JPS6364053A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance sensitivity and durability of an electrophotographic body by incorporating a specified N-phenyl-phthalimido type disazo pigment as a photoconductor in a photosensitive layer formed on a conductive substrate. CONSTITUTION:The disazo pigment to be used as the photoconductor is a N- phenyl-phthalimido type compound represented by formula I in which A is a coupler residue having phenolic OH or the coupler residue of an 2- methylindolenine derivative, or a group of formula II or III; X is a group capable of condensing with a benzene and forming a polycyclic aromatic ring or a polycyclic hetero ring; each of R1 and R2 is H, alkyl, aralkyl, aryl, imino, a heterocyclic group, or the like; R5 is H, alkyl, alkoxy, or the like. An electric charge generating layer is formed by using this disazo pigment as the organic photoconductor, thus permitting high sensitivity and electrification characteristics after repeated uses to be stabilized.

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 an organic photoconductive substance made of a disazo pigment with a specific structure. .

[Prior Art] Electrophotographic photoreceptors containing inorganic photoconductors such as selenium, cadmium sulfide, and zinc oxide in the photosensitive layer are well known. On the other hand, organic photoconductive polymers such as poly-N-vinylcarbazole and polyvinylanthracene, low-molecular organic photoconductors such as carbazole, anthracene, pyrazolines, oxadiazoles, and hydrazones, phthalocyanine pigments, azo pigments, indigo dye,
Organic photoconductors such as thioindigo dyes and methine squaric acid dyes have been developed. Furthermore, as disclosed in, for example, U.S. Pat. No. 4,123,270, U.S. Pat. No. 4,247,614, U.S. Pat. An electrophotographic photoreceptor using a photoconductive disazo pigment as a charge generating substance is known.

An electrophotographic photoreceptor using such an organic photoconductor can be produced using a coating method using dip coating by appropriately selecting a binder, making it possible to provide an extremely highly productive and inexpensive photoreceptor. Although it has the advantage of being able to select organic pigments that exhibit photoconductivity in the wavelength range, it has drawbacks in terms of sensitivity and durability against green return use.
Only a few have been put into practical use so far.

[Problems to be Solved by the Invention] An object of the present invention is to provide an electrophotographic photoreceptor containing a novel organic photoconductor in its photosensitive layer.

Still another object is to provide an electrophotographic photoreceptor that has a practical high sensitivity and exhibits stable charging characteristics even after being used for reversing.

[Means for Solving the Problems, Effects] The present invention provides an electrophotographic method characterized in that a photosensitive layer provided on a conductive substrate contains a disazo pigment represented by the following general formula (1) as a photoconductor. Consists of a photoreceptor.

General formula (wherein A represents a coupler residue having a phenolic OH group or a coupler residue of a 2-methylindolenine! conductor) To explain the disazo pigment represented by the above general formula (1), The coupler residue having a phenolic OH group or the coupler residue of a 2-methylindolenine derivative is, for example, a group represented by any of the following general formulas (2) to (8).

ゝX′ General formula R3 General formula R General formula 1. Y-1 H General formula 1. Y~, N.

(In the formula, X represents a residue condensed with a benzene ring to form a polynomial aromatic ring or a heterocycle; group, heterocyclic group, imino group, and R
1 and R2 together with the nitrogen atom to which they are bonded represent a cyclic amino group, R3 and R4 represent an optionally substituted alkyl group, aralkyl group, or aryl group, and Y represents a divalent aromatic hydrocarbon group. R5 and R6 represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a cyano group, or a nitro group.

In the above definitions, examples of alkyl groups, aralkyl groups, aryl groups and alkoxy groups include alkyl groups such as methyl, ethyl and propyl; aralkyl groups such as benzyl and naphthylmethyl; and aryl groups such as phenyl, diphenyl and naphthyl. , Unthrill, etc.
Examples of substituents for these groups include halogen atoms, nitro groups, cyano groups, substituted amine groups (eg, dimethylamino, diphenylamino, dibenzylamino, etc.), alkyl groups, and alkoxy groups.

Examples of the alkoxy group include methoxy, ethoxy, and propoxy, and examples of the heterocyclic group include dibenzofuran, benzimidacylon, benzthiazole, thiazole, and pyridine.

Examples of residues that form a polycyclic aromatic ring or heterocycle with the benzene ring of Can be mentioned.

