JPS62280851A - Organic photoconductor and electrophotographic sensitive body using said photoconductor - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body having a practicable high sensitivity characteristic and stable potential characteristic in repetitive use by using a specific org. photoconductor. CONSTITUTION:A photosensitive layer contg. the org. photoconductor expressed by the formula is provided on a conductive base. In the formula, R1 denotes a substd. or unsubstd. aralkyl group, etc., R11, R12 respectively denote a hydrogen atom, etc., and A denotes a coupler component having an arom. characteristic. Said disazo pigments are usable by combining 1 or >=2 kinds and are synthesized by tetrazonizing diamine and subjecting the corresponding coupler to a coupling, etc., in the presence of an alkali. The photosensitive layer is functionally separated to an electric charge generating layer and charge transfer layer and the org. photoconductor expressed by the formula is used for the charge generating material. The charge generating layer contains the org. photoconductor as much as possible in order to have substantial light absorptivity and is made into the thinner film layer in order to shorten the range of the generated charge carrier.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a novel organic photoconductor and an electrophotographic photoreceptor using the same.

[Conventional technology]

Electrophotographic photoreceptors using inorganic photoconductors such as selenium, cadmium sulfide, and zinc oxide as photosensitive components have been known so far.

On the other hand, since it was discovered that certain organic compounds exhibit photoconductivity, many organic photoconductors have been developed. For example, organic phototetraelectric materials such as polyJ + N-vinylcarbazole and polyvinylanthracene are known.

Electrophotographic photoreceptors using such organic photoconductors can be produced by coating by appropriately selecting a binder, so they are extremely productive and can be provided at low cost.Moreover, by selecting organic pigments, the photosensitive wavelength can be adjusted. Although this photoreceptor has the advantage of being able to freely control the area, it has problems with sensitivity and durability, so the ones that have been put into practical use so far are
Very little.

[Purpose and outline of the invention]

An object of the present invention is to provide an i-order organic photoconductor.

Another object of the present invention is to provide an electrophotographic photoreceptor with improved photographic properties through the use of a specific organic photoconductor, which provides practical high-sensitivity properties and repeatability. An object of the present invention is to provide an electrophotographic photoreceptor having stable first-position characteristics during use.

The above objects of the present invention are achieved by an organic photoconductor represented by the following general formula CD.

In the formula, R1 represents a substituted or unsubstituted alkyl group, aralkyl group, aryl group, multi-ring group, or amino group, specifically, an alkyl group such as methyl, ethyl, propyl, etc.
Hydroxyalkyl groups such as hydroxymethyl and hydroxyethyl, alkoxyalkyl groups such as methoxymethyl, ethoxymethyl and ethoxyethyl, cyanoalkyl groups,
aminoalkyl group, N-alkylaminoalkyl group,
N,N-soalkylamine alkyl groups, halogenated alkyl groups, aralkyl groups such as benzyl and phenethyl, phenyl groups and substituted phenyl groups, naphthyl groups and substituted naphthyl groups, pyridine, quinoline, pe/dioxazole, pe/
Monovalent heterocyclic groups such as dithiazole, benzimidazole, benzotriazole, dibenzofuran, and carbazole (substituents include alkyl groups such as methyl, ethyl, and propyl, alkoxy groups such as methoxy, ethoxy7, and globoxy, chlorine, bromine, Examples include halogen atoms such as iodine, nitro groups, and substituted amine groups such as trimethylamino)
Examples include substituted amine groups such as trimethylamino and noethylamino. Further, R and R each represent a hydrogen atom, a halogen atom, a cyan group, an alkyl group, or an alkoxy group. A represents a coupler component having aromatic properties, and is preferably selected from coupler components represented by the following general formulas [■] to CIV).

In general formula (II), Y represents a residue forming an aromatic hydrocarbon ring or a heterocycle such as a naphthalene ring, anthracene ring, carbazole ring, nobenzofuran ring, benzocarbazole ring, quinoline ring, inquinoline ring, etc. Represents a group selected from the group consisting of groups represented by the following general formulas (,) to (,).

