GB580258A - Coating compositions - Google Patents

Abstract

An ammonium iron phosphate preferably containing not less than seven per cent. ammonia and not more than ten per cent. ferric iron is used as an anti-corrosive pigment in coating compositions. Other pigments, e.g., zinc yellow, zinc oxide, zinc sulphide, lithopone, chrome orange, chrome yellow, titanium oxide, may be incorporated, the ammonium iron phosphate forming preferably 5-30 per cent. of the total pigment content. The pigments may be incorporated with oil type binders, e.g., treated or untreated drying oils or their derivatives; oleoresinous vehicles, e.g., linseed oil, chinawood oil, oiticica oil etc.; varnishes, resins, emulsions and water-soluble binders; synthetic resins, chlorinated rubber, and cellulose derivatives [see Group IV]-together with the usual thinners and driers. Examples show the preparation of the pigment as a green insoluble precipitate by mixing, warming, and stirring in solution ferrous salts wth disodium phosphate and ammonia, or diammonium phosphate and caustic soda, under controlled pH conditions in the presence of an anti-oxidant. The Specification as open to inspection under Section 91 comprises also the preparation of ammonium iron phosphate by bringing together the three component ions in any suitable manner. This subject matter does not appear in the Specification as accepted.ALSO:An ammonium iron phosphate preferably containing not less than 7 per cent ammonia and not more than 10 per cent ferric iron is used as an anticorrosive pigment in coating compositions. Other pigments, e.g. zinc yellow, zinc oxide, zinc sulphide, lithopone, chrome orange, chrome yellow, titanium oxide, may be incorporated, the ammonium iron phosphate forming preferably 5-30 per cent of the total pigment content. The pigments may be incorporated with synthetic resins, e.g. phenolformaldehyde, vinyl acetate, "Vinylite," (Registered Trade Mark), alkyd and alkyd fortified oleoresins, oil-modified polyhydric alcohol-polybasic acid resins, or polyhydric alcohol mixed esters of drying oil and other monofunctional, monocarboxylic acids such as b - furyl acrylic, d - 2 : 4 - hexadienoic, a -vinyl cinnamic or methacrylic acids; chlorinated rubber; nitrocellulose and cellulose derivatives; together with the usual thinners and driers.