JPH0797538B2 - Metallized polypropylene film capacitors - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metallized polypropylene film capacitor in which a case equipped with a pressure sensitive protection device is filled with a liquid or wax-like insulating material.

2. Description of the Related Art Conventionally, in a metallized polypropylene film capacitor equipped with a pressure-sensitive safety device, in order to sensitively transfer the pressure of gas generated when the capacitor is broken to the pressure-sensitive safety device, and also in the resistance of the capacitor itself. In order to increase the voltage, fill it with a liquid or wax-like insulating material,
It was impregnated.

As the insulating material, dioctyl phthalate (DO
P), ester-based insulating oil such as torque resyl phosphate (TCP) and aromatic hydrocarbon-based insulating oil such as alkylbenzene (AB) phenylxylylethane (PXE), castor oil, flaxseed oil, cottonseed salad oil, cottonseed Use vegetable oils such as white oil, tung oil, rapeseed oil, etc., or polybutene, silicone oil, etc., alone or in admixture of multiple kinds, or add appropriate antioxidants and epoxy type scavengers. Insulating oil, paraffin wax, microcrystalline wax, polyethylene wax, etc. are generally used alone or as a mixture of two or more kinds, or in addition, wax-like ones in which insulating oil such as polybutene is mixed are used.

Problems to be Solved by the Invention However, in recent years, miniaturization of these capacitors has been demanded, and under the high withstand voltage accompanying miniaturization, tan δ gradually rises during charging at high temperature. At last, it turned out that there is a danger of destruction. Therefore, in these metallized polypropylene film capacitors, it has been desired that the pressure sensitive safety device operates sensitively and that stable capacitor characteristics that are not easily destroyed are satisfied at the same time.

Means for Solving the Problems That is, the present invention provides a metallized polypropylene film capacitor element formed by winding a double-sided metallized polypropylene film and a non-metallized polypropylene film, or a pair of single-sided metallized polypropylene films, and A metallized polypropylene film capacitor housed in a case equipped with a safety device and filled with a liquid or wax-like insulating material, wherein at least the metallikon part of the metallized polypropylene film capacitor element is covered with a solid coating material, and The entire polypropylene film capacitor element is covered with the liquid or wax-like insulating material.

Action With the above configuration, the pressure-sensitive safety device operates sensitively because a liquid or wax-like insulating material that can sensitively transfer the pressure of gas generated when the capacitor is broken is used as the filling insulating material. However, it was found that by covering the metallikon part with a solid coating material and strengthening it, it is possible to prevent deterioration of tan δ with the passage of time at high temperature power application, and to achieve both properties.

Embodiments Embodiments of the present invention will be described below with reference to the accompanying drawings.

(Example 1) A zinc electrode was formed by vapor deposition on one surface of a double-sided corona-treated polypropylene film (trade name: YK-41, Toray, Inc .: thickness 6 μm). In this case, from the metallikon contact part
The range of 5 mm was low resistance (average 2.5 Ω / □), and the other parts were relatively high resistance (15 to 30 Ω / □, average 20 Ω / □).
Copper was used as the nuclear metal.

Two single-sided vapor-deposited films (width: 80 mm) were stacked, closely wound on a plastic bobbin 1 (PBT molded product) (external diameter 10 mmφ), subjected to zinc metallikon to lead out the electrodes, and then vacuum-aged ( 110 ℃, 15Hr), 45μF
A metallized film capacitor element 2 of was obtained. In addition, 3 shows a metallikon part. This capacitor element 2 was made into an epoxy resin composition (Matsushita Electric Works, Ltd. product name: Main agent MDR-4 (100),
Hardener MDH-4 (38)) and put under reduced pressure (10mmHg) 10
It was left for a minute, returned to atmospheric pressure, taken out with the epoxy resin composition impregnated in the capacitor element, and hung in a high temperature tank (90 ° C.) by an appropriate method to cure. After curing,
Although most of the resin dropped and dropped, a thin film-shaped epoxy resin composition (solid coating material) 4 was formed on the capacitor element 2 (FIG. 2). As shown in FIG. 1, the capacitor element 2 was housed in a case 6 equipped with a bellows type pressure sensitive safety device 5 in a round aluminum case and filled with a wax composition (insulating material) 7 having a melting point of 80 ° C. . Incidentally, 8 is an insulating inner case, and 9 and 9'are terminals. Further, in FIG. 1, the solid coating material 4 is thin and is omitted.

High temperature durability test (80 ℃, A
The result of C500V is shown in FIG. For comparison, the results for the capacitor (conventional product) filled with the wax composition without the epoxy impregnation treatment are also shown. In FIG. 3, A shows the characteristics of the product of this example and B shows the characteristics of the conventional product. It can be seen from FIG. 3 that the product of this example has a stable tan δ and exhibits stable high temperature durability due to the epoxy impregnation.

Example 2 A zinc vapor deposition electrode (average film resistance: 4.5 Ω / □) was provided on one surface of a double-sided corona-treated polypropylene film (trade name: YK-41, Toray, Inc .; thickness 7.5 μm).

