JPH0311466B2 - - 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 an azo compound. (Prior Art) Conventionally, inorganic photoreceptors having a photosensitive layer mainly composed of an inorganic photoconductive compound such as selenium, zinc oxide, or cadmium sulfide have been widely used as 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 bisazo compound or a trisazo compound in the photosensitive layer, JP-A-54-12742, JP-A-53-95033, JP-A-55-69148, etc. are already known. It is. However, these bisazo or trisazo compounds are not necessarily satisfactory in terms of sensitivity, residual potential, or stability during repeated use, and the selection range of carrier transport materials is also limited. It does not fully satisfy the wide range of demands of photographic processes. 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 copiers with image processing functions, such as intelligent copiers, and printers for computer output. Among them, He-Ne laser is widely used as a light source for laser beam printers due to its stable performance. However, the oscillation wavelength
Because it has a long wavelength of 632.8 nm, it is difficult to use conventional selenium photoreceptors or certain fused polycyclic compounds (for example, JP
126254) cannot be used as a photoreceptor. (Object of the Invention) An object of the present invention is to provide a photoreceptor containing a specific azo compound that is stable to 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 an azo 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 lasers. Still other objects of the present invention will become apparent from the description in the specification. As a result of intensive research to achieve the above objectives, the present inventors have found the following general formula [] or []
The present invention was completed based on the discovery that the azo compound represented by the formula can function as an active ingredient of a photoreceptor. (Structure and Effects of the Invention) The present invention provides the following general formula [] on a conductive support.
or [ ] A photoreceptor characterized by having a photosensitive layer containing at least one kind of azo compound. General formula [] General formula [] In the formula, A is a substituted or unsubstituted alkyl group (e.g., ethyl group, propyl group, pentyl group, methoxyethyl group, hydroxyethyl group, benzyl group, phenethyl group, etc.) or a substituted or unsubstituted aryl group (e.g., phenyl group). group, p-methylphenyl group, 2,
4-dimethylphenyl group, methoxyphenyl group,
chlorphenyl group, etc.), and R ₁ and R ₂ represent a hydrogen atom, an alkyl group (e.g. methyl group, ethyl group, etc.), an alkoxy group (e.g. methoxy group, ethoxy group, etc.) or a halogen atom (e.g. fluorine atom,
chlorine atom, etc.), and Cp is

