Patent ID: 8299192

Claim:
A suspension comprising an aqueous suspension of solids and a CCT dispersant comprising random comb polymers obtained by free-radical copolymerization according to catalytic chain transfer (CCT) method of a vinylic poly(alkylene oxide) compound (A) of the general formula (I) R 1 —O C m H 2m O n-1 —C m H 2m —Z (I) where R 1 =hydrogen, a C 1 -C 20 -alkyl radical, a cycloaliphatic C 5 -C 12 -cycloalkyl radical, a substituted or unsubstituted C 6 -C 14 -aryl radical, m=2 to 4, n=1 to 250, Y═O or NR 2 , R 2 =hydrogen, a C 1-12 -alkyl radical, a C 6 -C 14 -aryl radical, —C m H 2m O—C m H 2m n-1 OR 1 , m′=1 to 4 and n′=0 to 2, with an ethylenically unsaturated monomer compound (B) of the general formula (II), where R 3 ═H, CH 3 , COOH or a salt thereof, COOR 7 or CONR 7 R 7 , R 4 ═H, a substituted or unsubstituted C 6 -C 14 -aryl radical, R 5 ═H, CH 3 , COOH or a salt thereof, COOR 7 , CONR 7 R 7 , a substituted or unsubstituted aryl radical or OR 8 , PO 3 H 2 , SO 3 H, CONH—R 9 , R 6 ═H, CH 3 or CH 3 COOR 7 , R 7 ═H, C 1 -C 12 -alkyl, C 1 -C 12 -hydroxyalkyl, C 1 -C 12 -alkylphosphate or -phosphonate or a salt thereof, C 1 -C 12 -alkylsulfate or -sulfonate or a salt thereof, C m H 2m O—C m H 2m n-1 OR 1 , R 8 =acetyl and R 9 ═C 1 -C 12 -alkylphosphate or -phosphonate or a salt thereof, C 1 -C 12 -alkylsulfate or -sulfonate or a salt thereof, R 3 and R 5 together optionally form —O—CO—O—, the CCT dispersant is in an amount effective for providing the suspension with better water reduction capacity than with a non-CCT dispersant used in the same amount and the CCT dispersant is a comb polymer having the same monomers as the non-CCT dispersant which is not obtained by a CCT method.