JP2006012983A - Electrolytic capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrolytic solution for electrolytic capacitors with good high temperature life characteristic and also low impedance characteristics, and to provide an electrolytic capacitor using it. <P>SOLUTION: The third class of borodiglycolic-acid amine salt is used as solute of the electrolytic solution for electrolytic capacitors. A sealing body is used as provided with the tube consisting of a high boiling point solvent, a phosphated foil, the capacitor element not more than moisture content 0.7 wt%, the separator composed of heat-resistant synthetic resin, a water absorbing agent, or a flexible material. Thus, the electrolytic capacitor is obtained, having good high temperature life characteristic in addition to low impedance characteristic. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrolytic capacitor, and more particularly to an electrolytic capacitor having low impedance characteristics.

  An electrolytic capacitor is generally a strip-like high-purity aluminum foil that is chemically or electrochemically etched to enlarge the surface of the aluminum foil, and this aluminum foil is converted into a chemical conversion solution such as an ammonium borate aqueous solution. Anode electrode foil formed by chemical conversion treatment inside to form an oxide film layer on the surface, and a cathode electrode foil made of high-purity aluminum foil subjected only to etching treatment are wound through a separator made of manila paper or the like. Turn to form a capacitor element. The capacitor element is impregnated with an electrolytic solution for driving an electrolytic capacitor, and then stored in a bottomed cylindrical outer case made of aluminum or the like. A sealing body made of elastic rubber is attached to the opening of the outer case, and the outer case is sealed by drawing.

  Here, as an electrolytic solution for driving an electrolytic capacitor having high conductivity impregnated in the capacitor element, γ-butyrolactone is a main solvent, and imidazolinium cation or imidazole, which are cations obtained by quaternizing a cyclic amidine compound as a solute. A solution in which a salt having a cation component as a cation component and an acid conjugate base as an anion component is dissolved is used (see Patent Documents 1 and 2).

JP 08-32440 A Japanese Patent Laid-Open No. 08-324411

  However, in recent years, electronic information devices have been digitized, and further, the driving frequency of the microprocessor which is the heart of these electronic information devices has been increased. Along with this, the power consumption of the electronic components of the peripheral circuit has been increased, and the ripple current accompanying the increase has been remarkably increased. The electrolytic capacitor used in this circuit is required to have a low impedance characteristic.

  Accordingly, an object of the present invention is to provide an electrolytic capacitor having low impedance characteristics and good high-temperature life characteristics.

The first electrolytic capacitor of the present invention is characterized by using an electrolytic solution for an electrolytic capacitor containing a borodiglycolic acid tertiary amine salt and a high boiling point solvent.

  The high boiling point solvent is characterized by using 3-methylsulfolane or 2,4-dimethylsulfolane.

The second electrolytic capacitor of the present invention is an electrolytic capacitor in which an anode electrode foil, a cathode electrode foil, and a separator are wound, and a capacitor element impregnated with an electrolytic solution is housed in an exterior case. An electrolytic solution containing an acid tertiary amine salt is used, and an electrode foil subjected to phosphoric acid treatment is used as the anode electrode foil and / or the cathode electrode foil.

The third electrolytic capacitor of the present invention is an electrolytic capacitor in which an anode electrode foil, a cathode electrode foil, and a separator are wound, and a capacitor element impregnated with an electrolytic solution is housed in an outer case. An electrolytic solution containing an acid tertiary amine salt is used, and the amount of water contained in the capacitor element is 0.7 wt% or less, preferably 0.5 wt% or less, more preferably 0.4 wt% or less. It is said.

The fourth electrolytic capacitor of the present invention is an electrolytic capacitor in which an anode electrode foil, a cathode electrode foil, and a separator are wound and a capacitor element impregnated with an electrolytic solution is housed in an exterior case. An electrolyte solution containing an acid tertiary amine salt is used, and a separator made of a heat-resistant synthetic resin is used as the separator.

A fifth electrolytic capacitor of the present invention is an electrolytic capacitor in which an anode electrode foil, a cathode electrode foil, and a separator are wound, and a capacitor element impregnated with an electrolytic solution is housed in an outer case. An electrolytic solution containing an acid tertiary amine salt is used, and a water absorbing agent is provided in the outer case.

In the electrolytic capacitor, the water-absorbing agent is zeolite, molecular sieves, silica gel, activated alumina, or a highly water-absorbing polymer.

