Electrophotographic device

Abstract

To provide an electrophotographic device that prevents a deterioration in cleanability in a high temperature and high humidity environment.SOLUTION: In an electrophotographic device, an electrophotographic photoreceptor has a surface layer that contains a compound represented by the formula (A), a binder resin having a repeated structure represented by the formula (B), and alumina particles surface-treated with at least one selected from fatty acids and a silane coupling agents. Toner has toner particles containing a polyester resin having a polyethylene terephthalate segment.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to electrophotographic devices. [Background technology]

[0002] In recent years, various demands have been made on electrophotographic devices, such as higher speed, smaller size, and energy saving. Electrophotographic photoconductors used in electrophotographic devices are required to have higher sensitivity to accommodate the increased speed. For example, Patent Document 1 describes a technique for providing a highly sensitive electrophotographic photoconductor by using a method for increasing the content of a hole transport substance.

[0003] Furthermore, in order to realize an energy-saving electrophotographic device, a technique for fixing toner at a low temperature has been proposed. Patent Document 2 describes a technique related to a toner having, as one of its resin components, a polyester obtained by reacting polyethylene terephthalate with an alcohol component and a carboxylic acid component. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-045517 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-280085 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the above-mentioned Patent Documents 1 and 2 are used in combination, there is room for improvement in the cleaning performance in a high-temperature, high-humidity environment. That is, by increasing the content of the hole transport substance, the interaction with the toner containing polyester as one of the resin components may be strengthened, which may increase the amount of residual toner after transfer, resulting in a deterioration in the cleaning performance.

[0006] The present disclosure aims to provide an electrophotographic apparatus that suppresses deterioration of cleaning performance in a high-temperature, high-humidity environment. [Means for solving the problem]

[0007] According to the present disclosure, a charging means for charging the surface of an electrophotographic photoreceptor; an image exposure means for irradiating the charged surface of the electrophotographic photosensitive member with image exposure light to form an electrostatic latent image on the surface of the electrophotographic photosensitive member; a developing means having a toner and for developing the electrostatic latent image with the toner to form a toner image on the surface of the electrophotographic photosensitive member; and a transfer means for transferring the toner image from the surface of the electrophotographic photosensitive member to a transfer material. a cleaning means for removing residual toner remaining on the surface of the electrophotographic photosensitive member after the toner image has been transferred from the surface of the electrophotographic photosensitive member to a transfer material; An electrophotographic apparatus having the electrophotographic photoreceptor has a support, a charge generating layer, a first hole transport layer, and a second hole transport layer in this order, the second hole transport layer being a surface layer; the surface layer comprises a hole transport material represented by the following formula (A), a binder resin having a repeating structure represented by the following formula (B), and alumina particles as a metal oxide filler that have been surface-treated with at least one kind selected from a fatty acid and a silane coupling agent, the content of alumina particles in the surface layer is 10% to 100% based on the hole transport material in the surface layer; The content of the hole transport substance is 85% to 150% based on the binder resin, and the toner contained in the developing means has toner particles containing a polyester resin having a polyethylene terephthalate segment; An electrophotographic apparatus is provided. [ka] (In formula (A), Ar 1 ~Ar 4 each independently represents a phenyl group or a phenyl group substituted with a methyl group. [ka] (In formula (B), R 5 ~R 8 each independently represents a hydrogen atom or a methyl group, and X 1 represents a methylene group, a cyclohexylidene group, an oxygen atom, or a single bond, which may have an alkyl group or a phenyl group as a substituent. [Effects of the Invention]

[0008] According to one aspect of the present disclosure, an electrophotographic apparatus can be provided in which deterioration of cleaning performance in a high-temperature, high-humidity environment is suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of a process cartridge including an electrophotographic photosensitive member according to the present disclosure. [Figure 2] FIG. 1 is a diagram illustrating an example of an electrophotographic apparatus including an electrophotographic photoreceptor according to the present disclosure. [Figure 3] FIG. 2 is a schematic diagram illustrating an example of the configuration of an electrophotographic photosensitive member. DETAILED DESCRIPTION OF THE INVENTION

[0010] As a result of investigations by the present inventors, it has been found that the surface layer comprises a hole transport material represented by the above formula (A), a binder resin having a repeating structure represented by the above formula (B), and alumina particles as a metal oxide filler that have been surface-treated with at least one kind selected from a fatty acid and a silane coupling agent, the content of alumina particles in the surface layer is 10% to 100% based on the hole transport material in the surface layer; The content of the hole transport material is 85% to 150% based on the binder resin, and It has been found that the deterioration of cleaning properties in a high-temperature, high-humidity environment can be suppressed by using toner particles containing a polyester resin having a polyethylene terephthalate segment in the toner contained in the developing means.

[0011] The hole transport substance represented by formula (A) is a monomolecular substance and therefore tends to have a relatively higher polarity than the binder resin represented by formula (B). Therefore, if the content of the hole transport substance is increased in order to obtain a highly sensitive electrophotographic photoreceptor, the hydrophilicity of the surface layer also tends to increase.

[0012] On the other hand, compared with polyester resins commonly used in toners, toners having polyethylene terephthalate segments also tend to have higher polarity, and therefore are more likely to be hydrophilic. Therefore, when an electrophotographic photoreceptor with an increased content of hole transport material and a toner having polyethylene terephthalate segments are present, the interaction between the electrophotographic photoreceptor surface and the toner becomes stronger, increasing the possibility of an increase in transfer residual toner. This effect becomes particularly pronounced in high-temperature, high-humidity environments, resulting in a higher possibility of deterioration in cleanability.

[0013] As a result of investigations by the present inventors, it has been found that an electrophotographic device in which deterioration of cleaning properties is suppressed can be obtained by incorporating alumina particles, which have been surface-treated with at least one selected from fatty acids and silane coupling agents as a metal oxide filler, in the surface layer of an electrophotographic photosensitive member in an amount of 10% to 100% based on the hole transport material in the surface layer.

[0014] The present inventors speculate as follows about the reason why the electrophotographic apparatus of the present disclosure has an excellent effect of suppressing deterioration of cleaning performance. The surface layer of the electrophotographic photoreceptor of the present disclosure contains alumina particles that have been surface-treated with at least one selected from fatty acids and silane coupling agents, which tends to increase hydrophobicity. Therefore, it is believed that increasing the content of the hole transport substance suppresses the increased polarity and reduces hydrophilicity, thereby weakening the interaction between the electrophotographic photoreceptor surface and the toner, reducing the possibility of an increase in residual toner, and as a result, suppressing deterioration in cleanability. The present invention will be described in detail below with reference to preferred embodiments.

[0015] <Electrophotographic photoreceptor> The electrophotographic photoreceptor of the electrophotographic apparatus of the present invention comprises a hole transport material represented by the above formula (A), a binder resin having a repeating structure represented by the above formula (B), and alumina particles as a metal oxide filler that have been surface-treated with at least one agent selected from a fatty acid and a silane coupling agent, The content of alumina particles in the surface layer is 10% to 100% based on the hole transport material of the surface layer; and The surface layer has a hole transport material content of 85% to 150% based on the binder resin.

[0016] An example of the layer structure of the electrophotographic photoreceptor of the present disclosure is shown in Fig. 3. In Fig. 3, the electrophotographic photoreceptor is configured as a laminated photosensitive layer in which an undercoat layer 22, a charge generating layer 23, a first hole transport layer 24, and a second hole transport layer 25 are laminated on a support 21. In the present invention, the second hole transport layer of the electrophotographic photosensitive member is defined as the surface layer.

[0017] A method for producing the electrophotographic photoreceptor of the present disclosure includes preparing a coating liquid for each layer constituting the electrophotographic photoreceptor described below, coating the desired layers in order from the support, and drying the coating liquid. In this case, examples of the coating method for the coating liquid include dip coating, spray coating, inkjet coating, roll coating, die coating, blade coating, curtain coating, wire bar coating, and ring coating. Among these, dip coating is preferred from the viewpoints of efficiency and productivity. The support and each layer will be described below.

[0018] <Support> The support of the electrophotographic photoreceptor is preferably conductive (conductive support). The support may be cylindrical, belt-like, or sheet-like. Of these, a cylindrical support is preferred. The surface of the support may be subjected to electrochemical treatment such as anodization, blasting, cutting, or the like. The support is preferably made of a metal, a resin, or a glass. Examples of metals include aluminum, iron, nickel, copper, gold, stainless steel, and alloys thereof. Among these, an aluminum support using aluminum is preferred.

[0019] It is also preferable to impart electrical conductivity to the resin or glass by processing such as mixing or coating with an electrically conductive material. The surface of the conductive support may be subjected to a diffuse reflection treatment, such as anodizing, surface treatment with chemicals or hot water, coloring, or surface roughening, as needed, provided that the treatment does not affect image quality. The diffuse reflection treatment is particularly effective when the photoreceptor of the present invention is used in an electrophotographic process using a laser as the exposure light source. In other words, in an electrophotographic process using a laser as the exposure light source, the laser light has a uniform wavelength, so that the laser light reflected from the surface of the photoreceptor and the laser light reflected inside the photoreceptor interfere with each other, resulting in interference fringes appearing in the image and causing image defects. Therefore, by subjecting the surface of the conductive support to a diffuse reflection treatment, image defects caused by the interference of the laser light with the uniform phase can be prevented.

[0020] <Conductive layer> A conductive layer may be provided on the support, which can conceal scratches and irregularities on the surface of the support and control light reflection on the surface of the support. The conductive layer preferably contains conductive particles and a binder resin.

[0021] Examples of materials for the conductive particles include metal oxides, metals, carbon black, etc. Examples of metal oxides include zinc oxide, aluminum oxide, indium oxide, silicon oxide, zirconium oxide, tin oxide, titanium oxide, strontium titanate, magnesium oxide, antimony oxide, bismuth oxide, etc. Examples of metals include aluminum, nickel, iron, nichrome, copper, zinc, silver, etc. Among these, it is preferable to use metal oxide particles as the conductive particles, and it is particularly preferable to use titanium oxide particles, tin oxide particles, or zinc oxide particles.

[0022] When metal oxide particles are used as the conductive particles, the surfaces of the metal oxide particles may be treated with a silane coupling agent or the like, or the metal oxide particles may be doped with elements such as phosphorus or aluminum or oxides thereof.

[0023] The conductive particles may have a layered structure including a core particle and a coating layer covering the core particle. Examples of the core particle include titanium oxide particles, barium sulfate particles, and zinc oxide particles. Examples of the coating layer include metal oxide particles such as tin oxide.

[0024] When metal oxide particles are used as the conductive particles, the volume average particle size thereof is preferably 1 nm or more and 500 nm or less, and more preferably 3 nm or more and 400 nm or less.

[0025] Examples of the binder resin include polyester resin, polycarbonate resin, polyvinyl acetal resin, acrylic resin, silicone resin, epoxy resin, melamine resin, polyurethane resin, phenol resin, and alkyd resin. The conductive layer may further contain silicone oil, resin particles, a masking agent such as titanium oxide, and the like.

[0026] The conductive layer can be formed by preparing a coating solution for the conductive layer containing the above-mentioned materials and solvent, forming this coating film on a support, and drying it. Examples of solvents used in the coating solution for the conductive layer include alcohol-based solvents, sulfoxide-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents. Examples of dispersion methods for dispersing the conductive particles in the coating solution for the conductive layer include methods using a paint shaker, a sand mill, a ball mill, and a liquid collision-type high-speed disperser.

[0027] The 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.

[0028] <Undercoat layer> In the present disclosure, an undercoat layer may be provided on the support or the conductive layer. By providing an undercoat layer, adhesion between layers can be improved and a charge injection blocking function can be imparted. The undercoat layer preferably contains a binder resin. Alternatively, the undercoat layer may be formed as a cured film by polymerizing a composition containing a monomer having a polymerizable functional group.

[0029] Examples of binder resins include acetal resins such as polyvinyl butyral, polyester resins, polycarbonate resins, acrylic resins, epoxy resins, melamine resins, polyurethane resins, phenol resins, polyvinylphenol resins, alkyd resins, polyvinyl alcohol resins, polyethylene oxide resins, polypropylene oxide resins, polyamide resins, polyamic acid resins, polyimide resins, polyamideimide resins, and cellulose resins.

