Acidic galvanic zinc bath for depositing - lustrous zinc coatings

摘要

Acid bath for the formation of bright zinc coatings, especially at low current densities, contains Zn Cl2 and NH4Cl in an amount of 12-20 g./l. Zn2+ and a weight ratio Zn2+: NH4+ of 1:4 to 1:6, and 2.5 - 10 g./l. of sodium dodecyl ether sulphate. It may optionally contain aliphatic and/or aromatic aldehydes, and/or aromatic ketones, or their addition products, and also 0.1 - 2.0 g./l of polyvinylpyrolidone (mol. wt. 10000). Bright zinc coatings with good ductibility are obtained. The acid bath is more convenient than the cyanide and other alkaline baths.