JP2008096527A - Electrophotographic photoreceptor, image forming apparatus and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having a base coat layer capable of suppressing increase in a residual potential and generation of fog in an image accompanying the increase. <P>SOLUTION: The electrophotographic photoreceptor has a conductive layer and a photosensitive layer successively formed on a conductive substrate; wherein the conductive 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.

  As an attempt to further improve the image quality of an image forming apparatus, for example, it is known to provide an undercoat layer between a conductive substrate and a photosensitive layer of an electrophotographic photosensitive member. Providing the undercoat layer has the advantages of enabling coating of defects on the surface of the conductive substrate, improving the chargeability of the electrophotographic photosensitive member, and improving the adhesion of the photosensitive layer. The undercoat layer was originally made of a resin such as polyamide. However, an electrophotographic photosensitive member having such an undercoat layer suppresses an increase in residual potential and accompanying image fogging. It was not possible to do so and it was not suitable for practical use.

As means for solving such a problem, conventionally, for example, it further contains metal oxide particles surface-treated with a titanate coupling agent, a silane compound, or a coupling agent having an amino group. An electrophotographic photosensitive member provided with an undercoat layer has been proposed (see Patent Documents 1, 2, and 3).
JP-A-4-172362 JP-A-4-222972 JP-A-9-96916

  However, the conventional electrophotographic photosensitive members including the electrophotographic photosensitive members described in Patent Documents 1 to 3 do not sufficiently suppress the increase in residual potential and the accompanying image fogging, There was room for improvement. Since the undercoat layer has the advantages as described above, it is considered that there is a strong demand for an electrophotographic photosensitive member having an undercoat layer in which the above problems are sufficiently solved.

  Therefore, the present invention includes an electrophotographic photosensitive member provided with an undercoat layer that can sufficiently suppress an increase in residual potential and the accompanying image fogging, and such an electrophotographic photosensitive member. An object is to provide an image forming apparatus and a process cartridge.

In order to achieve the above object, the present invention provides:
An electrophotographic photoreceptor comprising a conductive layer and a photosensitive layer in this order on a conductive substrate,
The conductive 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. Provided is an electrophotographic photosensitive member characterized by being surface-treated. The conductive layer constitutes at least a part of the undercoat layer.

  The electrophotographic photosensitive member of the present invention includes the conductive layer as described above, thereby making it possible to sufficiently suppress an increase in residual potential and accompanying image fogging. Although the detailed reason is not clear, it is assumed that the electrical resistance of the undercoat layer decreases to an appropriate value when the metal oxide surface-treated as described above is contained in the undercoat layer. The

  By the way, in recent years, as a charging device in an image forming apparatus, a contact-type charging device that generates less ozone is often used instead of a conventional non-contact type charging device such as a corotron. When a contact-type charging device is used, if a locally deteriorated portion exists in the electrophotographic photosensitive member, a local high electric field is added to the deteriorated portion during charging, resulting in an electrical pinhole leak. Image quality defects are likely to occur. Although this pinhole leak may occur due to a coating film defect in the photosensitive layer, conductive foreign matter (carbon fiber, carrier powder, etc.) generated in the image forming apparatus comes into contact with the electrophotographic photosensitive member, or It may occur by penetrating and forming a conductive path between the charging device and the conductive substrate. The electrophotographic photosensitive member of the present invention also has sufficient leakage resistance, and can sufficiently suppress the occurrence of pinhole leakage as described above and the accompanying image quality defects.

  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 5 volume% or more and 60 volume% or less with respect to the volume of the said conductive layer. When the content is less than 5% by volume, the resistance of the conductive layer is higher than when the content is within the above range, and the residual potential tends to cycle up due to charge accumulation. . On the other hand, when the content exceeds 60% by volume, the film formability of the conductive layer tends to deteriorate as compared with the case where the content is in the above range.

  The average particle diameter of the metal oxide is preferably 10 nm or more and 100 nm or less. When the average particle diameter is less than 10 nm, the surface area is increased as compared with the case where the average particle diameter is within the above range, and the dispersibility of the metal oxide in the conductive layer tends to deteriorate. On the other hand, when the average particle size exceeds 100 nm, the chargeability tends to be lower than when the average particle size is in the above range, and good electrophotographic characteristics tend to be difficult to obtain. Here, the “average particle diameter” means an average diameter of 100 particles arbitrarily selected from a scanning electron microscope (SEM).

  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 conductive layer is preferably a phenol resin in terms of mechanical strength and electrical characteristics.

  It is preferable that a blocking layer is further provided between the conductive layer and the photosensitive layer. When the blocking layer is provided, it is possible to more reliably control the injection of charges from the conductive substrate to the photosensitive layer, and to further improve the electrical characteristics, image quality, photosensitive layer adhesion, and the like. The blocking layer constitutes at least a part of the undercoat layer together with the conductive layer.

  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, it is possible to stably supply a high-quality image with less fog and leakage defects over a long period of time.

  As the charging means in the image forming apparatus and the process cartridge, a contact type charging device or a non-contact type charging roller is suitable.

  In addition, as the image forming apparatus, an intermediate transfer type image forming apparatus, that is, a transfer unit includes an intermediate transfer body to which a toner image is primarily transferred, and the toner image is transferred to the medium to be transferred via the intermediate transfer body. An image forming apparatus that is transferred onto the surface is suitable.

  According to the present invention, an electrophotographic photosensitive member having an undercoat layer that can sufficiently suppress an increase in residual potential and the accompanying image fogging, and an image including such an electrophotographic photosensitive member. A forming apparatus and a process cartridge are provided.

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

(Electrophotographic photoreceptor)
(First embodiment)
FIG. 1 is a schematic cross-sectional view showing an electrophotographic photoreceptor according to the first embodiment of the present invention. An electrophotographic photoreceptor 1 shown in FIG. 1 is a functionally separated photoreceptor having a structure in which a conductive layer 3, a blocking layer 4, a charge generation layer 5 and a charge transport layer 6 are laminated in this order on a conductive substrate 2. The conductive layer 3 and the blocking layer 4 constitute an undercoat layer, and the charge generation layer 5 and the charge transport layer 6 constitute a photosensitive layer 7. The undercoat layer is usually required to have a function of adjusting electrical resistance (resistance adjusting function) and a function of suppressing charge injection (charge blocking function). In the electrophotographic photoreceptor 1, the resistance adjusting function is mainly used. The conductive layer 3 is responsible, and the blocking layer 4 is mainly responsible for the charge blocking function.

