Patent ID: 7960455

Claim:
A composition comprising: (1) a copolymer comprising alkylene oxide repeat units, wherein the copolymer comprises incorporated randomly or blockwise by polymerization: (a) 50-93 mol % of acrylic acid and/or a water-soluble salt of acrylic acid; (b) 5-30 mol % of methacrylic acid and/or a water-soluble salt of methacrylic acid; and (c) 2-20 mol % of at least one nonionic monomer of the formula I: wherein R 1 is hydrogen or methyl, R 2 is a chemical bond or an unbranched or branched C 1 -C 6 -alkylene, R 3 is an identical or different, unbranched or branched C 2 -C 4 -alkylene, R 4 is an unbranched or branched C 1 -C 6 -alkyl, and n an integer of 3-50; and (2) one or more phosphonates selected from the group consisting of 1-hydroxyethane- 1,1-diphosphonic acid, 2-phosphonobutane-1,2,4-tri-carboxylic acid, aminotrimethylenephosphonic acid, ethylenediaminetetramethylene phosphonate, hexamethylenediaminetetramethylene phosphonate and diethylenetriaminepentamethylene phosphonate.