JP2006259154A - Electrophotographic photoreceptor, process cartridge, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor, capable of sufficiently suppressing the adhesion of a discharge product etc., and forming quality images that are free of defects in image quality, such as image flow, over a long period of time. <P>SOLUTION: In the electrophotographic photoreceptor, equipped with a conductive support and the photosensitive layer arranged on the conductive support, the photosensitive layer has a closest to surface layer, containing first insulative particulates and second insulative particulates on the side farthest from the conductive support and the peak grain size, in the grain size distribution of the second insulative particulates, is smaller than 1/4 times the peak grain size, in the grain size distribution of the first insulative particulates. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrophotographic photosensitive member, a process cartridge, and an image forming apparatus that are used for electrophotographic image formation.

  In recent years, so-called xerographic image forming apparatuses having a charging unit, an exposure unit, a developing unit, and a transfer unit have been further increased in speed and life due to technical progress of each member and system. As a result, the demand for high-speed compatibility and high reliability of each subsystem is increasing. In particular, electrophotographic photoreceptors used for image writing (hereinafter abbreviated as “photoreceptors” in some cases) and cleaners that clean the photoreceptors are subject to a lot of stress due to sliding, and images due to scratches, wear, chips, etc. Defects are likely to occur, and demands for high-speed compatibility and high reliability are even stronger.

  On the other hand, there is a strong demand for high image quality, and the toner has been made in a solvent mainly composed of water as a method for producing a toner that satisfies the quality by reducing the particle size of the toner, making the particle size distribution uniform, and making it spherical. Toners, so-called chemical toners, have been actively developed. As a result, recently, so-called photographic image quality has been obtained.

There is also an increasing demand for extending the life of image forming apparatuses. In order to realize a long life of the image forming apparatus, the durability of the photoconductor is improved. For example, a photoconductor provided with a cross-linked surface layer has been proposed (see, for example, Patent Document 1). . Since this photoconductor is superior in thermal and mechanical strength as compared with conventional photoconductors, it is possible to reduce deterioration due to abrasion of the surface layer and to extend the life.
Japanese Patent Laid-Open No. 11-38656

  However, since the electrophotographic photosensitive member described in Patent Document 1 has high mechanical strength and is not easily worn, contamination of the discharge product or the like attached to the surface of the photosensitive member or penetrating into the photosensitive member by the image forming process. Since the material is less likely to be removed by wear, image quality defects due to image flow are likely to occur. Note that discharge products and the like are likely to adhere to and penetrate into the photosensitive member, particularly when a contact charging type charging means is used.

  As described above, in the conventional electrophotographic photoreceptor, it is difficult to achieve both improvement in mechanical strength and prevention and removal of discharge products and the like.

  The present invention has been made in view of the above-described problems of the prior art, and achieves both improvement in mechanical strength, prevention of adhesion of discharge products and removal of deposits, and image flow over a long period of time. It is an object of the present invention to provide an electrophotographic photosensitive member capable of forming an image of good image quality without image quality defects, and a process cartridge and an image forming apparatus using the electrophotographic photoreceptor.

  In order to achieve the above object, the present invention provides an electrophotographic photosensitive member comprising a conductive support and a photosensitive layer disposed on the conductive support, wherein the photosensitive layer includes the conductive layer. The outermost surface layer containing the first insulating fine particles and the second insulating fine particles is provided on the side farthest from the support, and the peak particle size in the particle size distribution of the second insulating fine particles is The electrophotographic photosensitive member is characterized by being not more than 1/4 times the peak particle size in the particle size distribution of the insulating fine particles.

  Here, the peak particle size in the particle size distribution of the first insulating fine particles (hereinafter sometimes referred to as “first peak particle size”) indicates the maximum peak in the particle size distribution of the first insulating fine particles. Means particle size. Similarly, the peak particle size in the particle size distribution of the second insulating fine particles (hereinafter sometimes referred to as “second peak particle size”) indicates the maximum peak in the particle size distribution of the second insulating fine particles. Means particle size. In the present invention, the particle size distribution can be measured as a volume-based particle size distribution using a particle size analyzer utilizing laser diffraction scattering.

  Such an electrophotographic photoreceptor has a configuration in which two types of insulating fine particles having different particle size distributions are contained in the outermost surface layer. That is, the first insulating fine particles having the first peak particle size as the large diameter particles and the second insulating particles having the second peak particle size not more than 1/4 times the first peak particle size as the small diameter particles. Insulating fine particles. According to the electrophotographic photosensitive member having such a configuration, when used in an image forming apparatus, it is possible to achieve both improvement in mechanical strength, prevention of adhesion of discharge products, and removal of adhesion. Therefore, it is possible to form an image with good image quality without image quality defects such as image flow over a long period of time.

  The reason why such an effect is obtained is not necessarily clear, but the present inventors speculate as follows. First, it is considered that the contamination resistance adhesion, lubricity and mechanical strength of the surface of the electrophotographic photosensitive member can be improved by incorporating insulating fine particles in the outermost surface layer. As the insulating fine particles, particularly by using the large diameter particles and the small diameter particles satisfying the above relationship of the peak particle diameter, the small diameter particles are uniformly dispersed in the gaps between the large diameter particles, and the denseness of the outermost surface layer is increased. It is thought that it can be improved. As a result, compared to the case where one kind of insulating fine particles is used alone, the contamination resistance adhesion, lubricity and mechanical strength of the surface of the photoreceptor can be remarkably improved, and the resulting photoreceptor Can achieve both improvement in mechanical strength, prevention of adhesion of discharge products and removal of deposits, and formation of good quality images without image quality defects such as image flow over a long period of time. Can be considered.

Here, the specific resistance of the first insulating fine particles and the specific resistance of the second insulating fine particles are both preferably 1 × 10 ⁵ Ω · cm or more. As a result, when the photosensitive member surface is charged, leakage of charged charges can be suppressed, and generation of image quality defects such as image flow due to charge leakage can be sufficiently suppressed. Can do.

  The peak particle size in the particle size distribution of the first insulating fine particles is preferably 50 to 1000 nm, and the peak particle size in the particle size distribution of the second insulating fine particles is preferably 1 to 200 nm. When the first and second peak particle diameters are in the above range, the denseness of the outermost surface layer of the photoreceptor can be further improved, and contamination resistance adhesion, lubricity and mechanical strength of the photoreceptor surface can be improved. Can be further improved. As a result, the resulting photoreceptor can achieve a higher level of both mechanical strength improvement and anti-adhesion properties such as discharge products and removal properties, and image quality such as image flow over a longer period of time. It is possible to form an image with good image quality without defects.

  Furthermore, in the electrophotographic photosensitive member of the present invention, the outermost surface layer preferably contains a resin having a crosslinked structure. By using a resin having a cross-linked structure as the constituent material of the outermost surface layer, the mechanical strength of the surface of the photoreceptor can be increased and the wear resistance can be improved. Here, in a conventional electrophotographic photoreceptor, when a resin having a crosslinked structure is used for the outermost surface layer, contaminants such as discharge products adhering to the photoreceptor tend to be difficult to be removed by abrasion. On the other hand, in the electrophotographic photoreceptor of the present invention, the discharge product adheres to the photoreceptor by using a resin having a crosslinked structure in the outermost surface layer together with the first and second insulating fine particles described above. Penetration can be sufficiently suppressed. As a result, the life of the photoconductor is increased, and the adhesion of discharge products and the like to the photoconductor is sufficiently suppressed, and a good quality image without image quality defects such as image flow is formed over a longer period of time. be able to.

  Here, the resin having the crosslinked structure is preferably at least one of a phenol resin and a siloxane resin. When a phenol resin or a siloxane resin is used as the resin having a cross-linked structure, it is possible to further extend the life of the photoconductor while sufficiently suppressing the adhesion of discharge products and the like to the photoconductor.

  In the electrophotographic photoreceptor of the present invention, the outermost surface layer preferably contains a charge transport material. When the outermost surface layer of the electrophotographic photoreceptor contains a charge transport material, the electrical characteristics of the photoreceptor can be improved and the image quality can be further improved. In addition, when the outermost surface layer contains the resin having the crosslinked structure, the charge transport material may react with the resin having the crosslinked structure and be incorporated in the resin. In this case, the crosslinking density of the resin having a crosslinked structure can be increased, and the wear resistance of the photoreceptor can be further improved.

  The present invention also provides the electrophotographic photosensitive member of the present invention, charging means for charging the electrophotographic photosensitive member, and developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image. There is provided a process cartridge comprising: a developing unit for forming; and at least one selected from the group consisting of a cleaning unit for removing toner remaining on the surface of the electrophotographic photosensitive member.

  The present invention further includes the electrophotographic photosensitive member of the present invention, a charging unit for charging the electrophotographic photosensitive member, an exposure unit for forming an electrostatic latent image on the charged electrophotographic photosensitive member, And developing means for developing the electrostatic latent image with toner to form a toner image, and transfer means for transferring the toner image from the electrophotographic photosensitive member to a transfer target. An image forming apparatus is provided.

  Since the process cartridge and the image forming apparatus include the above-described electrophotographic photosensitive member of the present invention, the mechanical strength of the photosensitive member is improved, the adhesion of discharge products to the photosensitive member, and the removal of the attached matter are reduced. Therefore, it is possible to form an image with good image quality without image quality defects such as image flow over a long period of time.

  According to the present invention, the improvement in mechanical strength and the prevention of adhesion of discharge products, etc. and the removal of deposits are compatible, and a good quality image free from image quality defects such as image flow is formed over a long period of time. It is possible to provide an electrophotographic photosensitive member that can be used. In addition, according to the present invention, by providing the electrophotographic photosensitive member of the present invention, the improvement of the mechanical strength of the photosensitive member, the prevention of adhesion of discharge products and the like to the photosensitive member, and the removal property of the adhered matter. It is possible to provide a process cartridge and an image forming apparatus that are compatible with each other and can form an image with good image quality without image quality defects such as image flow over a long period of time.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

(Electrophotographic photoreceptor)
FIG. 1 is a schematic cross-sectional view showing a first embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photoreceptor 100 shown in FIG. 1 is a so-called function-separated photoreceptor (or laminated photoreceptor), and has an undercoat layer 4, a charge generation layer 1, and a charge transport layer 2 on a conductive support 3. And the protective layer 5 are sequentially laminated. In the electrophotographic photoreceptor 100, a photosensitive layer 6 is constituted by the charge generation layer 1, the charge transport layer 2, and the protective layer 5. In the electrophotographic photosensitive member 100, the outermost surface layer located on the side farthest from the conductive support 3 is the protective layer 5, and as will be described later, the protective layer 5 includes the first insulating fine particles and the second insulating particles. Contains insulating fine particles.

  Hereinafter, each element constituting the electrophotographic photoreceptor 100 will be described.

  First, the conductive support 3 will be described. Examples of the conductive support 3 include a metal plate, a metal drum, a metal belt, or a conductive material using a metal or an alloy such as aluminum, copper, zinc, stainless steel, chromium, nickel, molybdenum, vanadium, indium, gold, or platinum. Examples thereof include paper, plastic film, belt and the like coated, vapor-deposited, or laminated with a conductive polymer, a conductive compound such as indium oxide, or a metal or alloy such as aluminum, palladium, or gold.

  Further, when the electrophotographic photoreceptor 100 is used in a laser printer, the surface of the conductive support 3 has a center line average roughness Ra of 0.04 in order to prevent interference fringes generated when laser light is irradiated. It is preferable that the surface is roughened to be ~ 0.5 μm. As a roughening method, wet honing is performed by suspending an abrasive in water and spraying the conductive support 3, and the conductive support 3 is pressed against a rotating grindstone to continuously grind. Centerless grinding, anodic oxidation, etc. are preferred. If Ra is less than 0.04 μm, the effect of preventing interference tends to be insufficient because it is close to a mirror surface, and if Ra exceeds 0.5 μm, the image quality tends to be coarse. When non-interfering light is used as a light source, roughening for preventing interference fringes is not particularly necessary, and generation of defects due to irregularities on the surface of the substrate can be prevented, which is suitable for longer life.

  Here, the roughening treatment by anodization is a treatment for forming an oxide film on the aluminum surface by anodizing in an electrolyte solution using aluminum as an anode. Examples of the electrolyte solution include a sulfuric acid solution and an oxalic acid solution. However, the porous anodic oxide film formed by anodic oxidation is chemically active as it is, easily contaminated, and has a large resistance fluctuation due to the environment. Therefore, the pores in the anodized film are sealed 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 a sealing process is performed to change to a more stable hydrated oxide. It is preferable.

  The thickness of the anodized film is preferably 0.3 to 15 μm. When the film thickness is less than 0.3 μm, the barrier property against implantation tends to be insufficient. On the other hand, if the film thickness exceeds 15 μm, the residual potential tends to increase due to repeated use.

