Non-flammable poly:isocyanurate foam prepn. - using poly:isocyanate and polyester derived from aromatic or aliphatic poly-acid and glycol

摘要

A novel foam of a plastic material contg. isocyanate and urethane gps. is obtained by reacting =1 polyisocyanate with =1 polyesters in the presence of a blowing agent and =1 catalyst, the proportion of isocyanate gps. w.r.t. OH gps. being 15/1-2/1. pref. 6/1-3/1. The viscosity of the polyester at 25 degrees C admitted with a non-flammable solvent is 1000-100000. The polyester is prepared by reacting =1 opt. esterified polyacid in the acid or anhydride form, with =1 glycol, the ratio of the sum of the wts. of the gps. -C- -CH= and -CH2- w.r.t. total wt. of polyester is 31-48, pref. 35-45%. The foam has class Mi flammability.