【formula】

【formula】

[expression] or

[Formula], Y is a substituted or unsubstituted carbamoyl group (

[Formula]), substituted or unsubstituted sulfamoy group (

[Formula]), R ₆ : hydrogen atom, substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, substituted or unsubstituted aralkyl group, substituted or unsubstituted phenyl group, R ₇ : hydrogen atom , a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aromatic carbocyclic group (e.g., a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted anthryl group) etc.), or substituted or unsubstituted aromatic heterocyclic groups (e.g., substituted or unsubstituted carbazolyl groups, substituted,
(unsubstituted dibenzofuryl group, etc.). Substituents for these groups include, for example, carbon atoms with 1
~4 substituted or unsubstituted alkyl groups (e.g. methyl group, ethyl group, isopropyl group, tertiary butyl group,
trifluoromethyl group, etc.), substituted or unsubstituted aralkyl groups (e.g., benzyl group, phenethyl group, etc.), halogen atoms (chlorine atom, bromine atom, fluorine atom, iodine atom), substituted or unsubstituted aralkyl groups having 1 to 4 carbon atoms, Substituted alkoxy groups (e.g. methoxy, ethoxy, isopropoxy, tertiary butoxy, 2-chloroethoxy, etc.), hydroxy groups, substituted and unsubstituted aryloxy groups (e.g. p-chlorophenoxy, 1- naphthoxy group, etc.), acyloxy group (e.g., acetyloxy group, p-cyanobenzoyloxy group, etc.), carboxy group, its ester group (e.g., ethoxycarbonyl group, m-bromophenoxycarbonyl group, etc.), carbamoyl group ( For example, aminocarbonyl group, tertiary butylaminocarbonyl group, anilinocarbonyl group, etc.), acyl group (e.g., acetyl group, o-nitrobenzoyl group, etc.), sulfo group, sulfamoyl group (e.g.,
aminosulfonyl group, tertiary butylaminosulfonyl group, p-tolylaminosulfonyl group, etc.), amino group, acylamino group (e.g., acetylamino group, benzoylamino group, etc.), sulfonamide group (e.g., methanesulfonamide group, p-tolylaminosulfonyl group, etc.) -toluenesulfonamide group, etc.), cyano group, nitro group, etc., but preferably substituted or unsubstituted alkyl groups having 1 to 4 carbon atoms (e.g., methyl group, ethyl group, isopropyl group, n-butyl group, trifluoromethyl group, etc.), halogen atoms (chlorine atom, bromine atom, fluorine atom, iodine atom), substituted or unsubstituted alkoxy groups 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 an atomic group necessary to form a substituted or unsubstituted aromatic carbocycle or a substituted or unsubstituted aromatic heterocycle, and specifically, for example, a substituted or unsubstituted benzene ring, a substituted, Represents an atomic group forming an unsubstituted naphthalene ring, a substituted or unsubstituted indole ring, a substituted or 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 ₆ and R ₇ , 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 ₃ is a hydrogen atom, a substituted or unsubstituted alkyl group,
Substituted or unsubstituted amino groups, carboxy groups, ester groups thereof, substituted or unsubstituted carbamoyl groups, or cyano groups, preferably hydrogen atoms, substituted or 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 ₆ and R ₇ . 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 or unsubstituted alkoxy groups having 1 to 4 carbon atoms (for example, methoxy group, ethoxy group, isopropoxy group, tertiary butoxy group, 2-chloroethoxy group). R ₄ and R ₅ are substituted or unsubstituted alkyl groups, substituted,
It represents an unsubstituted aralkyl group and a substituted or unsubstituted aryl group, preferably a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms (for example, a methyl group,
ethyl group, isopropyl group, tertiary butyl group, trifluoromethyl group, etc.), substituted or unsubstituted phenyl group (eg, phenyl group, p-methoxyphenyl group, m-chlorophenyl group, etc.). That is, in the present invention, by using an azo compound represented by the above general formula [] as a photoconductive substance constituting the photosensitive layer of the photoreceptor, it is stable against heat and light, which is the object of the present invention. In addition, we will create an excellent photoreceptor that has excellent electrophotographic properties such as charge retention, sensitivity, and residual potential, has little fatigue change even after repeated use, and has sufficient sensitivity even in the long wavelength region of 620 nm. be able to. Among the azo compounds represented by the general formulas [] and [] used in the present invention, compounds represented by the following general formulas [] to [] are preferred. General formula [] General formula [] Specific examples of the disazo compounds useful in the present invention represented by the general formulas [] to [] include those having the following structural formulas, but the azo compounds of the present invention are limited thereby. It's not a thing. (1-23) General formula [] (The number in R ₁ in the above formula [] and Table (A) below represents the bonding position of the substituent R _1. )

【table】

【table】

【table】

【table】

【table】

[Table] (24-28)

【table】

[Table] (29-53) General formula [] In R ₁ and R ₂ in the above formula [] and Table (C) below, the numbers represent the bonding positions of the respective substituents R ₁ and R ₂ . )

【table】

【table】

【table】

【table】

【table】

【table】

[Table] (54-57)