  Further, the conductive support 3 may be subjected to treatment with an acidic aqueous solution or boehmite treatment. The treatment with an acidic treatment liquid comprising phosphoric acid, chromic acid and hydrofluoric acid is carried out as follows. First, an acidic treatment liquid is prepared. The mixing ratio of phosphoric acid, chromic acid and hydrofluoric acid in the acidic treatment liquid is such that phosphoric acid is in the range of 10 to 11% by mass, chromic acid is in the range of 3 to 5% by mass, and hydrofluoric acid is in the range of 0.5 to 2% by mass. The concentration of these acids is preferably in the range of 13.5 to 18% by mass. The treatment temperature is preferably 42 to 48 ° C., but by keeping the treatment temperature high, a thicker film can be formed faster. The film thickness is preferably 0.3 to 15 μm. If it is less than 0.3 μm, the barrier property against injection tends to be poor and the effect tends to be insufficient. On the other hand, when it exceeds 15 μm, there is a tendency that the residual potential increases due to repeated use.

  The boehmite treatment can be performed by immersing in pure water at 90 to 100 ° C. for 5 to 60 minutes, or by contacting with heated steam at 90 to 120 ° C. for 5 to 60 minutes. The film thickness is preferably 0.1 to 5 μm. This may be further anodized using an electrolyte solution with low film solubility such as adipic acid, boric acid, borate, phosphate, phthalate, maleate, benzoate, tartrate, citrate, etc. Good.

  Next, the undercoat layer 4 will be described. The undercoat layer 4 includes, for example, an organometallic compound and a binder resin.

  As organometallic compounds, zirconium chelate compounds, zirconium alkoxide compounds, organic zirconium compounds such as zirconium coupling agents, titanium chelate compounds, titanium alkoxide compounds, organotitanium compounds such as titanate coupling agents, aluminum chelate compounds, aluminum coupling agents In addition to organoaluminum compounds such as antimony alkoxide compounds, germanium alkoxide compounds, indium alkoxide compounds, indium chelate compounds, manganese alkoxide compounds, manganese chelate compounds, tin alkoxide compounds, tin chelate compounds, aluminum silicon alkoxide compounds, aluminum titanium alkoxide compounds, And aluminum zirconium alkoxide compounds. . As the organometallic compound, in particular, an organozirconium compound, an organotitanyl compound, and an organoaluminum compound are preferably used because of their low residual potential and good electrophotographic characteristics.

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

  The undercoat layer 4 includes vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris-2-methoxyethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxy. Propyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-2-aminoethylaminopropyltrimethoxysilane, γ-mercapropropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, Silane coupling agents such as β-3,4-epoxycyclohexyltrimethoxysilane can also be included.

  In the undercoat layer 4, an electron transport pigment can also be mixed / dispersed. Examples of the electron transport pigment include organic pigments such as perylene pigment, bisbenzimidazole perylene pigment, polycyclic quinone pigment, indigo pigment, and quinacridone pigment described in JP-A-47-30330, cyano group, nitro group, Examples thereof include organic pigments such as bisazo pigments and phthalocyanine pigments having electron-withdrawing substituents such as nitroso groups and halogen atoms, and inorganic pigments such as zinc oxide and titanium oxide. Among these pigments, perylene pigments, bisbenzimidazole perylene pigments and polycyclic quinone pigments, zinc oxide, and titanium oxide are preferably used because of their high electron mobility.

  Further, the surface of these pigments may be surface-treated with the above coupling agent, binder resin or the like for the purpose of controlling dispersibility and charge transport property. If the amount of the electron transporting pigment is too large, the strength of the undercoat layer is lowered and a coating film defect is caused. Therefore, the amount is preferably 95% by mass or less, more preferably 90% by mass or less.

  In the undercoat layer 4, various organic compound fine powders or inorganic compound fine powders can be added for the purpose of improving electrical characteristics and light scattering properties. In particular, white pigments such as titanium oxide, zinc oxide, zinc white, zinc sulfide, lead white, lithopone, and inorganic pigments such as alumina, calcium carbonate, barium sulfate, polytetrafluoroethylene resin particles, benzoguanamine resin particles, Styrene resin particles and the like are effective. The added fine powder preferably has a particle size of 0.01 to 2 μm. The fine powder is added as necessary, but the addition amount is preferably 10 to 90% by mass, and 30 to 80% by mass with respect to the total mass of the solid content of the undercoat layer 4. More preferably.

  In addition, it is also effective in the undercoat layer 4 to contain an electron transporting substance, an electron transporting pigment or the like from the viewpoint of lowering the residual potential and environmental stability.

  The undercoat layer 4 is formed using a coating solution for forming an undercoat layer containing the above constituent materials.

  As a method for mixing / dispersing the coating solution for forming the undercoat layer, a conventional method using a ball mill, a roll mill, a sand mill, an attritor, an ultrasonic wave, or the like is applied. Mixing / dispersing is carried out in an organic solvent. The organic solvent dissolves a periodical metal compound and a binder resin, and does not cause gelation or aggregation when an electron transporting pigment is mixed / dispersed. I just need it.

  Examples of the organic solvent include methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, and methylene chloride. Ordinary organic solvents such as chloroform, chlorobenzene and toluene. These can be used individually by 1 type or in mixture of 2 or more types.

  The coating method used when providing the undercoat layer 4 is a normal method such as a blade coating method, a Mayer 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. Can be used.

  After coating, the coating film is dried to obtain an undercoat layer. Usually, the drying is performed at a temperature at which the solvent can be evaporated and a film can be formed. In particular, the conductive support 3 subjected to the acidic solution treatment and the boehmite treatment is preferably formed with the undercoat layer 4 because its defect concealing power tends to be insufficient.

  The thickness of the undercoat layer 4 is preferably 0.1 to 30 μm, more preferably 0.2 to 25 μm.

  Next, the charge generation layer 1 will be described. The charge generation layer 1 includes a charge generation material or a charge generation material and a binder resin.

  Charge generation materials include azo pigments such as bisazo and trisazo, condensed aromatic pigments such as dibromoanthanthrone, organic pigments such as perylene pigments, pyrrolopyrrole pigments, and phthalocyanine pigments, and inorganic pigments such as trigonal selenium and zinc oxide. All known ones can be used. As the charge generation material, an inorganic pigment is preferable when a light source with an exposure wavelength of 380 nm to 500 nm is used, and a metal and a metal-free phthalocyanine pigment are preferable when a light source with an exposure wavelength of 700 nm to 800 nm is used. Among them, hydroxygallium phthalocyanine disclosed in JP-A-5-263007 and JP-A-5-279591, chlorogallium phthalocyanine disclosed in JP-A-5-98181, JP-A-5-140472 and special Dichlorotin phthalocyanine disclosed in Kaihei 5-140473 or titanyl phthalocyanine disclosed in JP-A-4-189873 and JP-A-5-43813 is particularly preferable.

  The binder resin can be selected from a wide range of insulating resins. It can also be selected from organic photoconductive polymers such as poly-N-vinyl carbazole, polyvinyl anthracene, polyvinyl pyrene and polysilane. Preferred binder resins include polyvinyl butyral resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin. Insulating resins such as polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin can be mentioned, but are not limited thereto. These binder resins can be used individually by 1 type or in mixture of 2 or more types.

  The charge generation layer 1 is formed by vapor deposition using the charge generation material or using a charge generation layer forming coating solution containing the charge generation material and a binder resin.

  In the charge generation layer forming coating solution, the mixing ratio (mass ratio) of the charge generation material and the binder resin is preferably 10: 1 to 1:10. Further, as a method for dispersing them, a usual method such as a ball mill dispersion method, an attritor dispersion method, a sand mill dispersion method, or the like can be used. At this time, a condition that the crystal type does not change due to dispersion is required. Incidentally, it has been confirmed that the crystal form is not changed before dispersion in any of the above dispersion methods.

  Further, in this dispersion, it is effective that the particles have a particle size of preferably 0.5 μm or less, more preferably 0.3 μm or less, and still more preferably 0.15 μm or less.

  Moreover, as a solvent used for these dispersions, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, Examples include ordinary organic solvents such as tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene. These can be used individually by 1 type or in mixture of 2 or more types.

  In addition, as a coating method used when the charge generation layer 1 is provided, a normal method such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, or the like. Can be used.

  The film thickness of the charge generation layer 1 is preferably 0.1 to 5 μm, more preferably 0.2 to 2.0 μm.

  Next, the charge transport layer 2 will be described. The charge transport layer 2 includes a charge transport material and a binder resin, or includes a polymer charge transport material.

  Examples of charge transport materials include quinone compounds such as p-benzoquinone, chloranil, bromanyl, anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, xanthone compounds, benzophenone compounds , Electron transport compounds such as cyanovinyl compounds and ethylene compounds, triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds, etc. Examples thereof include pore transporting compounds. These charge transport materials can be used singly or in combination of two or more, but are not limited thereto.

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

In the above formula (1-1), R ¹⁴ represents a hydrogen atom or a methyl group, and n ¹ represents 1 or 2. Ar ¹¹ and Ar ¹² represent a substituted or unsubstituted aryl group, —C (R ¹⁸ ) ═C (R ¹⁹ ) (R ²⁰ ), or —CH═CH—CH═C (Ar) ₂ ; Examples of the substituent include a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a substituted amino group substituted with an alkyl group having 1 to 3 carbon atoms. R ¹⁸ , R ¹⁹ , and R ²⁰ represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, and Ar represents a substituted or unsubstituted aryl group.

In the above formula (1-2), R ¹⁵ and R ¹⁵ ′ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. R ¹⁶ , R ¹⁶ ′, R ¹⁷ and R ¹⁷ ′ may be the same or different, and are a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or 1 carbon atom. An amino group substituted with an alkyl group of ˜2, a substituted or unsubstituted aryl group, —C (R ¹⁸ ) ═C (R ¹⁹ ) (R ²⁰ ), or —CH═CH—CH═C (Ar) ₂ , R ¹⁸ , R ¹⁹ and R ^{20 each} represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, and Ar represents a substituted or unsubstituted aryl group. n ² and ^{n 3} represents an integer of 0 to 2.

In the above formula (1-3), R ²¹ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a substituted or unsubstituted aryl group, or —CH═CH—CH═. C (Ar) ₂ is shown. Ar represents a substituted or unsubstituted aryl group. R ²² and R ²³ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an amino group substituted with an alkyl group having 1 to 2 carbon atoms, or A substituted or unsubstituted aryl group is shown.

  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, poly-N-vinylcarbazole, polysilane, Polymer charge transport materials such as polyester polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 can also be used. These binder resins can be used individually by 1 type or in mixture of 2 or more types. The blending ratio (mass ratio) between the charge transport material and the binder resin is preferably 10: 1 to 1: 5.

  A polymer charge transport material can also be used alone. As the polymer charge transport material, known materials having charge transport properties such as poly-N-vinylcarbazole and polysilane can be used. In particular, polyester polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 have a high charge transporting property and are particularly preferable. The polymer charge transport material alone can be used as the charge transport layer, but it may be formed by mixing with the binder resin.

  The charge transport layer 2 is configured using a charge transport layer forming coating solution containing the above-described constituent materials. Solvents used in the coating solution for forming the charge transport layer include aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, ketones such as acetone and 2-butanone, and halogenation such as methylene chloride, chloroform and ethylene chloride. Examples include ordinary organic solvents such as aliphatic hydrocarbons, cyclic ethers such as tetrahydrofuran and ethyl ether, and linear ethers. These can be used individually by 1 type or in mixture of 2 or more types. Moreover, a well-known method can be used as a dispersion | distribution method of said each constituent material.

  Coating methods for applying the charge transport layer forming coating solution onto the charge generation layer 1 include blade coating method, Mayer bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain A usual method such as a coating method can be used.

  The film thickness of the charge transport layer 2 is preferably 5 to 50 μm, more preferably 10 to 30 μm.

  Next, the protective layer 5 that is the outermost surface layer in the electrophotographic photoreceptor 100 will be described. The protective layer 5 is a layer provided in order to give resistance to abrasion and scratches on the surface layer and to increase toner transfer efficiency. The protective layer 5 is a dispersion of conductive fine particles in a binder resin, a dispersion of lubricating fine particles such as fluororesin and acrylic resin in a normal charge transport layer material, and a hard coating agent such as silicon or acrylic. However, from the viewpoints of strength, electrical characteristics, image quality maintenance, and the like, it is preferable to contain a resin having a crosslinked structure, and it is more preferable to contain a charge transport material. The charge transport material may be incorporated into the crosslinked structure as a structural unit having a charge transporting ability by reacting with a resin having a crosslinked structure.

  The protective layer 5 has a configuration containing the first insulating fine particles and the second insulating fine particles. Here, the second insulating fine particles have a peak particle size (second peak particle size) in the particle size distribution of the peak particle size (first peak particle size) in the particle size distribution of the first insulating fine particles. It must be 1/4 times or less. By providing such a protective layer 5, the electrophotographic photoreceptor 100 can achieve both improvement in mechanical strength and prevention of adhesion of discharge products and removal of deposits, and image flow and the like over a long period of time. It is possible to form an image with good image quality without any image quality defect.

