JPH0753829B2 - 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 photoconductor in which a certain main azo compound is one form of an electrophotographic photoconductor,
It is known to be particularly useful as a charge generation pigment. As is well known, this laminated type photoreceptor is composed of a charge generating layer mainly composed of a charge generating pigment having the ability to generate charge carriers by light on a conductive support, and a charge generated in the charge generating layer thereon. It is a photoconductor provided with a charge carrier layer containing a charge carrier substance as a main component, which is capable of efficiently injecting the carrier 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. Stilbene bisazo compounds described, diphenylhexatriene bisazo compounds described in JP-A-58-222152,
Diphenyl butadiene-based bisazo compounds described in JP-A-58-222153 are known.

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.

The purpose of the present invention is to provide a bisazo compound useful as an organic photoconductor used for a high-sensitivity electrophotographic photosensitive member, especially for a high-speed copying machine or a laser printer, and particularly for a laminated type photosensitive member, and its production. Is to provide a method.

Structure One of the present invention is 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, and the other one is general II(Wherein X represents an anionic functional group) and a tetrazonium salt represented by the general formula III(However, Z and n are the same as those in the above-mentioned general formula I)
A bisazo compound represented by the general formula I
Is a manufacturing method. Where the anion officer in general formula II
A typical example of Nomoto group X is Cl , Br , I , BF_Four , PS₆ ，SbF₆ Etc., preferably BF_Four Is.

The bisazo compound represented by the general formula I of the present invention is produced as follows. First, the general formula II as a raw material
The tetrazonium salt of 1,8-bis (4-nitrophenyl) -1,3,5,7-octatetraene (hereinafter referred to as dinitro compound) is reduced to give 1,8-bis (4-aminophenyl) -1,3 It can be obtained by diazotization of 5,5,7-octatetraene (hereinafter referred to as a diamino compound). Both the dinitro compound and the diamino compound used here are novel substances. The dinitro compound is, for example, 4-nitrocinnamyltriphenylphosphonium bromide and 5- (4-nitrophenyl) -2,4-pentadienal-1 are condensed in the presence of a basic catalyst,
It can be produced by the so-called Wuititz reaction. The dinitro compound produced by this reaction partially contains a 3-monocis isomer, which is a crude hydrocarbon of the reaction product or after purification, together with a catalytic amount of iodine and an aromatic hydrocarbon such as toluene or xylene. It can be converted into an all-trans form by heat treatment in a system solvent.

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 thus obtained diamino compound is carried out by dispersing the diamino compound in an inorganic acid such as hydrochloric acid or sulfuric acid, and then 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, a tetrazonium salt of the general formula II can be obtained, and the diazotization reaction solution can be further treated with, for example, borofluoric acid,
The tetrazonium salt of the general formula II can be obtained by salt conversion by adding an aqueous solution of sodium borofluoride or the like.

In order to prepare the bisazo compound of the present invention using the tetrazonium salt thus obtained, first the tetrazonium salt is isolated from the reaction solution, and then this is combined with the cupula of the general formula II together with 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 purified by an appropriate method, for example, washing with water and / or an organic solvent, recrystallization, etc., to obtain the target bisazo compound. The production of the bisazo compound can also be carried out by allowing the diazotization reaction solution to react with the katsupler.

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

The bisazo compound of the present invention is used as an organic photoconductor, particularly as a charge generating substance, in various electrophotographic photoreceptors, for example, as follows.

1) A photoconductive layer containing the bisazo compound, a binder resin and, if necessary, a sensitizer as a main component is provided on a conductive support to obtain a single-layer type photoreceptor.

2) A single layer type photoreceptor is similarly prepared by adding a charge carrier substance to the system of 1) above.

3) A charge generating layer containing the bisazo compound as a main component is provided on a conductive support, and a charge carrying layer containing a charge carrying substance and a binder resin as a main component is further provided on the conductive support to obtain a laminated photoreceptor. .

