GB627817A - Improvements in or relating to electroplating copper - Google Patents

Abstract

A sulphided amine for use as a constituent of an electro-plating bath (see Group XXXVI) may be prepared by mixing a small proportion of sulphur with triethanolamine, followed by agitation and successive heating and cooling of the mixture for several hours. The sulphided amine may also be obtained by reacting toluidine with sulphur, after which triethanolamine is added. The product, after removal of a water layer, is dissolved in diethyleneglycolmonobutylether and agitated with water to form an emulsion. The reactions involved are indicated by the formul shown. The solubility of the amine employed as a starting material in preparing the sulphided amine may be increased by the presence of water-solubilizing groups, for example, hydroxyl, carboxyl and sulphonic groups. Thus anthranilic acid may be used instead of toluidine. In a similar manner, other amino carboxylic acids of the benzine and naphthalene series may be employed. The sulphiding of the amine may be effected with sulphur compounds instead of the sulphur element. The sulphur may be introduced by diazotizing the organic primary amine and treating the resulting compound with a solution of potassium sulphide or sodium sulphide or with hydrogen sulphide (under pressure). Another method involves dissolving the amino compound in a solvent and treating it with ammonium thiocyanate and an oxidizing agent such as bromine. In place of using triethanolamine other alkylolamines may be used such as aminoethylethanolamines, dimethylethanolamines, methylethanolamines, mixed isopropanolamines, monoisopropanolamines, di-isopropanolamine, tri-isopropanolamine, methyldiethanolamine, N-acetylethanolamine, phenylethanolamine, phenyldiethanolamine, cyclohexylethanolamine, trihexanolamine, benzylethanolamine and octylethanolamine.