DD292666A5 - METHOD OF MAKING NEW BROWN, WATER-SOLUBLE 2: 1 CHROMIUM COMPLEXAZOFFING MIXTURES - Google Patents

Abstract

The invention relates to a process for the preparation of new brown 2: 1 chromium complex azo dye mixtures, the hue of which is largely independent of the p H value of the dye bath. This is achieved by coupling the coupled product of diazotized 4- and / or 5-nitro-2-aminophenol onto 2-naphthol-6-sulfamide together with the dyestuffs of diazotised 4-nitro-2-aminophenol while maintaining certain proportions. Phenyl-3-methylpyrazolone and 1 (4-sulfophenyl) - or * chromated. {Intermediates; Nitroaminophenole; 2-naphthol-6-sulfamide; 1-phenyl-3-methylpyrazolone; * * o, o-dihydroxyazo dyes; 2: 1 chromium complex dyes}

Description

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 severe limitations of applicability. Finally, it is known that in so-called mixed chroming, ie at the common chroming of several ο, ο'-Dihydroxyazofarbstoffen to 2: 1 Chro, ^T tikomplexen the theoretically possible combinations correspond approximately to a statistical distribution. This means for the common chromation of two different ο, ο'-Dihydroxyazofarbstoffen that the three different 2: 1 metal complexes arise approximately in the molar ratio 1: 2: 1. This fact hardly leads to application problems with such 2: 1 metal complex dyes in which the constituents of the mixture show either a very similar shade (see, for example, 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.

Coloristic high-grade dyestuffs are therefore obtained in such cases by the process of mixed chromating only if 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 yields uniform unsymmetrical and thus coloristically high-grade dyes (see, for example, DD-PS 108318).

However, since the preparation of intermediates for ο, ο'-dihydroxyazofarbstoffe with sulfonamide is also a technically and economically complex multi-stage process, such high performance dyes are in any case expensive, value-intensive products.

Object of the invention

The aim of the invention is a process for the preparation of new brown, water-soluble 2: 1 chromium complex azo dyes or dye mixtures whose hue is largely independent of the pH of the dyebath.

Dailegung the nature of the invention

The invention is based on the object of ο, ο'-Dihydroxyazofarbstoffen that do not all have a sulfonamide and thus at least partially produced from relatively readily available intermediates to obtain new water-soluble, brown 2: 1 metal complex dyes, which also be characterized excellent should be that their color is largely independent of the pH of the dyebath. This technical object is achieved in that monoazo dyes from diazotized 4- and / or 5-nitro-2-aminophenol coupled to 2-naphthol-6-sulfamide coupled with the dyes of diazotized 4-nitro-2-aminophenol coupled to Phenylmethylpyrazolon and 1 (4'Sulfophenyl) - or 1 (2'-chloro-5'-sulfophenyl) -3-methylpyrazolone be chromated. The chromation can be after the bekannton variants of Mischchromierung, ie z. B. with chromium-III salts and salicylic acid. The molar ratio of the dyes based on 2-naphth-6-sulfamide to the sum of the dyes based on the pyrazolone coupling components should be 1: 0.75 to 1: 1.30 and the Mul ratio of pyrazolone without sulfo group to the dyes with sulfo should between 1 : 0.75 and 1: 1.25. It is convenient to prepare the pyrazolone dyes by co-coupling diazotized 4-nitro-2-amino-phenol to a mixture of phenylmethylpyrazolone and the pyrazolone sulfonic acid.

When using 4-nitro- and 5-nitro-2-aminophenol for the coupling to 2-naphthol-6-sulfamide, it is expedient to diazotize this two amines together. The variation of the molar ratios leads to the following effects: Increasing the proportion of pyrazolone dyes over those based on 2-naphthol-6-sulfamide shifts the color tone to a clearer redder. A proportion of 5-nitro-2-aminophenol in the diazo component for the 2-naphthol-6-sulfamide based dye increases the depth of shade and tarnishes the hue. Changes in the ratio of the individual components with different solubilizing groups lead to altered neutralizing power, but also the solubility can be influenced in this way

become. The new dye mixtures are characterized by a remarkable match of nuance in dyeing

under different conditions

 embodiments

example 1

The suspension of 0.025 mole of the dyes from diazotized! 4-nitro-2-aminophenol coupled to 2-naphthol-6-sulfamide (I) and 5-nitro-2-aminophenol coupled to 2-naphthol-6-sulfamide (II) is diazotized with 0.025 mol of the dyes from each!

4-nitro-2-aminophenol coupled to phenylmethylpyrazolone (III) and 4'-sulfophenylmethylpyrazolone (IV) 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 1OO ° 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 it is stirred for a further 2 hours.

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

She dyes wool and synthetic Polytmidfasern in a bluish brown color with very good fastness properties of acidic and neutral bathing.

If, on the other hand, the phenylmethylpyrazolone is replaced by 4'-sulfophenylmethylpyrazolone, where a dye is obtained which gives a bluish tint in the acidic range and stains dirty purple-gray in the neutral range.

Use of 4'-sulfophenylmethylpyrazolone by phenylmethylpyrazolone provides a dye with significantly poorer solubility and wholly unsatisfactory leveling properties.

example

When the coupling product (IV) used in Example 1 is replaced by the same amount of the dye of 4-nitro-2-aminophenol and 2'-chloro-5'-sulfophenylmethylpyrazolone (V), a dye mixture having similar coloristic properties is obtained.

Examples 3 to 5 According to Example 1 can be by combining the chromable monoazo dyes I, II, III and IV in different

The following 2: 1 metal complex dye mixtures are prepared in quantitative ratios: Example Moll MoIII MoIIII MoIIV Nuance

3 0.04 0.01 0.025 0.025 brown

4 0.02 0.03 0.028 0.022 gray brown

5 0.045 - 0.025 0.030 reddish brown

Examples 6 to 8

When the dye IV used in Examples 3 to 5 is replaced by the dye V, dyes similar to those in Examples 3 to 5 are obtained.

Claims (2)

A process for the preparation of new brown, water-soluble 2: 1 chromium complex azo dye mixtures whose hue is largely independent of the pH of the dyebath, by co-chromation of ο, ο'-Dihydroxyazofarbstoffen, characterized in that the coupling product of diazotized! 4- and / or 5-nitro-2-aminophenol 2-naphthol-6-sulfamide in a molar ratio of 1: 0.75 to 1: 1.3 with diazotized dyes! 4-nitro-2-aminophenol coupled to 1-phenyl-3-methylpyrazolone and 1 (4'-sulfophenyl) - or 1 (2'-chloro-5'-sulfophenyl) -3-methylpyrazolone in a molar ratio of 1: 0.75 to 1: 1.25 is chromated together. Field of application of the invention The invention relates to a process for the preparation of brown, water-soluble 2: 1 chromium complex azo dye mixtures for filing wool, polyamide but also leather whose hue is largely independent of the pH of the dyebath.