JP2008134573A - Electrophotographic photoreceptor, process cartridge, image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor which excels in resistance to external light, hardly generates a ghost even after long-term repeated use, and allows high-quality image formation over a long period of time, and a process cartridge, an image forming apparatus and an image forming method using the same. <P>SOLUTION: The electrophotographic photoreceptor includes a conductive support and a photosensitive layer disposed on the conductive support, wherein the photosensitive layer has an outermost surface layer comprising a resin composition containing a phenolic resin and a charge transporting compound having a functional group capable of reacting with the phenolic resin on a side farthest from the conductive support, and the outermost surface layer further contains a compound which has an absorption maximum wavelength within a range of 350-480 nm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

  Electrophotographic photosensitive members are used in electrophotographic apparatuses such as copying machines and laser printers because they can achieve high speed and high printing quality. At present, as electrophotographic photoreceptors (hereinafter sometimes referred to as “photoreceptors”), organic photoreceptors using an organic photoconductive material are mainly used. In particular, the photosensitive layer is divided into a charge generation layer and a charge generation layer. Attention has been focused on a function-separated type photoconductor that can obtain excellent characteristics in terms of sensitivity, chargeability, repetitive stability thereof, and the like by separating it into a transport layer. As such a function-separated type photoconductor, those having various structures have been proposed and put into practical use, but have a structure in which an undercoat layer, a charge generation layer, and a charge transport layer are sequentially laminated on a conductive support. Things are common.

  By the way, in recent years, in the so-called xerographic image forming apparatus having a photoconductor, a charging unit, an exposure unit, a developing unit, a transfer unit, a fixing unit, etc., further speeding up due to technical progress of each member and system, Long life has been achieved. As a result, the demand for high-speed compatibility and high reliability of each subsystem is increasing. In particular, the electrophotographic photosensitive member used for image writing and the cleaner that cleans the electrophotographic photosensitive member are subject to a lot of stress due to mutual sliding, and are liable to cause image defects due to scratches, abrasion, chipping, etc. There is a strong demand for reliability and high reliability.

  Therefore, in order to suppress the occurrence of scratches and abrasion on the surface of the photoreceptor, an undercoat layer, a charge generation layer, and a charge transport layer are sequentially laminated on the conductive support, and then a highly durable surface protection is provided on the charge transport layer. A photoconductor having a structure in which layers are further laminated has been proposed. In addition, for the purpose of increasing the mechanical strength of the surface protective layer and further extending the life of the photoreceptor, a technique for forming the surface protective layer with a three-dimensionally crosslinked resin has also been proposed (for example, Patent Documents 1 to 3). reference).

  On the other hand, another problem has arisen due to the longer life of the photoreceptor. Normally, a photoconductor is used inside a copying machine or a laser printer in a light-shielded state. For example, when a paper jam occurs, the photoconductor is inevitably external light to deal with by opening the front cover of the device. Exposed to. Since the light intensity of the external light is stronger than the exposure intensity for image formation, the influence on the electrical characteristics of the photosensitive member is large even if the exposure is performed for a short time. In the case of a photoreceptor having a surface protective layer intended for long-term use, it is more difficult to maintain image quality because the chance of exposure to light increases.

  As a technique for suppressing deterioration of the photoreceptor due to light, for example, photoreceptors containing a light-absorbing compound in the photosensitive layer have been proposed (for example, Patent Documents 4 to 6).

JP-A-7-234534 Japanese Patent Laid-Open No. 11-38656 JP 2002-82469 A JP 2004-206109 A Japanese Patent No. 3689546 Japanese Patent Laid-Open No. 10-48856

  However, the photoreceptors described in Patent Documents 4 to 6 are improved in deterioration of electrical characteristics when exposed to light, but exposure history remains on the photoreceptor when used repeatedly for a long time, such as so-called “ghost”. Image quality defects may occur, and a high-quality image cannot be formed over a long period of time.

  Accordingly, the present invention has been made in view of the above-described problems of the prior art, and is excellent in resistance to external light and hardly generates ghosts even when used repeatedly for a long period of time. It is an object of the present invention to provide an electrophotographic photosensitive member that can be formed, a process cartridge, an image forming apparatus, and an image forming method using the same.

  In order to solve the above-mentioned problems, the present inventors have conducted intensive studies. As a result, the outermost layer is formed of a phenol resin, a charge transporting compound having a functional group capable of reacting with the phenol resin, and a specific light absorption property. It has been found that a photoreceptor formed from a resin composition containing a compound can suppress the generation of ghosts for a long period of time even when exposed to external light, and has completed the present invention.

  That is, the electrophotographic photosensitive member of the present invention includes a conductive support and a photosensitive layer provided on the conductive support, and the photosensitive layer is disposed on the side farthest from the conductive support with a phenol resin. A charge transporting compound having a functional group capable of reacting with the phenol resin, and an outermost surface layer made of a resin composition, the outermost surface layer having an absorption maximum wavelength in a range of 350 nm to 480 nm. It further has the compound which has.

  According to the electrophotographic photoreceptor of the present invention, the above-mentioned light is applied to the outermost surface layer composed of a crosslinked film formed from a resin composition containing a phenol resin and a charge transporting compound having a functional group capable of reacting with the phenol resin. By containing an absorptive compound, it is excellent in light resistance, can sufficiently suppress the generation of ghosts even when used repeatedly for a long period of time, and can form a high-quality image over a long period of time. .

  Although the reason why the electrophotographic photosensitive member of the present invention can sufficiently prevent the occurrence of ghost over a long period of time has not yet been completely elucidated, the present inventors speculate as follows. First, a light-absorbing compound having an absorption maximum wavelength within a range of 350 nm to 480 nm is contained in the outermost surface layer, thereby sufficiently absorbing light that affects the charge transporting material contained in the photosensitive layer. It is considered that the generation of charge trap sites due to the deterioration of the charge transporting material contained in the photoreceptor can be effectively prevented. In addition, the phenolic resin crosslinked film has a hydroxyl group (OH group) in its structure and is in a state where it is easy to trap charges. The above light-absorbing compound also functions to fill this charge trapping site. Therefore, it is considered that the occurrence of ghost is suppressed. On the other hand, a cross-linked film made of a phenolic resin and a charge transporting compound having a functional group capable of reacting with the phenolic resin has high gas barrier properties and high resistance to highly oxidizing gases such as discharge products. In addition, the deterioration of the light absorbing compound can be prevented for a long time. Thereby, it is thought that the effect | action by the light absorptive compound mentioned above can continue over a long period of time. Then, the cross-linked film made of a phenol resin and a charge transporting compound having a functional group capable of reacting with the phenol resin and the light absorbing compound work complementarily, thereby generating a ghost for a very long time than before. Presumed to have been prevented.

  In addition, a photoreceptor provided with a film formed by crosslinking a phenolic resin and a charge transporting compound having a functional group capable of reacting with the phenolic resin as an outermost layer has an extremely high image density in a portion exposed to external light. The electrophotographic photosensitive member according to the present invention has a problem that a phenomenon of so-called “white spots” (hereinafter sometimes referred to as “light white spots”) is likely to occur. Light white spots can also be prevented. In addition, although the clear reason that such an effect is show | played is not clear, the present inventors guess as follows.

  First, when a cross-linked film composed of a phenol resin and the above charge transporting compound is exposed to external light, the reason why light whitening is likely to occur is that the cross-linking point between the phenol resin and the charge transporting compound, that is, the binding site This is considered to be due to the fact that photocharge transfer occurs due to light absorption and a stable charge separation state occurs over a long period of time. It is presumed that white spots occur due to the accelerated resistance reduction in such charge separated portions. On the other hand, in the electrophotographic photosensitive member of the present invention, it is considered that the occurrence of light white spots is sufficiently prevented by the light absorbing compound effectively suppressing the light absorption at the binding site. .

  In addition, since the electrophotographic photosensitive member of the present invention has excellent mechanical strength, it is possible to prevent the occurrence of fogging due to stress during transfer when the film is reduced over a long period of time.

  Further, according to the electrophotographic photosensitive member of the present invention, since it is excellent in light resistance, it is easy to handle, and it is possible to eliminate the necessity of applying a special light shielding means to the mounted image forming apparatus. In addition, since the photoreceptor of the present invention can be used for a long time, it is preferably used not only as a cartridge type that is premised on replacement as in the prior art, but also as a so-called built-in type that is integrated into the main body of the image forming apparatus. Can do.

  In the electrophotographic photoreceptor of the present invention, the compound is preferably at least one of an azo compound, a quinone compound, a coumarin compound, and a benzotriazole compound. In this case, it is possible to more effectively prevent ghosts and white spots from occurring.

