JPS607A - Oil-immersed insulated 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] The present invention relates to oil-immersed insulated cables.

Conventionally, a biaxially stretched polypropylene film with paper laminated on both sides, and a non-stretched polypropylene film with paper laminated on both sides are known. however,
Oil-immersed insulated cables using these cables have the disadvantage that the insulation layer tends to bunch up because of the large swelling caused by the insulating oil.

As a result of intensive research to eliminate these drawbacks, the density is 0.
．． 905-0.9151i'/mouth 3, birefringence 0. ．． 02
By using a tape consisting of a polypropylene film in the range of 0 to 0.035 and laminated with electrically insulating paper on one or both sides, an excellent oil-immersed insulated cable was successfully produced. The density of the PP film used here is 0.
905-0.91517 cm3, preferably 0.907
~0.912? /Cm3.

If the density is lower than this range, swelling due to oil will increase, and if the density is higher than this range, the film will become brittle and its mechanical strength will decrease. Also, the birefringence of this PP film is 0.020 to 0.035, preferably 0.0
It is necessary to be in the range of 25 to 0.032. If the birefringence is smaller than this range, swelling due to oil will increase, and if it is larger than this range, the film will be more likely to crack.

The electrically insulating paper laminated with this PP film is natural paper or synthetic paper containing cellulose as a main component. Particularly preferred paper has a density of 0.6 to 0.9 and an airtightness of 3,000 gal.seconds or more. Furthermore, a particularly preferred method for laminating the PP film and paper is lamination using a thermosetting adhesive.

Examples Examples will be explained below. First, by the usual method, unstretched p
Make p film. This unstretched film is inserted between a set of rolling rolls and rolled. The rolling ratio is preferably about 7 to 10 times. Also, the pressure during rolling is 100 to 1000 k.
y/cm is preferred. The 90 μm film thus produced and electrically insulating paper (density 0.77) were laminated in a sandwich pattern. For comparison, a laminated paper was made by laminating an extruded (unstretched) film of 90 μm extruded by a conventional method and the same insulating paper.

After cutting two pieces of laminated paper into a tape shape with a width of 22 cm, it costs 150 yen.
10 sheets of 1/3-inch plastic wrap were wrapped around a stranded copper wire of 1/2 mm thick. On top of this, 0.2 mm thick copper tape (width: 2.2 mm) was wrapped with 1/3 layer of plastic wrap.
3 I wrapped it in 3 layers of plastic wrap.

The resulting cable (2.5m) heated to 100℃
alkylbenzene (viscosity 10 centistres 30°
C) for 48 hours.

After immersion, a test was conducted 16 times by wrapping it around a cylinder with a radius of 50 cm.

After the top test, an AC destructive test was conducted. The results are shown in Table-1.

As shown in the table above, the AC breakdown value of the product of the present invention is larger than that of the comparative product. In this way, the invention was completed.

Ni'J Procedural Amendment October 1980, Article 72 1, Indication of the Case 1982 Patent Application No. 107293 2, Name of the Invention Oil-Insulated Cable 3, Person Making the Amendment Relationship to the Case Address of the Patent Applicant Osaka 5-15, Kitahama, Higashi-ku, City Name (213) President of Sumitomo Electric Industries, Ltd. Tetsube Yojo 4, Agent Address: 6, 1-1-3 Shimaya, Konohana-ku, Osaka City, Sumitomo Electric Industries, Ltd. Specification subject to amendment 7. Submit a clearly written specification with the contents of the amendment as attached.

Claims (1)

[Claims] Density 0.905-0.915 f 7cm3, birefringence 0
．． An oil-immersed insulated cable using a tape made by laminating electrically insulating paper on one or both sides of a polypropylene film in the range of 0.020 to 0.35.