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

Example 1 Preparation of 1,8-bis (4-nitrophenyl) -1,3,5,7-octatetraene (all-trans form) 4-nitrocinnamyltriphenylphosphonium bromide 31.5 g and 5- (4-nitrophenyl) ) -2,4-Pentadienal-1: 12.7 g was taken in a mixed solvent of 510 ml of dry methanol to 64 ml of dry dimethylformamide (DMF), and N ₂
28% methanol solution of sodium methoxide under air flow 1
5.6 g was dropped and reacted for 2 hours. Then, the reaction solution was stirred at room temperature for 6 hours, and then 50m methanol aqueous solution 300m
1, 1-bis (4-nitrophenyl) -1,3,5,7 containing 3-monocis isomer was collected by collecting the precipitate, washing with water and drying.
19.9 g of crude octatetraene was obtained. Next, this was heated under reflux in 500 ml of xylene together with a catalytic amount of iodine, and then recrystallized with DMF to obtain 1,8-bis (4-nitrophenyl) -1,3,5,7-octatetraene having an all-trans structure. 14.9 g (yield 69%) of dark red needle crystals were obtained.

mp.238.5-240.5 ° C Elemental analysis (as C ₂₀ H ₁₆ N ₂ O ₄ ): C H N actual value (%) 68.77 4.63 7.91 Calculated value (%) 68.95 4.64 8.04 Visible spectrum (in DMF): λmax.439nm The infrared absorption spectrum (KBr tablet method) of the product is shown in FIG. As can be seen from this figure, the absorption due to the stretching vibration of the nitro group at 1510 cm ^-1 and 1335 cm ^-1 is also 1010 and 950c.
Absorption due to out-of-plane bending vibration of trans-olefin was observed at m ^-1 .

Production of 1,8-bis (4-aminophenyl) -1,3,5,7-octatetraene (all-trans form) 1,8-bis (4-nitrophenyl) -1, obtained as described above 250 ml of DMF 250 ml of 3,5,7-octatetraene
After the addition of 22.5 g of iron powder to this, dilute hydrochloric acid consisting of 5.6 ml of concentrated hydrochloric acid and 19 ml of water was added with stirring, and stirring was continued at 80 to 88 ° C. for a further 5 hours. After allowing to cool to 50 ° C, 10% caustic soda aqueous solution was added to make it alkaline, and the insoluble portion was heated together with Celite. The liquid was diluted with water, and the precipitated crystals were filtered, washed with water and dried to obtain 7.9 g (yield 85%) of the diamino compound. This was recrystallized with a mixed solvent of DMF and water to obtain a dark red plate crystal of 1,8-bis (4-aminophenyl) -1,3,5,7-octatetraene. mp.262.5-264.5 ° C.

Elemental analysis (as C ₂₀ H ₂₀ N ₂ ): C H N measured value (%) 83.01 7.02 9.75 Calculated value (%) 83.28 7.00 9.71 The infrared absorption spectrum of this product is shown in FIG. The 3450～3200Cm ^-1 As can be seen from this figure the absorption based on the stretching vibration of primary amines, also in 1010 cm ^-1 and 955cm ^-1 is absorption based on the out-of-plane deformation vibration of trans olefinic was observed.

Preparation of tetrazonium salt 6.1 g of 1,8-bis (4-aminophenyl) -1,3,5,7-octatetraene obtained as described above was added to concentrated sulfuric acid 7.2 ml.
And 100 ml of water, and the mixture was stirred at 60 ° C. for 2 hours. 3.23g of sodium nitrite after quenching to -2 ℃
Was dissolved in 10 ml of water and added dropwise at −5 to −2 ° C. over 50 minutes. After that, stir at the same temperature for 20 minutes and cool water 400m
After adding l, trace amount of insoluble matter was removed by filtration, 42% borohydride aqueous solution was added to the solution, and the precipitated crystals were removed.
After drying, 8.4 g of a dark red tetrazonium salt (yield: 82%) was obtained.

