JPH02118579A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve the sensitivity and durability of the photosensitive body by incorporating a specific disazo compd. into the photosensitive layer thereof. CONSTITUTION:The desazo compd. expressed by formula I is incorporated into the photosensitive layer. In the formula, CP denotes a residual coupler group and is preferably the residual group of formulas II, III. In the formulas, X denotes a hydrocarbon ring, heterocycle; Y denotes H, -CON(-R<1>)-R<2>, etc.; R<1> to R<3> denote a hydrocarbon group, etc. The photosensitive layer may be formed of a single layer contg. the compd. expressed by the formula and may also be formed by laminating a charge carrier generating layer contg. the compd. expressed by the formula and a charge transfer layer contg. a hydrazone compd., etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having a photosensitive layer containing a disazo compound.

[Conventional technology]

So-called electrophotography, which combines a photoconductive material and electrostatic development to create an image, was developed by Carlson in U.S. Pat.
It originated from "electron photography" which was revealed in issue 1776. In electrophotography, a photoconductive material whose electrical resistance changes depending on the amount of light irradiation is dispersed in an insulating binder resin and coated on a support is used as a photoreceptor. . After this photoconductive material is given a uniform surface charge by corona charging in a dark place, it loses its surface charge depending on the brightness value of image exposure, and an electrostatic latent image is formed. The surface of such an electrostatic latent image is then treated with a suitable electrostatic indicator material, ie, a toner, to become a visible image.

The toner is used with a dry carrier or as a colloidal suspension in an organic solvent, and can be attached by Coulomb force depending on the charge of the electrostatic latent image. The attached display substance can be fixed by heat, pressure, or the like.

Further, the electrostatic latent image can be transferred to a second support (for example, paper, film, etc.) and then fixed thereon.

In such electrophotography, the basic characteristics required of an electrophotographic photoreceptor are (1) ability to be charged to an appropriate potential in the dark, and (2) ability to retain charge in the dark. and (3) the ability to rapidly dissipate charge in the d- direction by light irradiation.

In addition, from a practical standpoint, (4) photoconductors with a suitable area can be manufactured by FyK, (5) good repeatability, (6) durability, and (7) low cost. This is what is required.

Conventionally, selenium, sulfurized mium, zinc oxide, and the like have been widely used as photoconductive materials for electrophotographic photoreceptors. However, while these inorganic compounds have many advantages, they also have various disadvantages. For example, selenium has difficult molding conditions, high manufacturing costs, and high temperatures.

It has drawbacks such as the fact that it easily crystallizes due to humidity, fingerprints, etc., and its properties as a photoreceptor deteriorate, so care must be taken when handling it. Further, cadmium sulfide has particularly poor moisture resistance, and auxiliary means such as installing a heater are required to prevent the photoreceptor from absorbing moisture. In addition, zinc oxide has problems with mechanical strength such as hardness and abrasion resistance, and because it is sensitized with dyes such as rose bengal, photobleaching of the dye due to corona charging is approximately It was shortening his lifespan. These inorganic compounds contain heavy metals, and if handled incorrectly, there was a risk of developing a pollution problem.

In recent years, in order to overcome the drawbacks of these inorganic compound photoconductive materials, research and development of electrophotographic photoreceptors using various organic photoconductive compounds has been actively conducted. For example, poly-N-vinylcarbashield 2.4.7-
) An electrophotographic photoreceptor consisting of linitrofluorenone (
U.S. Patent No. 3,484,237), poly-N-vinylcarbazole sensitized with pyrylium salt dye (Japanese Patent Publication No. 48-25658), and eutectic material consisting of dye and resin as photoconductive materials. Things to do (Japanese Unexamined Patent Publication No. 47-10785
) etc. Compared to inorganic compound-based electrophotographic photoreceptors, such organic compound-based electrophotographic photoreceptors have the advantages of being easier to form a film, being extremely flexible, and being able to provide inexpensive photoreceptors. There is. However, e.g. Eve,
For photoconductive polymers such as poly-17 + N-vinylcarbazole, the primer alone does not provide good filmability, flexibility,
Adhesive properties are poor, and plasticizers, binders, etc. are added to improve these defects, but this causes problems such as a decrease in sensitivity and an increase in residual potential.

