JP2684038B2 - Electrophotographic photoreceptor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in an electrophotographic photoreceptor having a layer in which a charge generating substance is dispersed. [Prior Art] Conventionally, there has been known an electrophotographic photoconductor provided with a charge generation layer in which various resins are blended together with a charge generation substance. Examples thereof include polyvinyl butyral (JP-A-58-105154), fatty acid cellulose ester (JP-A-58-166353), acrylic resin having a Tg of 70 ° C. or less and an acid value of 10 to 40 (JP-A-58-106353). No. 58-192040), a mixture of a resin having a Tg of 70 ° C. or lower and a resin having a Tg of 75 ° C. or higher (JP-A-58-193).
No. 549), a resin-solvent system having a lower compatibility with the charge-generating material-resin-solvent system is added and redispersed (Japanese Patent Application Laid-Open No.
-12646), polyvinylpyrrolidone (JP-A-56-113140)
No.), polyvinyl formal resin (JP-A-61-235844)
No.) and the like. However, conventionally known photoconductors have a problem that the sensitivity and the chargeability against pre-exposure fatigue vary depending on the mixing ratio of the charge generating substance and the binder resin. That is, the conventional photoreceptor can increase the sensitivity by reducing the amount of the binder resin used for the charge generating substance, but the chargeability with respect to the pre-exposure fatigue becomes remarkable,
Conversely, if the amount of the binder resin used relative to the charge generating substance is increased, a decrease in the chargeability due to pre-exposure fatigue can be suppressed, but the problem that the sensitivity is significantly reduced is included. Further, the conventional photoreceptor also has a drawback that the charging potential is significantly reduced when charging and exposure are repeated. [Object] It is an object of the present invention to provide an electrophotographic photoreceptor that has high sensitivity and has a significantly small decrease in charging property due to pre-exposure fatigue, and that the charging potential does not decrease even after repeated charging and exposure. . [Structure] According to the present invention, in an electrophotographic photoreceptor having at least a layer in which a charge generating substance is dispersed on a conductive support,
In the layer in which the charge generating substance is dispersed, a polymer comprising a monomer represented by the following general formula (I) and / or a monomer represented by the following general formula (I) and another addition polymerizable unsaturated bond Provided is a photoreceptor for electrophotography, which is characterized by containing a copolymer with an individual compound. (However, R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a hydrogen atom, a lower alkyl group or a substituted or unsubstituted aryl group, and n represents an integer of 2 to 100.) The electrophotographic photoconductor of the present invention. Contains the above-mentioned polymer and / or copolymer in the layer in which the charge-generating substance is dispersed, so that the layer has high sensitivity and the deterioration of the charging property due to pre-exposure fatigue is extremely small, and further, in repeating charging and exposure. Also has a remarkable effect that the charging potential does not decrease. Generally, the chargeability of a highly sensitive photoreceptor is reduced due to pre-exposure fatigue. In the pre-exposure fatigue, as the time during which charges generated by light absorption remain in the photosensitive member in a movable state and the number of the charges are increased, the chargeability due to the pre-exposure fatigue is remarkably reduced. That is, even if the charging operation is performed in a state where the charge generated by the light absorption remains, the surface charge is neutralized by the movement of the remaining carrier, so that the surface potential does not increase until the residual charge is consumed. Therefore, the rise of the surface potential is delayed by the amount of the pre-exposure fatigue, and the apparent charging potential is lowered. As a result of intensive studies to improve this point, the present inventors have found that the above-mentioned drawbacks can be solved by incorporating the polymer and / or copolymer in a layer in which a charge generating substance is dispersed, Came to complete. The reason why the present invention has such a remarkable effect is not always clear at the local point of view, but the specific polymer and / or copolymer is chemically adsorbed on the charge generation substance, and the charge generated by light absorption is re-regenerated. It is considered that this is due to the fact that the charge generated by the pre-exposure fatigue is recombined promptly because it becomes a bond center and the charge disappears to suppress the decrease in the charging potential of the photoconductor. Further, since the effect on the pre-exposure fatigue as described above also appears during actual use in which charging and exposure are repeated, the electrophotographic photoreceptor according to the present invention is more electrically charged than the conventional one. Even when the exposure is repeated, the decrease in the charged potential is remarkably small. Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. FIGS. 1 to 4 are drawings for explaining a typical layer structure of the electrophotographic photoreceptor of the present invention. FIG. 1 shows a structure in which a charge generation layer 1 and a charge transfer layer 2 are sequentially laminated on a conductive support 3, and FIG. 2 shows a structure in which the charge generation layer 1 and the charge transfer layer 2 are laminated in FIG. The charge generation layer 1 is formed by a coating method that does not disturb the charge transfer layer 2, such as a spray coating method. FIG. 3 is different from the laminated photosensitive layer of FIGS.