(a) -CONR2R3 (b) -CONHNR4R5 (c) -CONHN=CH-Ar In the general formula (&), R2 is a hydrogen atom, methyl, ethyl, propyl, butyl, 2-hydroxyethyl, 3-hydroxypropyl, etc. A group selected from the group consisting of substituted or unsubstituted alkyl groups, aryl groups such as phenyl and naphthyl, R31d methyl, ethyl, propyl, butyl, 2-
It represents a group selected from the group consisting of substituted or non-tm alkyl groups such as hydroxyethyl and 3-hydroxypropyl, aryl groups such as phenyl and naphthyl, and heterocyclic residues such as pyrinol, quinolyl, carbaglyl and thiagylyl.

In the general formula (b), R4, R, represents a substituted or unsubstituted aryl group such as phenyl or naphthyl. Examples of substituents in R2 to R5 above include alkyl groups such as methyl and ethyl, halogen atoms such as fluorine, chlorine, and bromine, alkoxy groups such as methoxy and ethoxy, acetyl,
Acyl groups such as benzoyl, alkylthio groups such as methylthio and ethylthio, arylthio groups such as phenylthio, aryl groups such as phenyl, aralkyl groups such as benzyl, nitro groups, cyano groups, trimethylamino, diethylamino,
Examples include substituted amine groups such as dipenolamino and ethylamino. In the general formula (c), Ar represents a group selected from the group consisting of a phenyl group, a naphthyl group, an anthryl group, a pyridyl group, a chenyl group, a furyl group, and a carbazolyl group, which may have a substituent. In general formula (d), R
6 and R7 each represent an alkyl group or an aryl group which may have a substituent. General formula (,) represents a heterocyclic group.

Substituents for Ar in general formula (c) include alkyl groups such as methyl and ethyl groups; alkoxy groups such as methoxy and ethoxy groups; acyl groups such as acetyl and benzoyl groups; alkyl groups such as trimethylamine and diethylamino groups. Examples include amino group; alkyl ester group such as methyl ester group and ethyl ester group; phenyl ester group; phenylcarbamoyl group; nitro group; cyano group. Ar may have two or more of these substituents, and in this case, the substituents may be the same or different. Examples of the substituents for R6 and R in general formula (d) include the substituents for Ar represented by general formula (c). General formula (,
) may have a substituent, and the substituent is the general formula (c
) and the like can be mentioned.

General formulas [■] and [■] are represented by 8R8. In the formula, R8t-1 represents a group consisting of a substituted or unsubstituted aryl group such as an argyl group, a phenyl group, or a naphthyl group. More specifically, U and R8 are alkyl groups such as methyl, ethyl, and propyl, hydroxyalkyl groups such as hydroquinemethyl and hydroxyethyl, alkoxyalkyl groups such as methoxymethyl, ethoxymethyl, and ethoxyethyl, cyanoalkyl groups, and aminoalkyl groups. groups, N-alkylaminoalkyl groups, N,N-dialkylaminoalkyl groups, halogenated alkyl groups, aralkyl groups such as benzyl and phenethyl, phenyl groups and substituted phenyl groups, naphthyl groups, substituted naphthyl groups, (substituents include Examples include substituents at R2-R5 in general formula [■]).

[Detailed description and examples of the invention]

Typical organic photoconductors of the present invention include the following cis-sazo pigments.

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Although more than 20 types of compounds are illustrated, the organic photoconductor of the present invention is not limited thereto.

These disazo pigments can be used alone or in combination of two or more. In addition, these pigments can be obtained by, for example, tetrazotizing a diamine represented by the general formula (81 in the formula has the same meaning as 81 in the general formula [l]) by a conventional method, and then converting the corresponding coupler in the presence of an alkali. or once the tetrazonium salt of the diamine is isolated in the form of borofluoride salt or zinc chloride double salt, etc., a suitable solvent such as N,N-trimethylformamide, trimethylsulfoxide, etc. It can be easily produced by stirring in the presence of an alkali in the presence of an alkali.

Next, a typical synthesis example of the cis-sazo pigment used in the present invention is shown below.

