JPH0368952A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain a sensitive body having superior durability and high sensitivity by incorporating a specified bismesoionic compd. into a photosensitive layer. CONSTITUTION:A bismesoionic compd. represented by formula I is incorporated into a photosensitive layer 2a. In the formula I, A is an arom. hydrocarbon group which may have a substituent, a hydrocarbon group which may have an arom. heterocyclic group or a heterocyclic group which may have a substituent. The bismesoionic 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. The amt. of the bismesoionic compd. 3 in the photosensitive layer 2a is regulated to 10-70wt.%, preferably 30-50wt.% of the amt. of the layer 2a and the thickness of the layer 2a is regulated to 3-50mum, preferably 5-20mum.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having a photosensitive layer containing a bismesoion compound.

[Conventional technology]

So-called electrophotography, which combines photoconductive substances and electrostatic phenomena to record images, was developed by Carlson in U.S. Pat.
It originated from the ``electron photography'' that was revealed in issue 1776. In electrophotography, a photoconductive material whose electrical resistance changes depending on the amount of light irradiation is used.
A photoconductive material that is dispersed in an insulating binder resin and coated on a support is used as a photoreceptor. After this photoconductive material is given a uniform surface charge by corona charging in a dark place, it loses its surface charge depending on the brightness value of image exposure, and an electrostatic latent image is formed. This kind of electrostatic latent image is
The surface is then treated with a suitable electrolytic indicator material, ie, toner, to form a visible image. The toner can be used with a dry carrier or colloidally suspended in an organic solvent and can be deposited by Coulomb force depending on the charge of the electrostatic latent image. The attached display substance can be fixed by heat, pressure, or the like.

The electrostatic latent image can also be transferred to a second support (eg, paper, film, etc.), developed, and fixed.

In such electrophotography, the basic characteristics required of an electrophotographic photoreceptor are (1) ability to be charged to an appropriate potential in the dark, and (2) ability to retain charge in the dark. and (3) the ability to quickly dissipate charge by light irradiation.

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

Conventionally, selenium, cadmium sulfide, zinc oxide, and the like have been widely used as photoconductive materials for electrophotographic photoreceptors. However, while these inorganic compounds have many advantages, they also have various disadvantages. For example, selenium has drawbacks such as difficult manufacturing conditions, high manufacturing costs, and the need for careful handling as it easily crystallizes due to temperature, humidity, fingerprints, etc., and deteriorates its properties as a photoreceptor. had. Further, sulfurized cadmium 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), BoIJ N-vinylcarbazole enhanced with pyrylium salt dye. (Japanese Patent Publication No. 48-25658), 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. 47-10785). 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 photoconductive polymers such as poly-N-vinylcarbazole, the polymer alone has poor filmability, flexibility, adhesion, etc., and in order to improve these drawbacks, plasticizers,
A binder or the like is added, but this causes 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 has the following formula: R represents a hydrocarbon group which may have a substituent or a heterocyclic group which may have a substituent.

As A in general formula (I), 1,4-phenylene group, 1,3-phenylene group, (3,3'-dimethylbiphenyl)-4,4'-diyl group, (3,3'-dichlorobiphenyl group) ) -4,4'-diyl group, stilbene-
4,4'-diyl group, 9-fluorenone-2,7-diyl group, 2,5-biphenyloxadiazole-4',4
“-diyl group, 2-phenylbenzoxazole-5,
Examples include 4'-diyl group.

R in the general formula (1) is preferably an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group such as a phenyl group or a naphthyl group, or an aromatic group such as a pyridyl group, a carbazolyl group, or a benzotriazolyl group. Examples include group heterocyclic groups. As a specific example, when R is an alkyl group,
Methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, isopropyl group, isobutyl group, isobutyl group, isohexyl group, neopentyl group, ter
Examples include t-butyl group. When R is a substituted alkyl group, examples of the substituent include a halogen atom, a nitro group, a cyano group, a hydroxy group, a substituted hydroxy group, a thiol group, a substituted thiol group, an amino group, a substituted amino group,
Examples include aryl groups.

