JPH02207264A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body having high sensitivity and high durability by incorporating a specified compd. CONSTITUTION:A compd. represented by formula I (where Cp is a residue of a coupler) is incorporated. The compd. can easily be produced by diazotizing 2-methyl-4,5-bis(4-nitrophenyl)oxazole produced from acetylbenzoin by a two-stage reaction and coupling the obtd. diazo compd. with the coupler Cp in the presence of alkali. An electrophotographic sensitive body having superior durability and high sensitivity is obtd.

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]

So-called electrophotography, which records images by combining photoconductive substances and electrostatic phenomena, 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 used.
A photoconductive material that is dispersed in an insulating 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, toner, to form a visible image. L.Nur is used with a dry carrier or colloidally suspended in an organic solvent.
Depending on the charge of the electrostatic latent image, it can be attached by Coulomb force. 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 (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-)linitrofluorenone (U.S. Patent No. 3,484,237); Sensitized (
Japanese Patent Publication No. 48-25658), a photoconductive material using a eutectic consisting of a dye and a resin (Japanese Patent Publication No. 47-1078)
No. 5). Compared to inorganic compound electrophotographic photoreceptors, such organic compound-based electrophotographic photoreceptors have the advantage that they are easier to form a film, have extremely high productivity, and can provide inexpensive photoreceptors. . However, for photoconductive polymers such as poly-N-vinylcarbazole, the polymer alone has poor film properties, flexibility, adhesion, etc., and in order to improve these drawbacks, plasticizers and binders are used. However, this causes 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, improve the drawbacks of organic compound-based electrophotographic photoreceptors that have been proposed so far, and put them into practical use. An object of the present invention is to provide an electrophotographic photoreceptor having extremely high sensitivity and durability.

[Failure to solve the problem]

In order to solve the above-mentioned problems, the present invention provides an electrophotographic photoreceptor containing a compound represented by General 2〇) (wherein Cp represents a coupler residue).

The coupler residue in the compound represented by general formula (I) can be selected from known coupler components, but especially - formula (II) - formula (III) (wherein, X is a substituent represents a hydrocarbon ring or heterocycle which may have a hydrogen atom, - formula (IV) υ11 or - formula (V) R2 and R3 each independently have a hydrogen atom or a substituent; (R1 and R2 may mutually form a ring.) A coupler residue represented by the following formula is preferred.

Above - Formulas (n), (m), (IV) and (V
) Specific examples of R1, R2 and R3 in the coupler residue include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, isopropyl group, isobutyl group, isoamyl group, isohexyl group, neopentyl group, Examples include alkyl groups having 1 to 20 carbon atoms such as tert-butyl group; aromatic hydrocarbon groups such as phenyl group and naphthyl group; aromatic heterocyclic groups such as pyridyl group, carbazolyl group, hensitriazolyl group, etc. It will be done.

When R1, R2 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, 2-bromoethyl group;
- cyanoalkyl group such as 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; thiohydroxyalkyl groups such as thiohydroxymethyl group and 2-thiohydroxyethyl group; substituted thiohydroxyalkyl groups such as methylthiomethyl group and 2-methylthioethyl group; aminomethyl group, 2 −
Aminoalkyl groups such as aminoethyl group; substituted aminoalkyl groups such as methylaminomethyl group, ethylaminomethyl group, dimethylaminomethyl group, 2-(dimethylamino)ethyl group, phenylaminomethyl group, diphenylaminomethyl group, etc. Can be mentioned.

When R1, R2 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 when R1, R2 and R3 are substituted phenyl groups include alkylphenyl groups such as tolyl group and ethylphenyl group; halogen-substituted phenyl groups such as chlorophenyl group and bromophenyl group; nitrophenyl group; cyanophenyl group. ; Hydroxyphenyl group; Substituted hydroxyphenyl group such as methoxyphenyl group and ethoxyphenyl group; Thiohydroxyphenyl group; Substituted thiophenyl group such as methylthiophenyl group and ethylthiophenyl group;
Aminophenyl group; Examples include substituted aminophenyl groups such as methylaminophenyl group, dimethylaminophenyl group, phenylaminophenyl group, and diphenylaminophenyl group.