  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. Alternatively, carbon black, indium oxide, tin oxide, antimony oxide powder, metal powder, copper iodide, or the like may be dispersed in a binder resin and subjected to conductive treatment by coating. Also, for the purpose of preventing injection, improving adhesiveness, preventing interference fringes, for example, mirror cutting, etching, anodizing, rough cutting, centerless grinding, sandblasting, boehmite treatment or honing treatment, phosphoric acid, chromic acid In addition, those that have been treated with an acidic treatment solution comprising hydrofluoric acid 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 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 boehmite treatment is performed by immersing in pure water of 90 ° C. or higher and 100 ° C. or lower for 5 minutes or longer and 60 minutes or shorter, or by contacting with heated steam of 90 ° C. or higher and 120 ° C. or lower for 5 minutes or longer and 60 minutes or shorter. be able to. 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 conductive layer 3 will be described. The conductive layer 3 contains a resin having a crosslinked structure and a metal oxide.

  Examples of the resin having a crosslinked structure include acetal resins such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, Known polymer resin compounds such as vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol resin, phenol-formaldehyde resin, melamine resin, urethane resin and the like can be mentioned. Alternatively, a charge transporting resin having a charge transporting group or a conductive resin such as polyaniline can be used. Among these, resins that are insoluble in the upper-layer coating solvent, such as phenol resins, phenol-formaldehyde resins, melamine resins, urethane resins, and epoxy resins, are preferable, and phenol resins are particularly preferable in terms of mechanical strength and electrical characteristics.

  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.

  As the surface-treated metal oxide contained in the conductive layer 3, a known metal oxide can be used. However, tin oxide, zinc oxide, and oxide 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, 5 volume% or more and 60 volume% or less are preferable with respect to the volume of the conductive layer 3, and 10 volume% or more and 60 volume% or less are still more preferable. When the content is less than 5% by volume, the resistance of the conductive layer is higher than when the content is within the above range, and the residual potential tends to cycle up due to charge accumulation. . On the other hand, when the content exceeds 60% by volume, the film formability of the conductive layer tends to deteriorate as compared with the case where the content is in the above range.

The powder resistance value of the metal oxide is preferably 1 × 10 Ω · cm to 1 × 10 ¹¹ Ω · cm, more preferably 1 × 10 ² Ω · cm to 1 × 10 ⁶ Ω · cm. When the powder resistance value is less than 1 × 10 Ω · cm, the leakage resistance tends to be insufficient as compared with the case of 1 × 10 Ω · cm or more and 1 × 10 ¹¹ Ω · cm or less. On the other hand, when the powder resistance value exceeds 1 × 10 ¹¹ Ω · cm, the increase in the residual potential tends to be less likely to be suppressed than in the case of 1 × 10 ¹¹ Ω · cm or more and 1 × 10 ¹¹ Ω · cm or less. is there.

  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 conductive 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 chargeability tends to be lower than in the case of 10 nm or more and 100 nm or less, and good electrophotographic characteristics tend to be difficult to obtain.

  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 surface treatment is performed by a wet method, the treatment material is dissolved in a solvent in which the surface treatment agent does not react, and the metal oxide is stirred in the solvent, or ultrasonic, sand mill, attritor, ball mill, etc. Disperse and process. For the treatment, it is preferable to use a dispersion medium such as silica gel, alumina, zirconia or the like in order to perform a more uniform treatment. Although any media can be used, 0.5 mm or more and 50 mm or less are preferable. The treatment is completed by removing the solvent, but it is effective to regrind if the metal oxide has agglomerated. The solvent can be removed by filtration, distillation, etc., but it is preferable to distill off by distillation under reduced pressure in order to remove the solvent quickly. The reduced pressure can be arbitrarily set in the range of 0.1 mmHg to 760 mmHg. After removing the solvent, baking is performed at a temperature equal to or higher than the boiling point of the solvent used for the surface treatment. This completes the reaction of the surface treatment agent. 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 baking is performed at a temperature lower than the boiling point of the solvent, a large amount of the solvent remains in the metal oxide, which may cause a problem in the dispersibility and electrical characteristics of the metal oxide. In particular, when an undercoat layer is formed using a metal oxide with a solvent remaining, variations in film resistance occur, environmental fluctuations in electrical characteristics increase, and electrophotographic photoreceptor durability, image quality characteristics, leak resistance, etc. Affects. Thereafter, baking is further performed, and heat treatment is preferably performed at 180 ° C. or higher. Thereby, the remaining moisture and solvent are completely removed from the metal oxide, the surface of the metal oxide is more uniformly treated, and good dispersibility of the metal oxide is obtained. Further, since moisture is completely removed, the environmental dependency of the film resistance is reduced, and the environmental dependency of the electrophotographic photosensitive member is reduced. Furthermore, it becomes easy to adjust the resistance within a target range, and it becomes easy to control both the cycle characteristics and the image quality characteristics.

  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.

  The content ratio between the resin having a crosslinked structure and the metal oxide can be arbitrarily set within a range in which desired electrophotographic photoreceptor characteristics can be obtained.

  In addition to the surface-treated metal oxide, the conductive layer 3 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 conductive layer 3 can also contain various substances for improving electrical characteristics, environmental stability, image quality, and the like. Examples of such substances include quinone compounds such as chloranil, bromoanil and anthraquinone, tetracyanoquinodimethane compounds, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone and the like. Fluorenone compounds, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3,4- Oxadiazole, oxadiazole compounds such as 2,5-bis (4-diethylaminophenyl) -1,3,4-oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5′- Electron transport materials such as diphenoquinone compounds such as tetra-t-butyldiphenoquinone, electron transport pigments such as polycyclic condensation systems and azo systems, silane coupling agents, Benzalkonium chelate compounds, titanium chelate compounds, aluminum chelate compounds, and known materials such as titanium alkoxide compound. These substances can be used singly or as a mixture or polycondensate of two or more.

