JP2650715B2 - Electrophotographic photoreceptor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a photoreceptor for electrophotography, and more particularly, to a photoreceptor containing a bisazo pigment as a substance that generates charge carriers when irradiated with light (hereinafter referred to as “charge generation substance”). The present invention relates to an electrophotographic photosensitive member provided with a photosensitive layer.

As a photoconductor for electrophotography, an inorganic photoconductor using selenium and an alloy thereof, or a photoconductor in which dye-sensitized zinc oxide is dispersed in a binder resin, and an organic photoconductor. Representative examples include those using a charge transfer complex of 2,4,7-trinitro-9-fluorenone (hereinafter referred to as “TNF”) and poly-N-vinylcarbazole (hereinafter referred to as “PVK”). ing.

However, these photoreceptors have many advantages as well as various disadvantages. For example, the currently widely used selenium photoreceptor is difficult to manufacture, expensive to manufacture, difficult to process into a belt due to lack of flexibility, and sensitive to heat and mechanical shock. Therefore, care is required for handling. The zinc oxide photoreceptor can be manufactured by coating it on a support using inexpensive zinc oxide, so the cost is low, but generally the sensitivity is low, and the surface smoothness, hardness, tensile strength, friction resistance, etc. There is a mechanical defect, and there are many problems in durability and the like as a photoreceptor for a plain paper copying machine that is usually used repeatedly. A photoreceptor using a charge transfer complex of TNF and PVK has low sensitivity and is not suitable as a photoreceptor for a high-speed copying machine.

In recent years, extensive research has been conducted to eliminate the disadvantages of these photoconductors, and various organic photoconductors have been proposed. Among them, a laminated photoreceptor in which a thin film of an organic pigment is formed on a conductive support (a charge generation layer) and a layer mainly composed of a charge transport material (a charge transport layer) is formed thereon is a conventional organic material. Compared with the photoreceptor described above, the photoreceptor for plain paper copying machines has attracted attention because of its general sensitivity and stable chargeability, and some of the photoreceptors are practically used.

(1) A charge generating layer using a thin layer obtained by vacuum-depositing a perylene derivative and a charge transport layer using an oxadiazole derivative (see US Pat. No. 3,871,882). A thin layer formed by applying an organic amine solution of chlordiane blue as a generating layer, and using a hydrazone compound for a charge transport layer (see Japanese Patent Publication No. 55-42380). (3) Distyryl as a charge generating layer There are known ones using a thin layer formed by applying an organic solvent dispersion of a benzene-based bisazo compound and using a hydrazone compound for the charge transport layer (see JP-A-55-84943).

However, even with this type of laminated photoreceptor, the conventional one has many advantages as well as various disadvantages. That is, it has the following disadvantages.

The photoreceptor using the perylene derivative and the oxadiazole derivative shown in (1) has low sensitivity for higher-speed copying machines, even though there is no practical problem. Further, the perylene derivative, which is a charge generating substance that controls the spectral sensitivity of this photoconductor, is not suitable as a photoconductor for a color copying machine because it does not absorb over the entire visible range.

The photoreceptor using chlordiane blue and a hydrazone compound shown in (2) has relatively high sensitivity, but requires an organic amine (eg, ethylenediamine) which is generally difficult to handle as a coating solvent for forming a charge generation layer. And there are many disadvantages in producing the photoreceptor.

The photoreceptor using a distyrylbenzene-based bisazo compound and a hydrazone compound shown in (3) is very advantageous in production since a charge generation layer can be easily formed by applying a dispersion liquid of the bisazo compound. However, since the sensitivity is slightly low, it is insufficient as a photosensitive member for a high-speed copying machine.
On the other hand, in recent years, the demand for photoconductors for laser printers has been increasing, and development of high-sensitivity photoconductors particularly in the wavelength range of semiconductor lasers has been desired. However, the photoconductors described above have extremely high sensitivity to these semiconductor lasers. The fact is that it is low and cannot be put to practical use.

