Electrophotographic photoreceptor, process cartridge, electrophotographic device, and method of manufacturing electrophotographic photoreceptor

Abstract

To provide an electrophotographic photoreceptor which offers stable sensitivity during repeated use.SOLUTION: An electrophotographic photoreceptor is provided, comprising a support body, an undercoat layer, a charge generation layer, and a charge transport layer provided in the described order, the undercoat layer containing two electron transport substances.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an electrophotographic photoreceptor, a process cartridge, an electrophotographic apparatus, and a method for manufacturing an electrophotographic photoreceptor. [Background technology]

[0002] Currently, the mainstream electrophotographic photoreceptors used in process cartridges and electrophotographic devices are those containing organic photoconductive materials (organic electrophotographic photoreceptors; hereinafter also referred to as "photoreceptors"). Electrophotographic photoreceptors using organic photoconductive materials have advantages such as being non-polluting, highly productive, and easy material design.

[0003] Electrophotographic photoreceptors generally consist of a support and a photosensitive layer formed on the support. The photosensitive layer is typically a laminated type, with a charge generation layer and a charge transport layer stacked in that order from the support side. Furthermore, an intermediate layer is often provided between the support and the photosensitive layer to suppress charge injection from the support to the photosensitive layer and reduce the occurrence of image defects such as black spots. In some cases, a conductive layer or undercoat layer may also be provided between the support and the intermediate layer.

[0004] In recent years, charge-generating materials have become more sensitive, and using them results in a larger amount of charge being generated. However, this has led to the problem that the generated charge tends to remain in the charge-generating layer. One known technique for suppressing charge retention in such charge generation layers is to incorporate an electron transport material into the intermediate layer to facilitate the smooth movement of electrons from the charge generation layer to the support layer.

[0005] However, with the increasing speed of electrophotographic processes and the extended lifespan of cartridges, the performance requirements for photoreceptors have become more sophisticated. Even with such technologies, electron movement may not be sufficient, so development is underway to improve the intermediate layer. Patent Document 1 discloses a technique for incorporating an electron transport material with a specific structure into the intermediate layer. Patent Document 2 also discloses a technique for incorporating specific particles. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2014-215477 [Patent Document 2] Japanese Patent Publication No. 2017-203821 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] There is a need for a photoreceptor that can produce stable images even after long-term, repeated use. According to the inventors' investigations, the technologies disclosed in Patent Documents 1 and 2 still have room for improvement in terms of electrical characteristics during long-term repeated use. The object of the present invention is to provide an electrophotographic photoreceptor that maintains stable electrical properties even after long-term repeated use, a process cartridge having the electrophotographic photoreceptor, and an electrophotographic apparatus. [Means for solving the problem]

[0008] The present invention relates to an electrophotographic photoreceptor having a support, an undercoat formed on the support, and a photosensitive layer formed on the undercoat, wherein the undercoat is characterized in that it contains a polymer of a composition comprising at least a compound represented by the following formula (1), a compound represented by the following formula (2), and a crosslinking agent having a group capable of bonding to a hydroxyl group or a carboxyl group, or a compound represented by the following formula (3) and a compound represented by the following formula (4). [ka] [ka] [ka] [Chemical formula] (In formulas (1) and (2), R 1 , R 2 are not the same and are each represented by the following formula (10). -(R a ) m -(R b ) n -R c (10) In formula (10), R a is a branched or linear alkylene group having 1 to 10 carbon atoms which may have a substituent, or a phenylene group which may have a substituent, R b is -O-, -S- or a group represented by the following formula (11), [Chemical formula] However, in formula (11), R d is a hydrogen atom or a branched or linear alkyl group having 1 to 4 carbon atoms, R c is a hydrogen atom, a branched or linear alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 14 carbon atoms which may have a substituent, or a branched or linear arylalkyl group having 7 to 18 carbon atoms which may have a substituent, The substituent that the alkylene group or the alkyl group can have is a hydroxy group, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, or an alkoxycarbonyl group having 2 to 4 carbon atoms, The substituent that the phenylene group, the aryl group or the arylalkyl group can have is an alkyl group having 1 to 3 carbon atoms, a hydroxy group, a hydroxyalkyl group having l to 3 carbon atoms, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a halogen atom, a cyano group, or a nitro group, m is 0 or 1, and n is 0 or 1, R 1 and R 2At least one of them contains a hydroxyl group or a carboxyl group. In formulas (3) and (4), R 3 , R 4 These are not identical, and are represented by the following equation (10). -(R a ) m -(R b ) n -R c (10) In formula (10), R a This is a branched or linear alkylene group having 1 to 10 carbon atoms, which may have substituents, or a phenylene group which may have substituents. R b is a group represented by -O-, -S-, or the following formula (11), [ka] However, in equation (11), R d is a hydrogen atom or a branched or linear alkyl group having 1 to 4 carbon atoms. R c This is a hydrogen atom, a branched or linear alkyl group having 1 to 10 carbon atoms which may have substituents, an aryl group having 6 to 14 carbon atoms which may have substituents, or a branched or linear arylalkyl group having 7 to 18 carbon atoms which may have substituents. The substituents that the alkylene group or alkyl group may have are a hydroxyl group, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, or an alkoxycarbonyl group having 2 to 4 carbon atoms. The substituents that the phenylene group, the aryl group, or the arylalkyl group may have are an alkyl group having 1 to 3 carbon atoms, a hydroxyl group, a hydroxyalkyl group having 1 to 3 carbon atoms, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a halogen atom, a cyano group, or a nitro group. m is either 0 or 1, and n is either 0 or 1. In equations (1), (2), (3), and (4), X is selected from the tetravalent structures shown in equations (X1), (X2), and (X3). [ka] [ka] [ka] In formulas (X1), (X2), (X3), R 11 ~R 32 These independently represent a hydrogen atom, a halogen atom, a cyano group, and a nitro group, respectively.

[0009] Furthermore, the present invention relates to a process cartridge that integrally supports the electrophotographic photoreceptor and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, and a cleaning means, and is detachably attached to the main body of an electrophotographic apparatus.

[0010] Furthermore, the present invention relates to an electrophotographic apparatus having the above-mentioned electrophotographic photoreceptor, charging means, exposure means, developing means, and transfer means.

[0011] The present invention also relates to a method for manufacturing an electrophotographic photoreceptor having a support, an undercoat formed on the support, and a photosensitive layer formed on the undercoat, wherein the manufacturing method comprises the steps of forming a coating film of an undercoat coating liquid containing at least a compound represented by formula (1), a compound represented by formula (2), and a crosslinking agent having a group that can bond to a hydroxyl group or a carboxyl group, and polymerizing the coating film to form the undercoat. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an electrophotographic photoreceptor that maintains stable sensitivity even after long-term repeated use, as well as a process cartridge and electrophotographic apparatus having the electrophotographic photoreceptor. [Brief explanation of the drawing]

[0013] [Figure 1] This figure shows a schematic configuration of an example of an electrophotographic apparatus having a process cartridge equipped with an electrophotographic photoreceptor. [Figure 2] This figure shows an example of the layer structure of an electrophotographic photoreceptor. [Figure 3] This figure shows the 1H-NMR spectrum of electron transport material A1-1. [Modes for carrying out the invention]

[0014] In the present invention, the undercoat layer of the electrophotographic photoreceptor is a polymer of a composition comprising at least the compound represented by formula (1) and the compound represented by formula (2), and a crosslinking agent having a group capable of bonding to a hydroxyl group or a carboxyl group. Alternatively, in the present invention, the undercoat layer contains at least the compound represented by formula (3) and the compound represented by formula (4).

