JP2023118072A - Electrophotographic photoreceptor, process cartridge, electrophotographic device, and method of manufacturing electrophotographic photoreceptor - Google Patents

Abstract

To provide an electrophotographic photoreceptor comprising a surface layer that suppresses electric potential variations associated with repetitive use.SOLUTION: An electrophotographic photoreceptor is provided, comprising a surface layer containing fluorine atom-containing resin particles, a binding material, perfluorohexanoic acid, and a charge transport substance. Content of the perfluorohexanoic acid in the surface layer is in a range of 0.010 to 25 mass ppb, inclusive, with respect to the fluorine atom-containing resin particles in the surface layer. The charge transport substance is a compound with a specific structure.SELECTED DRAWING: None

Description

The present disclosure relates to an electrophotographic photoreceptor, a process cartridge having the electrophotographic photoreceptor, an electrophotographic apparatus, and a method for manufacturing the electrophotographic photoreceptor.

As an electrophotographic photoreceptor mounted in an electrophotographic apparatus, one containing an organic photoconductive substance (charge-generating substance) is widely used. In recent years, for the purpose of extending the life of electrophotographic photoreceptors and improving image quality during repeated use, improvements in mechanical durability (wear resistance) of electrophotographic photoreceptors, suppression of environmental fluctuations, suppression of deterioration in electrical properties, etc. , improvement in the characteristics of various electrophotographic photoreceptors is required.

As a technique for improving the abrasion resistance of an electrophotographic photoreceptor, there is a method of adding fluorine atom-containing resin particles as a lubricant to the surface layer of the electrophotographic photoreceptor to reduce the friction between the surface layer and the cleaning blade. Patent Document 1 discloses a technique of forming a surface layer using a dispersion liquid of fluorine atom-containing resin particles such as polytetrafluoroethylene resin particles as a surface layer coating liquid.
Patent Document 2 discloses an electrophotographic photoreceptor that has a surface layer containing a carboxylic acid compound as an acidic compound to suppress environmental differences in residual potential.
Patent Document 3 discloses an electrophotographic photoreceptor that has a surface layer containing a charge-transporting material having three butadiene structures in one molecule, thereby suppressing deterioration of electrical properties and reducing residual potential. there is

JP-A-06-332219 JP 2021-96343 A JP 2013-47751 A

However, when the techniques disclosed in Patent Document 2 and Patent Document 3 are used simultaneously, potential fluctuation during repeated use may increase. As a result of studies by the present inventors, it was found that an electrophotographic photoreceptor containing both perfluorohexanoic acid, which is a kind of carboxylic acid compound, and a charge-transporting substance having a butadiene structure in the surface layer, does not exhibit potential fluctuations during long-term repeated use. was found to increase. Therefore, there is room for improvement in suppressing potential fluctuations during repeated use of the electrophotographic photosensitive member.

One aspect of the present disclosure is directed to providing an electrophotographic photoreceptor having a surface layer in which potential fluctuation is suppressed during repeated use.
Another aspect of the present disclosure is directed to providing a process cartridge equipped with the electrophotographic photoreceptor, and an electrophotographic apparatus including the process cartridge.
Another aspect of the present disclosure is directed to providing a method for manufacturing the electrophotographic photoreceptor.

（式（１）中、Ｒ^１１、Ｒ^１２、Ｒ^１３、Ｒ^１４、Ｒ^１５、及びＲ^１６は、それぞれ独立に、水素原子、メチル基、又はメトキシ基を示す。）
また、本開示の他の態様によれば、前記電子写真感光体と、帯電手段、現像手段及びクリーニング手段からなる群より選ばれた少なくとも１つの手段と、を一体に支持し、電子写真装置本体に着脱自在であるプロセスカートリッジが提供される。
また、本開示の他の態様によれば、前記電子写真感光体、帯電手段、露光手段、現像手段及び転写手段を有する電子写真装置が提供される。
また、本開示の他の態様によれば、前記電子写真感光体の製造方法が提供される。 According to one aspect of the present disclosure, it has a surface layer, the surface layer contains fluorine atom-containing resin particles, a binder material, perfluorohexanoic acid, and a charge transport substance, and the surface layer is 0.010 mass ppb or more and 25 mass ppb or less with respect to the content of the fluorine atom-containing resin particles in the surface layer, and the charge transport material has the following formula (1 ), an electrophotographic photoreceptor is provided.

(In formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ each independently represent a hydrogen atom, a methyl group or a methoxy group.)
According to another aspect of the present disclosure, the electrophotographic photosensitive member and at least one means selected from the group consisting of charging means, developing means, and cleaning means are integrally supported, and an electrophotographic apparatus main body is provided. A process cartridge is provided that is detachable from the.
Further, according to another aspect of the present disclosure, there is provided an electrophotographic apparatus including the electrophotographic photoreceptor, charging means, exposure means, developing means and transfer means.
Further, according to another aspect of the present disclosure, there is provided a method for manufacturing the electrophotographic photoreceptor.

Further, according to one aspect of the present disclosure, it has a surface layer, and the surface layer comprises at least one selected from fluorine atom-containing resin particles, a binder material, and a raw material of the binder material, and perfluorohexane. A layer formed from a coating film of a coating liquid containing an acid and a charge-transporting substance, wherein the content of the perfluorohexanoic acid in the coating liquid is greater than the fluorine atom-containing resin particles in the coating liquid. is 0.010 mass ppb or more and 25 mass ppb or less, and the charge transport material is a compound represented by the above formula (1).

Further, according to one aspect of the present disclosure, there is provided a method for manufacturing an electrophotographic photoreceptor having a surface layer, wherein the manufacturing method comprises a step (i) of suppressing perfluorohexanoic acid adhering to fluorine atom-containing resin particles. , a fluorine atom-containing resin particle, at least one selected from a binder material and raw materials of the binder material, perfluorohexanoic acid, and a charge-transporting substance represented by the above formula (1). and a step of forming the surface layer by forming a coating film of the coating liquid prepared in the step (ii) and drying and/or curing the coating film (iii ), and the content of perfluorohexanoic acid in the coating liquid prepared in the step (ii) is 0.010 mass ppb or more and 25 mass ppb or less with respect to the fluorine atom-containing resin particles in the coating liquid. A method for manufacturing an electrophotographic photoreceptor is provided.

According to one aspect of the present disclosure, it is possible to provide an electrophotographic photoreceptor having a surface layer in which potential fluctuation is suppressed during repeated use.

1 is a schematic diagram showing an example of the configuration of an electrophotographic photoreceptor of the present disclosure; FIG. 1 is a diagram showing an example of a process cartridge provided with an electrophotographic photoreceptor of the present disclosure; FIG. 1 is a diagram showing an example of an electrophotographic apparatus provided with the electrophotographic photoreceptor of the present disclosure; FIG.

The present disclosure will be described in detail below with reference to preferred embodiments.
As a result of investigations by the present inventors, as a conventional technique, an electrophotographic photoreceptor containing both perfluorohexanoic acid, which is a type of carboxylic acid compound, and a charge transport material having a butadiene structure in its surface layer, has been found to It became clear that a technical problem of large potential fluctuation occurred.
As a result of studies by the present inventors, the surface layer of the electrophotographic photosensitive member contains fluorine atom-containing resin particles, a binder material, and perfluorohexanoic acid in an amount of 0.010 mass ppb or more and 25 mass ppb relative to the fluorine atom-containing resin particles. It has been found that an electrophotographic photoreceptor having a surface layer in which potential fluctuation is suppressed during long-term repeated use can be obtained by containing the charge transport material represented by formula (1) below.

The present inventors speculate as follows about the reason why the surface layer of the present disclosure is excellent in the effect of suppressing potential fluctuations during long-term repeated use.
Fluorine atom-containing resin particles may produce perfluorohexanoic acid as a by-product during the production process. Therefore, perfluorohexanoic acid is often attached to the fluorine atom-containing resin particles. An electrophotographic photoreceptor having a surface layer containing this perfluorohexanoic acid and the charge transporting substance represented by formula (1) has a large potential fluctuation after repeated use. This is probably because perfluorohexanoic acid contained in the surface layer inhibits charge transport of the charge transport material represented by formula (1).

As a result of studies by the present inventors, it was found that suppressing perfluorohexanoic acid to an appropriate amount produces an effect of suppressing potential fluctuations. As a result of further studies by the present inventors, it was found that by setting the content of perfluorohexanoic acid to the fluorine atom-containing resin particles within the range of 0.010 mass ppb or more and 25 mass ppb or less, the potential fluctuation suppressing effect We have found that an excellent electrophotographic photoreceptor can be obtained. This potential fluctuation suppressing effect is influenced by the positional relationship in the surface layer of the fluorine atom-containing resin particles, perfluorohexanoic acid, and the charge transport material represented by formula (1), which are contained in the surface layer of the electrophotographic photosensitive member. I'm assuming that. That is, perfluorohexanoic acid has a function of inhibiting charge transport with respect to the charge transport material represented by formula (1). Therefore, by suppressing the amount of perfluorohexanoic acid contained in the surface layer and making it difficult for perfluorohexanoic acid to exist around the charge transport material represented by formula (1), the charge due to perfluorohexanoic acid It is believed that the effect of transport inhibition was reduced, and a surface layer excellent in suppressing potential fluctuations was obtained.
When the content of perfluorohexanoic acid is greater than 25 mass ppb relative to the fluorine atom-containing resin particles, a certain amount or more of perfluorohexanoic acid is present around the charge transport material represented by formula (1). It is assumed that the effect of suppressing the potential fluctuation is reduced by this.

It is believed that the effects of the present disclosure can be achieved by synergistic effects of each configuration like the mechanism described above.

<Electrophotographic photoreceptor>
FIG. 1 shows an example of the layer structure of the electrophotographic photoreceptor of the present disclosure. In FIG. 1, an undercoat layer 102, a charge generation layer 103, and a charge transport layer 104 are laminated on a support 101. FIG. The photosensitive layer may be composed of a laminated photosensitive layer having a charge generation layer and a charge transport layer, or may be composed of a single layer type photosensitive layer containing a charge generation substance and a charge transport substance. Moreover, a protective layer may be further provided on the charge transport layer 104 .

In the present invention, the outermost layer of the electrophotographic photoreceptor is defined as the surface layer.
As a method for producing the electrophotographic photoreceptor of the present disclosure, there is a method of preparing a coating solution for each layer described later, coating desired layers in order, and drying. At this time, the method of applying the coating liquid includes dip coating, spray coating, inkjet coating, roll coating, die coating, blade coating, curtain coating, wire bar coating, ring coating, and the like. Among these, dip coating is preferable from the viewpoint of efficiency and productivity.

Each layer will be described below.
<Support>
The electrophotographic photoreceptor of the present disclosure preferably has a support. The support of the electrophotographic photosensitive member is preferably conductive (conductive support). Further, the shape of the support includes a cylindrical shape, a belt shape, a sheet shape, and the like. Among them, a cylindrical support is preferable. Further, the surface of the support may be subjected to electrochemical treatment such as anodization, blasting treatment, cutting treatment, and the like.
The material of the support is preferably metal, resin, glass, or the like.
Examples of metals include aluminum, iron, nickel, copper, gold, stainless steel, and alloys thereof. Among them, an aluminum support using aluminum is preferable.
In addition, it is preferable to impart conductivity to the resin or glass by treatment such as mixing or coating with a conductive material.

<Conductive layer>
A conductive layer may be provided on the support. By providing the conductive layer, it is possible to cover scratches and irregularities on the surface of the support and to control reflection of light on the surface of the support.
The conductive layer preferably contains conductive particles and a resin.
Materials for the conductive particles include metal oxides, metals, and carbon black.
Metal oxides include zinc oxide, aluminum oxide, indium oxide, silicon oxide, zirconium oxide, tin oxide, titanium oxide, strontium titanate, magnesium oxide, antimony oxide, and bismuth oxide. Metals include aluminum, nickel, iron, nichrome, copper, zinc, silver and the like.
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, and zinc oxide particles.
When metal oxide particles are used as the conductive particles, the surface 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 an element such as phosphorus or aluminum or an oxide thereof. good.
Also, the conductive particles may have a laminated structure including core particles and a coating layer that covers the particles. The core material particles include titanium oxide particles, barium sulfate particles, zinc oxide particles, and the like. The coating layer includes metal oxide particles such as tin oxide.
When metal oxide particles are used as the conductive particles, the volume average particle diameter is preferably 1 nm or more and 500 nm or less, more preferably 3 nm or more and 400 nm or less.
Examples of resins include polyester resins, polycarbonate resins, polyvinyl acetal resins, acrylic resins, silicone resins, epoxy resins, melamine resins, polyurethane resins, phenol resins, and alkyd resins.
In addition, the conductive layer may further contain silicone oil, resin particles, masking agents, and the like. Examples of the masking material include titanium oxide.
The conductive layer can be formed by preparing a conductive layer coating solution containing each of the above materials and a solvent, forming this coating film on a support, and drying the coating film. Solvents used in the conductive layer coating liquid include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, aromatic hydrocarbon solvents and the like. Examples of the dispersion method for dispersing the conductive particles in the conductive layer coating liquid include methods using a paint shaker, a sand mill, a ball mill, and a liquid collision type high-speed disperser.
The average film 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.

