DD292667A5 - PROCESS FOR PREPARING NEW BROWN, WATER-SOLUBLE 2: 1 CHROMIUM COMPLEX MIXTURES - Google Patents

Abstract

The invention relates to a process for the preparation of new brown 2: 1 chromium complex dye mixtures whose hue is largely independent of the p H value of the dye bath. This is accomplished by adding 1.0 to 1.6 moles of the dye of diazotized 4-nitro-2-aminophenol and * 0.1 to 0.75 moles of the diazotised dye for 1.0 "mole" of the new dye mixture. Amino-2-hydroxy-6-nitronaphthalene-4-sulfonic acid and 2-naphthol and 0.1 to 0.5 mol of the dye or dye mixture of diazotized 4- and / or 5-nitro-2-aminophenol coupled to Naphthol is chromated together, wherein up to 50 mole% of the pyrazolone-based dye can be replaced by the corresponding dyes of diazotized 4-chloro- or 5-nitro-aminophenol. {Intermediates; 2-naphthol; Nitroaminophenole; 1-amino-2-hydroxy-6-nitronaphthalene; * o, o-dihydroxyazo dyes; 2: 1 chromium complex dyes}

Description

Field of application of the invention

The invention relates to a process for the preparation of new brown, water-soluble 2: 1 chromium complex dye mixtures for dyeing wool and polyamide but also leather whose color shows good consistency at different 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 give better drawability from neutral and weakly acidic baths than corresponding dyes with sulfo groups, which show sufficient drawability only at much lower pH values. It is known that the drawability decreases in the neutral to weakly acidic range with increasing number of solubilizing groups and that this dependence leads to sulfosubstituents already at more than one sulfo group in the molecule to strong limitations of applicability.

Finally, it is still known that in the common chromation of several o, o'-dihydroxyazo dyes to 2: 1 chromium complexes, the theoretically possible combinations correspond approximately to a statistical distribution. That is, for the co-chromation of two different ο, ο'-dihydroxyazo dyes, three different 2: 1 meta-1 complexes are formed in a molar ratio of 1: 2: 1.

This fact hardly leads to application problems in the case of such 2: 1 metal complex dyes, in which the constituents of the mixture either show a very similar shade (cf., for example, DD-PS 15417 and DD-PS 21355) or a very similar drawing ability, which is caused, for example, by the same number of sulfonamide groups in each constituent of the mixture (cf., 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, by a different number and / or kind of solubilizing groups in the molecule also a different drawability, the nuance of such a mixture depends on the pH of the dyebath. Dyes or dye mixtures that show this deficiency, z. B. in DD-PS 34048, Dc-AS 1644356 and CH-PS 376600 described. Coloristically high-grade dyestuffs are therefore obtained in such cases by joint chromation of two different dyestuffs 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 through the 1: 1 chromium complex yields uniform unsymmetrical dyes, which are particularly valuable if they contain only one sulfo group (see, for example, DD-PS 108318). However, since the preparation of intermediates for ο, ο'-Dihydroxyazofarbstoffe with Sulfonanrdgruppen is a technically and economically complex multi-stage process, such high performance dyes with two sulfonamide, as well as the unsymmetrical dyes with a sulfo group, 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 dye mixtures whose hue shows a good consistency at different pH of the dye ¹ - " _g , from simple intermediates.

Explanation of the essence of the invention

The invention is based on the object of ο, ο'-Dihydroxyazofarbstoffen which have only partially sulfonamide groups and therefore can be prepared from readily available intermediates to win new water-soluble, brown 2: 1 metal complex azo dye mixtures, which should be characterized in that Hue shows a far-reaching consistency at different pH of the dyebath. This technical object is achieved in that monoazo dyes from diazotized 1-amino-2-hydroxy-6-nitronaphthalene-4-sulfonic acid and diazotized) 4-nitro or 5-nitro-2-aminophenol or mixtures of these diazotized aminophenols coupled on 2-naphthol, diazotized with the dye! 4-nitro-2-aminophenol coupled to 1- (4'-sulfamidophenyl) -3-

