Rigid polyurethane foam containing polyester residue digestion product and building panel made therefrom

Abstract

Rigid polyurethane foam is produced from polyisocyanate and polyol wherein 5-30% by weight of the polyol ingredient is a digestion product of polyalkylene terephthalate residues or scraps digested with organic polyols. The resulting rigid polyurethane foam exhibits uniform density and, when compared with a corresponding polyurethane foam which does not include the said digestion products, exhibits equivalent or superior physical strength properties. With fire retardant rigid polyurethane foams wherein the organic polyol ingredient includes halogenated organic polyols, use of 5-30% by weight of the said digestion product in the organic polyol ingredient, achieves a rigid fire retardant polyurethane foam having a lower flame spread and a lower smoke generation than a corresponding polyurethane foam which does not include the said digestion product. When fabricated in a closed mold, the present rigid polyurethane foam has a more uniform density, i.e., a higher core density, than corresponding rigid polyurethane foams which do not include the said digestion product.

Dependencies are inferred from the claim text.