JPS60233813A - Dry capacitor - 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 dry capacitors.

A conventional capacitor is a metalized polypropylene film in which a vapor-deposited metal 1 such as Zn or A14 is provided on one side of a plastic film 2 such as a polypropylene film (hereinafter referred to as PP) or a polyester film (hereinafter referred to as PET), as shown in Fig. 1. (hereinafter referred to as MPP)! Alternatively, a metalized polyester film (hereinafter referred to as MPET) is formed, and these are layered and wound, or double-sided MPP or double-sided Ml'ET, in which vapor-deposited metal 1 is provided on both sides of a plastic film 2, as shown in FIG. and PP or pET are layered and wound, and Zn or solder metallic metal 3 is sprayed on both end faces to take out the electrode parts. After that, solder the lead wire to this and pull it out, and solder it to the upper lid terminal part. It is attached and stored in an aluminum case. Approximately 0.02% of these dielectrics, MPP%PP, M
pET.

PET contains about 0.3% water, and the film shrinks due to heat, causing changes in capacitance, etc. Furthermore, by putting insulating oil on the end faces of the dielectric and inside the dielectric, various electrical properties can be improved. 100-120t for stability
It is usually impregnated with a liquid such as dioctyl phthalate or polybutene, a single microcrystalline wax, or a solid insulating oil in the form of a grease, which is a mixture of microcrystalline wax and polybutene oil.

However, since the above-mentioned insulating oil is expensive, research has been carried out to make it a dry process, but a fully satisfactory product has not yet been obtained.

In other words, for capacitors using MpET and double-sided MPET, it is basically possible to use a dry method, but
Since the dielectric loss that PET itself inherently has varies greatly with temperature characteristics, it is necessary to reduce the stain level gradient by drying, which is disadvantageous when economically evaluated.

In capacitors using conventional AIM clear MPP and AJ double-sided evaporated MPP shown in FIGS. 1 and 2, 4 J
When continuous durability tests and intermittent durability tests were conducted in accordance with ISC4908, the capacity reduction was extremely large as shown in sample group A1C in Table 1.

Losses at the rated voltage also increase. Also, Zn vapor tMP
When similar tests were conducted on capacitors using P and Zn double-sided evaporated PP, sample groups A' and C in Table 1 were obtained.
As shown in Figure 2, the hardness at which the dielectric breaks down becomes extremely large, making it impossible to obtain a stable dry film capacitor. The cause of these problems is that the cycorona level has decreased due to the omission of the insulating oil impregnation process and the use of a dry method.
This is because in vapor-deposited MPP and AJ double-sided vapor-deposited MPP, a coro-silon phenomenon occurs in the margin portion and the plane portion, and the material changes to an insulator of aluminum oxide, resulting in a large reduction in capacitance. Also Zn vapor deposited MPP.

In Zn double-sided evaporated PP, even if corona occurs, the evaporated metal does not easily disappear due to the corona, so corona often occurs especially in the margin area, which is the end face, so the PP itself, which is a dielectric, deteriorates and breaks down. occurs.

The present invention aims to solve the above-mentioned problems and provide a dry capacitor with stable quality.

That is, a copolymer of polyethylene and polypropylene (with a melting point of 100%
~14(1) is laminated and wound, or Zn or AJ double-sided MPP and the same copolymer as above are used on both sides of PP, and the melting point at this time is 100 to 140t, whichever is as low as possible. Laminate P laminated with good resin
It is constructed by wrapping □P and winding them together and spraying metallicon metal on the end surfaces.

The present invention will be explained below with reference to the embodiments shown in factors 3 to 8.

FIGS. 3 and 4 are explanatory diagrams of the main parts of a single-sided vapor-deposited IVIPP dry capacitor. First, as shown in FIG. Below, its melting point is 100
- After winding a metallized film made by laminating a copolymer of polyethylene and polypropylene of -140″C so that its margins are opposite to each other, and spraying Metallicon metal 3 on the end face, Temperature equal to or higher than the melting point of the laminated copolymer 4 (preferably melting point +
Heat at 5°C for at least 3 hours. At this time, the laminated copolymer 4 melts, and further shrinkage of the film brings the layers into close contact as shown in FIGS. 3 and 4. As a result, the air layer trapped between each layer when wound by υ can be completely removed due to the above-mentioned adhesion effect. Next, a drawer lead is connected to the metallcon metal 3 and connected to an external terminal, and the case is housed and sealed to complete the process.

Since the dry type capacitor of the present invention is constructed as described above, the corona level of the dry type capacitor is improved, and the capacitance reduction rate in the continuous durability test and the intermittent 1 durability test and the variation in loss when the rated voltage is applied can be significantly improved. .

