Method for producing an electrophotographic photosensitive member

Abstract

The present invention relates to a method for producing an electrophotographic photosensitive member. A method for producing an electrophotographic photosensitive member, the production method comprising: forming a photosensitive layer; and forming a protective layer, wherein the step of forming the photosensitive layer forms a photosensitive layer in which the residual solvent amount of the first solvent in the photosensitive layer is 0.05% by mass to 2.50% and the residual solvent amount of the second solvent in the photosensitive layer is 0.50% by mass to 2.50%, and the step of forming the protective layer includes a step (A) of forming a cured film and a step (B) of forming a protective layer having a wrinkled shape, wherein, in step (A), the coated film irradiated with heat is heated at a heating temperature lower than the boiling point of the first solvent, and in step (B), the cured film is heated at a heating temperature higher than the boiling point of the first solvent.

Description

Technical Field

[0001] The present invention relates to a method for producing an electrophotographic photosensitive member. Background Art

[0002] As an electrophotographic photosensitive member mounted on a process cartridge and an electrophotographic apparatus, an electrophotographic photosensitive member containing an organic photoconductive substance (charge generation substance) has been used. In recent years, there has been a need for electrophotographic apparatuses with longer lifetimes. Therefore, there is a desire to provide an electrophotographic photosensitive member that can improve image quality and abrasion resistance (mechanical durability) and suppress potential fluctuations.

[0003] As a method for improving the abrasion resistance of an electrophotographic photosensitive member (hereinafter, also simply referred to as "photosensitive member"), a technique has been proposed in which a radically polymerizable resin is used on the surface of the photosensitive member and a photosensitive member having a cured layer as a surface layer is provided to thereby increase the mechanical strength of the surface layer.

[0004] An electrophotographic photosensitive member is usually used in an electrophotographic image forming method including a charging step, an exposure step, a developing step, a transfer step, and a cleaning step. Among these, the cleaning step of removing residual toner on the electrophotographic photosensitive member after the transfer step is an important step for obtaining a clear image. As this cleaning method, a method of pressing a rubber-like cleaning blade against the electrophotographic photosensitive member to scrape off the toner is generally used.

[0005] However, for the above-described cleaning method, the frictional force between the cleaning blade and the electrophotographic photosensitive member is large, so the cleaning blade is likely to chatter and strip. In addition, poor cleaning is likely to occur due to grooves or chipping at the edge of the cleaning blade. Here, the chattering of the cleaning blade is a phenomenon caused by the vibration of the cleaning blade due to an increase in the frictional resistance between the cleaning blade and the outer peripheral surface of the electrophotographic photosensitive member. In addition, stripping is a phenomenon in which the cleaning blade is reversed in the moving direction of the electrophotographic photosensitive member.

[0006] The problem of the cleaning blade becomes more prominent as the mechanical strength of the surface layer of the electrophotographic photosensitive member is higher, that is, as the outer peripheral surface of the electrophotographic photosensitive member is less likely to be worn. That is, due to curing the surface layer of the electrophotographic photosensitive member as described above to form a cured layer that improves the mechanical strength of the surface layer, this problem occurs. In addition, the surface layer of the organic electrophotographic photosensitive member is usually formed by the dip coating method, but the surface of the surface layer formed by the dip coating method (that is, the outer peripheral surface of the electrophotographic photosensitive member) is very smooth. Therefore, the contact area between the cleaning blade and the outer peripheral surface of the electrophotographic photosensitive member becomes larger, and the frictional resistance between the cleaning blade and the outer peripheral surface of the electrophotographic photosensitive member increases, which makes the above problem prominent.

[0007] As a method for overcoming the above problems, a method has been proposed to reduce the contact area between the surface of the photosensitive member and the cleaning blade by appropriately roughening the surface of the photosensitive member to reduce the frictional force.

[0008] Japanese Patent Application Laid-Open No. H02-150850 discloses a technique of grinding the surface of the photosensitive member with a grinding film. In addition, Japanese Patent Application Laid-Open No. 2014-178425 discloses a technique of including metal oxide fine particles in the surface layer.

[0009] In Japanese Patent Application Laid-Open No. H02-150850, the surface is roughened by grinding with a grinding film by using a film winding device. However, the grinding film is a consumable and is costly. In addition, due to the non-uniformity of the grinding film itself, an uneven shape of the photosensitive member will be formed. Furthermore, due to the mechanical damage, powder scraping of the photosensitive layer occurs, and the grinding material derived from the film may cause problems. Therefore, the equipment must be adjusted and the grinding conditions must be set so that such problems do not occur. Such machining is complex because the machining basically requires countermeasures for problems such as special capital investment, cost increase due to consumables, machining non-uniformity, and mechanical damage. In Japanese Patent Application Laid-Open No. 2014-178425, an uneven shape is imparted by adding metal oxide fine particles to the surface layer. However, in order to prepare a coating liquid containing such fine particles, a step of applying mechanical force to the fine particles to disperse the particles in the coating liquid is usually required. In addition, due to the change in the dispersion of the fine particles and the change in the particle size caused by particle aggregation, irregular unevenness may occur. Furthermore, depending on the addition amount, the characteristics of the photosensitive member may be adversely affected, and thus the degree of freedom of this amount is not very large.

[0010] That is, in the surface roughening methods of the prior art, man-hours are required, the cost is high, and portions with non-uniform shapes are formed. Therefore, a surface roughening method that can uniformly impart a finely controlled shape by a simpler method is needed.

[0011] Therefore, an object of the present invention is to provide a method for roughening the surface of a photosensitive member to uniformly impart a finely controlled shape by a simpler method. Summary of the Invention

[0012] The above object can be achieved by the following present invention. That is, a method for producing an electrophotographic photosensitive member according to the present invention is a method for producing an electrophotographic photosensitive member, the electrophotographic photosensitive member sequentially including a support, a photosensitive layer, and a protective layer, the outer surface of the protective layer having wrinkles, the method including the following steps: (i) forming a photosensitive layer on the support, and (ii) forming a protective layer on the photosensitive layer, wherein step (i) is a step of forming a photosensitive layer coating film by coating a photosensitive layer coating liquid containing a first solvent, a second solvent having a boiling point higher than that of the first solvent, a charge transporting material, and a resin, and then heating the photosensitive layer coating film to form a photosensitive layer, wherein based on the total mass of the photosensitive layer, the residual solvent amount of the first solvent in the photosensitive layer is 0.05% by mass to 2.50% by mass, and based on the total mass of the photosensitive layer, the residual solvent amount of the second solvent in the photosensitive layer is 0.50% by mass to 2.50% by mass, and step (ii) includes the following steps: (A) forming a protective layer coating film by coating a protective layer coating liquid containing a compound having a chain polymerizable functional group, irradiating the protective layer coating film with radiation, and then heating to form a cured film having a film thickness of 1.5 μm or less, and (B) further heating the cured film to form a protective layer, wherein the heating temperature in step (A) is lower than the boiling point of the first solvent, and the heating temperature in step (B) is higher than the boiling point of the first solvent.