  The first insulating fine particles and the second insulating fine particles are mainly used for the purpose of controlling the contamination resistance adhesion, lubricity, hardness, etc. on the surface of the electrophotographic photosensitive member 100 and maintaining high image quality. If the first insulating fine particles and the second insulating fine particles have a ratio of peak particle sizes (second peak particle size / first peak particle size) of ¼ or less as described above. Well, each specific peak particle size is not particularly limited, but preferably has the following peak particle size. That is, the first insulating fine particles preferably have a peak particle size in the particle size distribution of 50 to 1000 nm, and more preferably 50 to 500 nm. The second insulating fine particles preferably have a peak particle size in the particle size distribution of 1 to 200 nm, and more preferably 5 to 150 nm. When the first and second peak particle diameters are in the above range, the denseness of the outermost surface layer of the photoreceptor can be further improved, and contamination resistance adhesion, lubricity and mechanical strength of the photoreceptor surface can be improved. Can be further improved.

  In addition, the total content of the first and second insulating fine particles in the protective layer 5 is 0.1 to 50 mass on the basis of the total solid content of the protective layer 5 in terms of film formability, electrical characteristics, and strength. %, Preferably 1 to 30% by mass.

  The ratio of the content of the first insulating fine particles and the second insulating fine particles in the protective layer 5 is preferably 3: 1 to 1: 5 by mass ratio. If the amount of the first insulating fine particles is larger than this range, the airtightness of the film may be lowered. On the other hand, when there are more second insulating fine particles than this range, the mechanical strength and surface adhesion of the protective layer 5 may be reduced.

  Examples of the first and second insulating fine particles include silicon-containing fine particles. Silicon-containing fine particles are fine particles containing silicon as a constituent element, and specific examples include colloidal silica and silicone fine particles. The colloidal silica used as the silicon-containing fine particles is selected from acidic or alkaline aqueous dispersions or those dispersed in organic solvents such as alcohols, ketones and esters, and commercially available ones can be used.

  The silicone fine particles used as the silicon-containing fine particles are selected from silicone resin particles, silicone rubber particles, and silicone surface-treated silica particles, and commercially available ones can be used. Silicone fine particles are small particles that are chemically inert and excellent in dispersibility in resin, and since the content required to obtain sufficient characteristics is low, the electron does not hinder the crosslinking reaction, The surface properties of the photographic photoreceptor 100 can be improved. That is, when used in the protective layer 5 together with a resin having a cross-linked structure, the lubricity and water repellency of the surface of the electrophotographic photosensitive member 100 are improved in a state of being uniformly incorporated into the strong cross-linked structure, and good for a long period of time. High wear resistance and contamination resistance can be maintained.

Further, as the types of the first and second insulating fine particles, as fine particles other than the silicon-containing fine particles, resin fine particles such as melanin, PMMA, and acrylic, tetrafluoroethylene, trifluoride ethylene, and hexafluoride are used. From fluorine-based fine particles such as propylene, vinyl fluoride, vinylidene fluoride, and resins obtained by copolymerizing the above fluororesin and a monomer having a hydroxyl group, as shown in "Proceedings of the 8th Polymer Material Forum Lectures p89" Fine particles, ZnO—Al ₂ O ₃ , SnO ₂ —Sb ₂ O ₃ , In ₂ O ₃ —SnO ₂ , ZnO—TiO ₂ , MgO—Al ₂ O ₃ , FeO—TiO ₂ , TiO ₂ , SnO ₂ , In Examples thereof include semiconductive metal oxides such as ₂ O ₃ , ZnO, and MgO. However, when a semiconductive metal oxide is used, an image flow may occur due to leakage of charges charged on the surface. Therefore, it is desirable to use resin particles having low conductivity as much as possible. Specifically, the specific resistance of the first and second insulating fine particles is preferably 1 × 10 ⁵ Ω · cm or more, and more preferably 1 × 10 ⁷ Ω · cm or more.

  Further, the protective layer 5 as the outermost surface layer may contain a plurality of first insulating fine particles and / or second insulating fine particles. That is, it may have a configuration including a first insulating fine particle group composed of a plurality of first insulating fine particles and a second insulating fine particle group composed of a plurality of second insulating fine particles. . At this time, the peak particle size of any insulating fine particles contained in the second insulating fine particle group is ¼ or less than the peak particle size of any insulating fine particles contained in the first insulating fine particle group. It is necessary to become.

  Further, the protective layer 5 as the outermost surface layer is an insulating fine particle not included in the first and second insulating fine particle groups (hereinafter referred to as “third insulating layer”) as long as the effect of the present invention is not impaired. May be included ”. As such third insulating fine particles, the peak particle size exceeds 1/4 times the peak particle size of at least one insulating fine particle among the insulating fine particles contained in the first insulating fine particle group, In addition, the insulating fine particles included in the second insulating fine particle group are those that are less than 4 times the peak particle size of at least one insulating fine particle. From the viewpoint of obtaining the effect of the present invention more sufficiently, the content of the third insulating fine particles in the entire insulating fine particles in the protective layer 5 is preferably as small as possible, and 20 masses based on the total amount of the insulating fine particles. % Or less is preferable.

  In the protective layer 5, the resin having a cross-linked structure may be any resin that can form a cross-linked structure, and various materials can be used, but in terms of characteristics, phenol resin, urethane resin, siloxane resin, epoxy resin, etc. Is preferred. Among these, a phenol resin and a siloxane resin are preferable, and a phenol resin is particularly preferable.

  As the resin having such a crosslinked structure, a compound represented by the following general formulas (2) and (3) and a structure derived therefrom are incorporated as structural units having a charge transport ability. It is preferable because of its excellent strength and stability.

F- [D-Si (R ¹ ) _(3-a) Q _a ] _b (2)
[In the formula, F represents an organic group derived from a compound having a hole transporting ability, D represents a divalent group having flexibility, and R ¹ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted group. Represents an aryl group, Q represents a hydrolyzable group, a represents an integer of 1 to 3, and b represents an integer of 1 to 4. ]

^{_{F - [(X) n R}} 2 -ZH] m (3)
[In the formula, F represents an organic group derived from a compound having a hole transport function, R ² represents an alkylene group, Z represents an oxygen atom, a sulfur atom, NH or CO ₂ , and X represents an oxygen atom or Represents a sulfur atom, n represents 0 or 1, and m represents an integer of 1 to 4; ]

  More preferable examples of the compounds represented by the general formulas (2) and (3) include those in which the organic group F is particularly represented by the following general formula (4).

［式中、Ａｒ^１〜Ａｒ^４はそれぞれ独立に置換又は未置換のアリール基を示し、Ａｒ^５は置換若しくは未置換のアリール基又はアリーレン基を示し、且つＡｒ^１〜Ａｒ^５のうち２〜４個は、上記式（２）で表される化合物における−Ｄ−Ｓｉ（Ｒ^１）_{（３−ａ）}Ｑ_ａで示される部位、又は、上記式（３）で表される化合物における−（Ｘ）_ｎＲ^２−ＺＨで示される部位と結合可能な結合手を有する。］

[Wherein, Ar ^{1 to} Ar ⁴ each independently represents a substituted or unsubstituted aryl group, Ar ⁵ represents a substituted or unsubstituted aryl group or an arylene group, and 2 to 4 of Ar ^{1 to} Ar ⁵ Is a moiety represented by -D-Si (R ¹ ) _(3-a) Q _a in the compound represented by the above formula (2) or-(X in the compound represented by the above formula (3). ) _n R having the moiety capable of binding a bond represented by ² -ZH. ]

Ar ¹ to Ar ⁴ in the general formula (4) each independently represent a substituted or unsubstituted aryl group, specifically, the structural unit shown in Table 1 are preferred.

  Here, Ar is preferably a structural unit selected from Table 2.

  Z ′ is preferably a structural unit selected from Table 3.

Here, R ⁶ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group substituted with an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, an unsubstituted phenyl group, or And an aralkyl group having 7 to 10 carbon atoms. R ^{7 to} R ¹³ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group substituted with an alkoxy group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, or unsubstituted. A phenyl group, a C7-10 aralkyl group, or a halogen is shown. r and s represent 0 or 1, g and h represent an integer of 1 to 10, and t and t ′ represent an integer of 1 to 3. X ¹ is a group represented by —D—Si (R ² ) _(3-a) Q _a in the general formula (2) or Z— (R ¹ ) in the general formula (3). _The group represented by _p (X) _q- is shown.

  W is preferably a structural unit shown in Table 4.

  Here, i represents an integer of 0 to 3.

In the general formula (4), Ar ⁵ is preferably an aryl group exemplified in the description of Ar ^{1 to} Ar ⁴ when k is 0, and when k is 1, the aryl group is selected from the aryl group. An arylene group in which a hydrogen atom is removed is preferable.

As specific examples of the compound represented by the general formula (2), Ar ^{1 to} Ar ⁵ and k in the general formula (4) are represented by the compounds (2-1) to ( 2-61), but not limited thereto. In Tables 5 to 10, S represented by a structure representing Ar ^{1 to} Ar ⁵ represents the structure in the right column of the same row. In Tables 5 to 10, Me represents a methyl group, Et represents an ethyl group, and iPr represents an isopropyl group.

  Specific examples of the compound represented by the general formula (3) include compounds (3-1) to (3-26) shown in Tables 11 to 16 below. In the following table, Me or a bond is described but a substituent is not described, a methyl group, Et represents an ethyl group.

  In addition, a compound represented by the following general formula (5) can also be added to the protective layer 5 in order to control various physical properties such as strength and film resistance of the protective layer 5.

Si (R ³⁰ ) _(4-c) Q _c (5)
In the above formula (5), R ³⁰ represents a hydrogen atom, an alkyl group or a substituted or unsubstituted aryl group, Q is shown a hydrolyzable group, c is an integer of 1-4.

  Specific examples of the compound represented by the general formula (5) include the following silane coupling agents. Examples of silane coupling agents include tetrafunctional silanes such as tetramethoxysilane and tetraethoxysilane (c = 4); methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, methyltrimethoxyethoxysilane, vinyltri Methoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxy Silane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, (tridecafluoro-1,1,2,2-tetrahydrooctyl L) Triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- (heptafluoroisopropoxy) propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H , 1H, 2H, 2H-perfluorodecyltriethoxysilane, trifunctional alkoxysilanes such as 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (c = 3); dimethyldimethoxysilane, diphenyldimethoxysilane, methyl And bifunctional alkoxysilanes such as phenyldimethoxysilane (c = 2); monofunctional alkoxysilanes such as trimethylmethoxysilane (c = 1), and the like. Trifunctional and tetrafunctional alkoxysilanes are preferable for improving the strength of the film, and monofunctional and bifunctional alkoxysilanes are preferable for improving the flexibility and film formability.

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

  In addition, in order to increase the strength of the protective layer 5, it is also preferable to use a compound having two or more silicon atoms as shown in the following general formula (6).

B- (Si (R ² ) _(3-a) Q _a ) ₂ (6)
In the above formula (6), B represents a divalent organic group, R ² represents a hydrogen atom, an alkyl group or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, and a represents 1 to 3 Indicates an integer.

  Specific examples of the compound represented by the general formula (6) include the following compounds (6-1) to (6-16).

  Further, a thermoplastic resin may be added to the protective layer 5 for the purposes of discharge gas resistance, mechanical strength, scratch resistance, particle dispersibility, viscosity control, torque reduction, wear amount control, pot life extension, and the like. As the thermoplastic resin, polyvinyl butyral resin, polyvinyl formal resin, partially acetalized polyvinyl acetal resin in which a part of butyral is modified with formal, acetoacetal or the like is soluble in alcohol or ketone solvents. Examples include acetal resins (for example, SLECK B, K manufactured by Sekisui Chemical Co., Ltd.), polyamide resins, cellulose resins, phenol resins, epoxy resins, polyimide resins, and the like. In particular, polyvinyl acetal resin, polyamide resin, and phenol resin are preferable in terms of electrical characteristics.

  The molecular weight of the resin is preferably 2000-100000, more preferably 5000-50000. If the molecular weight is less than 2000, the desired effect tends not to be obtained. If the molecular weight is more than 100000, the solubility tends to be low and the addition amount is limited, or the film formation tends to be poor during coating. The addition amount is preferably 1 to 40% by mass, more preferably 1 to 30% by mass, and most preferably 5 to 20% by mass based on the total solid content of the protective layer 5. If the addition amount is less than 1% by mass, the desired effect tends to be difficult to obtain, and if it exceeds 40% by mass, image blurring tends to occur under high temperature and high humidity. These resins may be used alone or in combination of two or more.

  Further, in order to extend pot life, control film properties, and reduce torque, the protective layer 5 contains at least one of a cyclic compound having a repeating structural unit represented by the following general formula (7) or a derivative thereof. It is preferable.

In the above formula (7), A ¹ and A ² each independently represent a monovalent organic group.

