JPH0153778B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to organic photoconductors. Prior Art Electrophotographic photoreceptors using inorganic photoconductors such as selenium, cadmium sulfide, and zinc oxide as photosensitive components have been known. On the other hand, since it was discovered that certain organic compounds exhibit photoconductivity, many organic photoconductors have been developed. For example, organic photoconductive polymers such as poly-N-vinylcarbazole and polyvinylanthracene, carbazole, anthracene, pyrazolines, oxadiazoles, hydrazones,
Organic pigments and dyes such as low-molecular organic photoconductors such as polyarylalkanes, phthalocyanine pigments, azo pigments, cyanine dyes, polycyclic quinone pigments, perylene pigments, indigo dyes, thioindigo dyes, or methine squaritate dyes are used. Are known. In particular, organic pigments and dyes with photoconductivity are easier to synthesize than inorganic materials, and the variety of compounds that exhibit photoconductivity in an appropriate wavelength range has expanded. Photoconductive organic pigments and dyes have been proposed. For example, U.S. Patent Nos. 4123270, 4247614, 4251613, 4251614, 4256821,
Same No. 4260672, Same No. 4268596, Same No. 4278747,
As disclosed in No. 4,293,628, electrophotographic photoreceptors are known in which a disazo pigment exhibiting photoconductivity is used as a charge-generating substance in a photosensitive layer that is functionally separated into a charge-generating layer and a charge-transporting layer. Electrophotographic photoreceptors using such organic photoconductors can be produced by coating by appropriately selecting a binder, so they can be produced with extremely high productivity and at low cost. Although this photoreceptor has the advantage of being able to freely control the sensitive wavelength range by selecting the photoreceptor, it has drawbacks in sensitivity and durability, and so far only a few have been put into practical use. OBJECT OF THE INVENTION An object of the invention is to provide a novel organic photoconductor. Another object of the present invention is to provide an electrophotographic photoreceptor having improved photographic properties through the use of a specific organic photoconductor.
The object of the present invention is to provide an electrophotographic photoreceptor having practical high sensitivity characteristics and stable potential characteristics during repeated use. The present invention comprises an organic photoconductor represented by the following general formula (1). general formula A represents a coupler component having aromaticity,
Preferably, A is selected from coupler components represented by the following general formulas (2) to (4). General formula (2) is

[Formula], where X is a residue that is condensed with a benzene ring to form an aromatic hydrocarbon ring or a heterocycle such as a naphthalene ring, anthracene ring, carbazole ring, dibenzofuran ring, or benzcarbazole ring, Y - CONR ₁ The group shown by R ₂ (where R ₁ is a hydrogen atom, methyl, ethyl, propyl,
A group selected from the group consisting of substituted or unsubstituted alkyl groups such as butyl, 2-hydroxyethyl, 3-hydroxypropyl, and aryl groups such as phenyl, naphthyl, etc., R ₂ is methyl, ethyl, propyl, butyl, 2- Represents a group selected from the group consisting of substituted or unsubstituted alkyl groups such as hydroxyethyl and 3-hydroxypropyl, aryl groups such as phenyl and naphthyl, and heterocyclic residues such as pyridyl, quinolyl, carbazolyl and thiazolyl), Or-
CONHNR ₃ represents a group represented by R ₄ (wherein R ₃ and R ₄ represent substituted or unsubstituted aryl groups such as phenyl and naphthyl). Substituents for R ₁ to _{R 4} above include alkyl groups such as methyl and ethyl, halogen atoms such as fluorine, chlorine, and bromine, alkoxy groups such as methoxy and ethoxy, acyl groups such as acetyl and benzoyl, methylthio, ethylthio, etc. an alkylthio group, an arylthio group such as phenylthio,
