| abstract |
PROBLEM TO BE SOLVED: To provide an additive for cement which provides a cement composition whose compressive strength is drastically improved with a small amount of addition. SOLUTION: At least one kind of a structural unit represented by Chemical Formula 1 is introduced by an acetalization reaction, or at least one structural unit represented by Chemical Formula 2 is introduced by a Michael addition reaction. More than one type, the total content of those structural units is 0.1 An additive for cement comprising a vinyl alcohol-based polymer in an amount of up to 45 mol%. Embedded image However, X is -COOH (or a salt thereof), - SO 3 H (Or a salt thereof), -CONR 2 R 3 , -N + R 4 R 5 R 6 ยท Y - (Y: halogen), - represents OH, R 1, R 2, R 3 , R 4 , R 5 and R 6 represent H, an alkyl group or a phenyl group. |