JPS5893106A - Sheet-shaped insulator - 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 a sheet-like electrical insulator used as conductor insulation for oil-immersed insulators such as OF cables or transformers.

With the recent trend toward higher voltages for power transmission, the insulators used in oil-immersed insulators (Wc) are required to have electrical strength and dielectric strength comparable to those of ordinary kraft paper.

In response to this request, we are currently using plastic, heptulose, and tS.
#1 production of paper-stretched or laminated synthetic paper is progressing, and it has been recognized as highly promising, and some of it is being put into practical use.

Olefin-based remers are mainly used as the plastics used in these products due to their electrical properties, workability, cost, etc., but crystalline high-polyethylene (1 m) , polypropylene (Pi>),
11T-4-methylpentene (C-11) etc. are used for CVH, but this 1-olefin polymer is also used as a carbon-1-hydrocarbon bulk insulating oil, which is mainly used as an insulating oil. Since their chemical structures are similar, Ilj[0 expansion caused by insulating oil is inevitable.
0 Also, as synthetic paper, there is a part of the synthetic paper type in which a plastic sheet and cellulose paper are pasted together, and a part of the paper type in which a plastic sheet is pasted together with cellulose paper, and a part of the paper-made paper type is a paper made of f-last ivy embroidery or cellulose pulp. However, in the case of the former O-runnate tights, it is made up of 1P of physical 2L-adhesion of fII-plastic intertwined between the layers of cellulose paper, and adhesive etc. Olefin-based polyols cannot be used because they reduce electrical conductivity and are used as the plastic foot for laminates. Since - is a non-polar polymer, chemical bonding with cellulose paper is not expected, and the adhesion of the pasted sheets - is weak, resulting in easy peeling.

However, when making slits on linate paper or winding it on a conductor, peeling lumps tend to occur, and the manufacturing efficiency is poor, and the If layer separation occurs in an oil-immersed state, it will have a serious effect on electrical performance. In addition, since the Tsukenate paper is laminated with a sheet-like O plastic, it is absolutely impossible! When used as a cable insulator, the oil can be used as a cable insulator, and the edge of the tape can be heated to high temperatures such as lead metal. There is a problem that there are deaths that stick out.

Semi-synthetic paper-type mixed paper does not have the above-mentioned separation problem, and even when plastic is used as an insulating oil, fine plastic fibers or 7 lakes are dispersed between each paper pulp fiber. Because of this structure, the paper pulp acts as a cushion for the material, and also has the advantage that the protrusion of molten glass can be reduced even when exposed to high-temperature heating of tin salt from lead moldings.

Glass stick used for mixed paper q) As for the shape, processing cost, paper arm By! When considering the dispersibility into paper, fiber-like fibers are advantageous, and among them, polypropylene fibers are preferable from the viewpoints of electrical properties, oil resistance, and ease of penetration. Cut to appropriate length
It can be produced by dispersing the polypropylene fibers in an aqueous paper pulp solution, making it into a paper shape using a fourdrinier or round net, and drying it.

Polypropylene mixed paper has a mechanical strength of ≦1 (KL) because the strong bond between cellulose fibers and fibers is inhibited when polypropylene fibers are incorporated. Therefore, thermal calendering, etc. is a must.Thermal pressure J611, such as thermal calendering with a bamboo rope, is used to control the mechanical strength and W! As a state.

Record the crimping. Generally, in the case of conventional mixed paper,
Since the glass material (polymer material) to be mixed is extremely homogeneous in terms of material and meltability, almost all of the polymer material will be melted and will not be formed into a film. Therefore, when used as an insulator for electrical equipment used in the ttm immersion state, the flow of insulating oil will be inhibited, and the insulation resistance will be reduced. Gurley airtightness [(J
I8 P11117) can be achieved in a few thousand seconds with RI/7T insulating paper, while it can be achieved in tens of thousands of seconds with l&gauze paper.
, f & Poor flowability -0 Also, when corona starting voltage tat is determined using a model cable, it is recognized that the corona starting voltage t is low with a probability of failure, but the reason for this is the part that is not completely impregnated with insulating oil. It is estimated that there is a certain amount of precision.

succeeded in obtaining it.

