MXPA01006956A - Crystalline modification of a water-insoluble monoazo dye - Google Patents

Abstract

A water-insoluble monoazo dye represented by structural formula (II) having a crystal modification characterized by an X-ray diffraction pattern (CuK&agr;) showing one strong peak at a diffraction angle (2&thgr;) of about 11.1°and also four intermediate peaks at about 8.1°, about 21.8°, about 23.1°and about 25.2°.

Description

CRYSTALLINE MODIFICATION OF A MONOAZO COLORANT INSOLUBLE IN WATER DESCRIPTIVE MEMORY The present invention relates to a monoazo dye and, in particular, refers to a blue monoazo dye with a novel crystal modification which is outstanding in its dispersion properties. Also, the present invention also relates to a method in which this monoazo dye is used for the dyeing of fibers, especially polyester fiber and, in particular, refers to a method for dyeing fibers, especially fiber of polyester, under conditions that are more severe than hitherto. In recent years, in the world of dyeing, the methods for dyeing have been rationalized differently. For example, in the case of polyester fiber dyeing using disperse dyes, for cloth there are liquid flow and wire dyeing methods there are cylindrical cross-winding dyeing methods or bundle dyeing methods, and the like, and these methods are carried out a lot. Because these dyeing methods comprise systems in which dyeing is carried out by strongly circulating a dye dispersion solution through tightly packed layers in which a number of layers of fiber have been wound up. , it is particularly important that the dispersion properties of the colorant in the dyebath be more outstanding than in the past. If, due to poor dispersion, the dye particles come together and produce comparatively large aggregates, a phenomenon of dye particle filtration occurs through the fiber layers, and due to poor penetration of the dye into the fiber interior and adhesion of the aggregates to the surface of the object being dyed, etc., problems arise such as non-uniform depths of dyeing in the inner and outer layers, and a reduction in solidity such as fastness to rubbing and the like. In particular, very recently, from the point of view of economizing resources and energy, there has been a movement towards more severe staining conditions, namely (1) reducing the bathing ratio of the dye bath (for example, reducing the ratio of material that is being dyed to the dye solution from 1: 30 to 1:10), (2) reduce the proportion of the dispersing agent used (e.g., reducing the ratio of the dye cake to the dispersing agent of 1: 3 to 1: 1), (3) raise the temperature and decrease the staining time (for example, change the staining conditions from 1 hour at 130 ° C to 0.5 hour at 135 ° C), and (4) increase the speed and reduce the heating time (for example, from 1 ° C / min to 2 ° C / min), but all these conditions work to the disadvantage of the dispersion stability of the dye, so from this point of view they need even more dyes with better dispersion properties.

