JP2012093521A - Apparatus for manufacturing electrophotographic photoreceptor and method for manufacturing electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for manufacturing an electrophotographic photoreceptor and a method for manufacturing an electrophotographic photoreceptor, by which problems of dripping a coating film or irregularity in coating that occurs in the process of forming a photosensitive layer of an electrophotographic photoreceptor by an immersion coating can be effectively suppressed and a uniform coating film can be formed.SOLUTION: The apparatus for manufacturing an electrophotographic photoreceptor includes means 10 of gripping a cylindrical coating object 9 to be vertically moved and a coating tank 1 housing a coating liquid 2, and carries out immersing the cylindrical coating object 9 in the coating liquid 2 housed in the coating tank 1 and then pulling up the object to form a coating film on the surface of the cylindrical coating object 9. The apparatus for manufacturing an electrophotographic photoreceptor includes a cap 3 above the coating tank 1, the cap having an opening 4 to allow the cylindrical coating object 9 to pass through, and a hood 5 having a larger cross-sectional area than the opening 4, disposed on the cap 3 as in contact with the cap 3 so as to enclose the periphery of the opening 4. An upper part of the hood 5 is formed into a mesh, while a lower part is not formed into a mesh.

Description

  The present invention relates to a manufacturing apparatus and a manufacturing method of an electrophotographic photosensitive member.

  An organic electrophotographic photoreceptor is produced by applying a photosensitive layer made of an organic material on the surface of a conductive support. Various means for applying the photosensitive layer are known, but the dip coating method is generally used. When the cylindrical coated body is dip-coated, the cylindrical coated body is immersed in a coating layer containing the photosensitive layer coating solution so that its longitudinal direction is perpendicular to the liquid surface, Next, the coated film is applied to the surface of the coated body by pulling up the coated body. The coating film begins to dry naturally immediately after it is lifted from the coating solution, but the coating film loses its fluidity and is naturally dried until it is solidified to the extent that the paint does not adhere to the finger even when touched with a finger. Sometimes called. Usually, the coating film is completely dried and solidified by performing a drying process such as hot air drying following the touch drying. In the laminated type photoconductor, the photoconductor is manufactured by repeating the coating step and the drying step for each layer.

The electrical characteristics of the photoreceptor depend on the film thickness of the photoreceptor. If there are parts of the photoconductor that have significantly different electrical characteristics, image defects such as image unevenness will occur, so the coating film thickness of each layer constituting the photosensitive layer may be in the longitudinal direction or the circumferential direction. It is desirable that the whole be uniform.
Immediately after the substrate is pulled up from the coating solution, the coating film has fluidity, so that the unevenness of the minute coating film is leveled by the fluidity. That is, the fluidity of the coating film is beneficial for smoothing the coating film.

However, until the fluidity of the coating liquid applied to the surface of the coated body is lost by touch drying, the applied coating liquid flows vertically downward due to gravity. Therefore, if the fluidity of the coating film is maintained for a long time, the coating film thickness cannot be kept uniform. For example, in the case of the above-mentioned cylindrical coated body, the film thickness is thin on the upper side at the time of coating, and on the contrary, it is thick on the lower side, resulting in a difference in film thickness in the longitudinal direction of the coated body. This problem is called sauce.
In order to suppress sagging, it is effective to include a quick-drying solvent in the paint and finish the touch drying in a short time. For this reason, it is widely used that a good solvent with a solid content in the paint and a highly volatile solvent is contained in the paint.

  However, when a fast-drying solvent is contained, solidification of the coating solution is completed in a short time, but minute coating unevenness will remain unless sufficient leveling is achieved before the coating film solidifies. . In addition, unevenness also occurs when the time required for the coating film to solidify varies depending on the location due to the airflow around the object to be coated. Furthermore, as described above, since the solvent is a good solvent for the solid content in the paint, the coating film that has just solidified comes into contact with the thick solvent vapor, so that fluidity is obtained again and dripping. An abnormal film thickness may occur. That is, how to properly control the atmosphere around the object to be coated immediately after being pulled up from the coating solution is a problem for achieving both coating unevenness and sagging.

Techniques related to a hood and an exhaust device that cover the periphery of the coated body have been proposed so far in order to control the atmosphere around the coated body immediately after being pulled up from the coating solution.
Patent Document 1 proposes a technique for covering the periphery of the coating liquid tank and the object to be coated. This is to provide a cover to prevent the influence of the wind around the coating device around the coating liquid tank and the object to be coated, but the concentration of the solvent vapor contained in the atmosphere inside the cover is in an arbitrary state. Can take. Therefore, sagging may occur when using a low-viscosity paint containing a low-boiling solvent.

  Patent Document 2 proposes an electrophotographic photosensitive member manufacturing apparatus provided with a mesh-shaped cylindrical wind shield having an opening diameter of 10 μm to 1 mm on the entire wall surface for shielding outside air above the coating tank. ing. However, since the entire wall surface of the wind shield is mesh-like, the solvent vapor at the bottom of the wind shield becomes dilute, and the level of the coating film may be insufficient when using a fast-drying paint. .

  Patent Document 3 proposes a dip coating apparatus in which a lid having an opening larger than the outer periphery of the coating tank is provided on the upper part of the coating liquid tray, and the upper end of the coating tank projects from the opening of the lid. The dip coating device has a cylindrical hood having an inner circumference equal to or larger than the opening diameter of the lid and provided with a communication hole communicating with the outside on the outer circumference. A dip coating device arranged so as to have a concentric circle is also proposed. In this device, since the main focus is on reducing the solvent vapor concentration at the top of the coating tank, it is necessary to quickly exchange the atmosphere inside and outside the hood at the portion of the communication hole of the hood. May occur. In addition, since the upper end of the coating tank protrudes above the lid, the solvent vapor evaporated from the liquid surface of the paint immediately diffuses to the outside of the hood through the communication hole of the hood. For this reason, when mass-producing electrophotographic photoreceptors, the treatment of solvent vapor diffused around the coating apparatus may be a problem.

  In Patent Document 4, a solvent vapor reservoir chamber that covers the entire upper surface of the coating tank, and a drying hood provided above the solvent vapor reservoir chamber, the solvent vapor is discharged between the solvent vapor reservoir chamber and the dry hood. There has been proposed a coating apparatus provided with a discharge port. In the case of this apparatus, since the concentration of the solvent vapor is diluted at the discharge port, it is effective for suppressing sagging. However, on the other hand, when the coating film reaches the portion where the discharge port exists, the coating film is rapidly solidified, so that coating unevenness may occur due to the flow of airflow near the discharge port.