<Undercoat layer>
In the present disclosure, a subbing layer may be provided over the support or conductive layer. By providing the undercoat layer, the adhesion function between the layers is enhanced, and the charge injection blocking function can be imparted.
The undercoat layer preferably contains a resin. Alternatively, the undercoat layer may be formed as a cured film by polymerizing a composition containing a monomer having a polymerizable functional group.
Examples of resins include polyester resins, polycarbonate resins, polyvinyl acetal resins, acrylic resins, epoxy resins, melamine resins, polyurethane resins, phenol resins, polyvinyl phenol resins, alkyd resins, polyvinyl alcohol resins, polyethylene oxide resins, polypropylene oxide resins, and polyamide resins. , polyamic acid resins, polyimide resins, polyamideimide resins, cellulose resins, and the like.
The polymerizable functional group possessed by the monomer having a polymerizable functional group includes 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 carboxyl group, a thiol group, Carboxylic anhydride groups, carbon-carbon double bond groups, and the like.

In addition, the undercoat layer may further contain an electron-transporting material, metal oxide particles, metal particles, a conductive polymer, or the like, for the purpose of enhancing electrical properties. Among these, it is preferable to use electron transport substances and metal oxide particles.
Examples of electron-transporting substances include quinone compounds, imide compounds, benzimidazole compounds, cyclopentadienylidene compounds, fluorenone compounds, xanthone compounds, benzophenone compounds, cyanovinyl compounds, halogenated aryl compounds, silole compounds, and boron-containing compounds. . An electron transporting substance having a polymerizable functional group may be used as the electron transporting substance, and an undercoat layer may be formed as a cured film by copolymerizing the electron transporting substance with the above-mentioned monomer having a polymerizable functional group.
Metal oxide particles include particles of indium tin oxide, tin oxide, indium oxide, titanium oxide, strontium titanate, zinc oxide, aluminum oxide, and the like. Particles of silicon dioxide can also be used. Metal particles include particles of gold, silver, aluminum, and the like.

The metal oxide particles contained in the undercoat layer may be subjected to surface treatment using a surface treatment agent such as a silane coupling agent.
A common method is used for the surface treatment of the metal oxide particles. For example, a dry method and a wet method are mentioned.
In the dry method, an alcohol aqueous solution, an organic solvent solution, or an aqueous solution containing a surface treatment agent is added while stirring the metal oxide particles in a mixer capable of high-speed stirring such as a Henschel mixer to uniformly disperse them. It will be dried later.
In the wet method, the metal oxide particles and the surface treatment agent are stirred in a solvent or dispersed in a sand mill using glass beads or the like. After dispersion, the solvent can be removed by filtration or distillation under reduced pressure. done. After removing the solvent, baking is preferably performed at 100° C. or higher.

The undercoat layer may further contain additives, for example, known materials such as metal particles such as aluminum particles, conductive particles such as carbon black, charge transport substances, metal chelate compounds, and organometallic compounds. can be included.
The undercoat layer can be formed by preparing an undercoat layer coating solution containing each of the above materials and a solvent, forming this coating film on a support or a conductive layer, and drying and/or curing it. can.
Solvents used in the undercoat layer coating solution include organic solvents such as alcohols, sulfoxides, ketones, ethers, esters, aliphatic halogenated hydrocarbons, and aromatic compounds. In the present disclosure, alcohol-based or ketone-based solvents are preferably used.
Dispersion methods for preparing the undercoat layer coating liquid include methods using a homogenizer, an ultrasonic disperser, a ball mill, a sand mill, a roll mill, a vibration mill, an attritor, and a liquid collision type high-speed disperser.
The average film thickness of the undercoat layer is preferably from 0.1 μm to 50 μm, more preferably from 0.2 μm to 40 μm, and particularly preferably from 0.3 μm to 30 μm.

<Photosensitive layer>
The photosensitive layer of an electrophotographic photoreceptor is mainly classified into (1) a laminated photosensitive layer and (2) a single-layer photosensitive layer. (1) The laminated photosensitive layer is a photosensitive layer having a charge generation layer containing a charge generation substance and a charge transport layer containing a charge transport substance. (2) The single-layer type photosensitive layer is a photosensitive layer containing both a charge-generating substance and a charge-transporting substance.

(1) Laminated photosensitive layer The laminated photosensitive layer has a charge generation layer and a charge transport layer.

(1-1) Charge Generation Layer The charge generation layer preferably contains a charge generation substance and a resin.
Examples of charge-generating substances include azo pigments, perylene pigments, polycyclic quinone pigments, indigo pigments, and phthalocyanine pigments. Among these, azo pigments and phthalocyanine pigments are preferred. Among the phthalocyanine pigments, oxytitanium phthalocyanine pigments, chlorogallium phthalocyanine pigments, and hydroxygallium phthalocyanine pigments are preferred.
The content of the charge-generating substance in the charge-generating layer is preferably 40% by mass or more and 85% by mass or less, more preferably 60% by mass or more and 80% by mass or less, relative to the total mass of the charge-generating layer. preferable.
Resins include polyester resins, polycarbonate resins, polyvinyl acetal resins, polyvinyl butyral resins, acrylic resins, silicone resins, epoxy resins, melamine resins, polyurethane resins, phenol resins, polyvinyl alcohol resins, cellulose resins, polystyrene resins, and polyvinyl acetate resins. , polyvinyl chloride resin, and the like. Among these, polyvinyl butyral resin is more preferable.
The charge generation layer may further contain additives such as antioxidants and UV absorbers. Specific examples include hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, and the like.
The charge-generating layer can be formed by preparing a charge-generating layer coating solution containing each of the above materials and a solvent, forming this coating film on the undercoat layer, and drying it. Solvents used in the coating liquid include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, aromatic hydrocarbon solvents and the like.
The average film thickness of the charge generation layer is preferably 0.1 μm or more and 1 μm or less, more preferably 0.15 μm or more and 0.4 μm or less.

(1-2) Charge Transport Layer The charge transport layer preferably contains a charge transport material and a resin.
Examples of charge-transporting substances include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, triarylamine compounds, and resins having groups derived from these substances. Among these, triarylamine compounds are preferred.
The content of the charge transport substance in the charge transport layer is preferably 25% by mass or more and 70% by mass or less, more preferably 30% by mass or more and 55% by mass or less, relative to the total mass of the charge transport layer. preferable.
Examples of resins include polycarbonate resins, polyarylate resins, acrylic resins, and polystyrene resins. Among these, thermoplastic resins are preferred, and polycarbonate resins and polyarylate resins are particularly preferred.
The content ratio (mass ratio) of the charge transport substance and the resin is preferably 4:10 to 20:10, more preferably 5:10 to 12:10.

The charge transport layer may also contain additives such as antioxidants, ultraviolet absorbers, plasticizers, leveling agents and lubricants. 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, boron nitride particles, and fluororesin particles.
The charge transport layer can be formed by preparing a charge transport layer coating solution containing each of the above materials and a solvent, forming this coating film on the charge generation layer, and drying the coating film. Solvents used in the coating liquid include alcohol solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents. Among these solvents, ether solvents and aromatic hydrocarbon solvents are preferred.
The average film thickness of the charge transport layer is preferably 5 μm or more and 50 μm or less, more preferably 20 μm or more and 40 μm or less.

(2) Single-layer type photosensitive layer A single-layer type photosensitive layer is prepared by preparing a photosensitive layer coating solution containing a charge generating substance, a charge transporting substance, a resin and a solvent, and forming this coating film on the undercoat layer, It can be formed by drying. The charge-generating substance, charge-transporting substance, and resin are the same as those exemplified in the above “(1) Laminated photosensitive layer”.

<Protective layer>
In the present disclosure, a protective layer may be provided over the photosensitive layer. Durability can be improved by providing a protective layer.
The protective layer preferably contains a charge-transporting substance and further contains a resin.
The protective layer may also contain conductive particles, and examples of the conductive particles include particles of metal oxides such as titanium oxide, zinc oxide, tin oxide, and indium oxide.
Charge-transporting substances include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, benzidine compounds, triarylamine compounds, and resins having groups derived from these substances. Among these, triarylamine compounds and benzidine compounds are preferred.
Examples of resins include polyester resins, acrylic resins, phenoxy resins, polycarbonate resins, polystyrene resins, phenol resins, melamine resins, and epoxy resins. Among them, polycarbonate resins, polyester resins, and acrylic resins are preferred.
Alternatively, the protective layer may be formed as a cured film by polymerizing a composition containing a monomer having a polymerizable functional group. The reaction at that time includes thermal polymerization reaction, photopolymerization reaction, radiation polymerization reaction, and the like. The polymerizable functional group possessed by the monomer having a polymerizable functional group includes 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 carboxyl group, a thiol group, A carboxylic acid anhydride group, a group containing a carbon-carbon double bond, and the like can be mentioned. Groups containing carbon-carbon double bonds include, for example, acryloyl groups and methacryloyl groups. A material having charge transport ability may be used as the monomer having a polymerizable functional group.
The protective layer may contain additives such as an antioxidant, an ultraviolet absorber, a plasticizer, a leveling agent, a lubricating agent, and an abrasion resistance improver. Specifically, hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, siloxane-modified resins, silicone oils, fluororesin particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, boron nitride particles. etc.
The average film thickness of the protective layer is preferably 0.5 μm or more and 10 μm or less, and more preferably 1 μm or more and 7 μm or less.
The protective layer can be formed by preparing a protective layer coating solution containing each of the materials and solvents described above, forming a coating film, and drying and/or curing the coating film. Solvents used in the coating liquid include alcohol solvents, ketone solvents, ether solvents, sulfoxide solvents, ester solvents, and aromatic hydrocarbon solvents.

（式（１）中、Ｒ^１１、Ｒ^１２、Ｒ^１３、Ｒ^１４、Ｒ^１５、及びＲ^１６は、それぞれ独立に、水素原子、メチル基、又はメトキシ基を示す。）
また、本開示の表面層は、フッ素原子含有樹脂粒子、結着材料及び結着材料の原料から選ばれる少なくともいずれか１つ、パーフルオロヘキサン酸、及び式（１）で示される電荷輸送物質を含有する塗布液の塗膜から形成された層である。 <Surface layer>
In the present disclosure, the outermost layer of the electrophotographic photoreceptor is defined as the surface layer.
In the case of the electrophotographic photoreceptor having the above laminated photosensitive layer, the charge transport layer or the protective layer is the surface layer. Further, in the case of the electrophotographic photoreceptor having the single-layer type photosensitive layer described above, the photosensitive layer or the protective layer is the surface layer.
The surface layer of the present disclosure contains fluorine atom-containing resin particles, a binding material, perfluorohexanoic acid, and a charge-transporting substance represented by the following formula (1).

(In formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ each independently represent a hydrogen atom, a methyl group or a methoxy group.)
In addition, the surface layer of the present disclosure contains at least one selected from fluorine atom-containing resin particles, a binder material, and raw materials for the binder material, perfluorohexanoic acid, and a charge-transporting substance represented by formula (1). It is a layer formed from the coating film of the coating liquid contained.

<Fluorine Atom-Containing Resin Particles>
The surface layer of the electrophotographic photoreceptor of the present disclosure contains fluorine atom-containing resin particles. Further, the coating liquid for forming the surface layer of the electrophotographic photoreceptor of the present disclosure contains fluorine atom-containing resin particles.
Examples of the resin contained in the fluorine atom-containing resin particles used in the present disclosure include the following. Examples include polytetrafluoroethylene resin, polychlorotrifluoroethylene resin, polytetrafluoroethylenepropylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, and polydichlorodifluoroethylene resin. It is also preferable to use particles containing a plurality of types of the above resins. Among the above, from the viewpoint of improving dispersibility, the fluorine atom-containing resin particles are more preferably polytetrafluoroethylene particles containing polytetrafluoroethylene resin.
In the cross-sectional observation of the surface layer, the fluorine atom-containing resin particles showed that the arithmetic mean of the major diameter of the primary particles (average primary particle diameter) measured from the secondary electron image with a scanning electron microscope improved dispersibility and suppressed potential fluctuation. from the point of view, it is preferably 150 nm or more and 300 nm or less. Furthermore, the fluorine atom-containing resin particles preferably have an average primary particle size of 180 nm or more and 250 nm or less.
The fluorine atom-containing resin particles should have an average circularity value (average circularity) of 0.75 or more calculated from the area and circumference of the primary particles measured from the secondary electron image by a scanning electron microscope. is preferred.
In order to keep the measured values of the average primary particle diameter and average circularity of the fluorine atom-containing resin particles contained in the surface layer of the electrophotographic photoreceptor of the present disclosure within the above ranges, the average Fluorine atom-containing resin particles having a primary particle size and average circularity falling within the above ranges can be used.

(Measuring method of average primary particle size and average circularity)
That is, in the examples of the present disclosure, the average primary particle diameter and average circularity of the fluorine atom-containing resin particles contained in the surface layer of the electrophotographic photoreceptor were measured using a field emission scanning electron microscope (FE-SEM). was measured as follows. The fluorine atom-containing resin particles were attached to a commercially available carbon conductive tape, and the fluorine atom-containing resin particles not attached to the conductive tape were removed with compressed air, followed by platinum vapor deposition. The vapor-deposited fluorine atom-containing resin particles were observed using an FE-SEM (S-4700) manufactured by Hitachi High Technology. The FE-SEM measurement conditions are as follows.
Accelerating voltage: 2 kV
WD: 5mm
Magnification: 20,000 times Number of pixels: 1280 vertical pixels, 960 horizontal pixels (size per pixel: 5 nm)
The Feret diameters of 100 particles were obtained from the resulting image using ImageJ (an open source software manufactured by the National Institutes of Health (NIH)), and the average value was calculated as the average primary particle diameter.
Similarly, the area and circumference were obtained, the circularity was obtained from the following formula (II), and the average value was calculated to be the average circularity.
Roundness = 4 × π × (area) ÷ (perimeter squared) Formula (II)
The fluorine atom-containing resin particles of the present disclosure may be used alone or in combination of two or more.

