JP3332254B2 - Aluminum electrolytic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum electrolytic capacitor.

[0002]

2. Description of the Related Art In a conventional aluminum electrolytic capacitor, a capacitor element is formed by interposing a separator such as electrolytic paper between an anode foil and a cathode foil, and impregnating the separator with an electrolytic solution. The separator has a function of holding the electrolyte between the electrodes and preventing a short circuit between the anode and the cathode. Paper (electrolytic paper) is often used as a material of the separator, and long fiber kraft pulp or manila hemp fiber is frequently used as a raw material. However, the electrolyte is only held in the voids of the separator fibers, and when the capacitor is used for a long time or at a high temperature, the electrolyte held in the separator is vaporized and gradually passes through the sealing body. There is a problem that the gas is volatilized to the outside and the performance is deteriorated. Various methods have been proposed to improve these problems. For example, as the method (1), JP-A-63-104317 and JP-A-63-2
As disclosed in Japanese Patent No. 54717, it has been proposed to use electrolytic paper in which an organic substituent is introduced into a cellulose fiber by a chemical reaction. Also, as the method (2),
As shown in JP-B-63-54208,
A method for gelling an electrolyte has been proposed. In addition to this, in recent years, at the time of overvoltage application, there is a demand for an aluminum electrolytic capacitor having a small amount of electrolyte vapor blowout and liquid leakage due to short-circuit, ignition, and opening of the outer case,
To satisfy this demand, an aluminum electrolytic capacitor having a high withstand voltage and using a solid electrolyte is required. For this purpose, the method (3) described in, for example,
As disclosed in Japanese Patent Publication No. 64, a method using a polymer solid electrolyte using a crosslinked polymer composed of polyethylene glycol, a trifunctional polyol and a polyisocyanate has been proposed.

[0003]

However, with the method (1) proposed above, it is still insufficient to prevent the performance degradation of the aluminum electrolytic capacitor, and with the method (2), the method of using the electrolytic solution is not sufficient. There is a problem that the impregnation property is significantly reduced. Further, the method (3) has a problem that tan δ is deteriorated in the characteristics of the aluminum electrolytic capacitor. The present invention is intended to solve such a problem, with less deterioration of performance and high withstand voltage,
Moreover, it is an object of the present invention to provide a separator for an aluminum electrolytic capacitor which can keep the equivalent series resistance and tan δ small.

[0004]

In order to achieve the above object, the present invention provides an aluminum electrolytic capacitor comprising a separator interposed between an anode foil and a cathode foil and impregnated with a predetermined electrolyte. A film made of hydroxyethyl (alkyl) cellulose is used, and an electrolytic solution containing at least an ammonium salt as an electrolyte component is used. More specifically, an aluminum electrolytic capacitor is constituted by a combination of a film made of hydroxyethyl (alkyl) cellulose and an electrolyte containing an ammonium salt and ethylene glycol.

[0005]

According to the above construction, the film made of hydroxyethyl (alkyl) cellulose used for the separator interposed between the anode foil and the cathode foil is brought into contact with the electrolyte containing ammonium salt and ethylene glycol. Because it swells, it is possible to maintain a larger amount of electrolyte between the electrodes than when using normal electrolytic paper, and at the same time, it is possible to suppress the volatilization of the solvent by the chemical interaction between hydroxyethyl (alkyl) cellulose and the electrolyte solvent. it can. As a result, it is possible to obtain an aluminum electrolytic capacitor which is excellent in equivalent series resistance and tan δ, and has little change over time in characteristics during use at a high temperature.

Further, in the aluminum electrolytic capacitor of the present invention, since the separator is a non-porous film, physical contact (physical short-circuit) between the electrodes due to burrs generated when the electrode foil is cut hardly occurs. In addition, a short circuit (electric short circuit) due to electric discharge when an overvoltage is applied is less likely to occur. As a result, an aluminum electrolytic capacitor having a high withstand voltage and a low short-circuit occurrence rate can be obtained.

[0007]

Embodiments of the present invention will be described below. The basis of the present invention is that in an aluminum electrolytic capacitor obtained by impregnating a predetermined electrolytic solution with a separator interposed between an anode foil and a cathode foil, a film made of hydroxyethyl (alkyl) cellulose is used for the separator, and An aluminum electrolytic capacitor using an electrolytic solution containing at least an ammonium salt as an electrolyte salt.

