| 摘要 |
PROBLEM TO BE SOLVED: To provide a thermoplastic polyurethane which is excellent in the thermal resistance, the hot-water resistance and elastic recovery characteristics. SOLUTION: The thermoplastic polyurethane is obtained by reacting (A) a polyol composition, which comprises (A-1) a polyester polyol having a crystallization enthalpy of 70 J/g or less and a number-average molecular weight of 1,000-5,000 and (A-2) a polyether polyol having a number-average molecular weight of 500-2,500 and which has a blend ratio of (A-1) the polyester polyol to (A-2) the polyether polyol of 80 mole% or more, and also which has (f) the mean functional group number of hydroxyl groups of 2.006-2.100, (B) an organic diisocyanate and (C) a chain-extending agent, in such a ratio as to satisfy the following equation: 1.00≤b/(a+c)≤1.10 (wherein, a is the whole number of moles of polyols in (A) the polyol composition; b is the number of moles of (B) the organic diisocyanate; and c is the number of moles of (C) the chain-extending agent). COPYRIGHT: (C)2008,JPO&INPIT
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