JP2004186236A - Electrolytic solution for driving electrolytic capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrolytic solution for driving electrolytic capacitor that can suppress the variation of the appearance of an electrolytic capacitor. <P>SOLUTION: This electrolytic solution is prepared by dissolving a carboxylic acid or its salt, a boric acid or its ammonium salt, and unsaturated hydrocarbon dinitrile (NC-R-CN: wherein, R is unsaturated hydrocarbon, the number of carbon atoms is 2-8, and number of double couplings is 1-7) in a solvent containing ethylene glycol as the main component as solutes. The dissolved amount of the unsaturated hydrocarbon dinitrile is adjusted to 0.10-5.0 wt%, and the dinitrile is composed of propylene dinitrile, 1,3-butadiene dinitrile, 1,2,3-pentatrien dinitrile, 1,2,3,4-heptatetraen dinitrile, 1,2,3,4,5-octapentaen dinitrile, etc. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００７】
そして、不飽和炭化水素ジニトリルの溶解量が、０．１０〜５．０ｗｔ％であることを特徴とする電解コンデンサの駆動用電解液である。
【０００８】
上記の不飽和炭化水素として、まず、エチレン、プロピレン、ブテン、ペンテン、へキセン、ヘプテン、オクテンを例示することができる。
【０００９】
さらに、２個の二重結合を有する不飽和炭化水素として、プロパジエン、１，２−ブタジエン、１，３−ブタジエン、１，２−ペンタジエン、１，３−ペンタジエン、１，４−ペンタジエン、２，３−ペンタジエン、２，４−ペンタジエン、１，２−ヘキサジエン、１，３−ヘキサジエン、１，４−ヘキサジエン、１，５−ヘキサジエン、２，３−ヘキサジエン、２，４−ヘキサジエン、１，２−ヘプタジエン、１，３−ヘプタジエン、１，４−ヘプタジエン、１，５−ヘプタジエン、１，６−ヘプタジエン、２，３−ヘプタジエン、２，４−ヘプタジエン、２，５−ヘプタジエン、３，４−ヘプタジエン、１，２−オクタジエン、１，３−オクタジエン、１，４−オクタジエン、１，５−オクタジエン、１，６−オクタジエン、１，７−オクタジエン、２，３−オクタジエン、２，４−オクタジエン、２，５−オクタジエン、２，６−オクタジエン、３，４−オクタジエン、３，５−オクタジエンを例示することができる。
【００１０】
また、３個の二重結合を有する不飽和炭化水素として、ブタトリエン、１，２，３−ペンタトリエン、１，２，４−ペンタトリエン、１，２，３−ヘキサトリエン、１，２，４−ヘキサトリエン、２，３，４−ヘキサトリエン、１，２，３−ヘプタトリエン、１，２，４−ヘプタトリエン、１，２，５−ヘプタトリエン、２，３，４−ヘプタトリエン、２，３，５−ヘプタトリエン、１，２，３−オクタトリエン、１，２，４−オクタトリエン、１，２，５−オクタトリエン、１，２，６−オクタトリエン、２，３，４−オクタトリエン、２，３，５−オクタトリエン、２，３，６−オクタトリエン、３，４，５−オクタトリエンを例示することができる。
【００１１】
そして、４個の二重結合を有する不飽和炭化水素として、ペンタテトラエン、１，２，３，４−ヘキサテトラエン、１，２，３，５−ヘキサテトラエン、１，２，４，５−ヘキサテトラエン、１，２，３，４−ヘプタテトラエン、１，２，３，５−ヘプタテトラエン、１，２，３，６−ヘプタテトラエン、１，３，４，５−ヘプタテトラエン、１，２，４，５−ヘプタテトラエン、１，２，５，６−ヘプタテトラエン、２，３，４，５−ヘプタテトラエン、１，２，３，４−オクタテトラエン、１，２，３，５−オクタテトラエン、１，２，３，６−オクタテトラエン、１，２，３，７−オクタテトラエン、１，２，４，５−オクタテトラエン、１，２，５，６−オクタテトラエン、１，２，６，７−オクタテトラエン、２，３，４，５−オクタテトラエン、２，３，４，６−オクタテトラエン、２，３，５，６−オクタテトラエンを例示することができる。
【００１２】