1 shows a photoconductor composed of a single-layer type photosensitive layer having a charge generation function and a charge transfer function in one layer. FIG. 4 shows a structure in which an undercoat layer 5 is provided between the conductive support 3 and the charge generation layer 1 in FIG. Such an undercoat layer 5 can be similarly applied to the structure shown in FIGS. 2 and 3. The subbing layer is a light-scattering subbing layer or a light-absorptive subbing layer when the purpose is to prevent light interference in the photoconductor for a laser printer, and is adhesive when the purpose is welding and flexibility. A resin subbing layer made of polyamide, polyester, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral or the like having good properties is used. Next, each constituent material used in the present invention will be described. The conductive support is intended to supply a charge having a polarity opposite to that of the charged charge to the substrate side, and has an electric resistance of
A material having a resistivity of 10 ⁸ Ωcm or less and capable of withstanding the conditions for forming the charge generation layer, the charge transfer layer, and the undercoat layer can be used. Examples of such materials include electrically conductive metals and alloys such as Al, Ni, Cr, Zn, and stainless steel; inorganic insulating materials such as glass and ceramics; and organic insulating materials such as polyester, polyimide, phenolic resin, nylon resin, and paper. The surface of the material is vacuum-evaporated, sputtered, spray-painted, etc., using Al, Ni, Cr, Zn, stainless steel, carbon,
Examples thereof include those obtained by coating an electrically conductive substance such as SnO ₂ or In ₂ O ₃ and performing a conductive treatment. The layer in which the charge generating substance is dispersed is constituted as a charge generating layer in the laminated photosensitive layer as shown in FIGS. 1, 2 and 4, and a single layer type as shown in FIG. In the photosensitive layer, it is formed in the photosensitive layer. In the multilayer photosensitive layer, the charge generation layer is composed of a charge generation substance and a binder. In the present invention, the specific polymer and / or copolymer is used as the binder as described above. Examples of the monomer constituting the polymer compound include the compounds shown below. [Example of Monomer represented by General Formula (I)] [Examples of Monomer Copolymerizable with Monomer of General Formula (I)] Other addition-polymerizable unsaturated compounds copolymerized as necessary include, for example, acrylates, acrylamides, and methacrylic acid. Esters, methacrylamides,
Allyl compounds, vinyl ethers, vinyl esters,
Examples thereof include styrenes and crotonic acid esters, and are selected from compounds having one addition-polymerizable unsaturated bond. Specifically, for example, acrylates, for example, alkyl acrylates (for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, ethylhexyl acrylate, octyl acrylate, tert-octyl acrylate) , Chloroethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 2-hydroxystyrene acrylate,
2,2-dimethylhydroxypropyl acrylate, 5-
Hydroxypentyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, glycidyl acrylate, metaglycidyl acrylate, trifluoroethyl acrylate, cyclohexyl acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-butoxyethyl acrylate, 2- Phenoxyethyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, di- (n-butyl) aminoethyl acrylate, di- (t-butyl) aminoethyl acrylate, N- (t-butyl) aminoethyl acrylate, benzyl acrylate, methoxy Benzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, etc.); Reel acrylate (e.g., phenyl acrylate); methacrylic acid ester acid,
For example, alkyl methacrylate (for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate,
2-hydroxystyrene methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 2,2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, glycidyl methacrylate, metaglycidyl methacrylate, trifluoro Ethyl methacrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-butoxyethyl methacrylate, 2-phenoxyethyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, di-
(N-butyl) aminoethyl methacrylate, di- (t