Synthesis Example 1 (Synthesis of the above-exemplified cis-sazo pigment) version 1) 3
In a 00d beaker, add 150 itJ of water and 11.3 liters of concentrated hydrochloric acid (0
, 019 mol) and stirred while cooling on ice water.
The liquid temperature was 3°C. Next, nitrous acid nug 2, 75 f! (
0,040%) in 5 liters of water! The solution dissolved in tl was added dropwise over 10 minutes while controlling the liquid temperature within the range of 5 to 10°C, and after the dropwise addition was completed, the mixture was further stirred at the same temperature for 30 minutes. Carbon was added to the reaction solution and filtered to obtain a tetrazotized solution.

Next, put 500 tnl of water into one beaker and dissolve 14.1F (CO, 354 mol) of caustic soda. ,040 mol) was added and dissolved.

This coupler solution was cooled to 5° C., and while controlling the liquid temperature at 5 to 10° C., the above-mentioned tetrazotized solution was added dropwise with stirring over 30 minutes, and then stirred at room temperature for 2 hours. The reaction solution was filtered and washed with water to obtain 14.0 g of a crude pigment. Next, 30
After washing with 0rILl N,N-dimethylformamide 5 times and replacing with acetone, the purified pigment 1 was dried under reduced pressure at room temperature.
3.21i was obtained. The yield was 85.2%.

Elemental analysis calculated value (%) Experimental value (%) C72,1371,98 H4,084,22 N 12.02 12.
18 Synthesis Example 2 (Synthesis of the exemplified disazo pigment &2)
150g, concentrated hydrochloric acid 9.2 +nl (0,104 mol)
Sodium nitrite 2.46.9 (0.03
A solution prepared by dissolving 57 mol) of water in 5 g of water was added dropwise over 10 minutes while keeping the liquid temperature at 0 to 5°C, and then stirred at the same temperature for 30 minutes and poured into 7 cars. Add 5.6% of sodium borofluoride to this solution.
:I (0,055 mol) dissolved in 5Qd of water was dissolved in 30
It was isolated as a tetrazotated borofluoride salt of the above noamine and washed twice with cold water. Borofluoride salt yield 6.731 (80.0%) DMF in 11 beakers
500 g was added to make a solution, and after bringing the liquid temperature to 'a-10°C, 5.0.9 (0.01 mol) of the borofluoride salt synthesized earlier was added, stirred and dissolved, and then 1.9.9 mol of sodium acetate was added. (0,0233
2 moles) dissolved in 5 d of water was added dropwise over 5 minutes.
The pigment was mixed by stirring for several hours. The obtained pigment was socked with MF and purified. : After 10 hours, the mixture was replaced with acetone and dried under reduced pressure. Yield 8.5y (Yield 92
．． 9%) Elemental analysis calculated value (%) Experimental value (%) C65,6465,42 I (3,643,81 N 10.72 10.74CL
7.75 7.86 Although the methods for synthesizing two types of pigments have been described above, other disazo pigments represented by general formula [I] can be synthesized in the same manner.

In a preferred embodiment of the present invention, the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer, and the organic photoconductor represented by the general formula (1) can be used as the charge generation substance.

The charge generation layer contains as much of the organic photoconductor as possible in order to obtain sufficient absorbance and is preferably a thin film layer, for example less than 5 microns, in order to shorten the range of the generated charge carriers. It is desirable to form a thin film layer having a thickness of 0.01 micron to 1 micron. This is due to the need to generate a large number of charge carriers and to inject the generated charge carriers into the charge transport layer without being deactivated by recombination or capture (drag).

The charge generating layer can be formed by dispersing the above-mentioned organic photoconductor in a suitable binder and coating it on the substrate, or can be obtained by forming a deposited film using a vacuum deposition apparatus. .

The binder can be selected from a wide range of insulating resins and organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene and polyvinylpyrene. Preferably, polyvinyl butyral, polyarylate (condensation polymer of bisphenol A and heptalic acid, etc.) polycargonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide resin, polyamide, polyvinylpyrinone, cellulose IIUW, Urethane resin, epoxy resin, casein, polyvinyl alcohol, polyvinyl P resin contained in the charge generation layer is 80% by weight or less, preferably 40% by weight. i
ii% or less is suitable.

