| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric insulating composition having excellent resistance to water treeing without damaging initial breakdown property of an insulator and electric wire or cable using the composition. SOLUTION: This electric insulating composition is obtained by previously crushing a styrene.maleic anhydride copolymer to fine particles having <=10μm particle diameter and blending the particles with a polyolefin. By the process, size of insoluble particles of the styrene.maleic anhydride copolymer existing in the polyolefin is made to <= severalμm and initial breakdown property of the insulator is significantly improved. The size of the insoluble particles of the styrene.maleic anhydride copolymer existing in the polyolefin is correlated with particle diameter of styrene.maleic anhydride before the blending. Therefore, when the particles diameter of the styrene.maleic anhydride before the blending is made to <=10μm by crushing, particle diameter of the insoluble particles in the polyolefin after the blending is also <=10μm. The particle diameter is prescribed to <=10μm because particles having a particle diameter of >=10μm after the crushing treatment cannot improve the initial breakdown property. |