  In the electrophotographic photosensitive member of the present invention, it is preferable that the compound is soluble in alcohol.

  When producing an electrophotographic photosensitive member, a method is generally used in which a coating solution for forming each functional layer is coated on a substrate in order. For the formation of the outermost surface layer, a dip coating method using a coating solution containing an alcohol solvent is generally used. In such a case, the light-absorbing compound according to the present invention is soluble in alcohol, so that it can be uniformly dissolved in the coating solution and prevents the light-absorbing compound from being precipitated during film formation. it can. As a result, the effect of the light absorbing compound can be more effectively exhibited in the produced photoreceptor.

Further, from the viewpoint of achieving higher image quality and longer life at a higher level, the above charge transporting compounds are represented by the following general formulas (I), (II), (III), (IV), (V) and (V). A compound represented by any one of VI) is preferred.
_{^{F [- (X 1) n1}} R 1 -Z 1 H] m1 (I)
[In Formula (I), F represents an organic group derived from a compound having a hole transporting ability, R ¹ represents an alkylene group, Z ¹ represents an oxygen atom, a sulfur atom, NH or COO, and X ¹ Represents an oxygen atom or a sulfur atom, m1 represents an integer of 1 to 4, and n1 represents 0 or 1. ]
_{^{F [- (X 2) n2}} - (R 2) n3 - (Z 2) n4 G] n5 (II)
[In Formula (II), F represents an organic group derived from a compound having a hole transporting ability, X ² represents an oxygen atom or a sulfur atom, R ² represents an alkylene group, Z ² represents an oxygen atom, S represents a sulfur atom, NH or COO, G represents an epoxy group, n2, n3 and n4 each independently represents 0 or 1, and n5 represents an integer of 1 to 4. ]
F [—D—Si (R ³ ) _(3-a) Q _a ] _b (III)
[In Formula (III), F represents an organic group derived from a compound having a hole transporting ability, D represents a divalent group having flexibility, and R ³ represents a hydrogen atom, a substituted or unsubstituted group. An alkyl group or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, a represents an integer of 1 to 3, and b represents an integer of 1 to 4; ]

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

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

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

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

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

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

  The present invention also provides 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 is developed with toner to form a toner image. And at least one selected from the group consisting of a cleaning unit for removing toner remaining on the surface of the electrophotographic photosensitive member.

  According to the process cartridge of the present invention, a high-quality image can be stably obtained over a long period of time by using the electrophotographic photoreceptor of the present invention.

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

  According to the image forming apparatus of the present invention, a high-quality image can be stably obtained over a long period of time by using the electrophotographic photosensitive member of the present invention.

  The present invention also includes a charging step for charging the electrophotographic photosensitive member of the present invention, an exposure step for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image, and developing the electrostatic latent image with toner. Thus, there is provided an image forming method comprising: a developing step for forming a toner image; and a transfer step for transferring the toner image to a transfer medium.

  According to the image forming method of the present invention, a high-quality image can be stably obtained over a long period of time by using the electrophotographic photosensitive member of the present invention.

  According to the present invention, an electrophotographic photosensitive member that is excellent in resistance to external light and hardly generates ghosts even when used repeatedly for a long period of time, and that enables high-quality image formation over a long period of time, and the use thereof are used. A process cartridge, an image forming apparatus, and an image forming method 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>
FIG. 1 is a schematic sectional view showing a preferred embodiment of the electrophotographic photosensitive member of the present invention. An electrophotographic photoreceptor 1 shown in FIG. 1 includes a conductive support 2 and a function-separated type photosensitive layer 3 in which a charge generation layer and a charge transport layer are separately provided. 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 photoreceptor 1 shown in FIG. 1, the protective layer 7 is the outermost surface layer. And this outermost surface layer consists of a crosslinked film formed from a resin composition containing a phenol resin and a charge transporting compound having a functional group capable of reacting with the phenol resin, and has a light absorption property according to the present invention described later. Contains compounds.

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

  Examples of the conductive support 2 include a metal plate, a metal drum, a metal belt, or a conductive metal using a metal or an alloy such as aluminum, copper, zinc, stainless steel, chromium, nickel, molybdenum, vanadium, indium, gold, or platinum. Examples thereof include paper, plastic film, belt and the like coated, vapor-deposited, or laminated with a conductive polymer, a conductive compound such as indium oxide, or a metal or alloy such as aluminum, palladium, or gold.

  Moreover, in order to prevent the interference fringes produced when irradiating a laser beam, it is preferable that the surface of the electroconductive support body 2 is roughened. The degree of roughening is preferably 0.04 μm or more and 0.5 μm or less in terms of centerline average roughness Ra. If Ra is smaller than 0.04 μm, it becomes close to a mirror surface, so that the effect of preventing interference cannot be obtained. If Ra is larger than 0.5 μm, the image quality becomes coarse and is not suitable.

  As a method for roughening the surface of the conductive support 2, wet honing is performed by suspending an abrasive in water and spraying the support, or by pressing the support against a rotating grindstone and continuously Centerless grinding with grinding, anodization, etc. are preferred. A layer in which conductive or semiconductive powder is dispersed in a resin layer without roughening the support surface itself is formed on the support surface. A method of roughening with fine particles formed and 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 in the anodized film are sealed with pressurized water vapor or boiling water (a metal salt such as nickel may be added) by volume expansion due to a hydration reaction, and a sealing process is performed to change to a more stable hydrated oxide. .

  The thickness of the anodic oxide film is preferably 0.3 to 15 μm. When it is thinner than 0.3 μm, the barrier property against injection is poor and the effect is not sufficient. On the other hand, if it is thicker than 15 μm, the residual potential tends to increase due to repeated use.

  The treatment with an acidic treatment liquid comprising phosphoric acid, chromic acid and hydrofluoric acid can be performed as follows. The mixing ratio of phosphoric acid, chromic acid and hydrofluoric acid in the acidic treatment liquid is such that phosphoric acid is in the range of 10% by mass to 11% by mass, chromic acid is in the range of 3% by mass to 5% by mass, and hydrofluoric acid is 0%. The concentration of these acids is preferably in the range of 13.5% by mass to 18% by mass. The processing temperature is 42 ° C. or higher and 48 ° C. or lower, but by keeping the processing temperature high, a thicker film can be formed more quickly. The film thickness is preferably 0.3 μm or more and 15 μm or less. When it is thinner than 0.3 μm, the barrier property against injection is poor and the effect is not sufficient. On the other hand, if it is thicker than 15 μm, the residual potential tends to increase due to repeated use.

  The boehmite treatment can be performed by immersing in pure water of 90 ° C. or more and 100 ° C. or less for 5 minutes or more and 60 minutes or less, or by contacting with heated steam of 90 ° C. or more and 120 ° C. or less for 5 minutes or more and 60 minutes or less. The film thickness is preferably 0.1 μm or more and 5 μm or less. 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. Good.

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

  The undercoat layer 4 is provided as necessary. Particularly, when the conductive support 2 is subjected to an acidic solution treatment and a boehmite treatment, the conductive support 2 has insufficient defect concealing power. Therefore, it is preferable to form the undercoat layer 4.

  Materials used for the undercoat layer 4 include zirconium chelate compounds, zirconium alkoxide compounds, organic zirconium compounds such as zirconium coupling agents, titanium chelate compounds, titanium alkoxide compounds, organic titanium compounds such as titanate coupling agents, and aluminum chelate compounds. In addition to organoaluminum compounds such as aluminum coupling agents, antimony alkoxide compounds, germanium alkoxide compounds, indium alkoxide compounds, indium chelate compounds, manganese alkoxide compounds, manganese chelate compounds, tin alkoxide compounds, tin chelate compounds, aluminum silicon alkoxide compounds, Aluminum titanium alkoxide compound, aluminum zirconium alkoxide compound And organic metal compounds such as, in particular an organic zirconium compound, an organic titanyl compound, since the organic aluminum compound to residual potential indicates a satisfactory electrophotographic properties lower, are preferably used.

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

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

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

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

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

  The charge generation layer 5 includes a charge generation material and a binder resin. Charge generation materials include azo pigments such as bisazo pigments and trisazo pigments, condensed aromatic pigments such as dibromoanthanthrone, organic pigments such as perylene pigments, pyrrolopyrrole pigments, and phthalocyanine pigments, and inorganic pigments such as trigonal selenium and zinc oxide. Known pigments and the like can be used, but metal and metal-free phthalocyanine pigments, trigonal selenium, dibromoanthanthrone, etc. are preferred particularly when exposure light having a wavelength of 380 nm to 500 nm is used for image formation. . 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.

