JPH0791481B2 - Novel bisazo compound and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel bisazo compound useful as an organic photoconductor and a method for producing the same.

2. Description of the Related Art Conventionally, an organic photoconductor used in a laminated type photoreceptor in which a certain azo compound is one form of an electrophotographic photoreceptor,
It is known to be particularly useful as a charge generation pigment. As is well known, this laminated type photoreceptor comprises a charge generation layer mainly composed of a charge generation pigment having the ability to generate charge carriers by light on a conductive support and a charge carrier generated in the charge generation layer thereon. The photoconductor is provided with a charge carrier layer containing a charge carrier substance as a main component, which is capable of efficiently injecting and carrying the carrier. Conventionally, as an azo compound used for such a photoreceptor, for example, in JP-A-47-37543, JP-A-52-55643, and benzidine-based bisazo compounds described in JP-A-52-8832. Known stilbene-based bisazo compounds, diphenylhexatriene-based bisazo compounds described in JP-A-58-222152, diphenylbutadiene-based bisazo compounds described in JP-A-58-222153, etc. There is.

However, a conventional laminated type photoreceptor using an azo compound generally has low sensitivity, and is therefore unsatisfactory as a photoreceptor for a high speed copying machine. On the other hand, in recent years, it has been desired to develop a high-sensitivity photoconductor capable of covering the wavelength range of a semiconductor laser as a photoconductor for a laser printer, but the above-mentioned laminated type photoconductor is suitable for such a purpose for the same reason. The reality is that I can't get it. Therefore, it is desired to produce an azo compound useful as an organic photoconductor that overcomes the conventional drawbacks.

The object of the present invention is not only for a high-speed copying machine, but also for a laser printer, a highly sensitive electrophotographic photoreceptor,
Particularly, it is to provide a bisazo compound useful as an organic photoconductor used for a laminated type photoreceptor and a method for producing the same.

Structure One of the present invention is represented by the general formula (I)(However, Z is benzene ring, naphthalene ring or carbazole
Represents a ring, R may be the same or different, a hydrogen atom,
Halogen atom, lower alkyl group, lower alkoxyl group or
Represents a nitro group, and n represents an integer of 1, 2 or 3.
You ) Is a bisazo compound represented by(Wherein X represents an anionic functional group) and a tetrazonium salt represented by the general formula III(Where Z and n are the same as those in the general formula I described below)
And a coupling reaction. The above
It is a method for producing a bisazo compound represented by the general formula I.
Representative examples of the anionic functional group X in the general formula (II)
As Cl , Br , I , BF_Four PF₆ ， B (C₆H_Five)_Four ， C
lO_Four ， SO_Four ^Two，AsF₆ ， SbF₆ Etc., preferably BF_Four And
It

The bisazo compound represented by the general formula (I) of the present invention is manufactured as follows. First, the tetrazonium salt of the general formula (II) as a raw material is 1,12-bis (4-nitrophenyl) -1,3,5,7,9,11-dodecahexaene (hereinafter referred to as a dinitro compound). It can be obtained by reducing 1,12-bis (4-aminophenyl) -1,3,5,7,9,11-dodecahexaene (hereinafter referred to as a diamino compound), and diazotizing this. Both the dinitro compound and the amino compound used here are novel substances. The dinitro compound can be produced by, for example, the so-called Wittig reaction in which 4-nitrocinnamyltriphenylphosphonium bromide and 2,4-hexadiene-1,6-dial are condensed in the presence of a basic catalyst. The dinitro compound produced by this reaction contains a portion of the cis isomer, which is either the reaction crude product as it is or after purification, after heat treatment with a catalytic amount of iodine in an aromatic hydrocarbon solvent such as toluene or xylene. By doing so, it can be converted into an all-trans form.

Reduction of dinitro compounds is usually iron-hydrochloric acid, stannous chloride-
The reaction is completed by heating to a temperature of 70 to 120 ° C. using hydrochloric acid or the like as a reducing agent, and the reaction is completed in about 0.5 to 3 hours. When an iron-hydrochloric acid reducing agent is used, it is preferably carried out in an organic solvent such as N, N-dimethylformamide.

Next, diazotization of the diamino compound thus obtained is carried out by dispersing the diamino compound in an inorganic acid such as hydrochloric acid or sulfuric acid, and adding sodium nitrite at a temperature of −10 to 20 ° C. The reaction is completed in about 0.5 to 3 hours.

By this reaction, the tetazonium salt of the general formula (II) can be obtained, and by further adding an aqueous solution of, for example, borohydrofluoric acid or sodium borofluoride to the diazotization reaction solution, salt conversion is carried out by the general formula (II) Can be obtained.

