JPH0313953A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance sensitivity and durability of a photosensitive body by incorporating a specified disazo compound in it. CONSTITUTION:The photosensitive layer of the photosensitive body contains the disazo compound of formula I in which Cp is a coupler residue, preferably, such as groups of formulae II, III, and the like; X is a hydrocarbon or hetero ring; Y is -CONR<1>R<2> or -CONHN=CR<1>R<2>; and each of R<1> - R<3> is H, a hydrocarbon group, or the like. The photosensitive body can be formed by laminating an electric charge generating layer obtained by dispersing the compound of formula I into a phenoxy resin and a charge transfer layer composed of a preferable hydrazone compound and polycarbonate on the polyester film on which Al is vapor deposited.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] 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]

The so-called electrophotographic method, in which images are recorded by combining a photoconductive substance and an electrostatic phenomenon, was developed by Carl Zuhl in U.S. Pat.
It originated from the ``electron photography'' that was revealed in issue 1776. Electrophotography uses a photoconductive material whose electrical resistance changes depending on the amount of light irradiated with it.
A photoconductive material that 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. This kind of electrostatic latent image is
The surface is then treated with a suitable electrolytic indicator material, ie, toner, to form a visible image. The toner can be used with a dry carrier or colloidally suspended in an organic solvent and can be deposited 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.

The electrostatic latent image can also be transferred to a second support (eg, paper, film, etc.), developed, and fixed.

In such electrophotography, the basic characteristics required of an electrophotographic photoreceptor are (I) 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 quickly dissipate charge by light irradiation.

In addition, from a practical standpoint, (4) a photoreceptor with an appropriate area can be easily manufactured, (5) it has good repeat stability,
(6) It must be durable, and (7) It must be inexpensive.

Conventionally, selenium, cadmium sulfide, 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 drawbacks such as difficult manufacturing conditions, high manufacturing costs, and the need for careful handling as it easily crystallizes due to temperature, humidity, fingerprints, etc., and deteriorates its properties as a photoreceptor. had. 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 since it is sensitized with dyes such as rose bengal, photobleaching of the dye due to corona charging can shorten the life of the photoreceptor. It was shrinking. These inorganic compounds contain heavy metals, and if handled incorrectly, there is 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,
Electrophotographic photoreceptor consisting of poly-N-vinylcarbazole and 2,4,7-dolinitrofluorenone (US Pat. No. 3,484,237), sensitizing poly-N-vinylcarbazole with a pyrylium salt dye. (Special Public Interest Act 1977)
-25658), and one in which a eutectic consisting of a dye and a resin is used as a photoconductive material (Japanese Patent Application Laid-open No. 10785/1983). Compared to inorganic compound-based electrophotographic photoreceptors, organic compound-based electrophotographic photoreceptors have the advantages of being easier to form a film, offering extremely high productivity (and being able to provide inexpensive photoreceptors). However, for example, poly-N
- Regarding photoconductive polymers such as vinyl carbazole, the polymer alone has poor coating properties, flexibility, adhesion, etc., and plasticizers, binders, etc. are added to improve these defects. This has led to problems such as a decrease in sensitivity and an increase in residual potential.

In addition, organic compound-based low-molecular photoconductive compounds have a wide range of binders to choose from, and if an appropriate polymer is selected,
Although it is possible to produce products with excellent mechanical properties such as filmability and adhesiveness, on the other hand, they do not fully satisfy the requirements for electrophotographic photoreceptors 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 improve the drawbacks of the organic compound-based electrophotographic photoreceptors that have been proposed so far, so as to be fully practical. The object of the present invention is to provide an electrophotographic photoreceptor having high sensitivity and high durability that can be used for various purposes.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides an electrophotographic photoreceptor containing a compound represented by - Shipin (I) (wherein Cp represents a coupler residue).

-i The coupler residue in the compound represented by formula (I) can be selected from known coupler components, but especially -Funenin (n) -Funenin (III) (wherein, X is , represents a hydrocarbon ring or a heterocycle which may have a substituent, and Y is represented by the general formula (IV) 3 n or -Funenin (V) 3 R2 and R3 each independently represent a hydrogen atom or a substituent. (represents a hydrocarbon group or a heterocyclic group which may have R1 and R2 may mutually form a ring) is preferably a coupler residue represented by the following.

R1. in the coupler residues of Saito (n), (I[r), (IV) and (V). Specific examples of R1 and R3 include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, isopropyl group, isobutyl group, isoamyl group, isohexyl group, neopentyl group, t
Alkyl groups having 1 to 20 carbon atoms such as er t-butyl group; aromatic hydrocarbon groups such as phenyl group and naphthyl group; aromatic heterocyclic groups such as pyridyl group, carbazolyl group, benzotriazolyl group, etc. Can be mentioned.

