JPH01201668A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide an electrophotographic sensitive body which has excellent carrier generating property, high sensitivity and high durability and is excellent in combination with a wide range of carrier transfer materials by providing a photosensitive layer contg. a specific bisazo pigment. CONSTITUTION:This photosensitive body has the bisazo compd. expressed by formula I. In formula, R1 and R2 respectively denote a hydrogen atom., halogen atom., alkyl group, alkoxy group, nitro group, cyano group or hydroxy group. Z denotes an atom. group necessary for forming a carbocyclic arom. ring or heterocyclic arom. ring and X denotes an atom. group necessary for forming a heterocyclic arom. ring having formula II or formula III as a part thereof cooperatively with the adjacent benzene ring. (m) and (n) denote 1, 2 or 3 integer. The photosensitive body which is excellent in the sensitivity, the durability, the combination with a wide range of the carrier transfer materials, etc., is thereby obtd.

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] Conventionally, inorganic photoreceptors having a photosensitive layer containing an inorganic photoconductive compound such as selenium, zinc oxide, cadmium sulfide, or silicon as a main component have been widely used as electrophotographic photoreceptors. 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, and 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-dolinitro-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, respectively. 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.
Another object of the present invention is to provide an electrophotographic photoreceptor that is highly durable and 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 uses an electrophotographic photoreceptor having a photosensitive layer containing a bisazo compound represented by the following [I] on a conductive support. R+ and R2 each represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a nitro group, a cyan group or a hydroxy group. However, R1 and R2 are
Each may be the same or different.

Z represents an atomic group necessary to form a carbocyclic aromatic ring or a heterocyclic aromatic ring, and X represents an atom necessary to form a cyclic aromatic ring in collaboration with an adjacent benzene ring. represents a group. l
and n represent an integer of 1.2 or 3, respectively.

] [Specific structure of the invention] The halogen atoms represented by R1 and R2 in general formula [I] include chlorine atom, bromine atom, fluorine atom, and iodine atom, but among these, chlorine atom or bromine atom preferable.

The alkyl groups represented by R1 and R2 are preferably alkyl groups having 1 to 4 carbon atoms, such as methyl, ethyl, isopropyl, t-butyl, trifluoromethyl and the like.

The alkoxy groups represented by R1 and R2 are preferably alkoxy groups having 1 to 4 carbon atoms, such as methoxy group, ethoxy group, isopropoxy group, t-butoxy group, 2-chloroethoxy group, etc. .

Among the substituents represented by R7 and R2, preferred are a hydrogen atom, a halogen atom, an alkyl group, and an alkoxy group.

Z represents an atomic group necessary to form a carbocyclic aromatic ring or a heterocyclic aromatic ring, and examples of a carbocyclic aromatic ring formed by such an atomic group include substitutions, Examples include unsubstituted benzene rings and naphthalene rings. Furthermore, examples of the heterocyclic aromatic ring include substituted and unsubstituted dibenzothiophene rings, carbazole rings, and the like. These aromatic rings can have substituents. Examples of the substituent include a halogen atom, an amino group, an alkyl group, a hydroxy group, a nitro group, and a cyano group. These aromatic rings can have one or more substituents.

X jointly with the adjacent benzene ring Represents the atomic group necessary to form a cyclic aromatic ring.

This heterocyclic aromatic ring includes one having a substituent.

In the above-murder [I], m and n are each 1.
represents an integer of 2 or 3, preferably 1 and n is 1
It is.

I or n may both be the same integer or different integers.

Specifically, the bisazo compound of the present invention represented by the above-mentioned -homicide [I] is represented by the following -homicide [A1-[R] above-mentioned general formula [A
] to [R], R1 and R2 are represented by the general formula [I
] has the same meaning as R1 and R2, and A represents.

Next, specific examples of the bisazo compound represented by the above general formula [I] of the present invention will be described. The compound can be easily synthesized by known methods.