  Examples of the cyclic compound having a repeating structural unit represented by the general formula (7) include commercially available cyclic siloxanes. Specifically, cyclic dimethylcyclosiloxanes such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, 1,3,5-trimethyl-1,3,5- Triphenylcyclotrisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetraphenylcyclotetrasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7 , 9-pentaphenylcyclopentasiloxane and other cyclic methylphenylcyclosiloxanes, hexaphenylcyclotrisiloxane and other cyclic phenylcyclosiloxanes, and 3- (3,3,3-trifluoropropyl) methylcyclotrisiloxane and other fluorine Atom-containing cyclosiloxanes, methylhydrosiloxa Mixture, pentamethylcyclopentasiloxane, mention may be made of phenyl hydrosilyl group-containing cyclosiloxanes of hydrocyclosiloxane like, cyclic siloxanes and vinyl group-containing cyclosiloxanes such as penta vinyl pentamethylcyclopentasiloxane like. These cyclic siloxane compounds may be used alone or in combination of two or more.

  Further, additives such as a plasticizer, a surface modifier, an antioxidant, and a photodegradation inhibitor can be used for the protective layer 5. Examples of the plasticizer include biphenyl, biphenyl chloride, terphenyl, dibutyl phthalate, diethylene glycol phthalate, dioctyl phthalate, triphenyl phosphate, methyl naphthalene, benzophenone, chlorinated paraffin, polypropylene, polystyrene, and various fluorohydrocarbons. An antioxidant having a hindered phenol, hindered amine, thioether or phosphite partial structure can be added to the protective layer 5, which is effective in improving the potential stability and image quality when the environment changes.

  Examples of the antioxidant include the following compounds. For example, hindered phenols include “Sumilizer BHT-R”, “Sumilizer MDP-S”, “Sumilizer BBM-S”, “Sumizer WX-R”, “Sumizer NW”, “Sumizer BP-76”, “ Sumilizer BP-101 "," Sumilizer GA-80 "," Sumilizer GM "," Sumilizer GS "or more manufactured by Sumitomo Chemical Co., Ltd.," IRGANOX1010 "," IRGANOX1035 "," IRGANOX1076 "," IRGANOX1098 "," IRGANOX1098 "," 114 " ”,“ IRGANOX1222 ”,“ IRGANOX1330 ”,“ IRGANOX1425WL ”,“ IRGANOX1 20L "," IRGANOX 245 "," IRGANOX 259 "," IRGANOX 3114 "," IRGANOX 3790 "," IRGANOX 5057 "," IRGANOX 565 "or more, manufactured by Ciba Specialty Chemicals," ADK STAB AO-20 "," ADK STAB AO-30 "," ADEKA STAB " "AO-40", "ADK STAB AO-50", "ADK STAB AO-60", "ADK STAB AO-70", "ADK STAB AO-80", "ADK STAB AO-330" or more manufactured by Asahi Denka. Examples of hindered amines include “Sanol LS2626”, “Sanol LS765”, “Sanol LS770”, “Sanol LS744”, “Tinuvin 144”, “Tinuvin 622LD”, “Mark LA57”, “Mark LA67”, “Mark LA62”. ”,“ Mark LA68 ”,“ Mark LA63 ”,“ Smilizer TPS ”,“ Smilizer TP-D ”for thioethers,“ Mark 2112 ”,“ Mark PEP 8 ”,“ Mark PEP ”for phosphites -24G "," Mark PEP.36 "," Mark 329K "," Mark HP.10 ", and hindered phenols and hindered amine antioxidants are particularly preferable. Furthermore, these may be modified with a substituent such as an alkoxysilyl group capable of undergoing a crosslinking reaction with the material forming the crosslinked film.

  In addition, an oil such as silicone oil can be added to the protective layer 5. 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 include reactive silicone oils such as modified polysiloxanes and phenol-modified polysiloxanes. These may be added in advance to a coating solution for forming the protective layer 5, or may be impregnated under reduced pressure or increased pressure after the production of the photoreceptor 100.

  The protective layer 5 is formed using a coating liquid for forming a protective layer containing the above-described constituent materials.

  When preparing the coating liquid for forming the protective layer, the first and second insulating fine particles can be introduced by adding and dispersing in a resin having a crosslinked structure. In preparing the coating solution, a conventionally known mixing / dispersing method using a ball mill, roll mill, sand mill, attritor, paint shaker, ultrasonic wave, or the like can be applied. It is important to control so as not to cause curing, gelation or aggregation.

  It is preferable to add or use a catalyst when forming the protective layer forming coating solution or the protective layer forming coating solution. Such catalysts include inorganic acids such as hydrochloric acid, acetic acid, phosphoric acid, sulfuric acid, organic acids such as formic acid, propionic acid, oxalic acid, paratoluenesulfonic acid, benzoic acid, phthalic acid, maleic acid, potassium hydroxide, hydroxide Examples include alkali catalysts such as sodium, calcium hydroxide, ammonia, triethylamine.

Furthermore, a solid catalyst insoluble in the system as shown below can also be used. As the solid catalyst, Amberlite 15, Amberlite 200C, Amberlyst 15E (above, manufactured by Rohm and Haas); Dowex MWC-1-H, Dowex 88, Dowex HCR-W2 (above, Dow Chemical Company); Lebatit SPC-108, Lebatit SPC-118 (above, Bayer); Diaion RCP-150H (Mitsubishi Kasei); Sumikaion KC-470, Duolite C26-C, Duolite C-433 Duolite-464 (above, manufactured by Sumitomo Chemical Co., Ltd.); Cation exchange resin such as Nafion-H (made by DuPont); Amberlite IRA-400, Amberlite IRA-45 (above, Rohm and Haas) Ltd.) anion exchange resin such _{as; Zr (O 3 PCH 2 CH} 2 SO 3 H Polyorgano containing protonic acid group of the polyorganosiloxane having a sulfonic acid _{group; 2, Th (O 3 PCH} 2 CH 2 COOH) groups containing protonic acid group of ₂ such as inorganic solids are bonded to the surface Siloxane; heteropolyacids such as cobalt tungstic acid and phosphomolybdic acid; isopolyacids such as niobic acid, tantalum acid and molybdic acid; unitary metal oxides such as silica gel, alumina, chromia, zirconia, CaO and MgO; silica-alumina, Composite metal oxides such as silica-magnesia, silica-zirconia, zeolites; clay minerals such as acid clay, activated clay, montmorillonite, kaolinite; metal sulfates such as LiSO ₄ and MgSO ₄ ; zirconia phosphate, lanthanum phosphate metal phosphate and the _{like; LiNO 3, Mn (NO 3} ) of ₂ such as Metal nitrate; inorganic solid obtained by reacting aminopropyltriethoxysilane on silica gel with a group containing amino group such as solid; polyorgano containing amino group such as amino-modified silicone resin Examples thereof include siloxane.

  In preparing the protective layer-forming coating solution, it is preferable to use a solid catalyst that is insoluble in a photofunctional compound, a reaction product, water, a solvent, or the like because the stability of the coating solution tends to be improved. The solid catalyst insoluble in the system is not particularly limited as long as the catalyst component is insoluble in a material for forming a resin having a crosslinked structure, other additives, water, a solvent and the like. Although the usage-amount of these solid catalysts is not restrict | limited in particular, 0.1-100 mass parts is preferable with respect to a total of 100 mass parts of the compound which has a hydrolysable group. Further, as described above, these solid catalysts are insoluble in raw material compounds, reaction products, solvents and the like, and therefore can be easily removed after the reaction according to a conventional method. The reaction temperature and reaction time are appropriately selected according to the type and amount of the raw material compound or solid catalyst, but the reaction temperature is usually 0 to 100 ° C, preferably 10 to 70 ° C, more preferably 15 to 50. The reaction time is preferably 10 minutes to 100 hours. If the reaction time exceeds the upper limit, gelation tends to occur.

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

  In addition to organoaluminum compounds, organotin compounds such as dibutyltin dilaurate, dibutyltin dioctiate, and dibutyltin diacetate; titanium tetrakis (acetylacetonate), titanium bis (butoxy) bis (acetylacetonate), titanium bis Organic titanium compounds such as (isopropoxy) bis (acetylacetonate); zirconium tetrakis (acetylacetonate), zirconium bis (butoxy) bis (acetylacetonate), zirconium bis (isopropoxy) bis (acetylacetonate), etc. Zirconium compounds can also be used, but from the viewpoint of safety, low cost, and pot life length, it is preferable to use an organoaluminum compound, particularly an aluminum chelate compound. It is more preferable. Although the usage-amount in particular of these catalysts is not restrict | limited, 0.1-20 mass parts is preferable with respect to a total of 100 mass parts of the compound which has a hydrolysable group, and 0.3-10 mass parts is especially preferable.

In the present invention, when an organometallic compound is used as a catalyst, it is preferable to add a multidentate ligand from the viewpoint of pot life and curing efficiency. Examples of such multidentate ligands include those shown below and those derived therefrom, but the present invention is not limited to these. Specifically, β-diketones such as acetylacetone, trifluoroacetylacetone, hexafluoroacetylacetone, and dipivaloylmethylacetone; acetoacetates such as methyl acetoacetate and ethyl acetoacetate; bipyridine and derivatives thereof; glycine and its Derivatives; ethylenediamine and derivatives thereof; 8-oxyquinoline and derivatives thereof; salicylaldehyde and derivatives thereof; catechol and derivatives thereof; bidentate ligands such as 2-oxyazo compounds; diethyltriamine and derivatives thereof; nitrilotriacetic acid and derivatives thereof And tridentate ligands such as ethylenediaminetetraacetic acid (EDTA) and derivatives thereof. In addition to the organic ligands as described above, inorganic ligands such as pyrophosphoric acid and triphosphoric acid can be exemplified. As the multidentate ligand, a bidentate ligand is particularly preferable, and a bidentate ligand represented by the following general formula (8) is more preferable, and R ⁴⁰ and R ^{41 in the following} general formula (8) are more preferable. Are particularly preferred. By making R ⁴⁰ and R ^{41 the} same, the coordination power of the ligand near room temperature becomes strong, and the coating liquid for forming the protective layer can be further stabilized.

In the formula (8), R ⁴⁰ and R ⁴¹ each independently represent an alkyl group having 1 to 10 carbon atoms, a fluorinated alkyl group, or an alkoxy group having 1 to 10 carbon atoms.

  The compounding amount of the polydentate ligand can be arbitrarily set, but is 0.01 mol or more, preferably 0.1 mol or more, more preferably 1 mol or more, with respect to 1 mol of the organometallic compound used. It is preferable to do this.

  The protective layer 5 can be formed in the absence of a solvent if the coating solution is liquid, but alcohols such as methanol, ethanol, propanol and butanol; ketones such as acetone and methyl ethyl ketone as necessary. In addition to tetrahydrofuran; ethers such as diethyl ether and dioxane; and the like, various solvents may be used. As such a solvent, those having a boiling point of 100 ° C. or less are preferable, and they can be arbitrarily mixed and used. When the organosilicon compound is contained in the coating solution, the organosilicon compound is likely to be precipitated if the solvent is too small. Therefore, the content is preferably 0.5 to 30 parts by mass with respect to 1 part by mass of the organosilicon compound. More preferably, it is part by mass.

  When the coating solution for forming the protective layer is applied onto the charge transport layer 2, the coating methods are blade coating method, Meyer bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain coating. Ordinary methods such as a method can be used. And after application | coating, the protective layer 5 forms by drying a coating film.

  In addition, in the case of application | coating, when a required film thickness cannot be obtained by one application | coating, a required film thickness can be obtained by apply | coating several times. When performing multiple times of repeated application, the heat treatment may be performed every time of application, or after multiple times of repeated application.

  The reaction temperature and reaction time for curing the curable component in the coating liquid for forming the protective layer are not particularly limited, but the reaction temperature is preferably 60 ° C. from the viewpoint of mechanical strength and chemical stability of the obtained resin. As mentioned above, More preferably, it is 80-200 degreeC, and reaction time becomes like this. Preferably it is 10 minutes-5 hours. In addition, maintaining the organic layer obtained by curing the coating liquid in a high humidity state is effective in stabilizing the characteristics of the organic layer. Furthermore, the protective layer 5 obtained can be subjected to surface treatment to be hydrophobized using hexamethyldisilazane, trimethylchlorosilane, or the like depending on the application.

  The thickness of the protective layer 5 is preferably 0.5 to 15 μm, more preferably 1 to 10 μm, and further preferably 1 to 5 μm.

  The photosensitive layer 6 contains additives such as an antioxidant, a light stabilizer, and a heat stabilizer for the purpose of preventing deterioration of the photoreceptor due to ozone, oxidizing gas, or light and heat generated in the image forming apparatus. Can be added. These additives can be added to at least one of the charge generation layer 1, the charge transport layer 2 and the protective layer 5 constituting the photosensitive layer 6.

  Examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds.

  Examples of the light stabilizer include derivatives such as benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine.

In addition, at least one kind of electron accepting substance can be contained for the purpose of improving sensitivity, reducing residual potential, and reducing fatigue during repeated use. 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, benzene derivatives having an electron-withdrawing substituent such as fluorenone, quinone, Cl, CN, and NO ₂ are particularly preferable.

