JPH06138670A - Removing method for excess photosensitive coating film on surface of cylindrical drum - Google Patents

Abstract

PURPOSE:To provide a removing method of an excess photosensitive coating film on the surface of a cylindrical drum equipped with a photosensitive coating film to be used for a copier or laser beam printer by an electrophotographic method, in order to effectively and surely remove an excess photosensitive coating, film remaining on edge part where a paper feeding mechanism of a copying machine is to be attached. CONSTITUTION:After a photosensitive coating film is formed by dipping a cylindrical drum in a photosensitive coating liquid, the excess photosensitive film on the edge part of the drum surface is removed. In this method, a peeling tape having a twill weave structure produced by twilling weft to warp is impregnated with a solvent, and then, this peeling tape is brought into contact with the drum edge and moved to remove the excess photosensitive coating film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing a surplus photosensitive coating film on the surface of a cylindrical drum, and more specifically, it is used in a copying machine or a laser beam printer by an electrophotographic system, A method for removing surplus photosensitive coating capable of surely and effectively removing the surplus photosensitive coating remaining on the end of a cylindrical drum provided with the photosensitive coating to which a paper feeding mechanism such as a copying machine should be attached. .

[0002]

2. Description of the Related Art An electrophotographic copying machine or a laser beam
In a muffler, an organic photosensitive paint or the like (hereinafter, simply referred to as photosensitive paint) is applied on the surface of a cylindrical drum made of metal such as aluminum, and the photosensitive material on the cylindrical drum (hereinafter simply referred to as drum) is exposed. Copying and printing are performed through the charging of the coating film. For forming the photosensitive coating film on the drum, for example, a coating method by dipping, a spray coating method, a roller coating method or a wire bar coating method has been put into practical use. Among these coating methods, the coating method by dipping is a method in which the drum is suspended and dipped in the photosensitive coating liquid, and the thickness of the photosensitive coating film formed is such that the viscosity of the coating liquid or the pulling speed of the drum. It is most commonly used as compared with other coating film formation because it can be adjusted by.

The photosensitive coating film usually has a three-layer structure consisting of an undercoat layer for blocking negative charges, a charge generation layer for charge generation, and a charge transfer layer for charge transfer. Each of these photosensitive coating layers is formed by successively immersing a drum.

When the photosensitive coating layer is sequentially formed on the surface of the drum by the immersion as described above, the photosensitive coating is formed on the entire surface of the drum and a part of the inner surface, so that the photosensitive coating on the inner surface of the drum is removed. Together with the drum surface, a paper feed mechanism, for example, to prevent scraping of the coating film due to contact with rollers or the like, and to prevent paper feeding failure due to uneven coating film at the drum end, It is necessary to remove the excess photosensitive coating film on the edges.

That is, the charge generation layer and the charge transfer layer of the photosensitive coating are connected via an undercoat layer, and at the time of copying, it is necessary to make the inner surface of the drum a ground with no electric charge. It is necessary to remove the excess photosensitive coating film.

On the other hand, the removal of the excess photosensitive coating film at the end portion of the drum surface mainly secures the smooth operation of the paper transport mechanism and the uniform contact of the toner removing blade with the surface of the photosensitive member. Required from above.

Therefore, from these requirements, it is necessary to completely remove the excess photosensitive coating film at the end without leaving a slight trace.

From the above, various methods have been conventionally proposed and implemented for removing the excess photosensitive coating film on the end portion of the drum surface, but all of them have drawbacks, and improvement thereof is desired. There is.

The first method is a method in which after coating by dipping, a cut of a constant width is made at the end of the drum surface, and the excess photosensitive coating film of a constant width is scraped off.

The second method is to immerse the end portion of the drum surface in a solvent to dissolve the excess photosensitive coating film, and then wipe it off with a brush of metal, rubber or the like (JP-A-60-97361).
Is.

The third method is a method in which the excess photosensitive coating film is dissolved in a solvent and then wiped off as in the above-mentioned method 2. In the wiping operation, a tape-shaped substrate is used by using a tape-shaped base material. This is a method of removing the excess photosensitive coating film by bringing the material into contact with the end portion of the surface of the rotating drum (JP-A-1-99056).

