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 cement dispersant and a concrete composition containing the cement dispersant, the cement dispersant having a superior effect of decreasing a high concrete paste viscosity while a water reducing effect, a slump flow retention, and rapid strength development are being satisfied in a region having a low water/binder ratio. [Solving Means] The cement dispersant for ultrahigh performance concrete is provided which is a water-soluble amphoteric copolymer obtained by copolymerizing (A) an alkylene oxide adduct of a polyamide polyamine having an unsaturated group, (B) (meta)acrylic acid or a salt thereof, (C) an ester of a short-chain alkylene glycol and (meth)acrylic acid, and (D) an ester of a long-chain alkylene glycol and (meth)acrylic acid at ratios A:B:C:D of 5 to 25:5 to 30:5 to 40:20 to 80 (percent by weight), in which the total is 100% percent by weight. In addition, the concrete composition containing the above cement dispersant is provided.

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.