JPH0310255A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the high sensitivity and high durability to the extent that the photosensitive body is sufficiently practiably usable by incorporating a specific compd. into the photosensitive body. CONSTITUTION:This electrophotographic sensitive body contains the compd. expressed by formula I. In the formula, Cp denotes a residual coupler group. This disazo compd. is dispersed into a binder soln. and the dispersion is applied on a conductive base and is dried or the disazo compd. is dispersed into a soln. dissolved with a charge transfer material and binder and this dispersion is applied on the conductive base and is dried, by which the photosensitive body is produced. The disazo compd. is otherwise deposited by vacuum evaporation on the conductive base and the soln. dissolved with the charge transfer material and the binder is applied on the conductive base and is dried, on which coating, the disazo compd. is deposited by vacuum evaporation. The photosensitive body has the excellent durability and the high sensitivity and is, therefore, widely utilized for 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 the 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 together with the dry carrier
Alternatively, it can be used as a colloidal suspension in an organic solvent, 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 (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-)linitrofluorenone (U.S. Pat. No. 3,484,237), poly-IJ N-vinylcarbazole enhanced with pyrylium salt dye. (Japanese Patent Publication No. 48-25658), and one using a eutectic consisting of dye and resin as a photoconductive material (Japanese Patent Publication No. 47-10785)
and so on. Compared to inorganic compound-based electrophotographic photoreceptors, such organic compound-based electrophotographic photoreceptors have the advantage of being easier to form a film, have extremely high productivity, and can provide inexpensive photoreceptors. There is. However, for example, PoI
Regarding photoconductive polymers such as J-N-vinylcarbazole, the polymer alone has poor film properties, flexibility, and adhesion, so plasticizers, binders, etc. are added to improve these defects. However, this caused 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 adhesion, on the other hand, they do not fully meet 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 for Solving the Problems) In order to solve the above problems, the present invention provides an electrophotographic photoreceptor containing a compound represented by -Formation (1) (wherein, Cp represents a coupler residue). I will provide a.

The coupler residue in the compound represented by general formula (I) can be selected from known coupler components, but especially -formation (II) -formation (III) general formula (TV) 3 H or -Formation (V) 3 (wherein, X represents a hydrocarbon ring or a heterocycle which may have a substituent, Y is, 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.

R1. in the above-forming coupler residues of (n), (III), (TV) and (V). Specific examples of R2 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, R2 and R3 are substituted alkyl groups, examples of the substituent include a halogen atom, a nitro atom, a cyan 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.

0 It may be a substituted alkyl group having two or more of these substituents. Specific examples of substituted alkyl groups include halogenoalkyl groups such as chloromethyl group, trifluoromethyl group, and 2-bromoethyl group; nitroalkyl groups such as nitromethyl group and 3-nitropropyl group; cyanomethyl group,
Cyanoalkyl groups such as 2-cyanoethyl group; Hydrodialkyl groups 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 groups; thiohydroxyalkyl groups;
thiohydroxyalkyl group such as 2=diohydroxyl-f-; substituted thiohydroxyalkyl group such as methylthiomethyl, 2-methylthioethyl group; aminoalkyl group such as aminomethyl group, 2-aminoethyl group; methylaminomethyl 2, such as ethylaminomethyl group, dimethylaminomethyl group, 2-(dimethylamino)ethyl group, phenylaminomethyl group, diphenylaminomethyl group, and JM aminoalni)yl group.

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

Specific examples of R1, R2 and R3 being substituted phenyl groups include alkylphenyl groups such as tolyl and ethylphenyl groups; halogen-substituted phenyl groups such as chlorophenyl and bromophenyl groups; nitrophenyl group; cyanophenyl% ; Human+:+ xyphenyl group; substituted hydroxyphenyl group such as methoxyphenyl group and 1-xyphenyl group; thiohydroxyphenyl group; substituted thiophenyl group such as methylthiophenyl group and ethylthiophenyl group; aminophenyl group; methylaminophenyl group group, 1 ] 2 methylaminophenyl group, phenylaminophenyl group,
Examples include substituted aminophenyl groups such as diphenylaminophenyl groups.

