| abstract |
Polyisocyanurate foams are prepared by reacting together an organic polyisocyanate, a blowing agent, a trimerization catalyst, and a minor amount of a polyol blend comprising(a) about 5 percent to about 95 percent by weight of said blend of an alkylene oxide adduct of an aromatic amine of the formulawherein Z is a divalent aromatic radical, x, x', y, and y' each independently have an average value from about 1 to about 5, and each R is independently selected from the group consisting of hydrogen, alkyl or aryl, provided that the adduct is capped with ethylene oxide units, and(b) about 5 percent to about 95 percent by weight of said blend of an aromatic polyester polyol having a molecular weight of from about 150 to about 5,000. Laminates of such foams exhibit a high degree of fire resistance, low foam friability, high compressive strength, and excellent facer adhesion. |