JP2910074B2 - Electrolyte for driving electrolytic capacitors - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic solution for driving an electrolytic capacitor used for an electrolytic capacitor for medium and high pressures.

2. Description of the Related Art As a conventional electrolytic solution for driving an electrolytic capacitor, particularly as a medium-to-high pressure electrolytic solution, as shown in Japanese Patent Publication No. 60-13293, an example using butyloctane diacid as a solute, As shown in Japanese Patent No. 15738, there are many cases where 5,6 decanedicarboxylic acid is used as a solute, but it is necessary to improve the specific resistance change of the driving electrolyte at a high temperature. In order to solve such a drawback, the main solvent is γ-butyrolactone, and by using these dibasic acids or salts thereof, there is no esterification reaction even at a high temperature, and the driving resistance hardly changes in specific resistance. It becomes an electrolyte.

Problems to be Solved by the Invention However, by using these dibasic acids or salts thereof in a solvent mainly composed of γ-butyrolactone, it is good in that the specific resistance does not easily change. A basic acid or a salt thereof alone has a disadvantage in that the complex formation reaction with aluminum used for the anode foil and the cathode foil is strong, so that the capacitance is greatly reduced at high temperatures.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a conventional drawback, and an object of the present invention is to provide an electrolytic solution for driving an electrolytic capacitor for medium and high pressure in which a decrease in the capacitance of the electrolytic capacitor at a high temperature is reduced.

Means for Solving the Problems To solve the above problems, the electrolytic solution for driving an electrolytic capacitor of the present invention comprises a solvent mainly composed of γ-butyrolactone, 1-methyl-1,7-heptanedicarboxylic acid, 1,7 -Dimethyl-1,7-heptanedicarboxylic acid, 1,3-dimethyl-
1,3,9-nonanetricarboxylic acid, 1,3-dimethyl-3-carbomethoxy-1,9-nonanedicarboxylic acid, 1,3-dimethyl-1,7-heptanedicarboxylic acid, 1-methyl-3-ethyl -1,7-heptanedicarboxylic acid, 7-ethyl-1,16
-Hexadecanedicarboxylic acid, 7,8,11,12-tetramethyl-1,18-octadecanedicarboxylic acid, 7,8-dimethyl-1,14-tetradecanedicarboxylic acid, 1-methyl-1,6
-Hexanedicarboxylic acid, 1,3-dimethyl-3-carbomethoxy-1,8-octanedicarboxylic acid, 1,3-dimethyl-1,3,8-octanetricarboxylic acid, 1-methyl-1,8-
Octanedicarboxylic acid, 1,3-dimethyl-3-carbomethoxy-1,10-decanedicarboxylic acid, 1,3-dimethyl-
1,3,10-decanetricarboxylic acid, 7-phenyl-7-methoxy-1-octanecarboxylic acid, 6-phenyl-6-
Methoxy-heptanecarboxylic acid, an acid selected from 6-ethyl-1,14-tetradecanedicarboxylic acid, or one or more of its salts as a main solute,
In addition, one or more of oxalic acid, malic acid, and tartaric acid are added and dissolved.

As the acid salt, an ammonium salt may be used, but a secondary amine salt, a tertiary amine salt, and a quaternary ammonium salt are preferable because they are less likely to deteriorate and have better solubility.

Examples of the above salts include secondary amine salts, tertiary amine salts, and quaternary ammonium salts. Specific examples of the secondary amine salts include dimethylamine salts, diethylamine salts,
Examples thereof include dipropylamine salt, dibutylamine salt, methylethylamine salt, methylpropylamine salt, methylbutylamine salt, ethylpropylamine salt, ethylbutylamine salt, and propylbutylamine salt. Specific examples of the tertiary amine salt include trimethylamine salt, dimethylethylamine salt, dimethylpropylamine salt, dimethylbutylamine salt, diethylmethylamine salt, methylethylpropylamine salt, methylethylbutylamine salt,
Dipropylmethylamine salt, methylpropylbutylamine salt, dibutylmethylamine salt, triethylamine salt,
Diethylpropylamine salt, diethylbutylamine salt,
Examples include dipropylethylamine salt, ethylpropylbutylamine salt, dibutylethylamine salt, tripropylamine salt, dipropylbutylamine salt, dibutylpropylamine salt, and tributylamine salt. Further, specific examples of the quaternary ammonium salts include tetramethylammonium salt, trimethylethylammonium salt, trimethylpropylammonium salt, trimethylbutylammonium salt, dimethyldiethylammonium salt, dimethylethylpropylammonium salt, dimethylethylbutylammonium salt, and dimethylethylammonium salt. Dipropyl ammonium salt,
Dimethylpropyl butyl ammonium salt, dimethyl dibutyl ammonium salt, triethyl methyl ammonium salt, diethyl methyl propyl ammonium salt, diethyl methyl butyl ammonium salt, dipropyl methyl ethyl ammonium salt, methyl ethyl propyl butyl ammonium salt, dibutyl methyl ethyl ammonium salt, tripropyl Methyl ammonium salt, dipropyl methyl butyl ammonium salt, dibutyl methyl propyl ammonium salt, tributyl methyl ammonium salt, tetraethyl ammonium salt, triethyl propyl ammonium salt, triethyl butyl ammonium salt, diethyl dipropyl ammonium salt, diethyl propyl butyl ammonium salt, diethyl dibutyl Ammonium salt, tripropylethylammonium salt, Propyl ethyl butyl ammonium salt, dibutyl ethylpropyl ammonium salt, tributyl ethyl ammonium salts, tetrapropylammonium salts, tripropyl butyl ammonium salt, dipropyl dibutyl ammonium salts, tributyl propyl ammonium salts.

