Use of block copolymers as dispersants for aqueous suspensions of solids

A method of superplasticizing aqueous suspensions of solids, the method comprising:

• blending block copolymers with an aqueous suspension of solids to superplasticize the suspension of solids, the suspension of solids including hydraulic binders which include materials selected from the group consisting of cement, lime, gypsum, anhydrite and mixtures thereof,
• wherein the block copolymers are prepared by reacting a poly(alkylene oxide) compound of the general formula (I)
• in which
• R1=hydrogen, a C1—C20-alkyl radical, a cycloaliphatic C5—C12-cycloalkyl radical, an optionally substituted C6—C14-aryl radical;
• m=2 to 4;
• n=1 to 250;
• and Z is selected from the group of formulas III, IV, and V
• where Y=0 or NR2
• R2=H, a C1—C12-alkyl radical, a C6—C14-aryl radical, or
• X=Cl or Br
• m′=1 to 4
• n′=0 to 2,
• where
• R3=an optionally substituted C6—C14-arylene radical
• X=Cl or Br,
• in which
• R4 is H, a C1—C12 alkyl radical, a C5—C8-cycloalkyl radical, a C6—C14-aryl radical, optionally substituted by hydroxyl, carboxyl or sulfo groups, or
• and R5 is C1—C12 alkyl, C6—C14-aryl, or
• and R1, R2,m and n have the abovementioned meaning, with an ethylenically unsaturated monomer compound of the general formula (II) in a free radical, anionic or cationic polymerization
• in which
• R6 and R7 may be H, CH3,COOH or salts thereof, COOR10, CONR10R10
• R6 and R9 together may be O—CO—O
• R8 may be H, CH3 or —CH2—COOR10
• R10 may be COOR10,an optionally substituted C6—C14-aryl radical or OR11
• R10 may be H, C1—C12-alkyl, C1—C12-hydroxyalkyl,
• R11 may be acetyl, and
• R1, m and n have the abovementioned meaning.