JPS59181411A - High voltage cable - 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 [Technical Field of the Invention] The present invention relates to a crosslinked polyethylene cable with excellent long-term stability 'I'=.

[Background and outline of the invention]

In addition to OF cables, crosslinked polyethylene cables and the like are used as high voltage cables.

Among these, the latter is becoming widely used in place of the former because of ease of maintenance, low power transmission loss, etc. However, the latter has the disadvantage that it is inferior to the former in terms of long-term stability, and various studies have been made to improve this disadvantage.
A satisfactory solution has not yet been obtained.

In view of the point 1, the inventors conducted various studies and found that by using di-t-butyl peroxide as a crosslinking agent, the long-term characteristics could be improved to a thick rl-+.

Furthermore, this effect can be obtained when the crosslinking method is dry and the insulation thickness is 7 mx or more.
The results of the investigation revealed that the problem becomes even more pronounced when a water-blocking layer containing a metal layer is provided.

The present invention has been made in view of the above points, and provides a crosslinked polyethylene insulated cable with excellent long-term stability.

[Detailed description of the invention]

In the present invention, di-1-butylbaroxide is used as a crosslinking agent because, as is clear from the experimental examples described below, long-term stability tends toward large rlJ. Although it is still unclear why this phenomenon occurs, it is clear that high-voltage cables with high performance can be provided for high-voltage cables based on this phenomenon.

f+! 11. In the present invention, an antioxidant or the like may be added to the crosslinked polyethylene used as the insulating layer, if necessary.

The effects of the present invention will now be explained using a single experimental example.

Low density polyethylene (MI=3, density 092) 4,4./-thiobis-(6-t-butyl-
3-Methylphenol) 0.2 parts by weight and the peroxide shown in Table 1 as a crosslinking agent were blended, and the polyethylene composition was extruded and coated on the outside of a 15 Q mx2 stranded wire. ．． Cables were obtained by forming insulating layers of 7 and 23 thicknesses on each side, and chemically crosslinking them using various heating methods.

The resulting cable! :) At a temperature of 0°C, 7 KV
/〃I, m air voltage is applied, and the distance between 11.1r and 11.1r for one soil is determined as 15-0. Example 2, Comparative Example 13 Sentence [11. ! T+, "I"2. The fracture times of the examples with the same hardness were determined as a ratio.

Cable size, insulation 1? , inner and outer ゛1'-conductive layer 1IJ
J1, formulation and destruction time (Comparative Examples 1.2, j3.
4. The ratio (to il) is shown in Table 1.

As is clear from the aerial charging results in Table 1, 3tn7n
Cables with insulation thicknesses of 1.23 m, 7 m1, and 1.23 m, using di-t-butyl peroxide as a crosslinking agent, have long-term dielectric breakdown characteristics that are better than the conventionally used dicumyl peroxide. It was superior to cables cross-linked with oglylide.

Furthermore, this effect can be obtained when cross-linking is performed using infrared cross-linking, or when the insulation thickness is 7 m or more.
It was even more noticeable.

Also, using the cables of Comparative Example 3 and Example 3,
A cable with a metal layer coated with a PVC sheath was created and the same test was conducted as before. As a result, the failure time of the cable using Example 3 was approximately 10 times that of the cable using Comparative Example 8. It became.

5- Procedural Amendment (Method) May 11, 1980 1. Indication of Item A 4 Patent Application No. 210 (No. 189 λ) Name of Invention High Voltage L-Pull 3. Person making the amendment Relationship to the incident Patent applicant address: Kita 1F, 5TT, Higashi-ku, Osaka City] No. 15 name
Name (213) Sumitomo Electric Industries, Ltd. President Kawa
Tetsu No. 4, Agent address: 1-111-3 Shimaya, Konohana-ku, Osaka Sumitomo Electric Co., Ltd. April 24, 1980 B 6, Specification subject to amendment 76 Contents of amendment Type stamped Please include a clearly written detailed statement on a separate sheet.
I will submit it.

2-

Claims (4)

[Claims] (1) A high voltage cable whose insulating layer is made of crosslinked polyethylene using di-1-butyl perogizide as a crosslinking agent. (2) Claim No. (]) where the crosslinking method is dry
High voltage cable as described in section. (3) The high voltage cable according to claim (1) or (2), wherein the insulation thickness is 7 myn or more. (4) A water-blocking layer having a metal layer is provided on the outside of the insulating layer.
A high voltage cable according to claim (1), (2) or (3).