Patent ID: 6670554
Filing Date: 2003-12-30
Classification: H01B

Abstract:
High voltage direct current cable insulation comprising:a blend of or which is made from a blend of at least one ethylene/alpha olefin polymer having a density of less than about 0.900 g/cc, a melt index of from about 0.5 to about 10 g/10 minutes, a crystallinity of less than about 10% and a catalyst residue of less than about 1000 ppm; at least one polar polymer modifier in an amount effective to provide an insulation made with the blend with an enhanced field conductivity and enhanced space charge leakage at high fields relative to an insulation made with a blend which does not include a polar polymer modifier; at least one ion scavenger in an amount effective to reduce ionic mobility relative an insulation made with a blend which does not include an ion scavenger; the ethylene/alpha olefin polymer, the polar polymer modifier and the ion scavenger being in amounts to provide the cable insulation with a charge density of less than 2 Coulomb/mm3 measured by a pulsed electro acoustic method after 24 hours with either positive or negative 20 kV/mm applied.