JP2008096528A - Electrophotographic photoreceptor, image forming apparatus and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having sufficient wear resistance and sufficiently suppressing image defects (particularly image deletion and stripe irregularity). <P>SOLUTION: The electrophotographic photoreceptor has a photosensitive layer and a protective layer successively formed on a conductive substrate; wherein the protective layer contains a resin having a crosslinked structure and a metal oxide, and the metal oxide is surface treated with at least one kind of organic silicon compound selected from a group consisting of hydrolyzable organic silicon compounds having a sulfonic acid ester group, organic silicon compounds having a thiol group and organic silicon compounds having a sulfide group. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member, an image forming apparatus, and a process cartridge.

  The electrophotographic system is used in image forming apparatuses (electrophotographic apparatuses) such as copying machines and laser beam printers because high-speed and high-quality printing is possible. Such image forming apparatuses are required to have higher speed, higher image quality, and longer life.

  In particular, in recent years, as a charging device in an image forming apparatus, instead of a conventional non-contact type charging device such as a corotron, a contact type charging device with less ozone generation has been used, and the life of the image forming apparatus has been extended. From the viewpoint, the abrasion resistance of the electrophotographic photosensitive member is strongly demanded.

As means for improving the abrasion resistance of the electrophotographic photosensitive member, conventionally, for example, pH buffering agents (alkali metal salts of organic acids, alkaline earth metal salts, etc.) and wear-resistant particles (fluorine resin, silicone resin, An electrophotographic photoreceptor in which a protective layer containing a metal oxide or the like is provided on a photosensitive layer has been proposed (see Patent Document 1). In addition, an electrophotographic photosensitive member provided with a surface layer containing a white pigment (ZnO, TiO ₂ or the like), metal oxide fine particles, and a binder (acrylic resin, phenol resin, or the like) has been proposed. (See Patent Document 2). Also, an electrophotographic photosensitive member provided with a surface protective layer containing a hole transport material having a specific structure in which fine powder of metal or metal oxide is dispersed in a binder resin (silicone resin, acrylic resin, etc.) Has been proposed (see Patent Document 3).
JP 2001-305761 A JP-A-62-18869 JP-A-4-281461

  However, conventional electrophotographic photosensitive members including the electrophotographic photosensitive members described in Patent Documents 1 to 3 cannot obtain sufficient wear resistance, or metal oxides are used to improve wear resistance. When particles such as the above are increased, the occurrence of image quality defects (particularly, image flow and streak unevenness) cannot be sufficiently suppressed.

  Therefore, the present invention provides an electrophotographic photosensitive member that has sufficient wear resistance and that can sufficiently suppress the occurrence of image quality defects (particularly, image flow and streak-like unevenness), and such An object of the present invention is to provide an image forming apparatus and a process cartridge provided with an electrophotographic photosensitive member.

In order to achieve the above object, the present invention provides:
An electrophotographic photoreceptor comprising a photosensitive layer and a protective layer in this order on a conductive substrate,
The protective layer contains a resin having a crosslinked structure and a metal oxide,
The surface of the metal oxide is at least one organosilicon compound selected from the group consisting of a hydrolyzable organosilicon compound having a sulfonate group, an organosilicon compound having a thiol group, and an organosilicon compound having a sulfide group An electrophotographic photoreceptor that has been processed is provided.

  The electrophotographic photoreceptor of the present invention has sufficient wear resistance and can sufficiently suppress the occurrence of image quality defects (particularly, image flow and streak-like unevenness). Although the detailed reason is not clear, even if the protective layer provided on the photosensitive layer does not contain many particles such as metal oxides, it has sufficient hardness and is imparted with appropriate conductivity. This is presumed to be due to

  The metal oxide may be subjected to a surface treatment with the organosilicon compound and then subjected to a further surface treatment. Preferred examples of such a further surface treatment include a fluorine-based silane coupling agent (fluorine Surface treatment with an atom-containing silane coupling agent).

  Moreover, it is preferable that content of the said metal oxide is 0.5 volume% or more and 10 volume% or less with respect to the volume of the said protective layer. When the content is less than 0.5% by volume, wear tends to increase as compared with the case where the content is within the above range. On the other hand, if the content exceeds 10% by volume, the resistance value of the protective layer becomes lower than that in the case where the content is in the above range, and image blur tends to occur.

  The average particle diameter of the metal oxide is preferably 10 nm or more and 100 nm or less. When the average particle size is less than 10 nm, the dispersibility of the metal oxide in the protective layer tends to deteriorate compared to the case where the average particle size is in the above range. On the other hand, when the average particle diameter exceeds 100 nm, the transparency of the protective layer tends to be impaired as compared with the case where the average particle diameter is within the above range. Here, the “average particle diameter” means an average diameter of 100 particles arbitrarily selected from a scanning electron microscope (SEM) photograph.

  The metal oxide is preferably at least one selected from tin oxide, zinc oxide, titanium oxide, and aluminum oxide in terms of conductivity.

  At least a part of the resin having a crosslinked structure contained in the protective layer is preferably a phenol resin or a siloxane resin in terms of mechanical strength, electrical characteristics, and deposit removability.

  The resin having a crosslinked structure contained in the protective layer is preferably a resin having a structure derived from a charge transporting compound. Examples of the charge transporting compound include the following general formulas (I) to (VI). ) Is preferred.

_{^{F [- (X 1) n1}} R 1 -Z 1 H] m1 (I)
[In Formula (I), F represents an organic group derived from a compound having a hole transporting ability, R ¹ represents an alkylene group, Z ¹ represents an oxygen atom, a sulfur atom, NH or COO, and X ¹ Represents an oxygen atom or a sulfur atom, m1 represents an integer of 1 to 4, and n1 represents 0 or 1. ]

^{_{F [- (X 2) n2}} - (R 2) n3 - (Z 2) n4 G] n5 (II)
[In Formula (II), F represents an organic group derived from a compound having a hole transporting ability, X ² represents an oxygen atom or a sulfur atom, R ² represents an alkylene group, Z ² represents an oxygen atom, S represents a sulfur atom, NH or COO, G represents an epoxy group, n2, n3 and n4 each independently represents 0 or 1, and n5 represents any integer of 1 to 4. ]

F [-D-Si (R ³ ) _(3-a) Q _a ] _b (III)
[In Formula (III), F represents a b-valent organic group derived from a compound having a hole transporting ability, D represents a divalent group having flexibility, and R ³ represents a hydrogen atom, substituted or unsubstituted. An alkyl group or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, a represents an integer of 1 to 3, and b represents an integer of 1 to 4. ]

［式（ＩＶ）中、Ｆは正孔輸送性を有する化合物から誘導される有機基を示し、Ｔは２価の基を示し、Ｙは酸素原子又は硫黄原子を示し、Ｒ^４、Ｒ^５及びＲ^６は各々独立に水素原子又は１価の有機基を示し、Ｒ^７は１価の有機基を示し、ｍ２は０又は１を示し、ｎ６は１〜４のいずれかの整数を示す。但し、Ｒ^６とＲ^７は互いに結合してＹをヘテロ原子とする複素環を形成してもよい。］

[In Formula (IV), F represents an organic group derived from a compound having a hole transporting property, T represents a divalent group, Y represents an oxygen atom or a sulfur atom, R ⁴ , R ⁵ and R ⁶ each independently represents a hydrogen atom or a monovalent organic group, R ⁷ represents a monovalent organic group, m 2 represents 0 or 1, and n 6 represents an integer of 1 to 4. However, R ⁶ and R ⁷ may combine with each other to form a heterocycle having Y as a heteroatom. ]

［式（Ｖ）中、Ｆは正孔輸送性を有する化合物から誘導される有機基を示し、Ｔは２価の基を示し、Ｒ^８は１価の有機基を示し、ｍ３は０又は１を示し、ｎ７は１〜４のいずれかの整数を示す。］

[In Formula (V), F represents an organic group derived from a compound having a hole transporting property, T represents a divalent group, R ⁸ represents a monovalent organic group, and m3 represents 0 or 1 N7 represents any integer of 1 to 4. ]

［式（ＶＩ）中、Ｆは正孔輸送性を有する化合物から誘導される有機基を示し、Ｌはアルキレン基を示し、Ｒ^９は１価の有機基を示し、ｎ８は１〜４のいずれかの整数を示す。］

[In Formula (VI), F represents an organic group derived from a compound having a hole transporting property, L represents an alkylene group, R ⁹ represents a monovalent organic group, and n8 represents any one of 1-4. Indicates an integer. ]

  The present invention also provides the electrophotographic photosensitive member, a charging unit that charges the electrophotographic photosensitive member, an exposure unit that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image, and an electrostatic latent image. An image forming apparatus (electrophotographic apparatus) is provided that includes developing means for developing with toner to form a toner image and transfer means for transferring the toner image to a transfer medium. In the present specification, “medium to be transferred” means a medium (paper or the like) to which a toner image formed on the electrophotographic photosensitive member is finally transferred.

The present invention further includes
The electrophotographic photoreceptor,
A charging means for charging the electrophotographic photosensitive member, a developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image, and a toner remaining on the surface of the electrophotographic photosensitive member At least one selected from the group consisting of cleaning means to be removed;
A process cartridge is provided.

  Since the image forming apparatus and the process cartridge include the electrophotographic photosensitive member, a high-quality image can be stably supplied over a long period of time.

  According to the present invention, an electrophotographic photosensitive member having sufficient wear resistance and capable of sufficiently suppressing the occurrence of image quality defects (particularly, image flow and streak-like unevenness), and such An image forming apparatus and a process cartridge provided with an electrophotographic photosensitive member are provided.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

(Electrophotographic photoreceptor)
FIG. 1 is a schematic cross-sectional view showing an electrophotographic photoreceptor according to a preferred embodiment of the present invention. An electrophotographic photoreceptor 1 shown in FIG. 1 is a function-separated photoreceptor having a photosensitive layer in which a charge generation layer and a charge transport layer are separately provided. More specifically, the electrophotographic photoreceptor 1 has a structure in which an undercoat layer 4, a charge generation layer 5, a charge transport layer 6 and a protective layer 7 are laminated in this order on a conductive substrate 2. The layer 7 constitutes the outermost surface layer, and the charge generation layer 5 and the charge transport layer 6 constitute the photosensitive layer 3.

  Hereinafter, each element of the electrophotographic photoreceptor 1 will be described in detail.

  First, the conductive substrate 2 will be described. Examples of the conductive substrate 2 include a metal plate, a metal drum, and a metal belt using a metal or an alloy such as aluminum, copper, zinc, stainless steel, chromium, nickel, molybdenum, vanadium, indium, gold, and platinum. However, it is not limited to these. For example, a paper, a plastic film, a belt, glass, or the like coated, evaporated, or laminated with a conductive polymer, a conductive compound such as indium oxide, or a metal or alloy such as aluminum, palladium, or gold may be used. In addition, for the purpose of preventing injection, improving adhesiveness, preventing interference fringes, etc., for example, anodizing treatment, boehmite treatment or honing treatment, or treatment with an acidic treatment liquid composed of phosphoric acid, chromic acid and hydrofluoric acid. It can also be used.

  Further, in order to prevent interference fringes generated when laser light is irradiated, the surface of the conductive substrate 2 is preferably roughened. The degree of roughening is preferably 0.04 μm or more and 0.5 μm or less in terms of centerline average roughness Ra. If Ra is smaller than 0.04 μm, it becomes close to a mirror surface, so that the effect of preventing interference cannot be obtained. If Ra is larger than 0.5 μm, even if a film according to the present invention is formed, the image quality becomes rough, which is not suitable.

  As a method for roughening the surface of the conductive substrate 2, wet honing in which an abrasive is suspended in water and sprayed on the substrate surface, centerless grinding in which the substrate is pressed against a rotating grindstone, and grinding is performed continuously, Anodization or the like is preferable, and without roughening the substrate surface itself, a resin layer in which conductive or semiconductive powder is dispersed is formed on the substrate surface, and particles dispersed in the resin layer are used. A roughening method is also preferred.

  In the anodizing treatment, aluminum is used as an anode, and an oxide film is formed on the aluminum surface by anodizing in an electrolyte solution. Examples of the electrolyte solution include a sulfuric acid solution and an oxalic acid solution. However, the porous anodic oxide film is chemically active as it is, easily contaminated, and has a large resistance fluctuation due to the environment. Therefore, the pores of the anodic oxide film are closed with pressurized water vapor or boiling water (a metal salt such as nickel may be added) by volume expansion due to a hydration reaction, and changed to a more stable hydrated oxide. Process.

  The thickness of the anodized film is preferably from 0.3 μm to 15 μm. When it is thinner than 0.3 μm, the barrier property against injection is poor and the effect tends to be insufficient. On the other hand, if it is thicker than 15 μm, the residual potential tends to increase due to repeated use.

  The treatment with the acidic treatment liquid can be performed as follows. The mixing ratio of phosphoric acid, chromic acid and hydrofluoric acid in the acidic treatment liquid is such that phosphoric acid is 10% by mass to 11% by mass, chromic acid is 3% by mass to 5% by mass, and hydrofluoric acid is 0.5% by mass or more. The concentration of these acids is preferably 13.5% by mass or more and 18% by mass or less. The processing temperature is 42 ° C. or higher and 48 ° C. or lower. However, by keeping the processing temperature high, a thicker film can be formed faster. The thickness of the film is preferably 0.3 μm or more and 15 μm or less. When it is thinner than 0.3 μm, the barrier property against injection is poor and the effect tends to be insufficient. On the other hand, if it is thicker than 15 μm, the residual potential tends to increase due to repeated use.

  The boehmite treatment is immersed in pure water of 90 ° C. or higher and 100 ° C. or lower for 5 minutes or longer and 60 minutes or shorter, or is contacted with heated steam of 90 ° C. or higher and 120 ° C. or lower for 5 minutes or longer and 60 minutes or shorter. Can be performed. The thickness of the film is preferably 0.1 μm or more and 5 μm or less. This is further treated with an electrolyte solution having low film solubility, such as adipic acid, boric acid, borate, phosphate, phthalate, maleate, benzoate, tartrate, citrate. An oxidation treatment may be performed.

  When non-interfering light is used as the light source, it is not particularly necessary to roughen the interference fringes, and it is possible to prevent the occurrence of defects due to irregularities on the surface of the conductive substrate 2, which is suitable for longer life. .

  Next, the undercoat layer 4 will be described. The undercoat layer 4 is provided as necessary. In particular, when the conductive substrate 2 is subjected to acidic solution treatment or boehmite treatment, the defect concealing power of the conductive substrate 2 becomes insufficient. Since it is easy, it is preferable to form the undercoat layer 4.

  Materials used for the undercoat layer 4 include zirconium chelate compounds, zirconium alkoxide compounds, organic zirconium compounds such as zirconium coupling agents, titanium chelate compounds, titanium alkoxide compounds, organic titanium compounds such as titanate coupling agents, aluminum chelate compounds, In addition to organoaluminum compounds such as aluminum coupling agents, antimony alkoxide compounds, germanium alkoxide compounds, indium alkoxide compounds, indium chelate compounds, manganese alkoxide compounds, manganese chelate compounds, tin alkoxide compounds, tin chelate compounds, aluminum silicon alkoxide compounds, aluminum Existence of titanium alkoxide compounds, aluminum zirconium alkoxide compounds, etc. Metal compounds. In particular, an organic zirconium compound, an organic titanyl compound, an organic aluminum compound, a low residual potential, preferable in that show good electrophotographic characteristics.

