JP3297066B2 - Polymer solid electrolyte for driving electrolytic capacitors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer solid electrolyte for driving an electrolytic capacitor.

[0002]

2. Description of the Related Art In recent years, with the development of the industrial field, higher performance and higher reliability of electronic devices have been required.
In particular, an electrolytic capacitor using an electrolytic solution has many problems in terms of liquid leakage, device mounting, workability, and the like, and solidification of the electrolytic solution has been conventionally studied. Among these, solid polymer electrolytes have attracted attention because they are superior in mechanical performance such as light weight, flexibility, moldability, etc., despite their much lower ionic conductivity than inorganic electrolytes. I have.

As the polymer solid electrolyte, for example,
Complex of polyethylene oxide (PEO) and lithium salt (ion conductivity: 10 ^-4 S / cm at 100 ° C) @Pol
ymer, 14,586 (1973)}, a diisocyanate crosslinked polymer of triol-type polyethylene oxide-metal salt complex (ionic conductivity: 10 ⁻⁵ S / 30 ° C.)
cm) {Japanese Patent Application Laid-Open No. 62-48716}, a counter ion-fixed solid electrolyte of polyoxyoligoethylene methacrylate / alkali metal methacrylate copolymer (ionic conductivity: 10 ^-7 S / cm at room temperature) Rep
prints Japan, 35, 583 (1986)
Etc. have been reported. As an example of actual application to an electrolytic capacitor, a composite of a mixture of a siloxane-alkylene oxide copolymer and polyethylene oxide and an alkali metal salt (ion conductivity: 10% at room temperature)
^-5 to 10 ^-6 S / cm) is known.

[0004]

However, these polymer solid electrolytes have low ionic conductivity at room temperature and have a large loss when applied to electrolytic capacitors.
Sufficient characteristics could not be obtained.

The present invention solves such a problem, and has high ionic conductivity at room temperature, excellent shape retention even at high temperatures, does not react with aluminum foil when a capacitor is formed, and has a high spark generation voltage. It is an object of the present invention to provide a polymer solid electrolyte for driving an electrolytic capacitor which is excellent in terms of moldability and long life.

[0006]

In order to solve the above-mentioned problems, a solid polymer electrolyte for driving a capacitor according to the present invention comprises: a solvent containing a polyhydric alcohol solvent having a molecular weight of 400 or less;
It is composed of an electrolyte salt, a polymer containing an acid group in the molecule, and a polymer salt made of an amine compound.

[0007]

According to the above construction, a solvent containing a polyhydric alcohol solvent having a molecular weight of 400 or less, an electrolyte salt, a polymer containing an acid group in the molecule, and a polymer salt made of an amine compound are more improved. It forms a solid polymer electrolyte, in which a solvent and an electrolyte salt are incorporated into a matrix of a crosslinked product of a polymer containing an acid group in the molecule and an amine compound, forming an ion-conductive polymer solid electrolyte. As a result, a material having high ionic conductivity at room temperature can be obtained. Further, the aluminum electrolytic capacitor using the polymer solid electrolyte of the present invention does not react with the aluminum foil and can obtain a capacitor excellent in spark generation voltage, moldability and long life.

[0008]

Embodiments of the present invention will be described below. The basis of the embodiment of the present invention is an electrolytic capacitor comprising a solvent containing a polyhydric alcohol solvent having a molecular weight of 400 or less, an electrolyte salt, a polymer containing an acid group in the molecule, and a polymer salt made of an amine compound. This constitutes a driving solid polymer electrolyte.

