Encapsulation process and resulting aqueous dispersion of encapsulated droplets

Claim 1

A process for the encapsulation of oil droplets which comprises the steps of: (a) Forming a dispersion of droplets of the oil in an aqueous alkaline liquid medium containing in solution an alkali metal salt of a polycarboxylate polymer; said alkali metal salt having been prepared by contacting an ethylene/maleic anhydride copolymer with an aqueous solution of an alkali metal hydroxide and an alkylamine or alkenylamine of up to 6 carbon atoms, a cycloalkylamine having 5 or 6 ring carbon atoms, a polyamine of the formula H.sub.2 N(CHRCH.sub.2 NH).sub.n CHRCH.sub.2 NH.sub.2 where R is hydrogen or methyl and n is an integer from 1 to 4; or a diamine of the formula H.sub.2 N(CH.sub.2).sub.m NH.sub.2 where m is an integer from 2 to 8; using a molar ratio of hydroxide to amine of from 3:5 to 5:3 and a combined quantity of hydroxide and amine which is from 80 to 120% of the stoichiometric quantity required for opening of the anhydride rings of the ethylene/maleic anhydride copolymer to form pendant alkali metal carboxylate and carboxylic amide groups; and (b) Acidifying the aqueous liquid medium to a pH in the range 5 to 8 while maintaining the droplets in dispersion, whereby polycarboxylate polymer is precipitated to form walls around the droplets.