FIGS. 5 and 6 show Zn or AJ vapor-deposited gold) g 1 on both sides of PP 2, and a double-sided laminated film in which the copolymer 4 described above is laminated on both sides of a plastic film 20 made of PP, which is rolled up. It is constructed by heat treating and spraying metallicon metal on the end face.
Effects similar to those described above can be obtained.

Note that the melting point of the copolymer 4 of polyethylene and polypropylene is less than 100'C, although the field attractiveness increases.
When metals such as Zn1kl are vapor-deposited on PP laminated with PP, the quality deteriorates due to peeling of the deposited metal due to the influence of heat, and if the melting point exceeds 140'C, the base P
A range of 100 to 140'c is desirable because the shrinkage of P or PET increases and the wound element deforms into a convex shape.

Moreover, the reason why the thickness of the above-mentioned copolymer 4 is limited to 2 μm or less is due to economic reasons. In addition, if the margin width A is less than 1.541, as shown in Figure 7, pressure will not be easily applied to the edges due to the thickness of the vapor-deposited metal J, and when the plastic film contracts, the film will not bend at an acute angle and will fit tightly. Or the strength of the fusion bond decreases. And the margin width A is 1.5
In the case where the contact area is larger than 100 cm, as shown in FIG. 8, even if the electrode contacts the back surface of the counter electrode at a relatively obtuse angle, a large contact area can be obtained, so that the strength of the dense layer or vapor deposition increases. Also, there is no problem in terms of quality with a margin width of 5 MIR or more, but it is economically disadvantageous, so the margin ++ Tortoise A is 1.5 to 51.
M(7) range is optimal.

Table is rated at 400 VAC based on the example above.

A 40 μF dry capacitor was manufactured and the comparative results of various tests are shown. In the table, the width of the film for each sample was 100 ja, and the margin @A was 2 to 3 ja.

In addition, the intermittent durability test conditions were 560V applied at 80"C, 2
Continuous durability test conditions were 480V applied at 80'C with 0N and 12 seconds oFF. The four-hoe change rate ΔC/C and the -lδ increase value when the rated voltage was applied were measured. Which test I!
The number of samples stacked is 20.

As is clear from the table, it was demonstrated that the quality of the dry capacitors according to the present invention of sample groups B, D, B', and D' was extremely stable.

It goes without saying that the arrangement of the evaporation electrodes is not limited to the above-mentioned embodiment, and similar effects can be obtained even if the evaporation electrodes are deposited in series. The base film is also PP.
The same effect can be obtained not only with PET but also with PET.

As described above, the dry capacitor of the present invention has significantly improved quality, greatly contributes to improved reliability and productivity, and has great industrial and practical value.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams of the electrode arrangement of a conventional capacitor, and FIGS. 3 to 8 are explanatory diagrams of the electrode arrangement of a dry type capacitor of the present invention. 1: Vapor deposited electrode 2 Niblastic film 3: Metallicon metal 4: Copolymer of polyethylene and polypropylene Patent applicant Nippon Capacitor Industries Co., Ltd.

Claims (4)

[Claims] (1) Zn on at least one side of the plastic film,
In a dry capacitor formed by winding a metallized plastic film coated with a metal such as AI, the surface of the plastic film in contact with the vapor-deposited metal during winding is
A dry method characterized by being constructed by laminating and winding a copolymer of polyethylene and polypropylene having a thickness of 2 μm or less and a melting point of 100 to 140″C, spraying metallicon metal on the end face, and heat-treating. capacitor. (2) 7. on one side of polypropylene film or polyester film. A metallized film laminated with a copolymer of polyethylene and polypropylene having a thickness of 2 μm or less and a melting point of 100 to 140°C is layered and wound on the other side. A dry type capacitor according to claim 1, characterized in that it is constructed by spraying metallicon metal onto the end face and heat-treating it. (3) A metallized film formed by vapor-depositing a metal such as Zns Al on both sides of a polypropylene film or a polyester film, and a metallized film with a thickness of 2 μm or less and a melting point of 100 to 140 on both sides of the polypropylene film or polyester film. Claim 1: A double-sided laminate film made by laminating a copolymer of polyethylene and polypropylene (C) is layered and wound, and metallicon metal is sprayed on the end face of the film, and then heat treated. Dry type capacitor as described in section. (4) Claim 1 or 2, characterized in that the margin width of the metallized film formed by vapor-depositing metals such as Zn and Aj' is within the range of 1.5 to 5M.
The dry capacitor described in item 3 or item 3.