  Examples of the silane coupling agent include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-glycidoxypropyl. Trimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -Γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, and the like.

  Zirconium chelate compounds include: zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, naphthenic acid Zirconium, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, titanium Examples include lactate, titanium lactate ethyl ester, titanium triethanolamate, and polyhydroxytitanium stearate.

  Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, and aluminum tris (ethyl acetoacetate).

  The conductive layer 3 is formed by applying a conductive layer forming coating solution containing the constituent material of the conductive layer 3 (including at least the resin having a crosslinked structure and the metal oxide) onto the conductive substrate 2 and drying the conductive layer 3. Can be formed.

  As a solvent used for preparing the coating solution for forming the conductive layer, any known organic solvent such as alcohol, aromatic, halogenated hydrocarbon, ketone, ketone alcohol, ether, ester, etc. Can be selected. For example, methanol, ethanol, n-propanol, isopropanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride Ordinary organic solvents such as chloroform, chlorobenzene, and toluene can be used. These solvent can be used individually by 1 type or in mixture of 2 or more types. The mixed solvent may be any as long as it dissolves the resin.

  As a method for dispersing or dissolving various constituent materials in a solvent, methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker can be used.

  As a method for applying the conductive layer forming coating solution, it is possible to use 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, or a curtain coating method. it can. Further, drying after coating is performed at a temperature at which the solvent can be evaporated and a film can be formed. 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 strength of the conductive layer is preferably 35 or more in terms of Vickers strength. The thickness of the conductive layer is preferably 3 μm or more, more preferably 5 μm or more and 25 μm or less.

  The surface roughness of the conductive layer is adjusted to 1 / (4n) (where n is the refractive index of the upper layer) to 1 / (2λ) of the exposure laser wavelength λ used to prevent moire images. In order to adjust the surface roughness, the conductive layer may contain resin particles. As the resin particles, silicone resin particles, cross-linked PMMA resin particles, and the like can be used. In addition, the conductive layer can be polished to adjust the surface roughness. As a polishing method, buffing, sand blasting, wet honing, grinding, or the like can be used.

  Next, the blocking layer 4 will be described.

  The blocking layer 4 is composed of acetal resin such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride It contains a polymer resin compound such as vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, melamine resin.

  Moreover, the blocking layer 4 further contains an organic compound containing a silicon atom, or an organometallic compound containing zirconium, titanium, aluminum, manganese, or the like. These compounds can be used individually by 1 type or as a mixture or polycondensate of 2 or more types. An organic compound containing a silicon atom or an organometallic compound containing zirconium is excellent in that the residual potential is low, the potential change due to the environment, and the potential change due to repeated use is small.

  Examples of organic compounds containing silicon atoms include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-glycidoxy. Propyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) ) -Γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, and the like. Among these, vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltri Methoxysilane, N-2- (aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3- Silane coupling agents such as aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane are preferred.

  Zirconium-containing organometallic compounds include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl zirconium acetoacetate, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, octanoic acid Zirconium, zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Examples of the organometallic compound containing titanium include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, and titanium lactate. Ammonium salts, titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, polyhydroxytitanium stearate and the like can be mentioned.

  Examples of the organometallic compound containing aluminum include aluminum isopropylate, monobutoxyaluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, and aluminum tris (ethyl acetoacetate).

  The blocking layer 4 can be formed by applying a coating solution for forming a blocking layer containing the constituent material of the blocking layer 4 on the conductive layer 3 and drying it.

  The solvent used for the preparation of the coating solution for forming the blocking layer, the method for dispersing or dissolving various constituent materials in the solvent, and the method for applying the coating solution for forming the blocking layer are the same as in the case of the coating solution for forming the conductive layer. .

  The thickness of the blocking layer 4 is preferably 0.1 μm or more and 3 μm or less. Although the blocking layer 4 functions as an electrical barrier, if the thickness is less than 0.1 μm, it tends to be difficult to function as an electrical barrier, while if it exceeds 3 μm, the electrical barrier becomes stronger. There is a tendency that the potential increases due to repeated use.

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

  As the charge generation material, a known charge generation material can be used. That is, for infrared light, phthalocyanine pigments, squarylium, bisazo, trisazo, perylene, dithioketopyrrolopyrrole, etc., for visible light, condensed polycyclic pigments, bisazo, perylene, trigonal selenium, dye-sensitized metal oxides Etc. can be used. Of these, phthalocyanine pigments are particularly preferable because they can obtain an electrophotographic photoreceptor having high sensitivity and excellent repeatability. In addition, phthalocyanine pigments generally have several crystal forms, and any of these crystal forms can be used as long as it is a crystal form capable of obtaining a sensitivity suitable for the purpose. Particularly preferred charge generating materials include chlorogallium phthalocyanine, dichlorosphthalocyanine, hydroxygallium phthalocyanine, metal-free phthalocyanine, oxytitanyl phthalocyanine, chloroindium phthalocyanine and the like.