Examples include aryl groups such as phenyl, aralkyl groups such as benzyl, nitro groups, cyano groups, and substituted amino groups such as dimethylamino, diethylamino, dibenzylamino, and ethylamino. General formulas (3) and (4) are

【formula】

It is represented by [Formula]. In the formula, R ₅ represents a group selected from the group consisting of substituted or unsubstituted alkyl groups, phenyl groups, aryl groups such as naphthyl groups. More specifically, R ₅ is an alkyl group such as methyl, ethyl, or propyl, a hydroxyalkyl group such as hydroxymethyl or hydroxyethyl, an alkoxyalkyl group such as methoxymethyl, ethoxymethyl, or ethoxyethyl, a cyanoalkyl group, or an aminoalkyl group. , N-alkylaminoalkyl group, N,N-dialkylaminoalkyl group, halogenated alkyl group, benzyl, aralkyl group such as phenethyl, phenyl group and substituted phenyl group, naphthyl group, substituted naphthyl group, (substituents include general Examples include substituents for R ₁ to _{R 4} in formula (2). Typical organic photoconductors of the present invention include the following disazo pigments. These disazo pigments can be used alone or in combination of two or more. In addition, these pigments are The diamine represented by is tetrazotized by a conventional method,
The corresponding coupler is then coupled in the presence of an alkali, or once the tetrazonium salt of the diamine is isolated in the form of a borofluoride salt or zinc chloride double salt, etc., a suitable solvent such as N,N-dimethylformamide is added. , can be easily produced by coupling with a coupler in the presence of an alkali in a solvent such as dimethyl sulfoxide. Next, a typical synthesis example of the disazo pigment used in the present invention is shown below. Synthesis Example 1 (Synthesis of Disazo Pigment No. 1 exemplified above) In a 500ml beaker, add 80ml of water and 16.6ml of concentrated hydrochloric acid (0.19ml).
mole)

[Formula] 6.7g (0.029 mol) was added and stirred while cooling in an ice water bath to bring the liquid temperature to 3°C. Next, 4.2g of sodium nitrite
(0.061 mol) dissolved in 7 ml of water and the temperature of the solution
The mixture was added dropwise over 10 minutes while controlling the temperature within the range of 10°C, and after the addition was completed, the mixture was stirred for an additional 30 minutes at the same temperature. Carbon was added to the reaction solution to obtain a tetrazotized solution. Next, put 700ml of water into 2 beakers and dissolve 21g (0.53mol) of caustic soda, then naphthol AS.
(3-hydroxy-2-naphthoic acid anilide)
16.2 g (0.061 mol) was added and dissolved. Cool this coupler solution to 6℃ and reduce the liquid temperature to 6-10℃.
Add the above-mentioned tetrazotization solution while controlling the temperature at
The mixture was added dropwise over 30 minutes with stirring, and then stirred at room temperature for 2 hours and further left overnight. After filtering the reaction solution, it was washed with water to obtain 20.4 g of a crude pigment. Next, 400ml of N,N
- Heating with dimethylformamide was repeated 5 times. Thereafter, 19.2 g of purified pigment was obtained by heat drying under reduced pressure. The yield was 84.8%. Elemental analysis: Calculated value (%) Experimental value (%) C 76.90 76.73 H 4.14 4.30 N 10.76 10.62 Synthesis example 2 (Synthesis of disazo pigment No. 2 illustrated above)

[Formula] Add 3.54 g (0.051 mol) of sodium nitrite to a solution of 5.81 g (0.025 mol) dissolved in 65 ml of water and 13.24 ml (0.15 mol) of concentrated hydrochloric acid.
A solution obtained by dissolving the above in 10.6 ml of water was added dropwise over 5 minutes while maintaining the liquid temperature at 4.5 to 7°C, and then stirred at the same temperature for 30 minutes. Next, the above tetrazotized solution was added to a solution in which 10.57 g (0.0525 mol) of 3-hydroxy-naphthalene-2-carboxylic acid methylamide and 16.8 g (0.42 mol) of caustic soda were dissolved in 420 ml of water while keeping the liquid temperature at 4 to 10°C. was added dropwise over 10 minutes, stirred at the same temperature for 2 hours, and then left overnight. After filtering, washing with water and drying, the dried pigment was soaked in methyl ethyl ketone for 2.0 hours.
