COPOLYMER IMPURITY SYSTEM FOR PRESERVING WORKABILITY OF CEMENT COMPOSITIONS Russian patent published in 2014 - IPC C04B24/26 C04B26/02 C08F220/18 C08F220/26 C08F283/06 C08F290/06 

FIELD: chemistry.

SUBSTANCE: invention relates to versions of a nonionic copolymer of a polyether and a polyester used in a cement composition for prolonging workability and to versions of a cement composition. The nonionic copolymer contains residues of monomers A, B and/or C. Monomer A is at least one ethylenically unsaturated monomer of a carboxylic ester containing a moiety which hydrolyses in a cement mixture, where the hydrolysed monomer residue contains an active binding portion for a component of the cement mixture. Component A is a hydroxyalkyl monoester, a hydroxylalkyl diester or mixtures thereof. Monomer B is at least one ethylenically unsaturated alkylene ether monomer containing at least one C_2-4 oxyalkylene side group consisting of 1-30 links. Monomer C is at least one ethylenically unsaturated alkylene ether monomer containing at least one C_2-4 oxyalkylene side group consisting of 31-350 links. Molar ratio of monomer A to the sum of molar ratios of monomers B and C is equal to 1:1-10:1. The cement composition contains water cement, water and an additive which contains said copolymer.

EFFECT: invention enables to preserve workability of the cement mixture, provides high fluidity, high stability and wear resistance thereof.

39 cl, 10 dwg, 9 tbl, 36 ex