JPH07183176A - Electrolytic solution for driving electrolytic capacitors - Google Patents

Abstract

PURPOSE:To provide an electrolytic capacitor which is improved in reliability by suppressing boehmite reaction of aluminum foil constituting the cathode of the capacitor without raising the specific resistance of the aluminum foil. CONSTITUTION:An electrolytic solution for driving electrolytic capacitor constituted of a solvent composed of ethylene glycol, solute composed of a borate, and one or more kinds of additives selected from among arabite, galactite, adonite, and xylite, with the additive content controlled to 0.01-10wt.%.

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 as a main solvent and a boric acid salt as a solute, an esterification reaction between ethylene glycol and boric acid occurs,
Water of reaction is produced. Since this reaction water causes a boehmite reaction with the cathode aluminum foil in the electrolytic capacitor element, a gas is generated by the boehmite reaction, and the explosion-proof valve is activated by the generated gas particularly at high temperatures, which is reliable. There was a problem that the property becomes low.

[0003]

As described above, in the driving electrolyte solution using ethylene glycol as a solvent and a boric acid salt as a solute, a gas is generated by the boehmite reaction generated in the cathode aluminum foil due to the presence of the reaction water produced. 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 solution for driving an electrolytic capacitor according to the present invention comprises a solvent composed of ethylene glycol, a solute composed of a salt of boric acid, and one or two of arabite, galactit, adonite and xylit. It is composed of at least one kind of additive, and the additive is composed of 0.01 to 10% by weight.

[0006]

According to the electrolytic capacitor driving electrolytic solution configured as described above, one or more of arabite, galactit, adnit and xylit are added even if water is produced by the esterification reaction. By doing
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, an electrolytic solution was prepared which is composed of an example and a comparative example in which the ratio of arabite added to the driving electrolytic solution is changed, and a conventional example in which no arabite is added. The specific resistance and spark voltage at 25 ° C. of each electrolytic solution were measured.

[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 examples shown in Table 1 above, comparative examples,
Capacitance, tan δ, initial characteristics of leakage current and characteristics after high temperature load test (105 ° C, 1000 hours), gas generation amount, valve operation number of an aluminum electrolytic capacitor manufactured by using a driving electrolytic solution of a conventional example Table 2 and Table 3 show the results of the investigation.

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.
Further, in Comparative Example 1 in which the amount of added arabite was as small as 0.005% by weight, the number of valves that could not operate to suppress gas generation after the high temperature load test was large, and the amount of added arabite was as large as 15% by weight. In Comparative Example 2, the capacitance change rate and t
The value of an δ is large.

(Example B) In the above (Example A), the case where arabite was used as an additive was described.
In this (Example B), the case where galactit is used will be described. A sample similar to (Example A) except that galactit 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 Examples 3 and 4 shown in Table 4 above.
250V-47 made by using the driving electrolyte
Similar to Example A, 10 μF electrolytic capacitors were investigated for capacitance, tan δ, initial characteristics of leakage current, characteristics after high temperature load test (105 ° C., 1000 hours), gas generation amount, number of valve operations. The results obtained are shown in Tables 5 and 6.

[0019]

[Table 5]

[0020]

[Table 6]

As can be seen from Tables 5 and 6, in Comparative Example 3 in which the amount of galactit added was as small as 0.005% by weight, the number of valves operated without suppressing the gas generation after the high temperature load test. The amount of galactit added is 15
In Comparative Example 4, which is as large as wt%, the capacitance change rate and tan δ
Has a large value and shows almost the same result as in (Example A).

(Example C) As the additive, the case of using arabite in (Example A) and the case of using galactit in (Example B) was described. In this (Example C), the case of using adnit is described. Samples similar to (Example A) and (Example B) were prepared and tested, except that Adnit was used as the additive.

[0023]

[Table 7]

As is clear from Table 7, no increase in the specific resistance and no decrease in the spark voltage were observed in Examples 5 and 6.
Then, Examples 5 and 6 and Comparative Example 5 shown in Table 7 above.
Rated 250V-4 produced by using the driving electrolyte of No. 6
7 μF electrolytic capacitors, 10 capacitors each, as in (Example A) and (Example B), initial characteristics of capacitance, tan δ, leakage current, and high temperature load test (105 ° C., 1000).
Tables 8 and 9 show the results of the investigation of the characteristics, the amount of gas generation, and the number of valve operations after (time).

