JP2017187657A - Method of removing cylindrical-substrate coated film and method of manufacturing electrophotoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coated film removing method capable of accurately and efficiently removing the unnecessary coated film on a lower-side outer peripheral surface of a cylindrical substrate made by a dip coating method.SOLUTION: Provided is a coated film removing method for removing the unnecessary coated film on a lower-side outer peripheral surface of a cylindrical substrate 2 made by a dip coating method, the coated film removing method comprising: an outer peripheral surface coated film-removing member abutment step of causing a portion of the substrate 2 outer peripheral surface coated film to be removed, from its upper end to its lower end, to abut against a first removing portion 6a and a second removing portion 6b of an outer peripheral surface coated film removing member 6; and an outer peripheral surface coated film-removing step of removing the portion of the substrate 2 outer peripheral surface coated film to be removed by rotating the substrate 2 and the first and second removing portions 6a, 6b relatively such that they slidingly rub each other, while supplying a solvent to abutting portions between the portion of the substrate 2 outer peripheral surface coated film to be removed and the first and second removing portions 6a, 6b. The first and second removing portions 6a, 6b of the outer peripheral surface coated film removing member 6 each have a different hardness.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for removing an unnecessary coating film below an axial direction of a cylindrical substrate on which a coating film of a coating solution for an electrophotographic photoreceptor is formed by a dip coating method.

  An electrophotographic photosensitive member used in a copying machine, a laser beam printer, or the like is provided with, for example, a conductive layer, an undercoat layer, a charge generation layer, a charge transport layer, and the like on a cylindrical substrate. As a method for producing such an electrophotographic photosensitive member, a method of forming a coating film of the above-mentioned respective layers constituting the electrophotographic photosensitive member (coating solution for an electrophotographic photosensitive member) on a substrate, and heating or curing the coating film There is. Among them, a dip coating method in which a coating film is formed by immersing a cylindrical substrate in a coating solution for an electrophotographic photosensitive member, for example, with the axis of the substrate in the vertical direction, and then pulling it up is highly productive. It is widely adopted from this point. However, in the dip coating method, a coating film is inevitably formed on the lower outer peripheral surface of the substrate.

Here, there may be a configuration in which a member (roller) for maintaining a constant distance between the electrophotographic photosensitive member and the developing member (developing sleeve or the like) is brought into contact with the electrophotographic photosensitive member. In that case, since the portion where the roller abuts is rubbed, there is a problem that if the coating film is present, it is peeled off unevenly or worn. Therefore, it is necessary that no coating film is formed on the contact portion of the member for keeping the distance constant.
Therefore, when a coating film is formed on a cylindrical substrate by a dip coating method, it is necessary to remove an unnecessary coating film on the outer peripheral surface below the substrate after the coating film is formed.

  On the other hand, an apparatus for removing the coating film at the lower end of the substrate has been proposed. For example, Patent Document 1 proposes an apparatus that removes an unnecessary coating film by immersing a portion of a base at the lower end of a substrate where the coating is removed in a solvent and rotating a wiping plate. Patent Document 2 proposes an apparatus for removing a coating film by discharging a solvent from an apparatus inserted into the lower end of a cylindrical substrate and rubbing with a brush. Further, Patent Document 3 proposes an apparatus for removing a coating film by rubbing the outer peripheral surface of a cylindrical substrate with a blade having a notch formed on the upstream surface of the substrate in the rotation direction.

Japanese Patent Laid-Open No. 11-212278 JP 2001-205178 A JP 7-84382 A

  However, even with the coating film removing apparatus described in Patent Documents 1 to 3, it is possible to remove the coating film firmly adhered to the substrate without wiping and without fail in a short time. It was very difficult and there was room for further improvement.

  Accordingly, an object of the present invention is to accurately and efficiently remove an unnecessary coating film on the outer peripheral surface under a cylindrical substrate on which a coating film of a coating solution for an electrophotographic photosensitive member is formed by a dip coating method. An object of the present invention is to provide a method for removing a coating film on a cylindrical substrate and a method for producing an electrophotographic photosensitive member.

The present invention relates to a coating film removing method for supporting a cylindrical substrate on which a coating film of a coating solution for an electrophotographic photosensitive member is formed in the vertical direction and removing a coating film on a portion to be removed that is located below the substrate in the axial direction. The method includes a first removing portion of the outer peripheral surface coating film removing member and a first removing portion of the outer peripheral surface coating film removing member from the upper end to the lower end of the coating film on the outer peripheral surface of the substrate. A first removing portion and a second removing portion of the outer peripheral surface coating film removing member from the upper end to the lower end of the coating film on the outer peripheral surface of the substrate. While supplying the solvent to the contact portion between the coating film of the portion to be removed and the first removal portion and the second removal portion of the outer peripheral surface coating film removal member, A step of relatively rotating and rubbing the first removal portion and the second removal portion of the outer peripheral surface coating film removing member to remove the coating film of the portion to be removed, A first removal of the outer peripheral surface film removal member, and the second removal unit of the outer peripheral surface film removal member is a film removal method of the cylindrical body, characterized in that different hardness.
The present invention also relates to a method for producing an electrophotographic photosensitive member, in which a coating film of a coating solution for an electrophotographic photosensitive member is formed on a cylindrical substrate by a dip coating method. This is a method for producing an electrophotographic photosensitive member, which comprises a step of removing a coating film in the axially lower side of the substrate after forming the coating film of the liquid by the coating film removing method for the cylindrical substrate.

  According to the present invention, it is possible to accurately and efficiently remove an unnecessary coating film on an outer peripheral surface below a cylindrical substrate on which a coating film of a coating solution for an electrophotographic photoreceptor is formed by a dip coating method. A method for removing a coating film can be provided. In addition, according to the present invention, an electrophotographic photosensitive member in which a layer is not provided in an unnecessary region of a substrate can be obtained by producing an electrophotographic photosensitive member using the coating film removing method. A method for producing a photoreceptor can be provided.

It is sectional drawing which shows an example of the schematic structure of the whole coating-film removal apparatus used for the coating-film removal method of this invention. (A) It is a perspective view which shows an example of the removal part of the outer peripheral surface coating-film removal member used for the coating-film removal method of this invention. (B) It is a perspective view which shows an example of the removal part of the outer peripheral surface coating-film removal member used for the coating-film removal method of this invention. It is a top view which shows an example of arrangement | positioning structure of the outer peripheral surface coating-film removal member used for the coating-film removal method of this invention, and a base | substrate. It is a top view which shows an example of arrangement | positioning structure of the outer peripheral surface coating-film removal member used for the coating-film removal method of this invention and a base | substrate, and these rotational drive states in the case of coating-film removal. It is a top view which shows an example of arrangement | positioning structure of the outer peripheral surface coating-film removal member used for the coating-film removal method of this invention and a base | substrate, and these rotational drive states in the case of coating-film removal. It is a top view which shows an example of arrangement | positioning structure of the outer peripheral surface coating-film removal member used for the coating-film removal method of this invention and a base | substrate, and these rotational drive states in the case of coating-film removal. (A) It is sectional drawing which shows schematic structure of the vicinity of the removal part in an example of the coating-film removal apparatus used for the coating-film removal method of this invention. (B) It is a top view which shows schematic structure of the vicinity of the removal part in an example of the coating-film removal apparatus used for the coating-film removal method of this invention. (A) It is sectional drawing which shows schematic structure of the vicinity of the removal part in an example of the coating-film removal apparatus used for the coating-film removal method of this invention. (B) It is a top view which shows schematic structure of the vicinity of the removal part in an example of the coating-film removal apparatus used for the coating-film removal method of this invention.

  The method for removing a coating film on a cylindrical substrate according to the present invention comprises a cylindrical substrate on which a coating film of a coating solution for an electrophotographic photosensitive member is supported in a vertical direction, and the object to be removed is located below the substrate in the axial direction. A coating film removing method for removing a coating film on a portion, wherein the method is a first removal section of an outer peripheral surface coating film removing member from the upper end to the lower end of the coating film on the outer peripheral surface of the substrate. And the second removal portion of the outer peripheral surface coating film removing member, and from the upper end to the lower end of the coating film of the removed portion of the outer peripheral surface of the substrate, With the first removal portion and the second removal portion being in contact, the solvent is removed between the coating film of the portion to be removed and the first removal portion and the second removal portion of the outer peripheral surface coating film removal member. While being supplied to the contact portion, the substrate and the first removal portion and the second removal portion of the outer peripheral surface coating film removing member are relatively rotated and rubbed to remove the object. The first removing portion of the outer peripheral surface coating film removing member and the second removing portion of the outer peripheral surface coating film removing member have different hardnesses. To do.

