JP5446244B2 - Electrophotographic photosensitive member using α-phenylstilbene compound, image forming apparatus using the same, and process cartridge for image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member using an α-phenylstilbene compound having high hole transportability and excellent matching with a charge generating material, and an image forming apparatus and a process cartridge for the image forming apparatus using the same. It is about.

For organic photoreceptors (hereinafter also referred to as electrophotographic photoreceptors or simply photoreceptors), materials that are easy to develop for various exposure light sources from visible light to infrared light are selected, and materials that are less affected by environmental pollution are selected. There are many advantages over inorganic photoreceptors due to the fact that they can be made and the manufacturing costs are low. Examples of the charge transport agent for the electrophotographic photoreceptor include an oxadiazole compound (see, for example, Patent Document 1), an oxazole compound (see, for example, Patent Document 2), a pyrazoline compound (see, for example, Patent Document 3), and a hydrazone compound ( Examples thereof include Patent Documents 4 to 7), diamine compounds (for example, see Patent Document 8), stilbene compounds (for example, see Patent Documents 9 to 12), butadiene compounds (for example, see Patent Document 13), and the like. Some of these charge transfer agents have excellent characteristics and have been put into practical use.
However, in recent years, as the speed and miniaturization of image forming apparatuses rapidly progress, further improvement of the charge transport function has become indispensable. In particular, the development of charge transport agents having high hole transportability is strongly developed. It has been demanded.

Japanese Patent Publication No.34-005466 JP 56-123544 A Japanese Patent Publication No. 52-04880 Japanese Patent Publication No.55-042380 Japanese Patent Publication No. 61-040104 Japanese Examined Patent Publication No. 62-035673 Japanese Patent Publication No. 63-035976 Japanese Patent Publication No. 58-032372 Japanese Examined Patent Publication No. 63-018738 Japanese Patent Publication No. 63-019867 Japanese Patent Publication No. 3-039306 Japanese Patent Publication No. 2-24864 Japanese Patent Laid-Open No. 62-030255

  The present invention has been made in view of the current state of the prior art, and provides an electrophotographic photoreceptor excellent in high-speed response and high sensitivity, an image forming apparatus using the same, and a process cartridge for the image forming apparatus. With the goal.

  As a result of intensive studies, the present inventors have solved the above problems by using α-phenylstilbene as a charge transport agent that has at least high hole transportability and excellent matching with a charge generation material. As a result, the present invention has been completed.

Specifically, in order to solve the above problems, an electrophotographic photosensitive member according to the present invention, an image forming apparatus using the same, and a process cartridge for the image forming apparatus are specifically described in the following (1) to (13) . Has technical features.

(1) : An electrophotographic photosensitive member having a photosensitive layer on a conductive support, the photosensitive layer containing an α-phenylstilbene compound represented by the following general formula (III).

(In the formula (III), R ₅ , R ₈ , R ₉ , R ₁₀ and R ₁₁ represent a hydrogen atom, an alkyl group, an alkoxy group, or a substituted or unsubstituted aryl group, and may be the same, It may be different.)

(2) The electrophotographic photosensitive member according to (1 ), wherein the photosensitive layer further contains a phthalocyanine pigment and / or an azo pigment.

(3) The electrophotographic photosensitive member according to (2) , wherein the azo pigment includes a compound represented by the following general formula (IV).

(In the formula (IV), Cp ₁ and Cp ₂ represent coupler residues represented by the following formula (V), and may be the same or different. R ₂₀₁ and R ₂₀₂ are hydrogen. An atom, a halogen atom, an alkyl group, an alkoxy group, or a cyano group, which may be the same or different.

(In the formula (V), R ₂₀₃ represents a hydrogen atom, an alkyl group or an aryl group, and R ₂₀₄ , R ₂₀₅ , R ₂₀₆ , R ₂₀₇ and R ₂₀₈ are a hydrogen atom, a nitro group, a cyano group, a halogen atom, a halogen atom. Represents an alkyl group, an alkyl group, an alkoxy group, a dialkylamino group, or a hydroxyl group, and may be the same or different, and Z is a carbocyclic aromatic group or heterocyclic aromatic group. Represents a group of atoms necessary for forming a ring, and may have a substituent.)

(4) The electrophotographic photosensitive member according to (3) , wherein Cp ₁ and Cp ₂ of the azo pigment are different from each other.

(5) : The phthalocyanine pigment includes any one or two or more selected from titanyl phthalocyanine, hydroxygallium phthalocyanine, and chlorogallium phthalocyanine, and any one of the above (2) to (4) The electrophotographic photosensitive member described in the item.

(6) : The titanyl phthalocyanine has a maximum intensity diffraction at least 27.2 ° out of the black angle (2θ ± 0.2 °) in an X-ray diffraction spectrum using CuKα characteristic X-ray (1.542 °). It has a peak, 9.4 °, 9.6 °, main peak at 24.0 °, a diffraction peak with a minimum angle at 7.3 °, 7.3 ° and 9.4 ° The electrophotographic photosensitive member as described in (5) above, which is a titanyl phthalocyanine crystal having no diffraction peak between and 26.3 °.

(7) The electrophotographic photosensitive member according to any one of (1) to (6) above, wherein a charge blocking layer is provided between the conductive support and the photosensitive layer. .

(8) The electrophotographic photosensitive member according to any one of (1) to (7) , wherein a protective layer is provided on the photosensitive layer.

(9) The electrophotographic photosensitive member according to (8) , wherein the protective layer contains an inorganic pigment and / or a metal oxide having a specific resistance of 10 ¹⁰ Ω · cm or more.

(10) The protective layer is formed by curing at least a trifunctional or higher functional radical polymerizable monomer having no charge transport structure and a radical polymerizable compound having a monofunctional charge transport structure. The electrophotographic photosensitive member according to (8) or (9) , wherein the electrophotographic photosensitive member is characterized.

(11) : In an image forming apparatus comprising at least a charging unit, an exposure unit, a developing unit, a transfer unit, and an electrophotographic photosensitive member, the electrophotographic photosensitive member is any one of the above (1) to (10) 2. An image forming apparatus comprising the electrophotographic photosensitive member according to item 1.

(12) A cartridge in which an electrophotographic photosensitive member and at least one means selected from a charging means, an exposure means, a developing means, a transfer means, and a cleaning means are mounted, and the cartridge forms an image. The image forming apparatus according to (11) , wherein the image forming apparatus is detachable from the apparatus main body.

(13) In the image forming apparatus cartridge in which the electrophotographic photosensitive member and at least one unit selected from a charging unit, an exposure unit, a developing unit, a transfer unit, and a cleaning unit are integrated. The body is an electrophotographic photosensitive member according to any one of (1) to (10) , and is a process cartridge for an image forming apparatus.

  According to the present invention, it is possible to provide an electrophotographic photoreceptor excellent in high-speed response and high sensitivity, an image forming apparatus using the same, and a process cartridge for the image forming apparatus.

Next, the electrophotographic photoreceptor using the α-phenylstilbene compound of the present invention will be described in more detail with reference to the drawings.
<About the layer structure of the electrophotographic photoreceptor>
The layer structure of the electrophotographic photosensitive member in the present invention may be a single layer or a stacked structure, and is not limited to the layer structure. For example, the following layer structure is mentioned. FIG. 1 shows an electrophotographic photosensitive member in which a photosensitive layer is formed on a conductive support. Further, as shown in FIG. 2, an undercoat layer may be provided between the photosensitive layer and the conductive support. FIG. 3 shows an electrophotographic photosensitive member in which a charge generation layer and a charge transport layer are sequentially laminated on a conductive support. Further, an undercoat layer may be provided between the charge generation layer and the conductive support as shown in FIG. Note that these layer configurations are representative, and the present invention is not limited to these layer configurations.

<About conductive support>
Examples of the conductive support include those having a volume resistance of 10 ¹⁰ Ω · cm or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, oxidation Metal oxide such as indium coated on film or cylindrical plastic or paper by vapor deposition or sputtering; aluminum, aluminum alloy, nickel, stainless steel plates and the like, and extruding, drawing, etc. After pipe formation, a surface-treated pipe such as cut, superfinished or polished can be used. Further, endless nickel belts and endless stainless steel belts disclosed in JP-A-52-36016 can also be used as the conductive support.

  Furthermore, what formed the electroconductive layer by dispersing electroconductive powder in binder resin on said electroconductive support body (it formed using coating etc.) can also be used as an electroconductive support body. Examples of such conductive powders include carbon black, acetylene black; metal powders such as aluminum, nickel, iron, nichrome, copper, zinc, silver, and metal oxide powders such as conductive tin oxide and ITO. It is done. The binder resin used at the same time is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, Polyvinyl acetate, polyvinylidene chloride, polyarylate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly (N-vinylcarbazole), acrylic resin, silicone resin, epoxy resin, melamine Examples thereof include thermoplastic resins such as resins, urethane resins, phenol resins, and alkyd resins, thermosetting resins, and photocurable resins. The conductive layer can be provided by dispersing conductive powder and a binder resin in a solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, or toluene and applying the conductive powder and the binder resin. Furthermore, using a heat-shrinkable tube containing conductive powder in materials such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, polytetrafluoroethylene fluororesin, etc. Those provided with a conductive layer can also be used as a conductive support.

  Of these, a cylindrical support made of aluminum that can be easily subjected to the anodic oxide film treatment can be used favorably. This aluminum includes either a pure aluminum system or an aluminum alloy. Specifically, aluminum or aluminum alloy of JIS 1000s, 3000s, and 6000s is most suitable. Anodized films are anodized various metals and various alloys in an electrolyte solution. Among them, a film called anodized aluminum or aluminum alloy that has been anodized in an electrolyte solution has an increase in residual potential. It is less effective and has a high effect of preventing scumming when reversal development is used.

The anodizing treatment is performed in an acidic bath such as chromic acid, sulfuric acid, oxalic acid, phosphoric acid, boric acid, sulfamic acid. Of these, treatment with a sulfuric acid bath is most suitable. For example, sulfuric acid concentration: 10 to 20%, bath temperature: 5 to 25 ° C., current density: 1 to 4 A / dm ² , electrolytic voltage: 5 to 30 V, treatment time: treatment in the range of about 5 to 60 minutes However, the present invention is not limited to this. Since the anodic oxide film produced in this way is porous and has high insulation, the surface is very unstable. For this reason, there is a change with time after fabrication, and the physical property value of the anodized film is likely to change. In order to avoid this, it is preferable to further seal the anodized film. Examples of the sealing treatment include a method of immersing the anodized film in an aqueous solution containing nickel fluoride and nickel acetate, a method of immersing the anodized film in boiling water, and a method of treating with pressurized steam. Among these, the method of immersing in the aqueous solution containing nickel acetate is the most preferable. Subsequent to the sealing treatment, the anodic oxide film is washed. The main purpose of this is to remove excess metal salts and the like attached by the sealing treatment. If this remains excessively on the surface of the support (anodized film), it not only adversely affects the quality of the coating film formed on this surface, but also generally low resistance components remain, resulting in the occurrence of soiling. It can also be a cause. Cleaning may be performed with pure water only once, but usually, multistage cleaning is performed. At this time, it is preferable that the final cleaning liquid is as clean as possible (deionized). Moreover, it is preferable to perform physical rubbing cleaning with a contact member in one of the multi-stage cleaning processes. The thickness of the anodized film formed as described above is preferably about 5 to 15 μm. If it is too thin, the barrier effect as an anodic oxide film is not sufficient, and if it is too thick, the time constant as an electrode becomes too large, resulting in the generation of residual potential and the response of the photoreceptor. There is a case.

<About photosensitive layer>
Next, the photosensitive layer will be described.
The photosensitive layer may be a single layer or a plurality of stacked layers (stacked type).

<About laminated photosensitive layer>
First, the laminated type will be described. The laminated photosensitive layer is constituted by laminating at least a charge generation layer and a charge transport layer.

<About the charge generation layer>
The charge generation layer is a layer mainly composed of a charge generation agent. A known charge generating agent can be used for the charge generating layer. For example, monoazo pigments, disazo pigments, asymmetrical disazo pigments, trisazo pigments, azo pigments having a carbazole skeleton (described in JP-A-53-95033), azo pigments having a distyrylbenzene skeleton (JP-A-53-133445) ), An azo pigment having a triphenylamine skeleton (described in JP-A-53-132347), an azo pigment having a diphenylamine skeleton, and an azo pigment having a dibenzothiophene skeleton (described in JP-A-54-21728) An azo pigment having a fluorenone skeleton (described in JP-A No. 54-22834), an azo pigment having an oxadiazole skeleton (described in JP-A No. 54-12742), an azo pigment having a bis-stilbene skeleton (special Described in Japanese Utility Model Laid-Open No. 54-17733), distyryloxadiazole skeleton Azo pigments such as azo pigments (described in JP-A No. 54-2129), azo pigments having a distyrylcarbazole skeleton (described in JP-A No. 54-14967), azulenium salt pigments, methine squaric acid Pigments, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, indigoid pigments, bisbenzimidazole pigments, and Examples thereof include phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine represented by the following general formula (1). These charge generating agents may be used alone or in combination of two or more.

  In formula (1), M (central metal) represents a metal and a metal-free (hydrogen) element. M (center metal) mentioned here is H, Li, Be, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga , Ge, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, TI , La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, Pa, U, Np, Am, etc., or oxide, chloride It consists of two or more elements such as fluoride, fluoride, hydroxide and bromide. The central metal is not limited to these elements.

  In the present invention, the charge generation material having a phthalocyanine skeleton may have at least the basic skeleton of the above general formula (1), and those having a multimeric structure such as a dimer and a trimer, and higher order It may have a polymer structure of In addition, the basic skeleton may have various substituents.

  The binder resin used for the charge generation layer as needed includes polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-. Examples thereof include vinyl carbazole, polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, and polyvinyl pyrrolidone. These binder resins can be used alone or as a mixture of two or more.

  Moreover, as a solvent to be used, generally used organic materials such as isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, ligroin, etc. Among them, it is preferable to use a ketone solvent, an ester solvent, or an ether solvent. These may be used alone or in combination of two or more.

  The coating solution for the charge generation layer is obtained by dispersing the charge generation agent in a solvent using a known dispersion method such as a ball mill, an attritor, a sand mill, or an ultrasonic wave together with a binder resin (binder resin) as necessary. Can be obtained. The binder resin may be added before or after the charge generator is dispersed. The coating solution for the charge generation layer is mainly composed of a charge generation agent, a solvent and a binder resin, and it contains additives such as a sensitizer, a dispersant, a surfactant, and silicone oil. May be. In some cases, it is possible to add a charge transporting agent described later to the charge generation layer. The addition amount of the binder resin is usually 0 to 500 parts by weight, preferably 10 to 300 parts by weight with respect to 100 parts by weight of the charge generator.

  The charge generation layer is formed by coating on a conductive support or an undercoat layer described later using the coating solution and drying. As the coating method, known methods such as dip coating, spray coating, bead coating, nozzle coating, spinner coating, ring coating, and the like can be used. The thickness of the charge generation layer is usually about 0.01 to 5 μm, preferably 0.1 to 2 μm. Further, drying after coating is performed by heating using an oven or the like. The drying temperature of the charge generation layer is preferably 50 to 160 ° C, more preferably 80 to 140 ° C.

