JPH06110233A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide an electrophotographic sensitive body contg. a specified bisazo compd. excellent in carrier generating ability and capable of effectively acting as a carrier generating material even in combination with various carrier transferring materials, having high sensitivity and low residual potential, undergoing no change in these characteristics even after repeated use and excellent in durability. CONSTITUTION:This electrophotographic sensitive body has a photosensitive layer contg. a bisazo compd. represented by the general formula on the electric conductive substrate. In the formula, each of R1 and R2 is H, halogen, lower alkyl, lower alkoxy or cyano, each of A1 and A2 is a residue of a coupler having coupling ability and contg. hydroxyl and A1 and A2 may be different from each other.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor,
Specifically, it relates to an electrophotographic photoreceptor having a photosensitive layer containing a specific bisazo compound.

[0002]

BACKGROUND OF THE INVENTION Conventionally, as an electrophotographic photosensitive member, an inorganic photosensitive member having a photosensitive layer containing an inorganic photoconductive compound such as selenium, zinc oxide, cadmium sulfide and silicon as a main component has been widely used. However, these are not always satisfactory in terms of sensitivity, thermal stability, moisture resistance, durability and the like. For example, when selenium is crystallized, the characteristics as a photoreceptor are deteriorated, which is difficult to manufacture, and crystallization is caused by heat, fingerprints, etc., and the performance as a photoreceptor is deteriorated. Further, cadmium sulfide has problems in moisture resistance and durability, and zinc oxide has problems in durability and the like.

For the purpose of overcoming the drawbacks of these inorganic photoconductors, research and development of organic photoconductors having a photosensitive layer containing various organic photoconductive compounds as main components have been actively conducted in recent years. For example, Japanese Examined Patent Publication No. 50-10496 describes an organic photoreceptor having a photosensitive layer containing poly-N-vinylcarbazole and 2,4,7-trinitro-9-fluorenone. However, this photoreceptor is not always satisfactory in sensitivity and durability.

In order to improve such a defect, attempts have been made to develop a higher performance organic photoconductor by allowing different substances to have a carrier generating function and a carrier transporting function, respectively. Such a so-called function-separated type photoconductor can be selected from a wide range of each material, a lot of research has been done since it is possible to relatively easily create a photoconductor having arbitrary performance, Some are in practical use.

As a laminated type photoreceptor of this type, USP 3,87
No. 1,882 using a perylene derivative as a carrier generating layer and an oxadiazole derivative as a carrier transporting layer, and JP-A-55-84943 discloses a distyrylbenzene bisazo compound as a carrier generating substance and a hydrazone compound as a carrier transporting substance. Those using are known.

However, it is also a fact that even in the case of this type of photoconductor, the conventional one has many advantages and at the same time has various drawbacks.

In the function-separated type photoreceptor as described above, as an example of using a large number of compounds as carrier generating substances, for example, amorphous selenium described in JP-B-43-16198 is used. However, this is used in combination with an organic photoconductive compound, but the disadvantage that the carrier generation layer made of amorphous selenium is crystallized by heat and the characteristics as a photoreceptor are deteriorated has not been improved.

Many electrophotographic photoreceptors using organic dyes and organic pigments as carrier generating substances have also been proposed. For example, as an electrophotographic photoreceptor containing a bisazo compound in the photosensitive layer, JP-A-54-22834, JP-A-55-73057,
Nos. 55-117151 and 56-46237 are already known.
However, in terms of characteristics, these bisazo compounds do not sufficiently satisfy a wide range of requirements for electrophotographic processes, such as a limited selection range of carrier transporting substances.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide an electrophotographic photoreceptor having a specific bisazo compound which is excellent in carrier generation ability.

Another object of the present invention is to provide an electrophotographic photoreceptor having high sensitivity, a small residual potential, and excellent durability which does not change their characteristics even after repeated use.

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

[0012]

The present inventors have conducted extensive studies to achieve the above object, and as a result, found that a specific bisazo compound can function as an excellent active ingredient of an electrophotographic photoreceptor.
The present invention has been completed. That is, the above object of the present invention is to provide the above-mentioned general formula [1] (Chemical Formula 1) on a conductive support.
This can be achieved by using an electrophotographic photoreceptor having a photosensitive layer containing a bisazo compound represented by

The present invention will be specifically described below.

The general formula [1] will be described. In the general formula [1], the lower alkyl group for R ₁ and R ₂ is preferably an alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, an isopropyl group, a t-butyl group, a trifluoromethyl group and the like. Is preferred. The lower alkoxy group for R ₁ and R ₂ is preferably an alkoxy group having 1 to 4 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, an isopropoxy group, a t-butoxy group, and a 2-chloroethoxy group. .

The halogen atom for R ₁ and R ₂ is Cl
A group, a Br group, an I group and an F group can be mentioned as specific examples.

The coupler residue containing a hydroxyl group having a coupling ability in the general formula [1] is selected from coupler components represented by the following general formulas [2], [3] and [4]. It is desirable to be done.

[0017]

[Chemical 2]

Specific examples of the polycyclic aromatic ring or hetero ring formed by the condensation of X with the benzene ring in the general formula [2] include, for example, naphthalene ring, anthracene ring, benzocarbazole ring, benzofuran ring and the like. Can be mentioned.
Examples of the alkyl group for R ₃ include a methyl group, an ethyl group, a propyl group, a butyl group, a 2-hydroxyethyl group,
Examples thereof include substituted and unsubstituted alkyl groups such as 2-chloroethyl group. Examples of the aryl group of R ₃ include a phenyl group and a naphthyl group, and examples of the aralkyl group of R ₃ include a benzyl group. Also R ₃
Examples of the heterocyclic group include a pyridyl group, a quinolyl group, a thiazolyl group and a furyl group.

Further, an aryl group of R ₃ , an aralkyl group,
The heterocyclic group may have the following substituents.
Substituted or unsubstituted alkyl group such as methyl group, ethyl group and trifluoromethyl group, halogen atom of F group, Cl group, Br group, I group, alkoxy group such as methoxy group and ethoxy group, acetyl group, benzoyl group Etc., methylthio group,
Alkylthio groups such as ethylthio group, substituted amino groups such as nitro group, cyano group, dimethylamino group and diethylamino group.

An alkyl group represented by R _{4 in} the general formula [3],
Specific examples of the aryl group, aralkyl group and heterocyclic group are the same as the specific examples of R _{3 in} the general formula [2].

Specific examples of Y in the general formula [4] are as follows.
Examples thereof include O-phenylene group and O-naphthylene group. Further, these divalent groups may have a substituent such as those mentioned as the substituent for R _{3 in} the general formula [2].

Next, specific examples of the bisazo compound represented by the general formula [1] of the present invention will be described, but the bisazo compound of the present invention is not specified by this.

The position of the substituent of the bisazo compound represented by the general formula [1] is defined by the following positions.

[0024]

[Chemical 3]

[0025]

[Chemical 4]

[0026]

[Chemical 5]

[0027]

[Chemical 6]

[0028]

[Chemical 7]

Specific examples of the substituents and the substitution positions of compounds 1 to 4) are shown in compound example tables 1 to 3.

Specific examples of the substituents and the substitution positions of the compounds 5 to 8) are shown in compound example tables 4 to 5.

Specific examples of the substituents and the substitution positions of the compounds 9 to 12) are shown in compound example tables 6 to 7.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

[Table 3]

[0035]

[Table 4]

[0036]

[Table 5]

[0037]

[Table 6]

[0038]

[Table 7]

[0039]

[Table 8]

[0040]

[Table 9]

The bisazo compound represented by the above general formula [1] of the present invention can be synthesized by a known method.

Synthesis Example 1 (Synthesis of Exemplified Compound No. 3) 6,6′-Diaminocoumarinoisocoumarin 2.90 g (0.01 mol)
Was dispersed in 10 ml of hydrochloric acid and 20 ml of water, and a solution prepared by dissolving 1.4 g (0.02 mol) of sodium nitrite in 5 ml of water was added dropwise while the temperature was kept at 5 ° C or lower. After stirring for another hour at the same temperature,
Insoluble matter was removed by filtration, and ammonium hexafluorophosphate was added to the filtrate.
A solution of 4.6 g dissolved in 50 ml of water was added. The precipitated tetrazonium salt was collected by filtration, and N, N-dimethylformamide (D
MF) dissolved in 100 ml. While maintaining the temperature below 5 ° C, 2-hydroxy-3-naphthoic acid-3'-chloroanilide 5.94 g (0.
A solution of 02 mol) dissolved in 200 ml of DMF was added dropwise.

Continuing, while maintaining the temperature below 5 ° C., a solution of 6 g (0.04 mol) of triethanolamine dissolved in 30 ml of DMF was added dropwise, and the mixture was stirred at 5 ° C. or less 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 6.0 g of the desired product.

In the elemental analysis, the measured value (C = 66.5%, H = 3.12%, N = 9.33%) of this compound was the theoretical value (C = 66.2%, H = 3.09%, N = 9.26%). It was confirmed to be Exemplified Compound No. 3 which was a target product because of good agreement.

Synthesis Example 2 (Synthesis of Exemplified Compound No. 9) 2.70 g (0.01 mol) of 7,7'-diaminocoumarinoisocoumarin was dispersed in 10 ml of hydrochloric acid and 20 ml of water, and nitrite was maintained at 5 ° C or lower. A solution prepared by dissolving 1.4 g (0.02 mol) of sodium in 5 ml of water was added dropwise. After continuing stirring at the same temperature for another hour,
Insoluble matter was removed by filtration, and ammonium hexafluorophosphate was added to the filtrate.
A solution of 4.6 g dissolved in 50 ml of water was added. The precipitated tetrazonium salt was collected by filtration, and N, N-dimethylformamide (D
MF) dissolved in 100 ml. While maintaining the temperature at 5 ° C or lower, 6.62 g (0.02 mol) of 2-hydroxy-3-naphthoic acid-3'-trifluoromethylanilide was dissolved in 200 ml of DMF.

Continuously, while maintaining the temperature at 5 ° C or lower, a solution of 6 g (0.04 mol) of triethanolamine dissolved in 30 ml of DMF 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 precipitated crystals were collected by filtration, washed with DMF, washed with water and dried to obtain 6.23 g of the desired product.

In the elemental analysis, the measured value (C = 64.2%, H = 2.93%, N = 8.91%) of this compound was the theoretical value (C = 64.1%, H = 2.87%, N = 8.62%). Since they match well, it was confirmed to be Exemplified Compound No. 9 that was the target product.

Synthesis Example 3 (Synthesis of Exemplified Compound No. 24) 7.28 g (0.01 mol) of 7-methyl-6'-chloro-6,7'-diaminocoumarinoisocoumarin was dispersed in 10 ml of hydrochloric acid and 20 ml of water, While keeping the temperature below 5 ° C, add 1.4 g (0.02 mol) of sodium nitrite to water 5
The solution dissolved in ml was added dropwise. After continuing stirring at the same temperature for another 1 hour, the insoluble matter was removed by filtration, and a solution prepared by dissolving 4.6 g of ammonium hexafluorophosphate in 50 ml of water was added to the filtrate. The precipitated tetrazonium salt was collected by filtration and dissolved in 100 ml of N, N-dimethylformamide (DMF). While keeping the temperature below 5 ° C, 2-hydroxy-3-naphthoic acid-3'-trifluoromethylanilide 6.62 g (0.02 mol) was added to DMF 200 ml.
Dissolved in.

Subsequently, while maintaining the temperature below 5 ° C, 6 g (0.04 mol) of triethanolamine dissolved in 30 ml of DMF was added dropwise, and the mixture was stirred at 5 ° C or less 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 6.25 g of the desired product.

In the elemental analysis, the measured value (C = 62.6%, H = 2.92%, N = 8.34%) of this compound was the theoretical value (C = 62.2%, H = 2.84%, N = 8.22%). It was confirmed to be Exemplified Compound No. 24 which was the target product because of good agreement.

Other compounds of the present invention were also prepared in the same manner as in the above-mentioned Synthesis Example by using a substituted or unsubstituted diaminocoumarinoisocoumarin to form a tetrazo compound, and then 2-hydroxy-3-naphthoic acid-substituted or unsubstituted. It can be made by reacting a phenolic coupler such as anilide.

The bisazo compound of the present invention has excellent photoconductivity, and the electrophotographic photoconductor of the present invention can be produced by providing a photosensitive layer having the photoconductive layer dispersed in a binder on a conductive support. it can. The bisazo compound of the present invention is a so-called function-separated type photosensitizer by utilizing its excellent carrier-generating ability, using it as a carrier-generating substance, and using it together with a carrier-transporting substance that can act effectively. Can be the body. The function-separated type photoconductor may be a mixed dispersion type of the above substances, but a laminated type photoconductor in which a carrier generation layer containing a carrier generation substance comprising the bisazo compound of the present invention and a carrier transport layer are laminated. It is more preferable to use the body.

1 and 2 are sectional views showing the layer structure of the electrophotographic photosensitive member of the present invention. The electrophotographic photosensitive member of the present invention is, for example, as shown in FIG. 1 (a), a carrier 1 and a carrier-generating substance, if necessary, on a support 1 (a conductive support or a sheet on which a conductive layer is provided). A carrier-generating layer 2 containing a binder resin is used as a lower layer, and a carrier transporting layer 3 containing a carrier transporting material and a binder resin is used as an upper layer.
As shown in FIG. 1B, a carrier 1 is provided on a support 1, a carrier transporting layer 3 is provided as a lower layer, and a carrier generating layer 2 is provided as an upper layer. A body 1 on which a photosensitive layer 4 having a single layer structure containing a carrier generating substance, a carrier transporting substance and a binder resin is provided.
Etc.

The carrier transport layer is electrically connected to the above-mentioned carrier generation layer and has a function of transporting the charged carriers injected from the charge generation layer to the surface in the presence of an electric field.

In the single-layer function-separated type photoreceptor, photocarriers are generated and transported in a single layer, and the carrier generating substance and the carrier transporting substance are electrically joined in the layer, and / or Alternatively, the carrier-generating substance also contributes to the carrier transportation.

Further, both the carrier-generating substance and a part of the carrier-transporting substance may be contained in the carrier-generating layer. In any of the layer configurations, FIG. 2 (g), (h),
A protective layer may be provided on the photosensitive layer as shown in (i), and a barrier function may be provided between the support and the photosensitive layer as shown in FIGS. 1 (d), (e) and (f). An undercoat layer (intermediate layer) having adhesiveness with may be provided.

Examples of the binder resin usable in the photosensitive layer, the protective layer and the undercoat layer include polystyrene, polyethylene, polypropylene, acrylic resin, methacrylic resin,
Vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, etc.Addition polymerization resin, polyaddition resin, polycondensation Type resins and copolymer resins containing two or more of the repeating units of these resins, for example, insulating resins such as vinyl chloride-vinyl acetate-maleic anhydride copolymer resins, and poly-N-vinyl. Examples include polymer organic semiconductors such as carbazole.

Further, 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.

Examples of the secondary amine include dimethylamine, diethylamine, di-npropylamine, diisopropylamine, di-nbutylamine, diisobutylamine, di-namylamine, di-nhexylamine, diisohexylamine, diamine. -N pentyl amine, diisopentyl amine, di-n octyl amine, diisooctyl amine, di-n nonyl amine, diisononyl amine, di-n decyl amine, diisodecyl amine, di-n
Mention may be made of monodecylamine, diisomonodecylamine, di-dodecylamine, diisododecylamine and the like.

The addition amount of such organic amines is as follows.
The number of moles of the carrier-generating substance is not more than 1 time, preferably 0.2 to 0.005 times that of the carrier-generating substance.

An antioxidant may be added to the photosensitive layer of the present invention for the purpose of preventing ozone deterioration.

Typical specific examples of such an antioxidant are shown below, but the antioxidant is not limited thereto.

Group (1): hindered phenols dibutylhydroxytoluene, 2,2'-methylenebis (6-t
-Butyl-4-methylphenol), 4,4'-butylidene bis (6-t-butyl-3-methylphenol), 4,4'-thiobis (6-t-butyl-3 methylphenol), 2,2 ' -Butylidene bis (6-t-butyl-4-methylphenol), α-tocophenol, β-tocophenol, 2,2,4-trimethyl-6-hydroxy-7-t-butylchroman, pentaerythyltetrakis [3 -(3,5-di-t-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-tetramethylpiperidyl and the like.

Group 2: para-phenylenediamines N-phenyl-N'-isopropyl-p-phenylenediamine,
N, N'-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylenediamine, N, N'-dimethyl-N,
N'-di-t-butyl-p-phenylenediamine and the like.

Group 3: Hydroquinones 2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl
-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2- (2-octadecenyl) -5-methylhydroquinone and the like.

Group 4: Organophosphorus compounds Dilauryl-3,3'-thiodipropionate, distearyl
-3-3'-thiodipropionate, ditetradecyl-3,3'-thiodipropionate and the like.

These compounds are known as antioxidants for rubbers, plastics, oils and fats, etc., and commercially available products can be easily obtained.

These antioxidants may be added to the carrier generation layer, the carrier transport layer or the protective layer, but are preferably added to the carrier transport layer. In that case, the amount of the antioxidant added is 0.1 to 100 parts by weight, preferably 1 to 50 parts by weight, particularly preferably 5 to 25 parts by weight, based on 100 parts by weight of the carrier transporting substance. Next, as the conductive support for supporting the photosensitive layer, aluminum, a metal plate such as nickel, a metal drum or a metal foil is laminated, or a plastic film or a conductive film obtained by vapor deposition of aluminum, tin oxide, indium oxide or the like. It is possible to use paper coated with the substance, films such as plastics or drums.

In the present invention, the carrier generation layer is typically a dispersion prepared by dispersing the above-mentioned bisazo compound of the present invention in a suitable dispersion medium or solvent alone or together with a suitable binder resin, for example, by dip coating, spray coating, It can be provided by a method of coating on a support or an undercoat layer or a carrier transport layer by blade coating, roll coating, etc. and drying.

The bisazo compound of the present invention can be dispersed in a dispersion medium after it is made into fine particles having an appropriate particle size by using, for example, a ball mill or a sand mill. A ball mill, homomixer, sand mill, ultrasonic disperser, attritor, or the like is used to disperse the bisazo compound of the present invention.

Examples of the dispersion medium of the bisazo compound of the present invention include hydrocarbons such as hexane, benzene, toluene, xylene; methylene chloride, methylene bromide, 1,2-dichloroethane, sym-tetrachloroethane, ci.
s-1,2-dichloroethane, 1,1,2-trichloroethane, 1,2-
Halogenated hydrocarbons such as dichloropropane, chloroform, bromoform and chlorobenzene; ketones such as acetone, methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate and butyl acetate; methanol, ethanol, propanol, butanol, cyclohexanol, heptanol, Alcohols such as ethylene glycol, methylcellosolve, ethylcellosolve, acetic acid cellosolve, and derivatives thereof; ethers such as tetrahydrofuran, 1,4-dioxane, furan, furfural, acetals; pyridine, butylamine, diethylamine, ethylenediamine, isopropanolamine, etc. Amines; N,
Nitrogen compounds such as amides such as N-dimethylformamide,
In addition, one or more of fatty acids and phenols, sulfur such as carbon disulfide and triethyl phosphate, and phosphorus compounds can be used.

When the photoconductor 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 5: 0 to 500.

If the content ratio of the carrier-generating substance is less than this range, the sensitivity is low and the residual potential is increased, and if it is more than this range, the dark decay and the receptive potential are lowered.

The thickness of the carrier generating layer formed as described above is preferably 0.01 to 10 μm, and particularly preferably
It is 0.1 to 5 μm.

The carrier-transporting substance can be formed by coating and drying the carrier-transporting substance alone or dissolved and dispersed together with the binder resin in a suitable solvent or dispersion medium. As the dispersion medium used, the dispersion medium used in the dispersion of the carrier generating substance can be used.

The carrier transporting substance which can be used in the present invention is not particularly limited, and examples thereof include oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives and bis. Imidazolidine derivative, styryl compound, hydrazone compound, pyrazoline compound, amine derivative, oxazolone derivative, benzothiazole derivative, benzimidazole derivative, quinazoline derivative, benzofuran derivative, acridine derivative, phenazine derivative, aminostilbene derivative, poly-N-vinylcarbazole, Examples thereof include poly-1-vinylpyrene and poly-9-vinylanthracene.

The carrier transporting material used in the present invention is excellent in the ability to transport holes generated upon light irradiation to the support side, and is preferably used in combination with the bisazo compound of the present invention. Preferable examples of the carrier transport material include those represented by the following general formulas (A) and (B).

[0078]

[Chemical 8]

However, Ar ₁ , Ar ₂ and Ar ₄ each represent a substituted or unsubstituted aryl group, Ar ₃ represents a substituted or unsubstituted arylene group, and R represents a hydrogen atom or an alkyl group or an arylene group. Represents an unsubstituted 2 group.

Specific examples of such compounds are disclosed in JP-A-58-654.
40, p3-4 and 58-198043, p3-6.

[0081]

[Chemical 9]

However, Ar ₁ and Ar ₂ each represent a substituted or unsubstituted aryl group, Ar ₃ represents a substituted or unsubstituted arylene group, and R is a hydrogen atom or an alkyl group, or a substituted or unsubstituted arylene group. 2 groups are represented. Specific examples of such compounds are disclosed in JP-A-60-175052 and JP-A-1-9.
It is described in detail in No. 3746.

Other preferable carrier transporting substances of the present invention include hydrazone compounds, styryl compounds, aromatic amine compounds, polymer semiconductors such as polyvinylcarbazole and the like.

The carrier transport material is preferably 20 to 200 parts by weight per 100 parts by weight of the binder resin in the carrier transport layer.
It is particularly preferably 30 to 150 parts by weight.

The thickness of the carrier transport layer formed is preferably 5 to 50 μm, particularly preferably 5 to 30 μm.

The ratio of the binder in the case of a single-layer function-separated type electrophotographic photoreceptor using the bisazo compound of the present invention: the bisazo compound of the present invention: the carrier transporting substance is from 1 to 10.
0: 1 to 500: 1 to 500 are preferred, and the thickness of the photosensitive layer formed is preferably 5 to 50 μm, particularly preferably 5 to 30 μm.
Is.

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

Examples of the electron accepting substance which can be used here include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride and 3-nitrophthalic anhydride. Acid, 4-nitrophthalic anhydride, pyromellitic dianhydride,
Mellitic anhydride, tetracyano utilene, tetracyano quinodimethane, 0-dinitrobenzene, m-dinitrobenzene, 1,3,5-trinitrobenzene, paranitrobenzene nitrile, picryl clyde, quinone chlorimide, chloralil, bulmannyl, Dichlorodicyanoparabenzonone, anthraquinone, dinitroanthraquinone, 2,7-dinitrofluorenone, 2,4,7-trinitrofluorenone,
9-fluorenylidene [dicyanomethylene malonodinitrile], polynitro-9-fluorenidene- [dicyanomethylene malonodinitrile], picric acid, 0-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluoro Examples thereof include benzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, meritic acid, and other compounds having a high electron affinity. Further, the addition ratio of the electron-accepting substance is a weight ratio of the bisazo compound of the present invention: the electron-accepting substance = 100: 0.01 to 200, preferably 10
It is 0: 0.1 to 100.

This electron-accepting substance may be added to the carrier-transporting layer. The addition ratio of the electron accepting substance to such a layer is, by weight ratio, total carrier transporting substance: electron accepting substance = 100: 0.01-
It is 100, preferably 100: 0.1 to 50.

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

The electrophotographic photoreceptor containing the bisazo compound of the present invention can be sensitively sensitive to visible light and near infrared light, but preferably has an absorption maximum at a wavelength of about 400 to 700 μm. There is.

As a light source having such a wavelength, a halogen lamp, a fluorescent lamp, a tungsten lamp or the like is generally used.

The electrophotographic photosensitive member of the present invention has the above-mentioned constitution and, as will be apparent from the examples described later, is excellent in the charging property, the sensitivity property and the image forming property, and particularly when repeatedly used. Also has little fatigue deterioration and excellent durability.

[0094]

EXAMPLES The present invention will be described below in greater detail by giving Examples, but the practical use of the present invention is not limited thereby.

Examples 1 to 20 Vinyl chloride-vinyl acetate-on a conductive support formed by laminating an aluminum foil on a polyester film.
A 0.05 μm-thick intermediate layer made of maleic anhydride copolymer “S-REC MF-10” (manufactured by Sekisui Chemical Co., Ltd.) was provided, and exemplary compound Nos. 1, 3, 9, 14, 23, 11, 19 were provided thereon. , 22, 2
6, 7, 27, 33, 1, 33, 38, 47, 53, 44, 43, 71 2
g and polycarbonate resin "Panlite L-1250" (Teijin Kasei Co., Ltd.) 2 g were added to 110 ml of 1,2-dichloroethane and dispersed for 12 hours with a ball mill. This dispersion was applied so that the film thickness when dried was 0.5 μm to form a carrier generation layer,
Further thereon, as a carrier transport layer, 6 g of the following structural formula (K-1) and a polycarbonate resin “Panlite L-
A liquid obtained by dissolving 10 g of 1250 "in 80 ml of 1,2-dichloroethane was applied so that the film thickness after drying would be 15 µm to form a carrier transport layer, and photoconductors 1 to 20 of the present invention were prepared.

[0096]

[Chemical 10]

The photosensitive member obtained as described above is manufactured by
The following characteristics were evaluated using an EPA-8100 type electrostatic paper tester manufactured by Kawaguchi Denki Seisakusho. After charging for 5 seconds at a charged voltage of -6 kv, leave it for 5 seconds, then illuminance on the surface of the photoconductor is 35 lus.se.
Exposure amount (half exposure amount) E used to reduce the surface potential by half by irradiating the halogen lamp light so that it becomes c
I asked for 1/2. The surface potential (residual potential) VR after exposure with an exposure amount of 30 lus · sec was determined. 1 more similar measurement
Repeated 00 times. The results are shown in Table 1.

Comparative Example (1) The following bisazo compound (G-1) was used as a carrier generating substance.
A comparative photoreceptor was prepared in the same manner as in Example 1 except that was used.

[0099]

[Chemical 11]

When this comparative photoreceptor was measured in the same manner as in Example 1, the results shown in Table 10 were obtained.

[0101]

[Table 10]

As is clear from the above results, the photoconductor of the present invention is extremely excellent in sensitivity, residual potential and stability of repetition as compared with the photoconductor for comparison.

Examples Nos. 21 to 22 Vinyl chloride was applied to the surface of an aluminum drum having a diameter of 60 mm.
Vinyl acetate-maleic anhydride copolymer "S-REC MF-1"
0 "(manufactured by Sekisui Chemical Co., Ltd.) is provided with an intermediate layer having a thickness of 0.05 μm, on which 2 g of Exemplified Compound No. 1,75 and 2 g of polyester resin" Vylon 200 "(manufactured by Toyobo Co., Ltd.) -Dichloroethane (100 ml) was mixed and dispersed with a ball mill disperser for 24 hours to apply a dispersion so that the film thickness after drying would be 0.6 μm to form a carrier generation layer.

Furthermore, a carrier transport material (K-
1) 30g and polycarbonate resin "Iupilon Z-200"
(Mitsubishi Gas Chemical Co., Ltd.) 50 g and 1,2-dichloroethane 400 m
Photosensitive materials 21 and 22 were prepared by dissolving in 1 l and applying the solution so that the film thickness after drying was 18 μm to form a carrier transport layer.

The photoconductors 21 and 22 thus created were mounted on a modified machine of the electrophotographic copying machine "U-Bix1550MR" (made by Konica), and when the image was copied, the contrast was high and the original image was faithful. A clear copy image was obtained. Also, this did not change after 10,000 repetitions. Furthermore, this machine was placed in an environment test room under high temperature and high humidity (33 ° C, 80%), and repeated durability tests were performed. As a result, clear and clear images with high contrast were obtained even after 10,000 cycles.

Comparative Example (2) A drum-shaped comparative photoconductor was prepared in the same manner as in Example 21, except that the bisazo compound represented by the following structural formula (G-2) was used instead of the exemplified compound in Example 21. Then, when the copied image was evaluated in the same manner as in Example 21, it was found that only about 500 images with a lowered contrast or a lot of fog were obtained in repeated durability under high temperature and high humidity.

[0107]

[Chemical 12]

Examples No. 23 to 26 Vinyl chloride-vinyl acetate-on a conductive support obtained by laminating an aluminum foil on a polyester film.
A 0.05 μm-thick intermediate layer made of maleic anhydride copolymer “S-REC MF-10” (manufactured by Sekisui Chemical Co., Ltd.) was provided, and the following structural formula (K-2) was used as a carrier-transporting substance on it.
g and 10 g of the polycarbonate resin “Panlite L-1250” dissolved in 80 ml of 1,2-dichloroethane were applied so that the film thickness after drying would be 15 μm to form a carrier transport layer.

[0109]

[Chemical 13]

Furthermore, Exemplified Compound Nos. 3-9 and 5-5
0, 6-98, 7-73 2g, the carrier transport material 1.5g,
Polycarbonate resin "Panlite L-1250" 2g and 1,
In addition to 30 ml of 2-dichloroethane, a liquid dispersed by a ball mill was applied for 24 hours, and a carrier generating layer having a film thickness after drying of 4 μm was provided to prepare photoconductors Nos. 23 to 26 of the present invention.

When these photoreceptors were measured in the same manner as in Example 1, the results shown in Table 11 were obtained.

[0112]

[Table 11]

As is clear from the results of the above Examples and Comparative Examples, the photoconductor of the present invention is more stable and stable than the photoconductor for comparison.
It is remarkably excellent in sensitivity, durability, and combination with a wide range of carrier transport substances.

[0114]

Industrial Applicability According to the present invention, a specific bisazo compound having an excellent carrier generating ability is provided, and the sensitivity is high, the residual potential is small, and the characteristics thereof do not change even after repeated use, and the durability is excellent. It has been possible to provide an electrophotographic photoreceptor containing a bisazo compound that can effectively act as a carrier generating substance even in combination with a wider range of carrier transporting substances.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a layer structure of a photoconductor of the present invention.

FIG. 2 is a cross-sectional view showing a layer structure of a photoconductor of the present invention.

[Explanation of symbols]

 1 Conductive Support 2 Carrier Generation Layer 3 Carrier Transport Layer 4 Photosensitive Layer 5 Intermediate Layer 6 Protective Layer

Claims (1)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer containing a bisazo compound represented by the following general formula [1] on a conductive support. [Chemical 1] [Wherein R ₁ and R ₂ represent a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, and a cyano group, respectively, and A ₁ and A ₂ represent a coupler residue containing a hydroxyl group having a coupling ability. As shown, A ₁ and A ₂ may be the same or different. ]