Hereinafter, the present invention will be described in detail with reference to the drawings.
A coating film removing apparatus used in the coating film removing method of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view showing an example of the overall schematic configuration of a coating film removing apparatus used in the coating film removing method of the present invention.

  As shown in FIG. 1, the coating film removing apparatus used in the coating film removing method of the present invention is a substrate holding device that supports a cylindrical substrate 2 on which a coating film of a coating solution for an electrophotographic photoreceptor is formed in the vertical direction. A member 1 is provided. The coating film removing apparatus also removes the coating film (the coating film to be removed) formed on the outer peripheral surface below the axial direction (longitudinal direction) of the substrate 2 supported by the substrate holding member 1. It has.

  The coating film removal mechanism has a support 8. The support 8 includes a shaft portion 15 that is vertically provided so as to be inserted into the base 2, and an outer peripheral surface coating film removing member holding member 7 that holds the outer peripheral surface coating film removing member 6. . By rotating the support 8 by the rotation motor 13, the shaft portion 15 and the outer peripheral surface coating film removing member holding member 7 can be rotated integrally around the shaft portion 15.

  The outer peripheral surface coating film removing member holding member 7 is attached with an outer peripheral surface coating film removing member 6 having a plurality of removing portions having different hardnesses (a first removing portion 6a and a second removing portion 6b whose details will be described later). It has been. The plurality of removal portions of the outer peripheral surface coating film removing member 6 are configured to be able to contact the outer peripheral surface of the base 2. When the support 8 is rotated in a state where the plurality of removing portions of the outer peripheral surface coating film removing member 6 are in contact with the outer peripheral surface of the base body 2, the plurality of removing portions of the outer peripheral surface coating film removing member 6 are changed to the base body 2. The unnecessary coating film existing on the outer peripheral surface of the substrate 2 can be removed by rubbing the outer peripheral surface of the substrate 2.

  The shaft portion 15 has a solvent supply channel 4 penetrating the shaft portion 15 therein, and has a solvent supply port 3 which is an opening through which the solvent 11 is discharged at the upper end portion. The solvent 11 is sent from the solvent supply tank 10 to the support 8 by the solvent supply pump 12, and is discharged from the solvent supply port 3 through the solvent supply channel 4 provided inside the shaft portion 15.

  Further, a solvent recovery tank 9 for recovering the solvent 11 discharged from the solvent supply port 3 is provided, and the used solvent 11 recovered in the solvent recovery tank 9 is refined as necessary, and then supplied to the solvent. It is configured to be sent to the tank 10 and reused.

Next, an example of the detailed shape of the outer peripheral surface coating film removing member 6 having the first removing portion 6a and the second removing portion 6b will be described with reference to FIGS. 2 (a) and 2 (b).
2 (a) and 2 (b) are perspective views showing an example of the shape of the removal portion of the outer peripheral surface coating film removing member used in the coating film removing method of the present invention. The outer peripheral surface coating film removing member of the present invention has a first removing portion and a second removing portion having different hardnesses. In the example of FIG. 2A and FIG. 2B, the first removal portion and the second removal portion have a blade shape (cuboid shape).

  FIG. 2A shows a second removal portion 6b in which one blade has one kind of blade hardness. When the second removal unit 6b shown in FIG. 2A is used, the first removal unit 6a having a hardness different from that of the second removal unit 6b is provided (separated). Therefore, the outer peripheral surface coating film removing member 6 includes a first removing portion 6a and a second removing portion 6b having different blade hardnesses, and the plurality of removing portions (6a, 6b) have separate structures. At this time, the outer peripheral surface coating film removing member 6 is not limited to the one including only the first removing portion 6a and the second removing portion 6b, and may further include another removing portion. For example, it may be an outer peripheral surface coating film removing section that is provided as a separate body and has three or more removing sections (except for those having the same hardness) that are spaced apart.

  In FIG. 2B, the outer peripheral surface coating film removing member 6 is configured such that the first removing portion 6 a and the second removing portion 6 b, which are a plurality of blades having different hardnesses, are integrated or in contact with each other. For example, a part of one blade is cured by crosslinking or the like, and the hardness of a part of the cured part is made different from the hardness of the other part. An existing configuration. The configuration in contact with each other means, for example, a configuration in which two blades having different hardnesses are in contact with each other with an adhesive or the like. At this time, the outer peripheral surface coating film removing member 6 is not limited to the one including only the first removing portion 6a and the second removing portion 6b, and may further include another removing portion. For example, it may be an outer peripheral surface coating film removing portion having three or more removal portions provided integrally or in contact with each other, and has a plurality of two or more removal portions provided integrally or in contact with each other. The outer peripheral surface coating film removing unit may be separated from each other. However, those with the same hardness are excluded.

  The first removing portion 6a having a higher hardness has an advantage that the coating film firmly attached to the substrate 2 can also be removed because the force for removing the coating film from the portion to be removed of the substrate 2 is stronger. On the other hand, since the second removal portion 6b having a lower hardness is more uniform in contact with the portion to be removed of the base body 2, there is an advantage that the coating film on the base body 2 can be removed without any remaining removal. is there. In the present invention, the removal is performed using removal parts having different hardnesses (the first removal part 6a having a higher hardness and the second removal part 6b having a lower hardness), thereby applying coating that takes advantage of both advantages. Since the film can be removed, the accuracy of coating film removal is synergistically improved.

  The configuration of the plurality of removal portions having different hardnesses is not particularly limited and may be appropriately selected, such as a configuration in which the plurality of removal portions are configured separately, configured integrally or in contact with each other, or a combination thereof. In any case, the coating film removability is improved.

  In the present invention, the hardness of the outer peripheral surface coating film removing member 6 can be measured by durometer type A of JIS K 6253. The difference in hardness between the first removal portion 6a having a higher hardness and the second removal portion 6b having a lower hardness is preferably 20 ° or more, because the advantages of both can be obtained efficiently. Further, the hardness of the first removal portion 6a having a higher hardness is preferably 60 ° or more, and more preferably 80 ° or more. The hardness of the second removal portion 6b having a lower hardness is preferably less than 60 °, and more preferably 40 ° or less.

  The material of the first removal portion 6a and the second removal portion 6b of the outer peripheral surface coating film removing member 6 can be selected in consideration of wear resistance and solvent resistance. For example, polyethylene, polyester, polypropylene, polyimide, etc. Rubbers such as resin, ethylene propylene rubber, ethylene propylene diene rubber, butyl rubber, and fluorine-based rubber can be used.

  As the shape of the first removal portion 6a and the second removal portion 6b of the outer peripheral surface coating film removing member 6, the solvent tends to ooze up to the contact portion, and dirt is not easily collected on the coating film removing member during continuous use. From the standpoint that the boundary between the surface from which the coating film is removed and the surface from which the coating is not removed is less likely to be disturbed, a blade shape is preferable.

  Here, the 1st removal part 6a and the 2nd removal part 6b of the outer peripheral surface coating-film removal member 6 shown to FIG. 2 (a) and FIG.2 (b) are blade shape (cuboid shape), The one surface The perpendicular direction is the contact direction with the base 2. However, the present invention is not limited to this, and the first removal portion 6a and the second removal portion 6b can be in contact with the base body 2 at arbitrary angles.

With respect to the coating film removing method of the present invention, a series of steps will be described using the coating film removing apparatus of FIG. 1 as an example.
First, a cylindrical substrate 2 having a coating film of a coating solution for an electrophotographic photoreceptor formed on the outer peripheral surface by a dip coating method is supported by a substrate holding member 1 in the vertical direction.

