| 摘要 |
PURPOSE:To obtain a low-density foam without using any evaporable blowing agent such as a chlorofluorocarbon by reacting an organic polyisocyanate with a polyol and water in the presence of a specified trimerization catalyst and a specified carbodiimidation catalyst. CONSTITUTION:This foam is obtained by reacting an organic polyisocyanate with a polyol and water in the presence of a trimerization catalyst comprising a hydroxyalkyl quat. ammonium compound of formula I (wherein R1, R2 and R3 are each alkyl; and R4 and R5 are each H or alkyl) and a carbodiimidation catalyst comprising a phospholene oxide of formula II or III (wherein R1 is (un)substituted alkyl, phenyl, naphthyl or benzyl; and R2 to R7 are each H, Cl or 1-4C alkyl). |