  Crystals of phthalocyanine pigments are obtained by mechanically dry-grinding phthalocyanine pigments produced by a known method with an automatic mortar, planetary mill, vibration mill, CF mill, roller mill, sand mill, kneader, etc. At the same time, it can be produced by wet pulverization using a ball mill, mortar, sand mill, kneader or the like. Solvents used in the above treatment include aromatics (toluene, chlorobenzene, etc.), amides (dimethylformamide, N-methylpyrrolidone, etc.), aliphatic alcohols (methanol, ethanol, butanol, etc.), aliphatic polyhydric alcohols (Ethylene glycol, glycerin, polyethylene glycol, etc.), aromatic alcohols (benzyl alcohol, phenethyl alcohol, etc.), esters (acetic ester, butyl acetate, etc.), ketones (acetone, methyl ethyl ketone, etc.), dimethyl sulfoxide, ethers (Diethyl ether, tetrahydrofuran, etc.), a mixed system of these organic solvents, and a mixed system of water and these organic solvents. The amount of the solvent to be used is 1 part by mass or more and 200 parts by mass or less, preferably 10 parts by mass or more and 100 parts by mass or less with respect to 1 part by mass of the pigment crystal. The treatment temperature is −20 ° C. or higher and the boiling point of the solvent or lower, preferably −10 ° C. or higher and 60 ° C. or lower. In addition, grinding aids such as sodium chloride and sodium nitrate can be used during grinding. The amount of the grinding aid used is 0.5 to 20 parts by mass, preferably 1 to 10 parts by mass with respect to 1 part by mass of the pigment crystal. Crystals of phthalocyanine pigments produced by a known method can be controlled by acid pasting, or by combining acid pasting and the above-described dry pulverization or wet pulverization. As the acid used for acid pasting, sulfuric acid having a concentration of 70% to 100% is preferable, and sulfuric acid having a concentration of 95% to 100% is more preferable. The amount of concentrated sulfuric acid is 1 part by mass or more and 100 parts by mass or less, preferably 3 parts by mass or more and 50 parts by mass or less with respect to 1 part by mass of the pigment crystal. The dissolution temperature in acid pasting is -20 ° C or higher and 100 ° C or lower, preferably -10 ° C or higher and 60 ° C or lower. As a solvent to be precipitated, water or a mixed solvent of water and an organic solvent is used in an arbitrary amount. The temperature for precipitation is not particularly limited, but it is preferable to cool with ice or the like in order to prevent heat generation.

  The charge generation material can be subjected to a surface treatment to improve the stability of electrical characteristics and prevent image quality defects. A coupling agent or the like can be used as the surface treatment agent, but is not limited thereto. As coupling agents used for the surface treatment, vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxy Propyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) ) -Γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, and the like. Among these, vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxy Silane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3- Aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane and the like are preferable.

  As the surface treatment agent, zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, Organic zirconium compounds such as zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide can also be used. Tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, titanium lactate, titanium lactate Organic titanium compounds such as ethyl ester, titanium triethanolamate, polyhydroxytitanium stearate, aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) An organoaluminum compound such as can also be used.

  The charge generation layer 5 may further contain a binder resin. 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 acetal 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 Examples thereof include insulating resins such as resins, polyacrylamide resins, polyvinyl pyridine resins, cellulose resins, urethane resins, epoxy resins, caseins, polyvinyl alcohol resins, and polyvinyl pyrrolidone resins. Among them, polyvinyl acetal resins are particularly preferable. 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 also contain various substances in order to improve electrical characteristics, environmental stability, image quality, and the like. Examples of such substances include quinone compounds such as chloranil, bromoanil and anthraquinone, tetracyanoquinodimethane compounds, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone and the like. Fluorenone compounds, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3,4- Oxadiazole, oxadiazole compounds such as 2,5-bis (4-diethylaminophenyl) -1,3,4-oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5′- Electron transport materials such as diphenoquinone compounds such as tetra-t-butyldiphenoquinone, electron transport pigments such as polycyclic condensation systems and azo systems, silane coupling agents, Benzalkonium chelate compounds, titanium chelate compounds, aluminum chelate compounds, and known materials such as titanium alkoxide compound. These substances can be used singly or as a mixture or polycondensate of two or more. For example, specific examples of the silane coupling agent, the zirconium chelate compound, the titanium chelate compound and the aluminum chelate compound are the same as those in the conductive layer 3.

  The charge generation layer 5 is formed by vacuum-depositing the constituent material of the charge generation layer 5 (including at least the charge generation material) on the blocking layer 4, or the constituent material of the charge generation layer 5 (at least the charge generation material and It can be formed by applying a coating solution for forming a charge generation layer containing the binder resin) on the blocking layer 4 and drying it.

  The solvent used for the preparation of the coating solution for forming the charge generation layer, the method of dispersing or dissolving various constituent materials in the solvent, and the coating method of the coating solution for forming the charge generation layer are the same as in the case of the coating solution for forming the conductive layer. It is. However, when the charge generating material is dispersed in the solvent, the particle size of the charge generating material is preferably 0.5 μm or less, more preferably 0.3 μm or less, and still more preferably 0 from the viewpoint of sensitivity and stability. .15 μm or less.

  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.

  Finally, the charge transport layer 6 will be described. The charge transport layer 6 contains a charge transport material.

  Examples of the charge transport material include oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-triphenyl-pyrazoline, 1- [pyridyl- (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline and other pyrazoline derivatives, triphenylamine, tri (P-methyl) phenylamine, N, N′-bis (3 Aromatic tertiary amino compounds such as 4-dimethylphenyl) biphenyl-4-amine, dibenzylaniline, 9,9-dimethyl-N, N′-di (p-tolyl) fluorenon-2-amine, N, N Aromatic tertiary diamino compounds such as' -diphenyl-N, N'-bis (3-methylphenyl)-[1,1-biphenyl] -4,4'-diamine, 3- ( 1,2,4-triazine derivatives such as 4′-dimethylaminophenyl) -5,6-di- (4′-methoxyphenyl) -1,2,4-triazine, 4-diethylaminobenzaldehyde-1,1-diphenyl Hydrazone derivatives such as hydrazone, 4-diphenylaminobenzaldehyde-1,1-diphenylhydrazone, [p- (diethylamino) phenyl] (1-naphthyl) phenylhydrazone, quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline, 6 Benzofuran derivatives such as -hydroxy-2,3-di (p-methoxyphenyl) -benzofuran, α-stilbene derivatives such as p- (2,2-diphenylvinyl) -N, N′-diphenylaniline, enamine derivatives, N -Carbazole derivatives such as ethylcarbazole, poly-N-vinyl Hole transport materials such as rubazole and derivatives thereof; quinone compounds such as chloranil, bromoanil, anthraquinone, tetracyanoquinodimethane compounds, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro- Fluorenone compounds such as 9-fluorenone, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1, Oxadiazole compounds such as 3,4-oxadiazole and 2,5-bis (4-diethylaminophenyl) -1,3,4-oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5 , 5′-tetra-t-butyldiphenoquinone and other electron transport materials such as diphenoquinone compounds; or a group consisting of the compounds shown above in the main chain or Is a polymer having a side chain. These charge transport materials can be used alone or in combination of two or more.

