JP2003040850A - Method for diazonium salt production and method for aromatic azo compound production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for high-purity diazonium salt production and a method for producing a clear aromatic azo compound using the high-purity diazonium salt. SOLUTION: This method for high-purity diazonium salt production comprises, in reacting an aromatic primary amine sulfate with sulfuric acid and an alkali metal nitrite, using 4-9 mols of sulfuric acid based on 1 mol of the aromatic primary amine sulfate. This method for producing an aromatic azo compound having high clarity comprises using the high-purity diazonium salt.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a diazonium salt and a method for producing an aromatic azo compound.

[0002]

2. Description of the Related Art A method for producing a diazonium salt of an aromatic primary amine by reacting a sulfuric acid salt of an aromatic primary amine with sulfuric acid and an alkali metal nitrite is well known, and generally, 3 mol or less of sulfuric acid is used with respect to 1 mol of a sulfate of an aromatic primary amine.

[0003]

However, the diazonium salt of an aromatic primary amine reacted in the above molar ratio has a relatively high content of by-products generated during the reaction and is opaque. There is a drawback that. The by-products and the like cannot be easily separated only by applying purification means such as filtration.

Moreover, the aromatic azo compound obtained by the diazo coupling reaction using such a diazonium salt has a drawback that the sharpness when used as a colorant is insufficient.

[0005]

Means for Solving the Problems The inventors of the present invention have made earnest studies in view of the above situation. As a result, when the number of moles of sulfuric acid used relative to the sulfate of an aromatic primary amine is increased, the aromatic primary amine is increased. The yield of diazonium salt of
As a result, it was found that a transparent aromatic primary amine diazonium salt having a very small content of by-products generated in the reaction can be obtained.

Further, the aromatic azo compound obtained by the diazo coupling reaction using such a diazonium salt, when used as a colorant, is more sharp than the one obtained under the above conventional conditions. After finding out that, the present invention has been completed.

That is, the present invention provides a method for producing a diazonium salt of an aromatic primary amine by reacting a sulfuric acid salt of an aromatic primary amine with sulfuric acid and an alkali metal nitrite. A method for producing a diazonium salt of an aromatic primary amine, characterized in that 4 to 9 moles of sulfuric acid is used for 1 mole of the salt, and sulfuric acid and an alkali metal nitrite as the sulfate of the aromatic primary amine. And a first step of obtaining a diazonium salt of an aromatic primary amine using 4 to 9 moles of sulfuric acid with respect to 1 mole of an aromatic primary amine sulfate, a diazo component comprising the diazonium salt, Provided is a method for producing an aromatic azo compound in which a coupler component composed of an aromatic compound capable of reacting with it is subjected to a diazo coupling reaction.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The first aspect of the present invention is to provide a method for producing a diazonium salt obtained by reacting a sulfate salt of an aromatic primary amine with nitrous acid. The aromatic primary amine of the present invention has a primary amino group, and in the aromatic ring, a halogen atom, an alkyl group, an alkoxyl group, a sulfonic acid group,
An aromatic amine that may have a carboxylic acid group or a group consisting of a salt thereof. These include aromatic di-primary amines and aromatic mono-primary amines. A second aspect of the present invention is to provide a method for producing an aromatic azo compound, which is characterized by using the aforementioned diazonium salt.

As a method for producing a diazonium salt from a sulfate of an aromatic primary amine, a high-purity diazonium salt can be produced by using a larger amount of sulfuric acid than the amount of sulfuric acid used in the conventional production method. This is the first feature of the invention.
Further, the aromatic azo compound obtained by the diazo coupling reaction using the above-mentioned high-purity diazonium salt, when used as a colorant, is more sharp than the aromatic azo compound obtained by the conventional production method. The further improvement is the second feature of the present invention.

In the present invention, first, a sulfate of an aromatic primary amine is reacted with nitrous acid to obtain a corresponding diazonium salt.