Due to this situation, a considerable number of dyes which have been comparatively satisfactory in their dispersion properties hitherto have become inadequate in terms of their dispersion properties in the most demanding staining methods and recent staining conditions. For example, the monoazo dye of the acetanilide type represented by the structural formula [I] in claim 1, which is obtained by performing a coupling reaction between a diazo component and a coupling component, uniformly dyes the polyester fiber under conventional mild staining conditions and is also outstanding in terms of the different strength measurements, but under more severe conditions as described above, their dispersion is inadequate and it is extremely difficult to obtain dyed materials of a uniform depth of staining. Also, this dye also has a problem in terms of its compatibility with various dyeing aids. For example, its dispersion stability at high temperatures in the presence of Glauber's salt (Na2S04) is extremely deficient and, consequently, when the staining of mixed polyester / cotton yarn products is carried out together using a reactive dye or the like in the presence of Glauber's salt, there is non-uniform staining. In addition, when used as a mixture with other dyes, there has been the problem that, due to poor compatibility with the mixed dye, color variation and non-uniform dyeing arise. Accordingly, there is a growing need for dyes that are outstanding in their dispersion properties and that, even when employing more severe dyeing methods and conditions, produce uniform dyeing with outstanding solidity. Accordingly, the problem addressed by the present invention is to solve the aforementioned conventional difficulties and provide a colorant which is excellent in its dispersion properties. As a result of a thorough investigation of the aforementioned difficulties, the inventors of the present invention have discovered that in the monoazo compound of the acetanilide type represented by the structural formula [I] in claim 1, at least two types of modification are present. crystal, one of these being the crystal modification obtained by the normal conventional method and the other being a modification of novel crystal; and that the stability of the dispersed state in the bath of the pigment dye is closely related not only to the size of the dye particles but also to the crystal modification present; and that when the compound shows the novel crystal modification mentioned above it is noticeably more outstanding in its dispersion properties than the conventional crystal modification; and also that by using this compound as a colorant it is possible to obtain a dye that provides more satisfactory staining under both conventional and more severe staining conditions. Based on these findings, the present invention has been reached. Accordingly, the present invention provides a monoazo dye insoluble in water represented by structural formula [I] in claim 1, of a crystal modification characterized by an X-ray diffraction pattern (CuKa) which shows a strong peak at a diffraction angle (2T) of 11.1 ± 0.1 ° and also four intermediate peaks at 8.1 ± 0.1 °, 21.8 ± 0.1 °, 23.1 ± 0.1 ° and 25.2 ± 0.1 °. The novel crystal modification of the present invention (hereinafter referred to as the crystal modification of form a) can be obtained in the following manner. For example, the monoazo compound of the aforementioned structural formula [I] is synthesized by diazotizing 6-chloro-2,4-dinitroaniline in the usual manner, and then carrying out a coupling reaction with the coupler 3- (N, N-diallyl) amino-4-methoxyacetanilide in an aqueous medium at a temperature of 5 to 15 ° C, and preferably 0 to 10 ° C, of 0.5 to 15 hours. By taking the crystal modification in the cake of the monoazo compound obtained by said synthesis as the crystal modification of β form, in the present invention, this cake is converted to the crystal modification in a form by further treatment under specified conditions. The method of treatment employed comprises, for example, (1) the method of dispersing the cake of the crystal modification of β form in an aqueous medium, under certain circumstances in the presence of a dispersing agent such as an acid formaldehyde condensate. Naphthalenesulfonic acid, or a concentrate of sulfur pulp waste solution in which the main component is sodium ligninsulfonate, and then carry out a stirring treatment at a temperature of 60 to 130 ° C, preferably 80 to 100 ° C , for 0.5 to 30 hours, preferably 1 to 10 hours, and (2) the method of dispersing the cake of the crystal modification of β form in an organic solvent such as an alcohol such as methanol, ethanol or butanol, an ether such as dioxane, or ethylene glycol or glycol ether, and carry out a stirring treatment at a temperature of 15 to 100 ° C, preferably 20 to 80 ° C, for 0.5 to 10 hours. Next, the crystal modification of form a and the crystal modification of the β form of the monoazo compound represented by the above-mentioned structural formula [I] are explained by the drawings. Figure 1 and Figure 2 are X-ray diffraction patterns obtained using a RAD-RB model produced by Rigaku Denki, under the following conditions: (X-radiation) CuK-alpha 1 / 40kV / 100mA (counter monochromator) monochromator curved glass (divergent slit) 1 degree (scattering slit) 1 degree (slit that receives light) 0.15 mm (scanning mode) continuous (scanning speed) 5.0 7min (scanning step) 0.1 min (scrutiny axis) 2T / T by the powder X-ray diffraction method, with the diffraction of the CuK radiation "being recorded using a proportional counter. The horizontal axis is the diffraction angle (2T) and the vertical axis is the diffraction intensity. Figure 1 is the diffraction pattern of the crystal modification of form a, which is the novel glass shape of the present invention, and, in particular, has a strong peak at a diffraction angle (2T) of about 11.1 ° and also four intermediate peaks at approximately 8.1 °, approximately 21.8 °, approximately 23.1 ° and approximately 25.2 °. Figure 2 is the diffraction pattern showing the crystal modification of conventional β-shape, and it is clear that this diffraction pattern is different from that of Figure 1. For identical crystal shapes, the diffraction angles based on the method X-ray diffraction patterns always agree within an error of approximately ± 0.1 °, so that these diffraction patterns clearly show mutually different crystal modifications. Because of this difference in crystal modification, the monazo compound in its novel shape-modifying crystal of the present invention has a different behavior at the time of dyeing of the conventional β-form and, as shown from the Experimental examples 1 and 2 below, the dispersion properties are extremely salient. Also, the present invention also offers a method for using the monoazo dye with this crystal modification in a novel way in the dyeing of fibers, in particular polyester fiber. The staining is carried out by dispersing the monoazo dye of the present invention in an aqueous medium, in the presence or absence of a dispersing agent, to prepare a dye bath or printing paste, after which staining is carried out. by immersion or printing, optionally under more severe conditions. For example, in the case of immersion staining, high temperature staining methods, carrier staining methods, Thermosol staining methods or other staining treatments and, in such circumstances, staining methods such as the method can be applied. The aforementioned liquid flow dyeing method, cylindrical cylindrical dyeing method or package dyeing method can be used favorably. With respect to the staining conditions, it is possible to use the normal conditions employed in the dispersed staining field, in particular conditions that are more severe than those used in a conventional manner can be favorably used. As examples of normal conditions, conditions comprising a dye bath ratio of 20 to 40 times the weight can be used in terms of the material being dyed, preferably about 30 times the weight, with the proportion of the dispersing agent used in terms of the dye being at least 3 times the weight and preferably about 3 times the weight. As examples of the most severe conditions, conditions comprising a dye bath ratio less than 15 times the weight can be used in terms of the material being dyed, preferably 8 to 13 times the weight, and in particular about 10 times the weight, with the proportion of dispersing agent used in terms of colorant being no more than 3 times the weight, preferably 0.5 to 2 times the weight, and in particular about the same proportions (1: 1). The monoazo dye according to the present invention shows good dispersion properties even under such conditions and can give uniform staining. The staining temperature can be selected on a wide scale. For example, in addition to the aforementioned conditions, the staining temperature can be selected from the scale of 100 to 150 °, and in particular 120 to 140 ° C. The staining time is not particularly restricted and should be sufficient to carry out a satisfactory staining, but a staining time of from 20 minutes to 90 minutes, in particular from 30 minutes to 60 minutes, is usually used, depending on the temperature of staining used.