【table】

[Table] These compounds can be synthesized by a combination of conventional and well-known methods. A synthesis example is shown below. Synthesis Example 1 (Synthesis of Exemplary Compound 2) S-1) Synthesis of Intermediate Dinitrophenothiazine Method of C. Bodea, M. Raileau (Chem. Abst.
Vol. 54, 22657g (1960)). That is, 25 g of phenothiazine is mixed with chloroform.
The mixture was dissolved in a mixed solution of 600 ml of glacial acetic acid and 50 ml of glacial acetic acid, and 25 g of sodium nitrite was added little by little over 1 hour. After the addition, the mixture was further stirred for 2 hours, and the resulting crystals were collected and thoroughly washed with methanol and then water. This product was recrystallized from DMF (N,N-dimethylformamide) to obtain 14 g of the intermediate dinitrophenothiazine. (Yield 38.6%) S-2) Synthesis of intermediate N-ethyl dinitrophenothiazine 5.8 g of dinitrophenothiazine was added to 200 ml of acetone.
8.4 g of potassium carbonate and 7.2 g of diethyl sulfate were added thereto, and the mixture was heated under reflux for 10 hours. After the reaction, 100 ml of acetone was distilled off, and then 100 ml of water was added to collect crystals. Wash with water, then methanol
Sufficient suspension washing was carried out in a mixed solution of 100 ml of water, 20 ml of water, and 5 g of sodium hydroxide, and unreacted raw materials were removed.
5.8 g of N-ethyldinitrophenothiazine was obtained.
(Melting point 215-216℃, yield 91%) S-3) Synthesis of intermediate N-ethyl-dinitrophenothiazine dioxide 5.0 g of N-ethyldinitrophenothiazine was dispersed in 50 ml of glacial acetic acid, and g of sodium tungstate was added. was added thereto, and 5 ml of hydrogen peroxide solution was added dropwise little by little at 100°C. After refluxing for another 2 hours and cooling, add 50% water.
ml was added and the resulting crystals were collected. 4.7g yield 88
% Melting point 275-280℃ S-4) Synthesis of intermediate 10-ethyl-2,7-diaminophenothiazine dioxide N-ethyldinitrophenothiazine oxide
Dissolve 5.0g in 80ml of N,N-dimethylformamide, add 10g of iron, 10ml of water and 2ml of hydrochloric acid,
Heated at 105-110°C for 1 hour. After the reaction, a suspension of 3 g of sodium bicarbonate in 10 ml of water was added, and the mixture was filtered while hot. 450 ml of ice water and 30 ml of a 10% aqueous solution of sodium hydroxide were added to the solution. The resulting crystals were collected, washed with water, and then evaporated to dryness with the addition of hydrochloric acid to obtain a hydrochloride. Yield 3.1g Yield, 54% as trihydrochloride Melting point 270
°C (decomposition) S-5) Synthesis of Compound 2 3.82 g of the above 10-ethyl-2,7-diaminophenothiazine dioxide hydrochloride was added to 10 ml of hydrochloric acid and 80 ml of water.
Dispersed in 1.7 g of sodium nitrite and 10 ml of water.
was added dropwise at -5°C. After dropping, stir at the same temperature for 10 minutes and immediately filter.
Add 10g of ammonium hexafluoride phosphate to the resulting liquid.
was added and the resulting crystals were collected to obtain tetrazonium hexafluorophosphate. The crystals were dissolved in 100 ml of N,N-dimethylformamide,
A dropping solution for the next coupling reaction was obtained. Next, 7.2 g of 2-hydroxy-3-(4-methoxyphenylcarbamoyl)-benzo[a]carbazole (naphthol ASSG, manufactured by Hoechst) and 10 g of triethanolamine were dissolved in 300 ml of N,N-dimethylformamide. The above-mentioned tetrazonium salt solution was added dropwise to this while cooling with ice at .degree. After further stirring at the same temperature for 2 hours, the mixture was left to stand at room temperature overnight, and the resulting crystals were collected. The crystals were washed twice with 300 ml of N,N-dimethylformamide.
After washing twice with acetone and drying, 5.09 g of the compound was obtained. Yield: 48% This compound was confirmed by elemental analysis. The chemical formula is C ₆₂ H ₄₅ N ₉ SO ₈ elements C H N S Actual value % 68.96 4.40 11.85 3.10 Calculated value % 69.20 4.21 11.71 2.98 Synthesis example 2 Synthesis of compound (40) T-1) Intermediate 2,7-dinitro −10−p−
Nitrophenylphenothiazine Mix 8.7g of dinitrophenothiazine and 12.0g of p-nitroiodobenzene with 50ml of nitrobenzene, add 10g of potassium carbonate and 0.5g of copper powder.
The reaction was carried out at 200-210°C for 15 hours. After the reaction, nitrobenzene was distilled off by steam distillation to obtain crude crystals. Chloroform 2.0 was added to this and extracted while hot. Pour the extract into silica gel (200 mesh)