An object of the present invention is to provide a photoreceptor which overcomes the above-mentioned conventional disadvantages, has a flat sensitivity over the entire visible range and the oscillation wavelength range of a semiconductor laser, and is easy to manufacture. The purpose is to provide the body.

Structure As a result of intensive studies to achieve the above object, the present inventor has found that a general formula (I) (Wherein, Ar represents a coupler residue) The present inventors have found that the object can be achieved by providing a photoconductor for electrophotography, wherein a layer containing a bisazo pigment represented by the following formula as an active ingredient is formed: Was.

Ar used for the production of the bisazo compound of the general formula (I)
Examples of the coupler represented by H include aromatic hydrocarbon compounds having a hydroxyl group such as phenols and naphthols, heterocyclic compounds having a hydroxyl group, aromatic hydrocarbon compounds having an amino group, and heterocyclic compounds having an amino group. Formula compounds, aromatic hydrocarbon compounds having a hydroxyl group and an amino group such as aminonaphthols and heterocyclic compounds, compounds having an aliphatic or aromatic enol ketone group (compounds having an active methylene group), and the like are used. Preferably, the coupler residue Ar has the following general formula (II), (III), (IV), (V), (VI), (VII),
They are represented by the general formulas (VIII), (IX), (X), (XI) and (XII).

[X, Y in the above formulas (II), (III), (IV) and (V)]
₁ , Z, m and n represent the following, respectively.

Or —NHSO ₂ —R ₃ (R ₁ and R ₂ represent hydrogen or a substituted or unsubstituted alkyl group, and R ₃ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group.) Y ₁ : Hydrogen, halogen, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, carboxy group, sulfo group, substituted or unsubstituted sulfamoyl group or (R ₄ represents hydrogen, an alkyl group or a substituted product thereof, a phenyl group or a substituted product thereof, Y ₂ represents a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof, or (Provided that R ₅ represents a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof, or a styryl group or a substituted product thereof, R ₆ represents a hydrogen atom, an alkyl group, a phenyl group or a substituted product thereof, or ₅ and R ₆ may form a ring together with the carbon atom to which they are attached.) Z: a hydrocarbon ring or a substituent thereof or a heterocycle or a substituent thereof n: an integer of 1 or 2 m: an integer of 1 or 2] [In the formulas (VI) and (VII), R ₇ represents a substituted or unsubstituted hydrocarbon group, and X is the same as described above. ] [Wherein, R ₈ represents an alkyl group, a carbamoyl group, a carboxyl group or an ester thereof, Ar ₁ represents a hydrocarbon ring group or a substituted product thereof, and X is the same as described above. ] [In the above formulas (IX) and (X), R ₉ represents hydrogen or a substituted or unsubstituted hydrocarbon group, and Ar ₂ represents a hydrocarbon ring group or a substituted product thereof. Examples of the hydrocarbon ring of Z in the general formulas (II), (III), (IV) and (V) include a benzene ring and a naphthalene ring, and examples of the heterocyclic ring include an indole ring, a carbazole ring and a benzolane ring. And the like. Examples of the substituent in the ring of Z include a halogen atom such as a chlorine atom and a bromine atom and an alkoxy group.

Examples of the hydrocarbon ring group for Y ₂ or R ₅ include a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group and the like, and examples of the heterocyclic group include a pyridyl group, a cyenyl group, a furyl group, an indolyl group, a benzofuranyl group, and a carbazolyl group. Group, a dibenzofuranyl group, and the like. Examples of the ring formed by combining R ₅ and R ₆ include a fluorene ring.

