JPH0414343B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a photoreceptor, and more particularly to a novel electrophotographic photoreceptor having a photosensitive layer containing a trisazo compound. (Prior Art) Conventionally, inorganic photoreceptors having a photosensitive layer containing an inorganic photoconductive compound such as selenium, zinc oxide, or cadmium sulfide as a main component have been widely used as electrophotographic photoreceptors. However, these are not necessarily satisfactory in terms of sensitivity, thermal stability, moisture resistance, durability, etc. For example, when selenium crystallizes, its properties as a photoreceptor deteriorate, making it difficult to manufacture.Also, selenium crystallizes due to heat, fingerprints, etc., and its performance as a photoreceptor deteriorates. In addition, cadmium sulfide has problems with moisture resistance and durability, and zinc oxide has problems with durability, etc. In order to overcome these drawbacks of inorganic photoreceptors, research and development have been actively conducted in recent years on organic photoreceptors having photosensitive layers containing various organic photoconductive compounds as main components. For example, in Japanese Patent Publication No. 50-10496, poly-N-vinylcarbazole and 2,4,7-
There is a description of an organic photoreceptor having a photosensitive layer containing trinitro-9-fluorenone. However, this photoreceptor is not necessarily satisfactory in sensitivity and durability. In order to improve these drawbacks, attempts have been made to develop organic photoreceptors with higher performance by assigning the carrier generation function and the carrier transport function to different substances. Many studies have been conducted on such so-called functionally separated electrophotographic photoreceptors because each material can be selected from a wide range and a photoreceptor with arbitrary performance can be produced relatively easily. Ta. Many compounds have been proposed as carrier generating substances for such functionally separated electrophotographic photoreceptors. As an example of using an inorganic compound as a carrier generating substance, for example,
-There is amorphous selenium described in Publication No. 16198,
Although this is used in combination with an organic photoconductive compound, the drawback that the carrier generation layer made of amorphous selenium crystallizes due to heat and deteriorates the properties as a photoreceptor has not been improved. Furthermore, many electrophotographic photoreceptors using organic dyes or organic pigments as carrier generating substances have been proposed. For example, as an electrophotographic photoreceptor containing a pisazo compound or a trisazo compound in a photosensitive layer, JP-A-53-132347, JP-A-57-124353
Publication No. 195255, Japanese Patent Application Laid-Open No. 1987-19525
Publication No. 200045 and the like are already known. However, these bisazo or trisazo compounds
They do not necessarily satisfy the characteristics of sensitivity, residual potential, or stability during repeated use, and the selection range of carrier transport materials is also limited, so they do not fully satisfy the wide range of requirements of electrophotographic processes. do not have. Furthermore, in recent years, Ar laser has been used as a light source for photoreceptors.
Gas lasers such as He-Ne lasers and semiconductor lasers are beginning to be used. A characteristic of these lasers is that they can be turned on and off in chronological order, making them particularly promising light sources for copying machines with image processing functions, including intelligent copying machines, and printers for computer output. Among these, semiconductor lasers are attracting attention because their nature does not require an electrical signal/optical signal conversion element such as an acousto-optic element, and because they can be made smaller and lighter. However, this semiconductor laser has a low output compared to a gas laser,
Furthermore, since the oscillation wavelength is long (approximately 780 nm or more), the spectral sensitivity of conventional photoreceptors is higher on the short wavelength side, and as it is, it is impossible to use them as photoreceptors using semiconductor lasers as light sources. (Object of the Invention) An object of the present invention is to provide a photoreceptor containing a specific trisazo compound that is stable against heat and light and has excellent carrier generation ability. Another object of the present invention is to provide an electrophotographic photoreceptor with high sensitivity, low residual potential, and excellent durability whose characteristics do not change even after repeated use. Still another object of the present invention is to provide an electrophotographic photoreceptor containing a trisazo compound that can effectively act as a carrier generating substance even in combination with a wide variety of carrier transport substances. Still another object of the present invention is to provide a photoreceptor having sufficient practical sensitivity even to long wavelength light sources such as semiconductor lasers. Still other objects of the present invention will become apparent from the description in the specification. As a result of extensive research to achieve the above object, the present inventors have discovered that a trisazo compound represented by the following general formula [] can act as an active ingredient of a photoreceptor, and have completed the present invention. be. (Structure of the invention) General formula [] However, in the formula, Ar: a substituted or unsubstituted carbocyclic aromatic residue (for example, an atomic group such as a benzene ring or a naphthalene ring that may have other substituents) or a substituted or unsubstituted heterocyclic group Aromatic residue (for example, atomic group such as pyridine ring or quinoline ring which may have other substituents), X ₁ , X ₂ , X ₃ , X ₄ , X ₅ and X ₆ : hydrogen atom,
A group selected from a cyano group, a nitro group, a halogen atom, or an alkyl group (for example, a methyl group, an ethyl group, an isopropyl group, a tertiary butyl group, a trifluoromethyl group, etc.), Q: an oxygen atom or a sulfur atom, Y ₁ , Y ₂ and Y ₃ : hydrogen atom, alkyl group (e.g. methyl group, ethyl group, isopropyl group, tertiary butyl group, trifluoromethyl group, etc.), or alkoxy group (e.g. methoxy group, ethoxy group, isopropoxy group, 3 butoxy group, 2-chloroethoxy group, etc.), l: m and n: an integer of 0 or 1. A:

