JPS6239626B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel trisazo compounds.

In recent years, many electrophotographic photoreceptors using organic photoconductive materials have been proposed. For example, a photoreceptor with a photosensitive layer containing poly-N-vinylcarbazole and 2,4,7-trinitrofluoren-9-one, a photosensitive layer with poly-N-vinylcarbazole sensitized with a pyrylium salt dye. A photoreceptor with a photoreceptor layer containing organic pigment as the main component, a photoreceptor with a photoreceptor layer consisting of a charge generation layer and a charge transport layer, a photoreceptor with a photoreceptor layer consisting of a charge generation layer and a charge transport layer, a photoreceptor with a eutectic complex consisting of a dye and a resin as the main component. There are photoreceptors that are provided with a photosensitive layer.

Although the above photoreceptors have some excellent properties, one of their major drawbacks as electrophotographic photoreceptors is that they generally have lower photosensitivity than inorganic photoreceptors such as selenium. There is.

An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a novel trisazo compound having excellent properties as a photoconductive material.

That is, the present invention is based on the general formula [] This is a novel trisazo compound represented by

The above trisazo compound of the present invention [] can be produced by the following method. That is, the general formula [] (where X is an anionic functional group) and a hexazonium salt represented by the general formula [] (However, R is an alkyl group, an alkoxy group, a nitro group, a dialkylamino group, or a halogen; n is an integer of 0, 1, 2, or 3; and when n is an integer of 2 or 3, R is They may be the same or different groups.) are reacted.

The hexazonium salt is, for example, 1, 2, 4-
General formula [] produced by reacting trihalobenzene and nitrostyrene By reducing 1,2,4-tris(nitrostyryl)benzene represented by the general formula [] It can be obtained by preparing 1,2,4-tris(aminostyryl)benzene shown by and then diazotizing it.

The reaction of 1,2,4-trihalobenzene with nitrostyrene typically requires a catalyst and a hydrogen halide scavenger. A suitable catalyst is a combination of a noble metal compound such as palladium acetate and a phosphorus compound such as triarylphosphine. The nitrostyrene is preferably P-nitrostyrene.

Triarylphosphines include triphenylphosphine, tri-O-tolylphosphine, tris(2,5-diiso-propylphenyl)phosphine, tri-α-naphthylphosphine, tris(2,3,4, Mention may be made of phosphine such as 5-tetramethyl)phenylphosphine, tris(2-methyl-5-t-butylphenyl)phosphine, tris(P-carbomethoxyphenyl)phosphine, but especially tri-O-tolyl Preference is given to using phosphine, tris(2-methyl-5-tert-butylphenyl)phosphine. The triarylphosphine used in the present invention is suitably used in an amount of 0.5 to 10 mol per mol of palladium acetate. Further, the appropriate amount of palladium acetate to be used is 0.25 to 2 mol% of the amount of styrene derivative used.

As hydrogen halide scavengers, secondary amines,
Tertiary amines and basic salts such as sodium bicarbonate and sodium carbonate are suitable. Such secondary amines and tertiary amines may be common amines such as diethylamine, di-n-butylamine, piperidine, morpholine, triethylamine, tri-n-butylamine, triamylamine, and tetramethylethylenediamine. The amount used is slightly in excess of the molar equivalent of hydrogen halide generated. Common reaction solvents such as N/N-dimethylformamide,
Dimethylacetamide, toluene, xylene, chlorobenzene, O-dichlorobenzene, trichlorobenzene, N-methyl-2-pyrrolidone, and dimethyl sulfoxide are used. Reaction is 75-150
It is carried out in a temperature range of ℃.

The 1,2,4-tris(nitrostyryl)benzene obtained in this way is reduced,
1,2,4-tris(aminostyryl)benzene is diazotized to form hexazonium salt,
Diazotization is performed by adding 1,2,4-tris(aminostyryl)benzene to a dilute inorganic acid such as dilute hydrochloric acid or dilute sulfuric acid, and then adding an aqueous sodium nitrite solution to this while keeping the temperature between -10 and 10°C. This is done by adding This diazotization is completed in 30 minutes to 2 hours. In this case, it is desirable that the reaction mixture is precipitated as a hexazonium salt by adding, for example, borofluoric acid, and then collected to obtain crystals.

Next, the compound [ ] is added to the hexazonium salt [ ] in an amount of 1 to 15 times, preferably 3 to 8 times, the mole of the hexazonium group to cause a coupling reaction. In practice, this reaction is carried out by dissolving the hexazonium salt and the coupling component in an organic solvent such as N/N-dimethylformamide or dimethyl sulfoxide, and then
This is carried out by dropping an alkaline aqueous solution such as an aqueous sodium acetate solution while maintaining the temperature at .degree.

The novel trisazo compound of the present invention thus obtained is particularly useful as a photoconductive material for electrophotographic photoreceptors. Therefore, for example, (1) a photosensitive layer made of a trisazo compound (2) a photosensitive layer containing a trisazo compound dispersed in a binder (3) a photosensitive layer containing a trisazo compound dispersed in a known charge transfer medium (4) the above ( Examples of uses of the novel trisazo compound include a photosensitive layer in which the photosensitive layers 1) to (3) are used as a charge generation layer, and a charge transfer layer containing a well-known charge transfer medium is laminated thereon.