A sixth electrolytic capacitor of the present invention is a sealing device in which an anode electrode foil, a cathode electrode foil and a separator are wound, and a capacitor element impregnated with an electrolytic solution is accommodated in an exterior case, and an opening of the exterior case is provided with a through hole. In an electrolytic capacitor sealed with a body, an electrolytic solution containing a borodiglycolic acid tertiary amine salt is used as the electrolytic solution, and a flexible material in which a round bar portion of an electrode lead-out means is inserted into the through hole It is characterized by having a tube.

The electrolytic solution for electrolytic capacitors used in the electrolytic capacitor of the present invention contains a borodiglycolic acid tertiary amine salt.

  Examples of the tertiary amine of the borodiglycolic acid tertiary amine salt include trimethylamine, triethylamine, ethyldimethylamine, tributylamine, 1,8-diazabicyclo (5,4,0) -undecene-7, triethanolamine and the like. .

  The following solvents can be used for the electrolytic solution for electrolytic capacitors used for the electrolytic capacitor of the present invention. That is, a protic polar solvent, an aprotic solvent, and a mixture thereof can be used. Protic polar solvents include monohydric alcohols (ethanol, propanol, butanol, pentanol, hexanol, cyclobutanol, cyclopentanol, cyclohexanol, benzyl alcohol, etc.), polyhydric alcohols and oxyalcohol compounds (ethylene glycol) Propylene glycol, glycerin, methyl cellosolve, ethyl cellosolve, methoxypropylene glycol, dimethoxypropanol, etc.). Examples of aprotic polar solvents include amides (N-methylformamide, N, N-dimethylformamide, N-ethylformamide, N, N-diethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-ethylacetamide, N, N-diethylacetamide, hexamethylphosphoricamide, etc.), lactones (γ-butyrolactone, δ-valerolactone, γ-valerolactone, etc.), cyclic amides (N-methyl-2-pyrrolidone) Etc.), nitrile type (acetonitrile etc.), sulfoxide type (dimethyl sulfoxide etc.) and the like.

  And in the 1st electrolytic capacitor of this invention, in addition to the above solvent, the following solvents can be mentioned as a high boiling point solvent to be used. 3-methylsulfolane, 2,4-dimethylsulfolane, 1,3-diethyl-2-imidazolidinone, 1,3-dipropyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazolidi 1,3,4-trialkyl-2-imidazolidinone: 1,3,4-trimethyl-2-imidazolidinone, etc. 1,3,4,5-tetraalkyl-2-imidazolidinone: 1,3,4,5-tetramethyl-2-imidazolidinone and the like, 3-ethyl-1,3-oxazolidine-2-one and the like, carbonate: ethylene carbonate, propylene carbonate and the like. Among these, 3-methylsulfolane and 2,4-dimethylsulfolane are preferable because they have good high-temperature characteristics at 125 ° C.

  And if content in the solvent of a high boiling point solvent is less than 25 wt%, a specific resistance characteristic will be favorable, and if it is 25-80 wt%, a 125 degreeC high temperature lifetime characteristic will become favorable. If it exceeds 80 wt%, the specific resistance increases and low impedance characteristics cannot be obtained. Furthermore, if it is less than 25 wt%, it is preferably 1 to 20 wt%, more preferably 3 to 15 wt%. If it exceeds this range, the specific resistance increases, and if it exceeds the lower limit of this range, the life characteristics are improved.

  In the second electrolytic capacitor of the present invention, an electrode foil subjected to phosphoric acid treatment is used as the electrode foil. One of the anode electrode foil and the cathode electrode foil has the effect of the present invention, but if used for both, the deterioration of both electrode foils is suppressed, which is more preferable. Usually, a high-purity aluminum foil is chemically or electrochemically etched to obtain an etched foil. The phosphoric acid treatment in the present invention is a pretreatment, an intermediate treatment, or a post-treatment of AC etching in this etching step. For example, a phosphate aqueous solution immersion treatment is performed as the treatment, and the etching foil obtained by the phosphoric acid treatment is used as the cathode electrode foil. Further, in the anode foil, the etching foil or the etching foil not subjected to the phosphoric acid treatment is subjected to phosphorylation, or is a means for performing phosphoric acid dipping before chemical conversion, intermediate or post-treatment. The electrode foil obtained by the treatment is used as the anode electrode foil.