[0030] Examples of the polymerizable functional group contained in the monomer having a polymerizable functional group include an isocyanate group, a blocked isocyanate group, a methylol group, an alkylated methylol group, an epoxy group, a metal alkoxide group, a hydroxy group, an amino group, a carboxy group, a thiol group, a carboxylic acid anhydride group, and a carbon-carbon double bond group.

[0031] Furthermore, for the purpose of improving electrical properties, the undercoat layer may further contain an electron transport material, metal oxide particles, metal particles, a conductive polymer, etc. Among these, it is preferable to use an electron transport material or metal oxide particles.

[0032] Examples of the electron transport substance include a quinone compound, an imide compound, a benzimidazole compound, a cyclopentadienylidene compound, a fluorenone compound, a xanthone compound, a benzophenone compound, a cyanovinyl compound, an aryl halide compound, a silole compound, a boron-containing compound, etc. An electron transport substance having a polymerizable functional group may be used as the electron transport substance, and the undercoat layer may be formed as a cured film by copolymerizing the electron transport substance with the above-mentioned monomer having the polymerizable functional group.

[0033] Examples of metal oxide particles include particles of indium tin oxide, tin oxide, indium oxide, titanium oxide, strontium titanate, zinc oxide, and aluminum oxide. Silicon dioxide particles can also be used. Examples of metal particles include particles of gold, silver, and aluminum.

[0034] The metal oxide particles contained in the undercoat layer may be surface-treated with a surface treatment agent such as a silane coupling agent. The surface treatment of the metal oxide particles can be carried out by a common method, such as a dry method or a wet method. In the dry method, metal oxide particles are stirred in a mixer capable of high-speed stirring, such as a Henschel mixer, and an alcohol aqueous solution, organic solvent solution, or aqueous solution containing a surface treatment agent is added to the metal oxide particles to uniformly disperse them, followed by drying. In the wet method, metal oxide particles and a surface treatment agent are stirred in a solvent or dispersed in a sand mill using glass beads or the like, and the solvent is then removed by filtration or vacuum distillation. After the solvent is removed, the mixture is preferably baked at 100°C or higher.

[0035] The undercoat layer may further contain additives, such as known materials such as metal particles such as aluminum particles, conductive material particles such as carbon black, charge transport materials, metal chelate compounds, and organometallic compounds.

[0036] The undercoat layer can be formed by preparing a coating solution for the undercoat layer containing the above-mentioned materials and solvent, forming the coating film on the support or the conductive layer, and drying and / or curing the coating film. Examples of solvents that can be used in the coating solution for the undercoat layer include organic solvents such as alcohols, sulfoxides, ketones, ethers, esters, halogenated aliphatic hydrocarbons, and aromatic compounds. In the present disclosure, it is preferable to use alcohol-based or ketone-based solvents. Dispersion methods for preparing the coating liquid for the undercoat layer include methods using a homogenizer, ultrasonic disperser, ball mill, sand mill, roll mill, vibration mill, attritor, and liquid collision type high-speed disperser. The thickness of the undercoat layer is preferably 0.1 μm or more and 50 μm or less.

[0037] <Charge generation layer> The charge generating layer preferably contains a charge generating substance and a binder resin.

[0038] Examples of charge-generating materials include azo pigments, perylene pigments, polycyclic quinone pigments, indigo pigments, and phthalocyanine pigments. Among these, azo pigments and phthalocyanine pigments are preferred. Among phthalocyanine pigments, titanyl phthalocyanine pigments, oxytitanium phthalocyanine pigments, chlorogallium phthalocyanine pigments, and hydroxygallium phthalocyanine pigments are preferred.

[0039] Examples of binder resins include polyester resins, polycarbonate resins, polyvinyl acetal resins, polyvinyl butyral resins, acrylic resins, silicone resins, epoxy resins, melamine resins, polyurethane resins, phenolic resins, polyvinyl alcohol resins, cellulose resins, polystyrene resins, polyvinyl acetate resins, polyvinyl chloride resins, etc. Among these, polyvinyl butyral resins are more preferred.

[0040] The charge generating layer may further contain additives such as antioxidants and ultraviolet absorbers, etc. Specific examples include hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, and benzophenone compounds.

[0041] The charge generating layer can be formed by preparing a coating solution for the charge generating layer containing the above-mentioned materials and solvent, forming a coating film of this on the undercoat layer, and drying it. Examples of the solvent 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.

[0042] The thickness of the charge generating layer is preferably from 0.01 μm to 5 μm, and more preferably from 0.05 μm to 2 μm.

[0043] <First Hole Transport Layer> The first hole transport layer can be formed by forming a coating film of a hole transport layer coating liquid in which a hole transport material and a binder resin are mixed in a solvent, and drying the coating film. The hole transport material and binder resin used in the hole transport layer will be described below.

[0044] Examples of hole-transporting substances include carbazole compounds, hydrazone compounds, N,N-dialkylaniline compounds, diphenylamine compounds, triphenylamine compounds, triphenylmethane compounds, pyrazoline compounds, styryl compounds, and stilbene compounds, and these may be used alone or in combination of two or more.

[0045] Examples of binder resins include acrylic acid esters, methacrylic acid esters, polyvinyl alcohol resins, polyvinyl acetal resins, polycarbonate resins, and polyester resins. Also usable are curable resins such as curable phenolic resins, curable urethane resins, curable melamine resins, curable epoxy resins, curable acrylic resins, and curable methacrylic resins. These binder resins may be used alone or in combination of two or more.

[0046] Examples of the solvent used in the coating liquid for the first hole transport layer include alcohol-based solvents, sulfoxide-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, aliphatic halogenated hydrocarbon-based solvents, and aromatic hydrocarbon-based solvents.

[0047] The thickness of the first hole transport layer is preferably from 1 μm to 100 μm, more preferably from 3 μm to 50 μm, and particularly preferably from 5 μm to 40 μm. If necessary, a leveling agent such as dimethyl silicone oil or methyl phenyl silicone oil may be added.

[0048] <Second Hole Transport Layer> The second hole transport layer (surface layer) of the electrophotographic photosensitive member of the present invention contains a hole transport substance, a binder resin, and alumina particles surface-treated with at least one agent selected from fatty acids and silane coupling agents.

[0049] In consideration of charge transportability and solubility, the hole transport material of the second hole transport layer contains at least the compound represented by formula (A). [ka] (In formula (A), Ar 1 ~Ar 4 each independently represents a phenyl group or a phenyl group substituted with a methyl group.

[0050] Examples of the compound represented by formula (A) of the present invention are shown below. Example Compound No. A-1 [ka] Example Compound No. A-2 [ka] Example Compound No. A-3 [ka] Example Compound No. A-4 [ka] Example Compound No. A-5 [ka] Example Compound No. A-6 [ka] Example Compound No. A-7 [ka]

[0051] The content of the compound represented by formula (A) is preferably 31% to 57%, more preferably 31% to 47%, based on the mass of the second hole transport layer (surface layer). The content of the hole transport substance is preferably 85% to 150%, more preferably 85% to 100%, based on the binder resin.

[0052] The surface layer may contain other hole transport materials such as polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, benzidine compounds, and resins having groups derived from these materials. These other charge transport materials may be used alone or in combination of two or more.

[0053] The binder resin contained in the second hole transport layer has at least the repeating structure represented by formula (B). [ka] (In formula (B), R 5 ~R 8 each independently represents a hydrogen atom or a methyl group, and X 1 represents a methylene group, a cyclohexylidene group, an oxygen atom, or a single bond, which may have an alkyl group or a phenyl group as a substituent.

[0054] Examples of the repeating structure represented by formula (B) of the present invention are shown below. Example repeat structure No.B-1 [ka] Example repeat structure No.B-2 [ka]

[0055] The content of the binder resin having the repeating structure represented by formula (B) is preferably 28% to 52% by mass, more preferably 35% to 52% by mass, of the second hole transport layer (surface layer). One or more types of binder resins may be used in combination.

[0056] The alumina particles surface-treated with at least one agent selected from fatty acids and silane coupling agents are added for the purpose of suppressing the hydrophilicity of the surface layer of the electrophotographic photosensitive member of the present invention.

[0057] Examples of alumina particles that can be used in the present disclosure include TM-DAR, TM-5D, and TM-5DA manufactured by Taimei Chemical Industry Co., Ltd., and Sumicorundum AA-03 manufactured by Sumitomo Chemical Co., Ltd.

[0058] Fatty acids that can be used in the present disclosure include lauric acid, stearic acid, adipic acid, oleic acid, maleic acid, maleic anhydride, terephthalic acid, oligomers and polymers having multiple carboxylic acid residues, and among these, carboxylic acids or polycarboxylic acids containing two or more carboxylic acid residues are preferred, such as BYK-P104 and BYK-P104S manufactured by BYK-Chemie.

[0059] Examples of silane coupling agents that can be used in the present disclosure include γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, trimethylmethoxysilane, and hexamethyldisilazane.

[0060] The amount of the fatty acid and silane coupling agent added is 0.01 to 50 parts by mass per 100 parts by mass of the alumina particles contained.

[0061] Examples of the surface treatment method include a method in which a powder is dispersed in a solvent such as water or an organic solvent and the powder is adsorbed with a surface treatment agent added to the solvent, a method in which a surface treatment agent is dissolved in a solvent and added to the powder to be treated to coat the surface of the powder, a method in which a surface treatment agent is mixed with a filler and the mixture is subjected to an impact force by an ejected airflow to surface treat the filler, etc. These surface treatments may be performed on the alumina particles before preparing the coating solution for the second hole transport layer, or may be performed in the coating solution for the second hole transport layer.

[0062] The content of alumina particles surface-treated with at least one selected from fatty acids and silane coupling agents is preferably 10% to 100% based on the hole transport material in the surface layer. If it is less than 10%, the cleaning stability effect may be reduced, while if it exceeds 100%, the sensitivity may be reduced.

[0063] The surface layer may also contain various additives such as antioxidants, ultraviolet absorbers, plasticizers, leveling agents, etc. Specific examples include hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, siloxane-modified resins, silicone oils, polystyrene resin particles, polyethylene resin particles, and boron nitride particles.

[0064] The surface layer can be formed by preparing a coating solution for the surface layer containing the above-mentioned materials and solvent, forming this coating film on the first hole transport layer, and drying it. Examples of the solvent used in the coating solution include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents. Among these solvents, ether-based solvents and aromatic hydrocarbon-based solvents are preferred. The thickness of the surface layer is preferably 0.1 μm or more and 15 μm or less.

[0065] [Toner and Developer] The toner used in the electrophotographic device of the present disclosure is a toner having toner particles containing a polyester resin having a polyethylene terephthalate segment. The toner according to the present disclosure will be described below.

[0066] <Polyester resin containing polyethylene terephthalate segments> Components constituting the polyester resin containing polyethylene terephthalate include a polyethylene terephthalate segment, a divalent or higher alcohol monomer component, and an acid monomer component such as a divalent or higher carboxylic acid, a divalent or higher carboxylic acid anhydride, or a divalent or higher carboxylic acid ester.

[0067] <Polyethylene terephthalate segment> The polyethylene terephthalate segment of the present disclosure is a structural unit of polyethylene terephthalate (C 10 H8O4) has a repeating structure.

[0068] The polyethylene terephthalate segment of the present disclosure can be one produced by a conventional method through a condensation reaction or transesterification reaction between ethylene glycol and terephthalic acid, dimethyl terephthalate, or the like, or can be a recovered polyethylene terephthalate resin.

[0069] Polyethylene terephthalate resin is used in various products such as containers and films, and from the viewpoint of environmental protection, it is preferable to recover and reuse the recovered polyethylene terephthalate resin. There are no limitations on the type of recovered polyethylene terephthalate resin, as long as it does not contain impurities that may affect the toner properties or reactions in the manufacturing process and has an appropriate purity.

[0070] <Dihydric or higher alcohol monomer component> Examples of dihydric or higher alcohol monomer components include alkylene oxide adducts of bisphenol A such as polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene(3.3)-2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene(2.0)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene(2.0)-polyoxyethylene(2.0)-2,2-bis(4-hydroxyphenyl)propane, and polyoxypropylene(6)-2,2-bis(4-hydroxyphenyl)propane; ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, neopentyl glycol, polyethylene glycol, and polypropylene glycol.

