GB765408A - Emulsion paints - Google Patents

Abstract

Emulsion paints comprise (1) an aqueous protein solution, and (2) a disperse phase comprising a liquid butadiene-1,3 polymer. Pigments, e.g. lithopone, titanium dioxide, cadmium sulphide and sulphoselenide, iron oxide and ultramarine, and inert fillers may be dispersed in the protein solution together with an amine-fatty acid soap, to which is added the polymer, paint driers, e.g. cobalt, manganese or lead naphthenates, and a fatty acid, e.g. oleic, linoleic, stearic or palmitic. The protein, e.g. casein or the alpha protein from soybeans, may be solubilized by borax, soluble phosphates or silicates, alkali or ammonium hydroxides, sodium stannate or preferably amines, e.g. triethanolamine. The butadiene polymer or copolymer with styrene or isoprene, 2,3-dimethyl butadiene-1,3, piperylene, 2-methyl pentadiene-1,3 or methyl, dimethyl, ethyl or diethyl styrenes may be prepared by polymerization in an inert hydrocarbon diluent, e.g. naphtha, mineral spirits, butane, xylene, benzene, toluene or cyclohexane, in the presence of sodium, potassium, sodium hydride or a sodium alloy. Ethereal codiluents, e.g. diethyl ether, di-isopropyl ether, dioxane, vinyl ethyl ether, vinyl isopropyl ether, vinyl isobutyl ether, anisole or phenetole, and modifying diluents, e.g. butene-2, may be added. The comonomer is preferably added after the polymerization of the diene has commenced. Aliphatic alcohols containing 1 to 5 carbon atoms are added as promoters, and when the polymerization is complete the catalyst is removed by adding excess alcohol, filtering and fractionally distilling the alcohol-hydrocarbon and ether-hydrocarbon azeotropes and excess diluent to leave a clear varnish to which resins, e.g. alkyd or phenolic resins, may be added.