The content of the fluorine atom-containing resin particles in the surface layer is preferably 5.0% by mass or more and 40% by mass or less, more preferably 5.0% by mass or more and 20% by mass or less, and 7.0% by mass. % or more and 15 mass % or less is particularly preferable. The content of the fluorine atom-containing resin particles in the coating liquid for forming the surface layer is preferably 5.0% by mass or more and 40% by mass or less, and more preferably 5.0% by mass or more and 20% by mass or more. More preferably, it is particularly preferably 7.0% by mass or more and 15% by mass or less.

When the photosensitive layer of the electrophotographic photoreceptor is a laminated photosensitive layer and the charge transport layer is a surface layer, the content of the fluorine atom-containing resin particles is 5.0% by mass or more and 40% by mass with respect to the charge transport layer. or less, more preferably 5.0% by mass or more and 20% by mass or less, and particularly preferably 7.0% by mass or more and 15% by mass or less. In this case, the same applies to the content of the fluorine atom-containing resin particles in the coating liquid for forming the charge transport layer.
When the photosensitive layer of the electrophotographic photoreceptor is a single-layer type photosensitive layer and the photosensitive layer is the surface layer, the content of the fluorine atom-containing resin particles is 5.0% by mass or more and 40% by mass with respect to the photosensitive layer. or less, more preferably 5.0% by mass or more and 20% by mass or less, and particularly preferably 7.0% by mass or more and 15% by mass or less. In this case, the same applies to the content of the fluorine atom-containing resin particles in the coating liquid for forming the photosensitive layer.

<Perfluorohexanoic acid>
Fluorine atom-containing resin particles may produce perfluorohexanoic acid as a by-product during the production process. Therefore, perfluorohexanoic acid is often attached to the fluorine atom-containing resin particles.
If the content of perfluorohexanoic acid is more than 25 mass ppb relative to the fluorine atom-containing resin particles, long-term repeated potential fluctuation tends to increase.
Therefore, the content of perfluorohexanoic acid in the surface layer of the electrophotographic photoreceptor of the present disclosure is set to 0.010 mass ppb or more and 25 mass ppb or less relative to the fluorine atom-containing resin particles in the surface layer. Alternatively, the content of perfluorohexanoic acid in the coating liquid forming the surface layer is set to 0.010 mass ppb or more and 25 mass ppb or less with respect to the fluorine atom-containing resin particles in the coating liquid. In other words, it is important to suppress perfluorohexanoic acid, which may be produced as a by-product in the process of producing fluorine atom-containing resin particles, in order to suppress long-term repeated potential fluctuations.

(Method for measuring content of perfluorohexanoic acid)
The content of perfluorohexanoic acid can be measured by an LC/MS/MS method using a reversed-phase solid phase column. HLB manufactured by Waters was used as a reversed-phase solid phase column, 1260 HPLC manufactured by Agilent was used for LC measurement, and QTRAP5500 manufactured by Sciex was used for MS/MS measurement. LC/MS/MS measurement conditions can be performed with reference to the JIS method (JIS K 0450-70-10).

（式（１）中、Ｒ^１１、Ｒ^１２、Ｒ^１３、Ｒ^１４、Ｒ^１５、及びＲ^１６は、それぞれ独立に、水素原子、メチル基、又はメトキシ基を示す。）
電荷輸送物質は、式（１）で示される電荷輸送物質単独で用いても良く、その他の電荷輸送物質と組み合わせて使用してもよい。
式（１）で示される電荷輸送物質と組み合わせて使用する電荷輸送物質としては、例えば、多環芳香族化合物、複素環化合物、ヒドラゾン化合物、スチリル化合物、エナミン化合物、トリアリールアミン化合物、これらの物質から誘導される基を有する樹脂などが挙げられる。これらの中でも、トリアリールアミン化合物が好ましい。
本開示における式（１）で示される電荷輸送物質としては、例えば下記表１に示す構造が挙げられる。 <Charge transport material>
The surface layer of the electrophotographic photoreceptor of the present disclosure contains a charge transport material represented by the following formula (1). Further, the coating liquid for forming the surface layer of the electrophotographic photoreceptor of the present disclosure contains a charge transport material represented by the following formula (1).

(In formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ each independently represent a hydrogen atom, a methyl group or a methoxy group.)
As the charge-transporting substance, the charge-transporting substance represented by Formula (1) may be used alone, or may be used in combination with other charge-transporting substances.
Charge-transporting substances used in combination with the charge-transporting substance represented by formula (1) include, for example, polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, triarylamine compounds, and these substances. and resins having a group derived from. Among these, triarylamine compounds are preferred.
Examples of the charge-transporting substance represented by formula (1) in the present disclosure include structures shown in Table 1 below.

The content of the charge-transporting substance represented by formula (1) in the surface layer is preferably 5% by mass or more and 45% by mass or less. The same applies to the content of the charge-transporting substance represented by the formula (1) in the coating liquid for forming the surface layer.

When the photosensitive layer of the electrophotographic photoreceptor is a laminated photosensitive layer and the charge transport layer is a surface layer, the content of the charge transport substance represented by formula (1) is preferably 5 masses relative to the charge transport layer. % or more and 45 mass % or less. In this case, the content of the charge-transporting substance represented by the formula (1) in the coating liquid for forming the charge-transporting layer is the same.
When the photosensitive layer of the electrophotographic photoreceptor is a single-layer type photosensitive layer and the photosensitive layer is the surface layer, the content of the charge-transporting substance represented by the formula (1) is preferably 5 mass with respect to the photosensitive layer. % or more and 45 mass % or less. In this case, the content of the charge-transporting substance represented by the formula (1) in the coating liquid for forming the photosensitive layer is the same.

（式（２）中、
Ｒ^２１は、水素原子又はメチル基を示す。
Ｒ^２２は、単結合、メチレン基、又はエチレン基のいずれかを示す。
Ｒｆ^１は、それぞれ独立に、炭素数１以上５以下のパーフルオロアルキレン基、又は炭素数１以上５以下のパーフルオロアルキリデン基を示す。
Ｒｆ^２は、炭素数１以上５以下のパーフルオロアルキル基を示す。
ｎは、１以上３以下の整数を示す。）

（式（４）中、
Ｒ^４１１は、炭素数１以上２以下のアルキリジン基を示し、
Ｒ^４２は、単結合、又は炭素数１以上３以下のアルキレン基を示し、
Ｒｆ^４は、炭素数１以上５以下のパーフルオロアルキル基を示す。）
前記式（４）中、Ｒ^４１１は、炭素数１以上２以下のアルキリジン基を示す。アルキリジン基は、アルカン－１，１，１－トリイルとも言う。 <Polymer A>
The surface layer of the electrophotographic photoreceptor of the present disclosure is a polymer A having at least one structural unit selected from the group consisting of structural units represented by the following formula (2) and structural units represented by the following formula (4): is good from the viewpoint of suppressing repeated potential fluctuations. Similarly, the coating liquid for forming the surface layer of the electrophotographic photoreceptor of the present disclosure contains at least one selected from the group consisting of structural units represented by the following formula (2) and structural units represented by the following formula (4): It is preferable to contain a polymer A having a structural unit of

(In formula (2),
^R21 represents a hydrogen atom or a methyl group.
^R22 represents either a single bond, a methylene group, or an ethylene group.
Each Rf ¹ independently represents a perfluoroalkylene group having 1 to 5 carbon atoms or a perfluoroalkylidene group having 1 to 5 carbon atoms.
^Rf2 represents a perfluoroalkyl group having 1 to 5 carbon atoms.
n represents an integer of 1 or more and 3 or less. )

(In formula (4),
R ⁴¹¹ represents an alkylidine group having 1 to 2 carbon atoms,
R ⁴² represents a single bond or an alkylene group having 1 to 3 carbon atoms,
Rf ⁴ represents a perfluoroalkyl group having 1 to 5 carbon atoms. )
In formula (4) above, R ⁴¹¹ represents an alkylidine group having 1 or more and 2 or less carbon atoms. An alkylidin group is also referred to as alkane-1,1,1-triyl.

The surface layer containing the polymer A having at least one structural unit selected from the group consisting of the structural unit represented by the formula (2) and the structural unit represented by the formula (4) has a long-term repeated potential fluctuation. The present inventors believe that the reason for the excellent suppressing effect is as follows.
The polymer A having at least one of the structural unit represented by the formula (2) and the structural unit represented by the formula (4) is a surface layer coating for forming a surface layer of an electrophotographic photoreceptor. The present inventors believe that it works as a dispersing agent for the fluorine atom-containing resin particles in the process of preparing the liquid. Therefore, when the polymer A having at least one of the structural unit represented by the formula (2) and the structural unit represented by the formula (4) is included in the surface layer, the fluorine atom-containing resin particles in the surface layer It is thought that a state with excellent dispersibility is formed.
The polymer A having the structural unit represented by the formula (2) has a structure in which an oxygen atom is present between the perfluoroalkylene group and the like, such as a perfluoroalkylene group, as the structural unit represented by the formula (2). It has become. Through this oxygen atom, the charge trapped by the fluorine atom-containing resin particles and perfluorohexanoic acid can be released to the charge transport material represented by the formula (1), and the inhibition of charge transport is suppressed. We believe that long-term repetitive potential fluctuations are suppressed.

In the polymer A having the structural unit represented by formula (2), R ²² is preferably a methylene group from the viewpoint of suppressing long-term repeated potential fluctuations. Further, Rf ¹ is each independently a perfluoroalkylene group having 1 to 3 carbon atoms or a perfluoroalkylidene group having 1 to 3 carbon atoms, and Rf ² is a perfluoroalkyl group having 1 to 3 carbon atoms. preferable. Further, the total number of carbon atoms of Rf ¹ and Rf ² is preferably 6 or more and 9 or less from the viewpoint of improving the dispersibility of the fluorine atom-containing resin particles.

Moreover, the polymer A having the structural unit represented by the formula (4) has a perfluoroalkyl group as the structural unit represented by the formula (4). A possible cause of the long-term repetitive potential fluctuations is the effect that electric charges tend to accumulate in the perfluoroalkyl groups of the dispersant attached to the fluorine atom-containing resin particles contained in the surface layer. As the number of carbon atoms in the perfluoroalkyl group increases, the electric charge tends to accumulate, and the effect of suppressing potential fluctuation may not be sufficiently obtained. By setting Rf ⁴ in formula (4) to a perfluoroalkyl group having 1 to 5 carbon atoms, it is possible to suppress accumulation of charges in the structural unit represented by formula (4), and suppress long-term repeated potential fluctuations. I think it will.

In the polymer A having the structural unit represented by formula (4), R ⁴¹¹ is preferably an ethylidine group having 2 carbon atoms from the viewpoint of dispersibility of the fluorine atom-containing resin particles in the surface layer. Further, Rf ⁴ is preferably a perfluoroalkyl group having 2 or more and 4 or less carbon atoms from the viewpoint of achieving both dispersibility and long-term repetitive potential fluctuation suppression.

式（３）中、
Ｙ^Ａ１は、無置換のアルキレン基を示し、
Ｙ^Ｂは、無置換のアルキレン基、ハロゲン原子で置換されたアルキレン基、ヒドロキシ基で置換されたアルキレン基、エステル結合（－ＣＯＯ－）、アミド結合（－ＮＨＣＯ－）、若しくは、ウレタン結合（－ＮＨＣＯＯ－）、又は、これらの基及び結合から選ばれる一種以上と－Ｏ－若しくは－Ｓ－とを組み合わせて導き出せる２価の連結基、あるいは単結合を示し、
Ｚ^Ａは、下記式（３Ａ）で示される構造、シアノ基、又はフェニル基を示し、
Ｒ^３１、及びＲ^３２は、それぞれ独立に、水素原子、又はメチル基を示し、
ｍは、２５以上１５０以下の整数である。

式（３Ａ）中、
Ｚ^Ａ１は、炭素数１以上４以下のアルキル基を示す。
式（３）中、Ｙ^Ｂがエステル結合を示す場合、－Ｙ^Ａ１－Ｙ^Ｂ－ＣＨ_２－は、－Ｙ^Ａ１－ＣＯ－Ｏ－ＣＨ_２－及びＹ^Ａ１－Ｏ－ＣＯ－ＣＨ_２－のどちらでもよく、好ましくは、－Ｙ^Ａ１－ＣＯ－Ｏ－ＣＨ_２－である。また、式（３）中、Ｙ^Ｂがアミド結合を示す場合、－Ｙ^Ａ１－Ｙ^Ｂ－ＣＨ_２－は、－Ｙ^Ａ１－ＮＨ－ＣＯ－ＣＨ_２－及びＹ^Ａ１－ＣＯ－ＮＨ－ＣＨ_２－のどちらでもよく、好ましくは、－Ｙ^Ａ１－ＮＨ－ＣＯ－ＣＨ_２－である。また、式（３）中、Ｙ^Ｂがウレタン結合の場合、－Ｙ^Ａ１－Ｙ^Ｂ－ＣＨ_２－は、－Ｙ^Ａ１－ＮＨ－ＣＯ－Ｏ－ＣＨ_２－及びＹ^Ａ１－Ｏ－ＣＯ－ＮＨ－ＣＨ_２－のどちらでもよく、好ましくは、－Ｙ^Ａ１－ＮＨ－ＣＯ－Ｏ－ＣＨ_２－である。 The surface layer of the electrophotographic photoreceptor of the present disclosure preferably contains a polymer A having a structural unit represented by the following formula (3) from the viewpoint of suppressing repeated potential fluctuations. Similarly, the coating liquid forming the surface layer of the electrophotographic photoreceptor of the present disclosure preferably contains a polymer A having a structural unit represented by the following formula (3).

