JPH10112421A - Electrolyte for driving electrolytic capacitor and electrolytic capacitor using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrolyte for driving an electrolytic capacitor in which odor of vaporized gas is less, a sealing rubber material of the electrolytic capacitor is not degraded, and conductivity is high, by dissolving, in a medium containing γ-butyrolactone, a salt of carboxylic acid and the amine expressed in a specific equation as an electrolytic salt. SOLUTION: An electrolyte for driving an electrolytic capacitor is obtained by dissolving, in a medium containing γ-butyrolactone, a salt of carboxylic acid and the amine expressed in an equation as an electrolytic salt. Here, R1-R3 are hydrogen, or alkyl group of carbon numbers, while two or more of R1-R3 can be identical, and at least, one of them should contain allyl group. The amine in the equation contains allyl group at its end, so ion mobility of the amine becomes large, for higher conductivity. In addition, the amine in the equation does not generate strong alkali under electrolysis, so no sealing rubber material is degraded. Further, the amine in the equation has less odor, with less odor of generated electrolyte vaporized gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrolytic solution for driving an electrolytic capacitor used for an electrolytic capacitor and an electrolytic capacitor using the same.

[0002]

2. Description of the Related Art As a conventional electrolytic solution for driving an electrolytic capacitor, there is known an electrolytic solution in which an ammonium salt of boric acid or adipic acid is dissolved as an electrolyte in an ethylene glycol solvent.

[0003] Further, as an electrolyte having excellent low-temperature characteristics,
An organic or inorganic acid or a salt thereof dissolved as an electrolyte in a solvent such as γ-butyrolactone having low viscosity at low temperatures is used as an electrolyte. 54-1024
Is known. Further, an electrolytic solution using a quaternary ammonium salt of maleic acid or citraconic acid as an electrolyte (JP-A-3-6646) or an electrolytic solution using a quaternary ammonium salt of an aromatic carboxylic acid as an electrolyte (JP-A-3-3648) No. 8092) is also known.

[0004]

However, an electrolytic solution in which an ammonium salt of boric acid or adipic acid is dissolved in an ethylene glycol solvent has a problem that the conductivity at a low temperature is greatly reduced.

[0005] An electrolytic solution obtained by dissolving a quaternary ammonium salt as an electrolyte in a γ-butyrolactone solvent has a high conductivity, but a strong alkaline substance is generated by electrolysis of quaternary ammonium ions, and this is a sealing member. However, there is a problem that the rubber packing may deteriorate, and it is difficult to guarantee for a long time.

An electrolytic solution in which a phthalic acid salt of triethylamine or a phthalic acid salt of diethylamine (secondary amine) is dissolved in a γ-butyrolactone solvent as an electrolyte does not produce a strongly alkaline substance, but has a sufficient electric conductivity. However, there was a problem that it was not.

As amine materials having relatively high conductivity,
Trimethylamine and N, N-dimethylethylamine are known, but the odor of amine components and their carboxylate solutions is putrid odor, and the vapor pressure of the amine components is high and it is easy to volatilize. At the time of valve opening or disposal, there is a problem in environmental protection that the odor is diffused over a wide area or in disposal of the electrolytic capacitor after use.

The present invention solves the above-mentioned conventional problems. The odor of the electrolyte vaporized gas generated when the electrolytic capacitor is opened or discarded is small, and the sealing rubber material of the electrolytic capacitor is not deteriorated. The purpose of the present invention is to provide an electrolytic solution for driving an electrolytic capacitor having high conductivity, and to provide a highly reliable low impedance electrolytic capacitor in consideration of environmental resistance by using this electrolytic solution. is there.

[0009]

Means for Solving the Problems To achieve the above object, an electrolytic solution for driving an electrolytic capacitor of the present invention comprises a solvent containing γ-butyrolactone and a salt of a carboxylic acid and an amine represented by the following chemical formula (4). It is dissolved as an electrolyte salt, and according to this configuration, the odor of the electrolyte vaporized gas generated at the time of opening and disposal of the electrolytic capacitor is small, and the sealing rubber material of the electrolytic capacitor is not deteriorated, and furthermore, An electrolytic solution for driving an electrolytic capacitor having high conductivity can be provided.

