JP2008310283A - Coating film removing method for electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of removing an extra coating film in a lower end part of a cylindrical body formed with the coating film on a surface by a dip coating method. <P>SOLUTION: A coating film removing member 47a provided with an opening part in its central part is provided to allow the lower end part of the cylindrical body 51 to be inserted into the opening part, a coating film removing liquid supply member 46 arranged with a coating film removing member 47b in its lower side, and provided with a coating film removing liquid discharge hole 48 for discharging upwards a coating film removing liquid in the uppermost part, to be inserted into the lower end part of the cylindrical body 51, and the extra coating film in the end part of the cylindrical body is removed by discharging the coating film removing liquid from the coating film removing liquid discharge hole 48 to rotate the cylindrical body 51 relatively with respect to the coating film removing members 47a, 47b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing an organic electrophotographic photosensitive member used in an image forming apparatus such as a copying machine, a printer, and a facsimile, and an organic electrophotographic photosensitive member produced by the production method, an electrophotographic apparatus, and a process for an electrophotographic apparatus. More specifically, the present invention relates to an improved manufacturing method for removing unnecessary portions at the edge of a substrate in a photosensitive layer formed on a cylindrical conductive substrate by a dip coating method.

Conventionally, a dip coating method has been adopted as a method for forming a photosensitive layer on a conductive substrate.
In the dip coating method, unnecessary portions at the edge of the substrate are removed from the photosensitive layer formed on the cylindrical conductive substrate.
Therefore, a method for removing unnecessary portions at the edge of the substrate in the conventional dip coating method will be described with reference to the drawings.

A cross-sectional view of an example of an apparatus used for dip coating is shown in FIG.
In FIG. 1, a dip coating apparatus 1 includes a coating tank 11 containing a coating solution 12 therein, a holding jig 14 that holds a substrate to be coated 13, a motor 15 that moves the holding jig 14 up and down, and a motor. When the substrate 15 is driven and the substrate to be coated 13 is lowered, the coating liquid 12 overflowing from the coating tank 11 is temporarily stored through the pipe 16, and the coating liquid 12 is rotated in the circulation tank 17 by the rotation of the motor 18. The agitation means for agitation by the rotating blade 19 and the circulation pump 21 for sending the coating solution 20 in the circulation tank 17 to the application tank 11 are configured. The dip coating apparatus 1 is generally provided with a filter for removing foreign substances in the coating liquid and a viscosity adjusting apparatus for adjusting the viscosity of the coating liquid, but is omitted in FIG.

In the above-described dip coating method, the entire substrate to be coated 13 is immersed in the coating liquid 12, so that the coating liquid is always applied to the lower end portion of the substrate to form a coating film having a non-uniform film thickness. In addition, a part of the coating solution also enters the inside of the substrate, and an unnecessary coating film is formed. FIG. 2 is a cross-sectional view of the main part showing the lower end portion of the photosensitive drum after coating. Excess coating films (photosensitive layers) 30a, 30b, 30c are formed on the lower end portion of the substrate 13 to be coated.
The extra coating film (30c) at the lower end may adhere to the pallet of the conveying line and stain the pallet. Further, unnecessary coating films (30b, 30c) on the inner side and the lower end surface of the base body cannot be inserted when the flange for driving the drum is fitted. This will cause problems in adhesive strength.

It is desirable that both ends of the electrophotographic photosensitive member have no photosensitive layer in order to energize or to connect various parts.
The extra coating film (30a) at the lower end is thicker than a predetermined film thickness. For example, when the photosensitive layer is heated and dried as it is, bubbles are generated by a large amount of solvent confined in the coating film, resulting in poor image quality. cause. Furthermore, since the film thickness of the photosensitive layer is not uniform, the edge of the cleaning blade for cleaning the toner on the unnecessary photosensitive layer after development and transfer does not contact the photosensitive layer with high accuracy, and the cleaning is poor. Toner dropping, filming, and film loss may occur. In general, rollers for positioning with the drum called DSD color are provided at both ends of the developing tank, which stabilizes the development by accurately contacting the both ends of the drum. In addition, since the portion where the color ring abuts is rubbed, there is a problem that when the coating film is present, it is peeled off unevenly or worn. Therefore, it is preferable that no coating film is formed on that portion.

For the above reason, it is necessary to completely remove the surplus coating film 30a with a predetermined wiping width as shown in FIG. Further, it is necessary to prevent the substrate from being damaged when removing the excessive coating film.
In addition, in order to improve image quality, there are cases where various abutting members are brought into contact with the end surface of the substrate to give accuracy, but in that case, the accuracy is significantly reduced due to the presence of the coating film on the end of the substrate. End up.

Various proposals have been made to solve the above problems.
Patent Document 1 has an outer peripheral surface and a lower surface formed in a tapered shape so that the diameter gradually increases from the upper side to the lower side. The outer peripheral surface facilitates insertion of the photosensitive drum, and is discharged by the lower surface. A coating film removing liquid supply member is also disclosed that can guide the coating film removing liquid to the coating film removing member.
However, at the time of dip coating, a film of the coating liquid is generated at the lower end of the substrate. However, in the method described in Patent Document 1, the film is deposited on the uppermost part of the coating film removing liquid supply member and the newly supplied coating film is removed. There is a problem that the liquid is contaminated, wiping of the excessive coating film inside the substrate becomes insufficient, and the uniformity of the wiping width of the excessive coating film outside the substrate is also lowered. Furthermore, in this method, the coating film removing liquid tends to flow unevenly, and it is difficult to supply the coating film removing liquid uniformly to the entire coating film removing member.
Therefore, there is a problem that the wiping of the excessive coating film inside the substrate becomes insufficient, and the uniformity of the wiping width of the excessive coating film outside the substrate is also lowered.
There is also a problem that a large amount of coating film removing liquid is required to completely wipe off the excess coating film on the inside of the substrate and improve the uniformity of the wiping width of the excess coating film on the outside of the substrate.

Patent Document 2 discloses a method in which a liquid supply hole for supplying a coating film removing liquid supplied from a liquid supply mechanism to an inner surface coating film removing member is provided in the inner surface coating film removing member presser.
However, at the time of dip coating, a film of the coating liquid is generated at the lower end of the substrate. However, in the method described in Patent Document 2, the film is deposited on the uppermost part of the coating film removing liquid supply member, and the newly supplied coating film is removed. There is a problem that the liquid is contaminated, wiping of the excessive coating film inside the substrate becomes insufficient, and the uniformity of the wiping width of the excessive coating film outside the substrate is also lowered. Further, in this method, since the coating film removing liquid is supplied from one direction of the coating film removing member, it is difficult to uniformly supply the coating film removing liquid to the entire surface of the coating film removing member.
Therefore, there is a problem that the wiping of the excessive coating film inside the substrate becomes insufficient, and the uniformity of the wiping width of the excessive coating film outside the substrate is also lowered.
There is also a problem that a large amount of coating film removing liquid is required to completely wipe off the excess coating film on the inside of the substrate and improve the uniformity of the wiping width of the excess coating film on the outside of the substrate.