[0025]

[Table 8]

[0026]

[Table 9]

As is clear from Tables 8 and 9, in Comparative Example 5 in which the amount of adnit added was as small as 0.005% by weight, the number of valves operating without suppressing the gas generation after the high temperature load test. In Comparative Example 6 in which the amount of addonite added was as large as 15% by weight, the capacitance change rate and the value of tan δ were large, and (Example A) and (Example B)
Shows almost the same result as.

(Example D) As an additive, arabite was used in (Example A), galactit was used in (Example B), and adnit was used in (Example C). The case where xylit is used will be described. Samples similar to (Example A), (Example B), and (Example C) were prepared and tested, except that xylite was used as the additive.

[0029]

[Table 10]

As is clear from Table 10, Examples 7 and 8
Also, no increase in resistivity or decrease in spark voltage was observed. Next, a rated voltage of 250 V was produced using the driving electrolytic solutions of Examples 7 and 8 and Comparative Examples 7 and 8 shown in Table 10 above.
As with (Example A), (Example B), and (Example C), electrolytic capacitors of −47 μF, 10 capacitors each, initial characteristics of capacitance, tan δ, leakage current and high temperature load test (105 ° C., 1000) Tables 11 and 12 show the results of investigation of the characteristics, the amount of gas generation, and the number of valve operations after (time).

[0031]

[Table 11]

[0032]

[Table 12]

As is clear from Tables 11 and 12, Comparative Example 7 in which the amount of xylite added was as small as 0.005% by weight.
However, after the high temperature load test, the gas generation after the high temperature load test could not be suppressed, and the number of valve operations was large.
In Comparative Example 8 which is as large as wt%, the capacitance change rate and tan δ
Is larger, (Example A), (Example B)
And (Example C) show almost the same results.

In the above examples, the case where arabite, galactit, adnit and xylit were used alone as additives was described, but two or more of these additives are added in the range of 0.01 to 10% by weight. However, the same effect can be obtained.

[0035]

As described above, according to the electrolytic capacitor driving electrolytic solution of the present invention, ethylene glycol is used as a solvent, and boric acid salt is used as a solute. It is possible to decrease tan δ and ESR without increasing the specific resistance by adding one or more of the above. 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 as a main solvent and a boric acid salt as a solute, an esterification reaction between ethylene glycol and boric acid occurs,
Water of reaction is produced. Since this reaction water causes a boehmite reaction with the cathode aluminum foil in the electrolytic capacitor element, a gas is generated by the boehmite reaction, and the explosion-proof valve is activated by the generated gas particularly at high temperatures, which is reliable. There was a problem that the property becomes low.

[0003]

As described above, in the driving electrolyte solution using ethylene glycol as a solvent and a boric acid salt as a solute, a gas is generated by the boehmite reaction generated in the cathode aluminum foil due to the presence of the reaction water produced. 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 solution for driving an electrolytic capacitor according to the present invention comprises a solvent composed of ethylene glycol, a solute composed of a salt of boric acid, and one or two of arabite, galactit, adonite and xylit. It is composed of at least one kind of additive, and the additive is composed of 0.01 to 10% by weight.

[0006]

According to the electrolytic capacitor driving electrolytic solution configured as described above, even if water is produced by the esterification reaction, one or more of arabite, galactit, adnit and xylit are added. 0.01 to 1
By adding 0% by weight, the boehmite reaction of the cathode aluminum foil can be suppressed without increasing the specific resistance.
Especially effective in suppressing gas generation at high temperatures,
Stable performance can be obtained in a wide temperature range, and reliability of the electrolytic capacitor can be remarkably improved.

[0007]

EXAMPLES Examples of the present invention will be described below.

(Example A) As shown in Table 1 below, an electrolytic solution was prepared which is composed of an example and a comparative example in which the ratio of arabite added to the driving electrolytic solution is changed, and a conventional example in which no arabite is added. The specific resistance and spark voltage at 25 ° C. of each electrolytic solution were measured.

[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 examples shown in Table 1 above, comparative examples,
Capacitance, tan δ, initial characteristics of leakage current and characteristics after high temperature load test (105 ° C, 1000 hours), gas generation amount, valve operation number of an aluminum electrolytic capacitor manufactured by using a driving electrolytic solution of a conventional example Table 2 and Table 3 show the results of the investigation.

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.
Further, in Comparative Example 1 in which the amount of added arabite was as small as 0.005% by weight, the number of valves that could not operate to suppress gas generation after the high temperature load test was large, and the amount of added arabite was as large as 15% by weight. In Comparative Example 2, the capacitance change rate and t
The value of an δ is large.