[0015] The inventors hypothesize the following reason why the underlying layer, by adopting the above-described configuration, maintains a stable charge potential even during long-term repeated use. In the lower layer, electrons move via electron transport materials, so identical molecules with the same electron cloud extent (electron distribution state) are considered to be favorable for electron transfer due to the overlap of their electron clouds. However, with repeated electron transfer due to long-term use, electron transport materials that have received electrons may form molecular complexes with other electron transport materials. Since these molecular complexes have different energy levels than the electron transport materials alone, they act as inhibitors of electron transfer (trap sites), causing electrons to accumulate and leading to a deterioration in sensitivity.

[0016] Therefore, the inventors conducted further research and found that by using a polymer of a composition containing the electron transport materials of formula (1) and formula (2) above, or a mixture of the electron transport materials of formula (3) and formula (4) above, in the undercoat layer, the increase in charge potential can be suppressed. The inventors believe that this is because, by containing two electron transfer materials with similar structures, the molecules can maintain a certain degree of electron cloud overlap while suppressing the formation of molecular complexes.

[0017] [Electrophotographic photoconductor] An electrophotographic photoreceptor has a support, an undercoat layer formed on the support, and a photosensitive layer formed on the undercoat layer. Figure 2 shows an example of the layer structure of an electrophotographic photoreceptor. In Figure 2, a support 101, a conductive layer 102 on the support 101, an undercoat layer 103 on the conductive layer 102, a charge generation layer 104 on the undercoat layer 103, and a charge transport layer 105 on the charge generation layer 104 are formed. That is, an electrophotographic photoreceptor has a support 101, a conductive layer 102, an undercoat layer 103, a charge generation layer 104, and a charge transport layer 105 in this order. Cylindrical electrophotographic photoreceptors are widely used, but they can also be made into other shapes such as belts or sheets.

[0018] <Support> The support is preferably made of a conductive material (conductive support). For example, a support made of metal or alloy such as aluminum, nickel, copper, gold, or iron can be used. Alternatively, a conductive support may be made by forming a thin film of a conductive material such as a metal or metal oxide on an insulating support. Examples include a support made by forming a thin film of a metal such as aluminum, silver, or gold on an insulating support such as polyester resin, polycarbonate resin, polyimide resin, or glass, or a support made by forming a thin film of a conductive material such as indium oxide or tin oxide. The surface of the support may be subjected to electrochemical treatments such as anodizing, wet honing, blasting, or cutting to improve electrical properties and suppress interference fringes.

[0019] <Conductive layer> A conductive layer may be provided on the support. By providing a conductive layer, scratches and irregularities on the surface of the support can be concealed, and light reflection on the surface of the support can be controlled. The conductive layer preferably contains conductive particles and a resin. Examples of materials for conductive particles include metal oxides, metals, and carbon black. Examples of metal oxides include zinc oxide, aluminum oxide, indium oxide, silicon oxide, zirconium oxide, tin oxide, titanium oxide, magnesium oxide, antimony oxide, and bismuth oxide. Examples of metals include aluminum, nickel, iron, nichrome, copper, zinc, and silver. Among these, it is preferable to use metal oxides as conductive particles, and it is more preferable to use titanium oxide, tin oxide, or zinc oxide. When using metal oxides as conductive particles, the surface of the metal oxide may be treated with a silane coupling agent or doped with elements such as phosphorus or aluminum, or their oxides. Furthermore, the conductive particles may have a laminated structure comprising core material particles and a coating layer covering those particles. Examples of core material particles include titanium oxide, barium sulfate, and zinc oxide. Examples of the coating layer include metal oxides such as tin oxide. Furthermore, when using metal oxides as conductive particles, their volume-average particle diameter is preferably 1 nm or more and 500 nm or less, and more preferably 3 nm or more and 400 nm or less. Examples of resins include polyester resin, polycarbonate resin, polyvinyl acetal resin, acrylic resin, silicone resin, epoxy resin, melamine resin, polyurethane resin, phenolic resin, and alkyd resin. Furthermore, the conductive layer may further contain silicone oil, resin particles, a concealing agent such as titanium dioxide, etc. The average thickness of the conductive layer is preferably 1 μm or more and 50 μm or less, and particularly preferably 3 μm or more and 40 μm or less. A conductive layer can be formed by preparing a coating solution for a conductive layer containing the above-mentioned materials and solvents, forming a coating film, and drying it. Examples of solvents used in the coating solution include alcohol-based solvents, sulfoxide-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents. Methods for dispersing conductive particles in the coating solution for a conductive layer include using a paint shaker, sand mill, ball mill, or liquid impaction type high-speed disperser.

[0020] <Underlayer> The undercoat layer of an electrophotographic photoreceptor according to one embodiment of the present invention contains a polymer of a composition containing an electron transport substance of formula (1) and formula (2) and a crosslinking agent. The crosslinking agent has a group that can bond to a hydroxyl group or a carboxyl group.

[0021] The mass ratio (mass of formula (1) / mass of formula (2)) of the electron transport substance represented by formula (1) in the composition is preferably 0.25 or more and 4 or less. A composition containing the electron transport substances of formula (1) and formula (2) and a crosslinking agent is preferably further containing the electron transport substance represented by formula (5).

[0022] Furthermore, the undercoat layer of the electrophotographic photoreceptor according to one embodiment of the present invention contains electron transport materials of formulas (3) and (4). The mass ratio of the electron transport material represented by formula (3) to the electron transport material represented by formula (4) (mass of formula (3) / mass of formula (4)) is preferably 0.25 or more and 4 or less. The undercoat layer containing the electron transport materials of formulas (3) and (4) preferably further contains an electron transport material represented by formula (6).

[0023] Furthermore, the undercoat layer of the electrophotographic photoreceptor preferably contains a resin having a carboxylic acid derivative as a functional group. Examples include acrylic acid resin and maleic acid resin.

[0024] The thickness of the undercoat layer is preferably 0.2 μm or more and 5.0 μm or less, and more preferably 0.5 μm or more and 3.0 μm or less.

[0025] Formulas (1) through (6) are shown below. Examples of compounds represented by formulas (1) through (4) are shown in Tables 1-1 through 1-4 below.

[0026] Regarding equations (1), (2), and (5): [ka] [ka] [ka] R 1 , R 2 These are not identical, and are represented by the following formula (10), where X is selected from one of the tetravalent structures shown in formulas (X1), (X2), and (X3) described below. -(R a ) m -(R b ) n -R c (10) In formula (10), R a This is a branched or linear alkylene group having 1 to 10 carbon atoms, which may have substituents, or a phenylene group which may have substituents. In formula (10), R b is a group represented by -O-, -S-, or the following formula (11), [ka] In formula (11), R d is a hydrogen atom or a branched or linear alkyl group having 1 to 4 carbon atoms. In formula (10), R c This is a hydrogen atom, a branched or linear alkyl group having 1 to 10 carbon atoms which may have substituents, an aryl group having 6 to 14 carbon atoms which may have substituents, or a branched or linear arylalkyl group having 7 to 18 carbon atoms which may have substituents. The substituents that the alkylene group or alkyl group may have are a hydroxyl group, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, or an alkoxycarbonyl group having 2 to 4 carbon atoms. The substituents that the phenylene group, the aryl group, or the arylalkyl group may have are an alkyl group having 1 to 3 carbon atoms, a hydroxyl group, a hydroxyalkyl group having 1 to 3 carbon atoms, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a halogen atom, a cyano group, or a nitro group. m is 0 or 1, n is 0 or 1, R 1 and R 2 At least one of them contains a hydroxyl group or a carboxyl group.

