JPS60113246A - Photosensitive body - Google Patents

Abstract

PURPOSE:To improve the sensibility and durability by using a specified diazo compd. as a carrier generating agent. CONSTITUTION:A disazo compd. expressed by the formula I (wherein R is H, halogen, alkyl, or alkoxy; n is an integer 1 or 2; Cp is expressed by the formulas II, III wherein Z is a group of atoms necessary for constituting an aromatic carbocyclic ring, or an aromatic heterocyclic ring; Y is a carbamoyl group or sulfamoyl group; R1 is H, alkyl, amino, carbamoyl, carboxy, or ester of said carboxy group, cyano; A is aryl; R2 and R3 are alkyl, aralkyl, wherein each group may be substituted) as a carrier generating substance in combination with a carrier transporting agent.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a photoreceptor, and more particularly to a novel electrophotographic photoreceptor having a photosensitive layer containing an azo compound.

(Prior art) Conventionally, photoconductors were made of 1 selenium, zinc oxide, 1111 m
Inorganic photoreceptors having a photosensitive layer mainly composed of an inorganic photoconductive compound such as cadmium chloride have been widely used. 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. In addition, cadmium sulfide has problems with moisture resistance and durability, and zinc oxide has problems with durability, etc.

In order to overcome these drawbacks of inorganic photoreceptors, research and development have been actively conducted in recent years on organic photoreceptors having photosensitive layers containing various organic photoconductive compounds as main components. For example, Japanese Patent Publication No. 50-10496 describes an organic photoreceptor having a photosensitive layer containing poly-N-vinylcarbazole (h2.4.7-) and nitro-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. In such a so-called function-separated type electrophotographic photoreceptor, each material can be selected from a wide range, and a lot of research has been conducted because it is relatively easy to create a photoreceptor with arbitrary performance. It's here.

Many compounds have been proposed as carrier generating substances for such functionally separated electrophotographic photoreceptors. An example of using an inorganic compound as a carrier generating substance is 1, for example, amorphous selenium described in Japanese Patent Publication No. 4B-16198, which is used in combination with an organic photoconductive compound. However, the drawback that the ray-generating layer crystallizes due to heat and deteriorates the characteristics as a photoreceptor has not been improved.

(Object of the Invention) An object of the present invention is to provide a photoreceptor containing a specific disazo compound that is stable against heat and light and has an excellent carrier generation potential pressure.

Another object of the present invention is to provide a durable electrophotographic photoreceptor that has high sensitivity, a low residual potential, and whose characteristics do not change even after repeated use.

As a result of extensive research aimed at achieving the above object, the present inventors have discovered that a disazotized metal represented by the general formula CD below can function as an active ingredient of a photoreceptor, and have completed the present invention. be.

General formula [I] In the formula, R represents a hydrogen atom, a halogen atom, an alkyl group (e.g., methyl group, ethyl group, etc.), or an alkoxy group (e.g., methoxy group, ethoxy group, etc.), and is an integer of 1 or 2. represents. (However, when sn is 2, R may choose a different group) Cp is present and 1 R4: Hydrogen atom, 1 substituted/unsubstituted alkyl group having 1 to 4 carbon atoms, and substituted/unsubstituted aralkyl group, substituted・Unsubstituted phenyl group, R5: hydrogen atom, substituted/unsubstituted argyl group having 1 to 4 carbon atoms, substituted/unsubstituted aromatic carbocyclic group (e.g. substituted/unsubstituted phenyl group, substituted/unsubstituted Naphthyl group, substituted and
(an unsubstituted anthryl group, etc.), or a substituted/unsubstituted aromatic polycyclic group (for example, a substituted/unsubstituted carbazolyl group, an unsubstituted dibenzofuryl group, etc.).

