JPS62247515A - Metallized film 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 Field of the Invention The present invention relates to metallized film capacitors whose casing is filled with a liquid or waxy insulating material.

Conventional technology: 17! ! It, f first 1
In film capacitors, in order to sensitively transmit the pressure of the gas generated when the capacitor breaks to the pressure-sensitive safety device, and to increase the withstand voltage of the capacitor itself. They were filled with or impregnated with a liquid or waxy insulating material to increase their performance.

In addition, as an insulating material, dioctyl phthalate (DOP
), ester-based insulating oils such as torque cresyl phosphate (TCP), alkylbenzene (AB), phenylxylethane (P Vegetable oils such as pressed oil, tung oil, rapeseed oil, or polybdenum,
Insulating oils that use silicone oil alone or in combination, or with the addition of appropriate antioxidants or scavengers such as epoxy, paraffin wax, microcrystalline wax, polyethylene wax, etc. Generally, υ is used either singly or as a mixture of multiple types, and wax-like products are used mixed with insulating oil such as polybutene.

Problems to be Solved by the Invention However, in recent years, there has been a demand for miniaturization of these capacitors, and with the increase in withstand voltage that accompanies miniaturization, −δ gradually increases during energization at high temperatures. However, it has become clear that there is a risk of destruction.

Means for Solving the Problems In order to solve the above problems, the present invention is characterized in that at least the metallized portion of the metallized film capacitor element is covered with a solid coating material.

Effect: According to the above configuration, -δ is stabilized and stable high temperature durability is exhibited.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(Example 1) A vapor-deposited zinc electrode was formed on one side of a double-sided corona-treated polypropylene film (Toshisha trade name: YK-41: thickness 6 μm). In this case, the range of the metal contact part is set to low resistance (average 2.tsQ1 mouth),
Other parts have relatively high resistance (15 to 30 Ω/mouth, average 20
Q/mouth).

Copper was used as the nuclear metal.

Two of these single-sided vapor-deposited films (width: som) are stacked together, tightly wound around a plastic bobbin 1 (molded PBT) with an outer diameter of 1018φ, coated with zinc metallion, and then subjected to electrode extraction, followed by vacuum aging ( 110℃, 15Hr)
4 sμF metallized film capacitor element 2
I got it. Note that 3 indicates a metallic contact portion. This capacitor element 2 is coated with an epoxy resin composition (Matsushita Electric Works product name: base agent MDR-4 (100), curing agent MDH-4 (38)).
The epoxy resin composition was impregnated into the capacitor element, and the capacitor element was taken out and placed in a high-temperature bath (SO'').
C) for curing by hanging in an appropriate manner. After curing, most of the resin dripped off, but a thin film-like epoxy resin composition (solid coating material) 4 was formed on the capacitor element 2 (FIG. 2). As shown in FIG. 1, this capacitor element 2 is housed in a round aluminum case 6 equipped with a bellows-type pressure-sensitive safety device 6, and filled with a wax composition (insulating material) 7 having a melting point of 80''C. Note that 8 is an insulating inner case, and 9 and 9' are terminals.Also, in FIG. 1, the solid covering material 4 is omitted because it is thin.

High temperature durability test (80°
c, AC300V) are shown in FIG.

For comparison, the results for a capacitor (conventional product) filled with a wax composition without epoxy impregnation treatment are also shown. In FIG. 3, A shows the characteristics of the product of this embodiment, and B shows the characteristics of the conventional product. From FIG. 3, it can be seen that the product of this example has a stable iδ due to the epoxy impregnation, and exhibits stable high-temperature durability.

(Example 2) On one side of a double-sided corona-treated polypropylene film (Toshisha trade name: YK-41; thickness 7.6 prn), a zinc vapor-deposited electrode (average film resistance: 4.6 Ω/hole) ft.

Two of these single-sided vapor deposited films (width: 40 m) were stacked, and a fourth
As shown in the figure, it is tightly wound around a bobbin 1 made of plastic (outer diameter 5jIIIφ), solder is applied to the bobbin 1, electrodes are led out, and then vacuum aging (100°C 216°
H) was carried out to obtain a 20 μF metallized film capacitor element 2. Using this capacitor element 2, the same epoxy resin composition as in Example 1 is dipped in the atmosphere so as to cover the metallcon part 3 of the capacitor element as shown in Fig. 4, and cured. Covered with resin composition (solid coating material) 4.

