JPH0254273A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide the photosensitive body which has excellent carrier generating power, high sensitivity, small residual potential, and excellent durability by providing a photosensitive layer contg. a specific bisazo compd. CONSTITUTION:The photosensitive layer contg. the bisazo compd. expressed by the formula I is provided on a conductive base. In the formula I, R1 denotes halogen atom or substd. or unsubstd. three groups of an alkyl group, alkoxy group and phenyl group. R2 to R6 respectively denote a hydrogen atom, halogen atom, nitro group, cyano group or substd. or unsubstd. two groups of an alkyl group and alkoxy group. The photosensitive body having the extremely good sensitivity, residual potential and repetitive stability is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having a photosensitive layer containing a specific bisazo compound.

[Background of the Invention] Conventionally, inorganic photoreceptors having a photosensitive layer containing an inorganic photoconductive compound such as selenium, zinc oxide, cadmium sulfide, silicon, etc. as a main component have been widely used as electrophotographic photoreceptors. However, these are not necessarily satisfactory in terms of sensitivity, thermal stability, moisture resistance, durability, etc. For example, when selenium crystallizes, its properties as a photoreceptor deteriorate, making it difficult to manufacture.Also, selenium crystallizes due to heat, fingerprints, etc., and its performance as a photoreceptor deteriorates.

Furthermore, cadmium sulfide has problems with moisture resistance and durability, while zinc oxide has problems with durability.

In order to overcome these drawbacks of inorganic photoreceptors, research and development of organic photoreceptors having photosensitive layers mainly composed of various organic photoconductive compounds has been actively conducted in recent years. For example, Japanese Patent Publication No. 50-10496 describes an organic photoreceptor having a photosensitive layer containing poly-N-vinylcarbazole and 2,4,7-dolinitro-9-fluorenone. However, this photoreceptor is not necessarily satisfactory in sensitivity and durability. In order to improve these drawbacks, attempts have been made to develop organic photoreceptors with higher performance by assigning the carrier generation function and the carrier transport function to different substances. Many studies have been conducted on such so-called function-separated type photoreceptors because each material can be selected from a wide range and a photoreceptor having arbitrary performance can be produced relatively easily.

(Problems to be Solved by the Present Invention) In the functionally separated type photoreceptor as described above, there are many compounds that can be used as carrier generating substances.
There is amorphous selenium described in Japanese Patent Publication No. 43-16198, which is used in combination with an organic photoconductive compound, but the carrier generation layer made of amorphous selenium is crystallized by heat and loses its properties as a photoreceptor. The drawback of deterioration has not been improved.

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

[Purpose of the invention]

An object of the present invention is to provide an electrophotographic photoreceptor containing a specific bisazo compound having excellent carrier generation ability.

Another object of the present invention is to provide high sensitivity and low residual potential.
Furthermore, it is an object of the present invention to provide an electrophotographic photoreceptor with excellent durability whose properties do not change even after repeated use.

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

[Structure of the invention]

As a result of repeated studies in accordance with the object of the present invention, it has been found that a specific bisazo compound is useful as an excellent carrier-generating component of an electrophotographic photoreceptor.

That is, the above object of the present invention can be achieved by providing an electrophotographic photoreceptor having a photosensitive layer containing a bisazo compound represented by the following general formula (1) on a conductive support.

General formula CI) R1 represents a halogen atom or a substituted or unsubstituted group of an alkyl group, an alkoxy group, or a phenyl group.

R2 to R each represent a hydrogen atom, a halogen atom, a nitro group, a cyan group, or I; represents two groups of alkyl groups, substituted or unsubstituted alkoxy groups.

[Specific structure of the invention]

In general formula (1), the alkyl group for R1 is preferably an alkyl group having 1 to 4 carbon atoms, such as a methyl group, ethyl group, isopropyl group, t-butyl group, etc.

The alkoxy group for R1 is preferably an alkoxy group having 1 to 4 carbon atoms, such as a methoxy group, an ethoxy group,
Examples include impropoxy group, t-butoxy group, and 2-chloroethoxy group.