  The binder resin for the charge generation layer 5 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. You can also. 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 alone or in admixture of two or more. 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.

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

  The charge transport layer 6 includes a charge transport material and a binder resin, or includes 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 formula ^{(a-1), R 34} is a methyl group, k10 represents an integer of 0 to 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 represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, and Ar represents a substituted or unsubstituted aryl group.

In the above formula (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 Represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, and Ar ′ represents a substituted or unsubstituted aryl group. 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. The polymer charge transport material alone can be used as a constituent material of the charge generation layer 6, but it may be formed by mixing with the binder resin.

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

  Further, for the purpose of preventing deterioration of the photoreceptor due to ozone, oxidizing gas, light, or heat generated in the copying machine, an antioxidant, a light stabilizer, Additives such as heat stabilizers 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, and reducing fatigue during repeated use.

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

  The protective layer 7 is composed of a crosslinked film formed from a curable resin composition containing a phenol resin and a charge transporting organic compound having a functional group capable of reacting with the phenol resin, and has a light absorption property according to the present invention described later. Further comprising a compound. First, the curable resin composition for forming a crosslinked film will be described.

  Examples of the phenol resin include resorcin, bisphenol, substituted phenols containing one hydroxyl group such as phenol, cresol, xylenol, paraalkylphenol, paraphenylphenol, substituted phenols containing two hydroxyl groups such as catechol, resorcinol, hydroquinone, and bisphenol. A, monomethylolphenols, dimethylolphenols obtained by reacting a compound having a phenol structure such as bisphenols such as bisphenol Z, biphenols, etc. with formaldehyde, paraformaldehyde, etc. in the presence of an acid or alkali catalyst, Examples thereof include monomers of trimethylolphenols, and mixtures thereof, or oligomers thereof, and mixtures of monomers and oligomers. Among these, a relatively large molecule having about 2 to 20 repeating molecular structural units is an oligomer, and a smaller molecule is a monomer.

As the acid catalyst used at this time, sulfuric acid, paratoluenesulfonic acid, phenolsulfonic acid, phosphoric acid and the like are used. Further, as the alkali catalyst, hydroxides or oxides of alkali metals and alkaline earth metals such as NaOH, KOH, Ca (OH) ₂ , Mg (OH) ₂ , Ba (OH) ₂ , CaO, MgO, or the like, or Amine-based catalysts and acetates such as zinc acetate and sodium acetate are used.

  Examples of the amine catalyst include, but are not limited to, ammonia, hexamethylenetetramine, trimethylamine, triethylamine, and triethanolamine.

  When a basic catalyst is used, carriers may be significantly trapped by the remaining catalyst, which may deteriorate electrophotographic characteristics. In such a case, it is preferable to inactivate or remove by distilling off under reduced pressure, neutralizing with an acid, or contacting with an adsorbent such as silica gel or an ion exchange resin.

  Moreover, a commercial item can be used for a phenol resin, for example, "PR-51206", "PR-50404" (above, Sumitomo Bakelite company make, brand name), "PL-2207", "PL-2211", “PL-2215”, “PL-2818”, “PL-4852” (product name, manufactured by Gunei Chemical Co., Ltd.) and “CKM-2400” (product name, Showa Polymer Co., Ltd.) are commercially available. Are available.

  The curable resin composition for forming the protective layer 7 may contain a curing catalyst in addition to the phenol resin. In this case, the catalyst to be used is not particularly limited as long as it does not adversely affect the electrical characteristics and the like.

  Examples of the charge transporting organic compound having a functional group capable of reacting with a phenol resin include compounds represented by the following general formula (I), (II), (III), (IV), (V) or (VI). It is preferable because it is excellent in film formability, mechanical strength and stability.

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

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

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

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

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

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

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

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

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

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

［式（ＶＩＩ）中、Ａｒ^１、Ａｒ^２、Ａｒ^３及びＡｒ^４はそれぞれ独立に置換又は未置換のアリール基を示し、Ａｒ^５は置換若しくは未置換のアリール基又はアリーレン基を示し、且つＡｒ^１〜Ａｒ^５のうち１〜４個は、上記一般式（Ｉ）で表わされる化合物における下記一般式（ＶＩＩＩ）で示される部位、上記一般式（ＩＩ）で表わされる化合物における下記一般式（ＩＸ）で示される部位、上記一般式（ＩＩＩ）で表わされる化合物における下記一般式（Ｘ）で示される部位、上記一般式（ＩＶ）で表わされる化合物における下記一般式（ＸＩ）で示される部位、上記一般式（Ｖ）で表される化合物における下記一般式（ＸＩＩ）で表される部位、又は上記一般式（ＶＩ）で表される化合物における下記一般式（ＸＩＩＩ）と結合するための結合手を有し、ｋは０又は１を示す。］

[In formula (VII), Ar ¹ , Ar ² , Ar ³ and Ar ⁴ each independently represent a substituted or unsubstituted aryl group, Ar ⁵ represents a substituted or unsubstituted aryl group or an arylene group, and Ar ^{1 to} 4 of ^{1 to} Ar ⁵ are a moiety represented by the following general formula (VIII) in the compound represented by the above general formula (I), a general formula (IX) in the compound represented by the above general formula (II), ), A site represented by the following general formula (X) in the compound represented by the above general formula (III), a site represented by the following general formula (XI) in the compound represented by the above general formula (IV), In the compound represented by the above general formula (V), a site represented by the following general formula (XII) or the following general formula (XIII) in the compound represented by the above general formula (VI) It has a bond for combining, and k represents 0 or 1. ]

_{^{- (X 1) n1 R 1}} -Z 1 H (VIII)
_{^{- (X 2) n2 - (}} R 2) n3 - (Z 2) n4 G (IX)
-D-Si (R ³ ) _(3-a) Q _a (X)

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

The formula (1) ~ ^{(7), R 11} is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, alkoxy group having 1 to 4 carbon atoms, phenyl which is substituted by them A group or an unsubstituted phenyl group, or an aralkyl group having 7 to 10 carbon atoms, wherein R ^{12 to} R ¹⁴ 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 the general formulas (VIII) to (XIII) 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 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, 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 the above formulas (10) to (17), R ¹⁷ and R ¹⁸ 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 represent an integer of 1 to 10, and t Represents an integer of 1 to 3, respectively.

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

In addition, the specific structure of Ar ⁵ in the general formula (VII) 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-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.

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

Specific examples of the compound represented by the general formula (III) include the following compounds (III-1) to (III-61). The following compounds (III-1) to (III-61) are 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 (IV) include the following compounds (IV-1) to (IV-40). In the following table, Me or a bond is described but a substituent is not described, a methyl group, Et represents an ethyl group.

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

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

  The above-described charge transporting organic compound is preferably compatible with the phenol resin.

  In addition, a compound represented by the following general formula (XIV) 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 (XIV)
[In the above formula (XIV), R ⁵⁰ represents a hydrogen atom, an alkyl group or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, and c represents an integer of 1 to 4. ]

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

  Moreover, in order to raise the intensity | strength of the protective layer 7, the compound which has a 2 or more silicon atom as shown to the following general formula (XV) is used for the curable resin composition for forming the protective layer 7 Is also preferable.

B- (Si (R ⁵¹ ) _(3-d) Q _d ) ₂ (XV)
[In the above formula (XI), B represents a divalent organic group, R ⁵¹ represents a hydrogen atom, an alkyl group or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, and d represents an integer of 1 to 3. Indicates. ]

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

  Furthermore, various resins can be added for the purpose 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 has been 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 molecular weight of the resin is preferably from 2,000 to 100,000, and more preferably from 5,000 to 50,000. If the molecular weight is less than 2000, the desired effect tends not to be obtained. If the molecular weight is more than 100000, the solubility tends to be low and the addition amount is limited, or the film formation tends to be poor during coating. The addition amount is preferably 1% by mass to 40% by mass, more preferably 1% by mass to 30% by mass, and most preferably 5% by mass 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 prolong pot life and control film properties, it is preferable to contain a cyclic compound having a repeating structural unit represented by the following general formula (XVI) or a derivative thereof.

［上記式（ＸＶＩ）中、Ａ^１及びＡ^２は、それぞれ独立に一価の有機基を示す。］

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

  Examples of the cyclic compound having the repeating structural unit represented by the general formula (XVI) 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 has a volume average particle diameter of preferably 1 nm or more and 100 nm or less, more preferably 10 nm or more and 30 nm or less, and an acidic or alkaline aqueous dispersion, or an organic material such as alcohol, ketone or ester. What was chosen from what was disperse | distributed in the solvent and generally marketed 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 mass% to 50 mass%, more preferably in the range of 0.1 mass% to 30 mass%.