After passing through 50 g, the liquid was concentrated. The crystals were crystallized with a small amount of ethyl acetate, suspended and washed with ethyl acetate. Then, the mixture was thoroughly suspended and stirred in a mixture of 50 ml of methanol, 50 ml of acetone, 3 g of sodium hydroxide, and 15 ml of water, and unreacted raw materials were removed.
Further washing with water and then methanol gave 4.3 g of the desired intermediate 2,7-dinitro-10-p-nitrophenylphenothiazine. Yield 34.7% Melting point 260℃~265℃ T-2) Intermediate 2,7-dinitro-10-p-
Synthesis of Nitrophenylphenothiazine Dioxide 4.10 g of 2,7-dinitro-10-p-nitrophenylphenothiazine was suspended in 50 ml of glacial acetic acid, and 0.20 g of sodium tungstate was added. this
While heating to 100°C, 5ml of 35% hydrogen peroxide was added dropwise at a time over an hour. After further heating under reflux for 2 hours, the mixture was allowed to cool, and the precipitated crystals were collected and washed with water. Yield 3.5g Yield 82% Melting point 300℃ or higher T-3) Intermediate 2,7-diamino-10-p-
Synthesis of aminophenylphenothiazine dioxide and compound (40) 2.13 g of 2,7-dinitro-10-p-nitrophenylphenothiazine oxide was dispersed in 60 ml of concentrated hydrochloric acid, and stannous chloride ( 25 g of dihydrate) was added thereto, and the mixture was heated under reflux for 4 hours. After cooling, the crystals were collected and washed with dilute hydrochloric acid to obtain a tin complex of 2,7-diamino-10-p-aminophenyl phenoxazine dioxide. Add the entire amount of the above triamino compound-tin complex to 10 ml of hydrochloric acid.
Dispersed in 100ml of water, add 1.5g of sodium nitrite
A solution prepared by dissolving the above in 10 ml of water was added dropwise at -5°C.
After the dropwise addition, stir at the same temperature for 30 minutes, filter immediately, and add phosphorus ammonium hexafluoride to the resulting liquid.
10 g was added and the resulting crystals were collected to obtain hexazonium hexafluorophosphate salt. This crystal was dissolved in 100 ml of N,N-dimethylformamide and used as a dropwise solution for the next coupling reaction. Next, 4.2 g of 2-hydroxy-3-(2,4-dimethylphenylcarbamoyl)benzo[a]carbazole (naphthol ASMX) and 6 g of triethanolamine were dissolved in 200 ml of N,N-dimethylformamide. The above-mentioned hexazonium salt solution was added dropwise to this while cooling with ice at .degree. 2 more
After stirring at the same temperature for a period of time, leave it at room temperature overnight.
The resulting crystals were collected. Add this crystal to 250 ml of N,
After washing twice with N-dimethylformamide and once with acetone, the compound (40) 2.7 was dried.
I got g. Yield 43.4% (from trinitro form) This compound was confirmed by elemental analysis. The chemical formula is C ₇₅ H ₅₈ N ₁₀ SO ₈ elements C H N S Actual value % 71.32 4.71 11.17 2.62 Calculated value % 71.53 4.64 11.12 2.55 The azo compound of the present invention has excellent photoconductivity,
When producing an electrophotographic photoreceptor using this, it can be produced by providing a photosensitive layer in which the azo compound of the present invention is dispersed in a binder on a conductive support. Another method is to use the azo compound of the present invention as a carrier-generating substance by utilizing its particularly excellent carrier-generating ability among its photoconductivity properties.
By using this in combination with a carrier transport substance that can effectively act, it is also possible to produce a so-called functionally separated electrophotographic photoreceptor, such as a laminated type or a dispersed type. Furthermore, the azo compound used in the present invention can be used alone or in combination of two or more of the azo compounds represented by the above general formula [] or [], and can also be used in combination with other azo compounds. Good too. 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. In FIG. 1 and FIG. 3, a laminate is formed of a carrier generation layer 2 containing the above-mentioned azo compound as a main component and a carrier transport layer 3 containing a carrier transport substance as a main component on a conductive support 1. A photosensitive layer 4 is provided.
As shown in FIGS. 2 and 4, this photosensitive layer 4
may be provided via an intermediate layer 5 provided on the 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 azo compound of the present invention is used as a carrier generating substance, examples of the carrier transporting substance used in combination with the azo compound include electron-accepting substances that easily transport electrons such as trinitrofluorenone or tetranitrofluorenone, as well as poly-N-vinyl Polymers having a side chain of a heterocyclic compound such as carbazole, triazole derivatives, oxadiazole derivatives, imidazole derivatives, pyrazoline derivatives, polyarylalkane derivatives,
Phenylene diamine derivatives, hydrazone derivatives,
Examples include electron-donating substances that easily transport holes, such as amino-substituted chalcone 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 an azo 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 an azo 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 a dispersion liquid is 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 dielectric constant, 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 P-18) Polyvinyl butyral These binders can be used alone It can be used alone or as 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. Further, when the carrier generation layer or the photosensitive layer is a dispersed type, the particle size of the azo 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. The azo compound of the present invention is useful as a substance whose conductivity changes upon irradiation with light, and it can be used in any photoreceptor that utilizes this property, without being limited to electrophotographic photoreceptors. Hereinafter, the present invention will be specifically explained in Examples,
This does not limit the embodiments of the present invention. (Example) Example 1 2 g of exemplified compound (3) and 2 g of polycarbonate resin "Panlite L-1250" (manufactured by Teijin Kasei) were mixed into 1
Add to 110 ml of 2-dichloroethane and use a ball mill to
Dispersed for 12 hours. This dispersion was applied onto a polyester film on which aluminum was vapor-deposited so that the dry film thickness was 1 μm to form a carrier generation layer, and on top of that, a carrier transport layer (formed by the following structural formula (K-1)). ) 6g and 10g of polycarbonate resin "Panlite L-1250" dissolved in 110ml of 1,2-dichloroethane, the film thickness after drying is
A carrier transport layer was formed by coating to a thickness of 15 μm, and an electrophotographic photoreceptor of the present invention was prepared. 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 in the dark for 5 seconds, then irradiate with halogen lamp light so that the illuminance on the photoreceptor surface is 35 lux, and calculate the exposure amount 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 A comparative photoreceptor was prepared in the same manner as in Example 1, except that the following disazo compound (G-1) was used as a carrier generating substance. 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 residual potential and repeated stability compared to the comparative electrophotographic photoreceptor. Examples 2 to 4 Exemplary compounds (2), (21) as carrier generating substances,
and A-(29) as a carrier transport substance,
(The following compound (K-2)) was used to prepare an electrophotographic photoreceptor of the present invention in the same manner as in Example 1,
Similar measurements were conducted and 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 was provided, and 2 g of Exemplified Compound (49) was mixed with 110 ml of 1,2-dichloroethane on top of it, and the dispersion was dispersed in a ball mill for 24 hours so that the film thickness after drying was 0.5 μm. was applied to form a carrier generation layer. On this carrier generation layer, 5 g of 4-methoxytriphenylamine and 10 g of methacrylic resin "Acrypet" (manufactured by Mitsubishi Rayon Co., Ltd.)
An electrophotographic photoreceptor of the present invention was prepared by coating a solution obtained by dissolving G and g in 70 ml of 1,2-dichloroethane so that the film thickness after drying was 10 μm to form a carrier transport layer. When the same measurements as in Example 1 were carried out on this electrophotographic photoreceptor, E1/2=
The result was 4.0lux·sec, V _R =OV. Example 6 On the conductive support provided with the intermediate layer used in Example 3, a 1% ethylenediamine solution of exemplified compound (9) was applied so that the film thickness after drying was 0.3 μm, and a carrier generation layer was formed. was formed. then on top of that 1.2 g of the above compound (K-3) and 10 g of polyester resin "Vylon 200" (manufactured by Toyobo Co., Ltd.)
-Dissolved in 70 ml of dichloroethane, and coated this solution so that the film thickness after drying was 12 μm to form a carrier transport layer, thereby producing an electrophotographic photoreceptor of the present invention. The same measurements as in Example 1 were performed on this electrophotographic photoreceptor, and the results shown in Table 4 were obtained.

