JPS5918810B2 - electrical equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to electrical equipment using insulating materials that have excellent electrical insulation performance under oil and gas impregnation.

With the increase in power transmission capacity and the miniaturization of equipment, the use of polymeric materials for insulating layers has been extensively studied.

For example, cables and capacitors are making use of the major features of polymers, such as high dielectric strength and low dielectric loss. On the other hand, there are issues to be considered in actual device manufacturing, such as oil and gas impregnation, swelling in the oil used, and oil resistance such as crazing. In order to use a polymeric material as such an insulating material, it is important to determine the form of the polymer, such as film, synthetic paper, textile, combination with other materials, etc. When a polymeric material is used as an insulating material, oil impregnation is very poor in film form, while dielectric breakdown strength decreases in synthetic paper form. When synthetic paper is made almost film-like in order to increase its breaking strength, oil impregnation becomes a problem. In view of this point, the present invention improves the above drawbacks by using a uniaxially stretched porous film.

That is, the uniaxially stretched porous film can provide excellent oil impregnation properties by a simpler method than uniaxial stretching, which could not be obtained sufficiently by biaxial stretching. Since oil impregnation and breaking strength are reciprocal to some extent, the present invention solves oil and gas impregnation by using a uniaxially stretched porous film, and also solves the problem of oil and gas impregnation by using a uniaxially stretched porous film. The feature is that the dielectric strength voltage is maintained by the film. In this case, the biaxially stretched porous film is required to have a low porosity. The uniaxially stretched porous film having excellent oil and gas impregnation properties can be obtained in the following manner. Extrusion equipment A sheet obtained by a chemical method such as thermal or solution state is sandwiched between elastic materials such as rubber and continuously rolled to generate a large number of voids and cracks made of glaze ink or cracks. After that, it is subjected to uniaxial stretching treatment to form a porous film. Note that the film described in the present invention also includes what is normally called a sheet, membrane, etc. The above-mentioned biaxially stretched porous film is made into a porous film by generating a large number of voids and cracks, and then biaxially stretching the film so that the voids and cracks do not disappear, similar to the uniaxially stretched porous film. . The uniaxially stretched porous film and the biaxially stretched porous film contain at least one type of crystalline polymer containing an inorganic or organic filler or a crystalline polymer not containing such a filler, and if necessary, an inorganic or organic Its composition is a polymer mixture containing a filler. As a crystalline polymer,
Crystalline olefin resins such as polyethylene, polypropylene, isotactic polybutylene, polymethylpentene-1, nylon 6, nylon 66, nylon 610
1 Crystalline polyamide resins such as nylon 11 and nylon 12, crystalline polyether resins such as polyoxymethylene and polyoxymethylene chloride, crystalline polyester resins such as polyethylene terephthalate and polybutylene terephthalate, and long chain molecules have ionic bonds. Examples include ethylene-acrylic acid ionomer resins, which are fluorine-based resins such as polyvinylidene fluoride, polychloroethylene trifluoride, and copolymers of propylene hexafluoride and ethylene tetrafluoride.

Polymer films other than mono-oil stretched porous films include almost all polymer resins and polymer mixtures with polymer resins or inorganic or organic fillers, in addition to the above-mentioned biaxially stretched porous films. Film can be used.

For example, in addition to the crystalline polymers mentioned above, polystyrene resins, polycarbonate resins, polyester resins (e.g. polyethylene 2,6 naplate, etc.), polyether resins (e.g. poly 2,6 dimethylphenylene oxide, etc.), polyether Sulfon (product name, 1CI),
Examples include polysulfone (trade name, Union Carbide), fluorine-based resins (polytetrafluoroethylene, etc.). The oil and gas impregnability of the uniaxially stretched porous finium obtained as described above is determined by the size of the spherulites of the basic component polymer, the stretching temperature, additives, etc.

The uniaxially stretched porous film and the polymeric film other than the uniaxially stretched porous film can be used by being layered alternately or by being pressed together with a hot roll.

When a uniaxially stretched porous film and a polymer film were alternately wound around a 20φ pipe, vacuum degassed, and impregnated with JIS No. 1 mineral oil, the film became transparent after about 5 hours and was impregnated. Examples are shown below. Example 1 Mixed pellets of 90 parts by weight of polypropylene resin and 5 parts by weight of nylon 12 resin were formed into a sheet using an extruder set at approximately 240°C, and this sheet was rolled between polyurethane rubber belts at room temperature. The sheet is rolled and stretched approximately 1.1 times in the longitudinal direction to generate a large number of voids and cracks in the sheet.

Next, the film was stretched approximately 4 times in the longitudinal direction using a uniaxial stretching machine set at approximately 120°C to produce a white, opaque, uniaxially stretched porous film. Next, the sheet, which has many voids and cracks within it, is stretched using a biaxial stretching machine set at approximately 130°C to form a biaxially stretched porous film! Got ilm. After extruding polypropylene resin into a sheet, the polymer film is made of approximately 13
It was obtained by biaxial stretching at 0°C. When the uniaxially stretched porous film and polypropylene film and the uniaxially stretched porous film and biaxially stretched porous film produced as described above were alternately heated and measured between flat electrodes,
Average impulse breaking strength at 0.5m1 thickness is 180KV/ML17OK/1! It was TIL. In addition, after sandwiching both samples between flat electrodes, we impregnated them with vacuum oil and measured the capacitance changes.
The time became constant within 14 hours and oil impregnation was completed. The results of measuring oil immersion characteristics similar to those in Example 1 for samples prepared by changing the film material, shape, etc. in accordance with Example 1 will be shown below.

It is also excellent for gas impregnation and is similarly useful for gas impregnated electrical articles.

Due to its permeability, a combination of a uniaxially stretched porous film and a biaxially stretched porous film can be used as a separator with a two-stage separation function. As described above, according to the present invention, it is possible to provide an electrical article having excellent electrical insulation performance even when impregnated with oil or gas.

Claims (1)

[Scope of Claims] 1. An electrical device in which a laminate of a uniaxially stretched porous film and a polymer film other than the uniaxially stretched porous film is used for all or part of an insulating layer. 2. The electrical device according to claim 1, wherein the polymer film is a biaxially stretched porous film.