-Butyl) aminoethylmethacrylate, N- (t-butyl) aminoethylmethacrylate, furfurylmethacrylate, tetrahydrofurfurylmethacrylate, etc.), arylmethacrylate (eg, phenylmethacrylate, etc.): acrylamides such as acrylamide, N-alkylacrylamide (Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a t-butyl group, a heptyl group, an octyl group, a cyclohexyl group, a hydroxyethyl group, and a benzyl group.), N-arylacrylamide (The aryl group includes, for example, a phenyl group, a tolyl group, a nitrophenyl group, a naphthyl group, a hydroxyphenyl group, etc.), N, N-dialkylacrylamide (as the alkyl group, a methyl group, an ether group). Group, butyl group, isobutyl group, ethylhexyl group, cyclohexyl group, etc.), N, N-diarylacrylamide (the aryl group includes, for example, phenyl group), N-methyl-N-phenylacrylamide. , N-hydroxyethyl-N-methylacrylamide, N-2-acetamidoethyl-N-acetylacrylamide and the like; methacrylamides such as methacrylamide, N-alkylmethacrylamide (as the alkyl group, a methyl group, an ethyl group, t-butyl group, ethylhexyl group, hydroxyethyl group, cyclohexyl group, etc.), N-arylmethacrylamide (the aryl group includes phenyl group, etc.), N, N-dialkylmethacrylamide (the alkyl group). As, ethyl group, propyl group, Cyl group, etc.), N, N-diarylmethacrylamide (the aryl group includes a phenyl group), N-hydroxyethyl-N-phenylmethacrylamide, N-ethyl-N-phenylmethacrylamide. Allyl compounds, such as allyl esters (for example, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetone acetate, allyl lactate, etc.), allyloxyethanol. Etc .; vinyl ethers such as alkyl vinyl ethers (eg hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether,
Chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether, etc. ), Vinyl aryl ethers (eg, vinyl phenyl ether, vinyl tolyl ether, vinyl chlorophenyl ether, vinyl 2,4-dichlorophenyl ether, vinyl naphthyl ether, vinyl anthranyl ether, etc.); vinyl esters such as vinyl butyrate, Vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, Luvalerate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxyacetate, vinyl butoxyacetate, vinylphenyl acetate, vinyl acetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinylcyclohexylcarboxylate, benzoic acid Vinyl, vinyl salicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, vinyl naphthoate, etc .; Styrenes such as styrene, alkylstyrenes (eg methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene,
Isopropyl styrene, butyl styrene, hexyl styrene, cyclohexyl styrene, decyl styrene, benzyl styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene, etc., alkoxy styrene (eg methoxy styrene, 4-methoxy-3-). Methylstyrene, dimethoxystyrene, etc., halogenostyrene (eg, chlorostyrene, dichlorostyrene, trichlorostyrene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2- Brom-
4-trifluoromethylstyrene, 4-fluoro-3-
Trifluoromethylstyrene, etc.): crotonic esters, for example, alkyl crotonates (for example, butyl crotonate, hexyl crotonate, glycerin monocrotonate, etc.): dialkyl itaconates (for example, dimethyl itaconate, diethyl itaconate, itaconic acid) Dibutyl and the like): dialkyls of maleic acid and fumaric acid (for example, dimethyl maleate, dibutyl fumarate and the like) and the like. In addition, acrylonitrile, methacrylonitrile, acrylic acid, methacrylic acid, and the like can be used. However, a polyfunctional addition polymerizable unsaturated polymer having two or more polymerizable vinyl groups in one molecule is not desirable. Further, the layer in which the charge generating substance of the present invention is dispersed contains the above-mentioned polymer and / or copolymer as a binder, but if necessary, it may be used in combination with another resin binder used in this kind of power generating layer. You can also Such resin binders include polystyrene,
Styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer,
Polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyacrylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly- Thermoplastic or thermosetting resins such as N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin. The total amount of the binder resin is 100
It is suitably used in an amount of 0.01 to 200 parts by weight, preferably 1 to 50 parts by weight based on parts by weight. Further, the polymer and / or copolymer must be contained in an amount of at least 0.01 part by weight, preferably 1 part by weight or more based on 100 parts by weight of the charge generating substance. Examples of the charge generating substance include C.I. Pigment Blue 25 (Color Index (CI) 21180), C.I. Pigment Red 41 (CI. 21200), C.I. Acid Red 52 (CI. 45100), and C.I.
(CI 45210), a phthalocyanine-based pigment having a porphyrin skeleton, an azulenium salt pigment, a squaric salt pigment, and an azo pigment having a carbazole skeleton (Japanese Patent Laid-Open No.
-95033), azo pigments having a stilstilbene skeleton (described in JP-A-53-138229), azo pigments having a triphenylamine skeleton (described in JP-A-53-132547), dibenzo Azo pigments having a thiophene skeleton (described in JP-A-54-21728), azo pigments having an oxadiazole skeleton (described in JP-A-54-12742), and azo pigments having a fluorenone skeleton (described in JP-A-54-12742) 54-2
2834), an azo pigment having a bisstilbene skeleton (described in JP-A-54-17733), an azo pigment having a distyryloxadiazole skeleton (described in JP-A-54-2129), Azo pigments having a distyrylcarbazole skeleton (described in JP-A-54-17734), triazo pigments having a carbazole skeleton (JP-A-57-195767,
Phthalocyanine pigments such as C.I. Pigment Blue 16 (CI 74100), indigo pigments such as C.I.Bat Brown 5 (CI 73410), C.I. Organic pigments such as perylene pigments such as Scarlet B (manufactured by Violet) and Indus Scarlet R (manufactured by Bayer) can be used. Among these charge generating substances, azo pigments are particularly preferred, and among the azo pigments, the following disazo pigments or trisazo pigments are most preferred. Specific examples of the azo pigment are shown below. The thickness of the charge generation layer 1 is suitably about 0.05 to 2 μm, and preferably 0.1 to 1 μm. The charge generation layer 1 can be formed by dissolving or dispersing a resin binder and a charge generation substance in an appropriate solvent, and applying and drying this. As a solvent, benzene, toluene, xylene, methylene chloride, dichloroethane, monochlorobenzene, dichlorobenzene, ethyl acetate, butyl acetate, methyl ethyl ketone, dioxane, tetrahydrofuran, cyclohexanone, methyl cellosolve, ethyl cellosolve, etc. may be used alone or in combination. it can. The charge transfer layer 2 is formed by dissolving or dispersing a charge transfer material and a resin binder in an appropriate solvent,
It can be formed by coating and drying on the top. If necessary, a plasticizer or a leveling agent can be added. Examples of charge transfer materials include poly-N-vinylcarbazole and its derivatives, poly-γ-carbazolylethylglutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, oxadiazole Derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyryl) anthracene, 1,1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazolin, phenylhydrazones, α-phenyl Electron donating substances such as stilbene derivatives; As the resin binder, polystyrene used in the charge generation layer, styrene-acrylonitrile copolymer, styrene-butanediene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer , Polyvinyl acetate, polyvinylidene chloride, polyacrylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic or thermosetting resins such as melamine resin, urethane resin, phenol resin, and alkyd resin. As the solvent at this time, tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride and the like can be used. The thickness of the charge transfer layer 2 is suitably about 5 to 100 μm. The layer in which the charge generating substance is dispersed is a single-layer type photosensitive layer as shown in FIG. 3, the charge generating substance used in the charge generating layer, the polymer and / or copolymer, It can be formed by mixing a resin binder and, if necessary, the charge transfer substance used in the charge transfer layer described above, and coating and drying these coating liquids on a conductive support. Further, in the present invention, as described above, an undercoat layer can be provided between the conductive support and the photosensitive layer, if necessary. The light-scattering subbing layer and the light-absorbing subbing layer are layers for preventing light interference in the photoreceptor for a printer as described above. The light-scattering subbing layer is formed by dispersing conductive powder such as tin oxide or antimony oxide and a white pigment such as zinc oxide, zinc sulfide or titanium oxide in a thermosetting resin as described below, The light absorbing undercoat layer is formed by dispersing a conductive light absorbing pigment such as carbon or various metals and / or a light absorbing organic pigment in a similar thermosetting resin. The thermosetting resin used here is, for example, active hydrogen (-OH group, -NH