[0071] <Acid monomer component> On the other hand, examples of acid monomer components such as divalent or higher carboxylic acids, divalent or higher carboxylic acid anhydrides, and divalent or higher carboxylic acid esters include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid, or anhydrides thereof; and alkyl dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, adipic acid, maleic acid, fumaric acid, citraconic acid, and itaconic acid, or anhydrides thereof.

[0072] <Method for producing polyester resin having polyethylene terephthalate segments> The polyester resin having a polyethylene terephthalate segment of the present disclosure can be produced by a conventional polyester synthesis method. For example, a desired polyester resin can be obtained by esterifying or transesterifying a carboxylic acid monomer and an alcohol monomer, followed by polycondensation under reduced pressure or by introducing nitrogen gas according to a conventional method.

[0073] <Toner particles containing binder resin> Furthermore, in the electrophotographic apparatus of the present disclosure, it is more preferable to use the toner described below, since this can improve low-temperature fixability and scratch resistance. A toner having toner particles containing a binder resin, The binder resin contains an amorphous resin A and a crystalline polyester resin C, The amorphous resin A is a polyester resin, and the structure forming the polyester skeleton is (i) a polyethylene terephthalate segment, and (ii) at least one structure selected from the group consisting of a structure represented by the following formula (1), a structure represented by the following formula (2), a structure represented by the following formula (3), and a structure represented by the following formula (4): and [ka] (In formula (1), R 1 represents an alkyl group having 6 to 16 carbon atoms or an alkenyl group having 6 to 16 carbon atoms, A represents a hydrocarbon group, * represents a bonding site in the polyester skeleton, and m represents an integer of 2 or greater. [ka] (In formula (2), R 2 represents an alkyl group having 6 to 16 carbon atoms or an alkenyl group having 6 to 16 carbon atoms, B represents a hydrocarbon group, * represents a bonding site in the polyester skeleton, and n represents an integer of 2 or greater. [ka] (In formula (3), * represents a bond in the polyester skeleton, and x represents an integer of 6 to 16.) [ka] (In formula (4), * represents a bond in the polyester skeleton, and y represents an integer of 6 to 16.) The SP value of the amorphous resin A is SPA (cal / cm 3 ) 0.5 The SP value of the crystalline polyester resin C is SPC (cal / cm 3 ) 0.5 When the SPA and the SPC satisfy the following formula (C), 1.00≦SPA-SPC≦1.35 (C) The toner contains phosphorus element derived from a phosphorus compound, and when the content of the phosphorus element in the toner is defined as WP (ppm) based on the mass of the toner, the WP satisfies the following formula (D). 5≦WP≦500 (D) More preferably, 20≦WP≦500···(E).

[0074] The reasons for the improvement in low-temperature fixability and scratch resistance will be explained below. As a result of investigations by the present inventors, it has been found that a toner having the following properties can exhibit good low-temperature fixability and improve scratch resistance. (i) The three-dimensional structure can be flexibly deformed in the direction of the applied external force. (ii) When the external force is removed, it can return to its original conformation. Such a toner can be achieved by using the above-mentioned composition. The amorphous resin A has at least one structure selected from the group consisting of structures (units) represented by the above formulas (1) to (4). The SP value between the amorphous resin A and the crystalline polyester resin C is controlled, thereby providing affinity with the crystalline polyester resin C. Therefore, in a fixed image, the amorphous resin A is affected by the crystalline polyester resin C and becomes flexible. This structure disperses applied external forces, allowing the three-dimensional structure to flexibly deform in the direction of the applied external force without breaking the molecular chain. Furthermore, the amorphous resin A contains polyethylene terephthalate segments, and thus has a repeating structure of a condensate of terephthalic acid and ethylene glycol in the polyester backbone. The ethylene glycol-derived structure of the polyethylene terephthalate segment undergoes esterification at both ends of the ethylene glycol, resulting in an ester structure with a molecular distance of two carbon atoms. Therefore, the amorphous resin A has an ester structure localized within the resin. Furthermore, the phosphorus compound with the three unshared electron pairs in the outermost shell reacting also has a bonding point with a molecular distance that is very close. Therefore, the amorphous resin A can form a three-dimensional crosslinked structure by interacting with the localized ester structure in the amorphous resin A, centering on the phosphorus element of the phosphorus compound. This structure allows the amorphous resin A to return to its original three-dimensional structure from a deformed state when the applied external force is removed. As described above, it is believed that the configuration of the present disclosure can provide excellent low-temperature fixability and scratch resistance.

[0075] The amorphous resin A of the present disclosure has, as a structure forming a polyester skeleton, at least one structure selected from the group consisting of a structure represented by formula (1), a structure represented by formula (2), a structure represented by formula (3), and a structure represented by formula (4). The structures of long-chain hydrocarbon groups such as alkyl groups and alkenyl groups contained in the structures represented by formulas (1) to (4) above are relatively less polar than the ethylene glycol-derived structure of the polyethylene terephthalate segment. Therefore, the structures of long-chain hydrocarbon groups such as alkyl groups and alkenyl groups contained in the structures represented by formulas (1) to (4) above become flexible due to their increased affinity with the crystalline polyester resin C. Furthermore, this structure disperses applied external forces, allowing the three-dimensional structure to flexibly deform in the direction of the applied external force without breaking the molecular chains. As a result, improved elastic deformation is achieved, resulting in excellent scratch resistance. Furthermore, the SPA (cal / cm) of the amorphous resin A of the present disclosure is 3 ) 0.5 and SPC (cal / cm) of crystalline polyester resin C 3 ) 0.5 satisfies the above formula (C). When SPA-SPC satisfies the above formula (C), the amorphous resin A and the crystalline polyester resin C are easily compatible, allowing the crystalline polyester C to smoothly interact with the structure of the amorphous resin A containing long-chain hydrocarbon groups such as alkyl and alkenyl groups. This structure therefore becomes flexible due to its increased affinity with the crystalline polyester resin C. Furthermore, this structure disperses applied external forces, allowing the three-dimensional structure to flexibly deform in the direction of the applied external force without breaking the molecular chains. As a result, improved elastic deformation properties are achieved, resulting in excellent scratch resistance.

[0076] Furthermore, the toner of the present disclosure contains phosphorus derived from a phosphorus compound, and the WP (ppm by mass) satisfies the above formula (D). When the content of phosphorus in the toner satisfies the above formula (D), it indicates that a sufficient amount of phosphorus is present to form a three-dimensional crosslinked structure by interacting with the localized ester structure in the amorphous resin A, with the phosphorus at the center. In other words, it is the minimum amount of phosphorus that can flexibly change the three-dimensional structure in the direction of the applied external force without breaking the molecular chains in order to disperse the applied external force, and the maximum amount of phosphorus that can ensure a certain level of plastic deformation that ensures low-temperature fixability.

[0077] <Amorphous resin A> The amorphous resin A is a polyester resin, and has the following (i) and (ii) as structures forming a polyester skeleton. (i) Polyethylene terephthalate segment (ii) at least one structure selected from the group consisting of units represented by the above formulas (1) to (4) The polyethylene terephthalate structure used in the amorphous resin A is obtained by polycondensing ethylene glycol and terephthalic acid. The synthesis of the amorphous resin A can be carried out in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and if necessary, in the presence of an esterification promoter, a polymerization inhibitor, etc., at a temperature preferably of 180°C or higher and 250°C or lower. Examples of esterification catalysts include tin compounds such as dibutyltin oxide and tin(II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropylate bistriethanolamine. Among these, tin compounds such as tin(II) 2-ethylhexanoate are preferred. The amount of the esterification catalyst used is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 1.5 parts by mass or less, more preferably 1.0 part by mass or less, per 100 parts by mass of the raw material monomers (alcohol component, carboxylic acid component, and PET). Examples of esterification promoters include gallic acid. The amount of the esterification promoter used is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 0.5 parts by mass or less, more preferably 0.1 parts by mass or less, per 100 parts by mass of the raw material monomers. Examples of polymerization inhibitors include tert-butylcatechol. The amount of the polymerization inhibitor used is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and preferably 0.5 part by mass or less, more preferably 0.1 part by mass or less, per 100 parts by mass of the raw material monomer. In addition, in the synthesis of amorphous resin A, polyethylene terephthalate may be present from the start of the condensation polymerization reaction, or may be added to the reaction system during the condensation polymerization reaction. In order for polyethylene terephthalate segments to be incorporated into the main skeleton of amorphous resin A in a block form to some extent, the timing of adding polyethylene terephthalate is preferably when the reaction rate between the alcohol component and the carboxylic acid component is 10% or less, and more preferably when it is 5% or less. Here, the reaction rate refers to the value of the amount of reaction water produced (mol) / the theoretical amount of water produced (mol) × 100.

[0078] Furthermore, used polyethylene terephthalate (so-called recycled PET) can be used as the polyethylene terephthalate segment contained in the amorphous resin A. Reusing polyethylene terephthalate is preferable from an environmental perspective. Used PET is collected, washed, sorted to remove other materials and waste, and then crushed into flakes or other shapes. The crushed material can be used as is, or it can be kneaded and coarsely crushed before use. If standard cleaning is unable to sufficiently remove chemicals adsorbed to the surface of PET bottles, alkaline cleaning can be performed. If the crushed material is partially hydrolyzed by alkaline cleaning, it is preferable to melt the washed crushed material and pelletize it to restore the reduced degree of polymerization. The solid-state polymerization process can be carried out by continuous solid-state polymerization of washed flakes or pellets made by melt-extrusion of flakes in an inert gas such as nitrogen gas or a rare gas at 180-245°C, preferably 200-240°C. Alternatively, the washed crushed material can be depolymerized to break down into monomer units and resynthesized. Recycled PET is not limited to the above-mentioned used PET; off-spec PET fiber waste or pellets discharged from factories can also be used.

[0079] Furthermore, in order to incorporate at least one unit selected from the group consisting of units represented by the above formulas (1) to (4) into the amorphous resin A, the following monomers can be used: 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, octadecanedioic acid, dodecenylsuccinic acid, n-octylsuccinic acid, isododecenylsuccinic acid, dodecylsuccinic acid, isooctenylsuccinic acid, hexadecylsuccinic acid, and the like. Among the above structures, it is preferable that the amorphous resin A contains units represented by formula (1) and formula (2). When an alkyl group or alkenyl group having 6 to 16 carbon atoms is branched from the main chain of the polyester skeleton, the affinity with the release agent is increased, and the dispersibility of the release agent is further improved.

[0080] In addition, in addition to the above-described structures and monomers, other polyhydric alcohols (divalent or higher alcohols), polycarboxylic acids (divalent or higher carboxylic acids), their acid anhydrides, or their lower alkyl esters may also be used as components for obtaining the amorphous resin A. The following polyhydric alcohol monomers can be used as the polyhydric alcohol monomer: Dihydric alcohol components include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, and bisphenols represented by the following formula (E) and their derivatives: [ka] (In formula (E), R represents an ethylene or propylene group, x and y each represent an integer of 0 or greater, and the average value of x+y is 0 or greater and 10 or less.) Diols represented by the following formula (F): [ka] (In formula (F), R' is an ethylene group, -CH2CH(CH3)-, or -CH2C(CH3)2-, x' and y' are each an integer of 0 or greater, and the average value of x' + y' is 0 or greater and 10 or less.) Examples include:

[0081] Examples of trihydric or higher alcohol components include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene. Of these, glycerol, trimethylolpropane, and pentaerythritol are preferred. These dihydric alcohols and trihydric or higher alcohols can be used alone or in combination.

[0082] Examples of dicarboxylic acid components include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, azelaic acid, malonic acid, anhydrides of these acids, and lower alkyl esters of these acids. Of these, maleic acid, fumaric acid, and terephthalic acid are preferably used. Examples of trivalent or higher carboxylic acids, their acid anhydrides, or their lower alkyl esters include 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra(methylenecarboxyl)methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, and empol. Examples of suitable carboxylic acids include trimer acids, their acid anhydrides, and lower alkyl esters. Among these, 1,2,4-benzenetricarboxylic acid, i.e., trimellitic acid or its derivatives, is particularly preferred because it is inexpensive and the reaction is easy to control. These dicarboxylic acids and tricarboxylic or higher carboxylic acids can be used alone or in combination.

