RIGID FOAM WITH IMPROVED K FACTOR

摘要

This invention is directed to a process for preparing a rigid polyurethane foam by reacting a polyol or a mixture of polyols suitable for use in preparing rigid polyurethane foams with a polyisocyanate or polyisothiocyanate in the presence of at least one foaming agent and at least one catalyst. The process is characterized by incorporating into the reaction mixture at least one compound having at least one aliphatic primary amine group, the aliphatic primary amine-containing compound being present in an amount such that the theoretical percent urea calculated by the method described herein is from 1 to 30 weight percent based on the total weight of the reactive ingredients. This invention is also directed to the rigid polyurethane foam produced by the process, and to a mixture of a polyol suitable for producing a rigid polyurethane foam and an aliphatic primary amine-containing compound. The foams produced by the process show an improvement in at least one property such as thermal conductivity, dimensional stability or expansion at demold.