Specific examples of R', R2 and R3 being substituted condensed aromatic hydrocarbon groups include alkylnaphthyl groups such as methylnaphthyl group and ethylnaphthyl group; halogen-substituted naphthyl groups such as chloronaphthyl group and bromonaphthyl group; Hydroxynaphthyl group; substituted hydroxynaphthyl group such as methoxynaphthyl group and ethoxynaphthyl group; thiohydroxynaphthyl group; substituted thionaphthyl group such as methylthionaphthyl group and ethylthionaphthyl group; aminonaphthyl group; methylaminonaphthyl group, dimethylaminonaphthyl group , a phenylaminonaphthyl group, a substituted aminonaphthyl group such as a diphenylaminonaphthyl group, and the like.

RI When R2 and R3 are substituted aromatic heterocyclic groups, particularly substituted hendithiazolyl groups, specific examples include alkylhendithiapril groups such as methylhendithiazolyl group and edylhendithiazolyl group; chlorohendithiazolyl group; halogen-substituted hendithiazolyl groups such as duryl and bromohendithiazolyl groups; nitrohenzothiazolyl groups; cyanohenzothiazolyl groups; hydroxyhenzothiazolyl groups;
Substituted hydroxyhendithiazolyl group such as methoxyhendithiazolyl group, methoxyhendithiazolyl group; thiohydroxyhendithiazolyl group; methylthiohendithiazolyl group, ethylthiohendithiazolyl group, etc. Substituted thiohendothiazolyl group; aminohenzothiazolyl group; substituted amino such as methylaminohendithiazolyl group, dimethylaminohendithiazolyl group, phenylaminobenzothiazolyl group, diphenylaminohenzothiazolyl group Examples include hengethiazolyl group.

The disazo compound represented by the general formula (r) according to the present invention can be produced by a conventionally known method. for example,
2,7- described in "Journal of Organic Chemistry" Volume 35, Page 2762 (1970)
It can be synthesized using the following 34 route using bis(chloroformyl)-9-fluorenone (Vl) as a starting material.

(Vl) Fe/lICff1 DMF (DMF) Next, the compound represented by the formula (■) is diazotized by a conventional method and coupled with the coupler Cp in the presence of an alkali, or the diazonium of the compound represented by the formula (■) is Once the salt is isolated as a hydrofluoride salt or a zinc salt, it is coupled with a coupler in the presence of an alkali in a suitable solvent, such as an inert organic solvent such as N,N'-dimethylformamide or dimethyl sulfoxide. The compound of formula ('I) can be easily produced by the following steps.

Specific examples of the disazo compounds of the above-mentioned -formation (J) 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 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) 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 Figure 2 is made by dispersing a disazo compound in a solution containing a charge transporting substance and a binder, and applying this dispersion to a conductive support.
It can be manufactured by coating and drying. 90 The photoreceptor shown in FIG. 3 can be prepared by vacuum-depositing a disazo compound on a conductive support, or by coating a dispersion obtained by dispersing fine particles of a disazo compound in a solvent or binder solution.
It can be manufactured by drying, applying a solution of a charge transporting substance and a binder thereon, and drying. The photoreceptor shown in Fig. 4 can be 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 m. 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 μm or less.
~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, or 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. The proportion of the charge transport substance in the charge transport medium in the photoreceptor of FIGS. 3 and 4 is 10 to 95% by weight, preferably 10 to 60% by weight.
It is.

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 an alloy, 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 polymers include 12 polycarbonate, polyester, methacrylic resin, acrylic resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, styrene-butadiene copolymer, and 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, Examples include, but are not limited to, polyvinyl formal and 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 the plasticizer include biphenyl, biphenyl chloride, 0-terphenyl, p-terphenyl, dibdelphthalate, diethylene glycol phthalate, dioctyl phthalate, triphenyl phosphorus 4, acid, methylnaphthalene,
Examples include benzophenone, chlorinated paraffin, polypropylene, polystyrene, and various fluorohydrocarbons.