<About the charge transport layer>
The charge transport layer is mainly composed of a charge transport agent and a binder resin. The charge transport agent includes a hole transport material and an electron transport material. In the present invention, the hole transport material is referred to as a charge transport agent.

  Among charge transporting agents, the α-phenylstilbene compound according to the present invention has a higher hole transportability than conventional α-phenylstilbene compounds, and therefore, a highly sensitive electrophotographic photoreceptor can be produced.

The α-phenylstilbene compound according to the present invention will be described in detail below.
The α-phenylstilbene compound according to the present invention is represented by the following general formula (I).

In the general formula (I), R ₁ , R ₂ , R ₃ and R ₄ each represents an alkyl group or a substituted or unsubstituted aryl group, and may be the same or different. Ar ₁ represents a substituted or unsubstituted arylene group, and R ₅ represents a hydrogen atom, an alkyl group, an alkoxy group, or a substituted or unsubstituted aryl group.

More preferably, in the general formula (I), R ₁ , R ₂ , R ₃ and R ₄ each represents a substituted or unsubstituted aryl group, which may be the same or different. . Ar ₁ represents a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group, and R ₅ represents a hydrogen atom, an alkyl group, an alkoxy group, or a substituted or unsubstituted aryl group.

  More preferred are compounds represented by the following general formula (II) or (III).

In the general formula (II), R ₅ , R ₆ , R ₇ , R ₈ and R ₉ represent a hydrogen atom, an alkyl group, an alkoxy group, or a substituted or unsubstituted aryl group, and may be the same. May be different.

In the general formula (III), R ₅ , R ₈ , R ₉ , R ₁₀ and R ₁₁ represent a hydrogen atom, an alkyl group, an alkoxy group, or a substituted or unsubstituted aryl group, and may be the same. May be different.

  The substituted or unsubstituted aryl group in the general formula (I), the general formula (II), and the general formula (III) may be any of a monocyclic group and a polycyclic group (a condensed polycyclic group or a non-condensed polycyclic group). Well, the following can be mentioned as an example. Examples thereof include a phenyl group, a naphthyl group, a pyrenyl group, a fluorenyl group, an azulenyl group, an anthryl group, a triphenylenyl group, a chrycenyl group, a biphenyl group, and a terphenyl group.

The alkyl group in general formula (I), general formula (II), and general formula (III) represents a linear or branched alkyl group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms. It is an alkyl group.
Specifically, methyl group, ethyl group, n-propyl group, i-propyl group, t-butyl group, s-butyl group, n-butyl group, i-butyl group, pentyl group, hexyl group, heptyl group, Examples include octyl group, nonyl group, decyl group, 3,7-dimethyloctyl group, 2-ethylhexyl group and the like.

  The alkoxy group represents a linear or branched alkoxy group having 1 to 20 carbon atoms, and preferably an alkoxy group having 1 to 12 carbon atoms. Specific examples include alkoxy groups substituted with the above-described alkyl groups.

  Specific examples of the α-phenylstilbene compounds represented by the general formulas (I) to (III) are shown below. The α-phenylstilbene compound used in the electrophotographic photoreceptor of the present invention is not limited to the following specific examples.

  The α-phenylstilbene compound used in the electrophotographic photosensitive member of the present invention comprises a ditriflate compound represented by the general formula (VII) and a general formula (VIII) in the presence of a palladium catalyst, a tertiary phosphine and a base. It is produced by reacting with an amine compound. The ditriflate compound represented by the general formula (VII) is a novel compound.

  Triflate compounds are described in J. Org. Org. Chem. Vol. 41, no. 26, 4099, 1976 describes a general synthesis method, but the ditriflate compound represented by the general formula (VII) is similarly dissolved in pyridine by dissolving the corresponding diphenol compound in pyridine. The product can be easily obtained by dropping at 0 ° C. and stirring at room temperature.

(Wherein R ³ , R ⁴ , and R ⁵ are the same as defined above.)

(In the formula, the definitions of R ¹ and R ² are the same as described above.)

  This reaction is represented by the following reaction formula, but is generally called the Buchwald-Hartwig reaction (MERCKINDEX13th.edition).

_{Ar-Y + H 2 N-} R → Ar-NHR
Y = Br, I, OSO ₂ CF ₃

  The palladium catalyst is preferably a homogeneous palladium catalyst. Specifically, for example, a tetravalent palladium compound such as sodium hexachloropalladium (IV) or a hydrate thereof, potassium hexachloropalladium (IV), such as palladium chloride. (II), palladium bromide (II), palladium acetate (II), palladium acetyl acetate (II), dichlorobis (benzonitrile) palladium (II), dichlorobis (acetonitrile) palladium (II), dichlorobis (triphenylphosphine) palladium (II), divalent palladium compounds such as dichlorotetraamminepalladium (II), dichloro (cycloocta-1,5-diene) palladium (II), palladium trifluoroacetate (II), for example, tris (dibenzylideneacetone) dipalladium 0), tris (dibenzylideneacetone) dipalladium chloroform complex (0), tetrakis (triphenylphosphine) palladium (0) 0-valent palladium compounds such like.

  The usage-amount of a palladium catalyst is 0.000001-20 mol% normally in conversion of palladium with respect to 1 mol of ditriflate compounds shown by general formula (VII), Preferably it is 0.0001-10 mol%.

Examples of tertiary phosphines include triethylphosphine, tricyclohexylphosphine, tri-n-butylphosphine, tri-iso-butylphosphine, tri-sec-butylphosphine, tri-tert-butylphosphine, and N-phenylpyrrole-2. -Yl-dicyclopentylphosphine, N-phenylpyrrol-2-yl-dicyclohexylphosphine, N-phenylpyrrol-2-yl-dicycloheptylphosphine, N-phenylpyrrol-2-yl-diisopropylphosphine, N-phenylpyrrole- 2-yl-dibutylphosphine, N-phenylpyrrol-2-yl-diisobutylphosphine, N-phenylpyrrol-2-yl-di-sec-butylphosphine, N-phenylpyrrol-2-yl-di-tert-butylphosphite N-phenylindol-2-yl-dicyclopentylphosphine, N-phenylindol-2-yl-dicyclohexylphosphine, N-phenylindol-2-yl-dicycloheptylphosphine, N-phenylindol-2-yl-diisopropyl Phosphine, N-phenylindol-2-yl-dibutylphosphine, N-phenylindol-2-yl-diisobutylphosphine, N-phenylindol-2-yl-di-sec-butylphosphine, N-phenylindol-2-yl -Di-tert-butylphosphine and the like.
The usage-amount of tertiary phosphine is 0.1-10 mol normally with respect to 1 mol of palladium catalysts, Preferably it is 1.0-5.0 mol.

  Examples of the base include alkali metal carbonates such as sodium carbonate and potassium carbonate, alkali metal phosphates such as sodium phosphate and potassium phosphate, metal alkoxides such as sodium tert-butoxide, potassium tert-butoxide and the like Is mentioned. The amount of the base used is usually 2 to 50 mol, preferably 2 to 10 mol, per 1 mol of the ditriflate compound represented by the general formula (VII).

The usage-amount of amine compound (VIII) is 2.0-10 mol normally with respect to 1 mol of ditriflate compounds shown by general formula (VII), Preferably it is 2.0 mol-6.0 mol.
Examples of the amine compound represented by the general formula (VIII) include diphenylamine, 4,4′-dimethyldiphenylamine, N-phenyl-1-biphenylamine, N-phenyl-1-naphthylamine, and N- (4-tolyl) -1- Examples include pyrenylamine, 9,9-dimethyl-2-phenylaminofluorene, 9,9-dimethyl-2- (4-tolyl) aminofluorene, and the like.

The solvent is not particularly limited as long as it does not affect the reaction. Specifically, it is an aromatic hydrocarbon solvent such as toluene or xylene, for example, aprotic polarity such as N, N-dimethylformamide or dimethylsulfoxide. Examples of the solvent include ether solvents such as diethyl ether and tetrahydrofuran.
The reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon.
The reaction temperature is usually 20 to 150 ° C, preferably 60 to 130 ° C, particularly preferably 80 ° C to 120 ° C.

Further, in place of the ditriflate compound represented by the general formula (VII), a dihalogen compound represented by the following general formula (VI) can also be used.

(In the formula (VI), X represents a halogen atom, and R ³ , R ⁴ and R ⁵ are the same as defined above.)

  Examples of the halogen atom in the general formula (VI) include Cl, Br, I and the like.

  The α-phenylstilbene compounds of the general formulas (I) and (III) react with a ditriflate compound represented by the general formula (VII) and an aryl boron compound in the presence of a palladium catalyst, a tertiary phosphine and a base. (Generally called the Suzuki-Miyaura reaction).

Instead of the above-described aryl boron compound, an aryl boronic acid ester synthesized from an aryl halide using bis (pinacolato) diboron which is thermally stable and can be easily handled in air may be used.
For the reaction, the conditions shown in the above Buchwald-Hartwig reaction can be applied as they are.

  Specific examples of the aryl boron compound include 4-dimethylaminophenylboronic acid, 4-diethylaminophenylboronic acid, 4- (diphenylamino) phenylboronic acid, 4- (4,4,5,5-tetramethyl-1, 3,2-Dioxaborolanyl-2) boronic acid esters having a tertiary amine derived from aniline can be exemplified.

  The content of the charge transfer agent is usually 20 to 300 parts by weight and preferably 40 to 150 parts by weight with respect to 100 parts by weight of the binder resin.

  Examples of the binder resin include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, poly Vinylidene chloride, polyarylate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly (N-vinylcarbazole), acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, Examples thereof include thermoplastic or thermosetting resins such as phenol resins and alkyd resins.

  In addition, as a binder resin, a polymer charge transporting agent having a charge transport function, for example, polycarbonate, polyester, polyurethane, polyether, and polyamine having an arylamine skeleton, a benzidine skeleton, a hydrazone skeleton, a carbazole skeleton, a stilbene skeleton, a pyrazoline skeleton, etc. Polymer materials such as siloxane and acrylic resins, polymer materials having a polysilane skeleton, and the like can be used and are useful.

  As the solvent used as the coating solution for the charge transport layer, tetrahydrofuran, dioxane, dioxolane, toluene, cyclohexanone, methyl ethyl ketone, xylene, acetone, diethyl ether, methyl ethyl ketone and the like are used. Although halogen-based solvents such as dichloromethane, dichloroethane, and monochlorobenzene are not problematic in terms of the characteristics of the electrophotographic photosensitive member, it is desirable not to use them for the purpose of reducing the burden on the global environment. Among these, as an effective solvent, cyclic ethers such as tetrahydrofuran and dioxane, and aromatic hydrocarbons such as toluene and xylene are preferably used. These may be used singly or in combination of two or more.

  Moreover, you may add additives, such as a plasticizer, a leveling agent, antioxidant, a lubricant, etc. individually or in 2 types or more to the coating liquid of a charge transport layer as needed. As the plasticizer, plasticizers such as dibutyl phthalate and dioctyl phthalate can be used and are effective. As addition amount, 0-30 weight% is preferable with respect to binder resin, and 1-10 weight% is more preferable. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers having a perfluoroalkyl group in the side chain, oligomers, etc. are used, and the amount used is 0 to 1% by weight based on the binder resin. Is preferable, and 0.01 wt% to 0.5 wt% is more preferable. Moreover, antioxidant can also be used effectively. For example, conventionally known materials such as phenolic compounds, paraphenylenediamines, hydroquinones, organic sulfur compounds, organic phosphorus compounds, hindered amines and the like can be used, which is effective for stabilizing electrostatic characteristics against repeated use. As addition amount, 0 to 10 weight% is preferable with respect to binder resin, and 0.1 to 2 weight% is more preferable. Lubricants are often added for the purpose of improving the slipperiness of the surface and obtaining the effect of preventing foreign matter adhesion on the surface of the electrophotographic photoreceptor. Specifically, conventionally known materials such as silicone oils, silicone fine particles, fluororesin fine particles, and waxes can be used as they are. As addition amount, 0 to 30 weight% is preferable with respect to binder resin, and 1 to 20 weight% is more preferable.

  As a method for coating the charge transport layer, known methods such as dip coating, spray coating, bead coating, nozzle coating, spinner coating, ring coating, and the like can be used. After coating, it is manufactured by drying with the touch and then heating and drying in an oven or the like. Although the drying temperature of a charge transport layer changes with kinds of solvent contained in the coating liquid of a charge transport layer, it is preferable that it is 80-150 degreeC, and 100-140 degreeC is more preferable. The film thickness of the charge transport layer thus obtained is usually 10 to 50 μm. Considering the durability of the electrophotographic photosensitive member, it is preferable that the film thickness is thick. The thickness of the charge transport layer is preferably 30 μm or less, more preferably 25 μm or less, from the viewpoint of resolution and responsiveness. Regarding the lower limit, although it differs depending on the system to be used (particularly the charging potential), it is preferably 5 μm or more.

<About single-layer photosensitive layer>
In the present invention, the photosensitive layer can be used even if it has a single layer structure. The photosensitive layer is formed by dissolving or dispersing the above-described charge generating agent, charge transporting agent, binder resin, etc. in an appropriate solvent, and coating and drying the solution on a conductive support or an undercoat layer described later. Is done. As the charge generating agent and charge transporting agent (electron transporting agent and hole transporting agent), it is possible to use the materials mentioned in the above-described charge generating layer and charge transporting layer. Further, as the binder resin, in addition to the resins mentioned in the charge transport layer, the resins mentioned in the charge generation layer may be mixed and used. Further, the above-described polymer charge transfer agent can also be used favorably as the binder resin. The amount of the charge generator relative to 100 parts by weight of the binder resin is preferably 5 to 40 parts by weight, more preferably 10 to 30 parts by weight, and the amount of the charge transport agent is preferably 0 to 190 parts by weight, more preferably 50 to 50 parts by weight. 150 parts by weight. The photosensitive layer is dissolved or dispersed in a solvent such as tetrahydrofuran, dioxane, dichloroethane, cyclohexanone, toluene, methyl ethyl ketone, and acetone together with a charge transporting agent and binder resin, and this is dip coated, spray coated, bead coated, or ring coated. It can be formed by coating with a coat. If necessary, various additives such as a plasticizer, a leveling agent, an antioxidant, and a lubricant can be added. The film thickness of the photosensitive layer is suitably about 5 to 25 μm.

<About the undercoat layer>
In the electrophotographic photoreceptor of the present invention, an undercoat layer can be provided between the conductive support and the photosensitive layer. These subbing layers generally contain a resin as a main component. However, considering that a photosensitive layer is applied with a solvent on these resins, these resins are highly solvent-resistant to general organic solvents. It is desirable to use Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymerized polyamide (copolymerized nylon) and methoxymethylated polyamide (nylon), polyurethane, melamine resin, and phenol. Examples thereof include curable resins that form a three-dimensional network structure, such as resins, alkyd-melamine resins, isocyanates, and epoxy resins.

  In addition, it is possible and effective to add a metal oxide to the undercoat layer in order to prevent moire and reduce residual potential. Moire is a type of image defect in which interference fringes called moire are formed in an image due to optical interference inside the photosensitive layer when writing with coherent light such as laser light. Basically, it is necessary to contain a material having a large refractive index in order to prevent the occurrence of moire by scattering the incident laser light by the undercoat layer. In order to prevent moiré, a configuration in which an inorganic pigment is dispersed in a binder resin is most effective. As the inorganic pigment used, white pigments are effectively used, and metal oxides such as titanium oxide, zinc oxide, calcium fluoride, calcium oxide, silicon oxide, magnesium oxide, aluminum oxide, tin oxide, and zirconium oxide are used. And indium oxide.