Y ₂ or R ₅ hydrocarbon ring group or heterocyclic group or R ₅
And a substituent in the ring formed by R ₆ is a methyl group, an ethyl group, a propyl group, an alkyl group such as a butyl group, a methoxy group, an ethoxy group, a propoxy group,
Alkoxy groups such as butoxy group, halogen atoms such as chlorine atom and bromine atom, dialkylamino groups such as dimethylamino group, diethylamino group, diaralkylamino groups such as dibenzylamino group, halomethyl groups such as trifluoromethyl group, and nitro Groups, cyano groups, carboxyl groups or esters thereof, hydroxyl groups, sulfonic acid groups such as —SO ₃ Na, and the like.

Examples of the substituent of the phenyl group for R ₄ include a halogen atom such as a chlorine atom or a bromine atom.

Representative examples of the hydrocarbon group for R ₇ or R ₉ include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, an aralkyl group such as a benzyl group, an aryl group such as a phenyl group, or a substituted product thereof. Can be illustrated.

Examples of the substituent in the hydrocarbon group of R ₇ or R ₉ include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a methoxy group, an ethoxy group, a propoxy group, an alkoxy group such as a butoxy group, a chlorine atom, Examples thereof include a halogen atom such as a bromine atom, a hydroxyl group, and a nitro group.

Examples of the hydrocarbon ring group in Ar ₁ or Ar ₂ include a phenyl group and a naphthyl group, and the substituents in these groups include a methyl group, an ethyl group,
Propyl group, alkyl group such as butyl group, methoxy group,
Examples thereof include alkoxy groups such as ethoxy group, propoxy group and butoxy group, halogen atoms such as nitro group, chlorine atom and bromine atom, and dialkylamino groups such as cyano group, dimethylamino group and diethylamino group.

 Among X, a hydroxyl group is particularly suitable.

Among the above coupler residues, preferred are those represented by the above general formulas (III), (VI), (VII), (VIII), (IX) and (X), wherein X in the general formula is a hydroxyl group Are preferred. Among them, the general formula (XI) (Y ₁ and Z are the same as described above.). (Z, Y ₂ and R ₂ are the same as described above.)

Furthermore, among the above preferred coupler residues, general formula (XIII) or (XIV) (Z, R ₂ , R ₅ and R ₆ are the same as those described above, and R ₁₀ is exemplified by the substituents of Y ₂ described above.).

Specific examples of the bisazo pigment used in the present invention as described above are shown by the structural formulas below. For simplicity, only the structural formula of Ar as a coupler residue is shown.

By using the bisazo pigment of the present invention as described above, an extremely sensitive electrophotographic photoreceptor can be easily produced.

The bisazo pigment of the present invention may be, for example, 1,10-bis (4-nitrophenyl) -1,3,5,
1,10-bis (4-aminophenyl) -1,3,5,7,9-decapentaene obtained by reducing 7,9-decapentaene is diazotized by a conventional method to form a bis (diazonium) salt. The (diazonium) salt and the corresponding coupler can be easily produced by allowing a base to act in a suitable organic solvent such as N, N-dimethylformamide to carry out a coupling reaction. As an example, a production example of the above-mentioned No. 58 bisazo pigment is shown below. Other bisazo pigments can be easily produced according to this production example except that the coupler is changed.

Production Example of Bisazo Pigment 30.0 g of 1,10-bis (4-aminophenyl) -1,3,5,7,9-decapentaene was added to 425 ml of a 15% by volume aqueous sulfuric acid solution.
Stirred at 50 ° C. for 90 minutes. After rapidly cooling to −5 ° C., a solution obtained by dissolving 14.46 g of sodium nitrite in 45 ml of water was −5 ° C. to −3 ° C.
It was added dropwise at 90 ° C. over 90 minutes. Then, after stirring at -5 ° C for 30 minutes, the product was filtered. The filter residue was dissolved in cold water 10 and trace amounts of insolubles were removed by filtration together with celite.
An aqueous borofluoric acid solution was added, and the precipitated crystals were collected by filtration, dried, and dark red bis (diazonium) salt 42.1 g (yield 86.0)
g) (decomposition point 120 ° C.).

