Polymer dispersion for use e.g. in oil extraction, comprises a copolymer of N-vinyl-amide or nitrogen heterocycle with unsaturated sulfonic acid and optionally other comonomers, dispersed in (poly)alkylene glycol

摘要

Dispersions (A) comprising (a) alkylene glycol, polyalkylene glycol, alkylene glycol ether and/or polyalkylene glycol ether and (b) dispersed particles of copolymers derived from (i) N-vinyl-amides of carboxylic acids or nitrogen heterocycles, (ii) unsaturated sulfonic acids and optionally (iii) unsaturated phosphonic acids, (iv) unsaturated carboxylic acids, (v) unsaturated carboxylic acid amides other than N-vinyl-amides and/or (vi) up to 20 wt% other comonomers (based on total monomers). Independent claims are included for (1) graft copolymers (B) derived from polyalkylene glycols (PAG) or polyesters with PAG units, grafted with monomers (i) and (ii) and optionally (iii)-(vi) as above (2) a method for the production of (A) by making copolymers (b) by known precipitation polymerisation of a monomer solution, isolating the copolymers and mixing them with a dispersion medium (a) which may also contain other miscible liquids (3) a method for the production of (A) by dissolving the monomers for (b) in component (a) or in a mixture of (a) and other suitable solvents, then polymerising the mixture and optionally removing the other solvents .