| 摘要 |
<p>An additive for cement comprising, as the effective component, a copolymer of a polyoxyalkylene derivative represented by following formula (1) and maleic anhydride, a hydrolyzed product of the copolymer, or a salt of the hydrolyzed product; <CHEM> wherein B represents a residue of a compound having from 2 to 8 hydroxy groups AO represents an oxyalkylene group having from 2 to 18 carbon atoms; X represents an unsaturated hydrocarbon group having from 2 to 5 carbon atoms or an unsaturated acyl group having from 2 to 5 carbon atoms; R represents hydrocarbon group having from 1 to 40 carbon atoms; a represents 0 to 1,000; b represents 0 to 1,000; c represents 0 to 1,000; l represents 1 to 7, m represents 0 to 2; and n represents 1 to 7; l + m + n = 2 to 8, m/( l + n) </= 1/2, and a l + bm + cn >/= 1.</p> |