Substituents for these groups include, for example, substituted/unsubstituted alkyl groups having 1 to 4 carbon atoms (e.g. evamethyl group, ethyl group,
isopropyl group, tertiary butyl group, trifluoromethyl group, etc.), substituted/unsubstituted aralkyl group (e.g. benzyl group, phenethyl group, etc.), halogen atom (chlorine atom, bromine atom, fluorine atom, iodine atom), carbon Substituted/unsubstituted alkoxy groups of numbers 1 to 4 (e.g. methoxy group, ethoxy group,
iso-10boxy group, tertiary butoxy group, 2-chloroethoxy group, etc.), hydroxy group, substituted/unsubstituted aryloxy group (e.g., p-chlorophenoxy group, 1-naphthoxy group, etc.), acyloxy group (e.g., acetyloxy group, p-cyanobenzoyloxy group, etc.), carboxy group,
Its ester group (e.g. ethoxycarbonyl l m-
bromophenoxycarbonyl group, etc.), carbamoyl group (
For example, aminocarbonyl group, tertiary butylaminocarbonyl group, anilinocarbonyl group, etc.), acyl group (e.g., acetyl group, 0-nido-benzoyl group, etc.), sulfo group, sulfamoyl group (e.g., aminosulfonyl group, 3
butylaminosulfonyl group, p-tolylaminosulfonyl group, etc.), amino group, acylamino group (e.g., acetylamino group, benzoylamino group, etc.), sulfonamide group (e.g., methanesulfonamide group, p-toluenesulfonamide group) groups), cyano groups, nitro groups, etc., but preferably substituted or unsubstituted alkyl groups having 1 to 4 carbon atoms (for example, methyl groups, ethyl groups, isopropyl groups, n-bu, nano-1 trifluoro methyl group), halogen atom (chlorine atom, bromine atom, fluorine atom, iodine atom),
Substituted/unsubstituted alkoxy groups having 1 to 4 carbon atoms (e.g.
These include a methoxy group, an ethoxy group, a tertiary butoxy group, a 2-ethoxy group), a cyano group, and a nitro group.

2 is an atomic group necessary to form a substituted/unsubstituted aromatic carbocycle or a substituted/unsubstituted aromatic heterocycle,
Specifically, it represents an atomic group forming a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted indole ring, or a substituted or unsubstituted carbazole ring.

As substituents for the atomic groups forming these rings, for example, a series of #t' as listed as substituents for R4*R@
, substituents are listed, preferably halogen atoms (salt rice atom, bromine atom, fluorine atom, iodine atom), sulfo-1-sulfamoyl group (eg, aminosulfonyl group, p-tolylaminosulfonyl group, etc.).

R1 is a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or
Unsubstituted amino groups, carboxy groups, ester groups thereof, substituted/unsubstituted carbamoyl groups, and cyano groups, preferably hydrogen atoms, substituted/unsubstituted alkyl groups having 1 to 4 carbon atoms (for example, methyl groups, Ethyl group, isopropyl group, 3
butyl group, trifluoromethyl group, etc.), and cyano group.

A is a substituted or unsubstituted aryl group, preferably a substituted or unsubstituted phenyl group, and examples of substituents for these groups include a series of substituents such as those listed as substituents for R4, R, etc. However, preferably a halogen atom (one chlorine atom, one bromine atom, fluorine atom, iodine atom), a substituted or unsubstituted furkyl having 1 to 4 carbon atoms (e.g., methyl group, ethyl group, isopropyl group, tertiary butyl group) (eg, methoxy, ethoxy, isopropoxy, tertiary butoxy, 2-chloroethoxy).

R8 and R8 represent a substituted/unsubstituted alkyl group, a substituted/unsubstituted aralkyl group, and a substituted/unsubstituted aryl group, preferably a substituted/unsubstituted alkyl group having 1 to 4 carbon atoms (e.g. , methyl group, ethyl group, inglovir group, tertiary butyl group, triph/l/olomethyl group, etc.),
Substituted e unsubstituted phenyl group (e.g. phenyl group, p-
methoxyphenyl group, m-chlorophenyl group, etc.).

Specific examples of the disazo compound useful in the present invention represented by the general formula [■] include the following structural formula and general formula C11.
1, but the disazo compounds of the present invention are not limited thereto.

Compound Layers (1) to (36) General Formula [11] (Table B) These compounds can be synthesized by well-known methods. A synthesis example is shown below.

Synthesis Example 1 Synthesis of Compound (1) S-(1) Intermediate Synthesis of 9-xanthenylidene malononitrile Method of M, M, Hafaz, N, Latif et al. (J, O
rg, Chem, wvat 26.3988 91 (
1961) ) was dispersed in 150 aJ of thionyl chloride and heated under reflux for 3 hours. After the reaction, thionyl chloride was evaporated to dryness under reduced pressure, and 100% of benzene was added and evaporated to dryness again to remove thionyl chloride. It was crystallized from a small amount of benzene and hexane and collected by filtration. Yield: 20.5g. obtained, 9,9-dichloroxanthine and malononitrile 5
0g were mixed and heated to 100°C for 1 hour.

