URETHANE-MODIFIED POLYISOCYANURATE RIGID FOAM

摘要

Improved crack-free rigid cellular polyisocyanurate polymers are disclosed that are derived from the reaction of an organic polyisocyanate combination comprising two particular types of polymethylene polyphenyl polyisocyanates (a) and (b), a trimerization catalyst, minor amount of a polyol, a surfactant, and an inert volatile blowing agent having a boiling point from about 30.degree.C to about 90.degree.C. The novel rigid foams are particularly useful in preparing high molded bodies of foam by making multiple pours or lifts on top of each other in a mold. The resultant molded body comprises a multiple of molded parts firmly fused to each other and crack-free. Such high molded bodies and process therefor are particularly useful in the insulation of ships.