JPH04337618A - Solid state electrolyte capacitor and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a solid state electrolyte capacitor whose impedance is made lower and whose loss is made lower. CONSTITUTION:A polymer electrolyte gel that is placed between both electrode foils consists of (a) matrix polymer, (b) solute consisting of salt having ammonium ion and or quarternary phosphonium ion (Specified by chemical formula) as cation components and having conjugate base of acid as anion components, and (c) an organic solute.

Description

Detailed Description of the Invention [0001] [Background of the Invention] [Field of Industrial Application] The present invention relates to solid electrolytic capacitors,
In particular, the present invention relates to a solid electrolytic capacitor using a highly ionic conductive polymer electrolyte gel as a solid electrolyte, and a method for manufacturing the same. More specifically, the present invention provides low impedance and low loss (ta) without increasing short circuit defects.
The present invention relates to a solid electrolytic capacitor that realizes n δ). [0002] Conventionally, most electrolytic capacitors have a wound structure in which an anode foil with a dielectric oxide film, a separator paper, and a cathode foil are wound, and many aluminum electrolytic capacitors have this structure. It has been adopted. These capacitors have the problem of leakage because they use a driving electrolyte in which an electrolyte is dissolved in water or an organic solvent in the form of a solution. In addition, paper separators made of fibers such as manila paper and kraft paper are generally used as separators, but in order to reduce the impedance of electrolytic capacitors, thinner separators and lower density separators are being considered. There is. However, when low-density electrolytic paper is used, the mechanical strength is significantly reduced, and the fibers become sparse, resulting in problems such as short circuits between the electrodes of the capacitor, and there is a limit to how low the density can be reduced. In order to improve leakage resistance and develop highly reliable solid electrolytic capacitors with low impedance and low loss without increasing short-circuit defects, we developed a capacitor that has high ionic conductivity comparable to that of liquid organic electrolytes. It is desired to develop a solid electrolytic capacitor having a solid electrolyte that is thermally and electrochemically stable, flexible, and has excellent flexibility. [Summary of the Invention] [Problems to be Solved by the Invention] In recent years, as electronic equipment has become more sophisticated and more compact, there has been an increase in the frequency of switching power supplies, miniaturization of electrolytic capacitors, etc. Due to increasing demands, it is important to develop solid electrolytes that exhibit high ionic conductivity as well as solid electrolytic capacitors that achieve low impedance and low loss without increasing short-circuit defects. <Summary> [Means for Solving the Problems] The present invention aims to solve the above-mentioned problems, and by using a specific solid polymer electrolyte gel, it can be used for this purpose, especially for electrolytic capacitors. The present invention aims to provide a solid electrolytic capacitor with low impedance and low loss as an electrolyte. That is, the solid electrolytic capacitor according to the present invention consists of a polymer electrolyte gel containing the following (a), (b), and (c) interposed between the electrodes of a cathode foil and an anode foil, and then wound. It is characterized by what has been done. (a)
A matrix polymer consisting of a polymer of polymerizable vinyl monomers, (b) an ammonium ion or quaternary phosphonium ion represented by the following general formula (I) or/and (II) as a cation component, and a conjugate base of an acid as an anion component. At least one solute consisting of a salt of
, and R4 may be the same or different,
Each represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and R5 is represented by the formula (II
) represents a group having 3 to 10 carbon atoms that forms an aliphatic heterocycle or an aromatic heterocycle by bonding with the nitrogen atom in the group. )(c)