According to the infrared absorption spectrum (KBr tablet method) of the bis (diazonium) salt thus obtained, 2230 cm ⁻¹
The absorption due to the stretching vibration of the diazonium salt and the absorption due to the out-of-plane bending vibration of the transolefin were observed at 1010 cm ^-1 .

2-hydroxy-3-phenylcarbamoyl-11H-
Dissolve 0.74 g of benzo [a] carbazole in 100 ml of DMF,
The bis (diazonium) obtained as described above
After adding 0.51 g of salt, 4 ml of 8.6% aqueous sodium acetate solution was added dropwise at room temperature. After the dropwise addition, the mixture was stirred at room temperature for 3 hours, and the formed precipitate was collected by filtration and washed with 200 ml of DMF seven times.
It was washed twice with water and dried to obtain 0.96 g (yield 92%) of a bisazo pigment represented by the following formula of blueish black powder.

Thermal analysis (DSC); 283 ° C. (exothermic peak temperature) Elemental analysis value (%) Actual value calculated value as C ₆₈ H ₄₈ N ₈ O ₄ C 78.66 78.43 H 4.62 4.66 N 10.49 10.76 Visible spectrum (10 vol% ethylenediamine DMF) ) Λm
ax 621 nm The infrared absorption spectrum (KBr tablet method) of this product is shown in FIG. 3. The C ＝ O stretching vibration of the second amide at 1670 cm ⁻¹ and the out-of-plane bending vibration of trans olefin at 1005 cm ⁻¹ are shown. Absorption was observed.

In the electrophotographic photoreceptor of the present invention, a bisazo pigment is used as a charge generating substance in a photosensitive layer, and a typical configuration of this photoreceptor is shown in FIGS. 1 and 2.

The photoreceptor shown in FIG. 1 has a laminated photosensitive layer 191 composed of a charge generation layer 15 mainly composed of a bisazo pigment 13 and a charge transport layer 17 mainly composed of a charge transport substance, on a conductive support 11. It is a thing.

In the photoreceptor shown in FIG. 1, the image-exposed light passes through the charge transport layer, reaches the charge generation layer 15, and charges are generated in the bisazo pigment 13 in that portion, while the charge transport layer 17 is charged. The charge is transported by the bisazo pigment 13, and the charge is transported by the charge transport layer 17.

The photosensitive member shown in FIG. 2 has a photosensitive layer 192 mainly composed of a bisazo pigment 13, a charge transport material and an insulating binder provided on a conductive support 11. Here too bisazo pigment 13
Is a charge generating substance.

As another photosensitive member, the charge generation layer and the charge transport layer in FIG. 1 can be reversed.

The thickness of the photosensitive layer is as shown in FIG. 1, and the thickness of the charge generation layer 15 is preferably 0.01 to 5 μm, more preferably 0.05 to 2 μm. When the thickness is 0.01 μm or less, the generation of electric charges is not sufficient, and when the thickness is 5 μm or more, the residual potential is high and cannot be put to practical use. The thickness of the charge transport layer 17 is preferably 3 to 50 μm,
More preferably, it is 5 to 20 μm. When the thickness is 3 μm or less, the charge amount is insufficient, and when the thickness is 50 μm or more, the residual potential is high and not practical.

The charge generation layer 15 is mainly composed of the bisazo pigment represented by the above general formula, and can further contain a binder, a plasticizer, and the like. The proportion of the bisazo pigment in the charge generation layer is preferably at least 30% by weight, more preferably at least 50% by weight.

The charge transport layer 17 is mainly composed of a charge transport material and a binder, and may further contain a plasticizer or the like. The proportion of the charge transport material in the charge transport layer is 10 to 95% by weight, preferably 30 to 95%.
90% by weight. 10% by weight of charge transport material
When the charge is less than the value, the charge is hardly transported, and
If the content is more than 95% by weight, the mechanical strength of the photoreceptor film is extremely poor and cannot be put to practical use.

