POWDERY WATER-REDUCING AGENT FOR PREMIXED CEMENT AND METHOD FOR PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a powdery water-reducing agent for premixed mortar, having a high proportion of water-reducing agent in the powder and having an excellent water reduction property and fluidity retention property and to obtain the powdery water-reducing agent by spray drying.SOLUTION: There is provided a powdery water-reducing agent for premixed mortar which contains: (a) a copolymer which has a neutralization degree of 90% or more and a composition of (i) 50 to 99 mass% of a monomer represented by the formula (1), (ii) 1 to 50 mass% of a constitutional unit based on maleic acid represented by the formula (2) and (iii) 0.1 to 5 mass% of a monomer represented by the formula (3); and (b) one or more kinds of inorganic powder selected from silica and lime powder in the mass ratio of (a):(b)=96:4 to 99:1.