[0010]

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[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention comprises dissolving a salt of a carboxylic acid and an amine represented by the formula (5) as an electrolyte salt in a solvent containing γ-butyrolactone; Since the amine represented by the chemical formula (5) has an allyl group at the terminal, the ionic radius of the amine is smaller than that of the amine having no allyl group at the terminal, thereby increasing the mobility of ions in the solution. Therefore, high conductivity can be obtained.

The amine represented by the above formula (5) is
Since it is a primary to tertiary amine, a strong alkaline substance is not generated at the time of electrolysis, and this does not deteriorate the sealing rubber material of the electrolytic capacitor, so that a highly reliable electrolytic capacitor can be obtained. You can do it.

Further, since the amine represented by the above chemical formula (5) has a low odor and a relatively low vapor pressure, the odor of the electrolyte vaporized gas generated at the time of opening the valve of the electrolytic capacitor or at the time of disposal is small. As a result, environmental problems are reduced.

[0014]

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According to a second aspect of the present invention, the amine represented by the chemical formula (6) is specified as N, N-dimethylallylamine or N, N-diallylmethylamine. Since the base component is used, the mobility of ions in the solution is large, and thereby high conductivity can be obtained. Therefore, an electrolytic capacitor having low impedance can be obtained.

[0016]

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According to the third aspect of the present invention, the carboxylic acid is converted to o
-1 selected from the group consisting of phthalic acid, maleic acid and benzoic acid
Higher conductivity can be obtained by the combination of these carboxylic acids and the amine represented by the chemical formula (7), so that an electrolytic capacitor having a low impedance can be obtained.

[0018]

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According to a fourth aspect of the present invention, the content of the electrolyte salt is set in the range of 10 to 50% by weight. When the content of the electrolyte salt is 10% by weight or less, the mobile ions in the solution are small. Therefore, when the content is 50% by weight or more, the conductivity is low because the viscosity of the solvent is high. Therefore, the content of the electrolyte salt is sufficient in the range of 10 to 50% by weight. The conductivity is obtained.

The invention according to claim 5 uses an electrolytic solution for driving an electrolytic capacitor in which a salt of a carboxylic acid and an amine represented by the following formula (8) is dissolved as an electrolyte salt in a solvent containing γ-butyrolactone. According to this configuration, a high conductivity can be obtained by the carboxylic acid and the amine represented by the chemical formula (8), so that an electrolytic capacitor having a low impedance can be obtained.

[0021]

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Hereinafter, specific examples of the embodiment of the present invention will be described. The electrolytic solution for driving an electrolytic capacitor of the present invention is basically a solution in which a salt of a carboxylic acid and an amine represented by Chemical Formula 9 is dissolved as an electrolyte salt in a solvent containing γ-butyrolactone.

[0023]

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Examples of the carboxylic acid used in the electrolytic solution for driving the electrolytic capacitor of the present invention include polycarboxylic acid (2
To 4): aliphatic polycarboxylic acid [saturated polycarboxylic acid, for example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,6-decanedicarboxylic acid Acid, 5,6
-Decanedicarboxylic acid: unsaturated polycarboxylic acid, such as maleic acid, fumaric acid, itaconic acid]; aromatic polycarboxylic acid, such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid; Carboxylic acids such as tetrahydrophthalic acid (cyclohexane-1,2-dicarboxylic acid) and hexahydrophthalic acid; alkyl (1 to 3 carbon atoms) or nitro-substituted polycarboxylic acids such as citraconic acid, dimethylmaleic acid; Nitrophthalic acid (3-nitrophthalic acid, 4-nitrophthalic acid); and sulfur-containing polycarboxylic acids such as thiopropionic acid; monocarboxylic acids: aliphatic monocarboxylic acids (1 to 30 carbon atoms) [saturated monocarboxylic acids such as formic acid Acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, ena Tonic acid, caprylic acid, pelargonic acid, lauric acid, myristic acid, stearic acid, behenic acid: unsaturated monocarboxylic acids, such as acrylic acid, meteoric acid, oleic acid]; aromatic monocarboxylic acids, such as benzoic acid, o- Nitrobenzoic acid, p-nitrobenzoic acid,
Cinnamic acid, naphthoic acid; oxycarboxylic acids such as salicylic acid, mandelic acid and resorcinic acid.

