JPH07201665A - Electrolytic solution for driving electrolytic capacitors - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an electrolytic capacitor in which the boehmite reaction of a cathode aluminum foil is suppressed without increasing the specific resistance and the reliability is improved. [Structure] A solvent consisting of ethylene glycol and water, succinic acid, adipic acid, azelaic acid, sebacic acid, 1,
6 Decane dicarboxylic acid, maleic acid, a solute consisting of a salt of an organic carboxylic acid such as a salt of citraconic acid, and one or more additives of a dioxysugar such as rhamnose monohydrate or fucose. An electrolytic solution for driving an electrolytic capacitor , wherein the additive is 0.01 to 10% by weight.

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.

[0002]

2. Description of the Related Art Generally, an electrolytic solution having a low specific resistance value and stable characteristics over a wide temperature range is used as an electrolytic solution for driving an electrolytic capacitor. In an electrolytic solution containing ethylene glycol and water as a solvent and a salt of an organic carboxylic acid as a solute, the proportion of water is increased in order to reduce the resistance. Gas generation occurs due to the boehmite reaction of the cathode aluminum foil, and the explosion-proof valve operates, especially at high temperatures, resulting in low reliability.

[0003]

As described above, in the driving electrolyte solution using ethylene glycol and water as the solvent and the salt of the organic carboxylic acid as the solute, the gas due to the boehmite reaction that occurs in the cathode aluminum foil due to the presence of water. However, there is a drawback that gas is generated particularly at high temperatures, and a solution to this problem has been desired.

The present invention solves the above problems and suppresses gas generation due to the boehmite reaction of the cathode aluminum foil without increasing the specific resistance and improves the reliability of the electrolytic capacitor driving electrolytic solution. The purpose is to provide.

[0005]

The electrolytic capacitor driving electrolytic solution according to the present invention comprises a solvent composed of ethylene glycol and water, a solute composed of a salt of an organic carboxylic acid, and a dioxy compound such as rhamnose monohydrate and fucose. Consists of one or two or more kinds of sugars, and the additive is 0.01 to 10
It is composed of weight%.

[0006]

With the electrolytic solution for driving an electrolytic capacitor configured as described above, even if a large amount of water is contained to reduce the resistance, one kind of dioxysaccharide such as rhamnose monohydrate and fucose is used. Alternatively, by adding two or more kinds, the boehmite reaction of the cathode aluminum foil can be suppressed without increasing the specific resistance. In particular, since it is effective in suppressing gas generation at high temperatures, stable performance can be obtained in a wide temperature range, and the reliability of the electrolytic capacitor can be significantly improved.

[0007]

EXAMPLES Examples of the present invention will be described below.

(Example A) As shown in Table 1 below, rhamnose 1 which is one of dioxy saccharides was added to the driving electrolyte.
An electrolytic solution was prepared from Examples and Comparative Examples in which the addition ratio of hydrate was changed and a conventional example in which rhamnose monohydrate was not added, and the specific resistance and spark voltage at 25 ° C. of each electrolytic solution were measured. did.

[0009]

[Table 1]

As is clear from Table 1, in Examples 1 and 2, no increase in resistivity or decrease in spark voltage was observed.

Next, the capacitance, tan δ, initial characteristics of leakage current, and high temperature load of 10 aluminum electrolytic capacitors produced by using the driving electrolytic solutions of the examples, comparative examples and conventional examples shown in Table 1 above. Test (105 ° C, 1000 hours)
Tables 2 and 3 show the results of the examination of the subsequent characteristics, gas generation amount, and valve operation number.

The samples are 10 electrolytic capacitors each rated at 250 V-47 μF.

[0013]

[Table 2]

[0014]

[Table 3]

As is clear from Tables 2 and 3, the difference between the initial values of Examples 1 and 2 and the conventional example is small, but in the conventional example after the high temperature load test, gas generation due to the boehmite reaction of the cathode aluminum foil. Because of this, all valves are operating.
In addition, in Comparative Example 1 in which the addition amount of rhamnose monohydrate was as small as 0.005% by weight, the number of valves operating without suppressing the gas generation after the high temperature load test was large. In Comparative Example 2 in which the addition amount is as large as 15% by weight, the capacitance change rate and the value of tan δ are large.

(Example B) In the above (Example A), the case where rhamnose monohydrate, which is one of the dioxysaccharides, was used as an additive was described. In this (Example B), fucose is used. The case of using will be described. A sample similar to (Example A) except that fucose was used as an additive was prepared and tested.

