JP4483726B2 - Curable resin composition, electrophotographic photosensitive member, process cartridge, and image forming apparatus - Google Patents

Description

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

    2. Description of the Related Art Conventionally, as an electrophotographic image forming apparatus, an apparatus that sequentially performs processes such as charging, exposure, development, transfer, and cleaning using an electrophotographic photosensitive member (hereinafter sometimes referred to as “photosensitive member”) is widely known. ing. In the field of such image forming apparatuses, recently, there are increasing demands for higher image quality and longer life of the apparatus, and improvement of each member and system is being studied to meet such demands.

  For example, a photoconductor used for image writing is susceptible to stress during charging, cleaning, and the like, and scratches and wear on the surface of the photoconductor may cause image defects. Therefore, a method has been proposed in which a protective layer formed by curing a curable resin composition containing a phenol resin is provided on the surface of the photoreceptor to improve the mechanical strength of the photoreceptor (for example, Patent Documents 1 to 4). reference).

Japanese Patent No. 3264218 JP 2002-6527 A JP 2002-82469 A JP 2003-186234 A

  However, even if it is possible to suppress the occurrence of scratches and wear on the photoconductor by the above method, the image quality may be deteriorated when the image forming apparatus is used for a long period of time. Cannot be achieved.

  According to the study by the present inventors, it has been found that one of the causes of image quality deterioration is poor film formation of a protective layer containing a phenol resin. More specifically, the functional layer such as a protective layer constituting the photoconductor is a thin film having a film thickness of several tens of μm or less. When such a thin film is formed by curing a phenol resin, protrusions are likely to be generated on the surface of the film. Turned out to be. If such a protrusion is present on the surface of the protective layer, the cleaning blade or the like is damaged, and an image quality defect due to poor cleaning tends to occur.

  The use of phenolic resin with excellent mechanical strength as a constituent material of the photoreceptor is expected to be effective in realizing high image quality and long life of the image forming apparatus. In fact, the film forming property that can sufficiently prevent the above has not been sufficiently studied.

  The present invention has been made in view of the above problems, and has a film forming property and a curable resin composition capable of forming a functional layer with sufficiently few protrusion defects, An object of the present invention is to provide an electrophotographic photosensitive member, a process cartridge, and an image forming apparatus capable of forming a quality image.

In order to achieve the above object, a curable resin composition of the present invention is a curable resin composition used as a constituent material of an electrophotographic photoreceptor, and includes a thermosetting phenol resin and a polyvinyl phenol resin. It is characterized by including.

  According to the curable resin composition of the present invention, by having the above-described configuration, a high level of film formability is achieved, and it is possible to form a functional layer that is sufficiently excellent in mechanical strength and has few protrusion defects. It becomes. By using a photoreceptor having such a functional layer, it becomes possible to form a high-quality image over a long period of time.

The reason why the above effect is obtained is not necessarily clear, but the present inventors speculate as follows. That is, when a functional layer is formed from a coating solution containing the curable resin composition, compatibility with alcohol is improved by including a thermosetting phenol resin and a polyvinyl phenol resin in the coating solution. It is considered that separation of both is sufficiently suppressed and a good coating film is formed because both have a phenol structure. Furthermore, by using the polyvinyl phenol resin having sufficient crosslinking points and the thermosetting phenol resin in combination, a crosslinked structure having a sufficiently high crosslinking density while relaxing shrinkage due to dehydration condensation during thermosetting. It is thought that the phenol resin crosslinked film which has is formed. As a result, the film formability is achieved at a high level, and even when a functional layer that is a thin film is formed, the occurrence of protruding defects is sufficiently prevented, and a functional layer that is sufficiently excellent in mechanical strength is formed. Inferred.

  Further, when a photoreceptor provided with a protective layer containing a conventional phenol resin is used for a long period of time, streaky peeling may occur on the surface of the photoreceptor, but the above-described curable resin composition of the present invention is used. Thus, it is possible to obtain a photoreceptor that can sufficiently prevent the occurrence of peeling for a long time. This is presumably because, as described above, according to the curable resin composition of the present invention, a protective layer having a sufficiently small number of protruding defects can be formed, and thus peeling that occurs from the protruding defects is sufficiently prevented.

  In addition, the curable resin composition of the present invention is used for forming not only the outermost layer of the photoreceptor such as a protective layer but also an intermediate layer such as an undercoat layer, a charge generation layer and a charge transport layer. However, an electrophotographic photosensitive member capable of forming a high-quality image over a long period of time can be realized due to the high film formability and the excellent physical properties of the formed functional layer.

  In the curable resin composition of the present invention, the thermosetting phenol resin is preferably a resol type phenol resin. As a result, a functional layer having excellent mechanical strength can be more reliably formed, and a functional layer having improved electrical property stability can be formed.

  Moreover, it is preferable that the curable resin composition of this invention further contains electroconductive fine particles and / or a charge transport substance. When forming a functional layer from a curable resin composition containing a conventional phenolic resin, it is difficult to effectively obtain the effect of improving electrophotographic characteristics by additives due to insufficient film formability. . On the other hand, since the curable resin composition of the present invention has excellent film formability, it further has a function of having excellent electrical characteristics by further containing the conductive fine particles and / or the charge transporting substance. The layer can be formed more reliably, and further image quality can be improved.

In addition, the curable resin composition of the present invention may further include one or more charge transporting substances represented by the following general formula (I), (II), (III), (IV) or (V). preferable.
F [-D-Si (R ¹ ) _(3-a) Q _a ] _b (I)
[In the formula (I), 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, a substituted or unsubstituted alkyl group. Alternatively, a substituted or unsubstituted aryl group, Q is a hydrolyzable group, a is an integer of 1 to 3, and b is an integer of 1 to 4. ]
F [— (X ¹ ) _n1 R ² —Z ¹ H] _m1 (II)
[In Formula (II), F represents an organic group derived from a compound having a hole transporting ability, R ² represents an alkylene group, Z ¹ represents an oxygen atom, a sulfur atom, NH or COO, and X ¹ Represents an oxygen atom or a sulfur atom, m1 represents an integer of 1 to 4, and n1 represents 0 or 1. ]
_{^{F [- (X 2) n2}} - (R 3) n3 - (Z 2) n4 G] n5 (III)
[In Formula (III), F represents an organic group derived from a compound having a hole transporting ability, X ² represents an oxygen atom or a sulfur atom, R ³ represents an alkylene group, Z ² represents an oxygen atom, S represents a sulfur atom, NH or COO, G represents an epoxy group, n2, n3 and n4 each independently represents 0 or 1, and n5 represents an integer of 1 to 4. ]


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


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

  When the curable resin composition contains at least one of the compounds represented by the general formulas (I) to (V) as a charge transporting substance, the image quality and the life can be further increased. Can be achieved at a high level. The reason why such an effect is obtained is that when the functional layer is formed using the above curable resin composition, the charge transport material is chemically bonded in the cross-linked structure of the phenol resin. This is probably because both the mechanical strength and electrical properties of the formed functional layer were achieved at a higher level.

Furthermore, from the viewpoint of achieving the film formability of the curable resin composition and the mechanical strength and electrical characteristics of the functional layer to be formed at a higher level, the above general formulas (I), (II), (III) , (IV) or (V) is preferably a group represented by the following general formula (VI).


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

  The present invention is also an electrophotographic photosensitive member comprising a conductive support and a photosensitive layer provided on the conductive support, wherein the photosensitive layer comprises the curable resin composition of the present invention. An electrophotographic photoreceptor having a functional layer formed by curing is provided.

  According to such an electrophotographic photoreceptor, since it has a functional layer formed by curing the curable resin composition of the present invention, when used in an image forming apparatus, it has a high quality over a long period of time. An image can be formed.

  In the electrophotographic photosensitive member of the present invention, it is preferable that the functional layer is provided on the side farthest from the conductive support.

  According to such an electrophotographic photosensitive member, the functional layer formed by curing the curable resin composition of the present invention is the outermost layer of the photosensitive member, so that protrusion defects on the surface of the photosensitive member can be sufficiently reduced, and defective cleaning is suppressed. In addition, since the occurrence of peeling can be prevented over a long period of time, an image forming apparatus capable of forming a high-quality image over a long period of time can be realized more effectively. In addition, it is considered that the functional layer having excellent adhesion to contaminants contributes to the achievement of higher image quality and longer life.

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

  The present invention also provides the electrophotographic photoreceptor of the present invention, a charging means for charging the electrophotographic photoreceptor, an exposure means for forming an electrostatic latent image on the charged electrophotographic photoreceptor, An image forming apparatus comprising: developing means for developing a latent image with toner to form a toner image; and transfer means for transferring the toner image from an electrophotographic photosensitive member to a transfer target. To do.

  These process cartridges and image forming apparatuses can form high-quality images over a long period of time by including the electrophotographic photosensitive member of the present invention.

  According to the present invention, a curable resin composition having excellent film formability and capable of forming a functional layer with sufficiently few protrusion defects, and an electrophotographic photosensitive member and process capable of forming a high-quality image over a long period of time. A cartridge and an image forming apparatus can be provided.

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

(Electrophotographic photoreceptor and curable resin composition)
FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the electrophotographic photosensitive member of the present invention. An electrophotographic photosensitive member 1 shown in FIG. 1 includes a conductive support 2 and a photosensitive layer 3. The photosensitive layer 3 has a structure in which an undercoat layer 4, a charge generation layer 5, a charge transport layer 6 and a protective layer 7 are laminated on the conductive support 2 in this order. In the electrophotographic photosensitive member 1 shown in FIG. 1, the protective layer 7 which is the outermost layer is a functional layer formed by curing a curable resin composition containing a thermosetting phenol resin and a polyvinyl phenol resin. .

  2 to 5 are schematic sectional views showing other preferred embodiments of the electrophotographic photosensitive member of the present invention. The electrophotographic photosensitive member shown in FIGS. 2 to 3 includes the photosensitive layer 3 in which the functions are separated into the charge generation layer 5 and the charge transport layer 6 as in the electrophotographic photosensitive member shown in FIG. 4 to 5 show that the charge generation material and the charge transport material are contained in the same layer (single-layer type photosensitive layer 8).

  The electrophotographic photoreceptor 1 shown in FIG. 2 has a structure in which a charge generation layer 5, a charge transport layer 6 and a protective layer 7 are sequentially laminated on a conductive support 2. The electrophotographic photoreceptor 1 shown in FIG. 3 has a structure in which an undercoat layer 4, a charge transport layer 6, a charge generation layer 5, and a protective layer 7 are sequentially laminated on a conductive support 2. In the electrophotographic photosensitive member 1 shown in FIGS. 2 and 3, the protective layer 7 is a functional layer formed by curing the curable resin composition.

  The electrophotographic photoreceptor 1 shown in FIG. 4 has a structure in which an undercoat layer 4, a single-layer type photosensitive layer 8 and a protective layer 7 are sequentially laminated on a conductive support 2. The electrophotographic photoreceptor 1 shown in FIG. 5 has a structure in which a single-layer type photosensitive layer 8 and a protective layer 7 are sequentially laminated on a conductive support 2. In the electrophotographic photosensitive member 1 shown in FIGS. 4 and 5, the protective layer 7 is a functional layer formed by curing the curable resin composition.