[0013] According to the present invention, a method for roughening the outer surface of a photosensitive member can be provided, which can uniformly impart finely controlled wrinkles by a simpler method. In addition, according to the present invention, a method for producing a photosensitive member that reduces the frictional force with a cleaning blade can be provided.

[0014] Referring to the accompanying drawings, further features of the present invention will become apparent from the following description of exemplary embodiments. Brief Description of the Drawings

[0015] Figure 1 is a schematic view of wrinkles when observing the surface of the electrophotographic photosensitive member from above.

[0016] Figure 2It is a schematic structural diagram of an electrophotographic apparatus provided with a process cartridge having an electrophotographic photosensitive member.

[0017] Figure 3 It is a schematic structural diagram of an apparatus for grinding the surface of an electrophotographic photosensitive member. Detailed Description of the Invention

[0018] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0019] The present invention relates to a method for producing an electrophotographic photosensitive member which sequentially has a support, a photosensitive layer, and a protective layer, and the outer surface of the protective layer has wrinkles. The method includes (i) forming a photosensitive layer on the support, and (ii) forming a protective layer on the photosensitive layer.

[0020] The relationship between the production method of the present invention and the shape of the wrinkles (hereinafter, also referred to as "wrinkle shape") on the outer surface of the protective layer obtained by the present invention will be described.

[0021] Generally, when forming the protective layer as a cured film, in step (ii), the phenomenon that the surface of the protective layer becomes a wrinkle shape is considered a coating film defect.

[0022] However, as a result of intensive experiments, the present inventors have found a method for simply controlling the occurrence of changes in the wrinkle shape and making the wrinkle shape fine and uniform. That is, the present inventors have found a simple production method of a photosensitive member having a wrinkle shape in which the frictional resistance (hereinafter, also referred to as "torque") between the outer peripheral surface of the electrophotographic photosensitive member and the cleaning blade is reduced when used in an electrophotographic apparatus.

[0023] The wrinkle shape formed on the outer surface (the outer surface of the photosensitive member) of the protective layer by the production method of the present invention has a concave-convex shape in the form of stripes (the black part is a concave portion, and the white part is a convex portion) that can be observed when observing the surface of the photosensitive member from above as described in Figure 1 The stripe shape is not unidirectional and has an arbitrary shape, such as a curved shape, a broken shape, and a branched shape. However, it shows isotropy. According to the present invention, the wrinkle shape is formed finely and uniformly.

[0024] It is considered that the mechanism for generating the wrinkle shape is that when in step (A) of step (ii), a cured film is formed on the photosensitive layer and then in step (B) the cured film is further heated and cured, a difference in the amount of deformation occurs between the cured film and the photosensitive layer, which causes the generation of compressive stress applied in the surface direction to cause buckling, thereby generating a wrinkle shape on the surface of the cured film.

[0025] The reason why it is considered that the wrinkle shape can be formed finely and uniformly is as follows.

[0026] When heating is carried out in step (B) of step (ii) for forming the protective layer according to the production method of the present invention, the first solvent and the second solvent with different boiling points are each uniformly distributed and present in the photosensitive layer. At this time, by heating at a temperature higher than the boiling point of the first solvent, the first solvent evaporates faster than the second solvent, so that this part is likely to become the starting point of buckling due to compressive stress, and these starting points are formed on the entire surface in a uniform manner. Thereafter, it is considered that the wrinkled shape is formed finely and uniformly by gradually evaporating the second solvent. In addition, the heating temperature in step (A) is lower than the boiling point of the first solvent, thereby suppressing the rapid evaporation of the solvent. Therefore, a cured film can be formed while maintaining an appropriate residual solvent amount in the photosensitive layer. As a result, appropriate deformation of the photosensitive layer and the cured film in step (B) above is ensured, and a fine and uniform wrinkled shape can be formed.

[0027] The coating liquid for a photosensitive layer of the present invention contains a first solvent, a second solvent having a boiling point higher than that of the first solvent, a charge transporting substance, and a resin.

[0028] The photosensitive layer is formed by coating the coating liquid for a photosensitive layer to form a coating film for a photosensitive layer, heating, and drying the film.

[0029] In this case, when forming the protective layer in step (ii) to form a protective layer having a fine and uniform wrinkled shape on the surface, it is necessary to specify the residual solvent amount in the photosensitive layer after step (i). The residual solvent amount of the first solvent in the photosensitive layer needs to be 0.05% by mass to 2.50% by mass. If this amount is less than 0.05% by mass, the number of starting points of buckling decreases, and it is difficult to form a uniform wrinkled shape. If this amount exceeds 2.50% by mass, the buckling becomes large and the wrinkled shape becomes large, or the uniformity of the wrinkled shape decreases. The residual solvent amount of the second solvent in the photosensitive layer needs to be 0.50% by mass to 2.50% by mass. If this amount is less than 0.50% by mass, it is difficult to form a fine wrinkled shape. If this amount exceeds 2.50% by mass, the buckling becomes large and the wrinkled shape becomes large, or the uniformity decreases.

[0030] In addition, the ratio of the residual solvent amount of the second solvent to the residual solvent amount of the first solvent is preferably 1.00 to 15.00. Within this range, the balance between the first solvent and the second solvent is favorable. The starting points of buckling caused by the evaporation of the first solvent are introduced onto the entire surface in a fine and uniform manner, and the promotion of the wrinkled shape is finer and more uniform.

[0031] The method for adjusting the residual solvent amount can be appropriately adjusted according to the mixing ratio between the first solvent and the second solvent when preparing the coating solution and the drying temperature and time during film formation. In addition, the rate of solvent evaporation varies according to the volume of the space to be dried and the amount of air discharged from the solvent vapor. Therefore, it is necessary to set the drying conditions according to the actual equipment.

[0032] Well-known methods can be used to measure the residual solvent amount. For example, gas chromatography can be used. The residual solvent amount is the mass ratio of the first solvent or the second solvent to the total mass of the photosensitive layer.

[0033] The solvents include, for example, alcohol solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents. Specifically, the first solvent includes, for example, toluene and xylene (including at least one solvent selected from the group consisting of o-xylene, m-xylene, and p-xylene). In addition, the second solvent includes, for example, methyl benzoate, cyclohexanone, and diethylene glycol monoethyl ether acetate. In addition to the first solvent and the second solvent, other solvents can also be used in combination as solvents. Specifically, the other solvents include, for example, tetrahydrofuran and dimethoxymethane.

[0034] The boiling point of the first solvent is preferably 90°C to 150°C, and the boiling point of the second solvent is 153°C to 230°C. In addition, when the first solvent and the second solvent are used in combination, a boiling point difference of 40°C to 100°C is preferred. In addition, the boiling point of the other solvents is preferably 40°C to 70°C.

