Process for dyeing leather with mixtures of dyes
OwnerAlois Puntener, Josef Koller +1inventors
InventorsAlois Puntener, Josef Koller, Fabio Beffa
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Abstract
A mixture of at least three selected 1:2 chromium or 1:2 cobalt complex dyes of different colors and belonging to the azo or azomethine series is used for dyeing leather and furs. The mixtures of dyes make it possible for the first time to dye leather by the trichromatic process.
Claims23
A process for dyeing leather and furs with a mixture of dyes, which comprises using, for dyeing, an aqueous liquor containing at least three 1:2 chromium or 1:2 cobalt complex dyes which have different colours, belong to the azo, azo-azomethine or azomethine series and have 1-6 sulfonic, carboxylic or phosphonic acid groups and which
- (a) have a depth of penetration on standard chrome leather of between 20 and 200 .mu.m, the differences in depth of penetration between the individual dyes in the mixture being within a range of 100 .mu.m, and
- (b) have no tendency, or only a slight tendency, to aggregate in an aqueous solution containing electrolytes.
Dependencies are inferred from the claim text.