Patent ID: 6790265
Filing Date: 2004-09-14
Classification: C23C,C25D

Abstract:
An aqueous alkaline zincate solution for electroless deposition of a zincate coating on aluminum or aluminum based alloy surfaces comprising hydroxide ions, zinc ions, nickel and/or cobalt ions, iron ions, copper ions and at least one inhibitor containing one or more nitrogen atoms, one or more sulfur atoms, or both sulfur and nitrogen atoms provided said nitrogen atoms are not present in an aliphatic amine or hydroxylamine, and the inhibitor is selected from the group consisting of nitrogen-containing disulfides; alkali metal thiocyanates; thiocarbamates; nitrogen-containing heterocyclic compounds; mercapto substituted nitrogen-containing heterocyclic compounds, thioacids, thioalcohols, compounds characterized by the formulaR2Nâ€”C(S)Yâ€ƒâ€ƒI wherein each R is independently hydrogen or an alkyl, alkenyl, or aryl group, and Y is XR1, NR2, or N(H)NR2; wherein X is O or S and R1 is hydrogen or an alkali metal; and mixtures thereof.