In formula (3),
Y ^A1 represents an unsubstituted alkylene group,
Y ^B is an unsubstituted alkylene group, a halogen-substituted alkylene group, a hydroxy-substituted alkylene group, an ester bond (-COO-), an amide bond (-NHCO-), or a urethane bond (- NHCOO-), or a divalent linking group or a single bond that can be derived by combining one or more selected from these groups and bonds with -O- or -S-,
Z ^A represents a structure represented by the following formula (3A), a cyano group, or a phenyl group,
R ³¹ and R ³² each independently represent a hydrogen atom or a methyl group,
m is an integer of 25 or more and 150 or less.

In formula (3A),
Z ^A1 represents an alkyl group having 1 to 4 carbon atoms.
In formula (3), when Y ^B represents an ester bond, -Y ^A1 -Y ^B -CH ₂ - represents -Y ^A1 -CO-O-CH ₂ - and Y ^A1 -O-CO-CH ₂ - It may be either, preferably -Y ^A1 -CO-O-CH ₂ -. Further, in formula (3), when Y ^B represents an amide bond, -Y ^A1 -Y ^B -CH ₂ - represents -Y ^A1 -NH-CO-CH ₂ - and Y ^A1 -CO-NH-CH ₂ -, preferably -Y ^A1 -NH-CO-CH ₂ -. Further, in formula (3), when Y ^B is a urethane bond, -Y ^A1 -Y ^B -CH ₂ - is -Y ^A1 -NH-CO-O-CH ₂ - and Y ^A1 -O-CO-NH It may be either -CH ₂ -, preferably -Y ^A1 -NH-CO-O-CH ₂ -.

It is preferable that the formula (3) does not have an acidic group with a pKa of 3 or less.
The pKa of an acidic group can be found by measurement using a known method such as titration. Acidic groups with a pKa of 3 or less include, for example, a sulfonic acid group (methanesulfonic acid: -2.6), a phosphonic acid group (first dissociation: 1.5), a phosphate group (first dissociation: 2.12), Fluorinated alkylcarboxylic acid groups (eg, trifluoroacetic acid: −0.25, difluoroacetic acid: 1.24, monofluoroacetic acid: 2.66).
It is preferable not to have —SO ₃ H in the formula (3).

In the polymer A having the structural unit represented by the formula (3), -Y ^A1 -Y ^B - is -Y ^A1 -(Y ^A2 ) _b -(Y ^A3 ) _c from the viewpoint of suppressing long-term repeated potential fluctuations. -(Y ^A4 ) _d -(Y ^A5 ) _e -(Y ^A6 ) _f - is preferred.
Y ^A1 represents an unsubstituted alkylene group,
Y ^A2 represents a methylene group substituted with at least one selected from the group consisting of a hydroxy group and a halogen atom,
Y ^A3 represents an unsubstituted alkylene group,
Y ^A4 represents an ester bond, an amide bond or a urethane bond,
Y ^A5 represents an unsubstituted alkylene group,
Y ^A6 represents an oxygen atom or a sulfur atom,
b, c, d, e and f each independently represent 0 or 1;

From the viewpoint of improving the dispersibility of the fluorine atom-containing resin particles and suppressing long-term repetitive potential fluctuations, the content of the polymer A contained in the surface layer is 2 times the amount of the fluorine atom-containing resin particles in the surface layer. 0% by mass or more and 10% by mass or less. Furthermore, it is more preferably 4.0% by mass or more and 8.0% by mass or less. The same applies to the coating liquid that forms the surface layer.

The ratio of the structural unit represented by the formula (2) in the polymer A is the total structural unit in the polymer A from the viewpoint of improving the dispersibility of the fluorine atom-containing resin particles and suppressing the long-term repeated potential fluctuation. It is preferable that it is 5% by number or more and 95% by number or less. Furthermore, it is more preferable that it is 50 number % or more and 95 number % or less. Furthermore, it is particularly preferable to be 70% by number or more and 90% by number or less. Further, the ratio of the structural unit represented by formula (2) in polymer A is preferably 0.1% by mass or more and 80% by mass or less with respect to all structural units in polymer A. Furthermore, it is more preferably 1% by mass or more and 80% by mass or less. Furthermore, it is particularly preferable to be 4% by mass or more and 66% by mass or less.

The ratio of the structural unit represented by the formula (4) in the polymer A is the total structural units in the polymer A from the viewpoint of improving the dispersibility of the fluorine atom-containing resin particles and suppressing long-term repeated potential fluctuations. , preferably 5% by mass or more and 50% by mass or less (0.05% by mass or more and 14.1% by mass or less). Furthermore, it is more preferably 20% by mass or more and 45% by mass or less (0.2% by mass or more and 11.9% by mass or less).

Polymer A has at least one structural unit selected from the group consisting of a structural unit represented by formula (2) and a structural unit represented by formula (4), and a structural unit represented by formula (3). It is preferable to consist only of structural units.
In the polymer A, from the viewpoint of improving the dispersibility of the fluorine atom-containing resin particles, the molar ratio of the structural unit represented by the formula (2) to the structural unit represented by the formula (3) is 1:19 to 19. :1 is preferred. Furthermore, it is more preferable that the molar ratio is from 1:1 to 19:1. Furthermore, it is particularly preferred that the molar ratio is from 7:3 to 9:1.
In the polymer A, from the viewpoint of improving the dispersibility of the fluorine atom-containing resin particles, the molar ratio of the structural unit represented by the formula (4) to the structural unit represented by the formula (3) is 1:19 to 19. :1, more preferably 1:4 to 9:11.

The weight average molecular weight of the polymer A having the structural unit represented by the formula (2) is 16,000 or more and 100,000 or less from the viewpoint of improving the dispersibility of the fluorine atom-containing resin particles and suppressing long-term repeated potential fluctuations. is preferably Furthermore, the weight-average molecular weight of polymer A having the structural unit represented by formula (2) is more preferably 18,000 or more and 80,000 or less.
The weight average molecular weight of the polymer A having the structural unit represented by the formula (4) is 16,000 or more and 300,000 or less from the viewpoint of improving the dispersibility of the fluorine atom-containing resin particles and suppressing long-term repeated potential fluctuations. is preferably Furthermore, the weight average molecular weight of polymer A having the structural unit represented by formula (4) is more preferably 40,000 or more and 250,000 or less.

The weight average molecular weight of polymer A can be measured and calculated by the following method.
(Weight average molecular weight measurement by GPC)
The weight average molecular weight according to the present disclosure is measured by gel permeation chromatography (GPC) as follows.
First, the sample is dissolved in tetrahydrofuran (THF) at room temperature for 24 hours. Then, the resulting solution is filtered through a solvent-resistant membrane filter "Maeshori Disk" (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm to obtain a sample solution. The sample solution is prepared so that the concentration of THF-soluble components is about 0.8% by mass. This sample solution is used for measurement under the following conditions.
・ Apparatus: HLC8120 GPC (detector: RI) (manufactured by Tosoh Corporation)
・Column: 7 columns of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko)
- Eluent: tetrahydrofuran (THF)
・Flow rate: 1.0 ml/min
・Oven temperature: 40.0°C
・Sample injection volume: 0.10 ml
In calculating the molecular weight of the sample, standard polystyrene resin (for example, trade name "TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F- 10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500", manufactured by Tosoh Corporation).

Examples of structural units represented by formula (2) used in the present disclosure include structures shown in Table 2 below.

Examples of structural units represented by formula (4) used in the present disclosure include structures shown in Table 3 below.

Examples of structural units represented by formula (3) used in the present disclosure include structures shown in Table 4 below.

<Binding material>
The surface layer of the electrophotographic photoreceptor of the present disclosure contains a binder material. Further, the coating liquid for forming the surface layer of the electrophotographic photoreceptor of the present disclosure contains at least one selected from a binder material and raw materials of the binder material. The binding material used in the present disclosure preferably includes the following. Examples include polymers obtained by polymerizing a composition containing a monomer having a polymerizable functional group, polycarbonate resins, polyarylate resins, acrylic resins, polystyrene resins, and the like. Among these, thermoplastic resins are preferred, and polycarbonate resins and polyarylate resins are particularly preferred. Raw materials for the binding material include, for example, monomers having a polymerizable functional group. Examples of polymerizable functional groups include isocyanate groups, blocked isocyanate groups, methylol groups, alkylated methylol groups, epoxy groups, metal alkoxide groups, hydroxy groups, amino groups, carboxy groups, thiol groups, carboxylic anhydride groups, carbon - group containing a carbon double bond, and the like. Groups containing carbon-carbon double bonds include, for example, acryloyl groups and methacryloyl groups.

<Process cartridge, electrophotographic device>
The electrophotographic photoreceptor of the present disclosure may be one of the components of a process cartridge or electrophotographic apparatus. The process cartridge integrally supports the electrophotographic photosensitive member described above and at least one means selected from the group consisting of charging means, developing means, transfer means and cleaning means, and is attached to the main body of the electrophotographic apparatus. It is characterized by being detachable. Further, the electrophotographic apparatus is characterized by having the electrophotographic photoreceptor, charging means, exposure means, developing means and transfer means described above.

FIG. 2 shows the configuration of a process cartridge including the electrophotographic photosensitive member of the present disclosure, and FIG. 3 shows an example of the schematic configuration of an electrophotographic apparatus having the process cartridge of FIG.
In FIG. 2, a cylindrical electrophotographic photosensitive member 1 is rotationally driven at a predetermined peripheral speed in the direction of the arrow. The circumferential surface of the rotationally driven electrophotographic photosensitive member 1 is uniformly charged to a predetermined positive or negative potential by charging means 2 . Next, the peripheral surface of the charged electrophotographic photosensitive member 1 receives exposure light (image exposure light) 3 output from exposure means (not shown) such as slit exposure or laser beam scanning exposure. In this way, electrostatic latent images corresponding to desired images are sequentially formed on the peripheral surface of the electrophotographic photosensitive member 1 . The voltage applied to the charging means (charging roller, etc.) 2 may be either a voltage obtained by superimposing an AC component on a DC component or a voltage containing only a DC component.
The electrostatic latent image formed on the circumferential surface of the electrophotographic photosensitive member 1 is developed with toner contained in the developer of the developing means 4 to form a toner image. Next, the toner images formed and carried on the peripheral surface of the electrophotographic photosensitive member 1 are sequentially transferred onto a transfer material (paper, intermediate transfer member, etc.) 6 by a transfer bias from transfer means (transfer roller, etc.) 5 . go. The transfer material 6 is fed in synchronism with the rotation of the electrophotographic photosensitive member 1 .
After the toner image has been transferred, the surface of the electrophotographic photosensitive member 1 is subjected to a charge elimination treatment by pre-exposure light 7 from pre-exposure means (not shown), and then cleaned by cleaning means 8 to remove residual toner after transfer. , the electrophotographic photoreceptor 1 is repeatedly used for image formation. The pre-exposure means may be used before or after the cleaning process, and the pre-exposure means is not necessarily required.
The electrophotographic photoreceptor 1 may be installed in an electrophotographic apparatus such as a copying machine or a laser beam printer. Further, a process cartridge 9 constructed by housing a plurality of constituent elements such as the electrophotographic photosensitive member 1, the charging means 2, the developing means 4 and the cleaning means 8 in a container and integrally supporting the main body of the electrophotographic apparatus. may be detachably attached to. In FIG. 2, an electrophotographic photosensitive member 1, a charging means 2, a developing means 4 and a cleaning means 8 are integrally supported to form a process cartridge 9 detachable from the main body of the electrophotographic apparatus.

Next, an electrophotographic apparatus provided with the electrophotographic photoreceptor of the present disclosure will be described.
FIG. 3 shows an example of the configuration of the electrophotographic apparatus of the present disclosure. A process cartridge 17 for yellow, a process cartridge 18 for magenta, a process cartridge 19 for cyan, and a process cartridge 20 for black corresponding to yellow, magenta, cyan, and black are provided. , are juxtaposed along the intermediate transfer member 10 . The diameter, constituent materials, developer, charging method, and other means of the electrophotographic photosensitive member do not necessarily have to be the same for each color.
When the image forming operation starts, toner images of respective colors are sequentially superimposed on the intermediate transfer member 10 according to the image forming process described above. In parallel, the transfer paper 11 is sent out from the paper feed tray 13 by the paper feed path 12 and fed to the secondary transfer means 14 in synchronization with the rotation of the intermediate transfer body. The toner image on the intermediate transfer member 10 is transferred to the transfer paper 11 by the transfer bias from the secondary transfer means 14 . The toner image transferred onto the transfer paper 11 is conveyed along the paper feed path 12 , fixed on the transfer paper by the fixing means 15 , and discharged from the paper discharge section 16 .
The electrophotographic photoreceptor of the present disclosure can be used for laser beam printers, LED printers, copiers, facsimiles, and multifunction devices thereof.