[0027] Note that in equations (1), (2), and (5), R 1 , R 2 At least one of these is preferably a group represented by the following formula (7). [ka] In formula (7), R 5 , R 6 Each of these groups is independently selected from the group consisting of branched or linear alkyl groups having 1 to 7 carbon atoms, benzyl groups, alkoxycarbonyl groups having 2 to 4 carbon atoms, and phenyl groups, and the substituents that the alkyl group may have are selected from the group consisting of alkoxycarbonyl groups having 2 to 4 carbon atoms, phenyl groups, phenol groups, hydroxyl groups, thiol groups, amino groups, or carboxyl groups.

[0028] Regarding equations (3), (4), and (6): [ka] [ka] [ka] R 3 , R 4 These are not identical, and are represented by the following formula (10), where X is selected from one of the tetravalent structures shown in formulas (X1), (X2), and (X3) described below. -(R a ) m -(R b ) n -R c (10) In formula (10), R a This is a branched or linear alkylene group having 1 to 10 carbon atoms, which may have substituents, or a phenylene group which may have substituents. In formula (10), R b is a group represented by -O-, -S-, or the following formula (11), [ka] In formula (11), R d is a hydrogen atom or a branched or linear alkyl group having 1 to 4 carbon atoms. In formula (10), R c This is a hydrogen atom, a branched or linear alkyl group having 1 to 10 carbon atoms which may have substituents, an aryl group having 6 to 14 carbon atoms which may have substituents, or a branched or linear arylalkyl group having 7 to 18 carbon atoms which may have substituents. The substituents that the alkylene group or alkyl group may have are a hydroxyl group, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, or an alkoxycarbonyl group having 2 to 4 carbon atoms. The substituents that the phenylene group, the aryl group, or the arylalkyl group may have are an alkyl group having 1 to 3 carbon atoms, a hydroxyl group, a hydroxyalkyl group having 1 to 3 carbon atoms, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a halogen atom, a cyano group, or a nitro group. m is either 0 or 1, and n is either 0 or 1.

[0029] In formulas (3), (4), and (6), R 3 , R 4 At least one of these is preferably a group represented by the following formula (8). [ka] In formula (8), R 7 , R 8 Each of these groups is independently selected from the group consisting of branched or linear alkyl groups having 1 to 7 carbon atoms, benzyl groups, alkoxycarbonyl groups having 2 to 4 carbon atoms, and phenyl groups, and the substituents that the alkyl group may have are selected from the group consisting of alkoxycarbonyl groups having 2 to 4 carbon atoms, phenyl groups, phenol groups, hydroxyl groups, thiol groups, amino groups, or carboxyl groups.

[0030] Regarding equations (X1), (X2), and (X3): The X represented by formulas (1), (2), (3), and (4) is selected from the tetravalent structures represented by the following formulas (X1), (X2), and (X3). [ka] [ka] [ka] In formulas (X1), (X2), (X3), R 11 ~R 32 These independently represent a hydrogen atom, a halogen atom, a cyano group, and a nitro group, respectively.

[0031] Derivatives of electron transport materials are available from Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich Japan, and Johnson Matthey Japan LLC. Derivatives having the structure of formula (X1) can be synthesized by the reaction of perylenetetracarboxylic dianhydride, available from Tokyo Chemical Industry Co., Ltd. or Sigma-Aldrich Japan, with a monoamine derivative. Derivatives having the structure of formula (X2) can be synthesized by the reaction of naphthalenetetracarboxylic dianhydride, available from Tokyo Chemical Industry Co., Ltd. or Johnson Matthey Japan LLC, with a monoamine derivative. Derivatives having the structure of formula (X3) can be synthesized by the reaction of benzenetetracarboxylic dianhydride, available from Tokyo Chemical Industry Co., Ltd. or Sigma-Aldrich Japan, with a monoamine derivative. More preferably as an electron transport material is a compound having the structure shown in formula (X1).

[0032] Furthermore, from the viewpoint of film formation properties and electrical properties, the content of the electron transport material is preferably 40% to 80% by mass of the entire undercoat layer, and more preferably 50% to 70% by mass.

[0033] Furthermore, from the viewpoint of suppressing molecular complex formation and electrical properties, the ratio of electron transporters of formula (1) and formula (2) (formula (1) / formula (2)) and the ratio of electron transporters of formula (3) and formula (4) (formula (3) / formula (4)) is preferably 0.13 or more and 4.0 or less, and more preferably 0.25 or more and 4 or less. When the electron transporters of formula (1) and formula (2) further contain formula (5), and the electron transporters of formula (3) and formula (4) further contain formula (6), the ratio of electron transporters of formula (5) / formula (2) and the ratio of electron transporters of formula (6) and formula (4) (formula (6) / formula (4)) is preferably 0.13 or more and 4.0 or less, and more preferably 0.25 or more and 4 or less.

[0034] Any known material can be used as a crosslinking agent. Specifically, examples include compounds listed in "Crosslinking Agent Handbook" edited by Shinzo Yamashita and Tosuke Kaneko, published by Taiseisha (1981). The crosslinking agent is preferably an isocyanate compound having an isocyanate group or a blocked isocyanate group, or an amine compound having an N-methylol group or an alkyl etherified N-methylol group. An isocyanate compound having 2 to 6 isocyanate groups or blocked isocyanate groups is preferred.

[0035] Examples of isocyanate compounds include, but are not limited to, the isocyanate compounds listed below. Furthermore, multiple isocyanate compounds may be used in combination. Examples include isocyanurate-modified diisocyanates such as triisocyanatebenzene, triisocyanate-methylbenzene, triphenylmethane triisocyanate, lysine triisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, naphthalene diisocyanate-diphenylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, methyl-2,6-diisocyanate hexanoate, norbornane diisocyanate, biuret-modified diisocyanates, biuret-type isocyanates, allophanate-modified diisocyanates, and adduct-modified diisocyanates with trimethylolpropane or pentaerythritol. The blocked isocyanate group is -NHCOX 1 (X 1 X is a group that has a structure called a protecting group. 1 This can be any protecting group that can be introduced to an isocyanate group.

[0036] Examples of commercially available isocyanate compounds include Asahi Kasei's Duranate MFK-60B, SBA-70B, 17B-60P, SBN-70D, SBB-70P, and Sumika Bayer Urethane's Desmodule BL3175 and BL3475, which are isocyanate-based crosslinking agents.

[0037] Amine compounds are preferably those having an N-methylol group or an alkyl etherified N-methylol group. More preferably, amine compounds have multiple (two or more) N-methylol groups or alkyl etherified N-methylol groups. Examples include methylolated melamine, methylolated guanamine, methylolated urea derivatives, methylolated ethyleneurea derivatives, methylolated glycoluryl, compounds in which the methylol moiety is alkyl etherified, and derivatives thereof.

