GB409334A - Improvements in or relating to coloured and protective coatings - Google Patents

Abstract

Pigments which are rust inhibitors consist of a finely divided alloy, or a finely divided mixture, of metallic aluminium and elemental silicon. To the powdered alloy may be added powdered aluminium or silicon or compounds of these with oxygen or carbon. Preparation of the alloy may be effected by melting the two elements together in the desired proportions or by smelting alumina and silica with carbon. The silicon content should not be less than 5 per cent and may be 20 to 60, or the eutectic alloy containing 13 per cent of silicon may be employed. In an example, very finely ground aluminium and silicon are mixed with boiled linseed oil as a vehicle in the proportions 186, 64 and 750 parts by weight respectively. In a second example, 500 to 600 parts of an alloy containing 32 per cent of aluminium and 53 of silicon, the remainder being oxygen and other compounds of these two constituents, are mixed with 500 to 400 of boiled linseed oil to which a small quantity of copal is added.