  Furthermore, when a phosphorus compound is added to the electrolytic solution for electrolytic capacitors, the effect of the present invention is improved. Examples of the phosphorus compound include the following. Orthophosphoric acid, phosphorous acid, hypophosphorous acid, and salts thereof, and salts thereof include ammonium salt, aluminum salt, sodium salt, calcium salt, and potassium salt. In addition, phosphoric acid compounds such as ethyl phosphate, diethyl phosphate, butyl phosphate, and dibutyl phosphate, phosphonic acid compounds such as 1-hydroxyethylidene-1,1-diphosphonic acid, aminotrimethylenephosphonic acid, and phenylphosphonic acid Is mentioned. Moreover, phosphinic acid compounds, such as methylphosphinic acid and butyl phosphinate, are mentioned.

  Furthermore, the following condensed phosphoric acid or salts thereof can be mentioned. Linear condensed phosphoric acid such as pyrophosphoric acid, tripolyphosphoric acid and tetrapolyphosphoric acid, cyclic condensed phosphoric acid such as metaphosphoric acid and hexametaphosphoric acid, or such chain and cyclic condensed phosphoric acid are combined. . And as a salt of these condensed phosphoric acids, ammonium salt, aluminum salt, sodium salt, calcium salt, potassium salt etc. can be used.

  The addition amount is 0.05 to 3 wt%, preferably 0.1 to 2 wt%.

  The electrolytic capacitor of the present invention described above has low impedance characteristics and good high temperature life characteristics. That is, when a borodiglycolic acid tertiary amine salt is used and a high-temperature life test is performed, borodiglycolic acid is hydrolyzed to produce boric acid and glycolic acid, and this glycolic acid reacts with the electrode foil and has characteristics. Although it deteriorates, since the electrolytic capacitor of this invention uses the electrode foil which performed phosphoric acid treatment, reaction of electrolyte solution and electrode foil is suppressed and the high temperature life characteristic is also stable.

  In the third electrolytic capacitor of the present invention, the amount of water contained in the capacitor element of the electrolytic capacitor is 0.7 wt% or less with respect to the total weight of the capacitor element. Here, the capacitor element means a part obtained by cutting a part of the lead wire of the capacitor element that is drawn from the capacitor element. The following method can be used for such a moisture content. That is, in the electrolytic capacitor manufacturing process, after the capacitor element is impregnated with the electrolytic solution, moisture is absorbed until the capacitor element is sealed in the outer case, and the amount of moisture in the capacitor element increases. Therefore, the moisture content in the capacitor element can be reduced to 0.7 wt% or less by performing this process in a dry atmosphere or by removing moisture in the capacitor element before encapsulation. For example, using an electrolytic solution for an electrolytic capacitor having a low water content of 0.1 wt% or less, the capacitor element is allowed to stand in high-temperature dry air before impregnation with the electrolytic solution, and after impregnation, a dry atmosphere such as a glove box Among them, a method of enclosing and sealing an outer case, a method of drying a capacitor element impregnated with an electrolytic solution under a reduced pressure at 40 to 60 ° C., and the like can be used.

  Borodiglycolic acid tertiary amine salt hydrolyzes in the presence of water to produce boric acid and glycolic acid. And this glycolic acid reacts with electrode foil, and a characteristic deteriorates. Thus, the present invention has been achieved by investigating the relationship between moisture in the element and deterioration of characteristics. That is, when the water permeating into the capacitor element exceeds 0.7 wt%, the hydrolysis reaction of the tertiary amine salt of borodiglycolic acid is promoted, and the generated glycolic acid reacts with the electrode foil, and the characteristics of the electrolytic capacitor Cause deterioration. Therefore, deterioration of the characteristics of the electrolytic capacitor can be prevented by setting the amount of water contained in the capacitor element to 0.7 wt% or less.

  Thus, when moisture is absorbed in the capacitor element impregnated with the electrolytic solution, moisture is unevenly distributed in the capacitor element. That is, moisture increases in a portion close to the end face of the capacitor element, hydrolysis of the borodiglycolic acid tertiary amine salt is promoted, glycolic acid production increases, and the reactivity with the electrode foil increases. Therefore, it is considered that the amount of water contained in the capacitor element that does not affect the characteristics of the capacitor even if there is such uneven distribution is 0.7 wt% or less.

