JPS58212004A - Semiconductive composition - 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 a semiconductive composition that is used as an external semiconductive layer of electrical equipment such as rubber/plastic insulated capacitors and has excellent peelability from an insulating coating layer.

Recently, there has been a strong demand for an external semiconducting layer extruded on top of the insulating layer, for example in polyethylene or cross-linked polyethylene insulated cables, to have excellent peelability in order to facilitate cable connection work. It became so.

Conventionally, a composition mainly composed of ethylene/vinyl acetate/vinyl chloride kraft poly-1 or chlorinated polyethylene 7 has been used as the external semiconductive layer having excellent releasability. However, since these chlorine-containing polymers have poor heat resistance, they thermally decompose and generate hydrogen chloride gas during heating and cross-linking of the cross-linked polyethylene insulation layer [this may corrode the shielding copper tape or reduce the commercial characteristics of There was a problem of lowering the

Heating τ of cross-linked polyethylene insulation layer especially for productivity
The operation of increasing the quality has become a necessity, and t+i
For example, if the temperature exceeds 220° C., thermal decomposition is severe, and conventional outer semiconducting layers made of polymers containing chlorine cannot be put to practical use.

The + invention eliminates the drawbacks of the prior art described above and relates to a semiconductive composition that has excellent heat resistance and peelability.

That is, the gist of the present invention is that tetrafluoroethylene/-
For 100 parts by weight of propylene copolymer, 4% (
/l carbon blank is mixed with 30 to 150 parts by weight -C
The composition is a semiconductive composition.

The tetrafluoroethylene-propylene/thread copolymer in the present invention includes, in addition to the main components tetrafluoroethylene and propylene, components copolymerizable with these, such as ethylene, imbutylene, acrylic acid and its alkyl esters, methacrylate, etc. -1 Such compounds may contain acids and their alkyl esters, vinyl fluoride, vinylitin fluoride, hexafluoroproprene, chloroethyl vinyl ether, chlorotrifluoro, loethylene, perfluoroalkyl vinyl ether, etc. In the polymer, the content molar ratio of tetrafluoroersin/propylene is selected from the range of 9515 to 30/70, particularly 90/10 to 45155.
It is preferable from the viewpoint of heat resistance, moldability, etc., and the content of components other than the main component, which may be added as appropriate, is usually selected from a range of 50 molti or less, particularly 30 molti or less.

In addition, this tetrafluoroethylene-propylene Itoi polymer has higher heat resistance than chlorine-based polymers, +7) gentleness, and
l-'! It is also possible to plaid ethylene polymers such as J ethylene and ethylene propylene rubber.

41M, Strength - The reason for specifying the blending amount of the bomb blank is that if it is less than 30 parts, it is half As' for electrical equipment.
This is because the electrical conductivity required as a di tL JtA material cannot be obtained/it is difficult to obtain, and if the amount exceeds 150 parts by weight, the mechanical strength and extrusion property are significantly reduced.

This composition can be prepared by kneading it in a conventional manner, but at this time, if necessary, a crosslinking agent such as dicumyl...-4oxide, υII 1', I such as metal soap, etc.
It is also possible to add fillers such as IJJ scraping and talc.

The composition of the invention can be applied as a semi-electronic forming material for power equipment in various forms. For example, the composition of the present invention,
The outer semiconductive layer of the electric cable is co-extruded with the crosslinked polyethylene insulation layer forming material.The outer semiconductive layer of the electric cable has adequate releasability and is extremely heat resistant. t1
Because of this, it does not generate corrosive gases even when subjected to high heat during the crosslinking process, unlike the case with the yarn polymer, and can maintain stable cable performance over a long period of time.

Next, examples of the present invention will be described together with comparative examples.

Examples 1 to 3 and Comparative Examples 1 to 3 After coextruding the compositions shown in Table 1 onto the conductor periphery together with an insulating layer-containing composite bottom made of crosslinkable polyethylene to form an external semiconductive layer, A crosslinked polyethylene insulated capeple was produced by crosslinking treatment.

(The compounding lid for each component in the table is for one scene).

In this case, crosslinking was carried out at 230° C. for 10 minutes in a gaseous medium. The diameter of the conductor is 20-1, the thickness of the insulating layer is 6 cm, and the thickness of the outer semi-conductor layer is 0.51 cm.

Table 1 also shows the characteristic measurement results for each side.

In Examples 1 to 3 according to the present invention, there was no discoloration of the copper tape for shielding, the peel strength was appropriate, and the properties of 4 were sufficient. On the other hand, if the amount of acetylene plaque blended is less than the limit value as in Comparative Example 1, the 24% L property is insufficient.

Furthermore, in Comparative Example 2.3, which has a conventional composition, discoloration of the copper tape was observed under the severe crosslinking conditions applied here.

Claims (1)

[Claims] (1) 3 parts by weight of conductive carbon blank per 100 parts by weight of tetrafluoroethylene-propylene copolymer.
1. A semiconductive composition comprising 0 to 150 parts by weight of the composition.