JPS62295058A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance sensitivity and durability by incorporating an azo compound having a specified type in a photosensitive layer formed on a conductive substrate. CONSTITUTION:The photosensitive layer formed on the conductive substrate contains one of the azo compounds represented by formula I in which A is a divalent aromatic hydrocarbon group or divalent heterocyclic group containing N in the ring; Ar is an aromatic or heterocyclic group linkable through a bonding group; and n is an integer of 1-4. This azo compound may be added into the photosensitive layer in a monolayer structure or in a laminated layer structure functionally separated into the charge generating layer and the charge transfer layer, thus permitting the obtained electrophotographic sensitive body to be superior in the points of sensitivity and durability as compared with the ones using conventional organic photoconductors.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having a photosensitive layer containing a specific azo pigment.

Conventional technology Conventionally, inorganic photoconductive substances such as amorphous selenium, selenium alloys, cadmium sulfide, and zinc oxide, and organic photoconductive substances such as polyvinyl carbazole and polyvinyl carbazole derivatives have been used as electrophotographic photosensitive materials. is widely known.

Organic photoconductive materials are more transparent and transparent than inorganic ones.
It has the advantage of being excellent in terms of film-forming properties, flexibility, and manufacturability.

Problems to be Solved by the Invention Despite having such many advantages, right-side photoconductive materials have not been used in electrophotographic photoreceptors because inorganic materials have been used in terms of sensitivity and durability. It was to be inferior.

Therefore, the present invention has been made in view of the above-mentioned drawbacks when using a right-front type photoconductive material, and its purpose is to provide an electrophotographic photoreceptor with high sensitivity and high durability. It is in.

Means for Solving the Problems The electrophotographic photoreceptor of the present invention is characterized in that the photosensitive layer on the conductive support contains an azo compound represented by the following general formula (I).

(In the formula, A represents a divalent aromatic hydrocarbon group or a divalent heterocyclic group containing a nitrogen atom in the ring, and Ar represents an aromatic hydrocarbon group or a heterocyclic group which may be bonded via a bonding group. Indicates a ring group,
(n represents an integer of 1.2.3 or 4) The present invention will be described in detail below.

The general formula (
To further explain the azo compound represented by I>, in the general formula (1), A represents a divalent aromatic hydrocarbon group or a divalent heterocyclic group containing a nitrogen atom in the ring. Examples of aromatic hydrocarbon groups include divalent monocyclic aromatic hydrocarbon groups such as ○-phenylene group, ○-naphthylene group, perinaphthylene group, 1,2-anthraquinonyl group, 9,10-phenanthrylene group, etc. divalent fused polycyclic aromatic hydrocarbon group. In addition, examples of the divalent heterocyclic group having a nitrogen atom in the ring include 3゜4-pyrazolediyl group, 2,3-pyridinediyl group, 3,4-
pyridinediyl group, 4,5-pyrimidinediyl group, 5,
Examples include heterocyclic groups such as 6-benzimidazolediyl group and 6,7-chiralindiyl group. The divalent aromatic hydrocarbon group and the divalent heterocyclic group containing a nitrogen atom in the ring may have a substituent. As a substituent, C1 to C18
alkyl group, C-C alkoxy group, C1-C4 alkoxycarlebonyl group, carboxyl group, hydroxy group, nitro group, cyan group, halogen atom, trifluoromethyl group, carbamoyl group, sulfamoyl group, phenoxy group, etc. Can be mentioned.

When considering sensitivity and durability, A may include 0-phenylene group, O-naphthylene group, berinaphthylene group, 2,
3-pyridinediyl group, 3,4-pyridinediyl group, 4
, 5-pyrimidinediyl group, 9.10-phenanthrylene group, and examples of substituents include alkyl group, alkoxy group, carboxyl group, hydroxy group,
A nitro group and a halogen atom are preferred.

In the general formula (I), Ar represents an aromatic hydrocarbon group or a heterocyclic group which may be bonded via a bonding group, and preferable examples include a phenyl group, a naphthyl group,
Monovalent monovalent monocyclic or fused polycyclic aromatic hydrocarbon groups such as 1-pyrenyl group, 2-anthryl group, 5-acenaphthynyl group, 2-fluorenonyl group, 1- or 2-anthraquinonyl group, phenylene group, 1,5- or 2,7-naphthylene group, 1,4-11,5- or 2,6-anthraquinonyl group, 2,4- or 2,7-fluorenonyl group, 2,7
-fluorenonyl group, pyrenylene group, 2,7-phenanthraquinonylene group, 2,7-(9-dicyanomethylene)
Divalent monocyclic or fused polycyclic aromatic hydrocarbon groups such as fluorenonyl group, dibenzotropondiyl group, dicyanomethylene dibenzotropondiyl group, penzanthronylene group, biphenylene group or biphelene group, etc. polycyclic aromatic hydrocarbon group, a divalent group represented by the following formula (wherein, Y is -0-1-S-1-SS-1N -N=N-1-CmiC-1 -C1l:l-CH-CI=C[l--CIl:
N-N: CH-2H5 or a trivalent group derived from triphenylamine, triphenylmethane, terphenylfluorenone, etc., a tetravalent group derived from tetraphenylbenzidine, benzimidazolyl group, benzoxacylyl group, benzothiazolyl monovalent heterocyclic group such as a group, a carbazolyl group, a quinolyl group, 2
-phenylbenzoxazolediyl group, 2-phenylbenzimidazolediyl group, carbazolediyl group,
Divalent heterocycles such as 2-phenylhenzothiazolediyl group, 2-phenylbenzotriazolediyl group, dibenzothiophenediyl group, dibenzothiophenoxidediyl group, 9-acridonediyl group, xanthonediyl group, phenoxazinediyl group Examples include 31i1fi heterocyclic groups derived from a group, triphenylpyridine, triphenyltriazole, N-phenylcarbazolnylphenoxazine, and the like.

