JPS6146499B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel dizazo compound and a method for producing the same.

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 provide a novel disazo compound having excellent properties as a photoconductive material and a method for producing the same.

That is, one of the present inventions is the general formula [] (However, R represents an alkyl group having 1 to 3 carbon atoms, n is an integer of 2, and R may be the same or different groups.)

The above-mentioned disazo compound of the present invention [] can be produced by the following method. That is, another aspect of the present invention is the general formula [] (However, X represents an anionic functional group.) A tetrazonium salt represented by the general formula [] (However, R represents an alkyl group having 1 to 3 carbon atoms, n is an integer of 2, and R may be the same or different groups.) This is a novel method for producing disazo compounds.

The tetrazonium salt [] has the general formula [] (However, Y represents bromine or iodine.) Produced by reacting 2,7-dihalofluoren-9-one represented by the following with nitrostyrene, the general formula [] By reducing 2,7-bis(nitrostyryl)fluoren-9-one of the new compound represented by the general formula [] It can be obtained by preparing 2,7-bis(aminostyryl)fluoren-9-one shown by and then diazotizing it.

The reaction of 2,7-dihalofluoren-9-ones 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.

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. or,
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 equivalent mole of hydrogen halide generated. Common reaction solvents are used, such as N,N-dimethylformamide, dimethylacetamide, toluene, xylene, chlorobenzene, O-dichlorobenzene, trichlorobenzene, N-methyl-2-pyrrolidone, and dimethylsulfoxide. . The reaction is
It is carried out at a temperature range of 75-150 °C.

The new compound 2,7-
Bis(nitrostyryl)fluoren-9-one [] is reduced to 2,7-bis(aminostyryl)fluoren-9-one [], which is diazotized to obtain a tetrazonium salt.
7-bis(aminostyryl)fluoren-9-one is added to a dilute inorganic acid such as dilute hydrochloric acid or dilute sulfuric acid, and then an aqueous solution of sodium nitrite is added to -10
This is done by adding while maintaining the temperature at ~10°C. This diazotization is completed in 30 minutes to 2 hours.
In this case, the reaction mixture is precipitated as a tetrazonium salt by adding, for example, borofluoric acid,
It is desirable to obtain crystals.

Next, the compound [ ] is added to the tetrazonium salt [ ] in an amount of 1 to 10 times the molar amount, preferably 2 to 5 times the molar amount of the tetrazonium group, to cause a coupling reaction. In reality, this reaction is carried out by dissolving the tetrazonium salt and the coupling component in an organic solvent such as N,N-dimethylformamide or dimethylsulfoxy, and then dissolving the tetrazonium salt and coupling component in an aqueous solution of sodium acetate while maintaining the temperature at -10 to 10°C. This is done by dropping an alkaline aqueous solution.

The novel disazo 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 bisazo compound; (2) a photosensitive layer containing a bisazo compound dispersed in a binder; (3) a photosensitive layer containing a bisazo compound dispersed in a well-known charge transfer medium; (4) the above ( Examples of uses of the novel disazo 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 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 83.1 parts of fluorene (parts by weight, same below) and N-
To a suspension of 174 parts of bromosuccinimide in 1000 parts of glacial acetic acid, 25 parts of a 47% aqueous solution of hydrobromic acid was added dropwise with stirring at room temperature. After dripping,
After stirring at room temperature for 3 hours, 500 parts of water was slowly added, the precipitate was collected, air-dried, and then recrystallized using a mixed solvent of ethanol and nitromethane. 88.2 parts of dibromofluorene (yield 54%) was obtained.

8.10 parts of 2,7-dibromofluorene to 180 parts of acetic acid
Chromic anhydride while stirring at 80℃.
A solution prepared from 4.5 parts of water, 3.0 parts of water, and 3.0 parts of acetic acid was added dropwise. After the dropwise addition, the mixture was stirred at 95°C for 1 hour and then cooled to room temperature. The reaction mixture was poured into 450 parts of water, the precipitate was collected, thoroughly washed with water, dried, and recrystallized from acetic acid to obtain 2,7-dibromofluorene-9- as yellow crystals.
Got 7.11 copies on.

2,7-dibromofluoren-9-one 4.39
4.27 parts of 4-nitrostyrene, 6.03 parts of tri-n-butylamine, 0.058 parts of palladium acetate, 0.16 parts of tri-o-tolylphosphine, and 45 parts of N,N-dimethylformamide (hereinafter abbreviated as DMF). at 100°C with stirring under nitrogen atmosphere.
The reaction was carried out for 5 hours. After cooling the reaction mixture, the precipitated crystals were collected, washed with DMF and then with methanol, and dried to obtain 5.79 parts of 2,7-bis(4-nitrostyryl)fluoren-9-one ( A yield of 94% was obtained.