The halogen atom of R4 is C(2, Br, F,
In addition, the phenyl group of R8 may have a substituent such as a methyl group, ethyl group, nitro group, or chlorine atom.

Examples of the alkyl group and alkoxy group represented by R'2 to R6 include the same groups as shown for R1 above, and specific examples of the halogen atom include CI, Br, F, and I. I can do it.

Next, specific examples of the bisazo compound of the present invention represented by the general formula (1) will be described, but the bisazo compound of the present invention is limited by these: Exemplary compounds: (R6=H) (R6=H) (R, -H) In the description of the present invention, R, provision 1003 (AI
), R1 is H and the combinations of R2, R, , R, , R are H, C4, H, H in this order, and the compound is No. 006.

Add Al-6. Other exemplified compounds also follow this example.

The bisazo compound represented by the general formula (1) of the present invention can be synthesized by a known method.

Synthesis Example 1 (Exemplary Compound No. Synthesis of Al-6) 2.7-
Cyamitsu-N-methylacridone 2.39g (0,0
1 mole) was dispersed in 10 ml of hydrochloric acid and 20 ml of water,
While keeping the temperature below 5°C, add 1.4g of sodium nitrite (
0.02 mol) dissolved in 5 ml of water was added dropwise.

After stirring for 1 hour at the same temperature, insoluble matter was removed by filtration. To the filtrate, 4.6 g of ammonium hexafluorophosphate was added to 50 m of water.
2 dissolved solution was added.

The precipitated tetrazonium salt was collected by filtration and dissolved in 100 mQ of N,N-dimerformamide (DMF). 5℃
2-Hydroxy-3-naphthoate 1- while keeping the
A solution of 5.94 g (0.02 mol) of 3'-chloroanilide dissolved in 200 mQ of IIIMF was added dropwise. While continuing to maintain the temperature below 5°C, add triethanolamine 6.
g (0.04 mol) dissolved in DMF3Qm (2) was added dropwise and 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, and washed with water. After drying, 6.21 g of the target product was obtained.

In elemental analysis, this compound showed actual values (C-67,
0%, H-3,91%, N-12,0%) was changed from the theoretical value (C-66,8%, H-3,67%, N-11,6%
), the target example compound N
o, confirmed to be AI-6.

Synthesis Example 2 (Synthesis of Exemplary Compound No. A11) 2.7-
Guamitsu-N-methylacridone 2.39g (0,0
1 mol) in 110 liters of hydrochloric acid11. Dispersed in 20m12 of water,
While keeping the temperature below 5℃, add 1.4g of sodium nitrite (0
, 22 mol) dissolved in 51Il12 of water was added dropwise. After stirring for another hour at the same temperature, insoluble matter was removed by filtration, and 4.6 g of ammonium hexafluorophosphate was added to the filtrate.
A solution of 5011+2 in water was added. The precipitated tetrazonium salt was collected by filtration and dissolved in N,N-dimethylformamide (DMF) 100+n12. 5.26g of 2-hydroxy-3-7toic acid while keeping the temperature below 5℃
(0.22 mol) was dissolved in 200 mff of DMF.

Subsequently, 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, followed by stirring at below 5°C for 1 hour and at room temperature for 4 hours. After the reaction, the precipitation pores were collected by filtration, washed with DMF, washed with water, and dried to obtain 5.53 g of the target product.

In elemental analysis, this compound showed actual values (C-72,
0%, H-4,22%, N = 12.2%) is the theoretical value (C-72,8%, H-4,11%, N-12,6%
), the target example compound No.
, it was confirmed to be A I-1.

Other compounds of the present invention can also be prepared using 2.7-
It can be prepared by preparing a tetrazo compound using cyamitsu-N-substituted acridone and then reacting with 2-hydroxy-3-naphthoic acid-substituted anilide.

