| 摘要 |
Polymers of esters of methacrylic acid or polyurethanes are made self-extinguishing by incorporating as flame-retarding additive a compound RBrxCly or a mixture of compounds having an average formula RBrxCLy, wherein R is diphenyl, diphenylamine, diphenyl ether, diphenylmethane or homologues thereof; x is a whole or fractional number from 3 to 7; y is a whole or fractional number from 0.5 to 5; x + y is from 4 to 8; and the proportions of polymer and additives being such that the composition contains 3 to 43% of halogen. A preferred additive is a mixture of pentato octa-chlorine and -bromine derivatives of diphenyl and/or diphenyl ether. Optionally esters of phosphorus acids also may be present. In Example (1) a foamed product is obtained from sorbitol ether, trichlorofluoromethane, C12H4.1Br4.4Cl1.5, trichloroethylphosphate and diphenylmethane - diisocyanate. In Examples (2) and (3), methyl methacrylate is polymerized in the presence of C12H5OBr4Cl or C12H4Br4.5Cl1.5. |