  As described above, the photosensitive layer provided in the electrophotographic photosensitive member of the present invention is a single-layer type photosensitive layer containing a charge generation material and a charge transport material in the same layer, or a layer containing a charge generation material (charge generation material). Layer) and a layer containing a charge transport material (charge transport layer) may be any function-separated type photosensitive layer provided separately. In the case of the function-separated type photosensitive layer, any of the stacking order of the charge generation layer and the charge transport layer may be the upper layer. In the case of a function-separated photosensitive layer, it is possible to achieve functional separation because it is possible to perform functional separation in which each layer only has to satisfy each function.

  Hereinafter, each element will be described based on the electrophotographic photosensitive member 1 shown in FIG. 1 as a representative example.

  Examples of the conductive support 2 include a metal plate, a metal drum, and a metal belt formed using a metal or an alloy such as aluminum, copper, zinc, stainless steel, chromium, nickel, molybdenum, vanadium, indium, gold, or platinum. Etc. Further, as the conductive support 2, paper, plastic film, belt or 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 can be used.

  The surface of the conductive support 2 is preferably roughened to a center line average roughness Ra of 0.04 μm to 0.5 μm in order to prevent interference fringes generated when laser light is irradiated. If Ra on the surface of the conductive support 2 is less than 0.04 μm, the effect of preventing interference tends to be insufficient because it is close to a mirror surface. On the other hand, if Ra exceeds 0.5 μm, the image quality tends to be insufficient even if a film is formed. When non-interfering light is used as a light source, it is not particularly necessary to roughen the interference fringes, and it is possible to prevent the occurrence of defects due to irregularities on the surface of the conductive support 2, which is suitable for longer life.

  Surface roughening methods include wet honing by suspending the abrasive in water and spraying it on the support, or centerless grinding and anodic oxidation in which the support is pressed against a rotating grindstone and continuously ground. Treatment etc. are preferred.

  Further, as another roughening method, a conductive or semiconductive powder is dispersed in a resin without roughening the surface of the conductive support 2 to form a layer on the surface of the support. A method of roughening with fine particles dispersed in the layer is also preferably used.

  The anodizing treatment is to form 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 intact porous anodic oxide film is chemically active, easily contaminated, and has a large resistance fluctuation due to the environment. Therefore, the pores of the anodic oxide 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. .

  The thickness of the anodized film is preferably 0.3 to 15 μm. When this film thickness is less than 0.3 μm, the barrier property against implantation 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.

  Further, the conductive support 2 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 can 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.

  The undercoat layer 4 is formed on the conductive support 2. The undercoat layer 4 includes, for example, an organometallic compound and / or a binder resin.

  As organometallic compounds, zirconium chelate compounds, zirconium alkoxide compounds, organozirconium 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, an organic zirconium compound, an organic titanyl compound, and an organoaluminum compound are particularly preferably used because of low residual potential and good electrophotographic characteristics.

  As the binder resin, polyvinyl alcohol, polyvinyl methyl ether, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, polyamide, polyimide, casein, gelatin, polyethylene, polyester, phenol resin, Examples include known vinyl chloride-vinyl acetate copolymers, epoxy resins, polyvinyl pyrrolidone, polyvinyl pyridine, polyurethane, polyglutamic acid, polyacrylic acid, and the like. When these are used in combination of two or more, the mixing ratio can be appropriately set as necessary.

  The undercoat layer 4 includes vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris-2-methoxyethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltri Methoxysilane, γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-2-aminoethylaminopropyltrimethoxysilane, γ-mercapropropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, β- A silane coupling agent such as 3,4-epoxycyclohexyltrimethoxysilane may be contained.

  In the undercoat layer 4, an electron transporting pigment can also be mixed / dispersed from the viewpoints of lowering the residual potential and environmental stability. Examples of the electron transport pigment include organic pigments such as perylene pigments, bisbenzimidazole perylene pigments, polycyclic quinone pigments, indigo pigments, quinacridone pigments described in JP-A-47-30330, cyano groups, nitro groups, 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, polycyclic quinone pigments, zinc oxide or titanium oxide are preferably used because of their high electron mobility.

  In addition, the surface of these pigments may be surface-treated with the above coupling agent or binder resin for the purpose of controlling dispersibility and charge transporting property.

  If the amount of the electron transporting pigment is too large, the strength of the undercoat layer 4 is lowered and causes a coating film defect. % Used.

  In addition, it is preferable to add various kinds of fine powders of organic compounds or fine powders of inorganic compounds to the undercoat layer 4 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, inorganic pigments such as alumina, calcium carbonate, barium sulfate, and the like, 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 mass%, more preferably 30 to 80 mass%, based on the total solid content of the undercoat layer 4. .

  The undercoat layer 4 is formed using an undercoat layer forming coating solution containing the above-described constituent materials. The organic solvent used in the coating solution for forming the undercoat layer is one that dissolves an organometallic compound or a binder resin and does not cause gelation or aggregation when an electron transporting pigment is mixed and / or dispersed. If it is.

  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. , Chloroform, chlorobenzene, toluene and the like. These can be used individually by 1 type or in mixture of 2 or more types.

  As a method for mixing and / or dispersing each constituent material, a conventional method using a ball mill, a roll mill, a sand mill, an attritor, a vibrating ball mill, a colloid mill, a paint shaker ultrasonic wave, or the like is applied. Mixing and / or dispersion is performed in an organic solvent.

  As a coating method for forming the undercoat layer 4, a normal method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method is used. be able to.

  The drying is usually performed at a temperature at which the solvent can be evaporated and a film can be formed. In particular, the conductive support 2 subjected to the acidic solution treatment and the boehmite treatment is preferably formed with the undercoat layer 4 because the defect concealing power of the substrate tends to be insufficient.

  The thickness of the undercoat layer 4 is preferably 0.01 to 30 μm, more preferably 0.05 to 25 μm.

  The charge generation layer 5 includes a charge generation material and, if necessary, a binder resin.

  Known 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. Can be used. As the charge generation material, metal and metal-free phthalocyanine pigments, trigonal selenium, dibromoanthanthrone and the like are particularly preferable when a light source having an exposure wavelength of 380 to 500 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 and titanyl phthalocyanine disclosed in JP-A-4-189873 and JP-A-5-43813 are particularly preferred.

Among the above hydroxygallium phthalocyanines, in particular, the spectral absorption spectrum has an absorption maximum at 810 to 839 nm, the primary particle diameter is 0.10 μm or less, and the specific surface area value by the BET method is 45 m ² / g. The above is preferable.

  The binder resin can be selected from a wide range of insulating resins, and can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, 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 5 is formed by vapor deposition of a charge generation material or a coating solution for forming a charge generation layer containing a charge generation material and a binder resin. When the charge generation layer 5 is formed using a charge generation layer forming coating solution, the blending ratio (mass ratio) of the charge generation material and the binder resin is preferably in the range of 10: 1 to 1:10.

  As a method for dispersing each of the constituent materials in the charge generation layer forming coating solution, 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 form of the pigment is not changed by the dispersion is required. Further, at the time of 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 further preferably 0.15 μm or less.

  Solvents used for dispersion 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.

  When forming the charge generation layer 5 using the coating solution for forming the charge generation layer, the coating methods are blade coating method, wire bar coating method, spray coating method, dip coating method, bead coating method, air knife coating. Ordinary methods such as a method and a curtain coating method can be used.

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

  The charge transport layer 6 includes a charge transport material and a binder resin, or a polymer charge transport material.

  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, but are not limited to, hole transporting compounds. These charge transport materials can be used singly or in combination of two or more.

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

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

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

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

  Examples of the binder resin used for the charge transport layer 6 include polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, and vinylidene chloride. -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, and the like. These binder resins can be used individually by 1 type or in mixture of 2 or more types. The blending ratio (mass ratio) of the charge transport material and the binder resin is preferably 10: 1 to 1: 5.

  As the polymer charge transporting material, known materials having charge transporting properties such as poly-N-vinylcarbazole and polysilane can be used. In particular, the polyester polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 have a high charge transporting property and are particularly preferable.

  Although the polymer charge transport material alone can be used as a constituent material of the charge transport layer 6, it may be mixed with the binder resin to form a film.

  The charge transport layer 6 is formed using a charge transport layer forming coating solution containing the above-described constituent materials.

  Examples of the solvent for 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 halogenated fats such as methylene chloride, chloroform and ethylene chloride. Examples thereof include ordinary organic solvents such as aromatic 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.

  As a coating method of the coating solution for forming the charge transport layer, a normal method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method should be used. Can do.

  The film thickness of the charge transport layer 6 is preferably 5 to 50 μm, more preferably 10 to 30 μm.

  In the photosensitive layer 3, additives such as an antioxidant, a light stabilizer, and a heat stabilizer are added for the purpose of preventing deterioration of the photoreceptor due to ozone, an oxidizing gas, or light or heat generated in the image forming apparatus. Can be added.

  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.

  The photosensitive layer 3 can contain at least one electron accepting substance for the purpose of improving sensitivity, reducing residual potential, reducing fatigue during repeated use, and the like.

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

In the electrophotographic photoreceptor 1 of the present embodiment, the protective layer 7 is a functional layer formed by curing a curable resin composition containing a thermosetting phenol resin and a polyvinyl phenol resin, and is the last layer of the photoreceptor. It is the outer layer. Hereinafter, each component which comprises curable resin composition is demonstrated.

  Examples of the thermosetting phenol resin include phenol resins that can be self-cured by heat or a catalyst. In the present embodiment, it is preferable to use a resol type phenol resin. Examples of such phenolic resins include monomethylolphenols, dimethylolphenols, monomers of trimethylolphenols, and mixtures thereof, or oligomers thereof, and mixtures of monomers and oligomers.

  The resol type phenol resin can be obtained, for example, by reacting a compound having a phenol structure with formaldehyde or a compound producing formaldehyde.

  Examples of the compound having a phenol structure include resorcin, bisphenol and the like, substituted phenols containing one hydroxyl group such as phenol, cresol, xylenol, paraalkylphenol and paraphenylphenol, and two hydroxyl groups such as catechol, resorcinol and hydroquinone. Examples thereof include substituted phenols, bisphenols such as bisphenol A and bisphenol Z, and biphenols.

  Formaldehyde or a compound that generates formaldehyde includes formaldehyde, aldehyde derivatives such as paraformaldehyde and hexamethylenetetramine, aliphatic aldehydes such as acetaldehyde and propionaldehyde, aromatic aldehydes represented by benzaldehyde, and furfural. And the like, and these can be used alone or in combination of two or more. Among these, formaldehyde and paraformaldehyde are preferable.