Further, examples of the divalent group of Y include a phenylene group and a naphthylene group.

Representative examples of the disazo pigment represented by the general formula (1) are listed below.

Note that since only A in the general formula (1) is different, only A will be shown in one example.

Pigment number A Js NLI in general formula (1) These disazo pigments can be used alone or in combination of two or more.

These disazo pigments can be produced by, for example, tetrazotizing the diamines described above by a conventional method, and then coupling the corresponding couplers represented by the above-mentioned general formulas (2) to (8) in the presence of an alkali, or by converting the above-mentioned diamines into tetrazonium. Once the salt is isolated in the form of a fluoroborate salt or zinc chloride double salt, it is dissolved in a suitable solvent such as N
, N-dimethylformamide, dimethyl sulfoxide, etc. in the presence of an alkali, the general formulas (2) to (
It can be easily produced by coupling with the coupler shown in 8).

In a 500 ml beaker, 80 mA of water, 16.6 g of concentrated hydrochloric acid (0.19 mol), and 7.3 g of the above diamine (0.19 mol) were added.
029 mol) was added thereto, and the mixture was stirred while cooling in an ice-water bath to bring the liquid temperature to 3°C.

Next, add 4.2 g (0,061 mol) of sodium nitrite to 7 m of water.
The solution dissolved in water was added dropwise over 10 minutes while controlling the liquid temperature within the range of 3 to 10°C. After the dropwise addition was complete, the mixture was stirred at the same temperature for an additional 30 minutes. Carbon was added to the reaction solution, filtered, and tetrazotized. I got the liquid.

Next, put 700ml of water in 22 beakers and add 22ml of caustic soda.
After dissolving 1 g (0.53 mol) of naphthol AS
(3-Hydroxy-2-naphthoic acid anilide')16.
2g (0,061 mol) was added and dissolved. This coupler solution was cooled to 6°C, and the above tetrazotized solution was added dropwise with stirring over 30 minutes while controlling the liquid temperature at 6 to 10°C. After that, the coupler solution was stirred at room temperature for 2 hours, and then left overnight. I did it.

The reaction solution was filtered and washed with water to obtain 19.7 g of crude pigment.

Hot filtration was then repeated five times with 400 ml of N,N-dimethylformamide. Thereafter, 18.6 g of purified pigment was obtained by heat drying under reduced pressure.

The yield was 80/5.

Elemental analysis: Calculated value (%) Experimental fia (, %) C71,9071,86 H3,903,88 N 12.22 12.20 Although the synthesis examples have been shown above, other disazo compounds represented by general formula (1) Pigments are also synthesized in a similar manner.

A film containing the disazo pigment represented by the general formula (1) exhibits photoconductivity and can therefore be used in a photosensitive layer of an electrophotographic photoreceptor.

The electrophotographic photoreceptor is prepared by forming a film of the disazo pigment on a conductive substrate by vacuum evaporation, or by dispersing the disazo pigment in a suitable binder to form a film.

In a preferred embodiment of the present invention, the photoconductive coating described above can be used as a charge generation layer in an electrophotographic photoreceptor in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer.

The charge generation layer contains as much photoconductive material as possible in order to obtain sufficient light absorption, and is coated with a coating, for example, 5μ or less, preferably 0.01 to 1L, to shorten the range of the generated charge carriers. It is desirable to form a thin film with a thickness of .

This means that most of the incident light is absorbed by the charge generation layer, generating a large number of charge carriers, and that the generated carriers must be injected into the charge transport layer without being deactivated by recombination or trapping. It is caused by something.

The charge generation layer can be formed, for example, by dispersing the azo pigment in a suitable binder and coating it on the substrate, or by forming a vapor deposited film using a vacuum vapor deposition apparatus.

The binder that can be used to form the charge generating layer by coating can be selected from a wide variety of insulating resins, and can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, and polyvinylpyrene. Preferably polyvinyl butyral, polyarylate (condensation polymer of bisphenol A and phthalic acid, etc.),
Examples include insulating resins such as polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide, polyamide, polyvinylpyridine, cellulose resin, polyurethane, epoxy resin, casein, polyvinyl alcohol, and polyvinylpyrrolidone.

The resin contained in the charge generation layer is suitably 80% by weight or less, preferably 40% by weight or less.

The solvent that dissolves these resins varies depending on the type of resin, and is preferably selected from those that do not dissolve the charge transport layer and undercoat layer described below.