The anode foil and the cathode foil in the present invention may be any aluminum foil used for an aluminum electrolytic capacitor.
The driving electrolyte is a solution in which at least an ammonium salt is dissolved as an electrolyte salt in a solvent containing ethylene glycol.

If necessary, another solvent may be used in combination with ethylene glycol which is a solvent for the electrolytic solution. Examples thereof include water, a lactone-based solvent (γ-butyrolactone,
γ-valerolactone, δ-valerolactone, 3-methyl-1,3-oxazolidine-2-one and 3-ethyl-1,3-oxazolidine-2-one), amide solvents (N-methylformamide, N, N-dimethylformamide, N-methylacetamide, N-methylpyrrolidinone, etc., alcohol solvents (methylcellosolve, propylene glycol, 1,4-butanediol, glycerin, polyoxyalkylene polyol, cyclohexanediol, etc.), ether System solvent (methylal, 1,2-
Dimethoxyethane, 1-ethoxy-2-methoxyethane, 1-2-diethoxyethane, etc.), nitrile solvents (acetonitrile, 3-methoxypropionitrile, etc.), furan solvents (2,5-dimethoxytetrahydrofuran, etc.), Examples thereof include 2-imidazolidinones (such as 1,3-dimethyl-2-imidazolidinone) and pyrrolidones, and two or more of these may be used in combination. Of these, lactone solvents, amide solvents, ether solvents, nitrile solvents, and furan solvents are preferred. Among lactone solvents, γ-butyrolactone, γ-
Valerolactone and δ-valerolactone are particularly preferred. When another solvent is used in combination, the amount is usually 50 parts by weight or less based on 100 parts by weight. Outside this range, good capacitor performance cannot be obtained.

[0010] Examples of the electrolyte salt include an ammonium salt. This can be used in combination with an amine salt, a quaternary ammonium salt and a diazabicycloalkene salt. This group is hereinafter referred to as a combined salt. The amine salt is a salt of an amine and an acid. Examples of the amine include primary amines (methylamine, ethylamine, propylamine, butylamine, ethylenediamine, etc.) and secondary amines (dimethylamine, diethylamine, dipropylamine, methylethylamine, diphenylamine). Tertiary amines (such as trimethylamine, triethylamine, tripropylamine, and triphenylamine). The quaternary ammonium salt is a salt of a quaternary ammonium and an acid. Examples of the quaternary ammonium include tetraalkylammonium (tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, methyltriethylammonium, dimethyldiethylammonium). Etc.), pyridinium (1-methylpyridinium,
1-ethylpyridinium, 1,3-diethylpyridinium, etc.). The diazabicycloalkene salt is a salt of a diazabicycloalkene and an acid, and the diazabicycloalkene is 1,5-diazabicyclo (4,3,0).
Nonene-5,1,8-diazabicyclo (5,4,0) undecene-7 and the like. Acids forming these salts include boric acid, phosphoric acid, carboxylic acids (formic acid, acetic acid, propionic acid, maleic acid, citraconic acid, phthalic acid, adipic acid, azelaic acid, benzoic acid, butyloctaninic acid, formic acid, decanedicarboxylic acid Acid and the like). Of these electrolyte salts, preferred are amine salts of carboxylic acid or boric acid. The mixing weight ratio of the ammonium salt and the combined salt is ammonium salt /
Combined salt = 100/0 to 30/70, preferably 100 /
0 to 50/50. Outside this range, favorable aluminum electrolytic capacitor performance cannot be obtained.

In the present invention, the hydroxyethoxyl group content of the hydroxyethyl (alkyl) cellulose is usually 4 to 47% by weight, preferably 4 to 15% by weight.
It is. Outside this range, good film swelling properties cannot be obtained, and the capacitor performance deteriorates. In addition, a separator made of cellulose other than hydroxyethyl (alkyl) cellulose has high solubility in an electrolyte containing an ammonium salt and ethylene glycol, and its strength is reduced by contact with the electrolyte. Drop,
Frequent shortage during aging.

