Prepolymers and polyurethane made of isocyanate components, one and two-component foams thereof

摘要

Isocyanate component (I) comprises diphenylmethane diisocyanate tri-, tetra- and pentanuclear homologs in a weight ratio of 8.0+- 4.0:3.5+- 1.8:1.2+- 0.9 respectively and contains no more than 2 wt.% diphenylmethane diisocyanate and no more than 6 wt.% uretone imines. Independent claims are also included for: (1) prepolymer produced by reacting a polyol component (II) with (I); (2) producing a one-part expanding foam by reacting a polyol component with excess (I) in the presence of a liquefied gas in a pressure vessel; (3) producing a hard foam by reacting (I) with a compound having at least two isocyanate-reactive hydrogen atoms.