DYNAMIC COPOLYMERS FOR PRESERVATION OF PLACEABILITY OF CEMENT COMPOSITIONS Russian patent published in 2014 - IPC C04B24/26 C04B28/02 C08F216/14 C08F220/26 C08F222/06 C04B103/30 

FIELD: chemistry.

SUBSTANCE: invention relates to method of obtaining cement compositions, holding sagging or holding sagging with high early strength. Method includes mixing hydraulic cement, filling agent, water and sagging-holding additive, which represent dynamic polycarboxilate copolymer. Copolymer contains residues of, at least, the following monomers: A) unsaturated dicarboxylic acid, B) at least, one ethylene-unsaturated alkenyl ether, which has C_2-4 oxyalkylene chain with from 1 to 25 links, C) at least, one ethylene-unsaturated alkenyl ether, which has C_2-4 oxyalkylene chain with from 26 to 300 links, D) ethylene-unsaturated monomer, which contains part, hydrolysed in cement composition, in which residue of ethylene-unsaturated monomer, when hydrolysed, contains active binding site. Ratio of component A acid monomer to alkenyl ethers of component B and component C(A):(B+C) constitutes from1:2 to 2:1. Ratio of acid monomer of component A to ethylene-unsaturated monomer of component D, which contains hydrolysed part, constitutes from 16:1 to 1:16.

EFFECT: invention makes it possible to preserve placeability of composition for a long period of time and increase compression strength.

30 cl, 5 dwg, 8 tbl, 29 ex