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[expression] or

[Formula], Y ₄ : substituted/unsubstituted carbamoyl group

[Formula] Substituted/unsubstituted sulfamoyl group

[Formula] where, R ₄ : hydrogen atom, substituted/unsubstituted alkyl group having 1 to 4 carbon atoms, substituted/unsubstituted aralkyl group, substituted/unsubstituted phenyl group, R ₅ : hydrogen atom, carbon Substituted/unsubstituted alkyl groups of numbers 1 to 4, and substituted/unsubstituted aromatic carbocyclic groups (for example, substituted/unsubstituted phenyl groups, substituted/unsubstituted
It represents an unsubstituted naphthyl group, a substituted or unsubstituted anthryl group, etc.), or a substituted or unsubstituted aromatic heterocyclic group (for example, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuryl group, etc.). Substituents for these groups include, for example, carbon atoms with 1
~4 substituted/unsubstituted alkyl groups (e.g. methyl group, ethyl group, isopropyl group, tertiary butyl group,
trifluoromethyl group, etc.), substituted/unsubstituted alkyl groups (e.g. benzyl group, phenethyl group, etc.),
Halogen atoms (chlorine atoms, bromine atoms, fluorine atoms,
iodine atom), substituted/unsubstituted alkoxy groups having 1 to 4 carbon atoms (e.g. methoxy group, ethoxy group, isopropoxy group, tertiary butoxy group, 2-chloroethoxy group, etc.), hydroxy group, substituted/unsubstituted Aryloxy groups (e.g., p-chlorophenoxy group, 1-naphthoxy group, etc.), acyloxy groups (e.g., acetyloxy group, p-cyanobenzoyloxy group, etc.), carboxyl groups, ester groups thereof (e.g., ethoxycarbonyl group, m-bromophenoxycarbonyl group, etc.), carbamoyl group (e.g., aminocarbonyl group, tertiary butylaminocarbonyl group, anilinocarbonyl group, etc.), amyl group (e.g., acetyl group, o-nitrobenzoyl group, etc.), sulfonyl group, etc. group, sulfamoyl group (e.g., aminosulfonyl group, tertiary butylaminosulfonyl group, p-tolylaminosulfonyl group, etc.), amino group, acylamino group (e.g., acetylamino group, banzoylamino group, etc.), sulfonamide group (e.g. , methanesulfonamide group, p-toluenesulfonamide group, etc.), cyano group, nitro group, etc. Preferably, substituted or unsubstituted alkyl groups having 1 to 4 carbon atoms (for example, methyl group, ethyl group, isopropyl group) group, n-butyl, trifluoromethyl group, etc.), halogen atom (chlorine atom, bromine atom, fluorine atom, iodine atom), substituted or unsubstituted alkoxy group having 1 to 4 carbon atoms (e.g. methoxy group,
ethoxy group, tertiary butoxy group, 2-chloroethoxy group, etc.) cyano group, nitro group. Z is substituted/unsubstituted aromatic carbocycle or substituted/unsubstituted aromatic carbocycle
Atom groups necessary to form an unsubstituted aromatic heterocycle, specifically, for example, substituted/unsubstituted benzene rings, substituted/unsubstituted naphthalene rings, substituted/unsubstituted indole rings, substituted/unsubstituted indole rings, etc. Represents a group of atoms forming an unsubstituted carbazole ring, etc. Examples of substituents for the atomic group forming these rings include a series of substituents such as those listed as substituents for R ₄ and R ₅ , but halogen atoms (chlorine, bromine, fluorine, etc.) are preferred. atom, iodine atom), a sulfo group, and a sulfamoyl group (for example, an aminosulfonyl group, a p-tolylaminosulfonyl group, etc.). R ₁ is a hydrogen atom, a substituted or unsubstituted alkyl group,
Substituted/unsubstituted amino groups, carboxy groups, ester groups thereof, substituted/unsubstituted carbamoyl groups, and cyano groups, preferably hydrogen atoms, substituted/unsubstituted alkyl groups having 1 to 4 carbon atoms (for example, methyl groups) ,
ethyl group, isopropyl group, tertiary butyl group, trifluoromethyl group, etc.), and cyano group. A' is a substituted or unsubstituted aryl group, preferably a substituted or unsubstituted phenyl group, and the substituents for these groups include a series of substituents such as those listed as substituents for R ₄ and R ₅ . Preferably, halogen atoms (chlorine atom, bromine atom, fluorine atom, iodine atom), substituted or unsubstituted alkyl groups having 1 to 4 carbon atoms (for example, methyl group, ethyl group, isopropyl group, tertiary butyl group, trifluoromethyl group, etc.), substituted/unsubstituted alkoxy group having 1 to 4 carbon atoms (e.g., methoxy group, ethoxy group, isopropoxy group, tertiary butoxy group, 2-chloroethoxy group, etc.) R ₂ and _R3 represent a substituted/unsubstituted alkyl group, a substituted/unsubstituted aralkyl group, and a substituted/unsubstituted aryl group, preferably those having 1 to 1 carbon atoms.
4 substituted/unsubstituted alkyl groups (e.g. methyl group, ethyl group, isopropyl group, tertiary butyl group,
trifluoromethyl group, etc.), substituted/unsubstituted phenyl group (e.g., phenyl group, p-methoxyphenyl group, m-chlorophenyl group, etc.). (Effects of the Invention) That is, in the present invention, by using the azo compound represented by the general formula [] as a photoconductive substance constituting the photosensitive layer of the photoreceptor, the heat and light resistance which is the object of the present invention can be achieved. It also has excellent electrophotographic properties such as charge retention, sensitivity, and residual potential, and has little fatigue change even after repeated use, and has sufficient sensitivity even in the long wavelength region of 780 nm or more. Excellent photoreceptors can be created. (Structure-2 of the Invention) Among the trisazo compounds represented by the general formula [] used in the present invention, atomic groups represented by the following general formulas [] to [] are preferable. General formula [] [In the formula, A, Q, Y ₁ , Y ₂ and Y ₃ are the same as the general formula [ ]. ] General formula [] [In the formula, A, Q, Y ₁ , Y ₂ and Y ₃ are the same as the general formula [ ]. ] General formula [] [In the formula, A, Q, Y ₁ , Y ₂ and Y ₃ are the same as the general formula [ ]. ] General formula [] [In the formula, A, Q, Y ₁ , Y ₂ and Y ₃ are the same as the general formula [ ]. ] The general formula used in the present invention [ ] ~
Among the trisazo compounds represented by [], the atomic groups represented by the following general formulas [] to [] are preferable because they have spectral sensitivity at long wavelengths. General formula [] [In the formula, A, Q, Y ₁ , Y ₂ and Y ₃ are the same as the general formula [ ]. ] General formula [] [In the formula, A, Q, Y ₁ , Y ₂ and Y ₃ are the same as the general formula [ ]. ] General formula [] [In the formula, A, Q, Y ₁ , Y ₂ and Y ₃ are the same as the general formula [ ]. ] General formula [] [In the formula, A, Q, Y ₁ , Y ₂ and Y ₃ are the same as the general formula [ ]. ] Specific examples of the trisazo compound useful in the present invention represented by the general formula [] include those having the following structural formula, but the trisazo compound of the present invention is not limited to this. do not have.