Synthesis Example 1 (Synthesis of Exemplary Compound N011 represented by -murder [A]) 2.6-Diamitwo-9-fluorenone 2.10(](0
Disperse 0.01 mol in 10 g of hydrochloric acid and 201 g of water, and heat at 5°C.
1.4 g of sodium nitrite (0,02
A solution of mol) dissolved in water 51i2 was added dropwise. After stirring for another hour at the same temperature, unnecessary materials were removed by filtration, and 4.6 g of ammonium hexafluoride phosphate was added to the filtrate in 50 g of water.
A solution dissolved in d was added.

The precipitated tetrazonium salt was collected by filtration and dissolved in 100.12 N,N-dimethylformamide (DMF).

While keeping the temperature below 5°C, 6.36 g (0.02 mol) of 2-hydroxy-3-naphthoic acid-[3',4'-dicarboximido]anilide was added to 0MF200. A solution dissolved in β was added dropwise.

While continuing to maintain the temperature below 5°C, add triethanolamine (3()) (00.04 mol) to DMF 301
The solution dissolved in fl was added dropwise, and the mixture was stirred at 5° C. or lower for 1 hour and at room temperature for 4 hours. After the reaction, the precipitate was collected by filtration, washed with DMF, washed with water, and dried to obtain the desired product 6.470. The results of elemental analysis of this compound were as follows.

Calculated value: C-67.6%, H=3.45%, N=
16.1% Actual value: C=65.5%, H-3, 75%
, N=17.9% Synthesis Example 2 (Synthesis of Exemplary Compound No, 128 represented by -homicide [E]) 2.6-Diami23.7-dichloro-9-fluorenone 3.68 (+ (0, 01 mole) was dispersed in 101 g of hydrochloric acid and 20 if water, and while keeping the temperature below 5°C, a solution of 1°4 (00.02 mole) of sodium nitrite dissolved in 5112 water was added dropwise. After stirring for a while, unnecessary materials were removed by filtration, and a solution of 4.6 g of ammonium hexafluorophosphate dissolved in 501 g of water was added to the filtrate.The precipitated tetrazonium salt was collected by filtration, and N,N-dimethylformamide was added. (DMF) Dissolved in 100 views.5
2-hydroxy-3-naphthoic acid-[3',4'-diiminocarbonyl]anilide 6 while keeping the temperature below ℃.
．． A solution of 62+1 (0.02 mol) dissolved in 0MF2001+2 was added dropwise.

While keeping the temperature below 5°C, 6 g (0.04 mol) of triethanolamine dissolved in DMF30n+2 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, and dried to obtain the desired product 6.570. The elemental analysis values of this compound were as follows.

Calculated values: C=63.4%, H=2.69%, N=1
1.6% actual value: C=59.8%, H-2, 82%,
N=13.5% Synthesis Example 3 (Synthesis of Exemplary Compound N017 represented by -murder [L]) 2.6-Diami2-9-fluorenone 2.10 (1(0
, 0.01 mol) was dispersed in 10 parts of hydrochloric acid and 20 parts of water, and a solution of 1.4 g (0.02 mol) of sodium nitrite dissolved in 51 parts of water was added dropwise while keeping 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 dissolved in 100 tfi of N,N-dimethylformamide (DMF).

6.360 (0.02 mol) of 2-hydroxy-3-α-benzocarbazole-[3',4'-dicarboximido]anilide was added to 0MF20 while keeping the temperature below 5°C.
A solution dissolved in water was added dropwise.

Triethanolamine 6 while continuing to maintain the temperature below 5℃! I+ (0.04 mol), DM F 30ne
Add the solution dissolved in
Stir for hours. After the reaction, the precipitated crystals were collected by filtration, washed with DMF,
After washing with water and drying, 6.47 (l) of the target compound was obtained. The results of elemental analysis of this compound were as follows.

Calculated values: C=69.7%, )l=3.62%, N=
16.0% actual value: C-65.5%, H=3.75
%, N-17.9% For other compounds of the present invention, in the same manner as in the above synthesis example, a tetrazo compound was prepared using 2,6-cyamitsu-substituted and unsubstituted-9-fluorenone, and then 2-hydroxy- It can be produced by reacting with 3-naphthoic acid-[substituted diiminocarbonyl-anilide] or 2-hydroxy-3-naphthoic acid-[substituted dicarboximide]-anilide.

The bisazo compound of the present invention has excellent photo-S conductivity,
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, the electrophotographic photoreceptor of the present invention is prepared by disposing a carrier-generating substance and optionally a binder on a support 1 (a conductive support or a conductive layer provided on a sheet) as shown in FIG. A carrier generation layer 2 containing resin is used as a lower layer,
A photosensitive layer 4 having a functionally separated laminated structure with a carrier transport layer 3 containing a carrier transport substance and a binder resin as an upper layer, and a carrier transport layer 3 as a lower layer on a support 1 as shown in FIG. A photosensitive layer 4 having a laminated structure with a carrier generation layer 2 as an upper layer, and a single layer structure containing a carrier generation substance, a carrier transport substance and a binder resin on a support 1 as shown in FIG. Examples include those provided with a photosensitive layer 4 of.

In the case of a photosensitive layer with a laminated structure, most of the incident light is absorbed by the charge generation layer, generating many charge generation carriers, and the generated charge carriers are deactivated by recombination or trapping. It is preferable to make the layer as thin as possible within a range of thickness sufficient to generate photocarriers in order to inject them into the carrier transport layer without causing damage.

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 may be provided on the photosensitive layer as shown in FIGS. 7 to 9, and a protective layer may be provided on the photosensitive layer as shown in FIGS. 4 to 6. A subbing layer (intermediate layer) having barrier function and adhesive properties may be provided between the two layers.

Examples of binder resins that can be used for the photosensitive layer, protective layer, and subbing layer include polystyrene, polyethylene, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, and phenol. addition-polymerized resins such as resins, polyester resins, alkyd resins, polycarbonate resins, silicone resins, and melamine resins;
Polyaddition type resins, polycondensation type resins, and copolymer resins containing two or more repeating units of these resins, such as vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-
In addition to insulating resins such as vinyl acetate-maleic anhydride copolymer resins, polymeric organic semiconductors such as poly-N-vinylcarbazole may be used.

Furthermore, organic amines can be added to the photosensitive layer of the present invention for the purpose of improving the carrier-generating function of the carrier-generating substance, and it is particularly preferable to add a secondary amine.

Such secondary amines include, for example, dimethylamine, diethylamine, di-n propylamine, di-isopropylamine, di-n butylamine, di-isobutylamine, di-0 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 molar amount of the organic amine added is preferably 1 times or less, preferably 0.2 times to 0.005 times, 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 dibutylhydroxytoluene, 2.2'-methylenebis(6-t-butyl-4-methylphenol), 4.4'
-butylidenebis(6-[-butyl-3-methylphenol), 4.4'-diobis(6-t-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) One Butiru 4
-hydroxyphenyl)propionate], 2.2'
-thiodiethylenebis[3-(3°5-di-t-butyl-4-hydroxyphenyl)propionate], 1.6
-hexanediol bis[3-(3,5-di[-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-
(droxyphenyl)propionyloxy]-2,2,
6,6-titramethylpiveridyl, etc.

Group (If): Paraphenylenediamines N-phenyl-
N'-isopropyl-p-phenylenediamine, N,N
'-5ec-butyl-p-phenylenediamine, N
-Phenyl-N-5eC-butyl-p-phenylenediamine, N.

N'-diisopropyl-p-phenylenediamine, N,
N'-dimethyl-N, N'-di-t-butyl-p-phenylenediamine, etc.

Group (III): Hydroquinones 2.5-d-mono-octylhydroquinone, 2゜6-sidodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-
Octyl-5-methylhydroquinone, 2-(2-octadecenyl)-5-methylhydroquinone, etc.

Group (IV): organic sulfur compounds dilauryl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, tatetradecyl-3,3'-thiodipropionate, etc.

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 the carrier generation layer, carrier transport layer, or retainer! Although it may be added to any of the i-layers, it is 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 Nando 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, 5yn-tetrachloroethane, cis-
Halogenated hydrocarbons such as 1,2-dichloroethylene, 1.1.2-trichloroethane, 1.1.1-trichloroethane, 1.2-dichloropropane, chloroform, bromoform, and chlorobenzene; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; class, ethyl acetate,
Esters such as butyl acetate, methanol, ethanol,
Alcohols and derivatives thereof such as propatool, butanol, cyclohexanol, heptatool, ethylene glycol, methyl cellosolve, ethyl cellosolve, acetic acid cellosolve, tetrahydrofuran, 1,4-dioxane,
Ethers such as furan and ralfural, acetals, amines such as pyridine, n-butylamine, diethylamine, ethylenediamine, and impropaturamine, N,
In addition to nitrogen compounds such as amides such as N-dimethylformamide, fatty acids and phenols, and sulfur and phosphorus compounds such as carbon disulfide and triethyl phosphate are included.