Next, the upper end of the region where the coating film removal of the base 2 is performed (also referred to as “removed portion”) is the upper end of the contact portion of the outer peripheral surface coating film removing member 6 with the base 2 (first removal portion The base 2 is lowered to a position where it is at the same height as the upper end of 6a and the upper end of the second removal portion 6b), and the shaft portion 15 is inserted (outer peripheral surface coating film removing member contact step). At this time, the 1st removal part 6a and the 2nd removal part 6b contact | abut from the upper end to the lower end of the coating film of the to-be-removed part which is the outer peripheral surface of the base | substrate 2 at the axial direction, respectively.
Further, the solvent supply pump 12 is operated to discharge the solvent 11 from the solvent supply port 3, thereby supplying the solvent 11 into the cylindrical base 2.

In this state, the first removing portion 6a and the second removing portion 6b of the outer peripheral surface coating film removing member 6 brought into contact with each other are rotated by rotating the support 8 with the rotary motor 13 while discharging the solvent 11. Rotate, scrape unnecessary coating, and remove (peripheral surface coating removal process). In the outer peripheral surface coating film removing step, the solvent 11 is removed while the first removing section 6a and the second removing section 6b are in contact from the upper end to the lower end of the coating film of the removed section. While being supplied to the contact portion between the first removal portion 6a and the second removal portion 6b, the coating film on the portion to be removed is removed by rubbing.
And after rotating for a predetermined time, the base | substrate 2 is pulled up and a series of coating-film removal process is complete | finished.

  In addition, although the 1st removal part 6a and the 2nd removal part 6b are rotating in the coating-film removal apparatus shown in FIG. 1, this invention is not limited to this. It is only necessary that the first removing portion 6a and the second removing portion 6b and the base 2 are relatively rotated and rubbed to remove the coating film on the portion to be removed. Accordingly, the first removal unit 6a and the second removal unit 6b may rotate, the base 2 may rotate, and the first removal unit 6a and the second removal unit 6b and the base 2 may be rotated. Both may rotate.

Here, FIG. 3 to FIG. 6 show examples of the arrangement configuration of the outer peripheral surface coating film removing member and the substrate used in the coating film removing method of the present invention, and specific examples of these rotational driving states at the time of coating film removal are shown. Will be described.
The outer peripheral surface coating film removing member 6 shown in FIG. 3 includes a blade-like second removing portion 6b shown in FIG. 2A and a first removing portion 6a having the same shape as the second removing portion 6b. And provided symmetrically about the axis of the cylindrical base 2. That is, in the top view shown in FIG. 3, the first removal portion 6a, the second removal portion 6b, and the center of the base 2 are arranged on a straight line. In the example shown in FIG. 3, the first removal unit 6a and the second removal unit 6b may rotate in an arbitrary direction, and the base 2 may rotate in an arbitrary direction.

  The outer peripheral surface coating film removing member 6 shown in FIG. 4 has two combinations of the first removing portion 6a and the second removing portion 6b that are configured in contact with each other as shown in FIG. These are provided symmetrically about the axis of the cylindrical base 2. In the example shown in FIG. 4, the first removal unit 6 a and the second removal unit 6 b rotate counterclockwise about the center of the cylindrical base 2 as the rotation axis. In addition, the 1st removal part 6a whose hardness is high compared with the 2nd removal part 6b is provided in the rotation head side, and the 2nd removal part 6b whose hardness is low compared with the 1st removal part 6a It is provided on the tail side of the rotation.

  The outer peripheral surface coating film removing member 6 shown in FIG. 5 has two combinations of the first removing portion 6a and the second removing portion 6b configured to be in contact with each other shown in FIG. These are provided symmetrically about the axis of the cylindrical base 2. In the example illustrated in FIG. 5, the first removal unit 6 a and the second removal unit 6 b rotate in the clockwise direction with the center of the cylindrical base 2 as the rotation axis. In addition, the 1st removal part 6a whose hardness is high compared with the 2nd removal part 6b is provided in the rotation tail side, and the 2nd removal part 6b whose hardness is low compared with the 1st removal part 6a. It is provided on the rotation head side. In the plurality of removing portions, it is preferable that the hardness of one removing portion on the rotational head side is lower than the hardness of the other removing portion on the trailing side.

  The outer peripheral surface coating film removing member 6 shown in FIG. 6 has two combinations of the first removing portion 6a and the second removing portion 6b that are configured in contact with each other shown in FIG. 2 (b). These are provided symmetrically about the axis of the cylindrical base 2. In the example shown in FIG. 6, the cylindrical base body 2 rotates counterclockwise around the center thereof. In addition, the 1st removal part 6a whose hardness is high compared with the 2nd removal part 6b is provided in the rotation downstream, and the 2nd removal part 6b whose hardness is low compared with the 1st removal part 6a. It is provided on the upstream side of the rotation. The plurality of removing portions preferably have a hardness of one removing portion on the upstream side of the rotation lower than the hardness of the other removing portion on the downstream side.

  In the coating film removing apparatus shown in FIG. 1, the solvent 11 is discharged into the substrate 2 in the solvent supply process. The discharged solvent 11 reaches the inner peripheral surface of the base body 2 via a tapered surface (a shape in which the diameter gradually increases downward) constituting the upper portion of the shaft portion 15. Next, the solvent 11 flows down on the inner peripheral surface of the base 2 and reaches the lower end of the base 2. Then, the solvent 11 forms a minute space at the contact portion between the first removal portion 6a and the second removal portion 6b from the lower end portion of the base 2 and the coating film of the portion to be removed that is axially below the base 2. By soaking up, the solvent 11 is supplied to the area where the coating film is removed.

  In the series of coating film removing steps, the solvent 11 may be always discharged when the first removing portion 6a and the second removing portion 6b are rubbed in the outer peripheral surface coating film removing step. , It may be discharged intermittently. Moreover, you may discharge before or after an outer peripheral surface coating-film removal process, such as when the base | substrate 2 is moved up and down in order to move to a predetermined position. That is, as long as the solvent 11 is sufficiently supplied to the region where the coating film is removed, the timing at which the solvent 11 is discharged from the solvent supply port 3 can be set arbitrarily.

  In this coating film removing method, the solvent 11 can be supplied to the contact portion when the coating film is rubbed with the first removing portion 6a and the second removing portion 6b. Therefore, this method of removing the coating film is not a method that removes the coating film while supplying the solvent to the contact portion, for example, a method that removes the coating film only with the solvent once soaked in the removing member in advance. Then, efficient removal becomes possible. In Patent Document 2, the coating film is removed by repeatedly moving up and down using a coating film removing member that is shorter in the axial direction of the substrate than the portion to be removed of the outer peripheral surface of the substrate. Therefore, the apparatus described in Patent Document 2 is configured such that the solvent contacts the outer surface coating film removing member while contacting the outer surface coating film removing member from the upper end to the lower end of the coating film on the outer surface of the substrate as in the present invention. It is not the structure which removes a coating film while supplying to.

  Furthermore, in the coating film removing method using the coating film removing apparatus shown in FIG. 1, since the solvent is discharged inside the substrate 2, the solvent is unlikely to scatter to the portion of the coating film that does not need to be removed. Therefore, a method of supplying a solvent directly to the contact portion between the removal portion of the outer peripheral surface coating film removing member and the coating film of the portion to be removed of the substrate, the outer peripheral surface coating film removing member, and the lower end of the substrate Compared with the method of rubbing while immersing the part in the solvent, the solvent can be removed accurately with less scattering.

  In order to soak up the solvent 11 in a minute space at the contact portion between the first removal portion 6a and the second removal portion 6b and the coating film of the portion to be removed of the base body 2, the bottom surface of the base body 2 is almost at the same position. The 1st removal part 6a and the 2nd removal part 6b need to contact | abut. However, even if the lower ends of the first removing portion 6a and the second removing portion 6b are located slightly above the lower end of the base 2, the solvent 11 can be used as long as the solvent 11 can wrap around the outer peripheral surface of the base 2. 11 can ooze into the minute space. The first removal unit 6 a and the second removal unit 6 b may be configured to extend downward from the lower end of the base 2. It is preferable that the lower ends of the first removing portion 6a and the second removing portion 6b are located below the lower end of the base 2 because the solvent 11 easily oozes up the contact portion and the coating film removal becomes efficient. .

  When the substrate 2 is lowered to the position where the coating film is removed, the outer circumferential surface coating film removing member 6 is placed in the radially outward direction of the substrate 2 so that the outer circumferential surface coating film removing member 6 does not contact the outer circumferential surface of the substrate 2. It is preferable to move and retract. Therefore, the outer peripheral surface coating film removing member holding member 7 can be moved to a position where the outer peripheral surface coating film removing member 6 does not come into contact with the outer side in the radial direction of the base 2 by an operating mechanism (not shown). Is preferred.