[0038] Examples of purchasable amine compounds include Super Melami No. 90 (manufactured by NOF Corporation (formerly Nippon Oil & Fats Co., Ltd.)), Super Beccamine(R) TD-139-60, L-105-60, L127-60, L110-60, J-820-60, G-821-60 (manufactured by DIC Corporation), Yuban 2020 (Mitsui Chemicals), Sumitex Resin M-3 (manufactured by Sumitomo Chemical Co., Ltd. (formerly Sumitomo Chemical Industries)), and Nika Examples include racks MW-30, MW-390, MX-750LM (manufactured by Sanwa Chemical Co., Ltd.), Super Beckamine(R) L-148-55, 13-535, L-145-60, TD-126 (manufactured by DIC Corporation), Nikalac BL-60, BX-4000 (manufactured by Sanwa Chemical Co., Ltd.), Nikalac MX-280, Nikalac MX-270, and Nikalac MX-290 (manufactured by Sanwa Chemical Co., Ltd.).

[0039] The composition for the undercoat layer may further contain an electron transport material, a crosslinking agent, and a thermoplastic resin having polymerizable functional groups. Examples of thermoplastic resins include polyacetal resins, polyvinyl acetal resins, polyolefin resins, polyester resins, polyether resins, and polyamide resins. The polymerizable functional groups are preferably groups that can be polymerized by the crosslinking agent, and examples include hydroxyl groups, thiol groups, amino groups, carboxyl groups, and methoxy groups.

[0040] Furthermore, thermoplastic resins are -(CH2-CH2-O) n -(n is an integer between 2 and 200), -(CH2-CH3CH-O) n-(n is an integer between 2 and 200) or -(CH2-CH2-O-CH2-CH2-SS) n A thermoplastic resin having repeating units consisting of -(n is an integer between 2 and 50) is preferred.

[0041] Examples of commercially available thermoplastic resins having polymerizable functional groups include, Polyether polyol resins such as AQD-457, AQD-473 (both manufactured by Nippon Polyurethane Industries), GP-400, and GP-700 (both manufactured by Sanyo Chemical Industries' Sannix); Polyester polyol resins such as Phthalkid W2343 (manufactured by Hitachi Chemical Co., Ltd.), Watersol S-118, CD-520, Bekkolite M-6402-50, M-6201-40IM (all manufactured by DIC), Haridip WH-1188 (manufactured by Harima Chemicals Co., Ltd.), ES3604, ES6538 (all manufactured by Nippon Yupika Co., Ltd.); Polyacrylic polyol resins such as Barnock WE-300 and WE-304 (both manufactured by DIC); Polyvinyl alcohol-based resins such as Kuraray PVA-203 (manufactured by Kuraray); Polyvinyl acetal resins such as BX-1, BM-1, and KS-5 (all manufactured by Sekisui Chemical Co., Ltd.); Polyamide resins such as Trezin FS-350 (manufactured by Nagase ChemteX); Carboxyl group-containing resins such as Aqualic (manufactured by Nippon Shokubai) and Finelex SG2000 (manufactured by Namari City); Polyamine resins such as Laccamide (manufactured by DIC); Examples include polythiol resins such as QE-340M (manufactured by Toray). Among these, polyvinyl acetal resins having polymerizable functional groups and polyester polyol resins having polymerizable functional groups are preferred from the viewpoint of polymerizability.

[0042] The undercoat can be formed by forming a coating film of an undercoat solution containing the above-mentioned substances and then drying the coating film. When polymerizing these compositions during the drying of the undercoat solution coating film, the polymerization reaction (curing reaction) is accelerated by applying heat or light energy. Solvents used in the undercoat solution coating include alcohol-based solvents, sulfoxide-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon solvents.

[0043] <Charge generation layer> The charge generation layer preferably contains a charge generation material and a binder resin. Examples of charge-generating materials include azo pigments, perylene pigments, anthraquinone derivatives, anthantrone derivatives, dibenzpyrenequinone derivatives, pyrantrone derivatives, quinone pigments, indigoid pigments, phthalocyanine pigments, and perinone pigments. Among these, phthalocyanine pigments are preferred. Among phthalocyanine pigments, oxytitanium phthalocyanine, chlorogallium phthalocyanine, and hydroxygallium phthalocyanine are preferred. Examples of binder resins include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid esters, methacrylic acid esters, vinylidene fluoride, and trifluoroethylene, as well as polyvinyl alcohol, polyvinyl acetal, polycarbonate, polyester, polysulfone, polyphenylene oxide, polyurethane, cellulose resin, phenolic resin, melamine resin, silicon resin, and epoxy resin. Among these, polyester, polycarbonate, and polyvinyl acetal are preferred.

[0044] In the charge generation layer, the ratio of charge generation material to binder resin (charge generation material / binder resin) is preferably in the range of 10 / 1 to 1 / 10, and more preferably in the range of 5 / 1 to 1 / 5.

[0045] Solvents used in the coating solution for the charge generation layer include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon solvents. The film thickness of the charge generation layer is preferably 0.05 μm or more and 5 μm or less.

[0046] <Charge transport layer> The charge transport layer preferably contains a charge transport material and a binder resin. The charge transport material is preferably a hole transport material. The charge transport layer is preferably a hole transport layer. Examples of charge transport materials include hydrazone compounds, styryl compounds, benzidine compounds, butadiene compounds, enamine compounds, triarylamine compounds, and triphenylamines. Polymers having groups derived from these compounds in their main chain or side chains are also included. Examples of binder resins include polyester, polycarbonate, polymethacrylate, polyarylate, polysulfone, and polystyrene. Among these, polycarbonate and polyarylate are preferred. Furthermore, the weight-average molecular weight (Mw) of these materials is preferably in the range of 10,000 to 300,000.

[0047] In the charge transport layer, the ratio of charge transport material to binder resin (charge transport material / binder resin) is preferably in the range of 10 / 5 to 5 / 10, and more preferably in the range of 10 / 8 to 6 / 10. The film thickness of the charge transport layer is preferably 5 μm or more and 40 μm or less. Examples of solvents used in the coating solution for the charge transport layer include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon solvents.

[0048] <Other layers> A protective layer containing conductive particles or a charge transport material and a binder resin may be provided on the charge transport layer. The protective layer may further contain additives such as lubricants. The binder resin of the protective layer may also have conductivity or charge transport properties, in which case the protective layer does not need to contain conductive particles or charge transport materials other than the binder resin. The binder resin of the protective layer may be a thermoplastic resin or a curable resin that is cured by heat, light, radiation (such as electron beams).

[0049] [Process cartridges and electrophotographic equipment] Figure 1 shows a schematic configuration of an electrophotographic apparatus having a process cartridge equipped with an electrophotographic photoreceptor. In Figure 1, the cylindrical electrophotographic photoreceptor 1 is rotated at a predetermined peripheral speed in the direction of the arrow around axis 2. The surface (circumferential surface) of the rotating electrophotographic photoreceptor 1 is charged to a predetermined positive or negative potential by a charging means 3 (e.g., a contact charger, a non-contact charger, etc.). Next, it is exposed with exposure light (image exposure light) 4 from an exposure means (not shown), such as slit exposure or laser beam scanning exposure. In this way, an electrostatic latent image corresponding to the desired image is sequentially formed on the surface of the electrophotographic photoreceptor 1.