As the solvent, BLG alone or a mixture thereof is used. As a solvent to be mixed, ethylene glycol,
Examples thereof include diethylene glycol and NN dimethylformamide, with ethylene glycol being particularly preferred.

The structural formula of the acid used in the present invention is as follows.

Action The acid used in the electrolytic solution for driving the electrolytic capacitor of the present invention has a smaller complexation reaction with aluminum than butyloctane diacid and 5,6-decanedicarboxylic acid. , Malic acid, tartaric acid or any one or more of them, they act to protect the aluminum etching pits used in the electrode foil, thereby preventing the complex formation reaction Therefore, an aluminum electrolytic capacitor having stable characteristics even at a high temperature can be obtained.

Examples Hereinafter, examples of the present invention will be described. First, Table 1 shows a comparison of characteristics of the composition and the specific resistance, the spark generation voltage, and the water content between the conventional example and the example of the present invention.

Among the electrolytes shown in Table 1, Conventional Examples 2 and 3 and Examples
Electrolytic capacitors using 1,16,23 electrolytes (rated 400V2
Table 2 shows the results of a high-temperature DC voltage application test performed at a temperature of 125 ° C. for 2000 hours for each of 20 pieces of 70 μF). Product aging is at 450V for 4 hours.

Also use an electrolytic capacitor (rated 350V330
Table 3 shows the results of a DC voltage application test performed at a temperature of 125 ° C. for 2000 hours for each of 20 μF). Aging of the product is a condition of 400V for 4 hours.

As is clear from Tables 2 and 3, the electrolytes of Examples 1, 16 and 23 of the present invention were subjected to a DC voltage application test at a high temperature of 125 ° C., and showed almost no change in capacitance. It can be seen that the electrolyte is very stable. The product ta
It is possible to obtain a highly reliable capacitor with little change in any of nδ change and appearance change.

Effects of the Invention As is clear from the above description of the embodiments, according to the present invention, it is possible to obtain an electrolytic solution for driving an electrolytic capacitor for medium and high pressures in which a change in the capacitance of a product at a high temperature is suppressed. Since γ-butyrolactone can be used as the main solvent, it is possible to provide an extremely reliable medium-to-high pressure electrolytic capacitor with little change in characteristics.

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Keiji Mori 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Hideki Shimamoto 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (56) References JP-A-62-254416 (JP, A) JP-A-57-27013 (JP, A) JP-A-1-152616 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01G 9/035

Claims (9)

(57) [Claims] (1) a solvent mainly composed of γ-butyrolactone,
1-methyl-1,7-heptanedicarboxylic acid, 1,7-dimethyl-1,7-heptanedicarboxylic acid, 1,3-dimethyl-1,3,
9-nonanetricarboxylic acid, 1,3-dimethyl-3-carbomethoxy-1,9-nonanedicarboxylic acid, 1,3-dimethyl-
1,7-heptanedicarboxylic acid, 1-methyl-3-ethyl-1,7-heptanedicarboxylic acid, 7-ethyl-1,16-hexadecanedicarboxylic acid, 7,8,11,12-tetramethyl-
1,18-octadecanedicarboxylic acid, 7,8-dimethyl-1,1
4-tetradecanedicarboxylic acid, 1-methyl-1,6-hexanedicarboxylic acid, 1,3-dimethyl-3-carbomethoxy-1,8-octanedicarboxylic acid, 1,3-dimethyl-1,3,
8-octanetricarboxylic acid, 1-methyl-1,8-octanedicarboxylic acid, 1,3-dimethyl-3-carbomethoxy-1,10-decanedicarboxylic acid, 1,3-dimethyl-1,3,10
An acid selected from -decanetricarboxylic acid, 7-phenyl-7-methoxy-1-octanecarboxylic acid, 6-phenyl-6-methoxy-heptanecarboxylic acid, 6-ethyl-1,14-tetradecanedicarboxylic acid, or An electrolytic solution for driving an electrolytic capacitor obtained by dissolving one or more of the salts as a main solute and adding one or more of oxalic acid, malic acid, and tartaric acid. 2. The electrolytic solution for driving an electrolytic capacitor according to claim 1, wherein the salt is an ammonium salt. 3. The electrolytic solution for driving an electrolytic capacitor according to claim 1, wherein the salt is a secondary amine salt. 4. The electrolytic solution for driving an electrolytic capacitor according to claim 1, wherein the salt is a tertiary amine salt. 5. The electrolytic solution for driving an electrolytic capacitor according to claim 1, wherein the salt is a quaternary ammonium salt. 6. The electrolytic solution for driving an electrolytic capacitor according to claim 3, wherein the substituent of the secondary amine salt is one or two selected from a methyl group, an ethyl group, a propyl group, and a butyl group. 7. The electrolytic solution for driving an electrolytic capacitor according to claim 4, wherein the substituent of the tertiary amine salt is one or more selected from a methyl group, an ethyl group, a propyl group and a butyl group. 8. The electrolytic solution for driving an electrolytic capacitor according to claim 5, wherein the substituent of the quaternary ammonium salt is one or more selected from a methyl group, an ethyl group, a propyl group and a butyl group. 9. The electrolytic solution for driving an electrolytic capacitor according to claim 1, wherein ethylene glycol is used as a solvent to be mixed with γ-butyrolactone.