JPH02208658A - 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 2a formed by dispersing the disazo 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 I is incorporated into such photosensitive body. In the formula I, 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]

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. 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 is used with a dry carrier or suspended in an organic solvent in the form of a colloid, 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.

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, cadmila μ 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 affect the lifespan of the photoreceptor. 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. Pat. No. 3,484,237), poly-N-vinylcarbazole sensitized with biryllium base dye (Tokuko Sho 4)
B-25658), a photoconductive material using a eutectic consisting of a dye and a resin (Japanese Unexamined Patent Publication No. 10785/1985)
and so on. 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 photoconductive polymers such as poly-N-vinylcarbazole, polymers alone have poor filmability, flexibility, and adhesion, and in order to improve these drawbacks, plasticizers have been developed. materials, binders, etc. are added, but this may cause a decrease in sensitivity,
There were problems such as 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 the general formula (I) (wherein Cp represents a coupler residue). .

The coupler residue in the compound represented by the general formula (I) can be selected from known coupler components, but especially the general formula (n), the general formula (III), the general formula (IV) 0w1 or the general formula (V) (wherein, X represents a hydrocarbon ring or a heterocycle which may have a substituent, Y is a hydrogen atom, and R1 and R3 each independently have a hydrogen atom or a substituent; is a hydrocarbon group or a heterocyclic group which may be a ring, and R1 and R2 may mutually form a ring.

R1 in the coupler residues of the above general formulas (n), (III), (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, 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 group such as phenoxymethyl group: thiohydroxyalkyl group such as thiohydroxymethyl group, 2-thiohydroxyethyl group; Substituted thiohydroxyalkyl group such as methylthiomethyl group, 2-methylthioethyl group, niaminomethyl 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 R', R'' 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, and a thiol group. 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 Rr, Rz 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, ethoxyphenyl group; Thiohydroxyphenyl group; Substituted thiophenyl group such as methylthiophenyl group, ethylthiophenyl group Niaminophenyl group: Methylaminophenyl group, dimethylaminophenyl group group, a phenylaminophenyl group, a substituted aminophenyl group such as a diphenylaminophenyl group, and the like.

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 RI, R1 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 (I) according to the present invention can be produced by a conventionally known method. for example,
As described in "Journal of Heterocyclic Chemistry" Volume 2, Page 441 (I965), p.
By reacting -aminobenzaldehyde and 3,3'-diaminobenzidine in polyphosphoric acid at 220°C, 2,2'-bis(P-aminophenyl Jtz) -5, represented by the following formula (Vl), is produced. 5'-bibenzimidazole is produced.

Once isolated under reflux or as a zinc salt, the formula can be easily converted by coupling 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. Compound (I) can be produced.

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

Next, the compound represented by the formula (VI) 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 (Vl) is converted into a borohydrofluoride salt according to the present invention. Electrophotographic photoreceptors can have various structures. The first example is
It is shown in Figure 4. The photoreceptor in FIG. 1 has a conductive support (I)
A photosensitive layer (2a) comprising a disazo compound (3) dispersed in a binder (4) is provided thereon. The photoreceptor shown in FIG. 2 has a photosensitive layer (2b) formed by dispersing a disazo compound (3) in a charge transport medium consisting of a charge transport material (5) and a binder on a conductive support. The photoreceptor shown in FIGS. 3 and 4 has a photosensitive layer (
2C) or (2d), respectively. 1st
In the case shown, the disazo compound (3) is responsible for the generation of charge carriers necessary for light attenuation and for the charge transport. 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 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 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 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. Further, 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, syndium, 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 co-I! combination, 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-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 casein, in addition to the polymer compound used for the binder.
Gelatin, polyvinyl alcohol, ethyl cellulose,
Examples include nitrocellulose, polyvinyl butyral, phenolic resin, polyamide, carboxymethylcellulose vinylidene chloride polymer latex, styrene-butadiene polymer latex, polyurethane, gelatin, aluminum oxide, tin oxide, titanium oxide, and the like.

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 the charge transport substance include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2.4.7-) dinitro-9-fluorenone, 2.
．． 4,5.7-tetranitro-9-fluorenone, 9-
Dicyanomethylene-2,4,7-)linitrofluorenone, 9-dicyanomethylene-2゜4+3+7-tetranitrofluorenone, 2.4.5.7-tetranitroxanthone, 2.4.8-trinidrothioxanthone, tetra Nitrocarbazole chloranil, 2.3-dichloro-5,6-dicyanobenzoquinone, 2.4.7-dolinitro9. Examples include lO-phenanthrenequinone and tetrachlorophthalic anhydride.