[0035] The charge transport materials include, for example, polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, benzidine compounds, triarylamine compounds, and resins having groups derived from these materials. Among them, triarylamine compounds and benzidine compounds are preferred, and those having the following structures are preferably used.

[0036]

[0037] (where R 1 to R 10 each independently represents a hydrogen atom or a methyl group.)

[0038] Examples of the structure represented by formula (1) are shown in formulas (1-1) to (1-10). Among them, the structures represented by formulas (1-1) to (1-6) are more preferred.

[0039]

[0040]

[0041] As the resin, a thermoplastic resin is used, and examples of the resin include, for example, polyester resins, polycarbonate resins, acrylic resins, polystyrene resins, etc. Among them, polycarbonate resins and polyester resins are preferred. As the polyester resin, polyarylate resins are particularly preferred.

[0042] The coating liquid for the protective layer of the present invention contains a compound having a chain polymerizable functional group.

[0043] The protective layer is formed as a cured film by coating the coating liquid for the protective layer and polymerizing the compound having a chain polymerizable functional group.

[0044] In the present invention, a cured film is formed by the step (A) of forming a coating film with the coating liquid for the protective layer, irradiating the coating film with radiation, and then heating at a heating temperature lower than the boiling point of the first solvent. Thereafter, by performing the step (B) of heating the cured film at a heating temperature higher than the boiling point of the first solvent, a protective layer having a wrinkled shape on the surface is formed.

[0045] Means for polymerizing the compound having a chain polymerizable functional group generally include means using heat, light, and radiation. However, in the present invention, radiation and heat are used in combination. When attempting to form a cured film by polymerization only with heat, high-temperature treatment for a long time is usually required, and since the polymerization of the coating film for the protective layer and the rapid evaporation of the residual solvent in the photosensitive layer proceed simultaneously, it is difficult to obtain a desired wrinkled shape. In addition, even in the case of polymerization by light or radiation, the temperature must be raised to a certain extent in order to sufficiently perform polymerization in a short time and form a cured film. Since radiation has higher energy than light and can effectively activate the polymerizable functional group, compared with those by light, the heating temperature can be lowered and the heating time can be shortened, and a protective layer can be formed while maintaining an appropriate amount of residual solvent in the photosensitive layer.

[0046] There is no particular limitation on the radiation, and it includes, for example, electron beams.

[0047] Irradiation with an electron beam is preferably performed in a low-oxygen atmosphere in order to prevent radical inactivation of the polymerizable functional group. In addition, step (A) is also preferably performed in a low-oxygen atmosphere in order to prevent radical inactivation and promote rapid polymerization.

[0048] In step (B), it is necessary to heat the cured film at a heating temperature higher than the boiling point of the first solvent. If the heating temperature is lower than the boiling point of the first solvent, almost no wrinkled shape appears. In addition, when step (B) is performed at a temperature lower than the boiling point of the second solvent, the first solvent evaporates more rapidly, and the second solvent evaporates later than the first solvent. Therefore, it is preferred that a fine and uniform wrinkled shape is formed.

[0049] Although it depends on the boiling point of the solvent used, the heating temperature in step (A) is 90°C to 130°C, and the heating temperature in step (B) is 140°C to 230°C. Here, the heating temperature refers to the atmosphere temperature during the production of the photosensitive member.

[0050] The film thickness of the protective layer according to the present invention is 1.5 μm or less, which can be said to be equivalent to the film thickness of the cured film according to the present invention. The film thickness specified in the present invention refers to the film thickness of the cured film formed in step (A). When the film thickness of the cured film exceeds 1.5 μm, the wrinkle shape tends to be large and uneven. When the film thickness of the cured film is 1.0 μm or less, the wrinkle shape becomes finer and more uniform, which is preferable.

[0051] The compound having a chain polymerizable functional group may have a molecular structure showing charge transportability in addition to the chain polymerizable functional group. As the molecular structure showing charge transportability, a triarylamine structure is preferable. The chain polymerizable functional group is preferably an acryloyl group and a methacryloyl group. The number of functional groups of the compound having a chain polymerizable functional group can be one or more. Among them, if a cured film is formed by using a compound having a plurality of functional groups and a compound having one functional group in combination, it is particularly preferable because the strain generated by the polymerization between the plurality of functional groups is easily eliminated.

[0052] Examples of the above-mentioned compound having one functional group are shown in formulas (2-1) to (2-6).

[0053]

[0054]

[0055] Examples of the above-mentioned compound having a plurality of functional groups are shown in formulas (3-1) to (3-7).

[0056]

[0057]

[0058] [Electrophotographic photosensitive member]

[0059] The electrophotographic photosensitive member of the present invention has a support, a photosensitive layer, and a protective layer.

[0060] The method for producing the electrophotographic photosensitive member of the present invention includes a method of preparing coating liquids for respective layers described later, coating the coating liquids onto the layers in a desired layer order, and drying the coating liquids. In this case, the coating method of the coating liquid includes dip coating, spraying, inkjet coating, roll coating, die coating, knife coating, curtain coating, wire bar coating, loop coating, etc. Among them, dip coating is preferable from the viewpoints of its efficiency and productivity.

[0061] Each layer will be described below.

[0062] <Support body>

[0063] In the present invention, the electrophotographic photosensitive member has a support body. In the present invention, the support body is preferably a conductive support body having conductivity. In addition, the shape of the support body includes, for example, cylindrical, belt-shaped, sheet-shaped, etc. Among them, a cylindrical support body is preferred. In addition, electrochemical treatment such as anodization, sandblasting treatment, cutting treatment, etc. can be performed on the surface of the support body.

[0064] The material of the support body is preferably metal, resin, glass, etc.

[0065] Metals include, for example, aluminum, iron, nickel, copper, gold, stainless steel, its alloys, etc. Among them, an aluminum support body using aluminum is preferred.

[0066] In addition, conductivity can be imparted to the resin or glass by, for example, mixing conductive materials or coating them.

[0067] <Conductive layer>

[0068] In the present invention, a conductive layer can be provided on the support body. By providing the conductive layer, scratches and uneven shapes on the surface of the support body can be covered, and light reflection on the surface of the support body can be controlled.

[0069] The conductive layer preferably contains conductive particles and resin.

[0070] The materials of the conductive particles include metal oxides, metals, carbon black, etc.

[0071] Metal oxides include zinc oxide, aluminum oxide, indium oxide, silicon oxide, zirconium oxide, tin oxide, titanium oxide, magnesium oxide, antimony oxide, bismuth oxide, etc. Metals include aluminum, nickel, iron, nickel-chromium alloy, copper, zinc, silver, etc.

[0072] Among them, it is preferable to use metal oxides as the conductive particles, and it is particularly preferable to use titanium oxide, tin oxide, and zinc oxide.

[0073] When using metal oxides as the conductive particles, the surface of the metal oxides can be treated with a silane coupling agent, etc., or the metal oxides can be doped with elements such as phosphorus or aluminum or their oxides.