[0083] The method for producing amorphous resin A is not particularly limited, and known methods can be used. For example, the aforementioned alcohol monomer and carboxylic acid monomer are simultaneously charged and polymerized via an esterification reaction or transesterification reaction and a condensation reaction to produce amorphous resin A. The polymerization temperature is not particularly limited, but is preferably in the range of 180°C to 290°C. For polymerization of the polyester unit, a polymerization catalyst such as a titanium-based catalyst, a tin-based catalyst, zinc acetate, antimony trioxide, or germanium dioxide can be used. In particular, amorphous resin A is more preferably a polyester resin polymerized using a tin-based catalyst.

[0084] The amorphous resin A may be a polyester resin having a vinyl resin portion. A preferred method for obtaining a polyester resin having a vinyl resin bonded thereto is to use a monomer component that can react with both the vinyl resin and the polyester unit. Such a monomer is preferably a monomer having an unsaturated double bond and a carboxyl group or a hydroxyl group. Examples of such a monomer include unsaturated dicarboxylic acids such as phthalic acid, maleic acid, citraconic acid, and itaconic acid, or their anhydrides, and acrylic acid or methacrylic acid esters. The peak molecular weight of the amorphous resin A is preferably 3500 or more and 20000 or less from the viewpoint of low-temperature fixability, etc. The glass transition temperature is preferably 40°C to 70°C. Furthermore, as the amorphous resin, various resins conventionally known as binder resins can be used in combination with the amorphous resin A. Examples of such resins include phenolic resins, natural resin-modified phenolic resins, natural resin-modified maleic resins, acrylic resins, methacrylic resins, polyvinyl acetate resins, silicone resins, polyester resins, polyurethane resins, polyamide resins, furan resins, epoxy resins, xylene resins, polyvinyl butyral resins, terpene resins, coumaroindene resins, and petroleum-based resins.

[0085] <Crystalline polyester resin C> Monomers used in the polyester unit of the crystalline polyester resin C used in the toner of the present disclosure include polyhydric alcohols (divalent or trivalent or higher alcohols), polycarboxylic acids (divalent or trivalent or higher carboxylic acids), their acid anhydrides, or their lower alkyl esters. As the polyhydric alcohol monomer used in the polyester unit of the crystalline polyester resin C, the following polyhydric alcohol monomers can be used. The polyhydric alcohol monomer is not particularly limited, but is preferably a chain (more preferably a straight-chain) aliphatic diol, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,6-hexanediol, dipropylene glycol, 1,4-butanediol, 1,4-butadiene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, nonamethylene glycol, decamethylene glycol, and neopentyl glycol. Among these, particularly preferred are straight-chain aliphatic α,ω-diols such as ethylene glycol, diethylene glycol, 1,4-butanediol, and 1,6-hexanediol.

[0086] In the present disclosure, polyhydric alcohol monomers other than the above polyhydric alcohols can also be used. Among the polyhydric alcohol monomers, dihydric alcohol monomers include aromatic alcohols such as polyoxyethylenated bisphenol A and polyoxypropylenated bisphenol A; and 1,4-cyclohexanedimethanol. Furthermore, among the polyhydric alcohol monomers, trihydric or higher polyhydric alcohol monomers include aromatic alcohols such as 1,3,5-trihydroxymethylbenzene; and aliphatic alcohols such as pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, elemental glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, and trimethylolpropane.

[0087] As the polycarboxylic acid monomer used in the polyester unit of the crystalline polyester resin C, the following polycarboxylic acid monomers can be used. The polycarboxylic acid monomer is not particularly limited, but is preferably a chain (more preferably a linear) aliphatic dicarboxylic acid. Specific examples include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, glutaconic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, and itaconic acid, as well as those obtained by hydrolyzing the acid anhydrides or lower alkyl esters of these acids.

[0088] In the present disclosure, polycarboxylic acids other than the above-mentioned polycarboxylic acid monomers can also be used. Among the other polycarboxylic acid monomers, dicarboxylic acids include aromatic carboxylic acids such as isophthalic acid and terephthalic acid; aliphatic carboxylic acids such as n-dodecylsuccinic acid and n-dodecenylsuccinic acid; and alicyclic carboxylic acids such as cyclohexanedicarboxylic acid, as well as their acid anhydrides and lower alkyl esters. Furthermore, among the other carboxylic acid monomers, tricarboxylic or higher polycarboxylic acids include aromatic carboxylic acids such as 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and pyromellitic acid; and aliphatic carboxylic acids such as 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, and 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, as well as their acid anhydrides and lower alkyl esters.

[0089] Furthermore, the crystalline polyester resin C is preferably a modified crystalline polyester resin having a structure in which the hydroxy group at the end of the main chain is terminally modified with an aliphatic monocarboxylic acid having 16 to 31 carbon atoms, or a modified crystalline polyester resin having a structure in which the carboxy group at the end of the main chain is terminally modified with an aliphatic monoalcohol having 15 to 30 carbon atoms. Examples of aliphatic monocarboxylic acid monomers having 16 to 31 carbon atoms include palmitic acid (hexadecanoic acid), margaric acid (heptadecanoic acid), stearic acid (octadecanoic acid), nonadecylic acid, arachidic acid (icosanoic acid), henicosanoic acid, docosanoic acid, tetracosanoic acid, hexacosanoic acid, octacosanoic acid, and triacontanoic acid. Examples of aliphatic monoalcohols having 15 to 30 carbon atoms include cetyl alcohol, palmityl alcohol (hexadecanol), margaryl alcohol (heptadecanol), stearyl alcohol (octadecanol), nonadecanol, arachidyl alcohol (icosanol), heneicosanol, behenyl alcohol, lignoceryl alcohol, ceryl alcohol, 1-heptacosanol, montanyl alcohol, 1-nonacosanol, and myricyl alcohol.

[0090] The crystalline polyester resin C can be produced by a conventional polyester synthesis method. For example, the carboxylic acid monomer and the alcohol monomer are subjected to an esterification reaction or a transesterification reaction, followed by a conventional polycondensation reaction under reduced pressure or by introducing nitrogen gas to obtain a crystalline polyester resin. The desired crystalline polyester resin can then be obtained by adding the above-mentioned aliphatic compound and carrying out an esterification reaction. The above esterification or transesterification reaction can be carried out, if necessary, using a conventional esterification catalyst or transesterification catalyst such as sulfuric acid, titanium butoxide, dibutyltin oxide, manganese acetate, or magnesium acetate. The polycondensation reaction can be carried out using a conventional polymerization catalyst, such as titanium butoxide, dibutyltin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide, germanium dioxide, etc. The polymerization temperature and the amount of catalyst are not particularly limited and may be determined appropriately. In the esterification or transesterification reaction or polycondensation reaction, all the monomers may be charged at once to increase the strength of the resulting crystalline polyester resin. Alternatively, to reduce the amount of low-molecular-weight components, a divalent monomer may be reacted first, and then a trivalent or higher valent monomer may be added and reacted. From the viewpoint of low-temperature fixability, the melting point of the crystalline polyester resin C is preferably 70° C. to 110° C., more preferably 80° C. to 100° C. In the toner of the present disclosure, the crystalline polyester resin C is preferably used in an amount of 3 parts by mass to 20 parts by mass per 100 parts by mass of the amorphous resin, from the viewpoints of low-temperature fixability, abrasion resistance, and charge retention in a high-temperature, high-humidity environment.

[0091] <Phosphorus compounds> Examples of phosphorus compounds that can be used in the toner of the present disclosure include trisodium phosphate, trimethyl phosphate, triethyl phosphate, tri-2-ethylhexyl phosphate, (trisisopropylphenyl) phosphate, triphenyl phosphate, tributyl phosphate, trimethyl phosphite, tributyl phosphite, triphenyl phosphite, etc. Among these, trivalent phosphorus compounds that can easily form three-dimensional crosslinks are preferred.

[0092] The optimum phosphorus content WP for forming a three-dimensional crosslinked structure is as described above. Furthermore, in order to form a three-dimensional crosslinked structure, it is necessary to use used polyethylene terephthalate (so-called recycled PET), as this facilitates the formation of polyethylene terephthalate blocks, allowing ester structures with close molecular distances to aggregate more closely together, forming a strong three-dimensional crosslinked structure. This structure can return to its original three-dimensional structure when the applied external force is removed.

[0093] <Release agent> The toner particles may contain wax as a release agent, such as polyethylene wax, polypropylene wax, polypropylene copolymer wax, microcrystalline wax, paraffin wax, Fischer-Tropsch wax, carnauba wax, rice wax, candelilla wax, and montan wax.

[0094] <Coloring agent> The toner may contain a colorant. Examples of the colorant include known organic pigments, oil-based dyes, and magnetic materials. Examples of the colorant include carbon black, phthalocyanine blue, permanent brown FG, brilliant fast scarlet, pigment red 122, pigment green B, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, isoindoline, disazo yellow, benzidine yellow, monoazo dyes and pigments, and disazo dyes and pigments.

[0095] <Charge control agent> The toner particles may contain a charge control agent as needed. As the charge control agent, known positive charge control agents and negative charge control agents can be used, but it is preferable to use a negative charge control agent, particularly when combined with the photoreceptor used in the present disclosure. Examples of the positive charge control agent include quaternary ammonium salt compounds, triphenylmethane compounds, imidazole compounds, and nigrosine dyes. Examples of negative charge control agents include benzilic acid metal compounds, salicylic acid metal compounds, copper phthalocyanine dyes, and quaternary ammonium salt compounds.

[0096] <Inorganic fine particles> The toner may contain inorganic fine particles as needed.

[0097] The inorganic fine particles may be internally added to the toner particles or may be mixed with the toner particles as an external additive. Examples of the inorganic fine particles include silica fine particles, titanium oxide fine particles, alumina fine particles, and fine particles of their double oxides. Among the inorganic fine particles, silica fine particles and titanium oxide fine particles are preferred for improving flowability and uniform charging. The inorganic fine particles are preferably hydrophobized with a hydrophobizing agent such as a silane compound, silicone oil, or a mixture thereof.

[0098] <External additives> As the external additive, in addition to the inorganic fine particles described above, organic fine particles such as melamine-based resin fine particles and polytetrafluoroethylene resin fine particles may be used.

[0099] From the viewpoint of improving flowability, the median diameter (D50) of the external additives on a number basis is preferably 10 nm or more, and preferably 250 nm or less, more preferably 200 nm or less, and even more preferably 90 nm or less.

[0100] The content of the external additive is preferably 0.1 to 10.0 parts by mass with respect to 100 parts by mass of toner particles. The toner particles and the external additive can be mixed using a known mixer such as a Henschel mixer.

[0101] <Developer> The toner can be used as a one-component developer, but in order to further improve dot reproducibility and to provide stable images over a long period of time, it is preferable to use the toner as a two-component developer by mixing it with a magnetic carrier. As the magnetic carrier, for example, commonly known particles of metals such as iron, cobalt, and nickel, and magnetic materials such as ferrite can be used.

[0102] <Method of manufacturing toner particles> The method for producing toner particles is not particularly limited, and known methods such as a pulverization method, a suspension polymerization method, a solution suspension method, an emulsion aggregation method, and a dispersion polymerization method can be used. Among these, the pulverization method is preferred from the viewpoint of controlling the wax on the surface of the toner particles. In other words, the toner particles are preferably pulverized toner particles. The procedure for producing toner using the pulverization method will be described below.

[0103] The pulverization method includes, for example, a raw material mixing step of mixing a crystalline polyester resin C and an amorphous resin A as binder resins, a phosphorus compound, and, if necessary, other components such as other amorphous resins, waxes, colorants, and charge control agents; a step of melting and kneading the mixed raw materials to obtain a resin composition; and a step of pulverizing the obtained resin composition to obtain toner particles.

[0104] In the raw material mixing process, materials constituting the toner particles, such as binder resin, wax, and, if necessary, other components such as colorants and charge control agents, are weighed out in predetermined amounts, blended, and mixed. Examples of mixing devices include a double cone mixer, a V-type mixer, a drum mixer, a super mixer, a Henschel mixer, a Nauta mixer, and a Mechano Hybrid (manufactured by Nippon Coke and Engineering Co., Ltd.).