Examples of the sensitizer include chloranil, tetracyanoethylene, methyl violet, rhodamine B1 cyanine dye, merocyanine dye, pyrylium dye, and thiapyrylium dye.

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

Furthermore, in the present invention, in order to improve the adhesion between the conductive support and the photosensitive layer and to prevent the injection of free charges from the conductive support to the photosensitive layer, Between,
An adhesive layer or barrier layer can also be provided as required. Materials used for these layers include, in addition to the polymer compound used for the binder, casein, gelatin, polyvinyl alcohol, ethyl cellulose, nitrocellulose, polyvinyl butyral, phenolic resin, polyamide, and carboxymethylcellulose 34-suchloride. Vinylidene polymer latex, styrene
Examples include 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 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-trinitrofluorenone, 9-dicyanomethylene-24,5,7-tetranitrofluorenone, 2,4,5.7tetra Nitroxanthone, 2,4.8-trinidrothioxanthone, tetranitrocarbazole chloranil, 2,3-dichloro-5,6
-dicyanobenzoquinone, 2,4,7-1-lytro-9,10-phenanthrenequinone, tetrachlorophthalic anhydride, and the like.

Examples of the hole transport substance include low molecular compounds such as evapyrene, N-ethylcarbazole, N-isopropylcarbazole, N-phenylcarbazole, or N-methyl-2-phenylhydrazino-3-methylidene-9-ethyl. Carbazole, NN-diphenylhydrazino-3-
Methylidene 9-ethylcarbazole, p-N,N-dimethylaminobenzaldehyde diphenylhydrazone, P
Hydrazones such as NN-diethylaminobenzaldehyde diphenylhydrazone, p-N,N-diethylaminobenzaldehyde diphenylhydrazone, 2,5-bis(p-diethylaminophenyl)-1,3,4-oxadiazole, 1-phenyl-3- Pyrazolines such as (p-diethylaminostyryl)-5(p-diethylaminophenyl) birapurine, triphenylamine, N, N
, N', N'tetraphenyl-1,1'-biphenyl-4,4'diamine, N,N'-diphenyl-N,N'
-Bis(3-methylphenyl)-Ll'-biphenyl564,4'-diamine, and the like. Further, examples of the polymer compound include poly-N-vinylcarbazole, halogenated poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polyvinylacridine,
Pyrene-bormaldehyde resin, ethylcarbazole-
Examples include bomaldehyde resin and triphenylmethane polymer.

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. 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. Class: 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 halosaponified hydrocarbons such as methylene chloride, chloropol 11, carbon tetrachloride, and trichloroethane; Examples include aromatics such as benzene, toluene, xylene, monochlorobenzene, and dichlorobenzene.

As the coating method, coating methods such as dip coating, spray coating, spinner coating, bead coating, wire per coating, blade coating, roller coating, and curtain coating can be used.

〔Example〕

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to the Examples. still,
In the examples, "parts" indicate "parts by weight." Further, No. of the disazo compound means No. in Tables 1 to 6.

7 8 Example 1 10 parts of polyester resin (trade name "Vylon 200" manufactured by Toyobo Co., Ltd.), 10 parts of disazo compound No. 1, and 80 parts of Tetrahydrof 5F were pulverized and mixed in a vibrating mill, and the resulting dispersion was mixed. The solution was applied with a wire bar onto a polyester film on which aluminum was vapor-deposited, 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 was applied to the photosensitive layer surface of this photoreceptor.
-428 (manufactured by Kawaguchi Denki Seisakusho Co., Ltd.), the mass photoreceptor was charged in the dark by corona discharge with an applied voltage of -6 kV, left in the dark for 10 seconds, and then the surface was illuminated by a tungsten lamp at an illuminance of 5 lux. The photosensitive layer is irradiated with light so that the surface potential decreases to 1/2 of the surface potential after being left in the dark for 10 seconds. When I asked for it, I got El/. −
It was 12.0 lux·sec.