[0074] In addition, the conductive particles can form a laminated structure having particles as core particles and a coating covering the core particles. The core particles include titanium oxide, barium sulfate, zinc oxide, etc. The coating includes metal oxides, such as tin oxide.

[0075] In addition, when using metal oxides as the conductive particles, the volume average particle diameter is preferably from 1 nm to 500 nm, and more preferably from 3 nm to 400 nm.

[0076] Examples of the resin include polyester resins, polycarbonate resins, polyvinyl acetal resins, acrylic resins, silicone resins, epoxy resins, melamine resins, polyurethane resins, phenolic resins, alkyd resins, etc.

[0077] In addition, the conductive layer may further contain a masking agent such as silicone oil, resin particles, titanium oxide, etc.

[0078] The average film thickness of the conductive layer is preferably from 1 μm to 50 μm, and particularly preferably from 3 μm to 40 μm.

[0079] The conductive layer can be formed by preparing a coating liquid for the conductive layer containing the above-mentioned various materials and a solvent, forming the coating film, and drying the coating film. Solvents for the coating liquid include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, aromatic hydrocarbon solvents, etc. Methods for dispersing the conductive particles in the coating liquid for the conductive layer include methods using a paint stirrer, a sand mill, a ball mill, and a liquid collision type high-speed disperser.

[0080] <Undercoat>

[0081] In the present invention, an undercoat can be provided on the support or the conductive layer. By providing the undercoat, the adhesion function between the layers is improved, and a charge injection blocking function can be imparted.

[0082] The undercoat preferably contains a resin. In addition, the undercoat can be formed into a cured film by polymerizing a composition containing a monomer having a polymerizable functional group.

[0083] Examples of the resin include polyester resins, polycarbonate resins, polyvinyl acetal resins, acrylic resins, epoxy resins, melamine resins, polyurethane resins, phenolic resins, polyvinylphenol resins, alkyd resins, polyvinyl alcohol resins, polyethylene oxide resins, polypropylene oxide resins, polyamide resins, polyamic acid resins, polyimide resins, polyamideimide resins, cellulose resins, etc.

[0084] Examples of the polymerizable functional group of the monomer having a polymerizable functional group include isocyanate group, blocked isocyanate group, hydroxymethyl group, alkylated hydroxymethyl group, epoxy group, metal alkoxide group, hydroxyl group, amino group, carboxyl group, mercapto group, carboxylic anhydride group, and carbon-carbon double bond group, etc.

[0085] In addition, for the purpose of improving the electrical properties, the undercoat may further contain an electron transporting material, a metal oxide, a metal, a conductive polymer, etc. Among them, an electron transporting material and a metal oxide are preferably used.

[0086] The electron transporting material includes, for example, a quinone compound, an imide compound, a benzimidazole compound, a subcyclopentadienyl compound, a fluorenone compound, an anthraquinone compound, a benzophenone compound, a cyano vinyl compound, an aryl halide compound, a silole compound, a boron-containing compound, etc. The undercoat layer can be formed into a cured film by using an electron transporting material having a polymerizable functional group as the electron transporting material and copolymerizing it with the above monomer having a polymerizable functional group.

[0087] The metal oxide includes, for example, indium tin oxide, tin oxide, indium oxide, titanium oxide, zinc oxide, aluminum oxide, silicon dioxide, etc. The metal includes gold, silver, aluminum, etc.

[0088] In addition, the undercoat layer may further contain an additive.

[0089] The average film thickness of the undercoat layer is preferably from 0.1 μm to 50 μm, more preferably from 0.2 μm to 40 μm, and particularly preferably from 0.3 μm to 30 μm.

[0090] The undercoat layer can be formed by preparing a coating liquid for the undercoat layer containing the above respective materials and a solvent, forming the coating film, and drying and / or curing the coating film. The solvent for the coating liquid includes, for example, an alcohol-based solvent, a ketone-based solvent, an ether-based solvent, an ester-based solvent, an aromatic hydrocarbon-based solvent, etc.

[0091] <Photosensitive layer>

[0092] The photosensitive layer of the electrophotographic photosensitive member is mainly classified into (1) a laminated photosensitive layer and (2) a single-layer photosensitive layer. The laminated photosensitive layer (1) has a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material. The single-layer photosensitive layer (2) has a photosensitive layer containing both a charge generation material and a charge transport material. The present invention is preferably used for producing a photosensitive member having a laminated photosensitive layer.

[0093] (1) Laminated photosensitive layer

[0094] The laminated photosensitive layer has a charge generation layer and a charge transport layer.

[0095] (1-1) Charge generation layer

[0096] The charge generation layer preferably contains a charge generation material and a resin.

[0097] The charge generation material includes, for example, an azo pigment, a perylene pigment, a polycyclic quinone pigment, an indigo pigment, a phthalocyanine pigment, etc. Among them, the azo pigment and the phthalocyanine pigment are preferred. Among the phthalocyanine pigments, oxotitanium phthalocyanine pigment, gallium chloride phthalocyanine pigment, and hydroxygallium phthalocyanine pigment are preferred.

[0098] The content of the charge generation substance in the charge generation layer is preferably 40% by mass to 85% by mass, and more preferably 60% by mass to 80% by mass, based on the total mass of the charge generation layer.

[0099] The resin includes, for example, polyester resin, polycarbonate resin, polyvinyl acetal resin, polyvinyl butyral resin, acrylic resin, silicone resin, epoxy resin, melamine resin, polyurethane resin, phenolic resin, polyvinyl alcohol resin, cellulose resin, polystyrene resin, polyvinyl acetate resin, polyvinyl chloride resin, etc., and polyvinyl butyral resin is more preferred.

[0100] In addition, the charge generation layer may further contain additives such as antioxidants and ultraviolet absorbers. Specifically, it includes hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, etc.

[0101] The average film thickness of the charge generation layer is preferably 0.1 μm to 1 μm, and more preferably 0.15 μm to 0.4 μm.

[0102] The charge generation layer can be formed by preparing a coating liquid for the charge generation layer containing the above-mentioned various materials and a solvent, forming the coating film, and drying the coating film. The solvents for this coating liquid include, for example, alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, aromatic hydrocarbon solvents, etc.

[0103] (1-2) Charge transport layer

[0104] When the present invention is a laminated photosensitive layer, step (i) according to the present invention is to sequentially form a photosensitive layer having a charge generation layer and a charge transport layer on a support.

[0105] The charge transport layer is obtained via the formation of a coating film for the charge transport layer obtained by a coating liquid for the charge transport layer containing a first solvent, a second solvent having a boiling point higher than that of the first solvent, a charge transport substance, and a resin. By heating the coating film for the charge transport layer, the residual solvent amount of the first solvent in the charge transport layer is 0.05% by mass to 2.50% by mass, and the residual solvent amount of the second solvent in the charge transport layer needs to be 0.50% by mass to 2.50% by mass. In addition, the residual solvent amount is the mass ratio of the first solvent or the second solvent to the total mass of the charge transport layer.

