JPS61232505A - Crosslinked polyethylene insulated wire - 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 (Field of Industrial Application) The present invention relates to a crosslinked polyethylene insulated wire, and more particularly to a wire made of a single conductor coated with crosslinked polyethylene.

(Prior art) Insulated wires made of a single conductor coated with cross-linked polyethylene are generally coated with polyethylene to which a cross-linking agent has been added.
It is produced by heating this at high temperature to crosslink it and then cooling it under pressure.

(Problem to be solved by the invention) However, when the insulating layer becomes thicker, it cools from the outside and hardens during cooling, creating a gap between the insulating layer and the conductor, which causes the problem that the insulating layer easily moves and makes terminal work difficult. .

There are methods to solve this problem, such as roughening the conductor surface or providing an adhesive layer on the conductor surface, but this method results in the conductor and insulating layer coming into close contact with each other.
It becomes difficult to remove the insulation at the terminal.

In view of the above, the present invention has been developed to solve these problems.

(Means for solving the problem) That is, in the present invention, the VICAT softening point between the conductor (1) and the crosslinked polyethylene insulating layer (2) is lower than that of the uncrosslinked polyethylene containing a crosslinking agent. It is characterized by providing an insulating layer (3) made of polyolefin whose temperature is lower than that and 30°C or higher (
(See Figure 1).

(Function) As described above, a crosslinked polyethylene insulated electric wire is provided in which the degree of adhesion between the crosslinked polyethylene insulating layer and the conductor is suppressed to a range that does not impair the workability of the terminal, and which is in close contact.

The present invention will be explained in detail below.

The present invention was developed after various studies were conducted to improve the above-mentioned workability.
If an AT material whose softening point is lower than that of uncrosslinked crosslinked polyethylene for insulating insulation is applied to the conductor and crosslinked polyethylene insulation interface by about 0.05 m to 0.3 m, this layer becomes a cushion layer and is similar to the conventional It was discovered that even when manufactured using the same method as , no gap occurs between the conductor and insulating layers.

It has been found that when a VICAT material with a softening point of less than 30° C. is used, no gap occurs, but the adhesion between the conductor and the insulation becomes large and the peelability of the insulation becomes extremely poor.

The material used for this is preferably a polymer that can be easily fused with polyethylene, such as ethylene vinyl acetate, monomer,
Polyolefins such as ethylene acrylic copolymer and ethifcine α-olefin copolymer (trade name: Yuchumer) are good.

Any method may be used to coat the conductor, such as using an extruder or dissolving it in a solvent.

Examples will be described below to help understand the present invention.

(Example) In order to confirm the effect of the present invention, various polymers (3) were extrusion coated to a thickness of 0.1 on a 2.0+mO copper wire (1), and then polyethylene containing a crosslinking agent (2) was coated with 411II11 Coat the copper wire thickly, cross-link it by heating at a saturated vapor pressure of 19cm to make an electric wire (see Figure 1), cut it to a length of 30 cm, measure the resistance force when pulling out the copper wire, and insulate it with cross-linked polyethylene. We also compared whether resin remained on the copper wire when the layers were peeled off. The results are shown in Table 1, and it can be seen that the electric wire of the present invention has excellent workability during terminal work.

Table 1 (Note) Vistanex (trademark): Polyisobutylene,
Evatate (trademark) manufactured by Esso: ethylene vinyl acetate copolymer; Tafmer (trademark) manufactured by Sumitomo Chemical Industries: ethylene α-olefin copolymer; (Effects of the invention) As described above, according to the present invention, terminal work is easy to perform. A crosslinked polyethylene insulated wire is obtained.

[Brief explanation of the drawing]

FIG. 1 illustrates a cross-sectional view of the crosslinked polyethylene insulated wire of the present invention. (1)...Conductor,

Claims (1)

[Claims] 1) In an electric wire formed by covering a single conductor with cross-linked polyethylene, the VICAT softening point of the cross-linked polyethylene at the boundary between the conductor and the cross-linked polyethylene is lower than that of uncross-linked polyethylene containing a cross-linking agent, A crosslinked polyethylene insulated wire, further comprising an insulating layer made of polyolefin having a temperature of 30° C. or higher.