Patent ID: 8324322

Claim:
A polymer composition comprising 1) a polymer (P1) comprising at least 50% by weight of monomeric units derived from an ethylenically unsaturated monomer (M1), and 2) at least one co-oligomer (O1) comprising at least: a) a component (A) comprising at least one monomeric unit identical to that derived from the monomer (M1) on which the polymer (P1) is based, and b) a component (B) comprising at least one monomeric unit (m2), derived from an ethylenically unsaturated monomer, carrying at least one phosphonate group —PO(OH)(OR 1 ) with R 1 being a hydrogen atom or an alkyl radical containing from 1 to 11 carbon atoms, wherein the number-average molar mass of polymer (P1) is greater than 30,000 and the number-average molar mass of co-oligomer (O1) is less than or equal to 30,000.