JP 59-127678 A JP 09-197689 A JP 10-337514 A Japanese Patent Laid-Open No. 2003-57858

  In recent years, the improvement in image quality and definition of electrophotographic apparatuses has been progressing. For this reason, it is necessary to manage the electrical characteristics of the electrophotographic photosensitive member more strictly than in the past. This is because a relatively slight disturbance in electrical characteristics at a level that did not appear as an image defect in a conventional electrophotographic apparatus can become an image defect that can be easily recognized in an image output by a high-definition electrophotographic apparatus. It is. In order to suppress the disturbance of the electrical characteristics of the photosensitive member and to achieve uniformity, the film thickness of the photosensitive layer must be kept uniform. Therefore, a photosensitive layer coating technique capable of forming a coating film having a more uniform film thickness and smoothness than the conventional coating technique is currently required. Control of the fluidity of the coating film immediately after being pulled up from the coating solution greatly affects the sagging and film thickness unevenness of the coating film. Therefore, if the control can be facilitated, the coating technique can be improved. From this point of view, there is room for further improvement in the conventional coating apparatus. Also, various types of electrophotographic apparatuses have been made to meet market needs, and there are a wide variety of types and configurations of photoconductors designed to be optimized for each electrophotographic apparatus. Therefore, from the viewpoint of productivity, there has been a demand for a manufacturing apparatus that can apply by changing the application conditions in a simple manner in an optimum state corresponding to each of various coating solutions for the photosensitive layer.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photosensitive film that can effectively suppress sagging and unevenness of a coating film generated when a coating solution for a photosensitive layer is applied by a simple method and can form a uniform photosensitive layer thickness. And a method of manufacturing an electrophotographic photosensitive member.

In order to achieve the above object, the electrophotographic photoreceptor manufacturing apparatus of the present invention is configured as follows.
That is, it has means for gripping the cylindrical coated body so that it can be moved up and down, and a coating tank for storing the coating liquid, and the cylindrical coated body is dipped in the coating liquid stored in the coating tank and then pulled up. An electrophotographic photosensitive body manufacturing apparatus for forming a coating film on a surface of a cylindrical coated body, wherein the electrophotographic photosensitive body manufacturing apparatus has a lid having an opening for allowing the cylindrical coated body to pass above the coating tank. And a hood having a cross-sectional area larger than the opening is provided in close contact with the lid so as to surround the opening, the upper portion of the hood is mesh-shaped, and the lower portion of the hood is An electrophotographic photoreceptor manufacturing apparatus characterized by being non-mesh.

  Further, in the electrophotographic photoreceptor manufacturing method according to the present invention, in the electrophotographic photoreceptor manufacturing apparatus, a boundary surface between a mesh-like region above the hood and a non-mesh region below the hood is defined as a boundary surface S. The operation of pulling up the cylindrical coated body performed after immersing the cylindrical coated body in the coating solution causes the lower end portion of the cylindrical coated body to reach a height higher than the boundary surface S. An electrophotographic photosensitive member manufacturing method characterized in that the process is carried out without stopping.

According to the electrophotographic photoreceptor manufacturing apparatus of the present invention, when performing dip coating of the coating material for the photosensitive layer, the concentration of the solvent vapor around the coated body immediately after being pulled up from the coating solution is gradually diluted. I can go. Therefore, the leveling property of the coating film can be appropriately maintained while suppressing the deterioration of the sagging, and the occurrence of coating unevenness can be suppressed. In addition, it is possible to prevent the surrounding airflow from directly blowing on the coating film before solidification, thereby preventing unevenness caused by the airflow.
Moreover, according to the electrophotographic photoreceptor manufacturing method of the present invention, it is possible to suppress the sagging of the paint that occurs at the lower end of the coated body.

It is the schematic of the electrophotographic photoreceptor manufacturing apparatus of this invention. It is an example of the hood applicable to the electrophotographic photoreceptor manufacturing apparatus of the present invention. It is an example of the hood applicable to the electrophotographic photoreceptor manufacturing apparatus of the present invention. It is an example of the hood applicable to the electrophotographic photoreceptor manufacturing apparatus of the present invention. It is an example of the hood applicable to the electrophotographic photoreceptor manufacturing apparatus of the present invention. It is a schematic sectional drawing of the electrophotographic photoreceptor manufacturing apparatus of this invention.

The electrophotographic photoreceptor manufacturing apparatus and the electrophotographic photoreceptor manufacturing method of the present invention will be described below.
FIG. 1 shows a schematic view of an electrophotographic photoreceptor manufacturing apparatus of the present invention. The upper end side of the coated body 9 is gripped by the coated body gripping means 10, and the gripping means 10 can move up and down while gripping the coated body 9. The gripping means 10 allows the coated body 9 to pass through the inside of the hood 5 and the opening 4 opened in the lid 3 of the coating tank, and is immersed in the coating liquid 2 accommodated in the coating tank 1 to a predetermined depth. it can. The cross-sectional area of the hood 5 is larger than the cross-sectional area of the opening 4. The hood 5 is provided closely on the lid 3 so as to surround the periphery of the opening. The upper portion of the hood 5 is a mesh-like portion 6, while the lower portion of the hood 5 is a non-mesh-like portion 7.

The coating film is applied by pulling up the substrate 9 immersed in the coating solution 2 from the coating solution 2 at a predetermined speed. The film thickness of the coating film can be adjusted by changing the lifting speed of the substrate 9 and the viscosity / solid content of the coating liquid 2.
The substrate 9 pulled up from the coating solution 2 passes through the opening 4 of the lid 3 and the inside of the hood 5 again. Here, in the operation of pulling up the object 9 to be applied, the lower end of the object 9 passes through the boundary surface (boundary surface S) 8 formed by the mesh-like portion 6 and the non-mesh-like portion 7 of the hood 5. Until it is done without stopping.

The coated body thus coated with the coating film is taken out of the system of the coating apparatus from above the hood, then sent to a drying step (not shown) and dried, and the formation of the coating film is completed. .
The region from the liquid level of the coating solution stored in the coating tank to the upper surface of the lid is the region where the solvent vapor is most concentrated. For the sake of simplicity, this region will be referred to herein as region A. While the coating film is in the region A, the fluidity of the coating film continues to be kept high, so that the coating film tends to sag. Therefore, it is better that the time during which the same portion of the coating film stays in the region A is short. As a guideline, it is preferable to pass through the region A within 10 seconds, more preferably within 5 seconds. The shortening of the time can be achieved by increasing the speed at which the coated body is pulled up or shortening the distance from the liquid surface of the coating liquid to the upper surface of the lid. However, the lifting speed of the coated body is one of the important parameters for determining the film thickness of the coating film, and if the lifting speed is too high, the coating film may be disturbed due to the influence of the wavy surface of the coating liquid. There is also. Therefore, in considering the configuration of an apparatus suitable for manufacturing various photoconductors, it is more realistic to shorten the distance from the coating liquid surface to the upper surface of the lid. Specifically, this distance may be about 20 mm or less.

  As described above, the hood is provided on the region A so as to be in close contact with the lid. Therefore, the atmosphere outside the hood does not flow from the part where both are in contact. The hood has a non-mesh shape at the bottom and a mesh shape at the top. For simplicity, the region in the hood surrounded by the non-mesh portion of the hood is referred to as region B, and the region in the hood surrounded by the portion on the mesh of the hood is referred to as region C.

