JPS5828101A - Composition for semiconductor electric layer of power cable - 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 relates to an improvement in a composition for forming an outer semiconducting layer for a plastic electrical cable.

Conventional high voltage cross-linked polyethylene insulated cable (hereinafter referred to as C
As an external semiconducting layer in a V-cable, it has been widely proposed to extrude and coat a conductive/IJ ethylene mixture from the viewpoint of excellent electrical properties and stability and not causing water tree phenomenon. There is. Recently, however, in medium and low voltage Cv cables, the outer conductive layer not only requires the above-mentioned characteristics, but also is required to facilitate connection work and terminal work. In other words, it adheres well and adheres to the insulating layer at all times, but when connection work or terminal work is required, K
In contrast, it is essential that the conductive layer be a so-called free strip binder conductive layer that can be easily peeled off from the insulating layer.

The fleece dripping type extruded conductive layer is usually made of vinyl chloride or chlorinated ethylene.

Semiconducting mixtures based on I-rimers having halodane polar groups such as ethylene-vinyl acetate-vinyl chloride tar F-rimers have been used.

However, these semiconductive admixtures have a peelability of 4.
Although it is excellent, it has the disadvantages of poor extrusion processability and poor heat resistance. That is, as a slow-sowing crosslinking method, a dry crosslinking method using an inert gas such as N2 gas is used in place of the steam crosslinking method, but this method requires a higher crosslinking temperature than the steam crosslinking method. This is what is being carried out at. Therefore, when manufacturing cables using the dry crosslinking method, some of the above-mentioned admixtures thermally decompose, impairing the appearance of the cables and deteriorating their properties.The present invention has been developed by conducting extensive research in view of the current situation. As a result, frame I
! ii/A puffer stripping type outer conductive layer composition has been found that has excellent peelability, extrusion processability, and heat resistance in the Lietelene insulating capeple or crosslinked EPR insulating capeple. That is, the present invention provides a mixture of 100% by weight of chlorosulfonated polyethylene and 80% to 20% by weight of ethylene-vinyl acetate copolymer.
% fine means that 5 to 70 parts by weight of conductive carbon black are uniformly kneaded into parts by weight.

Chlorosulfonation in the present invention? Liethylene 20~
The reason why the composition was limited to 80% by weight is that peelability from the insulating layer is poor when the composition is less than 20% by weight, and 801ij
This is because if the content exceeds 1%, extrusion processability becomes difficult.

Moreover, the reason for limiting the amount of ethylene vinyl acetate copolymer t-80 to 20 weight is that if the composition exceeds 80 weight %, the peelability from the insulating layer is poor, and if the composition exceeds 80 weight %, the peelability from the insulating layer is poor. This is because extrusion processability becomes difficult in the case of compositions.

Examples of conductive carmen black include acetylene black, furnace black, and ketjen black.The reason why the amount added is limited to 5 to 70 parts by weight is that if less than 5 parts by weight is added, This is because it is not possible to obtain a material with a predetermined conductivity, and if more than 70 parts by weight is added, the extrusion processability of the resulting composition becomes extremely difficult.

In addition, other additives such as antioxidants, stabilizers, lubricants, fillers, etc. may be added to the composition of the present invention as necessary, and in particular, the addition of stabilizers such as Lissage and Lead Baikou improves the composition obtained. This is the ninth most desirable thing for improving the stability of things.

Next, examples of the present invention will be described.

Examples (1) to (2) and Comparative Examples (1) to (2) 1st
All compositions of the present invention and comparative compositions were prepared according to the compositions shown in the table, and their properties were measured. The results are also listed in Table 1. Note that all parts indicate parts by weight.

Table 1 1m(1) A is Palcan XC-12 manufactured by Catalyst Co., Ltd.
(2) B is Akzo Ketjen Black EC (3) Antioxidant is 4,4'-chire! X-0-t@y-buty is 3-methylphenol.

The thus obtained compositions of the present invention and comparative compositions were applied to the outer semiconductive layer of a crosslinked polyethylene insulated electrical cable.
A 3 kV crosslinked polyethylene electrical cable was prepared and its mechanical properties were measured. The results are shown in Table 2.

Table 2 @ (1) Peel strength values are from crosslinked/'J ethylene insulation layer.

As is clear from Table 1 and the flcz table, the composition of the present invention has a low melt viscosity and is suitable for extrusion processing equipment, and can be easily peeled off from the insulating layer as an external conductive layer. Therefore, it is extremely useful as a stripped-type outer semiconducting layer in a turtle caple.

Claims (1)

[Claims] It is characterized by uniformly kneading 2225 to 0 parts by weight of conductive car knob to 100 parts by weight of a mixture consisting of 20 to 80 parts by weight of chlorosulfonated polyethylene and 80 to 20 parts by weight of ethylene vinyl acetate copolymer. An external semiconducting layer forming composition for an electric cable.