The solvent that dissolves these resins varies depending on the type of resin, and it is preferable to select a solvent that does not dissolve the underlying charge transport layer or subbing layer. Specific organic solvents include alcohols such as methanol, ethanol, and inglobil alcohol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, N,N-dimethylformamide,
Amides such as N,N-trimethylacetamide, sulfoxides such as dimethyl sulfoxide, tetrahydro7
ethyl ether, esters such as methyl acetate, ethyl acetate, aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, trichlorethylene, etc. Aromatics such as benzene, toluene, xylene, ligroin, monochlorobenzene, dichlorobenzene, etc. can be used.

This can be done using coating methods such as coating evaporation, dip coating, spray coating, spinner coating, heat r-ting, Mayer bar coating, Fleid 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 or more
It can be carried out stationary or under ventilation for a period of 2 hours.

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 or under the charge generation layer. However, it is desirable that the charge transport layer is laminated on the charge generation layer.

Since a photoconductor generally has the function of transporting charge carriers, a charge transport layer can be formed by using this 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" as used herein includes a broad definition of "light rays" that includes gamma rays, X-rays, ultraviolet rays, visible light, near infrared rays, infrared rays, 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 trap 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, tetracyanoquino dimethane, and 2.4.7-trinitro-9-fluorenone. ,
2,4,5.7-tetranitro-9-fluorenone, 2
．． 4.7-trinitro-9-nocyanomethylenefluorenone, 2,4,5.7-titranitroxanthone, 2
+418-)! Examples include electron-withdrawing substances such as j-nitrothioxant 7 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-diphenylhydrano-3-methylidene-10-ethylphenothiazine, N, N-diphenylhydrazino-3-methylidene-10-ditylphenoxanone, P-zoethylaminopenzaldehyde N, N-zophenylhydrazone,
P-zoethylaminopenzaldehyde N-α-naphthyl-N-7enylhydrazone, P-pyrrolidinobenzaldehyde-N,N-diphenylhydrazone.

11313- Trimethylindolenine-ω-aldehyde-N,N-diphenylhydrazo 7, P-diethyl 4-benzaldehyde 3-methylbenzthiazolinone-2-
Hydrazones such as hydrazone, 2,5-bis(p-diethylaminophenyl)-1,3,4-odF"j-)
7sol, 1-phenyl-3-(P-diethylaminosteryl)-5-(P-diethylaminophenyl)pyrazoline, ni[quinolyl(2))-3-(P-diethylaminostyryl)-5-(P-diethylamino phenyl)pyrazoline, 1-[pyridyl(2):] -3-(
P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, 1-[6-medoxypyrinol(2))-3-(P-diethylaminostyryl)-
5-(P-diethylaminophenyl)pyrazoline, 1-
[Pyridyl (3)) -3-(P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, 1-[Lepidyl (2):] -3-(P-・
diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, 1-[pyrinol(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--,'ethylaminophenyl)pyrazoline, spirobidizoline, etc. Pyrazoli/s, 2-(P-diethylaminostyryl)-6-diethylaminobenzoxazole, 2-(P-diethylaminostyryl)-6-diethylaminobenzoxazole,
Oxazole compounds such as -diethylaminephenyl)-4-(P-dimethylaminophenyl)-5-(2-chlorophenyl)oxazole, thiazole compounds such as 2-(P-diethylaminostyryl)-6-dinithylaminopenzothiazole Compound, bis(4-diethylamino-2
triarylmethane compounds such as -methylphenyl)-phenylmethane, 1.1-bis(4-N,N-diethylamino-2-methylphenyl)hebutane, 1.1,2
．． 2-tetrakis(4-N,N-dimethylamino-2-
polyarylalkane such as methylphenyl)ethane,
Examples include triphenylamine, poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polyvinylacrysine, poly-9-vinylphenylanthracene, pyrene-formaldehyde resin, ethylcarbazole formaldehyde resin, and the like.

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

Further, these charge transport substances can be used alone 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. Resins that can be used as binders include, for example, acrylic resin polyarylate, polyester, polycarbonate, polystyrene acrylonitrile styrene copolymer, acrylonitrile-butadiene copolymer, polyvinyl butyral, polyvinyl formal, polysulfone, polyacrylamide, polyamide, insulating rubber such as chlorinated rubber. Examples include resins, organic photoconductors such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, and 41J-mer.

Since the charge transport layer has a limit in its ability to transport charge carriers, it cannot be made thicker than necessary. Generally, the range is 5 microns to 30 microns, with a preferred range of 8 microns to 20 microns. When forming the charge transport layer by coating, an appropriate coating method can be used as described above.