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The above trisazo compounds can be easily synthesized by known methods. Synthesis Example 1 (Synthesis of Exemplified Compound A-(18)) 480 g of 1,3,5-tris-(6-amino-2-benzoxazolyl)-benzene synthesized according to the method of U.S. Pat. No. 3,314,894 ( 1 mole) was added and dispersed in a mixture of concentrated hydrochloric acid in step 5 and water in step 3, and a solution of 210 g (3 moles) of sodium nitrite dissolved in 1 part of water was added dropwise at 5°C under ice cooling, and after the dropwise addition was complete, The mixture was stirred for 1 hour to react. After the reaction was completed, the reaction solution was filtered, 42% hydroborofluoric acid 3 was added to the solution, and the resulting precipitate was collected, washed with water, and thoroughly dried. The obtained salt was dissolved in N,N-dimethylformamide 10 to prepare a tetrazonium salt solution to be used in the next reaction. Next, 2-hydroxy-3-(4-methoxy-2
-methylphenylcarbamoyl)-benzo[a]
Carbazole (naphthol AS-SR) 1.2Kg (3
mole), 1 kg of triethanolamine to 50 N,
The hexazonium salt solution prepared above was added dropwise to the solution dissolved in N-dimethylformamide and cooled with ice, and the mixture was further stirred for 2 hours to react. The resulting crystals were collected, washed twice with 10 parts of N,N-dimethylformamide and twice with 10 parts of acetone, and dried to yield 1.1 kg of the desired trisazo compound.
(65%). The melting point is 300℃ or higher, the infrared spectrum shows a peak of υ = 1690 cm ^-1 (amide absorption), and elemental analysis shows that C = 72.15% and N = 12.31.
%, H = 4.12% (calculated values are C = 72.20%, N =
12.38% and H=4.10%, it is understood that the target substance was synthesized. The trisazo compound of the present invention has excellent photoconductivity, and when producing an electrophotographic photoreceptor using the same, a photosensitive layer in which the trisazo compound of the present invention is dispersed in a binder is formed on a conductive support. It can be manufactured by providing. In addition, as another method, among the photoconductivity of the trisazo compound of the present invention,
By using it as a carrier generating substance that utilizes its particularly excellent carrier generating ability, and using it together with a carrier transporting substance that can act effectively in combination, a so-called functionally separated type electrophotographic photoreceptor such as a laminated type or a dispersion type can be produced. It is also possible. Further, the trisazo compound used in the present invention can be used alone or in combination of two or more of the trisazo compounds represented by the above general formula [], or may be used in combination with other trisazo compounds. . Various mechanical configurations of electrophotographic photoreceptors are known, and the electrophotographic photoreceptor of the present invention can take any of these forms. Usually, the configuration is as shown in FIGS. 1 to 6. 1 and 3, a carrier generation layer 2 containing the above-mentioned trisazo compound as a main component is provided on a conductive support 1.
and a carrier transport layer 3 containing a carrier transport substance as a main component. As shown in FIGS. 2 and 4, this photosensitive layer 4 may be provided via an intermediate layer 5 provided on a conductive support. When the photosensitive layer 4 has a two-layer structure in this manner, an electrophotographic photoreceptor having the most excellent electrophotographic properties can be obtained. Further, in the present invention, as shown in FIGS. 5 and 6, a photosensitive layer 4 comprising the carrier generating substance 7 dispersed in a layer 6 mainly composed of a carrier transporting substance is provided on the conductive support 1. It may be provided directly or via the intermediate layer 5. When the trisazo compound of the present invention is used as a carrier generating substance, carrier transporting substances that can be used in combination with it include electron-accepting substances that easily transport electrons such as trinitrofluorenone or tetranitrofluorenone, as well as poly-N
- Polymers having heterocyclic compounds in their side chains such as vinylcarbazole, triazole derivatives, oxadiazole derivatives, imidazole derivatives, birazoline derivatives, polyarylalkane derivatives, phenylenediamine derivatives, hydrazone derivatives, amino-substituted chalcone Examples include electron-donating substances that easily transport holes, such as derivatives, triarylamine derivatives, carbazole derivatives, and stilbene derivatives, but the carrier transport substance used in the present invention is not limited to these. The carrier generation layer 2 constituting the photosensitive layer 4 having a two-layer structure is the conductive support 1 or the carrier transport layer 3.
It can be formed directly thereon or, if necessary, with an intermediate layer such as an adhesive layer or a barrier layer provided thereon, for example, by the following method. M-1 A method of applying a solution in which a trisazo compound is dissolved in a suitable solvent, or a solution in which a binder is added and mixed as necessary. M-2 A method in which a trisazo compound is made into fine particles in a dispersion medium using a ball mill, a homomixer, etc., and a binder is added as necessary to mix and disperse the resulting dispersion and then applied. Solvents or dispersion media used for forming the carrier generation layer include n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N,N-dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, and toluene. , xylene, chloroform,
Examples include 1,2-dichloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, and the like. When using a binder in the carrier generation layer or carrier transport layer, any binder can be used, but it is preferable to use a film-forming polymer that is hydrophobic, has a high conductivity, and is electrically insulating. . Examples of such high molecular weight polymers include, but are not limited to, the following. P-1 Polycarbonate P-2 Polyester P-3 Methacrylic resin P-4 Acrylic resin P-5 Polyvinyl chloride P-6 Polyvinylidene chloride P-7 Polystyrene P-8 Polyvinyl acetate P-9 Styrene-butadiene copolymer P- 10 Vinylidene chloride-acrylonitrile copolymer P-11 Vinyl chloride-vinyl acetate copolymer P-12 Vinyl chloride-vinyl acetate-maleic anhydride copolymer P-13 Silicone resin P-14 Silicone-alkyd resin P-15 Phenol -Formaldehyde resin P-16 Styrene-alkyd resin P-17 Poly-N-vinylcarbazole These binders can be used alone or in a mixture of two or more. The thickness of the carrier generation layer 2 thus formed is preferably 0.01 μm to 20 μm, more preferably 0.05 μm to 5 μm. In addition, if the carrier generation layer or photosensitive layer is a dispersed system,
The particle size of the azone compound is preferably 5 μm or less, more preferably 1 μm or less. The conductive support used in the electrophotographic photoreceptor of the present invention is a metal plate including an alloy, a metal drum or a conductive polymer, a conductive compound such as indium oxide, aluminum including an alloy, palladium, gold, etc. Examples include paper, plastic film, etc. that have been made conductive by coating, vapor depositing, or laminating a thin metal layer. As an intermediate layer such as an adhesive layer or a barrier layer, in addition to the polymer used as the binder, an organic polymer material such as polyvinyl alcohol, ethyl cellulose, or carboxymethyl cellulose, or aluminum oxide is used. The electrophotographic photoreceptor of the present invention has the above-mentioned structure, and as is clear from the examples described later,
It has excellent charging characteristics, sensitivity characteristics, and image forming characteristics, and especially shows little fatigue deterioration even when used repeatedly, and has excellent durability. Hereinafter, the present invention will be specifically explained in Examples,
This does not limit the embodiments of the present invention. (Examples) Example 1 2 g of Exemplified Compound A-(7) and 2 g of polycarbonate resin "Panlite L-1250" (manufactured by Teijin Chemicals) were added to 110 ml of 1,2-dichloroethane, and dispersed in a ball mill for 12 hours. This dispersion was applied onto a polyester film on which aluminum had been vapor-deposited so that the dry film thickness was 1 μm to form a carrier generation layer, and on top of this a carrier transport layer was formed using 4,4′-dimethyl-4″. -(4-methoxy)styryl-triphenylamine (Structural formula K-(1) below)
6g of polycarbonate resin “Panlite L-
A carrier transport layer was formed by coating a solution obtained by dissolving 10 g of "1250" in 110 ml of 1,2-dichloroethane so that the film thickness after drying was 15 .mu.m, thereby producing an electrophotographic photoreceptor of the present invention. The photoreceptor obtained as described above was subjected to the following temporal evaluation using an electrostatic paper tester model SP-428 manufactured by Kawaguchi Electric Seisakusho Co., Ltd. After charging with a charging voltage of -6KV for 5 seconds, leave it for 5 seconds, and then irradiate the photoreceptor with halogen lamp light so that the illumination intensity on the photoreceptor surface is 35lux.The amount of exposure required to attenuate the surface potential by half ( Half-reduced exposure amount) E1/2 was determined. Also
The surface potential (residual potential) V _R after exposure with an exposure amount of 30 lux·sec was determined. Furthermore, similar measurements were repeated 100 times. The results are shown in Table 1.

