| 摘要 |
PROBLEM TO BE SOLVED: To provide hydrated silicic acid for a silicone rubber improved in reversion of plasticization while keeping high reinforcing performance and transparency. SOLUTION: The subject silicic acid satisfies the following requirements in a state compounded in a silicone rubber by a roll milling method, and preferably has a BET specific surface area of 150-250 m2/g obtained by the nitrogen adsorption method. (1) A dispersibility index of 40-60, which represents a ratio of particles of 1μm or less to the total loadings. (2) A mode radius, of particles of 1μm or more, of 4-8μm. It is further preferable that the dispersibility index exceeds 40 within 7 min in the roll milling method.
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