| 摘要 |
PROBLEM TO BE SOLVED: To obtain a delayed expansive composition which gives an excellent expansion effect, even when added in a smaller amount than those of conventional compositions, can be used in good workability and can give a static crushing material expressing an excellent crushing effect, by disposing a water- repelling coating film on the surface of a specific component to delay a hydration reaction. SOLUTION: This delayed expensive composition is obtained by disposing (B) a water-repelling coating film (preferably comprising a silicon compound or organic compound having a solubility of <=1 g/100 g of water at a temp. of 10 to 30 deg.C) to (A) the surface of a powdery or granular component which can be expanded by a hydration reaction). The coating film B is preferably formed of a silicon compound or organic compound which has in the molecule a >=5C hydrocarbon group and/or a hydrophobic group derived from a >=5C hydrocarbon group, especially a silicon compound or organic compound which has a polar group in the molecule.
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