[0017]

[Table 4]

As is clear from Table 4, no increase in resistivity or decrease in spark voltage was observed in Examples 3 and 4.
Then, Examples 3 and 4 and Comparative Example 3 shown in Table 4 above.
Rated 250V-4 produced by using the driving electrolyte of No. 4
7 μF electrolytic capacitors, 10 capacitors each, similar to (Example A), initial characteristics of capacitance, tan δ, leakage current and characteristics after high temperature load test (105 ° C., 1000 hours), gas generation amount, number of valve operations Table 5 and Table 6
Shown in.

[0019]

[Table 5]

[0020]

[Table 6]

As is clear from Tables 5 and 6, in Comparative Example 3 in which the amount of fucose added was as small as 0.005% by weight,
In Comparative Example 4 in which the number of valves that could not suppress the gas generation after the high temperature load test was large and the amount of fucose added was as large as 15% by weight, the capacitance change rate and the value of tan δ were large. And shows almost the same results as in (Example A).

In the above example, ammonium sebacate was used as the solute, but succinic acid, adipic acid, azelaic acid, sebacic acid, 1,6
Similar effects can be obtained by using salts of decanedicarboxylic acid, maleic acid, and citraconic acid.

Rhamnose monohydrate as an additive,
Although the case where fucose is used alone has been described, the same effect can be obtained by adding two or more of these additives in the range of 0.01 to 10% by weight. Further, similar effects can be obtained even when rhamnose monohydrate and other dioxy sugars other than fucose, such as quinovose, epifucose, allomethylose, altromethylose, glomethylose, and idmethylose, are used alone or in combination of two or more. .

[0024]

As described above, according to the electrolytic solution for driving an electrolytic capacitor of the present invention, rhamnose monohydrate is obtained by using ethylene glycol and water as a solvent and an organic carboxylic acid salt as a solute. The tan δ and ESR can be reduced without increasing the specific resistance by adding one or more dioxysaccharides such as fucose and fucose. In addition, since the boehmite reaction that occurs in the cathode aluminum foil can be suppressed, it is possible to provide an electrolytic capacitor having a long life by suppressing the gas generation. This suppression of gas generation has a remarkable effect of improving the life characteristics especially at high temperatures.

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[Procedure amendment]

[Submission date] August 9, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Title of Invention Electrolytic solution for driving electrolytic capacitor

[Claims]

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.

[0002]

2. Description of the Related Art Generally, an electrolytic solution having a low specific resistance value and stable characteristics over a wide temperature range is used as an electrolytic solution for driving an electrolytic capacitor. In an electrolytic solution containing ethylene glycol and water as a solvent and a salt of an organic carboxylic acid as a solute, the proportion of water is increased in order to reduce the resistance. Gas generation occurs due to the boehmite reaction of the cathode aluminum foil, and the explosion-proof valve operates, especially at high temperatures, resulting in low reliability.

[0003]

As described above, in the driving electrolyte solution using ethylene glycol and water as the solvent and the salt of the organic carboxylic acid as the solute, the gas due to the boehmite reaction that occurs in the cathode aluminum foil due to the presence of water. However, there is a drawback that gas is generated particularly at high temperatures, and a solution to this problem has been desired.

The present invention solves the above problems and suppresses gas generation due to the boehmite reaction of the cathode aluminum foil without increasing the specific resistance and improves the reliability of the electrolytic capacitor driving electrolytic solution. The purpose is to provide.

[0005]

The electrolytic capacitor driving electrolytic solution according to the present invention comprises a solvent composed of ethylene glycol and water, a solute composed of a salt of an organic carboxylic acid, and a dioxy compound such as rhamnose monohydrate and fucose. Consists of one or two or more kinds of sugars, and the additive is 0.01 to 10
It is composed of weight%.

[0006]

With the electrolytic solution for driving an electrolytic capacitor configured as described above, even if a large amount of water is contained to reduce the resistance, one kind of dioxysaccharide such as rhamnose monohydrate and fucose is used. Or, the additive consisting of two or more kinds is 0.01 to 10
Addition by weight% can suppress the boehmite reaction of the cathode aluminum foil without increasing the specific resistance. In particular, since it is effective in suppressing gas generation at high temperatures, stable performance can be obtained in a wide temperature range, and the reliability of the electrolytic capacitor can be significantly improved.

[0007]

EXAMPLES Examples of the present invention will be described below.

(Example A) As shown in Table 1 below, rhamnose 1 which is one of dioxy saccharides was added to the driving electrolyte.
An electrolytic solution was prepared from Examples and Comparative Examples in which the addition ratio of hydrate was changed and a conventional example in which rhamnose monohydrate was not added, and the specific resistance and spark voltage at 25 ° C. of each electrolytic solution were measured. did.

