| 摘要 |
<p>1,194,750. Cables. GENERAL ELECTRIC CO. 22 Dec., 1967 [29 Dec., 1966], No. 58270/67. Heading H1A. An electric cable has at least two insulating layers of cross-linked thermosetting polyethylenic material, the innermost incorporating 100 to 125 parts of alkoxy silane treated titanium dioxide filler per 100 of polymer and the outermost layer containing no titanium dioxide filler. The filler content of intermediate layers if any decreases outwardly. Such a cable has a specific inductive capacitance not greater than about 4 and a power factor not greater than about 1%. The outer insulating layer, while lacking filler quantities of titanium dioxide, may contain pigmenting amounts thereof, or other colouring pigments or dyes, e.g. carbon black. The outer insulating layer may contain a filler other than titanium dioxide, e.g. aluminium silicate or oxide, calcium or magnesium silicate or mixtures thereof, which fillers may also have been treated with an alkoxysilane. The polyethylenic material may be polyethylene, a copolymer of ethylene and other monomers or a blend of polyethylene with another polymer. The cross-linking agent may be a peroxide, e.g. dicumyl peroxide. As shown, stranded conductor has semi-conducting tape applied around it, then inner insulating layer 16 containing titanium dioxide filler and outer insulating layer 18 without filler. The cable is completed by second semi-conducting tape 20, copper shield 22 and an outer jacket (not shown).</p> |
