| abstract |
Monomeric or polymeric isocyanurates, e.g., polyisocyanate/polyisocyanurates, are prepared by catalytically cyclotrimerizing an isocyanate, e.g., an aliphatic or cycloaliphatic isocyanate, in the presence of an aminosilyl catalysis initiator, e.g., a mono- or diaminosilane, a silylurea or a silazane, having the structural formula: R(4-n)Si-NR'R'']n (I) wherein R is a saturated or unsaturated, aliphatic, cycloaliphatic, aryl, aralkyl or alkylaryl monovalent hydrocarbon radical, or halo or cyano substituted such radical, and further wherein any two radicals R may together form a single divalent such hydrocarbon radical; R' is R, SiR3 or an amido radical having the structural formula: <IMAGE> wherein R''' is R or SiR3, with R being as above defined, and further wherein R', when R' is neither the amido radical nor SiR3, may, together with the radical R'', form a single divalent such radical; R'' is R, or a hydrogen atom when R' is not the amido radical; and n is either 1 or 2, but when n is 2, R' is R. |