  The charge transport layer 6 may further contain a binder resin. As the binder resin, an electrically insulating resin capable of forming a film is preferable. Examples of such resins include 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. Polymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-carbazole, polyvinyl Butyral, polyvinyl formal, polysulfone, casein, gelatin, polyvinyl alcohol, ethyl cellulose, phenol resin, polyamide, carboxy-methyl cellulose, vinylidene chloride Mer wax, polyurethane and the like, but not limited thereto. These binder resins can be used singly or in combination of two or more. In particular, polycarbonate resins, polyester resins, methacrylic resins and acrylic resins are compatible with charge transport materials, solvents From the viewpoint of solubility in water and film strength. The blending ratio (mass ratio) of the binder resin and the charge transport material is preferably 10/90 to 90/10 in terms of electrical characteristics and film strength.

  When the charge transport layer 6 forms the outermost surface layer as in the electrophotographic photosensitive member 1, the charge transport layer 6 includes a charge transport layer 6 in order to control contamination resistance adhesion, lubricity, hardness, etc. on the surface of the electrophotographic photosensitive member. Various particles can also be contained.

  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.

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 ₂ —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.

  The charge transport layer 6 can also contain silicone oil in order to control the antifouling substance adhesion, lubricity, hardness and the like on the surface of the electrophotographic photosensitive member. 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 coating solution for forming the charge transport layer, or may be impregnated after the electrophotographic photosensitive member 1 is produced, for example, under reduced pressure or under pressure.

  The charge transport layer 6 is applied on the charge generation layer 5 with a coating solution for forming a charge transport layer containing the constituent materials of the charge transport layer 6 (including at least the charge generation material and the binder resin) and dried. Can be formed.

  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, Common organic solvents such as cyclic or linear ethers such as dioxane, tetrahydrofuran and ethyl ether can be mentioned. These can be used individually by 1 type or in mixture of 2 or more types.

  The method for dispersing or dissolving various constituent materials in a solvent and the method for applying the charge transport layer forming coating solution are the same as those for the conductive layer forming coating solution.

  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 40 μm or less.

  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 7 (the charge generation layer 5 and the charge transport layer 6) includes an antioxidant, A light stabilizer, a heat stabilizer, etc. can be contained.

  Antioxidants include, for example, phenolic, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, and spiroidanone compounds, and their derivatives, organic sulfur compounds, and organic phosphorus compounds. Can be mentioned.

  Examples of phenolic antioxidants include 2,6-di-t-butyl-4-methylphenol, styrenated phenol, n-octadecyl-3- (3 ′, 5′-di-t-butyl-4′-hydroxy Phenyl) -propionate, 2,2′-methylene-bis- (4-methyl-6-tert-butylphenol), 2-t-butyl-6- (3′-tert-butyl-5′-methyl-2′-) Hydroxybenzyl) -4-methylphenyl acrylate, 4,4′-butylidene-bis- (3-methyl-6-tert-butyl-phenol), 4,4′-thio-bis- (3-methyl-6-t) -Butylphenol), 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, tetrakis- [methylene-3- (3 ', 5'-di-t- Butyl 4'-hydroxyphenyl) propionate] -methane, 3,9-bis [2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl]- Examples include 2,4,8,10-tetraoxaspiro [5,5] undecane.

  Examples of hindered amine compounds include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy]- 2,2,6,6-tetramethylpiperidine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine succinate Polycondensate, poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diimyl} {(2,2,6,6-tetra Methyl-4-piperidyl) imino} hexamethylene {(2,3,6,6-tetramethyl-4-piperidyl) imino}], 2- (3,5-di-t-butyl-4-hydroxybenzyl)- 2-n-butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl- N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate and the like.

  Examples of organic sulfur-based antioxidants include dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, pentaerythritol-tetrakis. (Β-lauryl-thiopropionate), ditridecyl-3,3′-thiodipropionate, 2-mercaptobenzimidazole and the like. Examples of the organophosphorus antioxidant include trisnonylphenyl phosfte, triphenyl phosfeft, and tris (2,4-di-t-butylphenyl) phosphite. The organic sulfur-based and organic phosphorus-based antioxidants are called secondary antioxidants, but when used in combination with primary antioxidants such as phenolic and hindered amines, a synergistic effect is obtained.

  Examples of the light stabilizer include benzophenone-based, benzotriazole-based, dithiocarbamate-based, tetramethylpiperidine-based compounds, and derivatives thereof.

  Examples of the benzophenone light stabilizer include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, and the like. Examples of the benzotriazole-based light stabilizer include 2-(-2′-hydroxy-5′-methylphenyl) -benzotriazole, 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 "-Tetrahydrophthalimido-methyl) -5'-methylphenyl] benzotriazole, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2 ' -Hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-t-butylphenyl) benzotriazole, 2- (2' -Hydroxy-5'-t-octylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) benzotriazole and the like. It is. Examples of other compounds include 2,4-di-t-butylphenyl-3 ', 5'-di-t-butyl-4'-hydroxybenzoate and nickel dibutyldithiocarbamate.

The photosensitive layer 7 (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. be able to. 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.

(Second Embodiment)
FIG. 2 is a schematic cross-sectional view showing an electrophotographic photosensitive member according to the second embodiment of the present invention. The electrophotographic photoreceptor 10 shown in FIG. 2 is different from the electrophotographic photoreceptor 1 in that the electrophotographic photoreceptor 10 is not provided with the blocking layer 4 and the undercoat layer is composed only of the conductive layer 3.

