KR790000880B1 - Sheathed device of electrolytic condenser - Google Patents

Abstract

Sealing material (I) for an electrolytic condenser was prepd. from propylene and a rubber adhesive. Therein, one among talc, asbestos and calcium carbonate was used as a filler in propylene, and the rubber adhesive was cured by peroxide. When an elemental device of the electrolytic condenser was sealed by I, the chemical stability of I was increased, compared with the other sealing materials.

Description

Sealant for Electrolytic Capacitor

The present invention relates to a sealing material for accommodating and sealing an electrolytic capacitor element in a case.

Conventionally, in order to accommodate and seal an electrolytic capacitor element in a case, the bakelite board which attached rubber | gum as a sealing material was used.

However, the material of such a sealing material does not contain harmful impurities that influence the function of the capacitor, and is an electrochemically stable material at a high temperature. However, only the hardness of rubber and bakelite and the deterioration of heat, etc. It was noted that the most common phenol and formaldehyde-based bakelite plates were used as substrates, and natural rubber was used as base materials and sulfur-vulcanized rubber was used.

On the other hand, a chemically active acid amide solvent is used as the solvent of the electrolyte in order to lower the specific resistance of the driving electrolyte of the electrolytic capacitor and improve the low temperature characteristics. However, acid amides generally deteriorate polymer materials such as rubber and bakelite, and thus deteriorate polymer materials such as bakelite with conventional rubber, and use conventional rubber-bonded bakelite to seal the wetted part, and acid amide An electrolytic capacitor using an electrolyte solution of the solvent was not an exception, and in operation at high temperatures, harmful substances were eluted from rubber and bakelite, and the terminals drawn from the anode were corroded. The terminal may be disconnected.

In the case of using such a conventional rubber bonded bakelite, there is a problem in the electrochemical safety at the wetted portion at high temperature as described above. To solve this problem, silicone, teflon, polyphenylene oxide having excellent heat resistance and chemical resistance is solved. You must use materials such as these. However, since these are expensive, they are not suitable for use, and therefore, polypropylene can be considered as a suitable material in terms of heat deterioration resistance, chemical resistance, electrical characteristics, and price. Thus, by interposing a rivet of the bakelite plate on the liquid-contacting side of the conventional rubber bonded bakelite and a lead terminal with a washer or sheet of polypropylene, corrosion of the anodized terminal during high temperature operation is prevented to some extent. Although there are problems such as adhesion between bakelite and polypropylene, even in this case, corrosion cannot be completely prevented. Thus, in order to completely prevent corrosion, it is considered that the rubber and the polypropylene are bonded together. However, in this case, corrosion is completely prevented, but because polypropylene is soft, warpage may occur, and the rubber-bonded polypropylene may be used when the capacitor element is housed in an airtight container and sealed with a rubber-bonded polypropylene. This swells and the distance between the lag terminals changes. In addition, when the lag terminal is mounted on the rubber bonded polypropylene and subjected to a temperature cycle of +85 to 25 ° C., the adhesion between the lag terminal and the rubber bonded polypropylene is lowered and moves easily. In order to solve this drawback, the thickness of the polypropylene sheet must be thickened, and it is not only suitable for use in terms of finishing dimensions, price, etc., but also has a drawback in that it is difficult to adhere to rubber and easily peels off.

The present invention has been made in view of the above, and an object thereof is to obtain an electrolytic capacitor sealing material capable of stabilizing the characteristics of a capacitor during operation of the capacitor by stabilizing leakage current and preventing corrosion of the terminal. do.

Hereinafter, an embodiment of the present invention will be described in detail. A gap consisting of paper or other porous material in which at least one electrode forms an anodized oxide film in a pair of electrode foils having lead-out terminals using anodized oxide film forming metal In the condenser element wound together with a pair of electrodes so as not to short-circuit each other, acid electrolytes such as ethylene glycol, dimethylformamide, and monomethylformamide are used as a solvent to impregnate the electrolyte solution by dissolving the electrolyte. do.

Thus, the capacitor | condenser element impregnated with electrolyte is accommodated in a container, and an electrode terminal is taken out from a capacitor element. After doing so, peroxide vulcanization such as styrene-butylene rubber (SBR), isoprene rubber (IR), or the like is used as a base material, for example, benzoyl peroxide and dimethylmethyl 2-2 'azobis isobutytritrile. An electrolytic capacitor is constituted by sealing and sealing the container by using rubber such as polypropylene plate bonded to a polypropylene plate containing a filler such as talc, asbestos, calcium carbonate, glass fiber or the like. When sealing the container using this rubberized polypropylene plate, the rubber layer may be placed inside or outside of the container, but it is often sealed by winding the container opening edge. Therefore, it is common to place a rubber layer on the outer side. And corrosion does not occur at all in any case.