  As a detailed operation, the outer peripheral surface coating film removing member holding member 7 is placed on the base body so that the outer peripheral surface coating film removing member 6 does not contact the outer peripheral surface of the base body 2 while moving down the base body 2. 2 is moved outward in the radial direction of 2 and retracted. Next, after lowering the base body 2 to a predetermined position and stopping the movement, the outer peripheral surface coating film removing member holding member 7 is moved inward in the radial direction of the base body 2, and the outer peripheral surface coating film removing member 6 is moved. The first removal portion 6 a and the second removal portion 6 b are brought into contact with the outer peripheral surface of the base 2. Then, the support 8 is rotated to remove the coating film. When the base body 2 is lowered without moving the outer peripheral surface coating film removing member holding member 7 in the radially outward direction of the base body 2, the base body 2 becomes the upper end portions of the first removal portion 6 a and the second removal portion 6 b. Since it contacts and presses, wear and a deformation | transformation of the 1st removal part 6a and the 2nd removal part 6b will occur easily, and the boundary which removes a coating film will become disordered easily.

  In addition to the methods described above, the solvent may be supplied by immersing the lower end of the substrate or the outer peripheral surface removing member in the solvent, or by supplying the outer peripheral surface removing member to the substrate. For example, a method of directly supplying with a nozzle or the like so that the solvent is supplied to the contact portion of the removing portion with the coating film. From the viewpoint of scattering of the solvent, a coating film removing method using the coating film removing apparatus shown in FIG. 1 is preferable.

  A specific example in which the lower end portion of the base and the outer peripheral surface removal member are supplied in a solvent will be described with reference to FIG. FIG. 7 is a cross-sectional view (FIG. 7 (a)) and a top view (FIG. 7 (b)) showing a schematic configuration in the vicinity of the removing portion in an example of a coating film removing apparatus used in the coating film removing method of the present invention. is there. The same members as those in FIG. 1 are denoted by the same reference numerals, and the configuration thereof is the same as that in FIG.

  The coating film removing apparatus shown in FIG. 7 has a solvent reservoir 16 that temporarily stores the solvent 11. In such a coating film removing apparatus, the solvent 11 sent from the solvent supply tank 10 by the solvent supply pump 12 is discharged from the solvent supply port 3 and temporarily stored in the solvent storage unit 16 so as to overflow. It has become. The overflowed solvent 11 is recovered in the solvent recovery tank 9 and sent to the solvent supply tank 10 as in FIG. The lower end portion of the base 2 and the lower end portion of the outer peripheral surface coating film removing member 6 (the first removing portion 6a and the second removing portion 6b) come into contact (immersion) with the solvent inside the solvent storage portion 16. The solvent 11 is supplied to the contact portion between the coating film on the lower side in the axial direction of the substrate 2 and the outer peripheral surface coating film removing member 6.

  Although it does not specifically limit as the solvent 11 used with the coating-film removal method of this invention, The thing which can melt | dissolve or swell a coating film is desirable. Further, the surface of the solvent 11 is sufficiently wetted with respect to the wall surface of the minute space formed by the coating film on the lower side in the axial direction of the substrate 2 and the outer peripheral surface coating film removing member 6 and can soak up to the upper end of the minute space. It is desirable to have a tension. The solvent 11 may use only 1 type and may mix and use 2 or more types.

  Moreover, what is necessary is just to set the speed which rotates the support body 8 by the rotary motor 13 suitably. The larger the rotation speed, the shorter the time required for removal. However, if the rotation speed is too large, the outer peripheral surface coating film removing member 6 is excessively loaded, and the outer peripheral surface coating film removing member 6 may be deformed or cut. is there.

  When a plurality of layers are formed on the substrate 2 using the dip coating method, the coating film removing method of the present invention can be applied to some of the layers formed on the substrate 2 as necessary. May be performed only on all layers. Moreover, when performing the coating film removal method of the present invention for a plurality of layers, the coating film may be removed every time a coating film of each layer is formed, or after several dry coating films are formed in order, The coating film may be removed.

  In order to efficiently remove the coating film on the inner peripheral surface below the axial direction (vertical direction) of the substrate 2, for example, as shown in FIGS. 8 (a) and 8 (b), the outer peripheral surface is used as a coating film removing member. In addition to the coating film removing member 6, the inner peripheral surface coating film removing member 5 may be used.

  Even without using the inner peripheral surface coating film removing member 5, for example, by supplying a solvent to the inside of the base body 2, the coating film inside the base body 2 (that is, the coating film on the inner peripheral surface of the base body 2) can be removed. The coating film can be removed with high accuracy in a short time by providing the inner peripheral surface coating film removing member 5 and rubbing the coating film while supplying the solvent 11.

  In the coating film removing apparatus shown in FIG. 1, the solvent 11 supplied to the outer peripheral surface coating film removing member 6 is supplied along the inner surface of the substrate 2. Therefore, if the inner surface of the substrate 2 is dirty, the dirty solvent 11 is supplied to the outer peripheral surface. Therefore, the accuracy of removing the coating film on the outer peripheral surface becomes better when the inner peripheral coating film removing member 5 is provided and the coating film on the inner surface of the substrate 2 is removed with high accuracy in a short time.

  An example in which the inner peripheral surface coating film removing member 5 is provided will be described in more detail with reference to FIG. FIG. 8 is a cross-sectional view (FIG. 8 (a)) and a top view (FIG. 8 (b)) showing a schematic configuration in the vicinity of a removal portion in an example of a coating film removing apparatus used in the coating film removing method of the present invention. is there. In FIG. 8, the same members as those in FIG. 1 are denoted by the same reference numerals, and the configuration thereof is the same as that in FIG.

  The coating film removing apparatus shown in FIGS. 8A and 8B has two inner peripheral surface coating film removing members 5. The inner peripheral surface coating film removing member 5 is attached to the side surface of the shaft portion 15 and is rotatable together with the shaft portion 15. The inner peripheral surface coating film removing member 5 comes into contact with the inner peripheral surface of the substrate 2 when the shaft portion 15 is inserted into the substrate 2, and the substrate 8 is rotated by rotating the support 8 and the shaft portion 15. 2 Unnecessary coating film present on the inner peripheral surface of the substrate 2 can be removed by rubbing the inner surface. Therefore, when the coating film removing method of the present invention is performed using the coating film removing apparatus having the inner circumferential surface coating film removing member 5 shown in FIG. 8, the inner circumferential surface coating film removal is performed on the inner circumferential surface coating film of the substrate 2. A step of contacting the member 5 (inner peripheral surface coating film removing member contacting step) can also be performed. Further, while the inner peripheral surface coating film removing member 5 is kept in contact with the inner peripheral surface coating film of the base 2, the base 2 and the inner peripheral surface coating film removing member 5 are relatively rotated and rubbed. A step of removing the coating film on the inner peripheral surface (an inner peripheral surface coating film removing step) can also be performed. In FIG. 8, since the inner peripheral surface coating film removing member 5 is attached to the shaft portion 15 provided on the support 8 having the outer peripheral surface coating film removing member 6, the inner peripheral surface coating film removing step is The outer peripheral surface coating film removing step is performed at the same time.

  When providing the inner peripheral surface coating film removing member 5, as shown in FIGS. 8 (a) and 8 (b), an inner peripheral surface contact portion between the base 2 and the inner peripheral surface coating film removing member 5, Each of the outer peripheral surface contact portions of the base 2 and the outer peripheral surface coating film removing member 6 is preferably at a different position on the circumference of the base 2. When the respective contact portions are at the same position on the circumference of the base body 2, the inner peripheral surface coating film removing member 5 is compared with the case where the contact portions are at different positions as shown in FIGS. 8A and 8B. Thus, the flow of the solvent 11 is hindered, and the amount of the solvent 11 supplied to the outer peripheral surface coating film removing member 6 is reduced. Therefore, it is preferable that each contact part exists in a different position on the circumference. Note that the inner peripheral surface contact portion and the outer peripheral surface contact portion are at the same position on the circumference of the base body 2 that the inner peripheral surface coating film removing member extends in the same radial direction from the center of the circumference of the base body 2. 5 and the outer peripheral surface coating film removing member 6 are provided, that is, the inner peripheral surface contact portion and the outer peripheral surface contact portion are opposed to each other with the base 2 interposed therebetween.