Particularly preferable Ar groups include phenyl group, naphthyl group, pyrenyl group, fluorenonyl group, anthraquinonyl group, naphthylene group, anthraquinonyl group, fluorenonelene group, pyrenylene group, 9-dicyanomethylenefluorenonylene group, dibenzotropondiyl group, Biphenylene group, divalent group represented by the following general formula, (Y-〇′ 1N=N-, mil or 0 trivalent group derived from triphenylamine, 411IIi derived from tetraphenylbenzidine ( 7)l
, 2-phenylbenzoxazolediyl group, 2-phenylbenzimidazolediyl group, carbazolediyl group, 9-acridonediyl group, xanthonediyl group, phenoxazinediyl group, and phenylcarbazole group,
Examples include trivalent groups derived from N-phenylphenoxazine and the like.

Specific examples of the azo compounds used in the present invention include the following. However, the azo compound in the present invention is not limited to these compounds.

Ar(\=\-8).

Compounds The above-mentioned disazo compounds used in the present invention are, for example,
The corresponding diamine was tetrazotized by a conventional method, and the general formula
Coupling with a coupler represented by H-CD in the presence of an alkali, or alternatively, after isolating the corresponding tetrazonium salt of the diamine in the form of a regular fluoride salt or a polysulfur chloride salt, a suitable It can be synthesized by coupling with the above coupler in the presence of an alkali in a solvent (for example, N-dimethylfilmamide, demethylsulfoxide, etc.).

In the present invention, the above-mentioned azo compound may be contained in the photosensitive layer provided on the conductive support, or may be incorporated into the photosensitive layer (even if it is a single-layer groove) or the charge generation layer and the charge transport layer. It may also have a laminated structure with separated functions.

The electrophotographic photoreceptor of the present invention includes, for example, (1) a photosensitive layer formed by dispersing an azo compound in a binder resin containing a charge transport substance on a conductive support; ) Conductive [1 support 1) On the body, azo compound and charge transfer Ki:
(3) A charge generating layer containing an azo compound and a charge transporting layer containing a charge transporting substance are provided on a conductive support. It can be broadly classified into two types.

Examples of the conductive support in the electrophotographic photoreceptor of the present invention include a metal plate made of aluminum, nickel, chromium, stainless steel, etc., a metal drum, or a plastic film provided with a metal foil and a thin film of metal or other conductive substance. Paper or plastic film coated with or impregnated with a conductivity imparting agent is used.

In the present invention, when the azo compound is dispersed in the binder resin in the photosensitive layer formed on the conductive support, the azo compound is dispersed in the form of fine particles with a particle size of 3μ or less, preferably 0.3μ or less. Disperse, and the blending amount is
It is desirable that the amount is 20% to 90% by weight with respect to the photosensitive layer.

Examples of the resin include polystyrene, silicone resin, polycarbonate, acrylic resin, methacrylic resin, polyester, vinyl polymers such as polyvinyl butyral, celluloses such as cellulose ester,
Cellulose ether, alkyd resin, etc. can be used.

Examples of the charge transport substance used in the electrophotographic photoreceptor of the present invention include N-methyl-N-phenylhydrazino-3-methylidene-9-ethylcarbazole, N,
N-diphenylhydrazino-3-methylidene-9-ethylcarbazole, N.

