POLYURETHANE FOAM PREPARED WITH REDUCED LEVELS OF HARD HALOCARBON BLOWING AGENTS

摘要

Closed-cell polyisocyanate-based foams are prepared using a blowing agent mixture containing an organic compound having a boiling point in excess of 65 DEG C in conjunction with another organic compound having a boiling point below 40 DEG C. This invention provides for the use of high-boiling blowing agents which previously were not considered suitable for preparing closed-cell foam due to the higher temperatures required to vaporize same and their tendency to condense at ambient temperatures, causing shrinkage of the foam.