  The preferred embodiments of the electrophotographic photoreceptor of the present invention have been described above, but the electrophotographic photoreceptor of the present invention is not limited to the above. For example, the electrophotographic photoreceptor 100 shown in FIG. 1 has a structure in which an undercoat layer 4, a charge generation layer 1, a charge transport layer 2, and a protective layer 5 are sequentially laminated on a conductive support 3. However, the electrophotographic photosensitive member of the present invention does not need to have an undercoat layer like the electrophotographic photosensitive member 110 shown in FIG. Further, the electrophotographic photosensitive member 120 shown in FIG. 2A may not have a protective layer, and the undercoat layer and the protective layer may be protected like the electrophotographic photosensitive member 130 shown in FIG. It is not necessary to have both layers. When the electrophotographic photosensitive member does not have a protective layer like the electrophotographic photosensitive members 120 and 130, the first and second insulating fine particles are contained in the charge transport layer 2 that is the outermost surface layer. It will be.

  Further, the electrophotographic photoreceptor of the present invention may be a so-called single layer type photoreceptor such as the electrophotographic photoreceptor 140 shown in FIG. In this case, the photosensitive layer has a single-layer type photosensitive layer formed containing a charge generating material and a binder resin. The charge generation material is the same as that used for the charge generation layer in the function separation type photosensitive layer, and the binder resin is a binder resin used for the charge generation layer and the charge transport layer in the function separation type photosensitive layer. Similar ones can be used. The content of the charge generating material in the single-layer type photosensitive layer is preferably 10 to 85% by mass, more preferably 20 to 50% by mass, based on the total solid content in the single-layer type photosensitive layer. In addition, a charge transport material or a polymer charge transport material may be added to the single-layer type photosensitive layer for the purpose of improving photoelectric characteristics. The addition amount is preferably 5 to 50% by mass based on the total solid content in the single-layer type photosensitive layer. Moreover, the solvent and coating method used for coating can be the same as those for the above layers. The thickness of the single-layer type photosensitive layer is preferably about 5 to 50 μm, more preferably 10 to 40 μm.

  When the single layer type photoreceptor does not have a protective layer, the first and second insulating fine particles are contained in the single layer type photosensitive layer. On the other hand, when the single-layer type photoreceptor has a protective layer, the first and second insulating fine particles are contained in the protective layer.

(Image forming apparatus and process cartridge)
Next, an image forming apparatus and a process cartridge equipped with the electrophotographic photosensitive member of the present invention will be described.

  FIG. 3 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of the image forming apparatus of the present invention. An image forming apparatus 200 shown in FIG. 3 includes an electrophotographic photosensitive member 7, a non-contact charging unit 8 for charging the electrophotographic photosensitive member 7, a power source 9 connected to the charging unit 8, and a charging unit 8. An exposure unit 10 that exposes the charged electrophotographic photosensitive member 7 to form an electrostatic latent image; a developing unit 11 that develops the formed electrostatic latent image with toner to form a toner image; and The image forming apparatus includes a transfer unit 12 for transferring from the photoconductor 7 to a transfer medium, a cleaning unit 13, a static eliminator 14 and a fixing unit 15.

  FIG. 4 is a cross-sectional view schematically showing a basic configuration of another embodiment of the image forming apparatus of the present invention shown in FIG. The image forming apparatus 210 shown in FIG. 4 has the same configuration as the image forming apparatus 200 shown in FIG. 3 except that the image forming apparatus 210 includes a charging unit 8 that charges the electrophotographic photoreceptor 7 by a contact charging method. At this time, as the charging means 8, a contact-type charging means in which an AC voltage is superimposed on a DC voltage can be preferably used because it has excellent wear resistance. In this case, the static eliminator 14 may not be provided.

  Examples of the non-contact charging type charging means 8 used in the present invention include a corotron and a scorotron using corona discharge. Moreover, as the charging means 8 of the contact charging system, a charger using a contact charging member such as a charging roller or a charging brush can be cited.

Contact charging members include metals such as aluminum, iron and copper, conductive polymer materials such as polyacetylene, polypyrrole and polythiophene, polyurethane rubber, silicone rubber, epichlorohydrin rubber, ethylene propylene rubber, acrylic rubber, fluorine rubber, styrene A material obtained by dispersing metal oxide particles such as carbon black, copper iodide, silver iodide, zinc sulfide, silicon carbide, and metal oxide in an elastomer material such as butadiene rubber or butadiene rubber can be used. Examples of this metal oxide include ZnO, SnO ₂ , TiO ₂ , In ₂ O ₃ , MoO _{3 and the} like, or a composite oxide thereof. Further, as the contact charging member, a material obtained by adding perchlorate to 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 and the like are used alone or in combination. 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. In these resins, in order to further adjust the resistivity, conductive agent particles may be dispersed, or an antioxidant may be contained in order to prevent deterioration. In addition, in order to improve the film formability 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 type, a blade type, a belt type, and a brush type.

The volume resistivity of the contact charging member is preferably ^{1 × 10 2 ~1 × 10 14} Ωcm, more preferably ^{1 × 10 2 ~1 × 10 12} Ωcm. 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).

  As the exposure means 10, an optical system device that can expose a light source such as a semiconductor laser, an LED (light emitting diode), a liquid crystal shutter, or the like on the surface of the electrophotographic photoreceptor 7 in a desired image-like manner can be used. Among these, when an exposure apparatus capable of exposing non-interference light is used, interference fringes between the conductive support of the electrophotographic photosensitive member 7 and the photosensitive layer can be prevented.

  When laser light is used as the exposure light source, the oscillation wavelength is preferably 350 to 850 nm, and the shorter wavelength is preferable because the resolution is excellent.

  As the developing means 11, a conventionally known developing device or the like can be used. Further, the type of developer used and the method for producing the same are not particularly limited. For example, a kneading and pulverizing method for kneading, pulverizing, and classifying a binder resin and a colorant, a release agent, and a charge control agent as necessary, A method of changing the shape of the particles obtained by the kneading and pulverization method by mechanical impact force or thermal energy, an emulsion polymerization of a polymerizable monomer of a binder resin, a formed dispersion, a colorant, a release agent Emulsion polymerization aggregation method to obtain a toner particle by mixing a mold agent and, if necessary, a dispersion of a charge control agent, and agglomerating and heat-fusing, a polymerizable monomer and a colorant for obtaining a binder resin A suspension polymerization method in which a solution of a release agent, if necessary, a charge control agent or the like is suspended in an aqueous solvent and polymerized, a binder resin and a colorant, a release agent, and a charge control agent if necessary A solution suspension method in which a solution is suspended in an aqueous solvent and granulated can be used. 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 have a core-shell structure can be used. From the viewpoint, a suspension polymerization method, an emulsion polymerization aggregation method, and a dissolution suspension method produced with an aqueous solvent are preferable, and an emulsion polymerization aggregation method is particularly preferable.

The toner is composed of a binder resin, a colorant, and a release agent. If necessary, silica or a charge control agent may be used. The average particle diameter of the toner is preferably 2 to 12 μm, and more preferably 3 to 9 μm. Further, the average shape index (ML ² / A) of the toner is preferably 100 to 140, more preferably 115 to 140, since a high development, transferability, and high quality image can be obtained. .

  Binder resins used in the toner include 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 Examples of homopolymers and copolymers of acid esters, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl butyl ether, and vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropenyl ketone Particularly typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene. -Maleic anhydride copolymer, polyethylene, polypropylene and the like. Further examples include polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like.

  In addition, toner colorants include 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, and malachite green oxa. Rate, 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. Pigment Blue 15: 3 can be exemplified as a representative one.

  Typical examples of the release agent include low molecular weight polyethylene, low molecular weight polypropylene, Fischer tropic wax, montan wax, carnauba wax, rice wax, and candelilla wax.

  Further, a charge control agent may be added to the toner as necessary. As the charge control agent, known ones can be used. For example, 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.

  When an external additive is added, it can be produced by mixing the toner and the external additive with a Henschel mixer or a V blender. Further, when the toner is manufactured by a wet method, it can be externally added by a wet method.

  Lubricating particles added to the toner used in the present invention include solid lubricants such as graphite, molybdenum disulfide, talc, fatty acids, fatty acid metal salts, low molecular weight polyolefins such as polypropylene, polyethylene, and polybutene, and heating. Aliphatic amides such as silicones with softening point, oleic acid amide, erucic acid amide, ricinoleic acid amide, stearic acid amide, carnauba wax, rice wax, candelilla wax, wood wax, jojoba oil, etc. Plant waxes, animal waxes such as beeswax, montan waxes, ozokerites, ceresins, paraffin waxes, microcrystalline waxes, Fischer-Tropsch waxes, etc. Has one kind It can be used or in combination of two or more Germany. The average particle size of the slippery particles is preferably 0.1 to 10 μm, and may be pulverized to make the particle sizes uniform as necessary. The amount added to the toner is preferably 0.05 to 2.0 parts by mass, and more preferably 0.1 to 1.5 parts by mass with respect to 100 parts by mass of the toner.

  To the toner used in the present invention, inorganic fine particles, organic fine particles, composite fine particles obtained by adhering inorganic fine particles to the organic fine particles, and the like may be added for the purpose of removing deposits and deteriorated matters on the surface of the electrophotographic photoreceptor 7. Although it is possible, inorganic fine particles having excellent polishing properties are particularly preferable. Inorganic fine 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, Various inorganic oxides such as manganese oxide, boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride, and boron nitride, nitrides, borides, and the like are preferably used. Further, titanium coupling agents such as tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzenesulfonyl titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, γ- (2-amino) Ethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) γ-aminopropyltrimethoxysilane Hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxy The treatment may be performed with a silane coupling agent such as silane, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, and p-methylphenyltrimethoxysilane. Moreover, it is also preferable to hydrophobize with higher fatty acid metal salts, such as silicone oil, aluminum stearate, zinc stearate, calcium stearate.

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

  If the particle size of the inorganic or organic fine particles is too small, the polishing ability is insufficient, and if it is too large, the surface of the electrophotographic photosensitive member 7 is likely to be damaged. Therefore, the average particle size is preferably 5 to 1000 nm. 5 to 800 nm is more preferable, and 5 to 700 nm is particularly preferable. The addition amount of inorganic and organic fine particles to the toner is preferably 0.6 parts by mass or more as the sum of the addition amount of the slippery particles with respect to 100 parts by mass of the toner.

  As other inorganic oxides added to the toner, small-diameter inorganic oxides having an average primary particle size of 40 nm or less are used for powder fluidity, charge control, etc. It is preferable to add a larger-diameter inorganic oxide. These inorganic oxide fine particles may be known ones, but it is preferable to use silica and titanium oxide in combination in order to perform precise charge control. Further, the surface treatment of the small-diameter inorganic fine particles increases the dispersibility and increases the powder flowability.

  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 are used. The mixing ratio with the carrier can be set as appropriate.

  Examples of the transfer unit 12 include a roller-type contact charging member, a contact-type transfer charger using a belt, a film, a rubber blade, or the like, or a scorotron transfer charger or a corotron transfer charger using corona discharge. .

  Although untransferred toner may remain on the surface of the electrophotographic photosensitive member 7 after the transfer, the remaining toner can be removed by the cleaning means 13. As the cleaning means 13, those provided with a cleaning member such as a blade, a magnetic brush, or a conductive fiber brush are preferably used. Hereinafter, a cleaning apparatus including a blade member as an example of the cleaning unit 13 will be described in detail.

  The material of the blade is not particularly limited. For example, a urethane prepolymer composed of a polyol such as a polyester polyol such as polyethylene adipate and polycaprolactone and an isocyanate such as diphenylmethane diisocyanate, 1,4-butanediol, trimethylolpropane, ethylene A material using a cross-linking agent such as glycol or a mixture thereof as a raw material is preferable because the obtained blade member has excellent wear resistance and high mechanical strength. Moreover, as a urethane prepolymer which is a constituent material of a blade member, for example, an NCO group content of about 4 to 10% by mass and a viscosity at 70 ° C. of about 1000 to 3000 cP are preferably used.

  The thickness of the blade member is not particularly limited as long as it has sufficient strength to remove the residual toner on the surface of the photoreceptor, and is usually preferably about 1 to 3 mm. For example, when an adhesive that is reactively cured by irradiating ultraviolet rays or the like is used to obtain a cleaning blade by bonding a blade member and a mounting bracket, which will be described later, the blade member is transparent, ultraviolet rays, etc. It is preferable to have a thickness that can pass through. The rubber hardness of the blade member is not particularly limited as long as it has a strength sufficient to remove the residual toner on the surface of the electrophotographic photosensitive member 7, but is usually 65 to 80 (JIS K6253 A It is preferable that the measured value is about a value measured with a type hardness meter.