  The undercoat layer 4 may further contain a silane coupling agent. As silane coupling agents, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris-2-methoxyethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxy Silane, γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-2-aminoethylaminopropyltrimethoxysilane, γ-mercapropropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, β-3 , 4-epoxycyclohexyltrimethoxysilane and the like. These mixing ratios can be appropriately set as necessary.

  The undercoat layer 4 may further contain a binder resin. As binder resin, polyvinyl alcohol, polyvinyl methyl ether, poly-N-vinyl imidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, polyamide, polyimide, casein, gelatin, polyethylene, polyester, phenol resin , Vinyl chloride-vinyl acetate copolymer, epoxy resin, polyvinyl pyrrolidone, polyvinyl pyridine, polyurethane, polyglutamic acid, polyacrylic acid, and other known binder resins can be used. These mixing ratios can be appropriately set as necessary.

  The undercoat layer 4 may further contain an electron transporting pigment from the viewpoint of reducing residual potential and improving environmental stability. Examples of the electron transport pigment include organic pigments such as perylene pigment, bisbenzimidazole perylene pigment, polycyclic quinone pigment, indigo pigment, and quinacridone pigment described in JP-A-47-30330, cyano group, nitro group, and nitroso group. And organic pigments such as bisazo pigments having electron-withdrawing substituents such as halogen atoms, phthalocyanine pigments, and inorganic pigments such as zinc oxide and titanium oxide. Among these pigments, perylene pigments, bisbenzimidazole perylene pigments, polycyclic quinone pigments, zinc oxide, and titanium oxide are preferable because of their high electron mobility. In addition, these pigments may be surface-treated with the above coupling agent, binder or the like for the purpose of controlling dispersibility and charge transportability. If the amount of the electron transporting pigment is too large, the strength of the undercoat layer is lowered and a coating film defect is caused. Therefore, it is used at 95% by mass or less, preferably 90% by mass or less.

  In addition, the undercoat layer 4 may further contain fine powders of various organic compounds or inorganic compounds from the viewpoint of improving electrical characteristics, improving light scattering properties, and the like. In particular, white pigments such as titanium oxide, zinc oxide, zinc white, zinc sulfide, lead white, lithopone, extender pigments such as alumina, calcium carbonate, barium sulfate, polyethylene terephthalate resin particles, benzoguanamine resin particles, styrene resin particles, etc. It is valid. The particle size of the fine powder is preferably 0.01 μm or more and 2 μm or less. The fine powder is contained as necessary, but the content thereof is preferably 10% by mass or more and 90% by mass or less, and 30% by mass or more and 80% by mass with respect to the total mass of the solid content of the undercoat layer 4. The following is more preferable.

  The undercoat layer 4 can be formed by applying an undercoat layer forming coating solution containing the constituent material of the undercoat layer 4 on the conductive substrate 2 and drying it. Any solvent can be used for the coating solution as long as it dissolves an organometallic compound or resin and does not cause gelation or aggregation when an electron transport pigment is mixed / dispersed. For example, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene Ordinary organic solvents such as toluene can be used alone or in admixture of two or more. Further, as a dispersion treatment method for the coating liquid, methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, a paint shaker, and an ultrasonic wave can be used. Furthermore, as a coating method of the coating liquid, a normal method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, or the like can be used. Drying after coating is performed at a temperature at which the solvent can be evaporated and a film can be formed. The thickness of the undercoat layer 4 is generally 0.01 μm or more and 30 μm or less, preferably 0.05 μm or more and 25 μm or less.

  Next, the charge generation layer 5 will be described. The charge generation layer 5 contains a charge generation material and a binder resin.

  Examples of charge generation materials include azo pigments such as bisazo pigments and trisazo pigments, condensed aromatic pigments such as dibromoanthanthrone, organic pigments such as perylene pigments, pyrrolopyrrole pigments, and phthalocyanine pigments, and trigonal selenium and zinc oxide. Known pigments such as inorganic pigments can be used. In particular, when exposure light having a wavelength of 380 nm to 500 nm is used for image formation, metal and metal-free phthalocyanine pigments, trigonal selenium, dibromoanthanthrone, etc. preferable. Among them, hydroxygallium phthalocyanine disclosed in JP-A-5-263007 and JP-A-5-279591, chlorogallium phthalocyanine disclosed in JP-A-5-98181, JP-A-5-140472 and special Dichlorotin phthalocyanine disclosed in Kaihei 5-140473 and titanyl phthalocyanine disclosed in JP-A-4-189873 and JP-A-5-43813 are particularly preferred.

  Examples of the binder resin include a wide range of insulating resins and organic photoconductive polymers such as poly-N-vinyl carbazole, polyvinyl anthracene, polyvinyl pyrene, and polysilane. Preferred binder resins include polyvinyl butyral resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin. Insulating resins such as polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin are not limited thereto. These binder resins can be used individually by 1 type or in mixture of 2 or more types. The mixing ratio (mass ratio) of the charge generation material and the binder resin is preferably 10: 1 to 1:10.

  The charge generation layer 5 can be formed by applying a charge generation layer forming coating solution containing the constituent material of the charge generation layer 5 on the undercoat layer 4 and drying it. Solvents used in the coating solution include methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, and methylene. Usual organic solvents such as chloride, chloroform, chlorobenzene, and toluene can be used alone or in admixture of two or more. In addition, as a dispersion method when preparing the coating liquid, a usual method such as a ball mill dispersion method, an attritor dispersion method, a sand mill dispersion method, or the like can be used. Conditions that do not change the crystal form are required. Further, at the time of dispersion, it is effective to make the pigment particles have a particle size of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less. Furthermore, as a coating method of the coating liquid, a normal method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, or the like can be used. Drying after coating is performed at a temperature at which the solvent can be evaporated and a film can be formed. The thickness of the charge generation layer 5 is generally 0.1 μm or more and 5 μm or less, preferably 0.2 μm or more and 2.0 μm or less.

  Next, the charge transport layer 6 will be described. The charge transport layer 6 contains a charge transport material and a binder resin, or contains a polymer charge transport material.

  As charge transport materials, quinone compounds such as p-benzoquinone, chloranil, bromanyl, anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, xanthone compounds, benzophenone compounds Compounds, electron transport compounds such as cyanovinyl compounds, ethylene compounds, triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds, etc. Although a hole transportable compound is mentioned, it is not limited to these in particular. These charge transport materials can be used alone or in combination of two or more.

  Moreover, as a charge transport material, the compound represented by the following general formula (a-1), (a-2) or (a-3) from a mobility viewpoint is preferable.

In the above formula (a-1), R ³⁴ represents a hydrogen atom or a methyl group, and k10 represents 1 or 2. Ar ⁶ and Ar ^{7 each} represents a substituted or unsubstituted aryl group, —C ₆ H ₄ —C (R ³⁸ ) ═C (R ³⁹ ) (R ⁴⁰ ), or —C ₆ H ₄ —CH═CH. —CH═C (Ar) ₂ represents a substituent, which is substituted with a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkyl group having 1 to 3 carbon atoms. A substituted amino group is mentioned. R ³⁸ , R ³⁹ and R ⁴⁰ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, and Ar represents a substituted or unsubstituted aryl group.

In the formula (a-2), R ³⁵ and R ³⁵ ′ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms, R ³⁶ , R ³⁶ ', R ³⁷ and R ³⁷ ' are each independently a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an amino group substituted with an alkyl group having 1 to 2 carbon atoms, Or an unsubstituted aryl group, -C (R ³⁸ ) = C (R ³⁹ ) (R ⁴⁰ ), or -CH = CH-CH = C (Ar) ₂ , wherein R ³⁸ , R ³⁹ and R ⁴⁰ are each Independently, a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, Ar represents a substituted or unsubstituted aryl group. M4 and m5 each independently represents an integer of 0 to 2.

In the above formula (a-3), R ⁴¹ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a substituted or unsubstituted aryl group, or —CH═CH—CH. = C (Ar) ₂ is shown. Ar represents a substituted or unsubstituted aryl group. R ⁴² , R ⁴² ′, R ⁴³ , and R ⁴³ ′ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkyl having 1 to 2 carbon atoms. An amino group substituted with a group, or a substituted or unsubstituted aryl group is shown.

  Examples of the binder resin used for the charge transport layer 6 include polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, and vinylidene chloride. -Known films such as acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin An electrically insulating resin that can be formed is exemplified. Among these, polycarbonate resin, polyester resin, methacrylic resin and acrylic resin are preferable in terms of excellent compatibility with charge transport materials, solubility in solvents, and strength. These binder resins can be used individually by 1 type or in mixture of 2 or more types. The blending ratio (mass ratio) of the charge transport material and the binder resin is preferably 10: 1 to 1: 5.

  As the polymer charge transporting material, known materials having charge transporting properties such as poly-N-vinylcarbazole and polysilane can be used. In particular, the polyester polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 have a high charge transporting property and are particularly preferable. Although the polymer charge transport material alone can be used as a constituent material of the charge transport layer 6, it may be mixed with the binder resin to form a film.

  The charge transport layer 6 can be formed by applying a charge transport layer forming coating solution containing the constituent material of the charge transport layer 6 on the charge generation layer 5 and drying it. Solvents used in the coating solution include aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, ketones such as acetone and 2-butanone, and halogenated aliphatic hydrocarbons such as methylene chloride, chloroform and ethylene chloride. Ordinary organic solvents such as cyclic or linear ethers such as tetrahydrofuran and ethyl ether. These can be used individually by 1 type or in mixture of 2 or more types. As a coating method of the coating solution, a usual method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, or the like can be used. Drying after coating is performed at a temperature at which the solvent can be evaporated and a film can be formed. The thickness of the charge transport layer 6 is preferably 5 μm or more and 50 μm or less, more preferably 10 μm or more and 30 μm or less.

  Further, for the purpose of preventing deterioration of the photoreceptor due to ozone or oxidizing gas generated in the image forming apparatus, light, heat, or the like, the photosensitive layer 3 (the charge generation layer 5 and the charge transport layer 6) has an antioxidant. Additives such as an agent, a light stabilizer and a heat stabilizer can be contained. Examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and their derivatives, organic sulfur compounds, and organic phosphorus compounds. Examples of the light stabilizer include derivatives such as benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine.

  The photosensitive layer 3 (the charge generation layer 5 and the charge transport layer 6) contains at least one electron-accepting substance for the purpose of improving sensitivity, reducing residual potential, and reducing fatigue during repeated use. Can be made.

Examples of the electron acceptor include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, Examples include chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, and phthalic acid. Of these, fluorenone-based, quinone-based, and benzene derivatives having electron-withdrawing substituents such as Cl, CN, and NO ₂ are particularly preferable.

  Finally, the protective layer 7 will be described. The protective layer 7 contains a resin having a crosslinked structure and a metal oxide.

  Examples of the resin having a crosslinked structure include phenol resin, siloxane resin, epoxy resin, urethane resin, melamine resin, and acrylic resin. Among these, a phenol resin and a siloxane resin are preferable and a phenol resin is particularly preferable in terms of mechanical strength, electrical characteristics, and deposit removal.

  Examples of the phenol resin include a resin obtained by curing a phenol derivative having a methylol group. Phenol derivatives having a methylol group include two hydroxyl groups such as resorcin, bisphenol, etc., phenols, cresols, xylenols, paraalkylphenols, paraphenylphenols, substituted phenols containing one hydroxyl group, catechol, resorcinol, hydroquinone, etc. Substituted phenols, bisphenols such as bisphenol A and bisphenol Z, biphenols and the like, obtained by reacting a compound having a phenol structure with formaldehyde, paraformaldehyde, etc. in the presence of an acid catalyst or an alkali catalyst, As an example, what is generally marketed as a phenol resin is mentioned.

As the acid catalyst, sulfuric acid, paratoluenesulfonic acid, phenolsulfonic acid, phosphoric acid and the like can be used. Examples of the alkali catalyst include hydroxides and oxides of alkali metals and alkaline earth metals such as NaOH, KOH, Ca (OH) ₂ , Mg (OH) ₂ , Ba (OH) ₂ , CaO, and MgO. An amine catalyst or acetates such as zinc acetate and sodium acetate can be used. Here, examples of the amine-based catalyst include ammonia, hexamethylenetetramine, trimethylamine, triethylamine, triethanolamine, and the like, but are not limited thereto. When an alkali catalyst is used, carriers are remarkably trapped by the remaining catalyst and the electrophotographic characteristics tend to deteriorate. In such a case, it is preferable to inactivate or remove by distilling off under reduced pressure, neutralizing with an acid, or contacting with an adsorbent such as silica gel or an ion exchange resin.

  Examples of the siloxane resin include a resin obtained from an organosilicon compound having a hydrolyzable group such as methyltrimethoxysilane and tetramethoxysilane.

  The resin contained in the protective layer 7 preferably has a structure derived from a charge transporting compound in order to improve electrical properties. Examples of such a charge transporting compound include film forming properties, mechanical strength, and the like. In addition, the compounds represented by the following general formulas (I), (II), (III), (IV), (V) and (VI) are preferable because of excellent stability.

_{^{F [- (X 1) n1}} R 1 -Z 1 H] m1 (I)
[In Formula (I), F represents an organic group derived from a compound having a hole transporting ability, R ¹ represents an alkylene group, Z ¹ represents an oxygen atom, a sulfur atom, NH or COO, and X ¹ Represents an oxygen atom or a sulfur atom, m1 represents an integer of 1 to 4, and n1 represents 0 or 1. ]
_{^{F [- (X 2) n2}} - (R 2) n3 - (Z 2) n4 G] n5 (II)
[In Formula (II), F represents an organic group derived from a compound having a hole transporting ability, X ² represents an oxygen atom or a sulfur atom, R ² represents an alkylene group, Z ² represents an oxygen atom, S represents a sulfur atom, NH or COO, G represents an epoxy group, n2, n3 and n4 each independently represents 0 or 1, and n5 represents any integer of 1 to 4. ]
F [-D-Si (R ³ ) _(3-a) Q _a ] _b (III)
[In Formula (III), F represents a b-valent organic group derived from a compound having a hole transporting ability, D represents a divalent group having flexibility, and R ³ represents a hydrogen atom, substituted or unsubstituted. An alkyl group or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, a represents an integer of 1 to 3, and b represents an integer of 1 to 4. ]

［式（ＩＶ）中、Ｆは正孔輸送性を有する化合物から誘導される有機基を示し、Ｔは２価の基を示し、Ｙは酸素原子又は硫黄原子を示し、Ｒ^４、Ｒ^５及びＲ^６は各々独立に水素原子又は１価の有機基を示し、Ｒ^７は１価の有機基を示し、ｍ２は０又は１を示し、ｎ６は１〜４のいずれかの整数を示す。但し、Ｒ^６とＲ^７は互いに結合してＹをヘテロ原子とする複素環を形成してもよい。］

[In Formula (IV), F represents an organic group derived from a compound having a hole transporting property, T represents a divalent group, Y represents an oxygen atom or a sulfur atom, R ⁴ , R ⁵ and R ⁶ each independently represents a hydrogen atom or a monovalent organic group, R ⁷ represents a monovalent organic group, m 2 represents 0 or 1, and n 6 represents an integer of 1 to 4. However, R ⁶ and R ⁷ may combine with each other to form a heterocycle having Y as a heteroatom. ]

［式（Ｖ）中、Ｆは正孔輸送性を有する化合物から誘導される有機基を示し、Ｔは２価の基を示し、Ｒ^８は１価の有機基を示し、ｍ３は０又は１を示し、ｎ７は１〜４のいずれかの整数を示す。］

[In Formula (V), F represents an organic group derived from a compound having a hole transporting property, T represents a divalent group, R ⁸ represents a monovalent organic group, and m3 represents 0 or 1 N7 represents any integer of 1 to 4. ]

［式（ＶＩ）中、Ｆは正孔輸送性を有する化合物から誘導される有機基を示し、Ｌはアルキレン基を示し、Ｒ^９は１価の有機基を示し、ｎ８は１〜４のいずれかの整数を示す。］

[In Formula (VI), F represents an organic group derived from a compound having a hole transporting property, L represents an alkylene group, R ⁹ represents a monovalent organic group, and n8 represents any one of 1-4. Indicates an integer. ]

  The F in the compounds represented by the general formulas (I) to (VI) is preferably a group represented by the following general formula (VII).

