JPH0425256Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The invention is applicable to, for example, applying a coating liquid containing a photosensitive substance to the outer peripheral surface of a cylindrical drum when manufacturing an electrophotographic photoreceptor drum. The present invention relates to an apparatus for forming a coating film and then removing the coating film from the end of the drum.

(Prior Art) For example, in a method of manufacturing an electrophotographic photoreceptor drum by applying a coating liquid containing a photosensitive substance to a cylindrical drum, there is a method of manufacturing an electrophotographic photoreceptor drum by applying a coating liquid containing a photosensitive substance to a cylindrical drum. A common immersion method is to form a uniform film thickness on the outer circumferential surface of the drum by immersing the drum in the coating liquid and moving the drum out of the coating liquid at a constant speed in the axial direction.

In an electrophotographic photosensitive drum, in order to fit a flange to the end of the drum or perform conductive treatment on the end of the drum, it is preferable that no coating liquid is applied to the end of the drum. However, in the above-described dipping method, the drum shaft is held substantially vertically and withdrawn from the coating liquid, so that the coating liquid is always applied to the lower end of the drum to form a coating film. For this reason, it is necessary to remove the coating film formed on the ends of the drum to which the coating liquid has been applied by the dipping method.

In order to solve such problems, for example, Japanese Patent Application Laid-Open No. 170858/1983 discloses a method in which the end of the drum is immersed in a solvent capable of dissolving the coating film formed on the outer peripheral surface of the drum. Additionally, a method is disclosed in which an unnecessary coating film is removed from the immersed end of the drum by rubbing a flexible plate on the end of the drum.

(Problems to be Solved by the Invention) In the method disclosed in JP-A-60-170858, there is a risk that the coating film components dissolved in the solvent will re-adhere to the end of the drum immersed in the solvent. be.
This requires removing coating components from the solvent and frequently replacing the solvent with uncontaminated one. In addition, when a flexible plate is rubbed against the end of the drum immersed in the solvent, the paint film components dissolved in the solvent are reattached to the drum by this plate, completely removing the paint film on the end of the drum. It is not easy to remove the paint film, and as a result, it takes a long time to completely remove the paint film.

The present invention is intended to solve the above-mentioned conventional problems, and its purpose is to provide a drum end paint film removal device that can quickly and reliably remove the paint film on the outer peripheral surface of the drum end. It's about doing. Another object of the present invention is to provide a coating film removal device for the end of a drum that prevents deterioration of drum characteristics.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a coating film removal device at the end of the drum, which includes a solvent tank containing a solvent capable of dissolving the coating film inside, and a solvent tank containing a solvent capable of dissolving the coating film. A mesh member is supported by the solvent tank via an elastic means so as to be exposed at a predetermined distance from the upper surface, and is immersed into the solvent against the elastic force of the elastic means as the drum is immersed. It was characterized by

(Function) The present invention enables the coating film to be formed on the drum end by repeatedly dipping and withdrawing the drum end with a coating film formed on the peripheral surface into a solvent tank containing a solvent capable of dissolving the coating film multiple times. This device is for removing the paint film that has been removed, and is equipped with a mesh member that can be moved up and down by elastic means at a position opposite to the bottom end of the drum in the solvent tank, and the drum is moved together with the mesh member. The coating film on the end of the drum can be effectively removed by immersing it in a solvent bath.

By dipping the end of the drum into the solvent, the coating formed on the end of the drum is dissolved. After this, when the drum is withdrawn, the solvent liquid flows in the direction of detaching the coating film, and when the bottom end of the drum leaves the solvent surface, drops fall onto the solvent from the end, and at that time, the solvent is dissolved. The paint film falls off along with the solvent droplets, causing the paint film to come off. As a result, when the drum is repeatedly immersed and withdrawn, the force of the solvent to remove the coating film is enhanced, and the coating film at the end of the drum is reliably removed. However, when the drum is lifted from the liquid surface during exit, there is a risk that drops of solvent that have fallen from the bottom end of the drum will bounce off the solvent surface and adhere to the photosensitive layer in areas other than the removed area of the drum, resulting in deterioration of drum characteristics. In this invention, in order to prevent this solvent from splashing, there is a
A mesh member that can be moved up and down by elastic means is provided. When the drum is immersed, the lower end of the drum comes into contact with this mesh member and presses the mesh member while penetrating into the solvent. The mesh member is movable up and down in the axial direction of the drum, and is immersed in the solvent together with the drum, so that the coating removal area at the end of the drum is immersed in the solvent. After a period of immersion, the drum is removed from the solvent. At this time, the mesh member moves upward due to elastic force as the drum moves, and when the drum is lifted from the liquid surface, the mesh member is also exposed from the liquid surface. When the drum is pulled up until the mesh returns to its original position, the drum and mesh separate. Once separated from the mesh member, solvent drops begin to fall from the bottom end of the drum. These solvent drops fall onto the mesh member and are dispersed by the mesh, so that they do not bounce back toward the drum. This does not adversely affect drum characteristics.

(Example) The present invention will be described below with reference to the production of an electrophotographic photosensitive drum.

FIG. 1 is a sectional view showing an example of the implementation state of the apparatus for removing a coating film on the end of a drum according to the present invention. The apparatus of the present invention is implemented, for example, to remove a coating film at the end of the drum 10, which has been coated with a coating liquid containing a photosensitive substance by a dipping method and a coating film is formed on the entire outer peripheral surface. In the figure, 20 is a solvent tank in which a solvent 21 capable of dissolving the coating film on the outer peripheral surface of the drum 10 is stored.

The solvent stored in the solvent tank 20 may be any solvent as long as it can dissolve the coating film containing the photosensitive substance formed on the outer peripheral surface of the drum 10, and for example, tetrahydrofuran (THF) is used. When a volatile solvent 21 such as THF is stored in the solvent tank 20, the solvent 21 stored in the solvent tank 20 is
1, the lid part 22 is placed at a predetermined distance from the top surface.
will be placed. A through hole 22a through which the drum 10 can be inserted is formed in the center of the lid 22. A mesh member 30 is disposed within the solvent tank 20 so as to face the lower end of the drum. This state is shown in FIG. The mesh member 30 is made of metal mesh or the like, has a substantially square shape, and has four corners fixed to the four corners of the solvent tank via elastic means 31, 31, 31, 31 such as springs.

The device of the present invention is implemented as follows. For example, the drum 10 on which a coating film has been formed on the outer peripheral surface except for the upper end by a dipping method is held approximately vertically, and the lower end is inserted into the solvent 21 through the through hole 22a of the lid part 22. immerse through. In this case, the drum 10 is immersed in the solvent 21 by a predetermined length in the axial direction of the lower end where the coating film needs to be removed. After soaking in this state for a predetermined time, drum 1
0 from the solvent 21. After the drum 10 is removed, it is dipped into the solvent 21 again after a period of about 0.5 to 5 seconds. By repeating this process of dipping and withdrawing the drum 10 a plurality of times, the coating film on the end of the drum is removed.

By immersing the end of the drum 10 in the solvent 21, the photosensitive layer formed on the end is dissolved. When the drum 10 is then removed, a liquid flow occurs near the drum 10 and on the surface of the solvent as shown in FIG. 3a. Therefore, when the drum 10 is withdrawn from the liquid surface, the dissolved photosensitive layer is detached from the surface of the drum 10. Further, when the drum 10 is lifted from the solvent surface, drops of solvent fall from the bottom end of the drum. At this time, as shown in FIG. 3b, the photosensitive layer falls off along with the dissolved coating film of the photosensitive layer, so that the photosensitive layer is detached from the end of the drum. By repeating this process of dipping and withdrawing the drum, the photosensitive layer at the end is completely detached.
It is preferable to perform this drum dipping and withdrawal process 15 to 30 times (optimally 20 times). If it is less than 15 times,
The photosensitive layer at the end of the drum is not sufficiently desorbed.
If the number of cycles exceeds 30, solvent vapor will seep into the photosensitive layer of the drum other than the area where the photosensitive layer is removed, resulting in poor drum characteristics.