Moreover, in said reaction, it is preferable to use a catalyst, for example, a basic catalyst or an acid catalyst can be used. Basic catalysts include hydroxides and oxides of alkali metals and alkaline earth metals such as NaOH, KOH, Ca (OH) ₂ , Mg (OH) ₂ , Ba (OH) ₂ , CaO and MgO, or amines Examples thereof include system catalysts and acetates such as zinc acetate and sodium acetate. Here, examples of the amine-based catalyst include ammonia, hexamethylenetetramine, trimethylamine, triethylamine, triethanolamine, and the like, but are not limited thereto. Examples of the acid catalyst include sulfuric acid, paratoluenesulfonic acid, phenolsulfonic acid, and phosphoric acid. Depending on the catalyst used, carriers may be trapped significantly by the remaining catalyst, which may deteriorate the electrophotographic characteristics. In such a case, it is preferable to inactivate or remove the catalyst by distilling it off under reduced pressure, neutralizing it, or bringing it into contact with an adsorbent such as silica gel or an ion exchange resin.

The upper SL polyvinyl phenol resin refers to a singly or other copolymerizable component and polymerization was obtained a resin vinyl phenols. Examples of vinylphenols include p-hydroxystyrene, 4-vinyl-2-methylphenol, 4-vinyl-3-methylphenol, 4-vinyl-2-ethylphenol, 4-vinyl-3-ethylphenol, and the like. Compounds having a so-called vinyl group (CH ₂ ═CH—), 4-isopropenylphenol, 4-isopropenyl-2-methylphenol, 4-isopropenyl-3-methylphenol, 4-isopropenyl-2-ethylphenol, etc. And a compound having a vinyl group (CH ₂ ═C (CH ₃ ) —). Examples of other copolymerizable components include monomers such as styrenes, acrylic acid and ester derivatives thereof, α-substituted acrylic acid and ester derivatives thereof. Examples of styrenes include styrene and substituted styrene, examples of acrylic acid and ester derivatives thereof include acrylic acid and methyl acrylates, examples of α-substituted acrylic acid and ester derivatives thereof, Examples include methacrylic acid, ethyl methacrylate, tertiary butyl methacrylate and the like.

  Examples of commercially available polyvinylphenol resins include “Marcalinker M series”, “Marcalinker CHM”, “Marcalinker CMM”, “Marcalinker MB”, “Marcalinker PHM-C”, “Marcalinker”. CST series ”(above, trade name, manufactured by Maruzen Petrochemical Co., Ltd.).

300-100000 are preferable and, as for the weight average molecular weight of the said polyvinyl phenol resin, 500-5000 are more preferable. When the weight average molecular weight is less than 300, the effect of sufficiently improving the mechanical strength, scratch resistance, film formability and the like of the functional layer obtained by curing the curable resin composition tends to be difficult to obtain. On the other hand, when the weight average molecular weight exceeds 100,000, the solubility of the thermoplastic resin in the coating solution is reduced, so that the amount of the resin added is easily limited, or the curable resin composition is cured to function. When forming the layer (the protective layer 7 in the present embodiment), there may be inconveniences such as film formation failure easily occurring.

  In this embodiment, it is preferable that content of the said thermosetting phenol resin in curable resin composition is 10-95 mass% on the basis of the total amount of solid content in curable resin composition, and 20-90. More preferably, it is mass%. When this content is less than 10% by mass, the film strength tends to be insufficient, and when it exceeds 95% by mass, it tends to be difficult to sufficiently prevent the occurrence of protruding defects.

Moreover, it is preferable that content of the said polyvinyl phenol resin in curable resin composition is 5-80 mass% on the basis of the solid content whole quantity in curable resin composition, and it is 10-60 mass%. More preferably, it is 15-50 mass%, and it is especially preferable. When this content is less than 5% by mass, it tends to be difficult to sufficiently prevent the occurrence of protruding defects, and when it exceeds 80% by mass, the film strength tends to be insufficient.

  In order to form the protective layer 7 having good electrical characteristics, the curable resin composition preferably contains one or more of conductive fine particles, a charge transporting substance, or a derivative thereof.

  Examples of the conductive fine particles include metals, metal oxides, and carbon black. Examples of the metal include aluminum, zinc, copper, chromium, nickel, silver and stainless steel, or those obtained by depositing these metals on the surface of plastic particles. Examples of the metal oxide include zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, antimony and tantalum-doped tin oxide, and antimony-doped zirconium oxide. Can be mentioned. These electroconductive fine particles can be used individually by 1 type or in combination of 2 or more types. When two or more types are used in combination, they may be simply mixed, or may be in the form of a solid solution or fusion.

  In the present embodiment, it is preferable to use a metal oxide among the conductive fine particles from the viewpoint of sufficiently ensuring the transparency of the protective layer 7. For the same reason, the volume average particle size of the conductive fine particles is preferably 0.3 μm or less, and more preferably 0.1 μm or less.

  Furthermore, it is preferable that the surface of the conductive fine particles is treated for the purpose of controlling dispersibility. Examples of the treatment agent used for such treatment include a silane coupling agent, a silicone oil, a siloxane compound, and a surfactant. These preferably contain a fluorine atom.

The content of the conductive fine particles in the curable resin composition is preferably 10 to 200 parts by mass with respect to a total of 100 parts by mass of the thermosetting phenol resin and the polyvinyl phenol resin, and 20 to 100 parts by mass. It is more preferable that If the content is less than 10 parts by mass, good electrical characteristics tend to be difficult to obtain, and if it exceeds 200 parts by mass, the film formability tends to decrease and the strength tends to decrease.

  The charge transporting substance is preferably a substance having a reactive functional group and compatible with the thermosetting phenol resin, and more preferably one that forms a chemical bond with the phenol resin.

As the charge transporting substance having a reactive functional group, a compound represented by the following general formula (I), (II), (III), (IV) or (V) is a film forming property, mechanical strength and stability. It is preferable because it is excellent.
F [-D-Si (R ¹ ) _(3-a) Q _a ] _b (I)
[In the formula (I), 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, a substituted or unsubstituted alkyl group. Alternatively, a substituted or unsubstituted aryl group, Q is a hydrolyzable group, a is an integer of 1 to 3, and b is an integer of 1 to 4. ]
F [— (X ¹ ) _n1 R ² —Z ¹ H] _m1 (II)
[In Formula (II), F represents an organic group derived from a compound having a hole transporting ability, R ² represents an alkylene group, Z ¹ represents an oxygen atom, a sulfur atom, NH or COO, and X ¹ Represents an oxygen atom or a sulfur atom, m1 represents an integer of 1 to 4, and n1 represents 0 or 1. ]
_{^{F [- (X 2) n2}} - (R 3) n3 - (Z 2) n4 G] n5 (III)
[In Formula (III), F represents an organic group derived from a compound having a hole transporting ability, X ² represents an oxygen atom or a sulfur atom, R ³ represents an alkylene group, and Z ² represents an oxygen atom. , Sulfur atom, NH or COO, G represents an epoxy group, n2, n3 and n4 each independently represents 0 or 1, and n5 represents an integer of 1 to 4. ]


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


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

Moreover, it is preferable that said F in the compound represented by said general formula (I)-(V) is group represented by the following general formula (VI).


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

As the substituted or unsubstituted aryl group represented by Ar ^{1 to} Ar ⁴ in the general formula (VI), specifically, an aryl group represented by the following general formulas (1) to (7) is preferable. .

In the above formulas (1) to (7), R ⁹ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, phenyl substituted with them. A group or an unsubstituted phenyl group, or an aralkyl group having 7 to 10 carbon atoms, wherein R ^{10 to} R ¹² are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a carbon number, respectively. 1 to 4 alkoxy groups, phenyl or unsubstituted phenyl groups substituted therewith, aralkyl groups having 7 to 10 carbon atoms or halogen atoms, Ar represents a substituted or unsubstituted arylene group, and X represents the above One of the structures represented by general formulas (VII) to (XI) is shown, c and s each represent 0 or 1, and t represents an integer of 1 to 3.

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

In the above formulas (8) and (9), R ¹³ and R ¹⁴ are each substituted with a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms. A phenyl group, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, or a halogen atom, and t represents an integer of 1 to 3.

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

In formulas (10) to (17), R ¹⁵ and R ¹⁶ are each substituted with a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms. A phenyl group, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, or a halogen atom; W represents a divalent group; q and r each represents an integer of 1 to 10; Each represents an integer of 1 to 3.

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

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

Specific examples of the compound represented by the general formula (I) include the following compounds (I-1) to (I-61). In addition, the following compounds (I-1) to (I-61) are a combination of Ar ^{1 to} Ar ⁵ and k of the compound represented by the general formula (VI) as shown in the following table, and an alkoxysilyl group. (S) is the specific one shown in the table below.

  Specific examples of the compound represented by the general formula (II) include the following compounds (II-1) to (II-37). In addition, in the following table | surface, although the bond is described, the thing in which the substituent is not described shows a methyl group.

  Moreover, as a compound shown by the said general formula (III), the following compounds (III-1)-(III-47) are mentioned more specifically. In the following table, Me or a bond is described but a substituent is not described, a methyl group, Et represents an ethyl group.

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

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

Further, a compound represented by the following general formula (XII) is added to the curable resin composition for forming the protective layer 7 in order to control various physical properties such as strength and film resistance of the protective layer 7. You can also
Si (R ⁵⁰ ) _(4-c) Q _c (XII)
[In the above formula (XII), R ⁵⁰ represents a hydrogen atom, an alkyl group or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, and c represents an integer of 1 to 4. ]

  Specific examples of the compound represented by the general formula (XII) 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.

Further, in the curable resin composition for forming the protective layer 7, a compound having two or more silicon atoms as shown in the following general formula (XIII) is used in order to increase the strength of the protective layer 7. Is also preferable.
B- (Si (R ⁵¹ ) _(3-d) Q _d ) ₂ (XIII)
[In the above formula (XIII), B represents a divalent organic group, R ⁵¹ represents a hydrogen atom, an alkyl group or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, and d represents an integer of 1 to 3. Indicates. ]

  More specific examples of the compound represented by the general formula (XIII) include the following compounds (XIII-1) to (XIII-16).

  Further, a resin soluble in an alcohol solvent or a ketone solvent may be added for controlling the film characteristics and extending the liquid life. Examples of such resins include polyvinyl butyral resins, polyvinyl formal resins, and polyvinyl acetal resins such as partially acetalized polyvinyl acetal resins in which a part of butyral has been modified with formal, acetoacetal, or the like (for example, ESREC B, K manufactured by Sekisui Chemical Co., Ltd. Etc.), polyamide resin, cellulose resin and the like. In particular, polyvinyl acetal resin is preferable from the viewpoint of improving electrical characteristics.

  Various resins can be added 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. In the present embodiment, it is preferable to further add a resin that dissolves in alcohol. Examples of resins soluble in alcohol solvents include polyvinyl butyral resins, polyvinyl formal resins, and polyvinyl acetal resins such as partially acetalized polyvinyl acetal resins in which a part of butyral is modified with formal or acetoacetal (for example, manufactured by Sekisui Chemical Co., Ltd.). ESREC B, K, etc.), polyamide resin, cellulose resin and the like. In particular, polyvinyl acetal resin is preferable from the viewpoint of improving electrical characteristics.

