摘要 |
A composition comprises polyurethane, a two-component flame retardant system consisting of an additive first flame retardant containing organophosphorus, and a second flame retardant containing organochlorine or organobromine. The composition of the invention may be employed for polyurethane foams, especially rigid foams. Diminished combustibility for rigid foam is measured by a flame-spread index less than 75 and a smoke developed index less than 450 when subjected to ASTM Test E-84, Surface Burning Characteristics of Building Materials. Dimethyl methylphosphonate is a representative additive organophosphorus first flame retardant. Trichloroisopropyl alcohol is a representative second flame retardant containing organochlorine.
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