さらに、５個の二重結合を有する不飽和炭化水素として、ヘキサペンタエン、１，２，３，４，５−ヘプタペンタエン、１，２，３，４，６−ヘプタペンタエン、１，２，３，５，６−ヘプタペンタエン、１，２，３，４，５−オクタペンタエン、１，２，３，４，６−オクタペンタエン、１，２，３，４，７−オクタペンタエン、１，２，３，５，６−オクタペンタエン、１，２，３，６，７−オクタペンタエン、２，３，４，５，６−オクタペンタエンを例示することができる。
【００１３】
そして、６個の二重結合を有する不飽和炭化水素として、ヘプタヘキサエン、オクタヘキサエンを、また、７個の二重結合を有する不飽和炭化水素として、オクタヘプテンを例示することができる。
【００１４】
そして、カルボン酸としては、マロン酸、コハク酸、グルタル酸、アジピン酸、ピメリン酸、スベリン酸、アゼライン酸、セバシン酸、ウンデカン二酸、ドデカン二酸、トリデカン二酸、テトラデカン二酸、ペンタデカン二酸、１，６−デカンジカルボン酸、５，６−デカンジカルボン酸、２−メチルアゼライン酸、３−ｔｅｒｔ−ブチルアジピン酸、７−ビニルヘキサデセン−１，１６−ジカルボン酸、マレイン酸、フマル酸、シトラコン酸、安息香酸、サリチル酸、フタル酸、クエン酸等を例示することができる。
【００１５】
さらに、カルボン酸の塩としては、アンモニウム塩の他、メチルアミン、エチルアミン、ｔ−ブチルアミン等の１級アミン塩、ジメチルアミン、エチルメチルアミン、ジエチルアミン等の２級アミン塩、トリメチルアミン、ジエチルメチルアミン、エチルジメチルアミン、トリエチルアミン等の３級アミン塩、テトラメチルアンモニウム、トリエチルメチルアンモニウム、テトラエチルアンモニウム等の４級アンモニウム塩、イミダゾリニウム塩等を例示することができる。
【００１６】
エチレングリコールに混合する副溶媒としては水の他、プロピレングリコール等のグリコール類、γ−ブチロラクトン、Ｎ−メチル−２−ピロリドン等のラクトン類、Ｎ−メチルホルムアミド、Ｎ，Ｎ−ジメチルホルムアミド、Ｎ−エチルホルムアミド、Ｎ，Ｎ−ジエチルホルムアミド、Ｎ−メチルアセトアミド、Ｎ，Ｎ−ジメチルアセトアミド、Ｎ−エチルアセトアミド、Ｎ，Ｎ−ジエチルアセトアミド、ヘキサメチルホスホリックアミド等のアミド類、エチレンカーボネート、プロピレンカーボネート、イソブチレンカーボネート等の炭酸類、アセトニトリル等のニトリル類、ジメチルスルホキシド等のオキシド類、エーテル類、ケトン類、エステル類、スルホラン類等を例示することができる。
【００１７】
【発明の実施の形態】
不飽和炭化水素ジニトリルは主鎖に二重結合を有し、また、二つのニトリル基を持つ化合物で、二重結合部が電解コンデンサ中の水素ガスと優先的に反応し、電解コンデンサの防爆弁膨張などの外観異常を長期にわたり抑制することができる。また、二つのニトリル基が、電解コンデンサ中の水分と反応してジカルボン酸に変化するので製品の初期特性を長時間維持できる。
【００１８】
【実施例】
以下、本発明を実施例に基づき具体的に説明する。表１の組成で電解液を調合し、３０℃における電解液の比抵抗と８５℃における火花発生電圧（電解液の耐電圧）を測定し、表１の結果を得た。
【００１９】
【表１】

【００２０】
表１の電解液で、直径３５．０ｍｍ、長さ５０．０ｍｍ、定格電圧４００Ｖ、静電容量３３０μＦのアルミ電解コンデンサを各１０個作成した。これらの製品を１０５℃の恒温槽中で３０００時間、定格電圧印加し、外観、静電容量とｔａｎδを測定し、表２の結果を得た。
【００２１】
【表２】

【００２２】
表１、表２の結果より、不飽和炭化水素ジニトリルを溶解した実施例は、これを溶解しない従来例、およびこれの代わりにｐ−ニトロフェノールを溶解した比較例に比べて、比抵抗の上昇および耐電圧の低下を抑制しながら、外観変化、容量変化率ともに小さく、ｔａｎδの上昇も抑制されていることが分かる。また、不飽和炭化水素ジニトリルの溶解量が多いほど、外観変化、容量変化率、ｔａｎδの上昇の抑制に効果があるが、０．１０ｗｔ％未満では外観変化、容量変化率、ｔａｎδの上昇の抑制効果が十分ではなく、５．０ｗｔ％を超えると電解液の比抵抗上昇が著しいため、０．１０〜５．０ｗｔ％の範囲が好ましい。
【００２３】
【発明の効果】
上記のとおり、本発明による不飽和炭化水素ジニトリルを溶解した電解液を用いることで、電解コンデンサの外観変化、静電容量変化率、ｔａｎδ上昇を抑制することができ、信頼性の向上を図ることができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an improvement in an electrolytic solution for driving an electrolytic capacitor (hereinafter, referred to as an electrolytic solution), and particularly to an electrolytic solution that suppresses a change in appearance of an electrolytic capacitor for a long period of time.