[0050] The electrostatic latent image formed on the surface of the electrophotographic photoreceptor 1 is then developed by the toner contained in the developer of the developing means 5 to form a toner image. The toner image formed and supported on the surface of the electrophotographic photoreceptor 1 is sequentially transferred to the transfer material (paper, etc.) P by the transfer bias from the transfer means (transfer roller, etc.) 6. The transfer material P is supplied from a transfer material supply means (not shown) to the space between the electrophotographic photoreceptor 1 and the transfer means 6 (contact area) in synchronization with the rotation of the electrophotographic photoreceptor 1.

[0051] After transferring the toner image, the transfer material P is separated from the surface of the electrophotographic photoreceptor 1 and introduced to the fixing means 8, where it undergoes image fixing and is printed out outside the device as an image-formed product (print, copy).

[0052] After the toner image is transferred, the surface of the electrophotographic photoreceptor 1 is cleaned by a cleaning means (such as a cleaning blade) 7 to remove any remaining developer (transferred toner). Then, it is subjected to static discharge treatment by pre-exposure light (not shown) from a pre-exposure means (not shown) and used repeatedly for image formation. Note that, as shown in Figure 1, if the charging means 3 is a contact charging means using a charging roller, pre-exposure is not necessarily required.

[0053] An electrophotographic photoreceptor 1 and at least one means selected from the group consisting of a charging means 3, a developing means 5, a transfer means 6, and a cleaning means 7 may be housed in a container and supported as a single process cartridge, and this process cartridge may be configured to be detachable from the electrophotographic apparatus body. In Figure 1, the electrophotographic photoreceptor 1, the charging means 3, the developing means 5, and the cleaning means 7 are supported as a single cartridge and formed into a process cartridge 9 that is detachable from the electrophotographic apparatus body using guide means 10 such as rails on the electrophotographic apparatus body. [Examples]

[0054] Embodiments of the present invention will be described in more detail below with reference to examples. In the examples, "part" refers to "part by mass".

[0055] <Synthesis of electron transport materials> To 20 parts of dimethylacetamide, 2.0 parts of perylenetetracarboxylic dianhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) and 2.2 parts of L-(+)-leucinol (manufactured by Tokyo Chemical Industry Co., Ltd.) were added under a nitrogen atmosphere. The mixture was refluxed for 10 hours, and after separation by silica gel column chromatography (eluent: THF / toluene), the fraction containing the target compound was concentrated. The concentrate was recrystallized in a THF / n-hexane mixed solution to obtain 2.0 parts of exemplary compound A1-1 shown in Table 1-1.

[0056] The NMR spectrum measured using a nuclear magnetic resonance spectrometer is shown in Figure 3. Measuring instrument used: AVANCEIII 500 manufactured by BRUKER Solvent: Deuterated chloroform (CDCl3) Total count: 256

[0057] <Manufacturing of electrophotographic photoconductors> (Example 1) An aluminum cylinder (JIS-A3003, aluminum alloy) with a length of 260.5 mm and a diameter of 30 mm was machined (JIS B 0601:2014, 10-point average roughness Rzjis: 0.8 μm) and used as a support (conductive support).

[0058] Next, 3.00 parts of the exemplary compound (A1-1) from Table 1-1 as the first electron transport substance, 3.00 parts of the exemplary compound (A1-18) from Table 1-1 as the second electron transport substance, 0.10 parts of polyolefin resin (product name: UC-3920, manufactured by Toagosei Co., Ltd.), 0.10 parts of polyvinyl acetal resin (product name: KS-5Z, manufactured by Sekisui Chemical Co., Ltd.) as the resin, and 8.20 parts of a blocked isocyanate compound (product name: SBB-70P, manufactured by Asahi Kasei Corporation) as the crosslinking agent were dissolved in a mixed solvent of 88 parts THF / 12 parts orthoxylene. Subsequently, the mixture was pressure filtered using an ADVANTEC Teflon® filter (product name: PF020). The obtained undercoat coating solution was immersed and applied onto the conductive layer, and the resulting coating film was heated at 170°C for 40 minutes to cure (polymerize), thereby forming an undercoat layer with a thickness of 1.5 μm.

[0059] Next, hydroxygallium phthalocyanine crystals (charge-generating material) in a crystalline form having strong peaks at Bragg angles (2θ±0.2°) of 7.5°, 9.9°, 12.5°, 16.3°, 18.6°, 25.1°, and 28.3° in CuKα characteristic X-ray diffraction were prepared. Ten parts of these hydroxygallium phthalocyanine crystals, five parts of polyvinyl butyral resin (product name: S-Rec BX-1, manufactured by Sekisui Chemical Co., Ltd.), and 250 parts of cyclohexanone were placed in a sand mill using 1 mm diameter glass beads and dispersed for 2 hours. Next, 250 parts of ethyl acetate were added to prepare a coating solution for the charge-generating layer. This coating solution for the charge-generating layer was applied to the undercoat layer by immersion to form a coating film, and the resulting coating film was dried at 95°C for 10 minutes to form a charge-generating layer with a thickness of 0.15 μm.

[0060] Next, a coating solution for the charge transport layer was prepared by dissolving 5 parts of the compound shown in formula (B-1) below, 5 parts of the compound shown in formula (B-2) below, and 10 parts of polycarbonate (product name: Yupiron Z-400, manufactured by Mitsubishi Engineering Plastics) in a mixed solvent of 25 parts orthoxylene, 25 parts methyl benzoate, and 25 parts dimethoxymethane, as charge transport material (hole transport material). The charge transport layer coating solution prepared in this manner was applied to the aforementioned charge generating layer by immersion to form a coating film, and the coating film was heated and dried at a temperature of 120°C for 30 minutes to form a charge transport layer with a thickness of 25 μm. [ka] [ka] In this way, an electrophotographic photoreceptor having a conductive layer, an undercoat layer, a charge generation layer, and a charge transport layer on a support was manufactured.

[0061] [Sensitivity evaluation] An electrophotographic photoreceptor was mounted in a modified Canon laser beam printer (product name: LBP-2510), and the following process conditions were set. The surface potential (potential fluctuation) was then evaluated. The modifications included changing the process speed to 200 mm / s, setting the dark area potential to -700 V, and making the exposure light (image exposure light) variable. Further details are as follows. Under conditions of 23°C and 50% RH humidity, the developing cartridge was removed from the evaluation unit, and a potential measuring device was inserted to perform the measurement. The potential measuring device consisted of a potential measuring probe positioned at the developing location of the developing cartridge, with the probe positioned in the center of the drum axis relative to the electrophotographic photoreceptor. Sensitivity was evaluated based on the potential of the bright area when irradiated with the same amount of light. A lower bright area potential indicates good sensitivity, while a higher bright area potential indicates low sensitivity. First, the light intensity is 0.3 μJ / cm². 2The settings were adjusted, and the initial potential was measured. Next, the potential of the bright areas was measured after 20,000 prints and after 40,000 prints, and the potential difference (change) was calculated. The evaluation results are shown in Table 2.