As in Example 1, this capacitor element was housed in a round aluminum case equipped with a bellows-type pressure-sensitive safety device, and filled with dioctyl phthalate (DOP).

High temperature durability test (ao'c.

Figure 6 shows the results of the test (AC300V) along with a sample (conventional product) that was not subjected to dipping.

In FIG. 5, C indicates the characteristics of the product of this embodiment, and D indicates the characteristics of the conventional product.

As is clear from FIG. 5, the product of this example has a tan δ
There was little change in -δ of the conventional product, which increased over time.

As described above, it is clear that by covering at least the metallicon portion of the metallized film capacitor element with a solid coating material, the change in tan δ of the capacitor is small and stable durability is exhibited.

In addition, as the solid coating material 4, an epoxy resin composition,
Urethane resin compositions, diallylphthalate resin compositions, unsaturated polyester resin compositions, guanamine resin compositions, phenolic resin compositions, urea resin compositions, melamine resin compositions, acrylic resin compositions silicone resin compositions, polyimide resins, polycarbonate resins, polystyrene, cyanoethylated pullulan, sila/coupling agents (for example, Shin-Etsu Chemical Co., Ltd. product name: KBM403. Chemical name: γ-glycidoxypro viltrimethoxysilane), a titanium coupling agent, pitch (coal tar), etc. may also be used. In particular, epoxy resin compositions and acrylic resin compositions are excellent in terms of characteristics and industry.

Coating methods include casting, impregnation, dipping, and (flow immersion).

In addition to electrostatic) powder coating, various coating methods such as coating with a general brush-like object are possible.

If necessary, the coating may be cured using heat, light, ultraviolet light, electron beams, or the like.

In addition, the pressure-sensitive safety device 6 for wet and semi-wet capacitors includes one in which a bellows part is provided in the case 6, and the bellows is expanded by the gas pressure at the time of breakdown, thereby cutting the lead wire of the capacitor. The current path may be cut off by utilizing the deflection (deformation) of the lid at the top of the case due to the gas pressure.

Furthermore, the material of the case 6 is a metal case such as aluminum or iron, or polypropylene.

Resins such as nylon, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, and Duracon are used.

Capacitor electrodes include zinc, aluminum, chromium, cobalt, soot, titanium, copper, and nickel.

A vacuum-deposited film of molybdenum, tantalum, or the like is used, and it is effective to use it in combination with a film deposited to a uniform thickness or a film deposited particularly thickly on the metallicon contact portion. Also,
Single-sided metalized films or double-sided metalized films can be used.

Further, it is particularly effective to use a tightly wound element using a film that has adhesive properties (5 grams or more at 20 mm width) between the film layers, such as by using a double-sided corona-treated polypropylene film. In addition, any of the conventionally used insulating fillers can be used effectively.

Effects of the Invention As described above, according to the present invention, a capacitor with high withstand voltage,
In other words, miniaturization is possible, which has great industrial potential.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a metallized film capacitor showing an embodiment of the present invention, Fig. 2 is a sectional view of the same essential parts, Fig. 3 is a -δ characteristic diagram of the same metallized film capacitor, and Fig. 4 is a main part of the metallized film capacitor. FIG. 6 is a sectional view of a main part of a metallized film capacitor showing another embodiment of the invention, and is a -δ characteristic diagram of the same metallized film capacitor. 2...Metalized film capacitor element, 3...
...Metallicon part, 4...Solid covering material, e
...Case, finished...Insulating material. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2-U is 7m Figure 2 Figure 3

Claims (1)

[Claims] A metallized film capacitor in which a metalized film capacitor element formed by winding a double-sided metalized polypropylene film and a non-metallized polypropylene film, or a pair of single-sided metalized polypropylene films is housed in a case and filled with a liquid or wax-like insulating material. . A metallized film capacitor, characterized in that at least a metallicon portion of the metallized film capacitor element is covered with a solid coating material.