Specific examples of the aromatic primary amine include, for example, aniline and 2,5 as aromatic mono primary amines.
-Dichloroaniline, 4-methyl-2-nitroaniline, 2,5-dinitroaniline, 2-methyl-5-nitroaniline, 2,4,5-trichloroaniline, p-toluidine-m-sulfonic acid, 2-chloro -P-toluidine-5-sulfonic acid, tobiasic acid, anthranilic acid,
Sulfanilic acid, p-chloroaniline-m-sulfonic acid, or the like having a halogen atom, an alkyl group, or an alkoxy group in the aromatic ring, or a sulfone group, a carboxylic acid group or a salt thereof, an amide, or an ester bond in the aromatic ring. The thing which has, etc. are mentioned. Further, as the aromatic diprimary amine, 3,3 ′, 5,5′-tetrachlorobenzidine, 3,3′-dichlorobenzidine or 2,2 ′, 5,5′-
From tetrachlorobenzidine, 3,3'-dimethylbenzidine, 3,3'-dimethoxybenzidine and the like having a halogen atom, an alkyl group, an alkoxyl group, or a sulfonic acid group, a carboxylic acid group or a salt thereof in the aromatic ring And the like. Such an aromatic primary amine is formed into a salt of sulfuric acid based on a known and conventional method.

As a method of reacting the sulphate salt of an aromatic primary amine with nitrous acid, any known and conventional method using a hydrochloride salt of an aromatic primary amine can be adopted. Specifically, the sulphate may be directly reacted with nitrous acid for diazotization, but a method of diazotizing the sulphate with nitrite in sulfuric acid is preferable. A preferred method is a method in which nitrite is added to a solvent containing the same sulfate and sulfuric acid.

Examples of nitrites include sodium nitrite and potassium nitrite. The reaction is carried out in a solvent, usually water. The reaction charge ratio between the aromatic mono-primary amine and the nitrite is usually 1
The nitrite is preferably 1.00 to 1.5 mol, and more preferably 1.025 to 1.10 mol per mol. The reaction charge ratio of the aromatic diprimary amine and the nitrite is usually 2.0 mol to 3.0 mol per mol of the aromatic diprimary amine.
Among them, 2.05 to 2.20 mol is preferable.

The diazonium salt thus obtained has two atomic groups of the diazonium salt in the molecule when the aromatic primary amine used is an aromatic diprimary amine. When it is a mono-primary amine, one atom group of the diazonium salt is present in the molecule.

The molar ratio of the aromatic primary amine sulfate to the sulfuric acid is such that even if the aromatic primary amine sulfate is the aromatic mono-primary amine sulfate, the aromatic di-primary amine is The same applies to the sulfates of primary amines, and 4 to 9 moles of sulfuric acid, particularly 4.5 to 7 moles of sulfuric acid is used for 1 mole of the sulfate of aromatic primary amine. It is effective in fully exerting. That is, when the molar ratio of sulfuric acid is 3 mol or less, the reaction rate of diazotization becomes slow, the side reaction proceeds in parallel, and the content of the by-product increases,
The purity of the diazonium salt tends to decrease. Further, if the amount of sulfuric acid used exceeds 9 mol, a large amount of alkali for neutralization is required, which significantly deteriorates the economical efficiency.

The above-mentioned diazotization reaction is carried out, for example, at a temperature of 5 ° C.
It is carried out by stirring at 60 ° C, preferably over 20 ° C and 35 ° C for 1 to 90 minutes. The exponential increase of the reaction rate with the increase of the reaction temperature is shown by Arrhenius.
It is explained by the formula. According to the common sense of those skilled in the art, the reaction temperature is 1
It is said that the reaction rate will be doubled if the temperature rises by 0 ° C.
When the reaction temperature rises by 20 ° C., the reaction time becomes about 1/4. Therefore, the conventional reaction time of 45 minutes at 0 ° C. can be about 10 minutes at 20 ° C.

Therefore, even at a high temperature which is said to accelerate the decomposition of the diazonium salt, it is possible to avoid this problem by carrying out the reaction in a shorter time than before. Thus, the diazo component is obtained.

Next, the diazo component and the coupler component made of an aromatic compound are brought into contact with each other to cause a diazo coupling reaction to obtain an aromatic azo compound. The aromatic azo compound becomes an aromatic disazo compound when the diazo component used is a diazonium salt of an aromatic diprimary amine, while the diazo component used is a diazonium salt of an aromatic monoprimary amine. When it is, it becomes an aromatic monoazo compound.

As the coupler component in this case, any of the known and commonly used aromatic compounds that can react with the above-mentioned components used in obtaining an azo compound used as an organic pigment can be used. Specifically, β-naphthol is used. Examples thereof include a compound having a structure, a compound having an acetoacetic acid anilide structure, and a compound having a pyrazolone structure containing an aromatic ring.

Examples of the compound having a β-naphthol structure include β-naphthol, β-oxynaphthoic acid, 3-hydroxy-2-naphtho-o-anisidide, 3-hydroxy-2-naphthanilide and 3,6-disulfonyl-. Two
-Hydroxy-naphthalene and the like can be mentioned.

