Patent ID: 8058322

Claim:
A flexible polyurethane foam-forming composition which, under polyurethane foam-forming conditions, provides a flame-retardant flexible polyurethane foam, the composition comprising: a) at least one polyol; b) at least one polyisocyanate; c) at least one blowing agent; d) at least one catalyst for the polyurethane-forming reaction; e) at least one halogen-free flame retardant phosphonate compound of the general formula wherein R 1 and R 2 each independently is an alkyl, cycloalkyl, phenyl or alkyl-substituted phenyl group of up to about 8 carbon atoms or are joined together with their respective oxygen atoms and the phosphorus atom to form a heterocyclic ring having 6 ring members; R 3 is a straight or branched chain alkylene group of from 2 to 4 carbon atoms in the main chain; Z is â€”C(O)Oâ€”; R 4 is a hydrocarbon residue of from 2 to 4 carbon atoms and, n is 2.