Improvement in acid zinc electroplating and electrolyte therefor

摘要

693,606. Electro-deposition of zinc. POOR & CO. June 3, 1949 [June 19, 1948], No. 18033/51. Divided out of 693,557. Class 41. An acid zinc electro-plating bath comprises zinc sulphate dissolved in an acidic aqueous liquid containing lactic acid and an alkylated naphthalene sulphonate dissolved in the bath. The sulphonate is preferably isopropyl naphthalene sulphonic acid sodium salt. The bath may have a pH value between 1.0 and 5.5, the best range being 2.5 to 4.0. A bright plate is produced by dipping the product into a second bath consisting of nitric acid or other oxidizing acid, for example chromic acid.