Patent ID: 8512684

Claim:
A process for the preparation of a composition comprising an oil phase, an aqueous phase, at least one emulsifying system of water-in-oil (W/O) type in the form of an inverse latex comprising from 20% to 70% by weight of a branched or crosslinked polyelectrolyte, wherein the said polyelectrolyte is a copolymer of 2-acrylamido-2-methylpropanesulfonic acid partially or totally salified with acrylamide, said preparation process being an inversed emulsion polymerization process wherein the polymerization of the monomers is conducted in a water-in oil emulsion, said process comprising: mixing a powder of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic in acid form with an aqueous solution of acrylamide to form an aqueous solution; progressively neutralizing said aqueous solution by an aqueous alkalinized solution to form a neutralized aqueous solution; and adjusting the pH of said neutralized solution to about 6 with additional powder of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic in acid form and water to form the aqueous phase, which is involved in the subsequent inversed emulsion polymerization by weight; wherein the polyelectrolyte comprises between 60 mol % and 20 mol % of partially or totally salified 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid monomer and between 40 mol % and 80 mol % of acrylamide monomer.