| 摘要 |
The present invention provides: a cement dispersant which displays high dispersibility with a small addition amount and excellent dispersibility particularly even in a high water-reducing ratio area, and a cement composition comprising this. The first cement dispersant comprises a copolymer including: constitutional unit (I-1) derived from unsaturated (poly)alkylene glycol ether monomer (a1) as represented in general formula (1) below; and constitutional unit (II-1) derived from unsaturated monocarboxylic acid monomer (b1) as represented in general formula (2) below, as an essential component, wherein constitutional unit (II-1) includes at least one structure derived from an acrylic acid (salt), wherein general formula (1) is:<paragraph lvl="0"><in-line-formula>XO(R1O)nH (1)</in-line-formula>where: X represents an alkenyl group having 4 carbon atoms; R1O represents a mixture of one or more of an oxyalkylene group having 2 to 18 carbon atoms, and an oxyethylene group accounts for not less than 90 mol % of the entirety of the oxyalkylene groups; and n is an average addition number of moles and represents 1 to 300; and wherein general formula (2) is: where: R2, R3, and R4 each independently represent hydrogen or a methyl group; and M represents hydrogen, a monovalent metal, a divalent metal, an ammonium group, or an organic amine group.
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