JPH04101310A - Power cable - Google Patents

Abstract

PURPOSE:To liberate a power cable from directionality, enable exfoliation in any direction, and facilitate the termination work by providing a semiconductive layer consisting of a specific resin compound. CONSTITUTION:The conductor 1 of a power cable concerned is covered with an inner semiconductive layer 2, whereover an electric insulative layer 3 is put. The resin compound to constitute this semiconductive layer 2 consists in a mixture of 10-100 parts by wt. electroconductive carbon black and 100 parts by wt. blend polymer of ethylene chlorinate copolymer bridge alloy resin and non-polar polymer. To exfoliate the semiconductive layer from the insulative layer in the termination work for the cable, the exfoliation can be done for any required length in the desired direction. Thus the termination work will be facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a power cable such as a cross-linked polyethylene insulated cable, and the semiconductive layer thereof has improved peelability.

[Conventional technology]

Cross-linked polyethylene insulated cables (CV cables are made from an insulating layer made of cross-linked polyethylene or cross-linked ethylene propylene comb, etc., in order to facilitate the terminal processing work performed when connecting cables). '4' - Is it necessary to make the conductive layer easy to peel off?At the same time, it is also necessary to prevent interfacial peeling between the insulating layer and the semiconductive layer when an external bending force is applied to the electric cable. , the semiconducting layer needs to have both appropriate releasability and adhesion to the insulating layer.

For this reason, conventionally, polar polymers such as polyvinyl chloride, chlorinated polyethylene, and ethylene-vinyl acetate copolymers, fluororesins, and silicone resins are blended with appropriate amounts of polyolefin resins such as polyethylene to form haze polymers. The semi-conductive layer is made of a resin composition containing carbon brane and resin, and has appropriate peelability and adhesion to an insulating layer made of a polyolefin resin such as cross-linked polyethylene or cross-linked ethylene propylene rubber. I have to.

[Invention or problem to be solved]

Since the semiconducting layer made of the above resin composition is a blend of the resin composition or polyolefin resin and a polar polymer that is inherently poorly compatible with the polyolefin resin, it is difficult to avoid cross-conducting when wires are crossed. It is difficult to disperse the resin composition uniformly, and therefore, when peeling the semiconductive layer obtained from this resin composition from the insulating layer, it exhibits directional properties.
There was a problem in that it could not be peeled off in any direction, and it was not possible to easily process the terminals of power cables.

[Means to solve the problem]

In this invention, the resin composition for forming the semiconductive layer is one in which 10 to 100 parts of conductive carbon black is blended with 100 parts by weight of a blend polymer of a chlorinated ethylene copolymer crosslinked alloy resin and a nonpolar polymer. The above problem was solved by using .

The present invention will be explained in detail below.

FIG. 1 shows an example of the power cable of the present invention, and reference numeral 1 in the figure indicates a conductor. The outer periphery of the conductor 1 is coated with an internal semiconducting layer 2. This internal semiconducting layer 2 is
This is a true type of semiconductive layer, and the type is different from the one with good peelability in the present invention. Furthermore, an insulating layer 3 is coated on the internal semiconducting layer 2. This insulating layer 3 is composed of a resin composition obtained by extrusion coating a polyolefin resin such as crosslinked polyethylene or crosslinked ethylene propylene comb, and then heating and crosslinking the resin.

Furthermore, on this insulating layer 3, an external semiconducting layer 4 and a shielding layer 5 are formed.
and 6 are sequentially coated to form a power cable.

The outer semiconductive layer 4 is made of a resin in which 10 to 100 parts by weight of conductive carbon black is blended with 100 parts by weight of a blend polymer of 5% by weight or more of a chlorinated ethylene copolymer crosslinked alloy resin and 95% by weight or less of a nonpolar polymer. It is formed by extrusion coating the composition onto the insulating layer 3.

The chlorinated ethylene copolymer crosslinked alloy resin, which is one component of the heath polymer used here, was developed based on thermoplastic combs equivalent to chloroprene comb and nitrile butannin comb. It is sold as IALcRYNΣ (product name) by Teyupon.

In addition, the non-polar polymer that is the other component of the heath polymer includes low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), very low-density polyethylene (VLDPE), and high-density polyethylene (LDPE). HDPE), ethylene-butene l copolymer, etc.

In addition, when using a blend polymer of the above-mentioned chlorinated ethylene copolymer crosslinked alloy resin and a nonpolar polymer as the heath polymer, the mixing ratio is 5% by weight or more of the chlorinated ethylene copolymer crosslinked alloy resin and 95% by weight or less of the nonpolar polymer. Preferably, the resin content is 30% by weight or more, and the nonpolar polymer content is 70% by weight or less.