［式（ＶＩＩ）中、Ａｒ^１、Ａｒ^２、Ａｒ^３及びＡｒ^４は各々独立に置換又は未置換のアリール基を示し、Ａｒ^５は置換若しくは未置換のアリール基又はアリーレン基を示し、且つＡｒ^１〜Ａｒ^５のうち１〜４個は、上記一般式（Ｉ）で表わされる化合物における下記一般式（ＶＩＩＩ）で示される部位、上記一般式（ＩＩ）で表わされる化合物における下記一般式（ＩＸ）で示される部位、上記一般式（ＩＩＩ）で表わされる化合物における下記一般式（Ｘ）で示される部位、上記一般式（ＩＶ）で表わされる化合物における下記一般式（ＸＩ）で示される部位、上記一般式（Ｖ）で表される化合物における下記一般式（ＸＩＩ）で表される部位、又は上記一般式（ＶＩ）で表される化合物における下記一般式（ＸＩＩＩ）と結合するための結合手を有する。］
−（Ｘ^１）_ｎ１Ｒ^１−Ｚ^１Ｈ （ＶＩＩＩ）
−（Ｘ^２）_ｎ２−（Ｒ^２）_ｎ３−（Ｚ^２）_ｎ４Ｇ （ＩＸ）
−Ｄ−Ｓｉ（Ｒ^３）_{（３-ａ）}Ｑ_ａ （Ｘ）

[In formula (VII), Ar ¹ , Ar ² , Ar ³ and Ar ⁴ each independently represent a substituted or unsubstituted aryl group, Ar ⁵ represents a substituted or unsubstituted aryl group or an arylene group, and Ar ^{1 to} 4 of ^{1 to} Ar ⁵ are a moiety represented by the following general formula (VIII) in the compound represented by the above general formula (I), a general formula (IX) in the compound represented by the above general formula (II), ), A site represented by the following general formula (X) in the compound represented by the above general formula (III), a site represented by the following general formula (XI) in the compound represented by the above general formula (IV), It binds to the moiety represented by the following general formula (XII) in the compound represented by the general formula (V) or the following general formula (XIII) in the compound represented by the general formula (VI). Have a bond for ]
_{^{- (X 1) n1 R 1}} -Z 1 H (VIII)
_{^{- (X 2) n2 - (}} R 2) n3 - (Z 2) n4 G (IX)
-D-Si (R ³ ) _(3-a) Q _a (X)

In addition, as the substituted or unsubstituted aryl group represented by Ar ^{1 to} Ar ⁴ in the general formula (VII), specifically, aryl groups represented by the following general formulas (1) to (7) are preferable. .

In the above formula ^{(1) ~ (7),} R 10 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, alkoxy group having 1 to 4 carbon atoms, phenyl which is substituted by them A group or an unsubstituted phenyl group, or an aralkyl group having 7 to 10 carbon atoms, wherein R ^{11 to} R ¹³ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, carbon An alkoxy group having 1 to 4 carbon atoms, a phenyl or unsubstituted phenyl group substituted therewith, an aralkyl group having 7 to 10 carbon atoms or a halogen atom; Ar represents a substituted or unsubstituted arylene group; One of the structures represented by the above general formulas (VIII) to (XIII) is shown, c and s each represent 0 or 1, and t represents any integer of 1 to 3.

  Moreover, as Ar in the aryl group represented by the above formula (7), an arylene group represented by the following formula (8) or (9) is preferable.

In the above formulas (8) and (9), R ¹⁴ and R ¹⁵ are each substituted with a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. A substituted phenyl group, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, or a halogen atom, and t represents any integer of 1 to 3.

  Moreover, as Z 'in the aryl group represented by the above formula (7), divalent groups represented by the following formulas (10) to (17) are preferable.

In formulas (10) to (17), R ¹⁶ and R ¹⁷ are each substituted with a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. A phenyl group, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, or a halogen atom, W represents a divalent group, and q and r each represent an integer of 1 to 10 T represents an integer of 1 to 3, respectively.

  In the above formulas (16) to (17), W represents a divalent group represented by the following formulas (18) to (26). In formula (25), u represents an integer of 0 to 3.

In addition, the specific structure of Ar ⁵ in the general formula (VI) is as follows. When k = 0, the structure of c = 1 in the specific structure of Ar ^{1 to} Ar ⁴ and when Ar = 1, the Ar 5 ^The structure of c = 0 in the specific structure of ^{1 to} Ar ⁴ is given.

  Specific examples of the compound represented by the general formula (I) include the following compounds (I-1) to (I-38). In addition, in the following table | surface, although the bond is described, the thing in which the substituent is not described shows a methyl group.

  Specific examples of the compound represented by the general formula (II) include the following compounds (II-1) to (II-47). In the following table, Me or a bond is described but a substituent is not described, a methyl group, Et represents an ethyl group.

Specific examples of the compound represented by the general formula (III) include the following compounds (III-1) to (III-61). The following compounds (III-1) to (III-61) are prepared by combining Ar ^{1 to} Ar ⁵ and k of the compound represented by the general formula (VI) as shown in the following table, and alkoxysilyl The group (s) is the specific one shown in the table below.

  Specific examples of the compound represented by the general formula (IV) include the following compounds (IV-1) to (IV-40). In the following table, Me or a bond is described but a substituent is not described, a methyl group, Et represents an ethyl group.

  Specific examples of the compound represented by the general formula (V) include the following compounds (V-1) to (V-55). In the following table, Me or a bond is described but a substituent is not described indicates a methyl group.

  Specific examples of the compound represented by the general formula (VI) include the following compounds (VI-1) to (VI-17). In the following table, Me represents a methyl group, and Et represents an ethyl group.

  As the surface-treated metal oxide contained in the protective layer 7, known metal oxides can be used. However, tin oxide, zinc oxide, and oxidation can be used in terms of conductivity and dispersibility in the resin. Titanium and aluminum oxide are preferred, and tin oxide and zinc oxide are more preferred. The metal oxide may be doped with a small amount of other elements. For example, tin oxide doped with strontium or zinc oxide doped with aluminum can be used. A metal oxide can be used individually by 1 type or in combination of 2 or more types.

  As content of a metal oxide, 0.5 volume% or more and 10 volume% or less are preferable with respect to the volume of a protective layer. When the content is less than 0.5% by volume, wear tends to increase as compared with the case where the content is within the above range. On the other hand, if the content exceeds 10% by volume, the resistance value of the protective layer becomes lower than that in the case where the content is in the above range, and image blur tends to occur.

The powder resistance value of the metal oxide is preferably 1 Ω · cm to 1 × 10 ⁷ Ω · cm, and more preferably 1 × 10 Ω · cm to 1 × 10 ⁵ Ω · cm. When the powder resistance value is less than 1 Ω · cm, the resistance value of the protective layer is lower than when the resistance is 1 Ω · cm or more and 1 × 10 ⁷ Ω · cm or less, and image flow occurs under high temperature and high humidity. It tends to be easy to do. On the other hand, if the particle's resistance exceeds 1 × 10 ⁷ Ω · cm, as compared with the case of less than 1 [Omega · cm or more 1 × 10 ⁷ Ω · cm, electrical properties tend to deteriorate.

  The average particle size of the metal oxide is preferably 10 nm to 100 nm, and more preferably 30 nm to 80 nm. When the average particle size is less than 10 nm, the surface area becomes larger and the dispersibility of the metal oxide in the protective layer tends to be worse than when the average particle size is 10 nm or more and 100 nm or less. On the other hand, when the average particle diameter exceeds 100 nm, the metal oxide, the binder, the charge transport agent, and the like are not uniform in the protective layer and the transparency of the protective layer is impaired as compared with the case of 10 nm to 100 nm. Tend.

  The metal oxide was surface-treated with at least one organosilicon compound having a hydrolyzable organosilicon compound having a sulfonate group, an organosilicon compound having a thiol group, and an organosilicon compound having a sulfide group. Is.

  Examples of the hydrolyzable organosilicon compound having a sulfonic acid ester group include the following compounds (A-1) to (A-6).

Examples of the organosilicon compound having a thiol group and the organosilicon compound having a sulfide group include the following compounds (B-1) to (B-4). In formula (B-4), n and m each represent an integer of 1 or more.

  The metal oxide may be subjected to a surface treatment with the above-mentioned at least one organosilicon compound and then a further surface treatment. As a preferred example of such a further surface treatment, a fluorine-based silane coupling agent may be used. Surface treatment with (fluorine atom-containing silane coupling agent) can be mentioned. Examples of the fluorine-based silane coupling agent include the following compounds (C-1) to (C-5).

  The amount of the surface treatment agent (hydrolyzable organosilicon compound having a sulfonic acid ester group, organosilicon compound having a thiol group, or organosilicon compound having a sulfide group) used for the surface treatment of the metal oxide may be metal oxidation. 0.5 mass% or more and 20 mass% or less are preferable with respect to the mass of a thing, and 3 mass% or more and 10 mass% or less are still more preferable. When the amount of the surface treatment agent is less than 0.5% by mass, the effect of the surface treatment agent tends to hardly appear, and when it exceeds 20% by mass, the increase in the residual potential tends to be hardly suppressed.

  The surface treatment of the metal oxide can be performed using a known method such as a wet method or a dry method.

  For example, when a surface treatment is performed by a wet method, the metal oxide is dispersed in a solvent by stirring or using an ultrasonic wave, a sand mill, an attritor, a ball mill, etc., and a solution of an organosilicon compound is added, After stirring or dispersing, a uniform surface treatment can be performed by removing the solvent. The solvent can be removed by filtration or distillation. After removing the solvent, baking can be further performed at 100 ° C. or higher. The temperature and time for performing the printing can be set in an arbitrary range as long as desired electrophotographic characteristics can be obtained. In order to remove the moisture contained in the metal oxide, a method of removing with stirring and heating in a solvent used for the surface treatment, a method of removing by azeotropy with the solvent, or the like can also be used.

  In addition, when the surface treatment is performed by a dry method, the organosilicon compound is dropped directly or dissolved in an organic solvent while stirring the metal oxide with a mixer having a large shearing force, and the mixture is added to dry air or By spraying with nitrogen gas, a uniform surface treatment can be performed. The dropping of the organosilicon compound and the spraying of the mixture are preferably performed at a temperature lower than the boiling point of the solvent used. When dripping or spraying is performed at a temperature equal to or higher than the boiling point of the solvent, the solvent evaporates before being uniformly stirred, and the organosilicon compound is locally aggregated, making it difficult to perform uniform treatment. The surface-treated metal oxide can be further baked at 100 ° C. or higher. The temperature and time for performing the printing can be set in an arbitrary range as long as desired electrophotographic characteristics can be obtained.

  When a hydrolyzable organosilicon compound having a sulfonic acid ester group is used, the sulfonic acid ester group bonded to the metal oxide may be further heated to decompose after the surface treatment to generate a sulfonic acid group. Good. In addition, when an organosilicon compound having a thiol group or an organosilicon compound having a sulfide group is used, after the surface treatment, the thiol group or sulfide group bonded to the metal oxide is oxidized (for example, by hydrogen peroxide). ) It may be converted into a sulfonic acid group.

  In addition to the surface-treated metal oxide, the protective layer 7 may contain conductive inorganic particles. Examples of the conductive inorganic particles include metals, metal oxides, and carbon black. Examples of the metal include aluminum, zinc, copper, chromium, nickel, silver, and stainless steel, or those obtained by depositing these metals on the surface of plastic particles. Metal oxides include tin oxide, zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, antimony or tantalum-doped tin oxide, antimony-doped zirconium oxide, etc. Is mentioned. These can be used alone or in combination of two or more. When two or more types are used in combination, they may be simply mixed, formed into a solid solution, or fused. The average particle diameter of the conductive particles is preferably 0.3 μm or less, particularly preferably 0.1 μm or less, from the viewpoint of the transparency of the protective layer. Moreover, it is preferable to use a metal oxide in terms of transparency. Moreover, it is preferable to treat the particle surface in order to control dispersibility. Examples of the treating agent include silane coupling agents, silicone oils, siloxane compounds, and surfactants. These preferably contain a fluorine atom.

The protective layer 7 may contain a compound represented by the following general formula (XIV) in order to control various physical properties such as strength and film resistance of the protective layer 7.
Si (R ⁵⁰ ) _(4-c) Q _c (XIV)
[In the formula (XIV), R ⁵⁰ represents a hydrogen atom, an alkyl group, or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, and c represents an integer of 1 to 4. ]

  Specific examples of the compound represented by the general formula (XIV) include the following silane coupling agents. Examples of silane coupling agents include tetrafunctional silanes such as tetramethoxysilane and tetraethoxysilane (c = 4); methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, methyltrimethoxyethoxysilane, vinyltri Methoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxy Silane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, (tridecafluoro-1,1,2,2-tetrahydrooctyl L) Triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- (heptafluoroisopropoxy) propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H , 1H, 2H, 2H-perfluorodecyltriethoxysilane, trifunctional alkoxysilanes such as 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (c = 3); dimethyldimethoxysilane, diphenyldimethoxysilane, methyl Bifunctional alkoxysilanes such as phenyldimethoxysilane (c = 2); monofunctional alkoxysilanes such as trimethylmethoxysilane (c = 1) and the like. In order to improve the strength of the film, tri- and tetrafunctional alkoxysilanes are preferable, and in order to improve flexibility and film formability, mono- and bifunctional alkoxysilanes are preferable.

  In addition, a silicon-based hard coat agent produced mainly from these coupling agents can also be used. Commercially available hard coat agents include KP-85, X-40-9740, X-40-2239 (manufactured by Shin-Etsu Silicone), and AY42-440, AY42-441, AY49-208 (manufactured by Toray Dow Corning). Etc.) can be used.