Patent Document 3 discloses a method of injecting a coating film removing part liquid from the lower surface of a coating film removing member.
However, at the time of dip coating, a film of the coating solution is generated at the lower end of the substrate. However, in the method described in Patent Document 3, the film is deposited on the uppermost portion of the coating film removing member, and the newly supplied coating film removing solution is There is a problem in that the excess coating film on the inner side of the substrate is contaminated and the wiping width of the excessive coating film on the outer side of the substrate is reduced. Further, in this method, since the coating film removing liquid is supplied from the lower surface of the coating film removing member, it is difficult to uniformly supply the coating film removing liquid to the entire surface of the coating film removing member.
Therefore, there is a problem that the wiping of the excessive coating film inside the substrate becomes insufficient, and the uniformity of the wiping width of the excessive coating film outside the substrate is also lowered.
There is also a problem that a large amount of coating film removing liquid is required to completely wipe off the excess coating film on the inside of the substrate and improve the uniformity of the wiping width of the excess coating film on the outside of the substrate.

Patent Document 4 discloses a method of discharging a coating film removing liquid horizontally from above a coating film removing liquid supply member.
However, at the time of dip coating, a film of the coating liquid is generated at the lower end of the substrate. However, in the method described in Patent Document 4, the film is deposited on the uppermost part of the coating film removing liquid supply member, and the newly supplied coating film There is a problem that the removal liquid is contaminated, the wiping of the excess coating film inside the substrate becomes insufficient, and the uniformity of the wiping width of the excess coating film outside the substrate is also lowered. Furthermore, in this method, the coating film removing liquid tends to flow unevenly, and it is difficult to uniformly supply the coating film removing liquid to the entire coating film removing member.
Therefore, there is a problem that the wiping of the excessive coating film inside the substrate becomes insufficient, and the uniformity of the wiping width of the excessive coating film outside the substrate is also lowered.
There is also a problem that a large amount of coating film removing liquid is required to completely wipe off the excess coating film on the inside of the substrate and improve the uniformity of the wiping width of the excess coating film on the outside of the substrate.

Further, as a method for removing the coating film of the photosensitive layer formed on the lower end portion of the photosensitive drum, a blade (Patent Document 5), a brush (Patent Document 6), a porous material (Patent Documents 1 to 3, Patent Documents 7 to 7). 12) and a method of removing the coating film using a coating film removing liquid, a method of removing the coating film with a laser beam (Patent Document 13), and the like have been proposed.
However, the surplus coating film formed on the lower end portion of the photosensitive drum has a non-uniform film thickness, and its adhesion becomes non-uniform when it is removed by contact with a blade or a brush. As a result, depending on the film thickness of the surplus coating film, there is a problem that a part that is insufficiently removed occurs or a part that is excessively removed and damages the substrate.
Similarly, in the case of removing with laser light, there is a problem that a part that is insufficiently removed occurs due to the film thickness of the surplus coating film, or a part that damages the substrate due to excessive removal occurs. .

  On the other hand, Patent Documents 1 to 3 and Patent Documents 7 to 12 disclose a method of removing a porous material by contacting it, and due to the flexibility of the porous material, the adhesiveness to the surplus coating film is high and It is disclosed that the degree of cleaning is good because it absorbs the solvent without fear of damaging the substrate.

Patent Documents 1 to 3 disclose a method of removing a surplus coating film by pressing a planar porous member against a lower end surface of a substrate.
However, this method has a problem that the wiping width (FIG. 13) is 1 mm or less, and the excess coating film cannot be wiped with a predetermined wiping width. Further, since the corners of the end face of the substrate are repeatedly rubbed, there is also a problem that the coating film removing member is liable to crack and the durability of the coating film removing member is low.

According to Patent Document 7, the sponge is exposed from the treatment tank except during the edge treatment, and the base is lowered and the lower end of the base is pressed against the base support to be stored in the upper dish-shaped treatment tank and swelled by being immersed in the solvent. In addition, a method for removing a coating film in close contact with a substrate is disclosed.
However, in this method, the sponge is held by the spring, and the wiping position is not stable, so that there is a problem that the uniformity of the wiping width is inferior.
Furthermore, since the coating film removing member is twisted and greatly deformed during wiping, there is a problem that the uniformity of the wiping width is low.
Therefore, this method has a problem that finishing wiping is required. There is also a problem that when the deformation returns, the coating film removing liquid adheres to the coating film and causes a coating film defect.
And since a deformation | transformation is repeated, there also exists a problem that durability of a coating-film removal member is low.
In this method, since the sponge is held by the spring, it is not easy to replace the coating film removing member.

Patent Documents 9 to 11 disclose a method of pressing and wiping a plurality of porous members. However, even with this method, there is a problem in that the uniformity of the wiping width is low because the coating film removing member is twisted and greatly deformed at the time of wiping, and in addition to the problem that finishing wiping is necessary, the deformation returns. There is also a problem that the coating film removing liquid sometimes adheres to the coating film and becomes a coating film defect.
And since a deformation | transformation is repeated, there exists a problem that durability of a coating-film removal member is low.
Further, in this method, since the uniformity of the wiping width is inferior unless the attachment position of the coating film removing member is precisely set, it is not easy to replace the coating film removing member.

Patent Document 12 discloses a method of removing a coating film using a porous member having a plurality of concentric cuts with different diameters.
However, with this method, it is difficult to set the cut by predicting the shape change when the porous member contains the coating film removing liquid. There is a problem that the dimensional accuracy is lowered. As a result, the adhesion between the substrate and the coating film removing member at the time of removing the coating film is insufficient or excessive, and in some cases, the problem that the substrate does not fit into the cut occurs, and the uniformity of the wiping width is There is a problem of being inferior.
Furthermore, since the coating film removing member is twisted and greatly deformed during wiping, there is a problem that the uniformity of the wiping width is low.
Therefore, in this method, there is a problem that finishing wiping is necessary, and there is also a problem that when the deformation returns, the coating film removing liquid adheres to the coating film and becomes a coating film defect.
And since a deformation | transformation is repeated, there also exists a problem that durability of a coating-film removal member is low.
Further, in this method, if the attachment position of the coating film removing member is not set precisely, there arises a problem that the base body is not inserted into the cut, so that it is not easy to replace the coating film removing member.

In Patent Document 8, the upper part of the edge coating film removing member is exposed from the liquid surface of the solvent tank when the coating film is removed from the edge of the cylindrical substrate, and the lower edge of the cylindrical substrate is removed from the edge coating film. A method is disclosed in which the cylindrical substrate does not immerse in the solvent bath even if it contacts the member.
However, in this method, since the coating film removing member is pressed from one direction, the vertical axis of the substrate is easily displaced during wiping, and in addition, there is a problem that the uniformity of the wiping width is inferior. There is a problem that the uniformity of the wiping width is low because the coating film removing member is sometimes twisted and greatly deformed.
Therefore, this method has a problem that it is necessary to wipe off the finish, and there is also a problem that when the deformation returns, the coating film removing liquid adheres to the coating film and becomes a coating film defect.
And since a deformation | transformation is repeated, there also exists a problem that durability of a coating-film removal member is low.
Further, in this method, since the uniformity of the wiping width is inferior unless the attachment position of the coating film removing member is precisely set, it is not easy to replace the coating film removing member.

JP-A-2005-221918 JP 2002-346449 A JP 2006-068602 A Japanese Utility Model Publication No. 02-071850 JP 2001-281888 A Japanese Patent No. 3845465 JP 2000-275870 A JP 2002-287385 A JP 2000-305292 A JP 2006-231202 A JP 2002-278104 A JP 2001-157864 A Japanese Unexamined Patent Publication No. 2000-93887

In recent years, the performance of electrophotographic apparatuses has been remarkably improved. For example, electrophotographic apparatuses capable of full-color output and high-resolution electrophotographic apparatuses having a resolution of 1200 dpi or higher have been put on the market.
The electrophotographic photosensitive member used in these electrophotographic apparatuses is required to have a high dimensional accuracy, and for example, a total shake amount of 30 μm or less is required.