  The silicone fine particles used as the silicon atom-containing fine particles are spherical and have a volume average particle diameter of preferably 1 nm to 500 nm, more preferably 10 nm to 100 nm, and the silicone resin particles, the silicone rubber particles, and the silicone surface-treated silica particles. Those selected and generally commercially available 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% by mass to 30% by mass, more preferably 0.5%, based on the total solid content in the curable resin composition. The range is from 10% to 10% by mass.

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.

  Silicone oils other than polyether-modified silicone oils can also be added to control the antifouling substance adhesion, lubricity, hardness and the like on the surface of the electrophotographic photosensitive member. Examples of the silicone oil include silicone oils such as dimethylpolysiloxane, diphenylpolysiloxane, and phenylmethylsiloxane, amino-modified polysiloxane, epoxy-modified polysiloxane, carboxyl-modified polysiloxane, carbinol-modified polysiloxane, methacryl-modified polysiloxane, and mercapto. Examples 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, and antioxidant. 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, hindered phenols include “Sumilizer BHT-R”, “Sumilizer MDP-S”, “Sumilizer BBM-S”, “Sumizer WX-R”, “Sumizer NW”, “Sumizer BP-76”, “ Sumilizer BP-101 "," Sumilizer GA-80 "," Sumilizer GM "," Sumilizer GS "or more manufactured by Sumitomo Chemical Co., Ltd.," IRGANOX1010 "," IRGANOX1035 "," IRGANOX1076 "," IRGANOX1098 "," IRGANOX1098 "," 114 " ”,“ IRGANOX1222 ”,“ IRGANOX1330 ”,“ IRGANOX1425WL ”,“ IRGANOX1 20L "," IRGANOX 245 "," IRGANOX 259 "," IRGANOX 3114 "," IRGANOX 3790 "," IRGANOX 5057 "," IRGANOX 565 "or more, manufactured by Ciba Specialty Chemicals," ADK STAB AO-20 "," ADK STAB AO-30 "," ADEKA STAB " "AO-40", "ADK STAB AO-50", "ADK STAB AO-60", "ADK STAB AO-70", "ADK STAB AO-80", "ADK STAB AO-330" or more manufactured by Asahi Denka. As the hindered amine system, “Sanol LS2626”, “Sanol LS765”, “Sanol LS770”, “Sanol LS744” or more manufactured by Sankyo Lifetech Co., Ltd. "Mark LA57", "Mark LA67", "Mark LA62", "Mark LA68", "Mark LA63" or more manufactured by Asahi Denka, "Sumilyzer TPS" or more manufactured by Sumitomo Chemical Co., Ltd. As a phosphite system manufactured by Sumitomo Chemical Co., Ltd., "Mark 2112", "Mark PEP 8", "Mark PEP 24G", "Mark PEP 36", "Mark 329K", "Mark HP 10" or more Asahi Denka products, especially hindered phenol, hindert Min antioxidants are preferred. 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.

  Moreover, a catalyst can be added at the time of the curable resin composition for forming the protective layer 7, or its preparation. 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 the solid catalyst insoluble in the system include Amberlite 15, Amberlite 200C, Amberlyst 15E (above, manufactured by Rohm and Haas); Dowex MWC-1-H, Dowex 88, Dowex HCR- W2 (above, manufactured by Dow Chemical Co.); Lebatit SPC-108, Lebatit SPC-118 (above, manufactured by Bayer); Diaion RCP-150H (manufactured by Mitsubishi Kasei); Sumikaion KC-470, Duolite C26-C , Duolite C-433, Duolite-464 (manufactured by Sumitomo Chemical Co., Ltd.); Cation exchange resins such as Nafion-H (manufactured by DuPont); Amberlite IRA-400, Amberlite IRA-45 (above, Anion exchange resin such as Rohm &Haas); Zr (O ₃ PCH ₂₎ 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 charge transporting organic compound having the reactive functional group, other additives, water, solvent and the like.

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

  The reaction temperature and reaction time are appropriately selected according to the type and amount of the raw material compound or solid catalyst, but the reaction temperature is usually from 0 ° C. to 100 ° C., preferably from 10 ° C. to 70 ° C., more preferably Is from 15 ° C. to 50 ° C., and the reaction time is preferably from 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, 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 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the charge transporting organic compound having the reactive functional group, and 0.3 Particularly preferred is from 10 to 10 parts by weight.

  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 (XVII) in addition to the above.

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

[In the above formula (XVII), 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 (XVII) is preferably used, and those in which R ⁵¹ and R ⁵² in the above general formula (XVII) are the same 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.

  Next, the light absorbing compound according to the present invention contained in the protective layer 7 will be described.

  The light absorbing compound contained in the protective layer 7 has an absorption maximum wavelength in the range of 350 nm or more and 480 nm or less.

  The light absorbing compound can be contained in the protective layer 7 by being contained in the curable resin composition for forming the protective layer 7 described above.

  Whether or not the light-absorbing compound has an absorption maximum wavelength in the range of 350 nm or more and 480 nm or less can be confirmed with an ultraviolet-visible spectrophotometer. Specifically, the light-absorbing compound is dissolved in ethanol at a concentration such that the maximum absorbance of the solution in the range of 300 nm to 550 nm is in the range of 0.7 to 1.3, and a quartz solution cell (optical path direction cell) is obtained. It can be confirmed using a length of 10 mm).

  Examples of the light-absorbing compound used in the present invention include C.I. I. Solvent Yellow, C.I. I. Solvent Orange, C.I. I. Solvent Red, C.I. I. Disperse Yellow, C.I. I. Disperse Orange, C.I. I. In addition to dye compounds such as Disperse Red, various compounds such as azo compounds and quinone compounds that satisfy the above conditions can be used. Among these, an azo compound, a quinone compound, a coumarin compound, and a benzotriazole compound are particularly preferable because they can effectively suppress ghosts and white spots. These compounds may be used individually by 1 type, and may use 2 or more types together.

  In addition, the light absorbing compound used in the present invention is preferably from the viewpoint of preventing light absorption considered to occur at a crosslinking point between the phenol resin and a charge transporting compound having a functional group capable of reacting with the phenol resin. It is preferable to have an absorption maximum wavelength within a range of 350 nm to 460 nm, more preferably within a range of 370 nm to 460 nm.

  In addition, the production of an electrophotographic photoreceptor generally employs a method of coating each base material with a coating solution for forming each functional layer. The light absorbing compound used in the present invention is contained in such a coating solution. In addition, it is preferable that the resin composition is excellent in solubility in the coating solution. If the light-absorbing compound can be uniformly dissolved in the coating solution, the light-absorbing compound can be prevented from precipitating during film formation, and the light absorbing effect of the light-absorbing compound can be exhibited more effectively on the photoreceptor. Can do.

  In addition, in order to apply the outermost surface layer by the dip coating method generally used in the production of an electrophotographic photosensitive member, an alcohol-based solvent is often used preferably, and thus the light-absorbing compound used in the present invention Is preferably a compound soluble in alcohol. Furthermore, the light-absorbing compound used in the present invention is preferably one that can be dissolved in an amount of 0.2 parts by mass or more in 100 parts by mass of an alcohol having 4 or less carbon atoms. Examples of the alcohol having 4 or less carbon atoms include methanol, ethanol, propanol and butanol, and among these, methanol and ethanol are more preferable.

  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, if necessary, alcohols such as methanol, ethanol, propanol and butanol; ketones such as acetone and methyl ethyl ketone; tetrahydrofuran, diethyl ether, It can carry out using solvents, such as ethers, such as a dioxane. In order to apply the dip coating method generally used for the production of an electrophotographic photosensitive member, an alcohol solvent or a ketone solvent, or a mixed solvent thereof is preferable. Such solvents can be used singly or in combination of two or more, but preferably have a boiling point of 100 ° C. or lower. The amount of the solvent used can be arbitrarily set, but if the amount of the solvent is too small, the charge transporting organic compound having the reactive functional group is likely to be precipitated, and therefore 1 mass of the charge transporting organic compound having the reactive functional group. 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 parts.

