| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a cement admixture which, even when added in an amount less than that of a conventional cement admixture, gives high flowability to concrete, effects a marked viscosity decrease, and keeps slump change small for a long time. <P>SOLUTION: The cement admixture is a water-soluble vinyl copolymer (A) prepared from a monomer (a) represented by general formula (1): R<SP>1</SP>-CH=C(R<SP>2</SP>)-COO-(A<SP>1</SP>O)<SB>m</SB>-SO<SB>3</SB>M<SB>1/r</SB>(wherein R<SP>1</SP>and R<SP>2</SP>are each a hydrogen atom or methyl; A<SP>1</SP>is a 2-4C alkylene; M is a hydrogen atom or an r-valent cation; r is 1 or 2; and m is an integer of 1-300) and another monomer (b) as essential constituting monomers. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
