POLYALKYLENE GLYCOL-BASED BLOCK COPOLYMER FOR CEMENT ADMIXTURE, POLYALKYLENE GLYCOL-BASED BLOCK COPOLYMER, DISPERSANT, CEMENT ADMIXTURE AND CEMENT COMPOSITION

摘要

PROBLEM TO BE SOLVED: To provide a copolymer capable of exhibiting water-reducing property, workability and the like in a cement composition and the like at high level, and having a simple molecular structure.SOLUTION: A polyalkylene glycol-based block copolymer for cement admixture has an essential structure in which a polymer chain by unsaturated carboxylic acid-based monomer units (A) and a polymer chain by polyalkylene glycol-based constitutional units (B) are bound through a binding site (X) and in which the polymer chain (A) and the polymer chain (B) are bound in an order of the polymer chain (A), the polymer chain (B), and the polymer chain (A) through the binding site (X), and an average addition molar number of an oxyalkylene group of the polyalkylene glycol-based constitutional units in the polymer chain (B) is 25 or more.