  Further, the content of the light absorbing compound according to the present invention is preferably 0.1 parts by mass or more and 50 parts by mass or less, and 0.2 parts by mass or more and 40 parts by mass with respect to 100 parts by mass of the charge transporting compound. The following is more preferable. When the content of the light-absorbing compound is less than 0.1 parts by mass, it is difficult to obtain a sufficient effect. On the other hand, when the content is more than 50 parts by mass, the electrical characteristics of the photoreceptor tend to deteriorate.

  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 higher from the viewpoint of mechanical strength and chemical stability of the protective layer 7 to be formed. Preferably it is 80 degreeC or more and 200 degrees C or less, Reaction time becomes like this. Preferably it is 10 minutes or more and 5 hours or less. 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 on the charge generation layer 6, the application method is blade coating method, Meyer 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 μm or more and 15 μm or less, more preferably 1 μm or more and 10 μm or less, and further preferably 1 μm or more and 5 μm or less.

  The electrophotographic photosensitive member of the present invention is not limited to the above embodiment. For example, in the electrophotographic photosensitive member of the present invention, the undercoat layer 4 is not necessarily provided.

  The electrophotographic photoreceptor shown in FIG. 1 includes a protective layer 7 made of a crosslinked film of a curable resin composition containing a phenol resin and a charge transporting compound having a functional group capable of reacting with the phenol resin. However, since the curable resin composition contains a charge transporting organic compound having a reactive functional group, the resulting cured product has excellent mechanical strength and sufficient photoelectric characteristics. It can be used as it is as a charge transport layer of a multilayer photoreceptor. An example of such an electrophotographic photoreceptor is shown in FIG. The electrophotographic photoreceptor 1 shown in FIG. 2 has a structure in which an undercoat layer 4, a charge generation layer 5 and a charge transport layer 6 are sequentially laminated on a conductive support 2, and the charge transport layer 6 is composed of phenol resin and It is a surface layer composed of a crosslinked film of a resin composition containing a charge transporting compound having a functional group capable of reacting with the phenol resin. The conductive support 2, the undercoat layer 4 and the charge generation layer 5 are the same as those in the electrophotographic photosensitive member shown in FIG. 1 (hereinafter the same).

  Further, the order of stacking the charge generation layer 5 and the charge transport layer 6 may be reversed from the case of the above embodiment. An example of such an electrophotographic photoreceptor is shown in FIG. The electrophotographic photoreceptor 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. Is the outermost surface layer comprising a crosslinked film of a resin composition containing a phenol resin and a charge transporting compound having a functional group capable of reacting with the phenol resin.

  The electrophotographic photosensitive member shown in FIG. 1 is a function-separated type photosensitive member, but the electrophotographic photosensitive member of the present invention includes a layer containing both a charge generating substance and a charge transporting substance (charge generating / charge transporting layer). ) May be provided. Examples of electrophotographic photoreceptors having a single layer type photosensitive layer are shown in FIGS.

  The electrophotographic photoreceptor 1 shown in FIG. 4 has a structure in which an undercoat layer 4 and a charge generation / charge transport layer 8 are sequentially laminated on a conductive support 2. It is a surface layer. The charge generation / charge transport layer 8 is formed on the resin composition containing a phenol resin and a charge transport compound having a functional group capable of reacting with the phenol resin, the light absorbing compound, the charge generation material, and the charge transport material ( Preferably, a compound having a reactive functional group) and, if necessary, a coating solution containing a binder resin other than a phenol resin and other additives can be used. The charge generation material is the same as that used for the charge generation layer in the function-separated photosensitive layer, and the binder resin other than the phenol resin is polyvinyl butyral resin, polyvinyl formal resin, and a part of butyral is formal or acetate. Polyvinyl acetal resins such as partially acetalized polyvinyl acetal resins modified with acetal or the like (for example, ESREC B, K, etc. manufactured by Sekisui Chemical Co., Ltd.), polyamide resins, cellulose resins and the like can be used. The content of the charge generation material in the charge generation / charge transport layer 8 is preferably 10% by mass or more and 85% by mass or less, more preferably 20% by mass or more and 50% or less, based on the total solid content in the charge generation / charge transport layer 8. It is below mass%. A charge transport material or a polymer charge transport material may be added to the charge generation / charge transport layer 8 for the purpose of improving photoelectric characteristics. The amount added is preferably 5% by mass or more and 50% by mass or less based on the total solid content in the charge generation / charge transport 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 charge generation / charge transport layer 8 is preferably about 5 μm to 50 μm, and more preferably 10 μm to 40 μm.

  The electrophotographic photoreceptor 1 shown in FIG. 5 has a structure in which an undercoat layer 4, a charge generation / charge transport layer 8 and a protective layer 7 are sequentially laminated on a conductive support 2. The protective layer 7 Is the outermost surface layer comprising a crosslinked film of a resin composition containing a phenol resin and a charge transporting compound having a functional group capable of reacting with the phenol resin.

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

  FIG. 6 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of the image forming apparatus of the present invention. An image forming apparatus 200 shown in FIG. 6 includes an electrophotographic photosensitive member 100, a non-contact charging unit 18 for charging the electrophotographic photosensitive member 100, a power source 19 connected to the charging unit 18, and a charging unit 18. An exposure unit 20 that exposes the charged electrophotographic photosensitive member 100 to form an electrostatic latent image, a developing unit 21 that develops the formed electrostatic latent image with toner to form a toner image, and The image forming apparatus includes a transfer unit 22 for transferring from the photographic photoreceptor 100 to the transfer medium 30, a cleaning unit 23, a static eliminator 24, and a fixing unit 25.

  FIG. 7 is a cross-sectional view schematically showing a basic configuration of another embodiment of the image forming apparatus of the present invention. The image forming apparatus 210 shown in FIG. 7 has the same configuration as that of the image forming apparatus 200 shown in FIG. 6 except that the image forming apparatus 210 includes the charging unit 18 that charges the electrophotographic photoreceptor 100 by the contact charging method. At this time, as the charging means 18, a contact-type charging means in which an AC voltage is superimposed on a DC voltage can be preferably used because it has excellent wear resistance. In this case, the static eliminator 24 may not be provided.

  Examples of the non-contact charging type charging means 18 used in the present invention include a corotron and a scorotron using corona discharge. Further, as the charging means 18 of the contact charging method, a charger using a contact charging member such as a charging roller or a charging brush can be cited.

Contact charging members include metals such as aluminum, iron and copper, conductive polymer materials such as polyacetylene, polypyrrole and polythiophene, polyurethane rubber, silicone rubber, epichlorohydrin rubber, ethylene propylene rubber, acrylic rubber, fluorine rubber, styrene A material obtained by dispersing metal oxide particles such as carbon black, copper iodide, silver iodide, zinc sulfide, silicon carbide, and metal oxide in an elastomer material such as butadiene rubber or butadiene rubber can be used. Examples of this metal oxide include ZnO, SnO ₂ , TiO ₂ , In ₂ O ₃ , MoO _{3 and the} like, or a composite oxide thereof. Further, as the contact charging member, a material obtained by adding perchlorate to an elastomer material and imparting conductivity may be used.

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

Electrical resistance of the contact charging member, 1 × is preferably 10 ² [Omega] cm or more 1 × ^{10 14 Ωcm} or less at a volume resistivity, and more preferably less 1 × 10 ² Ωcm or more 1 × ^{10 12 Ωcm.} Further, as the voltage applied to the contact charging member, either direct current or alternating current can be used. It can also be applied in the form of direct current + alternating current (direct voltage and alternating voltage superimposed).

  As the exposure unit 10, an optical system device that can expose a light source such as a semiconductor laser, an LED (light emitting diode), and a liquid crystal shutter on the surface of the electrophotographic photoreceptor 100 in a desired image-like manner can be used. Among these, when an exposure apparatus capable of exposing non-interference light is used, interference fringes between the conductive support of the electrophotographic photoreceptor 100 and the photosensitive layer can be prevented.

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

  As the developing means 21, a conventionally known developing device or the like can be used. Further, the type of developer used and the method for producing the same are not particularly limited. For example, a kneading and pulverizing method for kneading, pulverizing, and classifying a binder resin and a colorant, a release agent, and a charge control agent as necessary, A method of changing the shape of the particles obtained by the kneading and pulverization method by mechanical impact force or thermal energy, an emulsion polymerization of a polymerizable monomer of a binder resin, a formed dispersion, a colorant, a release agent Emulsion polymerization aggregation method to obtain a toner particle by mixing a mold agent and, if necessary, a dispersion of a charge control agent, and agglomerating and heat-fusing, a polymerizable monomer and a colorant for obtaining a binder resin A suspension polymerization method in which a solution of a release agent, if necessary, a charge control agent or the like is suspended in an aqueous solvent and polymerized, a binder resin and a colorant, a release agent, and a charge control agent if necessary A solution suspension method in which a solution is suspended in an aqueous solvent and granulated can be used. In addition, a known method such as a production method in which the toner obtained by the above method is used as a core and agglomerated particles are further adhered and heat-fused to have a core-shell structure can be used. From the viewpoint, a suspension polymerization method, an emulsion polymerization aggregation method, and a dissolution suspension method produced with an aqueous solvent are preferable, and an emulsion polymerization aggregation method is particularly preferable.