[0062] (Examples 2-15) Except for changing the type and amount of electron transport materials mixed into the undercoating solution as shown in Table 2, an electrophotographic photoreceptor was manufactured and evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0063] (Example 16) An electrophotographic photoreceptor was manufactured in the same manner as in Example 1, except that the undercoating solution was prepared and used as described below. The results are shown in Table 2. <Coating liquid for undercoat layer> 1.50 parts of the exemplary compound (A1-1) from Table 1-1 as the first electron transport substance, 3.00 parts of the exemplary compound (A1-18) from Table 1-1 as the second electron transport substance, 1.50 parts of the exemplary compound (A1-5) from Table 1-1 as the third electron transport substance, 0.10 parts of polyolefin resin (product name: UC-3920, manufactured by Toagosei Co., Ltd.), 0.10 parts of polyvinyl acetal resin (product name: KS-5Z, manufactured by Sekisui Chemical Co., Ltd.) as the resin, and 8.20 parts of a blocked isocyanate compound (product name: SBB-70P, manufactured by Asahi Kasei Corporation) as a crosslinking agent were dissolved in a mixed solvent of 88 parts THF / 12 parts orthoxylene. Subsequently, the mixture was filtered under pressure using a Teflon® filter (product name: PF020) manufactured by ADVANTEC. The obtained undercoat coating solution was applied to the conductive layer by immersion, and the resulting coating film was heated at 170°C for 40 minutes to cure (polymerize), thereby forming an undercoat layer with a thickness of 1.5 μm.

[0064] (Examples 17-31) An electrophotographic photoreceptor was manufactured and evaluated in the same manner as in Example 16, except that the type and amount of electron transport material mixed into the undercoat coating solution were changed as shown in Table 2. The results are shown in Table 2.

[0065] (Example 32) An electrophotographic photoreceptor was manufactured and evaluated in the same manner as in Example 16, except that an aluminum cylinder with a diameter of 30 mm and a length of 260.5 mm was used as the support, and the following conductive layer was formed between the support layer and the underdrawing layer. The results are shown in Table 2. An anatase-type titanium dioxide with an average primary particle size of 200 nm was used as the substrate, and a titanium-niobium sulfate solution was prepared containing 33.7 parts titanium (in TiO2 equivalent) and 2.9 parts niobium (in Nb2O5 equivalent). 100 parts of the substrate were dispersed in pure water to make a 1000-part suspension, which was heated to 60°C. The titanium-niobium sulfate solution and 10 mol / L sodium hydroxide were added dropwise over 3 hours until the pH of the suspension reached 2-3. After the entire amount had been added, the pH was adjusted to near neutral, and a polyacrylamide-based flocculant was added to allow the solids to settle. The supernatant was removed, filtered, washed, and dried at 110°C to obtain an intermediate containing 0.1 wt% organic matter from the flocculant (in C equivalent). This intermediate was calcined at 750°C in nitrogen for 1 hour, and then calcined again at 450°C in air to produce titanium dioxide particles. The obtained particles had an average particle size (average primary particle size) of 220 nm, as determined by the aforementioned scanning electron microscope particle size measurement method. Next, as a binding material, we use phenolic resin (phenolic resin monomer / oligomer) (product name: Priofen J-325, manufactured by DIC, resin solids content: 60%, density after curing: 1.3 g / cm³). 2 50 parts of the solution were dissolved in 35 parts of 1-methoxy-2-propanol as a solvent to obtain a solution. 60 parts of titanium dioxide particles 1 were added to this solution, and this was placed in a vertical sand mill using 120 parts of glass beads with an average particle size of 1.0 mm as the dispersion medium. Dispersion treatment was carried out for 4 hours under the conditions of dispersion temperature 23±3℃ and rotation speed 1500 rpm (peripheral speed 5.5 m / s) to obtain a dispersion. The glass beads were removed from this dispersion using a mesh. To the dispersion after the glass beads had been removed, 0.01 parts of silicone oil (product name: SH28 PAINT ADDITIVE, manufactured by Toray Dow Corning) was added as a leveling agent, and silicone resin particles (product name: KMP-590, manufactured by Shin-Etsu Chemical Co., Ltd., average particle size: 2 μm, density: 1.3 g / cm³) were added as a surface roughening agent. 3The conductive layer coating solution was prepared by adding 8 parts of the solution, stirring, and then pressure filtering using PTFE filter paper (product name: PF060, manufactured by Advantec Toyo). The conductive layer coating solution prepared in this manner was applied to the aforementioned support by immersion to form a coating film, and the coating film was heated at 150°C for 20 minutes to cure it, thereby forming a conductive layer with a thickness of 25 μm.

[0066] (Example 33) An electrophotographic photoreceptor was manufactured in the same manner as in Example 1, except that the undercoating solution was prepared and used as described below. The results are shown in Table 2. <Coating liquid for undercoat layer> 3.00 parts of the example compound (A1-15) from Table 1-1 as the first electron transport material, 3.00 parts of the example compound (A1-33) from Table 1-2 as the second electron transport material, and 4.00 parts of polyvinyl acetal resin (product name: KS-5Z, manufactured by Sekisui Chemical Co., Ltd.) as the resin were dissolved in a mixed solvent of 88 parts THF / 12 parts orthoxylene. The mixture was then pressure filtered using an ADVANTEC Teflon® filter (product name: PF020). The resulting undercoat coating solution was immersed and applied onto the conductive layer, and the resulting coating film was heated at 125°C for 30 minutes to cure (polymerize), thereby forming an undercoat layer with a thickness of 1.5 μm.

[0067] (Examples 34-42) An electrophotographic photoreceptor was manufactured and evaluated in the same manner as in Example 33, except that the type and amount of electron transport materials mixed into the undercoating solution were changed as shown in Table 2. The results are shown in Table 2.

[0068] [Table 1-1]

[0069] [Table 1-2]

[0070] [Table 1-3]

[0071] [Table 1-4]

[0072] [Table 2]

[0073] (Comparative Example 1) An electrophotographic photoreceptor was manufactured in the same manner as in Example 1, except that the undercoating solution was prepared and used as described below. The results are shown in Table 3. <Coating liquid for undercoat layer> A coating solution for the undercoat layer was prepared by dissolving 3.10 parts of the example compound (A1-1) from Table 1-1, 0.36 parts of polyolefin resin (trade name: UC-3920, manufactured by Toagosei Co., Ltd.), and 6.41 parts of blocked isocyanate compound (trade name: SBB-70P, manufactured by Asahi Kasei Corporation) in a mixed solvent of 50 parts 1-methoxy-2-propanol / 50 parts tetrahydrofuran.

[0074] (Comparative Example 2) Similar to Example 32, an electrophotographic photoreceptor was manufactured in the same manner as in Comparative Example 1, except that a conductive layer was formed between the support and the undercoat layer, and evaluated in the same manner. The results are shown in Table 3.