Of these, o-phthalic acid, maleic acid, and benzoic acid, which have a large acid dissociation constant and a high electric conductivity and are thermally stable, are most preferable.

The mixing ratio of the acid and the amine constituting the electrolytic solution for driving the electrolytic capacitor is usually from 3 to 3 based on the pH of the electrolytic solution.
11, preferably 4 to 9. Outside this range, the spark voltage of the electrolyte decreases.

The electrolytic solution for driving the electrolytic capacitor of the present invention may contain water as necessary. The water content of this water is usually less than 10% based on the weight of the electrolyte. If the content of water is 10% or more, gas generation becomes large and the characteristics of the electrolytic capacitor are remarkably deteriorated.

The electrolytic solution for driving an electrolytic capacitor of the present invention may be mixed with various additives as necessary. As additives, phosphorus compounds [phosphoric acid, phosphoric acid ester, etc.],
Boric acid compounds [boric acid, complex compounds of boric acid with polysaccharides (mannitol, sorbite, etc.), complex compounds of boric acid with polyhydric alcohols (ethylene glycol, glycerin, etc.)], nitro compounds [p-nitro Benzoic acid, p-nitrophenol] and the like.

The electrolytic solution for driving the electrolytic capacitor of the present invention may contain a sub-solvent if necessary. Examples of the auxiliary solvent include polyhydric alcohols such as ethylene glycol and glycerin, and esters such as propylene carbonate and ethylene carbonate.

The content of the electrolyte salt in the electrolytic solution for driving an electrolytic capacitor of the present invention is usually 10 to 50% by weight, preferably 20 to 40% by weight based on the weight of the electrolytic solution.
It is. Outside this range, the electrical conductivity is significantly reduced.

The sealing material of the electrolytic capacitor of the present invention includes:
Peroxide vulcanized butyl rubber, resin vulcanized butyl rubber, quinoid vulcanized butyl rubber, sulfur vulcanized butyl rubber, ethylene propylene rubber, and the like. Among them, preferred is a peroxide-vulcanized butyl rubber.

Table 1 shows the compositions of the electrolytic solution for driving the electrolytic capacitors according to the first and second embodiments of the present invention and the first to third conventional examples. (Table 2) shows Embodiment 1 of the present invention.
4 shows the results of measuring the conductivity at a temperature of 30 ° C. for the electrolytic solutions for driving the electrolytic capacitors of Comparative Example 2 and Conventional Example 3.

[0033]

[Table 1]

[0034]

[Table 2]

As is clear from Table 2, the electrolytes for driving the electrolytic capacitors according to the first and second embodiments of the present invention use amine carboxylate having a small molecular weight as the electrolyte salt. It can be seen that the electrolyte has a higher conductivity than that of the electrolyte solution.

Next, a winding type aluminum electrolytic capacitor (rated voltage 4 V-capacitance 2) using the electrolytic solution for driving the electrolytic capacitor of the first and second embodiments of the present invention and the conventional example 1 was used.
20 μF, size: φ6.3 mm × L5.5 mm). Anodizing treatment was applied to both electrodes of the aluminum lead, and manila fiber paper was used for the electrolytic paper, and sulfur-vulcanized butyl rubber was used for the sealing rubber. A reverse voltage of -2.0 V is applied to this aluminum electrolytic capacitor,
The reliability was evaluated for 000 hours, and the state of the sealing rubber surface of the electrolytic capacitor after the test was observed. The results are shown in (Table 3).