_Two groups, hydrogen such as —NK group) and a compound containing a plurality of isocyanate groups and / or a compound containing a plurality of epoxy groups are thermally polymerized. As the compound containing a plurality of active hydrogen, for example, polyvinyl butyral, phenoxy resin, phenol resin, polyamide, polyester, polyethylene glycol, polypropylene glycol, polybutylene glycol, acrylic system containing active hydrogen such as hydroxyethyl methacrylate group. Examples include resins. As the compound containing a plurality of isocyanate groups, for example,
Examples include tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, and prepolymers thereof, and examples of the compound having a plurality of epoxy groups include bisphenol A epoxy resin. In any case, the light-scattering or light-absorbing undercoat layer is applied on a substrate with a solution obtained by dissolving or dispersing the above components on a substrate.
It is formed by thermal polymerization at 200 ° C. The thickness of the undercoat layer is suitably from 1 to 10 μm. The weight ratio of the conductive powder, the white pigment, and the thermosetting resin is suitably 2 to 6/1 to 5/2 to 6, and the weight ratio of the light-absorbing pigment to the thermosetting resin is 4 to 9/1 to 6 are suitable. [Effect] Since the electrophotographic photoreceptor of the present invention contains the polymer containing the monomer represented by the general formula (I) and / or the copolymer thereof in the layer in which the charge generating substance is dispersed. In addition to the high sensitivity, the deterioration of the charging property due to the fatigue of the pre-exposure is remarkably small, and the charging potential does not decrease even when the charging and the exposure are repeated. EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples. [Synthesis Example 1] 200 parts by weight of dimethylformamide was placed in a reaction vessel equipped with a stirrer, a thermometer, and a reflux condenser, and heated to 80 ° C while nitrogen gas was passed through. In this Was added dropwise over 1 hour. Then, stirring was continued for 6 hours at the same temperature to cause a reaction. After completion of the reaction, the product was poured into isopropyl ether to precipitate the polymer, which was vacuum dried at 60 ° C. The polymer thus obtained is referred to as Resin A. [Synthesis Example 2] A monomer having the following composition was reacted in the same manner as in Synthesis Example 1 to obtain a copolymer (resin B). [Synthesis Example 3] A monomer having the following composition was reacted in the same manner as in Synthesis Example 1 to obtain a copolymer (resin C). [Synthesis Example 4] In the same manner as in Synthesis Example 1, monomers having the following compositions were reacted to obtain a copolymer (Resin D). [Synthesis Example 5] In the same manner as in Synthesis Example 1, a copolymer (resin E) obtained by reacting the monomers having the following compositions was obtained. Example 1 [Coating liquid for charge generation layer] 5 parts by weight of azo pigment (Pigment No. 1) shown in Table 1 and resin A
A 0.78 wt% cyclohexanone solution of 160 parts by weight is mixed in a ball mill for 72 hours to obtain a pigment dispersion, and then 100 parts by weight of this pigment dispersion is further mixed with 90 parts by weight of methyl ethyl ketone with stirring to generate a charge generation layer. It was used as a coating liquid. [Coating Liquid for Charge Transfer Layer] 100 parts by weight of α-phenylstilbene type charge transfer substance (the following compounds) Polycarbonate (trade name, Panlite C 1400: Teijin Ltd.) 100 parts by weight Silicone oil (trade name, KF 50: Shin-Etsu Silicone Co., Ltd.) 0.