Specific organic solvents include methanol, ethanol,
Alcohols such as isopropanol.

Ketones such as acetone, methyl ethyl ketone, cyclohexanone, N, N-dimethylformamide, N, N-
Amides such as dimethylacetamide, sulfoxides such as dimethyl sulfoxide, ethers such as tetrahydrofuran, dioxane, ethylene glycol methyl ether, esters such as methyl acetate, ethyl acetate, chloroform, methylene chloride, dichloroethylene,
Fatty halogenated hydrocarbons such as carbon tetrachloride, trichlorethylene, benzene, toluene, xylene,
Aromatic hydrocarbons such as ligroin, monochlorobenzene, dichlorobenzene, etc. can be used.

Coating methods include dip coating, spray coating, spinner coating, bead coating,
This can be carried out using a coating method such as a Mayer coating method, a blade coating method, a roller coating method, or a curtain coating method.

Drying is preferably carried out by heating and drying after keeping it dry to the touch at room temperature.Heat-drying can be carried out at a temperature of 30 to 200"C for a period of 5 minutes to 2 hours, either stationary or under ventilation. .

The charge transport layer is electrically connected to the charge generation layer described above, and has the function of receiving and receiving charge carriers injected from the charge generation layer in the presence of an electric field, and transporting these charge carriers to the surface. have. At this time, this charge transport layer may be laminated on the charge generation layer,
Further, an 11 layer may be provided below it.

Is the substance that transports charge carriers in the charge transport layer (hereinafter referred to as charge transport material) that the charge generation layer described above sensitive to? ! ! It is preferable to be substantially insensitive to the wavelength range of magnetic waves, and the 1aaa wave herein refers to a broad range of light rays including gamma rays, X-rays, ultraviolet rays, visible light, near infrared rays, infrared rays, far infrared rays, etc. Contains a definition.

When the photosensitive wavelength range of the charge transport layer coincides with or overlaps that of the charge generation layer, charge carriers generated in both layers trap each other, resulting in a decrease in sensitivity.

Charge transporting substances include electron transporting substances and hole transporting substances, and electron transporting substances include chloranil, bromoanil, and tetracyanoethylene.

Tetracyanoquinodimethane, 2,4.7-)nitro-
9-fluorenone, 2,4,5,7-tetranitro-9
- Electron-withdrawing substances such as fluorenone, 2,4,7-dolinitro-9-dicyanomethylenefluorenone, 2,4,5,7-titranitroxanthone, 2,4,8-trinidrothioxanthone, and their electron-withdrawing properties There are also polymerized substances.

Pyrene, N-ethylcarbazole, N-isopropylcarbazole, N-methyl-N-
Phenylhydrazino-3-methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-10-ditylphenothiazine, N, N-diphenylhydrazino-3-methylidene-
10-Nitylphenoxazine, p-diethylaminobenzaldehyde-N, N-diphenylhydrazone, p-diethylaminobenzaldehyde-N-α-naphthyl-N
-Phenylhydrazone, p-pyrrolidinobenzaldehyde-N,N-diphenylhydrazone, 1.3.4-trimethylindolenine-ω-aldehyde-N,N-diphenylhydrazone, p-diethylbenzaldehyde-3-
Hydrazones such as methylbenzthiazolinone-2-hydrazone, 2,5-bis(P-diethylaminophenyl)-1,3,4-oxadiazole, 1-phenyl-5
-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, 1-[quinolyl (2)
] -2-(p-diethylaminostyryl)-5-
(p-diethylaminophenyl)pyrazoline, 1-[pyridyl(2)]-5-(p-diethylaminostyryl)
-5-(p-diethyl7minophenyl)pyrazoline, 1
-[6-Medoxypyridyl (2)] -5-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, 1-[pyridyl (3)] -3-
(P-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, l-[lepidyl (2)]-
5-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, 1-[pyridyl(2
)]-5-(p-diethylaminostyryl)-4-methyl-3-(P-diethylaminophenyl)pyrazoline,
l-[pyridyl (2)] -3-(α-methyl-p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, 1-phenyl-5-(p-diethylaminostyryl)-4-methyl-3 -(p-diethylaminophenyl)pyrazoline, l-phenyl-5-(α
-benzy-P-diethylaminostyryl')-5-(
Pyrazolines such as p-diethylaminophenyl) pyrazoline and spiropyrazoline, 2-(p-diethylaminostyryl)-6-ethylaminobenzoxazole,
Oxazole compounds such as 2-(p-diethylaminophenyl)-4-(p-dimethylaminophenyl)-5-(2-chlorophenyl)oxazole, 2-(p-diethylaminostyryl)-6-ethyl 7minobenzothi7ole, etc. thiazole compounds, triarylmethane compounds such as bis(4-diethylamino-2-methylphenyl)-phenylmethane, 1,1-bis(4-N
, N-diethylamino-2-methylphenyl)hebutane, 1, l, 2, 2-tetrakis (4-N, N
-Polyarylalkanes such as dimethylamino-2-methylphenyl)ethane, triphenylamine, poly-
Examples include N-vinylcarhezole, polyvinylpyrene, polyvinylanthracene, polyvinylacridine, poly-9-vinylphenylanthracene, pyrene-formaldehyde resin, and ethylcarbazole-formaldehyde resin.