The bisazo compound of the present invention has excellent photoconductivity,
The electrophotographic photoreceptor of the present invention can be manufactured by providing a photosensitive layer in which the photoreceptor is dispersed in a binder on a conductive support. The bisazo compound of the present invention makes use of its excellent carrier generation ability, and by using it as a carrier generation substance and using a carrier transport substance that can effectively act in combination with this, the bisazo compound can be used as a so-called functionally separated photosensitive material. It can be a body. The functional separation chamber photoreceptor may be a mixed and dispersed type of both of the above substances, but a laminated type photoreceptor in which a carrier generation layer containing a carrier generation substance made of the bisazo compound of the present invention and a carrier transport layer are laminated. It is more preferable to use the body.

The electrophotographic photoreceptor of the present invention, for example, as shown in FIG. As shown in FIG. 2, a photosensitive layer 4 is provided with a functionally separated laminated structure in which a carrier generation layer 2 containing a carrier-transporting substance and a binder resin is a lower layer, and a carrier-transporting layer 3 containing a carrier-transporting substance and a binder resin is an upper layer. A photosensitive layer 4 having a laminated structure including a carrier transport layer 3 as a lower layer and a carrier generation layer 2 as an upper layer is provided on a support L, and a carrier generation substance and a carrier are provided on a support L as shown in FIG. Examples include those provided with a single-layer photosensitive layer 4 containing a transport substance and a binder resin.

In addition, in the case of a photosensitive layer with a laminated structure, the carrier generation layer absorbs most of the incident light and generates a large amount of carriers, and the generated carriers are not deactivated by recombination or trapping. It is preferable to make the layer as thin as possible within a range of thickness sufficient to generate carriers for injection into the carrier transport layer.

Further, the carrier transport layer is electrically connected to the carrier generation layer described above, and has a function of transporting carriers injected from the carrier generation layer to the surface in the presence of an electric field.

In addition, in a functionally separated photoreceptor with a single layer structure, carrier generation and transport are performed in the single layer, and the carrier generation substance and carrier transport substance are electrically bonded within the layer, and the carrier generation substance also acts as a carrier. Contributes to transportation.

Also, the carrier generation layer may contain a part of the carrier transport substance in addition to the carrier generation substance. In either layer structure, a protective layer may be provided on the photosensitive layer as shown in FIGS. 7 to 9, and a protective layer may be provided on the photosensitive layer as shown in FIGS. 4 to 6. A subbing layer (intermediate layer) having a barrier function and adhesive properties may be provided between the layers.

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

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.

Such secondary amines include, for example, dimethylamine,
Diethylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine, cyamylamine, diethylamine, diisohexylamine, diisotylamine, diisopentylamine, dioctylamine, diisooctylamine, dinonylamine, diisononylamine, didecylamine, diisodecylamine, diisodecyl Examples include amine, diisomonodecylamine, didodecylamine, diisododecylamine, and the like.

The amount of the organic amines to be added is preferably 1 times or less, preferably 0.2 times to 0.005 times the amount of the carrier generating substance, based on the amount of the carrier generating substance.

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

Typical examples of such antioxidants are shown below, but the invention is not limited thereto.

(Group I): Hindered phenols dibutylhydroxytoluene, 2.2'-methylenebis=(6-t-butyl-4-methylphenol), 4.4
″-butylidenebis-(6-(-butyl-3-methylphenol), 4,4′-thiobis-(6-t-butyl-
3-methylphenol), 2,2'-butylidene bis-(
6-1-butyl-4-methylphenol), α-tocophenol, β-toco′phenol, 2.2.4-trimethyl-6-hydroxy-7-t-butylphenol, Roman, pentaerythyltetrakis-(3 -(3,5-di-butyl-4-hydroxyphenyl) flobionate), l
, 6-hexanethiol bis(3-(3,5-t-
butyl-4-hydroxyphenyl)propionate],
Butylhydroxyanisole, dibutylhydroxyanisole, 1(2-((3,5-diL-butyl-4-hydroxyphenyl)propionyloxy)ethyl)-4-
(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy)-2,2,6,6-titramethylpiperidyl, and the like.

(Group I [):/(rough unilene diamines N-phenyl-N'-isopropyl-p-phenylene diamine, N,
N'-di5ec-butyl-p-)1 dienediamine,
N-phenyl-N-sea-butyl-p7 phenylenediamine, N,N'-dimethyl-N, N'-di-t-butyl-p-phenylenediamine, and the like.