The infrared absorption spectrum of this product is shown in FIG. As can be seen from this figure, absorption due to stretching vibration of the diazonium salt was observed at 2230 cm ^-1 .

Production of Bisazo Compound of Compound No. 12 0.55 g of 3-hydroxy-2-naphthoic acid anilide was added to DMF20.
After dissolving in 0 ml and adding 0.49 g of the tetrazonium salt obtained as described above, 0.34 g of sodium acetate was added to water.
The solution dissolved in 4 ml was reacted dropwise at room temperature over 20 minutes. Next, after stirring at the same temperature for 3 hours, the bisazo pigment produced was filtered and washed with DMF (250 ml) 5 times, followed by water (250 m).
Wash twice with l. Further, it was dried by heating under reduced pressure, and the bisazo pigment of Compound No. 12 was 1,8-bis [4- (2-hydroxy-3-phenylcarbamoylnaphthyl-1-azo) phenyl] -1,3,5. 0.72 g (yield 82%) of 7,7-octatetraene was obtained as a bluish black powder. Decomposition point 276 ℃.

Elemental analysis (as C ₅₄ H ₄₀ N ₆ O ₄ ): C H N measured value (%) 77.44 4.72 9.87 calculated value (%) 77.48 4.83 10.04 Visible spectrum [ethylenediamine / DMF (1/9: vo
l)]: λmax.596nm The infrared absorption spectrum (KBr tablet method) of this product
Shown in the figure. To 1675 cm ^-1 as can be seen from FIG absorption based on the stretching vibration of C = O, also the 995 cm ^-1 absorption based on the out-of-plane deformation vibration of trans olefinic was observed.

Example 2 0.66 g of 3-hydroxy-2-phenylcarbamoylanthracene was dissolved in 200 ml of DMF, and 0.49 g of the tetrazonium salt obtained in Example 1 was added thereto, and then sodium acetate was added.
A solution of 0.34 g dissolved in 4 ml of water was added dropwise at room temperature over 20 minutes. Next, after stirring at the same temperature for 3 hours, the formed pigment was filtered, washed with DMF 250 ml 4 times, and further washed with water 250 ml 2 times. This was heated and dried under reduced pressure and the bisazo compound of Compound No. 29: 1,8-bis [4- (2-hydroxy-3
-Phenylcarbamoylanthryl-1-azo) phenyl] -1,3,5,7-octatetraene as blue-black powder
0.81 g (yield 86%) was obtained. Decomposition point 287 ° C.

Elemental analysis (as C ₆₂ H ₄₄ N ₆ O ₄ ): C H N measured value (%) 79.20 4.48 8.74 Calculated value (%) 79.46 4.74 8.97 Visible spectrum [ethylenediamine / DMF (1/9: vo
l.)]: λmax.634nm The infrared absorption spectrum (KBr tablet method) of this product
Shown in the figure. To 1680 cm ^-1 as can be seen from FIG absorption based on the stretching vibration of C = O, also the 1010 cm ^-1 and 960 cm ^-1 is absorption based on the out-of-plane deformation vibration of trans olefinic was observed.

Example 3 1.11 g of 2-hydroxy-3-phenylcarbamoyl-11H-benzo [a] carbazole was dissolved in 200 ml of DMF, to which 0.73 g of the tetrazonium salt obtained in Example 1 was added, and then 0.52 g of sodium acetate. Was dissolved in 5 ml of water and added dropwise at room temperature over 30 minutes. Next, after stirring at the same temperature for 3 hours, the bisazo pigment produced was passed over and the residue was added to DMF300.
It was washed 5 times with 300 ml and subsequently twice with 300 ml of water. This was heated and dried under reduced pressure and the bisazo compound of Compound No. 13:
1,8-bis [4- (2-hydroxy-3-phenylcarbamoyl-11H-benzo [a] carbazolyl-1-azo) phenyl] -1,3,5,7-octatetraene as blue-black powder 1.37 g (yield 90%) was obtained. Decomposition point 305 ℃.