<Manufacturing method>
One aspect of the present disclosure provides a method of manufacturing an electrophotographic photoreceptor having a surface layer. In the production method, the step (i) for suppressing perfluorohexanoic acid adhering to the fluorine atom-containing resin particles; , perfluorohexanoic acid, and a charge-transporting substance represented by formula (1); and drying and/or curing the coating film to form the surface layer (iii), wherein the perfluorohexanoic acid content of the coating liquid prepared in the step (ii) is , 0.010 mass ppb or more and 25 mass ppb or less with respect to the fluorine atom-containing resin particles in the coating liquid.

The present disclosure will be described in more detail below using examples and comparative examples, but the present disclosure is not limited to these. In the description of the following examples, "parts" are based on mass unless otherwise specified.

<Synthesis of Polymer A Having Structural Unit Represented by Formula (2)>
In the present disclosure, polymer A having a structural unit represented by formula (2) or a polymer corresponding thereto (hereinafter also referred to as "graft copolymer") was synthesized as follows. The acrylate compounds and macromonomer compounds used in the synthesis examples below can be produced, for example, by referring to JP-A-2009-104145.

(Graft copolymer 1)
50 parts of a compound represented by the following formula (B-1), 75 parts of a macromonomer represented by the following formula (A) (number average molecular weight: 6,000), 1,1'-Azobis (1-acetoxy-1-phenylethane) (1,1′-Azobis(1-acetoxy-1-phenylethane), trade name: OTAZO-15, manufactured by Otsuka Chemical Co., Ltd.) 0.437 parts, n-butyl acetate 338 parts, a stirrer, a reflux condenser , in a glass flask equipped with a nitrogen gas inlet tube, a constant temperature bath and a thermometer, 20 ° C., after mixing for 30 minutes under a nitrogen atmosphere, the reaction solution is heated to 85 to 90 ° C. and reacted for 5 hours. Ta. The reaction was stopped by cooling with ice, and 1500 parts by mass of 2-propanol was added to obtain a precipitate. The precipitate was washed with a mixed solvent of n-butyl acetate:2-propanol=1:5 and dried at a temperature of 80° C. under reduced pressure of 1325 Pa or less for 3 hours to obtain a graft copolymer 1.

(Graft copolymer 2)
Graft copolymer 2 was obtained in the same manner as for graft copolymer 1, except that 0.819 parts of 1,1′-azobis(1-acetoxy-1-phenylethane) was used.

(Graft copolymer 3)
Graft copolymer 3 was obtained in the same manner as for graft copolymer 1, except that 0.728 parts of 1,1′-azobis(1-acetoxy-1-phenylethane) was used.

(Graft copolymer 4)
Graft copolymer 4 was obtained in the same manner as for graft copolymer 1, except that 0.164 parts of 1,1′-azobis(1-acetoxy-1-phenylethane) was used.

(Graft copolymer 5)
Graft copolymer 5 was obtained in the same manner as for graft copolymer 1, except that 0.131 parts of 1,1′-azobis(1-acetoxy-1-phenylethane) was used.

(Graft copolymer 6)
A graft copolymer 6 was obtained in the same manner as for the graft copolymer 1, except that 0.874 parts of 1,1′-azobis(1-acetoxy-1-phenylethane) was used.

(Graft copolymer 7)
Graft copolymer 7 was obtained in the same manner as for graft copolymer 1, except that 0.119 parts of 1,1′-azobis(1-acetoxy-1-phenylethane) was used.

(Graft copolymer 8)
Except for changing to 28 parts of the compound represented by formula (B-1), 340 parts of the macromonomer represented by formula (A), and 0.119 parts of 1,1'-azobis(1-acetoxy-1-phenylethane) obtained graft copolymer 8 in the same manner as graft copolymer 1.

(Graft copolymer 9)
40 parts of the compound represented by the formula (B-1), 210 parts of the macromonomer represented by the formula (A), 1,1'-azobis (1-acetoxy-1-phenylethane) 0.119 parts other than obtained graft copolymer 9 in the same manner as graft copolymer 1.

(Graft copolymer 10)
Except for changing to 51 parts of the compound represented by formula (B-1), 68 parts of the macromonomer represented by formula (A), and 0.119 parts of 1,1′-azobis(1-acetoxy-1-phenylethane) obtained graft copolymer 10 in the same manner as graft copolymer 1.

(Graft copolymer 11)
Except for changing to 23 parts of the compound represented by formula (B-1), 420 parts of the macromonomer represented by formula (A), and 0.119 parts of 1,1'-azobis(1-acetoxy-1-phenylethane) obtained graft copolymer 11 in the same manner as graft copolymer 1.

(Graft copolymer 12)
Except for changing to 54 parts of the compound represented by formula (B-1), 32 parts of the macromonomer represented by formula (A), and 0.119 parts of 1,1′-azobis(1-acetoxy-1-phenylethane) obtained graft copolymer 12 in the same manner as graft copolymer 1.

(Graft copolymer 13)
The compound represented by the formula (B-1) was changed to 20 parts of the compound represented by the following formula (B-2), changed to 410 parts of the macromonomer represented by the formula (A), and 1,1'-azobis ( 1-Acetoxy-1-phenylethane) A graft copolymer 13 was obtained in the same manner as for the graft copolymer 1, except that the content was changed to 0.119 parts.

(Graft copolymer 14)
The compound represented by the formula (B-1) was changed to 21 parts of the compound represented by the following formula (B-3), changed to 420 parts of the macromonomer represented by the formula (A), and 1,1'-azobis ( 1-Acetoxy-1-phenylethane) A graft copolymer 14 was obtained in the same manner as for the graft copolymer 1, except that the content was changed to 0.119 parts.

(Graft copolymer 15)
The compound represented by the formula (B-1) was changed to 23 parts of the compound represented by the following formula (B-4), changed to 420 parts of the macromonomer represented by the formula (A), and 1,1'-azobis ( 1-Acetoxy-1-phenylethane) A graft copolymer 15 was obtained in the same manner as for the graft copolymer 1, except that the content was changed to 0.119 parts.

(Graft copolymer 16)
The compound represented by the formula (B-1) was changed to 25 parts of the compound represented by the following formula (B-5), changed to 420 parts of the macromonomer represented by the formula (A), and 1,1'-azobis ( 1-Acetoxy-1-phenylethane) A graft copolymer 16 was obtained in the same manner as for the graft copolymer 1, except that the content was changed to 0.119 parts.

(Graft copolymer 17)
The compound represented by the formula (B-1) was changed to 25 parts of the compound represented by the following formula (B-6), changed to 420 parts of the macromonomer represented by the formula (A), and 1,1'-azobis ( 1-Acetoxy-1-phenylethane) A graft copolymer 17 was obtained in the same manner as for the graft copolymer 1, except that the content was changed to 0.119 parts.

(Graft copolymer 18)
The compound represented by the formula (B-1) was changed to 25 parts of the compound represented by the following formula (B-7), changed to 420 parts of the macromonomer represented by the formula (A), and 1,1'-azobis ( 1-Acetoxy-1-phenylethane) A graft copolymer 18 was obtained in the same manner as for the graft copolymer 1, except that the content was changed to 0.119 parts.

(Graft copolymer 19)
The compound represented by the formula (B-1) was changed to 27 parts of the compound represented by the following formula (B-8), changed to 410 parts of the macromonomer represented by the formula (A), and 1,1'-azobis ( 1-Acetoxy-1-phenylethane) A graft copolymer 19 was obtained in the same manner as for the graft copolymer 1, except that the amount was changed to 0.119 parts.

(Graft copolymer 20)
The compound represented by the formula (B-1) was changed to 25 parts of the compound represented by the following formula (B-9), changed to 410 parts of the macromonomer represented by the formula (A), and 1,1'-azobis ( 1-Acetoxy-1-phenylethane) A graft copolymer 20 was obtained in the same manner as for the graft copolymer 1, except that the amount was changed to 0.119 parts.

(Graft copolymer 21)
The compound represented by the formula (B-1) was changed to 25 parts of the compound represented by the following formula (B-10), changed to 410 parts of the macromonomer represented by the formula (A), and 1,1'-azobis ( 1-Acetoxy-1-phenylethane) A graft copolymer 21 was obtained in the same manner as for the graft copolymer 1, except that the content was changed to 0.119 parts.

(Graft copolymer 22)
The compound represented by the formula (B-1) was changed to 25 parts of the compound represented by the following formula (B-11), changed to 420 parts of the macromonomer represented by the formula (A), and 1,1'-azobis ( 1-Acetoxy-1-phenylethane) A graft copolymer 22 was obtained in the same manner as for the graft copolymer 1, except that the content was changed to 0.119 parts. Graft copolymer 22 does not correspond to a polymer having a structural unit represented by formula (2).

(Graft copolymer 23)
The compound represented by the formula (B-1) was changed to 21 parts of the compound represented by the following formula (B-12), changed to 410 parts of the macromonomer represented by the formula (A), and 1,1'-azobis ( 1-Acetoxy-1-phenylethane) A graft copolymer 23 was obtained in the same manner as for the graft copolymer 1, except that the content was changed to 0.119 parts. Graft copolymer 23 does not correspond to a polymer having a structural unit represented by formula (2).

(Graft copolymer 24)
The compound represented by the formula (B-1) was changed to 19 parts of the compound represented by the following formula (B-13), changed to 420 parts of the macromonomer represented by the formula (A), and 1,1'-azobis ( 1-Acetoxy-1-phenylethane) A graft copolymer 24 was obtained in the same manner as for the graft copolymer 1, except that the content was changed to 0.119 parts. Graft copolymer 24 does not correspond to a polymer having a structural unit represented by formula (2).

The obtained graft copolymers 1 to 24 were subjected to GPC measurement by the method described above to calculate the weight average molecular weight. Table 5 shows the results.

<Synthesis of Polymer A Having Structural Unit Represented by Formula (4)>
In the present disclosure, polymer A having a structural unit represented by formula (4) or a polymer corresponding thereto (hereinafter also referred to as "graft copolymer") was synthesized as follows. The acrylate compounds and macromonomer compounds used in the synthesis examples below can be produced, for example, by referring to JP-A-2009-104145.

(Graft copolymer 25)
1H,1H,2H,2H-perfluorohexyl methacrylate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 3.31 parts, macromonomer represented by the following formula (A) (number average molecular weight 6,000) 75 parts, 1 , 1'-Azobis(1-acetoxy-1-phenylethane) (1,1'-azobis(1-acetoxy-1-phenylethane), trade name: OTAZO-15, manufactured by Otsuka Chemical Co., Ltd.) 14.18 parts , 900 parts of n-butyl acetate were mixed in a glass flask equipped with a stirrer, a reflux condenser, a nitrogen gas inlet tube, a constant temperature bath and a thermometer at 20° C. under a nitrogen atmosphere for 30 minutes. The mixture was heated to ~90°C and reacted for 5 hours. The reaction was stopped by cooling with ice, and 4500 parts of 2-propanol was added to obtain a precipitate. The precipitate was washed with a mixed solvent of n-butyl acetate:2-propanol=1:5 and dried at a temperature of 80° C. under reduced pressure of 1325 Pa or less for 3 hours to obtain a graft copolymer 25.

(Graft copolymer 26)
Graft copolymer 25 was prepared in the same manner as in the synthesis example of graft copolymer 25, except that 1H,1H,2H,2H-perfluorohexyl methacrylate was changed to 2.31 parts of 1H,1H,2H,2H-perfluorobutyl methacrylate. Copolymer 26 was obtained.

(Graft copolymer 27)
Grafting was carried out in the same manner as in the synthesis example of graft copolymer 25, except that 1H,1H,2H,2H-perfluorohexyl methacrylate was changed to 2.81 parts of 1H,1H,2H,2H-perfluoropentyl methacrylate. Copolymer 27 was obtained.

(Graft copolymer 28)
Except for changing 1H,1H,2H,2H-perfluorohexyl methacrylate to 3.81 parts of 1H,1H,2H,2H-perfluoroheptyl methacrylate, in the same manner as in Synthesis Example of graft copolymer 25, A graft copolymer 28 was obtained.

(Graft copolymer 29)
Grafting was carried out in the same manner as in the synthesis example of graft copolymer 25, except that 1H,1H,2H,2H-perfluorohexyl methacrylate was changed to 3.17 parts of 1H,1H,2H,2H-perfluorohexyl acrylate. Copolymer 29 was obtained.

(Graft copolymer 30)
Graft copolymer 30 was prepared in the same manner as in Synthesis Example of graft copolymer 25, except that the amount of 1,1′-azobis(1-acetoxy-1-phenylethane) used was changed to 70.88 parts. Obtained.

(Graft copolymer 31)
Grafting was performed in the same manner as in Synthesis Example of graft copolymer 30, except that 1H,1H,2H,2H-perfluorohexyl methacrylate was changed to 3.17 parts of 1H,1H,2H,2H-perfluorohexyl acrylate. A copolymer 31 was obtained.

(Graft copolymer 32)
Graft copolymer 32 was prepared in the same manner as in Synthesis Example of graft copolymer 25, except that the amount of 1,1′-azobis(1-acetoxy-1-phenylethane) used was changed to 42.53 parts. Obtained.

(Graft copolymer 33)
Grafting was carried out in the same manner as in the synthesis example of graft copolymer 32, except that 1H,1H,2H,2H-perfluorohexyl methacrylate was changed to 3.17 parts of 1H,1H,2H,2H-perfluorohexyl acrylate. Copolymer 33 was obtained.

(Graft copolymer 34)
Graft copolymer 34 was prepared in the same manner as in Synthesis Example of graft copolymer 25, except that the amount of 1,1′-azobis(1-acetoxy-1-phenylethane) used was changed to 21.26 parts. Obtained.

