JPH0368955A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain a sensitive body having superior durability and high sensitivity by incorporating a specified disazo compd. into a photosensitive layer. CONSTITUTION:A disazo compd. represented by formula I is incorporated into a photosensitive layer 2a. In the formula I, A is a divalent residue of an arom. heterocyclic group or an arom. hydrocarbon group which may have a substituent and Y is a group represented by formula II (where each of R<1> and R<2> is H, a hydrocarbon group which may have a substituent or a heterocyclic group which may have a substituent and R<1> and R<2> may bond to each other to form a ring). The disazo compd. 3 is dispersed in a binder 4 and an electrically conductive support 1 is coated with the resulting dispersion liq. and dried to form the photosensitive layer 2a.

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 dispersed in an insulating binder resin and coated on a support is used as a photoreceptor. . After this photoconductive material is given a uniform surface charge by corona charging in a dark place, it loses its surface charge depending on the brightness value of image exposure, and an electrostatic latent image is formed.

The surface of such an electrostatic latent image is then treated with a suitable electrostatic indicator material, ie, 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-trinitrofluorenone (U.S. Pat. No. 3,484,237), sensitized with poly-N-vinylcarbazole with biryllium base dye (Tokuko Sho 4)
8-25658), 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. 10785/1982). Such an organic compound-based electrophotographic photoreceptor is
Compared to inorganic compound-based electrophotographic photoreceptors, it has the disadvantage that it is easier to form a film, has extremely high productivity, and can provide an inexpensive photoreceptor. However, for example, poly-
Regarding photoconductive polymers such as N-vinylcarbazole, the polymer alone has poor coating properties, flexibility, and adhesive properties, 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 solves the above problems by using the general formula (I) % formula % (1) (wherein A is an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent). Residues of valence are represented in the table.R1
and R2 each independently represent a hydrogen atom, a hydrocarbon group which may have a substituent, or a heterocyclic group which may have a substituent.

Further, R1 and R2 may mutually form a ring. ) Provided is an electrophotographic photoreceptor characterized by containing a compound represented by the following.

As A in general formula (1), for example, C3,3'
-dimethylbiphenyl) -4,4'-diyl group, (3
, 3'-dichlorobiphenyl) -4,4'-diyl group, stilbene-4,4'-diyl group, 9-fluorenone-2,7-diyl group, 2,5-biphenyloxadiazole-4',4 -diyl group, 2-phenylbenzoxazole-51'-diyl group, etc.

R1 in general formula (I). Examples of R2 include an alkyl group having 1 to 20 carbon atoms; an aromatic hydrocarbon group such as a phenyl group and a naphthyl group; and an aromatic heterocyclic group such as a pyridyl group, a carbazolyl group, and a benzotriazolyl group. It will be done. As a specific example, when R1 and R2 are an alkyl group, for example, a methyl group, an ethyl group, a propyl group,
Butyl group, pentyl group, hexyl group, isopropyl group,
Examples include isobutyl group, isoalkyl group, isohexyl group, neopentyl group, and tert-butyl group.

When R1 and R1 are substituted alkyl groups, the substituents are:
Examples include a halogen atom, a nitro group, a cyano group, a hydroxy group, a substituted hydroxy group, a thio group, a substituted thiol group, an amino group, a substituted amino group, an aryl group, and the like.

Specific examples of substituted alkyl groups include halogenoalkyl groups (e.g., chloromethyl group, trifluoromethyl group, 2-bromoethyl group, etc.), nitroalkyl groups (e.g., nitromethyl group, 3-nitroprobyl group, etc.) , cyanoalkyl group (e.g., cyanomethyl group, 2-cyanoethyl group, etc.), hydroxyalkyl group (e.g., hydroxymethyl group, 2-hydroxyethyl group, 3-hydroxypropyl group, 2-hydroxypropyl group, etc.), substituted hydroxyalkyl group groups (e.g. methoxymethyl group, 2-
methoxyethyl group, ethoxymethyl group, phenoxymethyl group, etc.), thiohydroxyalkyl group (e.g., thiohydroxymethyl group, 2-thiohydroxyethyl group, etc.),
Substituted thiohydroxyalkyl group (e.g., methylthiomethyl group, 2-methylthioethyl group), aminoalkyl group (e.g., aminomethyl group, 2-aminoethyl group, etc.),
Substituted aminoalkyl groups (e.g., methylaminomethyl group, ethylaminomethyl group, dimethylaminomethyl group,
-(dimethylaminomethyl)ethyl group, phenylaminomethyl group, diphenylaminomethyl group, etc.).

