JP6551217B2 - Electrophotographic photosensitive member and electrophotographic image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member and an electrophotographic image forming apparatus, and more particularly to an electrophotographic photosensitive member with improved performance such as durability.

  In recent years, an organic photoreceptor containing an organic photoconductive material has been widely used as an electrophotographic photoreceptor (hereinafter also referred to as a photoreceptor). Organic photoconductors are advantageous over inorganic photoconductors because it is easy to develop materials compatible with various exposure light sources, from visible light to infrared light, to be able to select materials free from environmental pollution, and to be inexpensive to manufacture. It is a point.

On the other hand, since the electrophotographic photosensitive member is directly subjected to external electrical or mechanical external force by charging, exposure, development, transfer, cleaning, etc., even if image formation is repeatedly performed, charging stability, potential holding property, etc. There is a demand for durability to stably maintain the performance.
Particularly, in recent years, with the trend of digitization, the demand for high definition and high quality images is increasing, and toner of small particle diameter by polymerization method such as dissolution suspension toner and emulsion polymerization aggregation toner is in the mainstream. These toners having a small particle diameter have a large adhesion force to the surface of the photoconductor, and the removal of residual toner such as transfer residual toner adhering to the surface of the photoconductor tends to be insufficient.

In view of this, a technique for improving the mechanical strength by providing a protective layer (hereinafter also referred to as a surface layer) on the surface of the photoreceptor has been proposed. Specifically, a technique for improving the mechanical strength by dispersing inorganic fine particles such as silica in a protective layer has been proposed (for example, see Patent Document 1).
However, since the charge transport performance of the protective layer is inferior, providing the protective layer has a problem that the sensitivity as an electrophotographic photosensitive member is deteriorated as compared with the electrophotographic photosensitive member without the protective layer. . In order to solve this problem, it is possible to provide charge transport performance by including a charge transport material in the protective layer, but in general, the charge transport material of an organic compound has a plasticizing effect, so by adding a charge transport material, The strength of the protective layer is reduced.

Therefore, a technique for obtaining a protective layer having a charge transport function in the protective layer and excellent in wear resistance is disclosed. For example, a technique for a protective layer in which a radical polymerizable compound having a charge transport function and a radical polymerizable compound not having a charge transport function and a filler treated with a surface treatment agent having a polymerizable functional group is subjected to a curing reaction is disclosed. (See, for example, Patent Document 2). However, even with this technique, sufficient charge transport performance cannot be obtained, and the wear resistance is not satisfactory.
In addition, here, metal oxide particles such as silicon oxide, aluminum oxide, and titanium dioxide are added as fillers, but these metal oxide particles can be expected to have some effect on improving wear resistance, but holes The transport performance was not sufficient, and the image density difference due to the photosensitive member cycle, so-called image memory, was not sufficient to achieve both abrasion resistance and image characteristics.

Further, in Patent Document 3, conductive particles such as titanium dioxide, tin oxide, copper aluminate (CuAlO ₂ ), and the like are applied as a strength member / charge transport material to a protective layer of a photoreceptor, for example, SnO _Although application examples of ₂ and CuAlO ₂ are described, it is required to suppress the residual potential and further improve the durability and the like.

JP 2002-333733 A Unexamined-Japanese-Patent No. 2010-164646 JP 2013-130603 A

  The present invention has been made in view of the above problems and circumstances, and an object of the present invention is to suppress the generation of an image memory due to a photosensitive member cycle, to have excellent stability of image characteristics over a long period, and to generate no streak image. It is to provide a photographic photoreceptor.

In order to solve the above-mentioned problems, the present inventor includes conductive particles having a long-chain alkyl group having a reactive group on the surface of the protective layer of the electrophotographic photosensitive member in the process of examining the cause of the above-described problem. Thus, the present inventors have found that it is possible to provide an electrophotographic photosensitive member which can suppress the generation of an image memory due to the photosensitive member cycle, have excellent stability of image characteristics over a long period, and does not generate a streak image.
That is, the said subject which concerns on this invention is solved by the following means.

（ｎは、７〜１８の整数を表す。Ｘは、ＣＨ_２＝ＣＨ又はＣＨ_２＝Ｃ（ＣＨ_３）を表す。Ｍは導電性粒子の表面を表す。） 1. An electrophotographic photosensitive member having a photosensitive layer and a protective layer composed of at least an organic substance on a conductive support, wherein the protective layer has a structure represented by a binder resin and the following general formula (I) An electrophotographic photosensitive member comprising conductive particles surface-modified with an organic group.

(N is, .X represents an integer of 7 to 18 is, .M representing a _CH 2 = CH or _CH 2 = C (CH ₃₎ represents the surface of the conductive particles.)

2. _2. The electrophotographic photoreceptor according to item 1, wherein the surface-modified conductive particles contain at least one of SnO ₂ and CuAlO ₂ .

  3. An electrophotographic image forming apparatus comprising the electrophotographic photosensitive member according to item 1 or 2.

  By the above means of the present invention, it is possible to provide an electrophotographic photosensitive member that suppresses the generation of an image memory due to the photosensitive member cycle, has excellent image characteristic stability over a long period of time, and does not generate streak images.

The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.
A protective layer is provided on the photosensitive layer for the purpose of improving wear resistance, and metal oxide particles such as silicon oxide, aluminum oxide and titanium oxide are added to the protective layer, and wear resistance due to the filler effect of the metal oxide particles However, these metal oxide particles do not provide sufficient hole transport ability, and charge (carriers) are trapped in the protective layer, resulting in image memory. Conceivable.

Therefore, when conductive particles surface-modified with a modifying group having a structure represented by the general formula (I) containing a long-chain alkyl group having a reactive group are added to the protective layer of the photoreceptor, The surface modifiers used can also be reduced. This is considered to be because the dispersion state of the conductive particles in the protective layer is stabilized by the effect of the long-chain alkyl group. In addition, by reducing the surface modifier, hole traps at the particle interface can be reduced, so that the residual potential is lowered, and the memory resistance can be improved.
In addition, since the long-chain alkyl group has a reactive group, the protective layer can be provided with flexibility, the surface of the photoreceptor can be prevented from being rough due to long-term use, and the streak can be long-lasting. It is speculated that it is possible to provide a high quality photoreceptor which does not generate an image.