In the present invention, the degree of polymerization of hydroxyethyl (alkyl) cellulose is not particularly limited, but is usually 15 mPa · s or more, preferably in terms of a 2% aqueous viscosity (20 ° C.) of hydroxyethyl (alkyl) cellulose. Is preferably 80 mPa · s to 20 Pa · s. Outside this range, an appropriate separator strength cannot be obtained, and good capacitor performance cannot be obtained.

In the present invention, the chloride content in hydroxyethyl (alkyl) cellulose is usually 500 pp.
m, preferably 400 ppm or less. If the chloride content exceeds 500 ppm, the withstand voltage of the capacitor decreases.

The hydroxyethyl (alkyl) cellulose is in the form of powder and its particle size is not particularly limited, but is preferably in the form of fine powder which passes through a 42 mesh wire mesh. It is difficult to dissolve and / or disperse in a dispersing solvent other than hydroxyethyl (alkyl) cellulose in the form of fine powder.

In the present invention, the thickness of the film of hydroxyethyl (alkyl) cellulose before swelling of the separator (before contact with the electrolyte) is usually 100 μm or less, preferably 70 μm or less. When the thickness of the separator exceeds 100 μm, the distance between the electrodes increases,
Good impedance performance cannot be obtained.

In the present invention, the density of the separator of the film made of hydroxyethyl (alkyl) cellulose is 1.05 to 1.30 g / cm ³ , preferably 1.1.
0 to 1.20 g / cm ³ . If it is less than 1.05 g / cm ³ , the amount of swelling of the electrolytic solution is small, and good capacitor performance cannot be obtained.

As a method for forming hydroxyethyl (alkyl) cellulose into a film, a solution obtained by dissolving and / or dispersing hydroxyethyl (alkyl) cellulose powder in a dispersing solvent described below is heated and / or reduced in pressure to form a solvent. There is a method in which the components are volatilized to form a film. At this time, for the purpose of imparting flexibility to the film and preventing breakage of the film at the time of winding, it is desirable that 20% by weight or less of the solvent component for dispersion remain in the film on a weight basis. If the residual ratio of the dispersing solvent exceeds 20% by weight, the strength of the film decreases, and tearing during winding frequently occurs.

Examples of the dispersing solvent include water, alcohols (methanol, ethanol, isopropyl alcohol, octanol, ethylene glycol, etc.), ketones (acetone, methyl ethyl ketone, diethyl ketone, etc.), lactones (γ-butyrolactone, etc.). , Lactone solvents can be used as they are), and mixed solvents containing two or more of these solvents.

Further, a solution in which an electrolyte salt is dissolved in a dispersing solvent in which hydroxyethyl (alkyl) cellulose powder is dissolved and / or dispersed may be used for film formation. In this case, since the electrolyte salt is dispersed in the film, better impedance performance can be obtained. As the electrolyte salt, an electrolyte salt that is dissolved in the above-described driving electrolyte can be used as it is.

Further, a solution in which a polymer material soluble in ethylene glycol is dissolved and / or dispersed in a dispersing solvent in which hydroxyethyl (alkyl) cellulose powder is dissolved and / or dispersed is used for film formation. May be. In this case, the film contacts the electrolyte.
During the swelling process, the soluble polymer component dispersed in the film dissolves, and the film forms a stitch structure, so that the interelectrode resistance can be reduced and better impedance performance can be obtained.

In the present invention, the hydroxypropyl (alkyl) cellulose may be a conventional one and is not particularly limited, but preferably has a 2% aqueous solution viscosity at 20 ° C. of 20 mP · s or more.

In the present invention, examples of the polyolefin include olefin films (eg, polyethylene, polypropylene, etc.) and modified olefins thereof (eg, carboxyl-modified). However, modified olefins from modified olefin emulsions can be easily produced from composite separators. It is preferred to use

The content of hydroxypropyl (alkyl) cellulose or polyolefin in the composite film is not particularly limited, but is usually 50% by weight or less, preferably 1% by weight or less.
３０30% by weight. Outside this range, good capacitor performance cannot be obtained. Hydroxypropyl (alkyl) cellulose and polyolefin may be used in combination.

