JPH078960B2 - Monoazo dye mixture - Google Patents

Description

TECHNICAL FIELD The present invention relates to a monoazo dye mixture, and more specifically,
The present invention relates to a red monoazo dye mixture having a novel crystal form capable of uniformly dyeing polyester fibers and the like even under high temperature and severe conditions.

(Prior Art) In recent years, various dyeing methods have been rationalized in the dyeing industry. For example, when dyeing polyester fibers with a disperse dye, a jet dyeing method in which a large amount of fibers are dyed at one time is often adopted. Among them, widely used examples are beam dyeing, cheese dyeing, package dyeing, etc. There is a method.

These dyeing methods are methods in which a dye dispersion liquid is forcibly circulated in a dense layer in which stationary fibers are wound and dyeing, so that the dye particles dispersed in the dyeing bath are more than ever before. Are fine particles and excellent dispersion stability in the dyeing bath. That is, when the dye particles become large, an excessive phenomenon of the dye particles occurs due to the fiber layer, the dye does not permeate into the inside of the fiber poorly, or the inner or outer layer is shaded due to the adhesion of aggregates, and the dye only adheres to the fiber surface. Problems such as a decrease in the degree of fastness such as abrasion resistance will occur. Therefore, as the dye used in such a dyeing method, it is necessary that the dispersion is good in the dyeing bath and that the dispersibility is not lowered in a wide temperature range from room temperature to a high temperature at which actual dyeing occurs. It will be.

However, in general, the dispersibility of the dye in the dyebath when the temperature of the dyebath is high is apt to decrease, and as a result, the aggregated dye adheres to the surface of the article to be dyed in the form of overresidue as described above. In addition, the dyeing material overlapping the inner layer also has different dyeing densities in the outer layer portion and the inner layer portion, and a dyed article having a uniform concentration cannot be obtained.

Particularly recently, from the viewpoint of resource saving and energy saving, the dyeing bath has a low bath ratio (for example, the ratio of the dyeing solution to the dyeing solution is from 1:30).
1:10), lowering the dispersant usage (eg reducing the ratio of dye cake to dispersant from 1: 3 to 1: 1) and further increasing the dyeing conditions for a shorter time (eg 13).
Shorten high temperature from 0 ℃ × 1 hour to 135 ℃ × 0.5 hours)
For example, the dyeing conditions are shifting to severe ones. Moreover, since all of the severer dyeing conditions are disadvantageous to the dispersion stability of the dye, even a disperse dye having a relatively good dispersion stability according to the conventional dyeing method can be According to the severe and streamlined recent dyeing method, there are many cases where the dispersion stability becomes poor.

For example, the following structural formulas [I] and [II] The benzothiazole-based monoazo dye represented by the structure itself is included in the scope of the claims described in JP-B-44-30628, and the diazo component and the coupling component are subjected to a coupling reaction according to a conventional method. Although it is produced, since those having different chlorine atom introduction positions are inevitably mixed during the synthesis of the diazo component,
Usually, it is obtained as a mixture of the dyes represented by the structural formulas [I] and [II]. This monoazo dye mixture is capable of uniformly dyeing polyester fibers when used under conventional mild dyeing conditions, and the obtained dyed product has excellent fastness.

(Problems to be solved by the invention) However, if the above conventional monoazo dye mixture is used,
As described above, when polyester fibers are dyed under the recent rationalized high temperature and severe dyeing conditions, the dispersibility of the dye is markedly reduced, and it is extremely difficult to obtain a dyed product having a uniform dyeing concentration. There was a point. Further, conventionally, this type of dye also has a problem in compatibility with various dyeing aids, for example, the high temperature dispersion stability in the presence of Glauber's salt (Na ₂ SO ₄ ) is extremely poor, and therefore the reaction containing Glauber's salt When dyeing polyester / cotton blended products in combination with reactive dyes, etc., not only uneven dyeing but also when blending and using dyes will occur due to color blurring due to compatibility with the compounded dyes. There is a problem that uneven dyeing occurs.

An object of the present invention is to provide a novel monoazo dye mixture which can solve the above conventional problems.

(Means for Solving the Problems) As a result of intensive studies to achieve such an object, the present inventors have found that at least the benzothiazole-based monoazo compounds represented by the structural formulas [I] and [II] are at least present. There are two types of crystal forms, one of which is not very good in dispersion stability under high temperature dyeing conditions, and the other of which is dispersion stability even under high temperature and more severe dyeing conditions. It was found that the crystalline form was very good, and that the cake obtained by the usual synthetic reaction was the crystalline form of which the former was not so good in dispersion stability. Furthermore, the stability of the dispersed state of the dye composition in the high temperature dyeing bath is not determined only by the size of the dye particles, and has a significant relationship with the above-mentioned crystal form, in order to obtain a stable dispersion system of the dyeing bath. In the present invention, the inventors arrived at the present invention by obtaining the knowledge that the object can be achieved only by using one of the above-mentioned novel crystal forms which has not been hitherto known.
That is, the present invention provides the following structural formulas [I] and [II] And a diffraction angle (2θ).
X-ray diffractogram (Cu) showing two strong peaks at about 22.8 ° and 26.7 ° and two medium intensity peaks at 12.6 ° and 15.6 °, respectively.
The gist is a monoazo dye mixture having a crystal form characterized by Kα) (hereinafter referred to as “α-type crystal form”).

