum, for example, the self-shape after extrusion in the smooth part of the screw It is important to perform shape-hardening to such an extent that it can be held, and therefore to set the temperature in the extruder according to the type of thermosetting resin.

Here, as the thermosetting resin, phenol resin, melamine resin, urea resin, unsaturated polyester resin, epoxy resin, silicone resin, allyl resin, xylene resin, aniline resin, and polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride Examples include thermoplastic resins such as resins to which a crosslinking agent is added, and phenol resins and melamine resins are particularly preferably used.

In addition, it is preferable that the surface resistance of the raw tube of these materials is 10 ⁸ Ωcm or less, especially 10 ⁶ Ωcm or less, and therefore, carbon should be dispersed in an amount of 3 to 30 wt% in the entire molded product depending on the type of carbon. is necessary.

〔Example〕

 Hereinafter, the present invention will be further described with reference to examples.

Example It was confirmed that the thickness can be controlled by the apparatus shown in FIG. 1 using a raw tube having an outer diameter of 60 mm and a length of 1000 mm.

The immersion tank has an inner diameter of 70 mm at the opening and an inner diameter of 6 at the narrowest part.
It was 0.5 mm. An O-ring was used to prevent leakage in the gap between the base pipe and the base pipe. With this equipment, a 10 wt% polyester solution was used as the coating liquid, and the distance between the wall of the tube and the wall of the dipping tank was 3 m at the liquid level.
m, and the pulling speed was 60 mm / min and 50 mm / min, and the coating thickness was 4 μm and 3 μm, respectively.
Met.

When the pulling speed is 50 mm / min, when the liquid level is lowered so that the distance between the wall of the raw pipe and the wall of the immersion tank at the liquid level is 0.5 mm, the thickness of the coating film is 60 mm / min. It was 4 μm as in the case of

〔The invention's effect〕

By carrying out the present invention, a photoreceptor drum having a uniform thickness of the photoreceptor layer can be easily and continuously obtained, which is extremely industrially valuable.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of an apparatus suitable for carrying out the method of the present invention, and FIG. 2 is a perspective view thereof.

Claims (2)

[Claims] 1. A photoreceptor coating solution is placed in an immersion tank having a through hole having a diameter slightly larger than the outer diameter of a cylindrical photosensitive drum base pipe at the bottom, and the photosensitive drum base pipe is penetrated at the bottom of the immersion bath. In a method for continuously manufacturing a photoconductor drum by moving vertically upward through a hole, the dipping tank has a truncated cone shape in which a cone is cut parallel to the bottom side, and By providing a means capable of controlling the liquid level of the liquid, the coating liquid of the coating liquid in the dipping tank is moved up and down in accordance with the change in the moving speed of the photoconductor drum tube to continuously form a coating film of uniform thickness. 1. A continuous method for producing a photosensitive drum, which comprises: 2. A photosensitive drum material tube is continuously manufactured by using an extrusion molding machine having a screw having a smooth portion at its tip, and subsequently the photosensitive material coating liquid is continuously applied. Method described in section.