JPS58160355A - Production of monoazo dye - Google Patents

Abstract

PURPOSE:To obtain a nomoazo dye having improved filterability and reduced solid content, by diazotizing a p-nitroaniline derivative, coupling the diazotized product with an N-substd. aniline derivative, adding a hydrophobic org. solvent thereto, and heat-treating the mixture. CONSTITUTION:In the production of an azo disperse dye of the formula wherein X is H, halogen, sulfonyl group, R1, R2 are each -R', -C2H4OCOR', -C2H4OR', -CH2CO2R', C2H4CN (wherein R' is H, alkyl, aralkyl, alkenyl, aryl) ; R3 is H, -OR'; R4 is R' -NHCOR', halogen by diazotizing a p-nitroaniline derivative, coupling the diazotized product with an N-substd. aniline derivative and isolating the product, part or the whole of the reaction solution after the completion of the coupling reaction is neutralized, if desired, and then a hydrophobic org. solvent is added thereto, the mixture is heat-treated, the org. solvent is distilled off, and then filtration is conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved process for making monoazo disperse dyes.

Conventionally, the extraction of azo disperse dyes after the coupling reaction is carried out after the azo coupling reaction is completed in an aqueous solution containing acids such as hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, etc., followed by filtration, washing, and then again. This is done by making an aqueous suspension, neutralizing it if necessary, heating it, and then passing it through and washing it. However, in both cases, the transitivity of the dye cake is poor, which limits the number of transit devices that can be used in general.
The current situation is that a large amount of washing water has to be used because a passing device such as a filter press has a large passing area and can generate high overpressure, and also has poor cleaning performance.
In addition, the removed cake has a low solid content and can be handled in large quantities.
and are subject to various restrictions during commercialization.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that after the coupling reaction is completed, a hydrophobic organic solvent is added and heat treated, and then it is distilled off to improve filtration performance and reduce the problem. We have discovered that the problem of solid content can be solved.

That is, the present invention diazotizes a p-nitroaniline derivative, then performs a coupling reaction with an N-substituted aniline derivative, and then isolates it to form a compound of the general formula [I] 3 [wherein, X is hydrogen, a halogen atom, or a methyl Sulfonyl group, R1 and R2 are R, 42) I40COR.

2H40R, -C2H40COOR1-C2H40C
2H40R1-CH2CH(OH)ORS-CH2CO
2R matah-C2H4CN group (wherein R' represents hydrogen, an alkyl group, an aralkyl group, an alkenyl group or an aryl group), R3 is hydrogen or -OR', R4 is R'
, -NHCOR' or a halogen atom] When producing an azo disperse dye represented by, after the coupling reaction is completed, if necessary, neutralize part or all of the reaction solution, and then add a hydrophobic organic solvent, This is a method for producing monoazo disperse dyes, which is characterized by heat treatment, followed by distillation of the organic solvent, and then filtering.

In the present invention, a hydrophobic organic solvent means an organic solvent that does not mix freely with water. Specifically, benzene, toluene, xylene, ethylbenzene, isopropylbenzene, mesitylene, naphthalene, tetralin, triethylbenzene, butylbenzene, diisopropylbenzene,
Aromatic hydrocarbons such as dodecylbenzene, methylnaphthalene, cyclohexylbenzene, -cymene, etc.! [, Decalin,
Aliphatic hydrocarbons such as dodecane and cyclohexane, aromatic ethers such as anisole, phenethole, phenyl ether, benzyl ether, and dimethoxybenzene, ketones such as methisobutyl ketone and cyclohexanone,
Halogenated aliphatic hydrocarbons such as chloroform, carbon tetrachloride, dichloroethane, trichloroethane, tetrachloroethane, tetrachlorethylene, trichlorethylene, dichloroethylene, monochlorobenzene, dichlorobenzene, trichlorobenzene, α-chlornaphthalene, etc. Halogenated aromatic hydrocarbons, nitrobenzenes such as nitrobenzene, nitrotoluene, etc. are vignetted. Especially benzene, toluene, xylene, methyl isobutyl ketone, dichloroethane, dichloroethylene, tetrachlorethylene, monochlorobenzene/, dichlorobenzene,
Nitrobenzene and the like are effective.