The monoazo dye that is the object of the present invention has the structural formula [I] shown above.
And a mixture of monoazo compounds represented by [II], and the mixing ratio of the two is usually 70:30 to 30:70 (weight ratio), but this mixing ratio is the diazo component in synthesizing the monoazo dye. It is determined by the mixing ratio of isomers. The present invention specifies the crystal form of such a dye mixture, but this crystal form does not substantially differ even if the mixing ratio changes within the above range.

The novel α-type crystal form monoazo dye mixture of the present invention can be obtained as follows.

First, for example, the following structural formulas [III] and [IV] A dichlorobenzothiazol-2-amine isomer mixture represented by the formula (1) is diazotized by a conventional method, and then the following structural formula [V] In a water medium with a compound (coupling component) represented by
By carrying out a coupling reaction at 0 to 15 ° C., preferably 0 to 10 ° C. for 30 minutes to 10 hours, the above structural formulas [I] and [I
The monoazo dye mixture represented by I] is synthesized. The conventional cake of the monoazo dye mixture obtained by this synthesis has a crystal form that is almost amorphous (hereinafter referred to as "β-type crystal form").

On the other hand, in order to obtain the monoazo dye mixture of the present invention, the cake of the monoazo dye mixture having the β-type crystal form obtained above is further treated under specific conditions to transfer it to the α-type crystal form. Need to let. In such a case, as a treatment method under specific conditions, a β-type crystal form cake is dispersed in, for example, an aqueous medium, and a formaldehyde condensate of naphthalenesulfonic acid or sulfite containing sodium ligninsulfonate as a main component is used in some cases. In the presence of a dispersant such as a pulp waste liquor concentrate, 60 to 130 ° C., preferably 80 to 1
0.5 to 30 hours at a temperature of 00 ° C, preferably a method of stirring for 1 to 10 hours, or alcohols such as methanol, ethanol or butanol, ethers such as dioxane, and organic solvents such as ethylene glycol and glycol ether. A method of dispersing and stirring at a temperature of 15 to 100 ° C., preferably 20 to 80 ° C. for about 0.5 to 10 hours is used.

(Function) Next, the α-type crystal form of the present invention and the conventional β-type crystal form in the monoazo dye mixture represented by the structural formulas [I] and [II] will be described with reference to the drawings. 1 and 2
The figure is an X-ray diffraction diagram in which the state of diffraction by CuKα rays in the powder X-ray diffraction method is recorded using a proportional counter, and the horizontal axis shows the diffraction angle (2θ) and the vertical axis shows the diffraction intensity. FIG. 1 shows an α-type crystal form, which is a novel crystal form of the present invention. In particular, the diffraction angle (2θ) is about 22.8 ° and
It has two strong peaks at 26.7 ° and two medium intensity peaks at about 12.6 ° and 15.6 °. FIG. 2 shows a conventional β-type crystal form, which is clearly different from the α-type crystal form of FIG. The diffraction angles by the X-ray diffraction method are always the same with an error of about ± 0.1 ° if they are of the same crystal form, and these drawings clearly show the difference in crystal form. The behavior of the monoazo compound at the time of dyeing is different due to this difference in crystal form, and in the case of the present invention, at high temperature,
Moreover, good dyeing can be achieved even if the dyeing method under severe conditions is adopted.

Fibers that can be dyed with the monoazo dye mixture of the present invention include polyethylene terephthalate and terephthalic acid.
Examples thereof include polyester fibers composed of a polycondensation product with 1,4-bis- (hydroxymethyl) cyclohexane, or a blended product or a woven product of the above polyester fibers with a natural fiber such as cotton or wool. In order to dye polyester fibers using the monoazo dye mixture of the present invention, a condensate of naphthalenesulfonic acid and formaldehyde, a higher alcohol sulfate ester, a higher alkylbenzene sulfonate, etc. is used as a dispersant by an ordinary method in an aqueous medium. Dyeing or printing can be performed by adjusting the dyeing bath or printing paste dispersed therein. Further, for example, in the case of dip dyeing, it is possible to apply a dyeing treatment method such as the above-mentioned high temperature dyeing method, carrier dyeing method, thermosol dyeing method, etc., and even if severe dyeing conditions are adopted in these methods. Since the monoazo dye mixture of the present invention is excellent in dispersion stability, the polyester fiber or the blended product thereof can be dyed well.

In that case, if an acidic substance such as formic acid, acetic acid, phosphoric acid or ammonium sulfate is added to the dyeing bath, a better result can be obtained.

Further, the monoazo dye mixture represented by the above structural formulas [I] and [II] of the present invention may be used in combination with other dyes, and when the dyes are mixed with each other, good results such as improvement in dyeability may be obtained. is there.