  The material of the inner peripheral surface coating film removing member 5 can be selected in consideration of wear resistance and solvent resistance. Similarly to the outer peripheral surface coating film removing member, for example, resins such as polyethylene, polyester, polypropylene, and polyimide, and rubbers such as ethylene propylene rubber, ethylene propylene diene rubber, butyl rubber, and fluorine rubber can be used.

  The shape of the inner peripheral surface coating film removing member 5 is not particularly limited, such as a blade-like shape, a brush-like shape, or a cloth-like shape such as a nonwoven fabric, and can be appropriately selected. A blade-like one is preferred from the standpoint that dirt does not easily accumulate on the inner peripheral surface coating film removing member 5 during continuous use.

Next, a method for producing the electrophotographic photosensitive member of the present invention using the coating film removing method will be described.
An electrophotographic photoreceptor produced by the method for producing an electrophotographic photoreceptor of the present invention has a cylindrical substrate and a photosensitive layer containing a charge generating material and a charge transport material formed on the substrate. Even if the photosensitive layer is formed by laminating a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material in this order (laminated photosensitive layer), the charge generation material and the charge transport material (Single-layer type photosensitive layer) may be used. If the photosensitive layer is directly provided on the substrate, the photosensitive layer may be peeled off, or defects on the surface of the substrate (geometric defects such as scratches or material defects such as impurities) are directly reflected in the image, resulting in black spots or white spots. Image defects may occur. In order to solve these problems, it is preferable to have an undercoat layer between the photosensitive layer and the substrate.

[Cylindrical substrate]
As the cylindrical substrate, a conductive substrate (conductive substrate) is preferable. For example, a substrate made of metal or alloy such as aluminum, nickel, copper, gold, iron, or the like can be used. In addition to these, a base in which a thin film of metal such as aluminum, silver or gold is formed on an insulating base such as polyester resin, polycarbonate resin, polyimide resin or glass, or a conductive material such as indium oxide or tin oxide. And a substrate on which the thin film is formed.
The surface of the cylindrical substrate may be subjected to electrochemical treatment such as anodic oxidation, wet honing treatment, blast treatment, cutting treatment, etc. in order to improve electrical characteristics and suppress interference fringes.

[Conductive layer (first intermediate layer)]
A conductive layer may be provided between the base and the undercoat layer described later. The conductive layer is obtained by forming a coating film of a conductive layer coating liquid (first intermediate layer coating liquid) in which conductive particles are dispersed together with a resin and a solvent on a substrate and drying the coating film. Examples of the conductive particles include carbon black such as acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc, and silver, conductive tin oxide, and ITO (Indium Tin Oxide). Metal oxide powder.
Examples of the resin include polyester resin, polycarbonate resin, polyvinyl butyral resin, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin.
Examples of the solvent for the conductive layer coating solution include ether solvents, alcohol solvents, ketone solvents, and aromatic hydrocarbon solvents.

[Undercoat layer (second intermediate layer)]
An undercoat layer is provided between the substrate and the photosensitive layer for the purpose of suppressing charge injection from the substrate side to the photosensitive layer side and suppressing the occurrence of image defects such as fog.
Examples of the undercoat layer include a layer made of a binder resin such as polyamide, a layer in which a metal oxide is dispersed in the binder resin, and a layer containing an electron transport material.

  Examples of a method for producing an undercoat layer containing an electron transport material include, for example, an electron transport material having a polymerizable functional group, a crosslinking agent and a thermoplastic resin, and optionally a solvent and an undercoat layer containing silica particles. A coating film of the coating solution (second intermediate layer coating solution) is formed. And by heating-drying this coating film, the electron transport substance which has a polymeric functional group, and a crosslinking agent can be superposed | polymerized and an undercoat layer can be formed.

  Examples of the electron transport material include a quinone compound, an imide compound, a benzimidazole compound, and a cyclopentadienylidene compound. Examples of the polymerizable functional group include a hydroxy group, a thiol group, an amino group, a carboxy group, and a methoxy group. The polymerizable functional group may be directly bonded to the skeleton structure responsible for electron transport or may be present in the side chain (substituent bonded to the skeleton structure responsible for electron transport).

  Examples of the crosslinking agent include an electron transport material having a polymerizable functional group and a compound that polymerizes or crosslinks with a thermoplastic resin. Specific examples include compounds described in Shinzo Yamashita, Tosuke Kaneko “Crosslinking Agent Handbook” published by Taiseisha (1981), and the like.

The crosslinking agent used for the undercoat layer is preferably an isocyanate compound or an amine compound. An isocyanate compound having 2 to 6 isocyanate groups or blocked isocyanate groups is preferred. For example, triisocyanate benzene, triisocyanate methylbenzene, triphenylmethane triisocyanate, lysine triisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, naphthalene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, 2, Isocyanurate-modified products, biuret-modified products, allophanate-modified products of diisocyanates such as 2,4-trimethylhexamethylene diisocyanate, methyl-2,6-diisocyanate hexanoate, norbornane diisocyanate, adduct-modified products with trimethylolpropane and pentaerythritol Etc. Among these, an isocyanurate modified body and an adduct modified body are more preferable.
The blocked isocyanate group is a group having a structure of —NHCOX ¹ (X ¹ is a protecting group). X ¹ may be any protecting group that can be introduced into an isocyanate group.
Examples of the thermoplastic resin include polyvinyl acetal resin, polyolefin resin, polyester resin, polyether resin, and polyamide resin.
Examples of the silica particles include silica particles obtained by a wet method such as a sol-gel method or a water glass method, or a dry method such as a gas phase method. Moreover, the shape of the silica particles at the time of addition may be powdery, or may be added in the form of a slurry dispersed in a solvent.
Examples of the solvent used in the coating solution for the undercoat layer include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.

[Charge generation layer (in the case of laminated photosensitive layer)]
The charge generation layer is provided on the substrate, the conductive layer, or the undercoat layer.
The charge generation layer can be formed by forming a coating film of a coating solution for a charge generation layer obtained by dispersing a charge generation material together with a binder resin and a solvent, and drying the coating film.
Examples of the dispersion method include a method using a homogenizer, an ultrasonic wave, a ball mill, a sand mill, an attritor, and a roll mill.

  Examples of charge generating materials include azo pigments, perylene pigments, anthraquinone derivatives, anthanthrone derivatives, dibenzpyrenequinone derivatives, pyranthrone derivatives, violanthrone derivatives, isoviolanthrone derivatives, indigo derivatives, thioindigo derivatives, metal phthalocyanines, metal-free phthalocyanines, etc. Phthalocyanine pigments and bisbenzimidazole derivatives. Among these, at least one of an azo pigment and a phthalocyanine pigment is preferable. Among the phthalocyanine pigments, oxytitanium phthalocyanine, chlorogallium phthalocyanine, and hydroxygallium phthalocyanine are preferable.

  Oxytitanium phthalocyanine has a crystal form having strong peaks at 9.0 °, 14.2 °, 23.9 ° and 27.1 ° of the Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction. Oxytitanium phthalocyanine crystals and Bragg angles (2θ ± 0.2 °) of 9.5 °, 9.7 °, 11.7 °, 15.0 °, 23.5 °, 24.1 ° and 27.3 Crystalline oxytitanium phthalocyanine crystals having a strong peak at ° are preferred.

  Chlorogallium phthalocyanine has a crystal form having strong peaks at 7.4 °, 16.6 °, 25.5 ° and 28.2 ° of the Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction. Chlorogallium phthalocyanine crystals, crystal forms of chlorogallium phthalocyanine crystals having strong peaks at Bragg angles (2θ ± 0.2 °) of 6.8 °, 17.3 °, 23.6 ° and 26.9 °, Crystalline form of chlorogallium with strong peaks at Bragg angles (2θ ± 0.2 °) of 8.7 °, 9.2 °, 17.6 °, 24.0 °, 27.4 ° and 28.8 ° Phthalocyanine crystals are preferred.