  The undercoat layer preferably has a function of transferring a charge having the same polarity as the charge charged on the surface of the electrophotographic photosensitive member from the photosensitive layer to the conductive support side in terms of reducing the residual potential. Also plays its role. For example, in the case of a negatively charged electrophotographic photoreceptor, the residual potential can be reduced by having the undercoat layer have electronic conductivity. As these inorganic pigments, the metal oxides described above are effectively used, but the effect of reducing the residual potential by using an inorganic pigment with low resistance or increasing the addition ratio of the inorganic pigment to the binder resin. On the other hand, the effect of suppressing soiling may be reduced. Therefore, it is necessary to achieve both suppression of background contamination and reduction of residual potential by properly using them according to the layer structure and film thickness of the undercoat layer in the photoreceptor and adjusting the addition amount. In consideration of prevention of moire, increase in residual potential, and suppression of soiling, titanium oxide is most effectively used among the above metal oxides.

  These undercoat layers are mainly composed of a binder resin and an inorganic pigment (metal oxide), and can be wet-dispersed in a state including a solvent to obtain a coating dispersion. Examples of the solvent used include acetone, methyl ethyl ketone, methanol, ethanol, butanol, cyclohexanone, dioxane, and the like, and mixed solvents thereof. A coating liquid can be obtained by dispersing the inorganic pigment together with a solvent and a binder resin by a conventionally known method such as a ball mill, a sand mill, or an attriler. The binder resin may be added before dispersion or as a resin solution after dispersion. Further, if necessary, a dispersant may be added for the purpose of enhancing the dispersibility of the chemicals, additives, curing accelerators, and inorganic pigments necessary for curing (crosslinking). Using these coating liquids, they are formed on a conductive substrate using a conventionally known method such as dip coating, spray coating, ring coating, beat coating, or nozzle coating. After the application, it can be produced by drying or heating, and if necessary, drying or curing by a curing treatment such as light irradiation. Although the film thickness of an undercoat layer changes with kinds of inorganic pigment to contain, 0-20 micrometers is preferable and 2-10 micrometers is more preferable.

<About the charge blocking layer>
It is also possible to further provide a charge blocking layer between the conductive support and the undercoat layer or between the undercoat layer and the charge generation layer. The charge blocking layer is added to suppress the injection of holes from the conductive support, and the main purpose is to suppress the soiling. In the charge blocking layer, a binder resin is generally used as a main component. Examples of these resins include polyamide, alcohol-soluble polyamide (soluble nylon), water-soluble polyvinyl butyral, polyvinyl butyral, and polyvinyl alcohol. As a method for forming the charge blocking layer, the above-described method and a known coating method are employed. In addition, 0.05-2 micrometers is suitable for the thickness of a charge blocking layer. By adopting a two-layer structure of the charge blocking layer and the undercoat layer, the effect of suppressing scumming is drastically increased, but the influence of the increase in residual potential tends to increase. Therefore, it is necessary to determine the composition and thickness of the charge blocking layer and the undercoat layer with sufficient consideration.

<About protective layer>
The electrophotographic photoreceptor of the present invention is preferably provided with a protective layer on the photosensitive layer for the purpose of protecting the photosensitive layer.
As the frequency of computer use increases in recent years, there is an increasing tendency for image output by a printer, and high-speed output by a printer and longer life are desired. Therefore, it is desirable to provide a protective layer on the photosensitive layer to suppress deterioration of the photosensitive layer and improve durability.

Further, since the protective layer is provided on the photosensitive layer, it is necessary to consider the carrier transport ability that affects various characteristics.
For this reason, a film thickness and a layer structure are important also in a protective layer. Regarding the film thickness, in any case, it is important not to increase the film thickness more than necessary.

  The layer structure of the protective layer that can be effectively used in the present invention can be broadly classified into two types. One is a structure in which a filler is added to a binder resin, and the other is a structure using a crosslinked binder. However, it is not necessarily limited to these two types, and layer configurations other than the above two types may be adopted as long as the effects of the present invention are not impaired.

<About filler-added protective layer>
First, a configuration in which a filler is added to the protective layer (binder resin) will be described. (Hereinafter referred to as a filler-added protective layer).
The binder resin used in the protective layer is ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, polybutylene. , Polybutylene terephthalate, polycarbonate, polyarylate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, poly Examples thereof include resins such as vinyl chloride, polyvinylidene chloride, and epoxy resin. Of these, polycarbonate or polyarylate can be most preferably used.

Further, a filler is added to the binder resin. As the filler, either an organic filler material or an inorganic filler material may be used, or a mixture thereof may be used.
Among the fillers, examples of the organic filler material include fluorine resin powder such as polytetrafluoroethylene, silicone resin powder, and a-carbon powder. Examples of the inorganic filler material include copper, tin, aluminum, and indium. Metal powder, silica, tin oxide, zinc oxide, titanium oxide, indium oxide, antimony oxide, bismuth oxide, antimony-doped tin oxide, tin-doped indium oxide, metal oxides such as alumina, inorganics such as potassium titanate Materials. In particular, from the viewpoint of the hardness of the filler, among these, inorganic materials, inorganic pigments, and metal oxides are preferable, and silica, titanium oxide, and alumina can be used particularly effectively.

  The filler concentration in the protective layer varies depending on the type of filler used and the electrophotographic process conditions using the photoreceptor, but is preferably 5% by weight or more in terms of the ratio of filler to the total solid content on the outermost layer side of the protective layer. Is 10% by weight or more and 50% by weight or less, more preferably 30% by weight or less. Moreover, the volume average particle diameter of the filler to be used is preferably in the range of 0.1 μm to 2 μm, and preferably in the range of 0.3 μm to 1 μm. In this case, if the average particle size is too small, the wear resistance is not sufficiently exhibited, and if it is too large, the surface property of the coating film is deteriorated or the coating film itself cannot be formed.

  The average particle diameter of the filler in the present invention is a volume average particle diameter unless otherwise specified, and is determined by an ultracentrifugal automatic particle size distribution analyzer: CAPA-700 (manufactured by Horiba). At this time, the particle diameter (Median diameter) corresponding to 50% of the cumulative distribution was calculated. In addition, it is important that the standard deviation of each particle measured simultaneously is 1 μm or less. If the standard deviation is larger than this, the particle size distribution may be too wide to obtain the effects of the present invention.

Further, the pH of the filler used in the present invention greatly affects the resolution and the dispersibility of the filler. One possible reason is that hydrochloric acid or the like remains in the filler, particularly the metal oxide, during production. When the remaining amount is large, the occurrence of image blur is unavoidable, and depending on the remaining amount, the dispersibility of the filler may be affected.
Another reason is due to the difference in chargeability on the surface of the filler, particularly the metal oxide. Usually, particles dispersed in a liquid are charged positively or negatively, and ions having opposite charges gather to try to keep them electrically neutral, and an electric double layer is formed there. The dispersed state of the particles is stabilized. The potential (zeta potential) gradually decreases with increasing distance from the particle, and the potential in a region that is sufficiently away from the particle and electrically neutral is zero. Therefore, the stability increases as the repulsive force of the particles increases due to the increase in the absolute value of the zeta potential, and the particles tend to aggregate and become unstable as they approach zero. On the other hand, the zeta potential varies greatly depending on the pH value of the system, and at a certain pH value, the potential becomes zero and has an isoelectric point. Therefore, the dispersion system is stabilized by increasing the absolute value of the zeta potential as far as possible from the isoelectric point of the system.

In the configuration of the present invention, the filler having a pH at the isoelectric point of at least 5 is preferably from the viewpoint of image blur suppression, and the more basic the filler, the higher the effect. It was confirmed that there was. The filler having a high basic pH at the isoelectric point has a higher zeta potential when the system is acidic, so that dispersibility and stability thereof are improved.
Here, the pH of the filler in the present invention is the pH value at the isoelectric point from the zeta potential. At this time, the zeta potential was measured with a laser zeta potentiometer manufactured by Otsuka Electronics Co., Ltd.

Furthermore, as a filler that is less likely to cause image blurring, a filler having high electrical insulation (specific resistance is 10 ¹⁰ Ω · cm or more) is preferable, and a filler having a pH of 5 or more or a filler having a dielectric constant of 5 or more. The ones shown can be used particularly effectively. In addition, a filler having a pH of 5 or more or a filler having a dielectric constant of 5 or more can be used alone, or two or more fillers having a pH of 5 or less and a filler having a pH of 5 or more can be mixed. It is also possible to use a mixture of two or more fillers having a dielectric constant of 5 or less and a filler having a dielectric constant of 5 or more. Among these fillers, α-type alumina, which has high insulation properties, high thermal stability, and high wear resistance, is a hexagonal close-packed structure, from the viewpoint of suppressing image blur and improving wear resistance. It is particularly useful.

The specific resistance of the filler used in the present invention is defined as follows. Since the specific resistance value of a powder such as a filler varies depending on the filling rate, it is necessary to measure under certain conditions. In the present invention, the specific resistance value of the filler was measured using an apparatus having the same configuration as the measuring apparatus disclosed in JP-A-5-113688 (FIG. 1), and this value was used. In the measuring device, the electrode area is 4.0 cm ² . Prior to the measurement, a load of 4 kg is applied to the electrode on one side for 1 minute, and the sample amount is adjusted so that the distance between the electrodes is 4 mm. At the time of measurement, the measurement is performed with the upper electrode weight (1 kg) loaded, and the applied voltage is measured at 100V. The area of 10 ⁶ Ω · cm or higher was measured with a HIGH RESISTER METER (Yokogawa Hewlett Packard), and the area below it was measured with a digital multimeter (Fluk). The specific resistance value thus obtained is defined as the specific resistance value in the present invention.

  The dielectric constant of the filler was measured as follows. Using a cell similar to the measurement of the specific resistance as described above, after applying a load, the capacitance was measured, and the dielectric constant was determined from this. For the measurement of the capacitance, a dielectric loss measuring device (Ando Electric) was used.

Further, these fillers can be surface-treated with at least one kind of surface treatment agent, and it is preferable from the viewpoint of dispersibility of the fillers. Decreasing the dispersibility of the filler not only increases the residual potential, but also decreases the transparency of the coating, causes defects in the coating, and decreases the wear resistance. It can develop into a big problem. As the surface treatment agent, all conventionally used surface treatment agents can be used, but a surface treatment agent capable of maintaining the insulating properties of the filler is preferable. For example, a titanate coupling agent, an aluminum coupling agent, a zircoaluminate coupling agent, a higher fatty acid, or a mixed treatment of these with a silane coupling agent, Al ₂ O ₃ , TiO ₂ , ZrO ₂ , Silicone, aluminum stearate, or the like, or a mixture thereof is more preferable from the viewpoint of filler dispersibility and image blur. The treatment with the silane coupling agent is strongly influenced by image blur, but the influence may be suppressed by performing a mixing treatment of the surface treatment agent and the silane coupling agent. The surface treatment amount varies depending on the average primary particle size of the filler used, but is preferably 3 to 30 wt%, more preferably 5 to 20 wt%. If the surface treatment amount is less than this, the filler dispersion effect cannot be obtained, and if it is too much, the residual potential is significantly increased. These fillers may be used alone or in combination of two or more. The surface treatment amount of the filler is defined by the weight ratio of the surface treatment agent to be used with respect to the filler amount as described above.

  These filler materials can be dispersed by using an appropriate disperser. Further, from the viewpoint of the transmittance of the protective layer, it is preferable that the filler used is dispersed to the primary particle level and has less aggregates.

  In addition, the protective layer preferably contains a charge transport material in order to reduce residual potential and improve responsiveness. A known charge transport material can be used as the charge transport material. When a low molecular charge transport material is used as the charge transport material, a concentration gradient in the protective layer may be provided. In order to improve wear resistance, it is an effective means to reduce the concentration of the surface side. The concentration here refers to the ratio of the weight of the low molecular charge transporting material to the total weight of all the materials constituting the protective layer, and the concentration gradient is a gradient that lowers the concentration on the surface side in the above weight ratio. It shows that. The use of a polymer charge transport material is very advantageous in terms of enhancing the durability of the photoreceptor.

  In addition, a known polymer charge transport material can also be used as the binder resin for the protective layer. As an effect when this is used, an improvement in wear resistance and an effect of high-speed charge transport can be obtained.

  As a method for forming such a protective layer, a normal coating method is employed. In addition, about 0.1-10 micrometers is suitable for the thickness of the protective layer mentioned above.

<Cross-linked protective layer>
Next, a protective layer having a crosslinked structure will be described as a binder structure of the protective layer (hereinafter referred to as a crosslinked protective layer).
Regarding the formation of a cross-linked structure, a reactive monomer having a plurality of cross-linkable functional groups in one molecule is used to cause a cross-linking reaction using light or thermal energy to form a three-dimensional network structure. is there. This network structure functions as a binder resin and exhibits high wear resistance.

  Moreover, as the reactive monomer, a monomer having a charge transporting ability is used in whole or in part. By using such a monomer, a charge transporting site is formed in the network structure, and the function as a protective layer can be sufficiently exhibited. A reactive monomer having a triarylamine structure is effectively used as the monomer having charge transporting ability. By adopting such a configuration, a sufficient carrier transport speed can be secured and the transit time can be shortened.

  The protective layer having such a network structure has high wear resistance, but has a large volume shrinkage during the crosslinking reaction, and if it is too thick, it may cause cracks. In such a case, the protective layer may be a laminated structure, a low molecular dispersion polymer protective layer may be used for the lower layer (photosensitive layer side), and a protective layer having a crosslinked structure may be formed on the upper layer (surface side). good.

Among the crosslinkable protective layers, a crosslinkable protective layer having the following specific structure is particularly effectively used.
The cross-linkable protective layer having a specific configuration is formed by curing at least a trifunctional or higher functional radical polymerizable monomer having no charge transport structure and a radical polymerizable compound having a monofunctional charge transport structure. The electrophotographic photosensitive member according to the present invention preferably has this protective layer. Since it has a cross-linked structure obtained by curing a tri- or higher-functional radically polymerizable monomer, a three-dimensional network structure is developed, and a high hardness and high elasticity protective layer with a very high crosslink density is obtained, and it is uniform and smooth. High wear resistance and scratch resistance are achieved. As described above, it is important to increase the crosslink density on the surface of the photoreceptor, that is, the number of crosslink bonds per unit volume. However, since a large number of bonds are instantaneously formed in the curing reaction, internal stress due to volume shrinkage occurs. This internal stress increases as the thickness of the crosslinkable protective layer increases. Therefore, when the entire protective layer is cured, cracks and film peeling tend to occur. Even if this phenomenon does not appear initially, it may be likely to occur over time due to repeated use in the electrophotographic process and the influence of charging, development, transfer, cleaning hazards and thermal fluctuations.

