Conductive substrate for electrophotographic photoreceptor, electrophotographic photoreceptor, process cartridge, image forming apparatus, and method for manufacturing conductive substrate for electrophotographic photoreceptor

Abstract

To provide a conductive substrate for an electrophotographic photoreceptor with which a shake during rotation is reduced.SOLUTION: A conductive substrate for an electrophotographic photoreceptor has a cylindrical shape, and in a power spectrum obtained by performing fast Fourier transform on a roughness curve in an axial direction of an inner peripheral surface of the conductive substrate at both ends in the axial direction, an integrated value S of intensity within a period range of 0.01 mm or more and 0.1 mm or less is 0.02 or more and 0.10 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a conductive substrate for an electrophotographic photoreceptor, an electrophotographic photoreceptor, a process cartridge, and an image forming apparatus. [Background technology]

[0002] Patent Document 1 discloses an image forming member in which no free rotation occurs between a photosensitive member and a support member attached thereto even when exposed to a temperature of about -50°C. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 06-095559 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a conductive substrate for an electrophotographic photoreceptor which has a cylindrical shape and exhibits reduced runout during rotation compared to a conductive substrate for an electrophotographic photoreceptor in which the integrated value S of intensity in a periodic range of 0.01 mm or more and 0.1 mm or less is less than 0.02 or exceeds 0.10 in a power spectrum obtained by fast Fourier transform of the axial roughness curve of the inner peripheral surface of the conductive substrate at both axial end portions. [Means for solving the problem]

[0005] Specific means for solving the above problems include the following aspects. <1> It has a cylindrical shape, and In a power spectrum obtained by fast Fourier transform of the axial roughness curve of the inner peripheral surface of the conductive substrate at both axial ends, the integrated value S of intensity in a period range of 0.01 mm or more and 0.1 mm or less is 0.02 or more and 0.10 or less. Conductive substrate for electrophotographic photoreceptors. <2> The integrated value S is 0.03 or more and 0.08 or less. <1> The conductive substrate for an electrophotographic photoreceptor according to claim 1 <3> <1> or <2> and a photosensitive layer disposed on the conductive substrate. <4> <3> The electrophotographic photoreceptor according to claim 1, A process cartridge that is detachably attached to an image forming apparatus. <5> <3> an electrophotographic photoreceptor according to a charging device that charges the surface of the electrophotographic photosensitive member; an electrostatic latent image forming device for forming an electrostatic latent image on the charged surface of the electrophotographic photosensitive member; a developing device that develops the electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a developer containing toner to form a toner image; a transfer device that transfers the toner image onto a surface of a recording medium; An image forming apparatus comprising: <6> A method for manufacturing a conductive substrate for an electrophotographic photoreceptor, comprising a step of processing the inner peripheral surface of the conductive substrate at both axial end portions with a water jet, and setting the integrated value S of intensity in a range of a period of 0.01 mm or more and 0.1 mm or less to 0.02 or more and 0.10 or less in a power spectrum obtained by fast Fourier transform of an axial roughness curve of the inner peripheral surface of the conductive substrate at both axial end portions. [Effects of the Invention]

[0006] <1> According to the present invention, there is provided a conductive substrate for an electrophotographic photosensitive member which has a cylindrical shape and exhibits reduced runout during rotation compared to a conductive substrate for an electrophotographic photosensitive member in which the integrated value S of intensity in a periodic range of 0.01 mm or more and 0.1 mm or less is less than 0.02 or exceeds 0.10 in a power spectrum obtained by subjecting the axial roughness curve of the inner peripheral surface of the conductive substrate at both axial end portions to a fast Fourier transform. <2> According to this, an electroconductive substrate for an electrophotographic photoreceptor is provided which exhibits reduced vibration during rotation compared to an electroconductive substrate for an electrophotographic photoreceptor having an integrated value S of less than 0.03 or more than 0.08. <3> According to the method, an electrophotographic photoreceptor is provided which has a conductive substrate having an integrated value S of less than 0.02 or more than 0.10, or an integrated value S of less than 0.03 or more than 0.08, and a photosensitive layer disposed on the conductive substrate, and which exhibits reduced runout during rotation compared to an electrophotographic photoreceptor. <4> and <5> According to the present invention, there are provided a process cartridge and an image forming apparatus which are provided with a conductive substrate having an integrated value S of less than 0.02 or more than 0.10, or an integrated value S of less than 0.03 or more than 0.08, and a photosensitive layer disposed on the conductive substrate, and which reduce vibration of the electrophotographic photosensitive member during rotation compared to when an electrophotographic photosensitive member is used. <6> According to the method, the inner peripheral surface of the conductive substrate at both axial end portions is processed with a water jet, and the integrated value S of the intensity in a period range of 0.01 mm or more and 0.1 mm or less in a power spectrum obtained by performing a fast Fourier transform on the axial roughness curve of the inner peripheral surface of the conductive substrate at both axial end portions is made less than 0.02 or more than 0.10, thereby providing a method for manufacturing a conductive substrate for an electrophotographic photosensitive member in which runout during rotation of the electrophotographic photosensitive member is reduced compared to when the integrated value S of the intensity in a period range of 0.01 mm or more and 0.1 mm or less in a power spectrum obtained by performing a fast Fourier transform on the axial roughness curve of the inner peripheral surface of the conductive substrate at both axial end portions is made less than 0.02 or more than 0.10. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a partial cross-sectional view showing an example of a layer structure of the electrophotographic photoreceptor according to the present exemplary embodiment. [Figure 2] FIG. 3 is a partial cross-sectional view showing another example of the layer structure of the electrophotographic photosensitive member according to the present embodiment. [Figure 3] 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. [Figure 4] FIG. 10 is a schematic configuration diagram illustrating another example of an image forming apparatus according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008]

[0023] The following describes embodiments of the present disclosure. These descriptions and examples are intended to illustrate the embodiments and are not intended to limit the scope of the embodiments.

[0009] In the present disclosure, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples.

[0010] In the present disclosure, the term "step" includes not only an independent step but also a step that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved.

[0011] When embodiments of the present disclosure are described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Furthermore, the sizes of the components in each drawing are conceptual, and the relative size relationships between the components are not limited to these.

[0012] In the present disclosure, each component may contain multiple corresponding substances. When referring to the amount of each component in a composition in the present disclosure, if multiple substances corresponding to each component are present in the composition, the total amount of the multiple substances present in the composition is meant unless otherwise specified. In the present disclosure, the composition may contain multiple types of particles corresponding to each component. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified.

[0013] In the present disclosure, "axial direction" refers to the direction in which the rotation axis of the conductive substrate extends, and "radial direction" refers to the direction perpendicular to the rotation axis of the conductive substrate.

[0014] In the present disclosure, the integrated value of intensity in the period range of 0.01 mm or more and 0.1 mm or less in the power spectrum obtained by fast Fourier transform of the axial roughness curve of the inner peripheral surface of the conductive substrate at both axial ends may be simply referred to as the "integrated value S."

[0015] <Conductive substrate for electrophotographic photoreceptor> The conductive substrate for an electrophotographic photoreceptor according to this embodiment (hereinafter also referred to as "conductive substrate") has a cylindrical shape, and in a power spectrum obtained by fast Fourier transform of the axial roughness curve of the inner peripheral surface of the conductive substrate at both axial ends, the integrated value S of intensity in a range of a period of 0.01 mm to 0.1 mm is 0.02 to 0.10. With the above configuration, when applied to an image forming apparatus, runout during rotation is reduced. The reason for this is presumed to be as follows.