  One of the main reasons for providing the hood is to prevent the air current flowing outside the hood from directly applying to the coating film of the coated body passing through the inside of the hood, that is, the region B and the region C, so as not to cause unevenness. Because. Since the mesh-shaped part surrounding the region C has an opening, the atmosphere inside and outside the hood is gently exchanged through the opening. However, by setting the opening diameter to 2 mm or less, more preferably 1 mm or less, Can sufficiently suppress the effect of direct air flow on the substrate.

  The region A, the region B, and the region C communicate with each other in this order through an opening through which the coated body passes. Accordingly, the solvent vapor rising from the surface of the coating liquid moves in order from the region A to the region B and the region C. On the other hand, since the upper end portion of the hood is opened so that the coated body can pass therethrough, the atmosphere inside and outside the hood is exchanged from there. Further, in the region C, the atmosphere inside and outside the hood is gently exchanged through the mesh-shaped opening of the hood. Therefore, the solvent vapor is diluted in the region C as compared with the region A. In the region B sandwiched between the region A and the region C, the atmosphere is exchanged only between the region A and the region C, so that the solvent between the region A having the highest solvent vapor concentration and the region C having the lowest concentration is used. Vapor concentration.

  The coating film on the surface of the substrate to be coated that has been pulled up is smooth and smooth with little sagging while both leveling and solidification of the surface proceed slowly while passing through the region B where the concentration of the solvent vapor is moderately reduced. It will be formed into a simple film. Subsequently, when passing through the region C where the solvent vapor concentration is lower, the solidification of the coating film further proceeds, and at the same time, the fluidity of the surface of the coating film is greatly reduced. Therefore, the coating film passing through the region C is hardly leveled, but on the other hand, the occurrence of sagging can be suppressed. Then, by sufficiently solidifying the surface of the coating film from the upper end of the hood to the outside of the hood, it is possible to suppress unevenness that occurs when the coating film is exposed to the airflow outside the hood.

  If the entire hood is non-mesh, the solvent vapor rising from the region A fills the hood, and the fluidity of the surface of the coating film is maintained for a long time. Gets worse. As a countermeasure, a method of diluting the solvent vapor in the hood can be considered by shortening the length of the hood and using only the exchange of the atmosphere generated at the opening at the upper end of the hood. However, in that case, since the coating film with high surface fluidity is discharged from the upper end of the hood and directly exposed to the airflow outside the hood, the unevenness of the coating film becomes worse. Such a problem appears remarkably when a relatively thick coating film is applied using a low-viscosity coating solution. For example, this is likely to occur when a coating solution for a charge transport layer having a low viscosity is applied so that the thickness of the coating film after drying is 10 μm or more.

  Further, if the entire hood has a mesh shape, the atmosphere inside and outside the hood is exchanged through the opening at the upper end of the hood and the opening of the mesh, so that the solvent vapor in the hood is totally diluted. For this reason, the coating film passing through the hood is rapidly solidified, and sagging hardly occurs. However, on the other hand, the time during which the fluidity of the surface of the coating film is maintained is shortened, so that the minute coating unevenness caused by the operation of pulling up the coated body from the coating solution is solidified before being completely leveled and becomes uneven. Problems are likely to occur. To solve this problem, it is possible to consider a method of leveling by extending the time for passing through the region A. However, since the region A has a high solvent vapor concentration, the sagging of the coating film is deteriorated. Such a problem is likely to occur when a relatively thick coating film is applied using a paint containing a large amount of a low boiling point solvent. For example, this applies to a case where a coating solution for a charge transport layer containing 30 wt% or more of a solvent having a boiling point of about 40 ° C. to 80 ° C. is applied so that the thickness of the coating film after drying is 10 μm or more.

  As described above, in the electrophotographic photoreceptor manufacturing apparatus of the present invention, the coating film coated with the coating solution is protected from being directly blown by the airflow outside the hood, and the solvent vapor concentration is high, medium, and low. It is characterized by being discharged out of the hood through the order of the regions. Among these, the area | region B where the density | concentration of solvent vapor | steam is medium plays an important role in order to make smoothness of a coating film and prevention of sagging simultaneously. In order for the solvent vapor concentration in the region B to be medium, an atmosphere in the region C where the solvent vapor is relatively diluted is required. For this reason, the mesh-shaped portion of the hood must have openings having a suitable size for moderately changing the atmosphere inside and outside the hood. If the hole diameter is too small, it becomes difficult to exchange the atmosphere inside and outside the hood. Moreover, even if the ratio of the area which an opening part occupies per unit area is too small, exchange of the atmosphere inside and outside the hood becomes insufficient. As a guide, if the opening diameter of the opening is 100 μm or more, the atmosphere can be exchanged through the opening. As described above, since the influence of the airflow flowing outside the hood becomes a problem when the aperture diameter exceeds 2 mm, the aperture diameter is preferably 2 mm or less, more preferably 1 mm or less. Moreover, if the ratio of the area which an opening part occupies per unit area of a mesh-shaped part exists in the range of 30%-80%, since replacement | exchange of the atmosphere inside and outside a hood is performed moderately, it is preferable.

  Since the region B is a region where leveling and solidification of the coating film are performed in parallel, the coating film needs to pass through the region B over a certain amount of time. However, if the time for which the coating film remains in the region B is too long, the sagging may be deteriorated. Although it depends on the viscosity and temperature of the paint used, the solvent contained in the paint, the coating speed, etc., as a guideline, the time required for the coating film to pass through the region B should be 3 seconds or more and 20 seconds or less. Is preferred. From the upper surface of the coating tank lid to the boundary surface S between the non-mesh area and the mesh area of the hood, assuming a realistic coating speed that does not cause disturbance in the liquid surface of the coating liquid due to the lifting operation The standard of the distance is preferably 20 mm or more and 50 mm or less.

  The region C functions to protect the coating film from the airflow outside the hood until the coating film is sufficiently solidified. Therefore, it is necessary to allow the coating film to pass through the region C over a longer time than the time required for the surface of the coating film to solidify. Although it depends on the viscosity and temperature of the coating material used, the solvent contained in the coating material, the coating speed, etc., as a guideline, it is preferable that the time required for the coating film to pass through the region C is 20 seconds or more. Assuming a realistic coating speed at which the coating liquid surface is not disturbed by the lifting operation, a guideline for a preferable distance from the boundary surface S between the non-mesh area of the hood and the mesh area to the upper end of the hood Is 20 mm or more. These times and distances have no upper limit provided to eliminate adverse effects on the coating film. Therefore, these upper limits may be set in consideration of the actual device dimensions and production efficiency.

  The exchange of the atmosphere inside and outside the hood performed through the mesh-like portion of the hood is most preferably performed uniformly in the circumferential direction of the hood. Therefore, it is made of a metal that has a certain width and has a strength capable of maintaining the shape of the hood without using a frame, rather than a structure in which a mesh is attached to a frame that does not have an opening. It is preferable to form a mesh-like portion of the hood using a mesh or the like.