  In manufacturing the blade member, for example, the following method can be employed. First, the raw material of the blade material adjusted so as to have a desired blending amount is stirred and mixed for about 1 to 3 minutes using, for example, a mixing stirrer such as agitator to obtain a mixed solution, which is about 120 to 160 ° C. Rotating at about 100 to 300 rpm, for example, after being injected into a forming drum mold of a centrifugal molding machine, the number of rotations of the forming drum mold is increased to about 600 to 1200 rpm, and the injected mixed liquid is applied to the inner surface of the forming drum mold. The blade material is in a state in which bubbles that are uniformly spread and entrained at the time of injection float on the surface. Here, the amount of the liquid mixture injected into the molding drum mold may be adjusted so that, for example, a blade member having a desired thickness as described above can be obtained. Next, while maintaining the rotational speed of the forming drum mold at about 600 to 1200 rpm and the temperature at about 120 to 160 ° C., before the blade material is cross-linked and cured, for example, the abrasive fine particles are uniformly distributed using a spray gun or the like. After spraying the dispersed suspension onto the blade material, the blade material is cured while rotating the molding drum mold so that abrasive fine particles are present at least on the cleaning surface. The medium for obtaining the suspension in which the abrasive fine particles are uniformly dispersed is not particularly limited as long as it does not exhibit an interaction between the abrasive fine particles and the blade material. For example, when obtaining the blade material When silicone oil such as dimethylpolysiloxane, methylphenylpolysiloxane, trifluoropropylmethylpolysiloxane, etc., which is normally used for foaming, promotes defoaming, is used, the abrasive particles are uniformly distributed in the blade material. This is preferable because it can be transferred to the surface. Although it is sufficient that the abrasive fine particles are uniformly dispersed in the abrasive, the amount of the abrasive fine particles to be present on the cleaning surface can be adjusted by the blending amount of the abrasive fine particles in the suspension. The abrasive fine particles are preferably blended in an amount of about 1 to 20 parts by mass with respect to 100 parts by mass of the medium. Further, the desired amount of abrasive fine particles can be directly mixed and dispersed in the raw material of the blade material, and then molded.

A spray gun or the like is used to spray the suspension onto the blade material. The air pressure and spray amount during spraying may be adjusted according to the amount of abrasive fine particles to be present on the cleaning surface. Usually, the air pressure is about 1 to 10 kg / cm ² and the spray amount is It is preferably about 0.5 to ⁵ mg / cm ² . The time when the suspension material is sprayed onto the blade material may be any time as long as the blade material is spread uniformly in the molding drum mold and before the blade material is cured in a state where air bubbles emerge on the surface of the blade material. For example, since it varies depending on the target depth when impregnating the abrasive fine particles into the blade member, it cannot be determined unconditionally. However, after the blade material is put into the molding drum mold, it is usually 2-10. It is preferable that about a minute pass. In the blade member thus obtained, the abrasive fine particles are firmly adhered at least to the cleaning surface or immersed therein, so that the physical properties such as tensile strength and tear strength and the adhesion to the mounting bracket are reduced. It has excellent durability. Further, since the abrasive fine particles are present at least on the cleaning surface by centrifugal force, the degree of polishing performance can be adjusted by adjusting the spray amount of the suspension of the fine abrasive particles, the timing of spraying, the rotational speed of the molding drum mold, etc. The durability of polishing performance can be controlled.

  The blade member is integrated with the mounting bracket by using, for example, a hot melt adhesive, double-sided tape, etc. to form a cleaning blade, and is used by being mounted on an image forming apparatus such as for PPC, PPP, or PPF. it can. The mounting bracket is not particularly limited. For example, a mounting bracket made of a rigid metal, an elastic metal, plastic, ceramic, or the like, which is usually used for a cleaning blade, can be used. A mounting bracket made of a treated steel plate, a steel plate that has been subjected to a surface treatment such as zinc phosphate treatment or chromate treatment, or a steel plate that has been subjected to plating treatment is particularly preferred from the standpoint that it does not change over time such as corrosion. Further, the blade member may be a single layer or a laminate in which a plurality of materials are bonded together.

  It is preferable to appropriately control the wear amount and surface roughness of the electrophotographic photosensitive member 7. As the control means, the cleaning blade is brought into contact with the electrophotographic photosensitive member 7, the contact pressure and angle thereof are adjusted, the material of the surface layer of the electrophotographic photosensitive member 7 is optimized, the control by the material of the cleaning blade, the polishing roll And adjustment by combined use with a brush member, strength control by the material of the surface layer of the electrophotographic photosensitive member 7, control by adding inorganic fine particles such as aluminum oxide, cerium oxide, and barium sulfate to the toner. It is preferable to control to an appropriate range by combining these controls.

  FIG. 5 is a cross-sectional view schematically showing a basic configuration of another embodiment of the image forming apparatus of the present invention. An image forming apparatus 220 shown in FIG. 5 is an image forming apparatus that forms a color image by a tandem method. In the housing 400, four electrophotographic photosensitive members 401a to 401d (for example, the electrophotographic photosensitive member 401a is yellow and the electrophotographic photosensitive member is formed. The body 401b can form an image of magenta, the electrophotographic photoreceptor 401c can be cyan, and the electrophotographic photoreceptor 401d can be formed of a black color.) Are arranged in parallel with each other along the intermediate transfer belt 409.

  Here, the electrophotographic photoreceptors 401a to 401d mounted on the image forming apparatus 220 are the electrophotographic photoreceptors of the present invention.

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

  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 is irradiated with laser light emitted from the laser light source 403. Is possible. Accordingly, charging, exposure, development, primary transfer, and cleaning 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 roll 406, a backup roll 408, and a tension roll 407, and can rotate without causing deflection due to the rotation of these rolls. Further, the secondary transfer roll 413 is disposed so as to contact the backup roll 408 via the intermediate transfer belt 409. The intermediate transfer belt 409 passing between the backup roll 408 and the secondary transfer roll 413 is cleaned by, for example, a cleaning blade 416 disposed in the vicinity of the drive roll 406 and then repeatedly used for the next image forming process. Is done.

  A tray (transfer medium tray) 411 is provided at a predetermined position in the housing 400, and the transfer medium 500 such as paper in the tray 411 is transferred to the intermediate transfer belt 409 and the secondary transfer roll by the transfer roll 412. Then, the paper is sequentially transferred between the two fixing rolls 414 that are in contact with each other and the two fixing rolls 414, and then discharged to the outside of the housing 400.

  In the above description, the case where the intermediate transfer belt 409 is used as the intermediate transfer member has been described. However, the intermediate transfer member may have a belt shape like the intermediate transfer belt 409 or a drum shape. Also good. 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), ethylenetetrafluoroethylene copolymer (ETFE) / PC, ETFE / PAT, PC / PAT blend material, polyester Resin materials such as 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 an elastic material, polyurethane, chlorinated polyisoprene, NBR, chloropyrene rubber, EPDM, hydrogenated polybutadiene, butyl rubber, silicone rubber, or the like can be used, or a material obtained by blending two or more kinds can be used. If necessary, a conductive agent imparting electronic conductivity or a conductive agent having ionic conductivity is added to the resin material and elastic material used for these base materials in combination of one kind or two or more kinds. 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. When a belt-shaped configuration such as the intermediate transfer belt 409 is adopted as the intermediate transfer member, generally the thickness of the belt is preferably 50 to 500 μm, more preferably 60 to 150 μm, but the hardness of the material It can be selected as appropriate according to the conditions.

  For example, a belt made of a polyimide resin in which a conductive agent is dispersed is 5 to 20 mass as a conductive agent in a polyamic acid solution which is a polyimide precursor, as described in JP-A-63-311263. % Of carbon black 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 forming a belt.

  The film molding 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 to 200 ° C. at a rotational speed of 500 to 2000 rpm. The film was formed into a film by a centrifugal molding method while being rotated, and then the obtained film was demolded in a semi-cured state and covered with an iron core, and subjected to a polyimide reaction (polyamide acid) at a high temperature of 300 ° C. or higher. It can be carried out by proceeding a ring-closing reaction) and carrying out main curing. Also, the stock solution is cast on a metal sheet to a uniform thickness and heated to 100-200 ° C. to remove most of the solvent in the same manner as above, and then gradually raised to a high temperature of 300 ° C. or higher. There is also a method of forming a polyimide film. Further, the intermediate transfer member may have a surface layer.

  When a drum-shaped configuration is adopted as the intermediate transfer member, 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.

  The transfer medium according to the present invention is not particularly limited as long as it is a medium that transfers a toner image formed on an electrophotographic photosensitive member. For example, when transferring directly from an electrophotographic photosensitive member to a transfer medium such as paper, paper or the like is the transfer medium. When an intermediate transfer member is used, the intermediate transfer member is a transfer medium.

  FIG. 6 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of the process cartridge of the present invention. The process cartridge 300 is obtained by combining the electrophotographic photosensitive member 7 with the charging unit 8, the developing unit 11, the cleaning unit 13, the opening 18 for exposure, and the static eliminator 14 using the mounting rail 16. is there. The process cartridge 300 is detachable from the main body of the image forming apparatus including the transfer unit 12, the fixing unit 15, and other components (not shown). It constitutes. Such a process cartridge 300 can be applied to any of the image forming apparatuses shown in FIGS.

  Since the image forming apparatus and the process cartridge described above are provided with the electrophotographic photosensitive member of the present invention, the mechanical strength of the photosensitive member is improved and the adhesion of the discharge product to the photosensitive member is prevented. It is possible to form an image with good image quality that is compatible with removability and has no image quality defect such as image flow over a long period of time.

  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.

(Preparation of insulating fine particles A)
In a separable flask having an internal volume of 2000 mL equipped with a stirrer, a nitrogen introduction tube and a reflux condenser, 1000 parts by mass of ion-exchanged water, 100 parts by mass of styrene, 50 parts by mass of trimethylolpropane tri (meth) acrylate and reactive surface activity 0.1 parts by mass of an agent (trade name: HS-10, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added, and the temperature was raised to 70 ° C. under a constant stirring condition under a nitrogen gas stream. After maintaining at 70 ° C. for 30 minutes, 0.7 part by mass of ammonium persulfate was added as a polymerization initiator to initiate emulsion polymerization by radical polymerization reaction. Thereafter, the temperature of the reaction system was maintained at 70 ° C., and the emulsion polymerization was completed in about 15 hours to prepare an emulsion. This emulsion was dried over a day and night to obtain fine particles A in the form of white powder. In addition, a sample obtained by diluting the above emulsion with pure water is used as a sample, and the particle size distribution of fine particles A in the emulsion is measured using a laser diffraction / scattering type particle size distribution analyzer (HORIBA LA-910, manufactured by HORIBA, Ltd.). did. The measured particle size distribution had one peak, and the peak particle size was 25 nm.

(Preparation of insulating fine particles B)
Silica fine particles (trade name: AEROSIL 50, manufactured by Nippon Aerosil Co., Ltd.) were finely pulverized at 245 MPa with an optimizer (manufactured by Sugino Machine Co., Ltd.) using pure water as a medium, and sufficiently dried with a high-temperature dryer to prepare fine particles B. . The obtained fine particles B were diluted with pure water, and the particle size distribution was measured using the laser diffraction / scattering particle size distribution measuring apparatus. The particle size distribution had one peak, and the peak particle size was 40 nm. Met.
(Preparation of insulating fine particles C)
White powdery fine particles C were produced in the same manner as the production of the insulating fine particles A except that the emulsion polymerization was completed in about 24 hours. When the particle size distribution of the fine particles C was measured by the same method as in the case of the fine particles A, the particle size distribution had one peak, and the peak particle size was 105 nm.

(Preparation of insulating fine particles D)
PTFE particles (trade name: LD-100E, manufactured by Daikin Industries, Ltd.) were prepared as fine particles D. When the particle size distribution of the fine particles D was measured using the laser diffraction / scattering particle size distribution measuring apparatus, the particle size distribution had one peak, and the peak particle size was 221 nm.

(Preparation of insulating fine particles E)
Melanin-formamide condensate (trade name: Eposter S6, manufactured by Nippon Shokubai Co., Ltd.) was prepared as fine particles E. When the particle size distribution of the fine particles E was measured using the laser diffraction / scattering particle size distribution measuring apparatus, the particle size distribution had one peak, and the peak particle size was 415 nm.

[Example 1]
100 parts by mass of zinc oxide (trade name: SMZ-017N, manufactured by Teika) is stirred and mixed with 500 parts by mass of toluene, and 2 parts by mass of a silane coupling agent (trade name: A1100, manufactured by Nihon Unicar) is added. Stir for hours. Thereafter, toluene was distilled off under reduced pressure and baked at 120 ° C. for 2 hours. As a result of analyzing the obtained surface-treated zinc oxide by fluorescent X-ray, the ratio of Si element strength to zinc element strength was 1.8 × 10 ⁻⁴ .

  35 parts by mass of zinc oxide subjected to the above surface treatment, 15 parts by mass of blocked isocyanate (trade name: Sumidur 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.) as a curing agent, butyral resin (trade name: BM-1, Sekisui Chemical) 6 parts by mass) and 44 parts by mass of methyl ethyl ketone were mixed and dispersed in a sand mill for 2 hours using 1 mmφ glass beads to obtain a dispersion. To the obtained dispersion, 0.005 parts by mass of dioctyltin dilaurate as a catalyst and 17 parts by mass of Tospearl 130 (trade name, manufactured by GE Toshiba Silicone) are added to obtain a coating solution for forming an undercoat layer. It was. This coating solution was applied onto an 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 20 μm. The surface roughness of the undercoat layer was measured using a surface roughness shape measuring instrument (trade name: Surfcom 570A, manufactured by Tokyo Seimitsu Co., Ltd.) at a measurement distance of 2.5 mm and a scanning speed of 0.3 mm / sec. The value was 0.24.

