POLYISOCYANATE MIXTURES CONTAINING ISOCYANURATE GROUPS, A PROCESS FOR THEIR PRODUCTION AND THEIR USE FOR THE PRODUCTION OF POLYURETHANE FOAMS

摘要

Disclosed herein are liquid polyisocyanate mixtures containing isocyanurate groups and having an NCO content of 15 to 30% by weight obtainable by partial trimerization of the isocyanate groups of polyisocyanate mixtures of the diphenyl methane series containing 80 to 100% by weight diisocyanatodiphenyl methane isomers and 0 to 20% by weight higher than difunctional polyisocyanates of the diphenyl methane series, 40 to 80% by weight of the diisocyanatodiphenyl methane isomers consisting of 4,4'-diisocyanatodiphenyl methane, 20 to 60% by weight of 2,4'-diisocyanatodiphenyl methane and 0 to 8% by weight of 2,2'-diisocyanatodiphenyl methane and the percentages shown adding up to 100.