  Examples of hydroxygallium phthalocyanine include crystalline gallium phthalocyanine crystals having strong peaks at 7.3 °, 24.9 °, and 28.1 ° of the Bragg angle (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction. Strong peaks at 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 ° with Bragg angles (2θ ± 0.2 °) A crystalline form of hydroxygallium phthalocyanine crystal is preferred.

  Examples of the binder resin used for the charge generation layer include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinylidene fluoride, and trifluoroethylene, Polyvinyl alcohol resin, polyvinyl acetal resin, polycarbonate resin, polyester resin, polysulfone resin, polyphenylene oxide resin, polyurethane resin, cellulose resin, phenol resin, melamine resin, silicon resin, epoxy resin and the like can be mentioned. Among these, a polyester resin, a polycarbonate resin, and a polyvinyl acetal resin are preferable, and a polyvinyl acetal resin is more preferable.

  In the charge generation layer, the mass ratio of the charge generation material to the binder resin (charge generation material / binder resin) is preferably in the range of 10/1 to 1/10, and is preferably 5/1 to 1/5. A range is more preferable. Examples of the solvent used in the charge generation layer coating solution include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.

[Charge transport layer (in the case of laminated photosensitive layer)]
The charge transport layer is provided on the charge generation layer.
The charge transport layer can be formed by drying a coating film of a charge transport layer coating solution obtained by dispersing a charge transport material together with a binder resin and a solvent.

  Charge transport materials are roughly classified into hole transport materials and electron transport materials. As the hole transport material, for example, polyaryl aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, benzidine compounds, triarylamine compounds such as triphenylamine, or groups derived from these compounds are mainly used. Examples thereof include polymers having a chain or a side chain. Among these, a triarylamine compound, a benzidine compound, or a styryl compound is preferable. As the electron transport material, use of the electron transport material exemplified in the undercoat layer (may be in the form of an electron transport material alone or in the form of an electron transport material having a polymerizable functional group). it can.

  Examples of the binder resin used for the charge transport layer include polyester resin, polycarbonate resin, polymethacrylate resin, polyarylate resin, polysulfone resin, and polystyrene resin. Among these, polycarbonate resin or polyarylate resin is preferable.

  In the charge transport layer, the mass ratio of the charge transport material and the binder resin (charge transport material / binder resin) is preferably 10/5 to 5/10, and more preferably 10/8 to 6/10.

  Examples of the solvent used in the charge transport layer coating liquid include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.

(Single layer type photosensitive layer)
As described above, the photosensitive layer may be a single-layer type photosensitive layer containing a charge generating material and a charge transport material in the same layer. In the case of a monolayer type photosensitive layer, any of the charge generation materials, charge transport materials, binder resins and solvents listed in the case of a laminated type photosensitive layer functionally separated into a charge generation layer and a charge transport layer can be used.

Such a method for producing an electrophotographic photosensitive member includes a coating solution for an electrophotographic photosensitive member for forming each layer constituting the electrophotographic photosensitive member (coating solution for conductive layer, coating solution for undercoat layer, charge generating layer). A cylindrical substrate is dip-coated in a coating solution or a coating solution for a charge transport layer. For example, a coating film of the coating solution is formed on the substrate by immersing and lifting the cylindrical substrate in the coating solution so that the axis is in the vertical direction. After forming the coating film of the electrophotographic photoreceptor coating solution, the coating film on the portion to be removed, which is an unnecessary coating film formed below the base in the axial direction, is removed by the coating film removing method of the present invention.
After removing the coating film of the portion to be removed, each layer is formed by heating or curing the remaining coating film.

  The removal of the coating film may be performed every time one layer of the coating film is formed by the dip coating method, or may be removed at once after sequentially forming several dry coating films. In the method for producing an electrophotographic photosensitive member of the present invention, the coating film removing method of the present invention may be used in the formation of at least one layer. Other layers may be formed by heating or curing after forming a coating film by a coating method other than a dip coating method such as a spray coating method, a curtain coating method, or a spin coating method, or by vapor deposition or the like. It may be formed.

Hereinafter, the present invention will be described specifically by way of examples. However, the present invention is not limited to the examples. In the following, “part” means “part by mass”.
The evaluation was conducted on a cylindrical aluminum substrate with a conductive layer coating solution (first intermediate layer coating solution) and an undercoat layer coating solution (second intermediate layer coating solution) having the composition shown in the following examples. By applying the coating solution for the charge generation layer and the coating solution for the charge transport layer by dip coating, removing the coating film on the lower outer peripheral surface of the cylindrical substrate, and visually observing the degree of removal of the coating film on the lower outer peripheral surface of the substrate went.

Example 1
An aluminum cylinder (JIS-A3003, aluminum alloy) having a length of 260.5 mm and an outer diameter of 30 mm was used as the substrate 2 (conductive substrate).

(Adjustment of coating solution for undercoat layer)
10 parts of an electron transport material represented by the following formula (A12), 13.5 parts of a blocked isocyanate compound (trade name: Duranate SBN-70D, manufactured by Asahi Kasei Chemicals Corporation), a polyvinyl acetal resin (trade name: ESREC KS-5Z, manufactured by Sekisui Chemical Co., Ltd.) 1.5 parts, zinc hexanoate (II) as a catalyst (trade name: zinc hexanoate (II), manufactured by Mitsuwa Chemicals Co., Ltd.) 0.05 part Was dissolved in a mixed solvent of 100 parts of 1-methoxy-2-propanol and 100 parts of tetrahydrofuran to prepare a coating solution for an undercoat layer.

  This coating solution for undercoat layer was dip-coated on the aluminum cylindrical substrate 2 to form a coating film. In addition, the film thickness of the coating film was set so that the film thickness of the central part of the layer obtained when the coating film was heated at 160 ° C. for 40 minutes and cured (polymerized) was 0.7 μm. Then, the coating film removal of the base | substrate 2 lower outer peripheral surface was implemented as follows.

  As the coating film removing apparatus, as shown in FIG. 8 (a), two outer peripheral surface coating film removing members 6 and two inner peripheral surface coating film removing members 5 are provided, and the substrate is supplied from the solvent supply port 3 at the upper end of the shaft portion 15. 2 An apparatus for supplying the solvent 11 inside was used. As shown in FIG. 8B which is a top view, the contact portion of the outer peripheral surface coating film removing member 6 with the base body 2 and the contact portion of the inner peripheral surface coating film removing member 5 with the base body 2 are: It was a different position in the circumferential direction of the substrate 2. As the shape of the outer peripheral surface coating film removing member 6, a rubber blade made of ethylene propylene diene rubber having a shape shown in FIG. 2 (a) was used (height dimension: 20 mm, width dimension: 3 mm, hardness: 60 ° and 80 °). 2 types). The hardness is expressed by durometer type A of JIS K 6253 (the same applies to the following).

  First, the outer peripheral surface coating film removing member 6 was retracted radially outward so as not to touch when the base body 2 was lowered. Next, the base body 2 on which the undercoat layer coating solution was dip-coated was supported in the vertical direction and lowered.

  The first removal is performed at a position 15 mm from the lower end of the base 2 so that the first removal portion 6a and the second removal portion 6b of the outer peripheral surface coating film removing member 6 are in contact with a region from the lower end of the base 2 to 15 mm. The lowering of the base 2 was stopped at the position where the upper ends of the part 6a and the second removal part 6b were aligned. Then, the outer peripheral surface coating film removing member 6 evacuated in the outer direction is moved in the radial inner direction, and the first removing portion 6 a and the second removing portion 6 b of the outer peripheral surface coating film removing member 6 are moved to the base 2. It was made to contact | abut to the outer peripheral surface. At this time, the lower end 5 mm portions of the first removing portion 6 a and the second removing portion 6 b of the outer peripheral surface coating film removing member 6 extended downward from the lower end of the base 2. Further, the contact position relationship between the first removing portion 6a and the second removing portion 6b of the outer peripheral surface coating film removing member 6 and the base 2 is composed of two kinds of blades having different hardnesses as shown in FIG. The first removing portion 6a and the second removing portion 6b of the outer peripheral surface coating film removing member 6 and the base 2 were brought into contact with each other. While discharging the solvent 11 from the solvent supply port 3 at the upper end of the shaft portion 15, the outer peripheral surface coating film removing member 6 is rotated at a speed of 45 rpm for 15 seconds, so that the first removing portion 6 a and the second removing portion 6 b are rotated. Was rubbed against the outer peripheral surface of the substrate 2 to remove the coating film. At the same time, the inner peripheral surface coating film removing member 5 rubbed the inner peripheral surface of the base 2 and the coating film on the inner peripheral surface was also removed. Cyclohexanone was used as the solvent 11.