The toner is composed of a binder resin, a colorant, and a release agent. If necessary, silica or a charge control agent may be used. The volume average particle diameter of the toner is preferably 3 μm or more and 9 μm or less. In addition, the average shape index (ML ² / A) of the toner is preferably 100 or more and 140 or less, and preferably 115 or more and 140 or less, because high development, transferability, and high-quality images can be obtained. More preferred.

  Binder resins used in the toner include styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene and isoprene, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl butyrate. , Α-methylene aliphatic monocarboxylic such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Examples of homopolymers and copolymers of acid esters, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl butyl ether, and vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropenyl ketone Particularly typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene. -Maleic anhydride copolymer, polyethylene, polypropylene and the like. Further examples include polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like.

  In addition, toner colorants include magnetic powders such as magnetite and ferrite, carbon black, aniline blue, caryl blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, and malachite green oxa. Rate, lamp black, rose bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3 can be exemplified as a representative one.

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

  Further, a charge control agent may be added to the toner as necessary. As the charge control agent, known ones can be used. For example, an azo metal complex compound, a metal complex compound of salicylic acid, a resin type charge control agent containing a polar group, or the like can be used.

  When the toner is manufactured by a wet manufacturing method, it is preferable to use a material that is difficult to dissolve in water in terms of controlling ionic strength and reducing wastewater contamination. The toner may be either a magnetic toner containing a magnetic material or a non-magnetic toner containing no magnetic material.

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

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

  To the toner used in the present invention, inorganic fine particles, organic fine particles, composite fine particles obtained by adhering inorganic fine particles to the organic fine particles, and the like may be added for the purpose of removing deposits and deteriorated matters on the surface of the electrophotographic photoreceptor 100. Although it is possible, inorganic fine particles having excellent polishing properties are particularly preferable. Inorganic fine particles include silica, alumina, titania, zirconia, barium titanate, aluminum titanate, strontium titanate, magnesium titanate, zinc oxide, chromium oxide, cerium oxide, antimony oxide, tungsten oxide, tin oxide, tellurium oxide, Various inorganic oxides such as manganese oxide, boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride, and boron nitride, nitrides, borides, and the like are preferably used. Further, titanium coupling agents such as tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzenesulfonyl titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, γ- (2-amino) Ethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) γ-aminopropyltrimethoxysilane Hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxy The treatment may be performed with a silane coupling agent such as silane, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, and p-methylphenyltrimethoxysilane. Moreover, it is also preferable to hydrophobize with higher fatty acid metal salts, such as silicone oil, aluminum stearate, zinc stearate, calcium stearate.

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

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

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

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

  Examples of the transfer unit 22 include a roller-type contact charging member, a contact-type transfer charger using a belt, a film, a rubber blade, or the like, a scorotron transfer charger using a corona discharge, a corotron transfer charger, or the like. .

  Although untransferred toner may remain on the surface of the electrophotographic photosensitive member 100 after the transfer, the remaining toner can be removed by the cleaning means 23. As the cleaning means 23, those provided with a cleaning member such as a blade, a magnetic brush, or a conductive fiber brush are preferably used. Hereinafter, a cleaning apparatus including a blade member as an example of the cleaning unit 23 will be described in detail.

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

  The thickness of the blade member is not particularly limited as long as it has sufficient strength to remove the residual toner on the surface of the photoreceptor, but it is usually preferably about 1 mm to 3 mm. For example, when an adhesive that is reactively cured by irradiating ultraviolet rays or the like is used to obtain a cleaning blade by bonding a blade member and a mounting bracket, which will be described later, the blade member is transparent, ultraviolet rays, etc. It is preferable to have a thickness that can pass through. Further, the rubber hardness of the blade member is not particularly limited as long as it has sufficient strength to remove the residual toner on the surface of the electrophotographic photosensitive member 100, but is usually A65 / S or more and A80 / S. It is preferably about the following (measured value by JIS K6253 type A durometer hardness meter).

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

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

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

  FIG. 8 is a cross-sectional view schematically showing a basic configuration of another embodiment of the image forming apparatus of the present invention. An image forming apparatus 220 shown in FIG. 8 is an image forming apparatus that forms a color image by a tandem method. In the housing 400, four electrophotographic photoreceptors 100a to 100d (for example, the electrophotographic photoreceptor 100a is yellow and the electrophotographic photoreceptor is used. The body 100b can form an image of magenta, the electrophotographic photoreceptor 100c can be cyan, and the electrophotographic photoreceptor 100d can be formed of a black color.) Are arranged in parallel with each other along the intermediate transfer belt 409.

  Here, the electrophotographic photoreceptors 100a to 100d mounted on the image forming apparatus 220 are the electrophotographic photoreceptors of the present invention.

  Each of the electrophotographic photoreceptors 100a to 100d can be rotated in a predetermined direction (counterclockwise on the paper surface), and the charging rolls 402a to 402d, the developing devices 404a to 404d, and the primary transfer roll 410a along the rotation direction. To 410d and cleaning blades 415a to 415d are arranged. Each of the developing devices 404a to 404d can be supplied with toner of four colors of black, yellow, magenta and cyan accommodated in the toner cartridges 405a to 405d, and the primary transfer rolls 410a to 410d are respectively intermediate transfer belts. 409 is in contact with the electrophotographic photoreceptors 100a to 100d.

  Further, a laser light source (exposure means) 403 is arranged at a predetermined position in the housing 400, and the surfaces of the electrophotographic photoreceptors 100a to 100d after charging are irradiated with laser light emitted from the laser light source 403. Is possible. Accordingly, charging, exposure, development, primary transfer, and cleaning are sequentially performed in the rotation process of the electrophotographic photoreceptors 100a to 100d, and the toner images of the respective colors are transferred onto the intermediate transfer belt 409 in an overlapping manner.

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

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

  In the above description, the case where the intermediate transfer belt 409 is used as the intermediate transfer member has been described. However, the intermediate transfer member may have a belt shape like the intermediate transfer belt 409 or a drum shape. Also good. In the case of a belt shape, a conventionally known resin can be used as the resin material used as the base material of the intermediate transfer member. For example, polyimide resin, polycarbonate resin (PC), polyvinylidene fluoride (PVDF), polyalkylene terephthalate (PAT), ethylenetetrafluoroethylene copolymer (ETFE) / PC, ETFE / PAT, PC / PAT blend material, polyester Resin materials such as polyether ether ketone and polyamide, and resin materials using these as main raw materials. Furthermore, a resin material and an elastic material can be blended and used.

  As an elastic material, polyurethane, chlorinated polyisoprene, NBR, chloropyrene rubber, EPDM, hydrogenated polybutadiene, butyl rubber, silicone rubber, or the like can be used, or a material obtained by blending two or more kinds can be used. If necessary, a conductive agent imparting electronic conductivity or a conductive agent having ionic conductivity is added to the resin material and elastic material used for these base materials in combination of one kind or two or more kinds. Among these, it is preferable to use a polyimide resin in which a conductive agent is dispersed from the viewpoint of excellent mechanical strength. As the conductive agent, a conductive polymer such as carbon black, metal oxide, or polyaniline can be used. When a belt-shaped configuration such as the intermediate transfer belt 409 is adopted as the intermediate transfer member, generally the thickness of the belt is preferably 50 μm or more and 500 μm or less, more preferably 60 μm or more and 150 μm or less. Depending on the hardness, it can be selected appropriately.

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

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

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

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

  FIG. 9 is a sectional view schematically showing a basic configuration of a preferred embodiment of the process cartridge of the present invention. The process cartridge 300 is formed by combining the electrophotographic photosensitive member 100 with the charging unit 18, the developing unit 21, the cleaning unit 23, the opening 28 for exposure, and the static eliminator 24 using the mounting rail 26. is there. The process cartridge 300 is detachably attached to the image forming apparatus main body including the transfer unit 22, the fixing unit 25, and other components not shown. It constitutes. Such a process cartridge 300 can be applied to any of the image forming apparatuses shown in FIGS.