[0037]

[Table 3]

As is apparent from Table 3, the aluminum electrolytic capacitor using the electrolytic solution for driving the electrolytic capacitors according to the first and second embodiments of the present invention has a low alkali amine content as the base component of the electrolyte of the electrolytic solution. Is used, so that the sealing rubber material is not deteriorated. As a result, a highly reliable electrolytic capacitor can be formed.

Next, Embodiments 1 and 2 of the present invention and
Amine using the electrolytic solution for driving the electrolytic capacitor of Example 2
The scattering concentration of the components was measured. The test method is 154 bottom area
cm ^Two50 g of electrolyte solution is placed on a glass Petri dish of
The ambient temperature was kept at a temperature of 30 ° C. and a relative humidity of 50%. Arrangement
5 hours later, 10 cm and 30 cm vertical from the liquid level
The amine concentration was measured at the location. To measure amine concentration
A gas detector amine detector tube was used. The measurement results
It is shown in (Table 4).

[0040]

[Table 4]

As is clear from Table 4, the electrolytic solutions for driving the electrolytic capacitors according to the first and second embodiments of the present invention have a lower concentration of scattered amines than the electrolytic solution of the conventional example 2. It can also be seen that the electrolyte odor is also small. Also, the odor at the time of the test is that the electrolytic solution of Conventional Example 2 is putrid odor,
Since the odors of the electrolytic solutions according to Embodiments 1 and 2 of the present invention are not unpleasant odors such as putrefaction odors, the odors are at a level of no concern and are considered to be excellent in environmental resistance.

[0042]

As described above, the electrolytic solution for driving an electrolytic capacitor of the present invention is obtained by dissolving a salt of a carboxylic acid and an amine represented by the formula (10) as an electrolyte salt in a solvent containing γ-butyrolactone. Since the amine represented by the formula (III) has an allyl group at the terminal, the ionic radius of the amine is smaller than that of the amine having no allyl group at the terminal,
This increases the mobility of ions in the solution, so that high conductivity can be obtained, and as a result, an electrolytic capacitor having low impedance can be obtained.

Further, since the amine represented by the chemical formula (10) is a primary to tertiary amine, no strongly alkaline substance is generated at the time of electrolysis, which may deteriorate the sealing rubber material of the electrolytic capacitor. Therefore, a highly reliable electrolytic capacitor can be obtained.

Further, since the amine represented by the chemical formula (10) has a low odor and a relatively low vapor pressure, the odor of the electrolyte vaporized gas generated when the electrolytic capacitor is opened or discarded is small. Environmental issues are less likely.

By using such an electrolytic solution for driving an electrolytic capacitor of the present invention for an electrolytic capacitor, a highly reliable low impedance electrolytic capacitor can be obtained in consideration of environmental resistance.

[0046]

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Claims (5)

[Claims] 1. An electrolytic solution for driving an electrolytic capacitor in which a salt of a carboxylic acid and an amine represented by the formula (1) is dissolved as an electrolyte salt in a solvent containing γ-butyrolactone. Embedded image 2. An amine represented by the formula (2) is N, N-
2. The electrolytic solution for driving an electrolytic capacitor according to claim 1, wherein the electrolytic solution is dimethylallylamine or N, N-diallylmethylamine. Embedded image 3. The electrolytic solution for driving an electrolytic capacitor according to claim 1, wherein the carboxylic acid is at least one selected from the group consisting of o-phthalic acid, maleic acid and benzoic acid. 4. The electrolytic solution for driving an electrolytic capacitor according to claim 1, wherein the content of the electrolyte salt is in the range of 10 to 50% by weight. 5. An electrolytic capacitor using an electrolytic solution for driving an electrolytic capacitor in which a salt of a carboxylic acid and an amine represented by the formula (3) is dissolved as an electrolyte salt in a solvent containing γ-butyrolactone. Embedded image