Abstract: A superior cement dispersant and a concrete composition containing the cement dispersant, the cement dispersant being a water-soluble amphoteric copolymer which contains an alkylene oxide adduct of a polyamide polyamine having an unsaturated group and at least two types of polyalkylene glycol ester. When the cement dispersant is compounded with a concrete composition, the dispersion performance thereof increases with time, and the concrete viscosity is effectively decreased. The cement dispersant composition contains a water-soluble amphoteric copolymer or the neutralized salt thereof as an essential component, which is obtained by copolymerizing an alkylene oxide adduct of a polyamide polyamine having an unsaturated group, (meta)acrylic acid or an alkali metal, ammonium, or alkanolamine salt thereof, an ester of an alkylene glycol and methacrylic acid, and an ester of an alkylene glycol and acrylic acid. In addition, the concrete composition containing the above cement dispersant is also disclosed.

Abstract: [Object] To provide a superior cement dispersant and a concrete composition containing the cement dispersant, the cement dispersant being a water-soluble amphoteric copolymer which contains an alkylene oxide adduct of a polyamide polyamine having an unsaturated group and at least two types of polyalkylene glycol ester. When the cement dispersant is compounded with a concrete composition, the dispersion performance thereof increases with time, and the concrete viscosity is effectively decreased. [Solving Means] The cement dispersant composition contains a water-soluble amphoteric copolymer or the neutralized salt thereof as an essential component, which is obtained by copolymerizing (A) an alkylene oxide adduct of a polyamide polyamine having an unsaturated group, (B) (meta)acrylic acid or an alkali metal, ammonium, or alkanolamine salt thereof, (C) an ester of an alkylene glycol and methacrylic acid, and (C) an ester of an alkylene glycol and acrylic acid.

Abstract: A cement dispersant (especially a dispersant for concretes with ultrahigh performance) comprising as a main component a water-soluble amphoteric copolymer obtained by copolymerizing (A) a polyamide-polyamine of an alkylene oxide adduct thereof with (B) (meth)acrylic acid or an alkali metal, ammonium, or alkanolamine salt thereof and (C) a polyalkylene glycol ester of (meth)acrylic acid in an A/B/C ratio of (10-40)/(10-40)/(50-80) (wt. %); and a concrete composition (especially an ultral high-performance concrete) containing the dispersant. The dispersant satisfies all of a water-reducing effect, slump flow retention, strength development, etc.