In addition, in order to increase the strength of the protective layer 7, the protective layer 7 preferably contains a compound having two or more silicon atoms as shown in the following general formula (XV).
B- (Si (R ⁵¹ ) _(3-d) Q _d ) ₂ (XV)
[In the above formula (XI), B represents a divalent organic group, R ⁵¹ represents a hydrogen atom, an alkyl group, or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, and d represents 1 to 3. Indicates any integer. ]

  More specifically, for example, the following compounds (XV-1) to (XV-16) are preferable as the compound represented by the general formula (XV).

  Furthermore, the protective layer 7 contains various resins for the purpose of improving discharge gas resistance, mechanical strength, scratch resistance, particle dispersibility, viscosity control, torque reduction, wear amount control, pot life extension, and the like. Can do. Examples of such resins include resins that are soluble in alcoholic or ketone solvents, such as polyvinyl butyral resins, polyvinyl formal resins, partially acetalized polyvinyl acetal resins in which a part of butyral is modified with formal, acetoacetal, etc. Polyvinyl acetal resin (for example, SLECK B, K manufactured by Sekisui Chemical Co., Ltd.), polyamide resin, cellulose resin, phenol resin, epoxy resin, polyimide resin and the like are preferable. In particular, polyvinyl acetal resin, polyamide resin, and phenol resin are preferable in order to improve electrical characteristics.

  The molecular weight of the resin is preferably from 2,000 to 100,000, more preferably from 5,000 to 50,000. If the molecular weight is less than 2000, the desired effect tends not to be obtained. On the other hand, if the molecular weight is more than 100,000, the solubility tends to be low, the content is limited, or the film formation tends to be poor during coating. is there. The content is preferably 1% by mass to 40% by mass, more preferably 1% by mass to 30% by mass, and still more preferably 5% by mass to 20% by mass. When the content is less than 1% by mass, a desired effect tends to be difficult to be obtained. On the other hand, when the content is more than 40% by mass, image blur tends to occur under high temperature and high humidity. Said resin can be used individually by 1 type or in mixture of 2 or more types.

  In order to extend pot life and control film properties, the protective layer 7 preferably contains a cyclic compound having a repeating structural unit represented by the following general formula (XVI) or a derivative of the compound. .

［上記式（ＸＶＩ）中、Ａ^１及びＡ^２は、各々独立に一価の有機基を示す。］

[In the above formula (XVI), A ¹ and A ² each independently represent a monovalent organic group. ]

  Commercially available cyclic siloxane is mentioned as a cyclic compound which has a repeating structural unit shown by general formula (XVI). Specifically, cyclic dimethylcyclosiloxanes such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, 1,3,5-trimethyl-1,3,5- Triphenylcyclotrisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetraphenylcyclotetrasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7 , 9-pentaphenylcyclopentasiloxane and other cyclic methylphenylcyclosiloxanes, hexaphenylcyclotrisiloxane and other cyclic phenylcyclosiloxanes, and 3- (3,3,3-trifluoropropyl) methylcyclotrisiloxane and other fluorine Atom-containing cyclosiloxanes, methylhydrosiloxa Mixture, pentamethylcyclopentasiloxane, hydrosilyl group-containing cyclosiloxanes such as phenyl hydrocyclosiloxane, siloxanes annular vinyl group-containing cyclosiloxanes such as penta vinyl pentamethylcyclopentasiloxane and the like. These cyclic siloxane compounds can be used individually by 1 type or in mixture of 2 or more types.

  The protective layer 7 can also contain a resin having a plurality of groups having active hydrogen in the side chain and having a fluorine atom or a silicone bond for the purpose of further improving the lubricity. By including a resin having a fluorine atom or a silicone bond, discharge gas resistance, mechanical strength, scratch resistance, particle dispersibility, viscosity control, torque reduction, wear amount control, pot life extension, cleaning system life extension, etc. An effect is obtained. In addition, by using a compound having a plurality of active hydrogens in the side chain, chemical bonds can be formed in the crosslinked structure, so that these resins are easily dispersed uniformly in the film, and the above effects can be maintained over a long period of time. In addition, defects during coating can be reduced. Furthermore, by using these resins, it is possible to contain a large amount of fluorine-based and silicone-based materials whose contents are limited without causing defects in the coating film.

  Further, the protective layer 7 can contain various particles in order to control the contamination resistance adhesion, lubricity, hardness and the like of the surface of the electrophotographic photosensitive member.

  Examples of the particles include silicon atom-containing particles. The silicon atom-containing particles are particles containing silicon as a constituent element, and specific examples include colloidal silica and silicone particles. The colloidal silica used as the silicon atom-containing particles has a volume average particle diameter of preferably 1 nm or more and 100 nm or less, more preferably 10 nm or more and 30 nm or less, and an acidic or alkaline aqueous dispersion, or an organic solvent such as alcohol, ketone or ester. What was chosen from what was disperse | distributed in and generally marketed can be used. The content of colloidal silica is not particularly limited, but is preferably 0.1% by mass or more and 50% by mass with respect to the total solid content in the protective layer in terms of film formability, electrical characteristics, and strength. Hereinafter, it is more preferably 0.1% by mass or more and 30% by mass or less.

  Silicone particles used as silicon atom-containing particles are spherical and have a volume average particle diameter of preferably 1 nm to 500 nm, more preferably 10 nm to 100 nm, and are selected from silicone resin particles, silicone rubber particles, and silicone surface-treated silica particles. In general, commercially available products can be used.

  Silicone particles are small particles that are chemically inert and excellent in dispersibility in resin, and since the content required to obtain more sufficient properties is low, the electron does not hinder the crosslinking reaction. The surface properties of the photographic photoreceptor can be improved. That is, improve the lubricity and water repellency of the surface of the electrophotographic photosensitive member while being uniformly incorporated into a strong cross-linked structure, and maintain good wear resistance and contamination resistance adhesion over a long period of time. Can do. The content of the silicone particles is preferably 0.1% by mass or more and 30% by mass or less, and more preferably 0.5% by mass or more and 10% by mass or less with respect to the total solid content in the protective layer.

Other particles include fluorine-based particles such as ethylene tetrafluoride, ethylene trifluoride, propylene hexafluoride, vinyl fluoride, vinylidene fluoride, and the 8th Polymer Materials Forum Lecture Proceedings p89. As shown, particles made of a resin obtained by copolymerizing a fluororesin and a monomer having a hydroxyl group, ZnO—Al ₂ O ₃ , SnO ₂ —Sb ₂ O ₃ , In ₂ O ₃ —SnO ₂ , ZnO—TiO ₂ , ZnO—TiO ₂ , MgO—Al ₂ O ₃ , FeO—TiO ₂ , TiO ₂ , SnO ₂ , In ₂ O ₃ , ZnO, MgO, and other semiconductive metal oxides.

  Further, the protective layer 7 may contain silicone oil in order to control the contamination resistance adhesion, lubricity, hardness and the like of the electrophotographic photosensitive member surface. Examples of the silicone oil include silicone oils such as dimethylpolysiloxane, diphenylpolysiloxane, and phenylmethylsiloxane, amino-modified polysiloxane, epoxy-modified polysiloxane, carboxyl-modified polysiloxane, carbinol-modified polysiloxane, methacryl-modified polysiloxane, and mercapto. Examples thereof include reactive silicone oils such as modified polysiloxane and phenol-modified polysiloxane. These may be added in advance to the protective layer-forming coating solution, or may be impregnated, for example, under reduced pressure or under pressure after the electrophotographic photosensitive member 1 is produced.

  Further, the protective layer 7 can contain additives such as a plasticizer, a surface modifier, an antioxidant, and a photodegradation inhibitor. Examples of the plasticizer include biphenyl, biphenyl chloride, terphenyl, dibutyl phthalate, diethylene glycol phthalate, dioctyl phthalate, triphenyl phosphate, methyl naphthalene, benzophenone, chlorinated paraffin, polypropylene, polystyrene, and various fluorohydrocarbons. .

  The protective layer 7 may contain an antioxidant having a hindered phenol, a hindered amine, a thioether, or a phosphite partial structure. Such an antioxidant is effective in improving potential stability and image quality when the environment changes.

  Examples of the antioxidant include the following compounds. For example, as a hindered phenol-based antioxidant, “Sumilizer BHT-R”, “Sumilizer MDP-S”, “Sumilizer BBM-S”, “Sumizer WX-R”, “Sumizer NW”, “Sumizer BP-76”. ”,“ Sumilizer BP-101 ”,“ Sumilizer GA-80 ”,“ Sumilizer GM ”,“ Sumilizer GS ”(manufactured by Sumitomo Chemical Co., Ltd.),“ IRGANOX1010 ”,“ IRGANOX1035 ”,“ IRGANOX1076 ”,“ IRGANOX1098 ” “IRGANOX1135”, “IRGANOX1141”, “IRGANOX1222”, “IRGANOX1330”, “IRGANOX1425WL”, “ “RGANOX1520L”, “IRGANOX245”, “IRGANOX259”, “IRGANOX3114”, “IRGANOX3790”, “IRGANOX5057”, “IRGANOX565” (above, manufactured by Ciba Specialty Chemicals), “Adekastab AO-20”, “Adekastab AO-30” , "ADK STAB AO-40", "ADK STAB AO-50", "ADK STAB AO-60", "ADK STAB AO-70", "ADK STAB AO-80", "ADK STAB AO-330" (above, manufactured by Asahi Denka) . As the hindered amine-based antioxidants, “Sanol LS2626”, “Sanol LS765”, “Sanol LS770”, “Sanol LS744” (above, Sankyo Lifetech Co., Ltd.), “Tinubin 144”, “Tinuvin 622LD” (above) , Manufactured by Ciba Specialty Chemicals), “Mark LA57”, “Mark LA67”, “Mark LA62”, “Mark LA68”, “Mark LA63” (above, manufactured by Asahi Denka), “Sumilyzer TPS” (above, Sumitomo) Chemical Co., Ltd.), thioether-based antioxidants, "Sumilyzer TP-D" (manufactured by Sumitomo Chemical Co., Ltd.), and phosphite-based antioxidants, "Mark 2112", "Mark PEP-8", " "Mark PEP 24G", "Mark PEP 36", "Mark 329K", "Mark HP 10" (Above, Asahi Denka Co., Ltd.) can be mentioned, in particular hindered phenolic antioxidants and hindered amine antioxidants are preferred. Further, they may be modified with a substituent (for example, alkoxysilyl group) capable of undergoing a crosslinking reaction with the material forming the crosslinked film.

  The protective layer 7 can be formed by applying a coating liquid for forming a protective layer containing the constituent material of the protective layer 7 on the charge transport layer 6 and drying it. In the case of forming a resin having a structure derived from a charge transporting compound, a charge transporting compound capable of reacting with a raw material compound of the resin (for example, a phenol derivative having a methylol group) is also a constituent material.

  Preparation of the coating solution for forming the protective layer is carried out in the absence of a solvent or, if necessary, alcohols such as methanol, ethanol, propanol and butanol; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran, diethyl ether and dioxane Etc. can be carried out using a solvent such as Such solvents may be used alone or in combination of two or more, but preferably have a boiling point of 100 ° C. or lower. The amount of the solvent used can be arbitrarily set. However, when the charge transporting compound is contained, if the amount of the solvent is too small, the charge transporting compound is likely to be precipitated. And preferably 0.5 parts by mass or more and 30 parts by mass or less, more preferably 1 part by mass or more and 20 parts by mass or less.

  In the case of forming a resin having a structure derived from a charge transporting compound, it is preferable to add a catalyst that promotes the reaction between the resin raw material compound and the charge transporting compound to the protective layer forming coating solution. Such catalysts include inorganic acids such as hydrochloric acid, acetic acid, sulfuric acid, organic acids such as formic acid, propionic acid, oxalic acid, benzoic acid, phthalic acid, maleic acid, potassium hydroxide, sodium hydroxide, calcium hydroxide, In addition to alkaline catalysts such as ammonia and triethylamine, solid catalysts insoluble in the system as shown below can also be used. When a solid catalyst that is insoluble in a photofunctional compound, a reaction product, water, a solvent or the like is used, the stability of the coating solution tends to be improved.

The solid catalyst insoluble in the system is not particularly limited as long as the catalyst component is insoluble in the charge transporting compound, other additives, water, solvent and the like. Examples of the solid catalyst insoluble in the system include Amberlite 15, Amberlite 200C, Amberlyst 15E (above, manufactured by Rohm and Haas); Dowex MWC-1-H, Dowex 88, Dowex HCR- W2 (above, manufactured by Dow Chemical Co.); Lebatit SPC-108, Lebatit SPC-118 (above, manufactured by Bayer); Diaion RCP-150H (manufactured by Mitsubishi Kasei); Sumikaion KC-470, Duolite C26-C , Duolite C-433, Duolite-464 (manufactured by Sumitomo Chemical Co., Ltd.); Cation exchange resins such as Nafion-H (manufactured by DuPont); Amberlite IRA-400, Amberlite IRA-45 (above, Anion exchange resin such as Rohm &Haas); Zr (O ₃ PCH ₂₎ Inorganic solids in which a group containing a protonic acid group is bonded to the surface, such as CH ₂ SO ₃ H) ₂ or Th (O ₃ PCH ₂ CH ₂ COOH) ₂ ; a polyorganosiloxane having a sulfonic acid group, etc. Polyorganosiloxanes containing protonic acid groups; heteropolyacids such as cobalt tungstic acid and phosphomolybdic acid; isopolyacids such as niobic acid, tantalum acid and molybdic acid; unit systems such as silica gel, alumina, chromia, zirconia, CaO and MgO Metal oxides; complex metal oxides such as silica-alumina, silica-magnesia, silica-zirconia, zeolites; clay minerals such as acid clay, activated clay, montmorillonite, kaolinite; metal sulfate such as LiSO ₄ and MgSO ₄ salt; phosphoric acid zirconia, metals such as lanthanum phosphate phosphate; LiNO ₃ Mn (NO _{3) 2} and the like of a metal nitrate; such on silica gel by reacting aminopropyltriethoxysilane obtained solid, inorganic solids group containing an amino group is bonded to a surface; amino-modified silicone resin And polyorganosiloxane containing an amino group.

  The addition amount of the solid catalyst insoluble in the system is not particularly limited, but when a charge transporting compound is contained, it is preferably 0.1 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the charge transporting compound. Further, as described above, these solid catalysts are insoluble in the raw material compounds, reaction products, solvents and the like, and therefore can be easily removed after the reaction according to a conventional method.

  The reaction temperature and reaction time are appropriately selected according to the type and amount of the raw material compound and solid catalyst, and the reaction temperature is usually 0 ° C. or higher and 100 ° C. or lower, preferably 10 ° C. or higher and 70 ° C. or lower, more preferably 15 The reaction time is preferably 10 minutes or more and 100 hours or less. When the reaction time exceeds the above upper limit, gelation tends to occur.

  When preparing a coating solution for forming a protective layer, when a catalyst that is insoluble in the system is used, it is preferable to use a catalyst that is further dissolved in the system for the purpose of improving strength, liquid storage stability, and the like. . Such catalysts include, in addition to those described above, aluminum triethylate, aluminum triisopropylate, aluminum tri (sec-butyrate), mono (sec-butoxy) aluminum diisopropylate, diisopropoxyaluminum (ethyl acetoacetate). ), Aluminum tris (ethyl acetoacetate), aluminum bis (ethyl acetoacetate) monoacetylacetonate, aluminum tris (acetylacetonate), aluminum diisopropoxy (acetylacetonate), aluminum isopropoxy-bis (acetylacetonate) Organoaluminum compounds such as aluminum tris (trifluoroacetylacetonate) and aluminum tris (hexafluoroacetylacetonate) It is below.

