JPH01200364A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve stability by forming a photosensitive layer contg. a specified bisazo compd. on an electrically conductive support. CONSTITUTION:A photosensitive layer contg. a bisazo compd. represented by formula I is formed on an electrically conductive support. In formula I, each of R1 and R2 is H, halogen, alkyl, alkoxy, nitro, cyano or hydroxy, Z is a group of atoms required to form a carbocyclic arom. ring or a heterocyclic arom. ring, each of X and Y is H, optionally substd. alkyl, optionally substd. aryl or an optionally substd. heterocyclic group, and each of m and an is an integer of 1-3. The stability of the resulting sensitive body at the time of repeated use is improved.

Description

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

[Prior Art 1] Conventionally, as electrophotographic photoreceptors, inorganic photoreceptors having a photosensitive layer mainly composed of an inorganic photoconductive compound such as selenium, zinc oxide, cadmium sulfide, silicon, etc. have been widely used. However, these are not necessarily satisfactory in terms of sensitivity, thermal stability, moisture resistance, durability, etc. for example,
When selenium crystallizes, its properties as a photoreceptor deteriorate, making it difficult to manufacture.Also, selenium crystallizes due to heat, fingerprints, etc., and its performance as a photoreceptor deteriorates.

Furthermore, cadmium sulfide has problems with moisture resistance and durability, while zinc oxide has problems with durability.

In order to overcome these drawbacks of inorganic photoreceptors, research and development have been actively conducted in recent years on organic photoreceptors having photosensitive layers containing various organic photoconductive compounds as main components. For example, Japanese Patent Publication No. 50-10496 describes an organic photoreceptor having a photosensitive layer containing poly-N-vinylcarbazole and 2,4,7-dolinito-0-9-fluorenone. However, this photoreceptor is not necessarily satisfactory in sensitivity and durability. In order to improve these drawbacks, attempts have been made to develop organic photoreceptors with higher performance by assigning the carrier generation function and the carrier transport function to different substances. Many studies have been conducted on such so-called function-separated type photoreceptors because each material can be selected from a wide range and a photoreceptor having arbitrary performance can be produced relatively easily.

[Problems to be Solved by the Invention] Many compounds have been proposed as carrier-generating substances in the functionally separated type photoreceptor as described above.

An example of using an inorganic compound as a carrier generating substance is, for example, amorphous selenium described in Japanese Patent Publication No. 43-16198, which is used in combination with an organic photoconductive compound. The disadvantage that the carrier generation layer crystallizes due to heat and deteriorates the characteristics as a photoreceptor has not been improved.

Furthermore, many electrophotographic photoreceptors using organic dyes or organic pigments as carrier-generating substances have been proposed. For example, as electrophotographic photoreceptors containing a bisazo compound in the photosensitive layer, JP-A-54-22834, JP-A-55-73057, JP-A-55-117151, and JP-A-56-46237 are already known. However, these bisazo compounds do not necessarily satisfy the characteristics of sensitivity, residual potential, or stability during repeated use, and the range of selection of carrier transport materials is also limited, which makes them difficult to meet the wide demands of electrophotographic processes. It does not fully satisfy.

[Object of the Invention] An object of the present invention is to provide an electrophotographic photoreceptor containing a specific bisazo compound having excellent carrier generation ability.

Another object of the present invention is to provide high sensitivity and low residual potential.
Furthermore, it is an object of the present invention to provide an electrophotographic photoreceptor with excellent durability whose properties do not change even after repeated use.

Still another object of the present invention is to provide an electrophotographic photoreceptor containing a bisazo compound that can effectively act as a carrier generating substance even in combination with a wide variety of carrier transporting substances.

[Means for Solving the Problems] As a result of extensive research to achieve the above objectives, the present inventors have discovered that a specific bisazo compound can act as an excellent active ingredient for electrophotographic photoreceptors. , has completed the present invention.

That is, the above object of the present invention can be achieved by using an electrophotographic photoreceptor having a photosensitive layer containing a bisazo compound represented by the following general formula [I] on a conductive support.

5-11, knee Umbrella white below.

General Formula [I] [R1 and R2 each represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a nitro group, a cyan group, or a hydrogen atom. However, R1 and R2 may be the same or different.

Z represents an atomic group necessary to form a carbocyclic aromatic ring or a heterocyclic aromatic ring.

