Flame-resistant insulating compsn. for metal conductors, e.g. wire - contains polyolefin together with organo-polysiloxane rubber and lead cpd.

摘要

Compsn. contains 100 pts. wt. hydrocarbon polymer (I), 2-20 pts. wt. organopolysiloxane rubber (II) and 2-15 pts. wt. Pb cpd. (III). The compsns. may also contain 10 pts. wt. vapour-phase SiO2, 0-10 pts. wt. antioxidant, 0-50 pts. wt. filler and 0-10 pts. wt. organic peroxide, as crosslinking agent. The compsns. are used partic. for insulating wires and cables. Addn. of (II) and (III) improves flame-resistance, lowers spread of burning and increases carbonisation, without incorporating a halogen-contg. cpd. E.g. O2-index can be increased from 16.8% to 22%. Typical compsn. contains polyethylene, (II), dibasic Pb phthalate and opt. polymerised trimethyl-dihydro-quinoline together with 4,4'-thio-bis-6-tert. Bu-m-cresol as anti-oxidant.