In addition to this organic charge transport material, selenium, selenium-tellurium,
Inorganic materials such as amorphous silicon and cadmium sulfide can also be used.

Further, these charge transport substances can be used singly or in combination of two or more.

When the charge transport material does not have film-forming properties, a film can be formed by selecting an appropriate binder. What resins can be used as binders?

For example, acrylic resin, polyarylate, polyester,
Polycarbonate, polystyrene, acrylonitrile
Styrene copolymer, acrylonitrile-butadiene copolymer, polyvinyl butytail, polyvinyl formal, polysulfone, polyacrylamide, polyamide,
Examples include insulating resins such as chlorinated rubber, and organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, and polyvinylpyrene.

The charge transport layer has a limit in its ability to transport charge carriers, so it cannot be made thicker than necessary. Generally, the thickness is 5 to 30 JL, but the preferred range is 8 to 20 JL.
It's a pot. When forming a charge transport layer by coating,
Any suitable coating method, such as those described above, can be used.

A photosensitive layer having such a laminated structure of a charge generation layer and a charge transport layer is provided on a substrate having a conductive layer. Examples of the substrate having a conductive layer include those whose substrate itself is conductive, such as aluminum, aluminum alloy, copper, zinc,
Stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold, and platinum are used.

In addition, plastics (e.g., polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, polyfluoride, ethylene chloride, etc.), conductive particles (e.g. carbon black, silver particles, etc.) coated on plastic with a suitable binder, conductive particles impregnated into plastic or paper, and plastics containing conductive polymers. Can be used.

A subbing layer having barrier and adhesive functions can also be provided between the conductive TM layer and the photosensitive layer. The subbing layer can be formed from casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyamide (nylon 6, nylon 66, nylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, gelatin, aluminum oxide, etc. . The appropriate thickness of the undercoat layer is 0.1 to 5 mm, preferably 0.5 to 3 mm.

When using a photoreceptor in which a conductive layer, a charge generation layer, and a charge transport layer are laminated in this order, and the charge transport material is an electron transport material, the surface of the charge transport layer must be positively charged; During post-exposure, electrons generated in the charge generation layer are injected into the charge transport layer in the light-banded area, and then reach the surface and neutralize the positive charge, resulting in attenuation of the surface potential and static electricity between it and the unexposed area. Contrast occurs. A visible image is obtained by developing the electrostatic latent image thus formed with a negatively charged toner. This can be directly fixed, or the toner image can be transferred to paper or plastic film and then developed and fixed. Alternatively, a method may be used in which the electrostatic latent image on the photoreceptor is transferred onto an insulating layer of transfer paper, then developed and fixed. The type of developer, the developing method, and the fixing method may be any known ones or methods, and are not limited to the four given ones.

On the other hand, when the charge transporting material is made of a hole transporting material, the surface of the charge transporting layer must be negatively charged, and the band '1! After that, when exposed to light, holes generated in the charge generation layer are injected into the charge transport layer in the exposed area, and then reach the surface and neutralize the negative charge, causing a decrease in surface potential and static electricity between the exposed area and the unexposed area. Electrocontrast occurs. During development, it is necessary to use a positively charged toner, contrary to when an electron transporting substance is used.

Furthermore, as another specific example of the present invention, the above general formula (1)
Examples include an electrophotographic photoreceptor in which an organic photoconductor, which is an azo pigment represented by the above formula, is contained in the same layer together with the above-mentioned charge transporting substance.