  Further, while the coating film passes through the region B and the region C, it is desirable that the concentration of the solvent vapor that touches the coating film is uniform in the circumferential direction of the object to be coated. Therefore, it is preferable that the opening of the lid of the coating tank and the horizontal section of the hood are circular. In addition, during the application of the cylindrical coated body, all of the circle formed by the horizontal cross section of the cylindrical coated body, the circle formed by the opening of the lid of the coating tank, and the circle formed by the horizontal cross section of the hood are concentric. More preferably, they are arranged.

  If the atmosphere inside and outside the hood is not exchanged through the opening, it can be said that the opening of the peripheral surface of the hood performs substantially the same function as the non-mesh portion. Therefore, when the opening in the mesh-like portion of the hood is closed by some method, the area where the opening is closed corresponds to a non-mesh area. For example, as shown in FIG. 2, a hood having a shape in which the entire circumference of the lower portion of the cylindrical hood 11 having a mesh shape is covered with a cylindrical hood 12 having a non-mesh shape without gaps is used. In this case, this is one of the embodiments of the present invention. In FIG. 2, a configuration in which the cylindrical hood 12 is assembled to the outside of the cylindrical hood 11 is shown, but conversely, even if the cylindrical hood 12 is assembled to the inside of the cylindrical hood 11, This is also one embodiment of the present invention.

  Examples of the shape of the hood that can be suitably used in the electrophotographic photoreceptor manufacturing apparatus of the present invention are shown in FIGS. FIG. 3 shows a prismatic hood used when there is only one object to be coated. FIG. 4 and FIG. 5 are examples of hoods for use in a manufacturing apparatus capable of simultaneously applying 16 objects to be coated arranged in four rows and four columns. FIG. 4 shows a configuration in which the prismatic hoods of FIG. FIG. 5 shows a configuration in which cylindrical hoods are arranged side by side in four rows. The form of the hood used in the electrophotographic photoreceptor manufacturing apparatus of the present invention is not limited to these.

  The method for producing an electrophotographic photosensitive member of the present invention is characterized in that the coating liquid is applied to an object to be coated using the electrophotographic photosensitive member production apparatus of the present invention as follows. That is, the operation of pulling up the cylindrical coated body immersed in the coating liquid is performed at a height equal to or higher than the boundary surface S between the mesh-like region at the top of the hood and the non-mesh-shaped region at the bottom of the hood. It is performed without stopping until the lower end portion reaches.

  The region below the boundary surface S is the region A and / or the region B described above. When the operation of pulling up the coated body is stopped in a state in which a part of the lower end side of the coated body remains in the region A and / or the region B, the influence of a relatively high concentration of solvent vapor contained in the atmosphere of these regions Thus, sagging of the coating film may occur. This sagging appears in the coating film located below the boundary surface S when the pulling-up operation is stopped. In the sagging portion, film thickness unevenness occurs in the coating film, which causes a local abnormality in the electrical characteristics of the photoreceptor, which is not preferable. If the operation of pulling up the coated body is performed without stopping until the lower end of the cylindrical coated body reaches a height equal to or higher than the boundary surface S, the entire coated body to which the coating liquid has been applied is It is located at a height higher than the region C. In that case, as described above, only the solidification of the smoothly formed coating film is performed, so that it is possible to suppress the occurrence of a problem that uneven coating occurs in a part of the coating lower end side of the coated body.

Next, the structure of the electrophotographic photosensitive member manufactured by the electrophotographic photosensitive member manufacturing apparatus and the electrophotographic photosensitive member manufacturing method of the present invention will be specifically described.
The electrophotographic photoreceptor production apparatus and the electrophotographic photoreceptor production method of the present invention are used for producing a multilayer electrophotographic photoreceptor in which a charge generation layer and a charge transport layer are laminated on a cylindrical support. Can do. Further, it can also be used for the production of a single layer type electrophotographic photosensitive member comprising a single layer containing a charge generation material and a charge transport material.

  The following is a specific description of the structure of the support that supports the photosensitive layer of the electrophotographic photoreceptor and the conductive layer, intermediate layer, charge generation layer, charge transport layer, and protective layer of the multilayer photoreceptor formed on the support. State it. The electrophotographic photoreceptor manufacturing apparatus and the electrophotographic photoreceptor manufacturing method of the present invention can be applied to the application of these layers.

  The cylindrical support body should just be an electroconductive support body which has electroconductivity. Examples of the material of the conductive support include metals or alloys such as iron, copper, gold, silver, aluminum, zinc, titanium, lead, nickel, tin, antimony, indium, chromium, aluminum alloy, and stainless steel. . A plastic support having a layer formed by vacuum deposition of aluminum, an aluminum alloy, an indium oxide-tin oxide alloy, or the like can also be used. In addition, a support made by impregnating plastic or paper with carbon black, tin oxide particles, titanium oxide particles, silver particles or the like together with a suitable binder resin, or a plastic made using a conductive binder resin. A support or the like can also be used. The surface of these supports may be subjected to cutting treatment, roughening treatment, anodizing treatment, etc. for the purpose of preventing interference fringes due to scattering of laser light or the like.

Between the conductive support and an intermediate layer or charge generation layer, which will be described later, a conductive layer is formed for the purpose of preventing interference fringes due to scattering of laser light or the like and covering the scratches on the conductive support. Also good.
The conductive layer is formed by applying and drying a conductive layer coating liquid obtained by dispersing and / or dissolving carbon black, a conductive pigment or a resistance adjusting pigment in a solvent together with a binder resin on a support. Can do. The conductive layer coating liquid may contain a compound (polymerizable compound) that is polymerized by heating or radiation irradiation to become a cured product.
The thickness of the conductive layer is preferably 0.2 to 40 μm, more preferably 1 to 35 μm, and still more preferably 5 to 35 μm.

  Examples of the binder resin used for the conductive layer include polymers / copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinylidene fluoride, trifluoroethylene, and polyvinyl alcohol. , Polyvinyl acetal, polycarbonate, polyester, polysulfone, polyphenylene oxide, polyurethane, cellulose resin, phenol resin, melamine resin, silicon resin, epoxy resin and the like.

  Examples of conductive pigments and resistance control pigments used in the conductive layer include particles of metals and alloys such as aluminum, zinc, copper, chromium, nickel, silver, and stainless steel, and those deposited on the surface of resin particles. Etc. Alternatively, particles of metal oxide such as zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, antimony or tantalum-doped tin oxide may be used. These particles may be used alone or in combination of two or more. When two or more types are used in combination, they may be simply mixed, or may be in the form of a solid solution or fusion.

  An intermediate layer having a barrier function or an adhesive function may be formed between the conductive support or the conductive layer formed on the conductive support and the charge generation layer. The intermediate layer is formed for the purpose of improving the adhesion of the photosensitive layer, improving the coating property, improving the charge injection from the conductive support, and protecting the photosensitive layer from electrical breakdown.