In the embodiment of the present invention, the solvent has a molecular weight of 40.
It comprises a polyhydric alcohol solvent of 0 or less and another solvent which is compatible with the polyhydric alcohol solvent as required. Examples of the polyhydric alcohol solvent include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, glycerin, and polyoxyalkylene polyol. These may be used in combination of two or more. Of these, ethylene glycol and propylene glycol are preferred. Other solvents include water, amide solvents (N-methylformamide, N, N-dimethylformamide, N-methylacetamide, N-methylpyrrolidinone, etc.), ether solvents (methylal, 1,2-dimethoxyethane, 1- Ethoxy-2-methoxyethane,
1,2-diethoxyethane, etc.), lactone solvent (γ-
Butyrolactone, γ-valerolactone, δ-valerolactone, 3-methyl-1,3-oxazolindin-2-one, 3-ethyl-1,3-oxazolindin-2-one, etc.), nitrile solvent (acetonitrile, 3 -Methoxypropionitrile), a furan solvent (such as 2,5-dimethoxytetrahydrofuran), 2-imidazolidinones (such as 1,3-dimethyl-2-imidazolidinone),
A single or mixed solvent of pyrrolidones can be used. Of these, amide solvents, ether solvents, nitrile solvents and furan solvents are preferred. The amount of the other solvent is usually 5 parts by weight based on 100 parts by weight of the polyhydric alcohol solvent in the solvent.
0 parts by weight or less. Outside this range, good capacitor performance cannot be obtained. Electrolyte salts include amine salts, quaternary ammonium salts and diazabicycloalkene salts. The amine salt comprises 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 tetra (alkyl) ammonium (tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, methyltriethylammonium, dimethylammonium). Diethylammonium and the like, and pyridium (1-methylpyridium, 1-ethylpyridium, 1,3-diethylpyridium and the like). The diazabicycloalkene salt is a salt of a diazabicycloalkene and an acid, and as the diazabicycloalkene, 1,5-diazabicyclo (4,3,0) nonene-5,1,8-diazabicyclo (5,4, 0) Undecene-7 and the like. Acids constituting each salt include boric acid, phosphoric acid, carboxylic acid (formic acid, acetic acid, propionic acid, maleic acid, citraconic acid, phthalic acid, adipic acid, azelaic acid, benzoic acid, butyloctanoic acid, formic acid, decane Dicarboxylic acid, etc.). Among the electrolyte salts exemplified above, preferred are salts (amine salts and quaternary ammonium salts) formed from a secondary amine, a tertiary amine or a quaternary ammonium and a carboxylic acid or boric acid. These may be used in combination.

In the embodiments of the present invention, the polymer containing an acid group in the molecule includes a polymer containing a carboxylic acid group (such as a (co) polymer of (meth) acrylic acid) and a polymer containing a sulfonic acid group. Molecule (Styrenesulfonic acid (co)
Polymer), a polymer containing a phosphate group (such as a polymer of 2-acryloyloxyethyl acid phosphate and a copolymer thereof) and a polymer containing an amino acid group (such as a polyamino acid). Among these, preferred are a polymer containing a carboxylic acid group and a polymer containing a phosphoric acid group, and among them, a polymer containing a carboxylic acid group is particularly preferred. The molecular weight of the polymer containing an acid group is usually 100,000 to 10,000,000, and preferably 500,000 to 8,000,000. Outside this range, the shape retention at high temperatures deteriorates.

Examples of the amine compound in the examples of the present invention include primary amines (eg, methylamine, ethylamine, propylamine, butylamine, ethylenediamine),
Tertiary amines (dimethylamine, diethylamine, dipropylamine, methylethylamine, diphenylamine, etc.), tertiary amines (trimethylamine, triethylamine, tripropylamine, triphenylamine, triethylenediamine, tetramethylhexamethylenediamine, tetramethyltrimethylenediamine, Piperazine,
Hydrazine, morpholine, bis (2-dimethylaminoethyl) ether, 1,8diazabicyclo (5,4,
0) -undecene-7). Preferred among these are piperazine, triethylenediamine and hydrazine.

Next, the weight ratio of each component of the polymer solid electrolyte for driving the electrolytic capacitor in the embodiment of the present invention will be described. The amount of the electrolyte salt is usually 0.1 to 100 parts by weight of the solvent.
It is 1 to 50 parts by weight, preferably 1.0 to 40 parts by weight. Outside this range, the ionic conductivity is low. The amount of the polymer salt is usually 1.0 to 100 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of the solvent. Outside this range, the characteristics of the electrolytic capacitor deteriorate.

Next, a method for producing a solid polymer electrolyte for driving an electrolytic capacitor according to an embodiment of the present invention will be described. The first production method is a method in which an amine compound is dissolved in an electrolytic solution in which a solvent and an electrolyte salt are mixed, and then a polymer containing an acid group is mixed and solidified. The second production method is a method in which a polymer containing an acid group is added to a solvent to be heated and dissolved, then an electrolyte is added and heated and dissolved, and then an amine compound is mixed and solidified. A good solid polymer electrolyte for driving an electrolytic capacitor cannot be obtained by any other manufacturing method.

