JP3347154B2 - Electrolyte for driving electrolytic capacitors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic solution for driving an electrolytic capacitor (hereinafter referred to as an electrolytic solution).

[0002]

2. Description of the Related Art Conventionally, as an electrolyte for low pressure, an electrolyte obtained by dissolving an organic acid or a salt thereof with ethylene glycol as a main solvent has been used.

[0003]

In recent years, as the impedance of electrolytic capacitors has been reduced, downsized, and more reliable, an electrolytic solution having a low specific resistance and being stable over a wide temperature range has been required. , With ethylene glycol as the main solvent,
In an electrolytic solution obtained by dissolving an organic acid or a salt thereof, in order to lower the specific resistance, when the mixing ratio of water in the electrolytic solution is increased, there is a problem that reliability under a high-temperature atmosphere is significantly reduced. Therefore, as the electrolyte for 105 ° C. products, an electrolyte in which γ-butyrolactone is used as a main solvent and a quaternary ammonium salt of phthalic acid is dissolved is generally used. However, the quaternary ammonium salt of phthalic acid used in this electrolyte has a very high chemical cost,
[Ethylene glycol + water] based electrolyte solution
5 ° C. correspondence was desired.

[0004]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems. That is, diphenylacetic acid, azelaic acid, and sebacic acid are selected from a solution prepared by dissolving an organic acid or a salt thereof containing 5% by weight or more of adipic acid and a water content of 10% by weight or more with ethylene glycol as a main solvent. Electrolysis characterized in that at least one kind of organic acid or a salt thereof is blended in an amount of 0.5 to 5 wt%, and at least one kind selected from mannite and sorbite is added in an amount of 0.5 to 3 wt%. Liquid.

[0005]

The electrolytic solution according to the present invention prevents the hydration of the aluminum electrode foil even when a large amount of water is added to the electrolytic solution in order to lower the specific resistance of the electrolytic solution, and significantly improves the reliability in a high-temperature atmosphere.

[0006]

Embodiments of the present invention will be described below. Table 1 shows a comparative example of the composition, specific resistance, and spark generation voltage of the electrolytic solution of the present invention and the conventional electrolytic solution. Table 1
Medium electrolyte sample symbols A and B are conventional examples, C, D, E, F,
G, H, I, J, and K are examples of the present invention.

[0007]

[Table 1]

As is clear from Table 1, the electrolytes of sample symbols C, D, E, F, G, H, I, J and K according to the present invention have a higher specific resistance than the conventional electrolytes. Withstand voltage. Table 2 shows the results obtained by using an electrolytic capacitor having a rated voltage of 25 V and a resistance of 3300 μF, which was manufactured using the electrolytic solution shown in Table 1.
The result of performing a high-temperature load test at 5 ° C. for 2,000 hours is shown.

[0009]

[Table 2]

As apparent from Table 2, the electrolytic capacitors using the electrolytes of the sample symbols C, D, E, F, G, H, I, J and K according to the present invention use a conventional electrolyte. Compared with electrolytic capacitors that have been improved in reliability at high temperatures,
+ Water] -based electrolyte solution at 105 ° C.
In addition, various polyhydric alcohols such as xylose were tested in addition to the examples, and similar results were obtained. If the amount of diphenylacetic acid, azelaic acid, sebacic acid, mannite, and sorbite is less than 0.5 wt% with respect to the amount of the electrolytic solution, the above characteristics cannot be obtained. When the compounding amount of acid and sebacic acid exceeds 5 wt%, or when the compounding amount of mannitol and sorbite exceeds 3 wt%,
Electrolyte deposition occurs.

[0011]

As is evident from the above results, an electrolytic solution obtained by dissolving an organic acid or a salt thereof containing 5% by weight or more of adipic acid and 10% by weight or more of water with ethylene glycol as a main solvent. And diphenylacetic acid,
At least one kind of organic acid selected from azelaic acid and sebacic acid or a salt thereof is blended in an amount of 0.5 to 5 wt%, and at least one kind selected from mannite and sorbite is contained in an amount of 0.5 to 3 wt%. The added electrolyte prevents the hydration reaction of the aluminum electrode foil, exhibits excellent characteristics in a wide temperature range, and is very inexpensive compared to the electrolyte using a quaternary ammonium salt. Therefore, it is of great industrial and practical value.

Continuation of the front page (56) References JP-A-63-96906 (JP, A) JP-A-3-125417 (JP, A) JP-A-3-235318 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) H01G 9/035

Claims (1)

(57) [Claims] An ethylene glycol as a main solvent and 5 w
At least one or more organic acids selected from diphenylacetic acid, azelaic acid, and sebacic acid or a solution thereof in which at least t% or more of an adipic acid-based organic acid or a salt thereof and at least 10 wt% of water are dissolved. 0.5 to 5 wt% of a salt is blended, and at least one selected from mannitol and sorbite is used in an amount of 0.5 to 5 wt%.
An electrolytic solution for driving an electrolytic capacitor, wherein 3 wt% is added.