(Graft copolymer 35)
Grafting was carried out in the same manner as in the synthesis example of graft copolymer 34, except that 1H,1H,2H,2H-perfluorohexyl methacrylate was changed to 3.17 parts of 1H,1H,2H,2H-perfluorohexyl acrylate. Copolymer 35 was obtained.

(Graft copolymer 36)
Graft copolymer 36 was prepared in the same manner as in Synthesis Example of graft copolymer 25, except that the amount of 1,1′-azobis(1-acetoxy-1-phenylethane) used was changed to 17.72 parts. Obtained.

(Graft copolymer 37)
Grafting was carried out in the same manner as in the synthesis example of graft copolymer 36, except that 1H,1H,2H,2H-perfluorohexyl methacrylate was changed to 3.17 parts of 1H,1H,2H,2H-perfluorohexyl acrylate. Copolymer 37 was obtained.

(Graft copolymer 38)
Graft copolymer 38 was prepared in the same manner as in Synthesis Example of graft copolymer 25, except that the amount of 1,1′-azobis(1-acetoxy-1-phenylethane) used was changed to 11.70 parts. Obtained.

(Graft copolymer 39)
Grafting was performed in the same manner as in Synthesis Example of graft copolymer 38, except that 1H,1H,2H,2H-perfluorohexyl methacrylate was changed to 3.17 parts of 1H,1H,2H,2H-perfluorohexyl acrylate. Copolymer 39 was obtained.

(Graft copolymer 40)
Graft copolymer 40 was prepared in the same manner as in Synthesis Example of graft copolymer 25, except that the amount of 1,1′-azobis(1-acetoxy-1-phenylethane) used was changed to 10.63 parts. Obtained.

(Graft copolymer 41)
Grafting was carried out in the same manner as in the synthesis example of graft copolymer 40, except that 1H,1H,2H,2H-perfluorohexyl methacrylate was changed to 3.17 parts of 1H,1H,2H,2H-perfluorohexyl acrylate. A copolymer 41 was obtained.

(Graft copolymer 42)
Graft copolymer 42 was prepared in the same manner as in Synthesis Example of graft copolymer 25, except that the amount of 1,1′-azobis(1-acetoxy-1-phenylethane) used was changed to 9.57 parts. Obtained.

(Graft copolymer 43)
Grafting was carried out in the same manner as in the synthesis example of graft copolymer 42, except that 1H,1H,2H,2H-perfluorohexyl methacrylate was changed to 3.17 parts of 1H,1H,2H,2H-perfluorohexyl acrylate. Copolymer 43 was obtained.

(Graft copolymer 44)
Graft copolymer 44 was prepared in the same manner as in Synthesis Example of graft copolymer 25, except that the amount of 1,1′-azobis(1-acetoxy-1-phenylethane) used was changed to 8.51 parts. Obtained.

(Graft copolymer 45)
Grafting was carried out in the same manner as in the synthesis example of graft copolymer 44, except that 1H,1H,2H,2H-perfluorohexyl methacrylate was changed to 3.17 parts of 1H,1H,2H,2H-perfluorohexyl acrylate. Copolymer 45 was obtained.

(Graft copolymer 46)
Graft copolymer 46 was prepared in the same manner as in Synthesis Example of graft copolymer 25, except that the amount of 1,1′-azobis(1-acetoxy-1-phenylethane) used was changed to 7.80 parts. Obtained.

(Graft copolymer 47)
Grafting was carried out in the same manner as in the synthesis example of graft copolymer 46, except that 1H,1H,2H,2H-perfluorohexyl methacrylate was changed to 3.17 parts of 1H,1H,2H,2H-perfluorohexyl acrylate. Copolymer 47 was obtained.

(Graft copolymer 48)
Graft copolymer 48 was prepared in the same manner as in Synthesis Example of graft copolymer 25, except that the amount of 1,1′-azobis(1-acetoxy-1-phenylethane) used was changed to 6.38 parts. Obtained.

(Graft copolymer 49)
Grafting was performed in the same manner as in Synthesis Example of graft copolymer 48, except that 1H,1H,2H,2H-perfluorohexyl methacrylate was changed to 3.17 parts of 1H,1H,2H,2H-perfluorohexyl acrylate. Copolymer 49 was obtained.

(Graft copolymer 50)
The amount of the macromonomer represented by the formula (A) used is 1440 parts, the amount of 1,1′-azobis(1-acetoxy-1-phenylethane) used is 88.60 parts, and the amount of n-butyl acetate used is A graft copolymer 50 was obtained in the same manner as in the synthesis example of the graft copolymer 25, except that the amount was changed to 4500 parts.

(Graft copolymer 51)
The amount of the macromonomer represented by the formula (A) used is 1140 parts, the amount of 1,1′-azobis(1-acetoxy-1-phenylethane) used is 70.88 parts, and the amount of n-butyl acetate used is A graft copolymer 51 was obtained in the same manner as in the synthesis example of the graft copolymer 25, except that the amount was changed to 4200 parts.

(Graft copolymer 52)
240 parts of the macromonomer represented by the formula (A), 17.72 parts of 1,1′-azobis(1-acetoxy-1-phenylethane), and n-butyl acetate A graft copolymer 52 was obtained in the same manner as in the synthesis example of the graft copolymer 25, except that the amount was changed to 1200 parts.

(Graft copolymer 53)
2.98 parts of 1H,1H,2H,2H-perfluorohexyl methacrylate used, 66 parts of the macromonomer represented by the formula (A) used, 1,1′-azobis(1-acetoxy-1 -Phenylethane) was changed to 7.09 parts, and the amount of n-butyl acetate was changed to 500 parts in the same manner as in Synthesis Example of Graft Copolymer 25 to obtain graft copolymer 53. Ta.

(Graft copolymer 54)
60 parts of the macromonomer represented by the formula (A), 7.09 parts of 1,1'-azobis(1-acetoxy-1-phenylethane), and n-butyl acetate A graft copolymer 54 was obtained in the same manner as in the synthesis example of the graft copolymer 25, except that the amount was changed to 500 parts.

(Graft copolymer 55)
3.64 parts of 1H,1H,2H,2H-perfluorohexyl methacrylate used, 54 parts of the macromonomer represented by the formula (A) used, 1,1′-azobis(1-acetoxy-1 -Phenylethane) was changed to 7.09 parts, and the amount of n-butyl acetate was changed to 500 parts in the same manner as in Synthesis Example of Graft Copolymer 25 to obtain graft copolymer 55. Ta.

The obtained graft copolymers 25 to 55 were subjected to GPC measurement by the method described above to calculate the weight average molecular weight. Table 6 shows the results.

<Preparation of Electrophotographic Photoreceptor>
[Example 1]
(support)
As a support (conductive support), a cylindrical aluminum cylinder (JIS-A3003, aluminum alloy, outer diameter 30.6 mm, length 370 mm, thickness 1 mm) was cut. Ultrasonic cleaning is performed in a cleaning liquid containing pure water and a detergent (trade name: Chemicol CT, manufactured by Joban Chemical Co., Ltd.), followed by washing away the cleaning liquid, and then ultrasonic cleaning in pure water. , was degreased, and this was used as a support.

(Undercoat layer)
60 parts of zinc oxide particles (average particle diameter: 70 nm, specific surface area value: 15 m ² /g) were stirred and mixed with 500 parts of tetrahydrofuran, and a silane coupling agent (compound name: N-2-(aminoethyl)-3 -Aminopropyltrimethoxysilane (trade name: KBM603, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.75 parts was added and stirred for 2 hours. Thereafter, tetrahydrofuran was distilled off under reduced pressure, and the residue was dried by heating at 120° C. for 3 hours to obtain surface-treated zinc oxide particles.
Subsequently, 25 parts of butyral (trade name: BM-1, manufactured by Sekisui Chemical Co., Ltd.) and 22.5 parts of blocked isocyanate (trade name: Sumidule BL-3173, manufactured by Sumitomo Bayer Urethane Co., Ltd.) were added as polyols. and 142 parts of methyl ethyl ketone. To this solution, 100 parts of zinc oxide particles surface-treated as described above and 1 part of alizarin were added, and this was dispersed in a sand mill using glass beads with a diameter of 1 mm for 5 hours.
After the dispersion treatment, 0.008 part of dioctyltin dilaurate and 6.5 parts of silicone resin particles (Tospearl 145, manufactured by GE Toshiba Silicone Co., Ltd.) were added and stirred to prepare a coating solution for an undercoat layer.
The resulting undercoat layer coating solution was dip-coated on the support to form a coating film, and the coating film was dried at 190° C. for 24 minutes to form an undercoat layer having a thickness of 20 μm.

(Charge generation layer)
Next, a chlorogallium phthalocyanine crystal having strong diffraction peaks at Bragg angles (2θ±0.2°) of at least 7.4°, 16.6°, 25.5° and 28.3° for CuKα characteristic X-rays. 15 parts of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Union Carbite Co., Ltd.) 10 parts, and 300 parts of n-butyl alcohol are mixed and dispersed for 4 hours in a sand mill using glass beads with a diameter of 1 mm. Then, a charge generating layer coating solution was prepared.
This charge generation layer coating solution was dip-coated on the undercoat layer, and the resulting coating film was dried at 150° C. for 5 minutes to form a charge generation layer having a thickness of 0.2 μm.

その後、フッ素変性シリコーンオイル（商品名：ＦＬ－１００ 信越シリコーン社製）を５ｐｐｍとなるように前述の分散液に加え、ポリフロンフィルター（商品名：ＰＦ－０４０、アドバンテック東洋（株）製）で濾過を行い、電荷輸送層用塗布液を調製した。
この電荷輸送層用塗布液を前述の電荷発生層上に浸漬塗布して塗膜を形成し、得られた塗膜を１３０℃で４５分間乾燥させることによって、膜厚３０μｍの電荷輸送層を形成した。
このようにして、電子写真感光体を作製した。 (Charge transport layer)
Put 3 kg of commercially available polytetrafluoroethylene resin particles (average primary particle size 210 nm, average roundness 0.85) in a stainless steel container with a width of 400 mm, a depth of 400 mm, and a height of 50 mm, and heat the thermostat (model: SPH- 102, manufactured by Espec Co., Ltd.) at 150° C. for 3 hours to obtain dried polytetrafluoroethylene resin particles.
The perfluorohexanoic acid content of the commercially available polytetrafluoroethylene resin particles that were not dried and the polytetrafluoroethylene resin particles that were dried were measured by the above-described method for measuring the perfluorohexanoic acid content. It was measured. As a result, with respect to the mass of the polytetrafluoroethylene resin particles, the perfluorohexanoic acid content of the commercially available product that was not dried was 100 mass ppb. was 5 mass ppb.
Next, 10 parts of the dried polytetrafluoroethylene resin particles, 0.50 parts of the graft copolymer 1 described above, and 50 parts of tetrahydrofuran were stirred and mixed for 48 hours while maintaining the liquid temperature at 20 ° C. to prepare. A liquid B was obtained.
Next, 10 parts of the compound represented by the above exemplary compound (1-1) as the first charge-transporting substance, 50 parts of the charge-transporting substance represented by the following formula (C) as the second charge-transporting substance, and a binding material 65 parts of bisphenol Z type polycarbonate resin (viscosity average molecular weight 40,000) as an antioxidant, 1.4 parts of 2,6-di-t-butyl-4-methylphenol as an antioxidant, and 250 parts of tetrahydrofuran are mixed and dissolved. Then, a preparation liquid C was obtained.
The prepared liquid B was added to the prepared liquid C and mixed by stirring, and passed through a high-pressure disperser (trade name: Microfluidizer M-110EH, manufactured by Microfluidics, Inc., USA) to obtain a dispersion liquid.

After that, fluorine-modified silicone oil (trade name: FL-100, manufactured by Shin-Etsu Silicone Co., Ltd.) was added to the above-mentioned dispersion liquid so that the concentration was 5 ppm, and filtered through a polyflon filter (trade name: PF-040, manufactured by Advantech Toyo Co., Ltd.). Filtration was carried out to prepare a charge transport layer coating liquid.
The charge transport layer coating solution was dip-coated on the charge generation layer to form a coating film, and the resulting coating film was dried at 130° C. for 45 minutes to form a charge transport layer having a thickness of 30 μm. did.
Thus, an electrophotographic photoreceptor was produced.

[Examples 2 to 47, Comparative Examples 1 to 2, Reference Example 1]
In the formation of the charge transport layer, the type of commercially available polytetrafluoroethylene resin particles (average primary particle size and average circularity), the conditions for drying the commercially available polytetrafluoroethylene resin particles, and the type of graft copolymer. The same electron A photographic photoreceptor was produced.

[Examples 48 to 97, Comparative Examples 3 to 4, Reference Example 2]
In the formation of the charge transport layer, the conditions for drying the commercially available polytetrafluoroethylene resin particles, the type and mass of the graft copolymer, the type and mass of the charge transport material represented by formula (1), and the second An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that the type and mass of the charge transport material were changed as shown in Table 8.

<Evaluation of Electrophotographic Photoreceptor>
The electrophotographic photoreceptors obtained in Examples 1 to 97, Comparative Examples 1 to 4, and Reference Examples 1 and 2 were evaluated as follows.