  The weight average molecular weight of the resin is preferably 2000-100000, more preferably 5000-50000. If the weight average molecular weight is less than 2000, the desired effect tends not to be obtained. If the weight average molecular weight is more than 100,000, 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. When the addition amount is less than 1% by mass, it is difficult to obtain a desired effect. When the addition amount is more than 40% by mass, there is a risk of image blurring at high temperature and high humidity. Moreover, although said resin may be used independently, you may mix and use them.

  In order to extend the pot life and control the film properties, it is preferable to contain a cyclic compound having a repeating structural unit represented by the following general formula (XIV) or a derivative thereof.

[In the above formula (XIV), 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 (XIV) 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, various fine particles can be added to the curable resin composition for forming the protective layer 7 in order to control the contamination resistance adhesion, lubricity, hardness, etc. of the electrophotographic photoreceptor surface.

  Examples of the fine particles include silicon atom-containing fine particles. The silicon atom-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 atom-containing fine particles preferably has a volume average particle diameter of 1 to 100 nm, more preferably 10 to 30 nm, in an acidic or alkaline aqueous dispersion, or an organic solvent such as alcohol, ketone or ester. It is selected from those dispersed in, and commercially available products can be used. The solid content of colloidal silica in the curable resin composition is not particularly limited, but is preferably based on the total solid content in the curable resin composition in terms of film formability, electrical characteristics, and strength. Is used in the range of 0.1 to 50% by mass, more preferably in the range of 0.1 to 30% by mass.

  Silicone fine particles used as silicon atom-containing fine particles are spherical and preferably have a volume average particle diameter of 1 to 500 nm, more preferably 10 to 100 nm, and are selected from silicone resin particles, silicone rubber particles, and silicone surface-treated silica particles. A commercially available product 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 can be improved. In other words, in a state in which it is uniformly incorporated into a strong cross-linked structure, it improves the lubricity and water repellency of the surface of the electrophotographic photosensitive member, and maintains good wear resistance and contamination resistance adhesion over a long period of time. Can do. The content of the silicone fine particles in the curable resin composition is preferably in the range of 0.1 to 30% by mass, more preferably 0.5 to 10% by mass based on the total solid content in the curable resin composition. % Range.

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

  In addition, oil such as silicone oil can be added in order to control the contamination resistance adhesion, lubricity, hardness and the like of the surface of the electrophotographic photosensitive member. Examples of the silicone oil include silicone oils such as dimethylpolysiloxane, diphenylpolysiloxane, and phenylmethylsiloxane, amino-modified polysiloxane, epoxy-modified polysiloxane, carboxyl-modified polysiloxane, carbinol-modified polysiloxane, methacryl-modified polysiloxane, and mercapto. Examples include reactive silicone oils such as modified polysiloxanes and phenol-modified polysiloxanes. These may be added in advance to the curable resin composition for forming the protective layer 7, or may be impregnated under reduced pressure or increased pressure after producing the photoreceptor.

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

  An antioxidant having a hindered phenol, hindered amine, thioether or phosphite partial structure can be added to the curable resin composition for forming the protective layer 7, and the potential stability when the environment changes It is effective for improving image quality.

  Examples of the antioxidant include the following compounds. For example, as the hindered phenol type, “Sumizer BHT-R”, “Sumizer MDP-S”, “Sumizer 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 "," IRGANOX1098 " ”,“ 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, "Sanol LS2626", "Sanol LS765", "Sanol LS770", "Sanol LS744" or more Sankyo Lifetech Co., Ltd., "Tinuvin 144", "Tinubin 622LD" or more Ciba Specialty Made by Micals, "Mark LA57", "Mark LA67", "Mark LA62", "Mark LA68", "Mark LA63" or more Asahi Denka, "Sumilyzer TPS" or more Sumitomo Chemical Co., Ltd. "TP-D" or more, manufactured by Sumitomo Chemical Co., Ltd., and phosphite systems include "Mark 2112", "Mark PEP-8", "Mark PEP 24G", "Mark PEP 36", "Mark 329K", "Mark HP" -10 "or more manufactured by Asahi Denka, 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.

  The curable resin composition for forming the protective layer 7 includes polyvinyl butyral resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride- An insulating resin such as a vinyl acetate copolymer, a polyamide resin, an acrylic resin, a polyacrylamide resin, a polyvinyl pyridine resin, a cellulose resin, a urethane resin, an epoxy resin, casein, a polyvinyl alcohol resin, or a polyvinyl pyrrolidone resin may be contained. In this case, the insulating resin can be added at a desired ratio, and thereby, adhesion to the charge transport layer 6, coating film defects due to heat shrinkage and repellency, and the like can be suppressed.

  Moreover, a catalyst can be added at the time of the curable resin composition for forming the protective layer 7, or its adjustment. Catalysts include inorganic acids such as hydrochloric acid, acetic acid and sulfuric acid, organic acids such as formic acid, propionic acid, oxalic acid, benzoic acid, phthalic acid and maleic acid, potassium hydroxide, sodium hydroxide, calcium hydroxide, ammonia and triethylamine Further, an alkali catalyst such as the following, and a solid catalyst insoluble in the system as shown below can also be used.

Examples of solid catalysts insoluble in the system include Amberlite 15, Amberlite 200C, Amberlyst 15E (above, manufactured by Rohm and Haas); Dowex MWC-1-H, Dowex 88, Dowex HCR- W2 (above, manufactured by Dow Chemical Co.); Lebatit SPC-108, Lebatit SPC-118 (above, manufactured by Bayer); Diaion RCP-150H (manufactured by Mitsubishi Kasei); Sumikaion KC-470, Duolite C26-C , Duolite C-433, Duolite-464 (manufactured by Sumitomo Chemical Co., Ltd.); Cation exchange resins such as Nafion-H (manufactured by DuPont); Amberlite IRA-400, Amberlite IRA-45 (above, Anion exchange resin such as Rohm &Haas); Zr (O ₃ PCH ₂₎ An inorganic solid in which a group containing a protonic acid group such as CH ₂ SO ₃ H) ₂ or Th (O ₃ PCH ₂ CH ₂ COOH) ₂ is bonded to the surface; a protonic acid such as a polyorganosiloxane having a sulfonic acid group Group-containing polyorganosiloxanes; heteropolyacids such as cobalt tungstic acid and phosphomolybdic acid; isopolyacids such as niobic acid, tantalum acid and molybdic acid; monometallic oxides such as silica gel, alumina, chromia, zirconia, CaO and MgO Composite metal oxides such as silica-alumina, silica-magnesia, silica-zirconia, zeolites; clay minerals such as acid clay, activated clay, montmorillonite, kaolinite; metal sulfates such as LiSO ₄ and MgSO ₄ ; phosphorus acid zirconia, metal phosphates such as lanthanum phosphate; LiNO _3, Mn NO _{3) 2} and the like of a metal nitrate; inorganic solid by reacting aminopropyltriethoxysilane on silica gel containing amino groups such as the resulting solid which group is attached to the surface; amino and amino-modified silicone resin And polyorganosiloxane containing a group.

  In preparing the curable resin composition, 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 the compounds represented by the above general formulas (I) to (V), other additives, water, solvents and the like.

  The amount of the solid catalyst insoluble in these systems is not particularly limited, but is preferably 0.1 to 100 parts by mass with respect to 100 parts by mass in total of the compounds having hydrolyzable groups. 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. When the reaction time exceeds the above upper limit, gelation tends to occur.

  When preparing a curable resin composition, when a catalyst that is insoluble in the system is used, it is preferable to use a catalyst that is further dissolved in the system for the purpose of improving strength, liquid storage stability, and the like. Such catalysts include, in addition to those described above, aluminum triethylate, aluminum triisopropylate, aluminum tri (sec-butyrate), mono (sec-butoxy) aluminum diisopropylate, diisopropoxyaluminum (ethyl acetoacetate). ), Aluminum tris (ethyl acetoacetate), aluminum bis (ethyl acetoacetate) monoacetylacetonate, aluminum tris (acetylacetonate), aluminum diisopropoxy (acetylacetonate), aluminum isopropoxy-bis (acetylacetonate) 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; etc. can also be used, but from the viewpoints 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.

  The amount of the catalyst dissolved in these systems is not particularly limited, but is preferably 0.1 to 20 parts by weight, particularly 0.3 to 10% by weight, based on 100 parts by weight of the total of the compounds having hydrolyzable groups. preferable.

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

  Specifically, β-diketones such as acetylacetone, trifluoroacetylacetone, hexafluoroacetylacetone, and dipivaloylmethylacetone; acetoacetates such as methyl acetoacetate and ethyl acetoacetate; bipyridine and derivatives thereof; glycine and its Derivatives; ethylenediamine and derivatives thereof; 8-oxyquinoline and derivatives thereof; salicylaldehyde and derivatives thereof; catechol and derivatives thereof; bidentate ligands such as 2-oxyazo compounds; diethyltriamine and derivatives thereof; nitrilotriacetic acid and derivatives thereof And tridentate ligands such as ethylenediaminetetraacetic acid (EDTA) and derivatives thereof. 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 specific examples include a bidentate ligand represented by the following general formula (XV) in addition to the above.

[In the formula (XV), R ⁵¹ and R ⁵² 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. ]

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

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

  The protective layer 7 is formed using the curable resin composition containing each constituent material described above as a coating liquid for forming a protective layer.

  Preparation of the curable resin composition containing the above components is carried out in the absence of a solvent, or alcohols such as methanol, ethanol, propanol and butanol as necessary; ketones such as acetone and methyl ethyl ketone; tetrahydrofuran, diethyl ether, It can carry out using solvents, such as ethers, such as a dioxane. Such solvents can be used singly or in combination of two or more, but preferably have a boiling point of 100 ° C. or lower. Although the usage-amount of a solvent can be set arbitrarily, when using the compound represented by above-described general formula (I)-(V), since this compound will precipitate easily when there is too little solvent amount, the said general formula ( The solvent is preferably used in an amount of 0.5 to 30 parts by mass, more preferably 1 to 20 parts by mass with respect to 1 part by mass of the compounds represented by I) to (V).

  The reaction temperature and reaction time for curing the curable resin composition are not particularly limited, but the reaction temperature is preferably 60 ° C. or more from the viewpoint of the mechanical strength and chemical stability of the protective layer 7 to be formed. The reaction time is preferably 80 to 200 ° C., and the reaction time is preferably 10 minutes to 5 hours. In addition, maintaining the protective layer 7 obtained by curing the curable resin composition in a high humidity state is effective in stabilizing the characteristics of the protective layer 7. Further, depending on the application, the protective layer 7 may be subjected to a surface treatment using hexamethyldisilazane, trimethylchlorosilane, or the like to make it hydrophobic.

  When the curable resin composition is applied onto the charge transport layer 6, the coating method includes blade coating method, Mayer bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain coating method. A usual method such as can be used.