The method 1 is not suitable for removing the excessive photosensitive coating film which requires mass productivity, because the surface of the drum may be damaged unless careful attention is paid when making a cut with a knife or the like. Is.

Method 2 often damages the surface of the drum in the same manner when the excess photosensitive coating film is wiped off with a metal or rubber brush, and improvements in this area are desired.

In the method of 3, the tape-shaped base material used for wiping is constructed as a non-woven fabric to give desired mechanical strength so that the surplus photosensitive coating film can be completely wiped off and the surface of the photosensitive coating film is photosensitive. Do not harm the membrane. However, the non-woven fabric used in this case is usually one in which a sheet material is laminated via an adhesive. For this reason, when wiping off, the adhesive elutes and has an adverse effect, and since there is a limit to the retention of the solvent, it cannot be completely wiped off with a non-woven fabric. At that time, there is a risk that it will be eluted and even the required photosensitive coating film on the surface will be destroyed and damaged.

[0015]

SUMMARY OF THE INVENTION The present invention aims to solve the above-mentioned drawbacks. Specifically, after a photosensitive coating film is formed by immersing a drum in a photosensitive coating liquid, an excess of the outer surface end of the drum is formed. When removing the photosensitive coating film, it is possible to remove the excess photosensitive coating film on the outer surface edge while leaving the necessary photosensitive coating film without damaging it, and propose a method for removing the excess photosensitive coating film on the surface of the drum. .

[0016]

That is, according to the method of the present invention, a cylindrical drum is dipped in a photosensitive coating liquid to form a photosensitive coating film, and then the excess photosensitive coating film is removed at the end of the drum surface. In doing so, at the end of the drum surface, while having a twill weave structure in which the warp yarns are woven with the weft yarns diagonally woven together, and while being in contact with the solvent-impregnated peeling tape. The peeling tape is moved to remove the excess photosensitive coating film.

Therefore, the structure and operation of these means will be described more specifically as follows.

First, a cylindrical drum is formed from a metal such as aluminum or its alloy by a conventional method.
This drum is dipped in a photosensitive coating solution to form a photosensitive coating layer on at least the surface. In this case, it is also possible to hold the end of the drum and hang it to immerse it in a photosensitive coating liquid to form a photosensitive coating film, or hold the inner surface of the drum with a holding jig to immerse it in the photosensitive coating liquid. It is also possible to form a photosensitive coating film by suppressing contact with the photosensitive coating on the inner surface.

After the photosensitive coating film is formed on the surface of the drum by the immersion as described above, the excess photosensitive coating film is removed over a certain width at the end portion of the drum, and the roller of the paper feeding mechanism or the like is attached to the removed portion. Make contact.

On the surface of the drum after the dip coating, the drum is rotated in order to remove the excess photosensitive coating film existing in a certain width, while the end surface of the rotating drum is preliminarily impregnated with a solvent for peeling. The tape is moved while being in contact with it, and the excess photosensitive coating is dissolved and softened by the solvent impregnating it and wiped off. As the solvent to be impregnated into the peeling tape, any solvent can be used as long as it is related to the photosensitive coating film formed on the surface, as described later.

As the peeling tape, twill weave of acrylic fiber is used instead of the non-woven fabric or plain weave of the conventional example.

That is, the stripping tape having a twill weave structure has a very good expansion and contraction during sequential feeding, can secure sufficient tension even in a solvent-impregnated state, and can reliably absorb and remove only the excess photosensitive coating film. At the same time, it does not damage the photosensitive coating in the necessary areas. Further, among the synthetic fibers, particularly when the filaments are acrylic fibers, the solvent holding ability is larger than that of other synthetic fibers, and the surplus photosensitive coating film can be removed very effectively.

More specifically, according to one of the previously proposed conventional methods, a nonwoven fabric is used as a peeling tape. The non-woven fabric itself is formed by laminating synthetic resin filaments to form a web and bonding them by melt adhesion, chemical adhesion, mechanical adhesion or the like. For this reason, when removing the excess photosensitive coating film and applying a tension to the stripping tape of the nonwoven fabric, different tensions are applied to the respective sheet materials at the time of movement, resulting in different elongations. Therefore, the photoconductor coating cannot be removed accurately. In particular, in a non-woven fabric using an adhesive, the adhesive is deteriorated by the impregnated solvent during use, parts of the filament materials are easily separated from each other, and the parts are sent in a separated state. In some cases, the removal or absorption of the excess photosensitive coating does not proceed as desired, and even the required portion of the photosensitive coating is often dissolved and damaged.

On the other hand, in the peeling tape used in the present invention, the weft threads and the warp threads of the acrylic fiber are twill weave, in short,
It has a structure in which weft yarns are woven diagonally with respect to warp yarns. Therefore,
With this structure, tension is applied in the moving direction, that is, the length direction of the warp thread, and the weft thread pulled by the tension is a structure that is obliquely joined to the warp thread. Uniform tension is applied to the surface of the drum, and the expansion and contraction due to this tension are uniform, the contact of the peeling tape with the surface of the drum end is uniform, and only the excess photosensitive coating film can be reliably removed.

Further, the twill weave structure itself of the stripping tape is very good from the standpoint of retaining the solvent, and unlike the non-woven fabric and the film, the surface has moderate irregularities unique to the woven fabric and between the fiber filaments. The fine pores are formed. Therefore, at the time of contact with the drum, in addition to giving appropriate friction to the surface of the drum, the presence of fine pores enhances the retention of the solvent, absorbs the excess photosensitive coating film, and allows only the excess photosensitive coating film to be smoothly removed.

If the twill weave stripping tape is too thick, the amount of the solvent held becomes too large, and the excess solvent dissolves even the required photosensitive coating film. From this point, the thickness of the peeling tape does not exceed 1.5 mm and is preferably 1.0 m.
It is particularly preferable that the thickness is m or less. The reason for this is that if the thickness exceeds 1.5 mm, the amount of solvent retained becomes too large, and even the photosensitive coating film in the necessary portion is dissolved.

On the other hand, if the peeling tape is too thin, it will not be possible to retain enough solvent to dissolve the excess photosensitive coating film. In this sense, the peeling tape has a thickness of 0.5.
It is particularly preferable that the thickness is at least mm, preferably at least 0.8 mm.

Further, although the surface of the twill-woven stripping tape is appropriately formed with irregularities, it is not preferable that fuzz is generated. The fuzz adversely affects the end surface of the drum to be peeled off, and the surplus photosensitive coating cannot be accurately removed over a certain width, rather, a part of the required photosensitive coating is melted and the drum performance is deteriorated. For this reason, it is preferable that the surface of the twill-woven stripping tape is subjected to a fluffing treatment as necessary to suppress fluffing.

As the solvent to be impregnated, any solvent can be used as long as it can dissolve the excess photosensitive coating film. When the photosensitive coating film comprises an undercoat layer, a charge generating layer and a charge transfer layer, A solvent is used according to the type of paint in each layer.

[0030]

As described in detail above, the method of the present invention is
After forming a photosensitive coating by dipping the cylindrical drum,
A method for removing an excessive photosensitive coating film at the end portion of the drum surface, which comprises impregnating a release tape having a twill weave structure in which a warp yarn is woven with a weft yarn obliquely impregnated with a solvent. It is characterized in that the removal of the excessive photosensitive coating film is removed while the peeling tape is brought into contact with the end of the rotating cylindrical drum.

Therefore, according to the method of the present invention, of the photosensitive coating film formed on the surface of the cylindrical drum, the surplus photosensitive coating film remaining at the end can be removed reliably and effectively.

Claims (3)

[Claims] 1. When a cylindrical drum is dipped in a photosensitive coating liquid to form a photosensitive coating film, and when an excessive photosensitive coating film is removed at the end portion of the drum surface, the end portion of the drum surface is removed. In addition, it is made of acrylic fiber, and has a twill weave structure in which weft yarns are sewn diagonally to the warp yarns.
Removal of the excess photosensitive coating film on the surface of the cylindrical drum by moving the peeling tape while contacting the stripping tape impregnated with the solvent to remove the excess photosensitive coating film. Method. 2. The method for removing an excessive photosensitive coating film on the surface of a cylindrical drum according to claim 1, wherein the surface of the peeling tape is fluffed. 3. The thickness of the peeling tape is 0.5 mm to
The method for removing an excessive photosensitive coating film on the surface of a cylindrical drum according to claim 1 or 2, wherein the thickness is 1.5 mm.