[0105] Next, the mixed materials are melt-kneaded to disperse the materials in the binder resin. In this melt-kneading process, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used. Single- or twin-screw extruders are the mainstream due to their advantage of continuous production. Examples include a KTK twin-screw extruder (manufactured by Kobe Steel, Ltd.), a TEM twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.), a PCM kneader (manufactured by Ikegai Iron Works), a twin-screw extruder (manufactured by KCK Corporation), a Ko-Kneader (manufactured by Buss Co., Ltd.), and a Kneadex (manufactured by Nippon Coke and Engineering Co., Ltd.). Furthermore, the resin composition obtained by melt-kneading may be rolled using a twin roll or the like and cooled with water or the like in a cooling process.

[0106] The cooled resin composition is then pulverized to the desired particle size in a pulverization process. In the pulverization process, the resin composition is first coarsely pulverized using a pulverizer such as a crusher, hammer mill, or feather mill. The pulverized resin composition is then finely pulverized using a pulverizer such as a Kryptron System (Kawasaki Heavy Industries), a Super Rotor (Nisshin Engineering Element Co., Ltd.), a Turbo Mill (Turbo Kogyo), or an air jet pulverizer.

[0107] Thereafter, as necessary, the mixture is classified using a classifier or sieve such as an inertial classification type Elbow Jet (manufactured by Nittetsu Mining Co., Ltd.), a centrifugal classification type Turboplex (manufactured by Hosokawa Micron Corporation), a TSP Separator (manufactured by Hosokawa Micron Corporation), or a Faculty (manufactured by Hosokawa Micron Corporation).

[0108] Then, if necessary, external additives such as silica particles are added to the surface of the toner particles to obtain the toner. Examples of equipment for external addition include double cone mixers, V-type mixers, drum mixers, super mixers, Henschel mixers, Nauta mixers, Mechano Hybrid (manufactured by Nippon Coke and Engineering Co., Ltd.), and Nobilta (manufactured by Hosokawa Micron Corporation).

[0109] The methods for measuring various physical properties are explained below. (Method of separating each material from toner) By utilizing the difference in solubility of each material in the toner in a solvent and GPC, each material can be separated from the toner. The following physical properties can be measured using each separated material. First separation: The toner is dissolved in methyl ethyl ketone (MEK) at 23°C, and the soluble components (amorphous resin A, amorphous resin B, crystalline polyester resin C, phosphorus compounds) are separated from the insoluble components (wax, colorants, inorganic particles, etc.). Second separation: The soluble fraction (amorphous resin A, amorphous resin B, crystalline polyester resin C, phosphorus compound) obtained in the first separation is dissolved in tetrahydrofuran (THF) at 23°C, and the soluble fraction (amorphous resin A, amorphous resin B, phosphorus compound) and the insoluble fraction (crystalline polyester resin C) are separated. Third separation: The insoluble matter (wax, colorant, inorganic fine particles, etc.) obtained in the first separation is dissolved in MEK at 100°C, and the soluble matter (wax) is separated from the insoluble matter (colorant, inorganic fine particles, etc.). Fourth separation: The soluble fractions (amorphous resin A, amorphous resin B, and phosphorus compounds) obtained in the second separation are dissolved in tetrahydrofuran (THF) at 23°C, and the amorphous resin A, amorphous resin B, and phosphorus compounds are separated by preparative GPC.

[0110] <Method for identifying and measuring the content of various monomer units in amorphous resins and crystalline polyester resins> The identification of various monomer units in the amorphous resin and crystalline polyester resin and the measurement of the content ratio are carried out by 1H-NMR under the following conditions. Measuring device: FT NMR device JNM-EX400 (manufactured by JEOL Ltd.) Measurement frequency: 400MHz Pulse condition: 5.0 μs Frequency range: 10500Hz Accumulation count: 64 times Measurement temperature: 30℃ Sample: 50 mg of the measurement sample is placed in a sample tube with an inner diameter of 5 mm, deuterated chloroform (CDCl3) is added as a solvent, and the sample is dissolved in a thermostatic bath at 40°C. From the obtained 1H-NMR chart, the structures of various monomer units are identified, and the integral values ​​S1, S2, S3, . . . Sn of the peaks assigned to each monomer unit are calculated. The content ratio of each monomer unit is determined using the above integral values ​​S1, S2, S3, and Sn as follows: where n1, n2, n3...nn are the numbers of hydrogen atoms in each monomer unit. Content ratio of each monomer unit (mol%) = {(Sn / nn) / ((S1 / n1) + (S2 / n2) + (S3 / n3) + (Sn / nn))} × 100 The content ratio (mol%) of each monomer unit is calculated by changing the molecular term in the same procedure. When polymerizable monomers that do not contain hydrogen atoms are used in the various monomer units, 13C-NMR is used, the measurement nucleus is set to 13C, measurement is performed in single pulse mode, and calculation is performed in the same manner with 1H-NMR.

[0111] <Method for calculating the SP value of amorphous resin and crystalline polyester resin> The SP value of each of the amorphous resin and the crystalline polyester resin is calculated according to the calculation method proposed by Fedors. Specifically, the evaporation energy (Δei), molar volume (Δvi), and molar ratio (j) in the resin of each monomer unit are determined, and the SP value is calculated using the following formula. SP value (cal / cm 3 ) 0.5 ={(Σj×ΣΔei) / (Σj×ΣΔvi)} 0.5 The evaporation energy (Δei) and molar volume (Δvi) of the atom or atomic group in the monomer unit are the values ​​described in "Polym. Eng. Sci., 14(2), 147-154 (1974)".

[0112] <Method for measuring the content of phosphorus element WP in toner> The content WP (ppm) of phosphorus element in the toner is measured using a multi-element simultaneous ICP optical emission spectrometer Vista-PRO (manufactured by Hitachi High-Tech Science Corporation). Sample: 50 mg Solvent: nitric acid 6mL The above is weighed and subjected to decomposition treatment using a microwave sample pretreatment device ETHOS UP (Milestone General Co., Ltd.). Temperature: Raise from 20°C to 230°C and hold at 230°C for 30 minutes After passing the decomposition liquid through filter paper (5C), transfer it to a 50 mL volumetric flask and adjust the volume to 50 mL with ultrapure water. The phosphorus content in the toner can be quantified by measuring the aqueous solution in the volumetric flask using a Vista-PRO multi-element simultaneous ICP optical emission spectrometer under the conditions below. The content is quantified by creating a calibration curve using standard samples of the element to be quantified, and then calculating based on that calibration curve. Conditions: RF power 1.20 kW, Ar gas: plasma flow 15.0 L / min, Auxiliary flow: 1.50L / min, MFC:1.50L / min, Nebuuser flow: 0.90 L / min Liquid pump speed: 15 rpm, Measurement repeat: 3 times, Measurement time: 1.0 seconds

[0113] <Electrophotographic device> The electrophotographic apparatus of the present disclosure is characterized by having the electrophotographic photosensitive member, toner, charging means, exposure means, developing means, transfer means, and cleaning means described above.

[0114] FIG. 1 shows the configuration of a process cartridge equipped with an electrophotographic photosensitive member of the present disclosure, and FIG. 2 shows an example of the schematic configuration of an electrophotographic apparatus having the process cartridge of FIG.

[0115] In FIG. 1, a cylindrical electrophotographic photoreceptor 1 is rotated in the direction of the arrow at a predetermined peripheral speed. The peripheral surface of the rotationally driven electrophotographic photoreceptor 1 is uniformly charged to a predetermined positive or negative potential by charging means 2. The charged peripheral surface of the electrophotographic photoreceptor 1 is then irradiated with exposure light (image exposure light) 3 output from exposure means (not shown) such as slit exposure or laser beam scanning exposure. In this way, an electrostatic latent image corresponding to a target image is sequentially formed on the peripheral surface of the electrophotographic photoreceptor 1. The voltage applied to the charging means (such as a charging roller) 2 may be a voltage in which an AC component is superimposed on a DC component, or a voltage consisting of only a DC component.

[0116] The electrostatic latent image formed on the peripheral surface of the electrophotographic photosensitive member 1 is developed into a toner image by the toner contained in the developer of the developing means 4. Next, the toner image formed and carried on the peripheral surface of the electrophotographic photosensitive member 1 is sequentially transferred onto a transfer material (paper, intermediate transfer member, etc.) 6 by a transfer bias from a transfer means (transfer roller, etc.) 5. The transfer material 6 is fed in synchronization with the rotation of the electrophotographic photosensitive member 1.

[0117] After the toner image is transferred, the surface of the electrophotographic photoreceptor 1 is subjected to a charge removal process using pre-exposure light 7 from a pre-exposure means (not shown), and then the surface is cleaned by removing the transfer residual toner (residual toner remaining on the surface of the photoreceptor) using a cleaning means 8, and the electrophotographic photoreceptor 1 is then repeatedly used for image formation. The pre-exposure means may be placed before or after the cleaning step, and the pre-exposure means is not necessarily required.

[0118] The electrophotographic photosensitive member 1 may be mounted in an electrophotographic apparatus such as a copying machine or a laser beam printer. Alternatively, a process cartridge 9 may be configured by accommodating a plurality of components, such as the electrophotographic photosensitive member 1, charging means 2, developing means 4, and cleaning means 8, in a container and integrally supporting them, and the process cartridge 9 may be configured to be detachable from the main body of the electrophotographic apparatus. In FIG. 1, the electrophotographic photosensitive member 1, charging means 2, developing means 4, and cleaning means 8 are integrally supported to form the process cartridge 9, which is detachable from the main body of the electrophotographic apparatus.

[0119] Next, an electrophotographic apparatus equipped with the electrophotographic photoreceptor of the present disclosure will be described. An example of the configuration of the electrophotographic apparatus of the present disclosure is shown in Figure 2. A yellow process cartridge 17, a magenta process cartridge 18, a cyan process cartridge 19, and a black process cartridge 20, each corresponding to a different color, are arranged side by side along an intermediate transfer body 10. The diameter, constituent materials, developer, charging method, and other means of the electrophotographic photosensitive member do not necessarily need to be the same for each color.

[0120] When the image formation operation begins, toner images of each color are sequentially superimposed on the intermediate transfer body 10 according to the image formation process described above. In parallel, transfer paper 11 is sent out from paper feed tray 13 via paper feed path 12 and fed to secondary transfer means 14 in synchronization with the rotation of the intermediate transfer body. The toner image on the intermediate transfer body 10 is transferred onto the transfer paper 11 by a transfer bias from secondary transfer means 14. The toner image transferred onto the transfer paper 11 is transported along paper feed path 12, fixed on the transfer paper by fixing means 15, and then discharged from paper discharge section 16.

[0121] The electrophotographic photoreceptor of the present disclosure can be used in laser beam printers, LED printers, copiers, facsimiles, and multifunction machines thereof. [Example]

[0122] The present invention will be described in more detail below with reference to Production Examples and Examples, but is not limited thereto. Note that the number of parts in the following formulations is by weight unless otherwise specified.

[0123] [Example of manufacturing an electrophotographic photoreceptor] <Production Example of Electrophotographic Photoreceptor 1> ·Support As a support (conductive support), an aluminum cylinder having a length of 357.5 mm and an outer diameter of 30 mm was prepared.

[0124] Conductive layer and undercoat layer formation The conductive layer coating solution was prepared by dispersing 10.0 parts of tin oxide (SnO2)-coated barium sulfate, 2.0 parts of titanium oxide, 6.0 parts of phenolic resin, 0.001 parts of silicone oil, 4.0 parts of methanol, and 16.0 parts of methoxypropanol in a sand mill equipped with 1 mm diameter glass beads for 2 hours. The conductive layer coating solution was then dip-coated onto the support to form a coating film, which was then thermally cured at 140°C for 30 minutes to form a 15 μm thick conductive layer. Next, a solution of 5.0 parts of N-methoxymethylated nylon and 1.0 part of copolymer nylon dissolved in a mixed solvent of 65.0 parts of methanol and 30.0 parts of n-butanol was applied onto the conductive layer by immersion to form an undercoat layer with a thickness of 0.6 μm.