X and Y each represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. However, X and Y may be the same or different, and may also work together to form a ring.

Ugly and n represent an integer of 1, 2 or 3, respectively.

] [Specific Structure of the Invention] Examples of the halogen atoms for R1 and R2 in the general formula [I] include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom, and among these, a chlorine atom or a bromine atom is preferred.

The alkyl group for R1 and R2 is preferably a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, such as a methyl group, ethyl group, isopropyl group, [-butyl group, trifluoromethyl group, etc.].

As the alkoxy group of R1 and R2, the number of carbon atoms is 1
-4 substituted/unsubstituted alkoxy groups are preferred, such as methoxy, ethoxy, isopropoxy, [-butoxy, 2-chloroethoxy and the like.

Among the groups R1 and R2, preferred groups are a hydrogen atom, a halogen atom, an alkyl group, and an alkoxy group.

In the general formula [I], Z represents an atomic group necessary to form a carbocyclic aromatic ring or a heterocyclic aromatic ring,
Examples of carbocyclic aromatic rings formed by such atomic groups include substituted and unsubstituted benzene rings and naphthalene rings, and examples of heterocyclic aromatic rings include substituted and unsubstituted benzene rings and naphthalene rings. Examples include a dibenzothiophene ring and a carbazole ring. Among these carbocyclic and heterocyclic aromatic rings, substituted or unsubstituted benzene rings are preferred. Furthermore, these aromatic rings can have a substituent, and examples of the substituent include a halogen atom, an amino group, an alkyl group, and a hydroxy group.

In the general formula [I], X and Y each represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group; Examples of the alkyl group include a methyl group, and examples of the substituted alkyl group include a trifluoromethyl group. Furthermore, examples of the unsubstituted aryl group include a phenyl group and a naphthyl group. Further, examples of the heterocyclic group include a carbazole group and a pyrisili group, and examples of substituents for this heterocyclic group include an alkyl group,
Alkoxy group, halogen atom, .

Examples include a cyano group and an amino group.

X and Y may be the same or different.

In general, X and Y may jointly form a ring, and specific examples of such a ring include substituted and unsubstituted quinoline rings, indoline rings, and the like. X
The ring formed by and Y may have a substituent.

In general formula [I], ■ and n are each 1.2
or an integer of 3, preferably l and n are 1. When l or n is an integer of 2 or more, R1 or R2 may be the same or different groups.

The bisazo compound of the present invention represented by general formula [I] is
Preferably, the following general formulas [A], [8], [C], [D
], [E], [F], [G], [H], [I] and [
J].

General formula [A] General formula [B] General formula [C] General formula [D] General formula [E] General formula [F] General 2 rG] General ceremony [January] General formula [I] General formula [J] X.

In the general formulas [A] to [J], R1 and R2 and X and Y are R1 and R2 of the general formula [I]
and has the same meaning as X and Y.

Next, specific examples of the bisazo compound represented by the general formula [I] of the present invention will be described, but the bisazo compound of the present invention is not limited by these. The bisazo compound represented by can be easily synthesized by a known method.

Synthesis Example 1 (Synthesis of exemplary compound N 0.456 represented by general formula [A]) 3.6-Diami2-4-bromo-9-fluorenone2.
90 (+ (0.02 mol)) in 101Q of hydrochloric acid, 201Q of water
1.40% of sodium nitrite while keeping the temperature below 5°C. A solution of (0.02 mol) dissolved in water 5112 was added dropwise. After continuing stirring at the same temperature for an additional hour, unnecessary materials were removed by filtration, and a solution of 4.6 g of ammonium hexafluorophosphate dissolved in 50% of water was added to the filtrate. The precipitated tetrazonium salt was collected by filtration and dissolved in 100 vQ of N,N-dimethylformamide (DMF). A solution of 7.160 (0.02 mol) of 2-hydroxy-3-naphthoic acid-benzylideneamino (3'-trifluoromethyl 1 anilide) dissolved in 200 d of DMF was added dropwise while maintaining the temperature at 5° C. or lower.

While continuing to maintain the temperature below 5°C, add triethanolamine 6Q (0.04 mol) to DMF 301Q.
Add the solution dissolved in
Stir for hours. After the reaction, the precipitated product was collected by filtration, washed with DMF,
After washing with water and drying, the target compound 6.05(] was obtained. The results of elemental analysis of this compound were as follows.