  In addition to organoaluminum compounds, organotin compounds such as dibutyltin dilaurate, dibutyltin dioctiate, dibutyltin diacetate; titanium tetrakis (acetylacetonate), titanium bis (butoxy) bis (acetylacetonate), titanium bis Organic titanium compounds such as (isopropoxy) bis (acetylacetonate); zirconium tetrakis (acetylacetonate), zirconium bis (butoxy) bis (acetylacetonate), zirconium bis (isopropoxy) bis (acetylacetonate), etc. Zirconium compounds; etc. can also be used, but from the viewpoint of safety, low cost, and pot life length, organoaluminum compounds are preferred, and aluminum chelate compounds are more preferred. .

  The amount of the catalyst dissolved in the system is not particularly limited, but when a charge transporting compound is contained, it is preferably 0.1 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the charge transporting compound. Particularly preferred is from 10 to 10 parts by weight.

  Moreover, when forming the protective layer 7, when using an organometallic compound as a catalyst, it is preferable to add a polydentate ligand from the surface of pot life and hardening efficiency. Examples of such multidentate ligands include, but are not limited to, those shown below and those derived therefrom.

  Specifically, β-diketones such as acetylacetone, trifluoroacetylacetone, hexafluoroacetylacetone, and dipivaloylmethylacetone; acetoacetates such as methyl acetoacetate and ethyl acetoacetate; bipyridine and derivatives thereof; glycine and its Derivatives; ethylenediamine and derivatives thereof; 8-oxyquinoline and derivatives thereof; salicylaldehyde and derivatives thereof; catechol and derivatives thereof; bidentate ligands such as 2-oxyazo compounds; diethyltriamine and derivatives thereof; nitrilotriacetic acid and derivatives thereof And tridentate ligands such as ethylenediaminetetraacetic acid (EDTA) and derivatives thereof. Furthermore, in addition to the organic ligands as described above, inorganic ligands such as pyrophosphoric acid and triphosphoric acid can be used. As the multidentate ligand, a bidentate ligand is particularly preferable, and specific examples include a bidentate ligand represented by the following general formula (XVII) in addition to the above.

［上記式（ＸＶＩＩ）中、Ｒ^５１及びＲ^５２は各々独立に、炭素数１〜１０のアルキル基、フッ化アルキル基、又は炭素数１〜１０のアルコキシ基を示す。］

[In the formula (XVII), R ⁵¹ and R ⁵² each independently represents an alkyl group having 1 to 10 carbon atoms, a fluorinated alkyl group, or an alkoxy group having 1 to 10 carbon atoms. ]

As the multidentate ligand, a bidentate ligand represented by the above general formula (XVII) is preferably used, and those having the same R ⁵¹ and R ⁵² in the above general formula (XVII) are particularly preferable. By making R ⁵¹ and R ^{52 the} same, the coordination power of the ligand near room temperature becomes strong, and further stabilization of the curable resin composition can be achieved.

  The addition amount of the polydentate ligand can be arbitrarily set, but is preferably 0.01 mol or more, more preferably 0.1 mol or more, still more preferably with respect to 1 mol of the organometallic compound used. 1 mole or more.

  When the coating liquid for forming the protective layer is applied onto the charge transport layer 6, the coating methods are blade coating method, Mayer bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain coating. Ordinary methods such as the method can be used. In addition, when a required film thickness is not obtained by one application | coating, a required film thickness can be obtained by apply | coating several times. When performing multiple times of repeated application, drying may be performed every time of application or after being applied multiple times.

  The reaction temperature and reaction time for curing the applied coating solution for forming the protective layer are not particularly limited, but the reaction temperature is preferably 60 from the viewpoint of mechanical strength and chemical stability of the protective layer 7 to be formed. The reaction time is preferably 10 minutes or more and 5 hours or less, more preferably 80 ° C. or more and 200 ° C. or less. In addition, keeping the protective layer 7 obtained by curing the coating liquid for forming the protective layer in a high humidity state is effective in stabilizing the characteristics of the protective layer 7. Furthermore, depending on the application, the surface of the protective layer 7 can be hydrophobized by treatment with hexamethyldisilazane, trimethylchlorosilane, or the like. The thickness of the protective layer 7 is preferably 0.5 μm or more and 15 μm or less, more preferably 1 μm or more and 10 μm or less, and further preferably 1 μm or more and 5 μm or less.

  In the case of curing, a curing catalyst can be used as necessary. The curing catalyst is not particularly limited as long as it does not adversely affect the electrical characteristics and the like.

  The electrophotographic photosensitive member of the present invention is not limited to the above embodiment.

  For example, in the electrophotographic photosensitive member of the present invention, the undercoat layer 4 is not necessarily provided.

  In the electrophotographic photosensitive member of the present invention, the order of stacking the charge generation layer 5 and the charge transport layer 6 may be reversed from that in the above embodiment. That is, the electrophotographic photoreceptor of the present invention may have a structure in which the undercoat layer 4, the charge transport layer 6, the charge generation layer 5 and the protective layer 7 are laminated on the conductive substrate 2 in this order.

  The electrophotographic photosensitive member shown in FIG. 1 is a function-separated type photosensitive member having a photosensitive layer in which a charge generation layer and a charge transport layer are separately provided. A single-layer type photosensitive layer containing both the generating material and the charge transport material may be provided. An example of an electrophotographic photosensitive member having a single-layer type photosensitive layer is shown in FIG.

  The electrophotographic photoreceptor 10 shown in FIG. 2 has a structure in which an undercoat layer 4, a photosensitive layer 3, and a protective layer 7 are laminated in this order on a conductive substrate 2. The photosensitive layer 3 contains a binder resin, a charge generation material, and a charge transport material, and further contains other substances as necessary. As the binder resin, polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, Vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, etc. These resins are mentioned. These binder resins can be used individually by 1 type or in mixture of 2 or more types. As the charge generation material and the charge transport material, the same materials as those used for the charge generation layer 5 and the charge transport layer 6 can be used, respectively. The content of the charge generating material in the photosensitive layer 3 is preferably 10% by mass or more and 85% by mass or less, and more preferably 20% by mass or more and 50% by mass or less with respect to the total solid content in the photosensitive layer 3. The photosensitive layer 3 may contain a polymer charge transport material for the purpose of improving photoelectric characteristics. The content is preferably 5 mass% or more and 50 mass% or less with respect to the total solid content in the photosensitive layer 3. The solvent used for coating, the coating method, and the like are the same as those of the charge generation layer 5 and the charge transport layer 6. The thickness of the photosensitive layer 3 is preferably 5 μm or more and 50 μm or less, more preferably 10 μm or more and 40 μm or less.

(Image forming apparatus and process cartridge)
FIG. 3 is a schematic configuration diagram illustrating an image forming apparatus according to a preferred embodiment of the present invention. An image forming apparatus 100 shown in FIG. 3 includes, in an image forming apparatus main body (not shown), a process cartridge 20 including the above-described electrophotographic photoreceptor 1 of the present invention, an exposure apparatus (exposure means) 30, and a transfer apparatus 40. And an intermediate transfer member 50. The transfer device 40 and the intermediate transfer member 50 constitute a part of a transfer unit.

  In the image forming apparatus 100, the exposure device 30 is disposed at a position where the electrophotographic photosensitive member 1 can be exposed from the opening of the process cartridge 20, and the transfer device 40 is attached to the electrophotographic photosensitive member 1 via the intermediate transfer member 50. The intermediate transfer member 50 is disposed at a position facing each other, and a part of the intermediate transfer member 50 is disposed so as to be in contact with the electrophotographic photosensitive member 1.

  The process cartridge 20 includes a charging device (charging means) 21, a developing device (developing means) 25, a cleaning device (cleaning means) 27, and a static elimination device (static elimination means) 28 together with the electrophotographic photosensitive member 1 in the case. These are combined and integrated by rails, and are detachable from the main body of the image forming apparatus. The case is provided with an opening for exposure.

  The charging device 21 charges the electrophotographic photosensitive member. The charging device 21 may be a contact type charging device (contact type charging roller, charging brush, etc.) or a non-contact type charging device (corotron, scorotron, non-contact type charging roller, etc.).

For example, in the case of a contact-type charging device, the members (contact charging members) include metals such as aluminum, iron, and copper, conductive polymer materials such as polyacetylene, polypyrrole, and polythiophene, polyurethane rubber, silicone rubber, and epichloro Disperse metal oxide particles such as carbon black, copper iodide, silver iodide, zinc sulfide, or silicon carbide in an elastomeric material such as hydrin rubber, ethylene propylene rubber, acrylic rubber, fluorine rubber, styrene-butadiene rubber, and butadiene rubber. Can be used. Examples of this metal oxide include ZnO, SnO ₂ , TiO ₂ , In ₂ O ₃ , MoO ₃ , or a composite oxide thereof. In addition, as the contact charging member, a material obtained by adding perchlorate in an elastomer material and imparting conductivity may be used.

  Further, a coating layer may be provided on the surface of the contact charging member. As a material for forming the coating layer, N-alkoxymethylated nylon, cellulose resin, vinyl pyridine resin, phenol resin, polyurethane, polyvinyl butyral, melamine, etc. may be used alone or in combination of two or more. Can do. Also, emulsion resin-based materials such as acrylic resin emulsion, polyester resin emulsion, polyurethane, particularly emulsion resin synthesized by soap-free emulsion polymerization can be used. These resins may be further dispersed with conductive agent particles in order to adjust the resistivity, and may further contain an antioxidant in order to prevent deterioration. Moreover, in order to improve the film forming property when forming the coating layer, the emulsion resin may contain a leveling agent or a surfactant. Examples of the shape of the contact charging member include a roller shape, a blade shape, a belt shape, and a brush shape.

The electrical resistance value (volume resistivity) of the contact charging member is preferably 1 × 10 ² Ωcm or more and 1 × 10 ¹⁴ Ωcm or less, more preferably 1 × 10 ² Ωcm or more and 1 × 10 ¹² Ωcm or less. Further, as the voltage applied to the contact charging member, either direct current or alternating current can be used. It can also be applied in the form of direct current + alternating current (direct voltage and alternating voltage superimposed).

  The developing device 25 develops the electrostatic latent image on the electrophotographic photosensitive member 1 to form a toner image, and a known developing device can be used. The toner used in the developing device 25 may be an irregular toner, but a spherical toner is preferable from the viewpoint of improving the image quality.

  The average shape factor SF1 of the toner is preferably 100 or more and 150 or less, and more preferably 100 or more and 140 or less in terms of developability, transferability, and image quality. Moreover, as SF1, 110 or more and 135 or less are especially preferable. When SF1 is smaller than 110, the cleaning property tends to be deteriorated and cleaning failure tends to occur. On the other hand, when SF1 is larger than 135, the transfer property is deteriorated and the image quality is deteriorated or the waste toner that is not transferred increases. There is a tendency to do.

Here, the average shape factor SF1 of the toner refers to toner particles dispersed on a slide glass or an optical microscope image of the toner taken into a Luzex image analyzer (manufactured by Nireco) through a video camera, and 50 or more (for example, The maximum length and the projected area of 100 toners are obtained, calculated by the following formula, and an average value thereof is obtained.
SF1 = (ML ² / A) × (π / 4) × 100
[Wherein ML represents the maximum length of toner particles, and A represents the projected area of toner particles. ]

  The average particle diameter (volume average particle system) of the toner is preferably 2 μm or more and 12 μm or less, more preferably 3 μm or more and 12 μm or less, and further preferably 3 μm or more and 9 μm or less in terms of developability, transferability, and image quality. The volume average particle diameter of the toner can be determined using a multisizer.

  The toner is not particularly limited by the production method. For example, the toner is kneaded, pulverized, and binder resin, a colorant, and a release agent (or further added with a charge control agent, if necessary). Kneading and pulverizing method for classifying; Method for changing the shape of particles obtained by the kneading and pulverizing method by mechanical impact force or thermal energy; Dispersion formed by emulsion polymerization of a polymerizable monomer for obtaining a binder resin An emulsion polymerization agglomeration method in which a liquid is mixed with a dispersion of a colorant and a release agent (or further added with a charge control agent, if necessary), agglomerated, and heat-sealed; Suspension in which a polymerizable monomer to be obtained and a solution of a colorant and a release agent (or a solution to which a charge control agent or the like is further added as necessary) are suspended in an aqueous solvent and polymerized Polymerization method; binder resin, colorant and release agent (or charge control agent if necessary) Can be used toners produced by a further plus) and the solution, it was suspended in an aqueous solvent dissolution suspension method granulation, or the like. In addition, a known method such as a production method in which the toner obtained by the above method is used as a core, and agglomerated particles are further adhered and heat-fused to form a core-shell structure can be used. The toner production method is preferably a suspension polymerization method, an emulsion polymerization aggregation method and a dissolution suspension method, which are produced using an aqueous solvent, from the viewpoint of shape control and particle size distribution control. preferable.

  The toner base particles contain a binder resin, a colorant, and a release agent, and contain silica, a charge control agent, and the like as necessary.

  The binder resin used for the toner base particles includes styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene and isoprene, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl butyrate. , Α-methylene aliphatic monocarboxylic such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Homopolymers and copolymers of acid esters, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone Polyester resins by copolymerization of carboxylic acids and diols.

  Particularly representative binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer. A polymer, polyethylene, a polypropylene, a polyester resin etc. are mentioned. In addition, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like can be mentioned.

  In addition, as colorants, magnetic powders such as magnetite and ferrite, carbon black, aniline blue, caryl blue, chrome yellow, ultramarine blue, Dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, Lamp Black, Rose Bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment blue 15: 1, C.I. I. And CI Pigment Blue 15: 3.

  Examples of the mold release agent include low-molecular polyethylene, low-molecular polypropylene, Fischer tropical wax, montan wax, carnauba wax, rice wax, and candelilla wax.

  As the charge control agent, a known one, that is, an azo metal complex compound, a metal complex compound of salicylic acid, a resin type charge control agent containing a polar group, or the like can be used. When the toner is manufactured by a wet manufacturing method, it is preferable to use a material that is difficult to dissolve in water in terms of controlling ionic strength and reducing wastewater contamination. The toner may be either a magnetic toner containing a magnetic material or a non-magnetic toner containing no magnetic material.

  The toner used in the developing device 25 can be produced by mixing the toner base particles and the external additive with a Henschel mixer or a V blender. Further, when the toner base particles are produced by a wet method, external addition can also be performed by a wet method.

  Lubricating particles may be added to the toner used in the developing device 25. Lubricating particles include solid lubricants such as graphite, molybdenum disulfide, talc, fatty acids, fatty acid metal salts, low molecular weight polyolefins such as polypropylene, polyethylene, polybutene, silicones softened by heating, oleic acid amide, erucic acid Aliphatic amides such as amide, ricinoleic acid amide, stearic acid amide, carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil and other animal waxes, beeswax-like animal waxes, montan wax, ozokerite , Ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax and other minerals, petroleum wax, and modified products thereof. These can be used alone or in combination of two or more. However, the average particle size is preferably 0.1 μm or more and 10 μm or less, and those having the above chemical structure may be pulverized to make the particle sizes uniform. The amount added to the toner is preferably 0.05% by mass or more and 2.0% by mass or less, more preferably 0.1% by mass or more and 1.5% by mass or less.

  To the toner used in the developing device 25, inorganic particles, organic particles, composite particles obtained by attaching inorganic particles to the organic particles, and the like are added in order to remove deposits and deteriorated materials on the surface of the electrophotographic photosensitive member. Can do.

  Inorganic particles include silica, alumina, titania, zirconia, barium titanate, aluminum titanate, strontium titanate, magnesium titanate, zinc oxide, chromium oxide, cerium oxide, antimony oxide, tungsten oxide, tin oxide, tellurium oxide, Manganese oxide, boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride, boron nitride and other various inorganic oxides, nitrides, borides and the like are preferable.

  The inorganic particles include titanium coupling agents such as tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzenesulfonyl titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, γ- (2- Aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) γ-aminopropyltrimethoxy Silane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane You may process by silane coupling agents, such as a run, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane. Also preferred are those hydrophobized with higher fatty acid metal salts such as silicone oil, aluminum stearate, zinc stearate and calcium stearate.

  Examples of the organic particles include styrene resin particles, styrene acrylic resin particles, polyester resin particles, and urethane resin particles.

  The average particle size of these particles is preferably 5 nm to 1000 nm, more preferably 5 nm to 800 nm, and still more preferably 5 nm to 700 nm. When the average particle diameter is less than 5 nm, the polishing ability tends to be lacking, and when it exceeds 700 to 1000 nm, the surface of the electrophotographic photosensitive member tends to be damaged. Moreover, it is preferable that the sum of the addition amount of the particle | grains mentioned above and lubricity particle | grains is 0.6 mass% or more.

  Other inorganic oxides added to the toner are preferably small-diameter inorganic oxides having a primary particle size of 40 nm or less for powder fluidity, charge control, etc. Is preferably an inorganic oxide having a larger diameter. As such inorganic oxides, known ones can be used, but in order to perform precise charge control, it is preferable to use silica and titanium oxide in combination. Moreover, about a small diameter inorganic particle, dispersibility and powder fluidity | liquidity become high by surface-treating. Furthermore, in order to remove discharge products, it is also preferable to add carbonates such as calcium carbonate and magnesium carbonate and inorganic minerals such as hydrotalcite.

  Further, the color toner for electrophotography is used by mixing with a carrier. As the carrier, iron powder, glass beads, ferrite powder, nickel powder, or those having a resin coating on the surface thereof can be used. The mixing ratio with the carrier can be set as appropriate.

  The cleaning device 27 includes a fibrous member (roller shape) 27a and / or a cleaning blade (blade member) 27b (both are shown in FIGS. 3 and 4).

The fibrous member 27a may be fixed to the cleaning device main body, may be rotatably supported, and may be supported so as to be capable of oscillating in the axial direction of the electrophotographic photosensitive member. As the fibrous member 27a, polyester, nylon, acrylic, etc., cloth-like ones made of ultrafine fibers such as Toraysee (manufactured by Toray Industries, Inc.), resin fibers such as nylon, acrylic, polyolefin, polyester, etc. are used as a substrate or carpet. The brush-like thing etc. which were flocked to are mentioned. In addition, as the fibrous member 27a, the above-described materials are mixed with conductive powder or an ionic conductive agent to provide conductivity, or the conductive layer is formed inside or outside of each fiber. Can also be used. When conductivity is imparted, the resistance value of the single fiber is preferably 1 × 10 ² Ω or more and 1 × 10 ⁹ Ω or less. The fiber thickness of the fibrous member 27a is preferably 30 d (denier) or less, more preferably 20 d or less, and the fiber density is preferably 20,000 fibers / inch ² or more, more preferably 30,000 fibers. / Inch ² or more. The fibrous member 27a may have a toothbrush shape instead of a roller shape. As the cleaning blade 27b, for example, a blade made of an elastic material (rubber or the like) can be used.

  The cleaning device 27 is required to remove deposits (for example, discharge products) on the surface of the electrophotographic photosensitive member with a cleaning blade and a cleaning brush. In order to achieve this purpose over a long period of time and to stabilize the function of the cleaning member, a lubricating material (lubricating component) such as metal soap, higher alcohol, wax and silicone oil is supplied to the cleaning member. Is preferred. For example, when a rubber blade is used, chipping and wear of the blade can be suppressed by supplying a lubricating component.

  The neutralization device 28 neutralizes the outer peripheral surface of the electrophotographic photosensitive member 1. Thereby, when the electrophotographic photosensitive member 1 is repeatedly used, a phenomenon that the residual potential of the electrophotographic photosensitive member 1 is brought into the next cycle is prevented, so that the image quality can be further improved. As the static elimination apparatus 28, optical static elimination apparatuses, such as a tungsten lamp and LED, are mentioned, for example. When neutralization is performed using such a light neutralization device, the output intensity of the irradiation light is usually set so as to be several to 30 times the amount of light indicating the half exposure sensitivity of the electrophotographic photosensitive member 1.

  The process cartridge 20 described above is detachable from the image forming apparatus main body, and constitutes the image forming apparatus together with the image forming apparatus main body.

  The exposure device 30 may be any device that exposes the charged electrophotographic photosensitive member 1 to form an electrostatic latent image, but preferably uses a laser as a light source. As the laser, a known semiconductor laser (oscillation wavelength: 780 nm) or the like can be used, but a laser having a wavelength of 380 nm or more and 450 nm or less can also be used for the purpose of improving the image quality. Examples of the semiconductor laser include known exposure apparatuses such as a surface emitting laser array and an LED array having a plurality of laser beam generation sources in the main scanning direction and the sub-scanning direction.

  The transfer device 40 may be any device that transfers the toner image on the electrophotographic photosensitive member 1 to the intermediate transfer member 50. Any of a roller shape, a belt shape and a film shape may be used, and any of a contact type transfer charger using a rubber blade, a scorotron transfer charger using corona discharge, a corotron transfer charger, etc. may be used. Since the electrophotographic photosensitive member of the present invention is excellent in abrasion resistance, a contact-type transfer unit is particularly suitable as the transfer device 40. When the transfer device 40 is a roller, the hardness (Asker C hardness) is preferably 20 or more and 50 or less, more preferably 25 or more and 40 or less. Further, the contact pressure to the electrophotographic photosensitive member 1 is preferably 10 gf / cm or more and 30 gf / cm or less, more preferably 15 gf / cm or more and 25 gf / cm or less. If the hardness or the contact pressure is out of the above range, an appropriate gap cannot be obtained during transfer, and uniform discharge and uniform transfer tend to be difficult.

  In order to transfer the toner to the intermediate transfer member 50 using the transfer device 40, a constant current may be applied to the transfer device 40, but the applied current is preferably a direct current. The current range is preferably 10 μA or more and 50 μA or less, and more preferably 15 μA or more and 30 μA or less.

  As the intermediate transfer member 50, a known intermediate transfer member can be used. The intermediate transfer member may be belt-shaped or drum-shaped. In the case of a belt shape, a conventionally known resin can be used as the resin material used as the base material of the intermediate transfer member. For example, polyimide resin, polycarbonate resin (PC), polyvinylidene fluoride (PVDF), polyalkylene terephthalate (PAT), ethylene tetrafluoroethylene copolymer (ETFE) / PC, ETFE / PAT, PC / PAT blend material, Examples thereof include resin materials such as polyester, polyether ether ketone, and polyamide, and resin materials using these as main raw materials. Furthermore, a resin material and an elastic material can be blended and used.

  As the elastic material, polyurethane, chlorinated polyisoprene, NBR, chloropyrene rubber, EPDM, hydrogenated polybutadiene, butyl rubber, silicone rubber, or a material obtained by blending two or more of these materials can be used. If necessary, a conductive agent imparting electronic conductivity and a conductive agent having ionic conductivity may be used alone or in combination of two or more for the resin material and elastic material used for these base materials. Added. Among these, it is preferable to use a polyimide resin in which a conductive agent is dispersed from the viewpoint of excellent mechanical strength. As the conductive agent, a conductive polymer such as carbon black, metal oxide, or polyaniline can be used. In the case of using a belt-like intermediate transfer member, the thickness of the belt is generally preferably 50 μm or more and 500 μm or less, more preferably 60 μm or more and 150 μm or less, but it is appropriately selected according to the hardness of the material. Can do.

  For example, a belt made of a polyimide resin in which a conductive agent is dispersed is 5% by mass or more as a conductive agent in a polyamic acid solution as a polyimide precursor, as described in JP-A-63-111263. Carbon black of 20% by mass or less is dispersed, the dispersion is cast on a metal drum and dried, and then the film peeled off from the drum is stretched at a high temperature to form a polyimide film. It can be manufactured by cutting it out to make an endless belt.

  The film forming is generally performed by injecting a polyamic acid solution film-forming stock solution in which a conductive agent is dispersed into a cylindrical mold and, for example, heating at 100 ° C. or more and 200 ° C. or less, while rotating at 500 rpm or more and 2000 rpm or less. The film is formed into a film by centrifugal molding while rotating the cylindrical mold, and then the obtained film is demolded in a semi-cured state and covered with an iron core, and is polyimideized at a high temperature of 300 ° C. or higher. It can be carried out by allowing the reaction (ring-closing reaction of polyamic acid) to proceed and main curing. Also, the stock solution is cast on a metal sheet to a uniform thickness and heated to 100 ° C. or higher and 200 ° C. or lower in the same manner as described above to remove most of the solvent, and then gradually increased to a high temperature of 300 ° C. or higher. There is also a method of forming a polyimide film by raising the temperature. Further, the intermediate transfer member may have a surface layer.

  When a drum-shaped intermediate transfer member is used, it is preferable to use a cylindrical substrate formed of aluminum, stainless steel (SUS), copper, or the like as the substrate. If necessary, an elastic layer can be coated on the cylindrical substrate, and a surface layer can be formed on the elastic layer.

  FIG. 4 is a schematic configuration diagram showing an image forming apparatus according to a preferred embodiment of the present invention. In the image forming apparatus 110 shown in FIG. 4, the electrophotographic photosensitive member 1 is fixed to the main body of the image forming apparatus, and the charging device (charging means) 21, the developing device (developing means) 25, and the cleaning device (cleaning means) 27 are each cartridges. The charging cartridge, the developing cartridge, and the cleaning cartridge are independently provided.

  In the image forming apparatus 110, the electrophotographic photosensitive member 1 and other apparatuses are separated, and the charging device 21, the developing device 25, and the cleaning device 27 are screwed, caulked, bonded, or welded to the image forming apparatus main body. It is not fixed by, and can be detached by an operation by drawing and pushing.

  Since the electrophotographic photosensitive member of the present invention is excellent in wear resistance, it may not be necessary to form a cartridge. Accordingly, the charging device 21, the developing device 25, or the cleaning device 27 is not fixed to the main body by screws, caulking, adhesion, or welding, and can be detached by an operation by drawing and pushing, so that the member cost per print is achieved. Can be reduced. Also, two or more of these devices can be detachable as an integrated cartridge, thereby further reducing the member cost per print.

  The image forming apparatus 110 has the same configuration as the image forming apparatus 100 except that the charging device 21, the developing device 25, and the cleaning device 27 are each formed as a cartridge.

  FIG. 5 is a schematic configuration diagram showing an image forming apparatus according to another preferred embodiment of the present invention. The image forming apparatus 120 shown in FIG. 5 is a four-cycle image forming apparatus that forms toner images of a plurality of colors with one electrophotographic photosensitive member. The image forming apparatus 120 includes a photosensitive drum (electrophotographic photosensitive member) 1 that is rotated in a direction indicated by an arrow A in the drawing at a predetermined rotational speed by a driving device (not shown), and above the photosensitive drum 1. Is provided with a charging device (charging means) 21 for charging the outer peripheral surface of the photosensitive drum 1.

  An exposure device (exposure means) 30 including a surface emitting laser array as an exposure light source is disposed above the charging device 21. The exposure device 30 modulates a plurality of laser beams emitted from a light source in accordance with an image to be formed and deflects the laser beams in the main scanning direction so that the axis of the photosensitive drum 1 is on the outer peripheral surface of the photosensitive drum 1. Scan in parallel. Thereby, an electrostatic latent image is formed on the outer peripheral surface of the charged photosensitive drum 1.

  A developing device (developing means) 25 is disposed on the side of the photosensitive drum 1. The developing device 25 includes a roller-shaped container that is rotatably arranged. Four accommodating portions are formed inside the accommodating body, and developing devices 25Y, 25M, 25C, and 25K are provided in the accommodating portions. The developing devices 25Y, 25M, 25C, and 25K each include a developing roller 26, and store Y, M, C, and K color toners therein.

  The full color image is formed by the image forming apparatus 120 while the photosensitive drum 1 is rotated four times. That is, the exposure apparatus 30 scans the outer peripheral surface of the photosensitive drum 1 with a laser beam corresponding to any of Y, M, C, and K image data representing a color image to be formed. Here, every time the photosensitive drum 1 rotates, the exposure device 30 changes the image data, modulates the laser beam to be scanned, and scans the laser beam for all four image data during the four rotations. I do. Further, the developing device 25 operates the developing device facing the outer peripheral surface in a state where any of the developing rollers 26 of the developing devices 25Y, 25M, 25C, and 25K is facing the outer peripheral surface of the photosensitive drum 1. The electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 1 is developed into a specific color, and a toner image of the specific color is formed on the outer peripheral surface of the photosensitive drum 1. Here, the developing device 25 rotates the container so that the developing device is switched every time the photosensitive drum 1 rotates, and causes all four developing devices to form toner images during the four rotations. . Thus, every time the photosensitive drum 1 rotates, Y, M, C, and K toner images are sequentially formed on the outer peripheral surface of the photosensitive drum 1 so as to overlap each other. Is rotated four times, a full-color toner image is formed on the outer peripheral surface of the photosensitive drum 1.

  An endless intermediate transfer belt (intermediate transfer member) 50 is disposed substantially below the photosensitive drum 1. The intermediate transfer belt 50 is wound around rollers 51, 53, and 55, and is disposed so that the outer peripheral surface is in contact with the outer peripheral surface of the photosensitive drum 1. The rollers 51, 53, and 55 are rotated by a driving force of a driving device (not shown) to rotate the intermediate transfer belt 50 in the arrow B direction in FIG.

  A transfer device 40 is disposed on the opposite side of the photosensitive drum 1 across the intermediate transfer belt 50, and a toner image formed on the outer peripheral surface of the photosensitive drum 1 is transferred to the image forming surface of the intermediate transfer belt 50 by the transfer device 40. Is transcribed.