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

(Example 1)
First, 100 parts by mass of zinc oxide (trade name “SMZ-017N”, manufactured by Teika Co., Ltd.) is stirred and mixed with 500 parts by mass of toluene, and 2 parts by mass of a silane coupling agent (trade name “A1100”, manufactured by Nihon Unicar Co., Ltd.) is added. 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.

  Next, 35 parts by mass of the surface-treated zinc oxide obtained above, 15 parts by mass of blocked isocyanate (trade name “Sumijoule 3175”, manufactured by Sumitomo Bayern Urethane Co., Ltd.) as a curing agent, and butyral resin (trade name “ BM-1 "(manufactured by Sekisui Chemical Co., Ltd.) 6 parts by mass 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 parts by mass of dioctyltin dilaurate and 17 parts by mass of Tospearl 130 (manufactured by GE Toshiba Silicon Co., Ltd., trade name) were added to the resulting dispersion to obtain a coating liquid for forming an undercoat layer. This coating solution is applied onto an aluminum substrate (outer diameter 30 mm, length 404 mm, wall thickness 1 mm) by a dip coating method, dried and cured at 160 ° C. for 100 minutes, and an undercoat layer having a thickness of 20 μm is formed. Formed. The surface roughness (ten-point average roughness (Rz)) of the formed undercoat layer was measured using a surface roughness profile measuring device Surfcom 570A manufactured by Tokyo Seimitsu Co., Ltd., measuring distance 2.5 mm, scanning speed 0.3 mm / When measured in sec, the Rz value was 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 ° and 1 part by mass of hydroxygallium phthalocyanine having a strong diffraction peak at 28.3 ° is mixed with 1 part by mass of polyvinyl butyral (trade name “ESREC BM-L”, manufactured by Sekisui Chemical Co., Ltd.) and 100 parts by mass of n-butyl acetate. Then, the glass beads were dispersed in a paint shaker for 1 hour to obtain a coating solution for forming a charge generation layer. This coating solution was dip-coated on the undercoat layer and dried by heating at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of about 0.15 μm.

  Next, 2 parts by mass of a charge transporting compound represented by the following general formula (XVII) and 3 parts by mass of a polymer compound (viscosity average molecular weight 58,000) having a structural unit represented by the following general formula (XVIII) It was made to melt | dissolve in 30 mass parts of chlorobenzene, and the coating liquid for charge transport layer formation was obtained.

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

  Next, 30 parts by mass of the charge transporting compound (I-1), 30 parts by mass of a phenol resin (trade name “PR-51206”, manufactured by Sumitomo Bakelite Co., Ltd.), 0.1 parts by mass of the light absorbing compound 1 shown in Table 61 Part and 50 parts by mass of ethanol were mixed to obtain a coating solution for forming a protective layer. The obtained coating solution was dip-coated on the above charge transport layer, air-dried at room temperature for 10 minutes, then heated and cured at 150 ° C. for 85 minutes to form a protective layer having a thickness of about 4 μm. No. 1 electrophotographic photoreceptor was obtained.

(Example 2)
First, the charge transport layer was formed in the same manner as in Example 1. Next, 30 parts by mass of the charge transporting compound (II-15), 30 parts by mass of a phenol resin (trade name “PL-4852”, manufactured by Gunei Chemical Co., Ltd.), 0.1 to 0.1 of the light absorbing compound 2 shown in Table 61 Part by mass, 0.09 part by mass of triethylamine and 50 parts by mass of ethanol were mixed to obtain a coating solution for forming a protective layer. The obtained coating solution was dip-coated on the above charge transport layer, air-dried at room temperature for 10 minutes, then heated and cured at 150 ° C. for 85 minutes to form a protective layer having a thickness of about 4 μm. 2 electrophotographic photoreceptor was obtained.

(Example 3)
First, the charge transport layer was formed in the same manner as in Example 1. Next, 30 parts by mass of the charge transporting compound (III-1), 30 parts by mass of a phenol resin (trade name “PR-50404”, manufactured by Sumitomo Bakelite Co., Ltd.), 0.1 parts by mass of the light absorbing compound 3 shown in Table 61 Part and 50 parts by mass of ethanol were mixed to obtain a coating solution for forming a protective layer. The obtained coating solution was dip-coated on the above charge transport layer, air-dried at room temperature for 10 minutes, then heated and cured at 150 ° C. for 85 minutes to form a protective layer having a thickness of about 4 μm. 3 electrophotographic photosensitive member was obtained.

Example 4
First, the charge transport layer was formed in the same manner as in Example 1. Next, 30 parts by mass of the charge transporting compound (IV-3), 30 parts by mass of a phenol resin (trade name “PL-2215”, manufactured by Gunei Chemical Co., Ltd.), 0.1 to 0.1 of the light absorbing compound 4 shown in Table 61 Part by mass, 0.09 part by mass of triethylamine and 50 parts by mass of ethanol were mixed to obtain a coating solution for forming a protective layer. The obtained coating solution was dip-coated on the above charge transport layer, air-dried at room temperature for 10 minutes, then heated and cured at 150 ° C. for 85 minutes to form a protective layer having a thickness of about 4 μm. 4 electrophotographic photoreceptor was obtained.

(Example 5)
First, the charge transport layer was formed in the same manner as in Example 1. Next, 30 parts by mass of the charge transporting compound (V-7), 30 parts by mass of a phenol resin (trade name “PL-2211”, manufactured by Gunei Chemical Co., Ltd.), 0.1 to 0.1 of the light absorbing compound 5 shown in Table 61 Part by mass, Nacure 5225 (block sulfonic acid, manufactured by Enomoto Kasei Co., Ltd., 0.18 parts by mass) and 50 parts by mass of ethanol were mixed to obtain a coating solution for forming a protective layer. The obtained coating solution was dip-coated on the above charge transport layer, air-dried at room temperature for 10 minutes, then heated and cured at 150 ° C. for 85 minutes to form a protective layer having a thickness of about 4 μm. No. 5 electrophotographic photosensitive member was obtained.

(Example 6)
First, the charge transport layer was formed in the same manner as in Example 1. Next, 30 parts by mass of the charge transporting compound (V-16), 30 parts by mass of a phenol resin (trade name “BLS-3122”, manufactured by Showa Polymer Co., Ltd.), 0.1 of the light absorbing compound 6 shown in Table 61 Part by mass, 0.09 part by mass of sodium hydroxide and 50 parts by mass of ethanol were mixed to obtain a coating solution for forming a protective layer. The obtained coating solution was dip-coated on the above charge transport layer, air-dried at room temperature for 10 minutes, then heated and cured at 150 ° C. for 85 minutes to form a protective layer having a thickness of about 4 μm. No. 6 electrophotographic photoreceptor was obtained.

(Example 7)
First, the charge transport layer was formed in the same manner as in Example 1. Next, 30 parts by mass of the charge transporting compound (VI-7), 30 parts by mass of a phenol resin (trade name “CKM-2400”, manufactured by Showa Polymer Co., Ltd.), 0.1 of the light absorbing compound 7 shown in Table 62 A coating solution for forming a protective layer was obtained by mixing 0.1 part by mass, 0.18 parts by mass of Nacure 2500 (trade name, manufactured by Enomoto Kasei Co., Ltd.) and 50 parts by mass of ethanol. The obtained coating solution was dip-coated on the above charge transport layer, air-dried at room temperature for 10 minutes, then heated and cured at 150 ° C. for 85 minutes to form a protective layer having a thickness of about 4 μm. 7 was obtained.

(Example 8)
First, the charge transport layer was formed in the same manner as in Example 1. Next, 30 parts by mass of the charge transporting compound (VI-4), 30 parts by mass of a phenol resin (trade name “PL-2215”, manufactured by Gunei Chemical Co., Ltd.), 0.1 to 0.1 of the light absorbing compound 8 shown in Table 62 Part by mass, 0.09 part by mass of sodium hydroxide and 50 parts by mass of ethanol were mixed to obtain a coating solution for forming a protective layer. The obtained coating solution was dip-coated on the above charge transport layer, air-dried at room temperature for 10 minutes, then heated and cured at 150 ° C. for 85 minutes to form a protective layer having a thickness of about 4 μm. 8 electrophotographic photosensitive members were obtained.

