JP7815734B2 - Coating device, coating method, and photoreceptor manufacturing method - Google Patents

Description

The present invention relates to a coating device, a coating method, and a method for manufacturing a photoreceptor.

Patent Document 1 below discloses a coating device that coats the outer surface of a cylindrical substrate by immersing the cylindrical substrate in a coating liquid while holding the cylindrical axis approximately vertical and then lifting it out of the coating liquid. The coating device includes a coating tank that contains the coating liquid and in which the cylindrical substrate is immersed, a degassing tank that at least suppresses the generation of bubbles in the coating liquid, and a circulation tank that circulates the coating liquid to the coating tank. The coating liquid is sent from the bottom of the circulation tank to the bottom of the coating tank by a pressure pump, overflows from the upper edge of the coating tank, returns to the degassing tank, and is sent from the bottom of the degassing tank back into the coating liquid in the circulation tank. The degassing tank is also equipped with a coating liquid circulation mechanism.

Japanese Patent Application Laid-Open No. 2002-045754

The objective of the present disclosure is to provide a coating device, a coating method, and a method for manufacturing a photoreceptor that suppress the occurrence of bubble defects in the coating film on the outer surface of a cylinder, compared to when the coating liquid is allowed to flow down the outer surface of a cylinder and fall onto the surface of the coating liquid in a container.

The coating device according to the first aspect comprises a coating liquid holding unit having an upper opening and a lower opening, in which a coating liquid is held. The coating liquid holding unit applies the coating liquid to the outer peripheral surface of the cylinder by passing a cylinder through the upper opening and the lower opening and moving the cylinder upward in the vertical direction relative to the cylinder. The coating device also comprises a container for storing the coating liquid that has flowed down, a circulation unit for circulating the coating liquid inside the container to the coating liquid holding unit, and a receiving member that is positioned above the liquid level of the coating liquid inside the container and has an inclined surface that receives the coating liquid that flows downward along the outer peripheral surface of the cylinder.

The applicator according to the second aspect is the applicator according to the first aspect, wherein the inclined surface is flat or linear when viewed from a direction perpendicular to the axial direction of the coating liquid holding unit, and the angle of the inclined surface with respect to the vertical direction is between 10° and 60°.

The applicator according to the third aspect is the applicator according to the second aspect, wherein the angle of the inclined surface relative to the vertical direction is between 15° and 45°.

The applicator according to the fourth aspect is the applicator according to the first aspect, wherein the inclined surface is curved, and the angle between the tangent plane of the curved surface at the intersection of an extension line extending downward along the outer circumferential surface of the cylinder and the vertical direction is between 10° and 60°.

The applicator according to the fifth aspect is the applicator according to the fourth aspect, wherein the angle between the tangent plane and the vertical direction at the intersection of the curved surface of the extension line extending downward along the outer peripheral surface of the cylindrical body is between 15° and 45°.

The sixth aspect of the coating device is the coating device described in any one of the second to fifth aspects, wherein the inclined surface is inclined downward in one direction intersecting the vertical direction.

The seventh aspect of the applicator is the applicator according to the second or third aspect, wherein the inclined surface has a conical shape with a protruding center when viewed from the side.

The applicator according to the eighth aspect is the applicator according to the first aspect, wherein the inclined surface is a curved surface whose central portion protrudes in a mountain shape when viewed from the side.

The applicator according to the ninth aspect is the applicator according to the eighth aspect, wherein the angle between the tangent plane and the vertical direction at the intersection of the extension line extending downward along the outer peripheral surface of the cylindrical body and the inclined surface is between 10° and 60°.

The coating method according to the tenth aspect is a method for coating a coating liquid using the coating device according to any one of the first to ninth aspects, and includes the steps of: moving the cylindrical body upward in the vertical direction relative to the coating liquid holding unit and coating the coating liquid from the coating liquid holding unit onto the outer peripheral surface of the cylindrical body; receiving the coating liquid flowing downward along the outer peripheral surface of the cylindrical body on the inclined surface of the receiving member above the liquid level of the coating liquid in the container and storing the coating liquid in the container; and circulating the coating liquid inside the container to the coating liquid holding unit by the circulation unit.

The coating method according to the eleventh aspect is the coating method according to the tenth aspect, wherein the cylindrical body is a cylindrical member or a cylindrical core material with an endless belt-like member wrapped around it.

The photoreceptor manufacturing method according to the twelfth aspect is a photoreceptor manufacturing method that uses the coating method according to the tenth or eleventh aspect to manufacture a photoreceptor, wherein the cylindrical body is a metallic cylindrical member or a cylindrical core material with a metallic endless belt-like member wound around it, and the coating liquid contains a photosensitive material.

The coating device according to the first aspect reduces the occurrence of bubble defects in the coating film on the outer surface of the cylinder compared to when the coating liquid is allowed to flow down the outer surface of the cylinder and fall onto the surface of the coating liquid in the container.

With the applicator device of the second aspect, foaming caused by impact when the application liquid is received by the receiving member is suppressed compared to when the angle of the inclined surface with respect to the vertical is less than 10°. Foaming caused when the application liquid received by the receiving member joins the surface of the application liquid in the container is suppressed compared to when the angle of the inclined surface with respect to the vertical is greater than 60°.

With the application device of the third aspect, foaming caused by impact when the application liquid is received by the receiving member is suppressed compared to when the angle of the inclined surface with respect to the vertical is less than 15°. Foaming caused when the application liquid received by the receiving member joins the surface of the application liquid in the container is suppressed compared to when the angle of the inclined surface with respect to the vertical is greater than 45°.

With the application device of the fourth aspect, foaming caused by impact when the application liquid is received by the receiving member is suppressed compared to when the angle between the tangent surface and the vertical direction at the intersection of the curved surface of the extension line extended downward along the outer peripheral surface of the cylinder is less than 10°. Foaming caused when the application liquid received by the receiving member meets the surface of the application liquid in the container is suppressed compared to when the angle between the tangent surface and the vertical direction at the intersection of the curved surface of the extension line extended downward along the outer peripheral surface of the cylinder is greater than 60°.

With the application device of the fifth aspect, foaming caused by impact when the application liquid is received by the receiving member is suppressed compared to when the angle between the tangent surface and the vertical direction at the intersection of the curved surface of the extension line extended downward along the outer peripheral surface of the cylinder is less than 15°. Foaming caused when the application liquid received by the receiving member meets the liquid surface of the application liquid in the container is suppressed compared to when the angle between the tangent surface and the vertical direction at the intersection of the curved surface of the extension line extended downward along the outer peripheral surface of the cylinder is greater than 45°.