13.1g (yield 79.8%) was obtained. Elemental analysis: Calculated value (%) Experimental value (%) C 73.15 72.96 H 4.31 4.28 N 12.80 13.01 Synthesis example 3 (Synthesis of disazo pigment No. 5 illustrated above) 2 Pour 700 ml of water into a beaker, and add 21 g of caustic soda into it. (0.53 mol) was added and dissolved, 3-
Hydroxy-naphthalene-2-carboxylic acid-N,
N-diphenylhydrazide 21.6g (0.061mol)
was added and dissolved. This coupler solution was cooled to 6°C, and the liquid temperature was adjusted to 6°C.
Synthesis Example 1 described above while controlling the temperature to ~10℃
30% of the tetrazotized solution prepared by the same method as
The mixture was added dropwise over several minutes with stirring, then stirred at room temperature for 2 hours, and further left overnight. After filtering the reaction solution, it was washed with water to obtain 25.8 g of a crude pigment. Next, 400ml of N,
Heating with N-dimethylformamide was repeated five times. After that, 24.6g of purified pigment was purified by heat drying under reduced pressure.
I got it. The yield was 88.2%. Elemental analysis: Calculated value (%) Experimental value (%) C 77.31 77.41 H 4.40 4.31 N 11.64 11.62 The synthesis methods of the three types of pigments have been described above.
Other disazo pigments represented by general formula (1) are also synthesized in the same manner. In a preferred application of the organic photoconductor of the present invention,
The organic photoconductor represented by the general formula (1) can be used as the charge generating substance 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 of the organic photoconductor as possible in order to obtain sufficient absorbance, and in order to shorten the range of the generated charge carriers,
Thin film layer, e.g. less than 5 microns, preferably 0.01
It is preferable to form a thin film layer having a thickness of micron to 1 micron. This means that most of the incident light is absorbed by the charge generation layer and generates a large number of charge carriers, and that the generated charge carriers are not deactivated by recombination or trapping, and the charge transport layer This is due to the need to inject. The charge generation layer can be formed by dispersing the above-mentioned organic photoconductor in a suitable binder and coating it on the substrate, or by forming a deposited film using a vacuum deposition apparatus. be able to. Binders 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.), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide resin, polyamide, polyvinylpyridine, cellulose resin, urethane Examples include insulating resins such as resin, 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 or undercoat layer described below. Specific organic solvents include alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, N,N-dimethylformamide,
Amides such as N,N-dimethylacetamide,
Sulfoxides such as dimethyl sulfoxide, ethers such as tetrahydrofuran, dioxane, and ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, aliphatic halogens such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, and trichloroethylene. Hydrocarbons or aromatics such as benzene, toluene, xylene, ligroin, monochlorobenzene, dichlorobenzene, etc. can be used. Coating can be carried out using coating methods such as dip coating, spray coating, spinner coating, bead coating, Meyer bar coating, blade coating, roller coating, and curtain coating. For drying, it is preferable to dry to the touch at room temperature and then heat dry. Heat drying at a temperature of 30℃ to 200℃ for 5 minutes to 2
It can be carried out stationary or under blown air for a period of time within a range of hours. The charge transport layer is electrically connected to the charge generation layer described above, and has the function of receiving charge carriers injected from the charge generation layer in the presence of an electric field and transporting these charge carriers to the surface. ing. At this time, this charge transport layer may be laminated on or under the charge generation layer. However, it is desirable that the charge transport layer is laminated on the charge generation layer. Since the photoconductor generally has the function of transporting charge carriers, the charge transport layer can be formed by the photoconductor. The substance that transports charge carriers in the charge transport layer (hereinafter simply referred to as charge transport substance) is preferably substantially insensitive to the wavelength range of electromagnetic waves to which the charge generation layer is sensitive. The term "electromagnetic waves" used herein includes a broad definition of "light rays" that includes gamma rays, X-rays, ultraviolet rays, visible light, near infrared rays, infrared rays, far infrared rays, and the like. 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 capture each other, resulting in a decrease in sensitivity. Charge transport substances include electron transport substances and hole transport substances, and electron transport substances include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, and 2,4,7-trinitro-9-fluorenone. , 2, 4, 5, 7-
