| 摘要 |
PURPOSE:To supply power for a specified time without large reduction of insulation property of a fireproof layer in the case of a fire by providing two heat insulation layers of different combustion expansion ratios between a shielding copper tape and a sheath. CONSTITUTION:A first foam layer 13 is formed of foam fireproof composition in the form of a tape to be wound on a shielding copper tape 6. This foam layer 13 has a combustion expansion ratio of 1.5-2.0. A second foam layer 14 is formed of foam fireproof composition in the form of a tape to be wound on the foam layer 13. This foam layer 14 has a combustion expansion ratio of 3.0-6.5. Heat insulation layers are thus formed by the foam layer 13 and the foam layer 14. The foam layer 13 forms a carbonized layer by head added from the external at the time of a fire, and the foam layer 14 forms a foam layer by heat added from the external at the time of the fire. |
