CS215754B1 - Brown 1: 2 chromocomplex azo dye - Google Patents

Abstract

1:2 chromocomplex of pyrazolone and naphthalene o,6-dihydroxyazo dye, asymmetrically substituted with one sulfo group (see formula), expands the palette of dyes for dyeing wool and polyamides by a brown shade, excellent choice

Description

The invention relates to a new 1: 2 chromocomplex azo dye for dyeing wool and polyamide.

For dyeing wool and polyamide from weakly acid to neutral baths, so-called 1: 2 metal-complex azo dyes are used when the dyeing is required to have high dry and wet fastnesses. They are the coordination complexes of one metal atom with a coordination number of 6 (most often chromium or cobalt) with two identical or different o, 6-dihydroxy, o-hydroxy-6-carboxy or o-hydroxy-6-aminoazo dyes. The water solubility of these 1: 2 metal-complex dyes - if they do not carry any lyophilic substituents - is very low and for practical application to textile material from an aqueous environment it is necessary to convert them beforehand into fine form by dispersion milling.

Another way of treating them for use in practical dyeing is to increase solubility by appropriate substitution. 1: 2 metal-complex dyes solubilized by non-ingenic hydrophilicity-increasing substituents such as sulfamoyl or methanesulfonyl groups are known. However, the production of these dyes is relatively expensive. The same dyeing quality and even better results were achieved in some cases with sulfo-solubilized dyes. However, the incorporation of sulfo groups into the 1: 2 molecule of the metal complex dye is not without problems. While the non-inogenously substituted 1: 2 complexes are essentially monovalent acid salts, substitution with sulfo groups increases the negative charge of the color anion and, of course, can adversely affect its dyeing properties, namely dyeing as well as ductility. The dyeing behavior is influenced not only by the electric charge, but also by the substitution topography and the spatial arrangement of the colored complex molecule.

It has now been discovered that wool and polyamide are colored with a 1: 2 brown shade of the chromocomplex azo dye according to the invention, of the formula

The dye according to the invention is characterized by high solubility and dyeing power. My very good migration characteristics, which is reflected in the excellent flatness of coloring. It can be well combined with other dyes of the same or other metal-complex assortments, or with common acid dyes.

Example

49.2 g (0.1 mol) of chromium 1: 1 monoazo dye complex 4-nitro-2-aminophenol-6-sulfoacid -> 2-naphthol paste is introduced into 0.1 mol of alkaline aqueous monoazo dye suspension at 80 ° C 4-nitro-2-aminophenol-1-phenyl-3-methyl-5-pyrazolone. After a few hours of heating at 80-85 ° C, a brown solution of a mixed 1: 2 chromium complex was formed. Evaporation of the solution yielded 130 g of a strong dye, a coloring wave and a PAL brown color.

Claims (1)

OBJECT OF THE INVENTION: 2 chromocomplex azo dye of the formula Θ ©