JPH0311357A - Electrophotographic photosensitive body - Google Patents

Abstract

PURPOSE:To obtain excellent durability and high sensitivity by incorporating a specific disazo pigment into the photosensitive body. CONSTITUTION:A photosensitive layer 2a formed by dispersing the diazo compd. 3 expressed by formula I into a binder 4 is provided on a conductive base 1. The disazo compd. 3 provides both effects of generating the charge carrier necessary for light decay and transferring the charge at this time. In the formu la, Cp denotes a residual coupler group. The electrophotographic photosensitive body having the high sensitivity and high durability to the extent of allowing sufficient practicable use is obtd. in this way.

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 (I) ability to be charged to an appropriate potential in the dark, and (2) ability to retain charge in the dark. and (3) the ability to quickly dissipate charge by light irradiation.

In addition, from a practical standpoint, (4) a photoreceptor with an appropriate area can be easily manufactured, (5) it has good repeat stability,
(6) It must be durable, and (7) It must be inexpensive.

Conventionally, selenium, cadmium sulfide, zinc oxide, and the like have been widely used as photoconductive materials for electrophotographic photoreceptors. However, while these inorganic compounds have many advantages, they also have various disadvantages.For example, selenium has difficult manufacturing conditions, high manufacturing costs, and is sensitive to temperature, humidity, fingerprints, etc. However, it has disadvantages such as the need for careful handling because crystallization easily progresses and the properties as a photoreceptor deteriorate. 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), in which IJ-N-vinylcarbazole is sensitized with a 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. 10785/1983).
Compared to inorganic compound-based electrophotographic photoreceptors, it has the advantage 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 problems, the present invention provides an electrophotographic photoreceptor containing a compound represented by the general formula (I) Hj (wherein Cp represents a coupler residue).

The coupler residue in the compound represented by the general formula (N) can be selected from known coupler components, but in particular the general formula (n) and the general formula (I [I) (wherein, X is a substituted Represents a hydrocarbon ring or a heterocycle which may have a group, Y represents the general formula (IV) H or the general formula (V) 3 Rt and R3 each independently have a hydrogen atom or a substituent. R1 and R2 may mutually form a ring.) The coupler residue is preferably a coupler residue represented by the following.

Specific examples of R', R'' and R3 in the coupler residues of the above general formulas (U), (III), (IV) and (V) include methyl group, ethyl group, propyl group, butyl group,
Pentyl group, hexyl group, isopropyl group, isobutyl group, isoamyl group, isohexyl group, neopentyl group,
Alkyl groups having 1 to 20 carbon atoms such as tert-butyl group; aromatic hydrocarbon groups such as phenyl group and naphthyl group; aromatic heterocyclic groups such as pyridyl group, carbazolyl group, 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.

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 1 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, Rz and R2 are substituted aromatic hydrocarbon groups or substituted aromatic heterocyclic groups, the substituents include alkyl groups, halogen atoms, nitro groups, cyano groups, hydroxyl groups, substituted hydroxyl groups, thiol groups, 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, R1 and R'' 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. Group: hydroxyphenyl group; substituted hydroxyphenyl group such as methoxyphenyl group, ethoxyphenyl group; thiohydroxyphenyl group; substituted thiophenyl group such as methylthiophenyl group, ethylthiophenyl group;
Aminophenyl group; Examples include substituted aminophenyl groups such as methylaminophenyl group, dimethylaminophenyl group, phenylaminophenyl group, and diphenylaminophenyl group.

Specific examples when R1, R1 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 Rt and R3 are substituted aromatic heterocyclic groups, particularly substituted benzothiazolyl groups, include alkylbenzothiazolyl groups such as methylbenzothiazolyl group and ethylbenzothiazolyl group; chlorobenzothiazolyl group; Halogen-substituted benzothiazolyl groups such as zolyl group and bromobenzothiazolyl group; nitrobenzothiazolyl group; cyanobenzothiazolyl group; hydroxybenzothiazolyl group;
Substituted hydroxybenzothiazolyl groups such as methoxybenzothiazolyl group and ethoxybenzothiazolyl group; Thiohydroxybenzothiazolyl group; Substituted thiobenzobenzoyl groups such as methylthiobenzothiazolyl group and ethylthiobenzothiazolyl group Thiazolyl group; aminobenzothiazolyl group; substituted aminobenzothiazolyl group such as methylaminobenzothiazolyl group, dimethylaminobenzothiazolyl group, phenylaminobenzothiazolyl group, diphenylaminobenzothiazolyl group and the like.

The disazo compound represented by the general formula (I) according to the present invention can be produced by a conventionally known method, for example,
“Angevante Hemi” Volume 99, page 564 (I98
It can be synthesized by the following route using 1,4-diketo-3,6-diphenylpyrrolo-(3,4-c)-virol described in 1999) as a starting material.

Next, the compound represented by the formula (Vl) 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 or a zinc salt. Once isolated as a salt, compounds of formula (I) can be readily prepared by coupling with a coupler in the presence of an alkali in a suitable solvent, e.g., an inert organic solvent such as N,N'-dimethylformamide, dimethyl sulfoxide, etc. compounds can be manufactured.

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.

