CEMENT DISPERSING AGENT

摘要

PROBLEM TO BE SOLVED: To provide a cement dispersing agent consisting of a water-soluble vinyl copolymer and having excellent performance by producing a high quality polyether-ester monomer in the absence of solvent and using the high quality polyether-ester monomer thus produced as an intermediate raw material. SOLUTION: One-terminal substituted polyalkyleneglycol subjected to refining treatment so that the concentration of residual free acid is controlled to≤0.03 wt.% expressed in terms of acetic acid and unsaturated carboxylic acid are subjected to esterifying reaction under the specified condition allowing p-benzoquinone and/or phenothiazine of prescribed quantity to exist in the absence of solvent to produce a polyether-ester monomer. The polyether-ester monomer is used as an intermediate raw material at the time when a water-soluble vinyl copolymer utilized as a cement dispersing agent is produced. COPYRIGHT: (C)2005,JPO&NCIPI