Calculated values: C=57.6%, H-2, 82%, N=10
．． 5% actual value: C = 55.3%, H = 2.91%,
N=11.9% Synthesis Example 2 (Synthesis of exemplified compound NO,348 represented by general formula [G]) Hydrochloric acid 10112, water 2
A solution of 1.40 (0.02 mol) of sodium nitrite dissolved in 5 vQ of water was added dropwise while maintaining the temperature below 5°C. After continuing stirring at the same temperature for an additional hour, unnecessary materials were removed by filtration, and a solution of 4.6 g of ammonium hexafluorophosphate dissolved in 50 g of water was added to the filtrate.

The precipitated tetrazonium salt was collected by filtration, and 100 dl. of N,N-dimethylformamide (DMF) was collected. :Dissolved. 5℃
2-hydroxy-3-[benzylideneamino(3'-chloro)carbamoylcobenzo[a
] - Rubazol 7.58g (0.02 mol) in DMF
A solution dissolved in 200 ij2 was added dropwise.

Subsequently, while keeping the temperature below 5°C, a solution of triethanolamine 60 (0.04 mol) in DMF3C)+N was added dropwise, followed by stirring at below 5°C for 1 hour and at room temperature for 4 hours. After the reaction, the precipitated crystals were collected by filtration, washed with DMF, washed with water, dried, and 682 g of the target product was placed on the back. The results of elemental analysis of this compound were as follows.

Calculated value; C=64.8%, 1-1=3.19%, N
= 12.4% actual measurement; C = 66.5%, H = 3.
02%, N=13.8% Other compounds of the present invention were also used in the same manner as in the above synthesis example, including 3.6-diamitwo, unsubstituted-9-
A tetrazo compound is prepared using fluorenone, and 2-hydroxy-3-naphthoic acid-substituted methyleneaminocarbamoyl or 2-hydroxy-3-(substituted methyleneaminocarbamoyl)-benzo[a]-ffi-substituted/unsubstituted carbazole is added. It can be made by reacting.

The bisazo compound of the present invention has excellent photoconductivity,
The electrophotographic photoreceptor of the present invention can be manufactured by providing a photosensitive layer in which the photoreceptor is dispersed in a binder on a conductive support. The bisazo compound of the present invention makes use of its excellent carrier generation ability, and by using it as a carrier generation substance and using a carrier transport substance that can effectively act in combination with this, the bisazo compound can be used as a so-called functionally separated photosensitive material. It can be a body. The functionally separated photoreceptor may be a mixed and dispersed type of both of the above substances, but it may be a carrier generation layer containing a carrier generation substance made of the bisazo compound of the present invention, and a carrier transport layer containing a carrier transport substance. It is more preferable to use a laminated type photoreceptor.

For example, as shown in FIG. 1, the electrophotographic photoreceptor of the present invention is prepared by disposing a carrier-generating substance on a support 1 (a conductive support or sheet 1 on which a conductive layer is provided), and optionally a carrier-generating substance. As shown in FIG. 2, a photosensitive m4 is provided with a functionally separated laminated structure in which a carrier generation layer 2 containing a binder resin is a lower layer and a carrier transport layer 3 containing a carrier transport substance and a binder resin is an upper layer. A photosensitive WI 4 having a laminated structure including a carrier transport layer 3 as a lower layer and a carrier generation layer 2 as an upper layer is provided on a support 1, and as shown in FIG. Examples include those provided with a single-layer photosensitive layer 4 containing a transport substance and a binder resin.

In the case of a photosensitive layer with a laminated structure, the carrier generation layer absorbs most of the incident light and generates many charge generation carriers, and at the same time, the generated charge carriers are recombined or captured (1-wrap). In order to inject into the carrier transport layer without deactivation, it is preferable to make the layer as thin as possible within a range of thickness sufficient to generate photocarriers.

Further, the carrier transport layer is electrically connected to the carrier 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. are doing.

In addition, in a functionally separated photoreceptor with a single layer structure, photocarriers are generated and transported in a single layer, and the carrier generation substance and the carrier transport substance are electrically bonded within the layer, and/or the carrier generation substance and the carrier transport substance are electrically bonded within the layer. Substances also contribute to carrier transport.

Further, the carrier generation layer may contain both the carrier generation substance and a part of the carrier transport substance.