Add 4.74 parts of 2,7-bis(4-nitrostyryl)fluoren-9-one to a mixture consisting of 9.20 parts of iron powder, 3.9 parts of concentrated hydrochloric acid, 13 parts of water, and 170 parts of DMF,
After stirring for 3 hours at a temperature of 100°C, the pH was adjusted to 8 with a 20% aqueous sodium carbonate solution while hot, and the insoluble matter was filtered off. By pouring the liquid into water, collecting the precipitate, washing with water, drying, and recrystallizing from xylene, 2,7-bis(4-aminostyryl)fluorene was obtained as dark brown crystals. 9-on
3.96 parts (yield 96%) were obtained.

Add 1.45 parts of 2,7-bis(4-aminostyryl)fluoren-9-one to dilute hydrochloric acid prepared from 12 parts of concentrated hydrochloric acid and 12 parts of water, and stir well at 60°C for 30 minutes. Next, this mixture was cooled to about 0°C, and a solution prepared by dissolving 0.50 parts of sodium nitrite in 1.50 parts of water was added dropwise thereto at 0°C. After that, stir at the same temperature for 30 minutes, remove a small amount of unreacted material, and add 42
% borofluoric acid was added, and the precipitated crystals were collected, washed with water, and dried to obtain 2.04 parts of tetrazonium fluoroborate as red crystals.

The tetrazonium salt thus obtained and 2-hydroxy-3-naphthoic acid-m-xylidide (naphthol AS-MX) as a coupling component 2.24
1 part was dissolved in 300 parts of cooled DMF, and 4 to 8 parts of a solution consisting of 3.50 parts of sodium acetate and 40 parts of water was added to this.
The mixture was added dropwise at ℃, and after cooling was discontinued, the mixture was further stirred at room temperature for 3 hours. After that, remove the formed precipitate and add water.
After washing three times with 300 parts of DMF, it was washed three times with 300 parts of DMF. Further, residual DMF was washed away with acetone and dried under reduced pressure at 50°C to obtain 2.16 parts (yield 61%) of the indicated disazo compound as bluish-black crystals.

The elemental analysis values of the obtained disazo compound are shown below. The infrared absorption spectrum is shown in FIG.

Elemental analysis value C H N Actual value (%) 79.35 5.02 8.33 Calculated value (%) 78.96 4.95 8.25 Application example 1 part by weight of the disazo pigment synthesized in the example and polyester resin (manufactured by Toyobo Co., Ltd.: Vylon 200) 2
The weight part was a 6% by weight solution using tetrahydrofuran as a solvent, and this was kneaded in a ball mill for 8 hours. The resulting dispersion was applied onto an aluminum substrate using an applicator and dried to form a charge generation layer with a thickness of about 1 μm.

On top of this, P-diethylaminobenzaldehyde-N,N-diphenylhydrazone and polycarbonate resin (manufactured by Teijin: Panlite L) were blended at a weight ratio of 1:1, and dissolved in tetrahydrofuran to make a 18% by weight solution. , the film thickness after drying is
It was applied with an applicator to a thickness of 10 μm, and after drying, a charge transfer layer was formed to obtain an electrophotographic photoreceptor having a two-layer photosensitive layer.

This photoreceptor was tested at -6KV using an electrostatic copying paper tester (Kawaguchi Electric Manufacturing Co., Ltd.: SP-428 model).
After performing corona discharge for 15 seconds to make it negatively charged, it was left in a dark place for 20 seconds, and the surface potential Vo at that time was
(V), then irradiate the surface with light using a tungsten lamp so that the illumination intensity is 20 lux, and calculate the time (seconds) until the surface potential becomes 1/2 of Vo, the exposure amount for half reduction. E1/2 (Lutx)
seconds) was obtained.

The results were Vo=-830V and E1/2=24 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 disazo compound of the present invention produced according to Examples.

Claims (1)

[Claims] 1. General formula [] (However, R represents an alkyl group having 1 to 3 carbon atoms, n is an integer of 2, and R may be the same or different groups.) 2 General formula [] (However, X represents an anionic functional group.) A tetrazonium salt represented by the general formula [] (However, R represents an alkyl group having 1 to 3 carbon atoms, n is an integer of 2, and R may be the same or different groups.) General formula [] (However, R represents the above-mentioned group, and n is the above-mentioned integer.) A method for producing a novel dizazo compound represented by the following.