Examples of the material for the intermediate layer include polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide, N-methoxymethylated 6 nylon, copolymer nylon, glue, Examples include gelatin.
The intermediate layer can be formed by applying and drying an intermediate layer coating solution obtained by dissolving the above materials in a solvent.
The layer thickness of the intermediate layer is preferably 0.05 to 7 μm, and more preferably 0.1 to 5 μm.

A charge generation layer containing a charge generation material is formed on the conductive support, the conductive layer, or the intermediate layer.
Examples of the charge generating material used in the charge generating layer include selenium-tellurium, pyrylium, thiapyrylium dyes, various central metals, and various crystal systems (α, β, γ, ε, X type, etc.). And anthanthrone pigments, dibenzpyrenequinone pigments, pyranthrone pigments, azo pigments such as monoazo, disazo, and trisazo, indigo pigments, quinacridone pigments, asymmetric quinocyanine pigments, and quinocyanine pigments. These charge generation materials may be used alone or in combination of two or more.

  The coating solution for the charge generation layer is a homogenizer, ultrasonic dispersion, ball mill, vibration ball mill, sand mill, attritor, roll mill or high pressure, together with a binder resin and a solvent in an amount of 0.3 to 4 times (mass ratio). The dispersion can be obtained by a method using a disperser or the like. Examples of the binder resin include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinylidene fluoride, and trifluoroethylene. In addition, examples include polyvinyl alcohol, polyvinyl acetal, polycarbonate, polyarylate, polyester, polysulfone, polyphenylene oxide, polyurethane, cellulose resin, phenol resin, melamine resin, silicon resin, and epoxy resin.

The charge generation layer can be formed by applying and drying the charge generation layer coating solution.
The thickness of the charge generation layer is preferably 5 μm or less, and more preferably 0.1 to 2 μm.
A charge transport layer is formed on the charge generation layer.
The charge transport layer contains a charge transport material except when the binder resin itself contained therein has a charge transport capability. Examples of the charge transport material used in the charge transport layer include poly-N-vinyl carbazole, polystyryl anthracene and other high molecular compounds having a heterocyclic ring and a condensed polycyclic aromatic compound, pyrazoline, imidazole, oxazole, triazole, and carbazole. And low molecular weight compounds such as triarylalkane derivatives such as triphenylmethane, triarylamine derivatives such as triphenylamine, phenylenediamine derivatives, N-phenylcarbazole derivatives, stilbene derivatives, and hydrazone derivatives.

  The charge transport layer can be formed by applying and drying a charge transport layer coating solution obtained by dissolving a charge transport material and a binder resin in a solvent on the charge generation layer. As the binder resin, the same binder resin as that for the charge generation layer can be used. In addition, a tough charge transport layer can be formed by adding a crosslinkable monomer or oligomer to the coating solution and polymerizing it after coating it on the substrate. In addition, it is possible to use a binder resin having a charge transporting capability in which the binder resin itself has a charge transporting molecular structure. In that case, the charge transport layer is formed using only the binder resin having the charge transporting capability. Can also be formed.

The amount of the charge transport material contained in the charge transport layer is preferably 20 to 70% by mass, and more preferably 30 to 50% by mass. However, when the binder resin itself has a charge transport capability, the amount of the other charge transport material added may be 0 to 50% by mass.
Moreover, in order to improve the durability of the charge transport layer, various fillers and lubricants may be contained. Examples of the filler include alumina and silica. Examples of the lubricant include fluorine atom-containing resin particles.
The thickness of the charge transport layer is preferably 5 μm or more and 50 μm or less, and more preferably 8 μm or more and 35 μm or less.

  Some electrophotographic photoreceptors are completed by performing the formation of the charge generation layer and the charge transport layer as described above, but a protective layer may be provided on the outermost surface as necessary. Generally, the protective layer is used for improving the durability of the electrophotographic photosensitive member. Therefore, the protective layer often contains a binder resin, a filler, or the like that has excellent wear resistance. In addition, a charge transport material may be included so as not to deteriorate the electrical characteristics of the electrophotographic photosensitive member, but such a protective layer can be regarded as a second charge transport layer.

Examples of binder resins, charge transport materials, fillers and lubricants that can be used for the protective layer are the same as those listed in the description of the charge transport layer. An electrophotographic photosensitive member having a protective layer can be obtained by applying a coating solution for a protective layer obtained by dissolving these in a solvent to the outermost surface and drying.
The thickness of the protective layer is preferably 0.1 μm or more and 20 μm or less, and more preferably 1 μm or more and 10 μm or less.

Various additives such as an antioxidant and an ultraviolet absorber can be added to each layer described above as necessary.
In the case of a positively charged electrophotographic photosensitive member used by positively charging the surface of the electrophotographic photosensitive member, a charge transporting layer is formed first, and then a charge generating layer is applied to form the electrophotographic photosensitive member. It may be manufactured.

  As the solvent used in the coating solution for each layer described above, an appropriate solvent can be selected and used in accordance with each coating solution. For example, in the case of a charge transport layer, since a binder resin or a charge transport material is usually dissolved in a solvent to form a coating solution, the solvent may be selected from solvents that can dissolve these materials. In addition, in the case of a coating liquid containing a material used by being dispersed in a binder resin dissolved in a solvent, such as a charge generation material of a charge generation layer, a solvent having good dispersibility of those materials is selected. Good.

Examples of solvents that can be used in the coating solution include alcohols such as methanol, ethanol, and n-propanol, hydrocarbons such as cyclohexane, benzene, toluene, and xylene, halogenated hydrocarbons such as dichloromethane and monochlorobenzene, Examples include various organic solvents such as ethers such as tetrahydrofuran, acetals such as methylal, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, and esters such as ethyl acetate and n-butyl acetate. Water can also be used.
These solvents may be used alone, but a plurality of solvents having different boiling points can also be used in combination in order to improve the usability of the coating solution such as storage stability and coating property.
When measuring the viscosity of the coating solution, it is sufficient to select appropriate means and equipment in accordance with the solvent contained in the coating solution and the viscosity of the coating solution. For example, the viscosity can be measured by using a B-type viscometer. it can. In the present invention, the viscosity of the coating solution was measured at a measurement temperature of 23 ° C. and a rotation speed of 60 rpm using a single cylindrical rotational viscometer bismetron type VS-A1 manufactured by Shibaura System Co., Ltd.

Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to these. In the examples, “part” means “part by mass”.
[Example 1]
<Creation of electrophotographic photoreceptor>
A cylindrical aluminum cylinder having a length of 370 mm was used as a support. The diameter (outer diameter) φ1 of this support was 30 mm.

Next, the following ingredients:
Powder made of barium sulfate particles having a tin oxide coating layer (trade name: Pastoran PC1, manufactured by Mitsui Mining & Smelting Co., Ltd.) 60 parts Titanium oxide (trade name: TITANIX JR, manufactured by Teika Co., Ltd.) 15 parts Resol type Phenolic resin (trade name: Phenolite J-325, manufactured by Dainippon Ink & Chemicals, Inc., solid content 70%) 43 parts 2-methoxy-1-propanol 50 parts Methanol 50 parts a solution of 1 mm diameter glass beads Dispersion treatment was carried out for 3 hours with a sand mill using a to prepare a dispersion.