Example 2 3 parts of polyester resin (same product as Example 1), 2.4.
7-) 3 parts of Leetlow 9-Flu 112, 0.6 part of N01 cis-azu compound and 30 parts of Te) Rahi 1-Rofuran
The resulting dispersion was coated on a polyester film coated with aluminum using a wire bar and dried to form a photoreceptor having the structure shown in Fig. 2 with a photosensitive layer about 9 μm thick. Created. Next, the sensitivity of this photoreceptor was measured according to Example 1 and found to be E,/2=2.8 lux seconds.

Example 3 3 parts of the disazo compound No. 1 was pulverized and mixed using a vibrating mill in a solution in which 1 part of phenoxy resin (trade name "PKllll" manufactured by Union Carbide) was dissolved in 5 parts of Diol 9 Fufu. 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 of 5 parts of p-diethylaminohenzaldehyde diphenylhydrazone and 5 parts of polycarbonate resin (trade name "Panlite L-1250W, manufactured by J 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 10 μm was formed by coating with a 90% cloth and drying to obtain a photoreceptor having the structure shown in FIG. □-2.4 lux·sec.

Examples 4 to 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 disazo compounds in No. Sensitivity was measured in the same manner and the results listed in the same table were obtained.

Table? - / / 2 Example 21 The same method as in Example 3 was carried out except that N-ethylcarbasol-3-methylidene-N-aminoindoline was used instead of p-diethylaminohenzaldehydecyphenylhydrazone as the charge transport material. A photoreceptor having the structure shown in Figure 3 was prepared and its sensitivity was measured according to Example 1.
□-2, flux seconds.

Examples 22 to 4O In place of the disazo compound in No. 1, the disazo compounds listed in Table 8 below were used, and as the charge transport substance, N-ethylcarbazole 3-methylidene was used in place of p-diethylaminohenzaldehyde diphenylhydrapune. N-
A photoreceptor having the structure shown in FIG. 3 was prepared in the same manner as in Example 3 except that aminoindoline was used, and the sensitivity was measured in accordance with Example 1 to obtain the results listed in Table 8.

3 Example 41 The structure shown in FIG. 3 was prepared in the same manner as in Example 3 except that N-ethylcarbazole-3-methylidene-N-aminotetrahydroquinoline was used instead of p-diethylaminobenzaldehyde-diphenylhydrazone as the charge transport material. A photoreceptor was prepared, and the sensitivity was measured according to Example 1 and found to be El/□-2.8 lux·sec.

Examples 42 to 6O The disazo compounds shown in Table 9 below were used in place of the disazo compound in No. 1, and N-ethylcarbazole 3-methylidene-N was used in place of p-diethylaminohenzaldehyde 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.

5 Example 61 3 parts of polycarbonate resin (same product as Example 3), p-
A solution of 3 parts of diethylaminohensaldehyde diphenylhydrazone dissolved in 35 parts of tetrahydrofuran was applied onto a polyester film on which aluminum had been 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 to the second part of the charge transport layer using a wire bar and dried to form a charge generation layer with a thickness of about 0.8μ, and the structure shown in FIG. A photoreceptor was obtained. The sensitivity of the thus prepared photoreceptor was measured according to Example 1 by applying a corona discharge of ν to an applied voltage of +6 and found to be El/□-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 drawings]

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) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, X represents a hydrocarbon ring or heterocycle that may have a substituent, and Y is ▲Mathematical formulas, chemical formulas, tables, etc. There are ▼ or ▲ there are mathematical formulas, chemical formulas, tables, etc. ▼, which represents R^1, R^2 and R^
3 each independently represents a hydrogen atom, a hydrocarbon group or a heterocyclic group which may have a substituent, and 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.