JP2628383B2 - Thermally stable crystal modification of dye and its production method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a heat-stable dye crystal modification and a method for producing the same.

Conventional technology Equation (1) The dye represented by is known from JP-B-44-13389.

It is known that the dye of the formula (1) dyes synthetic fibers such as polyethylene terephthalate fibers red.

In recent years, in the dyeing industry, the rationalization of dyeing methods and energy saving measures have been advanced, and the bath ratio has been reduced. In order to prevent spotting due to a filter effect, dyes having excellent dispersion stability at high temperatures are strongly desired.

Problems to be Solved by the Invention When a dye represented by the formula (1) produced by a usual method is used for dyeing at a high temperature, there is a disadvantage that the dispersion state of the dye particles in the dye bath is reduced, and therefore, the uniformity is obtained. It is difficult to obtain a stain with a staining concentration.

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, completed the present invention. That is, the present invention
In the powder X-ray diffraction method using Cu-Kα ray, the diffraction angle (2
θ) [°] Strong peak at 17.0, 26.3, diffraction angle (2θ)
[°] Equation (1) characterized by an X-ray diffraction diagram with a rather strong peak at 23.0 The present invention provides a thermally stable crystal modification of the dye represented by the formula (hereinafter referred to as β-type crystal) and a method for producing the same. (Note that a normal error range (± 0.3) is allowed for the diffraction angle.) In the present invention, the expression (1) before being converted into a β-type crystal is used.
The thermally unstable crystal modification of the dye represented by
According to a known method, 2-amino-
It is obtained by diazotizing 6-nitrobenzothiazole and coupling to N-ethyl-N-cyanoethylaniline in acidic medium. This α-type crystal is, for example, CU-
It is a so-called amorphous type having a gentle undulating peak as shown in FIG. 3 in the Kα ray diffraction method. The α-type crystal dye is mechanically pulverized with a dispersing agent, for example, a soda salt of a formalin condensate of naphthalene sulfonic acid or a sodium lignin sulfonic acid salt by a sand mill or the like, according to a general method of commercialization, and then the polyester fiber When subjected to dyeing of a woven fabric or a blended fabric of polyester fiber and acrylic fiber or cotton, since the α-type crystal is unstable to heat, at a temperature of 95 to 135 ° C. at which the polyester fiber is dyed. Transformation of the crystals occurs, causing the dye particles to tar or form aggregates. Such tar compounds and coarse dye particles hinder uniform dyeing. Especially in the case of over-Meyer dyeing, cheese dyeing, bead dyeing, liquid flow dyeing, etc., aggregated particles are passed by the fiber layer, causing clogging, poor internal penetration, casing spots, etc. In addition, disadvantages such as a decrease in the fastness of the dyed product are caused.

As a result of investigations to improve such drawbacks and to meet the demands of the market, they have found that the β-type crystal characterized by the above-mentioned X-ray diffraction pattern is extremely excellent in dyeing stability at high temperatures. It is completed.

 Further, the present invention will be described in detail.

The β-form crystal of the dye represented by the formula (1), which is stable to dyeing at a high temperature, is prepared by subjecting a wet cake or a dry cake of an α-form crystal obtained by known diazotization to coupling to water.
It is obtained by heating at a temperature of 40 ° C. or more in water containing a water-soluble organic solvent or an anionic or nonionic surfactant. The processing time can be lengthened or shortened as required.

For example, 40 ° C or more and 200 ° C or less, preferably 50 ° C or more and 100 ° C
By heating for about 1 to 3 hours below, α-type crystals are converted to β-type crystals. At this time, maintaining the temperature at 100 ° C. or higher or increasing the processing time may be acceptable, but is economically disadvantageous. Examples of the water-soluble organic solvent used include methanol, ethanol, isopropyl alcohol, lower alcohols such as butyl alcohol,
Examples include ethylene glycol monoalkyl ethers such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; glycols such as ethylene glycol; ketones such as acetone and methyl ethyl ketone; and cyclic ethers such as tetrahydrofuran and dioxane.

Examples of the anionic surfactant used include β-
Salts of naphthalenesulfonic acid formalin condensate, ligninsulfonates, etc., and examples of nonionic surfactants are sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenols And polyoxyethylene alkyl amides. These can be used alone or in combination of two or more. Crystal transformation from α-form crystal to β-form crystal is a wet cake obtained by coupling, washing, and washing with water,
Or using a dried product thereof, or heating the reaction solution after completion of the coupling reaction without going through an excessive process, or a necessary amount of a water-soluble organic solvent for the reaction solution, or anionic or nonionic surface activity It is performed by heating after adding the agent.

If the coupling reaction is not adversely affected, these solvents or surfactants are added prior to the coupling reaction, and heat treatment is performed after the coupling reaction to convert the α-type crystal to the β-type crystal. Is possible.

Whether or not the desired crystal conversion is completed in the present invention can be easily confirmed by measuring an X-ray diffraction spectrum.

Examples of the fibers that can be dyed with the dye having a β-type crystal of the present invention include polyethylene terephthalate fibers or a blend thereof with natural fibers such as cotton, silk, and wool,
Mixed woven products.

In order to dye a fiber using the dye having the structure of the formula (1) of the present invention and having a β-type crystal, a dispersant such as a naphthalenesulfonic acid formalin condensate, a higher alcohol sulfate or a higher alkylbenzene sulfonate is usually used. The dye cake of the β-form crystal is finely dispersed in an aqueous medium in the presence of a dye bath, and a dyeing bath or a printing lake is prepared, and can be used for permeation or printing.

In the case of dip dyeing, it can be applied to dyeing methods such as high temperature dyeing, carrier dyeing and thermosol dyeing.

