JPS5810314A - Method of producing strand insulated conductor - 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 improvements in conductors for power cables.

Generally, in order to increase the power transmission capacity per line of large-capacity power transmission cables, conductors of larger size and higher voltage are used. However, especially when the size of the conductor is increased, a skin effect and a proximity effect occur, resulting in a significant increase in AC loss in the cable. In order to reduce this loss, it is known that it is extremely effective to make the conductor a multi-segmented conductor and to electrically insulate the surface of the wire. In other words, by providing at least part of the stranded wire conductor with insulation treatment applied to the strands, current concentration on the outer layer of the conductor can be suppressed and the skin effect and proximity effect of the conductor can be greatly reduced. It can be reduced to

Enamelled wires are used to hang insulated wires, but these wires use expensive plastic materials and require a thick enamel coating of 20 to 30μ, making them extremely costly and complicated to operate. . In addition, the insulated wire provided with the black copper oxide film has an extremely thin film thickness of 0.1 to 1μ, and has good electrical and mechanical properties.
Because it has excellent chemical stability, it has been put into practical use exclusively.

Conventionally, the processing solutions for producing copper oxide films usually include caustic soda (NaOH) and sodium chlorite (NaCIAO).
t) is used at a high temperature, for example, 80°C.

2- However, this mixed aqueous solution had the following problems.

(1) This mixed treatment liquid reacts slowly, and it takes a long time to form an oxide film of a desired thickness.

(2) Workability is poor and equipment requires a huge amount of expense.

(3) Sodium chlorite is toxic, so NaOH
When using a treatment liquid containing NaC and NaC, it is harmful to the human body and requires a great deal of cost to render it harmless in the treatment of contaminated waste liquid.

As a result of intensive research aimed at improving these drawbacks, the present invention has discovered a method for manufacturing strand insulated conductors using a treatment liquid that is harmless, has excellent mechanical properties, and forms a copper oxide film in a short time. .

That is, the method of the present invention involves using a mixed aqueous solution of caustic soda and persulfate as a treatment solution for forming a copper oxide film on the surface of a copper oxide film to produce an insulated wire conductor. This is a characteristic feature.

The mixing ratio of caustic soda and persulfate as the treatment liquid in the method of the present invention is not particularly limited, but it is preferable that the weight ratio of caustic soda/persulfate is 2 to 10, particularly 30 to 30 of caustic soda. ~200 no/
To: persulfate 10-40/! Good.

As persulfates, potassium persulfate (Kz8tOa), sodium persulfate (Nap, O,
), ammonium persulfate ((NH4)t Sto,
) etc.

Also, the temperature of the treatment liquid may be room temperature, but it may be 50 to 100℃.
By heating to .degree. C., copper oxide is formed more rapidly on the surface of the copper conductor, and workability is significantly improved.

Next, examples of the present invention will be described.

Examples (1) to (3) and comparative examples fi+ −= (2
In manufacturing a 6-segment conductor, a copper oxide film was formed on the surface of the conductor under the treatment conditions shown in Table 1.

Table 2 shows the results of measuring the skin effect (according to Japan Cable Industry Standard, JC8168C) for the insulated conductors of the present invention and the comparative insulated conductors obtained as shown in Table 1.

Table 2 * Resistance ratio of A C/D C The skin effect coefficient of untreated conductor is 1.18
(25°C) and 1.17 (90°C).

As detailed above, the method of the present invention has the following effects.

(1) An insulated conductor can be obtained in a short time.

(2) The skin effect coefficient of the conductor can be significantly reduced.

(3) An insulated conductor can be obtained using a treatment liquid that is extremely less toxic to the human body.

Claims (1)

[Claims] A method for producing an insulated wire conductor by forming a copper oxide film on the surface of a copper wire, characterized in that a mixed aqueous solution of caustic soda and persulfate is used as a treatment solution for forming the copper oxide film. Method for manufacturing wire insulated conductors.