(Third embodiment)
FIG. 3 is a schematic cross-sectional view showing an electrophotographic photosensitive member according to the third embodiment of the present invention. The electrophotographic photoreceptor 10 shown in FIG. 3 differs from the electrophotographic photoreceptor 1 in that the photosensitive layer 7 is not separated into the charge generation layer 5 and the charge transport layer 6.

  The photosensitive layer 7 contains a charge generation material and a charge transport material, and contains other substances such as a binder resin as necessary. 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 7 is preferably 10% by mass or more and 85% by mass or less, more preferably 20% by mass or more and 50% by mass or less, with respect to the total solid content in the photosensitive layer 7. The content of the charge transport material is preferably 5% by mass or more and 50% by mass or less with respect to the total solid content in the photosensitive layer 7. 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.

  The solvent used for the preparation of the coating solution for forming the photosensitive layer, the method of dispersing or dissolving various constituent materials in the solvent, and the coating method of the coating solution for forming the photosensitive layer are the same as the coating solution for forming the charge generation layer or the charge transport layer. The same as in the case of the coating liquid for use.

  The thickness of the photosensitive layer 7 is preferably 5 μm or more and 50 μm or less, more preferably 10 μm or more and 40 μm or less.

(Fourth embodiment)
FIG. 4 is a schematic cross-sectional view showing an electrophotographic photosensitive member according to the fourth embodiment of the present invention. The electrophotographic photoreceptor 12 shown in FIG. 4 is different from the electrophotographic photoreceptor 1 in that a protective layer 8 is further provided on the charge transport layer 6 and the protective layer 8 forms the outermost surface layer. The protective layer 8 is a layer provided for preventing chemical changes of the photosensitive layer during charging, improving the mechanical strength of the electrophotographic photosensitive member, and the like.

  The protective layer 8 is composed of a curable resin, a siloxane resin cured film containing a charge transporting compound, a film formed by containing a conductive material in an appropriate binder resin, and the like.

  Examples of the curable resin include phenol resin, polyurethane resin, melamine resin, diallyl phthalate resin, and siloxane resin. Examples of the charge transporting compound contained in the cured siloxane resin film include, for example, JP-A-10-95787, JP-A-10-251277, JP-A-11-32716, JP-A-11-38656, or JP-A-11-236391. The compound disclosed by the gazette is mentioned.

  As the binder resin contained in the protective layer 8, polyamide resin, polyvinyl acetal resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinyl ketone resin, polystyrene resin, polyacrylamide resin, polyimide resin, polyamide Examples thereof include imide resins, and these can be used after being crosslinked. Examples of the conductive material that can be contained in these binder resins include metallocene compounds such as N, N′-dimethylferrocene, N, N′-diphenyl-N, N′-bis (3-methylphenyl)- Aromatic amine compounds such as (1,1′-biphenyl) -4,4′-diamine, molybdenum oxide, tungsten oxide, antimony oxide, tin oxide, titanium oxide, indium oxide, solid solution of tin oxide and antimony, tin oxide And a solid solution of benzene and antimony oxide, a mixture thereof, or a mixture of these metal oxides in a single particle.

  The protective layer 8 contains an antioxidant, a light stabilizer, a heat stabilizer and the like 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. be able to.

  Antioxidants include, for example, phenolic, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, and spiroidanone compounds, and their derivatives, organic sulfur compounds, and organic phosphorus compounds. In addition, an antioxidant having a functional group such as a hydroxyl group, an amino group, or an alkoxysilyl group that can be bonded to the siloxane resin can be used. Examples of the light stabilizer include benzophenone-based, benzotriazole-based, dithiocarbamate-based, tetramethylpiperidine-based compounds, and derivatives thereof.

  In order to control the antifouling substance adhesion, lubricity, hardness, etc. on the surface of the electrophotographic photosensitive member, the protective layer 8 may contain various particles.

  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.

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 ₂ —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.

  In addition, the protective layer 8 can contain silicone oil in order to control the contamination resistance adhesion, lubricity, hardness, etc. 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 photoreceptor 10 is produced.

  The protective layer 8 can be formed by applying a coating liquid for forming a protective layer containing the constituent material of the protective layer 8 on the charge transport layer 6 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, Common organic solvents such as cyclic or linear ethers such as dioxane, tetrahydrofuran and ethyl ether can be mentioned. These can be used individually by 1 type or in mixture of 2 or more types.

  The solvent used for the preparation of the coating liquid for forming the protective layer, the method for dispersing or dissolving various constituent materials in the solvent, and the coating method for the coating liquid for forming the protective layer are the same as in the case of the coating liquid for forming the conductive layer. .

  The thickness of the protective layer 8 is preferably 1 μm or more and 20 μm or less, more preferably 1 μm or more and 10 μm or less.

(Image forming apparatus and process cartridge)
FIG. 5 is a schematic configuration diagram showing an image forming apparatus according to a preferred embodiment of the present invention. An image forming apparatus 100 shown in FIG. 5 includes, in an image forming apparatus main body (not shown), a process cartridge 20 including the above-described electrophotographic photosensitive member 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.). Since it has excellent leakage resistance, it can be particularly suitably used in an image forming apparatus provided with a contact charging device or a non-contact charging roller.

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 Ω · cm to 1 × 10 ¹⁴ Ω · cm, more preferably 1 × 10 ² Ω · cm to 1 × 10 ¹² Ω. -It is cm 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.

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 toners. The maximum length and the projected area are obtained, calculated by the following formula, and the average value 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 size is less than 5 nm, the polishing ability tends to be lacking, and when it exceeds 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. 5 and 6).

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 about 380 to 450 nm 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. The contact pressure on the electrophotographic photosensitive member 1 is preferably 10 gf / cm or more and 30 gf / cm or less (0.10 N / cm or more and 0.29 N / cm or less), more preferably 15 gf / cm or more and 25 gf / cm or less. (0.15 N / cm or more and 0.25 N / 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. 6 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. 6, 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 devices 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 and can be removed by pulling 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. 7 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. 7 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. 8 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. 8 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, 11 or 12 may be provided.