In either layer structure, a protective layer (6) may be provided on the photosensitive layer (4) as shown in FIGS. 7 to 9, or a protective layer (6) may be provided on the photosensitive layer (4) as shown in FIGS. to the support (1
) and the photosensitive layer (4) may be provided with a subbing layer (intermediate ff1) (5) having a barrier function and adhesive properties.

Examples of binder resins that can be used for the photosensitive layer, protective layer, and undercoat layer include polystyrene, polyethylene, and Bolibu O.
Pyrene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, phenolic resin, polyester resin, alkyd resin, polycarbonate resin,
Addition polymer resins such as silicone resins and melamine resins, polyaddition resins, polycondensation resins, and copolymer resins containing two or more repeating units of these resins, such as vinyl chloride-vinyl acetate copolymers Examples include insulating resins such as composite resins and vinyl chloride-vinyl acetate-maleic anhydride copolymer resins, as well as polymeric organic semiconductors such as poly-N-vinylcarbazole.

Further, organic amines may be added to the photosensitive layer of the present invention for the purpose of improving the carrier generation performance of the carrier generation substance, and it is particularly preferable to add a secondary amine.

Such secondary amines include, for example, diethylamine, diethylamine, di-n-propylamine, di-isopropylamine, di-0-butylamine, di-isobutylamine, di-n-amylamine, di-isoamylamine, di-n-
Hexylamine, di-isohexylamine, di-n-pentylamine, di-isopentylamine, di-n-octylamine, di-isooctylamine, di-n-nonylamine, di-isononylamine, di-n-decylamine, di- -isodecylamine, di-n-monodecylamine, di-isomonodecylamine, di-n-dodecylamine, di-isododecylamine, and the like.

The amount of the organic amines to be added is preferably 1 times or less, preferably 0.2 times to 0.005 times the amount of the carrier generating substance, based on the amount of the carrier generating substance.

Further, in the photosensitive layer of the present invention, an antioxidant can be added for the purpose of preventing ozone deterioration.

Typical examples of such antioxidants are shown below, but the invention is not limited thereto.

Group (I): Hindered phenols dibutylhuman O-oxytoluene, 2,2'-methylenebis(6-t-butyl-4-methylphenol), 4.4'
-butylidenebis(6-1-butyl-3-methylphenol), 4.4'-thiobis(6-[-butyl-3-
methylphenol), 2,2'-butylidene bis(6-
1-butyl-4-methylphenol), α-tocopherol, β-tocopherol, 2,2,4-trimethyl-
6=Hydroxy-7-t-butylchroman, pentaerythyltetrakis (3-(3,5-di-butyl-4
-Hydroxyphenyl)buObio? , -t], 2.2
' -thiodiethylenebis[3-(3゜5-di[-butyl-4-hydroxyphenyl)propionate], 1
．． 6-hexanediolbis[3-(3,5-di-t-
butyl-4-hydroxyphenyl)propionate],
Butylhydroxyanisole, dibutylhydroxyanisole, 1-[2-((3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy)ethyl]-4-[3-(3,5-di-tert-butyl-4- hydroxyphenyl)propionyloxy]-2,
2,6,6-tetramethylbiveridyl, etc.

Group (II): Paraphenyl diamines N-phenyl-
N'-isopropyl-p-phenylenediamine, N,N
'-5ec-butyl-p-phenylenediamine, N
-phenyl-N-sec-butyl-p-phenylenediamine, NIN'-diisopropyl-p-phenylenediamine, N,N'-dimethyl-N, N'-di-t-butyl-p-phenylenediamine, etc.

(Ill) group: Hydroquinones 2.5-di-t-octylhydroquinone, 2゜6-sidedecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-
Octyl-5-methylhydroquinone, 2-(2-octadecenyl)-5-methylhydroquinone, etc.

(rV) group: Ia sulfur compounds such as dilauryl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, ditetradecyl-3,3'-thiodipropionate;

Group (V): Organic phosphorus compounds triphenylphosphine, tri(nonylphenyl)phosphine, tri(dinonylphenyl)phosphine, tricresylphosphine, tri(2,4-dibutylphenoxy)phosphine, etc.

These compounds are known as antioxidants for rubber, plastics, oils and fats, and are easily available commercially.

These antioxidants may be added to any of the carrier generation layer, carrier transport layer, or Wi retaining layer, but are preferably added to the carrier transport layer.

In that case, the amount of antioxidant added is 10 parts of the carrier transport substance.
0.1 to 100 parts by weight, preferably 1 part by weight
~50 parts by weight, particularly preferably 5 to 25 parts by weight.

Next, the conductive support supporting the photosensitive layer is a metal plate made of aluminum, nickel, etc., a metal drum or metal foil, a plastic film deposited with aluminum, tin oxide, indium oxide, etc., or paper coated with a conductive substance. , a film or drum of plastic or the like can be used.

In the present invention, the carrier generation layer is typically formed by applying a dispersion of the bisazo compound of the present invention described above in a suitable dispersion medium or solvent alone or together with a suitable binder resin, for example, by dip coating, spray coating, blade coating, etc. It can be provided by a method of coating on the support or subbing layer or carrier transport layer by roll coating or the like and drying it.

The bisazo compound of the present invention is made into fine particles of an appropriate particle size using, for example, a ball mill or a sand mill.
It can be dispersed in a dispersion medium.

A ball mill, homomixer, sand mill, ultrasonic disperser, attritor, etc. are used for dispersing the bisazo compound of the present invention.

Examples of the dispersion medium for the bisazo compound of the present invention include hydrocarbons such as hexane, benzene, toluene, and xylene;
Methylene chloride, methylene bromide, 1,2-dichloroethane, sym-tetrachloroethane, cis-
Halogenated hydrocarbons such as 1,2-dichloroethylene, i,i, 2-trichloroethane, 1,1.1-trichloroethane, 1,2-dichloropropane, chloroform, bromoform, chlorobenzene, ketones such as acetone, methyl ethyl ketone, cyclohexanone, etc. esters such as ethyl acetate and butyl acetate, methanol, ethanol, propatool, butanol, cyclohexanol, heptatool, ethylene glycol, methyl cellosolve,
Alcohols and their derivatives such as ethyl cellosolve and acetic acid cellosolve, ethers and acetals such as tetrahydrofuran, 1,4-dioxane, furan, and ralfural,
Amines such as pyridine, n-butylamine, diegylamine, ethylenediamine, isopropanolamine,
In addition to nitrogen compounds such as amides such as N,N-dimethylformamide, one or more of fatty acids, phenols, sulfur and phosphorus compounds such as carbon disulfide and triethyl phosphate, etc. can be used.

When the photoreceptor of the present invention has a laminated structure, the weight ratio of binder: carrier generating substance: carrier transporting substance in the carrier generating layer is 0 to 100: 1 to 500: 0 to 500.
It is.

If the content of the carrier-generating substance is less than this, the photosensitivity will be low and the residual potential will increase, and if it is more than this, the dark decay and acceptance potential will decrease.

The thickness of the carrier generation layer formed as described above is
Preferably 0.01 to 10μ11, particularly preferably 0.1
~5 μm.

Further, the carrier transport layer can be formed by coating and drying a carrier transport substance dissolved or dispersed in an appropriate solvent or dispersion medium alone or together with the above-mentioned binder resin. As the dispersion medium used, the dispersion medium used in dispersing the carrier-generating substance can be used.

Carrier transport substances that can be used in the present invention include:
Although not particularly limited, examples include oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidasilone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds,
Pyrazoline derivatives, amine derivatives, oxalone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly -9-vinylanthracene and the like.

The carrier transport substance used in the present invention has an excellent ability to transport holes generated during light irradiation to the support side, and is also suitable for combination with the bisazo compound of the present invention. Preferable examples of such carrier transport substances that can be used are those represented by the following general formulas (A), (B) and (C).

General formula (△) However, Ar1, Ar2, Ar4 each represent a substituted or unsubstituted aryl group, Ara represents a substituted or unsubstituted arylene group, R1 is a hydrogen atom, a substituted or unsubstituted alkyl group, Or represents a substituted or unsubstituted aryl group.

Specific examples of such compounds are described in detail on pages 3 to 4 of JP-A-58-65440 and pages 3-6 of JP-A-58-198043.

General formula (B)', N N=C-fCH=CH')n-
R+■(:.

However, R1 is a substituted or unsubstituted aryl group, or a substituted group.

It is an unsubstituted heterocyclic group, and R2 is a hydrogen atom and is substituted.