In the case of the photoreceptor shown in FIG. 2, the thickness of the photosensitive layer 192 is preferably 3 to 50 μm, more preferably 5 to 20 μm. Further, the proportion of the bisazo pigment in the photoreceptor 192 is preferably 50% by weight or less, more preferably 20% by weight or less, and the proportion of the charge transporting substance is preferably 10 to 95% by weight, more preferably 30 to 90% by weight. % By weight.

The present invention is based on the use of the specific bisazo pigment represented by the general formula (I) as a charge generating material in an electrophotographic photoreceptor. As the components, any of conventionally known components can be used, and they will be specifically described below.

As the conductive support used in the photoreceptor of the present invention, aluminum, copper, a metal plate such as zinc, a plastic sheet or plastic film of polyester or the like, aluminum, a conductive material such as SnO ₂ is deposited, or a conductive material. Processed paper or the like is used.

Examples of the binder include condensation resins such as polyamide, polyurethane, polyester, epoxy resin, polyketone, polycarbonate, and polyacetal and polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, and vinyl polymers such as polyacrylamide. All insulating and adhesive resins can be used.

Examples of the plasticizer include halogenated paraffin, polychlorinated biphenyl, dimethylnaphthalene, dibutylphthalate, and the like. In addition, silicone oil or the like may be added to improve the surface properties of the photoconductor.

Charge transport materials include hole transport materials and electron transport materials. Examples of the hole transport material include compounds represented by the following general formulas (1) to (11).

Wherein R ₁₁₅ represents a methyl group, an ethyl group, a 2-hydroxyethyl group or a 2-chloroethyl group; R ₁₂₅ represents a methyl group, an ethyl group, a benzyl group or a phenyl group;
₁₃₅ is hydrogen, chlorine, bromine, an alkyl group having 1 to 4 carbon atoms,
Represents an alkoxy group having 1 to 4 carbon atoms, a dialkylamino group or a nitro group. ] [In the formula, Ar ₃ represents a naphthalene ring, an anthracene ring, a styryl group or a substituted product thereof, or a pyridine ring, a furan ring, or a thiophene ring, and R ₁₄₅ represents an alkyl group or a benzyl group. ] Wherein R ₁₅₅ is an alkyl group, a benzyl group, a phenyl group,
Represents a naphthyl group, R ₁₆₅ represents hydrogen, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group, a diaralkylamino group or a diarylamino group, and n is an integer of 1 to 4 And when n is 2 or more, R ₁₆₅ may be the same or different. R ₁₇₅ represents hydrogen or a methoxy group. ] [In the formula, R ₁₈₅ represents an alkyl group having 1 to 11 carbon atoms, a substituted or unsubstituted phenyl group or a heterocyclic group, and R ₁₉₅ R ₂₀₅
May be the same or different, each represents hydrogen, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, a chloroalkyl group, a substituted or unsubstituted aralkyl group, and R ₁₉₅ and R ₂₀₅ are bonded to each other; It may form a heterocycle containing nitrogen. R ₁₂₅ may be the same or different and represents hydrogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, or halogen. ] Wherein, R ₂₂₅ represents a hydrogen or halogen atom, Ar ₄
Represents a substituted or unsubstituted phenyl group, naphthyl group, anthryl group or carbazolyl group. ] Wherein R ₂₃₅ is hydrogen, halogen, cyano,
Represents an alkoxy group of 4 or an alkyl group having 1 to 4 carbon atoms, and Ar ₅ is R ₂₄₅ represents an alkyl group having 1 to 4 carbon atoms;
₂₅₅ represents hydrogen, halogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a dialkylamino group, and n is 1 or 2, and when n is 2, R ₂₅₅
May be the same or different, and R ₂₆₅ and R ₂₇₅ represent hydrogen, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted benzyl group. ] Wherein R ₂₈₅ and R ₂₉₅ are a carbazolyl group, a pyridyl group,
A phenyl group, an indolyl group, a furyl group or a substituted or unsubstituted phenyl group, a styryl group, a naphthyl group or an anthryl group, each of which is a dialkylamino group, an alkyl group, an alkoxy group, a carboxy group or an ester thereof. , A halogen atom, a cyano group, an aralkylamino group, an N-alkyl-N aralkylamino group, an amino group, a nitro group and an acetylamino group. ] Wherein R ₃₀₅ represents a lower alkyl group or a benzyl group; R ₃₁₅ represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a nitro group, an amino group or an amino group substituted with a lower alkyl group or a benzyl group. And n represents an integer of 1 or 2. ] Wherein, R ₃₂₅ represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, R ₃₃₅ and R ₃₄₅ represents an alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, R ₃₅₅ represents a hydrogen atom or a substituted or unsubstituted phenyl group, also, Ar ₆
Represents a phenyl group or a naphthyl group. ] [In the formula, n is an integer of 0 or 1, R ₃₆₅ represents a hydrogen atom, an alkyl group or a substituted or unsubstituted phenyl group,
A ₁ Represents a 9-anthryl group or a substituted or unsubstituted N-alkylcarbazolyl group, wherein R ₃₇₅ is a hydrogen atom,
Alkyl group, alkoxy group, halogen atom or (However, R ₃₈₅ and R ₃₉₅ represent an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, and R ₃₈₅ and R ₃₉₅ may form a ring)
m is an integer of 0, 1, 2 or 3, and when m is 2 or more, R ₃₇₅ may be the same or different. ] [Wherein, R ₄₀₅ , R ₄₁₅ and R ₄₂₅ represent hydrogen, a lower alkyl group, a lower alkoxy group, a dialkylamino group or a halogen atom, and n represents 0 or 1. The compound represented by the general formula (1) includes, for example, 9-
Ethylcarbazole-3-aldehyde, 1-methyl-1
-Phenylhydrazone, 9-ethylcarbazole-3-
Aldehyde 1-benzyl-1-phenylhydrazone, 9
-Ethylcarbazole-3-aldehyde 1,1-diphenylhydrazone.

