Lightfastness of dyeings obtained with acid dyes or metal complex dyes on polyamides: treatment with copper hydroxamates

A process for improving the lightfastness of dyeings obtained with acid dyes or metal complex dyes or a mixture thereof on polyamide textile materials by treating the materials, before, during or after dyeing, with a copper complex of a copper hydroxamate having the formula:

• ##STR19## wherein R is C.sub.17 -C.sub.17 -alkyl, or C.sub.3 -C.sub.8 -cycloalkyl, which is unsubstituted or substituted by one or two alkyl groups of 1 to 4 carbon atoms, a radical selected from the group consisting of:
• ##STR20## or a substituted or unsubstituted furanyl, thiophenyl or pyridinyl;
• R.sub.2, R.sub.3 and R.sub.4 are hydrogen, C.sub.1 -C.sub.17 -alkyl, methoxy or ethoxy, or one or two of the radicals R.sup.2, R.sup.3 and R.sup.4 are chlorine or bromine;
• and R.sup.1 is C.sub.1 -C.sub.12 -alkyl, C.sub.3 -C.sub.8 -cycloalkyl or ##STR21## wherein R.sup.5, R.sup.6 and R.sup.7 are hydrogen, C.sub.1 -C.sub.4 -alkyl or a methoxy group.