[0125] Formation of charge generation layer 10 parts of oxytitanium phthalocyanine crystals (charge generating material) having peaks at Bragg angles 2θ of 9.6° and 27.3° (maximum peak at 27.3°) in CuKα characteristic X-ray diffraction, 6.7 parts of polyvinyl butyral (trade name: BX-1, manufactured by Sekisui Chemical Co., Ltd.), and 300.0 parts of cyclohexanone as a dispersion solvent were placed in a sand mill equipped with 400.0 parts of 1 mm diameter glass beads (trade name: GB201M, manufactured by Toshiba Ballotini Co., Ltd.). The mixture was dispersed at 20°C for 4 hours to obtain a dispersion. The resulting dispersion was diluted with 500.0 parts of ethyl acetate to prepare a charge generating layer coating solution. This charge generating layer coating solution was dip-coated onto the undercoat layer, and the resulting coating was dried at 80°C for 15 minutes to form a charge generating layer with a thickness of 0.17 μm.

[0126] Formation of the first hole transport layer Next, the following materials were prepared: Hole transport material A-1 10.0 parts by weight Binder resin with repeating structure of B-1 (viscosity average molecular weight 40,000) 0.6 parts by mass Binder resin with repeating structure of B-2 (viscosity average molecular weight 50,000) 9.4 parts by mass Silicone oil (KF50-100CS, Shin-Etsu Chemical Co., Ltd.) 1.0 part The above materials were dissolved in 100.0 parts of tetrahydrofuran to prepare a coating solution for a first hole transport layer. The coating solution was dip-coated onto the charge generating layer, and the resulting coating was dried at 110°C for 50 minutes to form a first hole transport layer with a thickness of 18 μm.

[0127] Formation of a second hole transport layer Next, the following materials were prepared: Alumina particles (Taimicron TM-5D: manufactured by Taimei Chemical Industry Co., Ltd.) 3.5 parts by mass Polycarboxylic acid compound (BYK-P104, manufactured by BYK Chemie) 0.02 parts The above materials were added to 160.0 parts by mass of cyclohexanone and 520.0 parts by mass of tetrahydrofuran and dissolved, and dispersed in a ball mill using alumina balls for 24 hours. The following materials were dissolved in the dispersion to prepare a coating liquid for a second hole transport layer. Hole transport material A-1 10.0 parts by weight Binder resin with repeating structure of B-1 (viscosity average molecular weight 40,000) 0.6 parts by mass Binder resin with repeating structure of B-2 (viscosity average molecular weight 50,000) 9.4 parts by mass This second hole transport layer coating liquid was spray coated onto the first hole transport layer and dried to form a second hole transport layer with a thickness of 3 μm.

[0128] By the above treatment, an electrophotographic photoreceptor 1 having, in this order, a support, a conductive layer and an undercoat layer, a charge generating layer, a first hole transport layer, and a second hole transport layer as shown in FIG. 3 was obtained.

[0129] <Production Example of Electrophotographic Photoreceptor 2> Electrophotographic photoreceptor 2 was produced in the same manner as in the production example of electrophotographic photoreceptor 1, except that the amount of alumina particles contained in the surface layer was changed from 3.5 parts by mass to 1.1 parts by mass, and the amount of polycarboxylic acid compound was changed from 0.02 parts by mass to 0.01 parts by mass.

[0130] <Production Example of Electrophotographic Photoreceptor 3> Electrophotographic photoreceptor 3 was manufactured in the same manner as in the manufacturing example of electrophotographic photoreceptor 1, except that the alumina particles contained in the surface layer were changed from 3.5 parts by mass to 8.6 parts by mass, and the polycarboxylic acid compound was changed from 0.02 parts by mass to 0.04 parts by mass.

[0131] <Production Example of Electrophotographic Photoreceptor 4> Electrophotographic photoreceptor 4 was produced in the same manner as in the production example of electrophotographic photoreceptor 1, except that the amount of hole transport material A-1 contained in the surface layer was changed from 10.0 parts by mass to 8.5 parts by mass, the amount of alumina particles was changed from 3.5 parts by mass to 8.5 parts by mass, and the amount of polycarboxylic acid compound was changed from 0.02 parts by mass to 0.04 parts by mass.

[0132] <Production Example of Electrophotographic Photoreceptor 5> Electrophotographic photoreceptor 5 was produced in the same manner as in the production example of electrophotographic photoreceptor 1, except that the amount of hole transport material A-1 contained in the surface layer was changed from 10.0 parts by mass to 8.5 parts by mass, the amount of alumina particles was changed from 3.5 parts by mass to 0.9 parts by mass, and the amount of polycarboxylic acid compound was changed from 0.02 parts by mass to 0.01 parts by mass.

[0133] <Production Example of Electrophotographic Photoreceptor 6> Electrophotographic photoreceptor 6 was produced in the same manner as in the production example of electrophotographic photoreceptor 1, except that the amount of hole transport material A-1 contained in the surface layer was changed from 10.0 parts by mass to 15.0 parts by mass, the amount of alumina particles was changed from 3.5 parts by mass to 10.7 parts by mass, and the amount of polycarboxylic acid compound was changed from 0.02 parts by mass to 0.05 parts by mass.

[0134] <Production Example of Electrophotographic Photoreceptor 7> Electrophotographic photoreceptor 7 was produced in the same manner as in the production example of electrophotographic photoreceptor 1, except that the amount of hole transport material A-1 contained in the surface layer was changed from 10.0 parts by mass to 15.0 parts by mass, the amount of alumina particles was changed from 3.5 parts by mass to 1.5 parts by mass, and the amount of polycarboxylic acid compound was changed from 0.02 parts by mass to 0.01 parts by mass.

[0135] <Production Example of Electrophotographic Photoreceptor 8> Electrophotographic photoreceptor 8 was manufactured in the same manner as in the manufacturing example of electrophotographic photoreceptor 1, except that the binder resin (viscosity average molecular weight 40,000) having a repeating structure of B-1 contained in the surface layer was changed from 0.6 parts by mass to 0.0 parts by mass, and the binder resin (viscosity average molecular weight 50,000) having a repeating structure of B-2 was changed from 9.4 parts by mass to 10.0 parts by mass.

[0136] <Production Example of Electrophotographic Photoreceptor 9> An electrophotographic photoreceptor 9 was produced in the same manner as in the production example of the electrophotographic photoreceptor 1, except that the polycarboxylic acid compound contained in the surface layer was changed to γ-glycidoxypropylmethyldiethoxysilane, which is a silane coupling agent.

[0137] <Production Example of Electrophotographic Photoreceptor 10> Electrophotographic photoreceptor 10 was manufactured in the same manner as in the manufacturing example of electrophotographic photoreceptor 1, except that the amount of hole transport material A-1 contained in the surface layer was changed from 10.0 parts by mass to 7.5 parts by mass, and alumina particles and a polycarboxylic acid compound were not added.

[0138] <Production Example of Electrophotographic Photoreceptor 11> An electrophotographic photoreceptor 11 was produced in the same manner as in the production example of the electrophotographic photoreceptor 1, except that the alumina particles and polycarboxylic acid compound contained in the surface layer were not added.

[0139] <Production Example of Electrophotographic Photoreceptor 12> Electrophotographic photoreceptor 12 was manufactured in the same manner as in the manufacturing example of electrophotographic photoreceptor 1, except that the amount of hole transport material A-1 contained in the surface layer was changed from 10.0 parts by mass to 5.0 parts by mass, and alumina particles and a polycarboxylic acid compound were not added.

[0140] The electrophotographic photoreceptors 1 to 12 thus produced are shown in Tables 1 and 2. [Table 1]

[0141] [Table 2]

[0142] [Examples of toner particle, toner, and developer production] <Method for measuring the softening point of resin> The softening point of a resin is measured using a constant-load extrusion capillary rheometer (product name: Flow Property Evaluation Flow Tester CFT-500D, manufactured by Shimadzu Corporation) according to the manual that comes with the device. With this device, a constant load is applied from above the measurement sample using a piston, while the measurement sample filled in a cylinder is heated and melted, and the molten measurement sample is extruded from a die at the bottom of the cylinder, allowing a flow curve to be obtained that shows the relationship between the piston's descent amount and temperature. The softening point is the "melting temperature in the 1 / 2 method" described in the manual attached to the "Flow Tester CFT-500D, a flow property evaluation device." The melting temperature in the 1 / 2 method is calculated as follows: First, half of the difference between the amount of piston descent at the end of outflow (Smax) and the amount of piston descent at the start of outflow (Smin) is calculated (this is called X; X = (Smax - Smin) / 2). The temperature at which the amount of piston descent on the flow curve is the sum of X and Smin is the melting temperature in the 1 / 2 method. The measurement sample is prepared by compressing approximately 1.0 g of resin at 25°C using a tablet press (e.g., NT-100H, manufactured by NPA Systems Co., Ltd.) at approximately 10 MPa for approximately 60 seconds to form a cylindrical sample with a diameter of approximately 8 mm. The measurement conditions for the CFT-500D are as follows: Test mode: Temperature rising method Starting temperature: 50℃ Achieved temperature: 200℃ Measurement interval: 1.0℃ Heating rate: 4.0°C / min Piston cross-sectional area: 1.000cm 2 Test load (piston load): 10.0 kgf / cm 2 (0.9807MPa) Preheat time: 300 seconds Die hole diameter: 1.0mm Die length: 1.0mm

[0143] [Resin 1 manufacturing example] A reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube was charged with 100 parts of a propylene oxide adduct of bisphenol A (average number of moles added: 2.2 moles), 21 parts of recovered polyethylene terephthalate (diethylene glycol content = 1.3% by mass), and 0.08 parts of dibutyltin oxide under a nitrogen atmosphere. The reaction vessel was heated to 230 ° C while stirring at 200 rpm, and the reaction was carried out for 7 hours. The mixture was then cooled to 180 ° C, and 30 parts of fumaric acid and 0.08 parts of hydroquinone were added, followed by heating to 210 ° C over 4 hours. The pressure was then reduced to 8 kPa and the reaction was continued until the softening point reached 103 ° C, yielding Resin 1.

[0144] [Resin 2 manufacturing example] A reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube was charged with 100 parts of a propylene oxide adduct of bisphenol A (average number of moles added: 2.2 moles), 40 parts of an ethylene oxide adduct of bisphenol A (average number of moles added: 2.2 moles), 13 parts of dodecenyl succinic anhydride, 37 parts of terephthalic acid, 12 parts of trimellitic anhydride, and 0.5 parts of dibutyltin oxide under a nitrogen atmosphere. The reaction vessel was heated to 235 ° C. while stirring at 200 rpm, and the reaction was carried out for 4 hours. The pressure was then reduced to 8 kPa and the reaction was continued until the softening point reached 146 ° C., yielding Resin 2.

[0145] [Production example of toner particle 1] 170 parts resin 30 parts of resin 2 Colorant: 5 parts ECB-301 (Dainichi Seika Chemicals Co., Ltd., CI Pigment Blue 15:3) Charge control agent LR-147 (manufactured by Nippon Carlit Co., Ltd.) 1 part Release agent NP-105 (Mitsui Chemicals, melting point: 140°C) 4 parts The above materials were mixed in a Henschel mixer (FM-75 model, manufactured by Nippon Coke & Engineering Co., Ltd.) at a rotation speed of 20 s -1After mixing for 5 minutes, the mixture was kneaded at a discharge temperature of 135°C in a twin-screw kneader (PCM-30, manufactured by Ikegai Corporation) set at a temperature of 120°C and a screw rotation speed of 200 rpm. The resulting kneaded mixture was cooled at a cooling rate of 15°C / min and coarsely pulverized to 1 mm or less using a hammer mill to obtain a coarsely pulverized product. The resulting coarsely pulverized product was finely pulverized using a mechanical pulverizer (T-250, manufactured by Freund Turbo Corporation). It was further classified using a Faculty F-300 (manufactured by Hosokawa Micron Corporation) to obtain toner particles 1. The operating conditions were a classifying rotor rotation speed of 130 s -1 , distributed rotor rotation speed 120s -1 It was decided.