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. Guide tS
Substrates that have conductivity include those that have conductivity themselves;
For example, aluminum, aluminum alloy, copper, zinc, stainless steel, pananoum, molybdenum, chromium, titanium,
2. Plasti, which can use metal, indium, gold, platinum, etc., and has a layer formed by vacuum deposition of aluminum, aluminum alloy, indium oxide, tin oxide, indium oxide-tin oxide alloy, etc.; (e.g., polyethylene, polypropylene, polyvinyl chloride, ethylene terephthalate, acrylic resin, poly7tethylene, etc.), conductive particles (e.g., carnon black, silver particles, etc.) are placed on top of the plastic with a suitable binder. Coated substrates, substrates impregnated with conductive particles in plasti, glue or paper, plastics with conductive polymers, 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 lower layer, the force,
Polyvinyl alcohol, nitrocellulose, ethylene-
Acrylic acid copolymer, polyamide (nylon 6, nylon 66, nylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, gelatin,
It can be formed from aluminum oxide, aluminum, etc.

The thickness of the undercoat layer is suitably 0.1 micron to 5 micron, preferably 0.5 micron to 3 micron.

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, reaching the surface and neutralizing the positive charge, causing a decrease in surface potential and creating an electrostatic contrast between it and the unexposed area. arise. 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, and then visually imaged and fixed. The type of developer, developing method, and fixing method may be any known ones, and are not limited to any specific ones.

On the other hand, when the charge transport material consists of a hole transport material, it is necessary to negatively charge the surface of the charge transport layer, and when exposed to light after charging, holes generated in the charge generation layer are injected into the charge transport layer in the exposed area. , which then reaches the surface and neutralizes the negative charges, resulting in attenuation of the surface potential and an electrostatic contrast between the surface potential and the unexposed area.

During development, it is necessary to use a positively charged toner, contrary to the case where an electron transport material is used.

Another specific example of the present invention is an electrophotographic photoreceptor in which the above-mentioned organic photoconductor is contained in the same layer together with a charge transport material. At this time, a charge transfer complex compound consisting of BoIJ-N-vinylcarba:/'-#totrinitrofluorenone can be used in addition to the charge transport substance described above.

The electrophotographic photoreceptor of this example can be prepared by dispersing the organic photoconductor and charge transfer complex compound in a polyester solution dissolved in tetrahydrofuran to form a film.

In any photoreceptor, the pigment used is of the general formula (1)
The sensitivity of the photoreceptor is increased by containing at least one type of pigment selected from the disazo pigments shown in the following, and pigments with different light absorptions are used in combination as necessary. For this purpose, it is also possible to use a combination of two or more disazo pigments represented by the general formula (1)9, or a charge generating substance selected from known dyes and 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.

Furthermore, 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 produce the aforementioned organic light '4iI!' using, for example, indium oxide and aluminum. It can be prepared by sandwiching the body.

Hereinafter, the present invention will be explained according to examples.

Example 1 Ammonia aqueous solution of casein (casein 1
1.2g of 28% ammonia water (Ig, water 222M) was applied using a Mayer Parr so that the film thickness after drying would be 1.0 microns, and dried.

Next, an organic photoconductor 5y of the above-mentioned disazo pigment A1
was added to a solution prepared by dissolving 2 g of butyral resin (degree of butyralization: 63 mol %) in 95 ml of tetrahydrofuran, and dispersed with an attritor for 10 hours. This dispersion was applied onto the previously formed casein layer using a Mayer Par so that the film thickness after drying would be 0.3 microns, and dried to form a charge generation layer.

Next, 5 g of a hydrazone compound having the structural formula and 5 f! of polymethyl methacrylate resin (number of molecules zlOO, OOo) were dissolved in 73 m of benzene, and this was placed on the charge generation layer so that the film thickness after drying was 12 microns. A charge transport layer was formed by applying the same coating using Mayer Per and drying.

The electrophotographic photoreceptor thus prepared was statically charged with corona at -5 kV using an electrostatic copying paper tester Mod@l SP-428 manufactured by Kawaguchi Electric Co., Ltd., and held in a dark place for 1 second. It was exposed to light at an illuminance of 5 tux and the charging characteristics were examined.

