| abstract |
(57) [Summary] [PROBLEMS] In particular, to a hydraulic composition in an ultra-high strength region of W / C ≤ 30%, dispersibility and dispersion retention are exhibited by adding an appropriate amount, and a delay effect is small, Provided is a dispersant capable of suppressing excessive viscosity development of a composition immediately after kneading. SOLUTION: A copolymer of a specific alkenyl ether and maleic acid or a salt thereof (a), a specific monomer (a) such as a (meth) acrylic acid ester of methoxypolyethylene glycol, and (meth) acrylic acid And a copolymer (b) obtained by polymerizing a monomer mixture containing a specific monomer (b). |