The method of forming the composite film is not particularly limited, but the modified olefin emulsion is added and mixed in a dispersion solvent in which hydroxyethyl (alkyl) cellulose powder is dissolved and / or dispersed, and the dispersion solvent is decompressed. Alternatively, a composite film can be obtained by removing by heating. By forming the composite film, the modified olefin serves as a spacer, so that a short circuit between both electrodes can be prevented.

A solution obtained by adding a crosslinking agent to a dispersing solvent in which hydroxyethyl (alkyl) cellulose powder is dissolved and / or dispersed may be used for film formation. In this case, the film is partially crosslinked,
Strength is improved. As a crosslinking agent, urea / formalin,
Methylol melamine, glyoxal, tannic acid and polyisocyanates. Of these,
Preferred are urea / formalin, methylolmelamine, glyoxal and polyisocyanates.
Further, a crosslinking catalyst may be used if necessary. When the crosslinking agent is urea / formalin, examples of the crosslinking catalyst include an organic amine catalyst and a metal salt catalyst. When the crosslinking agent is a polyisocyanate, a tertiary amine or an organotin compound is used.

For the purpose of improving the impregnation of the capacitor element with the electrolytic solution, embossing, dimple processing, V-shaped groove processing, stitch groove processing, or the like may be applied to one or both surfaces of the film. These processes improve the impregnating property and shorten the aging time.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto. Hereinafter, parts are parts by weight, and the viscosity is 20 ° C. in a 2% aqueous solution viscosity.
It is the value in.

The raw materials used to form the aluminum electrolytic capacitor separator used in the examples are as follows. (Cellulose A) Powdered hydroxyethyl cellulose (viscosity: 5.7 Pa · s, chloride content: 150 pp
m, permeation through 42 mesh, hydroxyethoxyl group content of 40% by weight) (Cellulose B) Powdered hydroxyethylmethylcellulose (viscosity: 4.9 Pa · S, chloride content: 200 p)
pm, having a hydroxyethoxyl group content of 13% by weight and a methoxyl group content of 23% by weight. (Cellulose C) Cellulose A having a chloride content of 100%
Of 0 ppm. (Cellulose D) The viscosity of cellulose A is 0.01 Pa ·
s thing. (Cellulose E) Cellulose A having an ethoxyl group content of 61% by weight. (Cellulose F) Powdered hydroxypropylmethylcellulose (viscosity: 4.7 Pa · s, chloride content: 200
ppm, permeation through 42 mesh).

The separators used in the examples are as follows. (Separator A) A solution prepared by dissolving 5 parts of cellulose A in a dispersion solvent consisting of 40 parts of water and 60 parts of methanol was cast on a Teflon plate to a thickness of 800 μm. This was blown with hot air at 150 ° C. and dried to obtain a film having a thickness of 40 μm. (Separator B) A solution prepared by dissolving 5 parts of cellulose A in a dispersion solvent comprising 30 parts of water, 30 parts of methanol and 40 parts of acetone was cast on a Teflon plate to a thickness of 800 μm. This was blown with hot air at 150 ° C. and dried to obtain a film having a thickness of 40 μm. (Separator C) A solution prepared by dissolving 4 parts of cellulose A and 1 part of cellulose F in a dispersion solvent composed of 30 parts of water, 30 parts of methanol and 40 parts of acetone was cast on a Teflon plate to a thickness of 800 μm. did. This was blown with hot air at 150 ° C. and dried to obtain a film having a thickness of 40 μm. (Separator D) A solution prepared by dissolving 3 parts of cellulose A in 30 parts of water, 20 parts of methanol and 50 parts of acetone was mixed with 6 parts of a carboxyl-modified polyethylene emulsion (solid content: 25%) and uniformly added. Was cast on a Teflon plate to a thickness of 800 μm. It is dried by blowing hot air of 150 ° C on it.
A film having a thickness of 40 μm was obtained. (Separator E) 3 parts of Sumitec Resin M-3 (Melamine resin, Sumitomo Chemical Co., Ltd.) in a solution prepared by dissolving 5 parts of cellulose A in a dispersion solvent composed of 40 parts of water and 60 parts of methanol, A solution obtained by mixing 0.3 parts of Tech Accelerator ACX (organic amine, manufactured by Sumitomo Chemical Co., Ltd.) was cast on a Teflon plate to a thickness of 800 μm. Thereafter, in a hot air circulating drying oven, curing was performed at 50 ° C. for 2 hours, and further at 90 ° C. for 1 hour to obtain a crosslinked film having a thickness of 40 μm. Put this film in water at 20 ° C for 10
The insolubilization ratio of the film when immersed for a period of time was 49% by weight. (Separator F) 1 part of Sumitec resin FSK (Glyoxal, Sumitomo Chemical Co., Ltd.) in a solution obtained by dissolving 5 parts of cellulose A in a dispersion solvent composed of 40 parts of water and 60 parts of methanol, Sumitec accelerator A solution obtained by mixing 0.1 part of MX (metal salt, manufactured by Sumitomo Chemical Co., Ltd.) was cast to a thickness of 800 μm on a Teflon plate. Thereafter, in a hot air circulating drying oven, at 50 ° C. for 2 hours, and further for 90 hours.
Curing was performed at -1 hour to obtain a crosslinked film having a thickness of 40 µm. When this film was immersed in water at 20 ° C. for 10 hours, the insolubilization ratio of the film was 42% by weight. (Separator G) A film having a thickness of 15 μm was obtained in the same manner as for the separator A, except that the casting thickness of the solution was changed to 300 μm. (Separator H) Separator A was the same as separator A except that the casting thickness of the solution was 1800 μm.
In the same manner as in the above, a film having a thickness of 90 μm was obtained. (Separator I) In separator A, cellulose A
Separator A except that cellulose B was used in place of
As in the above, a film having a thickness of 40 μm was obtained. (Separator J) A film having a thickness of 40 μm was obtained in the same manner as in the film A, except that the cellulose C was used in place of the cellulose A. (Separator K) In separator A, cellulose A
A film having a thickness of 40 μm was obtained in the same manner as in the film A except that cellulose D was used in place of the above. (Separator L) In separator A, cellulose A
A film having a thickness of 40 μm was obtained in the same manner as in the film A except that cellulose E was used in place of the above. (Separator M) In separator A, cellulose A
A film having a thickness of 40 μm was obtained in the same manner as in the film A except that cellulose F was used in place of the above.

The composition of the driving electrolyte used in the examples is as follows. (Electrolyte A) A solution prepared by dissolving 10 parts of ammonium adipate and 1 part of p-nitrobenzoic acid in 100 parts of ethylene glycol. (Electrolyte B) A solution prepared by dissolving 10 parts of ammonium benzoate and 1 part of p-nitrobenzoic acid in 100 parts of ethylene glycol. (Electrolytic solution C) A solution obtained by dissolving 20 parts of tetraethylammonium maleate in 100 parts of γ-butyrolactone.

The electrolytic paper used in the comparative example is as follows. (Electrolytic paper A) Electrolytic paper for electrolytic capacitors (Manila hemp fiber,
(Thickness: 40 μm, density: 0.5 g / cm ³ ) (Electrolytic paper B) Electrolytic paper for electrolytic capacitor (swellable fiber obtained by modifying Manila hemp, thickness: 40 μm, density: 0.55 g /
cm ³ ) The swelling degree and equivalent series resistance of the produced separators A to M and electrolytic papers A and B were measured, and the results are shown in Table 1.

The degree of swelling was measured by measuring the thickness of each test piece with a micrometer by stacking 10 sheets of each separator and electrolytic paper.
The value was set to A (unit: μm). Then, the test piece was immersed in ethylene glycol for 15 minutes. Thereafter, the test piece was taken out, the thickness was measured with a micrometer in a wet state, and the value was set to B. The degree of swelling was determined by the following equation. Swelling degree (%) = 100 × (B−A) / A The equivalent series resistance is 1% for each separator and electrolytic paper in electrolytic solution A.
After immersion for 5 minutes, the test piece was taken out, sandwiched between ^two opposing platinum plates (area: 16.0 cm ² ) in a wet state, and the resistance component between the platinum plates was measured at a frequency of 100 kHz. The value was taken as the equivalent series resistance.

