Polycarboxylic acid copolymer, cement dispersant, cement admixture, and cement composition

摘要

The present invention aims to provide a polycarboxylic acid copolymer which is excellent in various properties, in particular dispersibility, and is useful in various uses such as dispersants and admixtures for cement. The present invention also aims to provide a dispersant for cement, an admixture for cement, and a cement composition each containing the above polycarboxylic acid copolymer. The polycarboxylic acid copolymer of the present invention includes a structural unit (I) derived from an unsaturated polyalkylene glycol monomer (a) and a structural unit (II) derived from an unsaturated carboxylic acid monomer (b). The copolymer has a weight average molecular weight (Mw) of 5000 to 25000. The copolymer includes a dimer including two units of the unsaturated polyalkylene glycol monomer (a) bonded to each other, and has an area percentage of the dimer of 7% or higher.