[0016] The conductive substrate according to this embodiment is used together with a flange when applied to an image forming apparatus. The flange is fitted to the conductive substrate at both axial ends of the conductive substrate and serves to transmit the rotational driving force (torque) of the rotating shaft passing through the center of the flange to the conductive substrate. However, during rotation, depending on the surface roughness of the inner peripheral surface of the conductive substrate at both axial ends, small slippage or vibration may occur between the inner peripheral surface and the flange fitting portion. Vibration can lead to a deterioration in image quality (specifically, uneven image density).

[0017] The conductive substrate according to this embodiment employs the integrated value S as an index of the surface quality of the inner peripheral surface of the conductive substrate at both axial ends. This integrated value S is set within a range where the inner peripheral surface of the conductive substrate at both axial ends is neither too rough nor too smooth. Therefore, when the conductive substrate according to this embodiment is applied to an image forming apparatus, it is expected that vibration during rotation will be reduced. In addition, deterioration of image quality (specifically, uneven image density) due to vibration can be suppressed.

[0018] -Conductive substrate material, etc.- The conductive substrate according to this embodiment has a cylindrical shape (that is, a drum shape). The material of the conductive substrate is, for example, metals such as aluminum, copper, zinc, chromium, nickel, molybdenum, vanadium, indium, gold, platinum, etc.; alloys such as stainless steel; conductive polymers, conductive compounds such as indium oxide, etc.; paper or resin sheet coated, vapor-deposited, or laminated with a metal or alloy; etc. "Conductive" means a material with a volume resistivity of 1×10 13 This means that the resistance is less than Ω·cm.

[0019] The conductive substrate may be a new product or a recycled product.

[0020] The conductive substrate may be subjected to an acid treatment or a boehmite treatment.

[0021] -Integrated value S- As described above, in the conductive substrate according to this embodiment, in the power spectrum obtained by fast Fourier transform of the axial roughness curve of the inner peripheral surface of the conductive substrate at both axial ends, the integrated value S of intensity in a range of a period of 0.01 mm to 0.1 mm is 0.02 to 0.10. When the integrated value S is in the above range, runout during rotation is reduced. The integrated value S is preferably 0.03 to 0.08, more preferably 0.035 to 0.07, and even more preferably 0.04 to 0.06. When the integrated value S is in the above preferred range, runout during rotation is further reduced. Here, "the inner peripheral surface of the conductive substrate at both axial ends" means the inner surface that comes into contact with the flange.

[0022] The integrated value S can be calculated by the following steps (1) to (3). (1) The axial roughness curve of the inner peripheral surface of the conductive substrate at both axial ends is determined. The roughness curve is the roughness curve specified in JIS B0601:2013. The roughness of the inner peripheral surface of the conductive substrate at both axial ends was measured using a contact surface roughness measuring instrument (Surfcom 1400A, Tokyo Seimitsu Co., Ltd.) in an environment with a temperature of 23°C and a relative humidity of 55%. The conductive substrate was scanned in the axial direction at a scanning speed of 0.3 mm / sec, a measurement length of 2.5 mm, and a cutoff value of 0.8 mm. The measuring probe was conical with an apex angle of 90°, a tip curvature radius of 5 μm, and a tip material made of diamond. Measurements were taken at three locations: the center in the axial direction and both ends of the image formation area. A roughness curve was calculated from the measured values ​​at the three locations. (2) The roughness curve is subjected to a fast Fourier transform to derive the power spectrum. Microsoft Excel is used as the analysis software. 4,096 height direction parameters are extracted from the roughness curve at intervals of 0.6 μm. The 4,096 height data points are converted so that the average is 0. The 4,096 parameter values ​​are subjected to a fast Fourier transform to derive a power spectrum with the horizontal axis representing the period (mm) and the vertical axis representing the intensity. (3) The intensity in the power spectrum in the period range of 0.01 mm or more and 0.1 mm or less is integrated to obtain the integrated value S. The integrated value S is the integrated value of the power spectrum value in the period range of 0.01 mm or more and 0.1 mm or less.

[0023] <Electrophotographic photoreceptor> The electrophotographic photoreceptor (hereinafter also referred to as "photoreceptor") according to this embodiment includes the conductive substrate and a photosensitive layer disposed on the conductive substrate. The electrophotographic photoreceptor according to this embodiment preferably includes an undercoat layer between the conductive substrate and the photosensitive layer.

[0024] FIG. 1 is a partial cross-sectional view schematically illustrating an example of the layer structure of a photoreceptor according to this embodiment. Photoreceptor 10A shown in FIG. 1 has a laminated photosensitive layer. Photoreceptor 10A has a structure in which an undercoat layer 2, a charge generation layer 3, and a charge transport layer 4 are laminated in this order on a conductive substrate 1, and the charge generation layer 3 and the charge transport layer 4 constitute a photosensitive layer 5 (a so-called function-separated photosensitive layer). Photoreceptor 10A may have an intermediate layer (not shown) between the undercoat layer 2 and the charge generation layer 3. Photoreceptor 10A may have a protective layer (not shown) on the charge transport layer 4.

[0025] Fig. 2 is a partial cross-sectional view schematically showing another example of the layer structure of a photoreceptor according to this embodiment. Photoreceptor 10B shown in Fig. 2 has a single-layer photosensitive layer. Photoreceptor 10B has a structure in which an undercoat layer 2 and a photosensitive layer 5 are laminated in this order on a conductive substrate 1. Photoreceptor 10B may have an intermediate layer (not shown) between the undercoat layer 2 and the photosensitive layer 5. Photoreceptor 10B may have a protective layer (not shown) on the photosensitive layer 5.

[0026] Each layer of the photoreceptor (excluding the conductive substrate) will be described in detail below.

[0027] -Charge generation layer- The charge generation layer is, for example, a layer containing a charge generation material and a binder resin. Alternatively, the charge generation layer may be a vapor-deposited layer of the charge generation material. A vapor-deposited layer of the charge generation material is suitable for use with an incoherent light source such as an LED (Light Emitting Diode) or an organic EL (Electro-Luminescence) image array.

[0028] Examples of the charge generating material include azo pigments such as bisazo and trisazo; fused-ring aromatic pigments such as dibromoanthanthrone; perylene pigments; pyrrolopyrrole pigments; phthalocyanine pigments; zinc oxide; and trigonal selenium.

[0029] Among these, in order to be compatible with laser exposure in the near-infrared region, it is preferable to use a metal phthalocyanine pigment or a metal-free phthalocyanine pigment as the charge generating material, specifically, for example, hydroxygallium phthalocyanine, chlorogallium phthalocyanine, dichlorotin phthalocyanine, or titanyl phthalocyanine.

[0030] On the other hand, in order to accommodate laser exposure in the near ultraviolet region, preferred charge generating materials include fused ring aromatic pigments such as dibromoanthanthrone; thioindigo pigments; porphyrazine compounds; zinc oxide; trigonal selenium; and bisazo pigments.

[0031] The above charge generating material may also be used when an incoherent light source such as an LED or organic EL image array having a central emission wavelength of 450 nm or more and 780 nm or less is used.