[0106] The content of the charge transport substance in the charge transport layer is preferably 25% by mass to 70% by mass, and more preferably 30% by mass to 55% by mass, based on the total mass of the charge transport layer.

[0107] The content ratio (mass ratio) between the charge transport substance and the resin is preferably 4:10 to 20:10, and more preferably 5:10 to 12:10.

[0108] In addition, the charge transport layer may contain additives such as antioxidants, ultraviolet absorbers, plasticizers, leveling agents, lubricity imparting agents, and abrasion resistance improvers. Specifically, the additives include, for example, hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, silicone-modified resins, silicone oils, fluororesin particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, boron nitride particles, and the like.

[0109] The average film thickness of the charge transport layer is preferably 5 μm to 50 μm, more preferably 8 μm to 40 μm, and particularly preferably 10 μm to 30 μm.

[0110] (2) Single-layer type photosensitive layer

[0111] In the case where the photosensitive layer of the present invention is a single-layer type, step (i) is carried out by forming a photosensitive layer coating film obtained from a photosensitive layer coating liquid containing a first solvent, a second solvent having a boiling point higher than that of the first solvent, a charge generating substance, a charge transport substance, and a resin. By heating the photosensitive layer coating film, the residual solvent amount of the first solvent in the photosensitive layer is 0.05% by mass to 2.50% by mass, and the residual solvent amount of the second solvent in the photosensitive layer needs to be 0.50% by mass to 2.50% by mass.

[0112] Examples of the materials of the charge generating substance, the charge transport substance, and the resin are the same as those in the above-mentioned "(1) Stacked type photosensitive layer".

[0113] <Protective layer>

[0114] In the present invention, the protective layer is provided on the photosensitive layer in step (ii). The protective layer is formed into a cured film by polymerizing a composition containing a compound having a polymerizable functional group.

[0115] The protective layer preferably further contains conductive particles and / or a charge transport substance and a resin.

[0116] The conductive particles include, for example, particles of metal oxides such as titanium oxide, zinc oxide, tin oxide, indium oxide, etc.

[0117] The charge transport substances include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, benzidine compounds, triarylamine compounds, and resins having groups derived from these substances, and triarylamine compounds and benzidine compounds are preferred.

[0118] The resin includes polyester resin, acrylic resin, phenoxy resin, polycarbonate resin, polystyrene resin, phenolic resin, melamine resin, epoxy resin, etc. Among them, polycarbonate resin, polyester resin and acrylic resin are preferred.

[0119] The protective layer may contain additives such as antioxidants, ultraviolet absorbers, plasticizers, leveling agents, slip property imparting agents, and abrasion resistance improvers. Specifically, it includes hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, silicone-modified resins, silicone oils, fluororesin particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, boron nitride particles, etc.

[0120] The protective layer can be formed by preparing a coating liquid for the protective layer containing the above-mentioned various materials and a solvent, forming the coating film, and drying and / or curing the coating film. The solvents used for this coating liquid include alcohol solvents, ketone solvents, ether solvents, sulfoxide solvents, ester solvents, and aromatic hydrocarbon solvents.

[0121] [Processing Cartridge and Electrophotographic Apparatus]

[0122] The processing cartridge of the present invention is characterized in that the processing cartridge integrally supports the electrophotographic photosensitive member and at least one unit selected from the group consisting of a charging unit, a developing unit, a transfer unit, and a cleaning unit, and can be easily detachably mounted to the main body of the electrophotographic apparatus.

[0123] In addition, the electrophotographic apparatus of the present invention is characterized in that the electrophotographic apparatus has the above-mentioned electrophotographic photosensitive member, charging unit, exposure unit, developing unit, and transfer unit.

[0124] Figure 2 An example of a schematic configuration of an electrophotographic apparatus having a processing cartridge equipped with an electrophotographic photosensitive member is shown.

[0125] Reference numeral 1 denotes a cylindrical electrophotographic photosensitive member that is rotationally driven at a predetermined peripheral speed about an axis 2 as a center in the direction indicated by the arrow. The surface of the electrophotographic photosensitive member 1 is charged to a predetermined positive or negative potential by a charging unit 3. Note that although a roller charging system based on a roller-type charging member is shown in the figure, charging systems such as a corona charging method, a proximity charging method, or an injection charging method may also be employed. The charged surface of the electrophotographic photosensitive member 1 is irradiated with exposure light 4 from an exposure unit (not shown), and thus, an electrostatic latent image corresponding to target image information is formed thereon. The electrostatic latent image formed on the surface of the electrophotographic photosensitive member 1 is developed with toner accommodated in a developing unit 5, and thus, a toner image is formed on the surface of the electrophotographic photosensitive member 1. The toner image formed on the surface of the electrophotographic photosensitive member 1 is transferred to a transfer material 7 by a transfer unit 6. The transfer material 7 having the toner image transferred thereon is conveyed to a fixing unit 8, undergoes a process for fixing the toner image, and is printed to the outside of the electrophotographic apparatus. The electrophotographic apparatus may include a cleaning unit 9 for removing attachments such as toner remaining on the surface of the electrophotographic photosensitive member 1 after transfer, for example. Additionally, a so-called cleanerless system configured to remove attachments with a developing unit or the like without separately providing a cleaning unit may be used. The electrophotographic apparatus may include a discharging mechanism configured to perform a discharging process on the surface of the electrophotographic photosensitive member 1 with pre-exposure light 10 from a pre-exposure unit (not shown). Furthermore, in order to detachably mount the processing cartridge 11 of the present invention to the main body of the electrophotographic apparatus, a guiding unit 12 such as a rail may be provided.

[0126] The electrophotographic photosensitive member of the present invention can be used in a laser beam printer, an LED printer, a copying machine, a facsimile machine, and a multi-functional machine thereof.

[0127] Examples

[0128] The present invention will be described in more detail by way of examples and comparative examples below. The present invention is not limited to the following examples as long as the present invention does not exceed its gist. Unless otherwise specified, in the description of the following examples, the term "parts" is based on mass.

[0129] <Production of electrophotographic photosensitive member>

[0130] [Example 1]

[0131] An aluminum cylinder (JIS-A3003, aluminum alloy) having a diameter of 24 mm and a length of 257.5 mm was used as a support (conductive support).

[0132] Next, the following materials were prepared.