Specific examples when R1, R2 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, R2 and R3 are substituted aromatic heterocyclic groups, particularly substituted benzothiazolyl groups, include alkylbenzothiazolyl groups such as methylbenzothiazolyl group and ethylhendithiazolyl group; chlorobenzo Halogen-substituted benzothiazolyl groups such as thiazolyl group and bromobenzothiazolyl group; nitrobenzothiazolyl group; cyanobenzothiazolyl group; hydroxybenzothiazolyl group; methoxyhendithiazolyl group, ethoxyhendithiazolyl group Substituted hydroxybenzothiazolyl group such as ethylthiobenzothiazolyl group; Thiohydroxybenzothiazolyl group; Substituted thiohendithiazolyl group such as methylthiobenzothiazolyl group, ethylthiobenzothiazolyl group; Aminobenzothiazolyl group Examples include substituted aminobenzothiazolyl groups such as methylaminobenzothiazolyl group, dimethylaminohendithiazolyl group, phenylaminobenzothiazolyl group, and diphenylaminohendithiazolyl 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,
“Journal Op Chemical Society J 1363
2-methyl 4,5-bis(4-nitrophenyl)oxazole of the following formula (VI) is prepared by carrying out a two-step reaction from acetylbenzoin as described on page I963.

Furthermore, the compound of formula (VI) is reduced with zinc in the presence of calcium chloride in ethanol to produce a 4,4'-diamino derivative represented by the following formula (■).

Next, the compound represented by the formula (Vl) is diazotized by a conventional method and combined with the coupler Cp in the presence of an alkali, or the diazonium salt of the compound represented by the formula (VI) is converted into a borohydrofluoride or a zinc salt. Once isolated as a salt, the formula (I ) can be produced.

Specific examples of the disazo compounds of formula (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 a disazo compound (3) in a binder (4) on a conductive support (I). The photoreceptor shown in FIG. 2 has a photosensitive layer (2b
). The photoreceptor shown in FIGS. 3 and 4 has a charge carrier generation layer (6) mainly composed of a disazo compound (3).
and a charge transport layer (7) consisting of a charge transport substance and a binder.
) and a photosensitive layer (2c) or (2d), respectively. In the case of Figure 1, a disazo compound (
3) performs both the functions of generating charge carriers necessary for light attenuation and transporting charges. In the case of the photoreceptor shown in FIG. 2, the charge transport material forms the charge transport medium (5) together with the 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 the disazo compound. That is, in the photoreceptor of FIG. 2, the generation of charge carriers necessary for light attenuation is performed by the disazo compound (3), while the transport of charge carriers is mainly performed by the charge transport medium (5). In the case of the photoreceptors shown in Figures 3 and 4, the disazo compound (3) contained in the charge carrier generation layer (6) generates charge carriers, while the charge transport layer (7) injects charge carriers. and transport it.

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 a binder solution. It can be manufactured by coating and drying a dispersion obtained by dispersing the liquid in the 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%, 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 I.
, polyester, methacrylic resin, acrylic resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, styrene-butadiene copolymer, vinylidene chloride acrylonitrile) copolymer, vinyl chloride-vinyl acetate copolymer, chloride Vinyl-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-vinylcarbazole,
Examples include, but are not limited to, polyvinyl butyral, polyvinyl formal, polysulfone, and the like.

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-terphel, p-terphenyl, dibutyl phthalate, diethylene glycol phthalate, dioctyl phthalate, triphenyl phosphoric acid, methylnaphthalene, benzophenone, chlorinated paraffin, polypropylene, polystyrene, and various fluorohydrocarbons. etc.

Examples of the sensitizer include chloranil, tetracyanoethylene, methyl violet, rhodamine B, cyanine dye, merocyanine dye, biryllium 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-dolinitro-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-trinidrothioxanthone, tetranitrocarbazole clo)nyl, 2,3-dichloro-5,
Examples include 6-dicyanobenzoquinone, 2,4,7-) 9,10-phenanthrenequinone, and tetrachlorophthalic anhydride.

Examples of the hole transport substance include low molecular weight compounds such as pyrene, N-ethylcarbazole, N-isopropylcarbazole, N-phenylcarbazole, N-methyl-2-phenylhydrazino-3-methylidene-9-ethylcarbazole, and N-methylcarbazole. , N diphenylhydrazino-3-methylidene-9ethylcarbazole, p-N, N-dimethylaminobenzaldehyde diphenylhydrazone, pN,
Hydrazones such as N-dimethylaminobenzaldehyde diphenylhydrazone, p-N,N-diphenylaminobenzaldehyde diphenylhydrazone, 2,5-bis(p-diethylaminophenyl)L3,4-oxadiazole, 1-phenyl-3(p Pyrazolines such as -diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, triphenylamine, N, N, N'
, N'-tetraphenyl-1,1'-biphenyl-
44'-diamine, N, N'-diphenyl-N, N'-
Bis(3methylphenyl)-LL'-biphenyl-44
Examples include diamine. In addition, as a polymer compound,
Examples include poly-N-vinylcarbazole, halogenated poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polyvinylacridine, pyrene-formaldehyde resin, ethyl carhadyl-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; and amides such as N,N-dimethylformamide and N,N-dimethylacetamide. Frequently; tetrahydrofuran,
Ethers such as dioxane and methyl cellosolve; 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 , aromatic compounds such as toluene, toluene, monochlorobenzene, dichlorobenzene, and the like.

As the coating method, coating methods such as dip coating, spray coating, spinner coating, bead coating, wire bar 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, the term "teeth" in the disazo compound means the positive 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 the disazo compound of No. 1, and 80 parts of tetrahydrofuran were pulverized and mixed in a vibrating mill, and the resulting dispersion was aluminum-deposited on a polyester film. It was coated on top with a wire bar and dried to obtain a photoreceptor having the structure shown in FIG. 1 having a photosensitive layer with a thickness of about 10 μm. Next, an electrostatic copying paper tester Model 5P-42 was applied to the photosensitive layer surface of this photoreceptor.
8 (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, and
The photosensitive layer was left in a dark place for 10 seconds, and then the photosensitive layer was irradiated with light from a tungsten lamp at an illuminance of 5 lux until the surface potential decreased to 172, which was the surface potential after leaving it in the dark for 10 seconds. The time is measured and the photosensitivity El/
When I calculated □ (looks seconds), I found that El/□-24,
It was 0 lux·sec.

Example 2 3 parts of polyester resin (same product as Example 1), 2.4.
7-) 3 parts of Leetlow 9-fluor 1 fufu, 0.6 parts of the disazo compound of floor 1, 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 found to be El/2=5.9 lux·sec.

Example 3 3 parts of the disazo compound of No. 1 was added to phenoxy resin (trade name:
PKHH) (manufactured by Union Carbide) was dissolved in 75 parts of dioxane and pulverized and mixed using a vibrating mill. The resulting dispersion was applied onto an aluminum-deposited polyester film using a wire bar and dried. A charge generation layer having a thickness of 1 μm was formed. On this charge generation layer, 5 parts of p-diethylaminobenzaldehyde-diphenylhydrazone and a polycarbonate resin (trade name "Panlite L-
A solution prepared by dissolving 5 parts of 1250WJ (manufactured by Teijin Kasei Co., Ltd.) in 65 parts of methylene chloride was coated using a wire bar and dried to form a charge transport layer with a thickness of 10 μm to obtain a photoreceptor having the structure shown in FIG. 3. The sensitivity of the thus produced photoreceptor was measured according to Example 1 and was found to be El/□-5.4 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 1 Ikll of the disazo compound, and in accordance with Example 1. Sensitivity was measured and the results listed in the same table were obtained.

Example 21 The same method as in Example 3 was performed except that N-ethylcarbazole-3-methylidene-N-aminoindoline was used instead of p-diethylaminobenzaldehyde-diphenylhydrazone as the charge transport material. A photoreceptor with the structure was prepared and its sensitivity was measured according to Example 1.
□-4.8 lux·sec.

Examples 22 to 40 The disazo compounds shown in Table 8 below were used in place of the disazo compound in Section 1, and N-ethylcarbazole 3-methylidene-N-amino was used as the charge transport material in place of p-diethylaminobenzaldehyde-diphenylhydrazonation. A photoreceptor having the structure shown in FIG. 3 was prepared in the same manner as in Example 3 except that indoline was used, and the sensitivity was measured in accordance with Example 1 to obtain the results listed in Table 8.

! / / Example 41 The same method as in Example 3 was carried out, except that N-ethylhydrupadzuru-3-methylidene-N-aminotetrahydroquinoline was used instead of p-diethylaminohenzaldehyde diphenylhydrazone as the charge transport material. A photoreceptor having the structure was prepared and the sensitivity was measured according to Example 1, and the sensitivity was found to be El/□-5.0 lux·sec.

Examples 42 to 60 Disazo compounds shown in Table 9 below were used in place of the disazo compound in Tooth 1, and N-ethylcarbazole 3-methylidene-N-amino 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 tetrahydroquinoline was used, and the sensitivity was measured in accordance with Example 1, and the results listed in the table were obtained.

of! / Table 9 Example 61 3 parts of polycarbonate resin (same product as Example 3), p-
A solution prepared by dissolving 3 parts of diethylaminobenzaldehydecyphenylhydrazone in 35 parts of tetrahydrofuran was applied onto a polyester film on which aluminum had been vapor-deposited using a wire spar and dried to form a charge transport layer with a thickness of about 10 μm.

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 in accordance with Example 1 by performing corona discharge at an applied voltage of +6 kV, and found to be E1/2-5.4 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 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. DESCRIPTION OF SYMBOLS 1... 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) ▲ 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.