Specific examples of R include halogenoalkyl groups (e.g., chloromethyl group, trifluoromethyl group, 2-bromoethyl group, etc.), nitroalkyl groups (e.g., nitromethyl group, 3-nitropropyl group, etc.), cyanoalkyl groups (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 (e.g., methoxymethyl group, 2-methoxyethyl group, ethoxymethyl group, phenoxymethyl group, etc.), thiohydroxyalkyl group (e.g., thiohydroxymethyl group, 2-methoxyethyl group, ethoxymethyl group, phenoxymethyl group, etc.),
thiohydroxyethyl group, etc.), substituted thiohydroxyalkyl group (e.g., methylthiomethyl group, 2-methylthioethyl group), aminoalkyl group (e.g., agonomethyl group, 2-agonoethyl group, etc.), substituted aminoalkyl group (
Examples include methylagonomethyl group, ethylaminomethyl group, dimethylaminomethyl group, 2-(dimethylami)ethyl group, phenylaminomethyl group, diphenylaminomethyl group, etc.).

When R is 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, a substituted thiol group, and an amino group. , substituted amino groups, etc. As a specific example, when R is a substituted phenyl group, an alkylphenyl group (e.g. tolyl group, ethylphenyl group, etc.), a chlorophenyl group, a nitrophenyl group, a cyanophenyl group, a hydroxyphenyl group, a substituted hydroxyphenyl group (e.g. , methoxyphenyl group, ethoxyphenyl group, etc.), thiohydroxyphenyl group, substituted thiol group (e.g., methylthionaphthyl group, ethylthiophenyl group, etc.), aminophenyl group, substituted amino group (
Examples include methylaminophenyl group, dimethylachinophenyl group, phenylaminophenyl group, dimethylaminomethyl group, etc.). Examples of fused aromatic hydrocarbon groups in which R is a substituted naphthyl group include alkylnaphthyl groups (e.g., methylnaphthyl group, ethylnaphthyl group, etc.), chloronaphthyl group, nitronaphthyl group, cyanonaphthyl group, hydroxy Naphthyl group, substituted hydroxynaphthyl group (e.g. methoxynaphthyl group, ethoxynaphthyl group, etc.), thiohydroxynaphthyl group, substituted thiol group (
Examples include methylthionaphthyl group, ethylthionaphthyl group, aminonaphthyl group, and substituted amino groups (eg, methylaminonaphthyl group, dimethylaminonaphthyl group, phenylaminonaphthyl group, diphenylaminonaphthyl group, etc.). Examples of aromatic heterocyclic groups include substituted benzothiazolyl groups, such as alkylbenzothiazolyl groups (e.g., methylbenzothiazolyl group, ethylbenzobenzothiazolyl group, etc.), and chlorobenzothiazolyl groups. ,
Nitrobenzothiazolyl group, cyanobenzothiazolyl group, hydroxybenzothiazolyl group, substituted hydroxybenzothiazolyl group (e.g., methoxybenzothiazolyl group, ethoxybenzothiazolyl group, etc.), thiohydroxybenzo Thiazolyl group, substituted thiol group (e.g., methylthiobenzothiazolyl group, ethylthiobenzothiazolyl group, etc.), aminobenzothiazolyl group, substituted aminobenzothiazolyl group (e.g., methylaminobenzothiazolyl group, etc.) group, dimethylaminobenzothiazolyl group, phenylaminobenzothiazolyl group, diphenylaminobenzothiazolyl group, etc.). In these examples, if the position of the substituent is not specified, any of the possible isomers may be used. Further, it may be a substituted aromatic hydrocarbon group or a substituted aromatic heterocyclic group having two or more of these substituents (which may be the same or different).

The bismesoionic compound represented by the general formula (1) according to the present invention can be produced by a conventionally known method.

For example, "Hekutsche Berichte" Volume 120, 41
1 (1987), it can be synthesized by the following route.

r 0 1 A +CHCOH) 2 (CF30) zo O Specific examples of the bismeso ion compound of formula (I) used in the present invention are shown in Table 1 as structural formulas.

The electrophotographic photoreceptor of the present invention can have various structures. Examples are shown in Figures 1-4. The photoreceptor in Figure 1 consists of a bismesoionic compound (3) on a conductive support (1).
A photosensitive layer (2a) formed by dispersing in a binder (4)
It has been established.

