Alkaline cyanide bath for electrodeposition of copper-tin alloy coating with ground color or gloss

摘要

There is provided a bath composition for the electrolytic deposition of copper-tin alloy coatings which contain besides the customary components (copper cyanide, stannate, complex former, free cyanide, and hydroxide) at least one organic material from at least one of the following groups: (a) fatty acid amidoalkyl dialkylamine oxides of the general formula R1CO-NH(CH2)n-N(R2)2-0, wherein R1 is an alkyl group having 11 to 17 carbon atoms, R2 is an alkyl group having 1 to 5 carbon atoms, and n is 1-30 (b) fatty acid amidoalkyl-dialkylamine betaines of the general formula R1CO-NH(CH2)n-(+)N(R2)2-CH2-COO(-), wherein R1 is an alkyl group having 11 to 17 carbon atoms, R2 is an alkyl group having 1 to 5 carbon atoms, and n is 1-30, and (c) ethoxylated naphthols of the general formula IMAGE wherein R3 is H or O(CH2-CH2O)mH, R4 is O(CH2CH2O)mH or H m=10 to 14, e.g., 10, 12, or 14 in an amount of 0.05 to 5 g/l.