EXAMPLES The present invention will be specifically explained below using Examples, but the present invention is not limited to these Examples.

Example Synthesis of 1,2,4-tribromobenzene 3.15 parts (weight parts, same below), P-nitrostyrene 4.92 parts, tri-n-butylamine 6.11 parts, tri-O-tolylphosphine 0.182 parts, palladium acetate 0.067 parts , N
- A mixture consisting of 7 parts of methyl-2-pyrrolidone (hereinafter abbreviated as NMP) was reacted at 100°C for 10 hours, then poured into methanol, the precipitated product was collected, and recrystallized from chlorobenzene. As a result, 3.29 parts (yield: 63%) of 1,2,4-tris(P-nitrostyryl)benzene as orange crystals was obtained.

6.97 parts of iron powder, 2.44 parts of concentrated hydrochloric acid, 11.6 parts of water,
Add 3.29 parts of 1,2,4-tris(P-nitrostyryl)benzene to a mixture of 100 parts of NMP and add 90
After stirring at ~100°C for 5 hours, the pH was adjusted to 8 with a 20% aqueous sodium carbonate solution while hot, and insoluble materials were separated while hot. By pouring the solution into water, the precipitate was collected and recrystallized from chlorobenzene to obtain 1.58 parts of 1,2,4-tris(P-aminostyryl)benzene (yield) as dark yellow crystals. rate 58
%) was obtained.

1.00 parts of 1,2,4-tris(P-aminostyryl)benzene was added to dilute hydrochloric acid prepared from 5.8 parts of concentrated hydrochloric acid and 5.8 parts of water, stirred at 60°C for 30 minutes, and then
The mixture was cooled to 0.degree. C., and a solution of 0.49 parts of sodium nitrite dissolved in 2 parts of water was added dropwise thereto. After that, it was stirred at the same temperature for 30 minutes, a small amount of insoluble matter was separated, and 6.2 parts of a 42% borohydrofluoric acid aqueous solution was added to the solution, and the precipitated crystals were collected, washed with water, and dried. Hexazonium trifluoroborate was obtained as dark brown crystals.

The hexazonium salt obtained in this manner and 2.02 parts of 2-hydroxy-3-naphthoic acid anilide (naphthol AS) as a coupling component are cooled in N/N-dimethylformamide (hereinafter referred to as
A solution consisting of 5.73 parts of sodium acetate trihydrate and 40 parts of water was added dropwise at 4 to 8°C over about 1 hour, followed by stirring at room temperature for 3 hours. . Take the formed precipitate,
After washing three times with 100 parts of water, three times with 150 parts of DMF, and once with acetone. This was dried to produce 1.24 parts of the indicated trisazo compound (yield: 42
%) was obtained. Melting point: 269°C (decomposition) The infrared absorption spectrum of the trisazo compound is shown in Figure 1.

Structural formula Elemental analysis value Measured value (%) C: 77.47 H: 4.62 N: 10.15 Calculated value (%) C: 77.68 H: 4.59 N: 10.07 Application example Trisazo pigment synthesized in the example and polyester resin (manufactured by Toyobo Co., Ltd.: Byron 200) ) were mixed in a weight ratio of 1:2, and this was dissolved in a mixed solvent of n-butylamine and ethylenediamine in a 1:1 (volume ratio) to prepare an 8.4% by weight solution.

This solution was applied onto an aluminum substrate with an applicator and dried to form a charge generation layer with a thickness of about 1 μm.

P-diethylaminobenzaldehyde-N/N-diphenylhydrazone and polycarbonate resin (Panlite L manufactured by Teijin) were blended thereon at a weight ratio of 1:1, dissolved in tetrahydrofuran to make a 18% solution by weight, and dried. The film thickness after is approx.
After applying with an applicator to a thickness of 10μ,
It was dried to form a charge transport layer. In this way, an electrophotographic photoreceptor having a two-layer photosensitive layer was obtained.

This photoconductor was negatively charged by performing -6KV corona discharge for 15 seconds using an electrostatic copying paper tester (SP-428 model manufactured by Kawaguchi Electric Manufacturing Co., Ltd.).
Leave it in the dark for a second, then the surface potential Vo (V)
Then, the surface is irradiated with light using a tungsten lamp at an illuminance of 20 lux, the time (seconds) until the surface potential becomes 1/2 of Vo is measured, and the half-reduction exposure amount E1 is determined. /2 (Luxus・
seconds) was calculated.

The results were Vo=-820v, E1/2=27 lux·sec, and both the charge retention in the dark and the photosensitivity were high.

[Brief explanation of the drawing]

FIG. 1 shows the infrared absorption spectrum of the trisazo pigment of the present invention produced in accordance with the examples.

Claims (1)

[Claims] 1. General formula [] A novel trisazo compound represented by