Abstract: The present invention is concerned with an emulsion copolymer latex comprising an acrylic/methacrylic copolymer obtainable by the emulsion copolymerisation of the following monomer components: A: from 75% weight to 97.5% by weight, based on the total weight of monomer components A+B+C+D, of methyl acrylate; B: from 0.1% to 15% by weight, based on the total weight of monomer components A+B+C+D, of at least one ethylenically unsaturated carboxylic acid monomer containing one C?C double bond capable of free radical copolymerisation with component A and at least one carboxylic acid (CO2H) group; C: from 1% to 20% by weight based on the total weight of monomer components A+B+C+D of at least one associative monomer being a (meth)acrylate ester of an alkoxylated alcohol; and D: from 0% to 15% by weight of one or more non-ionic ethylenically unsaturated monomers other than those defined above as A, B or C; wherein the total monomer components A+B+C+D together add up to 100%.