PRODUCTION OF RIGID POLYURETHANE FOAM

摘要

PROBLEM TO BE SOLVED: To obtain a rigid urethane foam which has markedly improved dimensional stability and flame retardancy even when prepared by using a hydrogen- containing halohydrocarbon as a blowing agent by using a specified polyol component and a specified foam stabilizer. SOLUTION: This production process comprises reacting a polyol (A) with an organic polyisocyanate (B) in the presence of a catalyst (C), a foam stabilizer (D) and a blowing agent (E). Component A is a polyol mixture comprising an ethylenediamine/propylene oxide adduct (a) having a hydroxyl value of 470-950 and a polyol (b) having 2-8 hydroxyl groups and being other than component (a) in an a/b weight ratio of 40/60 to 95/5 and having an overall hydroxyl value of 550-900. Component D used is a silicone foam stabilizer having OH groups in the molecule, and component E used is a blowing agent comprising a hydrogen-containing halohydrocarbon.