After the reaction was completed, the reaction mixture was thoroughly washed with methanol and recrystallized from benzene to obtain the desired 9-xantheniIJ-thenmalononitrile. Yield: 18.3g.

Yield: 80%, melting point: 242-244°C.

S-(2) Intermediate 2. Synthesis of 7-sinitro 9-xanthenylidene malononitrile 16.1 g of 9-xanthenylidene malononitrile was dissolved in 5 ow Lt of a-sulfuric acid, and 10 g of concentrated nitric acid was added at 10°C or lower. After dropping, stir at room temperature for 1 hour and add 1.5 ml of ice water.
poured into. The precipitated crystals were collected by filtration, washed with methanol and N
, recrystallized from 150d of N-dimethylformamide.

Yield: 13 g, yield: 55.1%, melting point: 267-269°C.

S-(3) Synthesis of Compound 1 3.34 g of 2,7-sinitro 9-xanthenylidene malononitrile was converted into a salt I! The mixture was dispersed in 1,100 wLl, and 5 g of stannous chloride diwater (aa) was added thereto, and the mixture was heated to reflux for 1 hour. After reacting for 6 hours, it was cooled, and the precipitated crystals were seeded and washed with a small amount of IN-hydrochloric acid to give 2.7-diamine-9.
-Xanthenylidene malononitrile loose tin complex was obtained.

Melting point: 270°C or higher (discoloration) Suspend 15 ml of this (all bottles) in ice water 2001 and add sodium sulfite 1.8 at -5 to θ°C.
A solution prepared by dissolving 20 g of g in 201 ml of water was added dropwise. After the dropwise addition was completed, the mixture was stirred at the same temperature for 9 minutes and quickly filtered. The filtrate was poured into 200 ml of ice water containing 10 g of ammonium phosphorous fluoride, and the precipitated crystals were collected by filtration to obtain 1-tetrazonium hexafluorophosphate salt. This product was dissolved in ice-cooled N,N-dimethylformamide 150- and used as a dropwise solution for the next coupling reaction.

Dissolve 7.6 g of 2-hydroxy-3-(2-methyl-4-methoxyphenylcarbamoyl)benzos carbazole (manufactured by Su7toll ASSR Hoechst) and 15 g of triethanolamine in N,N-dimethylformamide 2001, and add 5. The above dropwise solution was added slowly at .

After completion of the dropwise addition, the mixture was stirred at 5 to 10°C for 2 hours, returned to room temperature and left overnight, and the precipitated crystals were collected.

This product was diluted with 500% of N,N-dimethylformamide.
After washing twice and once with acetone 11, it was dried to obtain 5.6 g of compound (1).

Yield 51.4ti (from dinitro form) This was confirmed by elemental analysis.

Elemental analysis (chemical formula is C@H44Nso O?)
A cHN Actual value 72.58 4.23 12.94 Calculated value 7
2.79 4.07 12.86 Synthesis Example 2 Compound (9
) Synthesis of 2-human axy-3-(2,4-dimethylphenylcarbamoyl)naphthalene (S7toyl ASMX 15.9
Ji1 and triethanolamine 129 were dissolved in 200i*j of N + N-dimethylformamide to prepare a coupler solution. This was prepared in the same manner as in Synthesis Example 1 at 5°C. Tetrazonicum solution was added dropwise. After the completion of the dropwise addition, the mixture was stirred at the same temperature for 2 hours, returned to room temperature, and left overnight to remove the precipitated crystals. This product was washed twice with N,N-dimethylformamide 500- and once with 1 t of acetone and dried to obtain compound (9) 5.2f! I got i+. Yield 59
H (from dinitro form) This is an element confirmed by elemental analysis C) IN Actual value 73.62 4.5m 12.87 Calculated value 7
3.75 4J6 12.800 The disazo compound of the present invention has excellent photoconductivity, and when producing an electrophotographic photoreceptor using the same, the disazo compound of the present invention is placed on a conductive support in a binder. It can be manufactured by providing a photosensitive layer dispersed in. Another method is to use the disazo compound of the present invention as a carrier-generating substance that takes advantage of its particularly excellent gear-generating ability among its photoconductivity properties, and to use it together with a carrier-transporting substance that can effectively act in combination with this. Accordingly, it is also possible to make a so-called functionally separated electrophotographic photoreceptor, such as a laminated type or a dispersed type. Further, the disazo compound used in the present invention has the general formula CI
) from among the disazo compounds represented by
It can be used in combination with the above, or in combination with a disazo compound or a trinuazo compound.