[0146] [Toner 1 manufacturing example] The following materials were mixed in a Henschel mixer FM-10C (manufactured by Mitsui Miike Chemical Engineering Co., Ltd.) at a rotation speed of 30 s −1 for a rotation time of 10 min to obtain Toner 1. 100 parts of toner particles External additive 1 Aerosil R-972 (manufactured by Nippon Aerosil Co., Ltd., average particle size 16 nm) 1.0 part External additive 2 SI-Y (manufactured by Nippon Aerosil Co., Ltd., average particle size 40 nm) 1.0 part

[0147] [Magnetic Carrier 1 Manufacturing Example] Magnetite with a number-average particle size of 0.30 μm and a magnetization strength of 65 Am2 / kg under a magnetic field of 1000 / 4π (kA / m) Magnetite2 with a number average particle size of 0.50 μm and a magnetization strength of 65 Am2 / kg under a magnetic field of 1000 / 4π (kA / m) To 100 parts of each of the above materials, 4.0 parts of a silane compound (3-(2-aminoethylaminopropyl)trimethoxysilane) was added, and the mixture was mixed and stirred at high speed in a container at 100° C. or higher to treat each of the fine particles. Phenol: 10% by weight Formaldehyde solution: 6% by mass (Formaldehyde 40% by mass, methanol 10% by mass, water 50% by mass) Magnetite treated with the above silane compound 1: 58 mass% Magnetite 2 treated with the above silane compound: 26% by mass 100 parts of the above material, 5 parts of a 28% by mass aqueous ammonia solution, and 20 parts of water were placed in a flask, and the temperature was raised to 85°C over 30 minutes while stirring and mixing, and the temperature was maintained for 3 hours to cause a polymerization reaction, and the resulting phenolic resin was cured. The cured phenolic resin was then cooled to 30°C, and water was added. The supernatant was removed, and the precipitate was washed with water and air-dried. This was then dried under reduced pressure (5 mmHg or less) at 60°C to obtain spherical magnetic carrier 1 with dispersed magnetic material. The volume-based 50% particle size (D50) of magnetic carrier 1 was 34 μm.

[0148] [Example of manufacturing developer 1] The following materials were mixed in a V-type mixer (V-20, manufactured by Seishin Enterprises) to obtain developer 1. 1 / 8 toner Magnetic carrier 1 92 parts

[0149] [Example 1] The produced electrophotographic photoreceptor 1 was mounted on the cyan station of a modified electrophotographic copying machine iR-ADV C5560F III manufactured by Canon Inc., and developer 1 was set in the developing machine as the developer.

[0150] [Evaluation 1: Sensitivity evaluation] The above electrophotographic apparatus was placed in a high temperature and high humidity (HH) environment of 32.5°C temperature and 85% humidity, and the primary charging setting was adjusted so that the initial dark potential of the electrophotographic photosensitive member was -700 V. In addition, the laser light intensity on the surface of the prepared electrophotographic photosensitive member was 3.5 mJ / m 2 The light potential (VL) was measured and used as the sensitivity. The sensitivity was evaluated as good when the initial bright area potential was −140 VL to −105 VL.

[0151] [Evaluation 2: Cleaning performance evaluation] The electrophotographic device and the prepared electrophotographic photoreceptor were left for three days in a 32.5°C / 85% humidity environment, after which the electrophotographic photoreceptor was mounted in the station of a magenta process cartridge. A test chart with an image ratio of 5% was printed on 50,000 sheets of A4 portrait size paper. A halftone image was then printed, and the image quality (presence or absence of vertical streaks) was evaluated as follows: A: No vertical streaks are visible. B: Minor vertical lines are visible under magnification. C: Faint vertical lines are visible. D: Clear vertical lines are visible.

[0152] [Examples 2 to 9, Comparative Examples 1 to 3] The electrophotographic apparatus was evaluated in the same manner as in Example 1, except that the types of electrophotographic photosensitive member and developer were changed as shown in Table 3. The evaluation results are shown in Table 3.

[0153] [Table 3]

[0154] [Toner Production Example 2] <Preparation of amorphous resin A1> Polyethylene terephthalate (molecular weight: 2000, intrinsic viscosity: 0.1) :20.9 parts (42.0mol%) Propylene oxide adduct of bisphenol A (average number of moles added: 2.0 mol) :47.4 parts (29.0mol%) Terephthalic acid: 15.8 parts (18.3 mol%) Dodecenyl succinic acid: 15.8 parts (10.6 mol%) Titanium tetrabutoxide (esterification catalyst): 0.5 parts Gallic acid (cocatalyst): 0.1 parts The above materials were weighed into a reaction vessel equipped with a cooling tube, a stirrer, a nitrogen inlet tube, and a thermocouple. The molar ratio of polyethylene terephthalate is the value of the number of units, which is the sum of the number of units derived from ethylene glycol and the number of units derived from terephthalic acid.

[0155] Next, the atmosphere in the flask was replaced with nitrogen gas, and the temperature was gradually raised with stirring, and the mixture was allowed to react for 2 hours at 200°C with stirring. The pressure in the reaction vessel was then reduced to 8.3 kPa, and the mixture was allowed to react for 5 hours while maintaining the temperature at 200°C. After confirming that the weight-average molecular weight had reached 6,700, the temperature was lowered to terminate the reaction, yielding an amorphous resin A1 having a polyethylene terephthalate segment in the molecule. The physical properties of the amorphous resin A1 obtained by the above-described measurement methods are shown in Table 4.

[0156] <Preparation of amorphous resins A2 to A11> Amorphous resins A2 to A11 each having a polyethylene terephthalate segment in the molecule were obtained by carrying out the reaction in the same manner as in the preparation of amorphous resin A1, except that the types and parts of polyethylene terephthalate and polymerizable monomers were changed as shown in Table 4. The physical properties of amorphous resins A2 to A11 obtained by the above-mentioned measurement methods are shown in Table 4.

[0157] [Table 4-1] [Table 4-2] The abbreviations in Tables 4-1 and 4-2 are as follows: BPA-PO: Propylene oxide adduct of bisphenol A (average number of moles added: 2.0 mol)

[0158] <Preparation of amorphous resin B1> Polyethylene terephthalate (molecular weight: 2000, intrinsic viscosity: 0.1) :4.1 parts (9.8mol%) Propylene oxide adduct of bisphenol A (average number of moles added: 2.0 mol) :57.8 parts (42.8mol%) Terephthalic acid: 29.9 parts (41.9 mol%) Trimellitic acid: 7.0 parts (4.5 mol%) Stearic acid: 1.2 parts (1.0 mol%) Titanium tetrabutoxide (esterification catalyst): 0.5 parts Gallic acid (cocatalyst): 0.1 parts The above materials were weighed and placed in a reaction vessel equipped with a condenser, a stirrer, a nitrogen inlet tube, and a thermocouple. Next, the atmosphere in the flask was replaced with nitrogen gas, and the temperature was gradually raised with stirring, and the mixture was allowed to react for 2 hours at 200°C with stirring.

[0159] The pressure in the reaction vessel was then lowered to 8.3 kPa, and the reaction was continued for 5 hours while maintaining the temperature at 200°C. After it was confirmed that the weight average molecular weight had reached 1000, the temperature was lowered to stop the reaction, yielding amorphous resin B1. The physical properties of amorphous resin B1 obtained by the above-mentioned measurement methods included an SP value of 11.54 (cal / cm 3 ) 0.5 It was.

[0160] <Preparation of Crystalline Polyester Resin C1> Ethylene glycol: 10.2 parts (48.2 mol%) Tetradecanedioic acid: 81.3 parts (48.3 mol%) Behenic acid: 8.5 parts (3.5 mol%) Titanium tetrabutoxide (esterification catalyst): 0.5 parts The above materials were weighed and placed in a reaction vessel equipped with a condenser, a stirrer, a nitrogen inlet tube, and a thermocouple. After the atmosphere in the flask was replaced with nitrogen gas, the temperature was gradually raised with stirring, and the mixture was allowed to react at 200°C for 2 hours with stirring. The pressure in the reaction vessel was then lowered to 8.3 kPa, and the reaction was continued for 5 hours while maintaining the temperature at 200°C. The temperature was then lowered to stop the reaction, yielding crystalline polyester resin C1. The physical properties of the crystalline polyester resin C1 obtained by the above-described measurement methods were as follows: SP value of 10.09 (cal / cm 3 ) 0.5 It was.

[0161] <Toner 2 manufacturing example> Amorphous resin A1: 66 parts ·Amorphous resin B1: 34 parts Crystalline polyester resin C1: 10 parts Fischer-Tropsch wax (maximum endothermic peak temperature 100°C): 5 parts Carbon black: 5 parts Trisodium phosphate: 0.03 parts The above materials were mixed using a Henschel mixer (FM-75, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 1500 rpm for 5 minutes, and then kneaded in a twin-screw kneader (PCM-30, manufactured by Ikegai Corporation) set at a temperature of 130°C. The resulting kneaded mixture was cooled and coarsely pulverized to 1 mm or less using a hammer mill to obtain a coarsely pulverized product. The coarsely pulverized product was then finely pulverized using a mechanical pulverizer (T-250, manufactured by Turbo Kogyo Co., Ltd.). Further, classification was performed using a Faculty (F-300, manufactured by Hosokawa Micron Corporation) to obtain toner particles 2. The operating conditions were a classifying rotor rotation speed of 11000 rpm and a dispersing rotor rotation speed of 7200 rpm. Toner particles 2:95 parts Large-diameter inorganic particles: 4 parts fumed silica surface-treated with hexamethyldisilazane (median diameter (D50) on a number basis of 120 nm) Small-diameter inorganic particles: 1 part titanium oxide particles surface-treated with isobutyltrimethoxysilane (median diameter (D50) on a number basis of 10 nm) The above materials were mixed in a Henschel mixer (FM-75 model, manufactured by Mitsui Miike Chemical Engineering Co., Ltd.) at a rotation speed of 1900 rpm for 10 minutes to obtain Toner 2 exhibiting negative charging properties. The physical properties of Toner 2 obtained by the above-mentioned measurement methods are shown in Table 5.

[0162] <Production examples of toners 3 to 19> Toners 2 to 19 were obtained in the same manner as in Production Example of Toner 2, except that the amorphous resin A and the types and parts of additives were changed as shown in Table 4. The physical properties of Toners 2 to 19 obtained by the above-mentioned measurement methods are shown in Table 5.

[0163] [Table 5] The abbreviations in Table 5 are as follows: PNa: trisodium phosphate

[0164] <Production Examples of Developers 2 to 19> Developers 2 to 19 were obtained in the same manner as in the production example of developer 1, except for the changes shown in Table 6.

[0165] [Table 6]

[0166] [Examples 10 to 27] The electrophotographic device was evaluated in the same manner as in Example 1, except that the types of electrophotographic photosensitive member and developer were changed as shown in Table 7. In addition, scratch resistance and low-temperature fixability were also evaluated by the methods described below. The evaluation results are shown in Table 7. The image forming apparatus used was a modified Canon imagePress C800 digital commercial printing printer, and two-component developer 2 was placed in the cyan developer. The modifications to the apparatus included the fixing temperature, process speed, and DC voltage V of the developer carrier. DC , the charging voltage V of the electrophotographic photosensitive member D The image output evaluation was carried out by outputting a FFh image (solid image) with the desired image ratio, and adjusting V so that the amount of toner on the FFh image on the paper was the desired amount. DC , V DThe scratch resistance and low-temperature fixability were evaluated after adjusting the laser power. FFh is a value expressed in hexadecimal as 256 gradations, with 00h being the first gradation of 256 gradations (white background) and FFh being the 256th gradation of 256 gradations (solid area).