  Further, a lubricant supply device 29, a cleaning device 27, and a charge removal device 28 are disposed on the opposite side of the developing device 25 with the photosensitive drum 1 interposed therebetween. When the toner image formed on the outer peripheral surface of the photosensitive drum 1 is transferred to the intermediate transfer belt 50, the lubricant is supplied to the outer peripheral surface of the photosensitive drum 1 by the lubricant supply device 29, and the The area carrying the transferred toner image is cleaned by the cleaning device 27. Then, the charge removal device 28 removes electricity on the outer peripheral surface of the photosensitive drum 1.

  A tray 60 is disposed below the intermediate transfer belt 50, and a large number of sheets (transfer target media) P are accommodated in the tray 60 in a stacked state. A take-out roller 61 is disposed obliquely above and to the left of the tray 60, and a roller pair 63 and a roller 65 are sequentially arranged on the downstream side in the take-out direction of the paper P. The recording paper located in the uppermost position in the stacked state is taken out from the tray 60 when the take-out roller 61 is rotated, and is conveyed by the roller pair 63 and the roller 65.

  A transfer device 42 is disposed on the opposite side of the roller 55 with the intermediate transfer belt 50 interposed therebetween. The paper P conveyed by the roller pair 63 and the roller 65 is sent between the intermediate transfer belt 50 and the transfer device 42, and the toner image formed on the image forming surface of the intermediate transfer belt 50 is applied to the paper P by the transfer device 42. Transcribed. A fixing device 44 having a pair of fixing rollers is arranged downstream of the transfer device 42 in the conveyance direction of the paper P, and the transferred toner image is fused and fixed by the fixing device 44 on the paper P on which the toner image is transferred. After that, the image forming apparatus 120 is discharged out of the machine body and placed on a paper discharge tray (not shown). The transfer devices 40 and 42, the intermediate transfer belt 50, and the rollers 51, 53, and 55 constitute a part of transfer means.

  FIG. 6 is a schematic configuration diagram showing an image forming apparatus according to another preferred embodiment of the present invention. An image forming apparatus 130 shown in FIG. 6 is a tandem type full-color image forming apparatus and an intermediate transfer type image forming apparatus. Specifically, the image forming apparatus 130 includes a housing 400, and in the housing 400, four electrophotographic photosensitive members 401a to 401d (for example, the electrophotographic photosensitive member 401a is yellow, the electrophotographic photosensitive member 401b is magenta, and electrophotographic. The photosensitive member 401c can form an image of cyan, and the electrophotographic photosensitive member 401d can form an image of black.) Are arranged in parallel along the intermediate transfer belt 409. Here, each of the electrophotographic photoreceptors 401 a to 401 d mounted on the image forming apparatus 130 is the electrophotographic photoreceptor 1.

  Each of the electrophotographic photosensitive members 401a to 401d can be rotated in a predetermined direction (counterclockwise on the paper surface), and charging rollers (charging means) 402a to 402d and a developing device (developing means) 404a along the rotation direction. To 404d, primary transfer rollers 410a to 410d, and cleaning blades (cleaning means) 415a to 415d are arranged. The developing devices 404a to 404d can be supplied with toners of four colors (yellow, magenta, cyan and black) accommodated in toner cartridges 405a to 405d, respectively, and the primary transfer rollers 410a to 410d are intermediate transfer belts. 409 are in contact with the electrophotographic photoreceptors 401a to 401d, respectively.

  Further, a laser light source (exposure means) 403 is disposed at a predetermined position in the housing 400, and the surface of the electrophotographic photoreceptors 401a to 401d after charging can be irradiated with laser light emitted from the laser light source 403. It has become. Accordingly, charging, exposure, development, primary transfer, and cleaning processes are sequentially performed in the rotation process of the electrophotographic photosensitive members 401a to 401d, and the toner images of the respective colors are transferred onto the intermediate transfer belt 409 in an overlapping manner.

  The intermediate transfer belt 409 is supported with a predetermined tension by a drive roller 406, a backup roller 408, and a tension roller 407, and can rotate without causing deflection by the rotation of these rollers. Further, the secondary transfer roller 413 is disposed so as to contact the backup roller 408 via the intermediate transfer belt 409. The intermediate transfer belt 409 that has passed between the backup roller 408 and the secondary transfer roller 413 is cleaned by, for example, a cleaning blade 416 disposed in the vicinity of the driving roller 406 and then repeatedly used in the next image forming process. The

  A tray (transfer medium tray) 411 is provided at a predetermined position in the housing 400. The transfer medium 500 (paper or the like) in the tray 411 is sequentially transferred by the transfer roller 412 between the intermediate transfer belt 409 and the secondary transfer roller 413 and between the two fixing rollers 414 in contact with each other. Thereafter, the sheet is discharged outside the housing 400.

  In the tandem-type image forming apparatus 130, the amount of wear of each electrophotographic photosensitive member varies depending on the use ratio of each color, and thus the electrical characteristics of each electrophotographic photosensitive member tend to be different. Along with this, the toner development characteristics gradually change from the initial state, the hue of the printed image changes, and it tends to be difficult to obtain a stable image. In particular, this tendency becomes prominent when a small-diameter electrophotographic photosensitive member, particularly one having a direct diameter of 30 mm or less, is used to reduce the size of the image forming apparatus. However, in the electrophotographic photosensitive member of the present invention, even when the diameter is 30 mm or less, the surface wear is sufficiently suppressed. Therefore, the electrophotographic photosensitive member of the present invention is particularly effective for a tandem image forming apparatus.

  The image forming apparatus and the process cartridge of the present invention are not limited to the above embodiment.

  For example, the image forming apparatus and the process cartridge according to the above embodiment include the electrophotographic photosensitive member 1 as the electrophotographic photosensitive member, but the image forming apparatus and the process cartridge of the present invention include, for example, the electrophotographic photosensitive member 10. May be.

  For example, in the image forming apparatus according to the above-described embodiment, the transfer unit includes an intermediate transfer body on which a toner image is primarily transferred, and the toner image is transferred to a transfer medium (paper or the like) via the intermediate transfer body. An intermediate transfer type image forming apparatus. However, the image forming apparatus according to the present invention may be a direct transfer type image forming apparatus in which the transfer unit does not include the intermediate transfer member and the toner image on the surface of the electrophotographic photosensitive member is directly transferred to the transfer medium. The photographic photoreceptor is also suitable for a direct transfer type image forming apparatus. In the direct transfer type image forming apparatus, paper dust, talc, and the like are generated from the print paper, which are likely to adhere to the electrophotographic photosensitive member, and image quality defects due to the attached matter tend to occur. However, since the electrophotographic photosensitive member of the present invention has excellent cleaning properties, a stable image can be obtained even with a direct transfer type image forming apparatus.

  In addition, the image forming apparatus 100 includes a cleaning device (cleaning unit) 27 and a static elimination device (static elimination unit) 28. However, in the image forming apparatus of the present invention, the cleaning unit and the static elimination unit are not essential.

  Further, in the image forming apparatus 100, a charging roller (charging means) 21, a developing device (developing means) 25, a cleaning device (cleaning means) 27, and a charge eliminating device (charge eliminating means) 28 are accommodated in one process cartridge 20. . However, in the image forming apparatus of the present invention, at least one of charging means, developing means, cleaning means, etc., or this and the electrophotographic photosensitive member of the present invention may be housed in one process cartridge. Further, the process cartridge of the present invention only needs to include at least one of charging means, developing means, cleaning means and the like and the electrophotographic photosensitive member of the present invention.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

(Surface treatment 1)
In 100 mL of toluene, 2.5 g of a compound represented by the formula (A-1) (hydrolyzable organosilicon compound having a sulfonic acid ester group) is dissolved, and zinc oxide (MZ150 manufactured by Teika Co., Ltd., average particle size) is dissolved therein. 25 g) (diameter: 70 nm). The mixture was refluxed at 95 ° C. for 2 hours, and then the solvent was distilled off under reduced pressure. When the solvent was exhausted, the temperature was raised to 150 ° C. and held for 2 hours.

(Surface treatment 2)
The same operation as surface treatment 1 was performed except that tin oxide (S1, manufactured by Mitsubishi Materials Corporation, average particle size: 30 nm) was used instead of zinc oxide.

(Surface treatment 3)
25 g of tin oxide (S1 manufactured by Mitsubishi Materials Corporation, average particle size: 30 nm) was vigorously stirred and maintained in a suspended state, and the compound represented by the formula (A-1) (hydrolysis having a sulfonate group) A solution prepared by dissolving 2.5 g of a functional organosilicon compound in 2.5 g of toluene was added dropwise. After completion of dropping, the mixture was held at 90 ° C. for 2 hours, and then the heating temperature was raised to 150 ° C. and heated for 2 hours.

(Surface treatment 4)
Instead of the compound represented by the formula (A-1), the same operation as the surface treatment 2 was performed except that the compound represented by the formula (B-1) (an organosilicon compound having a thiol group) was used. went.

(Surface treatment 5)
Instead of the compound represented by the formula (A-1), the same operation as in the surface treatment 2 was performed except that the compound represented by the formula (B-2) (an organosilicon compound having a sulfide group) was used. went.

(Surface treatment 6)
Instead of the compound represented by the formula (A-1), the same operation as in the surface treatment 2 was performed except that an aminoethylsilane coupling agent represented by the following formula was used.

(Example 1)
First, an aluminum substrate having a diameter of 30 mm, a length of 404 mm, and a thickness of 1 mm was prepared as a conductive substrate.

  Next, 4 parts by mass of polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd., ESREC BM-S) dissolved in 170 parts by mass of n-butyl alcohol, 30 parts by mass of an organic zirconium compound (acetylacetone zirconium butyrate), and an organic silane compound 3 parts by mass of (γ-aminopropyltrimethoxysilane) was mixed and stirred to prepare a coating solution for forming an undercoat layer. The obtained coating solution was applied onto the aluminum substrate by a dip coating method, followed by drying and curing at 150 ° C. for 30 minutes to form an undercoat layer having a thickness of 1 μm.

  Next, a mixture of 15 parts by mass of hydroxygallium phthalocyanine, 10 parts by mass of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Union Carbide) and 300 parts by mass of n-butyl alcohol is dispersed in a sand mill for 4 hours. Thus, a coating solution for forming a charge generation layer was prepared. The obtained coating solution was dip-coated on the undercoat layer and dried to form a charge generation layer having a thickness of 0.2 μm.

  Next, 40 parts by mass of N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine and 60 parts by mass of bisphenol Z polycarbonate resin (viscosity average molecular weight: 40,000) were added to 280 parts of tetrohydrofuran. A solution for forming a charge transport layer was prepared by dissolving and mixing in a mixed solution of 120 parts by mass of toluene and 120 parts by mass of toluene. The obtained coating solution was dip-coated on the charge generation layer and dried at 130 ° C. for 40 minutes to form a charge transport layer having a thickness of 25 μm.

  Finally, 40 parts by mass of a compound represented by formula (I-38) (hereinafter referred to as “compound (I-38)”), 40 parts by mass of a phenol resin (PL4852 manufactured by Gunei Chemical Co., Ltd.), and a repellency inhibitor (Silicone oil) After dissolving 0.4 parts by mass in 75 parts by mass of butanol, 20 parts by mass of tin oxide obtained in the surface treatment 2 is added and dispersed in a sand mill for 5 hours to prepare a coating solution for forming a protective layer. did. The obtained coating solution is applied onto the charge transport layer by a ring-type dip coating method, air-dried at room temperature for 30 minutes, and then cured by heat treatment at 160 ° C. for 1 hour to form a protective layer having a thickness of 5 μm. did. Thus, an electrophotographic photosensitive member was produced. In addition, the content rate of the said tin oxide in a protective layer is 5 volume%.

  Furthermore, an image forming apparatus having the configuration shown in FIG. 6 was produced using the obtained electrophotographic photosensitive member. Here, the elements other than the electrophotographic photosensitive member were the same as those of the DocuCenter Color 400 manufactured by Fuji Xerox Co., Ltd.

(Example 2)
Except for the amount of the compound (I-38), phenol resin, repellency inhibitor and metal oxide (tin oxide obtained by surface treatment 2) used in the preparation of the coating solution for forming the protective layer, as follows. In the same manner as in Example 1, an electrophotographic photoreceptor and an image forming apparatus were produced. In addition, the content rate of the said tin oxide in a protective layer is 10 volume%.
Compound (I-38): 35 parts by mass Phenol resin: 35 parts by mass Repelling inhibitor: 0.35 parts by mass Metal oxide: 40 parts by mass

(Example 3)
Except for the amount of the compound (I-38), phenol resin, repellency inhibitor and metal oxide (tin oxide obtained by surface treatment 2) used in the preparation of the coating solution for forming the protective layer, as follows. In the same manner as in Example 1, an electrophotographic photoreceptor and an image forming apparatus were produced. In addition, the content rate of the said tin oxide in a protective layer is 0.5 volume%.
Compound (I-38): 50 parts by mass Phenol resin: 50 parts by mass Repelling inhibitor: 0.5 parts by mass Metal oxide: 3 parts by mass

Example 4
In place of the tin oxide obtained in the surface treatment 2, the tin oxide obtained in the surface treatment 3 was used, and the compound (I-38), phenol resin, An electrophotographic photosensitive member and an image forming apparatus were produced in the same manner as in Example 1 except that the amounts of the repellency inhibitor and the metal oxide (tin oxide obtained by the surface treatment 3) were changed as follows. In addition, the content rate of the said tin oxide in a protective layer is 5 volume%.
Compound (I-38): 40 parts by mass Phenolic resin: 40 parts by mass Anti-repellent agent: 0.4 parts by mass Metal oxide: 20 parts by mass

(Example 5)
In place of the tin oxide obtained in the surface treatment 2, the tin oxide obtained in the surface treatment 4 was used, and in the preparation of the coating liquid for forming the protective layer, the compound (I-38), phenol resin, An electrophotographic photosensitive member and an image forming apparatus were produced in the same manner as in Example 1 except that the amounts of the repellency inhibitor and the metal oxide (tin oxide obtained by the surface treatment 4) were changed as follows. In addition, the content rate of the said tin oxide in a protective layer is 5 volume%.
Compound (I-38): 40 parts by mass Phenol resin: 40 parts by mass Anti-repellent agent: 0.4 parts by mass Metal oxide: 15 parts by mass

(Example 6)
In place of the tin oxide obtained in the surface treatment 2, the tin oxide obtained in the surface treatment 5 was used, and the compound (I-38), phenol resin, An electrophotographic photosensitive member and an image forming apparatus were produced in the same manner as in Example 1 except that the amounts of the repellency inhibitor and the metal oxide (tin oxide obtained by the surface treatment 5) were changed as follows. In addition, the content rate of the said tin oxide in a protective layer is 5 volume%.
Compound (I-38): 40 parts by mass Phenol resin: 40 parts by mass Anti-repellent agent: 0.4 parts by mass Metal oxide: 15 parts by mass

(Example 7)
In place of the tin oxide obtained in the surface treatment 2, the zinc oxide obtained in the surface treatment 1 was used, and the compound (I-38) used in the preparation of the coating liquid for forming the protective layer, a phenol resin, An electrophotographic photosensitive member and an image forming apparatus were produced in the same manner as in Example 1 except that the amount of the repellency inhibitor and the metal oxide (zinc oxide obtained in the surface treatment 1) was changed as follows. In addition, the content rate of the said zinc oxide in a protective layer is 5 volume%.
Compound (I-38): 40 parts by mass Phenol resin: 40 parts by mass Anti-repellent agent: 0.4 parts by mass Metal oxide: 15 parts by mass

(Comparative Example 1)
A solution obtained by dissolving 40 parts by mass of Compound (I-38), 40 parts by mass of a phenol resin, and 0.4 parts by mass of an anti-repellent agent in 75 parts by mass of butanol was used as a coating solution for forming a protective layer. Except for the above, an electrophotographic photosensitive member and an image forming apparatus were produced in the same manner as in Example 1.

