| 摘要 |
PURPOSE:To obtain an electric wire with high fire resistance by coating the outside of a fire resisting wire core including an insulating layer on a fire resisting layer provided on the outside of a conductor with a plastic composition composed of polyolefin resin and etylene/vinyl acetate copolymer incorporated with hydrate of inorganic metal compound or the like. CONSTITUTION:A fire resisting wire core including a conductor 1 coated with a fire resisting layer 2 and a plastic insulating layer 3 is coated with a plastic sheath 4. The fire resisting wire core including the fire resisting layer 2 coated with an insulating layer such as polyetylene is coated with a sheath 4 comprising a fire resting composi tion, wherein 50 to 85 weight part of hydrate of inorganic metal compound, 1 to 5 weight part of phosphoric acid system fire resisting agent and 2 to 30 weight part of burned clay or silica are incorporated into 100 weight part of a plastic composition comprising 25 to 50 weight part of polyolefin resin and 50 to 75 weight part of etylene/ vinyl acetate copolymer. Thus, in case of fire disaster, the electric wire can hold the fire resistance and if the sheath is decomposed by burning, noxious gas such as halogen gas is not generated. In addition, if the polyetylene in the insulating part is burnt, the fire resisting layer is in good condition so as to retain the function of the wire. |