[0075] [Table 3]

[0076] The present invention includes the following configurations and methods. (Composition 1) An electrophotographic photoreceptor having a support, an undercoat formed on the support, and a photosensitive layer formed on the undercoat, The lower layer is The compound represented by the following formula (1), The compound represented by the following formula (2), A crosslinking agent having a group capable of bonding to a hydroxyl group or a carboxyl group, A polymer of a composition containing the following An electrophotographic photoreceptor characterized by the following features. [ka] [ka] In formula (1) and formula (2), R 1 , R 2 These are not identical, and are represented by the following formula (10), where X is the same in formulas (1) and (2), and is selected from the tetravalent structures represented by the following formulas (X1), (X2), and (X3). -(R a ) m -(R b ) n -R c (10) In formula (10), R a This is a branched or linear alkylene group having 1 to 10 carbon atoms, which may have substituents, or a phenylene group which may have substituents. In formula (10), R b is a group represented by -O-, -S-, or the following formula (11), [ka] In formula (11), R d is a hydrogen atom or a branched or linear alkyl group having 1 to 4 carbon atoms. In formula (10), R c This is a hydrogen atom, a branched or linear alkyl group having 1 to 10 carbon atoms which may have substituents, an aryl group having 6 to 14 carbon atoms which may have substituents, or a branched or linear arylalkyl group having 7 to 18 carbon atoms which may have substituents. The substituents that the alkylene group or alkyl group may have are a hydroxyl group, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, or an alkoxycarbonyl group having 2 to 4 carbon atoms. The substituents that the phenylene group, the aryl group, or the arylalkyl group may have are an alkyl group having 1 to 3 carbon atoms, a hydroxyl group, a hydroxyalkyl group having 1 to 3 carbon atoms, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a halogen atom, a cyano group, or a nitro group. m is 0 or 1, n is 0 or 1, R 1 and R 2 At least one of them contains a hydroxyl group or a carboxyl group. [ka] [ka] [ka] In formulas (X1), (X2), (X3), R 11 ~R 32 These independently represent a hydrogen atom, a halogen atom, a cyano group, and a nitro group, respectively. (Configuration 2) An electrophotographic photoreceptor having a support, an undercoat formed on the support, and a photosensitive layer formed on the undercoat, The lower layer is At least the compound represented by the following formula (3), The compound represented by the following formula (4), An electrophotographic photoreceptor characterized by containing the following. [ka] [ka] In formulas (3) and (4), R 3 , R 4 These are not identical, and are represented by the following formula (10), where X is the same in formulas (3) and (4), and is selected from the tetravalent structures represented by the following formulas (X1), (X2), and (X3). -(Ra ) m -(R b ) n -R c (10) In formula (10), R a is an optionally substituted branched or linear alkylene group having 1 to 10 carbon atoms, or an optionally substituted phenylene group, In formula (10), R b is -O-, -S- or a group represented by the following formula (11),

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0077] 1. Electrophotographic photoreceptor 2 axes 3. Charging means 4 Exposure light 5. Developing means 6. Transfer means 7. Cleaning methods 8 Fixing means 9 Process Cartridges 10 Guidance methods P Transfer Material

Claims

1. In an electrophotographic photoreceptor having a support, an undercoat layer formed on the support, and a photosensitive layer formed on the undercoat layer, the undercoat layer contains a polymer of a composition including a compound represented by the following formula (1), a compound represented by the following formula (2), and a crosslinking agent having a group capable of bonding to a hydroxy group or a carboxyl group, and is characterized in that it contains a polymer of a composition including an electrophotographic photoreceptor. 【Chemical 1】 [Chemical Formula 2] (In Formula (1) and Formula (2), R １ , R ２ are not the same and are each represented by the following formula (10). In Formula (1) and Formula (2), X is the same and is any one selected from the tetravalent structures represented by the following formula (X1), the following formula (X2), and the following formula (X3). -(R ａ ) ｍ -(R ｂ ) ｎ -R ｃ (10) In formula (10), R ａ is a branched or linear alkylene group having 1 to 10 carbon atoms which may have a substituent, or a phenylene group which may have a substituent, In formula (10), R ｂ is -O-, -S- or a group represented by the following formula (11), 【Chemical Formula 3】 In formula (11), R ｄ is a hydrogen atom or a branched or linear alkyl group having 1 to 4 carbon atoms, In formula (10), R ｃ is a hydrogen atom, a branched or linear alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 14 carbon atoms which may have a substituent, or a branched or linear arylalkyl group having 7 to 18 carbon atoms which may have a substituent, The substituent that the alkylene group or the alkyl group may have is a hydroxy group, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, or an alkoxycarbonyl group having 2 to 4 carbon atoms, The substituent that the phenylene group, the aryl group, or the arylalkyl group may have is an alkyl group having 1 to 3 carbon atoms, a hydroxy group, a hydroxyalkyl group having 1 to 3 carbon atoms, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a halogen atom, a cyano group, or a nitro group, m is 0 or 1, and n is 0 or 1. R １ and R ２ at least one of which contains a hydroxy group or a carboxyl group.) 【Chemical Formula 4】 [Chemical Formula 5] 【Chemical Formula 6】 (In formulas (X1), (X2), and (X3), R １１ ~R ３２ each independently represents a hydrogen atom, a halogen atom, a cyano group, or a nitro group.)

2. In an electrophotographic photoreceptor having a support, an undercoat layer formed on the support, and a photosensitive layer formed on the undercoat layer, the undercoat layer contains at least a compound represented by the following formula (3) and a compound represented by the following formula (4), and is characterized in that it contains 【Chemical Formula 7】 【Chemical 8】 (In formulas (3) and (4), R ３ , R ４ are not the same and are each represented by the following formula (10). In formulas (3) and (4), X is the same and is selected from any of the tetravalent structures represented by the following formula (X1), the following formula (X2), and the following formula (X3). -(R ａ ) ｍ -(R ｂ ) ｎ -R ｃ (10) In formula (10), R ａ is an optionally substituted branched or linear alkylene group having 1 to 10 carbon atoms, or an optionally substituted phenylene group, In formula (10), R ｂ is -O-, -S- or a group represented by the following formula (11), 【Chemical Formula 9】 In formula (11), R ｄ is a hydrogen atom or a branched or straight-chain alkyl group having 1 to 4 carbon atoms, In formula (10), R ｃ is a hydrogen atom, a branched or linear alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 14 carbon atoms which may have a substituent, or a branched or linear arylalkyl group having 7 to 18 carbon atoms which may have a substituent, an electrophotographic photoreceptor. The substituent that the alkylene group or the alkyl group may have is a hydroxy group, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, or an alkoxycarbonyl group having 2 to 4 carbon atoms, The substituent that the phenylene group, the aryl group, or the arylalkyl group may have is an alkyl group having 1 to 3 carbon atoms, a hydroxy group, a hydroxyalkyl group having 1 to 3 carbon atoms, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a halogen atom, a cyano group, or a nitro group, m is 0 or 1, and n is 0 or 1. 【Chemical Formula 10】 【Chemical Formula 11】 【Chemical 12】 (In formulas (X1), (X2), and (X3), R １１ ~R ３２ each independently represents a hydrogen atom, a halogen atom, a cyano group, or a nitro group.)

