PURPOSE: To obtain a rigid foam useful as a heat-insulating material for housing, refrigerators, etc., hardly causing release between laminated foam layers by reacting a polyhydroxy compound with a polyisocyanate in the presence of an alkane of a specific foaming agent, etc.
CONSTITUTION: This foam is obtained by reacting (A) a polyhydroxy compound with (B) a polyisocyanate compound, in the presence of (C) a foaming agent containing dichloromonofluoroethane, (D) a catalyst such as dibutyltin dilaurate, a foam stabilizer, etc., and (E) 0.01-10 pts.wt. of a 3-6C (fluorine-substituted) alkane based on 100 pts.wt. of the component C to provide the objective foam. Furthermore, an amount of dichlorofluroethane of the component C used is preferably 1080 pts.wt., especially 20-70 pts.wt. based on 100 pts.wt. of the component A.
ARAI AKIRA
ISHII MASASHI
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