| 摘要 |
PROBLEM TO BE SOLVED: To provided a method for producing a water-soluble polymer by mixing the first water-soluble monomer containing an unsaturated monocarboxylic acid-based monomer with a defoaming agent in the presence of water and subsequently polymerizing the mixture, capable of exhibiting a high water-reducing effect, preventing slump loss, and effectively inhibiting the generation of entrained air. SOLUTION: The first water-soluble monomer mixture of formula I (R1 is H or methyl; R2 is H or a 2-4C oxyalkyl; R3 is H or a 1-22C alkyl) containing an unsaturated monocarboxylic acid-based monomer is mixed with a defoaming agent under a condition that water is contained in an amount of <=50 wt.% based on the first water-soluble monomer. The obtained second monomer mixture is subjected to a polymerization reaction to obtain the water-soluble polymer for a cement additive. The water-soluble monomer mixture comprises 5-98 wt.% of a (alkoxy)polyalkylene glycol mono(meth)acrylate-based monomer, 95-2 wt.% of a (meth)acrylic monomer of formula II and 0-50 wt.% of a monomer capable of being copolymerized with the monomers. |