3. The electrophotographic photoreceptor according to claim 1, characterized in that the composition further contains a compound represented by the following formula (5). 【Chemical Formula 13】 (In formula (5), R2 is represented by the following formula (10), and in formula (5), X is any one selected from the tetravalent structures represented by the following formula (X1), the following formula (X2), and the following formula (X3). -(Ra)m-(Rb)n-Rc (10) In formula (10), Ra is a branched or linear alkylene group having 1 to 10 carbon atoms which may have a substituent, or a phenylene group which may have a substituent, In formula (10), Rb is -O-, -S- or a group represented by the following formula (11), [Chemical Formula 3] In formula (11), Rd is a hydrogen atom or a branched or linear alkyl group having 1 to 4 carbon atoms, In formula (10), Rc is a hydrogen atom, a branched or linear alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 14 carbon atoms which may have a substituent, or a branched or linear arylalkyl group having 7 to 18 carbon atoms which may have a substituent, The substituent that the alkylene group or the alkyl group can have is a hydroxy group, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, or an alkoxycarbonyl group having 2 to 4 carbon atoms, The substituent that the phenylene group, the aryl group or the arylalkyl group can have is an alkyl group having 1 to 3 carbon atoms, a hydroxy group, a hydroxyalkyl group having 1 to 3 carbon atoms, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a halogen atom, a cyano group, or a nitro group, m is 0 or 1, and n is 0 or 1) 【Chemical Formula 4】 【Chemical Formula 5】 【Chemical Formula 6】 (In formulas (X1), (X2), and (X3), R11 to R32 each independently represent a hydrogen atom, a halogen atom, a cyano group, or a nitro group.)

4. The electrophotographic photoreceptor according to claim 2, wherein the undercoat layer further contains a compound represented by the following formula (6). 【Chemical 14】 (In formula (6), R4 is represented by the following formula (10), and in formula (6), X is selected from any one of the tetravalent structures represented by the following formula (X1), the following formula (X2), and the following formula (X3). -(Ra)m-(Rb)n-Rc (10) In formula (10), Ra is a branched or linear alkylene group having 1 to 10 carbon atoms which may have a substituent, or a phenylene group which may have a substituent, In formula (10), Rb is -O-, -S- or a group represented by the following formula (11), 【Chemical Formula 9】 In formula (11), Rd is a hydrogen atom or a branched or linear alkyl group having 1 to 4 carbon atoms, In formula (10), Rc is a hydrogen atom, a branched or linear alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 14 carbon atoms which may have a substituent, or a branched or linear arylalkyl group having 7 to 18 carbon atoms which may have a substituent, The substituent that the alkylene group or the alkyl group can have is a hydroxy group, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, or an alkoxycarbonyl group having 2 to 4 carbon atoms, The substituent that the phenylene group, the aryl group or the arylalkyl group can have is an alkyl group having 1 to 3 carbon atoms, a hydroxy group, a hydroxyalkyl group having 1 to 3 carbon atoms, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a halogen atom, a cyano group, or a nitro group, m is 0 or 1, and n is 0 or 1.) 【Chemical Formula 10】 【Chemical 11】 【Chemical 12】 (In formulas (X1), (X2), and (X3), R11 to R32 each independently represent a hydrogen atom, a halogen atom, a cyano group, or a nitro group.)

5. In formulas (1) to (6), X is a structure represented by formula (X1), and the electrophotographic photoreceptor according to any one of claims 1 to 4 is characterized by this.

6. In formulas (1), (2), and (5), R １ , R ２ The electrophotographic photoreceptor according to claim 1 or 3, wherein at least one of them is a group represented by the following formula (7). 【Chemical Formula 15】 (In formula (7), R ５ , R ６ is each independently a group selected from the group consisting of a branched or linear alkyl group having 1 to 7 carbon atoms which may have a substituent, a benzyl group, an alkoxycarbonyl group having 2 to 4 carbon atoms, and a phenyl group, and the substituent that the alkyl group may have is a group selected from the group consisting of an alkoxycarbonyl group having 2 to 4 carbon atoms, a phenyl group, a phenol group, a hydroxy group, a thiol group, an amino group, or a carboxyl group.)

7. In formulas (3), (4), and (6), R ３ , R ４ The electrophotographic photoreceptor according to claim 2 or 4, wherein at least one of them is a group represented by the following formula (8). 【Chemical 16】 (In formula (8), R ７ , R ８ are each independently a group selected from the group consisting of a branched or linear alkyl group having 1 to 7 carbon atoms which may have a substituent, a benzyl group, an alkoxycarbonyl group having 2 to 4 carbon atoms, and a phenyl group, and the substituent that the alkyl group may have is a group selected from the group consisting of an alkoxycarbonyl group having 2 to 4 carbon atoms, a phenyl group, a phenol group, a hydroxy group, a thiol group, an amino group, or a carboxyl group.)

8. In the composition, the mass ratio (mass of formula (1) / mass of formula (2)) of the compound represented by formula (1) and the compound represented by formula (2) is 0.25 or more and 4 or less, and the electrophotographic photoreceptor according to claim 1 or 3 is characterized by this.

9. In the undercoat layer, the mass ratio (mass of formula (3) / mass of formula (4)) of the compound represented by formula (3) and the compound represented by formula (4) is 0.25 or more and 4 or less, and the electrophotographic photoreceptor according to claim 2 or 4 is characterized by this.

10. An electrophotographic photoreceptor according to any one of claims 1 to 4, and at least one means selected from the group consisting of a charging means, a developing means, and a cleaning means are integrally supported, and a process cartridge characterized by being detachable from the electrophotographic apparatus main body.

11. An electrophotographic apparatus having an electrophotographic photoreceptor according to any one of claims 1 to 4, a charging means, an exposure means, a developing means, and a transfer means.

12. A method for manufacturing an electrophotographic photoreceptor having a support, an undercoat layer formed on the support, and a photosensitive layer formed on the undercoat layer, A step of forming a coating film of a coating liquid for an undercoat layer containing at least a compound represented by formula (1), a compound represented by formula (2), and a crosslinking agent having a group capable of bonding to a hydroxy group or a carboxyl group, and a step of polymerizing the coating film to form the undercoat layer A method for manufacturing an electrophotographic photoreceptor having the above steps. 【Chemical 17】 【Chemical 18】 (In Formula (1) and Formula (2), R １ , R ２ are not the same and are each represented by the following Formula (10). In Formula (1) and Formula (2), X is the same and is any one selected from the tetravalent structures represented by the following Formula (X1), the following Formula (X2), and the following Formula (X3). -(R ａ ) ｍ -(R ｂ ) ｎ -R ｃ (10) In formula (10), R ａ is an optionally substituted branched or linear alkylene group having 1 to 10 carbon atoms, or an optionally substituted phenylene group, In formula (10), R ｂ is -O-, -S- or a group represented by the following formula (11), 【Chemical Formula 19】 In formula (11), R ｄ is a hydrogen atom or a branched or linear alkyl group having 1 to 4 carbon atoms, In formula (10), R ｃ is a hydrogen atom, a branched or straight-chain alkyl group having 1 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 14 carbon atoms which may have a substituent, or a branched or straight-chain arylalkyl group having 7 to 18 carbon atoms which may have a substituent, The substituent that the alkylene group or the alkyl group can have is a hydroxy group, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, or an alkoxycarbonyl group having 2 to 4 carbon atoms, The substituent that the phenylene group, the aryl group, or the arylalkyl group can have is an alkyl group having 1 to 3 carbon atoms, a hydroxy group, a hydroxyalkyl group having 1 to 3 carbon atoms, a carboxyl group, an amino group, a thiol group, an alkoxy group having 1 to 3 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a halogen atom, a cyano group, or a nitro group, m is 0 or 1, and n is 0 or 1. R １ and R ２ at least one of which contains a hydroxy group or a carboxyl group.) 【Chemical 20】 【Chemical 21】 【Chemical 22】 (In formulas (X1), (X2), and (X3), R １１ ~R ３２ each independently represents a hydrogen atom, a halogen atom, a cyano group, or a nitro group.)

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