Various types of mechanical configurations of electrophotographic photoreceptors are known, and the electrophotographic photoreceptor of the present invention can take any of these forms.

Usually, the configuration is as shown in FIGS. 1 to 6. In FIGS. 1 and 13, a laminate of a carrier generation layer 2 containing the above-mentioned disazo compound as a main component and a carrier transport layer 3 containing a carrier transport substance as a main component on a conductive support 1 is shown. A photosensitive layer 4 is provided.

As shown in FIGS. 2 and 4, this photosensitive layer 4 may be provided through an intermediate layer 5 provided on a conductive support. When the photosensitive layer 4 has a two-layer structure in this manner, an electrophotographic photoreceptor having the most excellent electrophotographic properties can be obtained. Further, in the present invention, as shown in FIGS. 5 and 6, a photosensitive layer 4 comprising the carrier-generating substance 7 dispersed in a layer 6 containing a carrier-transporting substance as a main component is provided on the conductive support 1. It may be provided directly or via the intermediate layer 5.

When the disazo compound of the present invention is used as a carrier-generating substance, the carrier-transporting substance used in combination with the disazo compound is an electron-accepting substance that easily transports electrons such as trinitrofluorenone or tetranitrofluorenone. - Polymers with a 1!1 ring compound on the side button, such as vinylcarbazole, triazole U conductors, oxadiazole derivatives, imidazole #j
J conductor, pyrazoline rust conductor, polyaryl alkane conductor, 7-enylene diamine spin conductor, hydrazone Hm body, amino-converted chalcone rust conductor, triarylamine rust conductor,
Examples include electron-donating substances that easily transport holes, such as a carbazole Wfj conductor and a stilbene conductor, but the carrier transporting substance used in the present invention is not limited to these.

The carrier generation layer 2 constituting the two-layered photosensitive layer 4 is in IF' contact with the conductive support 11 or the carrier transport layer 3, or if necessary, an intermediate layer such as an adhesive layer or a barrier layer is provided. For example, it can be formed by the following method.

M-1) A method of applying a solution in which a disazo compound is dissolved in a suitable solvent, or a solution in which a binder is added and mixed as necessary.

M-2) A method in which a disazo compound is made into fine particles in a dispersion medium using a ball mill, a homomixer, etc., and a binder is added as necessary to mix and disperse the resulting dispersion and then applied.

Examples of the solvent or dispersion medium used for forming the carrier generation layer include n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolatone, triethylenediamine, N,N-dimethylformamide, acetone, methylethylketone, cyclohexanone, benzene, toluene, xylene, chloroform,
Examples include 1,2-dichloroethane, dichloromethane, tetrahydrofuran, dioxane) methanol, ethanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, and the like.

When using a binder in the carrier generation layer or carrier transport layer, any binder can be used, but it is preferable to use a film-forming polymer that is hydrophobic, has a high dielectric constant, and is electrically insulating. .

Examples of such high molecular weight polymers include, but are not limited to, the following.

P-1) Polycarbonate P-2) Polyester P-3) Methacrylic resin P-4) Acrylic resin P-5) Polyvinyl chloride P-6) Polyvinylidene chloride P-7) Polystyrene P-8) Polyvinyl acetate P-9 ) Styrene-butadiene copolymer P-10)
[(f, vinylidene-acrylonitrile copolymer P-11) vinyl chloride-vinyl acetate copolymer P-12
) Vinyl chloride-vinyl acetate-maleic anhydride copolymer P-IE; ) Silicone resin P-111) Silicone-alkyd resin P-1!1
) Phenol-formaldehyde resin P-16) Styrene-alkyd resin P-17') Poly-N-vinylcarbazole P-18) Polyvinyl butyral These binders can be used alone or as a mixture of two or more. .

The thickness of the carrier generation layer 2 formed in this way is
It is preferably 0.01 μm to 5 μm, more preferably 0.05 μm to 5 μm. In addition, when the carrier generation layer or photosensitive layer is a dispersion system, the particle size of the azo compound is 5.
It is preferably 1 μm or less, more preferably 1 μm.
It is as follows.

The conductive support used in the electrophotographic photoreceptor of the present invention is a metal plate including an alloy, a metal drum, or a conductive polymer such as a conductive compound such as indium monooxide or an aluminum alloy including palladium monooxide. Apply a thin metal film of
Examples include paper and plastic films that have been made conductive by vapor deposition or lamination. As an intermediate layer such as an adhesive layer or a barrier layer, in addition to the polymer used as the binder, organic polymer substances such as polyvinyl alcohol, ethyl cellulose, carboxymethyl cellulose, or aluminum oxide are used.

