Additive mixt. for gold (alloy) electroplating bath - contains organic nitro cpd. and arsenic, antimony, bismuth, thallium or selenium cpd.

摘要

Additive mixt. for Au(alloy) electroplating bath contains organic water-soluble nitro cpd(s). (I) of the formula R(NO2) n (where n = 1-4; R is a 1-15C alkyl, aryl or heterocyclic gp., opt. substd by a gp. contg. C,H,O,N, and/or S) and water-soluble As, Sb, Bi, Tl or Se cpd(s). (II). The addn. of Tl sulphate and Na trinitrobenzenesulphonate to an acid Au cyanide bath gave homogeneous fine-grained pure Au plating of silky lustre and allowed high power operation (up to 2.5 A/dm2 instead of under 0.5 A/dm2 without the additives). Used esp. in acid, neutral or alkaline Au cyanide or sulphite baths. The crystal structure, colour, homogeneity, hardness, brightness, density and distribution of the plating on the substrate are modified or improved.