The dispersion contains the following ingredients:
Silicone resin (trade name: Tospearl 120, manufactured by Momentive Performance Materials Japan GK) 3.6 parts Silicone oil (trade name: SH28PA, manufactured by Toray Silicone Co., Ltd.) 0.015 part was added and stirred. .

Further, a solvent in which 2-methoxy-1-propanol and methanol are mixed in equal amounts is added, and the coating solution for the conductive layer is adjusted so as to have a viscosity of 48 mPa · s when measured at a solution temperature of 23 ° C. Got.
Here, the viscosity of the conductive layer coating solution was measured as follows.
Measuring apparatus: Single cylindrical rotational viscometer bismetron type VS-A1 (manufactured by Shibaura System Co., Ltd.).
The rotor is no. 1 was used. The rotor was placed in a 500 ml beaker containing about 500 ml of the coating solution, and then the rotor was rotated at 60 rpm. The value measured 60 seconds after the start of rotation of the rotor was taken as the viscosity of the conductive layer coating solution.
This conductive layer coating solution was dip-coated on the support at a room temperature of 23 ° C. at a lifting speed of 7 mm / s. Subsequently, by heating and curing in an oven at 140 ° C. for 1 hour, a conductive layer having a thickness of 15 μm measured at the center in the longitudinal direction of the coated body was formed.

  FIG. 6 shows a schematic diagram of a coating apparatus used for dip coating of the conductive layer. The lid 3 of the coating tank 1 has a circular opening 4 for allowing the article 9 to pass through, and its diameter (inner diameter) φ2 was 50 mm. A cylindrical hood 5 provided in close contact with the lid 3 is provided on the lid 3 so as to surround the opening 4. The diameter (inner diameter) φ3 of the hood 5 was 62 mm. Although the lower part of the hood 5 is a non-mesh portion 7, a Mylar sheet having no aperture is used here. Moreover, although the upper part of the food | hood has the mesh-shaped part 6, the stainless steel mesh was used here. The opening diameter (opening) M of the stainless steel mesh was 0.5 mm, and the ratio So (opening ratio) occupied by the area of the opening per unit area was 61%.

The distance L (a) from the liquid surface of the coating liquid 2 to the upper surface of the lid of the coating tank was 20 mm. Further, the distance L (b) from the upper surface of the lid of the coating tank to the boundary surface S (8 in FIG. 6) between the mylar sheet portion of the hood and the stainless steel mesh portion was 20 mm. Further, the distance L (c) from the boundary surface S to the upper end of the hood was 50 mm.
The coated body 9 is gripped by the coated body gripping means 10 and immersed in the coating liquid 2. At this time, the immersion was performed so that the liquid surface of the coating liquid 2 comes to a position 2 mm from the upper end of the body 9 to be coated. Subsequently, the object to be coated 9 was pulled up from the coating liquid 2 and the coating film was applied. This lifting operation is performed without stopping until the lower end of the object to be coated 9 reaches 20 mm above the boundary surface S. Was set as follows. The object to be coated 9 was stopped at that position for 5 seconds after the lifting operation was stopped, and then pulled up further, discharged out of the coating apparatus, and sent to the drying process.

  During coating, the coating solution was circulated through the following route. First, the coating liquid is introduced into the inside of the coating tank from the lower side of the coating tank 1 through the piping 14 for liquid feeding by a liquid feeding device 13 equipped with a pump for liquid feeding. The coating liquid overflows from the upper end of the coating tank and accumulates in the liquid receiving portion 16. The paint 17 collected in the liquid receiving portion 16 is returned again to the liquid feeding device 13 through the recovered liquid piping 15.

Next, the following ingredients:
Copolymerized nylon resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) 10 parts Methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Teikoku Chemical Co., Ltd.) 30 parts of methanol 400 parts / n- It was dissolved in a mixed solvent of 200 parts of butanol.

Further, a solvent in which methanol / n-butanol is mixed at a mass ratio of 2/1 is added, and the viscosity measured at 23 ° C. of the coating solution is adjusted to 4 mPa · s to obtain a coating solution for intermediate layer. It was.
Here, the viscosity of the intermediate layer coating solution was measured as follows.
Measuring apparatus: Single cylindrical rotational viscometer bismetron type VS-A1 (manufactured by Shibaura System Co., Ltd.).
A low viscosity adapter was used for the measurement. 20 ml of the coating solution was placed in a cup cylinder of a low viscosity adapter, and then the rotor was rotated at 60 rpm. The value measured 60 seconds after the start of rotation of the rotor was taken as the viscosity of the intermediate layer coating solution.
This intermediate layer coating solution was dip-coated on the conductive layer at a room temperature of 23 ° C. using a coating apparatus having the same configuration as the conductive layer applied at a lifting speed of 6 mm / s. . Subsequently, by drying (heating drying) in an oven at 100 ° C. for 30 minutes, an intermediate layer having a thickness of 0.4 μm measured at the center in the longitudinal direction of the coated body was formed.

Next, the following ingredients:
Hydroxygallium phthalocyanine (having strong peaks at 7.4 ° and 28.2 ° (Bragg angle 2θ ± 0.2 °) in CuKα characteristic X-ray diffraction)) 20 parts Calix represented by the following structural formula (1) Arene compound 0.2 parts

Polyvinyl butyral (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) 10 parts Cyclohexanone 600 parts were subjected to a dispersion treatment for 4 hours in a sand mill apparatus using glass beads having a diameter of 1 mm, and then 700 parts of ethyl acetate was added.

Furthermore, a solvent in which cyclohexanone / ethyl acetate was mixed at a mass ratio of 1/2 was added to adjust the solid content to 2 wt% to prepare a charge generation layer dispersion.
The charge generation layer coating solution is applied on the intermediate layer at a room temperature of 23 ° C. using the same coating apparatus as that applied to the conductive layer at a lifting speed of 6.5 mm / s. Immersion applied. Subsequently, by drying (heating drying) in an oven at 85 ° C. for 10 minutes, a charge generation layer having a thickness of 0.15 μm measured at the center in the longitudinal direction of the coated body was formed.

Next, the following ingredients:
50 parts of a charge transport material represented by the following structural formula (CTM-1)

下記構造式（ＣＴＭ−２）で示される電荷輸送物質 ５０部

50 parts of a charge transport material represented by the following structural formula (CTM-2)

100 parts of polycarbonate resin (trade name: Iupilon Z400, manufactured by Mitsubishi Engineering Plastics Co., Ltd.) were dissolved in a mixed solvent of 520 parts monochlorobenzene / 280 parts methylal.