1 part by weight Tetrahydrofuran 800 parts by weight Next, the above charge generation layer coating solution is blade coated onto a 75 μm polyester film substrate on which Al is vacuum-deposited, and dried by heating at 120 ° C. for 10 minutes to a thickness of about 0.2 μm. A charge generation layer was formed. Next, a coating solution for a charge transfer layer having the above composition was coated on the charge generation layer with a blade, and dried by heating at 120 ° C. for 20 minutes to form a charge transfer layer having a thickness of about 20 μm. Example 2 A 75 μm polyester film substrate on which Al was vacuum-deposited was coated with the coating solution for a charge transfer layer used in Example 1 by a blade in the same manner as in Example 1, and then dried to transfer a charge of about 20 μm. Layers were formed. Then, the coating liquid for a charge generation layer used in Example 1 was spray-coated on the charge transfer layer, and dried by heating at 120 ° C. for 30 minutes to form a charge generation layer of about 0.2 μm. Created. Example 3 A photoconductor was prepared in the same manner as in Example 1 except that the compound having the following structure was used as the α-phenylstilbene compound in the charge transfer layer coating liquid. Example 4 A photoconductor was prepared in the same manner as in Example 1 except that the 0.78 wt% cyclohexanone solution of the resin A used in the preparation of the coating liquid for the charge generation layer was changed to the 0.39 wt% cyclohexanone solution of the resin B. Example 5 A photoconductor was prepared in the same manner as in Example 1 except that the 0.78 wt% cyclohexanone solution of the resin A used for preparing the coating liquid for the charge generation layer was changed to the 0.78 wt% cyclohexanone solution of the resin C. Example 6 A photoconductor was prepared in the same manner as in Example 1 except that the 0.78 wt% cyclohexanone solution of the resin A used in the preparation of the coating liquid for the charge generation layer was changed to the 0.78 wt% cyclohexanone solution of the resin D. Example 7 A photoconductor was prepared in the same manner as in Example 1 except that the 0.78 wt% cyclohexanone solution of the resin A used in the preparation of the coating liquid for the charge generation layer was changed to the 1.56 wt% cyclohexanone solution of the resin E. Example 8 90 parts by weight of methyl ethyl ketone used for preparing the coating liquid for the charge generation layer was mixed with polyvinyl butyral (trade name: XYHL,
A photoconductor was prepared in the same manner as in Example 1, except that 90 parts by weight of a 0.67% by weight methyl ethyl ketone solution was used. Example 9 Tin oxide fine powder 8 containing 10% by weight of antimony oxide
12 parts by weight of titanium oxide white pigment powder and polyvinyl butyral (trade name: BL-1, manufactured by Sekisui Chemical Co., Ltd.)
68 parts by weight of the methyl ethyl ketone solution was ball milled for 72 hours and then 47 parts by weight of methyl ethyl ketone was added.