[0032] In contrast, when n-type semiconductors such as fused-ring aromatic pigments, perylene pigments, and azo pigments are used as charge-generating materials, dark current is less likely to occur, and image defects known as black spots can be suppressed even in thin films. The n-type is determined by the polarity of the photocurrent that flows using the commonly used time-of-flight method, and materials that more easily pass electrons as carriers than holes are considered n-type.

[0033] The binder resin used in the charge generating layer may be selected from a wide range of insulating resins, and may also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, and polysilane. Examples of binder resins include polyvinyl butyral resin, polyarylate resin (polycondensation product of bisphenols and aromatic dicarboxylic acids, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin, polyacrylamide resin, polyvinylpyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinylpyrrolidone resin, etc. Here, "insulating" means a resin having a volume resistivity of 10 13 This means that the resistance is Ω·cm or more. These binder resins can be used alone or in combination of two or more.

[0034] The compounding ratio of the charge generating material to the binder resin is preferably within the range of 10:1 to 1:10 by mass.

[0035] The charge generating layer may contain other known additives.

[0036] The formation of the charge generation layer is not particularly limited, and a known formation method can be used. For example, the charge generation layer can be formed by forming a coating film of a coating liquid for forming the charge generation layer by adding the above components to a solvent, drying the coating film, and heating it as necessary. The charge generation layer can also be formed by vapor deposition of the charge generation material. Formation of the charge generation layer by vapor deposition is particularly suitable when a fused ring aromatic pigment or a perylene pigment is used as the charge generation material.

[0037] Examples of solvents for preparing the coating liquid for forming the charge generating layer include methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, toluene, etc. These solvents may be used alone or in combination of two or more.

[0038] Methods for dispersing particles (e.g., charge-generating material) in the coating liquid for forming a charge-generating layer include media-based dispersers such as ball mills, vibration ball mills, attritors, sand mills, and horizontal sand mills, as well as media-less dispersers such as stirrers, ultrasonic dispersers, roll mills, and high-pressure homogenizers. Examples of high-pressure homogenizers include a collision method in which the dispersion liquid is dispersed by liquid-liquid collision or liquid-wall collision under high pressure, and a penetration method in which the dispersion liquid is dispersed by passing through a fine flow path under high pressure. During dispersion, it is effective to adjust the average particle size of the charge-generating material in the coating liquid for forming a charge-generating layer to 0.5 μm or less, preferably 0.3 μm or less, and more preferably 0.15 μm or less.

[0039] Examples of methods for applying the coating liquid for forming the charge generating layer onto the undercoat layer (or onto the intermediate layer) include conventional methods such as blade coating, wire bar coating, spray coating, dip coating, bead coating, air knife coating, and curtain coating.

[0040] The thickness of the charge generating layer is preferably set within the range of 0.1 μm to 5.0 μm, more preferably 0.2 μm to 2.0 μm.

[0041] -Charge transport layer- The charge transport layer is, for example, a layer containing a charge transport material and a binder resin, or may be a layer containing a polymer charge transport material.

[0042] Examples of charge transport materials include electron transport compounds such as quinone compounds such as p-benzoquinone, chloranil, bromanil, and anthraquinone; tetracyanoquinodimethane compounds; fluorenone compounds such as 2,4,7-trinitrofluorenone; xanthone compounds; benzophenone compounds; cyanovinyl compounds; and ethylene compounds. Examples of charge transport materials also include hole transport compounds such as triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, and hydrazone compounds. These charge transport materials may be used alone or in combination, but are not limited to these.

[0043] As the charge transport material, triarylamine derivatives represented by the following structural formula (a-1) and benzidine derivatives represented by the following structural formula (a-2) are preferred from the viewpoint of charge mobility.

[0044] [ka]

[0045] In structural formula (a-1), Ar T1 , Ar T2 , and Ar T3 each independently represents a substituted or unsubstituted aryl group, -C6H4-C(R T4 )=C(R T5 )(R T6 ), or -C6H4-CH=CH-CH=C(R T7 )(R T8 ) indicates R T4 , R T5 , R T6 , R T7 , and R T8each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. Examples of the substituents on each of the above groups include halogen atoms, alkyl groups having from 1 to 5 carbon atoms, and alkoxy groups having from 1 to 5 carbon atoms. Examples of the substituents on each of the above groups also include substituted amino groups substituted with alkyl groups having from 1 to 3 carbon atoms.

[0046] [ka]

[0047] In structural formula (a-2), R T91 and R T92 R each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. T101 , R T102 , R T111 and R T112 each independently represents a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an amino group substituted with an alkyl group having 1 to 2 carbon atoms, a substituted or unsubstituted aryl group, -C(R T12 )=C(R T13 )(R T14 ), or -CH=CH-CH=C(R T15 )(R T16 ) and R T12 , R T13 , R T14 , R T15 and R T16 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. Tm1, Tm2, ​​Tn1, and Tn2 each independently represent an integer of 0 or more and 2 or less. Examples of the substituents on each of the above groups include halogen atoms, alkyl groups having from 1 to 5 carbon atoms, and alkoxy groups having from 1 to 5 carbon atoms. Examples of the substituents on each of the above groups also include substituted amino groups substituted with alkyl groups having from 1 to 3 carbon atoms.

[0048] Among the triarylamine derivatives represented by the structural formula (a-1) and the benzidine derivatives represented by the structural formula (a-2), in particular, "-C6H4-CH=CH-CH=C(R T7 )(R T8 )" and triarylamine derivatives having "-CH=CH-CH=C(R T15 )(R T16 ) is preferred from the viewpoint of charge mobility.

[0049] As the polymer charge transport material, known materials having charge transport properties such as poly-N-vinylcarbazole and polysilane are used. In particular, polyester polymer charge transport materials are particularly preferred. The polymer charge transport material may be used alone or in combination with a binder resin.

[0050] Examples of binder resins used in the charge transport layer include polycarbonate resins, polyester resins, polyarylate resins, methacrylic resins, acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl acetate resins, styrene-butadiene copolymers, vinylidene chloride-acrylonitrile copolymers, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-maleic anhydride copolymers, silicone resins, silicone alkyd resins, phenol-formaldehyde resins, styrene-alkyd resins, poly-N-vinylcarbazole, and polysilanes. Among these, polycarbonate resins or polyarylate resins are preferred as binder resins. These binder resins may be used alone or in combination of two or more. The compounding ratio of the charge transport material to the binder resin is preferably from 10:1 to 1:5 by mass.

[0051] The charge transport layer may contain other known additives.

[0052] The formation of the charge transport layer is not particularly limited, and a known formation method can be used. For example, the charge transport layer can be formed by forming a coating film of a coating liquid for forming the charge transport layer in which the above components are added to a solvent, drying the coating film, and heating it if necessary.

[0053] Examples of solvents for preparing the coating solution for forming the charge transport layer include ordinary organic solvents such as aromatic hydrocarbons such as benzene, toluene, xylene, and chlorobenzene; ketones such as acetone and 2-butanone; halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, and ethylene chloride; and cyclic or linear ethers such as tetrahydrofuran and ethyl ether. These solvents may be used alone or in combination.

[0054] Examples of a coating method for applying the coating liquid for forming the charge transport layer onto the charge generating layer include common methods such as blade coating, wire bar coating, spray coating, dip coating, bead coating, air knife coating, and curtain coating.