(Group ■): Hydroquinones 2,5-di-t-octylhydroquinone, 2,6-sidodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-
Octyl-5-methylhydroquinone, 2-(2-octadecenyl)-5-methylhydroquinone, etc.

(Group ■): Organic sulfur compounds dilauryl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, ditetradecyl-3,3''-thiodipropionate, etc.

(Group v): Organophosphorus compounds triphenylphosphine, tri(nonylphenyl)phosphine, tri(dinonylphenyl)phosphine, tricresylphosphine, tri(2,4-dibutylphenoxy)phosphine, etc.

These compounds are known as antioxidants for rubber, plastics, oils and fats, and are easily available commercially.

These antioxidants may be added to any of the carrier generation layer, carrier transport layer, or protective layer, but are preferably added to the carrier transport layer.

In that case, the amount of antioxidant added is 10 parts of the carrier transport substance.
0.1-100 parts by weight, preferably 1 part by weight
~50 parts by weight, particularly preferably 5 to 25 parts by weight.

Next, the conductive support supporting the photosensitive layer may be a metal plate made of aluminum or nickel, a metal drum, a plastic film laminated with metal foil, a plastic film deposited with aluminum, tin oxide, indium oxide, etc., or a conductive support. A film or drum of paper, plastic, etc. coated with a substance can be used.

In the present invention, the carrier generation layer is typically formed by coating a dispersion of 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, tin spray coating, blade coating, etc. It can be provided by a method of coating on the support or subbing layer or carrier transport layer by roll coating or the like and drying it.

The bisazo compound of the present invention is made into fine particles of an appropriate particle size using, for example, a ball mill or a sand mill.
It can be dispersed in a dispersion medium.

A ball mill, homomixer, sand mill, ultrasonic disperser, attritor, etc. are used for dispersing the bisazo compound of the present invention.

Examples of the dispersion medium for the bisazo compound of the present invention include hydrocarbons such as evahexane, benzene, toluene, and xylene;
Methylene chloride, methylene bromide, 1,2-dichloroethane, sym-tetrachloroethane, cis-
1+2-dichloroethylene, l.

1.2-Trichloroethane, 1.1.1-1-lichloroethane, 1.2-dichloropropane, chloroform, bromoform, chlorobenzene and other halogenated hydrocarbons; acetone, methyl ethyl ketone, cyclohexanone and other ketones; ethyl acetate, Esters such as butyl acetate: methanol, ethanol, chlornol, butanol, cyclohexanol, heptatool, ethylene glycol,
Alcohols and their derivatives such as methyl cellosolve, ethyl cellosolve, acetic acid cellosolve; ethers and acetals such as tetrahydrofuran, 1,4-dioxane, furan, and furfural; pyridine, butylamine, diethylamine, ethylenediamine, impropaturamine, etc. Amines, nitrogen compounds such as amides such as N,N-dimethylformamide, other fatty acids and phenols,
1 of sulfur and phosphorus compounds such as carbon disulfide and triethyl phosphate
A species or two or more species 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 0-100:1-500:0-500.

If the content of the carrier-generating substance is less than this, the sensitivity will be low and the residual potential will increase, and if it is more than this, the dark decay and acceptance potential will decrease.

The thickness of the carrier generation layer formed as described above is
Preferably 0.01-10μ, particularly preferably 0.1
~5μ mouth.

Further, the carrier transport layer can be formed by applying and drying a carrier transport substance dissolved and dispersed in a suitable solvent or dispersion medium alone or together with the above-mentioned binder resin. As the dispersion medium used, the dispersion medium used in dispersing the carrier-generating substance can be used.

Carrier transport substances that can be used in the present invention include:
Although not particularly limited, examples include oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidasilone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds,
Pyrazoline derivatives, amine derivatives, oxacilone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilchene derivatives,
These include poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, and the like.

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

General formula (A) However, R1 is an aryl group, a substituted heterocyclic group, or an unsubstituted 2
R2 represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aryl group, and is described in detail in JP-A-53-134642 and JP-A-58-166354. .

