| 摘要 |
Polyisocyanurate foams of low smoke evolution are prepd. by decomposition of an organic polyisocyanate in the presence of a foaming agent, an isocyanate trimerisation catalyst and an organosilicate of formula Si(OR)4 or RnSi(OR')4-n (where R and R' can be the same of different and represent aliphatic, alicyclic or aromatichydrocarbon residues, pref. of 1-12C atoms, which can be substd. and where n = 1, 2, or 3). These foams combine the excellent heat resistance and flame resistance of conventional polyisocyanurate foams with low smoke evolution and smell tendency to disintegrate to powder when in contact with a flame. These 4 properties were not previously attainable in combination. |
