CEMENT ADMIXTURE, PRODUCTION THEREOF, AND CEMENT COMPOSITION

摘要

A cement admixt. comprises a crosslinked polymer, wherein a linkage having a structural unit comprising divalent gp(s) of formula (I) is formed between main chains each having a structure of a water-soluble polymer with a mol.wt. of 500-100,000. -R1-C(=O)-O-R2- (I) R1,R2 = -CH2-, -C(R)H- (II) -CRR1- or -CH2-CH(OH)- (i) wherein R2 = (i), R1 may be absent; and R, R1 = 1-5C alkyl, Also claimed are (A) the prepns. of the admixt. by (A) polymerising the water soluble polymer contg. structural unit (I) with a crosslinking agent; or (A'') polymerising monomers contg. at least 2 polymerisable double bonds and divalent gps. (I) between the double bonds with comonomer(s) capable of forming a main chain as mentioned above, the comonomer comprising at least one polymerisable double bond; and (B) cement compsn. comprising the admixt., cement and H2O.