DD292665A5 - METHOD OF MAKING NEW BROWN, WATER SOLUBLE 2: 1 CHROMIUM COMPLEX MIXTURES - Google Patents

Abstract

The invention relates to a process for the preparation of new brown, water-soluble 2: 1 chromium complex dye mixtures, the hue of which is largely independent of the p H value of the dye bath. This is accomplished by coupling the dyestuff diazotised 4-nitro-2-aminophenol * to the 2-naphthol and 2-naphthol dyestuffs with diazotised 4- and / or 5-nitro-2-amidophenol dyes, while maintaining certain proportions 6-sulfo acids is chromated together. {Intermediates; Nitroaminophenole; * 2-naphthol; 2-naphthol-6-sulfonic acid; o, o-Dihydroxyazofarbstoffe; 2: 1 chromium complex dyes}

Description

The invention relates to a process for the preparation of brown, water-soluble 2: 1 chromium complex dye mixtures for dyeing wool, polyamide but also leather whose hue is largely independent of the pH of the dyebath.

Characteristic of the known state of the art

It is known that the drawability of 2: 1 metal complex dyes is dependent on the number and type of solubilizing groups in the molecule. Sulfonamide groups consistently give better drawability from neutral and weakly acidic baths than corresponding dyes with sulfo groups, which show sufficient drawing power only at much lower pH values. It is also known that the drawability decreases in the neutral to weakly acidic range with increasing number of solubilizing groups and that this dependence leads to dyes with sulfo groups already at more than one sulfo group in the molecule to strong limitations of applicability.

Finally, it is known that in so-called mixed chromation, i. in the co-chromation of several ο, ο'-dihydroxyazo dyes to 2: 1 chromium complexes, which correspond theoretically possible combinations such as a statistical distribution. Dr: means for the common chromation of two different 0,0'-Dihyaroxyazofarbstoffen that the three different 2: 1 metal complexes arise approximately in the molar ratio 1: 2: 1.

This fact hardly leads to application problems in such 2: 1 metal complex dyes, in which the constituents of the mixture either show a very similar nuance (cf z, B. DD-PS 15417 or DD-PS 21355) or the same or at least very similar drawability, which is due to the same number and type of solubilizing groups in each component of the mixture (see, for example, DD-PS 15405, DD-PS 21158).

Have the components of the mixture in addition to a different nuance, what z. B. in brown or green dyes is usually the case, and a different drawability, which is caused by a different number and / or type solubilizing groups in the molecule, the nuance of such a mixture is dependent on the pH of the dyebath. Dyes or dye mixtures that show this deficiency, z. B. DD-PS 34048, DE-AS 1644356 and CH-PS 376600 described.

Colouristically high-grade dyestuffs are therefore obtained in such cases by the process of mixed chromating only when both starting dyestuffs each contain a sulphonamide group (cf., for example, DD-PS 21158). If this constitutional assumption is not met, only the complicated pathway via the 1: 1 chromium complex gives uniform unsymmetrical and thus coloristically high-quality dyes (cf., for example, DD-PS 108318). However, since the generation of suitable intermediates with sulfonamide groups is also a complicated process which proceeds over many stages, such coloristic high-grade dyes are in any case expensive, ie. H. value-intensive products.

Object of the invention

The aim of the invention is an effective process for the preparation of brown, water-soluble 2: 1 chromium complex azo dyes whose hue is as far as possible t. Depending on the pH of the dyebath with concomitant use of sulfonamide group-free intermediates.

Explanation of the essence of the invention

The object of the invention is to obtain water-soluble brown 2: 1 metal complex dyes from chromable monoazo dyes, which do not all possess a sulfonamide group and are thus at least partially obtainable from readily available inexpensive intermediates whose nuance is largely independent of the pH of the dyebath , This technical object is achieved according erfindungspemäß so that the monoazo dye of diazotized 4-nitro-2-aminophenol coupled to 1 (4'-sulfamidophenyl) -3-methylpyrazolone with the dye mixture of diazotized 4- and / or 5-nitro-2-aminophenol coupled to 2-naphthol and 2-naphthol-6-sulfonic acid, is chromated together, so that the dyes are converted into a mixture of the corresponding 2: 1 chromium complexes. The ratio of the dye of 1 (4'-sulfamidophenyl) -3-methylpyrazolone to the sum of the other two dyes should be 1: 0.75 to 1.25. The ratio of the dyes of 2-naphthol to the dyes of 2-naphthol-6-sulfonic acid should also be 1: 0.75 to 1: 1.25. It is expedient to prepare the dyes from 2-naphthol and 2-naphthol-6-sulfonic acid by coupling together with diazotized nitroaminophenol. Is not used for this coupling not pure 4-nitro or 5-nitro-2-aminophenol, but