At this time, a charge transfer complex compound consisting of polyvinylcarbazole and trinitrofluorenone can be used as the charge transport substance.

The electrophotographic photoreceptor of this example can be prepared by dispersing the above-described organic photoconductor and charge transfer complex compound in a polyester solution dissolved in tetrahydrofuran, and then forming a film thereon.

In any of the electrophotographic photoreceptors, the pigment used contains at least one type of pigment selected from disazo pigments represented by the general formula (1), and if necessary, pigments with different light absorptions are used in combination to sensitize the material. General formula (1) is used for the purpose of increasing the sensitivity of the body or obtaining a panchromatic photoreceptor.
It is also possible to use a combination of 2 or more ml of disazo pigments represented by the above, or a combination with a charge generating substance selected from known dye pigments.

The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines, but also in a wide range of electrophotographic applications such as laser printers and CRT printers.

[Example] Example 1 Ammonia aqueous solution of casein (casein 1
1.2 g of 28% ammonia water, 1 g of 28% ammonia water, 222 m of water) was applied using a Mayer bar so that the film thickness after drying was 1.0 μm, and dried.

Next, 5 g of the organic photoconductor of the exemplified disazo pigment (8)
was added to a solution prepared by dissolving 2 g of butyral resin (degree of butyralization: 63 mol %) in 953 ml of ethanol, and dispersed with an attritor for 2 hours. This dispersion was applied onto the previously formed casein layer using a Mayer bar so that the film thickness after drying was 0.5 g, and dried to form a charge generation layer.

Then, p-diethylaminobenzaldehyde-N-α
- Dissolve 5 g of naphthyl-N-phenylhydrazone and 5 g of polymethyl methacrylate (number average molecular weight: 100,000) in 70 mJL of benzene, and place this on a Meyer bar so that the film thickness after drying is 12 L. and dried to form a charge transport layer.

The electrophotographic photoreceptor thus prepared was statically charged with corona at -3 KV using Kawaguchi Denki's electrostatic copying paper test mounting Model 5P-428 (turntable) and held in a dark place for 1 second. After that, it was exposed to light at an illuminance of 2 mm UX, and the charging characteristics were examined.

The charging characteristics include the surface potential (Vo) and the amount of exposure (E) required to attenuate the potential to 1/2 when dark decaying for 1 second.
l/2) was measured.

Furthermore, in order to measure the fluctuations in bright area potential and dark area potential when using the electrophotographic photoreceptor prepared above -
Excludes 5.6KV corona charger, exposure optical system with exposure amount of 5mux, sec, developer, transfer charger, etc. It was attached to the cylinder of an electrophotographic copying machine equipped with exposure optics and a cleaner. This copying machine is configured to produce an image on transfer paper as a cylinder is driven.

Using this copying machine, the initial bright area potential (VL) and dark area potential (VD) and the bright area potential (VL) and dark area potential (Vo) after 5,000 uses were measured. The results are shown below.

Voney 600V, El/2: 3.01ux, see Initial After 5,000 cycles of durability VD VL VD VL
-610V -4OV -62OV -6OVExamples 2 to 15 Electrophotographic exposure was carried out in the same manner as in Example 1, except that the following exemplary disazo pigment was used in place of the exemplary azo pigment used in Example 1. created a body.

The charging characteristics and durability characteristics of each photoreceptor were measured in the same manner as in Example 1.

Show the results.

Example Disazo pigment Example Disazo pigment 2
605 3, 2 3 600 3.3 4 600 3.5 5 610 3, 0 6 615 3.17
600 3, 0
8 610 2.99
620 2,
810 605 3.
211 600 2.
112 610 2.
91 3 620 3
, 314 610
3.415 610
3.2 Example 16 On the charge generation layer prepared in Example 1, 2, 4, 7-
ToIJ Nitro 9-fluorenone 5g and poly-4,4-
Dioxydiphenyl-2,2-propane carbonate (
After drying a coating solution prepared by dissolving 5g of molecular weight 300,000) in 70ml of tetrahydrofuran, the coating amount was 10g/m2.
It was applied and dried.

The charging characteristics of the electrophotographic photoreceptor thus prepared were measured in the same manner as in Example 1. At this time, the charge was set to +. Show the results.

vo: +580V, E1/2: 4.89. ux, sec, initial VD: +590V, VL: +40V after 5,000 cycles VD: +610V, VL: +70V Example 17 A film thickness of 1.0V was deposited on the aluminum surface of an aluminum vapor-deposited polyethylene terephthalate film. A film of polyvinyl alcohol was formed.