[Table] Comparative Example 1 The following bisazo compound G was used as a carrier generating substance.
A comparative photoreceptor was prepared in the same manner as in Example 1 except that -(1) was used. Regarding this electrophotographic photoreceptor for comparison, Example 1
When measurements were carried out in the same manner as above, the results shown in Table 2 were obtained.

[Table] As is clear from the above results, the electrophotographic photoreceptor of the present invention is extremely superior in sensitivity, residual potential, and repetition stability compared to the comparative electrophotographic photoreceptor. Example 2-4 Exemplified compound A-(1) as a carrier generating substance,
A-(18) and A-(43) were used, and 1-(1-ethyl-4-carbazolyl)methylideneamine-1,2,3,4 was used as the carrier transport substance, respectively.
-tetrahydroquinoline (compound K-(2) below),
4-4′-dimethyl-4″-styryl-triphenylamine (compound K-(3) below), and 4-methyl-
An electrophotographic photoreceptor of the present invention was prepared using 4'-(4-chloro)-styryl-triphenylamine (compound K-(4) below) and in the same manner as in Example 1 except for the following:
When similar measurements were carried out, the results shown in Table 3 were obtained.

[Table] Example 5 A vinyl chloride-vinyl acetate-maleic anhydride copolymer "Eslec MF-10" (manufactured by Sekisui Chemical Co., Ltd.) was placed on a conductive support made of aluminum foil laminated on a polyester film. thickness
A 0.05 μm intermediate layer is provided, and exemplified compound A is placed on top of the intermediate layer.
2 g of -(59) was mixed with 110 ml of 1,2-dichloroethane and dispersed in a ball mill for 24 hours. The dispersion was applied to a dry film thickness of 0.5 μm to form a carrier generation layer. A solution prepared by dissolving 6 g of tri-p-tolylamine and 10 g of methacrylic resin "Acrypet" (manufactured by Mitsubishi Rayon Co., Ltd.) in 70 ml of 1,2-dichloroethane was poured onto this carrier generation layer so that the film thickness after drying was 10 μm. A carrier transport layer was formed by coating the electrophotographic photoreceptor of the present invention. When the same measurements as in Example 1 were carried out on this electrophotographic photoreceptor, E1/2=
The results were 2.0lux·sec and V _R =0V. Example 6 On the conductive support provided with the intermediate layer used in Example 5, a 1% ethylenediamine solution of Exemplary Compound A-(80) was applied to a dry film thickness of 0.3 μm, and a carrier was applied. A generation layer was formed. Then 6-methyl-1-(1-phenyl-4-carbazolyl)methylideneamino-1,
2,3,4-tetrahydroquinoline (compound K-(5) below) 6g and 10g of polyester resin "Vylon 200" (manufactured by Toyobo Co., Ltd.) and 70ml of 1,2-dichloroethane.
The electrophotographic photoreceptor of the present invention was prepared by dissolving this solution into a carrier transport layer and applying this solution to a dry film thickness of 12 μm. The same measurements as in Example 1 were performed on this electrophotographic photoreceptor, and the results shown in Table 4 were obtained. Comparative Example 2 A comparative electrophotographic photoreceptor was prepared in the same manner as in Example 6 except that exemplified compound A-(80) was replaced with bisazo compound G-(2) represented by the following structural formula. Measurements were carried out on this electrophotographic photoreceptor in the same manner as in Example 1, and the results are shown in Table 4.

[Table] Example 7 A carrier generation layer was formed in the same manner as in Example 5 except that Exemplified Compound A-(59) was replaced with Exemplified Compound A-(100). On top of this, 6-methyl-1-
(1-Phenyl-4-carbazolyl)methylideneamino-1,2,3,4-tetrahydroquinoline (compound K-(6) below) 6g and polycarbonate "Panlite L-1250" (manufactured by Teijin Chemicals) 10g of,
A carrier transport layer was formed by coating a solution dissolved in 70 ml of 1,2-dichloroethane so that the film thickness after drying was 10 μm, thereby producing an electrophotographic photoreceptor of the present invention. When this electrophotographic photoreceptor was measured in the same manner as in Example 1, E1/2=2.41ux・sec,
and V _R =0V. Example 8 An intermediate layer with a thickness of 0.05 μm made of vinyl chloride-vinyl acetate-maleic anhydride copolymer “Eslec MF-10” (manufactured by Sekisui Chemical Co., Ltd.) was provided on the surface of an aluminum drum with a diameter of 100 mm. Add 4 g of Exemplified Compound A-(140) to 400 g of 1,2-dichloroethane.
