Statistic comb polymers, method for producing the same and their use

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)

• R1—OCmH2mOn-1—CmH2m—Z (I)
• where
• R1=hydrogen, a C1-C20-alkyl radical, a cycloaliphatic C5-C12-cycloalkyl radical, a substituted or unsubstituted C6-C14-aryl radical,
• m=2 to 4,
• n=1 to 250,
• Y═O or NR2,
• R2=hydrogen, a C1-12-alkyl radical, a C6-C14-aryl radical, —CmH2mO—CmH2mn-1OR1,
• m′=1 to 4 and
• n′=0 to 2,
• with an ethylenically unsaturated monomer compound (B) of the general formula (II),
• where
• R3═H, CH3, COOH or a salt thereof, COOR7 or CONR7R7,
• R4═H, a substituted or unsubstituted C6-C14-aryl radical,
• R5═H, CH3, COOH or a salt thereof, COOR7, CONR7R7, a substituted or unsubstituted aryl radical or OR8, PO3H2, SO3H, CONH—R9,
• R6═H, CH3 or CH3COOR7,
• R7═H, C1-C12-alkyl, C1-C12-hydroxyalkyl, C1-C12-alkylphosphate or -phosphonate or a salt thereof, C1-C12-alkylsulfate or -sulfonate or a salt thereof, CmH2mO—CmH2mn-1OR1,
• R8=acetyl and
• R9═C1-C12-alkylphosphate or -phosphonate or a salt thereof, C1-C12-alkylsulfate or -sulfonate or a salt thereof,
• R3 and R5 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.