Fire proof insulation material - comprising mixts. of polyethylene, ethylene-propylene, polyisobutylene and aluminium hydroxide

摘要

Fire-proof material comprises a mixt. of filled polymers and additives, the mixt. comprising a combination of polyethylene, ethylene-propylene rubber, polyisobutylene and aluminium hydroxide. Pref. the mixt. comprises 20-60 pt wt. polyethylene, 20-60 pt. wt. ethylene propylene polymer, 10-40 pt. wt. polyiso-butylene, 125-250 pt. wt. aluminium hydroxide, 0-50 pt. wt. mineral filler or carbon black, 5-20 pt. wt. plasticiser and 1-2 pt. wt. each of vinylsilane anti-oxidant and lubricant. The mixt. can be cross-linked by use of a suitable peroxide, and is processable with normal extruders. The polymer combination has a good receptivity for the filler giving good processability for the mixt. The Al hydroxide decomposes at high temp. and brings about the flame-resistance of the material. The material gives off no corrosive gases or vapours, and develops min. amts. of smoke, under the action of fire. The material is suitable as insulation for cables esp. in nuclear power stations, computer installations, high rise flats, industrial installations etc.