It represents an unsubstituted alkyl group, a substituted or unsubstituted aryl group, n is an integer of 0.1 or 2, and in detail,
It is described in the publications No. 858-134642 and No. 58-166354.

General formula (C) However, R1 is a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, and R2 is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted.

They are an unsubstituted alkoxy group, a substituted or unsubstituted amino group, or a hydroxy group, and R3 represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group. Synthesis methods for these compounds and their illustrations are described in detail in Japanese Patent Publication No. 148750/1983, which can be incorporated into the present invention.

Other preferred carrier transport materials of the present invention include:
Examples include hydrazone compounds described in JP-A-57-67940, JP-A-59-15252, and JP-A-57-101844, respectively.

The carrier transporting substance in the carrier transport layer is preferably 20 to 200 parts by weight, particularly preferably 30 to 150 parts by weight, per 1 part by weight of the binder resin.

The thickness of the carrier transport layer to be formed is preferably 5 to 5.
0 μm1, particularly preferably 5 to 30 μm.

Further, in the case of a monolayer functionally separated type electrophotographic photoreceptor using the bisazo compound of the present invention, the ratio of binder: bisazo compound of the present invention: carrier transport substance is 0 to 100:
1 to 500: O to 500 is preferred, and the thickness of the photosensitive layer to be formed is preferably 5 to 50 μm, particularly preferably 5 to 30 μm.

In the present invention, the carrier generation layer may contain one or more electron-accepting substances for the purpose of improving sensitivity, reducing residual potential or fatigue during repeated use, etc.

Examples of electron-accepting substances that can be used here include succinic anhydride, maleic anhydride, dibromaleic anhydride, phthalic anhydride, tetrachlorophthalic anhydride,
Tetrabromo phthalic anhydride, 3-nitro phthalic anhydride,
4-Nitrophthalic anhydride, pyromellitic anhydride, mellitic anhydride, tetracyanoethylene, teracyanoquinodimethane, 0-dinitrobenzene, m-dinitrobenzene, 1.3.5-trinitrobenzene, varanitrobenzo Nitrile, picryl chloride, quinone chlorimide, chloranil, brumanil, dichlorodicyanobarabenzoquinone, anthraquinone, dinitroanthraquinone,
2,7-cinitrofluorenone, 2.4.7-trinitrofluorenone, 2゜''4.5.7-tetranitrofluorenone, 9-fluorenylidene [dicyanomethylenemalonodinitrile 1, polynitro-9-fluorenylidene-[dicyano methylenemalonodinitrile], picric acid, 0-nitrobenzoic acid, p-nitrobenzoic acid, 3.5-
Examples include dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, mellitic acid, and other compounds with high electron affinity.

Further, the addition ratio of the electron-accepting substance is bisazo compound of the present invention:electron-accepting substance=100:0.01 to
200, preferably 100:0.1-100.

This electron-accepting substance may be added to the carrier transport layer. The ratio of electron-accepting substances added to this layer is the following by weight: total carrier transport substance:electron-accepting substance=100:0
．． 01-100, preferably 100: 0.1-5
It is 0.

In addition, the photoreceptor of the present invention may also contain, if necessary, an ultraviolet absorber, an antioxidant, etc. for the purpose of protecting the photosensitive layer, and may also contain a dye for color sensitivity correction.

The electrophotographic photoreceptor containing the bisazo compound of the present invention can be sensitive to visible light and near-infrared light, but preferably has an absorption maximum at a wavelength of about 400 to 850 μm.

Examples of light sources with such wavelengths include halogen lamps,
Fluorescent lamps, tungsten lamps, gas lasers such as argon lasers, helium-neon lasers, and semiconductor lasers are generally used.

The electrophotographic photoreceptor of the present invention has the above structure,
As is clear from the Examples described below, it has excellent charging characteristics, sensitivity characteristics, and image forming characteristics, and especially shows little fatigue deterioration even when used repeatedly, and has excellent durability.

[Examples] Hereinafter, the present invention will be specifically explained using Examples, but the embodiments of the present invention are not limited thereby.