General formula (C) However, Ar+, Ar2, and Ar each represent a substituted or unsubstituted aryl group, Ar represents a substituted or unsubstituted arylene group, and R1 is a hydrogen atom, an alkyl group, or a substituted aryl group. , represents two groups of unsubstituted groups.

Specific examples of such compounds are JP-A No. 58-65440, pages 3 to 4, and JP-A No. 58-198043, pages 3 to 6.
is described in detail.

General formula (B) R.

However, R1 is a substituted or unsubstituted aryl group, Rz is a hydrogen atom, a halogen atom, a hydroxy group, or a substituted or unsubstituted group of an alkyl group, an alkoxy group, or an amino group, and R1 is an aryl group. , substituted heterocyclic group, unsubstituted 2
Represents a group radical. Synthetic methods and examples of these compounds are described in detail in Japanese Patent Publication No. 148750/1983.
It can be incorporated into the present invention.

Other preferred carrier transport materials of the present invention include:
Examples include hydrazone compounds described in JP-A-57-67940, JP-A-59-15252, and JP-A-57101844, respectively.

The amount of binder resin lOO in the carrier transport layer is preferably 20 to 200 parts by weight, particularly preferably 30 to 150 parts by weight.

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

Further, in the case of a monolayer functionally separated type electrophotographic photoreceptor using the bisazo compound of the present invention, the ratio of binder: bisazo compound of the present invention: carrier transport substance is 0 to 100:1 to 5.
00:0 to 500 is preferable, and the thickness of the photosensitive layer to be formed is preferably 5 to 50 μm, particularly preferably 5 to 30 μm.
It is tm.

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

Examples of electron-accepting substances that can be used here include succinic anhydride, yaleic anhydride, dibromaleic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, 3-nitrophthalic anhydride,
-Nitro-7tallic anhydride, pyromellitic anhydride, mellitic anhydride, tetracyanoethylene, tetracyanoquinodimethane, 〇-dinitrobenzene, m-dinitrobenzene,
1,3゜5-1-dinitrobenzene, paranitrobenzonitrile, vicryl chloride, quinone chlorimide,
Chloranil, brumanil, dichlordicyanobara benzoquinone, anthraquinone, dinitroanthraquinone, 2
．． 7-sinitrofluorenone, 2,4゜7-dolinitrofluorenone, 2.4.5.7-tetranitrofluorenone, 9-fluorenylidene [dicyanomethylene malonodinitrile], polynitro-9-fluorenylidene
[dicyanomethylenemalonodinitrile], picric acid,
0-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid,
Examples include mellitic acid and other compounds with high electron affinity. In addition, the addition ratio of the electron-accepting substance is
Bisazo compound of the present invention: Electron accepting substance-t in weight ratio
oo:o, oi~200, preferably 100:0.1-
It is 100.

This electron-accepting substance may be added to the carrier transport layer. The ratio of electron-accepting substances added to this layer is as follows: total carrier transport substance:electron-accepting substance=100:0.0 by weight
1 to 100, preferably loo:o, i to 50.

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

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

Examples of light sources with such wavelengths include halogen lamps,
Fluorescent lamps, tungsten lamps, etc. are commonly used.

The electrophotographic photoreceptor of the present invention has the above structure,
As is clear from the Examples described later, it has excellent charging characteristics, sensitivity characteristics, and image forming characteristics, and especially shows little fatigue deterioration even when used repeatedly, and has excellent durability.

〔Example〕

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the embodiments of the present invention are not limited thereby.

Example 1 A vinyl chloride-acetic acid-vinyl-maleic anhydride copolymer [S-LEC MF-10J
(manufactured by Tsukisui Kagaku Co., Ltd.) with a thickness of 0.05 μm was provided, and 2 g of Exemplified Compound No. A I-6 was placed on top of the intermediate layer with a thickness of 0.05 μm.
and polycarbonate resin "Panlite L1250J"
(manufactured by Teijin Chemicals) 2g and 1,2-dichloroethane 1
1012 and was dispersed in a ball mill for 12 hours. This dispersion was applied to a dry film thickness of 0.5 μm to form a carrier generation layer, and on top of that, 6 g of the following structural formula (K-1”) and polycarbonate resin were applied as a carrier transport layer. "Panlite L - 1250410g 1.2
- A solution dissolved in 80 mQ of dichloroethane was applied so that the film thickness after drying was 15 μm to form a carrier transport layer, thereby producing the photoreceptor of the present invention.