methylpyrazolone or together with mixtures of this dye with the dyes of diazotized 5-nitro-2-aminophenol or 4-chloro-2-aminophenol coupled onto 1- (4'-sulfamidophenyl) -3-methylpyrazolone. It is essential that to achieve brown shades and both good solubility and good drawability and a good consistency of shade when dyeing under different pH conditions certain proportions are observed. The molar ratio of the 2-naphthol-based dyes to the dyes based on 1- (4'-sulfamidophenyl) -3-methylpyrazolone must be between 1: 1 and 1 -.4. In the dyes based on 2-naphthol, the molar ratio of the dye of diazotized 1-amino-2-hydroxy-6-nitronaphthalenesulfonic acid to the dyes from the diazotized nitroaminophenols 1: 1 to 3: 1 afford, wherein the diazotized nitroaminophenols either from 4 Nitro or 5-nitro-2-aminophenol odp> · can be prepared from any mixtures of these two compounds. In the dye based on 1- (4'-sulfamidophenyl) -3-methylpyrazolone up to 50 mol% of diazotized 4-nitro-2-aminophenol by diazotized 5-nitro-2-aminophenol or 4-chloro-2-aminophenol be replaced, which increases the intensity of the dye mixture according to the invention. To carry out the process according to the invention, it is expedient to couple all the dyes required for the process, which have the same coupling component, together as a mixture. Furthermore, it is useful to also diazotize the proposed for coupling with a coupling component substituted aminophenols.

Since the diazotized 1-amino-2-hydroxy-6-nitronaphthalene-4-sulfonic acid, which is commercially available as quinone diazide, has a low coupling energy, it can be advantageously added as the first diazonium compound to the total amount of 2-naphthol. After the synthesis of the o, o'-Dihydroxyazofarbstoffe it is expedient to isolate one of the dyes or one of the dye mixtures and add the paste to the suspension of the second mixture or the second dye. Which dye is isolated depends on the composition of the mixtures and their volume and must be decided on a case by case basis. In any case, this can achieve a significant reduction in volumes. The chromation of the dye mixtures can then be carried out by all methods which operate without pressure, z. B. at temperatures between 90 and 10O ⁰ C by means of chromium-lll-salts in the presence of salicylic acid.

embodiments

example 1 The suspensions of 0.025 mole of diazotized dye ") 5-nitro-2-aminophenol coupled to 2-naphthol (I),

0.025 mole of the dye of 6-nitro-4-sulfonaphthoquinonediazide coupled to 2-naphthol (II) and 0.05 mole of diazotised 4-nitro-2-aminophenol dye coupled to 4'-sulfamidophenylmethylpyrazolone (III) are combined and washed with hydrochloric acid adjusted to pH 5.

After addition of 9 g 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 the temperature for about 3 hours. During this time, caustic soda is slowly added until the

Finally, a pH of ftwa 8 is reached.

By addition of 240 g of sodium chloride, the metal complex dye mixture is precipitated and isolated by addition of hydrochloric acid to pH 6 by filtration.

It dyes wool and synthetic polyamide fibers in a bluish dark brown color with very good fastness properties of acid and neutral bathing.

Example 2

If, according to Example 1, 0.005 mol of the dye of diazotised 4-nitro-2-aminophenol coupled to 2-naphthalene (IV) is chromated together with 0.015 mol of the dye II and 0.08 mol of the dye III, a yellowish brown is obtained.

Example 3

If, according to Example 1, 0.01 mol of the dye 1.01 mol of the dye IV, 0.02 mol of the dye II, 0.03 mol of the dye III and 0.03 mol of the dye from diazotized 5-nitro-2 Aminophenol coupled to 4'-Sulfamidophenylmethylpyrazolon (V) chromed together, a reddish dark brown is obtained.

Example 4 to 7

According to Example 1 can be tabulated by combining the dyes I to V (in molar amounts) following

Making brownstones:

Example I III III IV V Nuance acidic u. neutral

4 - 0,020 0,060 0,010 0,010 reddish brown 5 - 0,013 0,080 0,007 - tawny 6 0,006 0,014 0,080 - - tawny 7 0,010 0,030 0,040 0,010 0,010 black-brown

Example 8 to 10

If, in Examples 3, 4 and 7, the monoazo dye V is replaced by the same amount of the dye of diazotised 4-chloro-2-aminophenol coupled with 4'-sulfamidophenylmethylpyrazolone (VI), dye mixtures having a similar shade and comparable fastness properties are obtained.

Claims (2)

A process for the preparation of new brown, water-soluble 2: 1 chromium complex dye mixtures, the hue is largely independent of the pH of the dyebath by co-chromation of ο, ο'-dihydroxyazo in mixture under normal pressure and without isolation of a 1: 1 chromium complex characterized in that for the preparation of one "mole" of the dye mixture, ie the amount containing 3 VaI chromium (III) complexed, 1.0 to 1.6 moles of the dyestuff of diazotised 4-nitro-2-aminophenc1 coupled to 1- (4'Sulfamidphenyl) -3-methylpyrazolone, wherein up to 50% of the diazo component may be replaced by 4-chloro or 5-nitro-2-aminophenol, 0.2 to 0.75 mol of the dye from diazotized 2-amino-2-hydroxy-6-nitronaphthalene-4-sulfonic acid coupled to 2-naphthol and 0.1 to 0.5 mol of the dye diazotized! 4- or 5-nitro-2-aminophenol coupled to 2-naphthol or a mixture of both dyes are chromated together.