[Table] Comparative Example 2 A comparative photoreceptor was prepared in the same manner as in Example 4, except that the following disazo compound (G-2) was used as a carrier generating substance. Regarding this electrophotographic photoreceptor for comparison, Example 1
When measurements were carried out in the same manner as above, the results shown in Table 5 were obtained.

[Table] As is clear from the above results, the electrophotographic photoreceptor of the present invention is extremely superior in sensitivity and residual potential compared to the comparative electrophotographic photoreceptor. Example 7 A 0.05 μm thick intermediate layer 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, and then 4 g of Exemplary Compound (40) was mixed with 400 ml of 1,2-dichloroethane, and the dispersion was dispersed for 24 hours using a ball mill dispersion machine.The dispersion was then applied to a film thickness of 0.6 μm after drying to form a carrier generation layer. did. Furthermore, on top of this, 30g (the following compound (K-4))
and polycarbonate resin “Corpilon S-1000”
(manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dissolved in 400 ml of 1,2-dichloroethane and coated to form a carrier transport layer so that the film thickness after drying was 13 μm, and a drum-shaped electrophotographic photoreceptor was created. did. The photoreceptor thus created was attached to a modified electrophotographic copying machine "U-Bix V2" (manufactured by Konishiroku Photo Industry Co., Ltd.), and when the image was copied, the contrast was high and the image was clear and faithful to the original. A duplicate image was obtained. Moreover, this did not change even after repeating this 10,000 times. Example 8 On the surface of an aluminum drum with a diameter of 100 mm,
A 0.05 μm thick intermediate layer made of vinyl chloride-vinyl acetate-maleic anhydride copolymer "Eslec MF-10" (manufactured by Sekisui Chemical Co., Ltd.) was provided, and 4 g of Exemplified Compound (33) was added to the 1,2- dichloroethane 400
ml and dispersed for 24 hours using a ball mill dispersion machine, the dispersion was applied to a dry film thickness of 0.5 μm to form a carrier generation layer. Furthermore, 30 g of 4-methyl-4'-styryltriphenylamine and 50 g of polycarbonate resin "Panlite L-1250" (manufactured by Teijin Kasei) were added to
It was dissolved in 400 ml of 2-dichloroethane and coated to form a carrier transport layer so that the film thickness after drying was 12 μm, and an electrophotographic photoreceptor on a drum was prepared. The spectral sensitivity of this photoreceptor at 633nm is
It was 1.10 μJ/cm ² (half exposure amount). Next, this photoconductor was heated using a He-Ne laser (632.8nm) with a laser beam intensity of 10mW on the photoconductor surface.
A live-action test was conducted using an experimental machine equipped with the following. 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 -350 V. A good image without fogging was obtained. Moreover, this did not change even after repeating this 10,000 times.

[Brief explanation of the drawing]

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. A photoreceptor comprising a photosensitive layer containing at least one azo compound represented by the following general formula [] or [] on a conductive support. General formula [] General formula [] [In the formula, A represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, R ₁ and R ₂ represent a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom, and Cp is [Formula] [Formula] [Formula] or [Formula], where Z: a group of atoms necessary to constitute a substituted or unsubstituted aromatic carbocycle or a substituted or unsubstituted aromatic heterocycle, Y: substituted or unsubstituted carbamoyl group or substitution,
Unsubstituted sulfamoyl group, R ₃ : hydrogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted amino group, substituted or unsubstituted carbamoyl group, carboxy group and its ester group, or cyano group, A′: Substituted or unsubstituted aryl group, R ₄ and R ₅ : substituted or unsubstituted alkyl group, substituted,
Represents an unsubstituted aralkyl group or a substituted or unsubstituted aryl group. 2. The 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 an azo compound represented by the general formula [ ] or [ ].