JPH0332843B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing a cable conductor provided with a copper oxide film strand insulator.

[Prior Art] A conductor made of twisted copper wires is held in a humidified atmosphere (150 to 200°C, in air or in an atmosphere containing a trace amount of sulfur or a sulfur compound) to form an oxide film.

[Problem to be solved by the invention] In this method, the film thickness required for practical use is as follows:
A time of 48 to 100 h/m was required to form a film thickness of 0.5 μm or more, preferably 1.0 to 1.5 μm.

Also, maximum thickness / minimum thickness is 2 (μm) / 0.5 (μm)
However, the uniformity of the film thickness was not good.

[Means for solving the problem] (1) After immersing a running copper stranded wire in liquid peroxide, (2) In a gas atmosphere of the peroxide, the temperature at which the peroxide thermally decomposes is determined. The method is to heat it to a higher temperature.

Note that as the peroxide, mainly organic ones are used. Among these, those that have a low boiling point and are easily gasified are preferred. Some such organic peroxides, such as dicumyl peroxide, which are used as crosslinking agents in CV cables, are particularly suitable.

[Function] When the above liquid peroxide is heated, it easily gasifies, liberates oxygen, and increases the oxygen concentration in the surrounding atmosphere.

In addition, oxygen molecules are activated by heating, and a copper oxide film is easily formed on the surface of the conductive wire.

Furthermore, the liquid peroxide that has entered the inside of the stranded wire is gasified by heating at that location (inside the stranded wire), so the oxygen concentration inside and outside the stranded wire is no longer much different, and the formation of a copper oxide film is also reduced. There will be no big difference between inside and outside the line. That is, the uniformity of copper oxide film formation is improved.

[Example] In FIG. 1, 10 is a copper stranded wire. This is carried out in the chamber 12 by liquid peroxide 14.
(e.g. dicumyl peroxide) and then enters the oxidation chamber 16.

The oxidation chamber 16 contains a gaseous peroxide 18 (for example, dicumyl peroxide gas) at a high temperature (approximately 150°C), and the stranded copper wire 10 is heated by the high-frequency induction coil 20 in this atmosphere. 150℃
Degree (above the temperature at which liquid peroxide thermally decomposes)
heated to.

Then, the liquid peroxide adhering to the copper strands 10 is decomposed, and activated oxygen gas is present not only around the copper strands 10 but also inside the copper strands 10 at a high concentration and almost uniformly. It becomes like this.

Therefore, a copper oxide film is quickly and almost uniformly formed on the surface of each strand of the copper stranded wire 10.

In addition, to form a film thickness of 0.5 μm or more, preferably 1.0 to 1.5 μm, which is necessary for practical use,
It only takes 12-30h/m (previously it took 48-100h/m)
m), and the maximum/minimum thickness of the produced copper oxide film was 1.2 (μm)/0.5 (μm) (conventionally 2 (μm)/0.5 (μm)).

When a crosslinking agent is used in the peroxide, the stranded copper wire 10 insulated as described above is directly guided to the extruder 22, coated with a rubber or plastic insulator, and placed in the crosslinking tube 24. Crosslinking can be carried out.

The reason for this is that even if gaseous peroxide remains in the copper strands 10, it will not have a negative effect on the insulator since it is originally used as a crosslinking agent.

[Effect of the invention] After soaking the running copper stranded wire in liquid peroxide,
As it is heated, the liquid peroxide adhering to the copper strands decomposes, and activated gaseous oxygen is continuously generated around the strands, not only on the outside of the copper strands but also on the inside. , will be present at high concentration and almost uniformly.

Therefore, the copper oxide film is formed almost equally quickly on both the outer and inner strands of the stranded wire, and the thickness of the copper oxide film that is formed is also approximately the same, resulting in improved uniformity. Get better.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the present invention. 10: Copper stranded wire, 14: Liquid peroxide, 16:
Oxidation chamber, 18: gaseous peroxide, 20: high frequency induction heating coil, 22: extruder, 24: crosslinking tube.

Claims (1)

[Scope of Claims] 1. The running copper stranded wire is immersed in liquid peroxide, and then heated in a peroxide gas atmosphere to a temperature higher than the temperature at which the peroxide thermally decomposes. A method for manufacturing a bare wire insulated cable conductor, characterized in that a copper oxide film is continuously formed on the surface of a copper wire. 2. The method for manufacturing a bare wire insulated cable conductor according to claim 1, characterized in that the peroxide is a crosslinking agent for rubber-plastic power cables.