Example 1 Vinyl chloride-vinyl acetate-
Maleic anhydride copolymer “S-LEC MF-10J
(manufactured by Hosui Kagaku Co., Ltd.) with a thickness of 0.05 μm is provided, and on top of that is an exemplified compound N represented by the general formula [D].
O,438 to 20 and polycarbonate resin [Panlite L-1250J (manufactured by Yojin Kasei Co., Ltd.) 2 (l and 1,2
- It was added to 110 d of dichloroethane and dispersed in a ball mill for 12 hours. The film thickness when this dispersion is dried is 0.5 μm.
The following +i4 formula (CT-1
) 6a and polycarbonate resin [Panlite L-125
A solution obtained by dissolving 0J10o in 801 g of 1,2-dichloroethane was applied so that the film thickness after drying was 15 μm.
A carrier transport layer was formed to produce a photoreceptor of the present invention.

(CT-1) The photoreceptor prepared as described above was filtered using an EPA-8100 electrostatic paper test machine manufactured by Kawa Niyoki Seisakusho.
The following characteristics were evaluated. After charging at V for 5 seconds to a charging voltage of -6, leave in the dark for 5 seconds, then irradiate with halogen lamp light so that the illumination intensity on the photoreceptor surface is 35, ellX-SeC to attenuate the surface potential by half. The exposure amount (half exposure 1) El/2 required to achieve this was determined. Also 3 Q
The surface potential (residual potential) Vn after exposure with an exposure amount of jillX-Sec was determined. Further, similar measurements were repeated 100 times. The results are shown in Table 1.

Comparative Example 1 The following bisazo compound (CG-1
) A comparative photoreceptor was prepared in the same manner as in Example 1, except that the photoreceptor was used.

(CG-1> Regarding this comparative photoreceptor, measurements were performed in the same manner as in Example 1, and the results shown in Table 1 were obtained.

As is clear from the results in Table 1 and above, the photoreceptor of the present invention is extremely superior in sensitivity, residual potential, and repetition stability compared to the comparative photoreceptor.

Examples 2 to 4 Exemplary compound No. 258 represented by the general formula [A], exemplified compound No. 565 represented by the general formula [B], and exemplified compound No. 0 represented by the general formula [C] as carrier generating substances
．． A photoreceptor of the present invention was prepared in the same manner as in Example 1 except that 73 and the following compounds were used as carrier transport substances, respectively, and the same measurements were performed. The results are shown in Table 2. I got it.

(CT-2) (CT-3) (CT-4> From the results shown in Table 2 and above, the electrophotographic photoreceptor using the bisazo compound of the present invention as a carrier generating substance has high sensitivity as in Example 1. It can be seen that the residual potential is low and the repeatability is excellent.

Example 5 A layer of vinyl chloride-vinyl acetate-maleic anhydride copolymer "S-LEC MF-10J (manufactured by W4 Suikagaku Co., Ltd.) with a thickness of 0.0 mm was coated on the surface of an aluminum drum with a diameter of 5 Q mm.
An intermediate layer of 05 μl was provided thereon, and exemplified compound NO, 279 having the structure of general formula [E], exemplified compound NO, 331 having the structure of general formula [A], and exemplified compound NO, 331 having the structure of general formula [8] were provided. 2 g of compound No. 636 and polyester resin "Vylon 200J (manufactured by Toyobo Co., Ltd.) 2(+) were mixed in 100 g of 1,2-dichloroethane, and the dispersion was dispersed for 24 hours using a ball mill dispersion machine. The film thickness after drying was 0.
It was applied to a thickness of 6 μm to form a carrier generation layer.

Furthermore, on top of this, 309 of the following compound (CT-5) and 50 g of polycarbonate resin [Niepiron 3-1000J (manufactured by Mitsubishi Gas Chemical Co., Ltd.) were added to 400 g of 1,2-dichloroethane.
A photoreceptor was prepared by dissolving the carrier transport layer in d and applying it to a film thickness of 18 μm after drying to form a carrier transport layer.

(CT-5) Electrophotographic copying of the photoreceptor 13 created in this way
r U-B ix1550M RJ (K oni
When the image was copied using a modified machine (manufactured by CA), a copy image with high contrast, faithful to the original, and clear was obtained. Moreover, this did not change even after repeating 10,000 times.

Comparative Example 2 The exemplified compound in Example 5 was represented by the following structural formula (CG-2).
A drum-shaped comparative photoreceptor was prepared in the same manner as in Example 5, except that the bisazo compound represented by was used, and the copied images were evaluated in the same manner as in Example 5. Only images with a lot of fog were obtained. I couldn't. Also, as copying is repeated, the contrast 1- of the copied image decreases to 10.000.
After repeating this process several times, hardly any duplicate images were obtained.

