Improvements in or relating to protecting metals against the corrosive action of alkaline liquids

摘要

Alkali-sensitive metals and alloys are protected against alkaline cleansing-compositions, by adding cobalt amines or the components which form them, preferably those which are stable to boiling, such as dichloro-diethylene-diamino-cobaltic salts. Examples of such cleansing compositions are (1) trisodium phosphate, sodium metasilicate, and dichloro-diethylene-diamino-cobaltic nitrate, suitable for cleaning tinplate, (2) sodium carbonate, ethylene-diamino-monohydrate and cobaltous chloride, (3) sodium metasilicate and dichloro-diethylene-diamino cobaltic chloride, (4) sodium metasilicate, trisodium phosphate, sodium tetra-hydro-naphthalene sulphonate and dichloro-diethylene-diamino-cobaltic chloride.