If the content of the crosslinked chlorinated ethylene copolymer alloy resin is less than 5%, it becomes difficult to peel off the outer semiconductive layer, which is disadvantageous.

Conductive carbon black is added to such haze polymers to impart electrical conductivity.

As the conductive carbon black here, well-known carbon blacks such as acetylene black, lye, and fur-furanoku can be used. The amount of conductive carbon fiber mixed in the heath polymer is determined in consideration of the conductivity required for the outer semiconductive layer 4, and is determined in the range of 10 to 100 parts by weight based on 100 parts by weight of the base polymer.

Further, a crosslinking agent, a crosslinking aid, an anti-aging agent, etc. can be added to the resin composition made of the mixture of the heath polymer and carbon black, if necessary. As a crosslinking agent, Tsucumyl/'-oxide (DCP), 2.5
Common peroxide crosslinking agents such as -7methyl-2,5-di(t-butylperoquine)hexyne-3 can be suitably used. Blend of crosslinking agent II i: i The amount is about 0.2 to 3 parts by weight per 100 parts by weight of the base polymer. In addition, examples of crosslinking aids include triallylisocyanurate, triallylene anurate, tetraallyluoquinethane, N, N''
-m-phenylene bismaleimide, pp'-7 henzoylquinone oxime, p-+/N-N-Ogyunmu, etc. can be used, and about 0.5 to 3 parts by weight can be added to 100 parts by weight of the base polymer. These crosslinking agents and crosslinking aids may be used in combination, or either one may be used alone. When a crosslinking aid is used alone, a portion of the crosslinking agent in the insulator migrates to the semiconductive layer during crosslinking and reacts with the migrated crosslinking agent to effect crosslinking. In addition, as an anti-aging agent, 4,4''-thiobis (6-t-butyl-3 methylphenol) can be used, and other substances such as zinc stearate, zinc oxide, and magnesia can be added as necessary. You can also do it.

In order to form the outer semiconductive layer 4 using such a composition, an extrusion coating method can be applied in the same manner as the conventional method.

In such power cables, the outer semiconductive layer 4 is made of a resin composition mainly composed of a chlorinated ethylene fluoride polymer crosslinked alloy resin and a nonpolar polymer, so it is difficult to use crosslinked polyethylene or crosslinked ethylene propylene comb. In addition to having appropriate adhesion and appropriate peelability to the insulating layer 3 consisting of It can be easily peeled off in any direction as needed without causing any inconvenience.

Hereinafter, the effects of this invention will be clarified by showing examples.

〔Example〕

A resin composition having the formulation shown in Table 1 was prepared as an outer semiconductive layer. On the conductor (500 mm2), an internal semiconducting layer (1 mm thick), an insulating layer (crosslinked polyethylene, 11 mm thick)
mm), the outer semiconducting layer (thickness 0, 5 mm)
An electric cable was manufactured by coating by interlayer extrusion coating, followed by sequentially applying a shielding layer and/or a shielding layer.

Regarding the obtained power cable, the presence or absence of directionality during peeling of the outer semiconductive layer was investigated. Separately, a sheet piece with a two-layer structure made of this resin composition and crosslinked polyethylene was extruded and its peel force was determined. The results are also shown in Table 1.

As is clear from Table 1, in the electrical cable full of the present invention, there is no directionality when peeling off the semiconductive layer, and it can be peeled off in any direction, and the peeling force and adhesion force to the insulating layer are I know it's balanced.

〔Effect of the invention〕

As explained above, the power cable of the present invention includes 100 parts by weight of a blend polymer of a chlorinated ethylene copolymer crosslinked alloy resin and a nonpolar polymer, and 10 to 100 parts by weight of a conductive carphone bra. Since it has a semiconductive layer made of a resin composition containing Processing work can be done easily. Further, this semiconductive layer has appropriate adhesiveness and appropriate releasability to the insulating layer made of crosslinked polyethylene.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing an example of the power cable of the present invention. 4. Outer semiconducting layer.

Claims (2)

[Claims] (1) A power cable having a semiconductive layer made of a resin composition containing 10 to 100 parts by weight of conductive carbon black to 100 parts by weight of a blended polymer of a chlorinated ethylene copolymer crosslinked alloy resin and a nonpolar polymer. (2) The power cable according to claim 1, wherein the chlorinated ethylene copolymer crosslinked alloy resin is 5% by weight or more and the nonpolar polymer is 95% by weight or less.