(High temperature and high humidity environment residual potential)
The electrophotographic photoreceptors obtained in Examples 1 to 97, Comparative Examples 1 to 4, and Reference Examples 1 and 2 were mounted on a copying machine, imagePRESS C800 manufactured by Canon Inc., and evaluated.
The evaluation apparatus was installed in a high-temperature and high-humidity environment with a temperature of 28° C. and a humidity of 85% RH. , made an evaluation.
The charging potential and the exposure amount of the exposing means were adjusted so that the charging potential was -700V and the exposure potential was -200V.
The surface potential of the electrophotographic photosensitive member was measured by extracting the developing cartridge from the evaluation device and inserting a potential measuring device therein. The potential measuring device is configured by arranging a potential measuring probe (trade name: model 6000B-8, manufactured by Trek Japan Co., Ltd.) at the developing position of the developing cartridge. The position was the center of the generatrix direction of the electrophotographic photoreceptor, and the gap from the surface of the electrophotographic photoreceptor was 3 mm. Further, the potential at the central portion of the electrophotographic photosensitive member was measured using a surface potential meter (trade name: model 344, manufactured by Trek Japan Co., Ltd.).
After outputting 100 sheets of A4-size gloss paper, the residual potential _Vr1 of the electrophotographic photosensitive member was measured by a potential measuring device.

(Low temperature and low humidity environment residual potential)
The electrophotographic photoreceptors obtained in Examples 1 to 97, Comparative Examples 1 to 4, and Reference Examples 1 and 2 were mounted on a copying machine, imagePRESS C800 manufactured by Canon Inc., and evaluated.
The evaluation apparatus was installed in a low-temperature and low-humidity environment with a temperature of 15° C. and a humidity of 10% RH. made an evaluation.
The charging potential and the exposure amount of the exposing means were adjusted so that the charging potential was -700V and the exposure potential was -200V.
After outputting 100 sheets of A4 size gloss paper, the residual potential _Vr2 of the electrophotographic photosensitive member was measured by a potential measuring device.

(environmental difference)
The difference (absolute value) between the residual potential _Vr1 and the residual potential _Vr2 was obtained as the environmental difference. Table 9 shows the results. In the present disclosure, the smaller the environmental difference, the better.

(Potential fluctuation evaluation during repeated use)
The electrophotographic photoreceptors obtained in Examples 1 to 97, Comparative Examples 1 to 4, and Reference Examples 1 and 2 were mounted on a copying machine, imagePRESS C800 manufactured by Canon Inc., and evaluated.
The above-described evaluation apparatus was installed in an environment of a temperature of 23° C. and a humidity of 50% RH, and the produced electrophotographic photosensitive member was mounted in a process cartridge for magenta color, mounted in the station of the magenta process cartridge, and evaluated. went.
The charging potential and the exposure amount of the exposing means were adjusted so that the charging potential was -700V and the exposure potential was -200V.
The cartridge containing the electrophotographic photosensitive member was attached to the evaluation apparatus, and the photosensitive member was repeatedly used by passing 30,000 sheets of paper. At a station in which an electrophotographic photosensitive member was installed, a monochromatic character image with a printing rate of 1% was formed repeatedly on 30,000 sheets of A4 size plain paper. The initial bright area potential and the bright area potential after repeated image formation of 30,000 sheets are compared, and this value is defined as the potential fluctuation value (ΔVl). After 30,000 sheets of paper were passed, it was allowed to stand for 5 minutes, the developing cartridge was replaced with a potential measuring device, and the bright area potential (Vlb) after repeated use was measured. The difference between the light potential after repeated use and the initial light potential (Vla) was taken as the light potential variation (ΔVl=|Vlb|−|Vla|).
In the present disclosure, the smaller the change in light area potential, the better, and the effect of the present disclosure is obtained.
Table 9 shows the results of evaluation in this manner.

（式（１）中、Ｒ^１１、Ｒ^１２、Ｒ^１３、Ｒ^１４、Ｒ^１５、及びＲ^１６は、それぞれ独立に、水素原子、メチル基、又はメトキシ基を示す。）
（構成２）
表面層を有する電子写真感光体であって、
該表面層が、
フッ素原子含有樹脂粒子と、
結着材料及び結着材料の原料から選ばれる少なくともいずれか１つと、
パーフルオロヘキサン酸と、
電荷輸送物質と
を含有する塗布液の塗膜から形成された層であり、
該塗布液における該パーフルオロヘキサン酸の含有量が、該塗布液の該フッ素原子含有樹脂粒子に対して０．０１０質量ｐｐｂ以上２５質量ｐｐｂ以下であり、
該電荷輸送物質が、下記式（１）で示される化合物である、
ことを特徴とする電子写真感光体。

（式（１）中、Ｒ^１１、Ｒ^１２、Ｒ^１３、Ｒ^１４、Ｒ^１５、及びＲ^１６は、それぞれ独立に、水素原子、メチル基、又はメトキシ基を示す。）
（構成３）
前記表面層が、下記式（２）で示される構造単位及び下記式（４）で示される構造単位から成る群より選択される少なくとも一の構造単位を有する重合体Ａをさらに含有する、構成１に記載の電子写真感光体。

（式（２）中、
Ｒ^２１は、水素原子、又はメチル基を示し、
Ｒ^２２は、単結合、メチレン基、又はエチレン基を示し、
Ｒｆ^１は、それぞれ独立に、炭素数１以上５以下のパーフルオロアルキレン基、又は炭素数１以上５以下のパーフルオロアルキリデン基を示し、
Ｒｆ^２は、炭素数１以上５以下のパーフルオロアルキル基を示し、
ｎは、１以上３以下の整数である。）

（式（４）中、
Ｒ^４１１は、炭素数１以上２以下のアルキリジン基を示し、
Ｒ^４２は、単結合、又は炭素数１以上３以下のアルキレン基を示し、
Ｒｆ^４は、炭素数１以上５以下のパーフルオロアルキル基を示す。）
（構成４）
前記塗布液が、下記式（２）で示される構造単位及び下記式（４）で示される構造単位から成る群より選択される少なくとも一の構造単位を有する重合体Ａをさらに含有する、構成２に記載の電子写真感光体。

（式（２）中、
Ｒ^２１は、水素原子、又はメチル基を示し、
Ｒ^２２は、単結合、メチレン基、又はエチレン基を示し、
Ｒｆ^１は、それぞれ独立に、炭素数１以上５以下のパーフルオロアルキレン基、又は炭素数１以上５以下のパーフルオロアルキリデン基を示し、
Ｒｆ^２は、炭素数１以上５以下のパーフルオロアルキル基を示し、
ｎは、１以上３以下の整数である。）

（式（４）中、
Ｒ^４１１は、炭素数１以上２以下のアルキリジン基を示し、
Ｒ^４２は、単結合、又は炭素数１以上３以下のアルキレン基を示し、
Ｒｆ^４は、炭素数１以上５以下のパーフルオロアルキル基を示す。）
（構成５）
前記表面層における前記重合体Ａの含有量が、前記表面層における前記フッ素原子含有樹脂粒子の含有量に対して２．０質量％以上１０質量％以下である、構成３に記載の電子写真感光体。
（構成６）
前記塗布液における前記重合体Ａの含有量が、前記塗布液の前記フッ素原子含有樹脂粒子の含有量に対して２．０質量％以上１０質量％以下である、構成４に記載の電子写真感光体。
（構成７）
前記重合体Ａが、構造単位として、前記式（２）で示される構造単位を有し、前記重合体Ａの重量平均分子量が、１６，０００以上１００，０００以下である、構成３又は５に記載の電子写真感光体。
（構成８）
前記重合体Ａが、下記式（３）で示される構造単位をさらに有する、構成３、５及び７のいずれか１項に記載の電子写真感光体。

（式（３）中、
Ｙ^Ａ１は、無置換のアルキレン基を示し、
Ｙ^Ｂは、無置換のアルキレン基、ハロゲン原子で置換されたアルキレン基、ヒドロキシ基で置換されたアルキレン基、エステル結合（－ＣＯＯ－）、アミド結合（－ＮＨＣＯ－）、若しくは、ウレタン結合（－ＮＨＣＯＯ－）、又は、これらの基及び結合から選ばれる一種以上と－Ｏ－若しくは－Ｓ－とを組み合わせて導き出せる２価の連結基、あるいは単結合を示し、Ｚ^Ａは、下記式（３Ａ）で示される構造、シアノ基、又はフェニル基を示し、
Ｒ^３１、及びＲ^３２は、それぞれ独立に、水素原子、又はメチル基を示し、
ｍは、２５以上１５０以下の整数である。）

（式（３Ａ）中、Ｚ^Ａ１は、炭素数１以上４以下のアルキル基を示す。）
（構成９）
前記重合体Ａが、構造単位として、前記式（２）で示される構造単位、及び前記式（４）で示される構造単位から成る群より選択される少なくとも一の構造単位、並びに、前記式（３）で示される構造単位、のみから成る、構成８に記載の電子写真感光体。
（構成１０）
前記式（４）中のＲｆ^４の炭素数が、２以上４以下である、構成３、５及び７～９のいずれか１項に記載の電子写真感光体。
（構成１１）
前記式（４）のＲ^４１１が、エチリジン基であり、重合体Ａの重量平均分子量が、３００，０００以下である、構成３、５及び７～１０のいずれか１項に記載の電子写真感光体。
（構成１２）
前記フッ素原子含有樹脂粒子が、ポリテトラフルオロエチレン樹脂粒子であり、
前記表面層の断面観察において、前記ポリテトラフルオロエチレン樹脂粒子の走査型電子顕微鏡による二次電子像から測定した一次粒子の長径の算術平均が、１５０ｎｍ以上３００ｎｍ以下である、
構成１、３、５、及び７～１１のいずれか１項に記載の電子写真感光体。
（構成１３）
前記表面層における前記フッ素原子含有樹脂粒子の含有量が、前記表面層の全質量に対して５．０質量％以上２０質量％以下である、構成１、３、５、及び７～１２のいずれか１項に記載の電子写真感光体。
（構成１４）
前記塗布液における前記フッ素原子含有樹脂粒子の含有量が、前記表面層の全質量に対して５．０質量％以上２０質量％以下である、構成２、４及び６のいずれか１項に記載の電子写真感光体。
（構成１５）
構成１～１４のいずれか１項に記載の電子写真感光体と、帯電手段、現像手段及びクリーニング手段からなる群より選ばれた少なくとも１つの手段と、を一体に支持し、電子写真装置本体に着脱自在である、ことを特徴とするプロセスカートリッジ。
（構成１６）
構成１～１４のいずれか１項に記載の電子写真感光体、並びに、帯電手段、露光手段、現像手段及び転写手段を有する、ことを特徴とする電子写真装置。
（方法１）
表面層を有する電子写真感光体の製造方法であって、
該製造方法が、
フッ素原子含有樹脂粒子に付着したパーフルオロヘキサン酸を抑制する工程（ｉ）、
フッ素原子含有樹脂粒子と、結着材料及び結着材料の原料から選ばれる少なくともいずれか１つと、パーフルオロヘキサン酸と、下記式（１）で示される電荷輸送物質と、を含有する塗布液を調製する工程（ｉｉ）、並びに、
該工程（ｉｉ）で調製された該塗布液の塗膜を形成し、該塗膜を乾燥及び／又は硬化させることによって該表面層を形成する工程（ｉｉｉ）
を有し、
該工程（ｉｉ）で調製された該塗布液における該パーフルオロヘキサン酸の含有量が、該塗布液中における該フッ素原子含有樹脂粒子に対して０．０１０質量ｐｐｂ以上２５質量ｐｐｂ以下である、
ことを特徴とする電子写真感光体の製造方法。

（式（１）中、Ｒ^１１、Ｒ^１２、Ｒ^１３、Ｒ^１４、Ｒ^１５、及びＲ^１６は、それぞれ独立に、水素原子、メチル基、又はメトキシ基を示す。） Embodiments according to the present disclosure include the following configurations and methods.
(Configuration 1)
An electrophotographic photoreceptor having a surface layer,
The surface layer is
fluorine atom-containing resin particles;
a binding material;
perfluorohexanoic acid;
a charge transport material;
contains
The content of the perfluorohexanoic acid in the surface layer is 0.010 mass ppb or more and 25 mass ppb or less with respect to the content of the fluorine atom-containing resin particles in the surface layer,
The charge transport material is a compound represented by the following formula (1),
An electrophotographic photoreceptor characterized by:

(In formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ each independently represent a hydrogen atom, a methyl group or a methoxy group.)
(Configuration 2)
An electrophotographic photoreceptor having a surface layer,
The surface layer is
fluorine atom-containing resin particles;
at least one selected from a binding material and raw materials of the binding material;
perfluorohexanoic acid;
A layer formed from a coating film of a coating liquid containing a charge-transporting substance,
The content of the perfluorohexanoic acid in the coating liquid is 0.010 mass ppb or more and 25 mass ppb or less with respect to the fluorine atom-containing resin particles in the coating liquid,
The charge transport material is a compound represented by the following formula (1),
An electrophotographic photoreceptor characterized by:

(In formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ each independently represent a hydrogen atom, a methyl group or a methoxy group.)
(Composition 3)
Configuration 1, wherein the surface layer further contains a polymer A having at least one structural unit selected from the group consisting of structural units represented by the following formula (2) and structural units represented by the following formula (4): The electrophotographic photoreceptor described in .

