AQUEOUS, ALKALINE, CYANIDE-FREE BATH FOR ELECTRODEPOSITING ZINC AND ZINC ALLOY COATINGS

摘要

The invention relates to aqueous, alkali, cyanide-free baths containing: I) a zinc ion source and, optionally, a source for additional metal ions; II) at least one cationic polycondensation product that can be obtained by the condensation of i) non-cyclic amine (A1), produced by reacting mono(N,N-dialkylaminoalkyl)amine (A1a) with a bifunctional compound (A1b), selected from the group consisting of urea, thio urea, dialkyl carbonates, aliphatic and aromatic dicarboxylic acids and aliphatic and aromatic diisocyanates with a molar ratio of (A1a) to (A1b) ranging from 1.2: 1 to 2.1: 1 or; ii) of a mixture (A2) consisting of at least one non-cyclic amine (A1) and of at least one cyclic amine (A3) with a molar ratio (A1) to (A3) ranging from 10:1 to 1:10 with at least one bifunctional compound (B) selected from the group consisting of halomethyloxiranes and bisepoxides and, provided that at least one cyclic amine (A3) is condensed, with the alkylene dihalogenide and dihalogen alkylether having a molar ratio (B) to (A1) or (B) to (A2) ranging from 0.6: 1 to 1.3: 1.