CS215755B1 - Brown 1: 2 chromocomplex azo dye - Google Patents

Abstract

1:2 Chromium complex of pyrazolone and naphthol o,6-dihydroxyazo dye, asymmetrically substituted with one sulfo group (see formula), expands the palette of dyes for dyeing wool and polyamide with a reddish-brown shade, excellent in terms of excellent elongation, uniformity and fastness of dyeing.

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 coordination complexes of one metal atom with a coordination number of 6 (most often of stunning or cobalt) with two identical or different o, 6-dihydroxy-, o-hydroxy-o-carboxy or o-hydroxy-o-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 noninogenic 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 salts of monohydric acids, substitution with sulfo groups increases the negative charge of the color anion and thus, of course, can detrimentally 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 reddish brown shade of a 1: 2 chromocomplex azo dye according to the invention, of the formula

The dye according to the invention is characterized by high solubility and dyeing power. It has very good migration properties, which is manifested by 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.

He did

52.3 g (0.1 mol) of chromium 1: 1 monoazo dye complex 4-nitro-2-aminophenol-6-sulfoic acid-1-phenyl-3-methyl-5-pyraeolone as a dry ground powder was added at 70 ° C. ° C is added to 0.1 mol of an alkaline aqueous suspension of the monoazo dye 4-nitro-2-aminophenol-2-naphthol. After heating at 85 to 90 ° C for several hours, the resulting 1: 2 chromium complex of reddish brown is isolated by salting. Filtration and drying afforded 100 g of a strong dye, wool dye and PAD with a reddish brown hue.

Example 2

52.3 g (0.1 mol) of a 1: 1 monoazo dye complex of 4-nitro-2-aminophenol - + 1 (4'-sulfophenyl) -3-methyl-5-pyrazolone as a paste suspended in water were added at 70 ° C. ° C is added to 0.1 mol of an alkaline aqueous suspension of the monoazo dye 4-nitro-2-aminophenol-2-naphthol. It is heated to 85-90 ° C and after a few hours of heating, the resulting 1: 2 reddish-brown chromium complex is isolated by salting. Filtration of the precipitated dye and drying of the paste gave 100 g of a strong dye which stains wool and PAD with a reddish brown hue.

Claims (2)

SUBJECT OF THE INVENTION Brown 1: 2 chromocomplex azo dye formula 2 & NO, NO ₂