Tetranitro-9-fluorenone, 2,4,7-
trinitro-9-dicyanomethylenefluorenone, 2,4,5,7-tetranitroxanthone,
Examples include electron-withdrawing substances such as 2,4,8-trinitrothioxanthone, and polymerized versions of these electron-withdrawing substances. Examples of hole-transporting substances include 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-ethylphenothiazine,
N,N-diphenylhydrazino-3-methylidene-10-ethylphenoxazine, P-diethylaminobenzaldehyde-N,N-diphenylhydrazone, P-diethylaminobenzaldehyde-N
-α-naphthyl-N-phenylhydrazone, P-
Pyrrolidinobenzaldehyde-N,N-diphenylhydrazone, 1,3,3-trimethylindolenine-ω-aldehyde-N,N-diphenylhydrazone, P-diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone hydrazones such as 2,5-bis(P-diethylaminophenyl)-1,3,4-oxadiazole, 1
-Phenyl-3-(P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, 1-[quinolyl(2)]-3-(P-diethylaminostyryl)-5-(P-diethylaminophenyl) Pyrazoline, 1-[pyridyl (2)]-3
-(P-diethylaminostyryl)-5-(P-
diethylaminophenyl) pyrazoline, 1-[6
-Methoxy-pyridyl(2)]-3-(P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, 1-[pyridyl(3)]-3-
(P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, 1-[Lepidil (2)]-3-(P-diethylaminostyryl)
-5-(P-diethylaminophenyl)pyrazoline, 1-[pyridyl(2)]-3-(P-diethylaminostyryl)-4-methyl-5-(P-diethylaminophenyl)pyrazoline, 1-[pyridyl
(2)〕-3-(α-methyl-P-diethylaminostyryl)-5-(P-diethylaminophenyl)
Pyrazoline, 1-phenyl-3-(P-diethylaminostyryl)-4-methyl-5-(P-diethylaminophenyl)pyrazoline, 1-phenyl-3-(α-benzyl-P-diethylaminostyryl)-5-( P-diethylaminophenyl) pyrazoline, spiropyrazoline and other pyrazolines, 2-(P-diethylaminostyryl)-6-
Diethylaminobenzoxazole, 2-(P-
diethylaminophenyl)-4-(P-dimethylaminophenyl)-5-(2-chlorophenyl)
Oxazole compounds such as oxazole, 2-
Thiazole compounds such as (P-diethylaminostyryl)-6-diethylaminobenzothiazole, triarylmethane compounds such as bis(4-diethylamino-2-methylphenyl)-phenylmethane, 1,1-bis(4-N,N- diethylamino-2-methylphenyl)heptane, 1,
Polyarylalkanes such as 1,2,2-tetrakis(4-N,N-dimethylamino-2-methylphenyl)ethane, triphenylamine, poly-
N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polyvinylacridine,
Examples include poly-9-vinylphenylanthracene, pyrene-formaldehyde resin, and ethylcarbazole formaldehyde resin. In addition to these organic charge transport materials, inorganic materials such as selenium, selenium-tellurium amorphous silicon, and cadmium sulfide can also be used. Moreover, these charge transport substances may be one or two types.
More than one species can be used in combination. When the charge transport material does not have film-forming properties,
A film can be formed by selecting an appropriate binder. Resins that can be used as binders are:
For example, insulating resins such as acrylic resin polyarylate, polyester, polycarbonate, polystyrene acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer, polyvinyl butyral, polyvinyl formal, polysulfone, polyacrylamide, polyamide, chlorinated rubber, or poly-N-vinyl carbazole. , polyvinylanthracene, polyvinylpyrene, and the like. Since the charge transport layer has a limit in its ability to transport charge carriers, it cannot be made thicker than necessary. Typically it is between 5 microns and 30 microns, with a preferred range between 8 microns and 20 microns. When forming the charge transport layer by coating, an appropriate coating method as 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. As the substrate having the conductive layer, materials that are themselves conductive can be used, such as aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold, and platinum. In addition, plastics (e.g., polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, polyethylene fluoride, etc.), conductive particles (e.g. carbon black,
A substrate made of plastic coated with silver particles (silver particles, etc.) together with a suitable binder, a substrate made of plastic or paper impregnated with conductive particles, a plastic containing a conductive polymer, etc. can be used. A subbing layer having barrier and adhesive functions can also be provided between the conductive layer and the photosensitive layer. The undercoat layer is made of 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 thickness of the undercoat layer is 0.1 micron to 5 micron.
