Process for the preparation of polyisocyanurate foams having reduced thermal conductivity

摘要

A method for the preparation of polyisocyanurate foams with reduced thermal conductivity, comprises reacting optionally modified organic polyisocyanates (A) with at least one high mol.wt. compound (B) containing two or more reactive hydrogen atoms and optionally with low mol.wt. chain extenders and/or cross-linking agents (C), in the presence of catalysts (D), optional propellants (E) and optional auxiliary agents and/or additives (F). At least one recycled polyol obtained by glycolysis of polyisocyanurate foam using carrier polyols with a maximum OH content of 500 mg KOH/g and molar mass of at least 450 g/mole, is used as (B). Also claimed are polyisocyanurate foams prepared by the above method.