When R1, R1 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, Examples include aryl groups.

It may be a substituted alkyl group having two or more of these substituents. Specific examples of substituted alkyl groups include halogenoalkyl groups such as chloromethyl group, trifluoromethyl group, and 2-bromoethyl group; nitroalkyl groups such as nitromethyl group and 3-nitropropyl group; cyanomethyl group;
Cyanoalkyl group such as 2-cyanoethyl group; Hydroxyalkyl group such as hydroxymethyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 3-hydroxypropyl group; Methoxymethyl group, 2-methoxyethyl group, ethoxymethyl group , substituted hydroxyalkyl groups such as phenoxymethyl group; thiohydroxymethyl group, 2-
thiohydroxyalkyl group such as thiohydroxyethyl group; substituted thiohydroxyalkyl group such as methylthiomethyl group, 2-methylthioethyl group; aminomethyl group, 2
- Aminoalkyl groups such as aminoethyl; substituted aminoalkyl groups such as methylaminomethyl, ethylaminomethyl, dimethylaminomethyl, 2-(dimethylamino)ethyl, phenylaminomethyl, diphenylaminomethyl, etc. can be mentioned.

When R1, Rz and R3 are a substituted aromatic hydrocarbon group or a substituted aromatic heterocyclic group, examples of the substituent include an alkyl group, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a substituted hydroxyl group, a thiol group, substituted thiol group,
Examples include amino groups, substituted amino groups, and the like. It may be a substituted aromatic hydrocarbon group or a substituted aromatic heterocyclic group having two or more of these substituents.

Specific examples of R', R'' and R3 being substituted phenyl groups include alkylphenyl groups such as tolyl and ethylphenyl; halogen-substituted phenyl groups such as chlorophenyl and bromophenyl; nitrophenyl; 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 R', R'' and R3 are substituted condensed aromatic hydrocarbon groups include alkylnaphthyl groups such as methylnaphthyl group and ethylnaphthyl group; chloronaphthyl group;
Halogen-substituted naphthyl groups such as bromonaphthyl groups; hydroxynaphthyl groups; substituted hydroxynaphthyl groups such as methoxynaphthyl groups and ethoxynaphthyl groups; thiohydroxynaphthyl groups; substituted thionaphthyl groups such as methylthionaphthyl groups and ethylthionaphthyl groups; aminonaphthyl groups ;
Methylaminonaphthyl group, dimethylaminonaphthyl group,
Examples include substituted aminonaphthyl groups such as phenylaminonaphthyl group and diphenylaminonaphthyl group.

Specific examples when R1, RZ and R3 are substituted aromatic heterocyclic groups, particularly substituted benzothiazolyl groups, include alkylbenzothiazolyl groups such as methylbenzothiazolyl group and ethylbenzothiazolyl group; chlorobenzo Halogen-substituted benzothiazolyl groups such as thiazolyl group and bromobenzothiazolyl group; nitrobenzothiazolyl group; cyanobenzothiazolyl group; hydroxybenzothiazolyl group; methoxybenzothiazolyl group, ethylbenzothiazolyl group Substituted hydroxybenzothiazolyl group, such as ethylthiobenzothiazolyl group; Thiohydroxybenzothiazolyl group: Substituted thiobenzothiazolyl group, such as methylthiobenzothiazolyl group, ethylthiobenzothiazolyl group; Aminobenzothiazolyl group Examples include substituted aminobenzothiazolyl groups such as methylaminobenzothiazolyl group, dimethylaminobenzothiazolyl group, phenylaminobenzothiazolyl group, and diphenylaminobenzothiazolyl group.

The disazo compound represented by the general formula (I) according to the present invention can be produced by a conventionally known method. for example,
“Monash Hemi” Volume 98, Page 315 (I96
7), using a compound (Vl) obtained from acenaphthenequinone and malonitrile as a starting material,
It can be synthesized by the following route.

N (VI) N Next, 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 to borohydrogen fluoride. Once isolated as an acid salt or 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'-dimethylformamide or dimethyl sulfoxide. Compounds of formula (I) can be prepared.

Specific examples of the disazo compounds of the above-mentioned Funato (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 is made by dispersing a disazo compound (3) in a binder (4) on a conductive support (I). ! (2a) is provided. The photosensitive member shown in FIG. 2 has a photosensitive layer (
2b). The photoreceptor shown in FIGS. 3 and 4 has a charge carrier generation layer (
6) and a photosensitive layer N (2c) or (2d) consisting of a charge transport layer (7) comprising a charge transport substance and a binder. In the case of FIG. 1, the disazo compound (3) performs the function of generating the charge carriers necessary for light attenuation and of charge transport. In the case of the photoreceptor of FIG. 2, the charge transport material is a charge transport medium (5) along with a binder.
, while the disazo compound (3) acts as a charge carrier generating substance. Although this charge transport medium (5) does not have the ability to generate charge carriers like the disazo compound (3),
It has the ability to accept and transport charge carriers generated from disazo compounds. That is, in the photoreceptor shown in FIG.
), while the transport of charge carriers is carried out primarily by the charge transport medium (5). Figures 3 and 4
In the case of the photoreceptor shown in the figure, the disazo compound (3) contained in the charge carrier generation layer (6) generates charge carriers, while the charge transport layer (7) receives charge carriers and transports them. . That is, the mechanism of action is the same as in the case of the photoreceptor shown in FIG. 2, in that charge carriers necessary for light attenuation are generated by a disazo compound, and charge carriers are transported by a charge transport medium.

The photoreceptor shown in FIG. 1 can be manufactured by dispersing a disazo compound in a binder solution, coating this dispersion on a conductive support, and drying it. The photoreceptor shown in FIG. 2 can be manufactured by dispersing a disazo 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 obtained by vacuum-depositing a disazo compound on a conductive support, or by applying a dispersion obtained by dispersing fine particles of a disazo compound in a solvent or binder solution, and drying the disazo compound. 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 is produced by coating a conductive support with a solution containing a charge transport substance and a binder and drying it, and then vacuum-depositing a disazo compound thereon, or by depositing fine particles of a disazo compound in a solvent or binder solution. It can be manufactured by applying and drying a dispersion obtained by dispersing the liquid into a liquid.

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. In the photoreceptor shown in FIG. 1, the proportion of the disazo 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 FIG. 2, the proportion of the disazo 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. Figures 3 and 4
The proportion of charge transport material in the charge transport medium in the illustrated photoreceptor is 10 to 95% by weight, preferably 10 to 60% by weight.

Examples of the conductive support used in the photoreceptor of the present invention include aluminum, copper, zinc, stainless steel, chromium,
Metal plates or metal drums made of metals or alloys such as titanium, nickel, molybdenum, vanadium, indium, gold, platinum, or conductive polymers, conductive compounds such as indium oxide, metals such as aluminum, palladium, 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,
Polyester, methacrylic resin, acrylic resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl 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, polyvinyl formal , polysulfone, etc., but are not limited to these.

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

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, dioctyl phthalate, triphenyl phosphoric acid, methylnaphthalene, benzophenone chlorinated paraffin, polypropylene, polystyrene, and various fluorocarbons. Examples include hydrogen.

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

Examples of the surface modifier include silicone oil and fluorine resin.

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, Between,
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 binder, casein, gelatin, polyvinyl alcohol, ethyl cellulose, nitrocellulose, polyvinyl butyral, phenolic resin, polyamide, carboxymethylcellulose, 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-trinitro-9-fluorenone, 2.
, 4.5.7-tetranitro-9-fluorenone, 9-
dicyanomethylene-2,4,7-)linitrofluorenone, 9-dicyanomethylene-2゜4.5.7-tetranitrofluorenone, 2.4.5.7-tetranitroxanthone, 2.4.8-) linitrothioxanthone, tetranitrocarbazole chloranil, 2,3-dichloro-
Examples include 5,6-dicyanobenzoquinone, 2,4,7-dolinitro9,10-phenanthrenequinone, and tetrachlorophthalic anhydride.

Examples of the hole transport substance include low molecular weight compounds such as torene, N-ethylcarbazole, N-isopropylcarbazole, N-phenylcarbazole, or N-methyl-2-phenylhydrazino-3-methylidene-9-ethyl. Carbazole, N,N-diphenylhydrazino-3
-Methylidene-9-ethylcarbazole, P-N, N-
Hydrazones such as dimethylaminobenzaldehyde diphenylhydrazone, pN,N-diethylaminobenzaldehyde diphenylhydrazone, p-N,N-diphenylaminobenzaldehyde diphenylhydrazone,2.
5-bis(p-diethylaminophenyl) -1,3,
4-oxadiazole, pyrazolines such as 1-phenyl-3-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, triphenylamine, N, N, IIJ', N'-tetraphenyl- 1,
1'-biphenyl-4,4'-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)
-1,1'-biphenyl-4,4'-diamine and the like. Further, as a polymer compound, for example, poly-N-
Vinyl carbazole, halogenated poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polyvinylacridine, pyrene-formaldehyde resin, ethylcarbazole-formaldehyde resin, triphenylmethane polymer, and the like.

The charge transport materials are not limited to those described here, and can be used alone or in combination of two or more kinds.

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 n-propanol; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; N,N-dimethylformamide, N,N-
Amides such as dimethylacetamide; ethers such as tetrahydrofuran, dioxane, and methyl cellosolve; esters such as methyl acetate and ethyl acetate; sulfoxides and sulfones such as dimethyl sulfoxide and sulfolane;
Examples include aliphatic halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, and trichloroethane; and aromatics such as benzene, toluene, xylene, monochlorobenzene, and dichlorobenzene.

As the coating method, coating methods such as dip coating, spray coating, spinner coating, bead coating, wire per coating, blade coating, roller coating, and curtain coating 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, Nα of the disazo compound means Nα in Tables 1 to 6.

Example 1 10 parts of a polyester resin (trade name "Vylon 200" manufactured by Toyobo Co., Ltd.), 10 parts of a disazo compound of Nα1, and 80 parts of tetrahydrofuran were pulverized and mixed in a vibrating mill, and the resulting dispersion was coated on a polyester film coated with aluminum. The photoreceptor was coated with a wire bar 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 testing device Model SP was applied to the photosensitive layer surface of this photoreceptor.
428 (manufactured by Kawaguchi Denki Seisakusho Co., Ltd.), the photoreceptor was first charged in a dark place by corona discharge with an applied voltage of -6 kV, left in the dark for 10 seconds, and then the surface was illuminated with an illuminance of 5 lux from a tungsten lamp. The photosensitive layer was irradiated with light such that ,E.
, = 16.5 lux·sec.

Example 2 3 parts of polyester resin (same product as Example 1), 2.4.
7-) 3 parts of dinitro-9-fluoro12, 0.6 parts of Nα1 disazo compound, and 30 parts of tetrahydrofuran were pulverized and mixed in a ball mill, and the resulting dispersion was placed on a polyester film deposited with aluminum using a wire bar. A photoreceptor having the structure shown in FIG. 2 having a photosensitive layer having a thickness of about 9 μm was prepared by applying and drying the photoreceptor using the above-mentioned photoreceptor. Next, the sensitivity of this photoreceptor was measured according to Example 1, and it was E I/! = 2.8 lux·sec.

Example 3 3 parts of the disazo compound of Inhibition 1 was added to phenoxy resin (trade name:
PKHHJ (manufactured by Union Carbide) was dissolved in 75 parts of dioxane and pulverized and mixed using a vibrating mill.The resulting dispersion was coated onto an aluminum-deposited polyester film using a wire bar and dried. 1μ
A charge generation layer was formed. On this charge generation layer, p-
Diethylaminobenzaldehyde-diphenylhydrazone 5 parts, polycarbonate resin (product name "Panlite L")
A solution prepared by dissolving 5 parts of -1250W (manufactured by J Kijin Kasei Co., Ltd.) in 65 parts of methylene chloride was applied and dried using a wire bar to form a charge transport layer with a thickness of 10 μm, thereby obtaining a photoreceptor having the structure shown in FIG. The sensitivity of the thus prepared photoreceptor was measured according to Example 1, and El/□=2.5 lux・
It was seconds.

Examples 4 to 2O A photoreceptor having the structure shown in FIG. 3 was prepared in the same manner as in Example 3, except that the disazo compounds listed in Table 7 below were used in place of the Nα1 disazo compound, and the photoreceptor was prepared in accordance with Example 1. Sensitivity was measured and the results listed in the same table were obtained.

Table Example 21 The structure shown in Figure 3 was prepared in the same manner as in Example 3 except that N-ethylcarbazole-3-methylidene-°N-aminoindoline was used instead of p-diethylaminobenzaldehyde-diphenylhydrazone as the charge transport substance. A photoreceptor was prepared and its sensitivity was measured according to Example 1.
+7 g-2.5 lux·sec.

Examples 22 to 40 The disazo compounds shown in Table 8 below were used in place of the disazo compound of 40 kl, and N-ethylcarbazole-3-methylidene-N-amino was used in place 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 indoline 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 FIG. 3 was prepared in the same manner as in Example 3, except that N-ethylcarbazole-3-methylidene-N~lyaminotetrahydroquinoline 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 El/□=2. Flux Sec.

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

/ / / Example 61 3 parts of polycarbonate resin (same product as Example 3), p-
A solution prepared by dissolving 3 parts of diethylaminobenzaldehyde-diphenylhydrazone in 35 parts of tetrahydrofuran was coated on a polyester film coated with aluminum using a wire bar 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 bar 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 that El/□=2.9 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 PPC 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. ■... Conductive support, 2a, 2b, 2c, 2d-
Photosensitive layer, 3... Disazo compound, 4... Binder 5... Charge transport material, 6... Charge carrier generation layer, 7.
...Charge transport layer.

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) general formula (III) general formula (IV) or general formula (V) (wherein, X represents a hydrocarbon ring or a heterocycle which may have a substituent, Y represents ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and R^1, R^2, and R^3 each independently have a hydrogen atom or a substituent. represents a hydrocarbon group or a heterocyclic group which may be
1 and R^2 may mutually form a ring. ) The electrophotographic photoreceptor according to claim 1, which is a coupler residue represented by the following formula.