| abstract |
A rigid polyurethane foam derived from at least one isocyanate, a polyol or a mixture thereof; at least one expansion agent; and a fire retardant additive, wherein said fire retardant additive contains: a) at least one cyclic phosphonate flame retardant; b) at least one alkylated triaryl phosphate ester, and optionally c) one or more i) surfactants, ii) antioxidants, iii) diluents, iv) chain extenders or crosslinkers, v) synergistic agents; and vi) plasticizers, in which a) is present in an amount of less than 30% by weight, based on the total weight of a) and b), and b) is present in an amount of more than 70% by weight, based in the total weight of a) and b), and where the rigid polyurethane foam meets or exceeds the requirements of California Technical Bulletin 117 part A and D. |