[0055] The thickness of the charge transport layer is set, for example, preferably in the range of 5 μm to 50 μm, more preferably 10 μm to 30 μm.

[0056] -Sublayer- The undercoat layer is, for example, a layer containing inorganic particles and a binder resin.

[0057] For example, inorganic particles have a powder resistance (volume resistivity) of 1×10 2 Ω cm or more 1×10 11 Examples include inorganic particles with a particle size of Ω·cm or less. Among these, inorganic particles having the above resistance value are preferably metal oxide particles such as tin oxide particles, titanium oxide particles, zinc oxide particles, and zirconium oxide particles, with zinc oxide particles being particularly preferred.

[0058] The specific surface area of ​​inorganic particles measured by the BET method is, for example, 10 m 2 / g or more is preferable. The volume average particle size of the inorganic particles is, for example, 50 nm or more and 2000 nm or less (preferably 60 nm or more and 1000 nm or less).

[0059] The content of the inorganic particles is, for example, preferably 10% by mass or more and 80% by mass or less, more preferably 40% by mass or more and 80% by mass or less, relative to the binder resin.

[0060] The inorganic particles may be surface-treated, and two or more types of inorganic particles having different surface treatments or different particle sizes may be used in combination.

[0061] Examples of the surface treatment agent include a silane coupling agent, a titanate-based coupling agent, an aluminum-based coupling agent, a surfactant, etc. In particular, a silane coupling agent is preferred, and a silane coupling agent having an amino group is more preferred.

[0062] Examples of silane coupling agents having an amino group include, but are not limited to, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, and N,N-bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane.

[0063] Two or more silane coupling agents may be used in combination. For example, a silane coupling agent having an amino group may be used in combination with another silane coupling agent. Examples of other silane coupling agents include, but are not limited to, vinyltrimethoxysilane, 3-methacryloxypropyl-tris(2-methoxyethoxy)silane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N,N-bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, and 3-chloropropyltrimethoxysilane.

[0064] The surface treatment method using the surface treatment agent may be any known method, and may be either a dry method or a wet method.

[0065] The amount of the surface treatment agent to be used is preferably, for example, 0.5% by mass or more and 10% by mass or less relative to the inorganic particles.

[0066] Here, it is preferable that the undercoat layer contains an electron-accepting compound (acceptor compound) together with the inorganic particles, from the viewpoint of improving the long-term stability of the electrical properties and the carrier blocking property.

[0067] Examples of the electron-accepting compound include electron-transporting substances such as quinone compounds such as chloranil and bromoanil; tetracyanoquinodimethane compounds; fluorenone compounds such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitro-9-fluorenone; oxadiazole compounds such as 2-(4-biphenyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole, 2,5-bis(4-naphthyl)-1,3,4-oxadiazole and 2,5-bis(4-diethylaminophenyl)-1,3,4-oxadiazole; xanthone compounds; thiophene compounds; diphenoquinone compounds such as 3,3',5,5'-tetra-t-butyldiphenoquinone; and benzophenone compounds. In particular, the electron-accepting compound is preferably a compound having an anthraquinone structure, such as a hydroxyanthraquinone compound, an aminoanthraquinone compound, or an aminohydroxyanthraquinone compound, and specifically, for example, anthraquinone, alizarin, quinizarin, anthrarphine, or purpurin.

[0068] The electron-accepting compound may be contained in the undercoat layer in a dispersed state together with the inorganic particles, or may be contained in a state of being attached to the surfaces of the inorganic particles.

[0069] The electron-accepting compound can be attached to the surface of the inorganic particles by, for example, a dry method or a wet method.

[0070] The dry method is a method in which, while stirring inorganic particles using a mixer or the like with high shear force, an electron-accepting compound is added dropwise, either directly or dissolved in an organic solvent, or sprayed together with dry air or nitrogen gas to adhere the electron-accepting compound to the surface of the inorganic particles. The electron-accepting compound is preferably added dropwise or sprayed at a temperature below the boiling point of the solvent. After the electron-accepting compound has been added dropwise or sprayed, baking may be performed at 100°C or higher. The baking temperature and time are not particularly limited as long as they achieve electrophotographic properties.

[0071] The wet method involves dispersing inorganic particles in a solvent using, for example, stirring, ultrasonic waves, a sand mill, an attritor, or a ball mill, while adding an electron-accepting compound. The mixture is stirred or dispersed, and then the solvent is removed to adhere the electron-accepting compound to the surfaces of the inorganic particles. The solvent can be removed, for example, by filtration or distillation. After solvent removal, baking may be performed at 100°C or higher. The baking temperature and time are not particularly limited as long as electrophotographic properties are obtained. In the wet method, moisture contained in the inorganic particles may be removed before adding the electron-accepting compound. Examples of such methods include a method of removing the moisture by stirring and heating in a solvent, and a method of removing the moisture by azeotropy with the solvent.

[0072] The attachment of the electron-accepting compound may be carried out before or after the inorganic particles are surface-treated with a surface-treating agent, or the attachment of the electron-accepting compound and the surface treatment with a surface-treating agent may be carried out simultaneously.

[0073] The content of the electron-accepting compound is, for example, 0.01% by mass or more and 20% by mass or less, and preferably 0.01% by mass or more and 10% by mass or less, based on the inorganic particles.

[0074] Examples of binder resins used in the undercoat layer include known polymer compounds such as acetal resins (e.g., polyvinyl butyral, etc.), polyvinyl alcohol resins, polyvinyl acetal resins, casein resins, polyamide resins, cellulose resins, gelatin, polyurethane resins, polyester resins, unsaturated polyester resins, methacrylic resins, acrylic resins, polyvinyl chloride resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate-maleic anhydride resins, silicone resins, silicone-alkyd resins, urea resins, phenolic resins, phenol-formaldehyde resins, melamine resins, urethane resins, alkyd resins, and epoxy resins; zirconium chelate compounds; titanium chelate compounds; aluminum chelate compounds; titanium alkoxide compounds; organic titanium compounds; and silane coupling agents. Examples of binder resins used in the undercoat layer include charge transporting resins having charge transporting groups, conductive resins (such as polyaniline), and the like.

[0075] Among these, the binder resin used in the undercoat layer is preferably a resin that is insoluble in the coating solvent of the upper layer, and in particular, a resin obtained by reacting at least one resin selected from the group consisting of thermosetting resins such as urea resins, phenolic resins, phenol-formaldehyde resins, melamine resins, urethane resins, unsaturated polyester resins, alkyd resins, and epoxy resins, and polyamide resins, polyester resins, polyether resins, methacrylic resins, acrylic resins, polyvinyl alcohol resins, and polyvinyl acetal resins with a curing agent is preferred. When two or more of these binder resins are used in combination, the mixing ratio is set as necessary.

[0076] The undercoat layer may contain various additives to improve electrical properties, environmental stability, and image quality. Examples of additives include known materials such as polycyclic condensation and azo electron transport pigments, zirconium chelate compounds, titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, and silane coupling agents. Silane coupling agents are used for the surface treatment of inorganic particles as described above, and may also be added to the undercoat layer as an additive.

[0077] Examples of silane coupling agents as additives include vinyltrimethoxysilane, 3-methacryloxypropyl-tris(2-methoxyethoxy)silane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N,N-bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, and 3-chloropropyltrimethoxysilane.