Preferably, 0.5 micron to 3 micron is appropriate. 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, and exposure after charging is required. Then, in the exposed area, electrons generated in the charge generation layer are injected into the charge transport layer, and then reach the surface and neutralize the positive charge, causing a decrease in surface potential and creating an electrostatic contrast with the unexposed area. . A visible image can be 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, plastic film, etc. 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 known methods, and are not limited to specific ones. On the other hand, when the charge transport material consists of a hole transport material, the surface of the charge transport layer must be negatively charged.
After charging, when exposed to light, holes generated in the charge generation layer in the exposed area are injected into the charge transport layer, and then reach the surface and neutralize the negative charge, causing a decrease in the 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 the case where an electron transport material is used. Another application example of the present invention is an electrophotographic photoreceptor in which the above-described organic photoconductor is contained in the same layer together with a charge transport material. On this occasion,
In addition to the charge transport materials mentioned above, a charge transport complex compound consisting of poly-N-vinylcarbazole and trinitrofluorenone can be used. The electrophotographic photoreceptor of this example can be prepared by dispersing the aforementioned organic photoconductor and charge transfer complex compound in a polyester solution dissolved in tetrahydrofuran, and then forming a film thereon. In any of the photoreceptors, the pigment used contains at least one type of pigment selected from the disazo pigments represented by the general formula (1), and if necessary, pigments with different light absorptions are used in combination. For the purpose of increasing the photoreceptor or obtaining a panchromatic photoreceptor, two or more types of disazo pigments represented by general formula (1) are used in combination, or in combination with a charge-generating substance selected from known dyes and pigments. It is also possible to do so. The electrophotographic photoreceptor containing the organic photoconductor 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. Further, the organic photoconductor of the present invention can also be used in solar cells and optical sensors in addition to the above-mentioned electrophotographic photoreceptor. Solar cells can be prepared, for example, by sandwiching the aforementioned organic photoconductors with indium oxide and aluminum. Hereinafter, the present invention will be specifically explained using application examples. Example 1 Ammonia aqueous solution of casein (11.2 g of casein, 1 g of 28% ammonia water, 222 ml of water) on an aluminum plate.
was applied with a Mayer bar so that the film thickness after drying was 1.0 microns, and dried. Next, 5 g of the organic photoconductor of disazo pigment No. 1 illustrated above was added to a solution prepared by dissolving 2 g of butyral resin (degree of butyralization: 63 mol %) in 95 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 microns.
It was dried to form a charge generation layer. Then, the structural formula 5 g of hydrazone compound and 5 g of polymethyl methacrylate resin (number average molecular weight 100,000) were added to benzene.
The solution was dissolved in 70 ml and applied onto the charge generation layer using a Mayer bar so that the film thickness after drying was 12 microns, and dried to form a charge transport layer. The electrophotographic photoreceptor thus prepared was statically charged with corona at -5 KV using an electrostatic copying paper tester Model SP-428 manufactured by Kawaguchi Electric Co., Ltd.
After keeping it in the dark for 10 seconds, it was exposed to light at an illuminance of 5 lux to examine the charging characteristics. As for the charging characteristics, the surface potential (V ₀ ) and the exposure amount (E _1/2 ) required to attenuate the potential to 1/2 when dark decaying for 1 second were measured. Furthermore, in order to measure the fluctuations in bright area potential and dark area potential during repeated use, the photoreceptor fabricated in this example was charged with a -5.6 KV corona charger and exposed to 12 lux.