  Furthermore, it is preferable to add a nitro compound because the reactivity between the generated glycolic acid and the electrode foil can be suppressed. Nitro compounds include nitrophenol, dinitrophenol, nitrobenzoic acid, nitrotoluene, dinitrotoluene, nitroxylene, nitrobenzene, dinitrobenzene, nitrobenzyl alcohol, nitrobenzaldehyde, nitroacetophenone, nitroanisole, dimethoxynitrobenzene, nitroaniline, nitrophenetole Nitrophthalic acid, 2- (nitrophenoxy) ethanol, and the like.

  The electrolytic capacitor of the present invention described above has low impedance characteristics and good high temperature life characteristics. That is, since the electrolytic capacitor of the present invention has a moisture content of 0.7 wt% or less in the capacitor element, when a high temperature life test is performed using a borodiglycolic acid tertiary amine salt, Hydrolysis of the borodiglycolic acid tertiary amine salt is promoted by the moisture contained, and the generated glycolic acid and the electrode foil do not react with each other to deteriorate the characteristics, and the high-temperature life characteristics are stable. Yes.

  In the fourth electrolytic capacitor of the present invention, a separator made of a heat resistant synthetic resin is used as the separator. Examples of the separator include woven fabric, non-woven fabric, paper, and porous film. That is, polyester, polyamide, vinylon, rayon, aramid, polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, wholly aromatic polyester, polyimide, polyamideimide, polyetherimide, polytetrafluoroethylene, polyaminobismaleimide, ethylene-4 Examples thereof include a woven fabric, a nonwoven fabric or paper using a polymer fiber selected from ethylene fluoride, polyvinylidene fluoride, and the like, and a porous film using these polymers. An epoxy resin, a phenol resin, a polyurethane resin, or a melamine resin may be used as a binder.

  The electrolytic capacitor of the present invention described above has low impedance characteristics and good high temperature life characteristics. That is, when a separator made of ordinary manila paper or the like and a borodiglycolic acid tertiary amine salt are used and a high temperature life test is performed, borodiglycolic acid is hydrolyzed by moisture mixed from the separator, and boric acid and glycolic acid are converted. The glycolic acid is produced and reacts with the electrode foil to deteriorate the characteristics. However, since the electrolytic capacitor of the present invention uses a separator made of a heat-resistant synthetic resin, there is little moisture to be mixed in, the reaction between the electrolytic solution and the electrode foil is suppressed, and the high-temperature life characteristics are also stable.

  In the fifth electrolytic capacitor of the present invention, an anode electrode foil, a cathode electrode foil, and a separator are wound to form a capacitor element, and the capacitor element is impregnated with the electrolytic solution for electrolytic capacitor. The capacitor element is accommodated in an outer case made of bottomed cylindrical aluminum, and the lead wire of the capacitor element is inserted into the through hole of the sealing body, and then the opening is sealed to form the electrolytic capacitor of the present invention. In the present invention, a water absorbing agent is provided in a bottomed cylindrical aluminum case. The water-absorbing agent may be placed in a case such as a film, plate or sphere, or a powder or fine powder placed in the case or the end face of the capacitor element, or a separator, electrode foil It may be attached to. Moreover, you may disperse | distribute to the electrolyte solution for electrolytic capacitors. Furthermore, you may mix in a sealing body.

here. Examples of the water absorbing agent include an inorganic water absorbing agent and an organic water absorbing agent. Examples of inorganic water-absorbing agents include activated carbon, zeolite, molecular sieves, silica gel, activated alumina and other large surface areas, water-absorbing particles such as calcium alginate beads, transition metal dichalcogenite such as NbS3, NbSe2, TaSe2, and graphite. Layered materials such as: unsaturated oxides such as GeO, oxides of alkaline earth metals such as CaO and BaO, compounds with crystal water such as NiSO4, LiClO4, sodium paratoluenesulfonate, sodium acetate, sodium citrate, Inorganic compounds such as phosphorus oxide, calcium sulfate, zinc oxide, zinc bromide and anhydrous copper sulfate, metals such as lithium, beryllium, potassium, sodium, magnesium, rubidium, strontium, calcium, and TiO2, diatomaceous earth, activated carbon, semi-solid Give gypsum Door can be.

