Patent ID: 7001528

Claim:
A filter material treatment process comprising: resinating a filter material with an aqueous polymer dispersion comprising dispersed particles of at least one polymer A1 obtained by free-radical emulsion polymerization in the presence of a polymer A2 to form a resinated filter material, and curing the resinated filter material; wherein the polymer A2 comprises: (i) polymerized units of from 50 to 99.5% by weight of at least one of an ethylenically unsaturated monocarboxylic acid and an ethylenically unsaturated dicarboxylic acid, (ii) from 0.5 to 50% by weight of at least one ethylenically unsaturated compound having an amine containing at least one hydroxyl group selected from the group consisting of an ester of an ethylenically unsaturated monocarboxylic acid, a monoester of an ethylenically unsaturated dicarboxylic acid, and a diester of an ethylenically unsaturated dicarboxylic acid, and (iii) up to 20% by weight of at least one further monomer.