  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 thickness of the protective layer 7 is preferably 0.5 to 15 μm, more preferably 1 to 10 μm, and further preferably 1 to 5 μm.

  Further, the protective layer 7 obtained by curing the curable resin composition has excellent charge transportability and excellent mechanical strength and sufficient photoelectric characteristics. It can also be used as a transport layer.

  4 and 5, when the photosensitive layer 3 has a single-layer type photosensitive layer 8, the single-layer type photosensitive layer 8 contains a charge generating material and a binder resin. It is formed. The charge generation material is the same as that used for the charge generation layer 5 in the functional separation type photosensitive layer, and the binder resin is a binder used in the charge generation layer 5 and the charge transport layer 6 in the function separation type photosensitive layer. The same resin as the resin can be used. The content of the charge generating material in the single-layer type photosensitive layer 8 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 8. A charge transport material or a polymer charge transport material may be added to the single-layer type photosensitive layer 8 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 8. Moreover, the solvent and coating method used for coating can be the same as those for the above layers. The film thickness of the single layer type photosensitive layer 8 is preferably about 5 to 50 μm, more preferably 10 to 40 μm.

In the electrophotographic photoreceptor 1 shown in FIGS. 1 to 5, the protective layer 7 which is the outermost layer is a functional layer obtained by curing the curable resin composition of the present invention. It may not be the outermost layer. For example, the undercoat layer 4 may be a functional layer formed by curing the curable resin composition of the present invention. Such an undercoat layer can be formed by containing the thermosetting phenol resin and the polyvinyl phenol resin in a coating solution for forming the undercoat layer, and using this coating solution. Similarly, a coating solution for forming a charge generation layer, a coating solution for forming a charge transport layer, and a coating solution for forming a single-layer type photosensitive layer, containing the thermosetting phenol resin and the polyvinyl phenol resin are prepared. Thus, a charge generation layer, a charge transport layer, and a single-layer type photosensitive layer formed by curing the curable resin composition of the present invention can be formed.

(Image forming apparatus and process cartridge)
FIG. 6 is a schematic diagram showing a preferred embodiment of the image forming apparatus of the present invention. An image forming apparatus 100 shown in FIG. 6 includes, in an image forming apparatus main body (not shown), a process cartridge 20 including the above-described electrophotographic photoreceptor 1 of the present invention, an exposure device 30, a transfer device 40, and an intermediate transfer. A body 50. In the image forming apparatus 100, the exposure device 30 is disposed at a position where the electrophotographic photosensitive member 1 can be exposed from the opening of the process cartridge 20, and the transfer device 40 is interposed between the electrophotographic photosensitive member via the intermediate transfer member 50. The intermediate transfer member 50 is disposed such that a part of the intermediate transfer member 50 can come into contact with the electrophotographic photosensitive member 1.

  The process cartridge 20 is obtained by integrating a charging device 21, a developing device 25, a cleaning device 27, and a fibrous member (toothbrush shape) 29 together with an electrophotographic photosensitive member 1 by a mounting rail in a case. The case is provided with an opening for exposure.

  Here, the charging device 21 charges the electrophotographic photosensitive member 1 by a contact method. The developing device 25 develops the electrostatic latent image on the electrophotographic photosensitive member 1 to form a toner image.

Hereinafter, the toner used for the developing device 25 will be described. The toner preferably has an average shape factor (ML ² / A) of 100 to 150, and more preferably 100 to 140. Further, the toner preferably has a volume average particle diameter of 2 to 12 μm, more preferably 3 to 12 μm, and further preferably 3 to 9 μm. By using a toner satisfying such an average shape factor and volume average particle diameter, it is possible to obtain an image with high development, transferability and high image quality.

  The toner is not particularly limited by the production method as long as it satisfies the above average shape factor and volume average particle diameter. For example, the toner may include a binder resin, a colorant, a release agent, and the like. A kneading and pulverizing method in which a charge control agent is added, kneading, pulverizing, and classifying; a method in which the shape of particles obtained by the kneading and pulverizing method is changed by mechanical impact force or thermal energy; Emulsion polymerization of the body, and the resulting dispersion is mixed with a dispersion of a colorant, a release agent and, if necessary, a charge control agent, and then agglomerated and heat-fused to obtain toner particles. Suspension polymerization method in which a polymerizable monomer for obtaining a binder resin, a colorant, a release agent, and a charge control agent, if necessary, are suspended in an aqueous solvent and polymerized; A water-based solution of a resin, a colorant, a release agent, and a solution such as a charge control agent as necessary. Toner is used which is suspended in and produced by a dissolution suspension method in which granulated.

  Further, 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 give a core-shell structure can be used. The toner production method is preferably a suspension polymerization method, an emulsion polymerization aggregation method, or a dissolution suspension method in which an aqueous solvent is used from the viewpoint of shape control and particle size distribution control, and an emulsion polymerization aggregation method is particularly preferable.

  The toner base particles are composed of a binder resin, a colorant, and a release agent, and include silica and a charge control agent as necessary.

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

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

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

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

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

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

  Lubricating particles may be added to the toner used in the developing device 25. Lubricating particles include solid lubricants such as graphite, molybdenum disulfide, talc, fatty acids and fatty acid metal salts, low molecular weight polyolefins such as polypropylene, polyethylene and polybutene, silicones having a softening point upon heating, oleic amides Aliphatic amides such as erucic acid amide, ricinoleic acid amide, stearic acid amide, etc., plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil, animals such as beeswax Minerals such as system waxes, montan waxes, ozokerites, ceresins, paraffin waxes, microcrystalline waxes, Fischer-Tropsch waxes, etc., petroleum waxes, and modified products thereof can be used. These can be used individually by 1 type or in combination of 2 or more types. However, the average particle size is preferably in the range of 0.1 to 10 μm, and the particles having the above chemical structure may be pulverized to make the particle sizes uniform. The amount added to the toner is preferably in the range of 0.05 to 2.0 mass%, more preferably 0.1 to 1.5 mass%.

  To the toner used in the developing device 25, inorganic fine particles, organic fine particles, composite fine particles obtained by attaching inorganic fine particles to the organic fine particles, and the like can be added for the purpose of removing deposits and deteriorated matters on the surface of the electrophotographic photosensitive member. .

  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.

  In addition, the inorganic fine particles are mixed with a titanium coupling agent such as tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzenesulfonyl titanate, bis (dioctylpyrophosphate) oxyacetate titanate, γ- (2- Aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) γ-aminopropyltrimethoxy Silane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxy The treatment may be performed with a silane coupling agent such as silane, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, and p-methylphenyltrimethoxysilane. In addition, those hydrophobized with higher fatty acid metal salts such as silicone oil, aluminum stearate, zinc stearate and calcium stearate are also preferably used.

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

  The particle diameter is preferably a volume average particle diameter of 5 nm to 1000 nm, more preferably 5 nm to 800 nm, and still more preferably 5 nm to 700 nm. If the volume average particle diameter is less than the lower limit, the polishing ability tends to be lacking. On the other hand, if the volume average particle diameter exceeds the upper limit, the surface of the electrophotographic photosensitive member tends to be damaged. Moreover, it is preferable that the sum of the addition amount of the particle | grains mentioned above and lubricity particle | grains is 0.6 mass% or more.

  Other inorganic oxides added to the toner are small-diameter inorganic oxides with a primary particle size of 40 nm or less for powder flowability, 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 for precise charge control. Further, the surface treatment of the small-diameter inorganic fine particles increases the dispersibility and increases the powder flowability. Furthermore, it is also preferable to add carbonates such as calcium carbonate and magnesium carbonate and inorganic minerals such as hydrotalcite in order to remove the discharge purified product.

  In addition, 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.

  The cleaning device 27 includes a fibrous member (roll shape) 27a and a cleaning blade (blade member) 27b.

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

  The cleaning device 27 is required to remove deposits (for example, discharge products) on the surface of the photoreceptor with a cleaning blade and a cleaning brush. In order to achieve this purpose over a long period of time and stabilize the function of the cleaning member, the cleaning member may be supplied with a lubricating substance (lubricating component) such as metal soap, higher alcohol, wax, silicone oil or the like. preferable.

  For example, when a roll-shaped member is used as the fibrous member 27a, it is preferable to supply a lubricating component to the surface of the electrophotographic photosensitive member by bringing it into contact with a lubricating substance such as metal soap or wax. A normal rubber blade is used as the cleaning blade 27b. As described above, when a rubber blade is used as the cleaning blade 27b, supplying a lubricating component to the surface of the electrophotographic photosensitive member is particularly effective in suppressing chipping and wear of the blade.

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

  The exposure device 30 may be any device that exposes the charged electrophotographic photosensitive member 1 to form an electrostatic latent image. Further, it is preferable to use a multi-beam surface emitting laser as a light source of the exposure apparatus 30.

  The transfer device 40 may be any device that transfers the toner image on the electrophotographic photosensitive member 1 to a transfer medium (intermediate transfer member 50). For example, a roll-shaped one that is usually used is used.

  As the intermediate transfer member 50, a belt-like member (intermediate transfer belt) such as polyimide, polyamideimide, polycarbonate, polyarylate, polyester, rubber or the like having semiconductivity is used. Further, as the form of the intermediate transfer member 50, a drum-like member can be used in addition to the belt-like member. Although there is a direct transfer type image forming apparatus that does not include the intermediate transfer body, the electrophotographic photosensitive member of the present invention is suitable for such an image forming apparatus. The reason is that in a direct transfer type image forming apparatus, paper dust, talc, and the like are generated from the print paper and are likely to adhere to the electrophotographic photosensitive member, and image quality defects due to the attached matter tend to occur. However, according to the electrophotographic photoreceptor of the present invention, it is easy to remove paper dust and talc because of its excellent cleaning properties, and a stable image can be obtained even with a direct transfer type image forming apparatus. it can.

  The transfer medium referred to in the present invention is not particularly limited as long as it is a medium to which a toner image formed on the electrophotographic photoreceptor 1 is transferred. For example, when transferring directly from the electrophotographic photosensitive member 1 to paper or the like, paper or the like is a transfer medium, and when the intermediate transfer member 50 is used, the intermediate transfer member is a transfer medium.

  FIG. 7 is a schematic view showing another embodiment of the image forming apparatus of the present invention. In the image forming apparatus 110 shown in FIG. 7, the electrophotographic photosensitive member 1 is fixed to the main body of the image forming apparatus, and the charging device 22, the developing device 25, and the cleaning device 27 are each formed into a cartridge. It is provided independently as a cleaning cartridge. Note that the charging device 22 includes a charging device for charging by a corona discharge method.

  In the image forming apparatus 110, the electrophotographic photosensitive member 1 and other apparatuses are separated, and the charging device 22, the developing device 25, and the cleaning device 27 are fixed to the image forming apparatus main body by screws, caulking, adhesion, or welding. It is possible to detach it by the operation by pulling out and pushing in without being done.