(In formula (2),
R ²¹ represents a hydrogen atom or a methyl group,
R ²² represents a single bond, a methylene group, or an ethylene group,
Rf ¹ each independently represents a perfluoroalkylene group having 1 to 5 carbon atoms or a perfluoroalkylidene group having 1 to 5 carbon atoms,
Rf ² represents a perfluoroalkyl group having 1 to 5 carbon atoms,
n is an integer of 1 or more and 3 or less. )

(In formula (4),
R ⁴¹¹ represents an alkylidine group having 1 to 2 carbon atoms,
R ⁴² represents a single bond or an alkylene group having 1 to 3 carbon atoms,
Rf ⁴ represents a perfluoroalkyl group having 1 to 5 carbon atoms. )
(Composition 4)
Configuration 2, wherein the coating liquid further contains a polymer A having at least one structural unit selected from the group consisting of structural units represented by the following formula (2) and structural units represented by the following formula (4): The electrophotographic photoreceptor described in .

(In formula (2),
R ²¹ represents a hydrogen atom or a methyl group,
R ²² represents a single bond, a methylene group, or an ethylene group,
Rf ¹ each independently represents a perfluoroalkylene group having 1 to 5 carbon atoms or a perfluoroalkylidene group having 1 to 5 carbon atoms,
Rf ² represents a perfluoroalkyl group having 1 to 5 carbon atoms,
n is an integer of 1 or more and 3 or less. )

(In formula (4),
R ⁴¹¹ represents an alkylidine group having 1 to 2 carbon atoms,
R ⁴² represents a single bond or an alkylene group having 1 to 3 carbon atoms,
Rf ⁴ represents a perfluoroalkyl group having 1 to 5 carbon atoms. )
(Composition 5)
The electrophotographic photosensitive composition according to Structure 3, wherein the content of the polymer A in the surface layer is 2.0% by mass or more and 10% by mass or less with respect to the content of the fluorine atom-containing resin particles in the surface layer. body.
(Composition 6)
The electrophotographic photosensitive composition according to configuration 4, wherein the content of the polymer A in the coating liquid is 2.0% by mass or more and 10% by mass or less with respect to the content of the fluorine atom-containing resin particles in the coating liquid. body.
(Composition 7)
In structure 3 or 5, wherein the polymer A has a structural unit represented by the formula (2) as a structural unit, and the weight average molecular weight of the polymer A is 16,000 or more and 100,000 or less The electrophotographic photoreceptor described.
(Composition 8)
The electrophotographic photoreceptor according to any one of Structures 3, 5 and 7, wherein the polymer A further has a structural unit represented by the following formula (3).

(In formula (3),
Y ^A1 represents an unsubstituted alkylene group,
Y ^B is an unsubstituted alkylene group, a halogen-substituted alkylene group, a hydroxy-substituted alkylene group, an ester bond (-COO-), an amide bond (-NHCO-), or a urethane bond (- NHCOO—), or a divalent linking group or a single bond that can be derived by combining one or more selected from these groups and bonds with —O— or —S—, and Z ^A is the following formula (3A) A structure represented by, a cyano group, or a phenyl group,
R ³¹ and R ³² each independently represent a hydrogen atom or a methyl group,
m is an integer of 25 or more and 150 or less. )

(In formula (3A), Z ^A1 represents an alkyl group having 1 to 4 carbon atoms.)
(Composition 9)
The polymer A has, as structural units, at least one structural unit selected from the group consisting of structural units represented by the formula (2) and structural units represented by the formula (4), and the formula ( 3).
(Configuration 10)
The electrophotographic photoreceptor according to any one of Structures 3, 5 and 7 to 9, wherein Rf ⁴ in formula (4) has 2 or more and 4 or less carbon atoms.
(Composition 11)
The electrophotographic photosensitive member according to any one of Structures 3, 5, and 7 to 10, wherein R ⁴¹¹ in formula (4) is an ethylidine group, and the weight average molecular weight of polymer A is 300,000 or less. body.
(Composition 12)
the fluorine atom-containing resin particles are polytetrafluoroethylene resin particles,
In cross-sectional observation of the surface layer, the arithmetic mean of the major diameter of the primary particles measured from the secondary electron image of the polytetrafluoroethylene resin particles with a scanning electron microscope is 150 nm or more and 300 nm or less.
The electrophotographic photoreceptor according to any one of Structures 1, 3, 5, and 7 to 11.
(Composition 13)
Any one of structures 1, 3, 5, and 7 to 12, wherein the content of the fluorine atom-containing resin particles in the surface layer is 5.0% by mass or more and 20% by mass or less with respect to the total mass of the surface layer. 2. The electrophotographic photoreceptor according to 1. or 1.
(Composition 14)
Any one of configurations 2, 4 and 6, wherein the content of the fluorine atom-containing resin particles in the coating liquid is 5.0% by mass or more and 20% by mass or less with respect to the total mass of the surface layer. electrophotographic photoreceptor.
(Composition 15)
The electrophotographic photoreceptor according to any one of structures 1 to 14 and at least one means selected from the group consisting of charging means, developing means and cleaning means are integrally supported, and an electrophotographic apparatus main body is provided. A process cartridge characterized by being detachable.
(Composition 16)
An electrophotographic apparatus comprising: the electrophotographic photoreceptor according to any one of Structures 1 to 14; charging means; exposure means; developing means; and transfer means.
(Method 1)
A method for producing an electrophotographic photoreceptor having a surface layer,
The manufacturing method is
step (i) of suppressing perfluorohexanoic acid adhering to fluorine atom-containing resin particles;
A coating liquid containing fluorine atom-containing resin particles, at least one selected from a binder material and raw materials for the binder material, perfluorohexanoic acid, and a charge transport substance represented by the following formula (1): preparing step (ii), and
Step (iii) of forming the surface layer by forming a coating film of the coating liquid prepared in the step (ii) and drying and/or curing the coating film
has
The content of the perfluorohexanoic acid in the coating liquid prepared in the step (ii) is 0.010 mass ppb or more and 25 mass ppb or less with respect to the fluorine atom-containing resin particles in the coating liquid.
A method for producing an electrophotographic photoreceptor, characterized by:

(In formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ each independently represent a hydrogen atom, a methyl group or a methoxy group.)

101 support 102 undercoat layer 103 charge generation layer 104 charge transport layer 1 electrophotographic photoreceptor 2 charging means 3 exposure light 4 developing means 5 transfer means 6 transfer material 7 pre-exposure light 8 cleaning means 9 process cartridge 10 intermediate transfer body 11 Transfer paper 12 Paper feed path 13 Paper feed tray 14 Secondary transfer means 15 Fixing means 16 Paper discharge unit 17 Yellow process cartridge 18 Magenta process cartridge 19 Cyan process cartridge 20 Black process cartridge

Claims (17)

An electrophotographic photoreceptor having a surface layer,
The surface layer is
fluorine atom-containing resin particles;
a binding material;
perfluorohexanoic acid;
a charge transport material;
contains
The content of the perfluorohexanoic acid in the surface layer is 0.010 mass ppb or more and 25 mass ppb or less with respect to the content of the fluorine atom-containing resin particles in the surface layer,
The charge transport material is a compound represented by the following formula (1),
An electrophotographic photoreceptor characterized by:

(In formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ each independently represent a hydrogen atom, a methyl group or a methoxy group.) An electrophotographic photoreceptor having a surface layer,
The surface layer is
fluorine atom-containing resin particles;
at least one selected from a binding material and raw materials of the binding material;
perfluorohexanoic acid; and
A layer formed from a coating film of a coating liquid containing a charge-transporting substance,
The content of the perfluorohexanoic acid in the coating liquid is 0.010 mass ppb or more and 25 mass ppb or less with respect to the fluorine atom-containing resin particles in the coating liquid,
The charge-transporting substance is a compound represented by the following formula (1),
An electrophotographic photoreceptor characterized by:

(In formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ each independently represent a hydrogen atom, a methyl group or a methoxy group.) The surface layer further contains a polymer A having at least one structural unit selected from the group consisting of structural units represented by the following formula (2) and structural units represented by the following formula (4): 1. The electrophotographic photoreceptor according to 1.

(In formula (2),
R ²¹ represents a hydrogen atom or a methyl group,
R ²² represents a single bond, a methylene group, or an ethylene group,
Rf ¹ each independently represents a perfluoroalkylene group having 1 to 5 carbon atoms or a perfluoroalkylidene group having 1 to 5 carbon atoms,
Rf ² represents a perfluoroalkyl group having 1 to 5 carbon atoms,
n is an integer of 1 or more and 3 or less. )

(In formula (4),
R ⁴¹¹ represents an alkylidine group having 1 to 2 carbon atoms,
R ⁴² represents a single bond or an alkylene group having 1 to 3 carbon atoms,
Rf ⁴ represents a perfluoroalkyl group having 1 to 5 carbon atoms. ) The coating liquid further contains a polymer A having at least one structural unit selected from the group consisting of structural units represented by the following formula (2) and structural units represented by the following formula (4): 2. The electrophotographic photoreceptor according to 2 above.

(In formula (2),
R ²¹ represents a hydrogen atom or a methyl group,
R ²² represents a single bond, a methylene group, or an ethylene group,
Rf ¹ each independently represents a perfluoroalkylene group having 1 to 5 carbon atoms or a perfluoroalkylidene group having 1 to 5 carbon atoms,
Rf ² represents a perfluoroalkyl group having 1 to 5 carbon atoms,
n is an integer of 1 or more and 3 or less. )

(In formula (4),
R ⁴¹¹ represents an alkylidine group having 1 to 2 carbon atoms,
R ⁴² represents a single bond or an alkylene group having 1 to 3 carbon atoms,
Rf ⁴ represents a perfluoroalkyl group having 1 to 5 carbon atoms. ) 4. The electrophotography according to claim 3, wherein the content of the polymer A in the surface layer is 2.0% by mass or more and 10% by mass or less with respect to the content of the fluorine atom-containing resin particles in the surface layer. photoreceptor. 5. The electrophotography according to claim 4, wherein the content of the polymer A in the coating liquid is 2.0% by mass or more and 10% by mass or less with respect to the content of the fluorine atom-containing resin particles in the coating liquid. photoreceptor. 4. The polymer A according to claim 3, wherein the polymer A has a structural unit represented by the formula (2) as a structural unit, and the weight average molecular weight of the polymer A is 16,000 or more and 100,000 or less. electrophotographic photoreceptor. 4. The electrophotographic photoreceptor according to claim 3, wherein the polymer A further has a structural unit represented by the following formula (3).

(In formula (3),
Y ^A1 represents an unsubstituted alkylene group,
Y ^B is an unsubstituted alkylene group, a halogen-substituted alkylene group, a hydroxy-substituted alkylene group, an ester bond (-COO-), an amide bond (-NHCO-), or a urethane bond (- NHCOO—), or a divalent linking group or a single bond that can be derived by combining one or more selected from these groups and bonds with —O— or —S—, and Z ^A is the following formula (3A) A structure represented by, a cyano group, or a phenyl group,
R ³¹ and R ³² each independently represent a hydrogen atom or a methyl group,
m is an integer of 25 or more and 150 or less. )

(In formula (3A), Z ^A1 represents an alkyl group having 1 to 4 carbon atoms.) The polymer A has, as structural units, at least one structural unit selected from the group consisting of structural units represented by the formula (2) and structural units represented by the formula (4), and the formula ( 9. The electrophotographic photoreceptor according to claim 8, comprising only the structural unit represented by 3). 4. The electrophotographic photoreceptor according to claim 3, wherein ^Rf4 in the formula (4) has 2 or more and 4 or less carbon atoms. 4. The electrophotographic photoreceptor according to claim 3, wherein ^R411 in the formula (4) is an ethylidine group, and the weight average molecular weight of the polymer A is 300,000 or less. the fluorine atom-containing resin particles are polytetrafluoroethylene resin particles,
In cross-sectional observation of the surface layer, the arithmetic mean of the major diameter of the primary particles measured from the secondary electron image of the polytetrafluoroethylene resin particles with a scanning electron microscope is 150 nm or more and 300 nm or less.
The electrophotographic photoreceptor according to claim 1. 2. The electrophotographic photoreceptor according to claim 1, wherein the content of said fluorine atom-containing resin particles in said surface layer is 5.0% by mass or more and 20% by mass or less with respect to the total mass of said surface layer. 3. The electrophotographic photoreceptor according to claim 2, wherein the content of said fluorine atom-containing resin particles in said coating liquid is 5.0% by mass or more and 20% by mass or less with respect to the total mass of said surface layer. An electrophotographic apparatus body integrally supporting the electrophotographic photosensitive member according to any one of claims 1 to 14 and at least one means selected from the group consisting of charging means, developing means and cleaning means, and A process cartridge, characterized in that it is detachably attached to. An electrophotographic apparatus comprising: the electrophotographic photoreceptor according to any one of claims 1 to 14; charging means; exposure means; developing means; and transfer means. A method for producing an electrophotographic photoreceptor having a surface layer,
The manufacturing method is
step (i) of suppressing perfluorohexanoic acid adhering to fluorine atom-containing resin particles;
A coating liquid containing fluorine atom-containing resin particles, at least one selected from a binder material and raw materials for the binder material, perfluorohexanoic acid, and a charge transport substance represented by the following formula (1): preparing step (ii), and
Step (iii) of forming the surface layer by forming a coating film of the coating liquid prepared in the step (ii) and drying and/or curing the coating film
has
The content of the perfluorohexanoic acid in the coating liquid prepared in the step (ii) is 0.010 mass ppb or more and 25 mass ppb or less with respect to the fluorine atom-containing resin particles in the coating liquid.
A method for producing an electrophotographic photoreceptor, characterized by:

(In formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ each independently represent a hydrogen atom, a methyl group or a methoxy group.)

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