As for charging characteristics, the surface potential (vo) and the amount of exposure (-) required to attenuate the potential when dark decayed for 1 second were measured.

Furthermore, in order to measure the fluctuations in bright area potential and dark area potential when repeatedly used, the photoreceptor prepared in this example was
, a 6 kV corona charger, an exposure optical system with an illuminance of 5 tux, 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 (vL) and dark area potential (VD) and the bright area potential (vL) and dark area potential (VD) after 5000 uses were measured. The results are shown below.

V0 Knee 600 gelt Ey: 2.5 lux, see early
V knee after 5000 cycles 605. Nruto
VD Knee 595 & Ruto V Knee 11071 + #Ruto VL Knee 120 & Ruto Examples 2 to 20 Same as Example 1 except that the disazo pigment shown in Table 3 was used in place of the disazo pigment used in Example 1. An electrophotographic photoreceptor was prepared using the method described above.

The charging characteristics and durability characteristics of each photoreceptor were measured in the same manner as in Example 1. These results are shown below.

Example 21 On the charge generation layer prepared in Example 1, 5 g of 2.4.7-dolinitro-9-fluorenone and poly-4,4'-cyoxyzophenyl-2,2'-propanecargenate (
A coating solution prepared by dissolving 5ji (molecular weight: 300,000) in 70'Itl of tetrahydrofuran was applied to give a coating weight of 1097 m 2 after drying, and 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 to medium. The results are shown below.

VD: +610 Built Ey2: 3.5 ]ux, sec early
V after 5000 cycles: +60CJMk
V. : +575 N Volt V : +200 Volt V, : +220 Galt Example 22 A polyvinyl alcohol film having a thickness of 1.1 microns was entirely formed on the aluminum surface of an aluminum vapor-deposited polyethylene terephthalate film.

Next, the dispersion of the disazo pigment used in Example 1 was applied onto the previously formed polyvinyl alcohol layer using a Mayer perr so that the film thickness after drying was 0.5 microns, dried and charged. A generation layer was formed.

Next, pyrazoline compound 5I of the structural formula and polyarylate resin (condensation polymer of bisphenol and terephthalic acid-isophthalic acid)
A solution obtained by dissolving 5 g of the solution in 7Q+aJ of tetrahydrofuran was applied onto the charge generation layer so that the film thickness after drying would be 10 microns, 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, knee 600 volts Eη: 2.3 minutes 6c Initial After 5ooo cycles'/D: -
605N Ruto VD Knee 590 Porto V,, Knee] 1
5 fult VL knee 130 volts Example 23 An ammonia aqueous layer solution of casein was coated on an aluminum plate with a thickness of 100 microns and dried to form a subbing layer with a thickness of 1.1 microns.

Next, 2,4,7-trinitro-9-fluorenone 5
g $+) -N-vinylcarbazole<number average molecular weight 300,000) 511 was dissolved in 701 Lt of tetrahydrofuran to form a charge transfer complex compound. This charge transfer complex compound and the above-mentioned nosazo pigment A1
1 g of the photoconductor was added to a solution in which 5 g of polyester resin (Vylon; manufactured by Toyobo) was dissolved in 70% of tetrahydrofuran, and dispersed. This dispersion was coated on the entire subbing layer so that the film thickness after drying was 12 microns, and dried.

These prepared photoreceptor strips! The properties and durability were measured by the same method as in Example 1.The results are shown below. However, the charging polarity was set to e.

〔Effect of the invention〕

The electrophotographic photoreceptor using the specific organic photoconductor according to the present invention can exhibit high sensitivity characteristics and stable potential characteristics during repeated use.

Claims (2)

[Claims] (1) Organic photoconductor characterized by being represented by the following general formula [I]: ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] (In the formula, A represents a coupler component having aromaticity. ,
R_1 represents a substituted or unsubstituted alkyl group, aralkyl group, aryl group, heterocyclic group, or amino group. R
_1_1 and R_1_2 each represent a hydrogen atom, a halogen atom, a cyano group, an alkyl group, or an alkoxy group. ) (2) An electrophotographic photoreceptor characterized in that a photosensitive layer containing an organic photoconductor represented by the above general formula [I] is provided on a conductive support: