JPH05241359A - 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 acting effectively as a carrier generating material even in combination with any of various carrier transferring materials and an high electrophotographic sensitive body having high sensitivity and low residual potential, maintaining these characteristics even after repeated use and excellent in durability. CONSTITUTION:A bisazo compd. represented by the formula is incorporated into the photosensitive layer of an electrophotographic sensitive body on the electric conductive substrate. In the formula, each of R1 and R2 is H, halogen, lower alkyl or lower alkoxy, each of A and B is a residue of a coupler contg. a hydroxyl group having coupling ability and A and B 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]

2. Description of the Related Art 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, so that it is difficult to manufacture, and selenium is crystallized due to heat or fingerprints 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.

In order to overcome 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 drawbacks, attempts have been made to develop a higher performance organic photoconductor by allowing different substances to have a carrier generation function and a carrier transport 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 because it is possible to relatively easily create a photoconductor having any performance, Some are put to practical use.

As a laminated type photoreceptor of this type, US Pat.
No. 871,882 using a perylene derivative as a carrier generation layer and an oxadiazole derivative in a carrier transport layer,
Further, JP-A-55-84943 discloses that a distyrylbenzene-based bisazo compound is used as a carrier generating substance and a hydrazone compound is used as a carrier transporting substance.

However, it is a fact that even in the case of this type of photoconductor, the conventional one has many advantages as well as various drawbacks.

[0006]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention In the function-separated type photoreceptor as described above, examples of using a large number of compounds as carrier generating substances are described in, for example, JP-B-43-16198. Amorphous selenium is used, which is used in combination with an organic photoconductive compound.However, the carrier generation layer made of amorphous selenium is crystallized by heat and has the disadvantage that the characteristics as a photoreceptor are deteriorated. Not improved.

Many electrophotographic photoreceptors using organic dyes or 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 transport substances.

[0008]

It is an object of the present invention to provide an electrophotographic photosensitive member having a specific bisazo compound which is excellent in carrier generating ability.

An 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 the characteristics even if it is repeatedly used.

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.

[0011]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that a specific bisazo compound can act as an excellent active ingredient of an electrophotographic photoreceptor, The present invention has been completed. 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 [1] on a conductive support.

[0012]

[Chemical 2]

R ₁ and R ₂ each represent a hydrogen atom, a halogen atom, a lower alkyl group or a lower alkoxy group, and A
And B are coupler residues containing a hydroxyl group having a coupling ability, and A and B may be the same or different.

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, for example, methyl group, ethyl group, isopropyl group, t-
A butyl group and a trifluoromethyl group are 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. Can be mentioned. R ₁ ,
As the halogen atom for R ₂ , Cl, Br, I and F can be given as specific examples.

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

[0017]

[Chemical 3]

In the general formula [2], X represents a residue which is condensed with a benzene ring to form a polycyclic aromatic ring or hetero ring, and R
₃ represents a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group, an aryl group or a heterocyclic group.

In the general formula [3], R ₄ represents an optionally substituted alkyl group, aralkyl group, aryl group or heterocyclic group.

Further, in the general formula [4], Y represents a divalent group of an aromatic hydrocarbon or a divalent group forming a heterocycle with a nitrogen atom.

Specific examples of the polycyclic aromatic ring and 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. The alkyl group for R ₃ is, for example, a methyl group,
Examples thereof include substituted and unsubstituted alkyl groups such as ethyl group, propyl group, butyl group, 2-hydroxyethyl group and 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. Examples of the heterocyclic group of R ₃ include pyridyl group, quinolyl group, thiazolyl group, furyl group and the like.

Further, the aryl group, aralkyl group and heterocyclic group of R ₃ may have the following substituents. Substitution of methyl group, ethyl group, trifluoromethyl group, etc.,
Unsubstituted alkyl group, halogen atom of F group, C1 group, Br group, I group, alkoxy group such as methoxy group, ethoxy group, alkylthio group such as acetyl group, benzoyl group, methylthio group, ethylthio group, nitro group, Substituted amino groups such as 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 similar to those of R ₃ in the general formula [2].

As a specific example of Y in the general formula [4],
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 above general formula [1] of the present invention will be described, but the bisazo compound of the present invention is not limited thereto.

[0026]

[Chemical 4]

[0027]

[Chemical 5]

[0028]

[Chemical 6]

[0029]

[Chemical 7]

[0030]

[Chemical 8]

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) 4,4'-Dithioaniline 2.48 g (0.01 mol) was added to concentrated hydrochloric acid 10 ml,
A solution prepared by dissolving 1.4 g (0.02 mol) of sodium nitrite in 5 ml of water was added dropwise while dispersing in 20 ml of water and keeping the temperature below 5 ° C. After continuing stirring at the same temperature for 1 hour, insoluble matter was removed by filtration, and 4.6 g of ammonium hexafluorophosphate was added to the filtrate.
A solution dissolved in 0 ml was added. The precipitated tetrazonium salt was collected by filtration and N, N-dimethylformamide (DMF) 100 ml
Dissolved in. 2-hydroxy-3-while keeping below 5 ℃
Naphthoic acid-3'-chloroanilide 5.94 g (0.02 mol) D
A solution dissolved in 200 ml of MF was added dropwise. Subsequently, while maintaining the temperature at 5 ° C or lower, 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 6.0 g of the desired product.

In the elemental analysis, the measured value (C = 66.9%, H = 3.59%, N = 10.8%) of this compound was the theoretical value (C = 66.6%, H = 3.62%, N = 10.1%). Since there is a good agreement, the target compound No. It was confirmed to be 3.

Synthesis Example 2 (Synthesis of Exemplified Compound No. 9) 2.48 g (0.01 mol) of 4,4'-dithioaniline was added to 10 ml of concentrated hydrochloric acid,
A solution prepared by dissolving 1.4 g (0.02 mol) of sodium nitrite in 5 ml of water was added dropwise while dispersing in 20 ml of water and keeping the temperature below 5 ° C. After continuing stirring at the same temperature for 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 N, N-dimethylformamide (DMF) 10
It was dissolved in 0 ml. 2-Hydroxy-while maintaining below 5 ℃
3-Naphthoic acid-3'-trifluoromethylanilide 6.62g
(0.02 mol) was dissolved in 200 ml of DMF.

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 6.23 g of the desired product.

In the elemental analysis, the measured value (C = 62.1%, H = 3.32%, N = 9.3%) of this compound was the theoretical value (C = 61.8%, H = 3.22%, N = 9.0%). Since there is a good agreement, the target compound No. It was confirmed to be 9.

Synthesis Example 3 (Synthesis of Exemplified Compound No. 32) 3.13 g (0.01 mol) of 2-fluoromethyl-4,4′-dithioaniline was dispersed in 10 ml of concentrated hydrochloric acid and 20 ml of water, and the temperature was kept at 5 ° C. or lower. A solution prepared by dissolving 1.4 g (0.02 mol) of sodium nitrite in 5 ml of water was added dropwise. After continuing stirring at the same temperature for 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 maintaining the temperature below 5 ° C., 6.62 g (0.02 mol) of 2-hydroxy-3-naphthoic acid-3′-trifluoromethylanilide was dissolved in 200 ml of DMF.

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 = 59.2%, H = 2.83%, N = 8.63%) of this compound was the theoretical value (C = 58.9%, H = 2.7%, N = 8.4%). Since there is a good agreement, the target compound No. It was confirmed to be 32.

In the same manner as in the above-mentioned Synthesis Examples, other compounds of the present invention also form a tetrazo body using a substituted or unsubstituted benzyl, and then a phenol such as 2-hydroxy-3-naphthoic acid-substituted or unsubstituted anilide. It can be made by reacting a sex coupler.

The bisazo compound of the present invention has excellent photoconductivity, and the electrophotographic photoreceptor 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 utilizes what is called a carrier-generating substance by utilizing its excellent carrier-generating ability, and a carrier-transporting substance capable of effectively acting in combination with the bisazo compound is used together to obtain a so-called functional separation. Can be a photoconductor of the type.

The function-separated type photoreceptor may be a mixed dispersion type of the above-mentioned substances, but a carrier-generating layer containing a carrier-generating substance comprising the bisazo compound of the present invention,
It is more preferable to use a laminated type photoreceptor in which a carrier transport layer is laminated.

The electrophotographic photosensitive member of the present invention is, for example, as shown in FIG.
As shown in (a), a carrier generation layer 2 containing a carrier generation substance and optionally a binder resin is used as a lower layer on a support 1 (a conductive support or a sheet on which a conductive layer is provided), A photosensitive layer 4 having a laminated structure of a function separation type having a carrier transporting layer 3 containing a carrier transporting substance and a binder resin as an upper layer, and a support 1 as shown in FIG.
A photosensitive layer 4 having a laminated structure in which the carrier transporting layer 3 is a lower layer and the carrier generating layer 2 is an upper layer, and FIG.
As shown in (c), the support 1 may be provided with a single-layer photosensitive layer 4 containing a carrier-generating substance, a carrier-transporting substance and a binder resin.

In the case of a photosensitive layer having a laminated structure, the carrier generation layer absorbs most of the incident light amount by the charge generation layer to generate a large number of charge generation carriers, and recombines or traps (traps) the generated charge carriers. Therefore, it is preferable to make the layer as thin as possible within the range of a film thickness sufficient to generate photocarriers for injecting into the carrier transport layer without deactivation.

Further, the carrier transport layer is electrically joined 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 case of the function-separated type photoreceptor having a single-layer structure, photocarriers are generated and transported in a single layer. Whether the carrier-generating substance and the carrier-transporting substance are electrically joined in the layer, and / Alternatively, the carrier generating substance also contributes to the carrier transportation.

Further, the carrier generating layer may contain both the carrier generating substance and a part of the carrier transporting substance. In any of the layer configurations, a protective layer may be provided on the photosensitive layer, and further, as shown in FIGS. (A) to (f), a protective layer having a barrier function and an adhesive property may be provided between the support and the photosensitive layer. A pulling layer (intermediate layer) may be provided.

Binder resins usable for the photosensitive layer, the protective layer and the undercoat layer are, for example, 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 type resin, polyaddition type resin, polycondensation type resin Poly-N-vinylcarbazole in addition to insulating resins such as vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, etc. Polymer organic semiconductors such as

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, dipropylamine, diidpropylamine, dibutylamine, diisobutylamine, diamylamine, dihexylamine, diisohexylamine, dipentylamine, diisopentylamine,
Examples thereof include dioctylamine, diisooctylamine, dinonylamine, diisononylamine, didecylamine, diisodecylamine, dimonodecylamine, diisomonodecylamine, di-dodecylamine and diisododecylamine.

The amount of such organic amines added is
The number of moles of the carrier-generating substance is equal to or less than that of the carrier-generating substance, preferably 0.2 to 0.005 times.

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

Typical specific examples of such an antioxidant are shown below, but the invention 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-butyl chroman, pentaerythyl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl)
Propionate], 1,6-hexanediol bis [3- (3,5
-Di-t-butyl-4-hydroxyphenyl) propionate], butylhydroxyanisole, dibutylhydroxyanisole, 1- [2-{(3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy} ethyl] -4- 〔3- (3,5-
Di-t-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 etc.

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 etc.

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, and particularly preferably 5 to 25 parts by weight, based on 100 parts by weight of the carrier transport 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,
Alternatively, a plastic film deposited with aluminum, tin oxide, indium oxide, or the like, a paper coated with a conductive material, a film of plastic, or a drum can be used.

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, 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 using, for example, a ball mill or a sand mill. To disperse the bisazo compound of the present invention, a ball mill, a homomixer,
A sand mill, an ultrasonic disperser, an attritor, etc. are used.

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, chlorobenzene; ketones such as acetone, methyl ethyl ketone, cyclohexanone; esters such as ethyl acetate, butyl acetate; methanol, ethanol, propanol, butanol, cyclohexanol, heptanol, Alcohols such as ethylene glycol, methyl cellosolve, ethyl cellosolve, acetic acid cellosolve and their derivatives; ethers such as tetrahydrofuran, 1,4-dioxane, furan, furfural, acetals; pyridine, butylamine, diethylamine, ethylenediamine, isopropanolamine, etc. Amines; N,
One or more nitrogen compounds such as amides such as N-dimethylformamide, other fatty acids and phenols, sulfur such as carbon disulfide and triethyl phosphate, phosphorus compounds and the like 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 5: 0 to 500.

If the content ratio of the carrier-generating substance is less than the above range, the sensitivity is low and the residual potential is increased, and if it exceeds 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 may be formed by coating and drying a carrier-transporting substance alone or dissolved and dispersed with the above-mentioned 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 that can be used in the present invention is not particularly limited, but 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. Preferred examples of the carrier transport material include those represented by the following general formulas (A) and (B).

[0070]

[Chemical 9]

However, in the general formula (A), Ar ₁ and Ar ₂ each represent a substituted or unsubstituted aryl group, Ar ₃ represents a substituted or unsubstituted arylene group, and R represents a hydrogen atom, an alkyl group or an arylene group. It represents two groups of substituted and unsubstituted groups.

Specific examples of such compounds are disclosed in JP-A-58-654.
40, pp. 3-4 and 58-198043, pp. 3-6.

Further, in the general formula (B), Ar ₁ and Ar ₂ each represent a substituted or unsubstituted aryl group, Ar ₃ represents a substituted or unsubstituted arylene group, and R represents a hydrogen atom, an alkyl group or an arylene group. Represents a substituted or unsubstituted group of 2 groups.

Specific examples of such compounds are disclosed in JP-A-60-175.
It is described in detail in No. 052 and JP-A No. 1-93746.

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

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.

Further, in the case of a single-layer functionally separated type electrophotographic photoreceptor using the bisazo compound of the present invention, the ratio of the binder: the bisazo compound of the present invention: the carrier transporting substance is 1 to 10.
0: 1 to 500: 1 to 500 is preferable, the thickness of the photosensitive layer formed is preferably 5 to 50 μm, particularly preferably 5 to 30 μm.
m.

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. , 4-Nitrophthalic anhydride, Pyromellitic dianhydride, Mellitic anhydride, Tetracyanourylene, Tetracyanoquinodimethane, ο-Dinitrobenzene, m-Dinitrobenzene, 1,3,5-Trinitrobenzene, Paranitrobenzenenitrile , Picryl clyde, quinone chlorimide, chloralyl, bulmannyl, dichlorodicyanoparabenzonone, anthraquinone, dinitroanotraquinone, 2,7-dinitrofluorenone, 2,4,7-trinitrofluorenone,
9-fluorenylidene [dicyanomethylene malonodinitrile], polynitro-9-fluorenylidene- [dicyanomethylene malonodinitrile], picric acid, ο-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
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.
-100, preferably 100: 0.1-50.

In addition, the photoreceptor of the present invention may further contain an ultraviolet absorber, an antioxidant or the like for the purpose of protecting the photosensitive layer, if necessary, and may further 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 rays and near infrared rays, but preferably has an absorption maximum at a wavelength between about 400 and 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, especially when repeatedly used. Also has little fatigue deterioration and excellent durability.

[0086]

EXAMPLES The present invention will be specifically described below with reference to examples, but the embodiments of the present invention are not limited thereby.

Examples 1 to 20 Vinyl chloride-vinyl acetate-maleic anhydride copolymer "S-REC MF-10" (manufactured by Sekisui Chemical Co., Ltd.) on a conductive support obtained by laminating an aluminum foil on a polyester film. And an exemplary compound No. 1,3,7,9,12,15,17,21,2
2, 24, 27, 29, 31, 32, 34, 37, 40, 41, 45, 50 2g
And 2 g of polycarbonate resin "Panlite L-1250" (Teijin Kasei Co., Ltd.) were added to 110 ml of 1,2-dichloroethane and dispersed by a ball mill for 12 hours. 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 transporting layer, 6 g of the following structural formula (K-1) and 10 g of polycarbonate resin “Panlite L-1250” dissolved in 80 ml of 1,2-dichloroethane had a film thickness of 15 μm after drying. To form a carrier-transporting layer, to prepare photoconductors 1 to 20 of the invention.

The photosensitive member obtained as described above was manufactured by
The following characteristics were evaluated using an EPA-8100 type electrostatic paper testing machine manufactured by Kawaguchi Denki Seisakusho. After charging for 5 seconds at a charging voltage of -6 kv, leave it for 5 seconds, and then illuminance on the surface of the photoconductor is 35 lus.s.
The amount of exposure required to halve the surface potential by irradiating it with halogen lamp light to ec (half-exposure amount) E
I asked for 1/2. Further, the surface potential (residual potential) V _R after exposure with an exposure amount of 30 lus · sec was determined. The same measurement was repeated 100 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.

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

[0091]

[Chemical 10]

[0092]

[Table 1]

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 21 to 22 Vinyl chloride on the surface of an aluminum drum having a diameter of 60 mm
Vinyl acetate-maleic anhydride copolymer "ESREC MF
-10 "(manufactured by Sekisui Chemical Co., Ltd.), and an intermediate layer having a thickness of 0.05 μm is provided, and the exemplified compound No. 2g of 2,45 and 2g of polyester resin "Byron 200" (manufactured by Toyobo Co., Ltd.)
The carrier generation layer was formed by mixing 100 ml of 1,2-dichloroethane and coating the dispersion with a ball mill disperser for 24 hours so that the film thickness after drying would be 0.6 μm.

Furthermore, a carrier transporting material (K-
1) 30g and polycarbonate resin "Iupilon Z-200"
(Mitsubishi Gas Chemical Co., Ltd.) 50 g and 1,2-dichloroethane 400 ml
Was dissolved in the solution and coated so that the film thickness after drying would be 18 μm to form a carrier transport layer, and photoconductors 21 and 22 were produced.

The photoconductors 21 and 22 thus prepared were mounted on a modified machine of the electrophotographic copying machine "U-Bix1550MR" (manufactured 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 cycles. Furthermore,
When this machine was repeatedly tested for durability in an environment test room under high temperature and high humidity (33 ° C, 80%), a clear, high-contrast copy image was obtained even after 10,000 cycles.

Comparative Example (2) A drum-shaped comparative photosensitive member was prepared in the same manner as in Example 21 except that the exemplifying compound in Example 21 was replaced with the bisazo compound represented by the following structural formula (G-2). When prepared and evaluated in the same manner as in Example 21, a copy image was evaluated, and in repeated durability under high temperature and high humidity, the contrast decreased from about 500 times, and only an image with a large fog was obtained.

Examples 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 6 g of the following structural formula (K-2) as a carrier transporting substance and a polycarbonate were provided thereon. Resin "Panlite L-1250" 10g
A solution obtained by dissolving and was dissolved 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.

Furthermore, the exemplified compound No. 1, 20, 32,
2 g of 38, 1.5 g of the carrier-transporting substance, and 2 g of the polycarbonate resin "Panlite L-1250" were added to 30 ml of 1,2-dichloroethane, and the dispersion was applied by a ball mill for 24 hours, and the film thickness after drying was 4 μm. And a carrier generating layer of Created 23-26.

When these photoreceptors were measured in the same manner as in Example 1, the results shown in Table 2 were obtained.

[0101]

[Chemical 11]

[0102]

[Table 2]

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 materials.

[Brief description of drawings]

1 (a) to 1 (f) are cross-sectional views showing the layer structure of a photoreceptor 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] [R ₁ and R ₂ represent a hydrogen atom, a halogen atom, a lower alkyl group and a lower alkoxy group, respectively, A and B represent a coupler residue containing a hydroxyl group having a coupling ability, and A and B are the same. Or may be different. ]