With the application device according to the sixth aspect, the structure of the receiving member is simpler than when the inclined surface is inclined in multiple directions intersecting the vertical direction.

With the application device according to the seventh aspect, the application liquid that falls from the outer surface of the cylindrical body is less likely to come into contact with the liquid surface inside the container, compared to when the inclined surface has a valley-shaped recess.

With the application device according to the eighth aspect, the application liquid that falls from the outer surface of the cylinder is less likely to come into contact with the liquid surface inside the container, compared to when the inclined surface has a valley-shaped recess.

According to the application method of the ninth aspect, foaming caused by impact when the application liquid is received by the receiving member is suppressed compared to when the angle between the tangent plane and the vertical direction at the intersection of the inclined plane of the extension line extended downward along the outer peripheral surface of the cylindrical body is less than 10°. Compared to when the angle between the tangent plane and the vertical direction at the intersection of the inclined plane of the extension line extended downward along the outer peripheral surface of the cylindrical body is greater than 60°, foaming caused when the application liquid received by the receiving member meets the surface of the application liquid in the container is suppressed.

The coating method according to the tenth aspect reduces the occurrence of bubble defects in the coating film on the outer surface of the cylinder compared to when the coating liquid is allowed to flow down the outer surface of the cylinder and fall onto the surface of the coating liquid in the container.

The coating method according to the eleventh aspect reduces the occurrence of bubble defects in the coating film on the outer surface of a cylindrical member or endless belt-like member compared to when the coating liquid is allowed to flow down the outer surface of a cylinder and fall onto the surface of the coating liquid in a container.

The photoreceptor manufacturing method according to the twelfth aspect reduces the occurrence of bubble defects in the coating film on the outer surface of the photoreceptor compared to when the coating liquid is allowed to flow down the outer surface of the cylindrical body and fall onto the surface of the coating liquid in the container.

1 is a cross-sectional view showing an outline of the overall configuration of a coating apparatus according to a first embodiment. 3 is a cross-sectional view showing an enlarged view of a part of a coating liquid holding unit used in the coating device according to the first embodiment. FIG. 2 is a perspective view showing the configuration of a receiving member and a container for receiving a coating liquid used in the coating device according to the first embodiment. FIG. (A) is a schematic diagram showing the state before a cylindrical body is inserted into the coating liquid holding section of the coating device in the first embodiment, (B) is a schematic diagram showing the state after the cylindrical body has been inserted into the coating liquid holding section of the coating device and lowered, and (C) is a schematic diagram showing the state in the middle of moving the cylindrical body upward in the vertical direction relative to the coating liquid holding section. 5A is a side view showing a part of a cylindrical body on whose outer surface a coating film made of a coating liquid is formed, and FIG. 5B is a cross-sectional view taken along line 5B-5B in FIG. 5A. FIG. 3 is an enlarged side view of a receiving member used in the coating device according to the first embodiment. FIG. 10 is an enlarged side view of a receiving member used in a coating device according to a second embodiment. FIG. 11 is an enlarged side view of a receiving member used in a coating device according to a third embodiment. FIG. 10 is an enlarged side view of a receiving member used in a coating device according to a fourth embodiment. FIG. 10 is a schematic perspective view showing the configuration of a container of a coating device according to a comparative example.

The following describes embodiments of the technology disclosed herein. In the following description, the direction indicated by the arrow UP in the drawings refers to the upward direction of the device.

First Embodiment
<Overall configuration of coating device>
FIG. 1 shows a cross-sectional view of an example of a coating apparatus 10 according to the first embodiment.

As shown in FIG. 1, the coating device 10 is a device that coats the outer peripheral surface 100A of a cylindrical body 100 with a coating liquid L. The coating device 10 includes a coating liquid holding unit 12 that holds the coating liquid L, and a container 14 that contains the coating liquid L that has flowed down from the coating liquid holding unit 12. The coating device 10 also includes a circulation unit 16 that circulates the coating liquid L from the container 14 to the coating liquid holding unit 12, and a receiving member 18 that receives the coating liquid L that has flowed down the outer peripheral surface 100A of the cylindrical body 100. The coating device 10 includes a cylindrical housing 20. The coating liquid holding unit 12 is supported on the upper, vertical side inside the housing 20. The container 14 is provided at the lower, vertical side of the housing 20.

(Cylindrical body)
The cylindrical body 100 is, for example, a metallic cylindrical member, or a cylindrical core material with a metallic endless belt-like member wound around it. The cylindrical member or endless belt-like member constituting the cylindrical body 100 is, for example, a photoreceptor substrate for electrophotography. Furthermore, for example, when a photoreceptor substrate for electrophotography is used as the cylindrical body 100, a liquid containing a photosensitive material is used as the coating liquid L. In this embodiment, the coating device 10 applies the coating liquid L to the cylindrical member or endless belt-like member constituting the cylindrical body 100. By using a liquid containing a photosensitive material as the coating liquid L, a photoreceptor for electrophotography can be manufactured.

(Housing)
1, the housing 20 is made of a cylindrical member and is arranged so that the axial direction of the housing 20 is the vertical direction. As an example, the housing 20 includes a cylindrical portion 20A arranged along the vertical direction.

The upper end of the cylindrical portion 20A is provided with an upper wall portion 21B extending radially inward, and a circular opening 21C is formed in the upper wall portion 21B. The inner diameter of the opening 21C is larger than the outer diameter of the cylindrical body 100. The cylindrical body 100 is configured to pass through the opening 21C in the axial direction.

(Coating liquid holding section)
1 and 2, the coating liquid holding portion 12 is cylindrical and has a function of discharging the coating liquid L radially inward. This allows the coating liquid L to be applied to the outer peripheral surface 100A of a cylindrical body 100 inserted into the coating liquid holding portion 12. The coating liquid holding portion 12 includes a case 24. The case 24 includes a cylindrical portion 24A, an upper wall portion 24B bent radially inward from the upper end of the cylindrical portion 24A, and a block portion 24C provided on the lower side of the cylindrical portion 24A.

An inlet 24E through which the coating liquid L flows is provided at the bottom of one radial side of the cylindrical portion 24A.

A circular upper opening 25 is provided in the upper wall portion 24B (see Figure 2). The inner diameter of the upper opening 25 is larger than the outer diameter of the cylindrical body 100. The upper opening 25 of the upper wall portion 24B is configured so that the cylindrical body 100 passes through it in the axial direction.