[0002]
[Prior art]
Conventionally, the electrolytic solution of a medium-high pressure aluminum electrolytic capacitor has dissolved a higher dibasic acid or a salt thereof, boric acid or an ammonium salt thereof, and a polyhydric alcohol such as mannitol in a solvent such as ethylene glycol (for example, Patent Documents 1 and 2).
[0003]
[Patent Document 1]
Japanese Patent Publication No. 7-48460 (page 2, table)
[Patent Document 2]
Japanese Patent Publication No. 7-63047 (page 3, table 1)
[0004]
[Problems to be solved by the invention]
However, when a voltage is applied to an electrolytic capacitor using the above electrolyte at a high temperature, or when it is left unloaded, the explosion-proof valve expands due to the vapor generated from the electrolyte or the hydrogen gas generated from the cathode. There was a problem that an abnormality occurred. For this reason, a method of adding a nitro compound as a gas absorbent was considered, but the effect of gas absorption was small, and there was no effect of suppressing a change in appearance over a long period of time.
Because of the above-mentioned problems, there has been a demand for an electrolytic solution that does not cause abnormal appearance when an electrolytic capacitor is applied with a voltage at a high temperature or left unloaded.
[0005]
[Means for Solving the Problems]
The present invention has been found as a result of various studies to solve the above-mentioned problems, and aims to suppress an abnormal appearance of an electrolytic capacitor for a long time by dissolving unsaturated hydrocarbon dinitrile.
That is, the present invention is characterized in that a carboxylic acid or a salt thereof, boric acid or an ammonium salt thereof, and an unsaturated hydrocarbon dinitrile (Chemical Formula 2) are dissolved as solutes in a solvent containing ethylene glycol as a main component. It is an electrolytic solution for driving an electrolytic capacitor.
[0006]
Embedded image

[0007]
The electrolytic solution for driving an electrolytic capacitor is characterized in that the dissolved amount of the unsaturated hydrocarbon dinitrile is 0.10 to 5.0 wt%.