An electrophotographic photoreceptor is generally produced by forming an electrophotographic photoreceptor layer on a conductive substrate and attaching flanges to both ends thereof. In the electrophotographic apparatus, the cylindrical electrophotographic photosensitive member is held by the central axis of the flange and rotates.
Here, if the flange is not attached to the cylindrical electrophotographic photosensitive member at an accurate position, there is a problem that shake is increased when the electrophotographic photosensitive member is held by the flange and rotated.
One of the causes of a decrease in the flange mounting accuracy on the cylindrical electrophotographic photosensitive member is insufficient removal of the coating film at the lower end of the coating after dip coating. In other words, if an excess coating film remains at the lower end of the coating, the poorly removed coating film is sandwiched between the electrophotographic photosensitive member and the flange, and the flange is attached obliquely or the flange is displaced. Problem occurs.

As described in the background section above, the conventional coating film removing liquid supply method has the following technical problems.
(1) During dip coating, the coating liquid film generated at the lower end of the substrate is deposited on the upper part of the coating film removal liquid supply member and the coating film removal member, and the newly supplied coating film removal liquid is contaminated, and Wiping of the surplus coating film becomes insufficient, and the uniformity of the wiping width of the surplus coating film on the outside of the substrate also decreases.
(2) When removing the coating film, the coating film removing liquid tends to flow unevenly, and it is difficult to supply the coating film removing liquid uniformly in the circumferential direction of the coating film removing member. The removal becomes insufficient, and the uniformity of the wiping width of the excess coating film on the outside of the substrate is also lowered.
(3) In order to completely wipe off the excess coating film on the inner side of the substrate and improve the uniformity of the wiping width of the excess coating film on the outer side of the substrate, a large amount of coating film removing liquid is required.
(4) The coating film removing member cannot be uniformly brought into contact with the entire outer peripheral surface of the end portion of the substrate, and the wiping width uniformity is low.
(5) The substrate cannot be held vertically when wiping off the excess coating film, and the uniformity of the wiping width is poor.
(6) Since the coating film removing member is twisted and greatly deformed when the excess coating film is wiped off, the uniformity of the wiping width is low.
(7) When the uniformity of the wiping width is inferior, an extra step of finishing wiping is required.
(8) When wiping off the surplus coating film, the coating film removing member is twisted and deformed, and when this deformation returns, the coating film removing liquid is disturbed, and the disturbed liquid adheres to the coating film and becomes a coating film defect. .
(9) Since the deformation of the coating film removing member is repeated, the durability of the coating film removing member is lowered.
(10) Replacement of the coating film removing member is not easy.

  In view of the above problems, the first problem of the present invention is to remove the excess coating film at the lower end of the coating after dip coating in order to produce an electrophotographic photosensitive member with high total shake accuracy, Contamination of the coating film removal liquid due to the deposition of the coating liquid film generated at the lower end is prevented, and the coating film removal liquid is supplied uniformly to the entire coating film removal member. The object is to provide a method of completely wiping and improving the uniformity of the wiping width of the excess coating film outside the substrate.

Further, the second problem of the present invention is that, in the recent electrophotographic process, when the roll charging method is used instead of the conventional corotron or scorotron, the gap between the electrophotographic photosensitive member and the charging roll. In order to maintain high accuracy, it is necessary to completely remove the coating film on the outer peripheral surfaces of both ends of the photoconductor. This is possible.
Therefore, since the uniformity of the wiping width is high, there is no need for wiping of the finish, there is no coating film defect, the durability of the coating film removing member is provided, and a method for easily replacing the coating film removing member is provided. is there.

The present invention for solving the above-mentioned problems is as follows.
(1) In the coating film removing method of removing the excess coating film on the lower end portion of the cylindrical substrate on which the coating film is formed on the surface by the dip coating method, by contacting the end coating film removing member,
A coating film removing member a having an opening at the center is provided in the opening so that the lower end of the cylindrical substrate can be inserted, and
The coating film removing member b is disposed below, and a coating film removing liquid supply member provided with a coating film removing liquid discharge hole so that the coating film removing liquid is discharged upward is inserted into the lower end of the cylindrical substrate. The excess coating film on the end of the cylindrical substrate is formed by allowing the coating film removing liquid to be discharged from the coating film removing liquid discharge hole and rotating the cylindrical substrate and the coating film removing members a and b relatively. A method for removing a coating film comprising removing the coating film.
(2) The method for removing a coating film according to the above (1), wherein the coating film removing liquid is guided to the groove and supplied to the coating film removing member.
(3) A container that can be supplied with a coating film removing liquid from the outside, and a part or all of the upper surface is open and rotatable in the horizontal direction, and a through hole is formed in the upper surface in the container. Alternatively, a flexible porous member having a non-through hole is fitted, and the lower end of the dip-coated cylinder is rotated while the center of the hole provided in the flexible porous member is rotated as a rotation axis. The method for removing a coating film according to the above (1) or (2), wherein the excess coating film at the lower end is removed by inserting it into the hole of the flexible porous member.
(4) The method of removing a coating film according to (3) above, wherein the cross-sectional area of the upper outer shape of the coating film removing member is 105% or more and 120% or less of the cross-sectional area of the outer shape of the container upper part.
(5) The method for removing a coating film according to any one of the above (1) to (4), wherein a presser is provided on the upper part of the coating film removing member a, and the presser is inside the container. .
(6) The coating film removing method according to any one of (1) to (5) above, wherein the 25% hardness of the coating film removing member is 90N or more and 150N or less.
(7) The method for removing a coating film according to any one of the above (1) to (6), wherein the relative rotation number of the coating film removing member and the substrate is 20 rpm or more and 50 rpm or less.
Hereinafter, the above (1) to (7) are referred to as “aspects (1) to (7) of the invention”.

[Aspect (1) of the invention]
According to this aspect (1), the coating film removing member b is disposed below, and the coating film removing liquid is discharged upward from the uppermost part of the coating film removing liquid supply member provided with the coating film removing liquid discharge hole on the uppermost part. Therefore, even if the coating liquid film at the lower end of the substrate generated during the dip coating adheres, it can be completely washed away, and the newly supplied coating film removing liquid is not contaminated.
Therefore, the excess coating film on the inside of the substrate is completely wiped off, and the difference between the maximum value and the minimum value of the wiping width of the excess coating film on the outside of the substrate can be reduced to 1 mm or less, and the wiping for finishing is not necessary.
Further, there is an effect that the total runout of the photoconductor after inserting the flange becomes 30 μm or less.

[Aspect (2) of the invention]
According to this aspect (2), in addition to the effect of aspect (2) of the invention, the coating film removing liquid is guided to the groove and supplied to the coating film removing member, so that it is uniform over the entire surface of the coating film removing member. There is an effect that the coating film removing liquid can be supplied.

[Aspect (3) of the invention]
According to this aspect (3), in addition to the above-described effects, the coating film removing member is fitted to the container, so that the entire outer peripheral surface of the substrate end can be brought into contact with the substrate and the coating film can be removed. Since the frictional force of the member is uniform over the entire outer peripheral surface, there is an effect that deformation of the coating film removing member during wiping is reduced.
In addition, since the return of deformation is reduced, the coating film removal liquid is less spilled and scattered, so that no coating film defects occur.
Further, since the deformation is small, there is an effect that the durability of the coating film removing member is also improved.
And since the coating film removing member is fitted, even if it is not particularly adjusted, if it is installed in the container, it can be set at a position where it can uniformly contact the entire outer peripheral surface of the base end, so the coating film removing member can be replaced. It becomes easy.