The block portion 24C comprises a bottom wall portion 26A connected to the lower end of the cylindrical portion 24A, and a cylindrical inner wall portion 26B extending upward from the radially inner end of the bottom wall portion 26A. An inclined portion 27 is formed on the upper side of the inner wall portion 26B, sloping radially inward. A circular lower opening 28 is provided at the upper end of the inclined portion 27 of the inner wall portion 26B. The inner diameter of the lower opening 28 is larger than the outer diameter of the cylindrical body 100. The inner diameter of the lower opening 28 is also smaller than the inner diameter of the upper opening 25. The cylindrical body 100 is configured to pass axially through the lower opening 28 of the block portion 24C.

The application liquid holding unit 12 is supported on the upper side of the interior of the housing 20 by a support unit (not shown).

The case 24 comprises a cylindrical portion 24A, an upper wall portion 24B, and a block portion 24C, with the upper side of the block portion 24C opening radially inward. An annular body 32 is provided above the block portion 24C within the case 24. An installation surface 30 on which the annular body 32 is movably positioned is provided at the top of the block portion 24C. The installation surface 30 is flat and extends horizontally.

The annular body 32 is disposed in the open portion radially inward of the case 24. The inner diameter of the annular body 32 is larger than the outer diameter of the cylindrical body 100. As an example, the inner diameter of the annular body 32 is smaller than the inner diameter of the lower opening 28. The inner circumferential surface 32A of the annular body 32 is exposed in the area penetrated by the cylindrical body 100 (see FIG. 2). The cylindrical body 100 penetrates the interior of the annular body 32 in the axial direction. As an example, the annular body 32 is disposed on the installation surface 30 with the application liquid L interposed therebetween. The annular body 32 is movable (slidable in this embodiment) relative to the installation surface 30. In this embodiment, no drive unit is provided to directly drive the annular body 32, and the annular body 32 autonomously slides relative to the installation surface 30.

As an example, the inner peripheral surface 32A of the annular body 32 is provided with an inclined surface 33A located on the upper side and sloping downward from the upper opening 25 side, and a straight portion 33B located vertically from the lower end of the inclined surface 33A (see Figure 2).

Inside the case 24, flow paths 34 through which the coating liquid L flows are provided between the cylindrical portion 24A and the block portion 24C, and between the cylindrical portion 24A and the annular body 32. The upstream end of the flow path 34 in the flow direction of the coating liquid L is connected to the inlet 24E (see FIG. 1). The coating liquid holding portion 12 is provided with a slit-shaped discharge portion 36 running circumferentially between the upper opening 25 of the upper wall portion 24B and the annular body 32, and the coating liquid L is discharged from the discharge portion 36 (see FIG. 2). That is, the discharge portion 36 faces the area of the coating liquid holding portion 12 through which the cylindrical body 100 penetrates, and the coating liquid L is discharged toward the cylindrical body 100. The coating liquid L discharged from the discharge portion 36 overflows from the upper opening 25 onto the upper surface of the upper wall portion 24B and flows downward between the annular body 32 and the outer circumferential surface 100A of the cylindrical body 100.

In this state, by moving the cylindrical body 100 upward relative to the coating liquid holding unit 12, the coating liquid L is applied to the outer peripheral surface 100A of the cylindrical body 100 (see Figures 4(B) and 4(C)). In the coating liquid holding unit 12, the coating liquid L flows between the outer peripheral surface 100A of the cylindrical body 100 and the inner peripheral surface 32A of the annular body 32, and the pressure of the flowing coating liquid L causes the annular body 32 to move relative to the installation surface 30. At this time, the annular body 32 is movable relative to the installation surface 30 so that the gap between the outer peripheral surface 100A of the cylindrical body 100 and the inner peripheral surface 32A of the annular body 32 is uniform along the circumferential direction.

Figure 4 shows an example of a method for applying coating liquid L to the outer peripheral surface 100A of a cylindrical body 100 using the coating liquid holding unit 12 of the coating device 10. As shown in Figure 4(A), the cylindrical body 100 is inserted axially from above the coating liquid holding unit 12 and moved downward (in the direction of arrow A). As shown in Figure 4(B), the cylindrical body 100 is further lowered in the direction of arrow A, and coating liquid L is supplied to the coating liquid holding unit 12 by the circulation unit 16 (see Figure 1), thereby filling the space between the annular body 32 of the coating liquid holding unit 12 and the outer peripheral surface 100A of the cylindrical body 100. When the cylindrical body 100 reaches the bottom, the upper axial end of the cylindrical body 100 is positioned opposite the coating liquid holding unit 12.

Then, as shown in FIG. 4(C), the cylinder 100 is moved upward (in the direction of arrow B) relative to the coating liquid holding unit 12. At this time, the coating liquid L is ejected from the ejection unit 36 so that it overflows from above. As a result, the coating liquid L flows downward from the lower opening 28 and is applied to the outer peripheral surface 100A of the cylinder 100 located above the upper opening 25, thereby forming a coating film 102 on the outer peripheral surface 100A of the cylinder 100 (see FIG. 5(B)). Note that FIG. 4 is one example of a method for applying the coating liquid L to the outer peripheral surface 100A of the cylinder 100, and the application method can be changed.

As shown in Figure 5(A), during the process of applying the coating liquid L to the outer peripheral surface 100A of the cylindrical body 100, the coating liquid L applied to the outer peripheral surface 100A of the cylindrical body 100 flows downward along the outer peripheral surface 100A of the cylindrical body 100.

As shown in FIG. 1, the coating device 10 has a wall 50 below the coating liquid holding unit 12 inside the housing 20. The wall 50 has an opening 50A through which the cylinder 100 passes. The diagonally lower end of the wall 50 has a hole 50B located adjacent to the inner wall surface of the housing 20. This allows the coating liquid L to flow down from the hole 50B in the wall 50, along the inner wall surface of the housing 20, and be collected in the container 14.

(container)
1, the container 14 is connected to the lower end of the cylindrical portion 20A of the housing 20. The container 14 includes a cylindrical portion 14A connected to the cylindrical portion 20A, and a recessed portion 14B disposed below the cylindrical portion 14A and having a valley-shaped recessed bottom surface. In this embodiment, the bottom surface of the recessed portion 14B has an inverted conical recessed shape with an inner diameter that gradually decreases downward.

The recess 14B has a bottom surface that slopes downward from the cylindrical portion 14A side toward the center in the radial direction, with the center of the recess 14B being the lowest part. The recess 14B of the container 14 is designed to collect the coating liquid L that flows down from the coating liquid holding portion 12 side. As an example, the liquid level L1 of the coating liquid L is located on the upper side of the recess 14B.

(Receiving member)
As shown in FIGS. 1 and 3 , the receiving member 18 is provided within the container 14. The receiving member 18 has a conical shape with a central portion protruding upward in the vertical direction. More specifically, the receiving member 18 has an inclined surface 18A that slopes upward from the recess 14B toward the radial center, and an apex 18B formed at the upper end of the inclined surface 18A. In a direction perpendicular to the axial direction of the receiving member 18, the width of the maximum portion of the receiving member 18 is greater than the outer diameter of the cylindrical body 100. As a result, the receiving member 18 is configured to receive the coating liquid L flowing downward along the outer peripheral surface 100A of the cylindrical body 100 on the inclined surface 18A. In this embodiment, the portion of the inclined surface 18A that receives the coating liquid L is located above the liquid level L1 of the coating liquid L within the container 14. Therefore, the coating liquid L flowing downward along the outer peripheral surface 100A of the cylindrical body 100 does not fall directly onto the liquid level L1 of the coating liquid L.

In this embodiment, as shown in FIG. 6, the inclined surface 18A is linear when viewed in a direction perpendicular to the axial direction of the application liquid holding unit 12 (i.e., when viewed from the side). As an example, the inclined surface 18A of the receiving member 18 is symmetrical in the left-right direction shown in FIG. 6. The angle θ1 of the inclined surface 18A with respect to the vertical direction is preferably 10° or greater and 60° or less, more preferably 12° or greater and 52° or less, and even more preferably 15° or greater and 45° or less. For example, the angle θ1 of the inclined surface 18A with respect to the vertical direction is 45°.

(circulation department)
1, the circulation unit 16 includes a supply pipe 60 that supplies the coating liquid L in the container 14 to the coating liquid holding unit 12, and a pump 62 provided midway along the supply pipe 60. The pump 62 transfers the coating liquid L in the supply pipe 60 from the container 14 side to the coating liquid holding unit 12 side.

The upstream end 60A of the supply pipe 60 in the flow direction of the coating liquid L is connected to the lower part of the container 14. In this embodiment, the upstream end 60A of the supply pipe 60 is connected to the center, which is the lowest part of the recess 14B. The downstream end 60B of the supply pipe 60 in the flow direction of the coating liquid L penetrates the housing 20 and is connected to the inlet 24E of the coating liquid holding unit 12. As a result, the coating liquid L flowing through the supply pipe 60 is supplied from the inlet 24E to the flow path 34. Note that the upstream side or downstream side in the flow direction of the coating liquid L may sometimes be simply referred to as the "upstream side" or "downstream side" without referring to the "flow direction of the coating liquid L."

In addition, a filter 68 is provided in the supply pipe 60, downstream of the pump 62 in the flow direction of the coating liquid L, to remove foreign matter contained in the coating liquid L.

In the coating device 10, by driving the pump 62 of the circulation unit 16, the coating liquid L in the container 14 is supplied to the coating liquid holding unit 12 through the supply pipe 60. In the coating liquid holding unit 12, the coating liquid L is applied to the outer peripheral surface 100A of the cylindrical body 100. The coating liquid L that flows down the outer peripheral surface 100A of the cylindrical body 100 falls onto the inclined surface 18A of the receiving member 18, flows down the inclined surface 18A, and is collected into the container 14. The coating liquid L in the container 14 is then supplied to the coating liquid holding unit 12 through the supply pipe 60. Therefore, the circulation unit 16 circulates the coating liquid L in the container 14 to the coating liquid holding unit 12.

<Action and effect>
Next, the operation and effects of this embodiment will be described.

The coating device 10 is provided with a coating liquid holding section 12 that has an upper opening 25 and a lower opening 28 and holds the coating liquid L. In the coating liquid holding section 12, a cylindrical body 100 is inserted through the upper opening 25 and the lower opening 28, and the cylindrical body 100 is moved upward in the vertical direction relative to the cylindrical body 100, thereby coating the coating liquid L onto the outer peripheral surface 100A of the cylindrical body 100.

More specifically, as shown in Figure 4(A), the cylindrical body 100 is inserted in the direction of arrow A from above the coating liquid holding unit 12. As shown in Figure 4(B), the cylindrical body 100 is lowered in the direction of arrow A, and coating liquid L is supplied to the coating liquid holding unit 12 by the circulation unit 16 (see Figure 1), thereby filling the space between the annular body 32 of the coating liquid holding unit 12 and the outer peripheral surface 100A of the cylindrical body 100. The cylindrical body 100 is then allowed to reach the bottom.

Then, as shown in Figure 4(C), the cylinder 100 is moved upward (in the direction of arrow B) relative to the coating liquid holding unit 12, and the coating liquid L is ejected from the ejection unit 36 so that the coating liquid L overflows from above. This causes the coating liquid L to flow downward from the lower opening 28, and the coating liquid L is applied to the outer peripheral surface 100A of the cylinder 100 located above the upper opening 25. This forms a coating film 102 on the outer peripheral surface 100A of the cylinder 100 (see Figure 5(B)).

The coating device 10 is provided with a container 14 that contains the coating liquid L that has flowed down from the coating liquid holding section 12, and a receiving member 18 that receives, on an inclined surface 18A, the coating liquid L that flows downward along the outer peripheral surface 100A of the cylindrical body 100. The portion of the inclined surface 18A of the receiving member 18 that receives the coating liquid L is positioned above the liquid level L1 of the coating liquid L within the container 14. As a result, the coating liquid L that flows downward along the outer peripheral surface 100A of the cylindrical body 100 is received by the inclined surface 18A, and as the coating liquid L flows down along the inclined surface 18A, the coating liquid L is collected in the container 14 (see Figure 3).

The coating device 10 is further provided with a circulation unit 16 that circulates the coating liquid L inside the container 14 to the coating liquid holding unit 12. In the circulation unit 16, by driving a pump 62, the coating liquid L inside the container 14 is supplied to the coating liquid holding unit 12 through a supply pipe 60.

In the coating device 10 described above, the coating liquid L flowing downward along the outer peripheral surface 100A of the cylinder 100 is received by the inclined surface 18A of the receiving member 18. The coating liquid L flowing down along the inclined surface 18A meets the liquid surface L1 of the coating liquid L in the container 14, making the coating liquid L less likely to foam. This reduces the likelihood of the coating liquid L in the container 14 foaming compared to when the coating liquid flowing down the outer peripheral surface of the cylinder falls onto the liquid surface of the coating liquid in the container. Therefore, when the coating liquid L in the container 14 is supplied to the coating liquid holding unit 12 through the supply pipe 60 by the circulation unit 16, the presence of bubbles in the coating liquid L is reduced. Therefore, in the coating device 10, the occurrence of bubble defects in the coating film 102 on the outer peripheral surface 100A of the cylinder 100 is reduced compared to when the coating liquid flowing down the outer peripheral surface of the cylinder falls onto the liquid surface of the coating liquid in the container.

Figure 10 shows an application device 200 of a comparative example. As shown in Figure 10, the application device 200 has a container 202 for storing application liquid L provided in the lower part of the housing 20. The container 202 has a recessed portion 202A formed in an inverted cone shape. More specifically, the recessed portion 202A has an inclined surface 203 formed so that the inner diameter gradually decreases toward the lower part, with the center being the lowest position. In other words, the recessed portion 202A has an inclined surface 203 formed in a valley-like depression. The liquid level L1 of the application liquid L accumulated in the recessed portion 202A is located on the upper side of the recessed portion 202A. Note that the container 202 does not have a receiving member like the first embodiment.

In the coating device 200, the coating liquid L that flows down the outer peripheral surface 100A of the cylindrical body 100 falls onto the liquid surface L2 of the coating liquid L accumulated in the container 202. In other words, the coating liquid L that flows down the outer peripheral surface 100A of the cylindrical body 100 does not fall directly onto the inclined surface 203. At this time, the impact when the falling droplets of the coating liquid L hit the liquid surface L2 of the coating liquid L makes the coating liquid L more likely to foam. This causes bubbles 210 to form near the liquid surface L2 of the coating liquid L. For this reason, when the coating liquid L in the container 202 is supplied to the coating liquid holding section by the circulation section, the coating liquid L may contain bubbles.

In contrast, in the coating device 10 of the first embodiment, the coating liquid L flowing downward along the outer peripheral surface 100A of the cylinder 100 is received by the inclined surface 18A of the receiving member 18, and is allowed to flow down the inclined surface 18A and collected in the container 14. This reduces the impact when the coating liquid L flowing down the inclined surface 18A meets the coating liquid L in the container 14, making it less likely for bubbles to form in the coating liquid L in the container 14. Therefore, in the coating device 10, the occurrence of bubble defects in the coating film 102 on the outer peripheral surface 100A of the cylinder 100 is suppressed compared to when the coating liquid L flowing down the outer peripheral surface 100A of the cylinder 100 is allowed to fall onto the liquid level L1 of the coating liquid L in the container 202.

In addition, in the coating device 10, the inclined surface 18A is linear when viewed from a direction perpendicular to the axial direction of the coating liquid holding unit 12, and the angle θ1 of the inclined surface 18A with respect to the vertical direction is 10° or greater and 60° or less. Therefore, in the coating device 10, foaming due to impact when the coating liquid L is received by the receiving member 18 is suppressed compared to when the angle of the inclined surface with respect to the vertical direction is less than 10°. Also, in comparison to when the angle of the inclined surface with respect to the vertical direction is greater than 60°, foaming when the coating liquid L received by the receiving member 18 meets the liquid surface L1 of the coating liquid L in the container 14 is suppressed.

In addition, in the coating device 10, the angle θ1 of the inclined surface 18A with respect to the vertical is between 15° and 45°. Therefore, in the coating device 10, foaming due to impact when the coating liquid L is received by the receiving member 18 is suppressed compared to when the angle of the inclined surface with respect to the vertical is less than 15°. In addition, in the coating device 10, foaming when the coating liquid L received by the receiving member 18 meets the liquid surface L1 of the coating liquid L in the container 14 is suppressed compared to when the angle of the inclined surface with respect to the vertical is greater than 45°.

Furthermore, in the coating device 10, the inclined surface 18A has a conical shape with a protruding center when viewed from the side. Therefore, in the coating device 10, the coating liquid L that falls from the outer surface 100A of the cylindrical body 100 is less likely to come into contact with the liquid surface L1 of the coating liquid L in the container 14, compared to when the inclined surface has a valley-shaped recess.

A coating method for applying a coating liquid using the coating device 10 includes a step of moving the cylindrical body 100 upward relative to the coating liquid holding unit 12 and applying the coating liquid L from the coating liquid holding unit 12 to the outer peripheral surface 100A of the cylindrical body 100. The coating method also includes a step of receiving the coating liquid L flowing downward along the outer peripheral surface 100A of the cylindrical body 100 on the inclined surface 18A of the receiving member 18 above the liquid level L1 of the coating liquid L in the container 14, and storing the coating liquid L in the container 14. The coating method also includes a step of circulating the coating liquid L inside the container 14 to the coating liquid holding unit 12 by the circulation unit 16. Therefore, the coating method reduces the occurrence of bubble defects in the coating film 102 on the outer peripheral surface 100A of the cylindrical body 100 compared to a case in which the coating liquid flowing down the outer peripheral surface of the cylindrical body falls onto the liquid level of the coating liquid in the container.

In addition, in the coating method in which the coating device 10 is used to apply the coating liquid, the cylindrical body 100 is a cylindrical member or a cylindrical core material with an endless belt-like member wrapped around it. Therefore, in this coating method, the occurrence of bubble defects in the coating film 102 on the outer surface 100A of the cylindrical member or endless belt-like member is suppressed compared to when the coating liquid is allowed to flow down the outer surface of the cylindrical member and fall onto the surface of the coating liquid in a container.

In addition, in a photoreceptor manufacturing method that uses the above coating method to manufacture a photoreceptor, the cylindrical body 100 is a metallic cylindrical member or a cylindrical core material with a metallic endless belt-like member wound around it, and the coating liquid L contains a photosensitive material. Therefore, in this photoreceptor manufacturing method, the occurrence of bubble defects in the coating film 102 on the outer peripheral surface 100A of the photoreceptor is suppressed compared to when the coating liquid is allowed to flow down the outer peripheral surface of the cylindrical body and fall onto the surface of the coating liquid in a container.

Second Embodiment
Next, a coating apparatus 120 according to a second embodiment will be described with reference to Fig. 7. Note that the same components as those in the first embodiment described above are given the same reference numerals and the description thereof will be omitted.

As shown in FIG. 7 , the coating device 120 includes a receiving member 122 instead of the receiving member 18 of the coating device 10 of the first embodiment. The receiving member 122 is flat and has an inclined surface 122A on its upper surface that intersects with the vertical direction. The inclined surface 122A is inclined downward in one direction that intersects with the vertical direction. When the receiving member 122 is in place, the width of the receiving member 122 in a direction perpendicular to the vertical direction is greater than the outer diameter of the cylindrical body 100. As a result, the receiving member 122 is configured to receive the coating liquid L that flows downward along the outer peripheral surface 100A of the cylindrical body 100 on the inclined surface 122A.

The angle θ2 of the inclined surface 122A relative to the vertical direction is preferably 10° or greater and 60° or less, more preferably 12° or greater and 52° or less, and even more preferably 15° or greater and 45° or less. For example, the angle θ2 of the inclined surface 122A relative to the vertical direction is 45°. The other configuration of the coating device 120 is the same as that of the coating device 10 of the first embodiment.

The above-mentioned coating device 120 has the same configuration as the coating device 10 of the first embodiment, and can achieve the same functions and effects.

Furthermore, in the application device 120, the inclined surface 122A is inclined downward in one direction intersecting the vertical direction. Therefore, in the application device 120, the structure of the receiving member 122 is simpler than when the inclined surface is inclined in multiple directions intersecting the vertical direction.

Third Embodiment
Next, a coating apparatus 130 according to a third embodiment will be described with reference to Fig. 8. Note that the same components as those in the first and second embodiments are given the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 8 , the coating device 130 includes a receiving member 132 instead of the receiving member 18 of the coating device 10 of the first embodiment. The receiving member 132 is a curved plate-like body with an inclined surface 132A on its upper surface. The inclined surface 132A is an example of a curved surface. In this embodiment, the inclined surface 132A is a curved surface formed so as to be convex upward. When the receiving member 132 is in position, the width of the receiving member 132 in a direction perpendicular to the vertical direction is greater than the outer diameter of the cylindrical body 100. As a result, the receiving member 132 is configured to receive the coating liquid L flowing downward along the outer peripheral surface 100A of the cylindrical body 100 on the inclined surface 132A.

For example, a virtual tangent plane 135 is shown at the intersection 135A of one extension line 134A, which extends downward along the outer peripheral surface 100A of the cylindrical body 100, with the inclined surface 132A. A virtual tangent plane 136 is also shown at the intersection 136A of another extension line 134B, which extends downward along the outer peripheral surface 100A of the cylindrical body 100, with the inclined surface 132A. The tangent planes 135 and 136 shown in FIG. 8 are synonymous with tangents in a cross section. In this case, the angle θ31 between the tangent plane 135 and the vertical direction and the angle θ32 between the tangent plane 136 and the vertical direction are preferably 10° to 60°, more preferably 12° to 52°, and even more preferably 15° to 45°. For example, the angle θ31 between the tangent plane 135 and the vertical direction is 60°, and the angle θ32 between the tangent plane 136 and the vertical direction is 30°. Other configurations of the coating device 130 are similar to those of the coating device 10 of the first embodiment.

The above-mentioned coating device 130 has the same configuration as the coating device 10 of the first embodiment, and can achieve the same functions and effects.

In addition, in the coating device 130, the angle θ31 between the contact surface 135 and the vertical direction and the angle θ32 between the contact surface 136 and the vertical direction are between 10° and 60°. Therefore, in the coating device 130, foaming due to impact when the coating liquid L is received by the receiving member 132 is suppressed compared to when the angle θ31 between the contact surface 135 and the vertical direction and the angle θ32 between the contact surface 136 and the vertical direction are less than 10°. In addition, in the coating device 130, foaming when the coating liquid L received by the receiving member 132 joins the liquid surface L1 of the coating liquid L in the container 14 is suppressed compared to when the angle θ31 between the contact surface 135 and the vertical direction and the angle θ32 between the contact surface 136 and the vertical direction are greater than 60°.

Although not shown, in the coating device 130, the angle θ31 between the contact surface 135 and the vertical direction and the angle θ32 between the contact surface 136 and the vertical direction are preferably 15° or greater and 45° or less. In this case, in the coating device 130, foaming due to impact when the coating liquid L is received by the receiving member 132 is suppressed compared to when the angle θ31 between the contact surface 135 and the vertical direction and the angle θ32 between the contact surface 136 and the vertical direction are less than 15°. Also, foaming when the coating liquid L received by the receiving member 132 joins the liquid surface L1 of the coating liquid L in the container 14 is suppressed compared to when the angle θ31 between the contact surface 135 and the vertical direction and the angle θ32 between the contact surface 136 and the vertical direction are greater than 45°.

Fourth Embodiment
Next, a coating device 140 according to a fourth embodiment will be described with reference to Fig. 9. Note that the same components as those in the first to third embodiments described above are given the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 9, the application device 140 includes a receiving member 142 instead of the receiving member 18 of the application device 10 of the first embodiment. The receiving member 142 includes an inclined surface 142A, the central portion of which is a curved surface that protrudes in a mountain shape when viewed from the side perpendicular to the axial direction of the container 14. The receiving member 142 includes a vertex 142B, which is the uppermost portion of the curved surface, in the central portion of the inclined surface 142A.

The width of the receiving member 142 in a direction perpendicular to the vertical direction is greater than the outer diameter of the cylindrical body 100. As a result, the receiving member 142 is configured to receive the coating liquid L that flows downward along the outer peripheral surface 100A of the cylindrical body 100 on the inclined surface 142A.

For example, an imaginary tangent plane 145 is shown at the intersection 145A of an extension line 144 extending downward along the outer peripheral surface 100A of the cylindrical body 100 with the inclined surface 142A. The tangent plane 145 is synonymous with a tangent line in a cross section. In this case, the angle θ4 between the tangent plane 145 and the vertical direction is preferably 10° or greater and 60° or less, more preferably 12° or greater and 52° or less, and even more preferably 15° or greater and 45° or less. For example, the angle θ4 between the tangent plane 145 and the vertical direction is 20°. The other configuration of the coating device 130 is the same as that of the coating device 10 of the first embodiment.

The above-mentioned coating device 140 has the same configuration as the coating device 10 of the first embodiment, and can achieve the same functions and effects.