  Organic water-absorbing agents include starch, cellulose (graft polymerization, carboxymethyl: starch / polyacrylate, bridged carboxymethylated cellulose), synthetic polymer (acrylic, acrylamide, polyoxyethylene) -Based, methacrylic: bridged polyacrylate, acrylic fiber hydrolyzate), isobutylene / maleate, bridged polyvinyl alcohol, etc., super absorbent polymer, acetylcellulose, butylacetylcellulose, polyamide , Urea resin, polyester surrin A (ionomer), organic substances such as chlorinated rubber, ion exchange resin, polyvinyl alcohol, nylon, etc., in the molecule -NH2, -OH, -COOH, -SO3 H, -OH, -NH- Water absorption that has a hydrophilic group such as can absorb and retain a lot of moisture Resin, naphthylene diisocyanate, 4,4-diphenylmethane diisocyanate, paraphenylene diisocyanate, isopropylidenebis (4-cyclohexyl isocyanate), cyclohexyl diisocyanate, tolidine diisocyanate, lysine diisocyanate, tetramethylxylylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate And hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, a copolymer of vinyl alcohol and acrylic acid, a copolymer of starch and acrylonitrile, and C60 (fullerene).

  The electrolytic capacitor of the present invention described above has low impedance characteristics and good high temperature life characteristics. That is, when a borodiglycolic acid tertiary amine salt is used and a high-temperature life test is performed, borodiglycolic acid is hydrolyzed by moisture penetrating from the sealing portion to generate boric acid and glycolic acid, and this glycolic acid is used as an electrode. Reacts with foil and deteriorates properties. However, in the electrolytic capacitor of the present invention, since the water absorbing agent is provided in the outer case, the water absorbing agent absorbs the water permeated from the sealing portion, the reaction between the electrolytic solution and the electrode foil is suppressed, and the high temperature life characteristic is also achieved. stable.

  In the sixth electrolytic capacitor of the present invention, as shown in FIG. 1, a tube 91 made of a flexible material is provided in the through hole 92 of the sealing body.

  This tube can be provided by mounting the tube 92 on the outer periphery of the round bar portion 6 of the electrode lead-out means and inserting the round bar portion with the tube into the through hole 92 of the sealing body. Alternatively, a tube 91 can be mounted in a through-hole 92 provided in the sealing body, and the round bar portion 6 of the electrode lead-out means can be inserted into the tube.

  By providing a tube made of such a flexible material, airtightness can be improved. That is, both when inserting a round bar with a tube into the through hole of the sealing body and when inserting the round bar of the electrode lead-out means into the tube attached to the through hole, Since the tube extends in the insertion direction due to the pressing force of the electrode drawing means, the stress is diffused and the adhesion between the tube and the round bar is improved, resulting in an electrolytic capacitor. Improves airtightness.

  Then, with the tube attached to the round bar portion of the electrode lead-out means, the inner diameter of the tube is made smaller than the outer diameter of the round bar portion of the electrode lead-out means, and the outer diameter of the tube is made larger than the diameter of the through hole. Also, the diameter of the opening end of the through hole in the insertion side of the electrode lead-out means is made larger than the diameter of the central portion thereof. By adopting such means, the tight contact can be ensured over the entire contact area of each of the round bar portion, the tube, and the through-hole, thereby further improving the airtightness.

  Further, as shown in FIG. 1, the sealing body is made of a first sealing member 93 made of, for example, a hard material with low moisture permeability, and a second sealing member made of a flexible material attached to the outer periphery thereof. 94, even if there is a slight variation in the dimensions of the first sealing member and the airtightness of the first sealing member, the first sealing member is made of a flexible material disposed on the outer periphery thereof. Since the dimensional error can be absorbed by the elasticity of the sealing member 2, the airtightness is improved by the synergistic action of both the outer peripheral surface of the sealing means and the inner peripheral surface of the opening of the exterior case can be reliably adhered. be able to.

  Examples of the flexible material include rubber, fluororesin, shrinkable tube, polyethylene, polyester, polyimide, polyamide, nylon, polyamideimide, silicone resin, silicone rubber, poly-4-methylpentene-1 (crystalline polyolefin), Mention may be made of ethylene-vinyl alcohol copolymers.

  And the sealing body is a group of resin materials including fluororesin, polyphenylene sulfide, nylon, phenol resin, epoxy resin, polysulfone, polyimide, polyamideimide, polyoxybenzylene polyethylene, polypropylene, polycarbonate, aluminum, tantalum, magnesium, It can be composed of a material with low moisture permeability selected from a group of metallic materials including copper, nickel, titanium, or alloys thereof, hard rubber, ceramic, glass. Here, when using a metal material, for the purpose of ensuring insulation between the lead terminal and the capacitor element, a resin film or an oxide film made of an epoxy resin, a nylon resin, or the like is formed on the surface of the metal material. An insulating layer is formed. These materials can also be used as the hard material.