In the present invention, the dye of the formula (1) of the β-type crystal may be used in combination with another dye, and various additives may be added in the step of preparing the disperse dye.

Examples Hereinafter, the present invention will be described specifically with reference to examples.

Example 1. 22.5 g of 2-amino-6-nitrobenzothiazole was suspended in 316.8 g of 60% sulfuric acid, cooled, 51.3 g of 43% nitrosyl sulfuric acid was added at 0 ° C, and the mixture was stirred at the same temperature for 3 hours. A diazo solution of 2-amino-6-nitrobenzothiazole was obtained.

On the other hand, N-ethyl-N-
After dissolving 21.6 g of cyanoethylaniline, the mixture was cooled to 0 ° C. or lower, and the diazo solution was added dropwise to perform coupling. After completion of the reaction, the solution was neutralized with sodium carbonate to neutral Congo Red, and washed with water to recover 37.2 g (equivalent to dryness) of a dye cake.

The X-ray diffraction pattern of a part of this cake was an amorphous α-type crystal as shown in FIG.

Next, this dye cake was dispersed in 500 ml of water, and heated at 70 to 75 ° C. for 1 hour with stirring. After the treatment, the cake was passed, and a part thereof was analyzed according to the X-ray diffraction method. As a result, a β-type crystal having an X-ray diffraction pattern as shown in FIG.

Example 2. Wet cake 21 of α-form crystal obtained in the same manner as in Example 1
g (equivalent to dryness), 21 g of a naphthalenesulfonic acid formalin condensate, 28 g of a naphthalenesulfonic acid / cresolsulfonic acid formalin condensate, and 300 g of water at 70 to 75 ° C.
For 1 hour, and a part thereof was washed with water and dried under reduced pressure. The X-ray diffraction pattern of the obtained dye crystal is shown in FIG. 2 and is the same as that of FIG. After grinding the heat-treated liquid with a sand grinder, 3 g of the spray-dried dye composition was dispersed in 3 l of water, and acetic acid, 100 g of tetron cloth was immersed in a dye bath adjusted to pH 5 with sodium acetate at 130 ° C. for 60 minutes. Stained. After soaping, washing and drying,
A red dyed cloth uniformly dyed was obtained.

Example 3 The same operation as in Example 2 was performed using 7.5 g of rheodol TW-O (polyoxyethylene sorbitan nonionic surfactant, manufactured by Kao Atlas) instead of the dispersant for crystal transformation in Example 2. Performed to obtain a β-type crystal.

Example 4 The same treatment as in Example 2 was carried out except that 30 g of ethylene glycol monomethyl ether was used instead of the dispersant for crystal conversion in Example 2, to obtain β-type crystals.

Example 5 Coupling was carried out in the same manner as in Example 1, and then the coupling solution was stirred at 70 to 75 ° C. for 1 hour. The dye crystals obtained by washing with water exhibited β-form.

<Comparative test> 21 g of each of the dyes exhibiting α-type or β-type, 21 g of naphthalenesulfonic acid formalin condensate, naphthalenesulfonic acid
After wet pulverization with a sand grind mill together with 28 g of cresol sulfonic acid formalin condensate, they were vacuum-dried to prepare respective disperse dye compositions.

In order to compare the heat stability of each of the obtained dye compositions, 1) a thermal cohesion test and 2) a casing spot test were performed.

The details of each test method are as follows.

1) Thermal cohesion test A dye bath in which 0.5 g of the disperse dye composition was dispersed in 100 ml of water and the pH was adjusted to 4.5 with acetic acid and sodium acetate (without immersing the fiber = blank bath) was 40 minutes from 60 ° C. Over 130
C., and kept at the same temperature for 10 minutes, cooled to 95 ° C. in 5 minutes, suctioned using quantitative paper (Toyo No. 5A), and judged from the amount and state of the residue on the paper.

 Class 5 (good) to class 1 (poor) based on 5 levels.

2) Casing spot test 0.6 g of the disperse dye composition was dispersed in 180 ml of water, and tetron jersey 1 was placed in a dye bath adjusted to pH 4.5 with acetic acid and sodium acetate.
0g is immersed from 60 ° C to 130 ° C over 40 minutes (using a color pet dyeing machine), kept at the same temperature for 10 minutes, cooled to 60 ° C, and the area where the object is inscribed in the object holder It was determined from the state of the attached aggregate.

 Class 5 (good) to class 1 (poor) based on 5 levels.

Effect of the Invention A thermally stable crystal modification (β-type crystal) was obtained for the dye represented by the formula (1).

[Brief description of the drawings]

FIG. 1 and FIG. 2 are X-ray diffraction diagrams of a β-type crystal which is thermally stable. FIG. 1 shows the result of crystal transformation in water, and FIG. 2 shows the result of crystal transformation in a dispersant. FIG. 3 is an X-ray diffraction diagram of a thermally unstable α-type crystal (amorphous type). 1, 2 and 3, the horizontal axis indicates the diffraction angle 2θ, and the vertical axis indicates the diffraction intensity.

Claims (2)

(57) [Claims] 1. X-ray diffraction having a strong peak at a diffraction angle (2θ) [°] 17.0, 26.3 and a slightly strong peak at a diffraction angle (2θ) [°] 23.0 in a powder X-ray diffraction method using Cu-Kα radiation. Crystal modification of the dye of formula (1) characterized by the figure. 2. A method according to claim 1, wherein the dye having the structure represented by the formula (1) and having a crystal modification which is unstable to heat is dissolved in water, a water-soluble organic solvent or an anionic or nonionic surfactant. 2. The method for producing a crystal modification according to claim 1, wherein the heat treatment is performed at a temperature of 40 ° C. or more in water containing