By repeating this, the coating film was formed and the coating film was removed by the dip coating method of the undercoat layer coating solution for a total of 20 substrates. Further, in the same manner except that the rotation time was changed to 30 seconds and 60 seconds, the coating film was formed and the coating film was removed by the dip coating method for each of the 20 substrates. Table 1 shows the results of visual confirmation of the degree of removal of the coating film from the lower end of the outer peripheral surface of the substrate to the 15 mm position. The removal degree was ranked as follows.
A: The wiping residue of the coating film can be confirmed and is very good.
B: The wiping residue of a coating film can hardly be confirmed and is good.
C: The wiping residue of a coating film is seen.

(Example 2)
Example 1 is the same as Example 1 except that the hardness of the rubber blade (the first removal part 6a and the second removal part 6b) of the outer peripheral surface coating film removing member 6 is changed to 40 ° and 60 °, respectively. The coating film was removed and the degree of removal was ranked.

(Example 3)
In Example 1, two types of rubber blades (first removal portion 6a and second removal portion 6b) of the outer peripheral surface coating film removing member 6 (height dimension 20 mm, width dimension) as shown in FIG. 1.5 mm, hardness 60 °, height dimension 20 mm, width dimension 1.5 mm, hardness 80 °) were used by changing to a superposed blade. As shown in FIG. 4, the contact hardness relationship between the outer peripheral surface coating film removing member 6 (the first removing portion 6 a and the second removing portion 6 b) and the base 2 is such that the blade hardness on the upstream side of the rotation is the downstream side of the rotation. The coating film was removed in the same manner as in Example 1 except that the blade hardness was higher than that on the side, and the degree of removal was ranked.

Example 4
In Example 1, two types of rubber blades (first removal portion 6a and second removal portion 6b) of the outer peripheral surface coating film removing member 6 (height dimension 20 mm, width dimension) as shown in FIG. 1.5 mm, hardness 40 °, height dimension 20 mm, width dimension 1.5 mm, hardness 60 °) was used by changing to a superposed blade. As shown in FIG. 4, the contact hardness relationship between the outer peripheral surface coating film removing member 6 (the first removing portion 6 a and the second removing portion 6 b) and the base 2 is such that the blade hardness on the upstream side of the rotation is the downstream side of the rotation. The coating film was removed in the same manner as in Example 1 except that the blade hardness was higher than that on the side, and the degree of removal was ranked.

(Example 5)
In Example 1, two types of rubber blades (first removal portion 6a and second removal portion 6b) of the outer peripheral surface coating film removing member 6 (height dimension 20 mm, width dimension) as shown in FIG. 1.5 mm, hardness 60 °, height dimension 20 mm, width dimension 1.5 mm, hardness 80 °) were used by changing to a superposed blade. As shown in FIG. 5, the contact hardness relationship between the outer peripheral surface coating film removing member 6 (the first removing portion 6a and the second removing portion 6b) and the base 2 is such that the blade hardness on the upstream side of the rotation is the downstream side of the rotating surface. The coating film was removed in the same manner as in Example 1 except that the blade hardness was lower than the blade hardness on the side, and the degree of removal was ranked.

(Example 6)
In Example 1, two types of rubber blades (first removal portion 6a and second removal portion 6b) of the outer peripheral surface coating film removing member 6 (height dimension 20 mm, width dimension) as shown in FIG. 1.5 mm, hardness 40 °, height dimension 20 mm, width dimension 1.5 mm, hardness 60 °) was used by changing to a superposed blade. As shown in FIG. 5, the contact hardness relationship between the outer peripheral surface coating film removing member 6 (the first removing portion 6a and the second removing portion 6b) and the base 2 is such that the blade hardness on the upstream side of the rotation is the downstream side of the rotating surface. The coating film was removed in the same manner as in Example 1 except that the blade hardness was lower than the blade hardness on the side, and the degree of removal was ranked.

(Example 7)
In Example 1, two types of rubber blades (first removal portion 6a and second removal portion 6b) of the outer peripheral surface coating film removing member 6 (height dimension 20 mm, width dimension) as shown in FIG. 1.5 mm, hardness 60 °, height dimension 20 mm, width dimension 1.5 mm, hardness 80 °) were used by changing to a superposed blade. As shown in FIG. 6, the contact position relationship between the outer peripheral surface coating film removing member 6 (the first removing portion 6a and the second removing portion 6b) and the substrate 2 is set with the center of the cylindrical substrate as the rotation axis. The cylindrical substrate was rotated at 45 rpm, and the coating film was removed in the same manner as in Example 1, except that the blade hardness on the front side of rotation was lower than the blade hardness on the rear side of rotation. The degree of removal was ranked.

(Comparative Example 1)
Using the undercoat layer coating solution obtained by removing the polyvinyl acetal resin from the undercoat layer coating solution of Example 1, as shown in Table 1, the rubber blades (first removal portions 6a) of all the outer peripheral surface coating film removing members 6 were used. The coating film was removed in the same manner as in Example 1 except that the second removing portion 6b) was changed to only a rubber blade having a hardness of 40 °, and the degree of removal was ranked.

(Comparative Example 2)
In Comparative Example 1, as shown in Table 1, the rubber blades (first removal portion 6a and second removal portion 6b) of all outer peripheral surface coating film removal members 6 were changed to only rubber blades having a hardness of 80 °. Except for removing the coating film in the same manner as in Comparative Example 1 and ranking the degree of removal.

(Comparative Example 3)
Using the undercoat layer coating solution obtained by removing the polyvinyl acetal resin from the undercoat layer coating solution of Example 3, as shown in Table 1, the rubber blade (first removing portion 6a) of the same outer peripheral surface coating film removing member 6 was used. The coating film was removed in the same manner as in Example 3 except that the second removing portion 6b) was changed to a superposed rubber blade having a hardness of 40 °, and the degree of removal was ranked.

(Comparative Example 4)
In Comparative Example 3, as shown in Table 1, the rubber blades (the first removing portion 6a and the second removing portion 6b) of the same outer peripheral surface coating film removing member 6 are overlapped with a rubber blade having a hardness of 80 ° The coating film was removed in the same manner as in Comparative Example 3 except that the removal degree was changed, and the degree of removal was ranked.

(Example 8)
(Adjustment of coating solution for conductive layer)
50 parts of titanium oxide particles coated with oxygen-deficient tin oxide (powder resistivity: 120 Ω · cm, tin oxide coverage: 40%), phenol resin (Pryofen J-325, manufactured by DIC Corporation) 40 parts of resin solid content (60%) and 50 parts of methoxypropanol as a solvent (dispersion medium) are placed in a sand mill using glass beads with a diameter of 1 mm to prepare a coating solution for a conductive layer by dispersing for 3 hours. did.

  This conductive layer coating solution was dip coated on the same aluminum cylindrical substrate 2 as used in Example 1 to form a coating film. In addition, the film thickness of the coating film was set so that the film thickness at the center of the layer obtained when the coating film was dried and thermally cured at 150 ° C. for 30 minutes was 20 μm. Then, the coating film removal of the base | substrate 2 lower outer peripheral surface was implemented.

  The coating film removal method was performed in the same manner as in Example 5 except that methoxypropanol was used as the solvent 11 and the removal time was 30 seconds, 60 seconds, and 120 seconds. Table 2 shows the results of visual confirmation of the degree of removal of the coating film on the outer peripheral surface of the substrate.

Example 9
The same conductive layer coating solution as used in Example 8 was dip-coated on the same aluminum cylindrical substrate 2 as used in Example 1 to form a coating film. Then, the coating film removal of the outer peripheral surface was not implemented, but only the coating film removal of the inner peripheral surface was performed. The removal of the coating film only on the inner peripheral surface was performed by wiping the inner peripheral surface by hand with a sylbon paper soaked with a solvent. After removing the coating film on the inner peripheral surface, it was dried and thermally cured at 150 ° C. for 30 minutes to form a conductive layer having a thickness of 20 μm at the center.

