| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyethylene-based resin composition for a crosslinked insulator allowing a high-frequency coaxial cable having good heat resistance such as heat aging property and solder heat resistance and a low dielectric loss tangent (tanδ) of a crosslinked insulation layer in a high frequency band after electron beam irradiation, and to provide a high-frequency coaxial cable comprising the polyethylene-based resin composition for a crosslinked insulator.SOLUTION: The above polyethylene-based resin composition (γ) for a crosslinked insulator is obtained by comprising 0.05 to 0.3 pts.mass of a hindered phenol-based antioxidant in 90 to 60 pts.mass of linear polyethylene (α) and 10 to 40 pts.mass of high-pressure process low-density polyethylene (β) (the total of (α) and (β) is 100 pts.mass) and is characterized by satisfying the following requirements of (γ-1) to (γ-5): (γ-1) density of 930 to 960 kg/m; (γ-2) melt flow rate of 0.1 to 20 g/10 min at 190°C and a load of 2.16 kg; (γ-3) one melting point peak of an endothermic curve obtained in temperature rising measurement by differential scanning calorimetry; (γ-4) having strain hardening characteristic in measurement of elongational viscosity and a strain hardening index (λmax) of 2.0 to 30; and (γ-5) a tanδ at 2.45 GHz of 0.7×10to 1.5×10by cavity resonator perturbation method. |
