| 摘要 |
PROBLEM TO BE SOLVED: To provide a rigid polyurethane slab foam having good dimensional stability (dimensional stability after free foaming, that is, unshrinkability) without passing through a step such as foam curing by heating (e.g. at 40°C) during or after foaming when a simple apparatus (e.g. only a stirrer) is used. SOLUTION: A polyisocyanate composition is used which is composed of (A) a polyurethane prepolymer having an isocyanate group content of 22.0-29.0 mass% obtained by modifying polymeric MDI (A1) and an aliphatic polyhydric alcohol-based polyether polyol (A2) having three or more hydroxy groups per molecule, (B) a phosphoric acid ester, and (C1) a phthalic acid ester and/or (C2) a maleic acid ester. COPYRIGHT: (C)2009,JPO&INPIT |