[Aspect (4) of the invention]
According to this aspect (4), in addition to the above effects, the cross-sectional area of the upper outer shape of the coating film removing member is 105% or more and 120% or less of the cross-sectional area of the container upper outer shape. Adhesion of the substrate becomes appropriate, and the coating film removing member can be brought into uniform contact with the entire outer peripheral surface of the substrate end, and a uniform force is applied to the entire outer peripheral surface of the substrate end, so that the substrate can be held vertically. In addition, since the deformation of the coating film removing member at the time of wiping is reduced and the return of the deformation is also reduced, the coating film removing liquid is less drooled and scattered, so that no coating film defects occur. Further, since the deformation is small, there is an effect that the durability of the coating film removing member is also improved.

[Aspect (5) of the invention]
According to the present aspect (5), in addition to the above effects, the coating film removing member 47a is prevented from being lifted by the pressing, and the coating film removing member is uniformly distributed over the entire outer peripheral surface of the substrate end. It can be contacted, and the deformation of the coating film removing member at the time of wiping is also reduced, and the return of deformation is also reduced. Further, since the deformation is small, there is an effect that the durability of the coating film removing member is also improved.

[Aspect (6) of the invention]
According to this aspect (6), in addition to the above effects, the 25% hardness of the coating film removing member is 90N or more and 150N or less, so that the deformation of the coating film removing member during wiping is small, Since the return also becomes small, the coating film removing liquid is less spilled and scattered, and no coating film defects occur. Further, since the deformation is small, there is an effect that the durability of the coating film removing member is also improved.

[Aspect (7) of the invention]
According to this aspect (7), since the relative rotation speed of a coating-film removal member and a base | substrate is 20 rpm or more and 50 rpm or less, there exists an effect that an excess coating film can be removed efficiently.

The block diagram of an example of the suitable coating-film removal apparatus for enforcing the coating-film removal method of this invention is shown in FIG. 3, FIG.
The coating film removing apparatus 2 includes a liquid recovery tank 41, a container 42 provided in the liquid recovery tank 41, a rotation motor 43 that rotates the container 42, and a pulley and a belt that transmit the rotation of the rotation motor 43 to the container 42. And the like. The lower end of the liquid recovery tank 41 is connected to the liquid recovery tank 45. The liquid recovery after removing the coating film may be performed by overflow.
The container 42 includes an outer coating film removing member 47a and a coating film removing liquid supply member 46 having an inner coating film removing member 47b disposed below. A coating film removing liquid supply passage is formed through the coating film removing liquid supply member 46 from the bottom to the top, and has a coating film removing liquid discharge hole 48 at the top.
The coating film removing member 47a may or may not be fixed to the container 42.
Further, as shown in FIG. 23, it is desirable to provide a presser 54 on the upper part of the coating film removing member 47a.
The paint film removing liquid tank 50 is connected to the paint film removing liquid discharge hole 48 of the paint film removing liquid supply member 46 via the paint film removing liquid supply pump 49. It is provided to discharge the liquid upward.
The substrate lifting device after coating is omitted in the figure.

Examples of other apparatuses are shown in FIGS. In the apparatus shown in FIGS. 4 and 24, the coating film removing liquid is supplied not only from the discharge hole 48a but also from the discharge hole 48b. The inner coating film removing member 47b may be installed at the same height as the outer coating film removing member 47a. The liquid recovery after removing the coating film can be discharged from a discharge hole provided in the lower part of the container to the liquid recovery tank 41 and recovered in the liquid recovery tank.
FIG. 5 a is a perspective view of the outer coating film removing member 47 a installed in the container 42 of the coating film removing apparatus 2. The cavity inside the coating film removing member has a circular shape similar to the shape of the substrate, and the coating film removing member is fitted into the container 42.
FIG. 5b is another perspective view of the outer coating film removing member 47a. Further, the shape of the container 42 is not limited to these two examples.

  FIG. 6 is a diagram showing a state when the coating film inside the substrate is being removed. The substrate 51 after application is inserted from above. The base 51 may be inserted by lowering the base 51 from above or by inserting the coating film removing apparatus 2 from below. The rotation may be started before the substrate is inserted, or may be started after the substrate is inserted. And the coating-film removal member 47 rotates and an excess coating film is removed. The rotation may be started before the substrate is inserted, or may be started after the substrate is inserted. The coating film removing liquid is supplied from the coating film removing liquid discharge hole 48 to the inner coating film removing member 47b. The supply of the coating film removing liquid may be started before the substrate is inserted, or may be started after the substrate is inserted.

FIG. 7 is a view showing a state when the coating film on the outside of the substrate is removed. The base 51 may be inserted by lowering the base 51 from the top or by inserting the coating film removing apparatus 2 from the bottom. The rotation may be started before the substrate is inserted, or may be started after the substrate is inserted. And the coating-film removal member 47 rotates and an excess coating film is removed. The rotation may be started before the substrate is inserted, or may be started after the substrate is inserted. The coating film removing liquid is supplied from the coating film removing liquid discharge hole 48 to the outer coating film removing member 47a. The supply of the coating film removing liquid may be started before the substrate is inserted, or may be started after the substrate is inserted.
After removing the coating film, the substrate 51 is pulled up, and the removal operation ends. The rotation of the coating film removing member 47 may be stopped before the substrate is pulled up, or may be stopped after the substrate is pulled up.
The supply of the coating film removing liquid may be stopped after the substrate is pulled up, or may be stopped before the substrate is pulled up. Moreover, you may stop during coating film removal.
The coating film removing liquid overflows from the upper part of the container 42 and is discharged. However, as shown in FIG.
If necessary, after the substrate is pulled up, a coating film removing solution is supplied to clean the coating film removing members 47a and 47b.

Each aspect of the present invention will be described in detail with reference to the drawings.
<Aspect (1) of the invention>
This aspect is characterized in that the coating film removing liquid is discharged upward from the uppermost part of the coating film removing liquid supply member.
FIG. 8 is a view showing a state where the coating liquid film at the lower end portion of the substrate, which is generated at the time of coating, adheres, and the coating liquid film 52 adheres to the coating film removing liquid supply member 46.
The coating film removing liquid is discharged upward from the uppermost part of the coating film removing liquid supply member, so that the coating liquid film 52 attached to the lower end of the substrate during dip coating is completely washed out without being deposited, Since the new coating film removing solution is supplied to the coating film removing member, the excess coating film inside the substrate can be completely removed, and the newly supplied coating film removing solution is not contaminated.
Thereby, the excessive coating film inside a base | substrate is wiped off completely, and the uniformity of the wiping width of the excessive coating film outside a base | substrate is also improved.

  If the coating film removal liquid is not discharged upward from the top, the coating liquid film generated at the bottom of the dip coating is deposited on the coating film removal liquid supply member or the coating film removal member and newly supplied. The coating film removing solution is contaminated, the wiping of the excessive coating film inside the substrate becomes insufficient, and the uniformity of the wiping width of the excessive coating film outside the substrate is also lowered.