(CG-2) Examples 6 to 9 Vinyl chloride-vinyl acetate-maleic anhydride copolymer "S-LEC MF-10J" was placed on a conductive support consisting of a polyester film laminated with aluminum foil.
(Katsusui Kagaku Co., Ltd. 1 ton), and on top of that, 6 g of the following structural formula (CT-6) as a carrier transport substance and 71 (recarbonate resin "Panlite L-1250J100") were provided. 1. Apply a solution dissolved in 2-dichloroethane 80 so that the film after drying becomes 15 μm. Exemplary compound N0 having the structure [F]
．． 2[18, Exemplary compound N having the structure of general formula [G]
O, 354 and the exemplified compound NO, 63G having the structure of general formula [1-1], respectively 21], the above carrier transport substance 1.5 (1, polycarbonate resin [Panlite Shiichi 125QJ 2q and 1.2 -dichloroethane 30i
(In addition to step 2, a carrier generation layer having a film thickness of 4 μm after drying was provided by applying a solution dispersed in a ball mill for 24 hours to prepare a photoreceptor of the present invention.

When these photoreceptors were measured in the same manner as in Example 1, the results were 14, which are not shown in Table 3.

Table 3 Example 1〇 Exemplary compound No. having the structure of general formula [J].

502 and polycarbonate resin "Panlite Shiichi 1250J 20" and 1,2-dichloroethane 1101.
In addition to Q, the mixture was dispersed in a ball mill for 12 hours. This dispersion was applied onto a polyester film on which aluminum had been vapor-deposited so that the dry thickness was 1 μm, and as a carrier generation layer, the following structural formula (CT-7) 60 was applied to a polycarbonate resin “Panlite L- 1250" 10g and 1.
A carrier transport layer was formed by applying a solution dissolved in 2-dichloroethane 110112 to a film thickness of 15 μm after drying, thereby forming an electrophotographic photoreceptor of the present invention.

(CT-7) This photoreceptor was measured in the same manner as in Example 1, and the results shown in Table 4 were obtained.

Comparative Example 3 The following bisazo compound (CG-3
) was used to prepare a comparative photoreceptor in the same manner as in Example 10.

(CG-3) Regarding this comparative photoreceptor, measurements were performed in the same manner as in Example 1, and the results shown in Table 4 were obtained.

Table 4 Examples 11 to 13 Exemplary compounds N0.181 having the structure of general formula [F] as carrier generating substances, N having the structure of general formula [G]
00322, No. 98 having the structure of general formula [T1]
A photoreceptor of the present invention was prepared in the same manner as in Example 10, except that a compound having the following tM formula was used as a guillerial transport substance, respectively, and the same results were obtained. The following results were obtained.

(CT-8) (CT-9) (CT-10) As is clear from the results of the Examples and Comparative Examples in Table 5 and above, the photoreceptor of the present invention has better stability, sensitivity, and It has outstanding durability and compatibility with a wide range of carrier transport substances.

[Brief explanation of the drawing]

1 to 9 are sectional views showing the layer structure of the photoreceptor of the present invention, and 1 to 6 in the figures represent the following, respectively.

Claims (3)

[Claims] (1) An electrophotographic photoreceptor comprising a photosensitive layer containing a bisazo compound represented by the following general formula [I] on a conductive support. General formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. are included▼ [R_1 and R_2 each represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a nitro group, a cyano group, or a hydroxy group. However, R_1 and R_2
may be the same or different, respectively. Z represents an atomic group necessary to form a carbocyclic aromatic ring or a heterocyclic aromatic ring. X and Y each represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group. However, X and Y may be the same or different, and may also work together to form a ring. m and n each represent an integer of 1, 2 or 3. ] (2) The photosensitive layer contains a carrier-generating substance and a carrier-transporting substance, and the carrier-generating substance has the general formula [
The electrophotographic photoreceptor according to claim (1), which is a bisazo compound represented by I]. (3) Claim (1) or (2) characterized in that the photosensitive layer is constituted by a laminate of a carrier generation layer containing a carrier generation substance and a carrier transport layer containing a carrier transport substance. The electrophotographic photoreceptor described above.