In the present invention, the drum 10 is placed in the solvent tank 21.
A major feature is that a mesh member is provided opposite the lower end. The function of this mesh member 30 in the present invention will be explained below. First, when the drum 10 is moved downward to be immersed in the solvent bath 20, the lower end of the drum 10 and the mesh member 30 come into contact. If the drum 10 continues to move in this state,
The mesh member moves downward while stretching the elastic means 31, and the lower end of the drum 10 enters the solvent 21 as shown in FIG.
It also immerses below the liquid surface. As a result, the photosensitive layer removed area at the end of the drum 10 is immersed in the solvent 21, and the photosensitive layer is dissolved. In order to remove the drum 10 from the solvent 21 after a certain period of time has elapsed, the drum 10
pull upwards. Along with this, the mesh member 3
0 moves upward due to the elastic force of the elastic means 31,
When the mesh member 30 returns to its original position, the drum 10 and the mesh member 30 are separated. When the drum 10 separates from the mesh member 30, the solvent drops holding the molten photosensitive layer begin to fall from the lower end of the drum 10. Since the solvent drops fall onto the mesh member 30, they are dispersed by the mesh and do not bounce back toward the drum, thereby preventing deterioration of the drum characteristics.

The mesh members used in this invention are made of metals, resins, fibers, etc. that do not dissolve, deform, or corrode with solvents, and those with a mesh size of 100 to 400 mesh are preferably used. be done. If it is less than 100 meshes, the solvent will not be able to pass through it enough, and if it is more than 400 meshes, the meshes will become too large and the solvent diffusion effect will be weakened, which may cause the solvent to splash.

In the embodiment described above, the four corners of the square mesh member were fixed to the four corners of the solvent tank 20 via elastic means, but a structure as shown in FIG. 5 may also be used. In this configuration, a bottom plate 35 is provided on the lower surface of the mesh member via a plurality of supports 32, and a cylindrical member 36 protrudes downward from the bottom plate 35 and a column 37 fixedly disposed on the bottom surface of the solvent tank 20. Make it engage. By tensioning a spring member 38 between the support column 37 and the bottom plate 35, the mesh member 30 can be moved up and down. As a result, the mesh member along with the drum is immersed in the solvent and exposed.

It is desirable that the drum be immersed for 0.4 to 2 seconds each time. If the immersion time is 0.4 seconds or less, the solvent will not sufficiently penetrate into the photosensitive layer, and the photosensitive layer will not be completely detached. If the immersion time is 4 seconds or more, the solvent vapor will penetrate into the photosensitive layer other than the desorption area, and the processing efficiency will decrease.

In this invention, since the flow of the solvent when the drum is withdrawn and the solvent drop when the drum is lifted from the solvent tank are involved in the detachment of the photosensitive layer, the immersion/exit process takes about 15 to 30 minutes regardless of the immersion time. 30 times is preferred.

When immersing and leaving the drum in a solvent tank, the drum 10 may be moved up and down into a fixed solvent tank to perform the immersion and exit, or the drum 10 may be fixed and the solvent tank can be moved up and down.

(Effects of the invention) According to the invention, when removing the paint film on the end of the drum, it is possible to completely remove the paint film on the end of the drum by simply repeating immersion and withdrawal of the drum into and out of the solvent layer several times. It is. Thereby, there is no need to use special means or mechanisms in the device, and it can be performed with a simple configuration. Further, since deterioration of drum characteristics due to splashing of solvent drops can be effectively prevented, photosensitive drums of excellent quality can always be manufactured. Furthermore, since the solvent flows in the direction of removing the coating film when the drum exits, the removed coating film is prevented from adhering to the drum again.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of the implementation state of the present invention, FIG. 2 is an enlarged perspective view of main parts, FIGS. 3 and 4 are diagrams explaining the principle of the present invention, and FIG. The figure is a sectional view showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 10...Drum, 20...Solvent tank, 21...Solvent, 22...Lid part, 30...Mesh member, 31...
...elastic means.

Claims (1)

[Claims for Utility Model Registration] A device for removing a coating film from the end of a drum 10 having a coating film formed on its circumferential surface, comprising a solvent tank 20 containing therein a solvent 21 capable of dissolving the coating film. It is supported by the solvent tank 20 via an elastic means 31 so as to be exposed at a predetermined distance from the upper surface of the solvent 21, and as the drum 10 is immersed, the solvent 21 is pushed against the elastic force of the elastic means 31. A coating film removal device for an end of a drum, comprising: a mesh member 30 immersed in the drum end.