When R1 and R2 are an aromatic hydrocarbon group or an aromatic heterocyclic group, examples of the substituent include an alkyl group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a substituted hydroxy group, a thiol group, and a substituted thiol group. , an amino group, a substituted amino group, and the like.

Specific examples of substituted aromatic hydrocarbon groups include substituted phenyl groups, such as alkylphenyl groups (e.g. tolyl group, ethylphenyl group, etc.), chlorophenyl group, nitrophenyl group, cyanophenyl group, hydroxyphenyl group, Substituted hydroxyphenyl groups (e.g., methoxyphenyl group, ethoxyphenyl group, etc.), thiohydroxyphenyl group, substituted thiol groups (e.g., methylthiophenyl group, ethylthiophenyl group, etc.), aminophenyl group, substituted amino groups (e.g., methylthiophenyl group, etc.). Examples include a phenyl group, a diphenyl group, a phenylaminophenyl group, a diphenylaminophenyl group, and the like.

As a specific example of a substituted condensed aromatic hydrocarbon group, a substituted naphthyl group is given. An alkylnaphthyl group (e.g.
methylnaphthyl group, ethylnaphthyl group, etc.), chloronaphthyl group, nitronaphthyl group, cyanonaphthyl group, hydroxynaphthyl group, substituted hydroxynaphthyl group (e.g., methoxynaphthyl group, ethoxynaphthyl group, etc.), thiohydroxynaphthyl group, substituted Thiol groups (e.g., methylthionaphthyl group, ethylthionaphthyl group, etc.), aminonaphthyl groups, substituted amino groups (e.g., methylaminonaphthyl group, dimerua ξ nonaphthyl group, phenylaminonaphthyl group, diphenylagonononaphthyl group, etc.), etc. can be mentioned.

Specific examples of substituted aromatic heterocyclic groups include substituted benzothiazolyl groups such as alkylbenzothiazolyl groups (e.g., methylbenzothiazolyl group, ethylbenzobenzothiazolyl group, etc.), chlorobenzothiazolyl group, etc. Zolyl group, nitrobenzothiazolyl group, cyanobenzothiazolyl group,
Hydroxybenzothiazolyl group, substituted hydroxybenzothiazolyl group (e.g., methoxybenzothiazolyl group,
ethoxybenzothiazolyl group, etc.), thiohydroxybenzothiazolyl group, substituted thiol group (e.g., methylthiobenzothiazolyl group, ethylthiobenzothiazolyl group, etc.), aminobenzothiazolyl group, substituted aminobenzo Thiazolyl group (e.g., methylaminobenzothiazolyl group,
(dimeranobenzothiazolyl group, phenylaminobenzothiazolyl group, diphenylaminobenzothiazolyl group, etc.).

It may be a substituted aromatic hydrocarbon group or a substituted aromatic heterocyclic group having two or more of these substituents.

The compound represented by the general formula (I) according to the present invention is obtained by, for example, reducing the dinitro form of the partial structural formula A shown in Table 1 below by a conventional method, and then diazotizing it. This diazo compound and a compound of formula (n) (wherein Y represents the same meaning as Y in general formula (1)) are coupled in the presence of an alkali, or a diazonium salt of this diazo compound is Once isolated as a fluoroborate or zinc salt, N
, N'-dimethylformamide, dimethyl sulfoxide in the presence of an alkali in an inert organic solvent such as
By coupling reaction with the compound II),
The compound of general formula (I) can be easily produced.

Specific examples of the disazo compound of general formula (1) used in the present invention are shown in Tables 1 and 2 by structural formula.

/ / / Table 1 (Part 1) / / Table 1 (Part 2) Table (Part 4) / / / / / Table (Part 3) Table (Part 1) Table 2 (Part 2) Table 2 (Part 3) Table 2 (Part 4) 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 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.
) is provided with a photosensitive layer (2C) or (2d), respectively. In the case of Figure 1, a disazo compound (
3) is responsible for both the generation of charge carriers necessary for light attenuation and 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% 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 more than one type.

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 B1 cyanine dye, merocyanine dye, biryllium dye, and thiapyrylium dye.

Examples of the surface modifier include silicone oil and fan 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 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-trinitrofluorenone, 9-dicyanomethylene-2°4.5.7-tetranitrofluorenone, 2.4,5. 7-tetranitroxanthone, 2.4.8-trinidrothioxanthone, tetranitrocarbazole chloranil, 2,3-dichloro-5,
6-didianobenzoquinone, 2.4.7-trinitro-
Examples include 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, or N-methyl-2-phenylhydrazino-3-methylidene-9-ethylcarbazole. , N,N-diphenylhydrazino-3
-Methylidene 9-ethylcarbazole, I)-N,N-
Hydrazones such as dimethylaminobenzaldehyde diphenylhydrazone, p-N,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'-diaξ, N, N'-diphenyl-N, N'-bis(3-methylphenyl)-1,
Examples include 1'-biphenyl 4,4'-diamine.

