Cyanide-free alkaline zinc electroplating baths - contg. post-reacted reaction prods. of epihalohydrin with nitrogen cpd.

摘要

Zinc electroplating baths contain a Zn salt, an alkaline cpd an epihalohydrin reaction prod. (I), and conventional additives. Specifically, (I) is a prod. obtd. by reacting (a) the 1:1 reaction prod. of an epihalohydrin with >=1 N cpds. contg. >=2 reactive N atoms, with an equimolar amt. of either (b) the 1:1 reaction prod. of an epihalohydrin with >=1 alcohol and/or carboxylic acids or (c) a pyridine cpd. opt. substd. by 1-3 Me or Et gps. and/or 1-3 COOH gps. or their salts. The baths can be used to produce Zn coatings with a thickness of up to 40 mu which are bright and can be annealed without embrittlement or spalling.