Elemental analysis (as C ₆₆ H ₄₆ N ₈ O ₄ ): C H N actual value (%) 77.77 4.45 10.78 Calculated value (%) 78.08 4.58 11.04 Visible spectrum [ethylenediamine / DMF (1/9: vo
l.)]: λmax.620nm The infrared absorption spectrum (KBr tablet method) of this product is
Shown in the figure. Absorption based on the stretching vibration of the carbazole NH to 3450 cm ^-1 as can be seen from this figure, also the absorption based on the out-of-plane deformation vibration of the transformer olefinic was observed 1000 cm ^-1.

Examples 4 to 29 Compounds Nos. 1 to 11 and 14 to 28, respectively, were prepared in the same manner as in the production method of the bisazo compound No. 12 of Example 1 by using the kupplers corresponding to the compounds Nos. 1 to 11 and 14 to 28, respectively. A bisazo compound was prepared. The decomposition points, elemental analysis results and IR spectrum data of these are as shown in Table-1. No. 2
Infrared absorption spectrum (K
The Br method) is also shown in FIG.

Application example 7.5 parts of bisazo compound of compound No.22 as a charge generating substance and polyester resin [Vylon 20 manufactured by Toyobo Co., Ltd.
500 parts of a 0.5% tetrahydrofuran solution of 0] was pulverized and mixed in a ball mill, and the obtained dispersion was applied onto an aluminum vapor-deposited polyester film with a doctor blade,
It was 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 material was added to a polycarbonate resin [Panlite K-130 manufactured by Teijin Limited].
0] in 10% tetrahydrofuran solution, and this solution is coated on the charge generation layer with a doctor blade and heated at 80 ° C.
For 2 minutes, then for 5 minutes at 120 ℃, thickness about 20μm
Was formed on the charge transport layer.

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. 6
After KV corona discharge for 20 seconds to charge and then dark decay for 20 seconds, measure the surface potential V ₀ (volt) at this time, and then use a tungsten lamp so that the illuminance on the photoconductor surface becomes 4.5 lux. The time (sec) until the surface potential became 1/2 of V ₀ upon irradiation with light was obtained, and the half-exposure amount E1 / 2 (lux · sec) was calculated as the sensitivity in the visible region. As a result, V ₀
Was 533 volts and E1 / 2 was 0.49 lux.sec.

Further, the following measurement was carried out in order to examine the sensitivity of this photoreceptor to long-wavelength light. First, after charging the photoconductor in the dark by corona discharge, the surface potential is reduced by dark decay.
When you see 800 volts, use a monochromator to
Irradiation was performed with 1 μW / cm ² of monochromatic light dispersed at 80 nm. Next, the time (S) until the surface potential decays to 1/2 (400 volts) is determined, and the exposure dose (μW · s · cm ⁻² ) is also determined to determine the light decay rate S (volt · cm ² · μJ ⁻¹ ) was calculated. The result was S = 580 V · cm ² · μJ ⁻¹ .

Thus, it can be seen that the photoconductor using the bisazo compound of the present invention has extremely high sensitivity in the semiconductor laser region as well as sensitivity in the visible region.

Effect As can be seen from the above description, the bisazo compound of the present invention is used as an organic photoconductor used in electrophotographic photoreceptors, particularly laminated 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 are infrared absorption spectra of dinitro compounds, diamino compounds and tetrazonium salts, which are intermediates for producing the bisazo compound of the present invention, respectively, and FIGS.
The figures show the infrared absorption spectra of the bisazo compounds of Compound Nos. 12, 29, 13 and 22 of the present invention, respectively.

Continuation of the front page (56) Reference JP 58-222152 (JP, A) JP 58-222153 (JP, A) JP 59-53554 (JP, A) JP 59-72448 (JP , A) JP-A-59-129857 (JP, A) JP-A-59-136351 (JP, A)

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 tetrazonium salt represented by the general formula III (Wherein Z, R, and n are the same as those in the general formula I described later), 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.