[0133] · Titanium oxide (TiO₂) particles (average primary particle size: 230 nm) coated with oxygen-deficient tin oxide (SnO₂) as metal oxide particles: 214 parts

[0134] · Phenolic resin (monomer / oligomer of phenolic resin) (trade name: Pryofen J-325, manufactured by DIC Corporation, resin solid content: 60% by mass) as a binder: 132 parts

[0135] · 1-Methoxy-2-propanol as a solvent: 98 parts

[0136] Put the above materials into a sand mill using 450 parts of glass beads each with a diameter of 0.8 mm, and disperse them under the condition of a rotational speed of 2000 rpm. The dispersion treatment time is 4.5 hours, and the set temperature of the cooling water is 18 °C to obtain a dispersion. Remove the glass beads from this dispersion using a screen (screen opening: 150 μm). Add silicone resin particles (trade name: Tospearl120, manufactured by Momentive Performance Materials Inc., average particle size: 2 μm) as surface roughness imparting materials to the obtained dispersion. Based on the total mass of the metal oxide particles and the binder in the dispersion after removing the glass beads, set the addition amount of the silicone resin particles to 10% by mass. In addition, add silicone oil (trade name: SH28PA, manufactured by Dow Corning Toray Co., Ltd.) as a leveling agent to the dispersion so that the amount of the silicone oil is 0.01% by mass based on the total mass of the metal oxide particles and the binder in the dispersion. Next, add a mixed solvent of methanol and 1-methoxy-2-propanol (mass ratio 1:1) to the dispersion so that the total mass of the metal oxide particles, the binder, and the surface roughness imparting materials in the dispersion (i.e., the mass of the solid components) is 67% by mass based on the mass of the dispersion. Thereafter, prepare a coating liquid for the conductive layer by stirring. Dip-coat the obtained coating liquid for the conductive layer on a support, and heat the coated support at 140 °C for 1 hour to form a conductive layer with a film thickness of 30 μm.

[0137] Next, prepare the following materials.

[0138] · Electron transport material (Formula E-1): 4 parts

[0139] · Blocked isocyanate (trade name: Duranate SBN-70D, manufactured by Asahi Kasei Chemicals Corporation): 5.5 parts

[0140] · Polyvinyl butyral resin (Eslec KS-5Z, manufactured by Sekisui Chemical Co., Ltd.): 0.3 parts

[0141] · Zinc(II) hexanoate as a catalyst (manufactured by Mitsuwa Chemical Co., Ltd.): 0.05 parts

[0142] Dissolve the above materials in a mixed solvent of 50 parts of tetrahydrofuran and 50 parts of 1-methoxy-2-propanol to prepare a coating liquid for the undercoat. Dip-coat the coating liquid for the undercoat on the conductive layer, and heat the coating at 170 °C for 30 minutes to form an undercoat with a film thickness of 0.7 μm.

[0143]

[0144] Next, prepare 10 parts of crystalline hydroxygallium phthalocyanine having peaks at positions of 7.5° and 28.4° in the chart obtained from CuKα characteristic X-ray diffraction and 5 parts of polyvinyl butyral resin (trade name: Eslec BX-1, manufactured by Sekisui Chemical Co., Ltd.) and add them to 200 parts of cyclohexanone, and disperse the mixed solution in a sand mill using glass beads each having a diameter of 0.9 mm for 6 hours. Further add 150 parts of cyclohexanone for dilution and 350 parts of ethyl acetate to the dispersion to obtain a coating liquid for the charge generation layer. Dip-coat the obtained coating liquid on the undercoat, and dry the coating at 95 °C for 10 minutes to form a charge generation layer with a film thickness of 0.20 μm.

[0145] X-ray diffraction measurement is carried out under the following conditions.

[0146] [Powder X-ray diffraction measurement]

[0147] Measurement equipment used: X-ray diffractometer RINT-TTRII, manufactured by Rigaku Denki Co., Ltd.

[0148] X-ray tube: Cu

[0149] Tube voltage: 50 KV

[0150] Tube current: 300 mA

[0151] Scanning method: 2θ / θ scan

[0152] Scanning speed: 4.0° / min

[0153] Sampling interval: 0.02°

[0154] Start angle (2θ): 5.0°

[0155] Stop angle (2θ): 40.0°

[0156] Attachment: Standard sample holder

[0157] Filter: Not used

[0158] Incident monochromator: Used

[0159] Counter monochromator: Not used

[0160] Divergence slit: Open

[0161] Divergence vertical limiting slit: 10.00 mm

[0162] Scattering slit: Open

[0163] Receiving slit: Open

[0164] Flat monochromator: Used

[0165] Counter: Scintillation counter

[0166] Next, prepare the following materials.

[0167] · Charge transport material (hole transport material) represented by the above structural formula (1-1): 5 parts

[0168] · Charge transport material (hole transport material) represented by the above structural formula (1-3): 5 parts

[0169] · Polycarbonate (trade name: Iupilon Z400, manufactured by Mitsubishi Engineering-Plastics Corporation): 10 parts

[0170] · Polycarbonate resin having copolymer units of the following structural formula (C-4) and the following structural formula (C-5): 0.02 parts (x / y = 0.95 / 0.05: viscosity-average molecular weight = 20000)

[0171] Dissolve the above materials in a mixed solvent (60 parts of toluene / 2.3 parts of methyl benzoate / 12.8 parts of tetrahydrofuran) (first solvent: toluene, boiling point 110.6 °C; and second solvent: methyl benzoate, boiling point 199.6 °C) to prepare a coating solution for the charge transport layer. Dip-coat the coating solution for the charge transport layer on the charge generation layer to form a coating film for the charge transport layer, and dry the coating film at 100 °C for 20 minutes to form a charge transport layer with a film thickness of 16 μm.

[0172]

[0173] The amount of residual solvent in the charge transport layer was measured by gas chromatography-mass spectrometry (HP6890 / HP5973 manufactured by Hewlett-Packard Company) equipped with a headspace sampler. As the measurement conditions for the gas chromatography-mass spectrometry, using the headspace sampler, the charge transport layer was peeled off from the electrophotographic photosensitive member and heated at 150 °C for 30 minutes, and the gas generated therefrom was measured as follows: using a gas chromatography-mass spectrometry (HP6890 / HP5973 manufactured by Hewlett Packard Company) equipped with a capillary column (HP-5MS manufactured by Hewlet Packard Company, a copolymer of 5% diphenylpolysiloxane and 95% dimethylpolysiloxane, thickness 0.25 μm, inner diameter 0.25 mm and length 30 m), with the use of a carrier gas (He: 1 ml / min), the sample was held at 40 °C for 3 minutes, then for the first stage of temperature rise, the column was heated from 40 °C to 70 °C at a temperature rise rate of 2 °C / min, for the second stage of temperature rise, the column was heated from 70 °C to 150 °C at a temperature rise rate of 5 °C / min, and for the third stage of temperature rise, the column was heated from 150 °C to 300 °C at a temperature rise rate of 10 °C / min. A calibration curve was plotted using the solvent used in the charge transport layer as a reference substance for the calibration curve, and the amount of residual solvent in the charge transport layer was determined. The results are shown in Table 1.

[0174] Next, the following materials were prepared.