As described above, the sealing material for an electrolytic capacitor according to the present invention uses a material that is resistant to use even when the talc, asbestos, calcium carbonate, glass fiber, or the like is put into polypropylene as a filler, and is softened or softened. Is easily chemically bonded using an adhesive, and is chemically stable. Therefore, even at the time of high temperature operation, an electrochemically stable characteristic even when a driving electrolyte is used as an acid amide solvent is used. It is possible to obtain an electrolytic capacitor having a low voltage, a small change in leakage current, and no corrosion of the anode lead-out terminal. In addition, because of the filling material, it is soft or flaky, and has good adhesion with the lag terminal and no warping. Moreover, since it contains fillers, it easily adheres to rubber as an adhesive. (1) Airtightness, (2) Adhesiveness of lag terminals, (3) Warp of terminal plate when (propylene) rubberized filler and rubberized filler are used as sealant of electrolytic capacitor The results of the tests performed on the adhesive strength between rubber and polypropylene are compared with those of the first table. The value in a 1st table points out the number of the thing with a bad characteristic among ten samples. In addition, the composition of each test method and a sample is as follows.

(1) Confidentiality. The capacitor element was housed in a sealed container and sealed in accordance with a known method using a terminal plate in the table, and left at -25 ° C for 1 hour, and then subjected to 10 cycles of 1 hour at + 85 ° C, followed by 85 ± It is maintained at a winding pressure of 10 mmHg, and the presence or absence of leakage of electrolyte solution from the boundary between the lag terminal and the terminal plate when the rated voltage is applied for 1 hour at room temperature of 20 to 25 °.

(2) Adhesion of Lag Terminal. Calking the rag terminal to the non-rubber polypropylene plate was performed 10 times at -25 ° C for 1 hour and + 85 ° C for 1 hour, and then 2,000 gcm between the polypropylene plate and the lag terminal. Investigate whether a couple is moving when a couple is applied.

(3) deflection of the terminal plate; In order to seal the element in a sealed container using a terminal plate, check whether the terminal plate is bent or swelled when calking the terminal plate into the sealed container.

(4) adhesive strength between rubber and polypropylene. Put a compartment to the depth of 1/2 thickness in the polypropylene side of the center of the polypropylene with the rubber of 25 mm in width and 100 mm in length, leave the rubber plate by hand, bend and break the polypropylene plate, and again, The rubber sheet is pulled off in the direction of 180 °, and it is examined whether the adhesive surface is peeled off or how much the strength is when peeling.

(5) the composition of the sample

Rubber composition or anything is as follows.

TABLE 1

In view of the above, the rubber-filled fillers according to the present invention are superior to non-fillers in terms of mechanical strength, heat aging resistance, and the like. It also exhibits excellent electrochemical properties for acid amide solvents and excellent properties that show no corrosion with the anode lead-out terminals even at high temperatures.

Next, the leakage current and the anode withdrawal in the life test applied at 85 ° C. and 10 V of an operating voltage of 10 V, an aluminum electrolytic capacitor having a capacity of 1,500 μF, which were sealed by using a polypropylene terminal plate, were filled with peroxide vulcanized rubber according to the present invention. Corrosion of terminals is shown in Table 2 compared to conventional rubberized bakelite.

As the driving electrolyte, an electrolyte dissolved in an acid amide solvent was used.

The sample composition is as follows.

Conventional

Bakelite

Based on paper, impregnated and molded with phenol and formaldehyde

Of the present invention

The above-mentioned sample rubber and talc 15% polypropylene were bonded together in the above-mentioned first table, and the rubber layer of the terminal plate was disposed on the outer side of the condenser container, and the container opening edge was wound to tighten and sealed.

TABLE 2

However, in the second table, the terminal corrosion indicates the number of corrosion in 10 samples.

As described above, according to the present invention, it is possible to obtain a sealing material for an electrolytic capacitor capable of stabilizing the characteristics at the time of capacitor operation in accordance with the stabilization of the leakage current and preventing corrosion of the terminal.

Claims (1)

Sealing material for an electrolytic capacitor, characterized in that the peroxide vulcanized rubber is formed by bonding fillers to polypropylene plates.