Furthermore, in the coating device 140, the inclined surface 142A is a curved surface with a central protruding mountain-like shape when viewed from the side. Therefore, in the coating device 140, the coating liquid L that falls from the outer peripheral surface 100A of the cylindrical body 100 is less likely to come into contact with the liquid surface L1 of the coating liquid L in the container 14, compared to when the inclined surface has a valley-shaped recess.

In addition, in the coating device 140, the angle θ4 between the contact surface 145 and the vertical direction is between 10° and 60°. Therefore, in the coating device 140, foaming due to impact when the coating liquid L is received by the receiving member 142 is suppressed compared to when the angle between the contact surface 145 and the vertical direction is less than 10°. In addition, in the coating device 140, foaming when the coating liquid L received by the receiving member 142 joins the liquid surface L1 of the coating liquid L in the container 14 is suppressed compared to when the angle between the contact surface 145 and the vertical direction is greater than 60°.

In addition, in the coating device 140, the angle θ4 between the contact surface 145 and the vertical direction is between 15° and 45°. In the coating device 140, foaming due to impact when the coating liquid L is received by the receiving member 132 is suppressed compared to when the angle θ4 between the contact surface 145 and the vertical direction is less than 15°. In addition, in the coating device 140, foaming when the coating liquid L received by the receiving member 132 joins the liquid surface L1 of the coating liquid L in the container 14 is suppressed compared to when the angle θ4 between the contact surface 145 and the vertical direction is greater than 45°.

〔supplementary explanation〕
In the above first to fourth embodiments, the shape of the receiving member can be changed as long as the coating liquid L that has fallen down the outer peripheral surface 100A of the cylindrical body 100 is received by the inclined surface of the receiving member above the liquid surface of the coating liquid in the container.

In the first to fourth embodiments described above, the configuration of each component of the coating liquid holding unit 12 can be modified as long as it is capable of applying the coating liquid L to the outer peripheral surface 100A of the cylindrical body 100. The shape of the annular body 32 can also be modified.

While the present invention has been described in detail with reference to a specific embodiment, it will be apparent to those skilled in the art that the present invention is not limited to such an embodiment, and that various other embodiments are possible within the scope of the present invention.

The application device and application method of the present disclosure will be explained in more detail below using examples, but the application device and application method of the present disclosure are not limited to the following examples as long as they do not deviate from the gist of the disclosure.

[Example 1]
<Preparation of coating solution>
Coating liquid L for forming a charge transport layer was prepared by dissolving 2.6 parts by mass of a benzidine compound represented by formula (CT-1) shown in Chemical Formula 1 below and 3 parts by mass of a polymer compound (viscosity average molecular weight: 40,000) having a repeating unit represented by formula (B-1) shown in Chemical Formula 2 below in 25 parts by mass of tetrahydrofuran. Coating liquid L is a liquid containing a photosensitive material for producing an electrophotographic photoreceptor.

<Coating>
An aluminum pipe measuring φ84×340 mm was used as the cylindrical body 100, and the coating liquid L was applied to the cylindrical body 100 using the coating device 10 shown in Fig. 1 and the coating liquid L described above. The receiving member 18 shown in Fig. 1 was used as the receiving member (liquid receiving member in Table 1) installed in the container 14 of the coating device 10. The angle of the inclined surface 18A of the receiving member 18 with respect to the vertical direction was 45°.

The inner diameter of the annular body 32 of the coating device 10 is 85.0 mm. 0.4 L of coating liquid L was constantly circulated and supplied to the coating liquid holding section 12 at a rate of 0.4 L per minute, and 0.4 L per minute was supplied to the cylinder 100 below the upper opening 25. While constantly circulating and supplying the coating liquid L under these conditions, the upper inner surface of the cylinder 100 was gripped with a gripping section (not shown), and the cylinder 100 was lowered vertically from above. At this time, the cylinder 100 penetrated the upper opening 25 of the coating liquid holding section 12 at a constant speed of 500 mm per minute, moving vertically downward. By the time the cylinder 100 reached its lowest point, the coating liquid L had filled the coating liquid holding section 12 and overflowed.

Next, the cylinder 100 was pulled up at a constant speed of 150 mm per minute, forming a coating film 102 of coating liquid L on the outer surface 100A of the cylinder 100. While the cylinder 100 moved up and down over the upper opening 25, the entire outer surface 100A of the cylinder 100 below the upper opening 25 was covered with coating liquid L discharged from the slit-shaped discharge port 36 provided in the upper opening 25, and the coating liquid L flowed down the outer surface 100A of the cylinder 100 due to gravity. The sample of the cylinder 100 coated with coating liquid L (the coating film 102 formed on the outer surface 100A of the cylinder 100) was dried with hot air at 135°C for 40 minutes.

The bubble defects in the coating film 102 of the cylindrical body 100, which was an evaluation item, were observed using a microscope image, and judged according to the following criteria (a) to (c) based on the number of bubble defects of 100 μm or more per cylinder.
(a) ◯: No bubble defects occurred.
(b) △: Two or less bubble defects.
(c) ×: Three or more bubble defects.

[Example 2-4]
The angle of the inclined surface 18A of the receiving member 18 (liquid receiving member) relative to the vertical direction was changed as shown in Example 2-4 in Table 1, and the coating liquid L was applied.

[Comparative Examples 1-3]
The angle of the inclined surface 18A of the receiving member 18 (liquid receiving member) relative to the vertical direction was changed as shown in Comparative Example 1-2 in Table 1, and the coating liquid L was applied. In Comparative Example 3, the coating liquid L was applied without providing a receiving member in the container 14. The results of evaluating the occurrence of bubble defects in the coating film 102 of the cylindrical body 100 are shown in Table 1.

As shown in Table 1, in Example 2-4, it was confirmed that no bubble defects occurred in the coating film 102 of the cylindrical body 100. Furthermore, in Example 2-4, it was confirmed that the number of bubble defects that occurred in the coating film 102 of the cylindrical body 100 was 2 or less.

In contrast, in Comparative Examples 1-3, it was confirmed that the number of bubble defects that occurred in the coating film 102 of the cylindrical body 100 was three or more. In Comparative Example 2, the angle of the inclined surface of the receiving member 18 relative to the vertical was large (the inclination of the inclined surface relative to the horizontal was gentle), and it is thought that foaming occurred due to the impact of the falling coating liquid L colliding with the receiving member. On the other hand, when the angle of the inclined surface of the receiving member 18 relative to the vertical was small (the inclination of the inclined surface relative to the horizontal was steep), as in Comparative Example 1, the falling coating liquid L did not slow down sufficiently and joined the liquid surface, and it is thought that foaming could not be sufficiently prevented.