  Next, an undercoat layer coating solution similar to that used in Example 1 was dip-coated on the conductive layer to form a coating film. In addition, the film thickness of the coating film was set so that the film thickness of the center part of the layer obtained when the coating film was heated at 160 ° C. for 40 minutes and cured (polymerized) was 0.5 μm. Then, the coating film removal of the base | substrate 2 lower outer peripheral surface was implemented.

  The coating film removal method was performed in the same manner as in Example 5 except that the removal time was 30 seconds, 60 seconds, and 120 seconds, and evaluation was performed in the same manner. Table 2 shows the results of visual confirmation of the degree of removal of the coating solution for the undercoat layer on the outer peripheral surface of the substrate 2.

(Example 10)
The same conductive layer coating solution as used in Example 8 was dip-coated on the same aluminum cylindrical substrate 2 as used in Example 1 to form a coating film. Thereafter, the coating film on the outer circumferential surface was not removed, and only the coating film on the inner circumferential surface was removed in the same manner as in Example 9. The film was dried and heat-cured at 150 ° C. for 30 minutes to form a conductive layer having a thickness of 20 μm at the center.

  Next, the undercoat layer coating solution similar to that used in Example 1 was dip-coated on the conductive layer to form a coating film. Thereafter, the coating film on the outer peripheral surface was not removed, and only the coating film on the inner peripheral surface was removed by the same method as that for forming the conductive layer. It was heated at 160 ° C. for 40 minutes and cured (polymerized) to form an undercoat layer having a thickness of 0.5 μm at the center.

(Adjustment of coating solution for charge generation layer)
Next, Bragg angles (2θ ± 0.2 °) in CuKα characteristic X-ray diffraction of 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 ° and A crystalline hydroxygallium phthalocyanine crystal (charge generation material) having a peak at 28.3 ° was prepared. 10 parts of this hydroxygallium phthalocyanine crystal, 5 parts of polyvinyl butyral resin (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 250 parts of cyclohexanone are placed in a sand mill using glass beads having a diameter of 1 mm. Dispersed for 5 hours. Next, 250 parts of ethyl acetate was added thereto to prepare a charge generation layer coating solution.

  This charge generation layer coating solution was dip coated on the undercoat layer to form a coating film. In addition, the film thickness of the coating film was such that the film thickness at the center of the layer obtained when the coating film was dried at 95 ° C. for 10 minutes was 0.18 μm. Then, the coating film removal of the base | substrate 2 lower outer peripheral surface was implemented.

  The coating film removal method was performed in the same manner as the coating film removal of the coating solution for the undercoat layer of Example 9 and evaluated in the same manner. Table 2 shows the results of visual confirmation of the degree of removal of the charge generation layer coating solution on the outer peripheral surface of the substrate 2.

(Example 11)
The same conductive layer coating solution as used in Example 8 was dip-coated on the same aluminum cylindrical substrate 2 as used in Example 1 to form a coating film. Thereafter, the coating film on the outer circumferential surface was not removed, and only the coating film on the inner circumferential surface was removed in the same manner as in Example 9. The film was dried and heat-cured at 150 ° C. for 30 minutes to form a conductive layer having a thickness of 20 μm at the center.

  Next, the undercoat layer coating solution similar to that used in Example 1 was dip-coated on the conductive layer to form a coating film. Thereafter, the coating film on the outer peripheral surface was not removed, and only the coating film on the inner peripheral surface was removed by the same method as that for forming the conductive layer. It was heated at 160 ° C. for 40 minutes and cured (polymerized) to form an undercoat layer having a thickness of 0.5 μm at the center.

  Next, the same coating solution for charge generation layer as that used in Example 10 was dip-coated on the undercoat layer to form a coating film. Thereafter, the coating film on the outer peripheral surface was not removed, and only the coating film on the inner peripheral surface was removed by the same method as that for forming the conductive layer. The film was dried at 95 ° C. for 10 minutes to form a charge generation layer having a central thickness of 0.18 μm.

(Adjustment of coating solution for charge transport layer)
Next, 5 parts of a compound represented by the following formula (CTM-1), 5 parts of a compound represented by the following formula (CTM-2), 10 parts of a polycarbonate resin having a structural unit represented by the following formula (B1-1) Then, it was dissolved in 50 parts of monochlorobenzene to prepare a coating solution for charge transport layer.
This charge transport layer coating solution was dip coated on the charge generation layer to form a coating film. In addition, the film thickness of the coating film was set so that the film thickness at the center of the layer obtained when the coating film was dried at 120 ° C. for 30 minutes was 15 μm. Then, the coating film removal of the base | substrate 2 lower outer peripheral surface was implemented.

  The coating film removal method was performed in the same manner as in Example 5 except that monochlorobenzene was used as the solvent 11 and the removal time was 30 seconds, 60 seconds, and 120 seconds. Table 2 shows the results of visual confirmation of the degree of removal of the coating film of the charge transport layer and the charge transport layer coating solution on the outer peripheral surface of the substrate 2.

DESCRIPTION OF SYMBOLS 1: Base | substrate holding member 2: Base | substrate 3: Solvent supply port 4: Solvent supply flow path 5: Inner peripheral surface coating film removal member 6: Outer peripheral surface coating film removal member 6a: Hardness compared with 1st removal member (6b) High removal part)
6b: 2nd removal member (removal part with low hardness compared with 6a)
7: Holding member for outer peripheral surface coating film removing member 8: Support 9: Solvent recovery tank 10: Solvent supply tank 11: Solvent 12: Solvent supply pump 13: Rotating motor 15: Shaft 16: Solvent reservoir

Claims (8)

A coating film removing method for supporting a cylindrical substrate on which a coating film of a coating solution for an electrophotographic photosensitive member is formed in a vertical direction and removing a coating film on a portion to be removed that is below the axial direction of the substrate,
The method includes a first removing portion of the outer peripheral surface coating film removing member and a second removing portion of the outer peripheral surface coating film removing member from the upper end to the lower end of the coating film on the outer peripheral surface of the substrate. And contacting the first removal portion and the second removal portion of the outer peripheral surface coating film removing member from the upper end to the lower end of the coating film of the portion to be removed on the outer peripheral surface of the substrate. While supplying the solvent to the contact portion between the coating film of the portion to be removed and the first removal portion and the second removal portion of the outer peripheral surface coating film removing member, the base and the outer peripheral surface coating are supplied. A step of relatively rotating and rubbing the first removal portion and the second removal portion of the film removal member to remove the coating film of the portion to be removed,
A method of removing a coating film from a cylindrical substrate, wherein the first removal portion of the outer peripheral surface coating film removal member and the second removal portion of the outer peripheral surface coating film removal member have different hardnesses.   The method of removing a coating film on a cylindrical substrate according to claim 1, wherein the first removal section and the second removal section are separated from each other.   2. The method of removing a coating film from a cylindrical substrate according to claim 1, wherein the first removal portion and the second removal portion are integrated or in contact with each other. In the step of removing the coating film of the portion to be removed, the outer peripheral surface coating film removing member rotates with the center of the cylindrical base as the rotation axis,
4. The coating film on a cylindrical substrate according to claim 3, wherein the first removing portion and the second removing portion have one hardness on the rotation leading side lower than the other hardness on the rotation trailing side. Removal method. The step of removing the coating film of the portion to be removed includes rotating the cylindrical substrate around the center of the cylindrical substrate,
4. The cylindrical base body coating according to claim 3, wherein the first removing section and the second removing section have one hardness on the rotation upstream side lower than the other hardness on the rotation downstream side. Film removal method. In the method for producing an electrophotographic photosensitive member, which forms a coating film of a coating solution for an electrophotographic photosensitive member on a cylindrical substrate by dip coating,
After forming a coating film of a coating solution for an electrophotographic photosensitive member on the substrate by a dip coating method, the axially lower side of the substrate is removed by the method for removing a coating film on a cylindrical substrate according to any one of claims 1 to 5. A method for producing an electrophotographic photosensitive member, comprising a step of removing a coating film on a portion to be removed.   The method for producing an electrophotographic photosensitive member according to claim 6, wherein the coating solution for an electrophotographic photosensitive member is a coating solution for an undercoat layer.   8. The method for producing an electrophotographic photosensitive member according to claim 7, wherein the undercoat layer coating solution contains an electron transport material having a polymerizable functional group, a crosslinking agent, and a thermoplastic resin.

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