GB1382841A - Electrodeposition - Google Patents

Abstract

1382841 Electro-plating OXY METAL FINISHING (EUROPE) SA 9 March 1972 [19 March 1971] 11137/72 Heading C7B An aqueous alkaline cyanide-free electroplating solution (e.g. for plating with Cu, Ni, Cd, or Co) includes a sulphur-free organic amino compound together with a sulphonate of Formula I or II as set out below:- wherein A is a single bond between N and S or a linear or branched aliphatic radical containing up to 12 carbon atoms, B is a mono- or poly-cyclic aromatic or cycloaliphatic radical containing from 5 to 14 carbon atoms, R 1 and R 2 are radicals, identical or different, selected from hydrogen and alkyl radicals containing from 1 to 6 carbon atoms, n amd m are each equal to 1, 2 or 3 and each of the interrupted lines represents 1, 2 or 3 valency bands. The sulphur-free organic amino compound may be ethylene diamine, diethylene triamine, tetramethyl, ethylenediamine, triethylene tetramine, triethanolamine, propylene diamine, cyclohexylamine or diamino cyclohexane. The may be added free or as salts with Hcl, H 2 SO 4 , H 3 PO 4 or AcOH. The compound of Formula I may be sulphamic acid of taurine. The compound of Formula II may be sulphanilic acid 1-aminobenzene- 2-sulphonic acid or 2-naphthylamine-4, 8 di-- sulphonic acid. The metal to be deposited may be included in the solution as sulphate,sulphamate, halide or acetate. Chloride may be incorporated in the bath, e.g. as di- or tri-methyamine hydrochloride or butylamine hydrochloride. Specified conditions are a pH of between 7.01 and 14, a temperature between room temperature and 80‹C and use of D.C. or periodically reversed D.C. with the length of the anodic phase not more than 1/6 that of the cathodic phase and with the amplitude of the anodic phase current equal to or less than that of the cathodic phase current.