  Next, chlorogallium phthalocyanine having strong diffraction peaks at Bragg angles (2θ ± 0.2 °) of 7.4 °, 16.6 °, 25.5 ° and 28.3 ° in the X-ray diffraction spectrum is 1 1 part by mass, 1 part by mass of polyvinyl butyral (trade name: ESREC BM-S, Sekisui Chemical), and 100 parts by mass of n-butyl acetate are mixed and dispersed with a glass shaker for 1 hour using a paint shaker. A coating solution for forming a generation layer was obtained. This coating solution was dip coated on the undercoat layer and dried by heating at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of about 0.15 μm.

Next, 2 parts by mass of a charge transporting compound represented by the following general formula (9) and 3 parts by mass of a polymer compound (viscosity average molecular weight 39,000) having a structural unit represented by the following general formula (10) It was made to melt | dissolve in 20 mass parts of chlorobenzene, and the coating liquid for charge transport layer formation was obtained.

  The obtained coating solution was applied onto the charge generation layer by a dip coating method and heated at 110 ° C. for 40 minutes to form a charge transport layer having a thickness of 20 μm.

Next, 6 parts by mass of a compound represented by the following general formula (11), 6 parts by mass of methyltrimethoxysilane, 1.5 parts by mass of tetramethoxysilane, and 1 part by mass of colloidal silica were mixed with 8 parts by mass of isopropyl alcohol, 5 parts of tetrahydrofuran. It is dissolved in 1 part by weight of distilled water and 1 part by weight of distilled water, added with 0.5 parts by weight of an ion exchange resin (trade name: Amberlyst 15E, manufactured by Rohm and Haas), and stirred for 24 hours by stirring at room temperature. Went.

0.1 parts by mass of aluminum trisacetylacetonate (Al (aqaq) ₃ ) and 3,5-di-t-butyl-4-hydroxytoluene (with respect to the liquid obtained by filtering and separating the ion exchange resin from the hydrolyzed product, BHT) 0.4 parts by mass, and 1.1 parts by mass of mixed particles obtained by mixing fine particles A and C in a ratio of 4: 6 (mass ratio) were added, and 20 parts by glass shaker (φ1 mm) and 20 parts by paint shaker. Dispersed for minutes. Thereafter, the glass beads were separated by filtration to obtain a coating solution for forming a protective layer. The obtained coating solution is applied onto the charge transport layer by a ring-type dip coating method, air-dried at room temperature for 30 minutes, and then cured by heat treatment at 170 ° C. for 1 hour to form a protective layer having a thickness of about 3 μm. Formed. Thereby, the production of the electrophotographic photosensitive member was completed.

[Example 2]
A subbing layer having a thickness of 20 μm was formed on the aluminum base material in the same procedure as in Example 1.

  Next, the Bragg angle (2θ ± 0.2 °) in the X-ray diffraction spectrum is 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 ° and 1 part by mass of hydroxygallium phthalocyanine having a strong diffraction peak at 28.3 ° is mixed with 1 part by mass of polyvinyl butyral (trade name: ESREC BM-S, manufactured by Sekisui Chemical Co., Ltd.) and 100 parts by mass of n-butyl acetate. The glass beads were dispersed for 1 hour in a paint shaker to obtain a coating solution for forming a charge generation layer. The obtained coating solution was dip-coated on the undercoat layer and dried by heating at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of about 0.15 μm.

Next, 2 parts by mass of a charge transporting compound represented by the following general formula (12) and 3 parts by mass of a polymer compound (viscosity average molecular weight 39,000) having a structural unit represented by the above general formula (10) It was made to melt | dissolve in 20 mass parts of chlorobenzene, and the coating liquid for charge transport layer formation was obtained.

  The obtained coating solution was applied onto the charge generation layer by a dip coating method and heated at 110 ° C. for 40 minutes to form a charge transport layer having a thickness of about 20 μm.

Next, 15 parts by mass of n-butyl alcohol, 7.5 parts by mass of a compound represented by the following general formula (13), and 7.5 parts by mass of a resol type phenol resin (PL-2211, manufactured by Gunei Chemical Co., Ltd.) Mixing was performed to obtain a mixed solution.

  2 parts by mass of mixed particles obtained by further mixing fine particles A and D in a ratio of 6: 4 (mass ratio) was added to the obtained mixed liquid, and dispersed with a glass shaker (φ1 mm) of 30 parts by a paint shaker for 20 minutes. Thereafter, the glass beads were separated by filtration to obtain a coating solution for forming a protective layer. The obtained coating solution is applied onto the charge transport layer by a ring-type dip coating method, air-dried at room temperature for 30 minutes, and then cured by heat treatment at 170 ° C. for 1 hour to form a protective layer having a thickness of about 5 μm. Formed. Thereby, the production of the electrophotographic photosensitive member was completed.

[Example 3]
The cylindrical aluminum substrate was polished by a centerless polishing apparatus, and the surface roughness was set to Rz = 0.6 μm. In order to clean the aluminum substrate subjected to the centerless polishing treatment, a degreasing treatment, an etching treatment with a 2% by mass sodium hydroxide solution for 1 minute, a neutralization treatment, and a pure water washing were performed in this order. Next, an anodic oxide film (current density: 1.0 A / dm ² ) was formed on the surface of the base material with a 10% by mass sulfuric acid solution with respect to the aluminum base material. After washing with water, sealing treatment was performed by dipping in a 1 mass% nickel acetate solution at 80 ° C. for 20 minutes. Further, pure water washing and drying treatment were performed. In this way, an aluminum base material having an anodized film of about 7 μm formed on the surface was obtained.

  Next, 1 part by mass of titanyl phthalocyanine having a strong diffraction peak with a Bragg angle (2θ ± 0.2 °) in an X-ray diffraction spectrum of 27.2 ° was obtained by adding polyvinyl butyral (trade name: ESREC BM-S, Sekisui Chemical 1 part by mass) and 100 parts by mass of n-butyl acetate were mixed with glass beads and treated with a paint shaker for 1 hour to disperse to obtain a coating solution for forming a charge generation layer. The obtained coating solution was dip-coated on the aluminum base material on which the anodic oxide film was formed and dried by heating at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of about 0.15 μm.

  Next, a charge transport layer having a thickness of about 20 μm was formed on the charge generation layer in the same procedure as in Example 1.

  Next, instead of 2 parts by mass of the mixed particles in which the fine particles A and D are mixed at 6: 4 (mass ratio), 1.6 masses of the mixed particles in which the fine particles A and E are mixed at 5: 5 (mass ratio) A protective layer having a film thickness of about 4 μm was formed on the charge transport layer in the same procedure as in Example 2 except that the part was used. Thereby, the production of the electrophotographic photosensitive member was completed.

[Example 4]
In the same procedure as in Example 3, an aluminum base material on which an anodized film having a thickness of about 7 μm was formed was produced.

  Next, a charge generation layer having a thickness of about 0.15 μm was formed on the aluminum base material on which the anodic oxide film was formed in the same procedure as in Example 1.

  Next, a charge transport layer having a thickness of about 20 μm was formed on the charge generation layer in the same procedure as in Example 2.

  Next, instead of 1.1 parts by mass of the mixed particles in which the fine particles A and C are mixed at 4: 6 (mass ratio), the mixed particles in which the fine particles B and D are mixed at 5: 5 (mass ratio) 2. A protective layer having a thickness of about 3 μm was formed on the charge transport layer in the same procedure as in Example 1 except that 7 parts by mass was used. Thereby, the production of the electrophotographic photosensitive member was completed.

[Example 5]
First, the cylindrical aluminum base material which gave the honing process was prepared. Next, 100 parts by mass of a zirconium compound (trade name: Orgatics ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.), 10 parts by mass of a silane compound (trade name: A1100, manufactured by Nihon Unicar), 400 parts by mass of isopropanol, and 200 parts by mass of butanol By mixing, a coating solution for forming the undercoat layer was obtained. This coating solution was applied by dip coating on the above aluminum substrate and dried by heating at 150 ° C. for 10 minutes to form an undercoat layer having a thickness of about 0.1 μm.

  Next, a charge generation layer having a thickness of about 0.15 μm was formed on the undercoat layer in the same procedure as in Example 2.

  Next, a charge transport layer having a thickness of about 20 μm was formed on the charge generation layer in the same procedure as in Example 1.

  Next, instead of 1.1 parts by mass of the mixed particles in which the fine particles A and C are mixed at 4: 6 (mass ratio), the mixed particles in which the fine particles B and E are mixed at 7: 3 (mass ratio) 0. A protective layer having a thickness of about 5 μm was formed on the charge transport layer in the same procedure as in Example 1 except that 8 parts by mass was used. Thereby, the production of the electrophotographic photosensitive member was completed.

[Comparative Example 1]
A subbing layer having a film thickness of about 0.1 μm was formed on a cylindrical aluminum base material subjected to honing in the same procedure as in Example 5.

  Next, a charge generation layer having a thickness of about 0.15 μm was formed on the undercoat layer by the same procedure as in Example 3.

  Next, a charge transport layer having a thickness of about 20 μm was formed on the charge generation layer in the same procedure as in Example 2.

  Next, instead of 2 parts by mass of the mixed particles in which the fine particles A and D are mixed at 6: 4 (mass ratio), 0.8 mass of the mixed particles in which the fine particles A and B are mixed at 7: 3 (mass ratio) A protective layer having a film thickness of about 4 μm was formed on the charge transport layer in the same procedure as in Example 2 except that the part was used. Thereby, the production of the electrophotographic photosensitive member was completed.

[Comparative Example 2]
In the same procedure as in Example 1, an undercoat layer having a thickness of about 20 μm, a charge generation layer having a thickness of about 0.15 μm, and a charge transport layer having a thickness of about 20 μm were sequentially formed on the aluminum substrate.

  Next, instead of 1.1 parts by mass of mixed particles in which fine particles A and C are mixed at 4: 6 (mass ratio), mixed particles in which fine particles B and C are mixed at 4: 6 (mass ratio) 2. A protective layer having a thickness of about 4 μm was formed on the charge transport layer in the same procedure as in Example 1 except that 0 part by mass was used. Thereby, the production of the electrophotographic photosensitive member was completed.

[Comparative Example 3]
A subbing layer having a thickness of about 20 μm was formed on the aluminum base material in the same procedure as in Example 1.

  Next, a charge generation layer having a thickness of about 0.15 μm and a charge transport layer having a thickness of about 20 μm were sequentially formed on the undercoat layer in the same procedure as in Example 2.

  Next, in place of 2 parts by mass of the mixed particles obtained by mixing the fine particles A and D in a ratio of 6: 4 (mass ratio), the same charge as in Example 2 was used except that 1.6 parts by mass of the fine particles B were used. A protective layer having a thickness of about 4 μm was formed on the transport layer. Thereby, the production of the electrophotographic photosensitive member was completed.

[Comparative Example 4]
A subbing layer having a thickness of about 20 μm was formed on the aluminum base material in the same procedure as in Example 1.

  Next, a charge generation layer having a thickness of about 0.15 μm and a charge transport layer having a thickness of about 20 μm were sequentially formed on the undercoat layer in the same procedure as in Example 2.

  Next, in place of 1.1 parts by weight of the mixed particles obtained by mixing the fine particles A and C in a ratio of 4: 6 (mass ratio), the same procedure as in Example 1 except that 1.4 parts by weight of the fine particles D was used. A protective layer having a thickness of about 4 μm was formed on the charge transport layer. Thereby, the production of the electrophotographic photosensitive member was completed.

[Comparative Example 5]
In the same procedure as in Example 3, an aluminum base material on which an anodized film having a thickness of about 7 μm was formed was produced.

  Next, a charge generation layer having a thickness of about 0.15 μm was formed on the aluminum base material on which the anodic oxide film was formed in the same procedure as in Example 3.

  Next, a charge transport layer having a thickness of about 20 μm was formed on the charge generation layer in the same procedure as in Example 1.

  Next, a protective layer having a thickness of about 5 μm was formed on the charge transport layer in the same procedure as in Example 1 except that fine particles were not added. Thereby, the production of the electrophotographic photosensitive member was completed.

(Measurement of average particle size)
The volume average particle diameter of the mixed particles or fine particles added to the protective layer in the electrophotographic photoreceptors of Examples 1 to 5 and Comparative Examples 1 to 5 was measured using a laser diffraction / scattering particle size distribution measuring device (HORIBA LA-910, Horiba, Ltd.). The measurement was performed using The results are shown in Table 18. In addition, in the case of mixed particles, the ratio of the peak particle diameters of the two kinds of fine particles (second fine particles / first fine particles) used in Examples 1 to 5 and Comparative Examples 1 to 5 ) Is also shown in Table 18.