ml and dispersed for 24 hours using a ball mill dispersion machine, the dispersion was applied to a dry film thickness of 0.6 μm to form a carrier generation layer. Furthermore, on top of this, 30 g of 4-methoxy-4'-styryl-triphenylamine (compound K-(6) below)
and polycarbonate resin “Iupilon S-1000”
(Mitsubishi Gas Chemical Co., Ltd.) 50g and 1,2-dichloroethane A carrier transport layer was formed by dissolving the solution in 400 ml and coating it to a film thickness of 13 μm after drying, thereby producing a drum-shaped electrophotographic photoreceptor. The photoreceptor created in this way was attached to a modified electrophotographic copying machine "U-BixV2" (manufactured by Konishiroku Photo Industry Co., Ltd.), and the images were copied with high contrast and clear copies that were faithful to the originals. Got the image. Moreover, this did not change even after repeating this 10,000 times. Comparative Example 3 A drum-shaped comparative photoreceptor was prepared in the same manner as in Example 8, except that exemplified compound A-(140) was replaced with bisazo compound G-(3) represented by the following structural formula. When the copied images were evaluated in the same manner as in Example 8, only images with a lot of fog were obtained. Furthermore, as copying was repeated, the contrast of the copied image decreased, and after 2000 repetitions, almost no copied image could be obtained. Example 9 A layer of vinyl chloride-vinyl acetate-maleic anhydride copolymer "Eslec MF-10" (manufactured by Sekisui Chemical Co., Ltd.) was placed on a conductive support made of aluminum foil laminated on a polyester film.
A 0.05 μm intermediate layer is provided, and exemplified compound A is placed on top of the intermediate layer.
- Add 5 g of (148) and 3.3 g of polycarbonate resin "Panlite L-1250" (manufactured by Teijin Kasei) to 110 ml of dichloroethane and disperse the dispersion in a ball mill for 24 hours so that the film thickness when dried is 10 μm. An electrophotographic photoreceptor was prepared. The photoconductor obtained in the above manner is charged with a +
E was carried out in the same manner as in Example 1 except that 6KV was used.
1/2 and V _R were measured. The first result is E1/2=
It was 3.91ux·sec and V _R =+20V. Example 10 1-Phenyl-3- as a carrier transport layer on a polyester film deposited with aluminum
Dissolve 6 g of (p-diethylaminostyryl)-5-(p-diethylaminophenyl) pyrazoline and 10 g of polyester resin "Pylon 200" (manufactured by Toyobo Co., Ltd.) in 70 ml of 1,2-dichloroethane. It was coated to a film thickness of 10 μm. Next, 1 g of exemplified compound A-(18) and A-
(35) was mixed with 110 ml of 1,2-dichloroethane and dispersed in a ball mill for 24 hours. The dispersion was coated so that the film thickness after drying was 0.5 μm to form a carrier generation layer. A photoreceptor was formed. The thus obtained photoreceptor was evaluated in the same manner as in Example 9, and found to be E1/2 = 3.6 lux·sec and V _R = +10V. Example 11 A 2% ethylenediamine solution of Exemplified Compound A-(53) was applied onto an aluminum-laminated polyester film to a dry film thickness of 0.5 μm to form a carrier generation layer. Furthermore, 1-phenyl-3 is added as a carrier transport layer on top of that.
-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline (compound K-(7) below), 3-(p-methoxystyryl)-9-(p
-methoxyphenyl)carbazole (compound K-(8) below), or p-(N,N-diethylamino)
Approximately 10 g of each benzaldehyde-1,1-diphenylhydrazone (compound K-(9) below)
and polycarbonate Resin (manufactured by Teijin Chemicals, Panlite L-1250)
A solution prepared by dissolving 14 g of the photoreceptor in 140 ml of 1,2-dichloroethane was coated so as to have a dry film thickness of 12 μm and dried to obtain photoreceptors containing three different carrier transport substances. These three types of photoreceptors are manufactured by Kawaguchi Electric Manufacturing Co., Ltd.
The following characteristics were evaluated using an electrostatic paper tester model SP-428 manufactured by Co., Ltd. Charged for 5 seconds at a charging voltage of -6KV,
After leaving this in the dark for 5 seconds, halogen light is irradiated so that the material surface illuminance is 35 lux, and the exposure amount required to attenuate the surface potential by half (half-reduced exposure amount,
E1/2) was measured. In addition, the surface potential (residual potential) V _R after exposure with an exposure amount of 30 lux·sec was measured. As shown in Table 5, the results were good in combination with any carrier transport substance.