[0078] Examples of zirconium chelate compounds include zirconium butoxide, zirconium ethyl acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate zirconium butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octanoate, zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, and isostearate zirconium butoxide.

[0079] Examples of titanium chelate compounds include tetraisopropyl titanate, tetra-normal-butyl titanate, butyl titanate dimer, tetra(2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, titanium lactate, titanium lactate ethyl ester, titanium triethanolamine, and polyhydroxytitanium stearate.

[0080] Examples of aluminum chelate compounds include aluminum isopropylate, monobutoxyaluminum diisopropylate, aluminum butyrate, diethylacetoacetate aluminum diisopropylate, and aluminum tris(ethylacetoacetate).

[0081] These additives may be used alone or as a mixture or polycondensate of a plurality of compounds.

[0082] The undercoat layer preferably has a Vickers hardness of 35 or more. The surface roughness (ten-point average roughness) of the undercoat layer is preferably adjusted to between 1 / (4n) (n is the refractive index of the upper layer) and 1 / 2 of the wavelength λ of the exposure laser used to suppress moire images. Resin particles or the like may be added to the undercoat layer to adjust the surface roughness. Examples of resin particles include silicone resin particles and crosslinked polymethyl methacrylate resin particles. The surface of the undercoat layer may be polished to adjust the surface roughness. Examples of polishing methods include buffing, sandblasting, wet honing, and grinding.

[0083] The formation of the undercoat layer is not particularly limited, and a known formation method can be used. For example, the undercoat layer can be formed by forming a coating film of a coating liquid for forming an undercoat layer in which the above components are added to a solvent, drying the coating film, and heating it as necessary.

[0084] Examples of solvents for preparing the coating liquid for forming the undercoat layer include known organic solvents, such as alcohol-based solvents, aromatic hydrocarbon solvents, halogenated hydrocarbon solvents, ketone-based solvents, ketone alcohol-based solvents, ether-based solvents, and ester-based solvents. Specific examples of these solvents include ordinary organic solvents such as methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene.

[0085] Examples of a method for dispersing inorganic particles when preparing a coating liquid for forming an undercoat layer include known methods such as using a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker.

[0086] Examples of a method for applying the coating liquid for forming the undercoat layer onto the conductive substrate include conventional methods such as blade coating, wire bar coating, spray coating, dip coating, bead coating, air knife coating, and curtain coating.

[0087] The thickness of the undercoat layer is set, for example, preferably at least 15 μm, more preferably in the range of from 20 μm to 50 μm.

[0088] -Middle class- Although not shown, an intermediate layer may be further provided between the undercoat layer and the photosensitive layer. The intermediate layer is, for example, a layer containing a resin. Examples of the resin used in the intermediate layer include polymer compounds such as acetal resins (such as polyvinyl butyral), polyvinyl alcohol resins, polyvinyl acetal resins, casein resins, polyamide resins, cellulose resins, gelatin, polyurethane resins, polyester resins, methacrylic resins, acrylic resins, polyvinyl chloride resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate-maleic anhydride resins, silicone resins, silicone-alkyd resins, phenol-formaldehyde resins, and melamine resins. The intermediate layer may be a layer containing an organometallic compound. Examples of the organometallic compound used in the intermediate layer include organometallic compounds containing metal atoms such as zirconium, titanium, aluminum, manganese, and silicon. The compounds used in the intermediate layer may be used alone or as a mixture or polycondensation product of a plurality of compounds.

[0089] Among these, the intermediate layer is preferably a layer containing an organometallic compound containing zirconium atoms or silicon atoms.

[0090] The formation of the intermediate layer is not particularly limited, and a known formation method can be used. For example, the intermediate layer can be formed by forming a coating film of a coating liquid for forming an intermediate layer in which the above components are added to a solvent, drying the coating film, and heating it if necessary. The intermediate layer can be formed by any of the usual coating methods, such as dip coating, push-up coating, wire bar coating, spray coating, blade coating, air knife coating, and curtain coating.

[0091] The thickness of the intermediate layer is preferably set in the range of 0.1 μm to 3 μm, and the intermediate layer may also be used as an undercoat layer.

[0092] -Protective layer- A protective layer may be provided on the photosensitive layer as needed, for example, to prevent chemical changes in the photosensitive layer when charged, or to further improve the mechanical strength of the photosensitive layer. Therefore, it is preferable to apply a layer made of a cured film (crosslinked film) as the protective layer. Examples of such a layer include the following layers 1) and 2).

[0093] 1) A layer composed of a cured film of a composition containing a reactive group-containing charge transport material having a reactive group and a charge transport skeleton in the same molecule (i.e., a layer containing a polymer or crosslinked product of the reactive group-containing charge transport material). 2) A layer composed of a cured film of a composition containing a non-reactive charge transport material and a reactive group-containing non-charge transport material that does not have a charge transport skeleton and has a reactive group (i.e., a layer containing a non-reactive charge transport material and a polymer or crosslinked product of the reactive group-containing non-charge transport material).

[0094] The reactive group of the reactive group-containing charge transport material may be a chain polymerizable group, an epoxy group, -OH, -OR (wherein R represents an alkyl group), -NH2, -SH, -COOH, or -SiR. Q1 3-Qn (OR Q2 ) Qn [However, R Q1 represents a hydrogen atom, an alkyl group, or a substituted or unsubstituted aryl group, and R Q2 represents a hydrogen atom, an alkyl group or a trialkylsilyl group, and Qn represents an integer of 1 to 3.

[0095] The chain polymerizable group is not particularly limited as long as it is a functional group capable of radical polymerization, and is, for example, a functional group having a group containing at least a carbon double bond. Specific examples include groups containing at least one selected from a vinyl group, a vinyl ether group, a vinyl thioether group, a styryl group (vinylphenyl group), an acryloyl group, a methacryloyl group, and derivatives thereof. Among these, a group containing at least one selected from a vinyl group, a styryl group (vinylphenyl group), an acryloyl group, a methacryloyl group, and derivatives thereof is preferred as the chain polymerizable group because of its excellent reactivity.

[0096] The charge transport skeleton of the reactive group-containing charge transport material is not particularly limited as long as it has a known structure in electrophotographic photoreceptors, and examples thereof include a skeleton derived from a nitrogen-containing hole transport compound such as a triarylamine compound, a benzidine compound, or a hydrazone compound, and having a conjugated structure with a nitrogen atom. Among these, a triarylamine skeleton is preferred.

[0097] The reactive group-containing charge transport material having a reactive group and a charge transporting skeleton, the non-reactive charge transport material, and the reactive group-containing non-charge transport material may be selected from known materials.

[0098] The protective layer may also contain other known additives.

[0099] The formation of the protective layer is not particularly limited, and a known formation method can be used. For example, the protective layer can be formed by forming a coating film of a coating liquid for forming the protective layer in which the above components are added to a solvent, drying the coating film, and, if necessary, subjecting it to a curing treatment such as heating.

[0100] Examples of solvents for preparing the coating liquid for forming the protective layer include aromatic solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, ester solvents such as ethyl acetate and butyl acetate, ether solvents such as tetrahydrofuran and dioxane, cellosolve solvents such as ethylene glycol monomethyl ether, and alcohol solvents such as isopropyl alcohol and butanol. These solvents may be used alone or in combination. The coating liquid for forming the protective layer may be a solvent-free coating liquid.

