GB927517A - Coating compositions based on aqueous dispersions of synthetic resins - Google Patents

Abstract

Aqueous dispersions of synthetic resins suitable for use as coating compositions contain a methyl-polysiloxane oil and/or a silicone grease dispersed in one or more solvents capable of dissolving the synthetic resin binding agent. The proportion of methyl-polysiloxane oil and/or silicone grease (methyl-polysiloxane oil adsorbed on silicic acid) is preferably from 0,1 to 2% calculated on the weight of binding agent. The synthetic resin may be polyvinyl acetate, propionate or butyrate, a copolymer of vinyl acetate, propionate, butyrate or stearate with one another or with an ester of acrylic, methacrylic, maleic or fumaric acid with an aliphatic, saturated monohydric alcohol having 1 to 8 carbon atoms or with vinyl chloride, a polyacrylate or polymethacrylate, polyvinlyidene chloride, a copolymer of styrene and butadiene or an alkyd resin. The solvent may be butyl acetate, methoxy-butyl acetate, glycollic acid butyl ester, toluene, methylene chloride, methyl isobutyl ketone or butanol. Coatings with an orange peel effect may be produced by using a dispersion containing 3%, calculated on the weight of the binding agent, of silicone grease, by incorporating a flow agent such as an alkali metal polyacrylate or polymethacrylate, the ammonium salt of a copolymer of vinyl acetate and crotonic acid in the ratio by weight of 95:5, or a 2% solution of methyl cellulose. Special effects may also be produced by including ingredients such as metal powders, e.g. aluminium, copper, copper/nickel or copper/zinc alloys, organic dyestuffs, pigments such as manganese black, iron oxide, titanium dioxide, chromium oxide or ultramarine blue, guanine crystals, hexagonal lead crystals, mica, magnesium silicate or calcium magnesium carbonate. The dispersions may also contain emulsifiers such as polyvinyl alcohol, alkyl sulphonates, hydroxyethyl cellulose or hydroxyethyl starch. Specification 871,254 is referred to.