  As a method for solving this problem, (1) a polymer component is introduced into the crosslinked layer and the crosslinked structure, (2) a large amount of monofunctional and bifunctional radically polymerizable monomers are used, and (3) a flexible group is introduced. Although the directionality which makes a cured resin layer soft, such as using the polyfunctional monomer which has, is mentioned, the crosslink density of a bridge | crosslinking layer becomes thin in any case, and remarkable wear resistance is not achieved. On the other hand, the electrophotographic photoreceptor of the present invention preferably has a crosslinkable protective layer having a high crosslink density in which a three-dimensional network structure is developed on the photosensitive layer (charge transport layer), preferably with a thickness of 1 μm or more and 10 μm or less. By providing, the above-mentioned cracks and film peeling do not occur, and very high wear resistance is achieved. By making the film thickness of the crosslinkable protective layer 2 μm or more and 8 μm or less, in addition to further improving the margin for the above problem, it is possible to select a material for increasing the crosslink density that leads to further improvement in wear resistance. It becomes possible.

  The reason why the electrophotographic photosensitive member of the present invention can suppress cracks and film peeling is that the cross-linkable protective layer can be thinned so that the internal stress does not increase, and the surface has a photoconductive layer or charge transport layer, so that the surface cross-linked type This is because the internal stress of the protective layer can be relaxed. For this reason, it is not necessary to contain a large amount of polymer material in the crosslinkable protective layer, and the polymer material and radical polymerizable composition (radical polymerizable monomer or radical polymerizable compound having a charge transporting structure) generated at this time are generated. Scratches and toner filming due to incompatibility with the cured product resulting from the reaction are unlikely to occur.

  Furthermore, when the thick film over the entire protective layer is cured by irradiation with light energy, the light transmission from the absorption by the charge transporting structure is limited, and the curing reaction may not sufficiently proceed. Therefore, in the present invention, by setting the thickness of the cross-linking protective layer to a thin film of preferably 10 μm or less, the curing reaction proceeds uniformly to the inside, and high wear resistance is maintained inside as well as the surface. In addition to the trifunctional radical polymerizable monomer, the cross-linked protective layer having the above specific structure further contains a radical polymerizable compound having a monofunctional charge transporting structure, which is the trifunctional or higher functional group. These radically polymerizable monomers are incorporated into the cross-linking during curing. On the other hand, when a low molecular charge transport material having no functional group is contained in the cross-linking protective layer, precipitation of the low molecular charge transport material and white turbidity occur due to the low compatibility, and the cross-linking protective layer machine The mechanical strength also decreases. On the other hand, when a bifunctional or higher-functional charge transporting compound is used as the main component, the crosslink structure is fixed by a plurality of bonds and the crosslink density is further increased. However, the charge transporting structure is very bulky, so that the cured resin structure is distorted. Becomes very large, which increases the internal stress of the crosslinked protective layer.

  In addition, the electrophotographic photoreceptor of the present invention has good electrical characteristics, and therefore has excellent repetitive stability, realizing high durability and high stability. This is because a radical polymerizable compound having a monofunctional charge transporting structure is used as a constituent material of the crosslinkable protective layer and is immobilized in a pendant shape between the crosslinks. As described above, the charge transport material having no functional group causes precipitation and clouding phenomenon, and the electrical characteristics are remarkably deteriorated in repeated use such as reduction in sensitivity and increase in residual potential. When a bifunctional or higher-functional charge transporting compound is used as the main component, it is fixed in the crosslinked structure with a plurality of bonds, so the intermediate structure (cation radical) during charge transport cannot be kept stable, Sensitivity decreases due to traps and residual potential increases. Such deterioration of the electric characteristics appears as an image such as a decrease in image density and thinning of characters. Furthermore, in the electrophotographic photosensitive member of the present invention, a high mobility design with few charge traps used in the conventional electrophotographic photosensitive member can be applied as it is as a lower photosensitive layer (charge transport layer). The electrical side effects of the protective layer can be minimized.

Next, the constituent material of the crosslinking type protective layer coating solution will be described.
The trifunctional or higher functional radical polymerizable monomer having no charge transport structure used in the present invention includes a hole transport structure such as triarylamine, hydrazone, pyrazoline, and carbazole, and a condensed polycyclic quinone, for example. This refers to a monomer having no electron transport structure such as diphenoquinone, an electron-withdrawing aromatic ring having a cyano group or a nitro group, and having three or more radical polymerizable functional groups. The radical polymerizable functional group may be any group as long as it has a carbon-carbon double bond and is capable of radical polymerization. Examples of these radical polymerizable functional groups include 1-substituted ethylene functional groups and 1,1-substituted ethylene functional groups shown below.
(1) Examples of the 1-substituted ethylene functional group include functional groups represented by the following general formula (10).

_{CH 2 = CH-X 1 -} ··· formula (10)

(In the formula (10), X ₁ is an arylene group such as a phenylene group or a naphthylene group which may have a substituent, an alkenylene group which may have a substituent, a —CO— group, — COO- group, -CON (R ₁₀₎ - group (R ₁₀ is hydrogen, alkyl group such as a methyl group, an ethyl group, a benzyl group, naphthylmethyl group, an aralkyl group such as a phenethyl group, a phenyl group, a naphthyl group Represents an aryl group), or represents an -S- group.)

  Specific examples of these functional groups include vinyl group, styryl group, 2-methyl-1,3-butadienyl group, vinylcarbonyl group, acryloyloxy group, acryloylamide group, vinylthioether group and the like.

(2) Examples of the 1,1-substituted ethylene functional group include functional groups represented by the following general formula (11).

_{CH 2 = CY-X 2 -} ··· formula (11)

(In the formula (11), Y represents an alkyl group which may have a substituent, an aralkyl group which may have a substituent, a phenyl group which may have a substituent, or a naphthyl group. Aryl group such as halogen atom, cyano group, nitro group, alkoxy group such as methoxy group or ethoxy group, -COOR ₁₁ group (R ₁₁ is hydrogen atom, methyl group optionally having substituent, ethyl group Alkyl groups such as benzyl which may have a substituent, aralkyl groups such as phenethyl group, phenyl groups which may have a substituent, aryl groups such as naphthyl group, or -CONR ₁₂ R ₁₃ (R ₁₂ and R ₁₃ are a hydrogen atom, an alkyl group such as an optionally substituted methyl group or an ethyl group, an aralkyl group such as an optionally substituted benzyl group, naphthylmethyl group or phenethyl group; Or a substituent Has optionally also a phenyl group, an aryl group such as phenyl or naphthyl, may be identical to one another, represent represent.) A which may be.) A different, and, X ₂ is the general formula (10) And the same substituent as X ₁ , or a single bond or an alkylene group, provided that at least one of Y and X ₂ is an oxycarbonyl group, a cyano group, an alkenylene group, or an aromatic ring.

Specific examples of these functional groups include an α-acryloyloxy chloride group, a methacryloyloxy group, an α-cyanoethylene group, an α-cyanoacryloyloxy group, an α-cyanophenylene group, and a methacryloylamino group.
In addition, examples of the substituent further substituted on the substituents for X ₁ , X ₂ , and Y include, for example, halogen groups, nitro groups, cyano groups, methyl groups, ethyl groups and other alkyl groups, methoxy groups, ethoxy groups, and the like And an aryloxy group such as a phenoxy group, an aryl group such as a phenyl group and a naphthyl group, and an aralkyl group such as a benzyl group and a phenethyl group.

Among these radical polymerizable functional groups, acryloyloxy group and methacryloyloxy group are particularly useful. A compound having 3 or more acryloyloxy groups can be prepared by, for example, using a compound having 3 or more hydroxyl groups in the molecule and acrylic acid (salt), acrylic acid halide, or acrylic ester, and performing an ester reaction or a transesterification reaction. Can be obtained. A compound having three or more methacryloyloxy groups can be obtained in the same manner.
Further, the radical polymerizable functional groups in the monomer having three or more radical polymerizable functional groups may be the same or different.

  Specific examples of the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure include the following, but the present invention is not limited to these compounds.

  That is, examples of the radical polymerizable monomer used in the present invention include trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate, trimethylolpropane alkylene-modified triacrylate, trimethylolpropane ethyleneoxy-modified (hereinafter referred to as EO-modified). ) Triacrylate, trimethylolpropane propyleneoxy modified (hereinafter PO modified) triacrylate, trimethylolpropane caprolactone modified triacrylate, trimethylolpropane alkylene modified trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate Glycerol epichlorohydrin modified (hereinafter ECH modified) tria Relate, glycerol EO-modified triacrylate, glycerol PO-modified triacrylate, tris (acryloxyethyl) isocyanurate, dipentaerythritol hexaacrylate (DPHA), dipentaerythritol caprolactone-modified hexaacrylate, dipentaerythritol hydroxypentaacrylate, alkylated di Pentaerythritol pentaacrylate, alkylated dipentaerythritol tetraacrylate, alkylated dipentaerythritol triacrylate, dimethylolpropane tetraacrylate (DTMPTA), pentaerythritol ethoxytetraacrylate, phosphoric acid EO-modified triacrylate, 2, 2, 5, 5 , -Tetrahydroxymethylcyclopentanone tetraacrylate And the like, which may be used in combination either alone or in combination.

  Further, the trifunctional or higher functional radical polymerizable monomer having no charge transport structure used in the present invention has a molecular weight relative to the number of functional groups in the monomer in order to form a dense crosslink in the crosslinkable protective layer. The ratio (molecular weight / functional group number) is preferably 250 or less. On the other hand, if this ratio is larger than 250, the crosslinked protective layer tends to be soft and wear resistance tends to decrease somewhat. Therefore, among the monomers exemplified above, monomers having modifying groups such as EO, PO, caprolactone, etc. In the method, it is not preferable to use a compound having an extremely long modifying group alone. In addition, the proportion of the trifunctional or higher functional radical polymerizable monomer having no charge transporting structure used in the crosslinkable protective layer is 20 to 80% by weight, preferably 30 to 70% by weight, based on the total amount of the crosslinkable protective layer. is there. If the monomer component is less than 20% by weight, the three-dimensional crosslink density of the crosslinkable protective layer is small, and it is difficult to achieve a dramatic improvement in wear resistance as compared with the case of using a conventional thermoplastic binder resin. On the other hand, when it exceeds 80% by weight, the content of the charge transporting compound is lowered, and the electrical characteristics tend to be deteriorated. The electrical characteristics and abrasion resistance required differ depending on the process used, and the thickness of the cross-linked protective layer in the electrophotographic photosensitive member varies accordingly. A range of 70% by weight is most preferred.

  The radically polymerizable compound having a monofunctional charge transporting structure used for the crosslinked protective layer is, for example, a hole transporting structure such as triarylamine, hydrazone, pyrazoline, or carbazole, or a condensed polycyclic quinone, for example. It refers to a compound having an electron transport structure such as an electron-withdrawing aromatic ring having diphenoquinone, a cyano group or a nitro group and having one radical polymerizable functional group. Examples of the radical polymerizable functional group include those shown in the above radical polymerizable monomer, and acryloyloxy group and methacryloyloxy group are particularly useful. As a charge transporting structure, a triarylamine structure has a high effect, and in particular, when a compound represented by the structure of the following general formula (A) or (B) is used, the electrical characteristics such as sensitivity and residual potential Is well maintained.

(In Formulas (A) and (B), R ₁ may have a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Aryl group, cyano group, nitro group, alkoxy group, —COOR ₇ (R ₇ has a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. An aryl group), a carbonyl halide group or CONR ₈ R ₉ (R ₈ and R ₉ are a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or Represents an aryl group which may have a substituent, and may be the same or different from each other, and Ar ₁ and Ar ₂ represent a substituted or unsubstituted arylene group, and may be the same or different which may be .Ar _3, Ar ₄ is substituted if Represents an unsubstituted aryl group, which may be the same or different, X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, O represents an oxygen atom, a sulfur atom, or a vinylene group, Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether divalent group, or an alkyleneoxycarbonyl divalent group, and m and n are integers of 0 to 3. Represents.)

Specific examples of the compounds represented by the structures of the general formulas (A) and (B) are shown below.
In the general formulas (A) and (B), in the substituent of R ₁ , examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group, and examples of the aryl group include a phenyl group and a naphthyl group. The aralkyl group includes a benzyl group, a phenethyl group, and a naphthylmethyl group, and the alkoxy group includes a methoxy group, an ethoxy group, a propoxy group, and the like. These include a halogen atom, a nitro group, a cyano group, and a methyl group. Substituted with an alkyl group such as an ethyl group, an alkoxy group such as a methoxy group or an ethoxy group, an aryloxy group such as a phenoxy group, an aryl group such as a phenyl group or a naphthyl group, an aralkyl group such as a benzyl group or a phenethyl group, etc. May be.
Among the substituents for R ₁ , particularly preferred are a hydrogen atom and a methyl group.

Ar ₃ and Ar ₄ represent a substituted or unsubstituted aryl group, and in the present invention, the aryl group includes a condensed polycyclic hydrocarbon group, a non-condensed cyclic hydrocarbon group, and a heterocyclic group, The group of is mentioned.

  The condensed polycyclic hydrocarbon group preferably has 18 or less carbon atoms forming a ring, for example, a pentanyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptaenyl group, a biphenylenyl group, an as-indacenyl group. , S-indacenyl group, fluorenyl group, acenaphthylenyl group, preadenyl group, acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aceanthrylenyl group, triphenylyl group, pyrenyl group , A chrycenyl group, a naphthacenyl group, and the like.

  Examples of the non-fused cyclic hydrocarbon group include monovalent groups of monocyclic hydrocarbon compounds such as benzene, diphenyl ether, polyethylene diphenyl ether, diphenyl thioether and diphenyl sulfone, or biphenyl, polyphenyl, diphenylalkane, diphenylalkene, diphenylalkyne, Monovalent groups of non-condensed polycyclic hydrocarbon compounds such as triphenylmethane, distyrylbenzene, 1,1-diphenylcycloalkane, polyphenylalkane, and polyphenylalkene, or ring assemblies such as 9,9-diphenylfluorene And monovalent groups of hydrocarbon compounds.

  Examples of the heterocyclic group include monovalent groups such as carbazole, dibenzofuran, dibenzothiophene, oxadiazole, and thiadiazole.

The aryl group represented by Ar ₃ or Ar ₄ may have a substituent as shown below, for example.
(1) Halogen atom, cyano group, nitro group and the like.
(2) Alkyl groups, preferably C1 to C12, especially C1 to C8, more preferably C1 to C4 linear or branched alkyl groups. These alkyl groups further include a fluorine atom, a hydroxyl group, a cyano group, It may have a C1-C4 alkoxy group, a phenyl group, or a phenyl group substituted with a halogen atom, a C1-C4 alkyl group or a C1-C4 alkoxy group. Specifically, methyl group, ethyl group, n-butyl group, i-propyl group, t-butyl group, s-butyl group, n-propyl group, trifluoromethyl group, 2-hydroxyethyl group, 2-ethoxyethyl Group, 2-cyanoethyl group, 2-methoxyethyl group, benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, 4-phenylbenzyl group and the like.
(3) An alkoxy group (—OR ₂ ), and R ₂ represents the alkyl group defined in (2). Specifically, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, t-butoxy group, n-butoxy group, s-butoxy group, i-butoxy group, 2-hydroxyethoxy group, benzyloxy group And a trifluoromethoxy group.
(4) An aryloxy group, and examples of the aryl group include a phenyl group and a naphthyl group. This may contain a C1-C4 alkoxy group, a C1-C4 alkyl group or a halogen atom as a substituent. Specific examples include a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methoxyphenoxy group, and a 4-methylphenoxy group.
(5) Alkyl mercapto group or aryl mercapto group, and specific examples include methylthio group, ethylthio group, phenylthio group, p-methylphenylthio group and the like.
(6) A group represented by the following formula (C).