Next, the dispersion liquid of the disazo pigment used in Example 1 was placed on the polyvinyl alcohol layer formed previously so that the film thickness after drying was 0.
．． It was coated with a Mayer bar to a thickness of 5μ and dried to form a charge generation layer.

Then 1-[quinolyl(2)]-5-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)
5g of pyrazoline and polyarylate (bisphenol A)
A solution obtained by dissolving 5 g of terephthalic acid-isophthalic acid condensation polymer) in 70 layers of tetrahydrofuran is applied onto the charge generation layer to a dry film thickness of 10 μl, and dried to transfer and remove the charges. was formed.

The charging characteristics and durability characteristics of the electrophotographic photoreceptor thus prepared were measured in the same manner as in Example 1. Show the results.

Vo knee 600V, El/2: 3.2 sentences ux, sec, initial VD knee 600V, VL knee 35V after 5,000 cycles Vo knee 620V, VL knee 60V Example 18 Casein ammonia on a 100g thick aluminum plate Apply an aqueous solution and dry to a film thickness of 1. A subbing layer of OJL was formed.

Next, 5 g of 2,4.7-)unitro-9-fluorenone
A charge transfer complex compound was prepared by dissolving 5 g of poly-N-vinylcarbazole (number average molecular weight: 300,000) in 70ml of tetrahydrofuran.

This charge transfer complex compound and the exemplified disazo pigment (24)
1 g of the photoconductor was added to a solution in which 5 g of polyester (trade name Heiron, manufactured by Toyo Borin) was dissolved in 70 m of tetrahydrofuran and dispersed.

This dispersion was applied onto the undercoat layer so that the film thickness after drying was 12 mm, and dried.

What about the electrophotographic photoreceptor created in this way? The tF electrical characteristics were measured in the same manner as in Example 1.

However, the charging polarity was set to 10. Show the results.

vo: +595V, El/2: 4.81ux, see,

Claims (9)

[Claims] (1) The following general formula (
An electrophotographic photoreceptor comprising a disazo pigment represented by 1) as a photoconductor. General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (1) (In the formula, A represents a coupler residue having a phenolic OH group or a coupler residue of a 2-methylindolenine derivative.) (2) In the general formula (1), A is a general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (2) (In the formula, X is fused with a benzene ring to form a polycyclic aromatic ring or a heterocycle. Residues are indicated, R_1 and R_2
represents a hydrogen atom, an alkyl group that may have a substituent, an aralkyl group, an aryl group, a heterocyclic group, an imino group, and represents a cyclic amino group together with the nitrogen atom to which R_1 and R_2 are bonded) An electrophotographic photoreceptor according to claim 1. (3) In the general formula (1), A is a general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (3) (In the formula, R_3 is an alkyl group, an aralkyl group, or an aryl group that may have a substituent. The electrophotographic photoreceptor according to claim 1, which is represented by ). (4) In the general formula (1), A is the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (4) (In the formula, R_4 is an alkyl group, an aralkyl group, or an aryl group that may have a substituent. The electrophotographic photoreceptor according to claim 1, which is represented by ). (5) In the general formula (1), A is the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (5) (In the formula, Y forms a heterocycle with a divalent group of aromatic hydrocarbon or a nitrogen atom. 2. The electrophotographic photoreceptor according to claim 1, which represents a divalent group. (6) In the general formula (1), A is the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (6) (In the formula, Y forms a heterocycle with a divalent group of aromatic hydrocarbon or a nitrogen atom. 2. The electrophotographic photoreceptor according to claim 1, which represents a divalent group. (7) In general formula (1), A is a general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (7) (In the formula, R_5 is a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a cyano group, or a nitro group. )
An electrophotographic photoreceptor according to claim 1, which is represented by: (8) In general formula (1), A is a general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (8) (In the formula, R_6 is a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a cyano group, or a nitro group. )
An electrophotographic photoreceptor according to claim 1, which is represented by: (9) The photosensitive layer is a laminated photosensitive layer consisting of a charge generation layer and a charge transport layer, and the charge generation layer has the general formula (1).
Claim 1 containing a disazo pigment represented by
The electrophotographic photoreceptor described in .