<Aspect (2) of the invention>
This aspect is characterized in that the coating film removing liquid is guided to the groove and supplied to the coating film removing member, and in this aspect, in addition to the effect exhibited in the aspect (1) of the invention, it will be described later. The effect which does.
The coating film removing liquid supply method of this aspect 2 will be described in detail with reference to FIG.
The coating film removing member 47b is preferably located below the coating film removing liquid discharge port, whereby the deposition of the coating liquid film at the lower end portion of the substrate generated during dip coating can be prevented.
As a result, the newly supplied coating film removing liquid is not contaminated, and the excess coating film inside the substrate is completely wiped off, and the uniformity of the wiping width of the excess coating film outside the substrate is improved.
Since the coating film removing member is below the coating film removing liquid supply member 46, the contact between the substrate and the coating film removing member becomes smooth, and the durability of the coating film removing member is improved. The coating film removing member 47b is more preferably located on the lower side of the coating film removing liquid supply member 46 having a tapered surface that gradually increases in diameter as it goes down. Since the coating film removing liquid supply member 46 has a tapered surface that gradually increases in diameter as it goes down, the substrate is smoothly guided to the coating film removing member.

And a coating-film removal liquid can be uniformly supplied to the whole coating-film removal member surface by providing a groove | channel in the said coating-film removal liquid supply member 46. FIG. As shown in FIG. 10, the groove is preferably provided on the radiation from the discharge hole 48 toward the lower surface of the tapered surface, and the number is preferably 4 to 8.
Thereby, the excessive coating film inside a base | substrate is wiped off completely with a small amount of coating-film removal liquid, and the uniformity of the wiping width of the excessive coating film outside a base | substrate is also improved.

<Aspect (3) of the invention>
In this embodiment, the coating film removing liquid can be supplied from the outside, and a part or the whole of the upper part is open, and the container can be rotated in the horizontal direction, and a through hole is provided in the upper part of the container. Alternatively, a flexible porous member having a non-through hole is fitted, and the lower end of the dip-coated cylinder is rotated while the container is rotated about the center of the hole provided in the flexible porous member. By inserting into the hole of the flexible porous member, the excess coating film at the lower end is removed.

In this aspect, since the coating film removing member is fitted in the container, it can be uniformly brought into contact with the entire outer peripheral surface of the end portion of the substrate, thereby making the wiping width uniform and eliminating the need for wiping for finishing.
And since it is in uniform contact with the entire outer peripheral surface of the substrate end, a uniform force is applied to the entire outer peripheral surface of the substrate end, whereby the substrate can be held vertically, the wiping width becomes uniform, and the finish No wiping is required.
In addition, since the entire outer peripheral surface of the base end is in contact with each other, the frictional force between the base and the coating film removing member is uniform over the entire outer peripheral surface, so that the deformation of the coating film removing member during wiping is reduced. As a result, the wiping width becomes uniform and finishing wiping is not necessary. And since the return of deformation is also reduced, the coating film removal liquid is less likely to spill or scatter. Therefore, no coating film defects occur.
Further, since the deformation is small, the durability of the coating film removing member is also improved.

And since a coating-film removal member is fitted, even if it does not adjust in particular, if it installs in a container, there also exists an effect that it is set to the position which can contact the whole base-end part outer peripheral surface uniformly.
Therefore, the coating film removing member can be easily replaced.
If the coating film removing member is not fitted in the container, the adhesion between the substrate and the coating film removing member becomes insufficient, and it is impossible to uniformly contact the entire outer peripheral surface of the substrate end. Cannot be obtained. Further, the coating film removing member 47a may be partially cut away as shown in FIGS.
FIG. 19 is a top view of the coating film removing member 47a of FIG. 5a.
20 to 21 are views of another example of the coating film removing member 47a as viewed from above. FIG. 20 shows two cutouts, FIG. 21 shows three cutouts and FIG. Reference numeral 22 denotes one provided with four notches.
In addition, it is preferable to provide a notch with point symmetry.

In the present invention, the coating film removing member is preferably a porous body (also referred to as foam).
The porous body is a substance having a three-dimensional network structure, and there are no closed cells, that is, there are no independent chambers whose walls are completely partitioned by walls. preferable. In the present invention, it is preferable that 70% or more and 90% or less of the volume of the porous body is a space.
Such a porous body can be produced by molding or slab molding, and as the material thereof, urethane, polyethylene, polycellulose, ceramic, Teflon (registered trademark), or the like can be used.

The coating film removing liquid is capable of dissolving the coating film, and is particularly preferably a solvent used in the coating liquid. As the coating film removing liquid, for example, tetrahydrofuran, methanol, methyl ethyl ketone, 1,4-dioxane, toluene, N-methylpyrrolidone, cyclohexanone and the like can be used.
When removing the coating film, it is better that the wind is not applied and no wind is applied. This is to prevent coating film defects caused by softening of the coating film that does not need to be removed due to the coating film removing liquid vapor. Further, a protective member may be provided on the upper portion of the container 42 in order to protect the coating film that does not need to be removed from the coating film removing liquid vapor.

The temperature during the removal operation is preferably 18 ° C. or more and 26 ° C. or less and a constant temperature. By making the temperature constant, the dissolution of the coating film becomes constant and the wiping accuracy is improved.
The humidity during the removal operation is preferably 35% RH or more and 75% RH or less and constant humidity. By making the humidity constant, the evaporation of the coating film removing liquid becomes constant, and the wiping accuracy is improved.
The coating film removing apparatus shown in the present invention is provided with a cover that is opened and closed during the coating film removing operation in order to avoid evaporation of the coating film removing liquid in a state where the coating film is not removed. May be.
By providing this lid, not only the solvent evaporation from the coating film removing member can be suppressed, but also the temperature drop of the wiping member due to the heat of vaporization during the solvent evaporation can be avoided. Since the solubility at the time of removing the coating film decreases as the temperature decreases, it is effective to suppress evaporation.

<Aspect (4) of the invention>
In this aspect, the cross-sectional area of the upper outer shape of the coating film removing member is 105% or more and 120% or less of the cross-sectional area of the container upper outer shape.
More preferably, the cross-sectional area of the upper outer shape of the coating film removing member is 110% or more and 115% or less of the cross-sectional area of the container upper outer shape.
Here, the cross-sectional area of the upper outer shape of the coating film removing member and the cross-sectional area of the outer shape of the container upper part will be described with reference to FIGS.
FIG. 14A is an upper outer shape of the coating film removing member and the container shown in FIG. 5A, and a hatched portion is a cross-sectional area.
FIG. 14B is an upper outer shape of the coating film removing member and the container shown in FIG. 5B, and a hatched portion is a cross-sectional area.
The upper part is a part into which the substrate is inserted when the coating film is removed.
If the cross-sectional area of the upper outer shape of the coating film removing member is 105% or more and 120% or less of the cross-sectional area of the container upper outer shape, the adhesion to the substrate is appropriate, and the coating film removing member is attached to the entire outer peripheral surface of the substrate end. Can be uniformly contacted. As a result, the adhesion to the substrate becomes appropriate, and the entire surface of the outer periphery of the substrate end is uniformly applied, so that the substrate can be held vertically, the wiping width becomes uniform, and wiping for finishing is not required. .
In addition, since the adhesion with the substrate is appropriate, the friction force between the substrate and the coating film removing member is uniform over the entire outer peripheral surface, so that the deformation of the coating film removing member during wiping is reduced, and the wiping width is uniform. Therefore, it is not necessary to wipe off the finish.
And since the return of deformation is also small, the coating film removing liquid is less likely to spill or scatter and no coating film defects occur. Further, since the deformation is small, the durability of the coating film removing member is also improved.