What is particularly favorable is that the dispersion stability of the monoazo dye of the present invention can be maintained even at higher dyeing temperatures than those of 130 ° C or more used in conventional dyeing methods, and under such conditions, the Successful staining is carried out in a comparatively short staining time of less than 1 hour, preferably 20 to 40 minutes, and in particular of about 30 minutes. Furthermore, in the case of the monoazo dye of the present invention, it has been found that even when the temperature of the dye bath is raised to the dyeing temperature at a faster heating rate than hitherto, the dye dispersion in the The dye bath remains stable and no problems such as uneven staining or a reduction in fastness due to poor stability are observed. Therefore, in the case where the monoazo dye of the present invention is used, it is possible to employ a heating rate of more than 1 ° C / min, preferably 2 to 3 ° C / min and in particular 2 to 2.5. ° C / min. In the same manner as hitherto, first of all the dye bath temperature is increased to about 60-80 ° C, usually about 70 ° C, at any speed, after which the temperature is increased to the dyeing temperature at the previous heating speed.

The more severe conditions mentioned above may be employed individually or a combination thereof may be used. The dispersing agent used can be any dispersion agent normally employed in the field of dyeing by disperse dyes and is not particularly restricted but examples are the condensates of naphthalenesulfonic acid and formaldehyde, higher alcohol sulfate esters, higher alkylbenzene sulfonates and the like. The types of fiber that can be dyed using the monoazo dye of the present invention are those commonly employed in the fields of disperse dyes, ie, acetate, nylon, polyester and other hydrophobic fibers, mixed-spun and mixed-woven fabrics. the same, or mixed-spun or mixed-woven products of these hydrophobic fibers and natural fibers such as cotton or wool, in particular polyester fiber comprising polyethylene terephthalate or a polycondensate of terephthalic acid and 1,4-bis (hydroxymethyl) cyclohexane, or mixed-spun or mixed-woven products of natural fibers such as cotton or wool and these polyester fibers. Again, depending on the circumstances, it is possible to add an acidic material such as formic acid, acetic acid, phosphoric acid or ammonium sulfate to the dyebath, and thus obtain even better effects such as even more uniform dyeing. In addition, the novel crystal modification of the monoazo dye represented by the aforementioned structural formula [I] according to the present invention, also has outstanding compatibility with various types of staining aids, eg, Glauber's salt, and other types of dyes such as reactive dyes, such as Cl Reactive Blue 19, C.l. Reactive Blue 225 and the like, and by the combined use of said dyeing auxiliaries and dyes sometimes beneficial effects such as improved uniform staining and reproducibility can be obtained. In particular, this excellent compatibility with reactive dyes is favorable when dyeing mixed-spun and mixed-woven products of a aforementioned hydrophobic fiber and a natural fiber such as cotton or wool. As a preferred embodiment of the method of the present invention, the polyester fiber undergoes dyeing to exhaustion using the monoazo dye of the present invention, in an aqueous medium in the presence of the dispersing agent, under conditions comprising a dyeing temperature of 125-140 ° C, a dye bath ratio of no more than 15 times the weight, and a dispersion agent ratio in terms of the colorant of not more than 3 times the weight. The specified crystal modification of the water-insoluble monoazo pigment according to the present invention shows extremely outstanding properties in terms of dispersion compared to conventional glass modification and, because of these properties, the dispersion stability is maintained in the bath of dye even under the most severe dyeing conditions comprising, for example, a dyed material: dye solution ratio of 1: 10 and a dye cake: dispersion agent ratio of 1: 1, under dyeing conditions of 135 ° C for 0.5 hours, with the dyebath being heated at a rate of 2 ° C / minute, and the dyed material obtained under such dyeing conditions is outstanding in its fastness to light and fastness to rubbing. Accordingly, because of such good dispersion properties, with the dye pigment of the present invention the dyeing can be carried out more uniformly and with outstanding strength. In particular, the pigment is extremely useful from the point of view of conserving energy and resources where the staining is carried out under more severe conditions as described above. Also, in comparison with the water insoluble monoazo dye represented by the following structural formula [II], there is little sensitivity to metal ions and the accumulation is good, so it is very valuable as a disperse dye.