(In the formula (C), R ₃ and R ₄ each independently represents a hydrogen atom, an alkyl group defined in the above (2), or an aryl group. Examples of the aryl group include a phenyl group, a biphenyl group, and a naphthyl group. These may contain a C1-C4 alkoxy group, a C1-C4 alkyl group or a halogen atom as a substituent, and R ₃ and R ₄ may form a ring together.)
Specifically, amino group, diethylamino group, N-methyl-N-phenylamino group, N, N-diphenylamino group, N, N-di (tolyl) amino group, dibenzylamino group, piperidino group, morpholino group And pyrrolidino group.
(7) An alkylenedioxy group or an alkylenedithio group such as a methylenedioxy group or a methylenedithio group.
(8) A substituted or unsubstituted styryl group, a substituted or unsubstituted β-phenylstyryl group, a diphenylaminophenyl group, a ditolylaminophenyl group, and the like.

The arylene group represented by Ar ₁ or Ar ₂ is a divalent group derived from the aryl group represented by Ar ₃ or Ar ₄ .

  X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group.

  The substituted or unsubstituted alkylene group is a C1 to C12, preferably C1 to C8, more preferably a C1 to C4 linear or branched alkylene group. These alkylene groups further include a fluorine atom, a hydroxyl group, It may have a cyano group, a C1-C4 alkoxy group, a phenyl group, or a phenyl group substituted with a halogen atom, a C1-C4 alkyl group or a C1-C4 alkoxy group. Specifically, methylene group, ethylene group, n-butylene group, i-propylene group, t-butylene group, s-butylene group, n-propylene group, trifluoromethylene group, 2-hydroxyethylene group, 2-ethoxyethylene Group, 2-cyanoethylene group, 2-methoxyethylene group, benzylidene group, phenylethylene group, 4-chlorophenylethylene group, 4-methylphenylethylene group, 4-biphenylethylene group and the like.

  The substituted or unsubstituted cycloalkylene group is a C5 to C7 cyclic alkylene group, and these cyclic alkylene groups have a fluorine atom, a hydroxyl group, a C1 to C4 alkyl group, and a C1 to C4 alkoxy group. May be. Specific examples include a cyclohexylidene group, a cyclohexylene group, and a 3,3-dimethylcyclohexylidene group.

  The substituted or unsubstituted alkylene ether group represents ethyleneoxy, propyleneoxy, ethylene glycol, propylene glycol, diethylene glycol, tetraethylene glycol, tripropylene glycol, alkylene ether group alkylene group is hydroxyl group, methyl group, ethyl group, etc. You may have the substituent of.

  The vinylene group is a group represented by the following formula (D) or (E).

(In formula (D), R ₅ is hydrogen, an alkyl group (the same as the alkyl group defined in (2) above), an aryl group (the same as the aryl group represented by Ar ₃ or Ar ₄ above), and a is 1 Or 2, b represents 1-3.

Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether divalent group, or an alkyleneoxycarbonyl divalent group.
Examples of the substituted or unsubstituted alkylene group include the same alkylene groups as those described above for X.
Examples of the substituted or unsubstituted alkylene ether divalent group include the alkylene ether divalent group of X.
Examples of the alkyleneoxycarbonyl divalent group include a caprolactone divalent modifying group.

  Further, the radical polymerizable compound having a monofunctional charge transporting structure is more preferably a compound having the structure of the following general formula (F).

(In the formula (F), o, p and q are each an integer of 0 or 1, Ra represents a hydrogen atom or a methyl group, Rb and Rc represent a substituent other than a hydrogen atom and an alkyl group having 1 to 6 carbon atoms. And s and t each represent an integer of 0 to 3. Za is a single bond, a methylene group, an ethylene group, or a group represented by the following formula (G).)

  As the compound represented by the general formula (F), a compound in which the substituents of Rb and Rc are a methyl group and an ethyl group is particularly preferable.

The radical polymerizable compound having a monofunctional charge transporting structure represented by the above general formulas (A) and (B), particularly (F) used in the present invention is polymerized by releasing the carbon-carbon double bond on both sides. Therefore, in the polymer that does not become a terminal structure, is incorporated in the chain polymer, and is crosslinked by polymerization with a tri- or higher functional radical polymerizable monomer, it exists in the main chain of the polymer, and Present in the main chain-cross-linked chain (this cross-linked chain has an intermolecular cross-linked chain between one polymer and another polymer, and a main chain folded in one polymer. There is an intramolecular cross-linked chain that crosslinks the site and another site derived from the polymerized monomer at a position away from this in the main chain), but even if it exists in the main chain, Even if present in the triarylamine structure suspended from the chain moiety, It has at least three aryl groups arranged in the radial direction from and is bulky, but it is not directly bonded to the chain part and is suspended from the chain part via a carbonyl group etc. Since these triarylamine structures can be arranged adjacent to each other in the polymer, the structural distortion in the molecule is small, and the electrophotographic photoreceptor is protected. In the case of a layer, it is presumed that an intramolecular structure that is relatively free from interruption of the charge transport pathway can be adopted.

  Specific examples of the radically polymerizable compound having a monofunctional charge transporting structure suitably used in the present invention are shown below, but the present invention is not limited to compounds having these structures.

  In the present invention, the crosslinkable protective layer is obtained by simultaneously curing a radically polymerizable monomer having no charge transporting structure and a radically polymerizable compound having a charge transporting structure. For the purpose, filler fine particles can be contained.

  The filler fine particle-containing cross-linking protective layer has a high cross-linking density, and has higher wear resistance of the resin part than non-cross-linked filler-containing binder resin layers, thereby suppressing uneven wear. In addition to this, the filler fine particles dispersed in the resin are caught by the cured resin cross-linked matrix, and since the filler holding power of the cross-linked matrix is large, the filler is prevented from falling off. Therefore, it is considered that the wear resistance is greatly increased.

  As the filler fine particles, the following can be used. Examples of the organic filler material include fluorine resin powder such as polytetrafluoroethylene, silicone resin powder, and carbon fine particles. The carbon fine particles are particles having a structure mainly composed of carbon, and are particles having a structure such as amorphous, diamond, graphite, amorphous carbon, fullerene, zeppelin, carbon nanotube, carbon nanohorn. Among these structures, particles containing hydrogen-containing diamond-like carbon or amorphous carbon structure have good mechanical and chemical durability. The diamond-like carbon or amorphous carbon film containing hydrogen is a particle in which similar structures such as a diamond structure having an SP3 orbit, a graphite structure having an SP2 orbit, and an amorphous carbon structure are mixed. Diamond-like carbon or amorphous carbon fine particles are not limited to carbon, but may contain other elements such as hydrogen, oxygen, nitrogen, fluorine, boron, phosphorus, chlorine, bromine and iodine. Absent.

  Examples of inorganic filler materials include metal powders such as copper, tin, aluminum, and indium, metal oxides such as silicon oxide, tin oxide, zinc oxide, titanium oxide, indium oxide, antimony oxide, and bismuth oxide, and potassium titanate. An inorganic material is mentioned. In particular, it is advantageous to use an inorganic material among them from the viewpoint of the hardness of the filler. In particular, metal oxides are good, and silicon oxide, aluminum oxide, and titanium oxide can be used effectively. Also, fine particles such as colloidal silica and colloidal alumina can be used effectively.

  The average primary particle size of the filler is preferably 0.01 to 0.9 μm from the viewpoint of light transmittance and wear resistance of the crosslinked protective layer, and more preferably 0.1 μm to 0.5 μm. When the average primary particle size of the filler is 0.01 μm or less, it causes a decrease in wear resistance, a decrease in dispersibility, etc., and when it is 0.9 μm or more, the sedimentation property of the filler is promoted in the dispersion liquid. In addition, toner filming may occur.

  The higher the filler material concentration in the crosslinkable protective layer, the better the wear resistance, but if it is too high, the residual potential increases, the writing light transmittance of the surface layer decreases, and side effects may occur. is there. Therefore, it is about 50% by weight or less, preferably about 30% by weight or less based on the total solid content. Furthermore, these fillers can be surface-treated with at least one kind of surface treatment agent, and it is preferable from the viewpoint of dispersibility of the fillers. Decreasing the dispersibility of the filler not only increases the residual potential, but also decreases the transparency of the coating, causes defects in the coating, and decreases the wear resistance. It can develop into a big problem.

As the surface treatment agent, a conventionally used surface treatment agent can be used, but a surface treatment agent capable of maintaining the insulating properties of the filler is preferable. For example, a titanate coupling agent, an aluminum coupling agent, a zircoaluminate coupling agent, a higher fatty acid, etc., or a mixing treatment of these with a silane coupling agent, Al ₂ O ₃ , TiO ₂ , ZrO ₂ , Silicone, aluminum stearate, or the like, or a mixture thereof is more preferable from the viewpoint of filler dispersibility and image drift prevention. The treatment with the silane coupling agent has a strong influence on the image flow, but the influence may be suppressed by performing a mixing treatment of the surface treatment agent and the silane coupling agent. The surface treatment amount varies depending on the average primary particle size of the filler used, but is preferably 3 to 30% by weight, and more preferably 5 to 20% by weight. If the surface treatment amount is less than this, the filler dispersion effect cannot be obtained, and if it is too much, the residual potential is significantly increased. These filler materials may be used alone or in combination of two or more.

  In the present invention, in order to improve environmental resistance, in particular, for the purpose of preventing a decrease in sensitivity, an increase in residual potential, a decrease in charge, etc., a charge generation layer, a charge transport layer, a single-layer photosensitive layer, an undercoat layer, an intermediate layer It is possible and effective to add an antioxidant, a plasticizer, a lubricant, a UV absorber and a leveling agent to at least one layer such as a protective layer. Representative materials of these compounds are described below.

  Examples of the antioxidant that can be added to each layer include, but are not limited to, the following.

(A) Phenol compound 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, n-octadecyl-3- (4′- Hydroxy-3 ′, 5′-di-tert-butylphenol), 2,2′-methylene-bis- (4-methyl-6-tert-butylphenol), 2,2′-methylene-bis- (4- Ethyl-6-tert-butylphenol), 4,4′-thiobis- (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis- (3-methyl-6-tert-butylphenol), 1,1 , 3-Tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4 -Hydroxybenzyl) benzene, te Lakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, bis [3,3′-bis (4′-hydroxy-3′-t-butyl) Phenyl) butyric acid] cricol ester, tocopherols and the like.
(B) Paraphenylenediamines N-phenyl-N′-isopropyl-p-phenylenediamine, N, N′-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylene Diamine, N, N′-di-isopropyl-p-phenylenediamine, N, N′-dimethyl-N, N′-di-t-butyl-p-phenylenediamine and the like.
(C) Hydroquinones 2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2 -(2-octadecenyl) -5-methylhydroquinone and the like.
(D) Organic sulfur compounds Dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, ditetradecyl-3,3′-thiodipropionate, and the like.
(E) Organic phosphorus compounds Triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine and the like.

  Examples of the plasticizer that can be added to each layer include, but are not limited to, the following.

(A) Phosphate ester plasticizer Triphenyl phosphate, tricresyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, trichloroethyl phosphate, cresyl diphenyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, Triphenyl phosphate etc.
(B) Phthalate ester plasticizers Dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dibutyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, diisooctyl phthalate, di-n-octyl phthalate, phthalate Dinonyl acid, diisononyl phthalate, diisodecyl phthalate, diundecyl phthalate, ditridecyl phthalate, dicyclohexyl phthalate, butyl benzyl phthalate, butyl lauryl phthalate, methyl oleyl phthalate, octyl decyl phthalate, dibutyl fumarate, dioctyl fumarate Such.
(C) Aromatic carboxylic acid ester plasticizers Trioctyl trimellitic acid, tri-n-octyl trimellitic acid, octyl oxybenzoate, and the like.
(D) Aliphatic dibasic ester plasticizer dibutyl adipate, di-n-hexyl adipate, di-2-ethylhexyl adipate, di-n-octyl adipate, adipic acid n-octyl-n-decyl , Diisodecyl adipate, dicapryl adipate, di-2-ethylhexyl azelate, dimethyl sebacate, diethyl sebacate, dibutyl sebacate, di-n-octyl sebacate, di-2-ethylhexyl sebacate, di-2 sebacate -Ethoxyethyl, dioctyl succinate, diisodecyl succinate, dioctyl tetrahydrophthalate, di-n-octyl tetrahydrophthalate and the like.
(E) Fatty acid ester derivatives butyl oleate, glycerin monooleate, methyl acetylricinoleate, pentaerythritol ester, dipentaerythritol hexaester, triacetin, tributyrin and the like.
(F) Oxyacid ester plasticizers Methyl acetyl ricinoleate, butyl acetyl ricinoleate, butyl phthalyl butyl glycolate, tributyl acetyl citrate and the like.
(G) Epoxy plasticizer Epoxidized soybean oil, epoxidized linseed oil, butyl epoxy stearate, decyl epoxy stearate, octyl epoxy stearate, benzyl epoxy stearate, dioctyl epoxy hexahydrophthalate, didecyl epoxy hexahydrophthalate, etc. .
(H) Dihydric alcohol ester plasticizers such as diethylene glycol dibenzoate and triethylene glycol di-2-ethylbutyrate.
(I) Chlorinated plasticizer Chlorinated paraffin, chlorinated diphenyl, chlorinated fatty acid methyl, methoxychlorinated fatty acid methyl and the like.
(J) Polyester plasticizer Polypropylene adipate, polypropylene sebacate, polyester, acetylated polyester and the like.
(K) Sulfonic acid derivatives p-toluenesulfonamide, o-toluenesulfonamide, p-toluenesulfoneethylamide, o-toluenesulfoneethylamide, toluenesulfone-N-ethylamide, p-toluenesulfone-N-cyclohexylamide and the like.
(L) Citric acid derivatives Triethyl citrate, triethyl acetylcitrate, tributyl citrate, tributyl acetylcitrate, tri-2-ethylhexyl acetylcitrate, acetylcitrate-n-octyldecyl, and the like.
(M) Others Terphenyl, partially hydrogenated terphenyl, camphor, 2-nitrodiphenyl, dinonylnaphthalene, methyl abietate and the like.

  Examples of the lubricant that can be added to each layer include, but are not limited to, the following.

(A) Hydrocarbon compounds Liquid paraffin, paraffin wax, microwax, low-polymerized polyethylene and the like.
(B) Fatty acid compounds Lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid and the like.
(C) Fatty acid amide compounds Stearylamide, palmitylamide, oleinamide, methylenebisstearamide, ethylenebisstearamide and the like.
(D) Ester compounds Lower alcohol esters of fatty acids, polyhydric alcohol esters of fatty acids, fatty acid polyglycol esters, and the like.
(E) Alcohol compounds Cetyl alcohol, stearyl alcohol, ethylene glycol, polyethylene glycol, polyglycerol and the like.
(F) Metal soap Lead stearate, cadmium stearate, barium stearate, calcium stearate, zinc stearate, magnesium stearate and the like.
(G) Natural wax Carnauba wax, candelilla wax, beeswax, whale wax, ibota wax, montan wax and the like.
(H) Others Silicone compounds, fluorine compounds, etc.

  Examples of the ultraviolet absorber that can be added to each layer include, but are not limited to, the following.