The cross-sectional area may be the cross-sectional area from the beginning, or may be the cross-sectional area as a result of swelling. When the cross-sectional area is obtained by swelling, the elongation percentage of the coating film removing member is preferably 300% or more and 500% or less. Here, the elongation rate is measured in accordance with JISK6400.
If the cross-sectional area is smaller than 105%, the adhesion is insufficient, and the entire outer peripheral surface of the base end cannot be contacted, and the above-described effects cannot be obtained.
Moreover, when the said cross-sectional area is larger than 120%, there exists a problem that friction becomes large at the time of wiping off and wiping becomes inadequate.

<Aspect (5) of the invention>
In this embodiment, a presser is provided on the upper part of the coating film removing member, and the presser is inside the container.
Here, the pressing will be described with reference to FIGS. 15 to 18.
FIG. 15 is a top view of an example of the presser 54 provided on the upper part of the coating film removing member 47a.
FIG. 16 is a side view of an example of the presser 54 provided on the upper part of the coating film removing member 47a.
FIG. 17 is a top view of another example of the presser 54 provided on the upper part of the coating film removing member 47a.
FIG. 18 shows the cross-sectional area of the upper part of the coating film removing member 47a, and the hatched portion is the cross-sectional area.

If there is a presser 54, the coating film removing member 47a is prevented from floating, and the coating film removing member can be uniformly brought into contact with the entire outer peripheral surface of the substrate end, the wiping width becomes uniform, and no wiping is required for finishing. It becomes.
And since the coating film removing member can be brought into uniform contact with the entire outer peripheral surface of the substrate end, the deformation of the coating film removing member at the time of wiping is reduced and the return of the deformation is also reduced, so Since scattering is reduced, coating film defects do not occur. Further, since the deformation is small, the durability of the coating film removing member is also improved.
Presser 54 coating removing member 47a of 0.1 gf / cm ² or more, preferably be pressed at 10 gf / cm ² or less, more preferably 1 gf / cm ² or more and 5 gf / cm ² or less.
The member of the presser 54 is preferably melanin, polyethylene, urethane, polycellulose, ceramic, Teflon (registered trademark), or the like. In particular, when an organic solvent is used for the coating film removing liquid, solvent resistance is required, and therefore it is preferable to use a member having high solvent resistance for the presser 54.
The presser 54 preferably covers 10% or more and 99% or less of the cross-sectional area of the upper portion of the coating film removing member 47a, and more preferably 20% or more and 99% or less.
If the presser 54 is outside the container 42, the coating film removing liquid flows out to the outside of the container 42 due to a capillary phenomenon or the like, and not only the above-described effects are obtained, but also the surroundings of the coating film removing apparatus. In addition, when an organic solvent is used for the coating film removing liquid, there is a problem in safety.

<Aspect (6) of the invention>
In this embodiment, the 25% hardness of the coating film removing member is 90N or more and 150N or less.
The hardness of the coating film removing member is more preferably 110N or more and 130N or less.
Here, 25% hardness is measured in accordance with JIS K 6400.
If this hardness is 90N or more and 150N or less, the deformation of the coating film removing member at the time of wiping is reduced, the wiping width becomes uniform, and finishing wiping becomes unnecessary.
Moreover, since the return of deformation is also reduced, the coating film removal liquid is less spilled and scattered, so that no coating film defects occur.
Further, since the deformation is small, the durability of the coating film removing member is also improved.
If the main hardness is less than 90N, the effect as described above cannot be obtained because the coating film removing member is twisted and greatly deformed during wiping.
Moreover, when this hardness is larger than 150N, adhesiveness with a base | substrate will fall and the uniformity of the wiping width will become low.

<Aspect (7) of the invention>
This aspect is characterized in that the relative rotational speed between the coating film removing member and the substrate is 20 rpm or more and 50 rpm or less.
This rotational speed is more preferably 30 rpm or more and 50 rpm or less.
If this rotation speed is 20 rpm or more and 50 rpm or less, an excess coating film can be efficiently removed.
The rotation at the time of removing the coating film may rotate the substrate or the coating film removing member. Moreover, you may rotate both.
If the rotational speed is less than 10 rpm, the removal efficiency is poor, and a large amount of coating film removing liquid is required. If it exceeds 60 rpm, the friction between the substrate and the coating film removing member during wiping increases, and the removal efficiency decreases.

  Hereinafter, although the Example concerning this invention and a comparative example are given and demonstrated, this invention is not limited to the Example shown below.

[Example 1]
After applying an undercoat layer and a charge generation layer on an aluminum substrate having a diameter of 30 mm and a length of 340 mm, a charge transport layer was applied.
And the excess coating film was removed with the apparatus shown in FIG. The coating film removing liquid supply member 46 was formed by the apparatus shown in FIG.
The temperature was 22 ° C. and the humidity was 54% RH. The cross-sectional area of the container upper outer shape was 9847 cm ² , the coating film removing member was polyurethane foam, and the 25% hardness was 80 N.
The elongation was 350%. The cross-sectional area of the upper outer shape after the coating film removing member was immersed in tetrahydrofuran (coating film removing solution) overnight was 10044 cm ² (102% of the cross-sectional area of the upper outer shape of the container). The said coating-film removal member was installed in the container, and the excess coating film was removed.
The substrate after coating was lowered and brought into contact with the inner coating film removing member. Then, the coating film removing member started to rotate at 10 rpm, and one second later, tetrahydrofuran was supplied at 20 ml / min. Five seconds after that, the supply of tetrahydrofuran was stopped, and after 5 seconds, the rotation was stopped to remove the excess coating film on the inner end. After 1 second, the substrate was further pulled down and brought into contact with the outer coating film removing member. Then, the coating film removing member started to rotate at 10 rpm, and tetrahydrofuran was supplied at 20 ml / min after 1 second. Five seconds later, the supply of tetrahydrofuran was stopped, and five seconds later, the rotation was stopped. One second later, the substrate was further lifted to remove the excessive outer coating film.

[Example 2]
A charge transport layer was applied to the substrate in the same manner as in Example 1.
Excess coating film was removed under the same conditions as in Example 1 except that the coating film removing member was changed to the following.
The 25% hardness of the coating film removing member was 80N. The elongation was 450%. The cross-sectional area of the upper outer shape after immersing the coating film removing member in tetrahydrofuran (coating liquid removing solution) overnight was 12309 cm ² (125% of the cross-sectional area of the upper outer shape of the container).

[Example 3]
A charge transport layer was applied to the substrate in the same manner as in Example 1.
And the excess coating film was removed with the apparatus shown in FIG. The coating film removing liquid supply member 46 was performed using the apparatus shown in FIG. The number of grooves is four.
The temperature was 22 ° C. and the humidity was 54% RH. The cross-sectional area of the container upper outer shape was 9847 cm ² , the coating film removing member was polyurethane foam, and the 25% hardness was 80 N.
The cross-sectional area of the upper outer shape after immersing the coating film removing member in tetrahydrofuran (coating liquid removing solution) overnight was 10832 cm ² (110% of the cross-sectional area of the upper upper container shape). The elongation was 400%. The said coating-film removal member was installed in the container, and the excess coating film was removed.
The substrate after coating was lowered and brought into contact with the inner coating film removing member. Then, the coating film removing member started to rotate at 10 rpm, and tetrahydrofuran was supplied at 15 ml / min after 1 second. Five seconds after that, the supply of tetrahydrofuran was stopped, and after 5 seconds, the rotation was stopped to remove the excess coating film on the inner end. After 1 second, the substrate was further pulled down and brought into contact with the outer coating film removing member, and then the coating film removing member started to rotate at 10 rpm. One second later, tetrahydrofuran was supplied at 15 ml / min. Five seconds later, the supply of tetrahydrofuran was stopped, and five seconds later, the rotation was stopped. One second later, the substrate was further lifted to remove the excessive outer coating film.