A schematic view showing an example of the layer constitution of the photoreceptor according to the present invention A schematic sectional view showing an example of an image forming apparatus using the photosensitive member according to the present invention Evaluation chart for streak image evaluation

  The electrophotographic photosensitive member of the present invention is an electrophotographic photosensitive member having a photosensitive layer composed of at least an organic substance and a protective layer on a conductive support, and the protective layer comprises a binder resin and the compound represented by the general formula (I It is characterized by containing the electroconductive particle surface-modified with the modification group which has a structure represented by this. This feature is a technical feature common or corresponding to the invention according to each claim.

The surface-modified conductive particles preferably contain at least one of SnO ₂ and CuAlO ₂ from the viewpoint of the effect of the present invention.

  Moreover, it is preferable that the electrophotographic image forming apparatus of the present invention includes the electrophotographic photosensitive member of the present invention from the viewpoint of manifesting effects.

  Hereinafter, the components of the present invention and modes and modes for carrying out the present invention will be described in detail. In the present application, “to” is used in the sense of including the numerical values described before and after the lower limit value and the upper limit value.

<< Overview of the electrophotographic photosensitive member of the present invention >>
The electrophotographic photosensitive member of the present invention is an electrophotographic photosensitive member having a photosensitive layer composed of at least an organic substance and a protective layer on a conductive support, and the protective layer comprises a binder resin and a compound represented by the general formula (I) It contains the electroconductive particle surface-modified by the modifying group which has a structure represented by these.
That is, the electroconductive particle which concerns on this invention is a particle | grain surface-modified by the modification group which has a structure represented by the following general formula (I) by processing the surface with the said surface modifier.

n represents an integer of 7 to 18; X represents CH ₂ CHCH or CH ₂ CC (CH ₃ ). M represents the surface of the conductive particle.
As the chain length of the long chain alkyl group contained in the modifying group, a sufficient effect of dispersing the conductive particles in the protective layer can not be obtained in 4 to 6, and the property of the cured surface layer is impaired if it is more than 18 . That is, it is necessary to be within the range of 7 to 18 from the viewpoint of the dispersion state of the conductive particles in the protective layer and the provision of flexibility of the protective layer, and particularly preferably within the range of 8 to 12.

(Conductive particles)
The conductive particles before surface modification used in the present invention are preferably tin oxide (SnO ₂ ), copper aluminum oxide (CuAlO ₂ ), titanium oxide (TiO ₂ ) or the like, and in particular tin oxide or copper aluminum oxide It is preferable to use a product.
The number average primary particle diameter of the conductive particles before surface modification is preferably in the range of 1 to 300 nm. Particularly preferably, it is 3 to 100 nm.
The number average primary particle diameter of the conductive particles before surface modification was obtained by photographing a 100,000 × magnification photograph with a scanning electron microscope (eg, JSM-7500F made by Nippon Denshi) and randomly capturing 300 particles by a scanner The number average primary particle diameter can be calculated using an automatic image processing and analysis apparatus (for example, “Luzex AP” software Ver.1.32 manufactured by Nireco Co., Ltd.) with a photographic image (excluding aggregated particles).

(Surface modifier)
The surface modifier used in the present invention preferably has a structure represented by the following general formula (II).
Formula _{(II): X-COO (} CH 2) n Si (OCH 3) 3
n represents an integer of 7 to 18, particularly preferably in the range of 8 to 12. X represents CH ₂ CHCH or CH ₂ CC (CH ₃ ).
By using a surface modifier having such a structure, conductive particles surface-modified with the modifying group having the structure represented by the general formula (I) have long-chain alkyl groups on the particle surface, It is believed that the dispersion is maintained in the protective layer and the protective layer is given flexibility.

(Surface-modified conductive particles and method for producing the same)
When surface-modifying, it is preferable to process using a wet media dispersion type | mold apparatus using 0.1-100 mass parts of surface modifiers, and 50-5000 mass parts of solvent with respect to 100 mass parts of particle | grains. It can also be processed dry.
That is, by subjecting a slurry (suspension of solid particles) containing conductive particles and a surface modifier to wet pulverization, the conductive particles are refined and the surface modification of the particles proceeds at the same time. Thereafter, the solvent is removed and the mixture is pulverized to obtain conductive particles whose surface is uniformly modified with the surface modifier.

  The wet media dispersion type apparatus, which is a surface modification apparatus used in the present invention, comprises beads as media in a container, and further rotating at high speed a stirring disk mounted perpendicularly to a rotating shaft to obtain conductive particles. It is an apparatus that has a step of crushing and pulverizing and dispersing the aggregated particles, and the structure thereof is satisfactory as long as the conductive particles are sufficiently dispersed and surface-modified when conducting surface modification on the conductive particles. For example, various modes, such as vertical type, horizontal type, continuous type, and batch type (batch type), can be adopted. Specifically, a sand mill, ultra visco mill, pearl mill, glen mill, dyno mill, agitator mill, dynamic mill and the like can be used. These dispersion-type devices are pulverized and dispersed by impact crushing, friction, shearing, shear stress, etc. using a grinding medium (media) such as balls and beads.

  As the beads used in the wet media dispersion type device, balls made of glass, alumina, zircon, zirconia, steel, flint stone or the like as a raw material can be used, but those made of zirconia or zircon are particularly preferable. Further, as the size of the beads, those having a diameter of about 1 to 2 mm are usually used, but in the present invention, those having a diameter of about 0.1 to 1.0 mm are preferably used.

Various materials such as stainless steel, nylon, and ceramic can be used for the disk and container inner wall used in the wet media dispersion type apparatus. In the present invention, the disk and container inner wall made of ceramic such as zirconia or silicon carbide are particularly used. Is preferred.
By the wet treatment as described above, it is possible to obtain conductive particles that have been surface-modified with a modifying group having a structure represented by the general formula (I) that has been surface-modified with a surface modifier.

