Dyeing and printing of leather

摘要

Process for dyeing or printing leather with anionic monoazo and/or monoazomethine metal complex dyes, characterised in that, before or after the dye is applied, the leather is treated with a product (P) or a mixture of such products (P) or an acid adduct thereof, and the product (P) is a polymer obtainable by reaction of (A) a monofunction or polyfunctional amine with one or more primary and/or secondary and/or tertiary amino groups with (B) cyanamide, dicyandiamide, guanidine or biguanide, up to 50 mol per cent of cyanamide, dicyandiamide, guanidine or biguanide being replaceable by a dicarboxylic acid or a mono- or diester thereof, with elimination of ammonia, in the presence or absence of a catalyst K1, and optional further reaction with (C): (C1) an N-methylol derivative of a urea, melamine, guanamine, triazine, urone, urethane or acid amide or (C2) an epihalohydrin or a precursor thereof, and optionally further reaction with (C1), or (C3) formaldehyde or a formaldehyde-releasing compound, and optionally further reaction with (C1).