AQUEOUS ALKALINE BATH, DEVOID OF CYANIDE, FOR THE DEPOSITION OF ELECTROPLATED ZINC AND ZINC ALLOY COATINGS

摘要

The invention relates to an aqueous alkaline electrolyte bath, devoid of cyanide, for depositing zinc and zinc alloy coatings on substrate surfaces. Said bath comprises: (a) a zinc ion source and optionally a source for additional metal ions; (b) hydroxide ions; (c) a polymer of general formula (I) that can be dissolved in the bath; and (d) at least one pyridinium compound of general formula (Il) or (III). The electrolyte bath is suitable for the deposition of glossy, uniform zinc and zinc alloy coatings.