Patent ID: 6590005
Filing Date: 2003-07-08
Classification: C07C,C08G,C08J

Abstract:
A reaction system for preparation of rigid polyurethane foam comprising:(a) a polyphenylene polymethylene polyisocyanate composition including: (i) 15 to 42 percent by weight, based on 100% of the polyisocyanate composition, of diphenylmethane diisocyanate, (ii) 3-ring oligomers of polyphenylene polymethylene polyisocyanate in an amount such that the ratio of (i) to (ii) is equal to from about 0.2 to about 1.8, and (iii) higher homologues of polyphenylene polymethylene polyisocyanate; (b) an isocyanate-reactive composition containing a plurality of isocyanate-reactive groups; and (c) a blowing agent comprising 2-chloropropane and a hydrofluorocarbon, a hydrocarbon, or mixtures thereof.