  Since the electrophotographic photosensitive member of the present invention is excellent in wear resistance, it may not be necessary to form a cartridge. Therefore, the charging device 22, the developing device 25, or the cleaning device 27 can be detached and attached by an operation by pulling out and pushing in without being fixed to the main body by screws, caulking, adhesion, or welding. The member cost per hit can be reduced. Also, two or more of these devices can be detachable as an integrated cartridge, thereby further reducing the member cost per print.

  The image forming apparatus 110 has the same configuration as that of the image forming apparatus 100 except that the charging device 22, the developing device 25, and the cleaning device 27 are each formed as a cartridge.

  FIG. 8 is a schematic diagram showing another embodiment of the image forming apparatus of the present invention. The image forming apparatus 120 is a tandem full-color image forming apparatus equipped with four process cartridges 20. In the image forming apparatus 120, four process cartridges 20 are arranged in parallel on the intermediate transfer member 50, and one electrophotographic photosensitive member can be used for one color. The image forming apparatus 120 has the same configuration as that of the image forming apparatus 100 except that it is a tandem system.

  In the tandem-type image forming apparatus 120, the amount of wear of each electrophotographic photosensitive member varies depending on the use ratio of each color, and thus the electrical characteristics of each electrophotographic photosensitive member tend to vary. Along with this, the toner development characteristics gradually change from the initial state, and the hue of the print image changes, so that a stable image cannot be obtained. In particular, in order to reduce the size of the image forming apparatus, a small-diameter electrophotographic photosensitive member tends to be used, and this tendency becomes remarkable when one having a diameter of 30 mmΦ or less is used. Here, when the configuration of the electrophotographic photosensitive member of the present invention is adopted as the electrophotographic photosensitive member, the surface wear is sufficiently suppressed even when the diameter is 30 mmΦ or less. Further, when the diameter of the photoconductor is reduced, the number of rotations increases, and the cleaning member and the photoconductor surface tend to cause poor cleaning due to an increase in stress on the photoconductor and the photoconductor surface. By adopting the configuration of the electrophotographic photosensitive member, such a tendency is sufficiently suppressed. Therefore, the electrophotographic photosensitive member of the present invention is particularly effective for a tandem type image forming apparatus.

  FIG. 9 is a schematic view showing another embodiment of the image forming apparatus of the present invention. The image forming apparatus 130 shown in FIG. 9 is a so-called four-cycle image forming apparatus that forms toner images of a plurality of colors with one electrophotographic photosensitive member. The image forming apparatus 130 includes a photosensitive drum 1 that is rotated by a driving device (not shown) at a predetermined rotational speed in the direction of arrow A in the figure, and above the photosensitive drum 1 is a photosensitive member. A charging device 22 for charging the outer peripheral surface of the drum 1 is provided.

  Further, an exposure device 30 including a surface emitting laser array as an exposure light source is disposed above the charging device 22. The exposure device 30 modulates a plurality of laser beams emitted from a light source in accordance with an image to be formed and deflects the laser beams in the main scanning direction so that the axis of the photosensitive drum 1 is on the outer peripheral surface of the photosensitive drum 1. Scan in parallel. Thereby, an electrostatic latent image is formed on the outer peripheral surface of the charged photosensitive drum 1.

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

  The full-color image is formed by the image forming apparatus 130 while the photosensitive drum 1 is rotated four times. That is, while the photosensitive drum 1 rotates four times, the charging device 22 charges the outer peripheral surface of the photosensitive drum 1, and the exposure device 20 includes Y, M, C, and K image data representing a color image to be formed. Scanning the outer peripheral surface of the photosensitive drum 1 with the laser beam modulated according to any one of the above is repeated while switching the image data used for modulation of the laser beam every time the photosensitive drum 1 rotates. Further, the developing device 25 operates the developing device corresponding to the outer peripheral surface in a state where any of the developing rollers 26 of the developing devices 25Y, 25M, 25C, and 25K corresponds to the outer peripheral surface of the photosensitive drum 1. The photosensitive drum 1 is the one that develops the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 1 to a specific color and forms a toner image of the specific color on the outer peripheral surface of the photosensitive drum 1. Each time it rotates, the process is repeated while rotating the container so that the developing unit used for developing the electrostatic latent image is switched. As a result, every time the photosensitive drum 1 rotates, the Y, M, C, and K toner images are sequentially formed on the outer peripheral surface of the photosensitive drum 1 so as to overlap each other. When the drum 1 rotates four times, a full-color toner image is formed on the outer peripheral surface of the photosensitive drum 1.

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

  A transfer device (transfer device) 40 is disposed on the opposite side of the photosensitive drum 1 across the intermediate transfer belt 50, and the toner image formed on the outer peripheral surface of the photosensitive drum 1 is intermediate transferred by the transfer device 40. The image is transferred onto the image forming surface of the belt 50.

  A lubricant supply device 29 and a cleaning device 27 are disposed on the outer peripheral surface of the photosensitive drum 1 on the opposite side of the developing device 25 with the photosensitive drum 1 interposed therebetween. When the toner image formed on the outer peripheral surface of the photoconductive drum 12 is transferred to the intermediate transfer belt 50, the lubricant is supplied to the outer peripheral surface of the photoconductive drum 1 by the lubricant supply device 29. The area carrying the transferred toner image is cleaned by the cleaning device 27.

  A tray 60 is disposed below the intermediate transfer belt 50, and a large number of sheets P as recording materials are accommodated in the tray 60 in a stacked state. A take-out roller 61 is disposed obliquely above and to the left of the tray 60, and a roller pair 63 and a roller 65 are arranged in this order on the downstream side in the take-out direction of the paper P by the take-out roller 61. The uppermost recording sheet in the stacked state is taken out from the tray 60 by the take-out roller 61 rotating, and is conveyed by the roller pair 63 and the roller 65.

  A transfer device 42 is disposed on the opposite side of the roller 55 with the intermediate transfer belt 50 interposed therebetween. The paper P conveyed by the roller pair 63 and the roller 65 is sent between the intermediate transfer belt 50 and the transfer device 42, and the toner image formed on the image forming surface of the intermediate transfer belt 50 is transferred by the transfer device 42. . A fixing device 44 having a pair of fixing rollers is arranged on the downstream side of the transfer device 42 in the conveyance direction of the paper P. The paper P on which the toner image is transferred is transferred by the fixing device 44. After being fused and fixed, the sheet is discharged out of the image forming apparatus 130 and placed on a discharge tray (not shown).

  Next, a preferred example of the exposure apparatus 30 including a surface emitting laser array as an exposure light source will be described in detail with reference to FIG. The exposure apparatus 30 includes a surface emitting laser array 70 that emits m (m is at least 3) laser beams. In FIG. 10, only three laser beams are shown for simplification, but a surface emitting laser array 70 formed by arraying surface emitting lasers is configured to emit several tens of laser beams. In addition, the arrangement of the surface emitting lasers (arrangement of the laser beams emitted from the surface emitting laser array 70) may be arranged two-dimensionally (for example, in a matrix) in addition to the arrangement in one column. Is also possible.

  A collimating lens 72 and a half mirror 74 are sequentially arranged on the laser beam emission side of the surface emitting laser array 70. The laser beam emitted from the surface emitting laser array 70 is made into a substantially parallel light beam by the collimator lens 72 and then incident on the half mirror 74, and a part thereof is separated and reflected by the half mirror 74. A lens 76 and a light amount sensor 78 are sequentially arranged on the laser beam reflecting side of the half mirror 74, and a part of the laser beam separated and reflected from the main laser beam (laser beam used for exposure) by the half mirror 74 is The light passes through the lens 76 and enters the light quantity sensor 78, and the light quantity sensor 78 detects the light quantity.

  In addition, since the surface emitting laser does not emit a laser beam from the side opposite to the side from which the laser beam used for exposure is emitted (in the case of an edge emitting laser, it is emitted from both sides). Therefore, it is necessary to separate a part of the laser beam used for exposure as described above and use it for light quantity detection.

  On the main laser beam emission side of the half mirror 74, an aperture 80, a cylinder lens 82 having power only in the sub-scanning direction, and a folding mirror 84 are arranged in this order, and the main laser beam emitted from the half mirror 74 is the aperture 80. Is then refracted by the cylinder lens 82 so as to form an image in the shape of a long line in the main scanning direction in the vicinity of the reflecting surface of the rotary polygonal mirror 86 and reflected by the folding mirror 84 to the rotary polygonal mirror 86 side. The aperture 80 is desirably disposed in the vicinity of the focal position of the collimating lens 72 in order to uniformly shape a plurality of laser beams.

  The rotating polygonal mirror 86 is rotated in the direction of arrow C in FIG. 9 when a driving force of a motor (not shown) is transmitted, and deflects and reflects the incident laser beam reflected by the folding mirror 84 along the main scanning direction. . Fθ lenses 88 and 90 having power only in the main scanning direction are arranged on the laser beam emission side of the rotary polygonal mirror 86, and the laser beam deflected and reflected by the rotary polygonal mirror 86 is transmitted to the electrophotographic photosensitive member 1. It is refracted by the Fθ lenses 88 and 90 so that it moves on the outer peripheral surface at a substantially constant speed and the imaging position in the main scanning direction coincides with the outer peripheral surface of the electrophotographic photosensitive member 1.

  Cylinder mirrors 92 and 94 having power only in the sub-scanning direction are sequentially arranged on the laser beam emission side of the Fθ lenses 88 and 90, and the laser beam transmitted through the Fθ lenses 88 and 90 is connected in the sub-scanning direction. The image position is reflected by the cylinder mirrors 92 and 94 so as to coincide with the outer peripheral surface of the electrophotographic photosensitive member 1 and is irradiated on the outer peripheral surface of the photosensitive drum 1. The cylinder mirrors 92 and 94 also have a surface tilt correction function that conjugates the outer peripheral surface of the rotary polygon mirror 86 and the electrophotographic photosensitive member 1 in the sub-scanning direction.

  A pickup mirror 96 is disposed on the laser beam emission side of the cylinder mirror 92 at a position corresponding to an end portion (SOS: Start Of Scan) of the scanning range of the laser beam. A beam position detection sensor 98 is disposed on the laser beam emission side. When the laser beam emitted from the surface emitting laser array 70 reflects the incident beam in the direction corresponding to the SOS, the reflecting surface of the rotary polygonal mirror 86 reflects the laser beam. Then, the light is reflected by the pickup mirror 96 and enters the beam position detection sensor 98 (see also the imaginary line in FIG. 10).

  The signal output from the beam position detection sensor 98 is modulated each time when an electrostatic latent image is formed by modulating a laser beam scanned on the outer peripheral surface of the electrophotographic photosensitive member 1 as the rotary polygon mirror 86 rotates. This is used to synchronize the modulation start timing in the main scanning.

