| abstract |
An aqueous acidic plating bath for the electrodeposition of a bright zinc deposit on a substrate is disclosed and comprises zinc ions and an amount, sufficient to provide a level and bright deposit, of at least one bath-soluble composition obtained by the reaction of a nitrogen-containing heterocyclic compound with formaldehyde, an epihalohydrin or glycerol halohydrin and at least one amino compound selected from the group consisting of (i) ammonia, (ii) an aliphatic amine, or (iii) an amidine. Additionally, the plating baths of the invention may contain a nitrogen-containing compound obtained by the reaction of ammonia, an aliphatic amine containing at least one primary amine group, or mixtures thereof with one or more epihalohydrins, glycerol halohydrins or mixtures thereof. Thioureas and anionic aromatic sulfonic acids or salts thereof also are contemplated as being useful in the plating baths of the invention. Methods for depositing a bright zinc coating over a wide range of current densities also are described. |