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

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." Moreover, the fish of the disazo compound means Hiro in Tables 1 to 2.

Example 1 10 parts of a polyester resin (trade name "Vylon 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 vibration mill, and the resulting dispersion was aluminum-deposited into 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
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 1/2 of the surface potential after leaving it in the dark for 10 seconds. Measure the time it takes to
When z (looks/seconds) was calculated, El/□=21.
It was 0 lux·sec.

Example 2 3 parts of polyester resin (same product as Example 1), 2.4.
3 parts of 7-1-dinitro-9-fluorophore, 0.6 parts of the disazo compound of No. 1, and 30 parts of tetrahydrofuran were pulverized and mixed in a bowl, and the resulting dispersion was spread on a wire on a polyester film coated with aluminum. A photoreceptor having the structure shown in FIG. 2 having a photosensitive layer having a thickness of about 9 μm was prepared by coating and drying using a bar. Next, the sensitivity of this photoreceptor was measured according to Example 1 and found to be E+/z=6.9 lux·sec.

Example 3 3 parts of the disazo compound of No. 1 was added to phenoxy resin (trade name:
1 part of PKHHJ (manufactured by Union Carbai 1) was dissolved in 75 parts of dioxane and mixed by pulverization using a vibrating mill, and the resulting dispersion was applied onto an aluminum-deposited polyester film using a wire bar and dried. , thickness 1μ
A charge generation layer was formed. On this charge generation layer, p-
5 parts of diethyla ξ nobenzaldehyde diphenylhydrazone, polycarbonate resin (product name: Panlite L
-1250WJ manufactured by Teijin Chemical Co., Ltd.〉5 parts to methylene chloride 65
A photoreceptor having the structure shown in FIG. 3 was obtained by applying and drying the solution dissolved in the above solution using a wire bar to form a charge transport layer having a thickness of 10 μm. The sensitivity of the thus prepared photoreceptor was measured according to Example 1 and found that E wt = 4.2 Lusox.
It was seconds.

Examples 4 to 20 A photoreceptor having the structure shown in FIG. 3 was produced in the same manner as in Example 3, except that the disazo compounds shown in Table 3 below were used in place of the Ml disazo compound, and the photoreceptor was prepared in the same manner as in Example 1. The sensitivity was measured and the results listed in Table 3 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-7ξnoindoline was used instead of p-diethylaminobenzaldehyde-diphenylhydrazone as the charge transport material. When the sensitivity was measured according to Example 1, E,
7□=3.5 lux·sec.

Examples 22 to 40 The disazo compounds shown in Table 4 below were used in place of the disazo compound in Kou 1, and N-ethylcarbazole-3-methylidene-N- was used in place of p-diethylaminobenzaldehyde-diphenylhydrazone as the charge transport substance. The third step was carried out in the same manner as in Example 3 except that a short noindoline was used.
A photoreceptor having the structure shown in the figure was used, and the sensitivity was measured in accordance with Example 1, and the results listed in Table 4 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-diethylaminobenzaldehyde-diphenylhydrazone as the charge transport material. When the sensitivity was measured according to Example 1, El/□=3.2 Lux·sec.

Examples 22 to 40 The disazo compounds shown in Table 5 below were used in place of the disazo compounds in Magnet 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 Table 5 were obtained.

Example 61 3 parts of polycarbonate resin (same product as Example 3), p-
A solution prepared by dissolving 3 parts of diethylanobenzaldehyde diphenylhydrazone in 35 parts of tetrahydrofuran was applied onto a polyester film on which aluminum had been deposited using a wire bar 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 according to Example 1 by performing corona discharge at an applied voltage of +6 kV, and found that El/□=3.8 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 drawings]

1 to 4 are enlarged partial cross-sectional views of the electrophotographic photoreceptor according to the present invention. 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. General formula (I) ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, A is an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent. Represents a divalent residue, Y represents ▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, R^1 and R^2 each independently represent a hydrogen atom , represents a hydrocarbon group that may have a substituent or a heterocyclic group that may have a substituent. Also, R^1 and R^2 may mutually form a ring.) An electrophotographic photoreceptor comprising a compound represented by: