| 摘要 |
PROBLEM TO BE SOLVED: To provide a powdery cement dispersant which can be mixed into a premix product beforehand and which is excellent in fluidity and fluidity retention properties. SOLUTION: This powdery dispersant contains an inorganic powder and a powder consisting of a multivalent metal salt of a copolymer, wherein the copolymer has a weight average molecular weight of 5,000-100,000 and is formed by copolymerizing: (A) 3-25 mol% a monomer represented by the general formula (1) CH2=C(R1)COO(R2O)nR3 (wherein: R1 is a hydrogen atom or methyl group; R2O is a 2-4C oxyalkylene group; n is an integer of 5-40; and R3 is a hydrogen atom or 1-5C alkyl group); (B) 55-75 mol% methacrylic acid or its salt; (C) 5-35 mol% a monomer represented by the general formula (2) CH2=C(R4)COOR5 [wherein: R4 is a hydrogen atom or methyl group; and R5 is a 1-5C alkyl group optionally subtituted by a hydroxyl group, or (R6O)mH (wherein: R6O is a 2-3C oxyalkylene group; and m is an integer of 1-3)]; and (D) 0-10 mol% of another monomer (s). |
