METHOD OF PRODUCING POLYETHERESTER MONOMER AND CEMENT DISPERSANTS

摘要

Polyetherester monomer of the kind (see formula I) where R1, R2 and R3 are each a group of a specified kind and A is a residual group of another specified kind is produced by an esterification reaction of polyalkyleneglycol with a closed end and unsaturated carboxylic acid, each o f a specified kind, by using an acid catalyst under a heated and reduced-pressur e condition in the absence of solvents and in the presence of a specified amou nt of p-benzoquinone and/or phenothiazine. Cement dispersants with improved properties are obtained from water-soluble vinyl monomers produced by using the polyetherester monomer thus obtained as intermediate product.