[0175] · Compound represented by the above structural formula (2-1): 8 parts

[0176] · Compound represented by the above structural formula (3-1): 16 parts

[0177] · Siloxane-modified acrylic compound (Cymac US270, manufactured by Toagosei Co., Ltd.): 0.1 part

[0178] The above materials were mixed with 58 parts of cyclohexane and 25 parts of 1-propanol and stirred. A coating liquid for the protective layer was prepared in this manner.

[0179] The protective layer was impregnated and coated on the charge transport layer with a coating solution to form a coating film for the protective layer, and the obtained coating film was dried at 40°C for 5 minutes. Thereafter, in a nitrogen atmosphere, while rotating the support (the irradiated object) at a speed of 300 rpm, the coating film was irradiated with an electron beam for 1.6 seconds under the conditions of an acceleration voltage of 70 kV and a beam current of 5.0 mA. The dose at the position of the outermost surface layer was 15 kGy. Then, in a nitrogen atmosphere, as a heat treatment, the temperature was raised from 25°C to 100°C within 20 seconds to form a cured film with a film thickness of 1.5 μm (Step (A)). The oxygen concentration from the electron beam irradiation to the subsequent heat treatment was 10 ppm or less. Next, the coating film was naturally cooled in air until the temperature of the coating film reached 25°C, and then heated in air at 220°C for 15 minutes to form a protective layer having a wrinkled shape on the surface (Step (B)). A cylindrical (drum-shaped) electrophotographic photosensitive member having a protective layer of Example 1 was produced.

[0180] [Examples 2 to 20]

[0181] Except for changing the types and amounts of the respective compounds in the formation of the charge transport layer, the types and amounts of the solvents in the formation of the charge transport layer, and the drying conditions in the formation of the charge transport layer as shown in Table 1, each charge transport layer was formed in the same manner as in Example 1. In addition, except for changing the types and amounts of the respective compounds in the formation of the protective layer, the film thickness of the cured film, and the heating temperature conditions as shown in Table 2, each protective layer was formed in the same manner as in Example 1, and each electrophotographic photosensitive member was produced.

[0182] [Example 21]

[0183] Except for forming the charge transport layer as follows and changing the types of the respective compounds and the production conditions of the protective layer as shown in Table 1, the electrophotographic photosensitive member was produced in the same manner as in Example 1.

[0184] · Charge transport material (hole transport material) represented by the above structural formula (1-1): 5 parts

[0185] · Charge transport material (hole transport material) represented by the above structural formula (1-2): 5 parts

[0186] · Polyarylate resin having a repeating structural unit represented by the following formula (16-1) and a repeating structural unit represented by the following formula (16-2) in a ratio of 5 / 5 and a weight-average molecular weight (Mw) of 100,000: 10 parts

[0187] · Polycarbonate resin having copolymer units of the above structural formula (C-4) and the above structural formula (C-5): 0.02 parts (x / y = 0.95 / 0.05: viscosity-average molecular weight = 20,000)

[0188] A coating solution for the charge transport layer was prepared by dissolving the above compounds in a mixed solvent (45 parts of toluene / 15 parts of methyl benzoate / 15 parts of tetrahydrofuran) (first solvent: toluene, boiling point 110.6 °C; and second solvent: methyl benzoate, boiling point 199.6 °C). The coating solution for the charge transport layer was dip-coated on the charge generation layer to form a coating film, and the coating film was dried at 100 °C for 30 minutes to form a charge transport layer with a film thickness of 16 μm.

[0189]

[0190] [Comparative Examples 1 to 3, 5, and 7]

[0191] Except for changing the amounts, types, etc. of the respective compounds as shown in Tables 1 and 2, each electrophotographic photosensitive member was produced in the same manner as in Example 1.

[0192] [Comparative Example 4]

[0193] Except for the changes shown in Table 1, various conditions for forming the charge transport layer were the same as in Example 1. In the step of forming the protective layer, after irradiation with radiation, heating in step (A) was not performed. Thereafter, in step (B), heating was performed in air at 160 °C for 15 minutes to form a protective layer with a film thickness of 1.5 μm. Other conditions in step (ii) of forming the protective layer were the same as in Example 1.

[0194] [Comparative Example 6]

[0195] Except for the changes shown in Table 1, various conditions for forming the charge transport layer were the same as in Example 1. In the step of forming the protective layer, the dose at the position of the outermost surface layer after irradiation with radiation was 15 kGy. Then, in a nitrogen atmosphere, heat treatment was performed in step (A) by heating from 25 °C to 230 °C in 20 seconds to form a cured film with a film thickness of 1.5 μm. The oxygen concentration from electron beam irradiation to the end of subsequent step (A) was 10 ppm or less.

[0196] This cured film was used as the protective layer without performing step (B). Other conditions in the step of forming the protective layer were the same as in Example 1.

[0197] <Evaluation>

[0198] Under the following conditions, the photosensitive members produced in Examples 1 to 21 and the photosensitive members produced in Comparative Examples 1 to 7 were used for evaluation.

[0199] ·Observation of the formed shape

[0200] The surface shape of the electrophotographic photosensitive member was magnified and observed with a laser microscope (VK-X200 manufactured by KEYENCE CORPORATION), and it was confirmed that the corrugated shape as shown in Figure 1 was formed. The results are shown in Table 3.

[0201] ·Measurement of the corrugation pitch in the corrugated shape

[0202] As the measurement of the corrugation pitch, the cross-sectional curve was measured under the following conditions using a surface roughness meter, and the average value of the intervals between all adjacent convex portions was obtained. The measurement was carried out in the same manner at any 10 points, and the average value of the 10-point values was taken as the pitch of the corrugated shape in each photosensitive member. In addition, the difference between the maximum value and the minimum value of the average pitch of each 10-point interval was obtained and taken as the variation of the average pitch. The results are shown in Table 3.

[0203] Name of roughness meter equipment: SE3500 (manufactured by Kosaka Laboratory Ltd.)

[0204] Sampling length: 0.08 mm

[0205] Cut-off length: Sampling length × 1

[0206] Filter characteristic: 2CR

[0207] Evaluation length: 1.0 mm

[0208] Longitudinal magnification: 10000

[0209] Transverse magnification: 50

[0210] Feed length: 0.1 mm / second

[0211] Leveling: Straight (entire area)

[0212] Complies with JISB0601-1982

[0213] Evaluation length when processing the entire curve to be measured: Interval length obtained by dividing the entire curve into 8000 equal parts

[0214] λs filter: None

[0215] Polarity: Normal

[0216] ·Relative value evaluation of torque and image evaluation

[0217] Under the following conditions, the photosensitive members produced in Examples 1 to 21 and the photosensitive members produced in Comparative Examples 1 to 7 were used for evaluation.

[0218] As the electrophotographic apparatus, a modified machine of a laser beam printer manufactured by Hewlett-Packard Company under the trade name HP LaserJet Enterprise Color M553dn was used. The modified apparatus enabled measurement of the drive current value of the rotary motor for the photosensitive member, adjustment and measurement of the voltage applied to the charging roller, and adjustment and measurement of the amount of image exposure light.