The compound represented by the general formula (2) includes, for example, 4-
Diethylaminostyrene-β-aldehyde 1-methyl-
1-phenylhydrazone, 4-methoxynaphthalene-1
-Aldehyde 1-benzyl-1-phenylhydrazone.

Compounds represented by general formula (3) include, for example, 4-
Methoxybenzaldehyde 1-methyl-1-phenylhydrazone, 2,4-dimethoxybenzaldehyde 1-benzyl-1-phenylhydrazone, 4-diethylaminobenzaldehyde 1,1-diphenylhydrazone, 4-methoxybenzaldehyde 1-benzyl-1- (4- Methoxy) phenylhydrazone, 4-diphenylaminobenzaldehyde 1-benzyl-1-phenylhydrazone,
-Dibenzylaminobenzaldehyde-1,1-diphenylhydrazone.

Compounds represented by the general formula (4) include, for example, 1,1
-Bis (4-dibenzylaminophenyl) propane, tris (4-diethylaminophenyl) methane, 1,1-bis (4-dibenzylaminophenyl) propane, 2,2 '
-Dimethyl-4,4'-bis (diethylamino) -triphenylmethane.

Compounds represented by the general formula (5) include, for example, 9-
(4-Diethylaminostyryl) anthracene and 9-bromo-10- (4-diethylaminostyryl) anthracene.

Compounds represented by the general formula (6) include, for example, 9-
(4-dimethylaminobenzylidene) fluorene, 3-
(9-Fluorenylidene) -9-ethylcarbazole and the like.

Compounds represented by the general formula (7) include, for example, 1,2
-Bis (4-diethylaminostyryl) benzene, 1,2
-Bis (2,4-dimethoxystyryl) benzene.