The polymer solid electrolyte for driving an electrolytic capacitor according to the embodiment of the present invention can be compounded with an auxiliary material. In the case of compounding, the solid polymer electrolyte for driving the electrolytic capacitor of the embodiment of the present invention may be applied to the auxiliary material before solidifying. Examples of the auxiliary material include a film, paper, cloth, nonwoven fabric, and glass mat.

Hereinafter, specific embodiments of the present invention will be described, but the present invention is not limited thereto. Hereinafter, "part" indicates "part by weight". Example 1 14 parts of diammonium adipate was dissolved at 60 ° C. in 100 parts of ethylene glycol, and then 5 parts of triethylenediamine was dissolved. To this, 10 parts of polyacrylic acid (molecular weight: 1.4 million) was added and mixed uniformly to obtain a solid polymer electrolyte for driving an electrolytic capacitor. (Example 2) 15 parts of diammonium azelate was dissolved in 100 parts of ethylene glycol at 60 ° C, and then 7 parts of triethylenediamine was dissolved. To this, 10 parts of polyacrylic acid (molecular weight 5,000,000) was added and mixed uniformly,
A polymer solid electrolyte for driving an electrolytic capacitor was obtained. Example 3 100 parts of propylene glycol and 5 parts of 2-acryloyloxyethyl azide phosphate polymer were mixed by heating at 60 ° C. Then, 13 parts of diammonium adipate was added, and the mixture was heated and mixed at 60 ° C., and then 12.5 parts of 1,8 diazabicyclo (5,4,0) -undecene-7 was mixed to obtain a polymer solid electrolyte for driving an electrolytic capacitor. . (Comparative Example 1) 3 to potassium hexafluoroglutarate
50 × 10 ⁻⁵ g / mol of polyethylene oxide
%, 40% of polyethylene glycol 350 dalton siloxane and 10% of styrene, and a polymer electrolyte solution was prepared by dissolving potassium salt in a concentration of 0.04 mol per mol of ethylene oxide repeating unit. The polymer solid electrolyte for driving an electrolytic capacitor was obtained by being left for a time.

The ionic conductivity at 25 ° C. of the solid electrolytes for driving the electrolytic capacitors of Examples 1 to 3 of the present invention and Comparative Example 1 obtained as described above is measured by impedance using platinum as an electrode. Was measured by In addition, constant current formation was performed using an aluminum foil having a purity of 99.99% as an anode and platinum as a cathode, and a spark generation voltage was measured. Furthermore, the state of the shape change when left at 125 ° C. for 200 hours was observed. The results are shown in Table 1.

[0017]

[Table 1]

As is apparent from Table 1, Examples 1 to 3 of the present invention have higher ionic conductivity at room temperature, higher spark generation voltage and better shape retention than Comparative Example 1. Could be something.

[0019]

As described above, the polymer solid electrolyte for driving an electrolytic capacitor according to the present invention comprises a solvent containing a polyhydric alcohol solvent having a molecular weight of 400 or less, an electrolyte salt, and a high molecular weight compound containing an acid group in the molecule. A three-dimensional crosslinked product of the high molecular salt, and at the same time, a molecular weight of 40
Since the solvent containing the polyhydric alcohol-based solvent of 0 or less and the electrolyte salt are taken into the matrix of the three-dimensional crosslinked product, a polymer solid electrolyte for driving an electrolytic capacitor having a large ionic conductivity at room temperature can be formed. The aluminum electrolytic capacitor using the solid polymer electrolyte of the present invention does not react with the aluminum foil, has a high spark generation voltage, and is excellent in moldability and long life.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tetsuya Samura 11 Sanyo Kasei Kogyo Co., Ltd., at 11-11 Hitotsubashi-Honcho, Higashiyama-ku, Kyoto-shi, Kyoto (56) References JP-A 1-248509 (JP, A) JP Hei 1-309205 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01G 9/028 H01G 9/035

Claims (1)

(57) [Claims] 1. A solvent comprising a polyhydric alcohol solvent having a molecular weight of 400 or less, an electrolyte salt, a polymer containing an acid group in the molecule, and a polymer salt made of an amine compound. Polymer solid electrolyte for driving an electrolytic capacitor.