Examples of low-molecular-weight compounds as the tag transport substance include pyrene, N-ethylcarbazole, N-isopropylcarbazole, N-phenylcarbazole, or N-methyl-2-phenylhydrazino-3-methylidene-9-ethylcarbazole. 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, 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. Further, examples of the polymer compound include poly-N-vinylcarbazole, halogenated poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene,
Examples include polyvinyl acridine, 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 it is preferable to select one from among those that do not dissolve the lower layer. Examples of specific organic solvents include: , methanol, ethanol, n-propertool, and other alcohols; acetone, methyl ethyl ketone, cyclohexanone, and other ketones; N,N-dimethylformamide, N,N-dimethylacetamide, and other amides; 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 , toluene, xylene, monochlorobenzene, dichlorobenzene, and other aromatic compounds.

As a coating method, for example, a dip coating method, a spray coating method, a spinner coach ink method, a bead coating method, a wire bar coating method, a blade coating method, a roller coating method, a curtain coating method, or 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." Moreover, the symptoms of disazo compounds refer to the grades 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 Nal, 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 10μ. Next, an electrostatic copying paper testing device Model SP was applied to the photosensitive layer surface of this photoreceptor.
42B (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 its surface was illuminated with an illuminance of 5 lux using a tungsten lamp. The photosensitive layer was irradiated with light, and the time required for its surface potential to decrease to 172, which is the surface potential after being left in a dark place for 10 seconds, was measured, and the photosensitivity El/□ (lux seconds) was determined. However, EIi
t = 18.5 lux·sec.

Example 2 3 parts of polyester resin (same product as Example 1), 2.4.
7-) 3 parts of Rinitro 9-fluorenone, 0.6 parts of a disazo compound of about 1 liter, 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. After coating and drying, a photoreceptor having the structure shown in FIG. 2 having a photosensitive layer having a thickness of about 9 μm was prepared. Next, the sensitivity of this photoreceptor was measured according to Example 1 and found to be El/□=3.4 lux·sec.

Example 3 3 parts of kl disazo compound was added to phenoxy resin (trade name r
PKIII J Union Carbide Co., Ltd. 1d) 1 part dissolved in 75 parts of dioxane is pulverized and mixed using a vibrating mill, and the resulting dispersion is 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 of 5 parts of p-diethylaminobenzaldehyde-diphenylhydrazone and 5 parts of polycarbonate resin (trade name [Panlite L-1250W, manufactured by Kijin Kasei Co., Ltd.) dissolved in 65 parts of methylene chloride was placed on top of this charge generation layer using a wire bar. A charge transport layer having a thickness of 10μ was formed by coating and drying to obtain a photoreceptor having the structure shown in FIG. The sensitivity of the photoreceptor thus prepared was measured according to Example 1 and found to be E ryt = 3.2.
It was Lutx Sec.

Examples 4-2 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 Nal 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 7 Example 21 The structure shown in FIG. A photoreceptor was prepared and its sensitivity was measured according to Example 1.
□=3.0 lux·sec.

Examples 22 to 40 Disazo compounds shown in Table 8 below were used instead of the disazo compounds of 40 kl, and N-ethylcarbazole 3-methylidene-N-aminoindoline was used instead 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 the photoreceptor was used, and the sensitivity was measured in accordance with Example 1, and the results listed in Table 8 were obtained.

Example 41 The structure shown in FIG. 3 was photosensitized in the same manner as in Example 3, except that N-ethylcarbazole-3-methylidene-N-aminotetrahydroquinoline was used instead of p-diethylaminohenzaldehyde diphenylhydrazone as the charge transport material. When a body was prepared and the sensitivity was measured according to Example 1, it was found that El/□=2.9 Lux·sec.

Examples 42 to 60 Disazo compounds shown in Table 9 below were used in place of the disazo compounds of 42 to 60 kl, and N-ethylcarbazole 3-methylidene-N-aminotetrahydro 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 quinoline 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 applied onto a polyester film on which aluminum had been vapor-deposited using a wire bar and dried to form a charge transport layer having a thickness of about 10μ.

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°=3.3 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. ■... 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.▼, where R^1, R^2 and R^3 are each independently a hydrogen atom, a hydrocarbon group that may have a substituent, or Represents a heterocyclic group, R^
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.