In the following, the present invention is explained in more detail by examples.

EXAMPLE 1 f Example of production of dye crystals) 13. 0 g of 3- (N, N-diallyl) amino-4-methoxy-acetanilide was dispersed in 217 ml of water at 0-2 ° C and used as the coupling component. Next, 15.2 g of 43% nitrosyl sulfuric acid was added to 14.6 g of 98% sulfuric acid and, while stirring, 10.9 g, 6-chloro-2,4-dinitro-aniline was added slowly, to carry performed the diazotization and to produce a diazonium compound solution. This solution was added dropwise at 0 ± 2 ° C to the aforementioned coupling component solution and stirred for 1 hour at the same temperature. The precipitated crystals were filtered, washed with water and dried, and 22.7 g of dark green crystals represented by the aforementioned structural formula [I] were obtained. When the monoazo dye obtained by this reaction was analyzed in the form of powder by the X-ray diffraction method, it was the β-shape modification with the X-ray diffraction pattern shown in Figure 2, having characteristic peaks at angles of diffraction (2T) of approximately 8.9 ° and approximately 24.7 °. Then, the obtained β-form crystals were dispersed in 10 times the volume of water and stirred at 80 ± 2 ° C for 2 hours, to cause crystal transformation. After the glass transformation, filtration with reduced pressure was carried out with a Buchner funnel and a filtration flask, and then vacuum drying was carried out. When the crystals obtained were analyzed by the X-ray diffraction method, they were the crystals of form a with the X-ray diffraction pattern shown in Figure 1.

EXAMPLE 2 (Staining example) 0. 2 g of the crystal modification of form a of the monoazo compound obtained in the preceding example 1 was dispersed in 1 liter of water containing 0.2 g of naphthalenesulfonic formaldehyde acid condensate and 0.2 g of higher alcohol sulfate ester. 100 g of polyester fiber were immersed in this dye bath, and the temperature of the dye bath was raised from 70 ° C to 135 ° C at a rate of about 2 ° C / min. After dyeing for 30 minutes at this temperature, when soaping, washing with water and drying were carried out, the dispersion properties of the dye were excellent and there was uniform staining of the dyed material. The light fastness of the dyed material obtained with violet blue light was good at 5-6 and so also the friction fastness at 4-5. Now, when the same dyeing experiment was carried out with the β-shaped crystal modification obtained in part through the aforementioned production example, there was partial dye gathering in the dyebath and dyed material was obtained in non-dyed form. uniform. Also, the friction fastness was very poor, at 1.

EXAMPLE 3 (Example of staining) When the dyeing was carried out in the same manner as in Example 2, except that the amounts of the condensate of naphthalenesulfonic acid / formaldehyde and higher alcohol sulfate ester were used, namely 0.6 g in each case, plus three times the amount of water, namely 3 liters, under staining conditions of 60 minutes at 130 ° C, so that the staining method was somewhat less severe, it was possible to carry out excellent staining in the same way as in Example 2 with the glass modification of form a of the present invention, and the dyed material obtained had an excellent light fastness of 5-6 and an excellent rub fastness of 4-5. In contrast, when the ß-type crystal form was used, although there was a slight improvement compared to Example 2, a non-uniform dyed material was still obtained and the friction fastness was 3.

Claims (2)

NOVELTY OF THE INVENTION CLAIMS

1. - A monoazo dye insoluble in water represented by the following structural formula [I] which has a crystal modification characterized by an X-ray diffraction pattern (CuKa) that shows a strong peak at a diffraction angle (2T) of 11.1 ± 0.1 ° and also four intermediate peaks at 8.1 ± 0.1 °, 21.8 ± 0.1 °, 23.1 ± 0.1 ° and 25.2 ± 0.1 °.

2. A method for using the monoazo dye according to claim 1 for dyeing polyester fiber under conditions comprising a dye bath ratio of not more than 15 times the weight and a ratio of use of dispersion agent of no more than 3 times the weight in terms of the colorant.