PREPARATION OF FLAME RETARDED POLYISOCYANURATE FOAMS

摘要

Polyisocyanurate foams are produced by mixing at least one organic isocyanate and at least one polyol in the presence of at least one aliphatic or cycloaliphatic C4 - C7 hydrocarbon having a boiling point of 70°C or less at 760 millimeters pressure, at least one trimerization catalyst, at least one alkylene glycol ester of tetrabromophthalic anhydride, and at least one phosphorus ester selected from (i) tri(chloroalkyl)phosphate in which each alkyl group has 2 or 3 carbon atoms, (ii) dialkyl alkanephosphonates in which each alkyl group has 1 or 2 carbon atoms and in which the alkane group has 1 or 2 carbon atoms, and (iii) triethylphosphate, and wherein the organic isocyanate and polyol components are proportioned to form a polyisocyanurate having an isocyanate index in the range of 240 to 280.