| 摘要 |
PROBLEM TO BE SOLVED: To enhance high temperature insulating characteristics and voltage resistant characteristics, increase flexibility to improve wiring capability, and enhance productivity and economical efficiency by forming a fire resistant layer made of double layers of silicone rubber containing a flame retarder, silicone oil, and powdery mica and an insulating layer on a wire-like conductor. SOLUTION: A fire resistant layer 3 made of double rubber layers 3a, 3b formed with silicone rubber, and an insulating layer 4 made of synthetic resin such as polyethylene are formed in order on a wire-like conductor 2, and a sheath 5 is formed thereon to obtain a fire resistant electric wire 1. The silicone rubber in the fire resistant layer 3 is formed by mixing 15 pts.wt. or less flame retarder such as zinc borate, 35 pts.wt. or less silicone oil, 25 pts.wt. or less stearic acid, and filling 250 pts.wt. powdery mica having a particle size of 50 μm or more to the 100 pts.wt. silicone rubber. 0.1-3 wt.% vulcanizer is added to the silicone rubber when the rubber layer is formed. The composition of the rubber layers 3a, 3b may be the same or different to exhibit the similar effect. |