(Photoreceptor layer structure)
The photoreceptor of the present invention is obtained by forming a photosensitive layer and a protective layer on a conductive support. The layer structure of the photosensitive layer is not particularly limited, and examples of specific layer structures including a protective layer include the following.
(1) Layer structure in which a charge generation layer, a charge transport layer, and a protective layer are sequentially laminated on a conductive support. (2) A single layer containing a charge transport material and a charge generation material on a conductive support. Layer and layer structure in which protective layers are sequentially laminated (3) layer structure in which an intermediate layer, charge generation layer, charge transport layer, and protective layer are sequentially laminated on a conductive support (4) conductive support A layer structure in which an intermediate layer, a single layer containing a charge transport material and a charge generation material, and a protective layer are sequentially laminated on the photoreceptor. The photoreceptor of the present invention has any one of the above-described layer structures (1) to (4). Among these, those having a layer structure produced by sequentially providing an intermediate layer, a charge generation layer, a charge transport layer, and a protective layer on a conductive support are particularly preferable.

  FIG. 1 is a schematic view showing an example of the layer structure of the photoreceptor of the present invention. In FIG. 1, 1 indicates a conductive support, 2 a photosensitive layer, 3 an intermediate layer, 4 a charge generation layer, 5 a charge transport layer, 6 a protective layer, and R a surface-modified conductive particle.

(Configuration of protective layer)
The electrophotographic photoreceptor of the present invention has a structure in which a photosensitive layer and a protective layer composed of at least an organic material are sequentially laminated on a conductive support. This protective layer contains conductive particles surface-modified with a modifying group having a structure represented by the general formula (I). Further, the protective layer preferably contains a binder resin. As a binder resin, it is preferable to contain the component obtained by hardening a curable compound.

(Binder resin)
As the binder resin that can be used in the protective layer according to the present invention, a component obtained by curing a curable compound is preferable, but other than the curable compound, known resins such as a polyester resin, a polycarbonate resin, a polyurethane resin, and a silicone resin can be used. Resins can be mentioned. In addition, the curable compound and a resin other than the curable compound can be used in combination.
As a curable compound which can be used for the protective layer which concerns on this invention, a radically polymerizable compound is mentioned, As a radically polymerizable compound, it has at least any one of an acryloyl group and a methacryloyl group as a radically polymerizable reactive group A polymerizable monomer is preferred.
Examples of these polymerizable monomers include the compounds described in paragraphs [0037] and [0038] of JP2013-130603A, and the polymerizable monomer that can be used in the present invention. The body is not limited to these.

(Polymerization initiator)
As a method for curing reaction of a curable compound usable for the protective layer according to the present invention, curing reaction is carried out by a method utilizing electron beam cleavage reaction or a method utilizing light or heat in the presence of a radical polymerization initiator. It can be carried out. When the curing reaction is performed using a radical polymerization initiator, any of a photopolymerization initiator and a thermal polymerization initiator can be used as the polymerization initiator. Further, both light and heat initiators can be used in combination.

  Examples of the polymerization initiator that can be used in the present invention include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylazobisvaleronyl), 2,2′-azobis (2 Azo compounds such as -methylbutyronitrile), benzoyl peroxide (BPO), di-tert-butyl hydroperoxide, tert-butyl hydroperoxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, peroxide Thermal polymerization initiators such as peroxides such as lauroyl may be mentioned.

  Examples of the photopolymerization initiator include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1 (IRGACURE 369: manufactured by BASF Japan Ltd.), 2-hydroxy-2-methyl- 1-phenylpropan-1-one, 2-methyl-2-morpholino (4-methylthiophenyl) propan-1-one, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime and the like Acetophenone or ketal photoinitiator, benzoin, benzoin methyl ether, benzo Benzoin ether photopolymerization initiators such as ethyl ether, benzoin isobutyl ether, benzoin isopropyl ether, benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether , Benzophenone-based photopolymerization initiators such as acrylated benzophenone and 1,4-benzoylbenzene, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone And thioxanthone photopolymerization initiators.

  Other photopolymerization initiators include ethyl anthraquinone, 2,4,6-trimethyl benzoyl diphenyl phosphine oxide, 2,4,6- trimethyl benzoyl phenyl ethoxy phosphine oxide, bis (2,4,6- trimethyl benzoyl) phenyl phosphine Oxide (IRGACURE 819: manufactured by BASF Japan Ltd.), bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentyl phosphine oxide, methylphenylglyoxy ester, 9,10-phenanthrene, acridine type compound, triazine type The compounds include imidazole compounds. Moreover, what has a photopolymerization acceleration effect can also be used individually or in combination with the said photoinitiator. Examples include triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, (2-dimethylamino) ethyl benzoate, 4,4′-dimethylaminobenzophenone, and the like.

The polymerization initiator used in the present invention is preferably a photopolymerization initiator, preferably an alkylphenone compound or a phosphine oxide compound, more preferably an initiator having an α-hydroxyacetophenone structure or an acylphosphine oxide structure. preferable.
These polymerization initiators may be used alone or in combination of two or more. Content of a polymerization initiator is 0.1-40 mass parts with respect to 100 mass parts of polymeric compounds, Preferably it is 0.5-20 mass parts.

(Lubricant particles)
It is also possible to contain various lubricant particles in the protective layer. For example, fluorine atom-containing resin particles can be added. As fluorine atom-containing resin particles, tetrafluoroethylene resin, trifluorochlorinated ethylene resin, hexafluorochlorinated ethylene-propylene resin, vinyl fluoride resin, vinylidene fluoride resin, difluoride dichloride ethylene resin, and the like It is preferable to appropriately select one or two or more from among the copolymers, and in particular, a tetrafluoroethylene resin and a vinylidene fluoride resin are preferable.

(solvent)
As a solvent used to form a protective layer, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-2-propanol, benzyl alcohol, methyl isopropyl ketone, methyl isobutyl ketone Methyl ethyl ketone, cyclohexane, toluene, xylene, dichloromethane, ethyl acetate, butyl acetate, 2-methoxyethanol, 2-ethoxyethanol, tetrahydrofuran, 1-dioxane, 1,3-dioxolane, pyridine and diethylamine, etc. It is not limited.

