| 摘要 |
PROBLEM TO BE SOLVED: To provide a fire retardant insulated electric wire having a thin wall thickness, an excellent cut-through resistance, generating are toxic corrosive gas at burning. SOLUTION: This insulated electric wire has an extra-conductor insulating layer of double layer structure consisting of an inner layer and outer layer, wherein the inner layer has 40/55 of Shore-D hardness according to ASTM D2240 while the outer layer has no less than 360 Shore-D hardness according to ASTM D2240, and the ratio in thickness of the outer layer to inner layer ranges from 1/2 to 1/5. The inner layer is preferably formed from a compound prepared by mixing a metal hydrate as a fire retardant agent with polyolefin. The outer layer is preferably formed from polyethylene having a density of over 0.93, taking into consideration the mechanical properties. |
