DE2536052A1 - Stable beta-modification of azo dye - prepd. from alpha-modification, for cellulose esters and linear polyesters - Google Patents

Abstract

Novel beta-modification of the azo dyestuff are of formula (I): (I) shows principal lines on an X-ray diffraction diagram of angel 20: 6.5, 11.4 and 14.2 with intensities of 62%, 76% and 100% respectively, using Cu Alpha radiation. (I) is used for dyeing synthetic polyamide textiles and is colour stable.

Description

Stable Modification of an Azo Dye The invention relates to the B modification of the dye of the formula by the X-ray diffraction diagram (CuK, radiation) shown in FIG. 1, which has the following main lines: Angle 2 6.5 11.4 1), 2 14.2 18.4 19.5 20.4 21.7 22.6 25.124.7 Intensity in%: 62 76 42 100 21 25 29 56 47 29 40.

The dye is known from German Patent 1,069,114 and is obtained in the usual production by diazotization and coupling in a modification a, which is not suitable under all conditions occurring in dyeing practice and which has the X-ray diffraction diagram shown in FIG Main lines has: angle 2 5.5 11.2 17.1 18.4 24.1 26.2 Intensity in%: 50 65 56 40 26 100 To produce the new modifications, it is expedient to start with the suctioned one produced in accordance with the information in German Patent 1,069,114 and dyestuff washed with water in the form of the pressed material.

The stable modification can be formed, for example, by a) heating of the pressed material with stirring in aqueous suspension, optionally with the addition of a Dispersant and / or an organic solvent in the case of a dye content from about 10 to 50%, preferably 15 to 55%, to temperatures of about 60 to 125 ° C, preferably 70 to 11500 over a period of about 1 to 6 hours or b) grinding of the material to be pressed, preferably with the addition of a dispersant at elevated temperature, expediently between about 60 to 1000, in particular Reach 70 to 90 ° C.

Dispersants to be added according to a) and b) are, for example, condensation products from naphthalenesulfonic acid and formaldehyde or from phenol, phenolsulfonic acid and Formaldehyde, lignosulphonates and especially modified ligninsulphonates.

According to a), organic solvents that may be added are for example alcohols such as ethanol, n- or i-propanol, n-, i- or t-butanol, Ethers such as tetrahydrofuran or dioxane or glycols and glycol ethers such as ethylene glycol and ethylene glycol monomethyl or ethyl ether.

As test methods to check whether the desired modification change is completely finished and the crystals are big enough to start recording X-ray spectra or viewing samples under the (electron) microscope suitable.

The gradual conversion of the unstable modification into the invention & Be can be followed particularly well with the aid of X-ray diffraction spectra.

The new modification according to the invention produced according to a) or b) like the previously known non-color stable modification by conventional mechanical Process, if appropriate in the presence of suitable dispersants, and more customary Additives such as antifreeze, buffer substances, protective colloids or minor Amounts of solvent, be converted into high fine distribution. For customary devices are suitable for the fine distribution which may be carried out such as mills, for example ball mills, oscillating mills, sand mills or kneaders, as Dispersants are, for example, condensation products from naphthalenesulfonic acid and formaldehyde or from phenol, phenol sulfonic acid and formaldehyde and, for example, lignosulfonates containing sulphite or sulphate cellulose waste liquor and nonionic and anionic surface-active compounds into consideration. In the manufacturing process according to b) the conversion of the modification and the so-called finish are combined, it is preferred for this reason.

The novel dye modification according to the invention which has been converted into a high degree of fine division is particularly suitable for dyeing textile materials made from cellulose esters or synthetic linear polyesters such as polyethylene glycol terephthalate or chemically similarly structured polymers alone or in a mixture with protein or cellulose fibers at temperatures from about 100 to 2200C. The new dye modification has this does not have the disadvantages of the unstable modification that occurs with short-term dyeing processes and dyeing processes in which they are longer in the aqueous medium of a higher Exposure to temperature easily leads to dye flocculation and filtration. Especially when dyeing bobbins - for example cross-wound bobbins - with the Dye of the unstable modification is the risk of strong agglomeration, flocculation and finally filtering off the dye on the coils. Such Flocculation and filtration occur mainly when the dye liquor is only slowly exhausted or when working with such a large excess of dye will ensure that the dyebath is never exhausted. For example this is in apparatus dyeing for loose material and when dyeing bobbins or of yarn the case.

The new dye modification is stable in color, i.e. it changes its Crystal structure under the usual dyeing conditions for disperse dyes, i.e. in an aqueous medium at temperatures up to about 1400C, optionally in the presence common dyeing auxiliaries, if at all, then only so far that the coloring properties are not adversely affected.

In the following examples, parts and percentages relate to unless otherwise noted, by weight.

Example 1 100 parts of the a-modification of the dye in the form of Press cake containing 25 parts of dye are heated to boiling temperature for 4 hours with stirring heated. Then the dye is completely converted into the new ß-modification.

After the subsequent finish by wet grinding, e.g. in a sand mill, with the addition of 60 parts of a modified lignin sulfonate and drying a powdery setting of the dye is obtained, all of which are technical in terms of application Requirements are sufficient. If 1 part of a dispersant is used for the modification conversion or 20 parts of ethanol, if you get a product with similar properties after the finish.

Example 2 100 parts of the a-modification of the dye in the form of Press cake containing 40 parts of dye with the addition of 60 parts of a modified lignosulfonate by wet grinding, e.g. passages through a sand mill, Finished at approx. 800C, with the conversion to the new ß-modification at the same time he follows. After drying, a powdery setting of the dye is obtained, which meets all application requirements.

Claims (3)

Patent claims 1. The ß-modification of the dye of the formula characterized by the X-ray diffraction diagram reproduced in Figure 1, which has the following main lines: Angle 2 (E): 6.5 31.4 13.2 14.2 18.4 19.5 20.4 21.7 22S6 25.1 24, 7 intensity in%: 62 76 42 100 21 25 29 56 47 29 40 2. Process for the preparation of the dye modification according to Claim 1, characterized in that the dye of the formula characterized by the X-ray diffraction diagram reproduced in FIG. 2, which has the following main lines: angle 2 5.5 11.2 17.1 18.4 24.1 26, 2 intensity in%: 30 63 36 40 26 100 a) in aqueous Medium, optionally with the addition of dispersants and / or a solvent heated or that b) at elevated temperature, optionally with the addition of Dispersant grinds. 3. The use of the dye modifications according to claim 1 for Coloring of cellulose esters and synthetic polyesters.