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;
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 aℓ + bm + cn ≧ 1.
一种
水泥添加剂,其有效成分包括下式(1)所代表的聚氧亚烷基衍
生物与
马来酸酐的共聚物、共聚物的
水解产物或
水解产物的盐;
其中 B 代表具有 2 至 8 个羟基的化合物残基 AO 代表具有 2 至 18 个碳原子的氧亚烷基; X 代表具有 2 至 5 个碳原子的不饱和烃基或具有 2 至 5 个碳原子的不饱和酰基;R 代表具有 1 至 40 个碳原子的烃基;a 代表 0 至 1,000;b 代表 0 至 1,000;c 代表 0 至 1,000;ℓ 代表 1 至 7,m 代表 0 至 2;n 代表 1 至 7;ℓ + m + n = 2 至 8,m/(ℓ + n) ≦ 1/2,且 aℓ + bm + cn ≧ 1。