The compound represented by the general formula (8) includes, for example, 3-
Examples include styryl-9-ethylcarbazole and 3- (4-methoxystyryl) -9-ethylcarbazole.

The compound represented by the general formula (9) includes, for example, 4-
Diphenylaminostilbene, 4-dibenzylaminostilbene, 4-ditolylaminostilbene, 1- (4-
Examples include diphenylaminostyryl) naphthalene and 1- (4-diethylaminostyryl) naphthylene.

The compound represented by the general formula (10) includes, for example, 4 ′
-Diphenylamino-α-phenylstilbene, 4′-
Methylphenylamino-α-phenylstilbene and the like.

The compound represented by the general formula (11) includes, for example, 1-
Phenyl-3- (4-diethylaminostyryl) -5
(4-diethylaminophenyl) pyrazolin, 1-phenyl-3- (4-dimethylaminostyryl) -5- (4
-Dimethylaminophenyl) pyrazolin and the like.

Other hole transporting substances include, for example, 2,5-bis (4-diethylaminophenyl) -1,3,4-oxadiazole, 2,5-bis [4- (4-diethylaminostyryl) phenyl]- 1,3,4-oxadiazole, 2- (9
Oxadiazole compounds such as -ethylcarbazolyl-3-)-5- (4-diethylaminophenyl) -1,3,4-oxadiazole, 2-vinyl-4- (2-chlorophenyl) -5- There are low molecular compounds such as oxazole compounds such as (4-diethylaminophenyl) oxazole and 2- (4-diethylaminophenyl) -4-phenyloxazole. Further, high molecular compounds such as poly-N-vinyl carbazole, halogenated poly-N-vinyl carbazole, polyvinyl pyrene, polyvinyl anthracene, pyrene formaldehyde resin, and ethyl carbazole formaldehyde resin can also be used.

Examples of the electron transport material include chloranil, bromanil, tetracyanoethylene, tetracyanoquinonedimethane, 2,4,7-trinitro-9-fluorenone,
2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-
Tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b]
Thiofen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide and the like.

These charge transport materials are used alone or in combination of two or more.

In addition, any of the photoconductors obtained as described above can be provided with an adhesive layer or a barrier layer between the photoconductors of the conductive support as needed. As a material used for these layers, polyamide, nitrocellulose, aluminum oxide and the like are suitable, and the film thickness is preferably 1 μm or less.

To prepare the photoreceptor shown in FIG. 1, a bisazo pigment on a conductive support is vacuum-deposited by a vacuum deposition method described in US Pat. No. 3,973,959, US Pat. If necessary, it is dispersed in a suitable solvent in which a binder has been dissolved, and this is coated on a conductive support and dried, and if necessary, for example, as disclosed in JP-A-51-90827. After finishing the surface by a method such as buffing or adjusting the film thickness, a solution containing a charge transport substance and a binder is applied and dried.

The photoreceptor shown in FIG. 2 may be prepared by dispersing a fine powder of a bisazo pigment in a solution in which a charge transport substance and a binder are dissolved, and applying and drying the solution on a conductive support.

In any case, the bisazo pigment used in the present invention is pulverized by a ball mill or the like to a particle size of 5 μm or less, preferably 2 μm or less. The coating method is performed by usual means, for example, doctor blade, dipping, wire bar and the like.

Copying using the photoreceptor of the present invention can be accomplished by charging and exposing the surface of the photosensitive layer, developing it, and, if necessary, transferring it to paper or the like.

The electrophotographic photoreceptor of the present invention has 1,10-diphenyl-1,3,
By using a bisazo pigment having a 5,7,9-decapentaene skeleton as a charge generating material, it is easier to manufacture than conventional photoconductors, and has high sensitivity, and also has a wide visible range and semiconductor laser oscillation. It has excellent properties such as flat sensitivity over the wavelength range and stable characteristics even when the photoreceptor is used repeatedly.