Example 9
First, the charge transport layer was formed in the same manner as in Example 1. Next, 30 parts by mass of the charge transporting compound (VI-12), 30 parts by mass of a phenol resin (trade name “PR-51206”, manufactured by Sumitomo Bakelite Co., Ltd.), 0.1 parts by mass of the light absorbing compound 9 shown in Table 62 Part, 0.09 parts by mass of triethylamine and 50 parts by mass of ethanol were mixed to obtain a coating solution for forming a protective layer. The obtained coating solution was dip-coated on the above charge transport layer, air-dried at room temperature for 10 minutes, then heated and cured at 150 ° C. for 85 minutes to form a protective layer having a thickness of about 4 μm. 9 electrophotographic photoreceptors were obtained.

(Comparative Example 1)
First, the charge transport layer was formed in the same manner as in Example 1. Next, a protective layer was formed in the same manner as in Example 7 except that the light absorbing compound 7 in Example 7 was not blended, and an electrophotographic photoreceptor of Comparative Example 1 was obtained.

(Comparative Example 2)
First, the charge transport layer was formed in the same manner as in Example 1. Next, instead of the light absorbing compound 6 in Example 6, a protective layer was formed in the same manner as in Example 6 except that 0.1 part by weight of the light absorbing compound 10 shown in Table 62 was used. An electrophotographic photoreceptor of Example 2 was obtained.

(Comparative Example 3)
First, the charge transport layer was formed in the same manner as in Example 1. Next, instead of the light absorbing compound 8 in Example 8, a protective layer was formed in the same manner as in Example 8 except that 0.1 part by weight of the light absorbing compound 11 shown in Table 62 was used. An electrophotographic photoreceptor of Example 3 was obtained.

(Comparative Example 4)
First, the charge transport layer was formed in the same manner as in Example 1. Next, 20 parts by mass of the charge transporting compound (III-18) is dissolved in a mixed solvent of 50 parts by mass of ethanol, 30 parts by mass of tetrahydrofuran and 3.5 parts by mass of distilled water, and an ion exchange resin (trade name “Amberlyst”). 15E "(manufactured by Rohm and Haas) was added, and the mixture was stirred at room temperature and hydrolyzed for 24 hours. After filtering the ion exchange resin, 0.2 parts by mass of the light absorbing compound 6 shown in Table 61 was added to obtain a coating solution for forming a protective layer. The obtained coating solution was dip-coated on the above charge transport layer, air-dried at room temperature for 10 minutes, and then cured at 120 ° C. for 2 hours to obtain an electrophotographic photoreceptor of Comparative Example 4.

<Characteristics of light absorbing compound>
[Alcohol solubility]
0.1 mass part of a light absorptive compound was added to 100 mass parts of ethanol, and dissolution was attempted at a temperature of 25 ° C. At this time, whether or not the light absorbing compound is soluble was evaluated by visual observation, and the results are shown in Tables 61 and 62.

[Maximum absorption wavelength]
The light absorbing compound was dissolved in ethanol at a concentration such that the maximum absorbance of the solution in the range of 300 nm to 550 nm was in the range of 0.7 to 1.3. Next, for this ethanol solution, the absorption maximum wavelength in the wavelength region of 300 nm to 550 nm was determined with a Hitachi spectrophotometer U-4000 using a quartz solution cell (length in the optical path direction: 10 mm). The results are shown in Tables 61 and 62.

<Image formation test>
First, each electrophotographic photoreceptor obtained in Examples 1 to 9 and Comparative Examples 1 to 4 was irradiated with white light with an illuminance of 1000 Lux for 30 minutes in a state where a part of the photoreceptor was covered with black paper and shielded from light. .

  Next, the photoreceptors of Examples 1 to 9 and Comparative Examples 1 to 4 that were irradiated with white light were respectively mounted as photoreceptors of DCC400 manufactured by Fuji Xerox Co., Ltd., under a low temperature and low humidity environment of 10 ° C. and 20% RH, and A4. An image with an image density of about 20% was formed on a sheet of 10,000 sheets, and the initial image quality and the image quality after printing 10,000 sheets were visually evaluated based on the following evaluation criteria. Further, the wear amount of the photoconductor was measured and calculated as a wear rate per 1000 revolutions (nm / kcycle). The results obtained are shown in Table 63.

(Light white)
Regarding the initial image, the difference in image density between the portion shielded by black paper and the non-shielded portion was visually confirmed and evaluated according to the following criteria.
A: No difference in density is observed.
B: Slight white spots are seen (no problem in actual use).
C: Slight white spots can be seen (color machines with severe specifications have problems in actual use).
D: White spots are observed (there is a problem in actual use).

(ghost)
The initial image and the 10,000th image were visually evaluated according to the following criteria.
A: A ghost is not seen.
B: Slight ghost is seen (no problem in actual use).
C: Slight ghost is observed (there is a problem in actual use in color machines with strict specifications).
D: Ghost is seen (there is a problem in actual use).

As is apparent from the results shown in Table 63, when the electrophotographic photoreceptor of the present invention (Examples 1 to 9) was used, white spots were not observed even when the photoreceptor was exposed to external light. It was confirmed that the image quality can be sufficiently prevented and the occurrence of image quality defects due to ghost after the image formation test (image formation of 10,000 sheets) can be suppressed.

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 showing a preferred embodiment of the process cartridge of the present invention.

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 ... Charge generation / charge transport layer , 18 ... charging means, 19 ... power supply, 20 ... exposure means, 21 ... developing means, 22 ... transfer means, 23 ... cleaning means, 24 ... static eliminator, 25 ... fixing means, 26 ... mounting rail, 28 ... for exposure , 30 ... transferred body, 100, 100a to 100d ... electrophotographic photosensitive member, 200, 210, 220 ... image forming apparatus, 300 ... process cartridge.

Claims (6)

Comprising a conductive support and a photosensitive layer provided on the conductive support;
The photosensitive layer has an outermost surface layer made of a resin composition containing a phenol resin and a charge transporting compound having a functional group capable of reacting with the phenol resin on the side farthest from the conductive support. And
The electrophotographic photoreceptor, wherein the outermost surface layer further contains a compound having an absorption maximum wavelength in a range of 350 nm to 480 nm.   The electrophotographic photoreceptor according to claim 1, wherein the compound is at least one of an azo compound, a quinone compound, a coumarin compound, and a benzotriazole compound. The charge transporting compound is a compound represented by any one of the following general formulas (I), (II), (III), (IV), (V) and (VI): Item 3. The electrophotographic photosensitive member according to Item 1 or 2.
_{^{F [- (X 1) n1}} R 1 -Z 1 H] m1 (I)
[In Formula (I), F represents an organic group derived from a compound having a hole transporting ability, R ¹ represents an alkylene group, Z ¹ represents an oxygen atom, a sulfur atom, NH or COO, and X ¹ Represents an oxygen atom or a sulfur atom, m1 represents an integer of 1 to 4, and n1 represents 0 or 1. ]
_{^{F [- (X 2) n2}} - (R 2) n3 - (Z 2) n4 G] n5 (II)
[In Formula (II), F represents an organic group derived from a compound having a hole transporting ability, X ² represents an oxygen atom or a sulfur atom, R ² represents an alkylene group, Z ² represents an oxygen atom, S represents a sulfur atom, NH or COO, G represents an epoxy group, n2, n3 and n4 each independently represents 0 or 1, and n5 represents an integer of 1 to 4. ]
F [—D—Si (R ³ ) _(3-a) Q _a ] _b (III)
[In Formula (III), F represents an organic group derived from a compound having a hole transporting ability, D represents a divalent group having flexibility, and R ³ represents a hydrogen atom, a substituted or unsubstituted group. An alkyl group or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, a represents an integer of 1 to 3, and b represents an integer of 1 to 4; ]

[In Formula (IV), F represents an organic group derived from a compound having a hole transporting property, T represents a divalent group, Y represents an oxygen atom or a sulfur atom, R ⁴ , R ⁵ and R ⁶ 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. ]

[In Formula (VI), F represents an organic group derived from a compound having a hole transporting property, R ⁹ represents a monovalent organic group, L represents an alkylene group, and n8 represents an integer of 1 to 4. Indicates. ] The electrophotographic photosensitive member according to any one of claims 1 to 3,
A charging means for charging the electrophotographic photosensitive member; a developing means for developing a latent electrostatic image formed on the electrophotographic photosensitive member with toner to form a toner image; and At least one selected from the group consisting of cleaning means for removing toner remaining on the surface;
A process cartridge comprising: The electrophotographic photosensitive member according to any one of claims 1 to 3,
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: A charging step for charging the electrophotographic photosensitive member according to any one of claims 1 to 3,
Exposing the charged electrophotographic photosensitive member to form an electrostatic latent image; and
A developing step of developing the electrostatic latent image with toner to form a toner image;
And a transfer step of transferring the toner image to a transfer medium.

Images