Further, a mixed solvent in which monochlorobenzene / methylal was mixed at a mass ratio of 65/35 was added, and the viscosity of the coating liquid measured at a liquid temperature of 23 ° C. was adjusted to 250 mPa · s to prepare a coating liquid for a charge transport layer. Obtained.
Here, the viscosity of the charge transport layer coating solution was measured as follows.
Measuring apparatus: Single cylindrical rotational viscometer bismetron type VS-A1 (manufactured by Shibaura System Co., Ltd.).
The rotor is no. 2 was used. The rotor was placed in a 100 ml beaker containing about 100 ml of the coating solution, and then the rotor was rotated at 60 rpm. The value measured 60 seconds after the start of rotation of the rotor was taken as the viscosity of the charge transport layer coating solution.
The charge transport layer coating solution is applied on the charge generation layer at a lifting speed of 2.5 mm / s using a coating apparatus having the same configuration as that for coating the conductive layer in an environment of room temperature of 23 ° C. Was applied by dip coating.

Subsequently, it was dried (heat-dried) in an oven at 100 ° C. for 60 minutes to form a charge transport layer, thereby obtaining an electrophotographic photosensitive member. The thickness of the charge transport layer measured at the center in the longitudinal direction of the coated body was 18 μm.
In the same manner, the coating solution for the charge transport layer is applied and dried on a cylindrical aluminum cylinder having a length of 370 mm and a diameter (outer diameter) of 30 mm, which is used for evaluation of sagging at the upper end of the coating film. A sample was created.

<Image evaluation>
The electrophotographic photoreceptor thus obtained was mounted on an electrophotographic copying machine iR3245 manufactured by Canon Inc., and an entire halftone image was output. As shown in Table 1, rank A was obtained as a result of visually evaluating image unevenness generated in the output image according to the following rank criteria.
A = Good state with no image unevenness B = Slight image unevenness but no problem in actual use C = There is image unevenness and becomes a problem in actual use

<Evaluation of the sagging at the upper end of the coating film>
The following measurements were performed using a sample prepared for evaluating the sagging of the upper end portion of the coating film.
First, the average film thickness d (1) of the coating film at the center in the longitudinal direction of the coated body was measured. The average film thickness was determined by rotating the coated body by 45 ° in the circumferential direction for each measurement and averaging the film thicknesses measured at 8 locations in the circumferential direction of the coated body.

Subsequently, the average film thickness d (2) of the coating film was measured in the same manner at a position 10 mm from the end of the cylinder that was on the vertically upper side of the object to be coated when dip coating was performed.
Next, D = d (2) / d (1) was determined as a sagging index. D takes a value from 0 to 1, and the closer to 1, the less sagging and the better.
The measurement result of the sagging evaluation sample of Example 1 was 0.88.

[Example 2]
In the same manner as in Example 1, coating of the charge generation layer was performed.
Further, the charge transport layer coating solution was prepared in the same manner as in Example 1 except that the charge transport layer coating solution was adjusted to a monochlorobenzene / methylal ratio of 70/30.
Subsequently, φ2, φ3, L (a), L (b), L (c), M, and So of the coating device for the charge transport layer coating solution are changed as shown in Table 1, and the object to be coated is pulled up. However, it changed so that it might stop, when the lower end part of a to-be-coated body corresponds to the boundary surface S. Except for these changes, the charge transport layer coating solution was applied in the same manner as in Example 1 to prepare an electrophotographic photosensitive member and a sample for sagging evaluation.
Subsequently, in the same manner as in Example 1, image evaluation and sagging evaluation of the electrophotographic photosensitive member were performed. The evaluation results are shown in Table 1.

[Examples 3 to 6]
In the same manner as in Example 1, coating of the charge generation layer was performed.
Charge in the same manner as in Example 1 except that φ2, φ3, L (a), L (b), L (c), M, and So of the coating device for the coating solution for the charge transport layer were changed as shown in Table 1. The transport layer coating solution was applied to prepare an electrophotographic photoreceptor and a sample for sagging evaluation.
Subsequently, in the same manner as in Example 1, image evaluation and sagging evaluation of the electrophotographic photosensitive member were performed. The evaluation results are shown in Table 1.

Example 7
In the same manner as in Example 3, the application up to the charge generation layer was performed.
When applying the coating liquid for the charge transport layer, the operation of pulling up the coated body is the same as in Example 3 except that the lower end portion of the coated body is changed to stop at a position 25 mm below the boundary surface S. The charge transport layer coating solution was applied to prepare an electrophotographic photoreceptor and a sample for sagging evaluation.
Subsequently, in the same manner as in Example 1, image evaluation and sagging evaluation of the electrophotographic photosensitive member were performed. The evaluation results are shown in Table 1.
The image unevenness generated in the image evaluation occurred in a region located below the boundary surface S when the operation of lifting the object to be coated was stopped when the charge transport layer was applied.

[Comparative Example 1]
In the same manner as in Example 3, the application up to the charge generation layer was performed.
The coating liquid for the charge transport layer is the same as in Example 3 except that the hood of the coating apparatus for the coating liquid for the charge transport layer is changed to a hood having a diameter (inner diameter) of 60 mm and a length of 180 mm. Was applied to prepare an electrophotographic photosensitive member and a sample for sagging evaluation.
Subsequently, in the same manner as in Example 3, image evaluation and sagging evaluation of the electrophotographic photosensitive member were performed. The evaluation results are shown in Table 1.

[Comparative Example 2]
In the same manner as in Example 3, the application up to the charge generation layer was performed.
The hood of the coating device for the charge transport layer coating solution was changed to a hood composed of a stainless steel mesh having a diameter (inner diameter) of 60 mm, a length of 180 mm, and M = 0.5 mm and So = 61% as a whole. Except for this change, the charge transport layer coating solution was applied in the same manner as in Example 3 to prepare an electrophotographic photoreceptor and a sample for sagging evaluation.
Subsequently, in the same manner as in Example 3, image evaluation and sagging evaluation of the electrophotographic photosensitive member were performed. The evaluation results are shown in Table 1.

  From Table 1, it can be seen that the generation of unevenness and sagging can be suppressed simultaneously by changing the solvent vapor concentration in the hood stepwise. Further, the operation of pulling up the coated body immersed in the coating solution is performed without stopping until the lower end of the coated body reaches the boundary surface S or more, whereby a better coated film can be obtained. I understand.

Example 8
In the same manner as in Example 3, the application up to the charge generation layer was performed.
In the preparation of the coating solution for the charge transport layer, the charge transport material represented by the structural formula (CTM-1) is 100 parts, and the monochlorobenzene is used without using the charge transport material represented by the structural formula (CTM-2). Instead, a charge transport layer coating solution was prepared in the same manner as in Example 3 except that o-xylene was used.
Next, a charge transport layer coating solution was applied in the same manner as in Example 3 to prepare an electrophotographic photoreceptor.
Subsequently, in the same manner as in Example 3, image evaluation of the electrophotographic photosensitive member was performed. The evaluation results are shown in Table 2.

[Comparative Example 3]
An electrophotographic photosensitive member was prepared by applying the charge transport layer in the same manner as in Comparative Example 1 except that the charge transport layer coating solution used in Example 8 was used.
Subsequently, in the same manner as in Comparative Example 1, image evaluation of the electrophotographic photosensitive member was performed. The evaluation results are shown in Table 2.