Among them, as the coupler component, each aroma represented by the following general formula (1) corresponding to the compound having an acetoacetic anilide structure or the following general formula (2) corresponding to the compound having an aromatic ring-containing pyrazolone structure. Group compounds are preferred.

[0022]

[Chemical 1]

(In the formula, Z represents a phenyl group which may be the same or different and has 1 to 4 substituents selected from the group consisting of a methyl group, a methoxy group and a chlorine atom.)

[0024]

[Chemical 2]

(In the formula, A represents a phenyl group which may have the same or different 1 to 4 substituents selected from the group consisting of a methyl group, an ethyl group, a methoxy group and an ethoxy group. In the formula, B represents a group selected from the group consisting of a hydrogen atom, a methyl group, an ethyl group, a methoxy group, an ethoxy group, a carbomethoxy group, and a carboethoxy group.)

Specific examples of suitable coupler components of the general formula (1) or the general formula (2) include, for example, acetoacetanilide, acetoaceto-o-toluidide, acetoacet-m-xylidide, acetoaceto-o-anisidide,
Acetoaceto-p-anisidide, acetoaceto-o-chloroanilide, acetoaceto-2,5-dimethoxy-4
-Chloroanilide, 3-methyl-1-phenyl-5-pyrazolone, 3-methyl-1-p-toluyl-5-pyrazolone, 3-carbethoxy-5-pyrazolone and the like.
Among them, the coupler component (B) is preferably at least one aromatic compound selected from the group consisting of acetoacetanilide, acetoaceto-o-toluidide and acetoacet-m-xylidide.

As the coupler component, for example, a solvent solution of an aromatic compound capable of reacting with the above components and an alkali metal hydroxide can be used. Examples of the alkali metal hydroxide include potassium hydroxide and sodium hydroxide.

The aromatic azo compound is an azo compound having an azo group, and as mentioned above, examples thereof include an aromatic disazo compound and an aromatic monoazo compound. According to the present invention, specifically, C.I. I. Pigment Red
3, 5, 22, 2, 17, 112, 5, 245, 5
3, 57, 48, 64, 50, 63, 60, 58, or C.I. I. Pigment Yellow 1,
3, 74, 97, 98, 167, 154, 36, 12,
13, 14, 17, 55, 83, 81, 52, or
C. I. Pigment Orange 17, 13,
Aromatic azo compounds useful as organic pigments such as 34 and 38 can be obtained. The production method of the present invention is 3,3′-
C.I. obtained from the tetrazonium salt of dichlorobenzidine and acetoacetanilide. I. Pigment Ye
C.I. obtained from the tetrazonium salt of low 12,3,3'-dichlorobenzidine and acetoaceto-o-toluidide. I. Pigment Yellow 13,
C.I. obtained from a tetrazonium salt of 3,3'-dichlorobenzidine and acetoacet-m-xylidide. I.
Pigment Yellow 14 is particularly suitable for manufacturing.

As a method for bringing the diazo component (A) and the coupler component (B) into contact with each other, a conventionally known method may be used. That is, a method may be mentioned in which a coupler solution / suspension obtained by dispersing or dissolving the coupler component (B) in a buffer solution typified by sodium acetate or calcium carbonate is brought into contact with the diazo component.

As the contacting method, for example, a method of simultaneously mixing the coupler component (B) and the diazo component (A), or the stirring of the coupler component (B), the whole amount of the diazo component (A) is collectively or divided therein. And the like.

The temperature condition for the contact is usually
In order not to freeze both the diazo component (A) and the coupler component (B), -1 to 25 ° C, preferably 0 to 20 ° C,
Particularly preferably, the temperature is set to 0 to 10 ° C., both are brought into contact with each other, and the reaction is performed while maintaining this temperature. Further, in order to suppress the decomposition of the diazonium salt, it is preferable to shield the diazonium salt from light rays including ultraviolet rays, that is, the light rays of the sun, fluorescent lamps, etc., and to bring them into contact with each other. The pH condition for contacting is pH 3.0 to
The range is 7.0, but 4.0 to 6.0 is particularly preferable.

The diazonium salt obtained by the production method of the present invention is characterized by high purity. The purity of the diazonium salt is, for example, JIS Z8729-198.
It can be evaluated by measuring the hue such as L ^* a ^* b ^* according to 0. That is, the lower the L ^* value, the more opaque,
The higher the a ^* and b ^* values, the more the coloration. In any case, it is shown that the impurity content is high. The measurement of L ^* a ^* b ^* is
For example, it can be measured with a color difference meter CT-210 manufactured by Minolta. That is, when a cell having an optical path length of 10 mm is filled with a test solution and the cell is measured with a colorimeter, L ^* a ^*
b ^* is displayed. Hereinafter, unless otherwise specified, the L ^* a ^* b ^* of the diazonium salt is measured by this method.