[Table] Comparative Example 4 A comparative photoreceptor was prepared in the same manner as in Example 11, except that the exemplified compound A-(53) was replaced with the following bisazo compound (G-(4)), and the characteristics were evaluated. As a result, As shown in Table 6, the results varied depending on the carrier transport substance.

[Table] Example 12 On the conductive support provided with the intermediate layer used in Example 5, 2 g of Exemplified Compound A-(107) and 100 ml of 1,2-dichloroethane were well dispersed and mixed, and the film after drying was prepared. It was applied to a thickness of 0.3 μm to form a carrier generation layer. Then, 1-
(1-phenyl-4-carbazolyl)methylideneamino-1,2,3,4-tetrahydroquinoline (compound K-(10) below) 6g and polycarbonate "Panlite L-1250" (manufactured by Teijin Chemicals) A carrier transport layer was formed by dissolving 10 g of 1,2-dichloroethane in 90 g of 1,2-dichloroethane and applying the solution to a dry film thickness of 10 μm, thereby producing an electrophotographic photoreceptor of the present invention. The electrophotographic properties of this electrophotographic photoreceptor at room temperatures of 25° C. and 60° C. were measured in the same manner as in Example 7. The results are shown in Table 7.

[Table] As is clear from the above results, the electrophotographic photoreceptor of the present invention has good sensitivity and residual potential characteristics even at high temperatures, and is stable against heat. Example 13 2 g of Exemplified Compound A-(131) and 100 ml of 1,2-dichloroethane were well dispersed and mixed on the conductive support provided with the intermediate layer used in Example 5, and the film thickness after drying was 0.3 μm. A carrier generation layer was formed. This carrier generation layer was irradiated with UV light of 1500 cd/cm ² for 10 minutes by placing an ultra-high pressure mercury lamp (manufactured by Tokyo Shibaura Electric Co., Ltd.) 30 cm away. next. 1-[1-(p-anisoyl)-4-carbazolyl]methylideneamine-
7 g of indoline (compound K-(11) below) and 10 g of polycarbonate "Panlite L-1250" (manufactured by Teijin Chemicals) were mixed with 1,2-dichloroethane. A carrier transport layer was formed by coating a solution dissolved in 90 g of chlorine so as to have a dry film thickness of 12 μm, thereby producing an electrophotographic photoreceptor of the present invention. The same measurements as in Example 5 were performed on this electrophotographic photoreceptor. The results are shown in Table 8. Example 14 An electrophotographic photoreceptor of the present invention was prepared in the same manner as in Example 13, except that UV light was not irradiated after the carrier generation layer was formed, and the same measurements as in Example 5 were performed. The results are shown in Table 8.

