GB767729A - "emulsion paints" - Google Patents

Abstract

An emulsion paint comprises an aqueous dispersion of a copolymer of styrene or vinyl acetate with 1 to 60 per cent of units of an alkyl di-ester of an a ,b -unsaturated dicarboxylic acid, a dispersion stabilizer comprising an organic hydrophilic colloid, and a pigment, said di-ester containing from 14 to 24 carbon atoms. Di-esters specified are those of itaconic, fumaric and maleic acids, e.g. di-(2-ethylhexyl) maleate and di-n-octyl maleate. The copolymers are preferably prepared by aqueous emulsion polymerization using the stabilizer as dispersing agent, e.g. polyvinyl alcohol, partially hydrolysed polyvinyl acetate, starch, arabin gum, gum tragacanth, gum arabic, algae such as agar-agar or that known as "Gomogel," gelatin, methyl, benzyl or hydroxyethyl cellulose, and mixtures. Pigments disclosed are bone and mineral blacks, ultramarine blue, iron oxides, titanium dioxide, and Venetian and Tuscan reds. The dispersion stabilizer may optionally include an anionic surface-active agent, e.g. sodium lauryl sulphate or the sodium salt of sulphated oil or alkyl aryl sulphonic acid. The paint may contain plasticizers such as ethyl and butyl acetates, benzene, toluene, and diethyl and dibutyl phthalates. The examples further describe emulsion polymerization wherein the monomers and catalyst (e.g. ammonium persulphate) are added concurrently to the aqueous medium, the neutralization of the resultant emulsion, the use of fatty alcohol-ethylene glycol condensate as additional stabilizer and of sodium hexametaphosphate as sequestering agent.