Patent ID: 6939402

Claim:
A cement admixture comprising a copolymer or copolymer salt obtained by neutralizing the copolymer with an alkaline substance; wherein, the copolymer is obtained by copolymerizing a monomer mixture comprising a monomer represented by following Chemical Formula 1, a monomer presented by following Chemical Formula 2, and a reactive surfactant represented by following Chemical Formula 3: wherein: R 1 is a hydrogen atom or methyl; R 2 O is a C 2 to C 4 oxyalkylene, wherein each of the one or more oxyalkylenes may be identical or different, and wherein the oxyalkylenes may be added in block or random form in case they are different; R 3 is a C 1 to C 4 alkyl; and m is the average number of moles of the oxyalkylene groups, which is an integer from 1 to 50; wherein: R 4 is a hydrogen atom or methyl; and M 1 is a hydrogen atom, a monovalent metal atom, a bivalent metal atom, ammonium, or an organic amine; and wherein: R 5 is a hydrogen atom or methyl; R 6 is a C 1 to C 3 alkylene, phenylene, or alkylphenylene; R 7 O is a C 1 to C 4 oxyalkylene, wherein each of the one or more oxyalkylenes may be identical or different, and wherein the oxyalkylenes may be added in block or random form in case they are different; r is the average number of moles of the oxyalkylene groups, which is an integer from 1 to 50; n is 0 or 1; and M 2 is a hydrogen atom, a monovalent metal atom, ammonium, or an organic amine.