(A) Benzophenone series 2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,2 ′, 4-trihydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,2′-dihydroxy-4- Such as methoxybenzophenone.
(B) Salsylates Phenyl salsylates, 2,4 di-t-butylphenyl 3,5-di-t-butyl 4-hydroxybenzoate, and the like.
(C) Benzotriazole series (2′-hydroxyphenyl) benzotriazole, (2′-hydroxy5′-methylphenyl) benzotriazole, (2′-hydroxy5′-methylphenyl) benzotriazole, (2′-hydroxy3) '-Tertiarybutyl 5'-methylphenyl) 5-chlorobenzotriazole and the like.
(D) Cyanoacrylate-based ethyl-2-cyano-3,3-diphenyl acrylate, methyl 2-carbomethoxy 3 (paramethoxy) acrylate, and the like.
(E) Quencher (metal complex)
Nickel (2,2′thiobis (4-t-octyl) phenolate) normal butylamine, nickel dibutyldithiocarbamate, nickel dibutyldithiocarbamate, cobalt dicyclohexyldithiophosphate and the like.
(F) HALS (hindered amine)
Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3- (3 5-di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6 6-tetramethylpyridine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4-benzoyloxy- 2,2,6,6-tetramethylpiperidine and the like.

The present invention will be described more specifically with reference to the following examples.
Of the following examples, Examples 6 to 10, 12, 14, 16, 18, 20, 22, 24, and 26, that is, those using the α-phenylstilbene compound of Synthesis Example 1 described in detail later. These are test examples corresponding to reference examples not belonging to the scope of the present invention.
Production Example 1 (diphenol compound described in Japanese Patent No. 354099)
4,4′-Dimethyl-4 ″-[2,2-bis (4-methoxyphenyl) vinyl] triphenylamine 11.0 g (21.5 mmol) and sodium thioethylate 10.0 g (107 mmol) were dried. It was taken up in 110 ml of DMF, heated to reflux for 3 hours under a nitrogen stream, allowed to cool to room temperature, then the contents were poured into ice water and neutralized with concentrated hydrochloric acid, extracted with ethyl acetate, the organic layer washed with water and dried. After the solvent was distilled off, column chromatography with silica gel [eluent: toluene / ethyl acetate (7/1 vol.)] Gave 10.87 g of yellow powder, which was recrystallized from a mixed solvent of cyclohexane and toluene. After drying under reduced pressure, 9.59 g of 4,4′-dimethyl-4 ″-[2,2-bis (4-hydroxyphenyl) vinyl] triphenylamine in the form of a yellow powder Was obtained yield 92.3%).

Production Example 2
29.4 g of diphenol obtained in Production Example 1 was dissolved in 180 ml of dehydrated pyridine, and 22.5 ml of trifluoromethanesulfonic anhydride was added dropwise at 0 to 2 ° C. over 90 minutes under a nitrogen stream. After dropping, the mixture was stirred at the same temperature for 30 minutes, and further stirred at room temperature for 4 hours. The reaction product was poured into water, extracted with ethyl acetate, washed with dilute hydrochloric acid and water, dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. This was subjected to column chromatography (silica gel, eluent: toluene / hexane = 1/2) to obtain 43.3 g of ditriflate represented by the following chemical formula (2) as a yellow glassy substance.

  In addition, elemental analysis of the ditriflate obtained in Production Example 2 was performed, and it was confirmed that the target product was obtained. The elemental analysis values are shown in Table 1 below.

Furthermore, the infrared absorption spectrum (KBr tablet method) of ditriflate obtained in Production Example 2 is shown in FIG. The SO ₂ stretching vibration is detected in the spectrum of 1427 and 1141 (cm ⁻¹ ), and the CF stretching vibration is detected in the spectrum of 1212 and 885 (cm ⁻¹ ). As shown in FIG. 5, any stretching vibration of SO ₂ and CF is detected from the ditriflate obtained in Production Example 2.

Synthesis example 1
3.74 g of ditriflate obtained in Production Example 2 and 1.86 g of diphenylamine were dissolved in 25 ml of toluene, and 183 mg of tris (dibenzylideneacetone) dipalladium, 80 mg of N-phenylindol-2-yl-dicyclohexylphosphine and sodium -Tert-butoxide 1.44g was added and it recirculate | refluxed under nitrogen stream for 3 hours. After standing to cool, the insoluble matter was filtered off, the filtrate was dried, and the crude product was subjected to column chromatography (silica gel, eluent; toluene / hexane = 1/2), and yellow α- represented by the following chemical formula (3) 2.0 g of phenylstilbene compound was obtained. The melting point of the obtained α-phenylstilbene compound was 187.5 to 188.5 ° C.

  In addition, elemental analysis of the α-phenylstilbene compound obtained in Synthesis Example 1 was performed, and it was confirmed that the desired product was obtained. The elemental analysis values are shown in Table 2 below.

  Furthermore, the infrared absorption spectrum (KBr tablet method) of the α-phenylstilbene compound obtained in Synthesis Example 1 is shown in FIG.

Synthesis example 2
1.50 g of ditriflate obtained in Production Example 2, 1.45 g of 4- (diphenylamino) phenylboronic acid represented by the following chemical formula (4) (manufactured by Tokyo Chemical Industry Co., Ltd.), 72 mg of tetrakistriphenylphosphine palladium Dissolved in a degassed mixed solvent of 40 ml of toluene / 10 ml of ethanol, 4 ml of 2M sodium carbonate aqueous solution was added thereto, and the mixture was refluxed for 21 hours under a nitrogen stream. After cooling, the contents are poured into water, extracted with toluene, the toluene layer is washed with water and dried, and then subjected to column chromatography (silica gel, eluent: toluene / hexane = 2/3). 1.2 g of the α-phenylstilbene compound obtained was obtained. The melting point of the α-phenylstilbene compound obtained was glassy and could not be measured.

  Further, elemental analysis of the α-phenylstilbene compound obtained in Synthesis Example 2 was performed, and it was confirmed that the desired product was obtained. The elemental analysis values are shown in Table 3 below.

  Furthermore, the infrared absorption spectrum (KBr tablet method) of the α-phenylstilbene compound obtained in Synthesis Example 2 is shown in FIG.

Subsequently, a synthesis example of a charge generation material (titanyl phthalocyanine crystal) will be described.
(Synthesis Example 3)
(Synthesis of titanyl phthalocyanine crystal)
The synthesis was in accordance with Japanese Patent Application Laid-Open No. 2004-83859. That is, 292 g of 1,3-diiminoisoindoline and 1800 g of sulfolane are mixed, and 204 g of titanium tetrabutoxide is added dropwise under a nitrogen stream. After completion of the dropwise addition, the temperature was gradually raised to 180 ° C., and the reaction was carried out by stirring for 5 hours while maintaining the reaction temperature between 170 ° C. and 180 ° C. After the reaction is complete, the mixture is allowed to cool, and then the precipitate is filtered, washed with chloroform until the powder turns blue, then washed several times with methanol, then washed several times with hot water at 80 ° C. and dried. Crude titanyl phthalocyanine was obtained. Crude titanyl phthalocyanine is dissolved in 20 times the amount of concentrated sulfuric acid, added dropwise to 100 times the amount of ice water with stirring, the precipitated crystals are filtered, and then ion-exchanged water (pH: 7.) until the washing solution becomes neutral. 0, specific conductivity: 1.0 μS / cm) Repeated washing with water (pH value of ion-exchanged water after washing was 6.8, specific conductivity was 2.6 μS / cm), wet of titanyl phthalocyanine pigment A cake (water paste) was obtained.

  When 40 g of the obtained wet cake (water paste) was added to 200 g of tetrahydrofuran and stirred vigorously (2000 rpm) with a homomixer (Kennis, MARKIIf model) at room temperature, the dark blue color of the paste changed to pale blue Stirring was stopped (20 minutes after the start of stirring), and vacuum filtration was performed immediately. The crystals obtained on the filtration device were washed with tetrahydrofuran to obtain a wet cake of pigment. This was dried under reduced pressure (5 mmHg) at 70 ° C. for 2 days to obtain 8.5 g of titanyl phthalocyanine crystals. The solid content concentration of the wet cake was 15% by mass. The crystal conversion solvent was used in a mass ratio of 33 times that of the wet cake. In addition, the halogen-containing compound is not used for the raw material of the synthesis example 3. When the obtained titanyl phthalocyanine powder was subjected to X-ray diffraction spectrum measurement under the following X-ray diffraction spectrum measurement conditions, the Bragg angle 2θ with respect to the Cu—Kα ray (wavelength 1.542Å) was 27.2 ± 0.2 ° at the maximum. It has a peak at a minimum angle of 7.3 ± 0.2 ° and a major peak at 9.4 ± 0.2 °, 9.6 ± 0.2 °, and 24.0 ± 0.2 °. A titanyl phthalocyanine powder having a peak at 7.3 ° and a peak at 9.4 ° and having no peak at 26.3 ° was obtained. The result is shown in FIG.

<X-ray diffraction spectrum measurement conditions>
X-ray tube: Cu
Voltage: 50kV
Current: 30mA
Scanning speed: 2 ° / min Scanning range: 3 ° -40 °
Time constant: 2 seconds

  The titanyl phthalocyanine crystal was dispersed by the following dispersion method according to the following composition to prepare a charge generation layer coating solution. This dispersion is designated as Dispersion 1.

<Prescription>
Titanylphthalocyanine crystal 15 parts Polyvinyl butyral (manufactured by Sekisui Chemical: BX-1) 10 parts 2-butanone 280 parts

<Distribution method>
Using a PSZ ball having a diameter of 0.5 mm in a commercially available bead mill disperser, a 2-butanone solution in which polyvinyl butyral was dissolved and titanyl phthalocyanine crystal were introduced, and the rotor rotation speed was 1200 r. p. m. For 30 minutes to prepare a charge generation layer coating solution.

  The film thickness of the charge generation layer was adjusted so that the transmittance of the charge generation layer at 780 nm was 25%. The transmittance of the charge generation layer is determined by applying the charge generation layer coating solution of the above formulation to an aluminum cylinder wrapped with a polyethylene terephthalate film under the same conditions as the production of the photoreceptor, and the polyethylene without the charge generation layer applied The transmittance | permeability of 780 nm was evaluated with the commercially available spectrophotometer (Shimadzu: UV-3100) for the terephthalate film as a comparison object.

(Synthesis Example 4)
In accordance with Japanese Patent No. 3166293, Synthesis Examples and Example 1, hydroxygallium phthalocyanine was synthesized.
That is, 30 parts of 1,3-diiminoisoindoline and 9.1 parts of gallium trichloride were added to 230 parts of quinoline and reacted at 200 ° C. for 3 hours, and then the product was filtered off. Subsequently, it was washed with acetone and methanol, and the wet cake was dried to obtain 28 parts of chlorogallium phthalocyanine crystals.

  Subsequently, 3 parts of the chlorogallium phthalocyanine crystal was dissolved in 60 parts of concentrated sulfuric acid at 0 ° C., and then this solution was dropped into 450 parts of distilled water at 5 ° C. to precipitate a crystal. After washing with distilled water, dilute ammonia water or the like, it was dried to obtain 2.5 parts of hydroxygallium phthalocyanine crystal. Further, 0.5 parts of the hydroxygallium phthalocyanine crystal was milled for 24 hours together with 15 parts of dimethylformamide and 30 parts of glass beads having a diameter of 1 mm, and then the crystals were separated. Subsequently, it was washed with methanol and dried to obtain a target hydroxygallium phthalocyanine crystal.

  When the obtained hydroxygallium phthalocyanine crystal was subjected to X-ray diffraction spectrum measurement under the same conditions as in Synthesis Example 3, the Bragg angle 2θ with respect to the Cu—Kα ray (wavelength 1.542Å) was 7.5 °, 9.9 °, 12 It had strong diffraction peaks at .5 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 °. The obtained spectrum was the same as the X-ray diffraction spectrum described in Japanese Patent No. 3166293 and FIG.

  Hydroxygallium phthalocyanine crystals were dispersed according to the following composition by the following dispersion method to prepare a charge generation layer coating solution. This dispersion is designated as Dispersion 2.

<Prescription>
Hydroxygallium phthalocyanine crystal 15 parts Polyvinyl butyral (manufactured by Sekisui Chemical: BX-1) 10 parts 2-butanone 280 parts

<Distribution method>
Using a PSZ ball having a diameter of 0.5 mm in a commercially available bead mill disperser, a 2-butanone solution in which polyvinyl butyral was dissolved and a hydroxygallium phthalocyanine crystal were introduced, and the rotor rotation speed was 1200 r. p. m. For 30 minutes to prepare a charge generation layer coating solution.

  The film thickness of the charge generation layer was adjusted so that the transmittance of the charge generation layer at 780 nm was 25%. The transmittance of the charge generation layer is determined by applying the charge generation layer coating solution of the above formulation to an aluminum cylinder wrapped with a polyethylene terephthalate film under the same conditions as the production of the photoreceptor, and the polyethylene without the charge generation layer applied The transmittance | permeability of 780 nm was evaluated with the commercially available spectrophotometer (Shimadzu: UV-3100) for the terephthalate film as a comparison object.

(Synthesis Example 5)
Chlorogallium phthalocyanine was synthesized according to Japanese Patent No. 3123185, Synthesis Example and Example 2.
That is, 30 parts of 1,3-diiminoisoindoline and 9.1 parts of gallium trichloride are added to 230 parts of quinoline and reacted at 200 ° C. for 3 hours, and then the product is filtered and washed with acetone and methanol. did. Next, the wet cake was dried to obtain chlorogallium phthalocyanine crystals. This chlorogallium phthalocyanine crystal is dry-ground for 3 hours in an automatic mortar, and further 0.5 part of chlorogallium phthalocyanine is mixed with 60 parts of 1 mmφ glass beads at room temperature in 20 parts of a mixed solvent of water / chlorobenzene 1:10. After ball milling for 24 hours, it was filtered off, washed with 10 parts of methanol, and dried to obtain chlorogallium phthalocyanine crystals.

  The obtained chlorogallium phthalocyanine crystal was subjected to X-ray diffraction spectrum measurement under the same conditions as in Synthesis Example 3. As a result, the Bragg angle 2θ with respect to the Cu—Kα ray (wavelength 1.542Å) was 7.4 °, 16.6 °, 25 It had strong diffraction peaks at .5 ° and 28.3 °. The obtained spectrum was the same as the X-ray diffraction spectrum described in Japanese Patent No. 3123185, FIG.

  A chlorogallium phthalocyanine crystal was dispersed by the following dispersion method in accordance with the following composition to prepare a charge generation layer coating solution. This dispersion is designated as Dispersion 3.

<Prescription>
Chlorogallium phthalocyanine crystal 15 parts Polyvinyl butyral (manufactured by Sekisui Chemical: BX-1) 10 parts 2-butanone 280 parts

<Distribution method>
Using a PSZ ball having a diameter of 0.5 mm in a commercially available bead mill disperser, a 2-butanone solution in which polyvinyl butyral was dissolved and a chlorogallium phthalocyanine crystal were introduced, and the rotor rotation speed was 1200 r. p. m. For 30 minutes to prepare a charge generation layer coating solution.

  The film thickness of the charge generation layer was adjusted so that the transmittance of the charge generation layer at 780 nm was 25%. The transmittance of the charge generation layer is determined by applying the charge generation layer coating solution of the above formulation to an aluminum cylinder wrapped with a polyethylene terephthalate film under the same conditions as the production of the photoreceptor, and the polyethylene without the charge generation layer applied The transmittance | permeability of 780 nm was evaluated with the commercially available spectrophotometer (Shimadzu: UV-3100) for the terephthalate film as a comparison object.