N-diphenylhydrazino-3-methylidene-〇-methylcarbazole, p-diethylaminobenzaldehyde-N, N-diphenylhydrazone, p-diethylaminobenzaldehyde-N, \-di(p-methoxyphenyl)hydrazone, p-diethylaminobenzaldehyde-
N-(α-naphthyl)-N-phenylhydrazone, β,
Hydrazones such as β-di(4-methoxyphenyl)acroleindiphenylhydrazone, 1-phenyl-3-(
p-diethylaminostyryl)-5-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)
Pyrazoline, 1-U quinolyl(2>]-3-(p-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, 2-(p-dipropylaminophenyl/L,)-4 Oxazole compounds such as -(1)-dimethylaminophenyl)-5-(2-chlorophenyl)oxazole, 2-(p-diethylaminostyryl)-6-dinithylaminobenzoxazole, 2.5-bis(p-diethylaminobenzoxazole) phenyl)-1,
Oxadiazole compounds such as 3,4-oxadiazole, 2゜5-bis(4'-diethylamino-2-monomethylphenyl)-1,3,4-oxadiazole, bis(
Triarylmethane compounds such as 4-diethylamino-2-methylphenyl)-phenylmethane, triphenylamine, 2.4-. Triarylamine compounds such as 4''-trimethyltriphenylamine, 1,1-bis[4--N,N-di(p-methylphenyl)aminophenylcocyclohexane, 5-(p-diethylaminostyrylanthracene, etc.) Anthracene compound, α-phenyl-4=-N, N-diphenylaminostilbene, 4”-
Stilbene compounds such as N,N-di(p-methoxyphenyl)aminostilbene, N,N-diphenyl-N,
N--bis(3-methylphenyl)-[1゜1'-biphenyl]-4,4''-diamine, 3゜3-dimethyl-
Benzidine compounds such as N,\,N-,N-tetrakis(4-methylphenyl)-[1,1'-biphenyll-4,4-diamine, etc. are required, and these are Contained in resin. Furthermore, poly-N-vinylcarbazole, halogenated poly-N-vinylcarbazole,
Polyvinylanthracene, poly-9-vinylphenylanthracene, polyvinylpyrene, polyvinylacridine, polyvinylacenaphthylene, polyglycidylcarbazolehyde resin, and ethylcarbazole-formaldehyde may form a layer by themselves.

In the present invention, it is preferable that the photosensitive layer has a laminated structure because the sensitivity of the electrophotographic photoreceptor is high and the residual potential is low.

In this case, the charge generation layer contains an azo compound as described above,
It may be formed by dispersing it in a binder resin, but it may also be formed by sublimation or vaporization of an azo compound. Further, either a charge generation layer or a charge transport layer may be provided as an upper layer; when a charge generation layer is provided as an upper layer, the electrophotographic photoreceptor is of a positively charged type, and when a charge transport layer is provided as an upper layer It can be used as a negatively charged type.

In the electrophotographic photoreceptor of the present invention, a contact layer may be provided between the photosensitive layer and the conductive support.

The adhesive layer is made of commonly used synthetic resin such as polyester, and usually has a film thickness of 0.5 to 5.
It is formed to a size of about μ.

Example Hereinafter, the present invention will be explained by examples.

Example 1 1 part by weight of polyvinyl butyral resin (trade name: BLX Sekisui Water Chemical) was dissolved in 40 parts by weight of cyclohexanone, and exemplified compound No. 1 was dissolved therein.

1 was mixed in an amount of 3 parts by weight, and then well dispersed using a paint shaker. The mixture was applied onto an aluminum sheet using an applicator and dried to form a charge generation layer. The film thickness after drying was 0.2 μm.

On the formed charge generation layer, N, N--diphenyl-N,
N--bis(3-methylphenyl)-[1,'M-biphenyl]-4.4-diamine 1-layer hanging part, polycarbonate resin (trade name Nilexane 145, manufactured by GE Corporation, molecular weight 35,000-40. A homogeneous solution consisting of 000>1 part by weight and 15 parts by weight of dichloromethane was applied with an applicator and dried to form a charge transport layer.The film thickness was 20 μm.
Met.

The electrophotographic photoreceptor thus obtained was subjected to the following characteristic evaluation using an electrostatic copying paper tester (manufactured by Kawaguchi Den rA Seisakusho 5P-428). First, apply a -6KV corona charge to remove the charge, then leave it in a dark place for 2 seconds.
Measure the surface potential ■p o (volt) at that time, then irradiate the surface with light using a tungsten lamp so that the illumination intensity is 5 lux, and the surface potential becomes Vp
Find the time until it becomes 1/2 of o, and calculate the exposure ωE1/2 (
lux·sec) was calculated.

Furthermore, similar measurements were repeated 20 [111i] times.

The results are shown in Table 1.

Table 1 Examples 2 to 10 In Example 1, Exemplary Compound No. 1 was replaced with Exemplified Compound No. 2.3.14.15, 16°27.28,
Electrophotographic photoreceptors were produced in the same manner as in Example 1, except that 30.33 (Examples 2 to 10, respectively) were used, and their characteristics were evaluated.

The results are shown in Table 2.

Table 2 Effects of the Invention Since the electrophotographic photoreceptor of the present invention is constructed using the azo compound, it has higher sensitivity and higher sensitivity than electrophotographic photoreceptors using conventional 1jU-based photoconductive materials. It stands out in terms of durability.

Claims (1)

[Claims] (1) On the conductive support, there is the following general formula ▲ mathematical formula, chemical formula, table, etc. ▼ (wherein A is a divalent aromatic hydrocarbon group or a divalent heterocycle containing a nitrogen atom in the ring) group, Ar represents an aromatic hydrocarbon group or a heterocyclic group which may be bonded via a bonding group,
n is an integer of 1, 2, 3, or 4) An electrophotographic photoreceptor comprising a photosensitive layer containing an azo compound represented by the following.