JPS61184809A - Electrolytic liquid for driving electrolytic 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 U) Field of Industrial Application The present invention relates to a' (electrolytic solution for driving an electrolytic capacitor (hereinafter referred to as electrolytic solution) l2).

(b) Prior art In recent years, printed circuit board mounting has become more dense and reliable. Since such a solvent has high permeability, there is a possibility that the solvent may permeate and diffuse through the rubber backing and penetrate into the capacitor.

This infiltrated solvent decomposes into chloride ions, which cause corrosion when the capacitor is loaded at high temperatures, resulting in deterioration of its characteristics. In order to prevent deterioration due to this corrosion,
B-62989 Publication C; As can be seen, a method of adding boron oxide as a corrosion inhibitor to electrolyte C; has also been proposed, but although it has some degree of prevention effect, the high temperature load test (deterioration of the properties by 22 was significant) .Also, special public service 1986-1
Although a method of adding a silver compound has been proposed as in Japanese Patent No. 538, the solubility in solvent C is low and a sufficient effect of preventing corrosion has not been obtained.

(c) Problems to be Solved by the Invention Conventional electrolytes have problems such as corrosion during high-temperature loads when capacitors are cleaned with chlorinated solvents.

B) Means for Solving the Problems The present invention is characterized in that mandic acid or a salt thereof is added to and dissolved in an electrolytic solution consisting of a solvent and a solute.

(e) Action Mandelic acid (CaHsCH(OH)COOH) Also, mandelic acid salt forms a complex compound with chloride ions that cause corrosion, and removes chloride ions from the corrosion reaction system (by removing them). , which appears to prevent corrosion.

(F) Example In the present invention C2, the solvent may be ethylene butrycol, a mixed solvent of ethylene glycol and methylcarbyl, or a mixture of methylcellosolve, N-ethylformamide, diethylene glycol, dimethylformamide, etc. etc. are used.

In the case of unexploded 11C, the solute is an ammonium salt of an organic acid such as adipic acid, formic acid, or benzoic acid, or C-
Ammonium salts and amine salts such as boric acid, maleic acid, and azelaic acid are used.

The present invention provides an electrolytic solution consisting of the above-mentioned solvent and solute [: mandelic acid or its salt? It is added and dissolved. The amount of mandelic acid added is preferably 0.1y or more and 20
It is less than or equal to y. Hereinafter, the present invention will be described in detail with specific examples (g!, 1). Conventional electrolyte solutions (g) to (b) are shown.

Table 1 Table 2 uses each of the above electrolytes (A) to @, with a rating of 50V,
The results of aluminum electrolytic capacitors impregnated with 47 μF elements were prototyped, immersed in 1,1,1-trichloroethane for 10 minutes, and subjected to an accelerated high temperature load test at 105°C. The structure of the sample capacitor is a well-known structure, and consists of a capacitor element C made of chemically etched aluminum foil and shaded foil wrapped with separator paper 'kH':
The device is impregnated with electrolyte and housed in an aluminum case with a rubber backing.

Table 2: Application of rated voltage at 105°C As is clear from Table 2, accelerated high-temperature load test of capacitors under application of rated voltage for 500 hours at 105°C C:
With the conventional electrolyte, abnormalities such as I: Corrosion and impressions were observed during the test. This refers to a situation where the corroded portion has become disconnected. On the other hand, in non-inventive C: such electrolytes (8) to (E)-2, no such abnormality was observed.
The anti-corrosion effect of mandelic acid and its salts has been recognized.

In addition, as shown in Table 3 [: (
2. Two types of electrolytic solution CI) (J) and a conventional electrolytic solution (J) for comparison were prepared, and C: Corrosion prevention effect was confirmed in the same manner as described above.

@Table 3 Table 4 uses each of the above electrolytes (I) to (F), and the rating is 50.
The results of aluminum electrolytic capacitors impregnated with V and C of 470 μF were fabricated as prototypes, and then immersed in a fluorocarbon solvent for 10 minutes and subjected to a high-temperature load test at 85° C. The results are shown below. Note that the form of the capacitor is the same as that described above.

Table 4: Rated voltage application at 85°C As shown in Table 4, an abnormality of corrosion was observed with the conventional electrolyte, but the electrolysis of the present invention with C: in which mandelic acid and its salts were added. In the liquid, no abnormalities such as corrosion were observed, indicating that it has a corrosion-preventing effect.

Next, the amount of mandelic acid or its salt added was as shown in Table 5≦2 (; Various electrolytes (Q~0) were prepared.

Table 5 Table 6 μm Each of the above electrolytes 0 to 0 was applied in the same manner as shown in Table 2 1. Aluminum electrolytic capacitors impregnated with element C2 each having a rating of 50'/47 μF were prototyped. After that, 1t1*1-trichloroethane (soaked for -10 minutes,
The lid was subjected to an accelerated high temperature load test at 105°C and the results are shown below. Note that the form of the capacitor is the same as that described above.

Below is the margin No. 6 Table 105℃ rated voltage application From Table 6, accelerated high temperature load test of capacitor at 105℃ rated voltage application for 500 hours. It was found that an electrolytic solution of 0.1y or more has an effective effect on corrosion prevention I:. However, the amount of mandelic acid added is 100ff of the solvent.
If it exceeds 20y with respect to i/, although there is an anti-corrosion effect, capacitor characteristics such as an increase in tan σ deteriorate, which is not preferable. Therefore, 100ml of solvent is added to the amount of mandelic acid added.
1! It can be seen that c is preferably 011y or more and 209 or less.

(G) As described in detail of the invention, according to the present invention C2, the electrolyte C;
5. Effective against corrosion, etc. after cleaning with chlorinated solvents C;
It can be prevented. Furthermore, since the characteristics of the electrolytic capacitor do not change much even under long-term high-temperature loads, it is possible to extend the life of the electrolytic capacitor. Therefore, the performance of electrolytic capacitors is dramatically improved by the present invention.

Claims (2)

[Claims] (1) An electrolytic solution for driving an electrolytic capacitor, characterized in that mandelic acid or a salt thereof is added and dissolved in an electrolytic solution consisting of a solvent and a solute. (2) The amount of the mandic acid or its salt added is 10% of the solvent.
The electrolytic solution for driving an electrolytic capacitor according to claim 1, characterized in that the amount is 0.1 g or more and 20 g or less per 0 ml.