[0167] [Scratch resistance] Paper: UPM FINESSE GLOSS 300GSM Toner amount on paper: 0.05 mg / cm 2 (2Fh image) (The amount of toner carried is determined by the DC voltage V DC , the charging voltage V of the electrophotographic photosensitive member D , and adjusted by laser power) Evaluation image: A 3m x 15cm image placed in the center of the A4 paper. Fixing test environment: Normal temperature and humidity environment (temperature 23°C / humidity 50% RH (hereinafter referred to as N / N)) Fixing temperature: 180℃ Process speed: 377 mm / sec The above evaluation image was printed and the scratch resistance was evaluated. Specifically, a HEIDON TYPE14FW surface tester manufactured by Shinto Scientific Co., Ltd. was used to place a 200g weight on the image and scratch it with a 0.75mm diameter needle at a speed of 60mm / min and a length of 30mm, and the scratch resistance was evaluated based on the scratches that appeared on the image. The area ratio of toner peeled off was calculated by binarizing the area where toner peeled off relative to the scratched area using image processing. (Evaluation criteria) A: 0.0% B: 0.1% or more and less than 0.4% C: 0.4% or more and less than 0.9% D: 0.9% or more and less than 1.1% E: 1.1% or more

[0168] [Low temperature fixability] Paper: GFC-081 (81.0g / m 2 ) (Sold by Canon Marketing Japan Inc.) Toner amount on paper: 0.50 mg / cm 2(The amount of toner carried is determined by the DC voltage V DC , the charging voltage V of the electrophotographic photosensitive member D , and adjusted by laser power) Evaluation image: A 2cm x 5cm image placed in the center of the A4 paper. Test environment: Low temperature and humidity environment: Temperature 15°C / Humidity 10% RH (hereinafter referred to as "L / L") Fixing temperature: 150℃ Process speed: 630 mm / sec The above evaluation image was output, and the low-temperature fixability was evaluated. The value of the rate of decrease in image density was used as an evaluation index for the low-temperature fixability. First, the image density at the center was measured using an X-Rite color reflection densitometer (500 series, manufactured by X-Rite). Next, the area where the image density was measured was subjected to a pressure of 4.9 kPa (50 g / cm). 2 The fixed image was rubbed (five times back and forth) with Silbon paper under a load of 1000 kJ / cm2, and the image density was measured again. The rate of decrease in image density before and after rubbing was calculated using the following formula. The obtained rate of decrease in image density was evaluated according to the following evaluation criteria. If the evaluation was A to C, it was judged to be good. Image density reduction rate (%) = (image density before friction - image density after friction) / image density before friction x 100 (Evaluation criteria) A: Image density reduction rate less than 3% B: Image density reduction rate: 3% to less than 5% C: Image density reduction rate: 5% to less than 8% D: Image density reduction rate: 8% or more but less than 10% E: Image density reduction rate 10% or more

[0169] [Table 7]

[0170] The toner used in the electrophotographic device of the present disclosure can use polyethylene terephthalate recycled from used PET bottles and the like as a toner material, and therefore the technology described in this specification can contribute to the realization of a sustainable society, such as a carbon-free / circular economy.

[0171] The disclosure of this embodiment includes the following configuration. (Configuration 1) an electrophotographic photoreceptor; a charging means for charging the surface of the electrophotographic photoreceptor; an image exposure means for irradiating the charged surface of the electrophotographic photosensitive member with image exposure light to form an electrostatic latent image on the surface of the electrophotographic photosensitive member; a developing means having a toner and for developing the electrostatic latent image with the toner to form a toner image on the surface of the electrophotographic photosensitive member; a transfer means for transferring the toner image from the surface of the electrophotographic photoreceptor to a transfer material; and a cleaning means for removing residual toner remaining on the surface of the electrophotographic photosensitive member after the toner image is transferred from the surface of the electrophotographic photosensitive member to a transfer material, the electrophotographic photoreceptor has a support, a charge generating layer, a first hole transport layer, and a second hole transport layer in this order; the second hole transport layer is a surface layer; the surface layer comprises a hole transport material represented by the following formula (A), a binder resin having a repeating structure represented by the following formula (B), and alumina particles as a metal oxide filler that have been surface-treated with at least one kind selected from a fatty acid and a silane coupling agent, the content of alumina particles in the surface layer is 10% to 100% based on the hole transport material in the surface layer; The content of the hole transport material is 85% to 150% based on the binder resin, and An electrophotographic apparatus, wherein the toner contained in the developing means has toner particles containing a polyester resin having a polyethylene terephthalate segment. [ka] (In formula (A), Ar 1 ~Ar 4 each independently represents a phenyl group or a phenyl group substituted with a methyl group. [ka] (In formula (B), R 5 ~R 8 each independently represents a hydrogen atom or a methyl group, and X 1 represents a methylene group, which may have an alkyl group or a phenyl group as a substituent, a cyclohexylidene group, an oxygen atom, or a single bond. (Configuration 2) The electrophotographic apparatus according to Configuration 1, wherein the content of the hole transport material and the binder resin contained in the surface layer is within the following ranges based on the mass of the surface layer: Hole transport material: 31% to 57% Binder resin: 28% to 52% (Configuration 3) 3. The electrophotographic device according to configuration 1 or 2, wherein the content of the hole transport material contained in the surface layer is 85% to 100% based on the binder resin, and the contents of the hole transport material and the binder resin are within the following ranges based on the mass of the surface layer: Hole transport material: 31% to 47% Binder resin: 35% to 52% (Configuration 4) 4. The electrophotographic apparatus according to any one of Configurations 1 to 3, wherein the fatty acid contained in the surface layer is a polycarboxylic acid compound. (Configuration 5) 5. The electrophotographic apparatus according to any one of configurations 1 to 4, wherein the silane coupling agent contained in the surface layer is γ-glycidoxypropylmethyldiethoxysilane. (Configuration 6) the toner has toner particles containing a binder resin, The binder resin contains an amorphous resin A and a crystalline polyester resin C, The amorphous resin A is a polyester resin, and the structure forming the polyester skeleton is (i) a polyethylene terephthalate segment, and (ii) at least one structure selected from the group consisting of a structure represented by the following formula (1), a structure represented by the following formula (2), a structure represented by the following formula (3), and a structure represented by the following formula (4): and [ka] (In formula (1), R 1 represents an alkyl group having 6 to 16 carbon atoms or an alkenyl group having 6 to 16 carbon atoms, A represents a hydrocarbon group, * represents a bonding site in the polyester skeleton, and m represents an integer of 2 or greater. [ka] (In formula (2), R 2 represents an alkyl group having 6 to 16 carbon atoms or an alkenyl group having 6 to 16 carbon atoms, B represents a hydrocarbon group, * represents a bonding site in the polyester skeleton, and n represents an integer of 2 or greater. [ka] (In formula (3), * represents a bond in the polyester skeleton, and x represents an integer of 6 to 16.) [ka] (In formula (4), * represents a bond in the polyester skeleton, and y represents an integer of 6 to 16.) The SP value of the amorphous resin A is SPA (cal / cm 3 ) 0.5 The SP value of the crystalline polyester resin C is SPC (cal / cm 3 ) 0.5 When the SPA and the SPC satisfy the following formula (C), 1.00≦SPA-SPC≦1.35 (C) The electrophotographic device according to any one of configurations 1 to 5, wherein the toner contains a phosphorus element derived from a phosphorus compound, and when the content of the phosphorus element in the toner is defined as WP (ppm) based on the mass of the toner, the WP satisfies the following formula (D): 5≦WP≦500 (D) (Configuration 7) 7. The electrophotographic apparatus according to Constitution 6, wherein the WP satisfies the following formula (E): 20≦WP≦500 (E) [Explanation of symbols]

[0172] 1. Electrophotographic photoreceptor 2. Charging means 3 Exposure light 4. Developing methods 5 Transfer Method 6 Transfer material 7 Pre-exposure light 8 Cleaning Method 9 Process cartridge 10 Intermediate transfer body 11 Transfer paper 12 Paper feed path 13 Paper tray 14 Secondary transfer means 15 Fixation Method 16 Paper output section 17 Yellow process cartridge 18 Magenta process cartridge 19 Cyan process cartridge 20 Black process cartridge 21 Support 22 Undercoat layer 23 Charge generation layer 24 First hole transport layer 25 Second hole transport layer (surface layer)

Claims

1. an electrophotographic photoreceptor; a charging means for charging the surface of the electrophotographic photoreceptor; an image exposure means for irradiating the charged surface of the electrophotographic photosensitive member with image exposure light to form an electrostatic latent image on the surface of the electrophotographic photosensitive member; a developing means having a toner and for developing the electrostatic latent image with the toner to form a toner image on the surface of the electrophotographic photosensitive member; a transfer means for transferring the toner image from the surface of the electrophotographic photoreceptor to a transfer material; a cleaning means for removing residual toner remaining on the surface of the electrophotographic photosensitive member after the toner image has been transferred from the surface of the electrophotographic photosensitive member to a transfer material; An electrophotographic apparatus having the electrophotographic photoreceptor has a support, a charge generating layer, a first hole transport layer, and a second hole transport layer in this order; the second hole transport layer is a surface layer; the surface layer comprises a hole transport material represented by the following formula (A), a binder resin having a repeating structure represented by the following formula (B), and alumina particles as a metal oxide filler that have been surface-treated with at least one kind selected from a fatty acid and a silane coupling agent, the content of alumina particles in the surface layer is 10% to 100% based on the hole transport material of the surface layer; The content of the hole transport material is 85% to 150% based on the binder resin, and the toner contained in the developing means has toner particles containing a polyester resin having a polyethylene terephthalate segment; Electrophotographic apparatus characterized by: 【Chemical 1】 (In formula (A), Ar １ ~Ar ４ each independently represents a phenyl group or a phenyl group substituted with a methyl group. 【Chemistry 2】 (In formula (B), R ５ ~R ８ each independently represents a hydrogen atom or a methyl group, and X1 represents a methylene group which may have an alkyl group or a phenyl group as a substituent, a cyclohexylidene group, an oxygen atom, or a single bond.

2. 2. The electrophotographic apparatus according to claim 1, wherein the content of the hole transport material and the binder resin contained in the surface layer is within the following ranges based on the mass of the surface layer: Hole transport material: 31% to 57% Binder resin: 28% to 52%

3. 2. The electrophotographic apparatus according to claim 1, wherein the content of the hole transport material contained in the surface layer is 85% to 100% based on the binder resin, and the contents of the hole transport material and the binder resin are within the following ranges based on the mass of the surface layer: Hole transport material: 31% to 47% Binder resin: 35% to 52%

4. 2. The electrophotographic apparatus according to claim 1, wherein the fatty acid contained in the surface layer is a polycarboxylic acid compound.

5. 2. The electrophotographic apparatus according to claim 1, wherein the silane coupling agent contained in the surface layer is γ-glycidoxypropylmethyldiethoxysilane.

6. the toner has toner particles containing a binder resin, The binder resin contains an amorphous resin A and a crystalline polyester resin C, The amorphous resin A is a polyester resin, and the structure forming the polyester skeleton is (i) a polyethylene terephthalate segment, and (ii) having at least one structure selected from the group consisting of a structure represented by the following formula (1), a structure represented by the following formula (2), a structure represented by the following formula (3), and a structure represented by the following formula (4), 【Chemistry 3】 (In formula (1), R １ represents an alkyl group having 6 to 16 carbon atoms or an alkenyl group having 6 to 16 carbon atoms, A represents a hydrocarbon group, * represents a bonding site in the polyester skeleton, and m represents an integer of 2 or greater. 【Chemistry 4】 (In formula (2), R ２ represents an alkyl group having 6 to 16 carbon atoms or an alkenyl group having 6 to 16 carbon atoms, B represents a hydrocarbon group, * represents a bonding site in the polyester skeleton, and n represents an integer of 2 or greater. 【Chemistry 5】 (In formula (3), * represents a bond in the polyester skeleton, and x represents an integer of 6 to 16.) 【Chemistry 6】 (In formula (4), * represents a bond in the polyester skeleton, and y represents an integer of 6 to 16.) The SP value of the amorphous resin A is expressed as SPA (cal / cm ３ ) ０．５ The SP value of the crystalline polyester resin C is SPC (cal / cm ３ ) ０．５ When the SPA and the SPC satisfy the following formula (C), 1.00≦SPA-SPC≦1.35...(C) The electrophotographic device according to any one of claims 1 to 5, wherein the toner contains a phosphorus element derived from a phosphorus compound, and when the content of the phosphorus element in the toner is defined as WP (ppm) based on the mass of the toner, the WP satisfies the following formula (D): 5≦WP≦500...(D)

7. 7. The electrophotographic apparatus according to claim 6, wherein the WP satisfies the following formula (E): 20≦WP≦500...(E)

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