摘要 |
Nickel and/or zinc contamination can be handled by increasing the bath's level of tolerance to nickel and zinc, thereby eliminating the need to use precipitants. The instant invention relates to the use in a trivalent chromium bath contaminated with zinc and/or nickel, or an effective amount of a compound represented by the formula R-S, where S is selected from the group consisting of sulfinates, sulfonates, and the acids and soluble salts thereof, and R is either an aliphatic group having from 1 to 6 carbons, or an aromatic or heterocyclic group having up to 12 carbons. Preferably R is an unsaturated hydrocarbon and contains carbon to carbon unsaturation alpha or beta to the sulfur atom.
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