(Formation of protective layer)
For the protective layer, a coating solution prepared by adding a radically polymerizable curable compound, surface-modified conductive particles, a known resin, a polymerization initiator, a lubricant particle, an antioxidant and the like as required is known. It can be prepared by applying to the surface of the photosensitive layer by the above method, performing natural drying or heat drying, and then curing. 0.2-10 micrometers is preferable and, as for the layer thickness of a protective layer, the inside of the range of 0.5-6 micrometers is more preferable.

  In the present invention, curing of the protective layer is achieved by irradiating the coating film with actinic radiation to generate radicals for polymerization, and forming crosslinks between molecules by intramolecular and intramolecular crosslinking reaction to form a cured resin. It is preferable to do. As the actinic ray, light such as ultraviolet light or visible light or electron beam is preferable, and ultraviolet light is particularly preferable from the viewpoint of ease of use.

As the ultraviolet light source, any light source that generates ultraviolet light can be used without limitation. For example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, a flash (pulse) xenon, an ultraviolet LED, or the like can be used. The irradiation conditions vary depending on each lamp, but the irradiation dose of actinic radiation is usually 1 to 20 mJ / cm ² , preferably 5 to 15 mJ / cm ² . The output voltage of the light source is preferably 0.1 to 5 kW, particularly preferably 0.5 to 3 kW.

  There is no particular limitation on the electron beam irradiation apparatus as an electron beam source, and in general, a curtain beam system capable of obtaining a large output at relatively low cost as an electron beam accelerator for such electron beam irradiation is effective. Used. The acceleration voltage at the time of electron beam irradiation is preferably 100 to 300 kV. The absorbed dose is preferably 0.005 Gy to 100 kGy (0.5 to 10 Mrad).

  The irradiation time of the active ray is a time for obtaining the necessary irradiation amount of the active ray, specifically 0.1 seconds to 10 minutes is preferable, and 1 second to 5 minutes is more preferable from the viewpoint of curing efficiency or work efficiency. It is assumed.

  In the present invention, the protective layer can be dried before and after irradiation with actinic radiation, and during irradiation with actinic radiation, and the timing of drying can be appropriately selected in combination with the irradiation condition of actinic radiation. The drying conditions for the protective layer can be appropriately selected depending on the type of solvent used in the coating solution, the layer thickness of the protective layer, and the like. Also, the drying temperature is preferably room temperature to 180 ° C, and particularly preferably 80 to 140 ° C. Moreover, 1 to 200 minutes are preferable and, as for drying time, 5 to 100 minutes are especially preferable. In the present invention, the amount of solvent contained in the protective layer can be controlled in the range of 20 ppm to 75 ppm by drying the protective layer under the above drying conditions.

(Conductive support)
The support used in the present invention may be any one as long as it has conductivity, for example, a metal such as aluminum, copper, chromium, nickel, zinc and stainless steel formed into a drum or sheet, aluminum Or metal foil such as copper laminated on a plastic film, aluminum, indium oxide, tin oxide or the like deposited on a plastic film, metal or plastic on which a conductive material is coated alone or with a binder resin to provide a conductive layer Examples include film and paper.

(Intermediate layer)
In the present invention, an intermediate layer having a barrier function and an adhesive function can be provided between the conductive support and the photosensitive layer. The intermediate layer can be formed by dip coating or the like by dissolving a binder resin such as casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyamide, polyurethane and gelatin in a known solvent. Among the binder resins, an alcohol-soluble polyamide resin is preferable.

  The intermediate layer may contain various conductive fine particles or metal oxide particles for the purpose of adjusting the resistance. For example, various metal oxide particles such as alumina, zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide and bismuth oxide. Ultrafine particles such as indium oxide doped with tin, tin oxide doped with antimony, and zirconium oxide can be used. These metal oxide particles can be used alone or in combination of two or more. When two or more types are mixed and used, the form of solid solution or fusion may be taken. The number average primary particle diameter of such metal oxide particles is preferably 0.3 μm or less, and more preferably 0.1 μm or less.

  As a solvent which can be used for formation of an intermediate | middle layer, what disperse | distributes inorganic particles, such as electroconductive fine particles mentioned above and metal oxide particles, favorably, and melt | dissolves binder resin including a polyamide resin is preferable. Specifically, alcohols having 2 to 4 carbon atoms such as ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, t-butanol, sec-butanol and the like are preferred as the binder resin for the polyamide resin. It is preferable from expressing good solubility and coating performance. In order to improve the storage stability and the dispersibility of the inorganic fine particles, the following co-solvents can be used in combination with the solvent. As co-solvents from which a preferable effect can be obtained, for example, methanol, benzyl alcohol, toluene, cyclohexanone, tetrahydrofuran and the like can be mentioned.

The binder resin concentration at the time of forming the coating solution can be appropriately selected according to the thickness of the intermediate layer and the coating method. Moreover, when inorganic fine particles etc. are disperse | distributed, it is preferable that the mixing ratio of the inorganic fine particles with respect to binder resin shall be 20-400 mass parts with respect to 100 mass parts of binder resin, and is 50-200 mass parts. Is more preferred.
Examples of the means for dispersing the inorganic fine particles include, but are not limited to, an ultrasonic disperser, a ball mill, a sand grinder, and a homomixer.

Moreover, the drying method of an intermediate | middle layer can select suitably a well-known drying method according to the kind of solvent and layer thickness to form, and heat drying is especially preferable.
The layer thickness of the intermediate layer is preferably 0.1 to 15 μm, and more preferably 0.3 to 10 μm.

(Photosensitive layer)
As described above, the photosensitive layer constituting the photosensitive member of the present invention has a charge generation layer (CGL) and a charge transport layer (CTL) in addition to a single layer structure having a charge generation function and a charge transport function in one layer. And a layer structure in which the functions of the photosensitive layer are separated from each other. As described above, the layer structure of the function separation type can control the rise of the residual potential accompanying repeated use small, and has an advantage that it is easy to control various electrophotographic characteristics according to the purpose. The negatively chargeable photoreceptor has a charge generation layer (CGL) provided on the intermediate layer and a charge transport layer (CTL) provided thereon, and the positively chargeable photoreceptor has a charge transport layer (CTL) on the intermediate layer The charge generation layer (CGL) is provided thereon. The preferred layer configuration of the photosensitive layer is a negatively charged photosensitive member having the above function separation structure.
Hereinafter, each layer of the photosensitive layer of the function separation type negatively charged photosensitive member will be described as a specific example of the photosensitive layer.