[Example 4]
A charge transport layer was applied to the substrate in the same manner as in Example 1.
And the excess coating film was removed with the apparatus shown in FIG. The apparatus shown in FIG. 10 was used as the coating film removing liquid supply member. The number of grooves is eight.
The temperature was 22 ° C. and the humidity was 54% RH. The cross-sectional area of the container upper outer shape was 9847 cm ² , the coating film removing member was polyurethane foam, and the 25% hardness was 160 N. The cross-sectional area of the upper outer shape after immersing the coating film removing member in tetrahydrofuran (coating liquid removing solution) overnight was 10832 cm ² (110% of the cross-sectional area of the upper upper container shape). The elongation was 300%. The said coating-film removal member was installed in the container, and the excess coating film was removed.
The substrate after coating was lowered and brought into contact with the inner coating film removing member. Then, the coating film removing member started to rotate at 10 rpm, and one second later, tetrahydrofuran was supplied at 10 ml / min. Five seconds after that, the supply of tetrahydrofuran was stopped, and after 5 seconds, the rotation was stopped to remove the excess coating film on the inner end. After 1 second, the substrate was further pulled down and brought into contact with the outer coating film removing member. Then, the coating film removing member started to rotate at 10 rpm, and tetrahydrofuran was supplied at 10 ml / min after 1 second. Five seconds later, the supply of tetrahydrofuran was stopped, and five seconds later, the rotation was stopped. One second later, the substrate was further lifted to remove the excessive outer coating film.

[Example 5]
A charge transport layer was applied to the substrate in the same manner as in Example 1.
And the press of FIG. 15 was provided and the excess coating film was removed by the apparatus and conditions used in Example 4.
The material of the presser 54 was Teflon (registered trademark), and the coating film removing member 47a was pressed at 1 gf / cm ² to cover 20% of the upper cross-sectional area of the coating film removing member 47a.

[Example 6]
A charge transport layer was applied to the substrate in the same manner as in Example 1.
And the excess coating film was removed with the apparatus shown in FIG. The apparatus shown in FIG. 10 was used as the coating film removing liquid supply member. The number of grooves is eight.
The temperature was 22 ° C. and the humidity was 54% RH. The cross-sectional area of the container upper outer shape was 9847 cm ² , the coating film removing member was polyurethane foam, and the 25% hardness was 120 N. The cross-sectional area of the upper outer shape after immersing the coating film removing member in tetrahydrofuran (coating liquid removing solution) overnight was 10832 cm ² (110% of the cross-sectional area of the upper upper container shape). The elongation was 450%. The said coating-film removal member was installed in the container, and the excess coating film was removed.
The substrate after coating was lowered and brought into contact with the inner coating film removing member. Then, the coating film removing member started to rotate at 10 rpm, and one second later, tetrahydrofuran was supplied at 10 ml / min. Five seconds after that, the supply of tetrahydrofuran was stopped, and after 5 seconds, the rotation was stopped to remove the excess coating film on the inner end. After 1 second, the substrate was further pulled down and brought into contact with the outer coating film removing member. Then, the coating film removing member started to rotate at 10 rpm, and tetrahydrofuran was supplied at 10 ml / min after 1 second. Five seconds later, the supply of tetrahydrofuran was stopped, and five seconds later, the rotation was stopped. One second later, the substrate was further lifted to remove the excessive outer coating film.

[Example 7]
A charge transport layer was applied to the substrate in the same manner as in Example 1.
And the excess coating film was removed with the apparatus shown in FIG. The apparatus shown in FIG. 10 was used as the coating film removing liquid supply member. The number of grooves is eight.
The temperature was 22 ° C. and the humidity was 54% RH. The cross-sectional area of the container upper outer shape was 9847 cm ² , the coating film removing member was polyurethane foam, and the 25% hardness was 120 N. The cross-sectional area of the upper outer shape after immersing the coating film removing member in tetrahydrofuran (coating liquid removing solution) overnight was 10832 cm ² (110% of the cross-sectional area of the upper upper container shape). The elongation was 450%. The said coating-film removal member was installed in the container, and the excess coating film was removed.
The substrate after coating was lowered and brought into contact with the inner coating film removing member. Then, the coating film removing member started to rotate at 60 rpm, and one second later, tetrahydrofuran was supplied at 6 ml / min. Five seconds after that, the supply of tetrahydrofuran was stopped, and after 5 seconds, the rotation was stopped to remove the excess coating film on the inner end. After 1 second, the substrate was further pulled down and brought into contact with the outer coating film removing member, and then the coating film removing member started to rotate at 60 rpm. One second later, tetrahydrofuran was supplied at 6 ml / min. Five seconds later, the supply of tetrahydrofuran was stopped, and five seconds later, the rotation was stopped. One second later, the substrate was further lifted to remove the excessive outer coating film.

[Example 8]
A charge transport layer was applied to the substrate in the same manner as in Example 1.
And the excess coating film was removed with the apparatus shown in FIG. The apparatus shown in FIG. 10 was used as the coating film removing liquid supply member. The number of grooves is eight.
The temperature was 22 ° C. and the humidity was 54% RH. The cross-sectional area of the container upper outer shape was 9847 cm ² , the coating film removing member was polyurethane foam, and the 25% hardness was 120 N. The cross-sectional area of the upper outer shape after immersing the coating film removing member in tetrahydrofuran (coating liquid removing solution) overnight was 10832 cm ² (110% of the cross-sectional area of the upper upper container shape). The elongation was 450%. The said coating-film removal member was installed in the container, and the excess coating film was removed.
The substrate after coating was lowered and brought into contact with the inner coating film removing member, and then the coating film removing member started to rotate at 50 rpm. One second later, tetrahydrofuran was supplied at 6 ml / min. Five seconds after that, the supply of tetrahydrofuran was stopped, and after 5 seconds, the rotation was stopped to remove the excess coating film on the inner end. After 1 second, the substrate was further pulled down and brought into contact with the outer coating film removing member, and then the coating film removing member started to rotate at 50 rpm. One second later, tetrahydrofuran was supplied at 6 ml / min. Five seconds later, the supply of tetrahydrofuran was stopped, and five seconds later, the rotation was stopped. One second later, the substrate was further lifted to remove the excessive outer coating film.

[Comparative Example 1]
A charge transport layer was applied to the substrate in the same manner as in Example 1.
And the excess coating film was removed with the apparatus shown in FIG. In this apparatus, the container 42 provided with the coating film removing members 47a and 47b moves left and right, and the coating film is removed while pressing the coating film removing members 47a and 47b. The temperature was 22 ° C. and the humidity was 54% RH. The coating film removing member was a polyurethane foam, and the 25% hardness was 120N.
The substrate after coating was lowered and brought into contact with the coating film removing members 47a and 47b, and then the coating film removing member started to rotate at 50 rpm. One second later, tetrahydrofuran was supplied at 48 ml / min. Five seconds later, the supply of tetrahydrofuran was stopped, the rotation was stopped five seconds later, the coating film removing member was released, and one second later, the substrate was further lifted to remove the excess coating film.