  Furthermore, it is preferable that the tube and sealing body used in the present invention are made of an alkali-resistant resin. As the alkali-resistant resin, a material selected from a fluororesin or polyethylene can be used. As the fluororesin, PTFE (polytetrafluoroethylene), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), PFA ( Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), ETFE (ethylene-tetrafluoroethylene copolymer), ECTFE (ethylene-chlorotrifluoroethylene copolymer), PCTFE (polychlorotrifluoroethylene) Materials can be used.

  The electrolytic capacitor of the present invention described above has low impedance characteristics and good high temperature life characteristics. That is, when a borodiglycolic acid tertiary amine salt is used and a high-temperature life test is performed, borodiglycolic acid is hydrolyzed by moisture penetrating from the sealing portion to produce boric acid and glycolic acid. Reacts with foil and deteriorates properties. However, since the electrolytic capacitor of the present invention is provided with a tube made of a flexible material in the through hole of the sealing body, the hermeticity of the sealing body is improved and the penetration of moisture from the outside of the capacitor is reduced. The reaction of the electrode foil is suppressed, and the high-temperature life characteristics are stable.

  According to the present invention, it is possible to provide an electrolytic capacitor having low impedance characteristics and good high-temperature life characteristics.

    Hereinafter, the present invention will be described specifically by way of examples.

  The capacitor element is formed by winding an anode electrode foil and a cathode electrode foil through a separator. The anode electrode foil and the cathode electrode foil are connected to lead wires for anode extraction and lead wires for cathode extraction, respectively.

  These lead wires are composed of a connection portion that comes into contact with the electrode foil, a round bar portion formed integrally with the connection portion, and an external connection portion fixed to the tip of the round bar portion. The connecting part and the round bar part are made of 99% aluminum, and the external connecting part is made of a copper-plated steel wire. An anodized film made of aluminum oxide is formed on the surface of at least the round bar portion of the lead wire by chemical conversion treatment with an aqueous ammonium phosphate solution. This lead wire is electrically connected to the bipolar electrode foil by means such as stitching or ultrasonic welding at the connection portion.

  The anode electrode foil was obtained by subjecting an aluminum foil of 99.9% purity to chemical or electrochemical etching in an acidic solution to enlarge the surface, followed by chemical conversion treatment in an aqueous solution of ammonium adipate. What formed the oxide film layer is used.

  Then, the capacitor element impregnated with the electrolytic solution is housed in an outer case made of bottomed cylindrical aluminum, and a sealing body is attached to the opening of the outer case, and the end of the outer case is subjected to a drawing process and the outer case Seal the case. The sealing body is provided with through holes through which the lead wires are led out.

(Example 1)
The electrolytic solution for electrolytic capacitors used in this example is shown in (Table 1-1). As a conventional example, 90 wt% of γ-butyrolactone and 10 wt% of 1-ethyl-2,3-dimethylimidazolinium hydrogen phthalate were used. The spark voltage is 105 V and the specific resistance is 142 Ωcm.

The electrolytic capacitors configured as described above have a rating of 63 WV-47 μF, and the characteristics of these electrolytic capacitors were evaluated. The test conditions are 105 ° C. and 500 hours load. The results are shown in (Table 1-2).

GBL: γ-butyrolactone 3-MSL: 3-methylsulfolane A: ethyldimethylamine borodiglycolate

Cap: capacitance, tan δ: tangent of dielectric loss, ΔCap: capacitance change rate

  As is clear from (Table 1-1), the specific resistance of the electrolytic solution for electrolytic capacitor of the example is lower than that of the conventional example, and the spark voltage is also high. As can be seen from (Table 1-2), the tan δ of the electrolytic capacitor using this is low, and the high-temperature life characteristics are also better than the comparative example. Similar results were obtained by using 2,4-dimethylsulfolane instead of 3-methylsulfolane.

(Example 2)
In this example, the following electrode foil was used. As the cathode foil, an etching foil subjected to a phosphoric acid immersion treatment in an etching process was used, and as the anode foil, a chemical conversion foil in which an anodized film was formed on the etching foil by phosphorylation was used. As a comparative example, an electrode foil that does not perform such phosphoric acid immersion treatment and phosphorylation was used.

  Moreover, the electrolytic solution for electrolytic capacitors used is shown in (Table 2-1).

