Utilisation of highly brominated waste products - esp. from bi:phenyl and di:phenyl-ether prodn. as flame retardants for bitumen or tar

摘要

Mother liquors or residues from the prodn. of highly brominated biphenyls and diphenyl ethers are used as flame retardant additives for bitumen or tar masses. Residual solvent is pref. removed from the mother liquors, and the residues are pref. further brominated to improve their effectiveness and increase their m.pt. The amt. added is pref. 3-30 (esp. 5-15) wt.% based on the end product. Synergists such as Sb2O3 and P cpds. (e.g. tris(dibromopropyl), tricresyl or tris(bromocresyl) phosphate) can also be added. Process recycles a waste material and avoids poluttion.