▎ 摘　　要

NOVELTY - α,ω-Dihydroxypolysiloxane (I) is new. USE - The new α,ω-dihydroxypolysiloxane (I) is useful as sealing material for caulking of deformation joint in radioactive region, or sealing of reserved hole (all claimed). ADVANTAGE - The α,ω-dihydroxypolysiloxane provides sealing material, which has excellent fire resistance, shock resistance, air tightness, water tightness and scrub resistance. DETAILED DESCRIPTION - α,ω-Dihydroxypolysiloxane (HO(C2H6OSi)nH) of formula (I), is new. n = 800-1500. An INDEPENDENT CLAIM is included for preparation of α,ω-dihydroxypolysiloxane (I).