  In the exposure apparatus 30, the collimating lens 72, the cylinder lens 82, and the two cylinder mirrors 92 and 94 are arranged so as to be afocal in the sub-scanning direction. This is to suppress the difference in the scanning line curvature (BOW) of the plurality of laser beams and the variation in the scanning line interval due to the plurality of laser beams.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

<Production of electrophotographic photoreceptor>
(Photoreceptor-1)
First, an organic zirconium compound (tributoxyacetylacetonatozirconium [(C ₅ H ₇ O ₂ ) Zr (OC ₄ H ₉ ) ₃ , “Orgaxic ZC540”] on a cylindrical aluminum substrate subjected to honing treatment, Matsumoto Pharmaceutical Co., Ltd.]) 100 parts by mass, silane compound (trade name “A1100”, Nihon Unicar Co., Ltd.) 10 parts by mass, polyvinyl butyral (trade name “ESREC BM-S”, Sekisui Chemical Co., Ltd.) 3 parts by mass, isopropanol An undercoat layer forming coating solution obtained by stirring and mixing 380 parts by mass and butanol 200 parts by mass is applied by a dip coating method, and is heated and dried at 150 ° C. for 10 minutes to form an undercoat layer having a thickness of 0.17 μm. Formed.

  Next, 1 part by mass of 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 mixed with 1 part by weight of polyvinyl butyral (ESREC BM-S, manufactured by Sekisui Chemical Co., Ltd.) and 100 parts by weight of n-butyl acetate, and this is dispersed with a glass bead for 1 hour with a paint shaker to apply for a charge generation layer. A liquid was prepared. 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 benzidine compound represented by the following formula (CT-1) and a polymer compound having a repeating unit represented by the following formula (B-1) (viscosity average molecular weight: 39,000) 5 parts by mass was dissolved in 25 parts by mass of chlorobenzene to prepare a coating solution for charge transport layer. The obtained coating solution was applied onto the charge generation layer by a dip coating method, and heated at 130 ° C. for 40 minutes to form a charge transport layer having a thickness of 20 μm.

Next, 3 parts by mass of the compound represented by the formula (I-1), 0.5 part by mass of Me (MeO) ₂ —Si— (CH ₂ ) ₄ —Si—Me (OMe) ₂ , and hexamethyl 0.5 part by mass of cyclotrisiloxane was dissolved in 5 parts by mass of butyl alcohol. To this solution, 0.3 part by mass of an ion exchange resin (Amberlyst 15E, manufactured by Rohm and Haas) was added, and the protective group was exchanged for 5 hours by stirring at room temperature.

Thereafter, 8 parts by mass of n-butanol and 0.3 parts by mass of distilled water were added to this solution, followed by hydrolysis for 15 minutes. 0.1 parts by mass of aluminum trisacetylacetonate (Al (aqaq) ₃ ), 0.1 parts by mass of acetylacetone, 3,5-di-t with respect to the solution obtained by filtering and separating the ion exchange resin from the hydrolyzed product -0.4 parts by mass of butyl-4-hydroxytoluene (BHT), 1 part by mass of “Marcalinker CHM” (trade name, manufactured by Maruzen Petroleum Co., Ltd.) as a polyvinyl phenol resin and “PR-51206” as a resol type phenol resin 3 parts by mass (trade name, manufactured by Sumitomo Bakelite Co., Ltd.) was added to obtain a coating solution for forming a protective layer. This coating solution was applied on the charge transport layer by a ring-type dip coating method and air-dried at room temperature for 5 minutes. Thereafter, it was cured by heat treatment at 150 ° C. for 1 hour to form a protective layer having a film thickness of about 3 μm to obtain an electrophotographic photosensitive member. This electrophotographic photosensitive member was designated as “photosensitive member-1”.

(Photoreceptor-2)
JIS H4080 prepared drawn tube made of Material Symbol A3003 aluminum alloy, was 0.6μm the surface roughness _{R Z} is polished by centerless grinding apparatus. Next, a degreasing treatment, a 1 minute etching treatment with a 2% by mass sodium hydroxide solution, a neutralization treatment, and a pure water cleaning were performed in this order on the outer peripheral surface of the drawing tube. Next, as an anodizing treatment step, an anodized film (current density 1.0 A / dm ² ) was formed on the cylinder surface with a 10 mass% sulfuric acid solution. After washing with water, sealing was performed by dipping in a 1% by mass nickel acetate solution at 80 ° C. for 25 minutes. Further, pure water cleaning and drying treatment were performed. In this manner, an anodic oxide film having a thickness of about 7.5 μm was formed on the outer peripheral surface of the extraction tube to obtain a conductive support.

  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 ° is obtained as polyvinyl butyral (ESREC BM-S, manufactured by Sekisui Chemical Co., Ltd.) 1 A coating solution for charge generation layer was prepared by mixing with 100 parts by mass of n-butyl acetate and dispersing with a glass bead for 1 hour with a paint shaker. The obtained coating solution was dip-coated on the subbing layer formed above, 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 mass parts of a benzidine compound represented by the following formula (CT-2) and a polymer compound having a repeating unit represented by the following formula (B-2) (viscosity average molecular weight: 50,000) 3 mass A part was dissolved in 20 parts by mass of chlorobenzene to prepare a coating solution for a charge transport layer. The obtained coating solution was applied onto the charge generation layer by a dip coating method, and heated at 130 ° C. for 45 minutes to form a charge transport layer having a thickness of 20 μm.

Next, 3 parts by mass of the compound represented by the formula (I-18), 0.7 part by mass of Me (MeO) ₂ —Si— (CH ₂ ) ₄ —Si—Me (OMe) ₂ , and hexamethyl 0.5 part by mass of cyclotrisiloxane was dissolved in 5 parts by mass of butyl alcohol. To this solution, 0.3 part by mass of an ion exchange resin (Amberlyst 15E, manufactured by Rohm and Haas) was added, and the protective group was exchanged for 5 hours by stirring at room temperature.

Thereafter, 8 parts by mass of n-butanol and 0.3 parts by mass of distilled water were added to this solution, followed by hydrolysis for 15 minutes. 0.1 parts by mass of aluminum trisacetylacetonate (Al (aqaq) ₃ ), 0.1 parts by mass of acetylacetone, 3,5-di-t with respect to the solution obtained by filtering and separating the ion exchange resin from the hydrolyzed product -0.4 parts by mass of butyl-4-hydroxytoluene (BHT), 1 part by mass of “Marcalinker CHM” (manufactured by Maruzen Petroleum Co., Ltd., trade name) as a polyvinylphenol resin and “PR-4804” as a resol type phenolic resin 3 parts by mass (trade name, manufactured by Gunei Chemical Co., Ltd.) was added to obtain a coating solution for forming a protective layer. This coating solution was applied on the charge transport layer by a ring-type dip coating method and air-dried at room temperature for 5 minutes. Thereafter, it was cured by heat treatment at 150 ° C. for 1 hour to form a protective layer having a film thickness of about 3 μm to obtain an electrophotographic photosensitive member. This electrophotographic photosensitive member was designated as “photosensitive member-2”.

(Photoreceptor-3)
100 parts by mass of zinc oxide (SMZ-017N: manufactured by Teica) and 500 parts by mass of toluene were stirred and mixed, and 2 parts by mass of a silane coupling agent (A1100: manufactured by Nihon Unicar) was added and stirred for 5 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 Si element strength was 1.8 × 10 ⁻⁴ of the zinc element strength.

  35 parts by mass of surface-treated zinc oxide, 15 parts by mass of blocked isocyanate (Sumijoule 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.) as a curing agent, and 6 parts by mass of butyral resin (BM-1, manufactured by Sekisui Chemical Co., Ltd.) And 44 parts by mass of methyl ethyl ketone were mixed and dispersed for 2 hours with a sand mill using 1 mmφ glass beads to obtain a dispersion. As a catalyst, 0.005 part by mass of dioctyltin dilaurate and 17 parts by mass of Tospearl 130 (manufactured by GE Toshiba Silicon Co., Ltd.) were added to the resulting dispersion to obtain a coating solution for forming an undercoat layer. 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 obtain an undercoat layer having a thickness of 20 μm. The surface roughness was measured using a surface roughness profile measuring device 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, and had an Rz value of 0.24.

  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 °, 28 1 part by weight of hydroxygallium phthalocyanine having a strong diffraction peak at 3 ° is mixed with 1 part by weight of polyvinyl butyral (Esreck BM-S, manufactured by Sekisui Chemical Co., Ltd.) and 100 parts by weight of n-butyl acetate, and this is mixed with glass beads. A coating solution for a charge generation layer was prepared by dispersing for 2 hours with a paint shaker. The obtained coating solution was dip-coated on a conductive support on which an undercoat layer 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, 2 parts by mass of a benzidine compound represented by the above formula (CT-1) and a polymer compound having a repeating unit represented by the following formula (B-1) (viscosity average molecular weight: 50,000) 2. 5 parts by mass was dissolved in 25 parts by mass of chlorobenzene to prepare a coating solution for charge transport layer. The obtained coating solution was applied onto the charge generation layer by a dip coating method, and heated at 130 ° C. for 40 minutes to form a charge transport layer having a thickness of 20 μm.

  Next, 4 parts by mass of the compound represented by the formula (II-1), 1 part by mass of polyvinylphenol resin “Marcalinker CHM” (manufactured by Maruzen Petroleum Co., Ltd., trade name), resol type phenolic resin “PL-4804” ( A coating solution for forming a protective layer was prepared by dissolving 3 parts by mass of Gunei Chemical Co., Ltd., trade name) and 0.1 part by mass of “Nacure 4116” (trade name, manufactured by Enomoto Kasei Co., Ltd.) in 20 parts by mass of butanol. This coating solution was applied onto the charge transport layer by a dip coating method, cured by heat treatment at 140 ° C. for 40 minutes, and a protective layer having a thickness of 3 μm was formed to obtain an electrophotographic photoreceptor. This electrophotographic photosensitive member was designated as “photosensitive member-3”.

(Photoreceptor-4)
Except for using 4 parts by mass of the compound represented by the above formula (III-3) instead of 4 parts by mass of the compound represented by the above formula (II-1), An electrophotographic photoreceptor was obtained. This electrophotographic photosensitive member was designated as “photosensitive member-4”.

(Photoreceptor-5)
The charge transport layer was formed in the same manner as in the preparation of the photoreceptor-3.

  Next, 4 parts by mass of the compound represented by the above formula (IV-10), 1 part by mass of polyvinylphenol resin “Marcalinker MS-1” (trade name, manufactured by Maruzen Petroleum Corporation), resol type phenolic resin “PL-” 4804 "(manufactured by Gunei Chemical Co., Ltd., product name) and 3 parts by weight of" Nacure 4116 "(manufactured by Enomoto Kasei Co., Ltd., product name) are dissolved in 20 parts by mass of butanol to give a coating solution for forming a protective layer Prepared. This coating solution was applied onto the charge transport layer by a dip coating method, cured by heat treatment at 140 ° C. for 40 minutes, and a protective layer having a thickness of 3 μm was formed to obtain an electrophotographic photoreceptor. This electrophotographic photosensitive member was designated as “photosensitive member-5”.

(Photoreceptor-6)
The charge transport layer was formed in the same manner as in the preparation of the photoreceptor-3.