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 0401 to 10 μm, 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,
imidacilone derivatives, imidazolidine derivatives, hisimidazolidine derivatives, styryl compounds, hydrazone compounds, lazoline derivatives, amine derivatives, oxacilone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbenes derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, and the like.

The carrier transporting substance used in the present invention is preferably one that has an excellent ability to transport holes generated during light irradiation to the support side, and is suitable for combination with the bisazo compound of the present invention. Preferred substances are the following - murder (A), (B) and (
Examples include those represented by C).

General formula (A) However, Ar + , Ar 2 and Ar 4 are
s or an unsubstituted aryl group, Ars represents a substituted or unsubstituted arylene group, and R1 represents a hydrogen atom, a substituted or unsubstituted alkyl group, or 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 <8) However, R1 is a substituted or unsubstituted aryl group, or a substituted.

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 represents an integer of 0.1 or 2, and is described in detail in Japanese Patent Application Laid-Open No. 58-134642 and No. 58-166354. There is.

General formula (C) R3 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 amine L 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 amount of the carrier transport substance per 1001 parts of binder resin in the carrier transport layer is preferably 20 to 200 parts by weight, particularly preferably 30 to 150 parts by weight.

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: xeria 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. 2 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, tetracyanoquinodimethane, 0-dinitrobenzene, m-dinitrobenzene, 1.3.5-trinitrobenzene, paranitrobenzonitrile, Picryl chloride, quinone chlorimide,
Chloranil, brumanil, dichlorodicyanobarabenzoquinone, anthraquinone, dinitroanthraquinone, 2
, 7-sinitrofluorenone, 2.4.7-dolinitrofluorenone, 2゜4.5.7-titranitrofluorenone, 9-fluorenylidene [dicyanomethylene malonodinitrile], polynitro-9-fluorenylidene [
Dicyanomethylene malonodinitrile, picric acid, 0
-Nitrobenzoic acid, p-nitrobenzoic acid, 3.5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, mellitic acid, and others with high electron affinity Compounds can be mentioned.

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
．． 01-1001 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 commonly 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 I-Suikagaku 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 [G].
2g of 0.1 and polycarbonate resin “Panrai I-
2g of L-1250J (manufactured by Hitsuiri Kasei Co., Ltd.) and 1.2
-dichloroethane110. g, plus 12 g using a ball mill.
Spread out time. The thickness of this dispersion when dried is 0.5.
μm to form a carrier ordering layer, and on top of that, a carrier transport layer with the following structural formula (CT-1
) 6 (l is polycarbonate resin "Panlite l-12
A solution prepared by dissolving 50J 10(+ in 801 g of 1,2-dichloroethane) was applied to form a carrier transport layer such that the film thickness after drying was 15 μm, thereby producing a photoreceptor of the present invention.

(CT-1) The photoreceptor obtained as described above was subjected to the following characteristic evaluation using an EPA-8100 type electric paper tester manufactured by Shishuro Denki Seisakusho. After charging at V for 5 seconds to a charging voltage of -6,
Leave it in the dark for 5 seconds, then increase the illuminance on the photoreceptor surface to 3511.
The amount of exposure required to attenuate the surface potential by half by irradiating it with halogen lamp light so that the surface potential becomes JX-5I3C is
Half-exposure E1/2 was determined. Also 30 lux -
Surface potential (residual potential) V after exposure with an exposure amount of sec
I asked for R. 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. 20 represented by the general formula [E] as a carrier generating substance, Exemplary compound No. 20 represented by the general formula [8], Exemplary compound N represented by the general formula [A]
0.53 was used for each, and as a carrier transport substance,
Photoreceptors of the present invention were prepared using the following compounds and in the same manner as in Example 1, respectively, and the same measurements were performed to obtain the results shown in Table 2.