  For example, in the image forming apparatuses 100, 110, 120, and 130, 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. This is an intermediate transfer type image forming apparatus to be transferred. However, the image forming apparatus of the present invention may be a direct transfer type image forming apparatus in which the transfer unit does not include an intermediate transfer member and the toner image on the surface of the electrophotographic photosensitive member is directly transferred to the transfer medium.

  The image forming apparatuses 100, 110, and 120 include a cleaning device (cleaning unit) 27 and a neutralization device (static elimination unit) 28. However, in the image forming apparatus of the present invention, the cleaning unit and the neutralization 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)
After performing the same operation as the surface treatment 1, 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 3)
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 4)
The same operation as surface treatment 2 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 5)
Instead of the compound represented by the formula (A-1), the same operation as the surface treatment 3 was performed except that the compound represented by the formula (B-1) (an organosilicon compound having a thiol group) was used. went.

(Surface treatment 6)
The same operation as in the surface treatment 4 was performed except that the compound represented by the formula (B-1) (the organosilicon compound having a thiol group) was used instead of the compound represented by the formula (A-1). went.

(Surface treatment 7)
Instead of the compound represented by the formula (A-1), the same operation as the surface treatment 3 was performed except that the compound represented by the formula (B-2) (an organosilicon compound having a sulfide group) was used. went.

(Surface treatment 8)
Instead of the compound represented by the formula (A-1), the same operation as the surface treatment 4 was performed except that the compound represented by the formula (B-2) (an organosilicon compound having a sulfide group) was used. went.

(Surface treatment 9)
The same operation as in the surface treatment 4 was performed except that an aminoethylsilane coupling agent represented by the following formula was used instead of the compound represented by the formula (A-1).

(Surface treatment 10)
The same operation as in the surface treatment 4 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 1)
First, an aluminum substrate having a diameter of 84 mm, a length of 340 mm, and a thickness of 1 mm was prepared as a conductive substrate.

  Next, 40 parts by mass of tin oxide obtained in the surface treatment 3, 40 parts by mass of phenol resin (J325, manufactured by Dainippon Ink and Co., Ltd.), and 40 parts by mass of methanol were mixed, and silicone balls (Tospearl 120, Toshiba Silicone) were mixed therewith. 2 parts by mass) were added and dispersed with a sand mill for 2 hours using glass beads having a diameter of 1 mm to prepare a coating solution for forming a conductive layer. The obtained coating solution was applied on the aluminum substrate by a dip coating method, followed by drying and curing at 160 ° C. for 100 minutes to form a conductive layer having a thickness of 15 μm.

  Next, 40 parts by mass of methoxymethylated nylon (Rakkamide L5003, manufactured by Dainippon Ink Co., Ltd.) is dissolved in 200 parts by mass of methanol, and then 120 parts by mass of butanol and 50 parts by mass of distilled water are added to form a blocking layer. A coating solution was prepared. The obtained coating solution was dip coated on the conductive layer and dried at 130 ° C. for 10 minutes to form a 0.8 μm thick blocking layer.

  Next, a mixture of 15 parts of gallium chloride phthalocyanine (chlorogallium phthalocyanine), 10 parts by weight of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Union Carbide), and 300 parts by weight of n-butyl alcohol was obtained. A 1 mm glass bead was used for dispersion for 4 hours with a sand mill to prepare a coating solution for forming a charge generation layer. The obtained coating solution was dip-coated on the blocking layer and dried to form a charge generation layer having a thickness of 0.2 μm. As gallium chloride phthalocyanine, in an X-ray diffraction spectrum using Cukα rays, at least Bragg angles (2θ ± 0.2 °) of 7.4 °, 16.6 °, 25.5 ° and 28.3 ° are used. Those having a diffraction peak at the position were used.

  Finally, 4 parts by mass of N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1 ′] biphenyl-4,4′-diamine and bisphenol Z polycarbonate resin (molecular weight: 40, 000) 6 parts by mass was dissolved and mixed in 80 parts by mass of chlorobenzene to prepare a coating solution for forming a charge transport layer. 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. Thus, an electrophotographic photosensitive member was produced. In addition, the content rate of the said tin oxide in a conductive layer is 14 volume%.

  Further, an image forming apparatus having the configuration shown in FIG. 7 was produced using the obtained electrophotographic photosensitive member. Here, the elements other than the electrophotographic photosensitive member were the same as those of the full color printer Docu Print C620 manufactured by Fuji Xerox Co., Ltd.

(Example 2)
An electrophotographic photoreceptor 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 4 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 conductive layer is 14 volume%.

(Example 3)
First, an aluminum substrate having a diameter of 84 mm, a length of 340 mm, and a thickness of 1 mm was prepared as a conductive substrate.

  Next, 40 parts by mass of zinc oxide obtained by the surface treatment 1, 40 parts by mass of a phenol resin (J325, manufactured by Dainippon Ink Co., Ltd.) and 40 parts by mass of methanol were mixed, and this was mixed with silicone balls (Tospearl 120, Toshiba Silicone). 2 parts by mass) were added and dispersed with a sand mill for 2 hours using glass beads having a diameter of 1 mm to prepare a coating solution for forming an undercoat layer. The obtained coating solution was applied onto the above aluminum substrate by a dip coating method, followed by drying and curing at 160 ° C. for 100 minutes to form an undercoat layer having a thickness of 12 μm.

  Next, a mixture of 15 parts of gallium chloride phthalocyanine (chlorogallium phthalocyanine), 10 parts by weight of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Union Carbide), and 300 parts by weight of n-butyl alcohol was obtained. A 1 mm glass bead was used for dispersion for 4 hours by a sand mill to prepare a coating solution for forming a charge generation layer. 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. As gallium chloride phthalocyanine, in the X-ray diffraction spectrum using Cukα ray, at least Bragg angles (2θ ± 0.2 °) of 7.4 °, 16.6 °, 25.5 ° and 28.3 ° are obtained. Those having a diffraction peak at the position were used.