[Table] As is clear from the above results, the electrophotographic photoreceptor of the present invention has excellent sensitivity and residual potential characteristics against UV light irradiation, has small fluctuations in acceptance potential, and is stable against light. I can understand. Comparative Example 5 Compound A-(131) was mixed with the following bisazo compound (G
-(5)) Same as Example 13 and Example 14 except that An electrophotographic photoreceptor was prepared in the same manner, and Example 5
The same measurements were carried out. The results are shown in Table 9.

[Table] As is clear from the above results, the sensitivity and residual potential characteristics of the electrophotographic photoreceptor prepared using the above compound deteriorate when irradiated with UV light, and the amount of variation in acceptance potential is large. Example 14 In Example 5, Exemplified Compound A-(59) was replaced with A-
A drum-shaped electrophotographic photoreceptor was produced in the same manner except that (35) was replaced. The spectral sensitivity of this photoreceptor at 790 nm was 1.35 μj/cm ² (half exposure amount). The photoreceptor of the present invention was subjected to an actual photographic test using an experimental machine equipped with a semiconductor laser (790 nm) with a laser beam intensity of 0.85 mw on the surface of the photoreceptor. After the surface of the photoreceptor was charged to -6 KV, it was exposed to laser light and reverse development was performed at a bias voltage of -250 V. A good image without fogging was obtained. Comparative Example 6 A comparative photoreceptor was obtained in the same manner as in Example 14, except that the following comparative bisazo compound was used in place of Exemplified Compound A-35. The spectral sensitivity of this photoreceptor at 790nm is
It was 12.2 μj/cm ² (half exposure amount). Using this comparative photoreceptor, an actual photographic test using a semiconductor laser was conducted in the same manner as in Example 14, but there was a lot of fog and no good images could be obtained. As is clear from the results of the above Examples and Comparative Examples, the electrophotographic photoreceptor of the present invention has better characteristics such as stability, sensitivity, durability, and combination with a wide range of carrier transport materials than the comparative electrophotographic photoreceptor. It is extremely excellent.

[Brief explanation of drawings]

1 to 6 are sectional views showing examples of the mechanical structure of the electrophotographic photoreceptor of the present invention, and 1 to 7 in the figures represent the following, respectively. 1... Conductive support, 2... Carrier generation layer,
3... Carrier transport layer, 4... Photosensitive layer, 5... Intermediate layer, 6... Layer containing a carrier transport substance, 7
...Carrier generating substance.

Claims (1)

[Scope of Claims] 1. An electrophotographic photoreceptor comprising a photosensitive layer containing at least one trisazo compound represented by the following general formula [] on a conductive support. General formula [] [However, in the formula, Ar: substituted/unsubstituted carbocyclic aromatic residue or substituted/unsubstituted heterocyclic aromatic residue, X ₁ , X ₂ , X ₃ , X ₄ , X ₅ and X ₆ : hydrogen atom,
A group selected from a cyano group, a nitro group, a halogen atom or an alkyl group, Q: an oxygen atom or a sulfur atom, Y ₁ , Y ₂ and Y ₃ : a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, respectively, l: m and n: An integer of 0 or 1, respectively. A: [Formula] [Formula] [Formula] or [Formula], where Z: substituted/unsubstituted aromatic carbocycle or substituted/
Atom group necessary to constitute an unsubstituted aromatic heterocycle, Y ₄ : Substituted/unsubstituted carbamoyl group or substituted/unsubstituted sulfamoyl group, R ₁ : Hydrogen atom, substituted/unsubstituted alkyl group,
Substituted/unsubstituted amino groups, substituted/unsubstituted carbamoyl groups, carboxy groups and their ester groups,
or a cyano group, A': substituted/unsubstituted aryl group, R ₂ and R ₃ : substituted/unsubstituted alkyl group, substituted/unsubstituted aralkyl group, or substituted/unsubstituted aryl group. 2. The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer contains a carrier transporting substance and a carrier generating substance, and the carrier generating substance is a trisazo compound represented by the general formula [].