(Charge generation layer)
The charge generation layer formed in the present invention contains a charge generation material and a binder resin, and is preferably formed by applying a coating solution in which the charge generation material is dispersed in a binder resin solution.
Charge generating materials include azo raw materials such as sudan red and diane blue, quinone pigments such as pyrene quinone and anthanthrone, quinocyanine pigments, perylene pigments, indigo pigments such as indigo and thioindigo, phthalocyanine pigments, etc. is not. These charge generation materials can be used alone or in the form of being dispersed in a known binder resin.

  A known resin can be used as a binder resin for forming the charge generation layer. For example, polystyrene resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy Resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, and copolymer resin containing two or more of these resins (for example, vinyl chloride-vinyl acetate copolymer resin , Vinyl chloride-vinyl acetate-maleic anhydride copolymer resin) and poly-vinyl carbazole resin, but are not limited thereto.

  To form the charge generation layer, the charge generation material is dispersed in a solution in which a binder resin is dissolved in a solvent using a disperser to prepare a coating solution, and the coating solution is coated by a coating machine to a predetermined film thickness Preferably the membrane is made dry.

  As a solvent for dissolving and coating the binder resin used in the charge generation layer, for example, toluene, xylene, methyl ethyl ketone, cyclohexane, ethyl acetate, butyl acetate, methanol, ethanol, propanol, butanol, methyl cellosolve, ethyl cellosolve, tetrahydrofuran , 1-dioxane, 1,3-dioxolane, pyridine, diethylamine and the like, but are not limited thereto.

  As a means for dispersing the charge generating material, an ultrasonic disperser, a ball mill, a sand grinder, a homomixer, or the like can be used, but is not limited thereto.

  The mixing ratio of the charge generating material to the binder resin is preferably 1 to 600 parts by mass, more preferably 50 to 500 parts by mass with respect to 100 parts by mass of the binder resin. The thickness of the charge generation layer varies depending on the characteristics of the charge generation material, the characteristics of the binder resin, the mixing ratio, and the like, but is preferably 0.01 to 5 μm, more preferably 0.05 to 3 μm. The coating solution for the charge generation layer can prevent generation of image defects by filtering foreign matter and aggregates before coating. It can also be formed by vacuum deposition of the pigment.

(Charge transport layer)
The charge transport layer formed in the present invention contains at least a charge transport substance and a binder resin in the layer, and is formed by dissolving and applying the charge transport substance in a binder resin solution.
As the charge transporting substance, known compounds can be used, and the following can be mentioned, for example. That is, carbazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, pyrazoline compounds, oxazolone derivatives, benz Imidazole derivative, quinazoline derivative, benzofuran derivative, acridine derivative, phenazine derivative, aminostilbene derivative, triarylamine derivative, phenylenediamine derivative, stilbene derivative, benzidine derivative, poly-N-vinylcarbazole, poly-1-vinylpyrene and poly-9 -Vinylanthracene and the like. These compounds can be used alone or in combination of two or more.

  Moreover, well-known resin can be used for the binder resin for charge transport layers, for example, the following are mentioned. That is, polycarbonate resin, polyacrylate resin, polyester resin, polystyrene resin, styrene-acrylonitrile copolymer resin, polymethacrylic acid ester resin, styrene-methacrylic acid ester copolymer resin, and the like. Among these, polycarbonate resins are preferable, and polycarbonate resins of a type such as bisphenol A (BPA), bisphenol Z (BPZ), dimethyl BPA, BPA-dimethyl BPA copolymer and the like have crack resistance, abrasion resistance and charging characteristics. It is preferable from the viewpoint.

  The charge transport layer can be formed by a known method typified by a coating method. For example, in the coating method, a binder resin and a charge transport substance are dissolved to prepare a coating solution, and the layer is coated with a certain coating solution. After coating with a thickness, a desired charge transport layer can be formed by drying.

  Examples of the solvent for dissolving the binder resin and the charge transport substance include toluene, xylene, methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate, methanol, ethanol, propanol, butanol, tetrahydrofuran, 1,4-dioxane, 1,3- And dioxolane. The solvent used when preparing the coating liquid for forming the charge transport layer is not limited to the above.

  The mixing ratio of the binder resin and the charge transport material is preferably 10 to 500 parts by weight, and more preferably 20 to 100 parts by weight with respect to 100 parts by weight of the binder resin.

  The thickness of the charge transport layer varies depending on the characteristics of the charge transport material and the binder resin, the mixing ratio thereof, and the like, but is preferably 5 to 40 μm, and more preferably 10 to 30 μm.

  In the charge transport layer, a known antioxidant can be added. For example, an antioxidant described in JP-A-2000-305291 can be used.

(Photoreceptor application method)
Each layer such as an intermediate layer, a charge generation layer, a charge transport layer and a protective layer constituting the photoreceptor of the present invention can be formed by a known coating method. Specifically, a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, a beam coating method, a circular amount control type coating method and the like can be mentioned. The circular amount regulation type coating method is described in, for example, JP-A Nos. 58-189061 and 2005-275373.

≪Electrophotographic image forming device≫
An electrophotographic image forming apparatus (hereinafter, also referred to as an image forming apparatus) for realizing the effects of the present invention includes (1) an electrophotographic photosensitive member having at least the protective layer of the present invention, and (2) the surface of the electrophotographic photosensitive member described above. (3) An exposure unit that performs image exposure on the surface of the electrophotographic photosensitive member charged by the charging unit to form a latent image, and (4) a latent image formed by the exposure unit is visualized. Developing means for forming a toner image, and (5) transfer means for transferring the toner image formed on the surface of the electrophotographic photosensitive member by the developing means onto a transfer medium such as paper or a transfer belt.
It is preferable to use a non-contact charging device as the charging unit for charging the electrophotographic photosensitive member. Examples of the non-contact charging device include a corona charging device, a corotron charging device, and a scorotron charging device.

FIG. 2 is a cross-sectional view for explaining an example of a color image forming apparatus showing one embodiment of the present invention.
This color image forming apparatus is referred to as a tandem type color image forming apparatus, and includes four sets of image forming units (image forming units) 10Y, 10M, 10C, and 10Bk, an endless belt-like intermediate transfer member unit 7, and It comprises a paper conveying means 21 and a fixing means 24. A document image reader SC is disposed on the top of the main body A of the image forming apparatus.

  The image forming unit 10Y that forms a yellow image includes a charging unit (charging step) 2Y, an exposure unit (exposure step) 3Y, and a developing unit disposed around a drum-shaped photoconductor 1Y as a first image carrier. A means (developing step) 4Y, a primary transfer roller 5Y as a primary transfer means (primary transfer step), and a cleaning means 6Y. The image forming unit 10M for forming a magenta image includes a drum-like photosensitive member 1M as a first image carrier, a charging unit 2M, an exposure unit 3M, a developing unit 4M, a primary transfer roller 5M as a primary transfer unit, It has a cleaning means 6M. The image forming unit 10C for forming a cyan image includes a drum-shaped photoreceptor 1C as a first image carrier, a charging unit 2C, an exposure unit 3C, a developing unit 4C, a primary transfer roller 5C as a primary transfer unit, It has a cleaning means 6C. The image forming unit 10Bk for forming a black image includes a drum-shaped photosensitive member 1Bk as a first image carrier, a charging unit 2Bk, an exposure unit 3Bk, a developing unit 4Bk, a primary transfer roller 5Bk as a primary transfer unit, and a cleaning unit It has 6Bk.

  The four sets of image forming units 10Y, 10M, 10C, and 10Bk are charging units 2Y, 2M, 2C, and 2Bk, and image exposing units 3Y, 3M, and 3C, around photosensitive drums 1Y, 1M, 1C, and 1Bk. It comprises cleaning means 6Y, 6M, 6C, 6Bk for cleaning 3Bk, developing means 4Y, 4M, 4C, 4Bk, and photosensitive drums 1Y, 1M, 1C, 1Bk.

  The image forming units 10Y, 10M, 10C, and 10Bk have the same configuration except that the colors of the toner images formed on the photosensitive members 1Y, 1M, 1C, and 1Bk are different, and the image forming unit 10Y is an example. Explain to.

  The image forming unit 10Y has a charging unit 2Y (hereinafter simply referred to as a charging unit 2Y or a charger 2Y), an exposing unit 3Y, a developing unit 4Y, and a cleaning unit 6Y around a photosensitive drum 1Y that is an image forming unit. (Hereinafter simply referred to as the cleaning means 6Y or the cleaning blade 6Y) is arranged to form a yellow (Y) toner image on the photosensitive drum 1Y. Further, in the present embodiment, at least the photosensitive drum 1Y, the charging unit 2Y, the developing unit 4Y, and the cleaning unit 6Y in the image forming unit 10Y are integrally provided.

  The charging means 2Y is a means for giving a uniform potential to the photosensitive drum 1Y, and in the present embodiment, a corona discharge type charger 2Y is used for the photosensitive drum 1Y.

  The image exposure means 3Y performs exposure based on the image signal (yellow) on the photosensitive drum 1Y given a uniform potential by the charger 2Y, and forms an electrostatic latent image corresponding to the yellow image. Means, the exposure means 3Y comprising an LED in which light emitting elements are arranged in an array in the axial direction of the photosensitive drum 1Y and an imaging element (trade name: SELFOC (registered trademark) lens) Or, a laser optical system or the like is used.

  In the image forming apparatus of the present invention, the above-described photosensitive member and components such as a developing unit and a cleaning unit are integrally coupled as a process cartridge (image forming unit), and this image forming unit is It may be configured to be removable. In addition, at least one of a charger, an image exposure unit, a developing unit, a transfer or separator, and a cleaning unit is integrally supported together with the photosensitive member to form a process cartridge (image forming unit), which is detachable from the apparatus main body. The image forming unit may be a single image forming unit, and may be configured to be detachable using a guide such as a rail of the apparatus main body.

  The endless belt-shaped intermediate transfer body unit 7 has an endless belt-shaped intermediate transfer body 70 as a second image carrier having a semiconductive endless belt shape that is wound around a plurality of rollers and is rotatably supported.

  The images of the respective colors formed by the image forming units 10Y, 10M, 10C and 10Bk are sequentially transferred onto the endless belt-like intermediate transfer member 70 which is rotated by the primary transfer rollers 5Y, 5M, 5C and 5Bk as primary transfer means. And a composite color image is formed. A transfer material P as a transfer material (a support carrying a final image fixed thereon: for example, a plain sheet, a transparent sheet, etc.) accommodated in the sheet feeding cassette 20 is fed by the sheet feeding means 21 and a plurality of intermediate After passing through the rollers 22A, 22B, 22C, 22D, and the registration roller 23, the toner is conveyed to a secondary transfer roller 5b as a secondary transfer unit, and is secondarily transferred onto the transfer material P, and a color image is collectively transferred. The transfer material P onto which the color image has been transferred is fixed by the fixing means 24, is sandwiched between the paper discharge rollers 25, and is placed on a paper discharge tray 26 outside the apparatus. Here, a transfer support of a toner image formed on a photosensitive member such as an intermediate transfer member or a transfer material is generically called a transfer medium.

  On the other hand, after the color image is transferred to the transfer material P by the secondary transfer roller 5b as the secondary transfer means, the residual toner is removed by the cleaning means 6b from the endless belt-shaped intermediate transfer body 70 in which the transfer material P is separated by curvature. Ru.

  During the image forming process, the primary transfer roller 5Bk is always in contact with the photosensitive member 1Bk. The other primary transfer rollers 5Y, 5M, and 5C are in contact with the corresponding photoreceptors 1Y, 1M, and 1C, respectively, only during color image formation.