[Comparative Example 2]
A charge transport layer was applied to the substrate in the same manner as in Example 1.
And the coating-film removal liquid supply member 46 of the apparatus shown in FIG. 3 was changed into the member shown in FIG. 12, and the excess coating film was removed. The member shown in FIG. 12 is such that the coating film removing liquid that has passed through the coating film removing liquid supply member 46 is ejected horizontally from the coating film removing liquid discharge hole to remove the excess coating film on the edge of the substrate. It is.
The temperature was 22 ° C. and the humidity was 54% RH. The cross-sectional area of the container upper outer shape was 9847 cm ² , the coating film removing member was polyurethane foam, and the 25% hardness was 120 N. The cross-sectional area of the upper outer shape after immersing the coating film removing member in tetrahydrofuran (coating liquid removing solution) overnight was 10832 cm ² (110% of the cross-sectional area of the upper upper container shape). The elongation was 450%. The said coating-film removal member was installed in the container, and the excess coating film was removed.
The substrate after coating was lowered and brought into contact with the inner coating film removing member, and then the coating film removing member started to rotate at 50 rpm. One second later, tetrahydrofuran was supplied at 30 ml / min. Five seconds after that, the supply of tetrahydrofuran was stopped, and after 5 seconds, the rotation was stopped to remove the excess coating film on the inner end. After 1 second, the substrate was further pulled down and brought into contact with the outer coating film removing member. Then, the coating film removing member started to rotate at 50 rpm, and tetrahydrofuran was supplied at 30 ml / min after 1 second. Five seconds later, the supply of tetrahydrofuran was stopped, and five seconds later, the rotation was stopped. One second later, the substrate was further lifted to remove the excessive outer coating film.

Under the conditions of Examples 1 to 8 and Comparative Examples 1 and 2, the coating film was removed up to 10000 each. After removing the coating film, a flange was attached, and the total runout was measured with a Ricoh total runout measuring machine.
The wiping width was measured by measuring the wiping width of FIG. 13 at four points in the circumferential direction by cross-sectional measurement using a surface roughness meter Surfcom 1400D, and evaluating the difference between the maximum value and the minimum value.
In addition, when the difference between the maximum value and the minimum value of the wiping width becomes 5 or more continuously and 1.5 mm or more, it is determined that the life of the coating film removing member is reached, and the subsequent coating film removal is stopped. did. The results are shown in Table 1.

  According to the coating film removing method of the present invention, the excess coating film at the lower end of the coating after dip coating can be completely wiped off, and the image quality can be improved by maintaining the gap between the electrophotographic photosensitive member and the charging roll with high accuracy. Since it can be improved, it is suitable as a method for producing an organic electrophotographic photosensitive member used in image forming apparatuses such as copying machines, printers and facsimiles.

It is sectional drawing of an example of the apparatus used for dip coating. It is principal part sectional drawing which shows the photosensitive drum lower end part after application | coating. It is sectional drawing of an example of the apparatus used for this invention. It is sectional drawing of another example of the apparatus used for this invention. It is a perspective view when the coating-film removal member of the base | substrate outside which concerns on this invention is installed in the container. It is another perspective view when the coating-film removal member of the base | substrate outer side which concerns on this invention is installed in the container. It is a figure when the excess coating film inside a base | substrate is removed by the method which concerns on this invention. It is a figure when the excess coating film of the base | substrate outer side is removed by the method which concerns on this invention. It is the figure showing a mode that the film | membrane of the coating liquid of the base | substrate lower end part produced | generated at the time of application | coating adheres. It is the figure showing the coating-film removal liquid discharge hole which concerns on this invention, and an inner coating-film removal member. It is a figure showing the groove | channel provided in the coating-film removal liquid supply member which concerns on this invention. It is a figure of the coating-film removal apparatus used in the comparative example 1. It is a figure of the coating-film removal liquid supply member used in the comparative example 2. It is a figure which shows the measurement point of description of an wiping width, and an Example and a comparative example. It is a figure of description of the cross-sectional area of the upper external shape of the coating-film removal member which concerns on this invention, and the cross-sectional area of a container upper part external shape. It is another figure of description of the cross-sectional area of the upper external shape of the coating-film removal member which concerns on this invention, and the cross-sectional area of a container upper part external shape. It is the figure which looked at an example of the presser 54 with which the upper part of the coating-film removal member 47a was equipped from the top. It is the figure which looked at an example of the presser 54 with which the upper part of the coating-film removal member 47a was equipped from the side. It is the figure which looked at one example of the presser 54 with which the upper part of the coating-film removal member 47a was equipped from the top. The cross-sectional area of the upper part of the coating film removing member 47a is shown, and the hatched portion is the cross-sectional area. It is the figure which looked at the coating-film removal member 47a of FIG. 5a from the top. These are the figures which looked at the example of the coating-film removal member 47a from the top, and provided the notch in two places. It is the figure which looked at the example of the coating-film removal member 47a from the top, and provided the notch in three places. It is the figure which looked at one example of the coating-film removal member 47a from the top, and provided the notch in four places. It is sectional drawing of another example of the apparatus used for the coating-film removal method of this invention. It is sectional drawing of another example of the apparatus used for the coating-film removal method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Immersion coating apparatus 2 Coating film removal apparatus 11 Coating tank 12 Coating liquid 13 Substrate to be coated 14 Holding jig 15 Motor 16 Pipe 17 Circulating tank 18 Motor 19 Rotary blade 20 Coating liquid 21 in circulating tank Circulating pump 30 Coating film (photosensitive layer)
30a-c Extra coating (photosensitive layer)
41 Liquid recovery tank 41
42 Container 42
43 Rotating motor 44 Rotation transmission mechanism 45 Liquid recovery tank 46 Coating film removal liquid supply member 47a Coating film removal member 47b outside substrate Substrate inner coating film removal member 48 Coating film removal liquid discharge hole 49 Coating film removal liquid supply pump 50 Coating film Removal liquid tank 51 Substrate 52 after coating 52 Coating film 53 Groove 54 of coating film removal liquid supply member 46

Claims (7)

In the coating film removing method for removing the excess coating film on the lower end portion of the cylindrical substrate on which the coating film is formed on the surface by the dip coating method, contacting the end coating film removing member,
A coating film removing member a having an opening in the center is provided in the opening so that the lower end of the cylindrical substrate can be inserted,
The coating film removing member b is disposed below, and a coating film removing liquid supply member provided with a coating film removing liquid discharge hole so that the coating film removing liquid is discharged upward is inserted into the lower end of the cylindrical substrate. Possible,
Excess coating film at the end of the cylindrical substrate is removed by discharging the coating film removing liquid from the coating film removing solution discharge hole and rotating the cylindrical substrate and the coating film removing members a and b relatively. A method for removing a coating film.   The coating film removing method according to claim 1, wherein the coating film removing liquid is guided to the groove and supplied to the coating film removing member.   A coating film removal solution can be supplied from the outside, and a part or all of the upper surface is open and can be rotated in the horizontal direction. A flexible porous member having a hole is fitted, and the lower end of the dip-coated cylinder is rotated with the center of the hole provided in the flexible porous member as a rotation axis, and the flexible porous member is 3. The method of removing a coating film according to claim 1 or 2, wherein the excess coating film at the lower end is removed by inserting into the hole of the material member.   4. The method of removing a coating film according to claim 3, wherein the cross-sectional area of the upper outer shape of the coating film removing member is 105% or more and 120% or less of the cross-sectional area of the outer shape of the container upper part.   The coating film removing method according to any one of claims 1 to 4, wherein a presser is provided on an upper part of the coating film removing member a, and the presser is inside the container.   The method for removing a coating film according to any one of claims 1 to 5, wherein the 25% hardness of the coating film removing member is 90N or more and 150N or less.   The method for removing a coating film according to any one of claims 1 to 6, wherein a relative rotational speed of the coating film removing member and the substrate is 20 rpm or more and 50 rpm or less.

Images