In addition, organic low-molecular photoconductive compounds have a wide range of binders to choose from, and by selecting an appropriate primer, it is possible to create products with improved mechanical properties such as filmability and adhesiveness. However, on the other hand, it did not fully satisfy the requirements for an electrophotographic photoreceptor, such as photosensitivity and repeatability.

[Problems to be solved by the present invention]

The problem to be solved by the present invention is to overcome the drawbacks of conventional inorganic compound-based electrophotographic photoreceptors, and to improve the drawbacks of the organic compound-based electrophotographic photoreceptors that have been proposed so far, so as to be able to put them into practical use. It is an object of the present invention to provide an electrophotographic photoreceptor having extremely high sensitivity and high durability.

[! ! Means to solve the ode]

In order to solve the above-mentioned problems, the present invention has the following objectives: General formula (1) The residue can be selected from known coupler components, but in particular General formula (n) General formula (2) General formula (Incorporated) ・... (1) Provided is an electrophotographic photoreceptor containing a compound represented by the formula (wherein, Cp represents a coupler residue).

Coupler H in the compound represented by general formula (1) or general formula (to) (wherein, X represents a hydrocarbon ring or heterocycle which may have a substituent, and Y is a hydrogen atom) , R2 and R3 each independently represent a hydrogen atom, a hydrocarbon group or a heterocyclic group which may have a substituent, and R1 and R2 may mutually form a ring.) Preferably, it is a residue.

Specific examples of RR and R in the coupler residues of the above general formulas (n), (to), , isobutyl group, isoamyl group, isohexyl group, neopentyl group, C1-20 alkyl group such as t・rt-methyl group; aromatic hydrocarbon group such as phenyl group, naphthyl group; pyri-sol group, carbazolyl group and aromatic heterocyclic groups such as incitriazolyl group.

When RI B2 and R3 are substituted alkyl groups, examples of the substituent include a halogen atom, a nitro atom, a cyano group, a hydroxyl group, a substituted hydroxyl group, a thiol group, a substituted thiol group, an amino group, a substituted amino group, and an aryl group. Examples include groups. It may be a substituted alkyl group having two or more of these substituents. Specific examples of substituted alkyl groups include chloromethyl group, trifluoromethyl group, and 2-cl-T-! Chihalo-noalkyl group such as thyl group; Nitroalkyl group such as nitromethyl group, 3-nitroalkyl group; Cyanoalkyl group such as cyanomethyl group, 2-cyanoethyl group; Hydroxymethyl group, 2-hydroxyethyl group, 2-hydroxypropyl group hydroxyalkyl groups such as 3-hydroxypropyl; substituted hydroxyalkyl groups such as methoxymethyl, 2-methoxyethyl, ethoxymethyl and phenoxymethyl; thiohydroxymethyl and 2-thiohydroxyethyl groups; Thiohydroxyalkyl group; substituted thiohydroxyalkyl group such as methylthiomethyl group, 2-methylthioethyl group; aminoalkyl group such as aminomethyl group, 2-aminoethyl group; methylaminomethyl group, ethylaminomethyl group, dimethylaminomethyl group group, 2-(dimethylamino)ethyl group, phenylaminomethyl group, substituted aminoalkyl group such as diphenylaminomethyl group, and the like.

When R1R2 and R3 are substituted aromatic hydrocarbon groups or ring-opened aromatic heterocyclic groups, the substituents include alkyl groups,
Halodan atom, nitro group, cyano group, hydroxyl group,
Examples include a substituted hydroxyl group, a thiol group, a substituted thiol group, an amino group, and a substituted amino group. It may be a substituted aromatic hydrocarbon group or a substituted aromatic heterocyclic group having two or more of these substituents.

