JPS5864704A - Semiconductive mixture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides high voltage crosslinked polyethylene 7 (XLPg)
The present invention relates to semiconducting compounds useful as semiconducting layers in insulated cables and the like.

Generally, in cross-linked polyethylene insulating couples for high voltage use, it is common practice to provide a semiconducting layer such as extrusion in order to improve withstand voltage performance. For this purpose, it is considered desirable to also crosslink the semiconductive layer.

Conventional methods for manufacturing cables with cross-linked semiconducting layers based on this perspective include (a) adding a considerable amount of a crosslinking agent (for example, OCP) to a semiconducting mixture;
(b) A method of adding a crosslinking agent (for example, triallyl isocanurate) to a mild semiconducting material, or a method of transferring a crosslinking agent blended into an insulator to a semiconducting layer. etc. have been proposed.

However, in the method (a) of adding a crosslinking agent, the crosslinking agent must be kept at a temperature below which it does not cause a crosslinking reaction, from the step of kneading the crosslinking agent into the semiconductive mixture to the step of extrusion coating the cable. There is a need to work with it, but is it semiconductive? 11
Generally, cables have a high melt viscosity, and it is extremely difficult to work stably with wire crossing, rolling, which generates a lot of heat during the extrusion process, and it is especially difficult to manufacture long cables continuously and stably. It was very difficult. In addition, in the above method (b) of adding a crosslinking aid, when the temperature of the mixture increases during kneading, the melt viscosity gradually increases, causing the mixture's melt viscosity to become flaky and cause flaking, which can cause problems in the extrusion process. There was. Among these rounding and kneading operations, it is necessary to perform separate processes for carbon warming, where the mixture tends to reach high temperatures, and crosslinking aid kneading. There were also problems such as being at a disadvantage. Furthermore, with the method (c) of transferring the crosslinking agent, it was not possible to obtain sufficient crosslinking distance.

The present invention was invented in view of the above-mentioned circumstances, and its purpose is to facilitate kneading, extrusion processing, and The object of the present invention is to provide a semiconducting mixture that can be applied with a semiconductive layer such as a crosslinked extrusion to obtain a crosslinked polyethylene insulated cable.

The characteristics of the present invention are as follows: per 100 parts by weight of polyolefin, 10 to 10011 parts of conductive carbon, 0.05 to 5 parts by weight of crosslinking aid, and 0.0 part of phenolic anti-aging agent.
It is in a mixture containing 1 to 1 part by weight.

The polyolefin used here is polyethylene/
, ethylene-propylene copolymer (EPM), ethylene-propylene-diene ternary copolymer (gPDM), ethylene-vinyl acetate copolymer (gVA), ethylene-ethel acrylate (IJAλ ethylene-α-olefin copolymer) (For example, trade names: Tafmer, Elastomer Me 75) and mixtures thereof.If the amount of conductive carbon is less than 10 parts by weight, no conductivity will be obtained; Exceeding the weight part did not particularly improve the conductive performance and only worsened the economical efficiency.In other words, if it is specified within the above range from the purpose, conductivity, and economical points. Also, as a crosslinking aid, it can be used as an aid for organic peroxide crosslinking.
Maleimide compounds such as pi, N-m-7enylene bismaleimide, maleimide, etc., oxime compounds such as P-quinone dioxime, PXP dibenzoylquinone dioxime, aryl methacrylate, vinylbenzene and the like. In addition, triallyl noanurate, triallyl iso7 anurate, etc. can be used for 1 and 2,
If the number of parts is less than o, o''s parts by weight, the desired stability will not be obtained, and if it exceeds 5 parts by weight, the degree of crosslinking will not particularly increase and the freshness will deteriorate. As a phenolic anti-aging agent, 4,4'-thiobis(
6-t-butyl-3-methylphenol), 2,6-di-t-butyl-4-methylphenol, and the like can be used. If the number of compound needles is less than 0.01 part by weight, there will be almost no effect of the compounding, and if it exceeds 1 part by weight, a plume will occur in some places, and after making it into a cable, there will be a leaching effect on the cable cost. There was a risk that it would come.

In the mixture of the present invention with the above blending composition, crosstalk,
The reason why extrusion processing is easy and a sufficiently crosslinked semiconductive layer can be obtained is presumed to be due to the following reasons.

With a composition consisting of polyolefin, conductive carbon, and a crosslinking aid, as mentioned above, when the temperature of the mixture becomes high during cross-wiring, the viscosity increases, making cross-crossing difficult. Of course, the bridge will be able to travel sufficiently and become damaged. In this way, when there is no crosslinking agent such as peroxide and only a crosslinking agent, no crosslinking reaction should occur, but in the crosslinking process, mechanical force or heat Polymer cleavage occurs due to the above, and radicals are generated, and the generated radicals cause the crosslinking agent to react with VC11#J, resulting in an increase in viscosity. Therefore, when the phenolic anti-aging agent is added to a mixture having this composition, the anti-aging agent reacts with the radicals and the reaction of the crosslinking aid is suppressed.

This suppressing effect suppresses the increase in viscosity and enables smooth kneading and extrusion processing, making it possible to obtain sufficient crosslinking through smooth kneading and extrusion processing.

Next, the table in F, which describes one embodiment of the present invention, is as follows:
The composition of the mild product of the present invention and a comparative example without anti-aging agent are shown, as well as the results measured at 200 C, grapheng plastograph, where the viscosity y > rotor rotation torque. It is.

From the table above, it can be seen that in the case of the semiconducting mixture of the present invention, the viscosity does not increase even when crosstalk is performed, and the result is -U. On the other hand, it can be seen that in the comparative example (*), the viscosity increases as the mixture is kneaded.

As is clear from the above explanation, according to the semiconductive mixture of the present invention, the viscous pupil does not increase even when K such as crosstalk occurs.
Unlike conventional methods, there is no heat generation during the mixing-1 extrusion process, and there is no need for separate kneading, etc., and it is possible to stably create images using VC, and of course, continuous production of long cables is also possible. In addition, the processing cost is low, and a semiconducting layer having sufficient crosslinking lc can be obtained.

In addition to the semiconductive layer produced by extrusion, the semiconductive mixture of the present invention can also be formed into a tape and used as a semiconductive layer at the joint part of a Cv cable to form a crosslinked semiconductive layer. be.

Patent applicant: Fujikura Electric Wire Co., Ltd.

Claims (1)

[Claims] 1 part by weight of conductive carbon per 100 parts by weight of polyolefin
A semiconductive mixture comprising 0 to 100 parts by weight, 0.05 to 5 parts by weight of a crosslinking aid, and 0.01 to 1 parts by weight of a phenolic antioxidant.