NH Exposure The electrophotographic photoreceptor of the present invention can have various structures. Examples are shown in Figures 1-4. The photoreceptor shown in FIG. 1 has a photosensitive layer (2a) formed by dispersing a disazo compound (3) in a binder (4) on a conductive support (I). The photoreceptor shown in FIG. 2 has a photosensitive layer (2b
). The photoreceptor shown in FIGS. 3 and 4 has a charge carrier generation layer (6) mainly composed of a disazo compound (3).
and a charge transport layer (7) consisting of a charge transport substance and a binder.
) and a photosensitive layer (2C) or (2d), respectively. In the case of Figure 1, a disazo compound (
3) 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 FIGS. 3 and 4, the disazo compound (3) contained in the charge carrier generation N (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 substance is 1.0 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 6011%.
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, 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 a 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-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 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, O-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 aggravating agents include chloranil, tetracyanoethylene, methyl bioleft, 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 compounds used in the binder, casein, gelatin, polyvinyl alcohol, ethyl cellulose, nitrocellulose, polyvinyl butyral, phenolic resin, polyamide, carboxymethylcellulose, vinylidene chloride, etc. Examples include polymer latex, styrene-butadiene polymer latex, polyurethane, gelatin, aluminum oxide, tin oxide, and titanium oxide.

In addition, charge transport materials are generally classified into two types: compounds that transport electrons and compounds that transport holes.
Both can be used in the electrophotographic photoreceptor of the present invention.

Examples of electron transport substances include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4.7-dolinitro-9-fluorenone, 2.
4,5.7-tetranitro-9-fluorenone, 9-dicyanomethylene-2,4,7-)linitrofluorenone, 9-dicyanomethylene-2゜4.5.7-tetranitrofluorenone, 2,4.5 .7-tetranitroxanthone, 2.4.8-trinidrothioxanthone, tetranitrocarbazole chloranil, 2,3-dichloro-5
, 6-dicyazbensoquinone, 2,4,7-dolinitro-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, p-N, N-
Hydrazone M such as dimethylaminobenzaldehyde diphenylhydrazone, pN,N-diethylaminobenzaldehyde diphenylhydrazone, p-N,N-diphenylaminobenzaldehyde diphenylhydrazone,2.
5-bis(p-diethylaminophenyl) -1,3,
Pyrazolines such as 4-oxadiazole, 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. Examples of the polymer compound include poly-N-vinylcarbazole, halogenated poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polyvinylacridine, pyrene-formaldehyde resin,
Examples include ethylcarbazole-formaldehyde 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. Examples of specific organic solvents include: , alcohols such as methanol, ethanol, n-propanol;
Ketones such as acetone, methyl ethyl ketone, cyclohexanone; amides such as N,N-dimethylformamide, N,N-dimethylacetamide; ethers such as tetrahydrofuran, dioxane, methyl cellosolve; esters such as methyl acetate, ethyl acetate; dimethyl Examples include sulfoxides and sulfones such as sulfoxide and sulfolane; aliphatic halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, and trichloroethane; aromatics such as benzene, toluene, xylene, monochlorobenzene, and dichlorobenzene. .

As a coating method, coating methods such as a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a wire bar coach ink method, a Fried coach ink method, a roller coating method, a curtain coating method, etc. can be used. .

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to the Examples.
In the Examples, "part" indicates "part by weight", and the term "stone of the disazo compound" means the koji 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 NaI, and 80 parts of tetrahydrofuran were ground and mixed in a vibrating mill, and the resulting dispersion was mixed with a polyester coated with one layer of aluminum. It was coated on a film 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 about 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/□ (looks/seconds) was calculated, E r7t=
It was 20.0 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 Nα disazo compound, and 30 parts of tetrahydrofuran were pulverized and mixed in a ball mill, and the resulting dispersion was spread on a polyester film containing NM 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/□-5.2 lux·sec.

Example 3 3 parts of a disazo compound of Nα1 was pulverized and mixed using a vibration mill in a solution in which 1 part of phenoxy resin (product name: rPKHHJ Union Carbide) was dissolved in 75 parts of dioxane, and the resulting dispersion was mixed with aluminum. Coat on a vapor-deposited polyester film using a wire bar and dry to a thickness of 1 μm.
A charge generation layer was formed. On this charge generation layer, p-
Diethylaminobenzaldehyde-diphenylhydrazone 5 parts, polycarbonate resin (product name "Panlite L")
A solution prepared by dissolving 5 parts of -1250W (manufactured by J Kijin Kasei Co., Ltd.) in 65 parts of methylene chloride was applied and dried using a wire bar to form a charge transport layer with a thickness of 10 μm, thereby obtaining a photoreceptor having the structure shown in FIG. The sensitivity of the thus prepared photoreceptor was measured according to Example 1, and El was found to be 4.5 lux.
It was seconds.

Examples 4 to 2O A photoreceptor having the structure shown in FIG. 3 was prepared in the same manner as in Example 3, except that the disazo compounds listed in Table 7 below were used in place of the Nα1 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.

Example 2I of Table 1 The structure shown in FIG. 3 was carried out in the same manner as in Example 3, except that N-ethylcarbazole-3-methylidene-N-aminoindoline was used instead of p-diethylaminobenzaldehyde-diphenylhydrazone as the charge transport material. A photoreceptor was prepared and its sensitivity was measured according to Example 1.
/□=3.8 lux·sec.

Examples 22 to 40 The disazo compounds shown in Table 8 below were used in place of the disazo compound of 40 kl, and N-ethylcarbazole-3-methylidene-N-amino was used in place of p-diethylaminobenzaldehyde-diphenylhydrazone as the charge transport material. The third step was carried out in the same manner as in Example 3 except that indoline was used.
A photoreceptor having the structure shown in the figure was prepared, and the sensitivity was measured according to Example I, and the results listed in Table 8 were obtained.

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 the sensitivity was found to be El/-=4.0 lux·sec.

Examples 42 to 6O Each of the disazo compounds shown in Table 9 below was used in place of the disazo compound of N11, 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.

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 in accordance with Example 1 by performing corona discharge at an applied voltage of +6 kV, and found to be E+/□-4.2 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 1 photographic 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. 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.