[0101] Examples of a method for applying the protective layer-forming coating liquid onto a photosensitive layer (e.g., a charge transport layer) include conventional methods such as dip coating, push-up coating, wire bar coating, spray coating, blade coating, air knife coating, and curtain coating.

[0102] The thickness of the protective layer is set, for example, preferably in the range of 1 μm or more and 20 μm or less, more preferably 2 μm or more and 10 μm or less.

[0103] -Single-layer photosensitive layer- The single-layer photosensitive layer (charge generation / charge transport layer) is a layer containing, for example, a charge generation material, a charge transport material, and, if necessary, a binder resin and other known additives. These materials are the same as those described for the charge generation layer and the charge transport layer.

[0104] The content of the charge generating material in the single-layer photosensitive layer is preferably 0.1% by mass to 10% by mass, and more preferably 0.8% by mass to 5% by mass, based on the total solid content. The content of the charge transport material in the single-layer photosensitive layer is preferably 5% by mass to 50% by mass, based on the total solid content.

[0105] The method for forming the single-layer photosensitive layer is the same as the method for forming the charge generating layer and the charge transport layer.

[0106] The thickness of the single-layer photosensitive layer is, for example, 5 μm or more and 50 μm or less, and preferably 10 μm or more and 40 μm or less.

[0107] <Image forming apparatus, process cartridge> The image forming apparatus according to the present embodiment includes an electrophotographic photosensitive member, a charging device that charges the surface of the electrophotographic photosensitive member, an electrostatic latent image forming device that forms an electrostatic latent image on the surface of the charged electrophotographic photosensitive member, a developing device that develops the electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a developer containing toner to form a toner image, and a transfer device that transfers the toner image to the surface of a recording medium. The electrophotographic photosensitive member according to the present embodiment is used as the electrophotographic photosensitive member.

[0108] The image forming apparatus according to the present embodiment may be any of known image forming apparatuses, such as an apparatus including a fixing device that fixes a toner image transferred onto the surface of a recording medium; an apparatus of a direct transfer type that directly transfers a toner image formed on the surface of an electrophotographic photosensitive member onto a recording medium; an apparatus of an intermediate transfer type that primarily transfers a toner image formed on the surface of an electrophotographic photosensitive member onto the surface of an intermediate transfer member, and then secondarily transfers the toner image transferred onto the surface of the intermediate transfer member onto the surface of a recording medium; an apparatus including a cleaning device that cleans the surface of an electrophotographic photosensitive member after transfer of a toner image but before charging; an apparatus including a static elimination device that irradiates the surface of an electrophotographic photosensitive member with static elimination light to eliminate static electricity after transfer of a toner image but before charging; and an apparatus including an electrophotographic photosensitive member heating member that increases the temperature of the electrophotographic photosensitive member and reduces the relative temperature.

[0109] In the case of an intermediate transfer type device, the transfer device is configured to have, for example, an intermediate transfer body onto whose surface a toner image is transferred, a primary transfer device that performs primary transfer of the toner image formed on the surface of the electrophotographic photosensitive body onto the surface of the intermediate transfer body, and a secondary transfer device that performs secondarily transfer of the toner image transferred onto the surface of the intermediate transfer body onto the surface of the recording medium.

[0110] The image forming apparatus according to this embodiment may be either a dry development type image forming apparatus or a wet development type image forming apparatus (a development type using a liquid developer).

[0111] In the image forming apparatus according to the present embodiment, for example, a portion including an electrophotographic photosensitive member may have a cartridge structure (process cartridge) that is detachably attached to the image forming apparatus. As the process cartridge, for example, a process cartridge including the electrophotographic photosensitive member according to the present embodiment is preferably used. In addition to the electrophotographic photosensitive member, the process cartridge may include, for example, at least one selected from the group consisting of a charging device, an electrostatic latent image forming device, a developing device, and a transfer device.

[0112] An example of an image forming apparatus according to the present embodiment will be described below, but the present invention is not limited to this. The main parts shown in the drawings will be described, and descriptions of other parts will be omitted.

[0113] FIG. 3 is a schematic diagram showing an example of the configuration of an image forming apparatus according to the present embodiment. As shown in FIG. 3 , the image forming apparatus 100 according to the present embodiment includes a process cartridge 300 having an electrophotographic photosensitive member 7, an exposure device 9 (an example of an electrostatic latent image forming device), a transfer device 40 (a primary transfer device), and an intermediate transfer member 50. In the image forming apparatus 100, the exposure device 9 is disposed at a position where it can expose the electrophotographic photosensitive member 7 through the opening of the process cartridge 300, and the transfer device 40 is disposed at a position facing the electrophotographic photosensitive member 7 via the intermediate transfer member 50, with a portion of the intermediate transfer member 50 being in contact with the electrophotographic photosensitive member 7. Although not shown, the image forming apparatus 100 also includes a secondary transfer device that transfers the toner image transferred onto the intermediate transfer member 50 onto a recording medium (e.g., paper). The intermediate transfer member 50, the transfer device 40 (a primary transfer device), and the secondary transfer device (not shown) correspond to examples of transfer devices.

[0114] 3 integrally supports an electrophotographic photosensitive member 7, a charging device 8 (an example of a charging device), a developing device 11 (an example of a developing device), and a cleaning device 13 (an example of a cleaning device) within a housing. The cleaning device 13 has a cleaning blade (an example of a cleaning member) 131, which is disposed so as to come into contact with the surface of the electrophotographic photosensitive member 7. The cleaning member may not be in the form of the cleaning blade 131, but may be a conductive or insulating fibrous member, which may be used alone or in combination with the cleaning blade 131.

[0115] FIG. 3 shows an example of an image forming apparatus that includes a fibrous member 132 (roll-shaped) that supplies lubricant 14 to the surface of electrophotographic photosensitive member 7, and a fibrous member 133 (flat brush-shaped) that assists cleaning, which may be arranged as needed.

[0116] Hereinafter, each configuration of the image forming apparatus according to this embodiment will be described.

[0117] -Charging device- The charging device 8 may be, for example, a contact-type charger using a conductive or semi-conductive charging roller, charging brush, charging film, charging rubber blade, charging tube, etc. Also usable are non-contact type roller chargers, scorotron chargers and corotron chargers that utilize corona discharge, and other known chargers.

[0118] -Exposure equipment- The exposure device 9 may be, for example, an optical system that exposes the surface of the electrophotographic photosensitive member 7 to light such as semiconductor laser light, LED light, or liquid crystal shutter light in a predetermined image. The wavelength of the light source is within the spectral sensitivity range of the electrophotographic photosensitive member. The wavelength of semiconductor lasers is mainly near-infrared, with an oscillation wavelength around 780 nm. However, this wavelength is not limited to this, and lasers with an oscillation wavelength in the 600 nm range or blue lasers with an oscillation wavelength of 400 nm to 450 nm may also be used. Furthermore, for color image formation, a surface-emitting laser light source capable of outputting multiple beams is also effective.

[0119] -Developing device- The developing device 11 may be, for example, a general developing device that develops by contact or non-contact application of a developer. The developing device 11 is not particularly limited as long as it has the above-mentioned functions, and may be selected depending on the purpose. For example, it may be a known developing device that has a function of applying a one-component developer or a two-component developer to the electrophotographic photosensitive member 7 using a brush, roller, or the like. Among these, a developing roller that holds a developer on its surface is preferred.

[0120] The developer used in the developing device 11 may be a one-component developer containing only toner, or a two-component developer containing toner and a carrier. The developer may be magnetic or non-magnetic. Known developers are used.

[0121] -Cleaning device- The cleaning device 13 is a cleaning blade type device equipped with a cleaning blade 131. In addition to the cleaning blade type, a fur brush cleaning type or a simultaneous development cleaning type may also be used.

[0122] -Transfer device- Examples of the transfer device 40 include a contact type transfer charger using a belt, roller, film, rubber blade, etc., and a known transfer charger such as a scorotron transfer charger or corotron transfer charger that utilizes corona discharge.

[0123] -Intermediate transfer body- A belt-like intermediate transfer belt containing semiconductive polyimide, polyamideimide, polycarbonate, polyarylate, polyester, rubber, etc. is used as the intermediate transfer body 50. The intermediate transfer body may be in the form of a drum other than a belt.

[0124] FIG. 4 is a schematic diagram showing another example of the configuration of the image forming apparatus according to the present embodiment. The image forming apparatus 120 shown in Fig. 4 is a tandem-type multi-color image forming apparatus equipped with four process cartridges 300. In the image forming apparatus 120, the four process cartridges 300 are arranged in parallel on the intermediate transfer member 50, and one electrophotographic photosensitive member is used per color. The image forming apparatus 120 has the same configuration as the image forming apparatus 100, except that it is a tandem-type apparatus.

[0125] <Method of manufacturing conductive substrate for electrophotographic photoreceptor> The method for producing a conductive substrate for an electrophotographic photoreceptor according to the present embodiment includes the steps of: The method includes a process (hereinafter also referred to as the "processing process") in which the inner peripheral surface of the conductive substrate at both axial ends is processed using a water jet, and the integrated value S of intensity in a range of a period of 0.01 mm or more and 0.1 mm or less is set to 0.02 or more and 0.10 or less in a power spectrum obtained by fast Fourier transform of the axial roughness curve of the inner peripheral surface of the conductive substrate at both axial ends.

[0126] - Processing process - In the processing step, the inner peripheral surface of the conductive substrate (cylindrical) at both axial ends is processed using a water jet. A water jet is preferable because it is unlikely to chemically modify or contaminate the surface of the conductive substrate and can impart the desired integrated value S to the conductive substrate.

[0127] In the processing step, a water jet is used to perform a fast Fourier transform on the axial roughness curve of the inner peripheral surface of the conductive substrate at both axial ends, and the integrated value S of the intensity over a period of 0.01 mm to 0.1 mm in the power spectrum is set to 0.02 to 0.10. By setting the integrated value S in this range, runout during rotation is reduced when the conductive substrate is applied to an image forming apparatus. The preferred range of the integrated value S is the same as the preferred range of the integrated value S described above for the conductive substrate for electrophotographic photoreceptor according to this embodiment.

[0128] The water pressure, water volume, and water temperature of the water jet are not limited as long as they can keep the integrated value S within the above-mentioned range, and may be set according to the material of the conductive substrate. The water used in the water jet may be water to which a surfactant has been added.

[0129] The manner of processing using the water jet is not particularly limited as long as the integrated value S can be set within the above-mentioned predetermined range. For example, when the method for manufacturing a conductive substrate for an electrophotographic photosensitive member according to the present embodiment is used in a method for recycling a conductive substrate for an electrophotographic photosensitive member, the processing treatment using a water jet may be carried out simultaneously with or after immersing a used photosensitive member in a solvent and peeling off all or part of the softened outer peripheral surface layer with the water jet. Alternatively, for example, the processing treatment may be carried out simultaneously with or after removing all or part of the outer peripheral surface layer with air blasting. Furthermore, the inner surface of a used photoreceptor may be coated with adhesive, dried photosensitive layer-forming coating liquid, flange resin, and other deposits. These deposits can also cause vibration of the photoreceptor. Therefore, the water jet processing may also serve as a process for removing the deposits. In this embodiment, the water pressure, water volume, and water temperature of the water jet are set to conditions that remove the deposits while keeping the integrated value S within the above range. [Example]

[0130] Hereinafter, embodiments of the present disclosure will be described in detail using examples, but the embodiments of the present disclosure are not limited to these examples. In the following description, unless otherwise specified, "parts" and "%" are by mass.

[0131] Example 1 The photoreceptor was prepared according to the following procedure.

[0132] -Manufacturing of conductive substrates- A used photoreceptor was provided, which was equipped with the aluminum cylindrical tube from which it was manufactured. For the used photoreceptor, all layers on the outer peripheral surface were removed using a water jet, and the inner peripheral surface was processed using a water jet (conditions: water pressure 100 MPa) so that the integrated value S became the value in Table 1, thereby producing (regenerating) a conductive substrate (outer diameter: 30 mm, length: 250 mm, thickness: 1 mm).

[0133] - Formation of undercoat layer - 20 parts of blocked isocyanate (product name: Sumidur BL3175, manufactured by Sumitomo Bayer Urethane Co., Ltd., solids content 75%) and 7.5 parts of butyral resin (polyvinyl butyral, S-LEC BL-1, manufactured by Sekisui Chemical Co., Ltd.) were dissolved in 150 parts of methyl ethyl ketone. 34 parts of a mixture of perinone compound (1-1) and perinone compound (2-1) (mass ratio 50:50) were mixed with this solution and dispersed in a sand mill using 1 mm diameter glass beads for 10 hours to obtain a dispersion. 0.005 parts of bismuth carboxylate (K-KAT XK-640, manufactured by King Industries Co., Ltd.) was added to this dispersion to obtain a coating solution for forming an undercoat layer. This coating solution was dip-coated onto the outer surface of a conductive substrate and dried and cured at 160°C for 60 minutes to form a 20 μm thick undercoat layer.

[0134] [ka]

[0135] - Formation of charge generation layer - A mixture consisting of 15 parts of hydroxygallium phthalocyanine (CGL) as a charge-generating material (having diffraction peaks at Bragg angles (2θ±0.2°) of at least 7.5°, 9.9°, 12.5°, 16.3°, 18.6°, 25.1°, and 28.3° in the X-ray diffraction spectrum using CuKα characteristic X-rays), 10 parts of vinyl chloride-vinyl acetate copolymer resin (trade name: VMCH, manufactured by Nippon Unicar Co., Ltd.) as a binder resin, and 200 parts of n-butyl acetate was dispersed in a sand mill using 1 mm diameter glass beads for 4 hours. 175 parts of n-butyl acetate and 180 parts of methyl ethyl ketone were added to the dispersion and stirred to obtain a coating solution for forming a charge-generating layer. This coating solution was dip-coated onto the undercoat layer and dried at room temperature to form a 0.25 μm-thick charge-generating layer.

[0136] - Formation of charge transport layer - A coating solution for forming a charge transport layer was prepared by dissolving 60 parts of polycarbonate resin (1) (viscosity average molecular weight: 40,000; the numerical values ​​in the structural formula below are molar ratios) and 40 parts of CTM-1, a charge transport material, in a mixed solvent of 270 parts of tetrahydrofuran and 30 parts of toluene. This coating solution was then dip-coated onto the charge generation layer, and the coating was dried at 150°C for 30 minutes to form a charge transport layer with a thickness of 20 μm.