(Examples) Next, the present invention will be described more specifically with reference to Examples and Reference Examples.

Reference Example 1 (Production Example of Crystal of Dye Mixture Shown by Structural Formulas [I] and [II] Shown Above) First, 5,6-dichloro-2-aminobenzothiazole 2.2
g and 6,7-dichloro-2-aminobenzothiazole 2.2 g
Of nitrosyl sulfuric acid in 65% sulfuric acid at 0 ° C.
Diazotization was carried out for 2 hours to prepare a diazo solution.

In addition, 4.1 g of N-ethyl-N-acetoxyethylaniline
Was dissolved in 2% sulfuric acid to prepare a coupling component solution.

The diazo liquid obtained above was added dropwise to the coupling component solution at 0 to 2 ° C to cause a coupling reaction, and the mixture was allowed to stand at 0 ° C for 3 hours.
After the reaction was completed by stirring for a period of time, the precipitated crystals were separated, washed with water and dried to obtain 7.9 g of red crystals. The powder of the monoazo dye mixture obtained in this reaction was analyzed by X-ray diffraction,
It was a crystalline form. The X-ray diffraction pattern is shown in FIG.

Then, the obtained red dye mixture having a β-type crystal form was dispersed in 20 volumes of water and stirred at 90 to 95 ° C. for 3 hours to transfer crystals. After completion of the crystal transition, the crystals were dried and dried, and the crystals thus obtained were analyzed by X-ray diffractometry to find that they were in the α-type crystal form shown in the X-ray diffraction pattern of FIG.

Example 1 (Dyeing test under severe conditions at high temperature) 0.5 g of the monoazo dye mixture having the α-type crystal form of the present invention obtained in Reference Example 1 above was mixed with 0.25 g of naphthalene sulfonic acid-formaldehyde condensate and higher alcohol sulfuric acid. A dyebath was prepared by dispersing 0.25 g of the ester in water 1. Immerse 100 g of polyester fiber in this dyeing bath and
After dyeing at 30 ° C. for 30 minutes, soaping, washing with water and drying were carried out. As a result, the dispersibility of the dye was good, and the dyed fabric was dyed uniformly. The obtained dyed cloth exhibited a vivid red color, and the fastnesses thereof were excellent in light fastness grade 5 and abrasion fastness grade 5.

A similar dyeing test was conducted using the monoazo dye mixture having a β-type crystal form in the process of preparation in Reference Example 1, and a partial aggregation of the dye occurred in the dyeing bath, resulting in an uneven dyeing fabric. And, the abrasion resistance was extremely inferior to the first grade.

Example 2 (Dyeing test under conventional mild conditions) In Example 1, the naphthalenesulfonic acid-formaldehyde condensate and the higher alcohol sulfate were each tripled to 0.75 g, and water was tripled to 3 l to dye. The temperature is 130 ℃
It was carried out in the same manner as in Example 1 except that the dyeing was carried out for 60 minutes at a mild temperature.

As a result, when the mixed dye having the α-type crystal form of the present invention was used, good uniform dyeing could be carried out as in Example 1, and the dyeing fastness of the obtained coating was light fastness 5 grade,
The abrasion resistance was 5 which was extremely good.

On the other hand, when the conventional mixed dye having the β-type crystal form in the production in Reference Example 1 is used,
Although a slight improvement was observed in comparison with the case of No. 3, uneven dyeing was still obtained, and the resistance to abrasion fastness was 3rd grade, which was slightly inferior.

(Effect of the Invention) As is clear from the above results, the benzothiazole-based monoazo disperse dye mixture of the present invention, which is novel in that it has an α-type crystal form, is a conventional benzothiazole-based benzothiazole-type Compared with the monoazo disperse dye mixture, it has much better dispersion stability, and if it is used for dyeing polyester fiber, for example, it can maintain the dispersion stability under any of the recent rationalized high temperature and severe dyeing conditions. Therefore, it is possible to obtain a dyed product which has an industrial value and is capable of always performing good uniform dyeing and obtaining a dyed product having excellent light fastness and abrasion fastness.

[Brief description of drawings]

FIG. 1 is an X-ray diffraction diagram of the α-type crystal form of the present invention obtained in Reference Example 1, and FIG. 2 is an X-ray diffraction diagram of the same conventional β-type crystal form. It represents the diffraction angle (2θ), and the vertical axis represents the diffraction intensity.

Claims (2)

[Claims] 1. The following structural formulas [I] and [II] And a diffraction angle (2θ).
X-ray diffraction diagram (Cu) showing two strong peaks at about 22.8 ° and 26.7 ° and two medium intensity peaks at about 12.6 ° and 15.6 °.
Mixtures of monoazo dyes having a crystalline form characterized by Kα). 2. The mixing ratio of the monoazo dyes represented by the structural formulas [I] and [II] shown above in the weight ratio of 70:30 to 30:70. Monoazo dye mixture.