  The secondary transfer roller 5b contacts the endless belt-shaped intermediate transfer body 70 only when the transfer material P passes through the secondary transfer roller 5b.

  Further, the housing 8 can be pulled out of the apparatus main body A via the support rails 82L and 82R.

  The housing 8 includes image forming units 10Y, 10M, 10C, and 10Bk, and an endless belt-like intermediate transfer member unit 7.

  The image forming units 10Y, 10M, 10C, and 10Bk are arranged in tandem in the vertical direction. An endless belt-shaped intermediate transfer body unit 7 is disposed on the left side of the photoreceptors 1Y, 1M, 1C, and 1Bk in the drawing. The endless belt-like intermediate transfer body unit 7 is rotatable around an endless belt-like intermediate transfer body 70, primary transfer rollers 5Y, 5M, 5C, 5Bk, and cleaning means 6b, which are rotatable by winding rollers 71, 72, 73, 74. It consists of

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these. In addition, in an Example, although the display of "part" or "%" is used, unless otherwise indicated, it represents "mass part" or "mass%."

<Production of electrophotographic photoreceptor>
(Synthesis of surface modifier (C7))
Into a reaction vessel equipped with a stirrer, 50 g of 6-heptenyl methacrylate, 250 mg of hydroquinone monomethyl ether and 1.5 mL of a 1% tetrahydrofuran solution of hexachloroplatinate (IV) hexahydrate were added, and the mixture was heated to 40 ° C. Thereto, 42 g of trichlorosilane was gradually added dropwise while stirring, during which the temperature of the reaction mixture was adjusted so as not to exceed 45.degree.
After completion of the dropwise addition, the mixture was heated to 60 ° C. and further reacted at this temperature for 1 hour to synthesize 7-methacryloyloxyheptenyltrichlorosilane.

Next, 500 mL of methanol and 100 g of triethylamine were placed in a reaction vessel equipped with a stirrer and cooled to 0 ° C.
The previously synthesized 6-methacryloyloxyheptenyltrichlorosilane was placed in a dropping funnel and connected to a reaction vessel. The solution in the reaction vessel was vigorously stirred, and 6-methacryloyloxyheptenyltrichlorosilane was slowly added dropwise while blowing in dry N ₂ gas.
The temperature was kept at 0 ° C. for 24 hours after completion of the dropping, and then the temperature was raised to room temperature. The solvent of the reaction mixture was distilled under reduced pressure, and a large amount of ethyl ether was added to the residue. After the insoluble triethylamine hydrochloride was filtered off, the ethyl ether was distilled off under reduced pressure to obtain 78 g of a crude product of 7-methacryloyloxyheptenyltrimethoxysilane.

When this crude product was analyzed by gas chromatography, the purity of 7-methacryloyloxyheptenyltrimethoxysilane was 87.5%. To this crude product, 1.0 g of anhydrous iron (II) chloride is added, fractional distillation is performed, and a fraction having a boiling point of 143 to 144 ° C. (0.1 mmHg) is collected to obtain 77.0% pure 7-methacryloyloxy hep. 52 g of tenyltrimethoxysilane were obtained. Identification of the target substance was performed by measuring ¹ H-NMR and an infrared absorption spectrum.

(Preparation of surface modified particles 1)
100 parts by mass of “SnO ₂ ” having a number average primary particle diameter of 20 nm as conductive particles, 7 parts by mass of the produced surface modifier C7, and 1000 parts by mass of methyl ethyl ketone are placed in a wet sand mill (alumina beads having a diameter of 0.5 mm). After mixing for 6 hours at ° C., the methyl ethyl ketone and alumina beads were separated by filtration and dried at 60 ° C. to prepare “surface modified particle 1”.

(Preparation of Electrophotographic Photoreceptor 1)
The surface of a cylindrical aluminum support having a diameter of 60 mm was cut to prepare a conductive support having a maximum height Rz = 1.5 (μm).

<Intermediate layer>
The dispersion liquid of the following composition was diluted twice with the same mixed solvent, and allowed to stand overnight, followed by filtration (filter; using Ligi mesh 5 μm filter manufactured by Nippon Pall Co., Ltd.) to prepare an intermediate layer coating liquid.
Polyamide resin CM 8000 (manufactured by Toray Industries, Inc.) 1 part by mass Titanium oxide SMT 500 SAS (manufactured by Tayca Corporation) 3 parts by mass Methanol 10 parts by mass Dispersion was performed in a batch system for 10 hours using a sand mill as a dispersing machine.
It apply | coated by the dip coating method so that it might become 2 micrometers of dry layer thickness on the said support body using the said coating liquid.

<Charge generation layer>
In a Cu-Kα characteristic X-ray diffraction spectrum measurement, a titanyl phthalocyanine pigment having a maximum diffraction peak at a position of at least 27.3 ° is mixed as a charge generating material with the following materials, dispersed for 10 hours using a sand mill, and charged A generating layer coating solution was prepared.
Titanyl phthalocyanine pigment 20 parts by mass Polyvinyl butyral resin (# 6000-C: manufactured by Denki Kagaku Kogyo Co., Ltd.) 10 parts by mass t-Butyl acetate 700 parts by mass 4-methoxy-4-methyl-2-pentanone 300 parts by mass A charge generation layer having a dry layer thickness of 0.3 μm was formed on the intermediate layer by dip coating.

<Charge transport layer>
4,4′-Dimethyl-4 ″-(β-phenylstyryl) triphenylamine was mixed as a charge transport material with the following materials and dissolved to prepare a charge transport layer coating solution. The layer was applied by dip coating to form a charge transport layer having a dry layer thickness of 20 μm.
4,4'-Dimethyl-4 '-(β-phenylstyryl) triphenylamine
225 parts by mass Binder: polycarbonate (Z300: manufactured by Mitsubishi Gas Chemical Co., Ltd.) 300 parts by mass Antioxidant (IRGANOX 1010: manufactured by BASF Japan Ltd.) 6 parts by mass THF 1600 parts by mass Toluene 400 parts by mass Silicone oil (KF-54: Shin-Etsu 1 part by mass)

<Protective layer>
Surface modified particles 1 150 parts by mass Binder (SR350: manufactured by SARTOMER) 100 parts by mass Polymerization initiator (Irgacure 819: manufactured by BASF Japan) 15 parts by mass 2-Butanol 500 parts by mass It disperse | distributed and prepared the protective layer coating liquid. A protective layer was coated on the photosensitive member, which had been made up to the charge transport layer, using a circular slide hopper coater. After the coating, ultraviolet rays were irradiated for 1 minute using a xenon lamp to obtain a protective layer having a dry layer thickness of 2.0 μm. In this way, an “electrophotographic photoreceptor 1” was produced.

