Semi-conductive rubber for inner sheath of intelligent medium-voltage rubber sheathed cable and preparation method thereof

Abstract

The invention relates to semiconductive rubber for an intelligent medium-pressure rubber sleeve cable internal protective sleeve and a preparation method thereof. The semiconductive rubber is prepared from the following ingredients in parts by weight: 85-100 parts of ternary copolymerized epichlorohydrin-ethylene oxide rubber, 0-15 parts of butyl elastomer, 2.5 parts of magnesium oxide, 2.0-3.0 parts of antioxygen, 8.0-11.0 parts of a plasticizer, 60-90 parts of graphitized carbon black, 3.5-5.0 parts of a processing agent and 0.9-1.2 parts of a vulcanizing agent. The ternary copolymerized epichlorohydrin-ethylene oxide rubber and the butyl elastomer are combined to prepare the semiconductive rubber for the internal protective sleeve; the ternary copolymerized epichlorohydrin-ethylene oxide rubber is prepared by ternary polymerization of epichlorohydrin, ethylene oxide and allyl glycidyl ether, is good in oil resistance property, good in semiconductive property and low in volume resistivity which is up to 107-108 omega.cm; since the butyl elastomer is used, the heat-resistant property of the semiconductive rubber is improved, and the technological operation property of epichloro-hydrin rubber is effectively improved.

Description

technical field [0001] The invention relates to a semiconductive rubber and a preparation method thereof, in particular to a semiconductive rubber for an inner sheath of an intelligent medium-voltage rubber sheath cable and a preparation method thereof. Background technique [0002] my country's low-voltage and medium-voltage rubber-sheathed cables often use a 3-phase 4-wire system, and some use a 3-phase 5-wire system, and the neutral wire is usually grounded. From the perspective of use, it is not safe to use over-current relay protection for rubber-sheathed cables, and leakage relays are often used for protection. The change of the protection system has prompted the improvement of the rubber-sheathed cable structure. [0003] As we all know, most of the outer shields of medium-voltage XLPE insulated cables are composed of extruded semi-conductive XLPE and copper tape. However, rubber-sheathed cables often move during use, and their mechanical properties must be both soli...

AI Technical Summary

Problems solved by technology

However, rubber-sheathed cables often move during use, and their mechanical properties must be both solid and soft. Obviously, the structure of copper tape covering and wrapping is not suitable; some older medium-voltage rubber-sheathed cables (3.6 / 6kV and 6 / 10kV) have external Shielding, the copper wire is braided outside the extruded semi-conductive vulcanized rubber. This structure is not ideal. On the one hand, it consumes a lot of copper. At the same time, the copper wire braid is not soft enough and has poor bending performance. After frequent bending, the braid may break The copper wire head will pierce the semi-conductive rubber layer and enter the insulating layer, causing insulation hazards

Whether it is a medium-voltage or low-voltage rubber-sheathed cable, it is possible not to use the phase-separated metal shielding outside the insulation of the main line or the overall shielding structure after cabling, but to use a semiconductor rubber inner sheath instead, which can also effectively obtain protection against faults. function, but does not have the function of electric or magnetic field shielding

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