[0137] [ka]

[0138] <Examples 2 to 5 and Comparative Examples 2 and 3> A photoreceptor was produced in the same manner as in Example 1, except that the water jet conditions (water pressure) were changed according to Table 1 and processing was carried out so that the integral value S became the value in Table 1.

[0139] <Comparative Example 1> A photoreceptor was prepared in the same manner as in Example 1, except that a new product (a cylindrical aluminum tube with an outer diameter of 30 mm, a length of 250 mm, and a thickness of 1 mm) was used as the conductive substrate and no water jet processing was performed.

[0140] <Evaluation> -image quality- The photoreceptors prepared in the examples and comparative examples were incorporated into a modified Fujifilm Business Innovation "DocuColor-7171P" machine, and cyan halftone images with image densities ranging from 5% to 100% in 5% increments were printed on A3-sized plain paper in an environment of 23°C temperature and 55% relative humidity, and the occurrence of image quality defects (uneven image density) caused by vibration during rotation of the photoreceptor was evaluated visually. Evaluation was performed according to the following criteria. A: No uneven image density occurs B: Slight unevenness in image density (tolerable range) C: Image density unevenness occurs D: Image density unevenness is so severe that the image disappears

[0141] The results are shown in Table 1.

[0142] [Table 1]

[0143] As shown in Table 1, the photosensitive member of this embodiment, which uses a conductive substrate with an integrated value S of 0.02 to 0.10, suppresses image quality defects (uneven image density) caused by vibration during rotation of the photosensitive member compared to the photosensitive member of the comparative example.

[0144] The conductive substrate for an electrophotographic photoreceptor, the electrophotographic photoreceptor, the process cartridge, and the image-forming apparatus of the present disclosure include the following aspects.

[0145] (((1))) It has a cylindrical shape, and In a power spectrum obtained by fast Fourier transform of the axial roughness curve of the inner peripheral surface of the conductive substrate at both axial ends, the integrated value S of intensity in a period range of 0.01 mm or more and 0.1 mm or less is 0.02 or more and 0.10 or less. Conductive substrate for electrophotographic photoreceptors. (((2))) The conductive substrate for an electrophotographic photoreceptor according to (((1))), wherein the integrated value S is 0.03 or more and 0.08 or less. (((3))) An electrophotographic photoreceptor comprising the conductive substrate according to (((1))) or (((2))) and a photosensitive layer disposed on the conductive substrate. (((4))) (((3))) A process cartridge that is detachably attached to an image forming apparatus. (((5))) (((3))) and an electrophotographic photoreceptor a charging device that charges the surface of the electrophotographic photosensitive member; an electrostatic latent image forming device for forming an electrostatic latent image on the charged surface of the electrophotographic photosensitive member; a developing device that develops the electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a developer containing toner to form a toner image; a transfer device that transfers the toner image onto a surface of a recording medium; An image forming apparatus comprising: (((6))) A method for manufacturing a conductive substrate for an electrophotographic photoreceptor, comprising a step of processing the inner peripheral surface of the conductive substrate at both axial end portions with a water jet, and setting the integrated value S of intensity in a range of a period of 0.01 mm or more and 0.1 mm or less to 0.02 or more and 0.10 or less in a power spectrum obtained by fast Fourier transform of an axial roughness curve of the inner peripheral surface of the conductive substrate at both axial end portions.

[0146] According to (((1))), there is provided a conductive substrate for an electrophotographic photosensitive member which has a cylindrical shape and exhibits reduced runout during rotation compared to a conductive substrate for an electrophotographic photosensitive member in which the integrated value S of intensity in a periodic range of 0.01 mm or more and 0.1 mm or less is less than 0.02 or exceeds 0.10 in a power spectrum obtained by fast Fourier transform of the axial roughness curve of the inner peripheral surface of the conductive substrate at both axial end portions. According to (((2))), a conductive substrate for an electrophotographic photosensitive member is provided which exhibits reduced vibration during rotation compared to a conductive substrate for an electrophotographic photosensitive member having an integrated value S of less than 0.03 or more than 0.08. According to (((3))), there is provided an electrophotographic photoreceptor which has a conductive substrate having an integrated value S of less than 0.02 or more than 0.10, or an integrated value S of less than 0.03 or more than 0.08, and a photosensitive layer disposed on the conductive substrate, and which exhibits reduced runout during rotation compared to an electrophotographic photoreceptor. According to (((4))) and (((5))), there are provided a process cartridge and an image forming apparatus which are provided with a conductive substrate having an integrated value S of less than 0.02 or more than 0.10, or an integrated value S of less than 0.03 or more than 0.08, and a photosensitive layer disposed on the conductive substrate, and which exhibit reduced vibration during rotation compared to when an electrophotographic photosensitive member is used. According to (((6))), a method for producing a conductive substrate for an electrophotographic photoreceptor is provided, which reduces runout during rotation. [Explanation of symbols]

[0147] 1 Conductive substrate, 2 Undercoat layer, 3 Charge generation layer, 4 Charge transport layer, 5 Photosensitive layer, 10A photoreceptor, 10B photoreceptor

[0148] 7 electrophotographic photosensitive member, 8 charging device, 9 exposure device, 11 developing device, 13 cleaning device, 14 lubricant, 40 transfer device, 50 intermediate transfer body, 100 image forming apparatus, 120 image forming apparatus, 131 cleaning blade, 132 fibrous member (roll-shaped), 133 fibrous member (flat brush-shaped), 300 process cartridge

Claims

1. It has a cylindrical shape, and In a power spectrum obtained by fast Fourier transform of the axial roughness curve of the inner peripheral surface of the conductive substrate at both axial ends, the integrated value S of intensity in a period range of 0.01 mm or more and 0.1 mm or less is 0.02 or more and 0.10 or less. Conductive substrate for electrophotographic photoreceptors.

2. 2. The conductive substrate for an electrophotographic photoreceptor according to claim 1, wherein the integrated value S is 0.03 or more and 0.08 or less.

3. 3. An electrophotographic photoreceptor comprising the conductive substrate according to claim 1 or 2 and a photosensitive layer disposed on the conductive substrate.

4. The electrophotographic photoreceptor according to claim 3 is provided, A process cartridge that is detachably attached to an image forming apparatus.

5. The electrophotographic photoreceptor according to claim 3; a charging device that charges the surface of the electrophotographic photosensitive member; an electrostatic latent image forming device for forming an electrostatic latent image on the charged surface of the electrophotographic photosensitive member; a developing device that develops the electrostatic latent image formed on the surface of the electrophotographic photosensitive member with a developer containing toner to form a toner image; a transfer device that transfers the toner image onto a surface of a recording medium; An image forming apparatus comprising:

6. A method for manufacturing a conductive substrate for an electrophotographic photoreceptor, comprising a step of processing an inner peripheral surface of the conductive substrate at both axial end portions with a water jet, and adjusting an integrated value S of intensity in a range of a period of 0.01 mm or more and 0.1 mm or less to 0.02 or more and 0.10 or less in a power spectrum obtained by fast Fourier transform of an axial roughness curve of the inner peripheral surface of the conductive substrate at both axial end portions.

Images