| 摘要 |
PROBLEM TO BE SOLVED: To provide a shrinkage reducing agent for cement, the agent giving low air-entraining property to cement, hardly causing setting retardation, and showing a high shrinkage reducing effect. SOLUTION: The shrinkage reducing agent for cement comprises a compound expressed by formula (1): R<SP>1</SP>O-(AO)<SB>m</SB>-X-O(AO)<SB>n</SB>R<SP>2</SP>. In formula (1), X represents a residue of an alkane diol having a plurality of 2-5C saturated hydroxy groups as branched chains and having the total of carbon atoms of 8 to 10, from which a hydroxy group is removed; AO represents one or a mixture of two or more of 2-4C oxyalkylene groups, and when two or more are included, the groups may be added in a block state or a random state; m and n each represents an average addition molar number of oxyalkylene groups, with m+n ranging from 2 to 30; and R<SP>1</SP>and R<SP>2</SP>each represents a hydrogen atom or a methyl group. COPYRIGHT: (C)2011,JPO&INPIT |