[0008]
First, examples of the unsaturated hydrocarbon include ethylene, propylene, butene, pentene, hexene, heptene, and octene.
[0009]
Further, as unsaturated hydrocarbons having two double bonds, propadiene, 1,2-butadiene, 1,3-butadiene, 1,2-pentadiene, 1,3-pentadiene, 1,4-pentadiene, 2,2 3-pentadiene, 2,4-pentadiene, 1,2-hexadiene, 1,3-hexadiene, 1,4-hexadiene, 1,5-hexadiene, 2,3-hexadiene, 2,4-hexadiene, 1,2- Heptadiene, 1,3-heptadiene, 1,4-heptadiene, 1,5-heptadiene, 1,6-heptadiene, 2,3-heptadiene, 2,4-heptadiene, 2,5-heptadiene, 3,4-heptadiene, 1,2-octadiene, 1,3-octadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-o Tajien, 2,3-octadiene, 2,4-octadiene, 2,5-octadiene, 2,6-octadiene, 3,4-octadiene, can be exemplified 3,5-octadiene.
[0010]
As unsaturated hydrocarbons having three double bonds, butatriene, 1,2,3-pentatriene, 1,2,4-pentatriene, 1,2,3-hexatriene, 1,2,4 -Hexatriene, 2,3,4-hexatriene, 1,2,3-heptatriene, 1,2,4-heptatriene, 1,2,5-heptatriene, 2,3,4-heptatriene, 2,3,5 Heptatriene, 1,2,3-octatriene, 1,2,4-octatriene, 1,2,5-octatriene, 1,2,6-octatriene, 2,3,4-octatriene, 2, Examples include 3,5-octatriene, 2,3,6-octatriene, and 3,4,5-octatriene.
[0011]
As unsaturated hydrocarbons having four double bonds, pentatetraene, 1,2,3,4-hexatetraene, 1,2,3,5-hexatetraene, 1,2,4, 5-hexatetraene, 1,2,3,4-heptatetraene, 1,2,3,5-heptatetraene, 1,2,3,6-heptatetraene, 1,3,4,5- Heptatetraene, 1,2,4,5-heptatetraene, 1,2,5,6-heptatetraene, 2,3,4,5-heptatetraene, 1,2,3,4-octatetra Ene, 1,2,3,5-octatetraene, 1,2,3,6-octatetraene, 1,2,3,7-octatetraene, 1,2,4,5-octatetraene, 1,2,5,6-octatetraene, 1,2,6,7-octatetraene, 2,3,4,5-O Tatetoraen 2,3,4,6 cyclooctatetraene, it can be exemplified 2,3,5,6-cyclooctatetraene.
[0012]
Further, as unsaturated hydrocarbons having five double bonds, hexapentaene, 1,2,3,4,5-heptapentaene, 1,2,3,4,6-heptapentaene, 1, 2,3,5,6-heptapentaene, 1,2,3,4,5-octapentaene, 1,2,3,4,6-octapentaene, 1,2,3,4,7- Examples include octapentaene, 1,2,3,5,6-octapentaene, 1,2,3,6,7-octapentaene, and 2,3,4,5,6-octapentaene. it can.
[0013]
Then, heptahexaene and octahexaene can be exemplified as unsaturated hydrocarbons having six double bonds, and octaheptene can be exemplified as an unsaturated hydrocarbon having seven double bonds.
[0014]
And, as the carboxylic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecandioic acid, dodecandioic acid, tridecandioic acid, tetradecandioic acid, pentadecandioic acid 1,6-decanedicarboxylic acid, 5,6-decanedicarboxylic acid, 2-methylazeleic acid, 3-tert-butyladipic acid, 7-vinylhexadecene-1,16-dicarboxylic acid, maleic acid, fumaric acid, citracone Examples include acids, benzoic acid, salicylic acid, phthalic acid, citric acid and the like.