(K-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 t; was used.

(G-1) The photoreceptor obtained as described above was tested using Kawaguchi Electric Co., Ltd.'s rupture EP A-8100 electrostatic paper tester.
The following characteristics were evaluated. After charging at a charging voltage of -6KV for 5 seconds, leave it in the dark for 5 seconds, and then reduce the illumination intensity to 3 on the photoreceptor surface.
The amount of exposure required to attenuate the surface potential by half by irradiating halogen lamp light for 5αux" sec.
Half-reduction exposure amount) El/2 was determined. Also 30(lux-s
Surface potential (residual potential) vR after exposure with an exposure amount of ec
I asked for Further, similar measurements were repeated 100 times.

The results are shown in Table 1.

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

As is clear from the above results, the photoreceptor of the present invention is extremely superior in sensitivity, residual potential, and repetition stability compared to the comparative photoreceptor.

Examples 2 to 4 Exemplary compound No., AI-5 as carrier generating substance
, B1-4, and A2-27, respectively, and the following compounds as carrier transport substances, and otherwise in the same manner as in Example 1, a photoreceptor of the present invention was prepared, and the same measurements were performed. As a result, the results shown in Table 2 were obtained.

(K-2) (K-4) 2HS Table 2 (K-3) From the above results, the electrophotographic photoreceptor using the bisazo compound of the present invention as a carrier generating substance has the same sensitivity as in Example 1. It can be seen that the residual potential is high, the residual potential is low, and the repeatability is excellent.

Examples 5 to 9 The intermediate layer used in Example 1 was provided on a polyester film subjected to aluminum MR, and the exemplified compound N
o, A l-27, A 2-73, C1-74,
2 g of B2-8 and B1-76 and 2 g of polycarbonate resin "Panlite L-1250J" were added to 1,2-dichloroethane 110+++12 and dispersed for 8 hours using a sand grinder. This dispersion was dried to a film thickness of 0. ．．
It was applied to a thickness of 5 μm to form a carrier generation layer.

Furthermore, on top of that, as a carrier transport layer, the following structural formula (K
-5) 6g of polycarbonate resin
300J (manufactured by Ondai Kasei Co., Ltd.) 10g dissolved in 80ml of 1,2-dichloroethane, the film thickness after drying was 1.
A carrier transport layer was formed by coating the photoreceptors 5 to 9 of the present invention at a concentration of 5 .mu.I.

(K-5) The same measurements as in Example 1 were performed on these photoreceptors, and the results are shown in Table 3.

Comparative Example (2) Electrophotographic photoreceptors were produced in the same manner as Examples 5 to 9, except that a bisazo compound represented by the following structural formula CG-2) was used as a carrier generating substance.

The same measurements as in Example 1 were performed on this comparative photoreceptor, and the results are shown in Table 3.

(G-2) The following structural formulas (K-6) and (K-7 ), (K-8) and 10 g of polycarbonate resin "Nipilon Z-200J (Mitsubishi Gas Chemical Co., Ltd.)" were dissolved in 80 mQ of 1,2-dichloroethane, and the film thickness after drying was A carrier transport layer was formed by coating the photoreceptor 10-12 of the present invention so as to have a thickness of 15 .mu.-.

(K-6) Examples 1O to 12 Vinyl chloride vinyl acetate-maleic anhydride copolymer "S-LEC MF-10J" was placed on a conductive support formed by laminating aluminum foil on a polyester film.
(manufactured by Sekisui Chemical Co., Ltd.) with a thickness of 0.05 μm, and on top of that, 2 g of exemplified compound No. Al-73.
and polycarbonate resin [Panlite L-1250J
2 g was added to Tetrahydro 7ran 11011112 and dispersed in a ball mill for 12 hours. This dispersion (K-
7) CH.