It was again ball milled for 48 hours. Then this pigment dispersion
While stirring 80 parts by weight, 8 parts by weight of a 20% by weight solution of tolylene diisocyanate in methyl ethyl ketone was additionally mixed to obtain a coating solution for the undercoat layer for light scattering. Next, the above-mentioned undercoat layer coating solution for light scattering was coated on a 75 μm polyester film substrate on which Al was vacuum-deposited with a blade, and heated and cured at 120 ° C. for 30 minutes to form an undercoat layer for light scattering of about 2.5 μm. Was formed. Then, a photoreceptor having a charge generation layer and a charge transfer layer formed on the light-scattering subbing layer was prepared in the same manner as in Example 1. Example 10 A photoreceptor was prepared in the same manner as in Example 1 except that the azo pigment in the charge generation layer coating solution was replaced with Pigment No39. Comparative Examples 1 and 2 Photoreceptors were prepared in the same manner as in Examples 1 and 2 except that polyvinyl butyral (trade name: XYHL, manufactured by Union Carbide Plastics Co., Ltd.) was used as the resin A of the charge generation layer coating liquid. did. Comparative Example 3 A photoconductor was prepared in the same manner as in Example 9 except that polyvinyl butyral (trade name: XYHL, manufactured by Union Carbide Plastics Co., Ltd.) was used as the resin A of the charge generation layer coating liquid. Comparative Example 4 Example 10 except that the resin A of the charge generation layer coating liquid was polyester (trade name: Byron 200, manufactured by Toyobo Co., Ltd.)
A photoreceptor was prepared in the same manner as described above. Comparative Example 5 A 0.78 wt% cyclohexanone solution of Resin A at the time of preparing the coating liquid for the charge generation layer was changed to polyvinyl butyral (trade name: XYH
A photoconductor was prepared in the same manner as in Example 1 except that a 5.88% by weight cyclohexanone solution (L, manufactured by Union Carbide Plastic Co., Ltd.) was used. The electrophotographic photoreceptor prepared as described above was evaluated for electrophotographic characteristics as follows using an electrostatic copying paper test apparatus (Kawaguchi Electric Mfg. Co., Ltd., Model SP 428). First, a -6 KV corona discharge was applied to each photoconductor for 20 seconds, during which a charge potential V ₂ (volt) 2 seconds after the start of corona discharge was measured.
After that, when the surface potential became −800 V by discharging in a dark place, tungsten light was irradiated to obtain the exposure amount S (lux sec) necessary for the surface potential to be attenuated to −400 V. After that, the tungsten light with a color temperature of 2856 ° K is exposed to 100000 lux sec.
After the irradiation, the charged potential V ₂ ′ after the light fatigue is again applied as described above.
(Volt) and the exposure amount S ′ (lux sec) were obtained. Table 1 shows the above results. In addition, the type photoreceptor shown in FIG.
The charging was performed for 0 seconds, during which time the charged potential V ₂ was measured 2 seconds after the start of corona discharge, and then left in a dark place to increase the surface potential to +80.
When the voltage reached 0 V, the substrate was irradiated with tungsten light, and an exposure amount S required for the surface potential to attenuate to +400 V was obtained. After that, after irradiation with 100000 lux sec in the same manner as described above, the charged potential V ₂ ′ and the exposure amount S ′ after light fatigue were determined.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 4 are schematic cross-sectional views of various electrophotographic photoconductors according to the present invention. 1; charge generation layer 2; charge transfer layer 3; conductive support 4; single layer type photosensitive layer 5; undercoat layer

Continuation of front page    (72) Inventor: Shu Taniguchi               1-3-6 Nakamagome, Ota-ku, Tokyo               Ricoh Company                (56) References JP-A-60-256148 (JP, A)                 JP 60-130743 (JP, A)                 JP-A-59-168451 (JP, A)                 JP-A-58-219556 (JP, A)

Claims (1)

(57) [Claims] In an electrophotographic photoreceptor having at least a layer in which a charge generating substance is dispersed on a conductive support, a polymer comprising a monomer represented by the following general formula and / or the following general formula in the layer in which the charge generating substance is dispersed. An electrophotographic photoreceptor comprising a copolymer of the monomer represented by and another compound having one addition-polymerizable unsaturated bond. (However, R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a hydrogen atom, a lower alkyl group or a substituted or unsubstituted aryl group, and n represents an integer of 2 to 100.)