Next, the present invention will be described specifically with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1 7.5 parts by weight of bisazo pigment No. 58 and 500 parts by weight of a polyester resin (Vylon 200 manufactured by Toyobo Co., Ltd.) in tetrahydrofuran (solid content: 0.5%) were pulverized and mixed in a ball mill to obtain a dispersion. Is applied using a doctor blade on an aluminum surface of a polyester base (conductive support) on which aluminum is vapor-deposited, and is naturally dried to a thickness of about 1 μm.
m of the charge generation layer was formed.

On this charge generation layer, 9 parts by weight of 9-ethylcarbazole-3-aldehyde-1-methyl-1-phenylhydrazone, 2 parts by weight of a polycarbonate resin (Panlite K-1300 manufactured by Teijin Ltd.) and 16 parts of tetrahydrofuran 16 A solution obtained by mixing and dissolving parts by weight was applied using a doctor blade, and dried at 80 ° C. for 2 minutes and then at 105 ° C. for 5 minutes to form a charge transport layer having a thickness of about 20 μm. No. 1 photoreceptor was prepared.

Examples 2 to 45 Photoconductors Nos. 2 to 45 were prepared in the same manner as in Example 1 except that bisazo pigments shown in Table 1 below were used instead of bisazo pigment No. 58 used in Example 1.

Examples 46 to 71 Example 1 was repeated except that 1-phenyl-3- (4-diethylaminostyryl) -5- (4-diethylaminophenyl) pyrazoline was used as a charge transporting material and bisazo pigments shown in Table 2 below were used. Photoconductor Nos. 46 to 71
It was created.

Examples 72 to 108 Photoconductor N was prepared in the same manner as in Example 1 except that α-phenyl-4′-N, N-diphenylaminostilbene was used as a charge transport material and bisazo pigments shown in Table 3 below were used.
o.72 to 108 were created.

Examples 109 to 144 Photoconductor N was prepared in the same manner as in Example 1 except that 1,1-bis (4-dibenzylaminophenyl) propane was used as a charge transport material and bisazo pigments shown in Table 4 below were used.
o.109-144 were created.

For these photoconductors Nos. 1 to 144, using an electrostatic copying paper test device (SP428 type, manufactured by Kawaguchi Electric Works, Ltd.)
After performing a −6 KV corona discharge for 20 seconds to make it negatively charged, it is left in a dark place for 20 seconds, and the surface potential Vpo (V) at that time
And then irradiating light with a tungsten lamp so that the surface has an illuminance of 4.5 lux to obtain a time (second) until the surface potential becomes 1/2 of Vpo, and an exposure amount E1 / 2 ( Looks second). Table-
1 to Table 4.

Further, the photoconductors No. 4 and No. 7 of the present invention were mounted on a Ricoh copier Myricopy M5 model, and image output was repeated 10,000 times.As a result, both photoconductors were repeatedly subjected to the copying process. A clear image was obtained without any change.

Effects As is clear from the above examples, the electrophotographic photoreceptor of the present invention is easier to produce than the conventional photoreceptor by using a specific bisazo pigment as a charge generating substance, It has excellent properties such as high sensitivity and stable characteristics even when the photoreceptor is used repeatedly.

[Brief description of the drawings]

FIG. 1 and FIG. 2 are enlarged cross-sectional views showing a configuration example of the photoconductor of the present invention. FIG. 3 shows a bisazo pigment used in the present invention.
It is an infrared absorption spectrum (KBr tablet method) of No. 58. 11: conductive support, 13: bisazo pigment 15: charge generation layer, 17: charge transport layer 191,192: photosensitive layer

Claims (1)

(57) [Claims] 1. A compound of the formula (I) on a conductive support (Wherein Ar represents a coupler residue). A photoreceptor for electrophotography, wherein a layer containing a bisazo pigment represented by the following formula as an active ingredient is formed.