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

Table 4 A 0.05 μm thick intermediate layer made of Sletsk MF-10J (manufactured by Sekisui Chemical Co., Ltd.) was provided, and exemplified compounds No., B 1-36, A 2-75. CI-76
, DI-5, D2-4, D 3-76, D 4-
2g of 73 and polyester resin “Byron 200J”
(manufactured by Toyobo Co., Ltd.) 2g and 1°2-dichloroethane 10
0 m+2 and dispersed for 24 hours using a ball mill dispersion machine, the dispersion was applied so that the film thickness after drying was 0.6 μm to form a carrier generation layer.

Furthermore, on top of this, 30 g of the following compound (K-9) and 50 g of polycarbonate resin "Nipilon Z-200" (manufactured by Mitsubishi Gas Chemical Co., Ltd.) were added to 400 mA of 1,2-dichloroethane.
A photoreceptor 13 was prepared by dissolving the carrier transport layer and coating it so that the film thickness after drying would be 18 μm.

Example I3 A vinyl chloride-vinyl acetate-maleic anhydride copolymer was coated on the surface of an aluminum drum having a diameter of 60 m.
-Bix1550M RJ (manufactured by Konica)
When installed on a modified machine and copied images, the resulting copied images were high in contrast, faithful to the original, and clear.

Also, this will not change even if you repeat it 10,000 times.

Comparative Example (3) The exemplified compound in Example I3 was represented by the following structural formula (G-3).
A drum-shaped comparative photoreceptor was prepared in the same manner as in Example 13, except that the bisazo compound represented by
When the copied images were evaluated in the same manner as in Example 3, only images with a lot of fog were obtained.

Furthermore, as copying is repeated, the contrast of the copied image decreases, and after 10,000 repetitions, it becomes almost impossible to copy (G). In addition, the vinyl chloride vinyl acetate-maleic anhydride copolymer "S-LEC MF-1"
A 1.05 μm thick intermediate layer made of 0J (manufactured by Tsukisui Kagaku Co., Ltd.) was provided, and 6 g of the structural formula (K-10) and polycarbonate resin [Ba>
Light, L-1250J lOg To'a: 1.
2 = Carrier transport (
K-10) Furthermore, exemplified compound No., A I-10, B 1
-24°A 2-28. 2 g of Cl-27, 1.5 g of the above carrier transport substance, 2 g of polycarbonate resin "Panlite L-1250J" and 3 g of 1,2-dichloroethane.
In addition to omQ, a solution dispersed in a ball mill for 24 hours was applied to provide a carrier generation layer having a thickness of 4 μm after drying, thereby producing photoreceptors Nos. 14 to 17 of the present invention.

When these photoreceptors were measured in the same manner as in Example 1, the results shown in Table 5 were obtained.

As is clear from the results of the Examples and Comparative Examples shown in Table 5 and above, the photoreceptor of the present invention has better stability, sensitivity, durability, and combinations with materials sent to a wide range of gears than the comparative photoreceptor. It is extremely superior in terms of performance.

[Brief explanation of the drawing]

1 to 9 are cross-sectional views showing the layer structure of the photoreceptor of the present invention, respectively.

Claims (3)

[Claims] (1) An electrophotographic photoreceptor comprising a photosensitive layer containing a bisazo compound represented by the following general formula [1] on a conductive support. General formula [1] ▲ Numerical formulas, chemical formulas, tables, etc. are included ▼ [R_1 represents a halogen atom or a substituted or unsubstituted group of an alkyl group, an alkoxy group, or a phenyl group. R_2
~R_6 represents two groups of substituted and unsubstituted groups of a hydrogen atom, a halogen atom, a nitro group, a cyano group, an alkyl group, and an alkoxy group, respectively. ] (2) The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer contains a bisazo compound represented by the general formula [1] and a carrier transporting substance together. (3) Claim 1 characterized in that the photosensitive layer is constituted by a laminate of a carrier generation layer containing a bisazo compound represented by the general formula [1] and a carrier transport layer.
Or the electrophotographic photoreceptor according to 2.