In order to produce the bisazo compound of the present invention using the tetrazonium salt thus obtained, first a tetrazonium solution is isolated from the reaction solution, and then this is combined with the coupler of the general formula II, N, N-dimethylformamide, dimethylsulfoxide and the like. It may be dissolved in an organic solvent, and an alkaline aqueous solution such as an aqueous solution of sodium acetate may be added dropwise thereto at a temperature of about -10 to 40 ° C to cause a coupling reaction. This reaction takes about 5 minutes
It will be completed in 3 hours. After completion of the reaction, the precipitated crystals are collected and washed by an appropriate method, for example, water and / or an organic solvent,
The desired bisazo compound can be obtained by purification by recrystallization or the like. The bisazo compound can also be produced by allowing the diazotization reaction solution to act on the coupler as it is.

Specific examples of the bisazo compound of the present invention produced as described above are shown in Table 1 together with the results of elemental analysis and infrared absorption spectrum data.

The present invention will be described below with reference to examples and application examples.

Example 1 Preparation of 1,12-bis (4-nitrophenyl) -1,3,5,7,9,11-dodecahexaene 4-nitrocinnamyl triphenylphosphonium bromide 28.7 g and 2.4-hexadiene-1,6 -Gear 2.9g
Was taken in 250 ml of dry methanol, and 14.4 g of a 28% methanol solution of sodium methoxide was added dropwise at 23 to 26 ° C under a nitrogen stream. It took an hour. After dropping, the mixture was stirred at room temperature for 7 hours, diluted with 200 ml of 50% aqueous methanol solution, and the precipitate was collected, washed with water and dried. 9.0 g (yield 87%) of a crude product containing cis isomer was obtained. Next, this was heated under reflux in 200 ml of xylene together with a catalytic amount of iodine for 8 hours, and then recrystallized with a mixed solvent of DMF-dioxane to obtain all-trans 1,12-bis (4-nitrophenyl) -1,3. 7.2 g of dark red needle crystals of 5,5,7,9,11-dodecahexaene were obtained. Melting point 250 ° C Elemental analysis value (%) Although infrared absorption spectrum (KBr tablet method) is shown in FIG. 1, the absorption based on the stretching vibration of a nitro group to 1510,1340Cm ^-1 is also based on the out-of-plane deformation vibration of the transformer olefin 1005,975Cm ^-1 Absorption was observed.

Production of 1,12-bis (4-aminophenyl) -1,3,5,7,9,11-dodecahexaene 7.0 g of the dinitro compound obtained as described above was added to DMF250.
Take 1 ml of iron powder and add 14.0 g of iron powder to the mixture, add 3.3 ml of concentrated hydrochloric acid and 10 ml of water with stirring, and add diluted hydrochloric acid to 80-90 ° C.
It was stirred for 4 hours. Then, after cooling to 60 ° C., a 10% aqueous sodium hydroxide solution was added to make the mixture alkaline, and the insoluble portion was heated with Celite. The liquid was diluted with water, and the precipitated crystals were filtered, washed with water and dried to obtain 5.1 g (yield 85%) of the diamino compound. Recrystallization from a mixed solvent of DMF-water gave 1,1
Dark brown plate crystals of 2-bis (4-aminophenyl) -1,3,5,7,9,11-dodecahexaene were obtained. Melting point 276 ℃ (decomposition point) Elemental analysis value (%) The infrared absorption spectrum (KBr tablet method) is shown in Fig. 2, and the stretching vibration of the primary amine is 100 at 3450-3200 cm ^-1 .
Absorption due to out-of-plane bending vibration of trans-olefin was observed at 0,975 cm ^-1 .

Preparation of tetrazonium salt 4.0 g of the diamino compound obtained as described above was concentrated sulfuric acid.
The mixture was added to dilute sulfuric acid consisting of 7 ml and 100 ml of water, stirred at 60 ° C for 2 hours, and then rapidly cooled to -3 ° C. Then add a solution of 1.74 g of sodium nitrite in 5 ml of water at -3 to -2 ° C.
It dripped over 40 minutes. After that, stir at the same temperature for 20 minutes,
After adding 200 ml of water, a trace amount of insoluble matter was excessively removed, and a 42% aqueous solution of borofluoric acid was added to the solution to precipitate crystals.
5.5g of dark red tetrazonium salt (yield 87
%) Was obtained. The infrared absorption spectrum is shown in FIG. 3, and absorption due to N ₂ stretching vibration was observed at 2220 cm ⁻¹ .