The photoreceptor shown in Fig. 2 has a photosensitive layer (2b) formed by dispersing a bismeso ion compound (3) in a charge transport medium consisting of a charge transport substance (5) and a binder on a conductive support. . The photoreceptor shown in FIGS. 3 and 4 includes a charge carrier generation layer (6) mainly composed of a bismesoionic compound (3), and a charge transport layer (7) composed of a charge transport substance and a binder.
A photosensitive layer (2c) or (2d) consisting of the following is provided. In the case of FIG. 1, the bismesoionic compound (3) performs both the generation of charge carriers necessary for light attenuation and charge transport. In the case of the photoreceptor of FIG. 2, the charge transport material is a charge transport medium (5) along with a binder.
, while the bismesoionic compound (3) acts as a charge carrier generating substance. Although this charge transport medium (5) does not have the ability to generate charge carriers like the bismesoionic compound (3), it has the ability to accept charge carriers generated from the bismesoionic compound and transport them. That is, in the photoreceptor of FIG. 2, the generation of charge carriers necessary for light attenuation is performed by the bismesoionic compound (3), while
Transport of the charge carriers is primarily carried out by the charge transport medium (5). In the case of the photoreceptors shown in FIGS. 3 and 4, the bismeso ion compound (3
) generates charge carriers, while the charge transport layer (7) receives charge carrier injection and transports them. That is, the mechanism of action is the same as that of the photoreceptor shown in FIG. 2, in which the generation of charge carriers necessary for light attenuation is carried out by a bismeso ion compound, and the transport of charge carriers is carried out by a charge transport medium.

The photoreceptor shown in FIG. 1 is made by dispersing a bismeso ion compound in a binder solution, coating this dispersion on a conductive support,
It can be manufactured by drying. The photoreceptor shown in FIG. 2 can be manufactured by dispersing a bismeso ion 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 bismesoionic compound on a conductive support, or by applying a dispersion obtained by dispersing fine particles of a bismesoionic compound in a solvent or binder solution, and drying the resulting material. 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 bismesoion compound thereon, or by depositing fine particles of a bismesoion 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 am, preferably 5 to 20 μm in the case of the photoreceptors shown in FIGS. 1 and 2.
It is. In the case of the photoreceptor shown in FIGS. 3 and 4, the thickness of the charge carrier generation layer is 5 μm or less, preferably 0.01 to 5 μm.
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 bismeso ion 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 bismeso ion 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 10% by weight.
-90% by weight, preferably 10-60% by weight. The proportion of the charge transport material in the charge transport medium in the photoreceptor of FIGS. 3 and 4 is 10 to 95% by weight, preferably 10 to 95% by weight.
It is 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 and metal drums made of metals or alloys such as titanium, nickel, molybdenum, vanadium, indium, gold, and platinum, or conductive polymers, conductive compounds such as indium oxide, argonium, palladium, gold, etc. Examples include paper, plastic film, etc. coated with, vapor-deposited, or plated with metals or alloys.

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 two or more.

Additionally, additives such as plasticizers, sensitizers, surface modifiers, etc. can also be used together with these binders.

Examples of plasticizers include biphenyl, chlorinated biphenyl, 0-terphel, p-terphenyl, dibutyl phthalate, diethylene glycol phthalate, dioctyl phthalate, triphenyl phosphoric acid, methylnaphthalene, benzophenone, chlorinated paraffin, polypropylene, polystyrene, and various fluorohydrocarbons. etc.

Examples of the sensitizer include chloranil, tetracyanoethylene, methyl violet, rhodamine B, cyanine dye, merocyanine dye, 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, carboxymethyl cellulose, vinylidene chloride polymer latex, and styrene. -Butadiene polymer latex, polyurethane, gelatin, aluminum oxide, tin oxide, titanium oxide and the like.

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

Examples of electron transport substances include chloranil, furoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4.7-trinitro-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-)linitrothioxanthone, Tetranitrocarbazole chloranil, 2,3-dichloro-5
, 6-didianobenzoquinone, 2,4.7-)dinitro-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-
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.

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 such as acetone, methyl ethyl ketone, and cyclohexanone; and amides such as N,N-dimethylformamide and N,N-dimethylacetamide. ;Tetrahydrofuran,
Ether necks 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 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." Further, No. of the bismeso ion compound means No. in Table 1.