[Production of developer]
In the following description regarding the developer, each physical property value was measured by the following method. That is, the particle size distribution of the toner and composite particles was measured using a multisizer (manufactured by Nikka Kisha Co., Ltd.) with an aperture diameter of 100 μm. Further, the average shape factor ML ² / A of the toner and the composite particles is expressed by the following formula:
ML ² / A = (maximum length) ² × π × 100 / (area × 4)
In the case of a true sphere, ML ² / A = 100. As a specific method for obtaining an average shape factor, a toner image is taken from an optical microscope into an image analyzer (trade name: LUZEX III, manufactured by Nireco), an equivalent circle diameter is measured, and from the maximum length and area, The ML ² / A value of the above formula was determined for each particle.

<Manufacture of toner base particles>
(Adjustment of resin fine particle dispersion)
A solution obtained by mixing 370 g of styrene, 30 g of n-butyl acrylate, 8 g of acrylic acid, 24 g of dodecanethiol and 4 g of carbon tetrabromide and a nonionic surfactant (trade name: Nonipol 400, manufactured by Sanyo Chemical Co., Ltd.) 6 g and 10 g of an anionic surfactant (trade name: Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were mixed with a solution of 550 g of ion-exchanged water, and emulsion polymerization was started in the flask. Then, 50 g of ion-exchanged water in which 4 g of ammonium persulfate was dissolved was added to this mixed solution. After carrying out nitrogen substitution in the flask, the mixed solution was heated with an oil bath until the temperature of the mixed solution reached 70 ° C. while stirring, and emulsion polymerization was continued for 5 hours. As a result, a resin fine particle dispersion in which resin fine particles having an average particle diameter of 150 nm, a glass transition temperature (Tg) of 58 ° C., and a weight average molecular weight (Mw) of 11500 was obtained. The solid content concentration of this dispersion was 40% by mass.

(Preparation of colorant dispersion)
Cyan pigment (B15: 3, manufactured by Dainichi Seika Co., Ltd.) 60 g, nonionic surfactant (trade name: Nonipol 400, manufactured by Sanyo Kasei Co., Ltd.) 5 g and ion-exchanged water 240 g were mixed together, and a homogenizer (trade name: Ultra Tarlux). The mixture was stirred for 10 minutes using T50 (manufactured by IKA). Thereafter, a colorant dispersion liquid in which colorant (cyan pigment) particles having a volume average particle diameter of 250 nm were dispersed was prepared by dispersing with an optimizer.

(Preparation of release agent dispersion)
100 g of paraffin wax (trade name: HNP0190, manufactured by Nippon Seiwa Co., Ltd., melting point: 85 ° C.), 5 g of a cationic surfactant (trade name: Sanizol B50, manufactured by Kao Corporation) and 240 g of ion-exchanged water are mixed, and round stainless steel The mixture was dispersed for 10 minutes in a steel flask using a homogenizer (trade name: Ultra Turrax T50, manufactured by IKA). Thereafter, a dispersion treatment was performed using a pressure discharge type homogenizer to prepare a release agent dispersion liquid in which release agent particles having an average particle diameter of 550 nm were dispersed.

(Adjustment of toner base particle C1)
234 parts by mass of the resin fine particle dispersion, 30 parts by mass of the colorant dispersion, 40 parts by mass of the release agent dispersion, and 0.5 mass of polyaluminum hydroxide (trade name: Paho2S, manufactured by Asada Chemical Co., Ltd.) And 600 parts by mass of ion-exchanged water were each put into a round stainless steel flask, and mixed and dispersed using a homogenizer (trade name: Ultra Turrax T50, manufactured by IKA). Thereafter, the mixed liquid in the flask was heated with stirring in an oil bath for heating, and kept at 40 ° C. for 30 minutes. At this time, it was confirmed that aggregated particles having an average particle diameter D50 of 4.5 μm were generated in the mixed solution. Further, when the temperature of the heating oil bath was raised and held at 56 ° C. for 1 hour, D50 was 5.3 μm. After adding 26 parts by mass of the resin fine particle dispersion to the dispersion containing the aggregate particles, the mixture was held at 50 ° C. for 30 minutes using a heating oil bath. After adding 1N sodium hydroxide to the dispersion containing the aggregate particles to adjust the pH of the dispersion to 7.0, the flask is sealed and heated to 80 ° C. while continuing stirring using a magnetic seal. Hold for 4 hours. After the dispersion was cooled, the toner base particles produced in the dispersion were filtered off, washed four times with ion exchange water, and then lyophilized to obtain toner base particles C1. The toner base particle C1 has an average particle diameter D50 of 5.8 μm and an average shape factor ML ² / L of 131.

<Manufacture of carriers>
14 parts by mass of toluene, 2 parts by mass of a styrene-methacrylate copolymer (component ratio: 90/10) and 0.2 parts by mass of carbon black (trade name: R330, manufactured by Cabot) were mixed and stirred with a stirrer for 10 minutes. A dispersion liquid was prepared. Next, 100 parts by mass of the coating liquid and ferrite particles (average particle size: 50 μm) are put in a vacuum degassing kneader and stirred at 60 ° C. for 30 minutes. To get a career. This carrier had a volume resistivity of 10 ¹¹ Ω · cm when an applied electric field of 1000 V / cm was applied.

<Preparation of Toner 1 and Developer 1>
100 parts by mass of the toner mother particles C1, 1 part by mass of rutile titanium oxide (particle size: 20 nm, treated with n-decyltrimethoxysilane), silica (particle size: 40 nm, prepared by vapor phase oxidation method) 2.0 parts by weight of a silicone oil-treated product, 1 part by weight of cerium oxide (average particle size: 0.7 μm), and 5% of higher fatty acid alcohol (higher fatty acid alcohol having a molecular weight of 700) and zinc stearate: What was mixed at a ratio of 1 (mass ratio) was pulverized with a jet mill, and 0.3 parts by mass of a mixed material having an average particle diameter of 8.0 μm was blended with a 5 L Henschel mixer at a peripheral speed of 30 m / s for 15 minutes. Thereafter, coarse particles were removed using a sieve having an opening of 45 μm to obtain toner 1 (cyan). Further, 100 parts by mass of the carrier and 5 parts by mass of the toner were stirred at 40 rpm for 20 minutes using a V-blender, and sieved with a sieve having an opening of 212 μm to obtain developer 1 (cyan color).

<Preparation of Toner 2 and Developer 2>
100 parts by mass of styrene-nBA resin (Tg = 58 ° C., Mn = 4000, Mw = 23500) and 3 parts by mass of carbon black (trade name: Mogal L, manufactured by Cabot) were kneaded with an extruder and pulverized with a jet mill. After that, it was dispersed with a wind classifier to obtain toner particles having D50 = 5.0 μm and ML ² /A=139.6.

  Next, 100 parts by mass of colloidal silica (trade name: R972, manufactured by Nippon Aerosil Co., Ltd.) as inorganic fine particles and 20 parts by mass of silicone oil (dimethylsilicone oil) are added to a 30% by mass methanol aqueous solution. After dispersion, the solvent was evaporated using an evaporator and dried. Thereafter, the obtained dried product was pulverized using a pin mill to obtain silica fine particles treated with dimethyl silicone oil.

  To 100 parts by mass of the above toner particles, 0.5 part by mass of the obtained silica fine particles and 1.0 part by mass of titanium dioxide hydrophobized with alkylsilane are added and mixed by a Henschel mixer to obtain toner 2 ( K color) was obtained. Further, 5 parts by mass of the toner and 100 parts by mass of the carrier were mixed and stirred (rotation speed: 40 rpm) for 20 minutes using a V-type blender to obtain Developer 2.

[Examples 6 to 12 and Comparative Examples 6 to 12]
The electrophotographic photoreceptors of Examples 1 to 5 and Comparative Examples 1 to 5 and developers 1 to 2 are mounted on a printer (DocuCenter Color 400CP, manufactured by Fuji Xerox Co., Ltd.) in the combinations shown in Table 19, and Examples 6 to 12 and Comparative Examples 6 to 12 were formed.

  Using the image forming apparatuses of Examples 6 to 12 and Comparative Examples 6 to 12, an image forming test for 10,000 sheets was performed in an environment of high temperature and high humidity (28 ° C., 85% RH), and then low temperature and low humidity (10 The image formation test was performed on 10,000 sheets of A4 paper in an environment of 20 ° RH. Adhesion of contaminants such as discharge products on the surface of the photoconductor after a total of 20,000 sheets of image formation test, and image flow in each 10,000th printed image in a high temperature and high humidity environment and a low temperature and low humidity environment The presence or absence of image quality defects such as ghosts and fog was visually evaluated.

  Contaminant adhesion was determined visually and evaluated according to the following evaluation criteria. The results are shown in Table 19.

○: No adhesion △: Partial adhesion (almost no problem in image quality)
X: Adherence (problems in image quality).

  The presence or absence of image quality defects was determined visually and evaluated according to the following evaluation criteria. The results are shown in Table 19.

○: Good image quality defect is not observed △: Image quality defect is partially present (almost practically no problem)
X: Image quality is defective (a level that can be easily detected visually and has a practical problem).

  As is clear from the results shown in Table 19, according to the image forming apparatuses of Examples 6 to 12 using the electrophotographic photoreceptors of Examples 1 to 5, the electrophotographic photoreceptors of Comparative Examples 1 to 5 were used. Compared with the image forming apparatuses of Comparative Examples 6 to 12, the adhesion of contaminants such as discharge products to the photosensitive member can be sufficiently suppressed, and in any environment of high temperature and high humidity and low temperature and low humidity. It was confirmed that an image with good image quality without image quality defects such as image flow can be formed over a long period of time.

  As described above, according to the electrophotographic photosensitive member of the present invention and the image forming apparatus of the present invention using the same, the mechanical strength of the photosensitive member is improved and the adhesion of the discharge product and the like to the photosensitive member is prevented. It was confirmed that both good removability and good image quality without image quality defects such as image flow could be formed over a long period of time.

(A)-(b) is a schematic cross section which shows 1st-2nd embodiment of the electrophotographic photoreceptor of this invention, respectively. (A)-(c) is a schematic cross section which shows other embodiment of the electrophotographic photoreceptor of this invention, respectively. 1 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of an image forming apparatus of the present invention. It is sectional drawing which shows schematically the basic composition of other suitable one Embodiment of the image forming apparatus of this invention. It is sectional drawing which shows schematically the basic composition of other suitable one Embodiment of the image forming apparatus of this invention. 1 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of a process cartridge of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Charge generating layer, 2 ... Charge transport layer, 3 ... Conductive support body, 4 ... Undercoat layer, 5 ... Protective layer, 6 ... Photosensitive layer, 7 ... Electrophotographic photoreceptor, 8 ... Charging means, 9 ... Power supply DESCRIPTION OF SYMBOLS 10 ... Exposure means, 11 ... Developing means, 12 ... Transfer means, 13 ... Cleaning means, 14 ... Static eliminator, 15 ... Fixing means, 16 ... Mounting rail, 18 ... Opening for exposure, 20 ... Transfer object 100, 110, 120, 130, 140 ... electrophotographic photosensitive member, 200, 210, 220 ... image forming apparatus, 300 ... process cartridge, 500 ... medium to be transferred.

Claims (8)

An electrophotographic photoreceptor comprising a conductive support and a photosensitive layer disposed on the conductive support,
The photosensitive layer has an outermost surface layer containing first insulating fine particles and second insulating fine particles on the side farthest from the conductive support,
An electrophotographic photoreceptor, wherein a peak particle size in the particle size distribution of the second insulating fine particles is ¼ times or less than a peak particle size in the particle size distribution of the first insulating fine particles. 2. The electrophotographic photosensitive member according to claim 1, wherein a specific resistance of the first insulating fine particles and a specific resistance of the second insulating fine particles are both 1 × 10 ⁵ Ω · cm or more.   The peak particle size in the particle size distribution of the first insulating fine particles is 50 to 1000 nm, and the peak particle size in the particle size distribution of the second insulating fine particles is 1 to 200 nm. The electrophotographic photosensitive member according to 1 or 2.   The electrophotographic photosensitive member according to claim 1, wherein the outermost surface layer contains a resin having a crosslinked structure.   The electrophotographic photosensitive member according to claim 4, wherein the resin having a crosslinked structure is at least one of a phenol resin and a siloxane resin.   The electrophotographic photosensitive member according to any one of claims 1 to 5, wherein the outermost surface layer contains a charge transport material. The electrophotographic photoreceptor according to any one of claims 1 to 6,
A charging means for charging the electrophotographic photosensitive member; a developing means for developing a latent electrostatic image formed on the electrophotographic photosensitive member with toner to form a toner image; and At least one selected from the group consisting of cleaning means for removing toner remaining on the surface;
A process cartridge comprising: The electrophotographic photoreceptor according to any one of claims 1 to 6,
Charging means for charging the electrophotographic photosensitive member;
Exposure means for forming an electrostatic latent image on the charged electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image with toner to form a toner image;
Transfer means for transferring the toner image from the electrophotographic photosensitive member to a transfer target;
An image forming apparatus comprising:

Images