Preparation of No. 1 bisazo compound of Table 1 Compound 0.35 g of 3-hydroxy-2-naphthoic acid anilide was added to DMF13
After dissolving 0 ml of the solution and adding 0.34 g of the tetrazonium salt obtained as described above, 2.5 ml of an 8.6% sodium acetate aqueous solution was added dropwise at room temperature over 20 minutes, and then stirred at the same temperature for 3 hours. After that, pass the generated bisazo pigment,
It was washed 5 times with 150 ml of DMF and subsequently twice with 150 ml of water. Further, it was dried by heating under reduced pressure, and the bisazo pigment of compound No. 1 was 1,12-bis [4- (2-hydroxy-3-phenylcarbamoylnaphthyl-1-azo) phenyl]-
1,3,5,7,9,11-dodecahexaene as a bluish black powder.
50 g (yield 89%) was obtained. Decomposition point 263 ℃ Elemental analysis (as C ₅₄ H ₄₀ N ₆ O ₄ ) C H N Actual value (%) 78.08 4.89 9.20 Calculated value (%) 78.35 5.00 9.45 Visible spectrum [Ethylenediamine / DMF (1/9: vo
l)]: λmax.596nm The infrared absorption spectrum (KBr tablet method) of this product is
Shown in the figure. To 1675 cm ^-1 as can be seen from FIG absorption based on the stretching vibration of C = 0, also in 1030 cm ^-1 is absorption based on the out-of-plane deformation vibration of trans olefins was observed.

Examples 2 to 29 Example 1 using couplers corresponding to compound Nos. 2 to 29
The bisazo compounds of Compound Nos. 2 to 29 were produced in the same manner as in the production method of. The elemental analysis results and IR spectrum data are shown in Table-1.

Next, application examples of the bisazo compound of the present invention are shown below.

Application Example As a charge generating substance, 7.5 parts of the bisazo compound of the compound No. 1 in Table 1 above and 500 parts of a 0.5% tetrahydrofuran solution of a polyester resin [Vylon 200 manufactured by Toyobo Co., Ltd.] are pulverized and mixed in a ball mill to obtain The obtained dispersion liquid was applied onto an aluminum vapor-deposited polyester film with a doctor blade and naturally dried to form a charge generation layer having a thickness of about 1 μm. Next, 2 parts of 9-ethylcarbazole-3-aldehyde-1-methyl-1-phenylhydrazone as a charge transport substance was dissolved in a 10% tetrahydrofuran solution of a polycarbonate resin [Panlite K-300 manufactured by Teijin Limited],
This solution was applied onto the charge generation layer with a doctor blade and dried at 80 ° C. for 2 minutes and then at 120 ° C. for 5 minutes to form a charge transport layer having a thickness of about 20 μm.

Next, in order to examine the sensitivity of the thus obtained laminated electrophotographic photosensitive member in the visible region, an electrostatic copying paper test apparatus [SP428 type manufactured by Kawaguchi Electric Co., Ltd.] was used for this photosensitive member in the dark. After charging with 6KV corona discharge for 20 seconds and charging, dark decay for 20 seconds, measure the surface potential Vo (volt) at this time, and then set the illuminance on the photoconductor surface to 4.5lux. When light is irradiated, the surface potential is
The time (sec) until 1/2 of Vo was obtained, and the half-exposure amount E1 / 2 was obtained as the sensitivity in the visible range. As a result, Vo = 858
Volts, E1 / 2 = 6.1ux.sec.

As described above, it can be seen that the photoreceptor using the bisazo compound of the present invention has extremely high sensitivity in the visible region.

Effects As can be seen from the above description, the tetrazonium chloride of the present invention is used as an organic photoconductor used for electrophotographic photoreceptors, especially for laminated type photoreceptors, which show high sensitivity both for high speed copying machines and for laser printers. Extremely useful.

[Brief description of drawings]

FIGS. 1 to 3 show infrared absorption spectra of dinitro compounds, diamino compounds and tetrazonium salts, which are intermediates for producing the bisazo compound of the present invention, and FIG. 4 shows the compounds of Table 1 of the present invention. The infrared absorption spectrum of the No. 1 bisazo compound is shown.

Claims (2)

[Claims] 1. A general formula (I) (However, Z represents a benzene ring, a naphthalene ring or a carbazole ring, R may be the same or different, a hydrogen atom,
It represents a halogen atom, a lower alkyl group, a lower alkoxyl group or a nitro group, and n represents an integer of 1, 2 or 3. ) A bisazo compound represented by. 2. General formula (II) (Wherein X represents an anionic functional group) and a general formula III. (Wherein Z, R, and n are the same as those in the general formula I described below), and a coupling reaction is carried out with a coupler represented by the general formula I (However, Z represents a benzene ring, a naphthalene ring or a carbazole ring, R may be the same or different, a hydrogen atom,
It represents a halogen atom, a lower alkyl group, a lower alkoxyl group or a nitro group, and n represents an integer of 1, 2 or 3. ] The manufacturing method of the bisazo compound shown by these.