Mixtures of these two compounds, as well as their common diazotization is appropriate. After combining the dyes of 2-naphthol and 2-naphthol-6-sulfonic acid with the dye of 1 (4'-sulfamidophenyl) -3-methylpyrazolone, the mixture for all variants of the so-called mixed chromium, z. Chromium-III salts and salicylic acid, after which brown, water-soluble 2: 1 chromium complex dyes werdendenden nuance on wool, polyamide and leather remarkably little of the pH of the dyebath is dependent.

Version ·:! Jelsplele

BelspleJ 1

The coupling suspensions of 0.050 mole of the dye diazotized! 4-nitro-2-aminophencl coupled to 4'-sulfamidophenylmethylpyrazolone and 0.050 mole of the dyes obtained by diazotizing a mixture of 0.026 mole of 4-Nuo-2-aminophenol and 0.025 mole of 5-nitro-2-aminophenol and coupling to a mixture of 0.025 mol of 2-naphthol and 0.025 mol of 2-naphthol-6-sulfonic acid were combined and adjusted to pH 6 with hydrochloric acid.

After addition of 13.8 g (0.1 mol) of salicylic acid and 15.2 g of a basic chromium sulfate with 25% Cr ₂ O ₃ content is heated to 95 to 100 ⁰ C and held for 5 hours the temperature. During this time, a pH of 2 to 3 is maintained by the addition of soda solution. The pH is brought to 8.5 with sodium hydroxide solution and stirred for a further 2 hours.

After addition of 150 g of sodium chloride and 7 ml of glacial acetic acid, the dye is deposited at pH6.

The dye obtained dyes wool and synthetic polyamide fibers with a bluish brown hue with very good fastness properties of acidic and neutral bathing.

If, on the other hand, the 2-naphthol is replaced by 2-naphthol-6-sulfonic acid, a dye is obtained which gives a bluish tint in the acidic range and dyes wool in the neutral range in an orange-brown color.

Replacement of 2-naphthol-6-sulfonic acid with 2-naphthol provides a dye which has significantly poorer solubility and exhibits completely unsatisfactory leveling power.

Example 2 to 5

According to Example 1 can be obtained by combining the dye 14-nitro-2-aminophenol -> 4'-Sulfamidophenylmethylpyrazolone with the dyes II, represented by common diazotization of A mole of 4-nitro-2-aminophenol and B moles of 5-nitro-2 aminophenol and coupling on a mixture of CMoI 2-naphthol and D mole naphthol-6-sulfonic acid following tabulation brown dyes produce:

Example minor MoIII A B C D Nuance

2 0,055 0,045 0,025 0,020 0.023 0,022 brown 3 0,055 0,045 0,045 - 0.023 0,022 maroon 4 0,045 0,055 0,025 0,030 0,025 0,030 dun 5 0,04t 0,055 0,020 0,035 0,030 0,025 black-brown

Claims (2)

A process for the preparation of new brown, water-soluble 2: 1 chromium complex dye mixtures whose hue is largely independent of the pH of the dyebath, by co-chromation of ο, ο'-Dihydroxyazofarbstoffen, characterized in that the dye from diazotized! 4-nitro-2-aminophenol coupled to 1 (4'-sulfamidophenyl) -3-methylpyrazolone together with a dye mixture of diazotized! 4- and / or 5-nitro-2-aminophenol coupled on 2-naphthol and 2-naphthol-6-sulfonic acid in a molar ratio of 1: 0.75 to 1: 1.25 is chromieit, wherein these dyes to the dye with sulfamide group also in the molar ratio 1: 0.75 to 1: 1.25. Field of application of the invention