[0033]

[Table 1] As is clear from Table 1, in the aluminum electrolytic capacitor of the present invention, the separators A to J have excellent swelling properties with respect to ethylene glycol, and can maintain a large amount of electrolyte in the separator. In addition, the separator for an electrolytic capacitor of the present invention does not have fibers between the opposed electrodes, so there is no obstacle at the time of ion migration, compared with electrolytic paper,
Shows excellent equivalent series resistance. The separator K has a 2% aqueous solution concentration (20%) of cellulose D as a material.
° C), which is 15 mPa · s or less, so that the shape retention is inferior and does not function as a separator. Since the material of the separator L (cellulose E) has a hydroxyethoxyl group content of 47% by weight or more, it cannot be dissolved in ethylene glycol to maintain its shape, and does not function as a separator. Since the material (cellulose F) of the separator M is hydroxypropylmethylcellulose, it does not swell in ethylene glycol and does not function as a separator because the resistance component between the electrodes is too large.

Next, in the electrolytic capacitor of the present invention, in order to confirm the effect of improving the life of the aluminum electrolytic capacitor due to the excellent swellability of the separator, the prepared separators A to M and electrolytic papers A and B were used as separators. A roll-up type aluminum electrolytic capacitor element having a rated voltage of 25 V and a capacitance of 100 μF was prepared. The capacitor element was impregnated with an electrolyte containing ethylene glycol as a main solvent, and the capacitor element was put in a case and sealed with a sealing agent. An aluminum electrolytic capacitor was prepared by sealing, and an accelerated life test at high temperature was performed. Table 2 shows the combinations of the separator and the electrolyte used.

[0035]

[Table 2] A rated voltage was applied to these Examples 1 to 10 and Comparative Examples 1 to 7, and a high-temperature load test was performed at 105 ° C. for 2,000 hours. The test results are shown in (Table 3). In addition, 105 ° C
The capacitor characteristics after -2000 hours are shown in% as a change from each initial characteristic. The number of tests was 10 in each case, and the characteristics were indicated by the average value of 10 capacitors.

[0036]

[Table 3] As is evident from Table 3, the capacitor prepared using the separator for an aluminum electrolytic capacitor of the present invention is excellent in tan δ, and has a characteristic of capacity (Cap) and tan δ even when used for a long time at a high temperature. Less deterioration.

A voltage of 38 V was applied to the aluminum electrolytic capacitors of Examples 1 to 10 and Comparative Examples 1 to 7 having the structure shown in Table 2 to perform an overvoltage test at 105 ° C. for 200 hours.
The results are shown in (Table 4). The number of tests was 10 in each case, and the number of capacitors in which a short circuit or valve opening occurred after the test is shown in the table.

[0038]

[Table 4] As is clear from Table 4, the capacitors prepared using the aluminum electrolytic capacitor separators A to I of the present invention have no liquid leakage, no short circuit at the time of overvoltage printing, and no electrolytic solution blowout due to valve opening.

[0039]

As described above, the aluminum electrolytic capacitor of the present invention uses a film made of hydroxyethyl (alkyl) cellulose as a separator, and uses an electrolytic solution obtained by dissolving at least an ammonium salt as an electrolyte salt in ethylene glycol. Therefore, with this configuration, the withstand voltage is high, the tan δ is excellent, and even when used for a long time at a high temperature, the deterioration of these characteristics is small, the liquid does not leak, and the short circuit or the open circuit when applying an overvoltage is performed. It is possible to obtain an aluminum electrolytic capacitor in which the amount of electrolytic solution blown out due to the valve is small, and it is possible to obtain excellent effects such that a conventional manufacturing process of an aluminum electrolytic capacitor can be used as it is.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuya Samura 11-11, Hitotsubashi Nohonmachi, Higashiyama-ku, Kyoto Inside Sanyo Kasei Kogyo Co., Ltd. Koji Osawa, Examiner at Kasei Kogyo Co., Ltd. (56) References JP-A-5-251275 (JP, A) JP-A-63-254717 (JP, A) JP-A-60-254721 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) H01G 9/02 H01G 9/035

Claims (13)