  Next, 4 parts by mass of the compound represented by the above formula (V-54), 1 part by mass of polyvinylphenol resin “Marcalinker MS-1” (trade name, manufactured by Maruzen Petroleum Corporation), resol type phenolic resin “PL-” 4804 "(manufactured by Gunei Chemical Co., Ltd., trade name) 2.5 parts by mass and" Nacure 4116 "(manufactured by Enomoto Kasei Co., Ltd., trade name) 0.1 parts by mass were dissolved in 20 parts by mass of butanol to apply a protective layer. A liquid was prepared. This coating solution was applied onto the charge transport layer by a dip coating method, cured by heat treatment at 140 ° C. for 40 minutes, and a protective layer having a thickness of 3 μm was formed to obtain an electrophotographic photoreceptor. This electrophotographic photosensitive member was designated as “photosensitive member-6”.

(Photoreceptor-7)
Except for using 4 parts by mass of the compound represented by the above formula (V-47) instead of 4 parts by mass of the compound represented by the above formula (V-54), the same as the production of the photoreceptor-6, An electrophotographic photoreceptor was obtained. This electrophotographic photosensitive member was designated as “photosensitive member-7”.

(Photoreceptor-8)
In the production of the photoreceptor-7, the same procedure as in the production of the photoreceptor-7 was performed except that 1 part by mass of the polyvinyl phenol resin “Marcalinker PHM-C” was used instead of 1 part by mass of “Marcalinker MS-1”. An electrophotographic photosensitive member was obtained. This electrophotographic photosensitive member was designated as “photosensitive member-8”.

(Photoreceptor-9)
Production of photoconductor-7 except that 1 part by mass of vinylphenol-styrene copolymer "Marcalinker CST-70" was used instead of 1 part by mass of "Marcalinker MS-1" in the production of photoconductor-7. In the same manner as above, an electrophotographic photoreceptor was obtained. This electrophotographic photosensitive member was designated as “photosensitive member-9”.

(Photoreceptor-10)
Photoreceptor except that 1 part by mass of novolak-type phenolic resin “CMK2400” (trade name, manufactured by Showa Polymer Co., Ltd.) was used instead of 1 part by mass of “Marcalinker MS-1” in the production of Photoreceptor-7 In the same manner as in Preparation No. 7, an electrophotographic photosensitive member was obtained. This electrophotographic photosensitive member was designated as “photosensitive member-10”.

(Photoreceptor-11)
An electrophotographic photoconductor was obtained in the same manner as the photoconductor-7 except that “Marcalinker MS-1” was not used in the production of the photoconductor-7. This electrophotographic photosensitive member was designated as “photosensitive member-11”.

<Filmability evaluation test>
The surfaces of the photoconductors 1 to 11 produced above (the surface of the protective layer) are observed with an optical microscope, and the number of protrusion failures on the surface (projections having a maximum width of about 50 μm or more) are counted. Based on the evaluation. The results are shown in Table 51.
A: No protrusion failure is found on the photoreceptor.
B: 50 or less protrusion failures are confirmed on the photoconductor (with regard to the possibility of long-term use, there is no problem if the evaluation of the surface of the photoconductor becomes A or B after a subsequent actual machine running test. To do).
C: Protrusion failure is confirmed to be more than 50 and 100 or less on the photosensitive member (there is a problem in actual use in a color machine with strict specifications).
D: More than 100 protrusion failures are confirmed on the photosensitive member (there is a problem in actual use).

(Examples 1 to 9, Reference Example 1 , Comparative Example 1)
As shown in Table 51, each of the photoconductors 1 to 11 produced as described above was mounted as a photoconductor for a black portion of a printer Docu Center C6501 manufactured by Fuji Xerox Co., thereby constituting an image forming apparatus.

<Real machine running test>
Using the image forming apparatuses of Examples 1 to 9, Reference Example 1 and Comparative Example 1 (printer Docu Center C6501 manufactured by Fuji Xerox Co., Ltd.), actual machine running tests were performed. That is, first, image formation of 10,000 sheets (image density of about 10%) is performed in an environment of high temperature and high humidity (28 ° C., 80% RH), and then, an environment of low temperature and low humidity (10 ° C., 25% RH). Below 10,000 images were formed (image density about 10%). Thereafter, evaluation of the surface of the photosensitive member, evaluation of image quality, evaluation of the amount of wear and cleaning property of the photosensitive member were performed based on the following methods. The results obtained are shown in Table 51.

<Evaluation of photoreceptor surface>
The surface of the electrophotographic photosensitive member (the surface of the protective layer) after the actual machine running test was observed with an optical microscope, and the number of surface stripe defects (process direction 1 mm, width 0.5 mm or more peeling) It counted and evaluated based on the following evaluation criteria.
A: No streak breakage failure is found on the photoreceptor.
B: Five or less streak-like peeling failures are confirmed on the photosensitive member (no problem in actual use).
C: A stripe-like peeling failure is confirmed to be more than 5 and 20 or less on the photosensitive member (there is a problem in actual use in a color machine having strict specifications).
D: More than 20 stripe-like peeling failures are confirmed on the photosensitive member (there is a problem in actual use).

<Evaluation of image quality>
After performing the above-mentioned actual machine running test, image formation was performed in an environment of high temperature and high humidity (28 ° C., 80% RH), and the image quality at that time (1 dot line oblique 45 ° fine line reproducibility and 30% halftone reproducibility) ) Was evaluated based on the following evaluation criteria.
A: No problem.
B: Slight thinning of thin line or slight halftone density abnormality is observed (no problem in actual use).
C: Thin line thinness or slight halftone density abnormality is observed (a color machine with strict specifications has a problem in actual use).
D: Partial disappearance of thin line or halftone density abnormality is observed (there is a problem in actual use).

<Evaluation of cleaning properties>
After performing the actual machine running test, one 100% density non-transferred image is output on A4 paper, and immediately after that, the image forming apparatus is forcibly stopped, the surface of the photoreceptor is visually observed, and the cleaning is poor. The degree of was evaluated based on the following evaluation criteria.
A: No problem.
B: Some cleaning defects are observed (no problem in actual use).
C: A cleaning defect is observed (there is a problem in actual use).

<Abrasion amount of photoconductor>
The film thickness of the photoconductor was measured before and after the actual machine running test, and the film thickness loss per 10,000 rotations of the photoconductor (nm / 10,000 rotations) was calculated.

  In the actual machine running test and the image quality evaluation, the exposure amount is -300V ± 10V for the 100% density portion on the surface of the photoconductor and -705V ± 10V for the white portion according to each photoconductor. It adjusted suitably so that it might become.

As shown in Table 51, it was confirmed that the photoreceptors 1 to 9 produced using the curable resin composition of the present invention had sufficiently small occurrence of protruding defects. Then, the image forming apparatus of the embodiment 1-9 having these photoreceptor 1-9, even in the case of performing long-term image forming peeling and cleaning failure of the photosensitive member surface is sufficiently suppressed confirmed. Furthermore, in the image forming apparatuses of Examples 1 to 9 , it was confirmed that the wear amount of the photosensitive member is sufficiently small, and the fine line reproducibility and the halftone reproducibility are well maintained over a long period of time. In addition, the photoconductors 1 to 9 produced by using a resol type phenolic resin and a polyvinylphenol resin together achieve a higher level of film formability, and the image forming apparatuses of Examples 1 to 9 including these photoconductors. Was confirmed to achieve higher image quality and longer life. Therefore, according to the present invention, it has been found that a high-quality image can be formed over a long period of time.

1 is a schematic cross-sectional view showing a preferred embodiment of an electrophotographic photoreceptor of the present invention. FIG. 6 is a schematic cross-sectional view showing another preferred embodiment of the electrophotographic photosensitive member of the present invention. FIG. 6 is a schematic cross-sectional view showing another preferred embodiment of the electrophotographic photosensitive member of the present invention. FIG. 6 is a schematic cross-sectional view showing another preferred embodiment of the electrophotographic photosensitive member of the present invention. FIG. 6 is a schematic cross-sectional view showing another preferred embodiment of the electrophotographic photosensitive member of the present invention. 1 is a schematic diagram showing a preferred embodiment of an image forming apparatus of the present invention. It is a schematic diagram which shows other suitable embodiment of the image forming apparatus of this invention. It is a schematic diagram which shows other suitable embodiment of the image forming apparatus of this invention. It is a schematic diagram which shows other suitable embodiment of the image forming apparatus of this invention. It is a schematic block diagram which shows an example of the exposure apparatus (optical scanning apparatus) provided with a surface emitting laser array as an exposure light source.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electrophotographic photosensitive member, 2 ... Conductive support body, 3 ... Photosensitive layer, 4 ... Undercoat layer, 5 ... Charge generation layer, 6 ... Charge transport layer, 7 ... Protective layer, 8 ... Single layer type photosensitive layer, 20 Process cartridge, 100, 110, 120, 130 Image forming apparatus.

Claims (7)

A curable resin composition used as a constituent material of an electrophotographic photoreceptor,
A curable resin composition comprising a thermosetting phenol resin and a polyvinyl phenol resin. The curable resin composition according to claim 1, wherein the thermosetting phenol resin is a resol type phenol resin. Conductive fine particles and / or curable resin composition according to claim 1 or 2, further comprising a charge transporting substance. Following general formula (I), (II), (III), any of the claims 1-3, characterized by further comprising one or more charge-transporting substance represented by (IV) or (V) The curable resin composition according to claim 1.
F [-D-Si (R ¹ ) _(3-a) Q _a ] _b (I)
[In the formula (I), 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, a substituted or unsubstituted alkyl group. Alternatively, a substituted or unsubstituted aryl group, Q is a hydrolyzable group, a is an integer of 1 to 3, and b is an integer of 1 to 4. ]
F [— (X ¹ ) _n1 R ² —Z ¹ H] _m1 (II)
[In Formula (II), F represents an organic group derived from a compound having a hole transporting ability, R ² represents an alkylene group, Z ¹ represents an oxygen atom, a sulfur atom, NH or COO, and X ¹ Represents an oxygen atom or a sulfur atom, m1 represents an integer of 1 to 4, and n1 represents 0 or 1. ]
_{^{F [- (X 2) n2}} - (R 3) n3 - (Z 2) n4 G] n5 (III)
[In Formula (III), F represents an organic group derived from a compound having a hole transporting ability, X ² represents an oxygen atom or a sulfur atom, R ³ represents an alkylene group, and Z ² represents an oxygen atom. , Sulfur atom, NH or COO, G represents an epoxy group, n2, n3 and n4 each independently represents 0 or 1, and n5 represents an integer of 1 to 4. ]

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

[In Formula (V), F represents an organic group derived from a compound having a hole transporting property, T represents a divalent group, R ⁸ represents a monovalent organic group, and m3 represents 0 or 1 N7 represents an integer of 1 to 4. ] An electrophotographic photoreceptor comprising a conductive support and a photosensitive layer provided on the conductive support,
An electrophotographic photoreceptor, wherein the photosensitive layer has a functional layer obtained by curing the curable resin composition according to any one of claims 1 to 4 . An electrophotographic photoreceptor according to claim 5 ;
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: An electrophotographic photoreceptor according to claim 5 ;
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: