JPH02208656A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the electrophotographic sensitive body having the high sensitivity sufficient for practicable use and high durability by incorporating a specific compd. into the above-mentioned body. CONSTITUTION:This photosensitive body is constituted by providing a photosensitive layer 2a dispersed with a disazo compd. 3 in a binder 4 onto a conductive base 1. A photosensitive layer 2b formed by dispersing the diazo compd. 3 into a charge transfer medium consisting of a charge transfer material 5 and a binder is otherwise provided on the conductive base. The compd. expressed by the formula is incorporated into such photosensitive body. In the formula, Cp denotes a residual coupler group. The excellent durability and the high sensitivity are obtd. in this way and, therefore, this photosensitive body is widely usable as a PPC copying machine, etc.

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 combines photoconductive substances and electrostatic phenomena to record images, was developed by Carlson in U.S. Pat.
It originated from the ``electron photography'' that 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 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 (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 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 (U.S. Pat. No. 3,484,237), poly-N-vinylcarbazole sensitized with biryllium base dye Things (Special Public Service 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 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 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, 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.

[Means to solve the problem]

In order to solve the above problems, the present invention provides an electrophotographic photoreceptor containing a compound represented by general formula (1) (wherein Cp represents a coupler residue).

The coupler residue in the compound represented by general formula (1) can be selected from known coupler components, but in particular general formula (n) general formula (1) (wherein, X is a substituent Y represents a hydrocarbon ring or a heterocycle which may have a hydrogen atom, general formula (IV) or general formula (V), and Rg and R3 each independently have a hydrogen atom or a substituent. R1 and R8 each represent a hydrocarbon group or a heterocyclic group which may form a ring, and R1 and R8 may form a ring with each other.

R1 in the coupler residues of the above general formulas (II), (III), (rV) and (V). R1+ and R″
Specific examples include methyl group, ethyl group, propyl group,
Butyl group, pentyl group, hexyl group, isopropyl group,
1 or more carbon atoms such as isobutyl group, isoamyl group, isohexyl group, neopentyl group, ter L-butyl group
20 alkyl groups: aromatic hydrocarbon groups such as phenyl group and naphthyl group; aromatic heterocyclic groups such as pyridyl group, carbazolyl group, benzotriazolyl group, and the like.

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.

Specific examples of substituted alkyl groups that may have two or more of these substituents include halogenoalkyl groups such as chloromethyl group, trifluoromethyl group, and 2-bromoethyl group; nitromethyl group, - nitroalkyl group such as 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, R1 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, Rg 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 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 group such as bromonaphthyl group; hydroxynaphthyl group: substituted hydroxynaphthyl group such as methoxynaphthyl group, ethoxynaphthyl group; thiohydroxynaphthyl group; substituted thionaphthyl group such as methylthionaphthyl group, ethyl onaphthyl group; aminonaphthyl group ;
Methylaminonaphthyl group, dimethylaminonaphthyl group,
Examples include substituted aminonaphthyl groups such as phenylaminonaphthyl group and diphenylaminonaphthyl group.

Specific examples when R+, Rg 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, ethoxybenzothiazolyl 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 (1) according to the present invention can be produced by a conventionally known method, for example,
Using 2,7-sinitrofluorene as a raw material, 3,6-diamitfluorenone represented by the following formula (Vl) is produced by the following method.

Next, the compound represented by the formula (Vl) is diazotized by a conventional method and cuffed with the coupler Cp in the presence of an alkali, or the diazonium salt of the compound represented by the formula (Vl) is converted into a borohydrofluoride or a zinc salt. Once isolated as a formula (1), the formula (1) can be easily obtained by coupling with a coupler in the presence of an alkali in a suitable solvent, for example, an inert organic solvent such as N,N'-dimethylformmamide or dimethyl sulfoxide. Compounds of can be produced.

Specific examples of the disazo compounds of the general formula (1) 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 (1). The photoreceptor shown in Figure 2 has a disazo compound (3) on a conductive support as a charge transport material! (5) and a photosensitive layer (2) dispersed in a charge transport medium consisting of a binder.
b). 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 (
A photosensitive layer (2c) or (2d) consisting of (7) and (7) is provided, respectively. In the case of FIG. 1, the disazo compound (3) performs both the functions of generating charge carriers necessary for light attenuation and of charge transport. In the case of the photoreceptor of FIG. 2,
The charge transport material together with the binder forms a charge transport medium (5), while the disazo 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 disazo compound (3), it has the ability to accept and transport charge carriers generated from the disazo compound. That is, in the photoreceptor shown in Figure 2, the charge carriers necessary for light attenuation are generated by the disazo compound (3).
The transport of charge carriers, on the other hand, is carried out primarily 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. 1 and 2.
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.
The thickness of the charge transport layer is 3 to 50 μm, preferably 5 to 20 μm. In the photoreceptor shown in FIG. The amount is 10 to 70% by weight, preferably 30 to 50% by weight. 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 this camphor polymer 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- Hynylacetate-maleic anhydride ['-II combination, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-vinylcarbazole, polyvinyl butyral, polyvinyl formal,
Examples include, but are not limited to, polysulfone.

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 compound used in the binder, casein, gelatin, polyvinyl alcohol, ethyl cellulose, nitrocellulose, polyvinyl butyral, phenolic resin, polyamide, carboxy-methyl cellulose, vinylidene chloride polymer latex, Examples include 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 genuine tags.
Both can be used in the electrophotographic photoreceptor of the present invention.

Examples of the electron transporting substance include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4.7-)rinitrow-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 chloranil, 2,3-dichloro-5,6-dicyanobenzoquinone, 2,4.7-)
Examples include limtro-9,1O-phenanthrenequinone and tetrachlorophthalic anhydride.

Examples of low-molecular-weight compounds as transport substances include pyrene, N-ethylcarbazole, N-isopropylcarbazole, N-phenylcarbazole, N-methyl-2-phenylhydrazino-3-methylidene-9-ethylcarbazole, and , N diphenylhydrazino-3-methylidene-9-ethylcarbazole, p-N,N-dimethylaminobenzaldehyde diphenylhydrazone,
Hydrazones such as pN,N-diethylaminobenzaldehyde diphenylhydrazone, p-N,N-diphenylaminobenzaldehyde diphenylhydrazone,2.
5-bis(p-diethylaminophenyl)-1,3,4
-oxadiazole, pyrazolines such as l-phenyl-3-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, triphenylamine, N, N, N', 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. Examples of polymer compounds include poly-N-vinylcarbazole, halogenated poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polyvinylacridine, pyrene-formaldehyde resin, ethylcarbazole-formaldehyde resin, and triphenylmethane polymer. etc.

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 it is preferable to select one from among those that do not dissolve the lower layer. Examples of specific organic solvents include: , alcohols such as methanol, ethanol, 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.

Examples of coating methods include dip coating, spray coating, spinner coating, and tocoating.
Coating methods such as coating method, wire bar coating method, blade coating method, roller coating method, curtain coating method, etc. 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", and "arashi" of the disazo compound means the positive in Tables 1 to 6.

Example 1 10 parts of a polyester resin (trade name: "Vylon 200J" manufactured by Toyobo Co., Ltd.), 10 parts of a disazo compound (11 ml), and 80 parts of tetrahydrofuran were pulverized and mixed in a vibrating mill, and the resulting dispersion was placed 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 having a photoreceptor layer with a thickness of approximately 10μ.
428 (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 10 seconds, then irradiate the photosensitive layer with light from a tungsten lamp so that the surface has an illuminance of 5 lux, and the surface potential decreases to 172, which is the surface potential after leaving it in the dark for 10 seconds. Measure the time until the photosensitivity E
When l/z (lux seconds) was calculated, E+zz =
It was 16.0 lux·sec.

Example 2 3 parts of polyester resin (same product as Example 1), 2.4.
7. 3 parts of trinitro-9-fluorenone, 0.6 parts of a 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 coated with aluminum using a wire bar. 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, when the sensitivity of this photoreceptor was measured according to Example 1, it was found that E+z*=3.5 lux·sec. ) manufactured by Union Carbide Co.) 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. A solution prepared by dissolving 5 parts of p-diethylaminobenzaldehyde-diphenylhydrazone and 5 parts of polycarbonate resin (trade name: "Panlite L-1250WJ, manufactured by Teijin Kasei Co., Ltd.") in 65 parts of methylene chloride was placed on top of this charge generation layer using a wire bar. The coating was 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 prepared photoreceptor was measured according to Example 1 and found that El/Z = 3.0 Lux.・It was seconds.

Examples 4 to 20 Photoreceptors having the structure shown in FIG. 3 were 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 compounds in Arashi 1, and the photoreceptors were prepared in accordance with Example 1. The sensitivity was measured and the results listed in the same table were obtained.

Example 21 A photoreceptor having the structure shown in FIG. 3 was prepared in the same manner as in Example 3, except that N-ethylcarbazole-3-methylidene-N-7 minoindoline was used instead of p-diethylaminobenzaldehyde-diphenylhydrazone as the charge transport material. was prepared and its sensitivity was measured according to Example 1.E I
yt=2. Flux Sec.

Examples 22 to 40 Each of the disazo compounds listed in Table 8 below was used in place of 11 ml of the disazo compound, and! A photoreceptor having the structure shown in FIG. 3 was prepared in the same manner as in Example 3, except that N~N ethylcarbazole 3-methylidene-N-aminoindoline was used as a cargo transporting substance for p-diethylaminobenzaldehyde-diphenylhydrazonation. The sensitivity was measured according to Example 1, and the results listed in Table 8 were obtained.

2'/Example 41 The procedure of FIG. A photoreceptor with this structure was prepared, and the sensitivity was measured according to Example 1, and it was found that El/□=2.4 lux·sec.

Examples 42 to 60 Disazo compounds shown in Table 9 below were used in place of the disazo compound in Section 1, and N-ethylcarbazole-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.

Table 9 Example 61 3 parts of polycarbonate resin (same product as Example 3), p-
A solution prepared by dissolving 3 parts of diethylaminobenzaldehyde-diphenyl 515 fufu in 35 parts of tetrahydrofuran was coated onto an aluminum-deposited polyester film 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 prepared photoreceptor was measured according to Example 1 by performing corona discharge at an applied voltage of +6 kV, and found that E17°=2.6 lux·sec.

〔Effect of the invention〕

The electrophotographic photoreceptor of the present invention has good durability and high sensitivity, so 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.▼, and R^1, R^2, and R^3 are each independently a hydrogen atom or a hydrocarbon group that may have a substituent. or represents a heterocyclic group, 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.