[0009]

[Table 1]

As is clear from Table 1, in Examples 1 and 2, no increase in resistivity or decrease in spark voltage was observed.

Next, the capacitance, tan δ, initial characteristics of leakage current, and high temperature load of 10 aluminum electrolytic capacitors produced by using the driving electrolytic solutions of the examples, comparative examples and conventional examples shown in Table 1 above. Test (105 ° C, 1000 hours)
Tables 2 and 3 show the results of the examination of the subsequent characteristics, gas generation amount, and valve operation number.

The samples are 10 electrolytic capacitors each rated at 250 V-47 μF.

[0013]

[Table 2]

[0014]

[Table 3]

As is clear from Tables 2 and 3, the difference between the initial values of Examples 1 and 2 and the conventional example is small, but in the conventional example after the high temperature load test, gas generation due to the boehmite reaction of the cathode aluminum foil. Because of this, all valves are operating.
In addition, in Comparative Example 1 in which the addition amount of rhamnose monohydrate was as small as 0.005% by weight, the number of valves operating without suppressing the gas generation after the high temperature load test was large. In Comparative Example 2 in which the addition amount is as large as 15% by weight, the capacitance change rate and the value of tan δ are large.

(Example B) In the above (Example A), the case where rhamnose monohydrate, which is one of the dioxysaccharides, was used as an additive was described. In this (Example B), fucose is used. The case of using will be described. A sample similar to (Example A) except that fucose was used as an additive was prepared and tested.

[0017]

[Table 4]

As is clear from Table 4, no increase in resistivity or decrease in spark voltage was observed in Examples 3 and 4.
Then, Examples 3 and 4 and Comparative Example 3 shown in Table 4 above.
Rated 250V-4 produced by using the driving electrolyte of No. 4
7 μF electrolytic capacitors, 10 capacitors each, similar to (Example A), initial characteristics of capacitance, tan δ, leakage current and characteristics after high temperature load test (105 ° C., 1000 hours), gas generation amount, number of valve operations Table 5 and Table 6
Shown in.

[0019]

[Table 5]

[0020]

[Table 6]

As is clear from Tables 5 and 6, in Comparative Example 3 in which the amount of fucose added was as small as 0.005% by weight,
In Comparative Example 4 in which the number of valves that could not suppress the gas generation after the high temperature load test was large and the amount of fucose added was as large as 15% by weight, the capacitance change rate and the value of tan δ were large. And shows almost the same results as in (Example A).

In the above example, ammonium sebacate was used as the solute, but succinic acid, adipic acid, azelaic acid, sebacic acid, 1,6
Similar effects can be obtained by using salts of decanedicarboxylic acid, maleic acid, and citraconic acid.

Rhamnose monohydrate as an additive,
Although the case where fucose is used alone has been described, the same effect can be obtained by adding two or more of these additives in the range of 0.01 to 10% by weight. Further rhamnose monohydrate, other dioxy sugars e.g. quinovose except fucose, and Epifukosu, Aromechirosu, alto b methylate loin, Guromechirosu, and <br/> alone or two or more additives such as Idomechirosu, 0.01 this 10
Similar effects can be obtained even when added in a weight percentage .

[0024]

As described above, according to the electrolytic solution for driving an electrolytic capacitor of the present invention, rhamnose monohydrate is obtained by using ethylene glycol and water as a solvent and an organic carboxylic acid salt as a solute. 0.01 to 10 weight of an additive consisting of one or more dioxy sugars such as fucose and fucose
% Without increasing the specific resistance by adding
It is possible to reduce tan δ and ESR. Also,
Since the boehmite reaction that occurs in the cathode aluminum foil can be suppressed, it is possible to provide an electrolytic capacitor having a long life by suppressing the gas generation.
This suppression of gas generation has a remarkable effect of improving the life characteristics especially at high temperatures.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kiyoshi Sakamoto 1-1, Sachimachi, Nagai City, Yamagata Prefecture Marcon Electronics Co., Ltd. (72) Inventor, Kazuhiro Higuchi 1-1, Sachimachi, Nagai City, Yamagata Prefecture Marcon Electronics Co., Ltd. (72) Inventor Tetsuo Aoyama 182 Tayuhama Shinwari Niigata, Niigata Prefecture Mitsubishi Gas Chemical Co., Ltd. Niigata Research Center (72) Inventor Mayumi Haneda Tayuhama Shinwari 182 Niigata City, Niigata Mitsubishi Gas Chemical Co., Ltd. Niigata Research Center

Claims (1)

[Claims] 1. A solvent composed of ethylene glycol and water, a solute composed of a salt of an organic carboxylic acid, and one or more additives of a dioxy saccharide. % Electrolytic solution for driving electrolytic capacitors.