[0015]
Further, examples of the carboxylic acid salts include ammonium salts, primary amine salts such as methylamine, ethylamine and t-butylamine, secondary amine salts such as dimethylamine, ethylmethylamine and diethylamine, trimethylamine, diethylmethylamine, and the like. Examples include tertiary amine salts such as ethyldimethylamine and triethylamine, quaternary ammonium salts such as tetramethylammonium, triethylmethylammonium and tetraethylammonium, and imidazolinium salts.
[0016]
As a secondary solvent to be mixed with ethylene glycol, in addition to water, glycols such as propylene glycol, lactones such as γ-butyrolactone, N-methyl-2-pyrrolidone, N-methylformamide, N, N-dimethylformamide, N- Amides such as ethylformamide, N, N-diethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-ethylacetamide, N, N-diethylacetamide, hexamethylphosphoramide, ethylene carbonate, propylene carbonate, Carbonates such as isobutylene carbonate, nitriles such as acetonitrile, oxides such as dimethyl sulfoxide, ethers, ketones, esters, sulfolane and the like can be exemplified.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Unsaturated hydrocarbon dinitrile is a compound having a double bond in the main chain and two nitrile groups. The double bond reacts preferentially with hydrogen gas in the electrolytic capacitor, and the explosion-proof valve of the electrolytic capacitor External appearance abnormalities such as expansion can be suppressed for a long time. In addition, the two nitrile groups react with water in the electrolytic capacitor to change into dicarboxylic acids, so that the initial characteristics of the product can be maintained for a long time.
[0018]
【Example】
Hereinafter, the present invention will be specifically described based on examples. An electrolytic solution was prepared using the composition shown in Table 1, and the specific resistance of the electrolytic solution at 30 ° C. and the spark generation voltage at 85 ° C. (withstand voltage of the electrolytic solution) were measured.
[0019]
[Table 1]

[0020]
Ten aluminum electrolytic capacitors each having a diameter of 35.0 mm, a length of 50.0 mm, a rated voltage of 400 V, and a capacitance of 330 μF were prepared using the electrolytic solutions shown in Table 1. The rated voltage was applied to these products in a thermostat at 105 ° C. for 3,000 hours, and the appearance, capacitance and tan δ were measured, and the results shown in Table 2 were obtained.
[0021]
[Table 2]

[0022]
From the results of Tables 1 and 2, it can be seen that the example in which the unsaturated hydrocarbon dinitrile was dissolved showed an increase in the specific resistance as compared with the conventional example in which it was not dissolved and the comparative example in which p-nitrophenol was dissolved instead. It can be seen that both the change in appearance and the rate of change in capacitance are small and the rise in tan δ is also suppressed, while suppressing the decrease in the withstand voltage. Further, the larger the amount of the unsaturated hydrocarbon dinitrile dissolved, the more the effect of suppressing the appearance change, the rate of change in capacity, and the increase in tan δ. If the effect is not sufficient and the specific resistance exceeds 5.0 wt%, the specific resistance of the electrolytic solution increases significantly. Therefore, the range of 0.10 to 5.0 wt% is preferable.
[0023]
【The invention's effect】
As described above, by using the electrolytic solution in which the unsaturated hydrocarbon dinitrile according to the present invention is dissolved, it is possible to suppress the change in appearance of the electrolytic capacitor, the rate of change in capacitance, and the increase in tan δ, and to improve the reliability. Can be.

Claims (2)

Driving of an electrolytic capacitor characterized by dissolving, as a solute, a carboxylic acid or a salt thereof, boric acid or an ammonium salt thereof, and an unsaturated hydrocarbon dinitrile (formula 1) in a solvent containing ethylene glycol as a main component. Electrolyte.

An electrolytic solution for driving an electrolytic capacitor, wherein the amount of the unsaturated hydrocarbon dinitrile according to claim 1 is 0.10 to 5.0 wt%.