The amount of the organic solvent to be used is preferably 1 to 40 parts (weight), particularly preferably 10 to 35 parts, relative to the dry weight of the dye cake present in the reaction solution.

(5) To explain the production method of the present invention in detail, the acid concentration of the reaction solution after the completion of the coupling reaction is adjusted to 0 to 20, preferably 0 to 5. ) Add a hydrophobic organic solvent to the prepared reaction solution.

After addition of organic solvent, 85-100℃, preferably 40-8
Heat to 0°C. The heating time may be 80 minutes or more, but is generally preferably 2 to 5 hours. After heating, the organic solvent is removed by steam distillation, vacuum distillation, etc.
Clean and wash.

According to the method of the present invention, crystal growth and crystal conversion occur at the end of the coupling reaction and compared to the dye cake of the conventional method, and the permeability is much improved compared to the conventional method. Therefore, the filters that can be used are no longer limited to filter presses, but vacuum filters, leaf filters, centrifugal filters, and even continuous rotation filters can now be used. In addition, the amount of washing water used is 20 to 80% of that of the conventional method (6), and the solid content of the cake is 45 to 80 μm, which is much larger than that of the conventional method. improved. Furthermore, surprisingly, when the taken out dye cake is peptized and atomized with a dispersant, the time it takes to atomize it to a particle size that can be used as a general disperse dye is longer than that of the conventional dye cake. It was found that the particles could be sufficiently atomized in 50 to 80% of the time required to do so. Then, during the actual dyeing,
Not only has the high-temperature cohesive property improved, problems that can occur during dyeing such as specs can now be easily avoided, but it has also become possible to increase the concentration of the dye.

In the present invention, a dispersant such as polyvinyl sulfonate, a condensation product of naphthalene sulfonic acid and formaldehyde, a condensation product of phenol, formaldehyde and sodium bisulfite, and an alkali salt of lignin sulfonate is added to the coupling reaction solution. Even if it exists, the effects of the present invention will still be achieved.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Furthermore, in the text, parts by weight refer to parts by weight unless otherwise specified.

Example 1 14 parts of p-nitroaniline hydrochloride is diazotized with sodium nitrite. Next, 88 parts of 3-benzoinol-N,N-bis-(acetoxyethyl)aniline are added at 5°C or lower. After the reaction is completed, neutralize with caustic solution and adjust the pH to 5.5 to 6.5.

After adjustment, add 10 parts of toluene and heat at 70C for 2 hours. Thereafter, toluene is distilled off under reduced pressure, and the aqueous suspension after distillation is filtered. - After filtration, wash with 200 parts of water. Formula (1
85 parts of a filter cake containing 58 parts of the dye shown in ) are obtained.

When the peptizing property, high-temperature flocculating property, and crystallinity of the dye cake produced in Example 1 were investigated by conducting Tests 1 and 2 below, the results shown in Table 1 were obtained.

[Test method-1] 30 parts of dye cake, 20 parts of an alkali salt of lignin sulfonate (dispersant A), and 10 parts of a condensation product of naphthalene sulfonic acid and formaldehyde (dispersant B) were mixed to a slurry concentration of 30%. Adjust with water to bring the pH to 7,
Add 400 parts of glass peas to peptize.

The time required for the average particle size to reach 1.0 microns was used to evaluate the peptizing property.

[Test method-2] (High temperature cohesiveness) [Dyeing test method] Polyester jersey cloth was firmly placed in the inner tube of the cloth dyeing holder of the test dyeing device Colorbed (manufactured by Nippon Senzo Kikai Co., Ltd.) without leaving any gaps. Wrap it around and secure the top and bottom of the holder using a rubber band so that it does not come loose. Next, after setting the outer cylinder on this, separate coating (9): Pour the dyeing bath into the prepared dyeing pot, rapidly raise the temperature from 90°C to 115°C, then 115°C for 20 minutes.
Maintain at 16°C. The total amount of the dye bath was 30 times the weight of the fibers, and the dye (atomized and dried using test method = 1) was added in an amount that was 64 times the weight of the fibers, as well as acetic acid and sodium acetate J as pH adjusters. Adjust the pH of the dye bath to approximately 5 using . In this case no auxiliaries are added. After that, it is rapidly cooled to 90°C, and then the dyed product is taken out, washed lightly with water, and then spread out and air-dried.