<Preparation of electrophotographic photosensitive members 2 to 14>
(Synthesis of surface modifier)
As shown in Table 1, 7-octenyl methacrylate is used as a raw material for the surface modifier C8, 7-octenyl acrylate is used as a raw material for Ac-C8, 11-dodecenyl methacrylate is used as a raw material for C12, and 14-penta is used as a raw material for C15. Each surface modifier was synthesized in the same procedure as surface modifier C7, except that 17-octadecenyl methacrylate and 19-icocenyl methacrylate as the raw material for C20 were used as the raw material for decenyl methacrylate and C18. . In addition, as the surface modifier S-15, known CH ₂ CC (CH ₃ ) COO (CH ₂ ) ₃ Si (OCH ₃ ) (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) is used as S-35. Used the known CH ₂ ═CHCOO (CH ₂ ) ₂ Si (C ₁₀ H ₂₁ ) (OCH ₃ ) ₂ .

(Preparation of surface modified particles 2 to 13)
Surface modified particles 2 to 13 were produced in the same manner as the surface modified particles 1 except that the materials and amounts shown in Table 1 were changed.

  The protective layer of the electrophotographic photosensitive member 1 was changed as shown in Table 2, and similarly, the electrophotographic photosensitive members 2, 4 to 14 were produced. Further, to the protective layer of the electrophotographic photosensitive member 3, 10 parts by mass of CTM-1 of the following structural formula was added as a charge transport material.

<Evaluation of electrophotographic photoreceptor>
Evaluation was performed by using “bizhub PRO C6501” manufactured by Konica Minolta Co., Ltd. having the configuration of FIG. 2 as the evaluation machine, and mounting each electrophotographic photosensitive member on the evaluation machine.
In a 23 ° C, 50% RH environment, a durability test was performed in which a 300,000 character image with a 6% image ratio was printed on both sides continuously at A4 horizontal feed. After the durability test, the residual potential of the photoconductor, image memory, Evaluation of maximum height Rz and streak image was performed. Evaluation was performed according to the following indicators.

[Evaluation of residual potential]
The residual potential after the endurance test was measured as an indicator of the potential characteristics of the electrophotographic photosensitive member. The evaluation was performed by using “CYNTHIA59” manufactured by Gentec Co., Ltd., by charging the electrophotographic photosensitive member with a scorotron charger in the dark under the conditions of 20 ° C. and 65% RH so that the surface potential becomes −500 V, and strength after 33 msec. A white exposure of 148 μW / cm ² was performed, and the post-exposure potential (residual potential) on the surface of the photoreceptor was measured.

[Evaluation of image memory]
After the endurance test, ten images of solid black and solid white mixed are printed continuously, and then a uniform halftone image is printed, and the solid black and solid white history appears in the halftone image. The following criteria were used to determine whether the
:: Memory is not generated ○: Memory is slightly generated (there is no problem in practical use)
:: Memory is generated (no problem in practical use)
X: Memory is generated (there is a problem in practical use)
The above evaluation results are shown in Table 2.

[Evaluation of maximum photoconductor height]
After the endurance test, the maximum height (Rz) of the photoreceptor surface was evaluated using a palpation type surface roughness measuring device.
(Measurement condition)
Measuring device: Surfcom 1400D (manufactured by Tokyo Seimitsu Co., Ltd.)
Measurement mode: Roughness measurement Measurement length: 20.0 mm
Cutoff: 0.08 mm (Gaussian)
Measurement speed: 0.15 mm / sec

[Stripe image evaluation]
In the drum after the endurance test, when the evaluation chart as shown in FIG. 3 is continuously printed on both sides of A3 paper P on 2000 sheets and left for 1 hour to separate from the previous image memory, a uniform half image is printed. The difference in density due to toner slipping between the band X and the non-band Z corresponding to the evaluation chart was visually evaluated.

  As apparent from the above results, the electrophotographic photosensitive members 1 to 8, 10 and 11 of the present invention have residual potential, image memory, maximum height and streaks as compared with the comparative electrophotographic photosensitive members 9, 12 and 13. It was found that the electrophotographic photosensitive member had excellent characteristics in any of the image evaluations.

DESCRIPTION OF SYMBOLS 1 Conductive support body 2 Photosensitive layer 3 Intermediate layer 4 Charge generation layer 5 Charge transport layer 6 Protective layer R Surface-modified conductive particles 1Y, 1M, 1C, 1Bk Photosensitive drums 2Y, 2M, 2C, 2Bk Charging means 3Y 3M, 3C, 3Bk Image exposing means 4Y, 4M, 4C, 4Bk Developing means 6Y, 6M, 6C, 6Bk Cleaning means 10Y, 10M, 10C, 10Bk Image forming unit X Band part Z Non-band part P Paper

Claims (3)

An electrophotographic photosensitive member having a photosensitive layer and a protective layer composed of at least an organic substance on a conductive support, wherein the protective layer has a structure represented by a binder resin and the following general formula (I) An electrophotographic photosensitive member comprising conductive particles surface-modified with an organic group.

(N is, .X represents an integer of 7 to 18 is, .M representing a _CH 2 = CH or _CH 2 = C (CH ₃₎ represents the surface of the conductive particles.) The electrophotographic photoreceptor according to claim 1, wherein the surface-modified conductive particles contain at least one of SnO ₂ and CuAlO ₂ .   An electrophotographic image forming apparatus comprising the electrophotographic photosensitive member according to claim 1.

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