(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.

Examples 5 to 9 Aluminum was vapor-deposited on a polyester film, the intermediate layer used in Example 1 was provided, and the general formula [C]
Exemplified Compound No. represented by 69°-Homicide [F], Exemplified Compound No. represented by 80°-Homicide [1], 101.

- Exemplary compound No. 0.126° represented by murder [D] -
2 g each of exemplified compound N 0.132 represented by Homicide [H] and polycarbonate resin [Panlite L-
1250J2! 7 to 1,2-dichloroethane 110
In addition to 1β, the mixture was dispersed for 8 hours using a sand grinder.

Each of these dispersions was applied so that the dry film thickness was 0.5 μm to form a carrier generation layer.

Further, on each of these carrier generation layers, a carrier transport layer is formed using polycarbonate resin "Panlite-13004 (manufactured by Yojin Kasei Co., Ltd.) 10
g and 1,2-dichloroethane 80m! A carrier transport layer was formed by coating each of the liquids dissolved in No. 2 so as to have a dry film thickness of 15 μm, thereby producing photoreceptors of the present invention.

(CT-5) The same measurements as in Example 1 were performed on this photoreceptor, and the results are shown in Table 3.

Comparative Example 2 An electrophotographic photoreceptor was produced in the same manner as in Example 5, except that a bisazo pigment represented by the following structural formula (CG-2) was used as a carrier-generating substance. The same measurements as in Example 1 were performed on this comparative photoreceptor, and the results are shown in Table 3.

L Below margin ゛Liyu Ika (CG-2) Table 3 Examples 10 to 12 Vinyl chloride-vinyl acetate-
Maleic anhydride copolymer “S-LEC MF-10J
(&I + manufactured by Suikagaku Co., Ltd.) with a thickness of 0.05 μl, and on top of that, 2 g of the exemplified compound NO,158 represented by the general formula [F] and polycarbonate resin “Panlite L-1250J 2 tJ was added to tetrahydrofuran 11 (11Q) and dispersed in a ball mill for 12 hours. This dispersion was applied to a dry film thickness of 0.5 μm to form a carrier generation layer. 6 g of each of the compounds having the structural formula (% formula %) and 10 g of polycarbonate resin rZ-200J (manufactured by Mitsubishi Gas Chemical Co., Ltd.) were added to 1,2
A carrier transport layer was formed by applying a solution dissolved in 80 vQ of -dichloroethane so that the film thickness after drying was 15 μm, thereby producing a photoreceptor of the present invention.

(CT-7> (CT-8) Measurements were carried out in the same manner as in Example 1, except that a fluorescent lamp was used instead of the halogen lamp in Example 1, and the results are shown in Table 4.

Table 4 Example 13 The surface of an aluminum drum with a diameter of 60 m + 1 was coated with a 0.0 mm thick vinyl chloride-vinyl acetate-maleic anhydride copolymer [S-LEC MF-10J (manufactured by Block Chemical Co., Ltd.)].
Exemplary compound No. 177 represented by the general formula [C] with an intermediate layer of 0.05 μm on top of A.

- Exemplary compound No.19G represented by murder [E].

- 2 g each of Exemplary Compound No. 205 represented by Homicide [8] and polyester resin "Vylon 200" (manufactured by Toyobo Co., Ltd.) 20 were added to 100 iN of 1,2-dichloroethane.
The dispersion liquid was mixed with the following and dispersed for 24 hours using a ball mill dispersion machine, and then applied so that the film thickness after drying was 0.6 μm.
A carrier generation layer was formed respectively.

Furthermore, on top of this, 300 g of the following compound (CT-9) and 50 g of polycarbonate-1 resin [Nipiron 3-10004 (manufactured by Mitsubishi Gas Chemical Co., Ltd.) were added to 40 g of 1,2-dichloroethane.
A carrier transport layer was formed by dissolving the solution at 0 tN and applying it to a film thickness of 18 μI after drying.

(CT-9) The photoreceptor produced in this way is transferred to an electrophotographic copying machine.
- When the image was copied by installing it on a modified Bix1550M RJ (manufactured by Konica), a copy image with high contrast, faithful to the original image, and clear was obtained.

Also, this did not change even after repeating it io, ooo times.

Comparative Example 3 The exemplified compound in Example 13 was represented by the following structural formula (CG-3
) Example 13 except that the bisazo compound represented by
A drum-shaped comparative photoreceptor was prepared in the same manner as in Example 13, and the copied images were evaluated in the same manner as in Example 13. Only images with a lot of fog were obtained. Also, as copying is repeated, the contrast of the copied image decreases, and
After repeating this process 00 times, hardly any copied images were obtained.

(CG-3) Example 14 2 g of exemplified compound [P]-1 and polycarbonate resin [
Panrai L-L-1250] (manufactured by Yojin Kasei Co., Ltd.) 2g
and 1,2-dichloroethane 110. ．． 12 and then dispersed in a ball mill for 12 hours. This dispersion was applied onto a polyester film on which aluminum was vapor-deposited so that the dry film thickness was 1 μm to form a carrier generation layer, and on top of that a carrier transport layer was formed using the following structural formula (CT
-10) 60 is polycarbonate resin [Panlite l-
1250] 10(+ and 1,2-dichloroethane 11
A carrier transport layer was formed by applying a solution dissolved in 0.01 g to a film thickness of 15 .mu.m after drying to form an electrophotographic photoreceptor of the present invention.

(CT-10) This photoreceptor was measured in the same manner as in Example 1, and the results shown in Table 5 were obtained.

Comparative Example 4 The following bisazo compound (CG-4
A comparative photoreceptor was prepared in the same manner as in Example 14, except that the following was used. ' Regarding this comparative photoreceptor, measurements were carried out in the same manner as in Example 1, and the results shown in Table 5 were obtained.

Table 5 Examples 15 to 17 Exemplary compounds [N]-20, [K
]-28 and [J]-53, and each compound having the following structural formula was used as a carrier transport substance, and the other conditions were the same as in Example 15 to prepare a photoreceptor of the present invention, and the same measurements were carried out. The results shown in Table 6 were obtained.

(CT-11) (CT-12) (CT-13) Table 6 Example 18 Vinyl chloride-vinyl acetate-maleic anhydride copolymer [S-LEC MF-10] (building block (manufactured by Kagakusha) thickness 1.
An intermediate layer of 05 μm was provided, and exemplified compounds No. and L were added thereon.
4 g of -69 was mixed with 1,2-dichloroethane 400112 and dispersed for 24 hours using a ball mill dispersion machine. A dispersion liquid was coated so that the film thickness after drying was 0.6 μm to form a carrier generation layer.

Furthermore, 30 g of the structural formula (CT-9) already described above and polycarbonate resin [Nipiron S-1000] (
Mitsubishi Gas Chemical Co., Ltd.) 50g 1,2-dichloroethane 4
001.12 and coated to form a carrier transport layer such that the film thickness after drying was 13 μm, thereby forming a drum-shaped photoreceptor.

The photoreceptor created in this way can be printed on an electrophotographic printer [
When installed on a modified LP-30101 (manufactured by Konica), a copy image with high contrast, faithful to the original, and clear was obtained. Also, this is io, oo.

No matter how many times it was repeated, it didn't change.

Comparative Example 5 A drum-shaped comparative photoreceptor was prepared in the same manner as in Example 18, except that the carrier generating substance in Example 18 was replaced with a bisazo compound (CG-5) represented by the following structural formula. When the copied image was evaluated in the same manner as in Example 18,
Only images with a lot of fog were obtained. Also, as copying is repeated, the contrast of the copied image decreases,
After repeating 2000 times, hardly any duplicate images were obtained.

It has outstanding properties such as sensitivity, durability, and compatibility with a wide range of carrier transport substances.

(CG-4) (CG-5) As is clear from the results of the above examples and comparative examples, the photoconductor of the present invention has a It has outstanding stability, sensitivity, 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. Z represents an atomic group necessary to form a carbocyclic aromatic ring or a heterocyclic aromatic ring. X together with the adjacent benzene ring is necessary to form a heterocyclic aromatic ring having as part of Represents a group of atoms. m
and n represent an integer of 1, 2 or 3, respectively. ] (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), wherein 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.