Fujikura Limited

Kazuo Watanabe

Hiroshi Niinobe

Tohru Takahashi

Shoutaroh Yoshida

A high-permittivity rubber compound (MX) to be over 10, 15, or 20 in relative permittivity is produced by filling, to 100 weight parts of base material (M), 300 or more, 400 or more, or 500 or more weight parts of barium titanate family material as powder (M) over 2000 in relative permittivity at temperatures from room temperature to 90&#xb0; C. A high-permittivity rubber compound (M, M) crosslinked by peroxide is heat-treated (S, S) to remove decomposition residue of the peroxide, and powder (BT) of barium titanate family material of industrial grade is washed (S) by de-ionized water (Mc) to remove ionic impurities, suppressing degradation of insulating characteristics.

High-permittivity rubber compounds and power cable members

A cylindrical pre-molded rubber insulation tube made by a plurality of layers using a rubber material as a base material has in a central part and at both ends of an inner periphery thereof a sheet-shaped electrode layer formed at an insde thereof with a semi-conductive rubber layer and at an outside thereof with a high-permittivity rubber layer, as an inner electrode layer configured with the semi-condutctive rubber layer to be thin and sheet-shaped and the high-permittivity rubber layer covering a vicinity of a respective distal end of the semi-conductive rubber layer, and the distal end of the semi-conductive rubber layer is rounded by a radius of curvature substantially equal to half the thickness.

Growing community of inventors

Futtsu, Japan

Kazuo Watanabe