The electrophotographic photoreceptor of the present invention having the above-mentioned structure exhibits little fatigue deterioration even when used repeatedly, and has excellent durability.

The trisazo compound of the present invention is useful as a compound whose conductivity changes due to light reflection, and it can be used not only in electrophotographic photoreceptors, but also in any photoreceptor that utilizes this property.

The present invention will be specifically explained below using Examples, but the embodiments of the present invention are not limited thereto.

Example 1 Vinyl chloride-Sa vinyl-
A 0.05 μm thick intermediate layer made of a maleic anhydride copolymer “S-LEC MF-10J (manufactured by Yutaka Kagaku Co., Ltd.) was provided, and 2 g of compound (3) was mixed with 1.2-dichloroethane IIOMK on top of the intermediate layer. A carrier-generating layer was formed by applying a dispersion that had been dispersed in a ball mill so that the film thickness after drying would be 0.5 fim.On this carrier-generating layer, 4-methoxy-4'-styryltriphenylamine was applied. 6
g and methacrylic resin "Acrivet" (manufactured by Mitsubishi Rayon Co., Ltd.) 1019 in 1,2-dicrIe+ethane 70m
The electrophotographic photoreceptor of the present invention was prepared by applying the fermented solution to form a carrier transport layer so that the film thickness after drying was 10 μm.

The photoreceptor produced in this way is transferred to an electrophotographic copying machine r U
-Bl! 2000 RJ (Konishi Roku Photo Industry Co., Ltd. 1k
) (7) When the device was installed on a modified machine and the image was copied, a copy of 1iin* was obtained. This did not change even after repeating 5000 times.

Example 2 Diameter 100, with the intermediate layer used in Example 1 provided on the surface.
A 1% ethylenediamine solution of compound (9) was applied onto an aluminum drum to form a carrier generation layer 15 to a dry film thickness of 0.3 μm. Next, 6 g of the following compound (K-1) and 10 g of polyester resin "Vylon 200J (manufactured by Toyobo Co., Ltd.)" were dissolved thereon in 70 ml of 1,2-diacao ethane, and the film thickness after drying this solution was 11 μm. A carrier transport layer was formed by coating the powder to form an electrophotographic photoreceptor of the present invention.

The drum-shaped photoreceptor thus prepared was installed in a modified electrophotographic photoreceptor r U-Blx V2 J (manufactured by Konishiroku Photo Industries Co., Ltd.), and when the image was copied L7, a clear image with high contrast was obtained. was gotten.

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[Brief explanation of drawings]

Figures 1 to 6 are cross-sectional views showing functional structural examples of the electrophotographic photoreceptor of the present invention, and 1 to 7 in the figures do not represent the following, respectively. 1... Conductive support 2... Carrier generation layer 3... Carrier transport layer 4... Photosensitive layer 5... Intermediate layer 6 ...Layer 7 containing gear transport material...
...Carrier-generating substance agent Yoshi Kuwahara Mishima Figure 1 Figure 5 Figure 2 Diagram

Claims (2)

[Claims] (1) A photoreceptor characterized by having a photosensitive layer containing at least one kind of azo compound represented by the following general formula [1] on a conductive support. General formula [■] [In the formula, R represents a hydrogen atom, a halogen atom, an achikyl group, or an alkoxy group, and n represents an integer of 1 or 2. (However, when the number is 2, a different group may be selected for R.) Cp is H and 2: constitutes a substituted/unsubstituted aromatic carbocycle or a substituted/unsubstituted aromatic heterocycle. Necessary atomic group, Y: unsubstituted carbamoyl group or substituted/unsubstituted sulfamoyl group, R1: hydrogen atom, fIt-substituted-unsubstituted furkyl group, substituted/unsubstituted amino group, substituted/unsubstituted sulfamoyl group, carbamoyl group,
Carboxy group and its ester group, or cyano group, A: f-substituted/unsubstituted aryl group, R3 and R1,: substituted/unsubstituted alkyl group, substituted/unsubstituted aralkyl group, or substituted/unsubstituted aryl group represents. ] (2) The photosensitive layer contains a carrier transporting substance and a carrier generating substance, and 1 the carrier generating substance has the general formula [
The photoreceptor according to claim 1, which is a disazo compound represented by [2].