Aromatic aromatic compounds obtained by the production method of the present invention
When used as a colorant, zo compound is a conventional production method.
Compared to the one obtained by
It This sharpness is due to the disazo compound obtained in the present invention.
Prepare a test ink from the colorant, vehicle and additives
Can be evaluated. That is, L of this ink^*a
^*b^*If you measure^*Is the expression
Given in.

[0034]

[Formula 1]

L of test ink^*a^*b^*The measurement of
Measure with a Minolta spectrophotometer CM-2600d
it can. In other words, the meat of the test ink
Place a spectrophotometer on the area and measure the color. Below, especially
Unless otherwise specified, L of test ink ^*a^*b^*The measurement of this
Do by the way.

Concretely, for example, the test ink is spread on a white spread paper on which a black band is printed using black ink, and the color is measured. According to such a measuring method, the test ink prepared by using the aromatic azo compound obtained by the production method of the present invention is higher than the test ink prepared by using the aromatic azo compound obtained by the conventional production method. Has sharpness. As a common knowledge of those skilled in the art, such an evaluation method is described in “Printing ink color matching and adjustment” and “Printing ink test” in the printing ink introduction supplement version (written by Jiro Aihara.
It can be performed based on (12).

Of course, in order to impart suitability suitable for various uses, a method in which an aromatic compound component having a polar group capable of reacting with the component (A) is used in combination with the coupler component (B) (cocoupling method) Alternatively, subjecting the aromatic azo compound to surface treatment with rosin or a surfactant belongs to the scope of the present invention.

The aromatic azo compound can be obtained by removing the liquid medium from the reaction mixture thus subjected to the diazo coupling reaction and drying it if necessary. Removal of the liquid medium from the reaction mixture can usually be performed by filtration.

When an aromatic disazo compound is obtained by the production method of the present invention, a liquid medium constituting the reaction mixture, typically a filtrate, is used as a test sample, and the TEQ concentration of the coplanar PCB contained therein is conventionally determined. 1/3 or less, and 1/5 or less by optimization, it can be greatly reduced. In the method for producing an aromatic azo compound of the present invention, coplanar P
The reason why an aromatic disazo compound having a small degree of CB contamination can be produced is that (1) the presence of a sulfate ion increases the stability of the tetrazonium salt of an aromatic diprimary amine, and (2) chlorine. Since there are no ions (chlorine radicals), it is thought that the principle that the chlorine atom is not introduced into the aromatic ring due to radical reaction etc. even if the tetrazonium salt of the aromatic diprimary amine decomposes .

The TEQ concentration of the coplanar PCB is measured by the conventional high resolution gas chromatograph mass spectrometer (HRGCM).
S) may be used, but in the present invention, 20th Interna
tionalSymposium on Halogenated Environment Organic
CALUXT, which was announced at Pollutants & POPs, has the features of requiring a smaller amount of test sample, shorter analysis time, higher sensitivity and excellent repeatability of measurement.
It is preferable to use the M Assay (Caylux® assay) method.

The CALUX ™ Assay method is a bioassay method utilizing cells in which a synthetic gene for cytochrome P450 enzyme (CYP1A1) which is a detoxifying enzyme in eukaryotic cells and a luciferase enzyme synthetic gene are recombined, and HRGCMS was used. It has a high correlation with the official method.

The CALUX ™ Assay method utilizes the fact that luciferase emits fluorescence, and the intensity of fluorescence is used as an index of the TEQ concentration of coplanar PCB.
Specifically, using a fluorescence intensity curve obtained by using 2,3,7,8-tetrachlorodibenzo-p-dioxin having different concentrations as a standard, the coplanar PC of the test sample is used.
Calculate BTEQ concentration.

The aromatic azo compound obtained by the production method of the present invention can be used as an organic pigment such as a monoazo pigment or a disazo pigment by itself or, if necessary, further subjected to a pigmenting treatment such as a solvent method or a solvent salt milling method. , Use as a conventionally known colorant, that is,
It can be used in various applications such as printing inks, paints, plastics, toners for electrostatic image development, and color filters.

[0044]

EXAMPLES The present invention will be described in more detail with reference to Examples, Comparative Examples and Test Examples, but the present invention is not limited to these Examples. In addition, "part" and "%" in the following examples are based on mass unless otherwise specified.

