CS255292B1 - Process for preparing unsymmetrical brown metal complex dyes - Google Patents

Abstract

Method for preparing 2:1 unsymmetrical brown metallocomplex dyes based on chromium complexes of constitution I, where Ay is -NO2 or -SO3 and A2 is -SO3 or -NO2 by the action of a 1:1 chromium complex of constitution II on an azo dye of constitution III, where Ay and A2 have the indicated meaning, in an alkaline medium.

Description

(54) A method for preparing unsymmetrical brown metal-complex dyes

Method for preparing 2: 1 unsymmetrical brown metal-complex dyes based on chromium complexes of constitution I where Ay is -NO2 or -SO3 and A2 is -SO3 or -NO2 by treating 1: 1 chromium complex of constitution II on azo dye of constitution III, where Ay and A2 has in the alkaline environment.

A1

SUMMARY OF THE INVENTION The present invention provides a process for the preparation of unbalanced 2: 1 metal-complex dyes based on chromium complexes of constitution I which color the wool, silk and polyamide textile materials with a brown shade

where

A 1 is -NO 2 or SO 3 H

H 1 is -SO 4 H or -NC 2

The methods currently used for preparing the aforementioned types of metallocomplex dyes, comprising either simultaneous chromation of an equimolar mixture of starting azo dyes, where the disadvantage of producing a dye mixture containing, in addition to the desired 2: 1 unsymmetrical overwhelming complex, alternative asymmetric dyes. or in the 1: 1 interaction of the overwhelming Constitution II dye complex

prepared by chromium-plating of the corresponding azo dye with complementary azo dyes of Constitution III

III where

A 1, A 2 are as defined above.

The disadvantage of this preparation process is the unbalanced production caused by the varying amount of symmetrical 2: 1 metal-reflex dye in the products II, whose presence causes, besides the color shift of the products I, also their considerable turbidity, which is not desirable. It has now been found that said type of unsymmetrical constitutional chromium complexes can be prepared from the currently produced 1: 1 metal-complex dyes of constitution IV without the above drawbacks.

where

A 1, A ₂ is as previously defined by their action on the azo dyes of the constitution V

NO.

- N-N -

OH HO in an alkaline reaction medium containing ammonia and alkali carbonates at 80 to 100 ° C. The process for the preparation of unsymmetrical constitutional chromite complexes I according to the invention is carried out by adding a neutral or weakly alkaline suspension of chromite complexes IV to an ammoniacal azo dye solution in the presence of alkaline carbonates at said temperature. Carrying out the complexing reaction according to the invention makes it possible to work at high concentrations of the starting components IV and V without the need for isolation of product 1, and the colorant obtained, besides its high solubility, has excellent coloristic properties.

The advantage of the process for the preparation of the chromium unsymmetrical constitutional complexes according to the invention is the achievement of a highly productive utilization of the production equipment with minimum energy and auxiliary consumption. Another advantage is the possibility of waterproofing and waste-free method of technological process.

The invention is further illustrated by the following non-limiting examples.

Example 1

To the parts of the vat, the dyes are charged, with stirring, with 1 250 parts by weight of water 50 of constitution up to ° C warm and 480

The acidity of the suspension is blunted by adding ca 50 parts by weight of Na 2 CO 4 to a pH of 7 to 8 and the mixture is heated to a temperature of 80 to 90 ° C. The stirred reactor is charged with 1000 parts by weight of water 50-60 ° C warm, in which 44 parts by weight of 200 wt.% Are dissolved and 440 parts by weight of azo dye of constitution IV are introduced into the solution. ammonia so that the pH of the solution ranged from 8.5 to 9. The contents of the reactor were heated to 85-90 ° C and a 1: 1 chromium complex slurry was gradually introduced into the reactor over 30 minutes. After this operation, the reaction mixture is maintained at this temperature for an additional 30 minutes when the starting components are quantitatively reacted. The reaction mixture is spray dried, optionally after pre-treatment with sodium sulfate and an emulsion of oily substances to reduce the dusting of the final dye.

Example 2

The procedure for the preparation of the complex mentioned in is identical to Example 1 except that the 1: 1 chromium complex of constitution is used instead of the 1: 1 chromium compound of Example 1.

Claims (1)

OBJECT OF THE INVENTION Process for the preparation of unsymmetrical brown metal-complex dyes based on chromium complexes of the constitution I wherein A 1 is a group A 6 is a 1: 1 treatment group -NO2 or SOgH -SOgH or chromite complexes of constitution II Wherein the azo dye of the formula III - N - N - cQS - SO 3 H is as defined above III OH OH in alkaline medium! containing ammonia and alkali carbonates at 80 to 100 ° C.