After air-drying, visually determine the amount of dye aggregates adhering to the fibers in contact with the liquid flow opening of the dyeing holder inner cylinder.

When the judgment is a symbol, the following criteria were used.

◎: Adhesion of aggregates is not observed. ○: Only slight adhesion of aggregates is observed.

△: Slightly more curds were observed.

(10) ×: Adhesion of aggregates is observed in large amounts.

XX: Significant adhesion of aggregates is observed.

In the case of this staining test, it is practically preferable that the staining value be '' (marked with ○) or higher, at which only a small amount of adhesion of one aggregate is observed.

Comparative Example 1 The reaction mass obtained by carrying out the same operation as in Example 1 was filtered, washed with 1000 parts of water, and then the filter cake was mixed with 50 parts of water.
Discharge into 0 parts of water.

After adjusting to 1:1 H=6 to 7 with a caustic solution, the temperature is raised to 90°C and heated at the same temperature for 2 hours. Then filter, 3
After washing with 0.00 parts of water, 65 parts of a filter cake containing 38 parts of dye of formula (1) are obtained.

Test-1 similar to Example 1 was performed on the obtained cake.
, 2 were conducted and the results are shown in Table 1.

Table 1 Example 2 17 parts of 2-chloro-4-nitroaniline hydrochloride is diazotized with sodium nitrite. Next, 19 parts of NN-ethyl-cyanoethyl-m-toluidine are added at below 5°C. After the reaction is completed, neutralize with caustic solution and adjust the acid concentration to 1.

After the preparation, add 101 m of ethylene dichloroethane and
Heat at ℃ for 2 hours. Thereafter, the mixture is distilled off under reduced pressure, and the aqueous suspension after distillation is filtered.

After filtration, washing with 150 parts of water yields 68 parts of a filter cake containing 88 parts of the dye represented by formula (2).

The obtained cake was subjected to the same test as in Example 1. The results are shown in Table-2.

Comparative Example 2 A reaction solution subjected to the same operation as in Example 2 was filtered, and 15
After washing with 0.00 parts of water, 500 parts of filter cake are obtained. The cake was made into a slurry with 1,000 parts of water, neutralized with caustic solution, heated and filtered at 60°C for 1 hour, washed with 500 parts of water, and 250 parts (dye content: 20%) of the filter cake was obtained. obtain.

A test similar to that in Example 2 was conducted using this cake. The results are shown in Table-2.

Table 2 Examples 3 to 36 Table 4 shows the deflocculability, high temperature cohesiveness, and solid content of the overcake when compared with the conventional method in the same manner as in Example 1.2. .

Further, Table 8 shows the conditions at that time.

In Table 3, dispersant A means an alkali salt of lignin sulfonate, dispersant B means a condensate of naphthalene sulfonic acid and formaldehyde, and dispersant C means a condensate of phenol, formaldehyde and sodium bisulfite.

Moreover, the numerical value in the solvent item means the weight ratio range with respect to the dye content. The values in the peptization results in Table 4 are the time (h) required for the average particle size of the atomized particles to reach 1.0 microns. The same is true.

(14) Table-4 (Results) Table-4 (Results) (19) Table-4 (Results) (20) Table-4 (Results)

Claims (1)

[Claims] A p-nitroaniline derivative is diazotized, then subjected to a coupling reaction with an N-substituted aniline derivative, and then isolated to form a compound of the general formula CI] 3 4 [wherein, X is hydrogen, a halogen atom or a methyl group] Ilz
E: + group, R1, R2 bar R', -02H4OC
OR% Tsukasa 2H40R', Ba2H40C00R', Mi2H
40C2H40R', -CH2CH(OH)OR', -
CH2CO2R' or -CI2H4CN group (where R
'represents hydrogen, an alkyl group, an aralkyl group, an alkenyl group, or an aryl group), R3
represents hydrogen or -OR', Rt represents R1-4HCOR' or a halogen atom], after the completion of the coupling reaction, if necessary, after neutralizing part or all of the reaction solution. A method for producing a monoazo dye, which is characterized by adding a hydrophobic organic solvent, heat-treating it, then distilling off the organic solvent, and then passing it through.