(Example B) In the above (Example A), the case where arabite was used as an additive was described.
In this (Example B), the case where galactit is used will be described. A sample similar to (Example A) except that galactit 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 Examples 3 and 4 shown in Table 4 above.
250V-47 made by using the driving electrolyte
Similar to Example A, 10 μF electrolytic capacitors were investigated for capacitance, tan δ, initial characteristics of leakage current, characteristics after high temperature load test (105 ° C., 1000 hours), gas generation amount, number of valve operations. The results obtained are shown in Tables 5 and 6.

[0019]

[Table 5]

[0020]

[Table 6]

As can be seen from Tables 5 and 6, in Comparative Example 3 in which the amount of galactit added was as small as 0.005% by weight, the number of valves operated without suppressing the gas generation after the high temperature load test. The amount of galactit added is 15
In Comparative Example 4, which is as large as wt%, the capacitance change rate and tan δ
Has a large value and shows almost the same result as in (Example A).

(Example C) As the additive, the case of using arabite in (Example A) and the case of using galactit in (Example B) was described. In this (Example C), the case of using adnit is described. Samples similar to (Example A) and (Example B) were prepared and tested, except that Adnit was used as the additive.

[0023]

[Table 7]

As is clear from Table 7, no increase in the specific resistance and no decrease in the spark voltage were observed in Examples 5 and 6.
Then, Examples 5 and 6 and Comparative Example 5 shown in Table 7 above.
Rated 250V-4 produced by using the driving electrolyte of No. 6
7 μF electrolytic capacitors, 10 capacitors each, as in (Example A) and (Example B), initial characteristics of capacitance, tan δ, leakage current, and high temperature load test (105 ° C., 1000).
Tables 8 and 9 show the results of the investigation of the characteristics, the amount of gas generation, and the number of valve operations after (time).

[0025]

[Table 8]

[0026]

[Table 9]

As is clear from Tables 8 and 9, in Comparative Example 5 in which the amount of adnit added was as small as 0.005% by weight, the number of valves operating without suppressing the gas generation after the high temperature load test. In Comparative Example 6 in which the amount of addonite added was as large as 15% by weight, the capacitance change rate and the value of tan δ were large, and (Example A) and (Example B)
Shows almost the same result as.

(Example D) As an additive, arabite was used in (Example A), galactit was used in (Example B), and adnit was used in (Example C). The case where xylit is used will be described. Samples similar to (Example A), (Example B), and (Example C) were prepared and tested, except that xylite was used as the additive.

[0029]

[Table 10]

As is clear from Table 10, Examples 7 and 8
Also, no increase in resistivity or decrease in spark voltage was observed. Next, a rated voltage of 250 V was produced using the driving electrolytic solutions of Examples 7 and 8 and Comparative Examples 7 and 8 shown in Table 10 above.
As with (Example A), (Example B), and (Example C), electrolytic capacitors of −47 μF, 10 capacitors each, initial characteristics of capacitance, tan δ, leakage current and high temperature load test (105 ° C., 1000) Tables 11 and 12 show the results of investigation of the characteristics, the amount of gas generation, and the number of valve operations after (time).

[0031]

[Table 11]

[0032]

[Table 12]

As is clear from Tables 11 and 12, Comparative Example 7 in which the amount of xylite added was as small as 0.005% by weight.
However, after the high temperature load test, the gas generation after the high temperature load test could not be suppressed, and the number of valve operations was large.
In Comparative Example 8 which is as large as wt%, the capacitance change rate and tan δ
Is larger, (Example A), (Example B)
And (Example C) show almost the same results.

In the above examples, the case where arabite, galactit, adnit and xylit were used alone as additives was described, but two or more of these additives are added in the range of 0.01 to 10% by weight. However, the same effect can be obtained.

[0035]

As described above, according to the electrolytic capacitor driving electrolytic solution of the present invention, a solution of ethylene glycol as a solvent and a salt of boric acid as a solute can be used among arabite, galactit, adonite, and xylit. Addition of 0.01 to 10% by weight of the additive consisting of one kind or two or more kinds of
nδ and ESR can be reduced. 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.

 ─────────────────────────────────────────────────── ─── 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, a solute composed of a salt of boric acid, arabite, galactit,
An electrolytic solution for driving an electrolytic capacitor, which comprises one or more additives of adnit and xylit, and the additive is 0.01 to 10% by weight.