Use of nitromethane, nitroethane and 1-nitropropane to inhibit degradation of hydrochlorofluorocarbons used as blowing agents in the preparation of polyurethanes and polyisocyanurates expanded.

摘要

Method for inhibiting the degradation of hydrochlorofluorocarbons used as agents lathering IN THE PREPARATION OF CELLULAR polyurethanes and polyisocyanurates. The invention relates to a method for inhibiting degradation by dehydrohalogenation of hydrochlorofluorocarbons, SUCH AS MIXTURE OF 123 AND 123A which are used as foaming agents during the reaction for the formation of polyurethanes or POLIISICIANURATOS CELLULAR from polyols and polyisocyanates . Before you start the reaction, the reaction medium SE adds a small amount of a substance selected from STABILIZING group consisting of nitromethane, nitroethane and 1-nitropropane.