Example 1 10 parts of polyester resin (trade name "Vylon 200" manufactured by Toyobo Co., Ltd.), 10 parts of bismesoionic compound No. 1, and 80 parts of tetrahydrofuran were pulverized and mixed in a vibrating mill, and the resulting dispersion was mixed to form a polyester coated with aluminum. Apply onto the film with a wire bar and dry to a thickness of about 10
A photoreceptor having the structure shown in FIG. 1 having a photoreceptor layer of .mu. was obtained. Next, an electrostatic copying paper tester Model was placed on the photosensitive layer surface of this photoreceptor.
Using 5P-428 (manufactured by Kawaguchi Electric Seisakusho Co., Ltd.), the photoreceptor was first 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 with an illuminance of 5 by a tungsten lamp. irradiate the photosensitive layer with light such that the photosensitive layer becomes lux, and measure the time until the surface potential decreases to 172, which is the surface potential after leaving it in a dark place for 10 seconds,
When the photosensitivity El/□ (lux/sec) was calculated, E
1/z=20.5 lux·sec.

Example 2 3 parts of polyester resin (same product as Example 1), 2.4.
7-) Rinitro 9-fluorenone 3 parts, no.

0.6 parts of the bismesoionic compound No. 1 and 30 parts of tetrahydrofuran were pulverized and mixed in a ball mill, and the resulting dispersion was applied onto a polyester film coated with aluminum using a wire bar and dried to form a photosensitive layer with a thickness of about 9 μm. A photoreceptor having the structure shown in FIG. 2 was prepared. Next, the sensitivity of this photoreceptor was measured according to Example 1, and E, /2=
It was 4.0 lux·sec.

Example 3 3 parts of NOll bismethionic compound were pulverized and mixed using a vibrating mill in a solution in which 1 part of phenoxy resin (product name: PKHHJ, manufactured by Union Carby Company 1) was dissolved in 75 parts of dioxane, and the resulting dispersion was mixed. The solution was applied onto an aluminum vapor-deposited polyester film using a wire bar and dried to form a charge generation layer with a thickness of 1 μm. A solution of 5 parts of p-diethylaminobenzaldehyde-diphenylhydrazone and 5 parts of polycarbonate resin (trade name: "Panlite L-1250W, manufactured by J Teijin Kaoru 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 and drying using
A photoreceptor having the structure shown in the figure was obtained. When the sensitivity of the photoreceptor thus prepared was measured according to Example 1, E I/2 = 3.
．． It was 5 lux·sec.

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 bismeso ion compounds shown in Table 2 below were used in place of the Nα1 bismeso ion compound, and the photoreceptor was prepared according to Example 1. The sensitivity was measured and the results listed in Table 2 were obtained.

Table/Example 21 The structure shown in Figure 3 was prepared 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. When a photoreceptor was prepared and its sensitivity was measured according to Example 1, El
/□=3.2 lux seconds.

Examples 22 to 4O Disazo compounds shown in Table 3 below were used in place of the bismeso ion compound of Nα1, and p-
N-Ethylcarbazole-3-methylidene-instead of Diethylua Bay nobenzaldehyde diphenylhydrazone
A photoreceptor having the structure shown in FIG. 3 was prepared in the same manner as in Example 3 except that N-A[noindoline was used. The sensitivity was measured in accordance with Example 1, and the results listed in Table 3 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 in accordance with Example 1, El/□=3.6 lux·sec.

Examples 42 to 6O The bismeso ion compounds shown in Table 4 below were used in place of the bismeso ion compound of Nα1, and N-ethylcarbazole-3-methylidene-N-amino was used instead of p-diethylaminobenzaldehyde-diphenylhydrazone as the charge transport substance. A photoreceptor having the structure shown in FIG. 3 was produced in the same manner as in Example 3 except that tetrahydroquinoline was used.
Sensitivity was measured according to Example 1, and the results listed in Table 4 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 an aluminum-deposited polyester film 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 to be El/□-3, flux seconds.

〔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 drawings]

1 to 4 are enlarged partial cross-sectional views of the electrophotographic photoreceptor according to the present invention. DESCRIPTION OF SYMBOLS 1... Conductive support, 2a, 2b, 2c, 2d-photosensitive layer, 3... Bismeso ion 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. R represents a hydrocarbon group which may have a substituent or a heterocyclic group which may have a substituent). Photoreceptor for use.