Patent ID: 8003708

Claim:
A process for making rigid polyurethane or urethane-modified polyisocyanurate foams comprising the step of reacting an organic polyisocyanate composition with an isocyanate-reactive composition in the presence of a hydrocarbon as a blowing agent, characterised in that the isocyanate-reactive composition consists of (i) between 3 and 30 wt % of polyester polyols derived from side streams, waste or scrap residues from the manufacture of DMT and/or PET; (ii) between 20 and 50 wt % of polyether polyols obtained from reacting propylene oxide with aromatic amine initiators containing at least 2 active hydrogens per molecule; optionally, (iii) a non-aromatic amine initiated polyether polyol; and, optionally, (iv) water; and wherein when component (iii) is present, component (ii) is present in an amount ranging from 30 and 50 wt % and component (iii) is present at an amount ranging from 30 and 50 wt %; and wherein the amounts being calculated on the basis of total isocyanate-reactive compound.