Patent ID: 8536251

Claim:
A copolymer comprising: i) 3 to 40 mol % of an isoprenolpolyether derivative structural unit α ii) 3 to 40 mol % of a vinyloxypolyether derivative structural unit β and iii) 35 to 93 mol % of an acid structural unit γ, the isoprenolpolyether derivative structural unit α being represented by the following general formula (Ia) where A are identical or different and are represented by an alkylene group according to C x H 2x where x=2, 3, 4 or 5, and a are identical or different and are represented by an integer between 4 and 300, the vinyloxypolyether derivative structural unit β being represented by the following general formula (Ib) where R A are identical or different and are represented by a hydrogen atom, a linear C 1 -C 12 alkyl group or branched C 3 -C 12 alkyl group, C 5 -C 8 cycloalkyl group, phenyl group or C 7 -C 12 arylalkyl group, A are identical or different and are represented by an alkylene group according to C x H 2x where x=2, 3, 4 or 5, and b are identical or different and are represented by an integer from 6 to 450, the arithmetic mean of the alkylene groups A of the structural units which belong to the vinyloxypolyether derivative structural unit β being higher by at least the factor 1.5 than the arithmetic mean of the alkylene groups A of the structural units which belong to the isoprenolpolyether derivative structural unit α.