POWDERY POLYCARBOXYLIC-ACID CEMENT DISPERSANT AND DISPERSANT COMPOSITION CONTAINING THE DISPERSANT

摘要

A powdery polycarboxylic-acid cement dispersant having a polymer backbone comprising a polyamide-polyamine. It has the effect of being capable of improving water amount reduction, slump flow retention, and concrete strength development. Furthermore, it is effectively prevented from suffering blocking and has excellent solubility in a slurry. It can be evenly mixed with an inorganic powder. The dispersant is characterized in that it comprises a powdery cement dispersant obtained by drying a solution or dispersion of a copolymer having a polymer backbone comprising a polyamide-polyamine to obtain a powder of the copolymer, and that the powder is composed of spherical particles having an average particle diameter of 30-300 mum and a particle size distribution in which particles having a particle size of 50-350 mum account for 70% or more of the total mass amount.