(57) [Claims] 1. An aluminum electrolytic capacitor comprising a separator interposed between an anode foil and a cathode foil and impregnated with a predetermined electrolytic solution, wherein the separator is a film made of hydroxyethyl (alkyl) cellulose, and An aluminum electrolytic capacitor in which the electrolytic solution contains at least an ammonium salt as an electrolyte salt. 2. The aluminum electrolytic capacitor according to claim 1, wherein the electrolytic solution contains ethylene glycol. 3. A separator comprising: hydroxyethyl (alkyl) cellulose; hydroxypropyl (alkyl)
3. The aluminum electrolytic capacitor according to claim 1, which is a composite film made of cellulose and / or polyolefin. 4. A separator having a density of 1.05 to 1.30.
The aluminum electrolytic capacitor according to any one of claims 1 to ³ , wherein the g / cm3 is g / cm3. 5. The aluminum electrolytic capacitor according to claim 1, wherein the separator is a cross-linked film obtained by cross-linking hydroxyethyl (alkyl) cellulose with a cross-linking agent. 6. The aluminum according to claim 1, wherein the crosslinked film is crosslinked with a crosslinking agent selected from the group consisting of urea / formalin, methylolmelamine, glyoxal, tannic acid and polyisocyanate. Electrolytic capacitor. 7. A film comprising hydroxyethyl (alkyl) cellulose, wherein the film comprises hydroxyethyl (alkyl)
A solution obtained by dissolving and / or dispersing a cellulose powder in a dispersion solvent containing at least one of water, alcohols, ketones, and lactones is heated and / or decompressed to evaporate the solvent component, and the film The aluminum electrolytic capacitor according to any one of claims 1 to 6, wherein the film is a film in which the residual ratio of the solvent for dispersion is 20% by weight or less on a weight basis. 8. A composite film comprising: hydroxyethyl (alkyl) cellulose and hydroxypropyl (alkyl)
The solvent component in a solution obtained by dissolving and / or dispersing cellulose in a dispersion solvent containing at least one of water, alcohols, ketones, and lactones is volatilized, and the residual ratio of the dispersion solvent in the film is reduced. 8. A film having a weight of not more than 20% by weight.
The aluminum electrolytic capacitor according to any one of the above. 9. A solution in which a composite film is obtained by dissolving and / or dispersing hydroxyethyl (alkyl) cellulose in a dispersion solvent containing at least one of water, alcohols, ketones, and lactones, and an olefin. An aluminum electrolyte according to any one of claims 1 to 8, wherein the film is mixed with an emulsion, and the solvent component in the mixed solvent is volatilized so that the residual ratio of the dispersing solvent in the film is 20% by weight or less on a weight basis. Capacitors. 10. A film comprising hydroxyethyl (alkyl) cellulose is prepared by mixing hydroxyethyl (alkyl) cellulose powder with water, alcohols, ketones,
A urea formalin resin, a methylol melamine resin, a glyoxal, a tannic acid, and then adding a crosslinking agent to a solution obtained by dissolving and / or dispersing in a dispersing solvent containing at least one of lactones and lactones, and heating these if necessary. The aluminum electrolytic capacitor according to any one of claims 1 to 9, wherein the film is a film in which the solvent component is volatilized so that the residual ratio of the solvent for dispersion in the film is 20% by weight or less on a weight basis. 11. A dispersion solvent comprising a film made of hydroxyethyl (alkyl) cellulose containing an electrolyte salt and hydroxyethyl (alkyl) cellulose powder containing at least one of water, alcohols, ketones and lactones. A solvent obtained by dissolving and / or dispersing in a solvent is heated and / or depressurized to volatilize a solvent component, and the residual ratio of the dispersing solvent in the film to 20% by weight or less on a weight basis. 10
The aluminum electrolytic capacitor according to any one of the above. 12. The aluminum electrolytic capacitor according to claim 1, wherein a 2% aqueous solution of hydroxyethyl (alkyl) cellulose at 20 ° C. has a viscosity of 15 mPa · s or more. 13. The hydroxyethyl (alkyl) cellulose having a hydroxyethoxyl group content of 4 to 47% by weight.
The aluminum electrolytic capacitor according to any one of claims 1 to 12, wherein