(Azo pigment dispersion)
(Synthesis Example 6)
The following asymmetric azo pigments and symmetric azo pigments were prepared according to the methods described in Japanese Patent Publication No. 60-29109 and Japanese Patent No. 3026645, and dispersed by the following method.

  Dispersion was carried out by the following dispersion method with a formulation having the following composition to prepare a dispersion as a charge generation layer coating liquid. This dispersion is referred to as dispersion 4.

<Prescription>
Asymmetric azo pigment represented by the following chemical formula (6) 5 parts Polyvinyl butyral (manufactured by Sekisui Chemical: BX-1) 2 parts Cyclohexanone 250 parts 2-butanone 100 parts

<Distribution method>
Using a PSZ ball having a diameter of 10 mm for the ball mill disperser, all of the solvent and azo pigment in which polyvinyl butyral was dissolved were charged, and the rotational speed was 85 r. p. m. Was dispersed for 7 days to prepare a dispersion.

  The film thickness of the charge generation layer was adjusted so that the transmittance of the charge generation layer at 655 nm was 40%. The transmittance of the charge generation layer is determined by applying the charge generation layer coating solution of the above formulation to an aluminum cylinder wrapped with a polyethylene terephthalate film under the same conditions as the production of the photoreceptor, and the polyethylene without the charge generation layer applied The transmittance | permeability of 655 nm was evaluated with the terephthalate film as a comparison object with the commercially available spectrophotometer (Shimadzu: UV-3100).

(Azo pigment dispersion)
(Synthesis Example 7)
Dispersion was carried out by the following dispersion method with a formulation having the following composition to prepare a dispersion as a charge generation layer coating liquid. This dispersion is designated as Dispersion Liquid 5.

<Prescription>
Symmetrical azo pigment represented by the following chemical formula (7) 5 parts Polyvinyl butyral (manufactured by Sekisui Chemical: BX-1) 2 parts Cyclohexanone 250 parts 2-butanone 100 parts

<Distribution method>
Using a PSZ ball having a diameter of 10 mm for the ball mill disperser, all of the solvent and azo pigment in which polyvinyl butyral was dissolved were charged, and the rotational speed was 85 r. p. m. Was dispersed for 7 days to prepare a dispersion.

  The film thickness of the charge generation layer was adjusted so that the transmittance of the charge generation layer at 655 nm was 40%. The transmittance of the charge generation layer is determined by applying the charge generation layer coating solution of the above formulation to an aluminum cylinder wrapped with a polyethylene terephthalate film under the same conditions as the production of the photoreceptor, and the polyethylene without the charge generation layer applied The transmittance | permeability of 655 nm was evaluated with the terephthalate film as a comparison object with the commercially available spectrophotometer (Shimadzu: UV-3100).

<Example 1>
Undercoat layer coating solution, charge generation layer coating solution, and charge transport layer coating solution having the following composition are applied and dried in sequence on an aluminum cylinder having a diameter of 30 mm as a conductive support, and the thickness is about 3.5 μm. A pulling layer, a charge generation layer of about 0.5 μm, and a charge transport layer of about 23 μm were formed to produce a laminated photoreceptor. After the coating of each layer, touch drying is performed, and then the undercoat layer is dried at 130 ° C., the charge generation layer is 95 ° C., and the charge transport layer is dried at 120 ° C. for 20 minutes, respectively. An organic photoreceptor (electrophotographic photoreceptor) composed of an undercoat layer / charge generation layer / charge transport layer was obtained.

(Coating solution composition for undercoat layer)
Titanium oxide (CR-EL, average primary particle size: about 0.25 μm, manufactured by Ishihara Sangyo Co., Ltd.): 50 parts Alkyd resin (Beckolite M6401-50, solid content: 50%,
Dainippon Ink & Chemicals, Inc.): 14 parts Melamine resin (L-145-60, solid content: 60%, manufactured by Dainippon Ink & Chemicals, Inc.): 8 parts 2-butanone: 70 parts

[Coating liquid composition for charge generation layer]
Dispersion 1

[Coating liquid composition for charge transport layer]
Α-phenylstilbene compound represented by the following chemical formula (5) 7 parts Bisphenol Z polycarbonate 10 parts (Panlite TS-2050, manufactured by Teijin Chemicals)
Tetrahydrofuran 68 parts 1% silicone oil (solvent: tetrahydrofuran)
(KF50-1CS, manufactured by Shin-Etsu Chemical) 0.2 parts

<Example 2>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge generation layer coating solution in Example 1 was changed to Dispersion 2.

<Example 3>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge generation layer coating solution in Example 1 was changed to Dispersion 3.

<Example 4>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge generation layer coating solution in Example 1 was changed to Dispersion 4 and the drying temperature after coating the charge generation layer was 125 ° C.

<Example 5>
An electrophotographic photosensitive member was produced in the same manner as in Example 4 except that the charge generation layer coating solution in Example 4 was changed to Dispersion 5.

<Example 6>
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the α-phenylstilbene compound represented by the chemical formula (5) used in Example 1 was changed to an α-phenylstilbene compound represented by the following chemical formula (3). Produced.

<Example 7>
An electrophotographic photosensitive member was produced in the same manner as in Example 6 except that the charge generation layer coating solution in Example 6 was changed to Dispersion 2.

<Example 8>
An electrophotographic photosensitive member was produced in the same manner as in Example 6 except that the charge generation layer coating solution in Example 6 was changed to Dispersion 3.

<Example 9>
An electrophotographic photosensitive member was produced in the same manner as in Example 6 except that the charge generation layer coating solution in Example 6 was changed to Dispersion 4 and the drying temperature after coating the charge generation layer was 125 ° C.

<Example 10>
An electrophotographic photosensitive member was produced in the same manner as in Example 9 except that the charge generation layer coating solution in Example 9 was changed to Dispersion 5.

<Example 11>
In Example 1, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that a charge blocking layer coating solution having the following composition was applied and dried between the conductive support and the undercoat layer to provide a charge blocking layer. Was made. The thickness of the charge blocking layer was about 0.5 μm. The charge blocking layer was dried at 130 ° C. for 10 minutes.

[Charge blocking layer coating solution composition]
N-methoxymethylated nylon (FR101: manufactured by Lead City) 5 parts Methanol 70 parts n-Butanol 30 parts

<Example 12>
In Example 6, an electrophotographic photosensitive member was prepared in the same manner as in Example 6 except that a charge blocking layer coating solution having the following composition was applied and dried between the conductive support and the undercoat layer to provide a charge blocking layer. Was made. The thickness of the charge blocking layer was about 0.5 μm. The charge blocking layer was dried at 130 ° C. for 10 minutes.

[Charge blocking layer coating solution composition]
N-methoxymethylated nylon (FR101: manufactured by Lead City) 5 parts Methanol 70 parts n-Butanol 30 parts

<Example 13>
In Example 4, an electrophotographic photosensitive member was prepared in the same manner as in Example 4 except that a charge blocking layer coating liquid having the following composition was applied and dried between the conductive support and the undercoat layer to provide a charge blocking layer. Was made. The thickness of the charge blocking layer was about 0.5 μm. The charge blocking layer was dried at 130 ° C. for 10 minutes.

[Charge blocking layer coating solution composition]
N-methoxymethylated nylon (FR101: manufactured by Lead City) 5 parts Methanol 70 parts n-Butanol 30 parts

<Example 14>
In Example 9, an electrophotographic photosensitive member was prepared in the same manner as in Example 9 except that a charge blocking layer coating solution having the following composition was applied and dried between the conductive support and the undercoat layer to provide a charge blocking layer. Was made. The thickness of the charge blocking layer was about 0.5 μm. The charge blocking layer was dried at 130 ° C. for 10 minutes.

[Charge blocking layer coating solution composition]
N-methoxymethylated nylon (FR101: manufactured by Lead City) 5 parts Methanol 70 parts n-Butanol 30 parts

<Example 15>
In Example 1, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that a filler-added protective layer coating solution having the following composition was applied and dried on the charge transport layer to provide a filler-added protective layer. . The film thickness of the filler-added protective layer was about 5 μm. The filler-added protective layer was dried at 150 ° C. for 20 minutes.

[Filler-added protective layer coating solution composition]
Alumina (AA03 average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical Co., Ltd.) 3 parts Polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals) 5.5 parts Tetrahydrofuran 220 parts Cyclohexanone 80 parts Charge represented by the following chemical formula (8) Transport material 4 parts

<Example 16>
In Example 6, an electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that a filler-added protective layer coating solution having the following composition was applied and dried on the charge transport layer to provide a filler-added protective layer. . The film thickness of the filler-added protective layer was about 5 μm. The filler-added protective layer was dried at 150 ° C. for 20 minutes.

[Filler-added protective layer coating solution composition]
Alumina (AA03 average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical Co., Ltd.) 3 parts Polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals) 5.5 parts Tetrahydrofuran 220 parts Cyclohexanone 80 parts Charge represented by the chemical formula (8) Transport material 4 parts

<Example 17>
In Example 4, an electrophotographic photoreceptor was prepared in the same manner as in Example 4 except that a filler-added protective layer coating solution having the following composition was applied on the charge transport layer and dried to provide a filler-added protective layer. . The film thickness of the filler-added protective layer was about 5 μm. The filler-added protective layer was dried at 150 ° C. for 20 minutes.

[Filler-added protective layer coating solution composition]
Alumina (AA03 average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical Co., Ltd.) 3 parts Polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals) 5.5 parts Tetrahydrofuran 220 parts Cyclohexanone 80 parts Charge represented by the chemical formula (8) Transport material 4 parts

<Example 18>
In Example 9, an electrophotographic photosensitive member was produced in the same manner as in Example 9 except that a filler-added protective layer coating solution having the following composition was applied on the charge transport layer and dried to provide a filler-added protective layer. . The film thickness of the filler-added protective layer was about 5 μm. The filler-added protective layer was dried at 150 ° C. for 20 minutes.

[Filler-added protective layer coating solution composition]
Alumina (AA03 average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical Co., Ltd.) 3 parts Polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals) 5.5 parts Tetrahydrofuran 220 parts Cyclohexanone 80 parts Charge represented by the chemical formula (8) Transport material 4 parts

<Example 19>
In Example 1, a coating solution for a crosslinking protective layer having the following composition was applied onto the charge transport layer, and a lamp output of 200 W / cm was used using a UV lamp (bulb type H bulb) (manufactured by FusionUV Systems). The film was crosslinked by light irradiation under the conditions of illuminance: 450 mW / cm ² and irradiation time: 30 seconds. Thereafter, drying was performed at 130 ° C. for 20 minutes to form a crosslinked protective layer of about 5 μm. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except for the crosslinkable protective layer.

[Coating liquid for cross-linked protective layer]
10 parts of radically polymerizable monomer having no charge transporting structure Trimethylolpropane triacrylate (KAYARAD TMPTA, manufactured by Nippon Kayaku)
Molecular weight: 296, number of functional groups: trifunctional, molecular weight / number of functional groups = 99
10 parts of radically polymerizable compound having a charge transporting structure (Exemplary Compound No. 54)
Photopolymerization initiator 1 part (1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals))
Alumina (average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical) 2 parts Tetrahydrofuran 100 parts

<Example 20>
In Example 6, a coating solution for a crosslinking type protective layer having the following composition was applied onto the charge transport layer, and a lamp output of 200 W / cm was used using a UV lamp (bulb type H bulb) (manufactured by FusionUV Systems). The film was crosslinked by light irradiation under the conditions of illuminance: 450 mW / cm ² and irradiation time: 30 seconds. Thereafter, drying was performed at 130 ° C. for 20 minutes to form a crosslinked protective layer of about 5 μm. An electrophotographic photosensitive member was produced in the same manner as in Example 6 except for the crosslinkable protective layer.

[Coating liquid for cross-linked protective layer]
Radical polymerizable monomer having no charge transport structure 10 parts Trimethylolpropane triacrylate (KAYARAD TMPTA, Nippon Kayaku)
Molecular weight: 296, number of functional groups: trifunctional, molecular weight / number of functional groups = 99
10 parts of radically polymerizable compound having a charge transporting structure (Exemplary Compound No. 54)
Photopolymerization initiator 1 part (1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals))
Alumina (average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical) 2 parts Tetrahydrofuran 100 parts

<Example 21>
In Example 4, a coating solution for a crosslinking type protective layer having the following composition was applied onto the charge transport layer, and a lamp output of 200 W / cm was used using a UV lamp (bulb type H bulb) (manufactured by FusionUV Systems). The film was crosslinked by light irradiation under the conditions of illuminance: 450 mW / cm ² and irradiation time: 30 seconds. Thereafter, drying was performed at 130 ° C. for 20 minutes to form a crosslinked protective layer of about 5 μm. An electrophotographic photosensitive member was produced in the same manner as in Example 4 except for the crosslinked protective layer.

[Coating liquid for cross-linked protective layer]
10 parts of radically polymerizable monomer having no charge transporting structure Trimethylolpropane triacrylate (KAYARAD TMPTA, manufactured by Nippon Kayaku)
Molecular weight: 296, number of functional groups: trifunctional, molecular weight / number of functional groups = 99
10 parts of radically polymerizable compound having a charge transporting structure (Exemplary Compound No. 54)
Photopolymerization initiator 1 part (1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals))
Alumina (average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical) 2 parts Tetrahydrofuran 100 parts

<Example 22>
In Example 9, a coating solution for a crosslinking type protective layer having the following composition was applied on the charge transport layer, and a lamp output of 200 W / cm was used using a UV lamp (bulb type H bulb) (manufactured by FusionUV Systems). The film was crosslinked by light irradiation under the conditions of illuminance: 450 mW / cm ² and irradiation time: 30 seconds. Thereafter, drying was performed at 130 ° C. for 20 minutes to form a crosslinked protective layer of about 5 μm. An electrophotographic photosensitive member was produced in the same manner as in Example 9 except for the crosslinked protective layer.

[Coating liquid for cross-linked protective layer]
10 parts of radically polymerizable monomer having no charge transporting structure Trimethylolpropane triacrylate (KAYARAD TMPTA, manufactured by Nippon Kayaku)
Molecular weight: 296, number of functional groups: trifunctional, molecular weight / number of functional groups = 99
10 parts of radically polymerizable compound having a charge transporting structure (Exemplary Compound No. 54)
Photopolymerization initiator 1 part (1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals))
Alumina (average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical) 2 parts Tetrahydrofuran 100 parts

<Example 23>
In Example 1, a charge blocking layer coating solution having the following composition was applied and dried between the conductive support and the undercoat layer to provide a charge blocking layer. Further, a crosslinked type having the following composition was formed on the charge transport layer. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the protective layer coating solution was applied and a crosslinkable protective layer was provided. The thickness of the charge blocking layer was about 0.5 μm, and the thickness of the cross-linked charge transport layer was about 5 μm. The charge blocking layer was dried at 130 ° C. for 10 minutes, and the cross-linked charge transport layer was dried at 130 ° C. for 20 minutes. The UV irradiation conditions are the same as in the above example.