  As described above, the rating of the electrolytic capacitors formed using the electrolytic solutions of the examples is 63 WV-47 μF, and the characteristics of these electrolytic capacitors were evaluated. The test conditions are 105 ° C. and 500 hours load. The results are shown in (Table 2-2).

GBL: γ-butyrolactone A: ethyldimethylamine borodiglycolate B: 1-ethyl-2,3-dimethylimidazolinium hydrogen phthalate C: dibutyl phosphate

Cap: capacitance, tan δ: tangent of dielectric loss, LC: leakage current, ΔCap: capacitance change rate

  As is clear from (Table 2-1), the specific resistance of the electrolytic solution for electrolytic capacitor of the example is reduced to about ½ compared to the conventional example, and the spark voltage is also high. As can be seen from (Table 2-2), the tan δ of the electrolytic capacitor using this is low, the leakage current after the high-temperature life test is reduced as compared with the comparative example, and the effect of the present invention is clear. .

Example 3
In this example, the capacitor element was dried before impregnation with the electrolytic solution, and the subsequent steps were performed in a glove box under humidity control, and the moisture content of the element was measured by housing, sealing, and disassembling after aging.

The electrolytic solution for an electrolytic capacitor used here is γ-butyrolactone 74 wt%, borodiglycolic acid ethyldimethylamine 25 wt%, and p-nitrophenol 1 wt%.

  The electrolytic capacitors configured as described above have a rating of 63 WV-47 μF, and the characteristics of these electrolytic capacitors were evaluated. The test conditions are 105 ° C. and 500 hours load. The results are shown in (Table 3-1).

Cap: capacitance, tan δ: tangent of dielectric loss, LC: leakage current, ΔCap: capacitance change rate

  As is clear from Table 3-1 in the examples, an electrolytic capacitor having a low impedance characteristic is realized, and the high-temperature life characteristic is 0.7 wt% compared to the comparative example in which the element moisture content is 0.9 wt%. % Of Example 3 is good, and 0.4 wt% and 0.2 wt% of Examples 2 and 1 are even better.

Example 4
In this example, a separator made of polyethylene terephthalate (PET) and a separator made of conventional Manila paper were used as the separator.

  Moreover, the electrolytic solution for electrolytic capacitors used is shown in (Table 4-1).

  As described above, the rating of the electrolytic capacitors formed using the electrolytic solutions of the examples is 63 WV-47 μF, and the characteristics of these electrolytic capacitors were evaluated. The test conditions are 105 ° C. and 500 hours load. The results are shown in (Table 4-2).

GBL γ-butyrolactone A: ethyldimethylamine borodiglycolate B: 1-ethyl-2,3-dimethylimidazolinium hydrogen phthalate

Cap: capacitance, tan δ: tangent of dielectric loss, LC: leakage current, ΔCap: capacitance change rate

  As is clear from (Table 4-1), the specific resistance of the electrolytic solution for electrolytic capacitors of the example is reduced to about ½ compared to the conventional example, and the spark voltage is also high. As can be seen from (Table 4-2), the tan δ of the electrolytic capacitor using this is low, the leakage current after the high-temperature life test is reduced as compared with the comparative example, and the effect of the present invention is clear. .

(Example 5)
In this example, a molecular sieve was placed in the outer case of the electrolytic capacitor.

  Moreover, the electrolytic solution for electrolytic capacitors used is shown in (Table 5-1).

  As described above, the rating of the electrolytic capacitors formed using the electrolytic solutions of the examples is 63 WV-47 μF, and the characteristics of these electrolytic capacitors were evaluated. The test conditions are 105 ° C. and 500 hours load. The results are shown in (Table 5-2).

GBL γ-butyrolactone A: ethyldimethylamine borodiglycolate B: 1-ethyl-2,3-dimethylimidazolinium hydrogen phthalate

Cap: capacitance, tan δ: tangent of dielectric loss, LC: leakage current, ΔCap: capacitance change rate

  As is clear from (Table 5-1), the specific resistance of the electrolytic solution for electrolytic capacitors of the example is reduced to about ½ compared to the conventional example, and the spark voltage is also high. As can be seen from (Table 5-2), the tan δ of the electrolytic capacitor using this is low, the leakage current after the high-temperature life test is reduced as compared with the comparative example, and the effect of the present invention is clear. .

(Example 6)
In this example, a sealing body provided with a PTFE tube in a through hole of a sealing rubber made of PTFE and a conventionally used sealing body made of butyl rubber were used as the sealing body.

