| 摘要 |
PURPOSE:To obtain a polyurethane foam having excellent thermal insulation properties by reducing the amount of a physical foaming agent such as chlorofluorocarbon to be added. CONSTITUTION:In the rigid polyurethane foam which is obtained by reaction of a polyisocyanate with a polyol in the presence of a catalyst and a foam stabilizer, water and a trimerization catalyst are essentially used as a foaming agent and a catalyst, respectively, and the reaction is carried out under such conditions as the isocyanate index is kept less than 150. |