[Charge blocking layer coating solution composition]
N-methoxymethylated nylon (FR101: manufactured by Lead City) 5 parts Methanol 70 parts n-Butanol 30 parts

[Coating liquid for cross-linked protective layer]
10 parts of radically polymerizable monomer having no charge transporting structure Trimethylolpropane triacrylate (KAYARAD TMPTA, manufactured by Nippon Kayaku)
Molecular weight: 296, number of functional groups: trifunctional, molecular weight / number of functional groups = 99
10 parts of radically polymerizable compound having a charge transporting structure (Exemplary Compound No. 54)
Photopolymerization initiator 1 part (1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals))
Alumina (average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical) 2 parts Tetrahydrofuran 100 parts

<Example 24>
In Example 6, a charge blocking layer coating solution having the following composition was applied and dried between the conductive support and the undercoat layer to provide a charge blocking layer. Further, a crosslinked type having the following composition was formed on the charge transport layer. An electrophotographic photosensitive member was produced in the same manner as in Example 6 except that the protective layer coating solution was applied and a crosslinkable protective layer was provided. The thickness of the charge blocking layer was about 0.5 μm, and the thickness of the cross-linked charge transport layer was about 5 μm. The charge blocking layer was dried at 130 ° C. for 10 minutes, and the cross-linked charge transport layer was dried at 130 ° C. for 20 minutes. The UV irradiation conditions are the same as in the above example.

[Charge blocking layer coating solution composition]
N-methoxymethylated nylon (FR101: manufactured by Lead City) 5 parts Methanol 70 parts n-Butanol 30 parts

[Coating liquid for cross-linked protective layer]
10 parts of radically polymerizable monomer having no charge transporting structure Trimethylolpropane triacrylate (KAYARAD TMPTA, manufactured by Nippon Kayaku)
Molecular weight: 296, number of functional groups: trifunctional, molecular weight / number of functional groups = 99
10 parts of radically polymerizable compound having a charge transporting structure (Exemplary Compound No. 54)
Photopolymerization initiator 1 part (1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals))
Alumina (average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical) 2 parts Tetrahydrofuran 100 parts

<Example 25>
In Example 4, a charge blocking layer coating liquid having the following composition was applied and dried between the conductive support and the undercoat layer to provide a charge blocking layer, and the crosslinked type having the following composition was further formed on the charge transport layer. An electrophotographic photosensitive member was produced in the same manner as in Example 4 except that the protective layer coating solution was applied and a crosslinkable protective layer was provided. The thickness of the charge blocking layer was about 0.5 μm, and the thickness of the cross-linked charge transport layer was about 5 μm. The charge blocking layer was dried at 130 ° C. for 10 minutes, and the cross-linked charge transport layer was dried at 130 ° C. for 20 minutes. The UV irradiation conditions are the same as in the above example.

[Charge blocking layer coating solution composition]
N-methoxymethylated nylon (FR101: manufactured by Lead City) 5 parts Methanol 70 parts n-Butanol 30 parts

[Coating liquid for cross-linked protective layer]
10 parts of radically polymerizable monomer having no charge transporting structure Trimethylolpropane triacrylate (KAYARAD TMPTA, manufactured by Nippon Kayaku)
Molecular weight: 296, number of functional groups: trifunctional, molecular weight / number of functional groups = 99
10 parts of radically polymerizable compound having a charge transporting structure (Exemplary Compound No. 54)
Photopolymerization initiator 1 part (1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals))
Alumina (average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical) 2 parts Tetrahydrofuran 100 parts

<Example 26>
In Example 9, a charge blocking layer coating solution having the following composition was applied and dried between the conductive support and the undercoat layer to provide a charge blocking layer. Further, a crosslinked type having the following composition was formed on the charge transport layer. An electrophotographic photosensitive member was produced in the same manner as in Example 9 except that the protective layer coating solution was applied and a crosslinkable protective layer was provided. The thickness of the charge blocking layer was about 0.5 μm, and the thickness of the cross-linked charge transport layer was about 5 μm. The charge blocking layer was dried at 130 ° C. for 10 minutes, and the cross-linked charge transport layer was dried at 130 ° C. for 20 minutes. The UV irradiation conditions are the same as in the above example.

[Charge blocking layer coating solution composition]
N-methoxymethylated nylon (FR101: manufactured by Lead City) 5 parts Methanol 70 parts n-Butanol 30 parts

[Coating liquid for cross-linked protective layer]
10 parts of radically polymerizable monomer having no charge transporting structure Trimethylolpropane triacrylate (KAYARAD TMPTA, manufactured by Nippon Kayaku)
Molecular weight: 296, number of functional groups: trifunctional, molecular weight / number of functional groups = 99
10 parts of radically polymerizable compound having a charge transporting structure (Exemplary Compound No. 54)
Photopolymerization initiator 1 part (1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals))
Alumina (average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical) 2 parts Tetrahydrofuran 100 parts

<Comparative Example 1>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the α-phenylstilbene compound of Example 1 was changed to a compound represented by the following chemical formula (8) described in JP-B-3-39306.

<Comparative example 2>
An electrophotographic photosensitive member was produced in the same manner as in Comparative Example 1 except that the charge generation layer coating solution in Comparative Example 1 was changed to Dispersion 2.

<Comparative Example 3>
An electrophotographic photosensitive member was produced in the same manner as in Comparative Example 1 except that the charge generation layer coating solution in Comparative Example 1 was changed to Dispersion 3.

<Comparative Example 4>
An electrophotographic photosensitive member was produced in the same manner as in Comparative Example 1 except that the charge generation layer coating solution in Comparative Example 1 was changed to Dispersion 4 and the drying temperature after the charge generation layer coating was 125 ° C.

<Comparative Example 5>
An electrophotographic photosensitive member was produced in the same manner as in Comparative Example 4 except that the charge generation layer coating solution in Comparative Example 4 was changed to Dispersion 5.

<Comparative Example 6>
An electrophotographic photosensitive member was produced in the same manner as in Example 15 except that the α-phenylstilbene compound of Example 15 was changed to the compound represented by the chemical formula (8) described in JP-B-3-39306.

<Comparative Example 7>
An electrophotographic photosensitive member was produced in the same manner as in Example 17 except that the α-phenylstilbene compound of Example 17 was changed to the compound represented by the chemical formula (8) described in JP-B-3-39306.

<Comparative Example 8>
An electrophotographic photosensitive member was produced in the same manner as in Example 19 except that the α-phenylstilbene compound of Example 19 was changed to the compound represented by the chemical formula (8) described in JP-B-3-39306.

<Comparative Example 9>
An electrophotographic photosensitive member was produced in the same manner as in Example 21 except that the α-phenylstilbene compound of Example 21 was changed to the compound represented by the chemical formula (8) described in JP-B-3-39306.

<Comparative Example 10>
An electrophotographic photoreceptor was prepared in the same manner as in Example 11 except that the α-phenylstilbene compound of Example 11 was changed to the compound represented by the chemical formula (8) described in JP-B-3-39306.

<Comparative Example 11>
An electrophotographic photosensitive member was produced in the same manner as in Example 13 except that the α-phenylstilbene compound of Example 13 was changed to the compound represented by the chemical formula (8) described in JP-B-3-39306.

(Light area potential measurement)
Using the electrophotographic photoreceptors produced in Examples 1 to 10 and Comparative Examples 1 to 5, the bright part potential was measured.
For the bright part potential measurement, a modified Ricoh imagio Neo 270 machine was used.
Disassemble Ricoh's imgio Neo 270 development unit using a 655 nm semiconductor laser as the image exposure light source, attach an electrometer probe connected to the surface electrometer to the development unit, set the photoconductor to it, and the dark part potential is- The applied potential was adjusted to 700 (V), and then a black solid image was output to measure the bright portion potential. A TREK MODEL 344 was used as the surface electrometer.
The measurement results of the light portion potential are shown in Table 45 below.

  From the results shown in Table 45 above, the electrophotographic photosensitive member using the α-phenylstilbene compound according to the present invention, the image forming apparatus using the same, and the process cartridge for the image forming apparatus are compared with the conventional α-phenylstilbene compound. Thus, the bright part potential can be reduced.

(Paper test)
Using the Ricoh imagio Neo 270 remodeling machine, 30,000 sheets were tested. The bright part potential and the amount of wear were measured before and after the paper passing test, and the background contamination was further evaluated.
The background contamination evaluation was performed so that the electric field strength represented by the following formula (A) or (B) was 34.8 (V / μm) before the sheet passing test and 30,000 sheets passing test. Was charged and evaluated.

1) Electric field strength (V / μm) when the photosensitive layer is a photosensitive member on the surface of the photosensitive member
= Absolute value of surface potential of unexposed portion of photoreceptor at development position (V) / (photosensitive layer thickness) (μm)
-Formula (A)

2) In the case of a photoreceptor having a protective layer on the surface of the photosensitive layer, electric field strength (V / μm)
= Absolute value of surface potential of photosensitive member unexposed portion at developing position (V) / (photosensitive layer thickness + protective layer thickness) (μm)
-Formula (B)

Evaluation of dirt:
A white solid image was output, and rank evaluation was performed from the number and size of black spots generated on the background. The rank evaluation was performed in four stages, and very good ones were indicated by ◎, good ones by ○, slightly inferior by Δ, and very bad by x.

  Table 46 below shows the results of the measurement of the bright part potential using the electrophotographic photoreceptors prepared in Examples 15 to 22 and Comparative Examples 6 to 9.

  From this result, the electrophotographic photosensitive member of the present invention can reduce the increase in bright portion potential before and after the paper passing test even when a protective layer is provided on the photosensitive layer. Furthermore, the change in the light portion potential before and after the paper passing test is small.

  As a result of the evaluation of soiling and the amount of wear after conducting a paper passing test using the electrophotographic photoreceptors prepared in Examples 1, 4, 6, 9, and 11 to 26 and Comparative Examples 1, 4, 10, and 11. The results are shown in Table 47 below.

From the results shown in Table 47 above, the electrophotographic photosensitive member of the present invention has a high margin of soiling and high wear resistance.
Further, the provision of the charge blocking layer increases the margin of background contamination. Furthermore, wear resistance is improved by providing a protective layer. Furthermore, by combining the two, it is possible to improve both the margin of dirt and the wear resistance. Even in the α-phenylstilbene compound of the comparative example, the provision of the charge blocking layer and the protective layer increases the margin of scumming and improves the wear resistance, but the increase in the bright part potential is large.

  From the results of this example, the electrophotographic photosensitive member using the α-phenylstilbene compound according to the present invention, the image forming apparatus using the same and the process cartridge for the image forming apparatus are brighter than the conventional α-phenylstilbene compound. The potential can be reduced, which can be said to be very useful. Further, even if a charge blocking layer or a protective layer is provided, the increase in the bright portion potential is small, so that the life of the electrophotographic photosensitive member can be extended.

It is the schematic which shows an example of the layer structure of embodiment which has a single layer photosensitive layer in the electrophotographic photoreceptor which concerns on this invention. It is the schematic which shows the other example of the layer structure of embodiment which has a single layer photosensitive layer in the electrophotographic photoreceptor which concerns on this invention. It is the schematic which shows an example of the layer structure of embodiment which has a lamination type photosensitive layer in the electrophotographic photoreceptor which concerns on this invention. It is the schematic which shows the other example of the layer structure of embodiment which has a lamination type photosensitive layer in the electrophotographic photoreceptor which concerns on this invention. 5 is an infrared absorption spectrum diagram of ditriflate obtained in Production Example 2. FIG. 2 is an infrared absorption spectrum diagram of the α-phenylstilbene compound obtained in Synthesis Example 1. FIG. 4 is an infrared absorption spectrum diagram of an α-phenylstilbene compound obtained in Synthesis Example 2. FIG. It is a figure of the X-ray-diffraction spectrum of the titanyl phthalocyanine synthesize | combined in the Example.

Claims (13)

Having a photosensitive layer on a conductive support;
The photosensitive layer contains an α-phenylstilbene compound represented by the following general formula (III).

(In the formula (III), R ₅ , R ₈ , R ₉ , R ₁₀ and R ₁₁ represent a hydrogen atom, an alkyl group, an alkoxy group, or a substituted or unsubstituted aryl group, and may be the same, It may be different.) The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer further contains a phthalocyanine pigment and / or an azo pigment. The electrophotographic photoreceptor according to claim 2 , wherein the azo pigment contains a compound represented by the following general formula (IV).

(In the formula (IV), Cp ₁ and Cp ₂ represent coupler residues represented by the following formula (V), and may be the same or different. R ₂₀₁ and R ₂₀₂ are hydrogen. An atom, a halogen atom, an alkyl group, an alkoxy group, or a cyano group, which may be the same or different.

(In the formula (V), R ₂₀₃ represents a hydrogen atom, an alkyl group or an aryl group, and R ₂₀₄ , R ₂₀₅ , R ₂₀₆ , R ₂₀₇ and R ₂₀₈ are a hydrogen atom, a nitro group, a cyano group, a halogen atom, a halogen atom. Represents an alkyl group, an alkyl group, an alkoxy group, a dialkylamino group, or a hydroxyl group, and may be the same or different, and Z is a carbocyclic aromatic group or heterocyclic aromatic group. Represents a group of atoms necessary for forming a ring, and may have a substituent.) The electrophotographic photosensitive member according to claim 3 , wherein Cp ₁ and Cp ₂ of the azo pigment are different from each other. 5. The electrophotographic photosensitive material according to claim 2 , wherein the phthalocyanine pigment contains one or more selected from titanyl phthalocyanine, hydroxygallium phthalocyanine, and chlorogallium phthalocyanine. 6. body. The titanyl phthalocyanine has a maximum intensity diffraction peak at least 27.2 ° of the black angle (2θ ± 0.2 °) in an X-ray diffraction spectrum using CuKα characteristic X-ray (1.542Å). , 9.4 °, 9.6 °, 24.0 ° with a major peak, 7.3 ° with a minimum angle diffraction peak, between 7.3 ° and 9.4 ° 6. The electrophotographic photoreceptor according to claim 5 , wherein the electrophotographic photoreceptor is a titanyl phthalocyanine crystal having no diffraction peak and having no diffraction peak at 26.3 °. The electrically and conductive support, an electrophotographic photosensitive member according to any one of claims 1 to 6, characterized in that it has a charge blocking layer between the photosensitive layer. The electrophotographic photosensitive member according to any one of claims 1 to 7, characterized in that it has a protective layer on the photosensitive layer. The electrophotographic photosensitive member according to claim 8 , wherein the protective layer contains an inorganic pigment and / or a metal oxide having a specific resistance of 10 ¹⁰ Ω · cm or more. The protective layer is formed by curing at least a trifunctional or higher functional radical polymerizable monomer having no charge transporting structure and a radical polymerizable compound having a monofunctional charge transporting structure. Item 10. The electrophotographic photosensitive member according to Item 8 or 9 . In an image forming apparatus comprising at least a charging unit, an exposure unit, a developing unit, a transfer unit, and an electrophotographic photosensitive member,
The image forming apparatus according to claim 1, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1 . A cartridge in which an electrophotographic photosensitive member and at least one unit selected from a charging unit, an exposure unit, a developing unit, a transfer unit, and a cleaning unit are integrated is mounted, and the cartridge is attached to the image forming apparatus main body. The image forming apparatus according to claim 11 , wherein the image forming apparatus is detachable. In an image forming apparatus cartridge in which an electrophotographic photosensitive member and at least one means selected from a charging means, an exposure means, a developing means, a transfer means, and a cleaning means are integrated.
The process cartridge for an image forming apparatus, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of claims 1 to 10 .

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