GB284786A - - Google Patents

Abstract

284,786. Warren, A. I. G., and Precious Metal Industries, Ltd. Nov. 5, 1926. Gilding and silvering. - Metallic surfaces are produced on non-metallic substances, such as wood, bone, ivory, phenol formaldehyde condensation products, casein products, tortoiseshell, mother of pearl, bituminous compounds, celluloid and other cellulose products, and vulcanized fibre, by causing a readily-reducible salt of the metal to penetrate the surface of the non-metallic body, and then subjecting the body to heat and pressure in the presence of steam. Substances such as bone, ivory, hom, condensation products, tortoiseshell, mother of pearl, and wood are given a preliminary treatment with a solvent, such as acetic acid, in order to open their pores. Substances having greater surface porosity, such as casein products, some condensation products, galalith, vulcanized fibre, and cellulose, may be impregnated with a chemically-active reagent, such as sulphur, by treating them, for instance, with carbon bisulphide. The surface is then coated with the metallic salt, which may be an oxide or sulphide of silver or gold in a fine state of division, and formed into a liquid or thin paste with a medium, such as chloroform, spirit of turpentine, benzol, or water. The salt may be applied by spraying, painting, or dipping, and the surface is then treated with steam under pressure. The salt may be reduced to the metallic form during the steam treatment, or a reducing- agent or an electrolytic bath may be used. Specifications 196,063, 278,437, and 280,651 are referred to.