That is, 1. The present invention relates to an insulator obtained by thermal compression bonding of a mixed sand body of fine particles of kraft pulp and synthetic polymeric material, which is applied to a thermal differential meter as fine particles of synthetic polymeric material. Use of two or more types of insulators with temperature differences of at least 5°C
7L) Using different synthetic molecular substances, to-r1
-1 Lowering the temperature at which melting starts = # In a range where the components with low melting start temperature are the majority of the substance, it becomes a film.
It is possible to obtain an insulating sheet that maintains proper flowability without any problems.

In general, synthetic polymers have a distribution in which one molecular weight is included, so they exhibit a clear melting point within a certain range.As a means of accurately measuring the melting characteristics of such synthetic polymers, a thermophotometer is used. (D80) is 69, and when this is used to determine the melting property tm of a synthetic polymer substance, W! The solution is recorded as an endotherm, and the endothermic start temperature tS is the solution start temperature station.

The melting start temperature differs depending on the polymer substance o@@vcx, but even if the same type has different molecular weight distribution and crystallinity,
A clear change is observed. Therefore, the polymeric substances used in Honkyomei may be of different types.

Even if they are of the same type, it is sufficient that the openings 1f of the openings are different.

By the way, in the present invention, materials whose melting start temperature differs by 5°C or more are used, but in the case of a thermo-pressure layer of a sheet having a thickness of 1, it is difficult to keep the temperature distribution below 5°C. If different sounds at temperatures below 5°C are used, almost all of the polymeric substances will melt and the temperature will be longer. Therefore, it is preferable that the difference in melting start temperature is as large as possible, and at least 5°C. It is necessary that there be 110 or more.

The polymeric substance used in the present invention has low loss due to the properties required for the insulator of the present invention, and is also excellent in oil resistance.
It has to be something that is true.

Specifically, polypropylene, poly-4-methylpentene-1, polycarbonate, polytetrafluoroethylene, fl fluoroethylene hexafluoride glopylene copolymer! -, VM 弗1t ethylene・ethyleneco1dev! -The tatami mats are destroyed. The future material form is powder.

Microscopic bodies such as fibers, i-lakes, and pulp-like bodies
Any material that can be mixed uniformly with Tonoshichiruzo and has a high possibility of uniform distribution is fine.

Next, regarding an example of the present invention, a 2-denier polypropylene fiber t cut into 1.5 mm pieces, a polypropylene trunk (50 meshes passed through 1001 mm), and kraft pulp were prepared. In this case, the melting start temperature f of the polypropylene fiber and #body is 148°C and 13°C, respectively.
It is 3℃.

The difference is measured at 15°C.

The mixing ratio of kraft pulp and polypropylene was 50:50 in irises weight ratio, and the ratio of polypropylene fiber to polypropylene powder was 3:2.

As a comparative example, a mixed paper product was prepared using only polypropylene fibers and subjected to Kraft No Celzo Ell papermaking.

The heat-pressing layer m of the 1-second paper was formed using a heating metal roll and an elastic roll. The surface temperature of the metal roll for heating mixed paper was 160°C in the inventive example, and 1180°C in the comparative example. The thickness of the obtained mixed paper is 125 #wI in both cases, but the Gurley tightness is 3. UO (J seconds ~ 12.Ot) 0
seconds, and in the comparative example it was 100,000 seconds or more.

In addition, the corona starting voltage was added to the model cable with an insulation thickness of approximately 1 layer made of mixed paper RC.

The number of cases in which corona was generated at a potential gradient of f18 KV/ or less was 3 out of 20 in the case of the INFI, but 0 out of 30 in the example of the present invention.

Patent applicant: Fujikura Electric Wire Co., Ltd. Yoshioiri Patent Attorney Mamoru Takeyen

Claims (1)

[Claims] A mixed sand body of kraft pulp and a synthetic polymeric substance [
In the insulator formed by thermocompression bonding, the melting start temperature as measured by a thermal glide meter as a single synthetic polymer material is low (the combination of two or more materials that differ by 15°C or more is considered a 1* sign). Sheet insulation.