Process for the preparation of rigid foams containing urethane and predominantly isocyanurate groups and their use as an insulating material.

摘要

Rigid foams containing urethane and isocyanurate groups are made by reacting a polyisocyanate with a compound containing at least two isocyanate reactive hydrogen atoms in the presence of an aqueous solution of alkali metal carboxylate in accordance with known techniques. The aqueous alkali metal carboxylate solution has an alkali metal carboxylate content of from about 10 to about 50% by weight. The alkali metal carboxylates are preferably alkali metal acetates such as potassium acetate. This process is carried out at an index above 150. The product foams are particularly useful as insulating materials.