Examples of variants when HI R2 and R3 are substituted phenyl groups include tolyl group, alkylphenyl group such as ethylphenyl group; herodane-substituted phenyl group such as chlorophenyl group and bromophenyl group; ditrophenyl group; cyano Phenyl group; Hydroxyphenyl group; Substituted hydroxyphenyl group such as methoxyphenyl group, ethoxyphenyl group; Thiohydroxyphenyl group; Substituted thiophenyl group such as methylthiophenyl group, ethylthiophenyl group; Aminophenyl group; Methylaminophenyl group, dimethyl Substituted aminophenyl groups such as an aminophenyl group, a phenylaminophenyl group, and a diphenylaminophenyl group can be mentioned.

Specific examples when R1, 12 and R3 are substituted condensed aromatic hydrocarbon groups include alkylnaphthyl groups such as methylnaphthyl group and ethylnaphthyl group; chloronaphthyl group;
7thyl group substituted with bromonaphthyl group;
r: I xynaphthyl group; substituted hydroxynaphthyl group such as methoxynaphthyl group and ethoxynaphthyl group; thiohydroxynaphthyl group; substituted thionaphthyl group such as methylthionaphthyl group and ethylthionaphthyl group; ayononaphthyl group; methylaminonaphthyl group, dimethyl Examples thereof include substituted aminonaphthyl groups such as aminonaphthyl group, phenylaminonaphthyl group, and diphenylaminonaphthyl group.

Specific examples when R1, R2 and R3 are substituted aromatic heterocyclic groups, particularly nzothiazolyl groups, include alkylbenzothiazolyl groups such as methylbenzothiazolyl group and ethylbenzothiazolyl group; chloro Halodane-substituted benzothiazolyl groups such as benzothiazolyl group and bromobenzothiazolyl group; nitrobenzothiazolyl group; cyanobenzothiazolyl group; hydroxybenzothiazolyl group; methoxybenzothiazolyl group, ethoxybenzothia Substituted hydroxybenzothiazolyl group such as zolyl group; thiohydroxybenzothiazolyl group; substituted thiobenzothiazolyl group such as methylthiobenzothiazolyl group, ethylthiobenzothiazolyl group; aminobenzothiazolyl group Groups include substituted aminobenzothiazolyl groups such as methylaminobenzothiazolyl group, dimethylaminobenzothiazolyl group, phenylaminobenzothiazolyl group, and diphenylaminobenzothiazolyl group.

The disazo compound represented by general formula (1) according to the present invention can be produced by a conventionally known method. For example, "Journal of Heterocyclic Chemistry"
As described in Vol. 2, p. 244 (1965), p-nitrophenacyl bromide and dithiooxamide are heated in dimethylacetamide to react with 4,4'-bis( p-nitrophenyl)-2,2'-bisthiazole is produced.

Furthermore, compound 2M was cyclically modified with zinc in the presence of calcium chloride in ethanol to obtain 4 represented by the following formula (2).
, 4'-bis(p-aminophenyl)-2,2'-bisthiazole is produced.

(Then, the compound represented by the formula (■) is diazotized by a conventional method and coupled with the coupler Cp in the presence of an alkali, or the diazonium salt of the compound represented by the formula (■) is converted into a borohydrofluoride. Alternatively, once isolated as a zinc salt, it can be easily coupled with a coupler in the presence of an alkali in a suitable solvent, such as an inert organic solvent such as N,N'-zomethyformamide or dimethyl sulfoxide. The compound of formula (1) can be produced in the following manner.

Specific examples of the disazo compounds of the above-mentioned Monna (I) that can be used in the present invention are shown in Tables 1 to 6 as structural formulas.