  Finally, 4 parts by mass of N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1 ′] biphenyl-4,4′-diamine and bisphenol Z polycarbonate resin (molecular weight: 40, 000) 6 parts by mass was dissolved and mixed in 80 parts by mass of chlorobenzene to prepare a coating solution for forming a charge transport layer. 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. Thus, an electrophotographic photosensitive member was produced. In addition, the content rate of the said zinc oxide in a conductive layer is 17 volume%.

  Further, an image forming apparatus having the configuration shown in FIG. 7 was produced using the obtained electrophotographic photosensitive member. Here, the elements other than the electrophotographic photosensitive member were the same as those of the full color printer Docu Print C620 manufactured by Fuji Xerox Co., Ltd.

Example 4
An electrophotographic photoreceptor and an image forming apparatus were produced in the same manner as in Example 3 except that the zinc oxide obtained in the surface treatment 2 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 conductive layer is 17 volume%.

(Example 5)
An electrophotographic photoreceptor 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 5 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 conductive layer is 14 volume%.

(Example 6)
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 6 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 conductive layer is 14 volume%.

(Example 7)
An electrophotographic photoreceptor 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 7 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 conductive layer is 14 volume%.

(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 3. In addition, the content rate of the said tin oxide in a conductive layer is 14 volume%.

(Comparative Example 1)
An electrophotographic photoreceptor and an image forming apparatus were produced in the same manner as in Example 1 except that tin oxide not subjected to surface treatment was used instead of tin oxide obtained in the surface treatment 3. In addition, the content rate of the said tin oxide in a conductive layer is 14 volume%.

(Comparative Example 2)
An electrophotographic photosensitive member and an image forming apparatus were produced in the same manner as in Example 3 except that zinc oxide not subjected to surface treatment was used instead of zinc oxide obtained in the surface treatment 1. In addition, the content rate of the said zinc oxide in a conductive layer is 17 volume%.

(Comparative Example 3)
An electrophotographic photosensitive member and an image forming apparatus were produced in the same manner as in Example 3 except that tin oxide obtained in surface treatment 9 was used instead of zinc oxide obtained in surface treatment 1. In addition, the content rate of the said zinc oxide in a conductive layer is 17 volume%.

(Comparative Example 4)
An electrophotographic photosensitive member and an image forming apparatus were produced in the same manner as in Example 3 except that tin oxide obtained by surface treatment 10 was used instead of zinc oxide obtained by surface treatment 1. In addition, the content rate of the said zinc oxide in a conductive layer is 17 volume%.

(Measurement of residual potential)
In the image forming apparatuses obtained in Examples 1 to 8 and Comparative Examples 1 to 4, a surface potential meter was installed in place of the developing device at the position of the developing device, and the residual potential was measured in the following procedure using this. Measurements were made.

  While rotating the electrophotographic photosensitive member, first, the electrophotographic photosensitive member was charged to −650 V by a charging device. Next, without performing image exposure and development, transfer and cleaning were performed in order, and further, static elimination was performed with static elimination light (wavelength 660 nm). Then, the charging was stopped when the portion on the electrophotographic photosensitive member that started charging reached the position of the charging device. Finally, the surface potential (residual potential) was measured when the portion on the electrophotographic photosensitive member that started charging further rotated and reached the position of the surface potentiometer.

(Image formation test)
Using the image forming apparatuses obtained in Examples 1 to 8 and Comparative Examples 1 to 4, continuous 10,000 images were formed in a high temperature and high humidity (30 ° C., 80% RH) environment, and the image quality (fogging Existence) was visually evaluated. Further, the initial image quality (after one image was formed) was evaluated in the same manner.

  In addition, 100 mg of carbon fiber was added to 100 g of Docu Print C620 toner, and the image forming apparatus obtained in Examples 1 to 8 and Comparative Examples 1 to 4 was used to obtain high temperature and high humidity (30 ° C., 80% RH). ) 100 images were continuously formed under the environment, and the presence or absence of a leak defect was confirmed.

The results of the residual potential measurement and the image formation test are shown in the following table. In the following table, the content of the metal oxide is indicated by the content (volume%) in the conductive layer. The meanings of symbols (◯, ×, Δ) in the following table are as follows.
Image quality: ○… Good, △… No problem in practical use (slight fogging), ×… Problem in practical use (with fogging)
Leak defect: ○… None, △… Less than 10 (no problem for practical use), X ... 10 or more (for practical use)

  As is clear from the above table, the electrophotographic photoreceptors obtained in Examples 1 to 8 show a remarkably low residual potential as compared with the electrophotographic photoreceptors obtained in Comparative Examples 1 to 4. . In addition, the image forming apparatuses obtained in Examples 1 to 8 are more or less free from leak defects in terms of image quality (after forming 10,000 images) as compared with the image forming apparatuses obtained in Comparative Examples 1 to 4. Also, the results show remarkably excellent results.

  By the measurement of the residual potential and the image formation test, the electrophotographic photosensitive member of the present invention can sufficiently suppress the increase of the residual potential and the accompanying image fogging and has sufficient leakage resistance. It was shown that it has.

1 is a schematic cross-sectional view showing an electrophotographic photosensitive member according to a first embodiment of the present invention. It is a schematic cross section showing an electrophotographic photosensitive member according to a second embodiment of the present invention. It is a schematic cross section showing an electrophotographic photosensitive member according to a third embodiment of the present invention. It is a schematic cross section which shows the electrophotographic photoreceptor which concerns on 4th Embodiment of this 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 1,10-12,410a-d ... Electrophotographic photoreceptor, 2 ... Conductive base | substrate, 3 ... Conductive layer, 4 ... Blocking layer, 5 ... Charge generation layer, 6 ... Charge transport layer, 7 ... Photosensitive layer, 8 ... 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 (4)

An electrophotographic photoreceptor comprising a conductive layer and a photosensitive layer in this order on a conductive substrate,
The conductive 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.   2. The electrophotography according to claim 1, wherein the metal oxide is surface-treated with the at least one organosilicon compound and further surface-treated with a fluorine-based silane coupling agent. 3. Photoconductor. The electrophotographic photosensitive member according to claim 1 or 2,
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 photosensitive member according to claim 1 or 2,
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