10 Coating device 12 Coating liquid holding section 14 Container 16 Circulation section 18 Receiving member 18A Inclined surface 18B Top 20 Housing 22 Container 25 Upper opening 28 Lower opening 100 Cylinder 100A Outer circumferential surface 120 Coating device 122 Receiving member 122A Inclined surface 130 Coating device 132 Receiving member 132A Inclined surface (an example of a curved surface)
134A Extension line 134B Extension line 135 Contact surface 135A Intersection 136 Contact surface 136A Intersection 140 Coating device 142 Receiving member 142A Inclined surface 144 Extension line 145 Contact surface 145A Intersection θ1 Angle θ2 Angle θ31 Angle θ32 Angle θ4 Angle L1 Liquid surface L Coating liquid

Claims (15)

a coating liquid holding section having an upper opening and a lower opening, in which a coating liquid is held, wherein a cylindrical body is passed through the upper opening and the lower opening, and the cylindrical body is moved upward in a vertical direction relative to the cylindrical body, thereby coating the coating liquid on an outer peripheral surface of the cylindrical body;
a container for accommodating the flowing coating liquid;
a circulation unit that circulates the coating liquid inside the container to the coating liquid holding unit;
a receiving member that is disposed in the container above the liquid level of the coating liquid and receives, with an inclined surface, the coating liquid that flows down from the lower end of the cylinder along the outer peripheral surface of the cylinder ;
An application device having the above structure. the inclined surface is flat or linear when viewed from a direction perpendicular to the axial direction of the coating liquid holding portion,
The coating apparatus according to claim 1 , wherein the angle of the inclined surface with respect to the vertical direction is equal to or greater than 10° and equal to or less than 60°. The coating device described in claim 2, wherein the angle of the inclined surface relative to the vertical direction is greater than or equal to 15° and less than or equal to 45°. The inclined surface is a curved surface,
2. The coating device according to claim 1, wherein an angle between a tangent plane at an intersection of a line extending downward along the outer peripheral surface of the cylindrical body and the vertical direction is 10 degrees or more and 60 degrees or less. The coating device described in claim 4, wherein the angle between the tangent plane at the intersection of the curved surface and the vertical direction of the extension line extending downward along the outer circumferential surface of the cylindrical body is between 15° and 45°. The applicator device described in any one of claims 2 to 5, wherein the inclined surface is inclined downward in one direction intersecting the vertical direction. The applicator device described in claim 2 or claim 3, wherein the inclined surface has a conical shape with a protruding center when viewed from the side. The applicator device of claim 1, wherein the inclined surface has a curved surface with a central protruding mountain-like shape when viewed from the side. The coating device described in claim 8, wherein the angle between the tangent plane and the vertical direction at the intersection of the extended line extending downward along the outer peripheral surface of the cylindrical body and the inclined surface is between 10° and 60°. a coating liquid holding section having an upper opening and a lower opening, in which a coating liquid is held, wherein a cylindrical body is passed through the upper opening and the lower opening, and the cylindrical body is moved upward in a vertical direction relative to the cylindrical body, thereby coating the coating liquid on an outer peripheral surface of the cylindrical body;
a container for accommodating the flowing coating liquid;
a circulation unit that circulates the coating liquid inside the container to the coating liquid holding unit;
a receiving member that is disposed in the container above the liquid level of the coating liquid and receives, via an inclined surface, the coating liquid that flows downward along the outer peripheral surface of the cylindrical body;
and
the inclined surface is flat or linear when viewed from a direction perpendicular to the axial direction of the coating liquid holding portion,
the angle of the inclined surface with respect to the vertical direction is equal to or greater than 10° and equal to or less than 60°;
The inclined surface has a conical shape with a protruding center when viewed from the side of the coating device. a coating liquid holding section having an upper opening and a lower opening, in which a coating liquid is held, wherein a cylindrical body is passed through the upper opening and the lower opening, and the cylindrical body is moved upward in a vertical direction relative to the cylindrical body, thereby coating the coating liquid on an outer peripheral surface of the cylindrical body;
a container for accommodating the flowing coating liquid;
a circulation unit that circulates the coating liquid inside the container to the coating liquid holding unit;
a receiving member that is disposed in the container above the liquid level of the coating liquid and receives, via an inclined surface, the coating liquid that flows downward along the outer peripheral surface of the cylindrical body;
and
The inclined surface is a curved surface ,
An application device wherein an angle between a tangent plane at an intersection of a line extending downward along the outer peripheral surface of the cylindrical body and the vertical direction is 10° or more and 60° or less. a coating liquid holding unit having an upper opening and a lower opening, in which a coating liquid is held, the coating liquid holding unit having a cylindrical body that passes through the upper opening and the lower opening, and the cylindrical body that is moved upward in a vertical direction relative to the cylindrical body, thereby coating the coating liquid on an outer peripheral surface of the cylindrical body;
a container for accommodating the flowing coating liquid;
a circulation unit that circulates the coating liquid inside the container to the coating liquid holding unit;
a receiving member that is disposed in the container above the liquid level of the coating liquid and receives, via an inclined surface, the coating liquid that flows downward along the outer peripheral surface of the cylindrical body;
and
The inclined surface is a curved surface portion whose central portion protrudes in a mountain shape when viewed from the side . A coating method for coating a coating liquid using the coating device according to any one of claims 1 to 12 , comprising:
a step of moving the cylindrical body upward in a vertical direction relative to the coating liquid holding portion, and applying the coating liquid from the coating liquid holding portion to an outer peripheral surface of the cylindrical body;
a step of receiving the coating liquid flowing downward along the outer peripheral surface of the cylindrical body at the inclined surface of the receiving member above the liquid level of the coating liquid in the container, and storing the coating liquid in the container;
circulating the coating liquid in the container to the coating liquid holding section by the circulation section;
The coating method comprising the steps of: 14. The coating method according to claim 13 , wherein the cylindrical body is a cylindrical member or a cylindrical core member around which an endless belt-like member is wound. A method for manufacturing a photoreceptor by using the coating method according to claim 13 or 14 , comprising the steps of:
the cylindrical body is a metallic cylindrical member or a cylindrical core member around which an endless metallic belt-like member is wound,
The method for producing a photoreceptor, wherein the coating liquid contains a photosensitive material.