| 摘要 |
PROBLEM TO BE SOLVED: To obtain a cement dispersant excellent in water-reducing performance and slump retaining performance, controlling air entraining property by slight addition and capable of stably imparting prescribed strength by using a polymer of a monomer compsn. contg. at least a specified oxyacrylic acid monomer. SOLUTION: This cement dispersant is based on a polymer having structural units represented by formula I [where each of R1 and R2 is H or an org. residue, R3 is H or a counter ion, (n) is an integer of 1-3 and (m) is the average mol number of added oxyalkylene groups and is an integer of 1-100]. In the polymer, parts derived from a cyclic ether compd., that is, the repetitive structure of oxyalkylene groups may be block-or random-bonded. The polymer preferably has H or 1-8C alkyl as R1 , H, 1-8C alkyl or phenyl as R2 and H, a mono- or divalent metal, ammonium or org. amine as R3 in the formula I. |
