| 摘要 |
PURPOSE:To provide a rigid urethane foam having excellent low-temperature dimensional stability even if the density is extremely low, and having excellent mechanical strength and heat-insulation, by reacting an organic polyisocyanate with a specific polyol. CONSTITUTION:The objective foam can be produced by reacting (A) an organic polyisocyanate with (B) a polyol comprising a combination of (i) a polyether polyol having a low OH-value (115-300, especially 140-280), (ii) an amine polyol having an OH-value of >=300 (especially 400-1,000) and (iii) a non-amine polyol having an OH-value of >=300 (especially 400-550) containing a sucrose poly- ether polyol as at least a part of (preferable 50-100wt% of) said polyol, in the presence of a foaming agent, and if necessary, catalyst and other assistant. The amounts of the polyol components are preferably 7-15% for (i), 50-85% for (ii) and 8-35% for (iii). the component A is preferably pentaerythritol compound, and the component B is preferably (poly)arylene polyamine compound. |