[Comparative Example 4]
The charge transport layer was applied in the same manner as in Comparative Example 2 except that the charge transport layer coating solution used in Example 8 was used to prepare an electrophotographic photosensitive member.
Subsequently, in the same manner as in Comparative Example 1, image evaluation of the electrophotographic photosensitive member was performed. The evaluation results are shown in Table 2.

Example 9
In the same manner as in Example 3, the application up to the charge generation layer was performed.
Further, in the adjustment of the coating solution for the charge transport layer, the charge was obtained in the same manner as in Example 8 except that monochlorobenzene was used instead of o-xylene and the ratio of monochlorobenzene and methylal was adjusted to 40/60. A coating solution for the transport layer was prepared.
Next, a charge transport layer coating solution was applied in the same manner as in Example 8 to prepare an electrophotographic photoreceptor.
Subsequently, image evaluation of the electrophotographic photosensitive member was performed in the same manner as in Example 8. The evaluation results are shown in Table 2.

[Comparative Example 5]
The charge transport layer was applied in the same manner as in Comparative Example 1 except that the charge transport layer coating solution used in Example 9 was used to prepare an electrophotographic photosensitive member.
Subsequently, in the same manner as in Comparative Example 1, image evaluation of the electrophotographic photosensitive member was performed. The evaluation results are shown in Table 2.

Example 10
In the same manner as in Example 3, the application up to the charge generation layer was performed.
Further, in the adjustment of the coating solution for the charge transport layer, the coating solution for the charge transport layer was prepared in the same manner as in Example 8 except that monochlorobenzene was used instead of o-xylene and tetrahydrofuran was used instead of methylal.
Next, a charge transport layer coating solution was applied in the same manner as in Example 8 to prepare an electrophotographic photoreceptor.
Subsequently, image evaluation of the electrophotographic photosensitive member was performed in the same manner as in Example 8. The evaluation results are shown in Table 2.

[Comparative Example 6]
The charge transport layer was applied in the same manner as in Comparative Example 1 except that the charge transport layer coating solution used in Example 10 was used to prepare an electrophotographic photosensitive member.
Subsequently, in the same manner as in Comparative Example 1, image evaluation of the electrophotographic photosensitive member was performed. The evaluation results are shown in Table 2.

[Comparative Example 7]
A charge transport layer was applied in the same manner as in Comparative Example 2 except that the charge transport layer coating solution used in Example 10 was used to prepare an electrophotographic photosensitive member.
Subsequently, in the same manner as in Comparative Example 1, image evaluation of the electrophotographic photosensitive member was performed. The evaluation results are shown in Table 2.

Example 11
In the same manner as in Example 3, the application up to the charge generation layer was performed.
Further, in the adjustment of the charge transport layer coating solution, a charge transport layer coating solution was prepared in the same manner as in Example 10 except that methyl ethyl ketone was used instead of tetrahydrofuran.
Next, a charge transport layer coating solution was applied in the same manner as in Example 10 to prepare an electrophotographic photoreceptor.
Subsequently, image evaluation of the electrophotographic photosensitive member was performed in the same manner as in Example 10. The evaluation results are shown in Table 2.

[Comparative Example 8]
The charge transport layer was applied in the same manner as in Comparative Example 1 except that the charge transport layer coating solution used in Example 11 was used to prepare an electrophotographic photosensitive member.
Subsequently, in the same manner as in Comparative Example 1, image evaluation of the electrophotographic photosensitive member was performed. The evaluation results are shown in Table 2.

[Comparative Example 9]
The charge transport layer was applied in the same manner as in Comparative Example 2 except that the charge transport layer coating solution used in Example 11 was used to prepare an electrophotographic photosensitive member.
Subsequently, in the same manner as in Comparative Example 1, image evaluation of the electrophotographic photosensitive member was performed. The evaluation results are shown in Table 2.

Example 12
In the same manner as in Example 3, the application up to the charge generation layer was performed.
In addition, the charge transport layer coating solution was prepared in the same manner as in Example 10 except that dichloromethane was used instead of tetrahydrofuran in preparing the charge transport layer coating solution.
Next, a charge transport layer coating solution was applied in the same manner as in Example 10 to prepare an electrophotographic photoreceptor.
Subsequently, image evaluation of the electrophotographic photosensitive member was performed in the same manner as in Example 10. The evaluation results are shown in Table 2.

[Comparative Example 10]
The charge transport layer was applied in the same manner as in Comparative Example 1 except that the charge transport layer coating solution used in Example 12 was used to prepare an electrophotographic photosensitive member.
Subsequently, in the same manner as in Comparative Example 1, image evaluation of the electrophotographic photosensitive member was performed. The evaluation results are shown in Table 2.

[Comparative Example 11]
The charge transport layer was applied in the same manner as in Comparative Example 2 except that the charge transport layer coating solution used in Example 12 was used to prepare an electrophotographic photosensitive member.
Subsequently, in the same manner as in Comparative Example 1, image evaluation of the electrophotographic photosensitive member was performed. The evaluation results are shown in Table 2.
From Table 2, by using the coating apparatus and the coating method of the examples, it is possible to suppress unevenness generated in the coating film with coating liquids using various types of solvents, and as a result, it is possible to suppress the occurrence of image unevenness. I understand.

DESCRIPTION OF SYMBOLS 1 ... Coating tank 2 ... Coating liquid 3 ... Coating tank lid 4 ... Opening 5 ... Hood 6 ... Hood-like mesh part 7 ... Hood non-mesh-like part 8 ... Interface S
9 ... Subject 10 ... Subject gripping means 11 ... Cylindrical hood 12 with whole mesh ... Cylindrical hood 13 with whole mesh 13 ... Liquid feeding device 14 ... For liquid feeding Piping 15 Piping for recovered liquid 16 Paint remaining in liquid receiving part 17 Liquid receiving part

Claims (2)

  It has means for gripping the cylindrical coated body so that it can be moved up and down, and a coating tank for storing the coating liquid, and the cylindrical coated body is pulled up after being immersed in the coating liquid stored in the coating tank. In the electrophotographic photosensitive body manufacturing apparatus for forming a coating film on the surface of the coated body, the electrophotographic photosensitive body manufacturing apparatus has a lid having an opening for allowing the cylindrical coated body to pass above the coating tank. On the lid, a hood having a cross-sectional area larger than that of the opening is provided in close contact with the lid so as to surround the opening, and the upper portion of the hood is mesh-shaped, and the lower portion of the hood is An electrophotographic photoreceptor manufacturing apparatus characterized by being non-mesh.   The electrophotographic photosensitive member manufacturing method using the electrophotographic photosensitive member manufacturing apparatus according to claim 1, wherein a boundary surface between a mesh-like region above the hood and a non-mesh region below the hood is a boundary surface S. In this case, the operation of pulling up the cylindrical coated body performed after immersing the cylindrical coated body in the coating liquid has a lower end portion of the cylindrical coated body at a height higher than the boundary surface S. An electrophotographic photosensitive member manufacturing method, which is performed without stopping until it reaches.

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