JPS5936818B2 - capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a capacitor whose lifespan is extended by improving the sealing material that seals the opening of an outer container in which a capacitor element is housed.

Conventionally, a rubber-covered phenol resin laminate, a rubber-covered polypropylene resin plate, or the like has been used as a sealing material at the opening of the outer container in order to seal the outer container in which a capacitor element is housed.

The material of this type of sealing material does not contain harmful impurities that affect the function of the capacitor, and is electrochemically stable at high temperatures, as well as exhibiting properties such as heat deterioration resistance and chemical resistance. It is used with consideration given to the combination of the following:

On the other hand, electrolytic capacitors generally generate a large amount of hydrogen gas, especially when a high-temperature voltage is applied or when there is no load at high temperatures, and the pressure inside the capacitor gradually increases, which often causes the capacitor to break down.

In order to overcome this drawback, some attempts have been made to add an oxidizing agent called a hydrogen gas absorbent to the driving electrolyte, but this is not a complete solution either.

The above-mentioned sealing materials that have been used so far do not exhibit any behavior such as absorption, adsorption, or permeation when hydrogen gas is generated, and have the disadvantage that the capacitor may break down due to an increase in internal pressure at the end of its so-called service life.

The present invention has been made in view of the above points, and uses a sealing material that adsorbs hydrogen gas generated when high-temperature voltage is applied to the capacitor or when it is left unloaded at high temperature, suppressing the increase in internal pressure and extending the life of the capacitor. The purpose is to provide vine capacitors.

An embodiment of the present invention will be described in detail below.

That is, kraft paper, porous plastic film,
A capacitor element is formed by winding the pair of electrode foils through a separator made of a porous material such as gauze without shorting each other.

The pair of electrode foils are made of a metal capable of forming an anodic oxide film, such as aluminum, tantalum, or titanium, and at least one of the electrode foils has been roughened to increase its surface area and/or to form an anodic oxide film. be.

The capacitor element is impregnated with a driving electrolyte, and the impregnated capacitor element is housed inside a container made of metal such as aluminum or synthetic resin with excellent chemical resistance, and electrode terminals are drawn out from the capacitor element. .

After that, for example, natural rubber (NR), styrene butadiene rubber (SBR), isoprene rubber (IR), nitrile butadiene rubber (NBR), isoprene isobutylene rubber (IIRL ethylene propylene rubber (EP)
The opening of the container is sealed and hermetically sealed using a laminated plate in which a rubber plate such as R) is laminated to a resin plate having a giant network structure made of polymethacrylic acid ester or polyaminophenol and capable of adsorbing hydrogen gas. This constitutes a capacitor.

The manufacturing technology of the resin plate capable of adsorbing hydrogen gas has recently made significant progress, and the resin plate has tens to thousands of pores, has a surface area of 10 to several hundreds of tri'/90, and has an excellent gas adsorption capacity. are beginning to be manufactured.

All of these are porous, but some have various ion exchange groups, and some have ion exchange functions in addition to gas adsorption ability.

When sealing and sealing the opening of a container using the rubber-covered resin plate, the resin plate is placed inside the container so that the rubber plate is on the outside of the container.

Note that the rubber plate of the laminated plate may be made of any material other than those mentioned above, but the resin plate is limited to one that has hydrogen gas adsorption ability, so the above-mentioned polymethacrylic acid ester or polyaminophenol is optimal. .

It goes without saying that a third layer of material may be inserted between the rubber plate and the resin plate to form a sandwich-like structure to form a three-layer plate.

The hydrogen gas generated inside the capacitor has a very large intermolecular distance in its gaseous state, and if a certain amount (weight) of hydrogen gas is generated, the pressure in a limited space will increase, but the resin plate When adsorbed to a capacitor, the increase in internal pressure of the capacitor can be ignored because the intermolecular distance is close.

Therefore, the sealing material of the present invention seals the capacitor by arranging a resin plate having hydrogen gas adsorption ability inside the capacitor container. With this structure, hydrogen gas is adsorbed on the resin plate and the inside of the capacitor is sealed. This can suppress pressure increases and extend life.

Next, a comparison of the amounts of hydrogen gas generated between Examples A, B, and C according to the present invention and conventional reference examples and E will be shown.

Table 1 shows the amount of hydrogen gas generated up to 3000 hours in a life test in which a voltage of 50 V and DC was applied to the sample in a constant temperature atmosphere of 105° C. using aluminum electrolytic capacitors with a rating of 50 Wv and DC-2000 μF.

The amount of hydrogen gas was collected by the underwater displacement method and weighed, considering that it is insoluble in water.

As is clear from Table 1, Example 2 of the present invention.

(B), (0 is the conventional reference example 0. It is well understood that the amount of hydrogen gas generated is extremely small compared to (f), and the hydrogen gas is adsorbed on the resin plate of the sealing material, which has the ability to adsorb hydrogen gas. .

Since hydrogen gas is generated regardless of the composition of the driving electrolyte, the sealing material of the present invention is effective regardless of the composition of the driving electrolyte.

Furthermore, although the above explanation has been given as an example of an electrolytic capacitor, the sealing material of the present invention can also be applied to paper capacitors, plastic film capacitors, and the like.

As described in detail above, according to the present invention, the opening of the capacitor container is made of a laminated plate in which a rubber plate is laminated to a resin plate having a giant network structure made of polymethacrylic acid ester or polyaminophenol and having hydrogen gas adsorption ability. Using a sealing material of A capacitor that can have a long life can be provided.

Claims (1)

[Claims] 1. The opening of the container containing the capacitor element is sealed using a sealing material consisting of a rubber plate laminated to a resin plate having a giant network structure made of polymethacrylic acid ester or polyamide phenol and capable of adsorbing hydrogen gas. A capacitor characterized in that a resin plate of the sealing material is placed inside the container to seal the container.