The electrophotographic photoreceptor of the present invention can have various structures. Examples are shown in Figures 1-4. The photoreceptor shown in FIG. 1 has a photosensitive layer (2a) formed by dispersing an azo compound (3) in a binder (4) on a conductive support (1). The photoreceptor shown in FIG. 2 has a photosensitive layer (2b) formed by dispersing an azo compound (3) in a charge transport medium consisting of a charge transport substance (5) and a binder on a conductive support. The photoreceptor shown in FIGS. 3 and 4 has a photosensitive layer (2c) consisting of a charge carrier generation layer (6) mainly composed of an azo compound (3) and a charge transport layer (7) composed of a charge transport substance and a binder. or (2d) respectively. In the case of FIG. 1, the azo compound (3) performs both the functions of generating charge carriers necessary for light attenuation and transporting charges. In the case of the photoreceptor of FIG. 2, the charge transport material together with the binder forms the charge transport medium (5), while the azo compound (3) acts as a charge carrier generating material. Although this charge transport medium (5) does not have the ability to generate charge carriers like the azo compound (3), it has the ability to accept and transport charge carriers generated from the azo compound. That is, in the photoreceptor shown in FIG. 2, the generation of charge carriers necessary for light attenuation is carried out by the azo compound (3), while the transport of charge carriers is carried out mainly by the charge transport medium (5).

In the case of the photoreceptors shown in FIGS. 3 and 4, the azo compound (3) contained in the charge carrier generation layer (6) generates one charge carrier, while the charge transport layer (7) generates one charge carrier. Receives injection and transports it. That is, the mechanism of action is the same as that of the photoreceptor shown in FIG. 2, in which the generation of charge carriers necessary for light attenuation is carried out by an azo compound, and the transport of charge carriers is carried out by a charge transport medium.

The photoreceptor shown in FIG. 1 can be manufactured by dispersing an azo compound in a binder solution, coating this dispersion on a conductive support, drying it, and then combing it.

The photoreceptor shown in FIG. 2 can be manufactured by dispersing an azo compound in a solution containing a charge transporting substance and a binder, coating this dispersion on a conductive support, and drying it. The photoreceptor shown in Fig. 3 can be made by vacuum-depositing an azo compound on a conductive support, or by applying a dispersion obtained by dispersing fine particles of an azo compound in a solvent or a non-ingu solution, and then drying it. It can be manufactured by applying a solution containing a charge transporting substance and a binder thereon and drying it. The photoreceptor shown in Fig. 4 can be prepared by dissolving a charge transporting substance and a binder in a solution on a conductive support, drying the solution, and then vacuum-depositing an azo compound thereon, or by depositing fine particles of an azo compound in a solvent or a similar method. It can be produced by coating and drying a dispersion obtained by dispersing in an Ingu solution.

The thickness of the photosensitive layer of these photoreceptors is 3 to 50 μm, preferably 5 to 20 μm in the case of the photoreceptors shown in FIGS.
It is. In the case of the photoreceptor shown in FIGS. 3 and 4, the thickness of the charge carrier generation layer is 5 μm or less, preferably 0.01 to 5 μm.
2 μm, and the thickness of the charge transport layer is 3 to 50 μm, preferably 5 to 20 μm.

Further, in the photoreceptor shown in FIG. 1, the proportion of the azo compound in the photosensitive layer is 10 to 70% by weight, preferably 30 to 50% by weight, based on the photosensitive layer. In the photoreceptor shown in Figure 2,
The proportion of the azo compound in the photosensitive layer is 1 to 50% by weight, preferably 3 to 30% by weight, and the proportion of the charge transport material is 10 to 90% by weight, preferably 10 to 60% by weight. The proportion of the charge transport material in the charge transport medium in the photoreceptor of FIGS. 3 and 4 is 10 to 95 cm, preferably 10 to 95 cm.
It is 60% by weight.

Examples of the conductive support used in the photoreceptor of the present invention include aluminum, steel, zinc, stainless steel, chromium,
Metal plates and metal drums made of metals or alloys such as titanium, nickel, molybdenum, panadicum, indium, gold, and platinum, or conductive polymers, conductive compounds such as indium oxide, and metals such as aluminum, tucladium, gold, etc. Examples include paper coated with, vapor-deposited, or laminated with an alloy, a plastic film, and the like.

As the binder, it is preferable to use a hydrophobic polymer capable of forming an electrically insulating film. Examples of such high molecular weight polymers include polycarbonate? Nate,
Polyester, methacrylic resin, acrylic resin, previnyl chloride, polyvinylidene chloride, polystyrene, privinyl acetate, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride
Vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-vinylcarbazole, polyvinyl butyral, ? Examples include, but are not limited to, ribinylformal, presulfone, and the like.

These binders can be used individually or as a mixture of two or more types.

Additionally, additives such as plasticizers, sensitizers, surface modifiers, etc. can also be used together with these binders.

Examples of plasticizers include biphenyl, chlorinated biphenyl, 0-terphenyl, p-terphenyl, dibutyl phthalate, diethylene glycol phthalate, so-octyl phthalate, triphenyl phosphoric acid, methylnaphthalene, benzophenone, chlorinated paraffin, -lipropylene, and polypropylene. Examples include styrene, various fluoro tetrahydrocarbons, and the like.

Examples of the sensitizer include chloranil, tetracyanoethylene, methyl violet, rhodamine B, cyanine dye, merocyanine dye, pyrillicum dye, and thiapyrylium dye.

Examples of the surface modifier include silicone oil and fluororesin.

Furthermore, in the present invention, in order to improve the adhesion between the conductive support and the photosensitive layer, and to prevent the injection of free charges from the conductive support to the photosensitive layer, the conductive support and the photosensitive layer are bonded. Between the layers,
An adhesive layer or barrier layer can also be provided as required. Materials used for these layers include, in addition to the polymer compounds used in the Bi/Goo, casein, gelatin, teribinyl alcohol, ethyl cellulose, nitrocellulose, polyvinyl butyral, phenolic resin, polyamide, carboxy-methyl cellulose, vinylidene chloride, etc. Examples include polymer latex, styrene-butadiene polymer latex, polyurethane, gelatin, aluminum oxide, tin oxide, and titanium oxide.

In addition, charge transport materials are generally classified into two types: compounds that transport electrons and compounds that transport holes.
Both can be used in the electrophotographic photoreceptor of the present invention.

Examples of electron transport substances include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4.7-) dinitro-9-fluorenone, 2
, 4,5.7-tetranitro-9-fluorenone, 9-
Dicyanomethylene-2,4,7-)-nitrofluorenone, 9-dicyan/lf-7-2.4,5.7-tetranitrofluorenone, 2,4,5.7-f-tranitroxanthone, 2,4 .8-) IJ nidrothioxanthone, tetranitrocarnozole clo 5=yv, 2.3-
Dichloro-5,6-dicyatupenzoquinone, 2,4.7
-) dinitro-9,10-phenanthrenequinone, tetrachlorophthalic anhydride, and the like.

Examples of the hole transport substance include low molecular weight compounds such as evapyrene, N-ethylcarbazole, N-isozolobylcarbazole, N-phenylcarbazole, or N-methyl-2-phenylhydradi/-3-fi methylidene. 9-
Ethylcarbazole, N,N-diphenylhydrazino-
3-methylidene-9-ditylcarnozole, p -N
, N-dimethylaminobenzaldehyde diphenylhydrazone, p-N,N-diethylaminobenzaldehyde diphenylhydrazone, p-N,N-diphenylaminobenzaldehyde diphenylhydrazone and other hydrazones, 2.5-bis(p-diethylaminophenyl) -
1,3,4-oxadiazole, l-phenyl-3-(
Pyrazolines such as p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, triphenylamine, N,N, and N''-tetraphenyl-1,
1'-biphenyl-4,4'-diamine, N, N'-diphenyl-N, N'-bis(3-methylphenyl) -
Examples include 1,1'-biphenyl-4,4'-diamine. In addition, examples of high molecular compounds include haholly N-vinylcarbazole and halodanized #! J -N-vinylcarbazole, -rivinylpyrene, ? Lipinyl anthracene, polyvinylacridine, pyrene-formaldehyde resin, ethylcarbazole-formaldehyde resin,
Examples include triphenylmethane polymer.

The charge transport materials are not limited to those described herein, and may be used alone or in combination of 21 or more types.

When forming a laminated photoreceptor by coating, the solvent that dissolves the binder varies depending on the type of binder, but is preferably selected from those that do not dissolve the lower layer. Specific examples of organic solvents include alcohols such as methanol, ethanol, and nf rononol; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; N,N-dimethylformamide, N,N
- Amides such as dimethylacetamide; ethers such as tetrahydrofuran, dioxane, methylselonulp;
Esters such as methyl acetate and ethyl acetate; Sulfoxides and sulfones such as dimethyl sulfoxide and sulfolane; Aliphatic halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, and trichloroethane; Benzene, toluene, xylene, monochlorobenzene, and Examples include aromatics such as chlorobenzene.

As the coating method, for example, a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a wire percoat ink method, a blade coating method, a roller coating method, a curtain coating method, and the like can be used.

〔Example〕

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to the Examples. still,
In the examples, "parts" indicate "parts by weight." Further, the grave of disazo compounds means the graves in Tables 1 to 6.

Example 1 10 parts of a polyester resin (trade name "Pylon 200" manufactured by Toyobo Co., Ltd.), 10 parts of I61 disazo compound and 80 parts of tetrahydrofuran were pulverized and mixed in a vibration mill, and the resulting dispersion was coated on a polyester film coated with aluminum. The photoreceptor was coated with a wire parser and dried to obtain a photoreceptor having the structure shown in FIG. 1 and having a photoreceptor layer with a thickness of about 10 μm. Next, an electrostatic copying paper tester Model 5P-4 was applied to the photosensitive layer surface of this photoreceptor.
28 (manufactured by Kawaguchi Electric Seisakusho Co., Ltd.), the photoreceptor was first charged by corona discharge at an applied voltage of -6 kV in a dark place.
Leave it in the dark for 0 seconds, then turn on the tungsten lamp,
The photosensitive layer is irradiated with light so that the surface has an illuminance of 5 lux, and the time required for the surface potential to decrease to 1/2 of the surface potential after being left in a dark place for 10 seconds is measured, and the photosensitivity E1
/2 (looks/second) was found, E, /2=4
It was 1.5 lux·sec.

Example 2 3 parts of polyester resin (same product as Example 1), 2.4.
7-) 3 parts of dinitro-9-fluorene, 0.6 parts of the disazo compound of Tomb 1, and 30 parts of tetrahydrofuran were ground and mixed in a sol mill, and the resulting dispersion was spread on a polyester film coated with aluminum using a wire parr. The photoreceptor was coated and dried to produce a photoreceptor having the structure shown in FIG. 2 and having a photoreceptor layer with a thickness of about 9 μm. Next, the sensitivity of this photoreceptor was measured according to Example 1 and found to be E,/2=4.1 lux·sec.

Example 3 3 parts of the disazo compound of A1 was added to phenoxy resin (trade name: r
1 part of PKHHJ (manufactured by Union Carbide Co., Ltd.) was dissolved in 75 parts of dioxane and mixed by pulverization using a vibrating mill, and the resulting dispersion was applied onto an aluminum vapor-deposited preester film using a wire parlor and dried. Thickness 1μ
A charge generation layer was formed. On this charge generation layer, p-
5 parts of diethylaminobenzaldehyde-diphenylhydrazone, polycarbinate resin (product name: "Panlite L")
-1250W (manufactured by J Konjin Kasei) 5 parts methylene chloride 6
A solution prepared by dissolving 5 parts of the photoreceptor was coated using a wire parser and dried to form a charge transport layer having a thickness of 10 .mu.m, thereby obtaining a photoreceptor having the structure shown in FIG. Example 1 The sensitivity of the photoreceptor thus prepared
When measured according to the method, E and A were 2.5 lux·sec.

Examples 4 to 20 A photoreceptor having the structure shown in FIG. 3 was prepared in the same manner as in Example 3, except that the disazo compounds shown in Table 7 below were used in place of the disazo compound in No. 41, and in accordance with Example 1. Sensitivity was measured and the results listed in the same table were obtained.

Table 7 Example 21 The structure shown in FIG. A photoreceptor was prepared and its sensitivity was measured according to Example 1.
2=2.4 lux·sec.

Examples 22 to 40 The disazo compounds listed in Table 8 below were used in place of the disazo compound in Black 1, and N-ethylcarbasol-3-methylidene was used instead of p-diethylaminobenzaldehyde-diphenylhydrazone as the charge transport material. The third step was carried out in the same manner as in Example 3 except that N-aminoindoline was used.
A photoreceptor having the structure shown in the figure was prepared, and the sensitivity was measured according to Example 1, and the results listed in Table 8 were obtained.

Example 41 The structure shown in Figure 3 was prepared in the same manner as in Example 3, except that N-ethylcarbasol-3-methylidene-N-aminotetrahydroquinoline was used instead of p-diethylaminobenzaldehyde-diphenylhydrazone as the charge transport material. A photoreceptor was prepared and the sensitivity was measured according to Example 1, and the sensitivity was found to be E1/2=2.9 lux·sec.

Examples 42 to 60 Disazo compounds shown in Table 9 below were used in place of the disazo compound in A1, and KN-ethylcarbasol-3-methylidene-N- was used in place of p-diethylaminobenzaldehyde-diphenylhydrazone as the charge transport substance. A photoreceptor having the structure shown in FIG. 3 was prepared in the same manner as in Example 3, except that aminotetrahydroquinoline was used, and the sensitivity was measured in accordance with Example 1, and the results listed in the table were obtained.

Example 61 1 3 parts of recarbonate resin (same product as Example 3), p-
A solution of 3 parts of diethylaminobenzaldehyde-diphenylhydrazone dissolved in 35 parts of tetrahydrofuran was applied onto a polyester film coated with aluminum using a wire spool and dried to form a charge transport layer with a thickness of about 10 microns.

Next, the paint used to form the charge generation layer in Example 3 was applied onto the charge transport layer using a wire parser and dried to form a charge generation layer with a thickness of about 0.8 μm. A photoreceptor was obtained. The sensitivity of the thus produced photoreceptor was measured according to Example 1 by performing corona discharge at an applied voltage of +6 kV, and found to be E,/2=2.4 lux·sec.

〔Effect of the invention〕

Since the electrophotographic photoreceptor of the present invention has excellent durability and high sensitivity, it can be widely used in RPC copying machines and the like.

[Brief explanation of the drawing]

1 to 4 are enlarged partial cross-sectional views of the electrophotographic photoreceptor according to the present invention. 1... Conductive support, 2m, 2b, 2c, 2d...
Photosensitive layer, 3... Disazo compound, 4... Binder 5... Charge transport material, 6... Charge carrier generation layer, 7.
...Charge transport layer. Agent Patent Attorney Katsutoshi Takahashi

Claims (1)

[Claims] 1. Electrophotography characterized by containing a compound represented by the general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, Cp represents a coupler residue.) Photoreceptor for use. 2. Cp is general formula (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ General formula (III) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ General formula (IV) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or General formula (V) ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, X represents a hydrocarbon ring or heterocycle that may have a substituent, Y is a hydrogen atom, ▲ Numerical formula, chemical formula ,
There are tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. Alternatively, it represents a heterocyclic group, and R^1 and R^2 may mutually form a ring. 2. The electrophotographic photoreceptor according to claim 1, which is a coupler residue represented by the following formula.