  Moreover, the electrolytic solution for electrolytic capacitors used is shown in (Table 6-1).

  As described above, the rating of the electrolytic capacitors formed using the electrolytic solutions of the examples is 63 WV-47 μF, and the characteristics of these electrolytic capacitors were evaluated. The test conditions are 105 ° C. and 500 hours load. The results are shown in (Table 6-2).

GBL γ-butyrolactone A: ethyldimethylamine borodiglycolate B: 1-ethyl-2,3-dimethylimidazolinium hydrogen phthalate

Cap: capacitance, tan δ: tangent of dielectric loss, LC: leakage current, ΔCap: capacitance change rate

  As is clear from (Table 6-1), the specific resistance of the electrolytic solution for electrolytic capacitors of the example is reduced to about ½ compared to the conventional example, and the spark voltage is also high. As can be seen from (Table 6-2), the tan δ of the electrolytic capacitor using this is low, the leakage current after the high-temperature life test is reduced as compared with the comparative example, and the effect of the present invention is clear. .

It is an internal sectional view showing the structure of the electrolytic capacitor of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Capacitor element 4 Lead wire for anode lead-out 5 Lead wire for cathode lead-out 6 Round bar part 8 External connection part 10 Exterior case

Claims (10)

An electrolytic capacitor using an electrolytic solution for electrolytic capacitors containing a tertiary amine salt of borodiglycolic acid and a high boiling point solvent. 2. The electrolytic solution for an electrolytic capacitor according to claim 1, wherein the high boiling point solvent is 3-methylsulfolane or 2,4-dimethylsulfolane. An electrolytic capacitor in which a capacitor element wound with an anode electrode foil, a cathode electrode foil and a separator and impregnated with an electrolytic solution is housed in an outer case, wherein the electrolytic solution contains a borodiglycolic acid tertiary amine salt as the electrolytic solution And an electrolytic capacitor using an electrode foil subjected to phosphoric acid treatment as the anode electrode foil and / or the cathode electrode foil. In an electrolytic capacitor in which an anode electrode foil, a cathode electrode foil and a separator are wound and a capacitor element impregnated with an electrolytic solution is housed in an outer case, an electrolytic solution containing a borodiglycolic acid tertiary amine salt as the electrolytic solution And an electrolytic capacitor in which the amount of water contained in the capacitor element is 0.7 wt% or less. In an electrolytic capacitor in which an anode electrode foil, a cathode electrode foil and a separator are wound and a capacitor element impregnated with an electrolytic solution is housed in an outer case, an electrolytic solution containing a borodiglycolic acid tertiary amine salt as the electrolytic solution And an electrolytic capacitor using a separator made of a heat-resistant synthetic resin as the separator. In an electrolytic capacitor in which an anode electrode foil, a cathode electrode foil and a separator are wound and a capacitor element impregnated with an electrolytic solution is housed in an outer case, an electrolytic solution containing a borodiglycolic acid tertiary amine salt as the electrolytic solution And an electrolytic capacitor with a water absorbent in the outer case. The electrolytic capacitor according to claim 6, wherein the water-absorbing agent is zeolite, molecular sieves, silica gel, activated alumina, or a highly water-absorbing polymer. In the electrolytic capacitor formed by winding the anode electrode foil, the cathode electrode foil and the separator, and storing the capacitor element impregnated with the electrolytic solution in the outer case, and sealing the opening of the outer case with a sealing body having a through hole. An electrolytic capacitor comprising a tube made of a flexible material, wherein an electrolytic solution containing a borodiglycolic acid tertiary amine salt is used as the electrolytic solution, and a round bar portion of an electrode lead means is inserted into the through hole. The flexible material is rubber, fluororesin, shrinkable tube, polyethylene, polyester, polyimide, polyamide, nylon, polyamideimide, silicone resin, silicone rubber, poly-4-methylpentene-1 (crystalline polyolefin), ethylene- The electrolytic capacitor according to claim 8, which is a material selected from vinyl alcohol copolymers. The sealing body is a group of resin materials including fluororesin, polyphenylene sulfide, nylon, phenol, epoxy, polysulfone, polyimide, polyamideimide, polyoxybenzylene polyethylene, polypropylene, polycarbonate, aluminum, tantalum, magnesium, copper, nickel The electrolytic capacitor according to claim 8, wherein the electrolytic capacitor is a material selected from a group of metallic materials including titanium, titanium, or an alloy thereof, hard rubber, ceramic, and glass.