(Comparative Example 2)
In place of the tin oxide obtained in the surface treatment 2, the tin oxide obtained in the surface treatment 6 was used, and the compound (I-38), phenol resin, An electrophotographic photoreceptor and an image forming apparatus were produced in the same manner as in Example 1 except that the amounts of the repellency inhibitor and the metal oxide (tin oxide obtained by the surface treatment 6) were changed as follows. In addition, the content rate of the said tin oxide in a protective layer is 5 volume%.
Compound (I-38): 40 parts by mass Phenol resin: 40 parts by mass Anti-repellent agent: 0.4 parts by mass Metal oxide: 15 parts by mass

(Image formation test 1)
Using the image forming apparatuses obtained in Examples 1 to 7 and Comparative Examples 1 and 2, 10,000 images were formed in a high-temperature and high-humidity (30 ° C., 80% RH) environment. A formation test was performed. As the material to be transferred, plain paper P paper manufactured by Fuji Xerox Co., Ltd. was used.

  After 10,000 images are formed, the electrophotographic photosensitive member is left in the image forming apparatus overnight, and a halftone image is printed on the next morning to visually check the image quality (image flow / streaks, other defects). It was evaluated with. Further, the initial image quality (after one image was formed) was evaluated in the same manner.

  Also, after 10,000 images were formed, the amount of wear of the electrophotographic photosensitive member was measured to determine the wear rate (nm / 1000 rotations).

The results are shown in the table below. In the following table | surface, content of a metal oxide is shown by the content rate (volume%) in a protective layer. In addition, the meanings of symbols (◯, ×) in the following table are as follows.
Image flow / straight line irregularity: ○… No, ×… Yes Other defects: ○… No, × ... Yes

  As is apparent from the above table, there is no difference between Examples 1 to 7 and Comparative Examples 1 and 2 in terms of image quality, and image quality defects are sufficiently suppressed in any of the image forming apparatuses. However, regarding the wear rate, the electrophotographic photoreceptors obtained in Examples 1 to 7 showed significantly superior results as compared to the electrophotographic photoreceptors obtained in Comparative Examples 1 and 2.

(Surface treatment 7)
In 100 mL of toluene, 2.5 g of a compound represented by the formula (A-1) (hydrolyzable organosilicon compound having a sulfonic acid ester group) is dissolved, and zinc oxide (MZ150 manufactured by Teika Co., Ltd., average particle size) is dissolved therein. 25 g) (diameter: 70 nm). The mixture was refluxed at 95 ° C. for 2 hours, and then the solvent was distilled off under reduced pressure. When the solvent was exhausted, the temperature was raised to 150 ° C. and held for 2 hours.

  Next, the obtained zinc oxide was pulverized in a mortar. Then, 2.0 g of the compound represented by the formula (C-1) (fluorine silane coupling agent) was dissolved in 100 mL of toluene, and 20 g of the zinc oxide pulverized with a mortar was added thereto. The mixture was refluxed at 95 ° C. for 2 hours, and then the solvent was distilled off under reduced pressure. When the solvent was exhausted, the temperature was raised to 150 ° C. and held for 2 hours.

(Surface treatment 8)
The same operation as surface treatment 7 was performed except that tin oxide (S1, manufactured by Mitsubishi Materials Corporation, average particle size: 30 nm) was used instead of zinc oxide.

(Surface treatment 9)
25 g of tin oxide (S1 manufactured by Mitsubishi Materials Corporation, average particle size: 30 nm) was vigorously stirred and maintained in a suspended state, and the compound represented by the formula (A-1) (hydrolysis having a sulfonate group) A solution prepared by dissolving 2.5 g of a functional organosilicon compound in 2.5 g of toluene was added dropwise. After completion of dropping, the mixture was held at 90 ° C. for 2 hours, and then the heating temperature was raised to 150 ° C. and heated for 2 hours.

  Next, the obtained tin oxide was pulverized in a mortar. Then, 2.0 g of the compound represented by the formula (C-1) (fluorine silane coupling agent) was dissolved in 100 mL of toluene, and 20 g of the tin oxide pulverized with a mortar was added thereto. The mixture was refluxed at 95 ° C. for 2 hours, and then the solvent was distilled off under reduced pressure. When the solvent was exhausted, the temperature was raised to 150 ° C. and held for 2 hours.

(Surface treatment 10)
Instead of the compound represented by the formula (A-1), the same operation as the surface treatment 8 was performed except that the compound represented by the formula (B-1) (an organosilicon compound having a thiol group) was used. went.

(Surface treatment 11)
Instead of the compound represented by the formula (A-1), the same operation as the surface treatment 8 was performed except that the compound represented by the formula (B-2) (an organosilicon compound having a sulfide group) was used. went.

(Surface treatment 12)
The same operation as surface treatment 8 was performed except that an aminoethylsilane coupling agent represented by the following formula was used instead of the compound represented by formula (A-1).

(Surface treatment 13)
The same operation as surface treatment 8 was performed except that the compound represented by the formula (C-1) (fluorine silane coupling agent) was used instead of the compound represented by the formula (A-1). It was.

(Example 8)
An electrophotographic photosensitive member and an image forming apparatus were produced in the same manner as in Example 1 except that the tin oxide obtained in the surface treatment 8 was used instead of the tin oxide obtained in the surface treatment 2. In addition, the content rate of the said tin oxide in a protective layer is 5 volume%.

Example 9
An electrophotographic photosensitive member and an image forming apparatus were produced in the same manner as in Example 2 except that the tin oxide obtained in the surface treatment 8 was used instead of the tin oxide obtained in the surface treatment 2. In addition, the content rate of the said tin oxide in a protective layer is 10 volume%.

(Example 10)
An electrophotographic photosensitive member and an image forming apparatus were produced in the same manner as in Example 3 except that the tin oxide obtained in the surface treatment 8 was used instead of the tin oxide obtained in the surface treatment 2. In addition, the content rate of the said tin oxide in a protective layer is 0.5 volume%.

(Example 11)
An electrophotographic photoreceptor and an image forming apparatus were produced in the same manner as in Example 4 except that the tin oxide obtained in the surface treatment 9 was used instead of the tin oxide obtained in the surface treatment 3. In addition, the content rate of the said tin oxide in a protective layer is 5 volume%.

(Example 12)
An electrophotographic photoreceptor and an image forming apparatus were produced in the same manner as in Example 5 except that the tin oxide obtained in the surface treatment 10 was used instead of the tin oxide obtained in the surface treatment 4. In addition, the content rate of the said tin oxide in a protective layer is 5 volume%.

(Example 13)
In the preparation of the coating solution for forming the protective layer, the amount of the compound (I-38), phenol resin, repellency inhibitor and metal oxide (tin oxide obtained by the surface treatment 10) to be used is as follows. In the same manner as in Example 12, an electrophotographic photosensitive member and an image forming apparatus were produced. In addition, the content rate of the said tin oxide in a protective layer is 0.5 volume%.
Compound (I-38): 50 parts by mass Phenol resin: 50 parts by mass Repelling inhibitor: 0.5 parts by mass Metal oxide: 3 parts by mass

(Example 14)
An electrophotographic photosensitive member and an image forming apparatus were produced in the same manner as in Example 6 except that the tin oxide obtained in the surface treatment 11 was used instead of the tin oxide obtained in the surface treatment 5. In addition, the content rate of the said tin oxide in a protective layer is 5 volume%.

(Example 15)
An electrophotographic photoreceptor and an image forming apparatus were produced in the same manner as in Example 7, except that the zinc oxide obtained in the surface treatment 7 was used instead of the zinc oxide obtained in the surface treatment 1. In addition, the content rate of the said zinc oxide in a protective layer is 5 volume%.

(Comparative Example 3)
An electrophotographic photosensitive member and an image forming apparatus were produced in the same manner as in Comparative Example 2 except that the tin oxide obtained in the surface treatment 12 was used instead of the tin oxide obtained in the surface treatment 6. In addition, the content rate of the said tin oxide in a protective layer is 5 volume%.

(Comparative Example 4)
An electrophotographic photosensitive member and an image forming apparatus were produced in the same manner as in Comparative Example 3 except that tin oxide obtained by surface treatment 13 was used instead of tin oxide obtained by surface treatment 12. In addition, the content rate of the said tin oxide in a protective layer is 5 volume%.

(Image formation test 2)
Using the image forming apparatuses obtained in Examples 8 to 15 and Comparative Examples 1, 3 and 4, 20,000 images were formed in a high temperature and high humidity (30 ° C., 80% RH) environment as follows. An image formation test was conducted. As the material to be transferred, plain paper P paper manufactured by Fuji Xerox Co., Ltd. was used.

  After initial (after one image is formed) and after 20,000 images are formed, the electrophotographic photosensitive member is left in the image forming apparatus overnight, and a halftone image is printed on the next morning to obtain image quality (image flow / streaks). The presence or absence of upper unevenness and other defects) was visually evaluated.

  Further, after the image formation of 20,000 sheets, the wear amount of the electrophotographic photosensitive member was measured to obtain the wear rate (nm / 1000 rotations).

The results are shown in the table below. In the following table | surface, content of a metal oxide is shown by the content rate (volume%) in a protective layer. The meanings of symbols (◯, ×, Δ) in the following table are as follows.
Image flow / straight line irregularity: ○… No, ×… Yes Other defects: ○… No, × ... Yes

  As is clear from the above table, in terms of image quality, there is no difference between Examples 8 to 15 and Comparative Examples 3 and 4, and the occurrence of image quality defects is sufficiently suppressed in any of the image forming apparatuses. However, regarding the wear rate, the electrophotographic photoreceptors obtained in Examples 1 to 7 showed significantly superior results as compared to the electrophotographic photoreceptors obtained in Comparative Examples 1, 3, and 4. Yes.

  According to image formation tests 1 and 2, the electrophotographic photosensitive member of the present invention has sufficient wear resistance and can sufficiently suppress the occurrence of image quality defects (particularly, image flow and streak-like unevenness). It was shown that.

1 is a schematic cross-sectional view showing an electrophotographic photoreceptor according to a preferred embodiment of the present invention. 1 is a schematic cross-sectional view showing an electrophotographic photoreceptor according to a preferred embodiment of the present invention. 1 is a schematic configuration diagram illustrating an image forming apparatus according to a preferred embodiment of the present invention. 1 is a schematic configuration diagram illustrating an image forming apparatus according to a preferred embodiment of the present invention. 1 is a schematic configuration diagram illustrating an image forming apparatus according to a preferred embodiment of the present invention. 1 is a schematic configuration diagram illustrating an image forming apparatus according to a preferred embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,10,410a-d ... Electrophotographic photoreceptor, 2 ... Conductive substrate, 3 ... Photosensitive layer, 4 ... Undercoat layer, 5 ... Charge generation layer, 6 ... Charge transport layer, 7 ... Protective layer, 20 ... Process Cartridge, 21 ... charging means, 25 ... developing means, 27 ... cleaning means, 28 ... static discharge means, 30 ... exposure means, 40 ... transfer device (transfer means), 50 ... intermediate transfer member (transfer means), 100, 110, 120, 130: Image forming apparatus.

Claims (7)

An electrophotographic photoreceptor comprising a photosensitive layer and a protective layer in this order on a conductive substrate,
The protective layer contains a resin having a crosslinked structure and a metal oxide,
The metal oxide is at least one organosilicon compound selected from the group consisting of hydrolyzable organosilicon compounds having a sulfonate group, organosilicon compounds having a thiol group, and organosilicon compounds having a sulfide group. An electrophotographic photosensitive member characterized by being surface-treated.   The electrophotographic photosensitive member according to claim 1, wherein the metal oxide has an average particle size of 10 nm to 100 nm.   The electrophotographic photosensitive member according to claim 1, wherein at least a part of the resin is a phenol resin or a siloxane resin.   The electrophotographic photoreceptor according to claim 1, wherein the resin has a structure derived from a charge transporting compound. The electrophotographic photosensitive member according to claim 1, wherein the charge transporting compound is a compound represented by any one of the following general formulas (I) to (VI). .
_{^{F [- (X 1) n1}} R 1 -Z 1 H] m1 (I)
[In Formula (I), F represents an organic group derived from a compound having a hole transporting ability, R ¹ represents an alkylene group, Z ¹ represents an oxygen atom, a sulfur atom, NH or COO, and X ¹ Represents an oxygen atom or a sulfur atom, m1 represents an integer of 1 to 4, and n1 represents 0 or 1. ]
_{^{F [- (X 2) n2}} - (R 2) n3 - (Z 2) n4 G] n5 (II)
[In Formula (II), F represents an organic group derived from a compound having a hole transporting ability, X ² represents an oxygen atom or a sulfur atom, R ² represents an alkylene group, Z ² represents an oxygen atom, S represents a sulfur atom, NH or COO, G represents an epoxy group, n2, n3 and n4 each independently represents 0 or 1, and n5 represents any integer of 1 to 4. ]
F [-D-Si (R ³ ) _(3-a) Q _a ] _b (III)
[In Formula (III), F represents a b-valent organic group derived from a compound having a hole transporting ability, D represents a divalent group having flexibility, and R ³ represents a hydrogen atom, substituted or unsubstituted. An alkyl group or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, a represents an integer of 1 to 3, and b represents an integer of 1 to 4. ]

[In Formula (IV), F represents an organic group derived from a compound having a hole transporting property, T represents a divalent group, Y represents an oxygen atom or a sulfur atom, R ⁴ , R ⁵ and R ⁶ each independently represents a hydrogen atom or a monovalent organic group, R ⁷ represents a monovalent organic group, m 2 represents 0 or 1, and n 6 represents an integer of 1 to 4. However, R ⁶ and R ⁷ may combine with each other to form a heterocycle having Y as a heteroatom. ]

[In Formula (V), F represents an organic group derived from a compound having a hole transporting property, T represents a divalent group, R ⁸ represents a monovalent organic group, and m3 represents 0 or 1 N7 represents any integer of 1 to 4. ]

[In Formula (VI), F represents an organic group derived from a compound having a hole transporting property, L represents an alkylene group, R ⁹ represents a monovalent organic group, and n8 represents any one of 1-4. Indicates an integer. ] The electrophotographic photoreceptor according to any one of claims 1 to 5,
Charging means for charging the electrophotographic photoreceptor;
Exposure means for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image;
Developing means for developing the electrostatic latent image with toner to form a toner image;
Transfer means for transferring the toner image to a transfer medium;
An image forming apparatus comprising: The electrophotographic photoreceptor according to any one of claims 1 to 5,
Charging means for charging the electrophotographic photosensitive member; developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image; and remaining on the surface of the electrophotographic photosensitive member At least one selected from the group consisting of cleaning means for removing the toner that has been removed,
A process cartridge comprising:

Images