It was attached to the cylinder of an electrophotographic copying machine equipped with a sec exposure optical system, a developing device, a transfer charger, a static elimination exposure optical system, 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 (V _L ), dark area potential (V _D ) and 5000
Light potential (V _L ) and dark potential (V _D ) after multiple uses
was measured. The results are shown below. V ₀ : -605 volts E _1/2 : 5.2lux.sec Initial After 5000 cycles V _D : -610 volts, V _L : -25 volts
V _D : -595 volts, V _L : -40 volts Examples 2 to 14 Completely the same as Example 1 except that the disazo pigments Nos. 2 to 14 as illustrated above were used in place of the disazo pigments used in Example 1. An electrophotographic photoreceptor was prepared using the method. The charging characteristics and durability characteristics of each photoreceptor were measured in the same manner as in Example 1. These results are shown below.

【table】

[Table] Example 15 On the charge generation layer created in Example 1, 2, 4, 7
-Trinitro-9-fluorenone 5g and poly-
A coating solution prepared by dissolving 5 g of 4,4'-dioxydiphenyl-2,2-propane carbonate (molecular weight 300,000) in 70 ml of tetrahydrofuran was applied ^so that the coating amount after drying was 10 g/m2. , dried. The electrostatic charge of the electrophotographic photoreceptor thus prepared was measured in the same manner as in Example 1. At this time, the charging polarity was set. The results are shown below. V ₀ : +610 volts E _1/2 : 6.0lux.sec Initial dark potential V _D : +600 volts Initial light potential V _L : +55 volts Dark potential after 5000 cycles V _D : +590 volts Light area after 5000 cycles Potential V _L : +60 volts Example 16 A polyvinyl alcohol film with a thickness of 1.1 microns was formed on the aluminum surface of an aluminum vapor-deposited polyethylene terephthalate film. Next, the disazo pigment dispersion used in Example 1 was applied onto the previously formed polyvinyl alcohol layer using a Mayer bar so that the film thickness after drying was 0.5 microns, and dried to form a charge generation layer. Formed. Then, the structural formula A solution prepared by dissolving 5 g of pyrazoline compound and 5 g of polyarylate resin (condensation polymer of bisphenol A and terephthalic acid-isophthalic acid) in 70 ml of tetrahydrofuran is placed on the charge generation layer so that the film thickness after drying is 10
It was applied to a micron thickness and dried to form a charge transport layer. The charging characteristics and durability characteristics of the photoreceptor thus prepared were measured in the same manner as in Example 1. The results are shown below. V ₀ : -580 volts E _1/2 : 4.5lux.sec Initial dark potential V _D : -610 volts Initial light potential V _L : -25 volts Dark potential after 5000 cycles V _D : -600 volts 5000 cycles Later bright area potential V _L : -35 volts Example 17 An ammonia aqueous solution of casein was applied onto an aluminum plate with a thickness of 100 microns and dried to form a subbing layer with a thickness of 1.1 microns. Next, 5 g of 2,4,7-trinitro-9-fluorenone and 5 g of poly-N-vinylcarbazole (number average molecular weight 300,000) were added to 70 ml of tetrahydrofuran.
to form a charge transfer complex. This charge transfer complex compound and 1 g of the photoconductor of disazo pigment No. 1 mentioned above were mixed with polyester resin (Vylon:
Toyobo Co., Ltd.) 5g was dissolved in 70ml of tetrahydrofuran and dispersed. This dispersion was applied onto the undercoat layer so that the film thickness after drying was 12 microns, and dried. The charging characteristics and durability characteristics of the photoreceptor thus prepared were measured in the same manner as in Example 1. The results are shown below. However, the charging polarity was determined. V ₀ : +610 volts E _1/2 : 5.4lux.sec Initial dark potential V _D : +595 volts Initial light potential V _L : Dark potential after 5000 cycles of +50 volts V _D : Light potential after 5000 cycles of +580 volts Potential V _L : +50 volts

Claims (1)

[Claims] 1. An organic photoconductor represented by the following general formula (1). However, in the formula, A represents a coupler component having aromaticity.