[0219] The photosensitive members of the Examples and Comparative Examples were each installed in the cyan cartridge of the image forming apparatus.

[0220] A test chart with a printing rate of 5% was used, and 100 images thereof were output on plain paper of A4 size. As the charging condition, the dark potential was set to -500 V, and as the exposure condition, the amount of image exposure light was set to 0.25 μJ / cm 2 . The drive current value (current value A) was read when 100 sheets were output. This indicates that the greater the obtained current value, the greater the frictional force between the electrophotographic photosensitive member and the cleaning blade.

[0221] Furthermore, an electrophotographic photosensitive member was produced as a control for the relative torque value by the following method. In the production of the electrophotographic photosensitive member of Example 1, without performing step (B), an electrophotographic photosensitive member without wrinkles was formed and used as the control electrophotographic photosensitive member. Using the produced control electrophotographic photosensitive member, the drive current value (current value B) of the rotary motor of the electrophotographic photosensitive member was measured in the same manner as in Example 1.

[0222] The ratio of the drive current value (current value A) of the rotary motor of the electrophotographic photosensitive member thus obtained to the drive current value (current value B) was calculated. The calculated value of (current value A) / (current value B) was used as the relative torque value for comparison. This indicates that the smaller the relative value, the more the frictional force between the electrophotographic photosensitive member and the cleaning blade is reduced.

[0223] The evaluation results are shown in Table 3.

[0224] [Reference Example 1]

[0225] In the production of the photosensitive member of Example 1, without performing step (B), a photosensitive member without wrinkle formation was produced. By using Figure 3 the grinding machine shown in, the surface of the photosensitive member was ground under the following conditions.

[0226] Grinding sheet feed speed: 400 mm / minute

[0227] Rotational speed of the photosensitive member: 240 rpm

[0228] Abrasive grains for grinding: Silicon carbide

[0229] Average particle size of the abrasive grains for grinding: 3 μm

[0230] Grinding time: 20 seconds

[0231] In the grinding method, while conveying the grinding sheet 1-1 having a layer in which abrasive grains are dispersed in a binder resin provided on a substrate sheet in the arrow direction, and while pressing the electrophotographic photosensitive member 1-7 for 20 seconds and rotating it in the arrow direction, the surface of the electrophotographic photosensitive member 1-7 is roughened. The surface roughness Ra of the photosensitive member after surface roughening is evaluated under the same conditions as those used for measuring the wrinkle pitch, and the surface roughness is found to be 0.018 μm. The relative torque value of the photosensitive member is found to be 0.67. Here, Figure 3 In the drawings, reference numerals 1-2 to 1-5 denote guide rollers, reference numeral 1-6 denotes a support roller, reference numeral 1-8 denotes a feed roller, and reference numeral 1-9 denotes a take-up roller.

[0232]

[0233] [Table 2]

[0234] Table 2

[0235]

[0236] [Table 3]

[0237] Table 3

[0238]

[0239] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation to cover all such modifications as well as equivalent structures and functions.

Claims

1. A method for producing an electrophotographic photosensitive member, characterized in that, The electrophotographic photosensitive member sequentially includes a support, a photosensitive layer, and a protective layer, and the outer surface of the protective layer has wrinkles. The method includes the following steps: (i) forming the photosensitive layer on the support, and (ii) forming the protective layer on the photosensitive layer, wherein the photosensitive layer is a laminated photosensitive layer or a single-layer photosensitive layer, when the photosensitive layer is a laminated photosensitive layer, the laminated photosensitive layer has a charge generation layer and a charge transport layer, and the step (i) is a step of sequentially forming on the support a photosensitive layer having a charge generation layer containing a charge generation substance and a charge transport layer containing a charge transport substance, the charge transport layer is obtained through the formation of a coating film for the charge transport layer obtained from a coating liquid for the charge transport layer containing a first solvent, a second solvent having a boiling point higher than that of the first solvent, the charge transport substance, and a resin, wherein based on the total mass of the charge transport layer, the residual solvent amount of the first solvent in the charge transport layer is 0.05% by mass to 2.50% by mass, and based on the total mass of the charge transport layer, the residual solvent amount of the second solvent in the charge transport layer is 0.50% by mass to 2.50% by mass; when the photosensitive layer is a single-layer photosensitive layer, the step (i) is carried out through the formation of a coating film for the photosensitive layer obtained from a coating liquid for the photosensitive layer containing a first solvent, a second solvent having a boiling point higher than that of the first solvent, a charge generation substance, a charge transport substance, and a resin, wherein based on the total mass of the photosensitive layer, the residual solvent amount of the first solvent in the photosensitive layer is 0.05% by mass to 2.50% by mass, and based on the total mass of the photosensitive layer, the residual solvent amount of the second solvent in the photosensitive layer is 0.50% by mass to 2.50% by mass, and the step (ii) includes the following steps: (A) forming a coating film for the protective layer by coating a coating liquid for the protective layer containing a compound having a chain polymerizable functional group, irradiating the coating film for the protective layer with radiation, and then heating to form a cured film having a film thickness of 1.5 μm or less, and (B) further heating the cured film to form the protective layer, wherein the heating temperature in the step (A) is lower than the boiling point of the first solvent, and the heating temperature in the step (B) is higher than the boiling point of the first solvent.

2. The method for producing an electrophotographic photosensitive member according to claim 1, wherein the ratio of the residual solvent amount of the second solvent to the residual solvent amount of the first solvent in the photosensitive layer is 1.00 to 15.

00.

3. The method for producing an electrophotographic photosensitive member according to claim 1 or 2, wherein the heating temperature in the step (B) is higher than the boiling point of the first solvent and lower than the boiling point of the second solvent.

4. The method for producing an electrophotographic photosensitive member according to claim 1 or 2, wherein the boiling point of the first solvent is 90°C to 150°C, and the boiling point of the second solvent is 153°C to 230°C.

5. The production method of the electrophotographic photosensitive member according to claim 4, wherein the difference between the boiling point of the second solvent and the boiling point of the first solvent is 40°C to 100°C.

6. The production method of the electrophotographic photosensitive member according to claim 1 or 2, wherein the step (i) is a step of forming a photosensitive layer having a charge generation layer and a charge transport layer in sequence on the support, and the step (i) includes: forming a coating film for the charge transport layer by coating a coating liquid for the charge transport layer containing the first solvent, the second solvent having a boiling point higher than that of the first solvent, a charge transport material, and a resin, and then heating the coating film for the charge transport layer to form the charge transport layer, wherein based on the total mass of the charge transport layer, the residual solvent amount of the first solvent in the charge transport layer is 0.05% by mass to 2.50% by mass, and based on the total mass of the charge transport layer, the residual solvent amount of the second solvent in the charge transport layer is 0.50% by mass to 2.50% by mass.

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