METHOD OF PREPARING RIGID POLYURETHANE OR URETHAN-MODIFIED POLYISOCYANURATE FOAM, RIGID POLYURETHANE OR URETHAN-MODIFIED POLYISOCYANURATE FOAM, MULTIFUNCTIONAL ISOCYANATE-REACTIVE COMPOSITION

FIELD: polymers, chemical technology. SUBSTANCE: invention relates to methods of preparing rigid polyurethane or urethan-modified polyisocyanurate foams, foams prepared by these methods and novel compositions used in this method. Invention describes method of preparing rigid polyurethane or urethane-modified polyisocyanurate foam involving stage of interaction of organic polyisocyanate composition with multifunctional isocyanate-reaction composition in the presence of hydrocarbon frothing agent. Multifunctional isocyanate-reaction composition comprises tolylenediamine-initiated polyester polyol synthesized with use of propylene oxides in the amount between 10 and 40 wt.% with respect to total mass of isocyanate-reactive components, and multifunctional isocyanate-reactive composition does not comprise polyester polyols initiated by aliphatic amine. The use of tolylenediamine-initiated polyester polyols allows to enhance solubility of hydrocarbon frothing agent in polyols mixtures. EFFECT: improved method of preparing and properties. 16 cl, 3 tbl