Two sheets of this single-sided vapor-deposited film (width: 40 mm) are stacked, wound closely on a bobbin 1 made of plastic (outer diameter 8 mm ^φ ) as shown in Fig. 4, metallikon of solder is applied, and electrodes are led out, then vacuumed. aging (110 ℃, 15 ^H) performs, 20 [mu]
A metallized film capacitor element 2 of F was obtained. Using this capacitor element 2, the same epoxy resin composition as in Example 1 was used to dip and cover the metallikon portion 3 of the capacitor element in the atmosphere as shown in FIG. Covered with resin composition (solid coating material) 4.

This capacitor element was housed in a round aluminum case in a case equipped with a bellows type pressure sensitive protection device as in Example 1, and was filled with dioctyl phthalate (DOP). The results of the high temperature durability test (80 ° C, AC500V) are shown in Fig. 5 together with the sample (conventional product) not subjected to the dip treatment.

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

As is clear from FIG. 5, the tan δ of the product of this example showed little change, and the tan δ of the conventional product increased with the passage of time.

As described above, by covering at least the metallikon portion of the metallized polypropylene film capacitor element with the solid coating material, it is apparent that the tan δ of the capacitor is little changed and stable durability is exhibited.

The solid coating material 4 is an epoxy resin composition,
Urethane-based resin composition, diallyl phthalate-based resin composition, unsaturated polyester-based resin composition, guanamine-based resin composition, phenol-based resin composition, urea-based resin composition, melamine-based resin composition, acrylic-based resin composition Material, silicone resin composition, polyimide resin, polycarbonate resin, polystyrene, cyanoethylated pullulan,
A silane coupling agent (for example, Shin-Etsu Chemical Co., Ltd. product name: KBM403, chemical name: γ-glycidoxypropyltrimethoxysilane), titanium coupling agent, pitch (coal tar), etc. may be used. . In particular, the epoxy resin composition and the acrylic resin composition are characteristically and industrially excellent. The coating methods include casting, impregnation, dipping,
In addition to powder coating (fluxing, electrostatic), general coating methods such as coating with a brush-like material are possible.

If necessary, the coating may be cured using heat, light, ultraviolet rays, electron beams, or the like. Further, as a pressure sensitive type safety device 5 for wet and semi-wet capacitors, a bellows portion is provided in a case 6 so that the bellows is extended by the gas pressure at the time of breakage so as to cut the lead wire of the capacitor, or at the time of breakage. The current path may be cut off by utilizing the deflection (deformation) of the lid at the upper part of the case due to the gas pressure.

Further, as the material of the case 6, a metal case such as aluminum or iron, or a resin such as polypropylene, nylon, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, or Duracon is used.

Zinc, aluminum, chrome,
Cobalt, tin, titanium, copper, nickel, molybdenum,
A vacuum deposition film of tantalum or the like is used, and it is effective to use it in combination with a film deposited to a uniform film thickness, or in particular, a film deposited with a thick metallikon contact portion. Further, a single-sided vapor deposition metallized polypropylene film or a double-sided vapor deposition metallized polypropylene film can be used.

Furthermore, by using a double-sided corona-treated polypropylene film, adhesion is provided between the film layers (5 mm at 20 mm width).
It is particularly effective to use a device that is densely wound with a film having a thickness of at least gram). In addition, any of the conventionally used insulating fillers can exert the effect.

EFFECTS OF THE INVENTION As described above, according to the present invention, it is possible to realize a metallized polypropylene film capacitor that is compact and has a high withstand voltage and that is equipped with a pressure-sensitive type safety device with sensitive operability. .

[Brief description of drawings]

FIG. 1 is a sectional view of a metallized polypropylene film capacitor showing an embodiment of the present invention, and FIG.
Figure 3 shows the same metallized polypropylene film capacitor.
FIG. 4 is a tan δ characteristic diagram, FIG. 4 is a sectional view of a main part of a metallized polypropylene film capacitor showing another embodiment of the present invention, and FIG. 5 is a tan δ characteristic diagram of the metallized polypropylene film. 2 ... Metallized polypropylene film capacitor element,
3 ... Metallicon part, 4 ... Solid coating material, 6 ... Case, 7 ... Insulating material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hirayuki Nakajima 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP 54-118567 (JP, A) JP 59- 52826 (JP, A) JP 52-10556 (JP, A) Actual development 60-169832 (JP, U) JP 55-7935 (JP, B2)

Claims (1)

[Claims] 1. A metallized polypropylene film capacitor element formed by winding a double-sided metallized polypropylene film and a non-metallized polypropylene film, or a pair of single-sided metallized polypropylene films, is housed in a case equipped with a pressure sensitive safety device. A metallized polypropylene film capacitor filled with a liquid or waxy insulating material, wherein at least the metallikon portion of the metallized polypropylene film capacitor element is covered with a solid coating material, and the entire metallized polypropylene film capacitor element is A metallized polypropylene film capacitor characterized by being covered with a liquid or wax-like insulating material.