METHOD OF MOLDING RIGID POLYURETHANE FOAMS WITH ENHANCED THERMAL CONDUCTIVITY

摘要

The present invention is to a molded rigid polyurethane foam for application in appliance, having a reduced thermal conductivity at densities between 33 and 38 kg/m3 and a process for the production of such foams. The molded rigid polyurethane foam have a ratio of applied foam density (kg/m3) to lambda (mW/mK), measured at 10~C, 24 hours after foam production from 1.65 and to 2.15 and are obtained by the process of injecting into a closed mold cavity under reduced pressure a reaction mixture at a packing factor of 1.1 to 1.9 and the reaction mixture comprises: A) an organic polyisocyanate; B) a physical blowing agent, C) a polyol composition containing at least one polyol with a functionality of 3 or greater and a hydroxyl number between 200 and 800 and a water content of 0 to 2.5 weight percent of the total polyol composition; D) catalyst and E) auxiliary substances and/or additives.