<Example 1> 25 parts of 3,3'-dichlorobenzidine sulfate as 3,3'-dichlorobenzidine, 61.2 parts of 95% sulfuric acid and 660 parts of water were mixed to obtain 20 parts. To ℃. 40% sodium nitrite 35.8
When parts are added, heat is generated, and in the range of 21 to 33 ° C, 1
After stirring for 0 minute, a tetrazo solution of 3,3′-dichlorobenzidine (solution A) was obtained. L of the obtained tetrazo solution
^{* A *} b ^* is 77.2 according to the above measurement method,
It was 9.3 and 58.8. The solution A was transparent, had almost no coloring, and had high purity.

<Example 2> 42.7 parts of acetoaceto-o-toluidide was dissolved in an aqueous solution containing 203.6 parts of 25% sodium hydroxide and 800 parts of water (solution B).

880 parts of water was heated to 20 ° C. and 90% acetic acid was added.
7 g was added. The above alkaline solution was added dropwise until the pH reached 5.5.

Solution A was added dropwise over 3 hours. At this time, solution B was added to maintain pH 5.5. Solution A
After completion of dropping, the mixture was stirred for 1 hour. This liquid contained C.I. as a disazo compound. I. Pigment Yellow
Contains the compound corresponding to 13 (Suspension C).

The suspension C is filtered, I. Pigmen
t Yellow 13 was obtained.

The L ^* a ^* b ^* of this product was 75.3, 13.8, and 7 according to the test ink measurement method described above.
1.0, and C ^* calculated from this is 72.4.
And it was very clear.

Comparative Example 1 25 parts of 3,3'-dichlorobenzidine as 3,3'-dichlorobenzidine hydrochloride, 15.6 parts of 95% sulfuric acid and 300 parts of water were mixed, and ice was mixed. After adding 360 parts, the mixture was cooled to 0 ° C or lower. Add 35.8 parts of 40% sodium nitrite, stir for 45 minutes,
A tetrazo solution of 3,3′-dichlorobenzidine (solution A ′) was obtained. The L ^* a ^* b ^* of this solution were 69.9, 18.9, and 91.3, respectively, according to the above-mentioned assumed method, and were opaque, markedly colored, and low in purity as compared with Example 1. there were. This was not changed even by filtration with filter paper.

Instead of solution A, this solution A'and suspension B
The same operation as in Example 1 was carried out except that the same amount of each of C. I. Pigmen
A suspension C ′ containing tYellow 13 was obtained.

This suspension C'is filtered and I. Pi
gment Yellow 13 was obtained. This thing L
^{* A *} b ^* are 63.9, 15.3 and 54.0, respectively, and C ^* is 56.
It was 1, which was very unclear as compared with Example 2.

Coplanar PC in the pigment and in the filtrate
The TEQ density of B and the degree of transparency of the ink and the like were almost the same in both Examples and Comparative Examples.

[0055]

According to the production method of the present invention, the number of moles of sulfuric acid relative to the number of moles of a sulfate salt of an aromatic primary amine is larger than that in the prior art, so that a diazonium salt having a higher purity than in the prior art can be produced. The aromatic azo compound produced by using this diazonium salt exhibits a very vivid color as a colorant for ink and the like.

Claims (4)

[Claims] 1. A process for producing a diazonium salt of an aromatic primary amine, which comprises reacting a sulfuric acid salt of an aromatic primary amine with sulfuric acid and an alkali metal nitrite, and 1 mol of a sulfate salt of an aromatic primary amine. 4. A process for producing a diazonium salt of an aromatic primary amine, characterized in that 4 to 9 mol of sulfuric acid is used. 2. The diazotization reaction temperature exceeds 20 ° C. and is 35 ° C.
The manufacturing method according to claim 1, wherein the manufacturing method is performed within the range. 3. A sulfuric acid salt of an aromatic primary amine, sulfuric acid and an alkali metal nitrite, and a sulfate salt of an aromatic primary amine 1.
A first step of obtaining a diazonium salt of an aromatic primary amine using 4 to 9 moles of sulfuric acid to a mole, and a coupler component comprising a diazo component comprising the diazonium salt and an aromatic compound capable of reacting with the diazo component. A method for producing an aromatic azo compound in which a diazo coupling reaction is carried out. 4. The diazotization reaction temperature exceeds 20 ° C. and is 35 ° C.
The manufacturing method according to claim 3, wherein the manufacturing method is performed within the range.