Polyethylene composition for use in insulations and joints of extra-high voltage power cables, and an extra-high voltage power cable and joint therefor employing this polyethylene composition

摘要

A polyethylene composition which is useful in insulations and joints of extra-high voltage power cables, and in which a cross-linking agent, comprising an organic peroxide subjected to purification processing, and an antioxidant, are blended, wherein the cross-linked composition has a dielectric loss tangent (tanδ) of less than or equal to 0.07% at a temperature of 90°C and under an electric field stress of 20 kV/mm. This polyethylene composition exhibits little dielectric loss, even at high temperatures or high electric field stresses, and is optimally employed in insulations and joints for extra-high voltage power cables of 275 kV or more.