Thioether sulphonates of nitriles or amides - useful additives to nickel plating baths to give high sulphur corrosion resistant nickel interlayers

摘要

Thioether sulphonates of nitriles or amides of formula (I) are claimed where M = Na, K, NH4 or H, R = 2-4 C alkylene gp., R1 = H, or 1-4 C alkyl gp., R2 = H, aryl or -(CH2-)m-Y where m = 1-2, Y = X or aryl gp., X = -CN or -CO-N(R3)-(R4), R3, R4 = H or 1-4 C alkyl and n = 0-3. (I) are esp. useful as additives to nickel plating baths, e.g. at 0.01-4 g/l., to give composite nickel platings on metals in which the intermediate layer of Ni contains 0.05-0.3% sulphur and the top layer contains 0.02-0.15% sulphur. The resulting platings have excellent corrosion resistance.