[0008] <Effects> The solid electrolytic capacitor according to the present invention has a solid electrolytic capacitor that is electrochemically stable, flexible, and has excellent heat resistance between the cathode and anode electrodes. By interposing the highly ionic conductive polymer electrolyte gel, it can be used as a solid electrolytic capacitor that not only achieves the objectives of lower impedance and lower loss, but also has excellent safety. [Detailed description of the invention] <Matrix polymer (component (a))> The matrix polymer forming the matrix or linking phase of the solid polymer electrolyte gel in the present invention is composed of a polymer of polymerizable vinyl monomers. Here, the polymerizable vinyl monomer is a monomer having a CH2=C(R)- group (in the formula, R is a hydrogen atom or a C1-C2 alkyl group) in the molecule. It means a monomer that can form a polymer by addition polymerization of this monomer. Therefore, "vinyl monomer" as used in the present invention has the same meaning as "ethylenic unsaturated monomer". "Polymer of polymerizable vinyl monomers" means, in addition to homopolymers and copolymers of polymerizable vinyl monomers having polar groups as described below, a predominant amount of the polymerizable vinyl monomers and a smaller amount of the polymerizable vinyl monomers. It means a copolymer with a copolymerizable monomer. Preferred examples of the polymerizable vinyl monomer having a polar group include a hydroxyl group or a lower alkoxyl group (about C1 to C4), a carboxyl group, and an amide group. or having an amino group.Specific examples of such monomers include (a) (meth)acrylic acid esters, such as alkoxyalkyl (meth)acrylates, hydroxyalkyl (meth)acrylates, glycerol; = mono-, di- and tri-(meta)
Examples include acrylate, alkylene glycol mono- and di-(meth)acrylate, (meth)acrylic acid, (meth)acrylamide, dimethylaminoethyl (meth)acrylate, and the like. Of these,
At least one type selected from alkoxyalkyl (meth)acrylate, hydroxyalkyl (meth)acrylate, glycerol mono-, di- and tri-(meth)acrylate, and alkylene glycol mono- and di-(meth)acrylate (meth)acrylic acid esters are preferably used. Here, "(meth)acrylic acid" and "
"(Meth)acrylate" shall mean both acrylic acid and methacrylic acid, and acrylate and methacrylate, respectively. Preferred (meta) for obtaining high conductivity
One group of acrylic esters is alkoxyalkyl=(
meth)acrylate. The "alkoxy" group is also preferably a lower one, particularly one having about 1 to 4 carbon atoms, preferably about 1 to 3 carbon atoms for an "alkoxy" group, and about 2 to 3 carbon atoms for an "alkyl" group. Such alkoxyalkyl=(meth)
Specific examples of acrylates include methoxyethyl, ethoxyethyl and propoxyethyl esters of acrylic and methacrylic acids. Another group of preferred (meth)acrylic esters are hydroxyalkyl (meth)acrylates. The "alkyl" group in this case is also preferably a lower one, particularly one having about 2 to 4 carbon atoms. The "hydroxylalkyl" group preferably has one hydroxyl group. Such hydroxyalkyl=(meth)
Specific examples of acrylates include hydroxyethyl and hydroxypropyl esters of acrylic and methacrylic acids. Another group of preferred (meth)acrylic esters are glycerol (meth)acrylates. This (meth)acrylate is preferably one in which one or two of the three hydroxyl groups of glycerol are esterified. Specific examples of such glycerol (meth)acrylates include glycerol monomethacrylate, glycerol dimethacrylate, and glycerol acrylate methacrylate. Another group of preferred (meth)acrylic esters are alkylene glycol (meth)acrylates. Specific examples of such alkylene glycol (meth)acrylate include diethylene glycol (meth)acrylate, triethylene glycol (meth)acrylate, and polyethylene glycol (meth)acrylate.
meth)acrylate (average molecular weight about 200 to 2,000), dipropylene glycol = (meth)acrylate, tripropylene glycol = (meth)acrylate,
Polypropylene glycol = (meth)acrylate (average molecular weight approximately 300 to 3,000), polyalkylene glycol = (meth)acrylate (ethylene oxide/propylene oxide block copolymer, average molecular weight approximately 200 to 3,000), methoxypolyethylene glycol =(meth)acrylate (average molecular weight 200-2
,000), ethoxypolyethylene glycol = (
meth)acrylate (average molecular weight of about 200 to 2,000), propoxypolyethylene glycol = (meth)acrylate (average molecular weight of about 200 to 2,000), phenoxypolyethylene glycol = (meth)acrylate (average molecular weight of about 300 to 2,000) ), Methoxypolypropylene glycol = (meth)acrylate (average molecular weight approximately 250 to 3,000), Ethoxypolypropylene glycol = (meth)acrylate (average molecular weight 2
50 to 3,000) and ethylene glycol = (
There are meta)acrylates. These esters are for some or all of a given hydroxyl group. As mentioned above, the polymer of these polar group-containing polymerizable vinyl monomers may be a copolymer with a small amount of copolymerizable monomer; Specific examples include (a) monofunctional monomers, such as (meth)acrylic acid alkyl esters (the alkyl group has about 1 to 3 carbon atoms), and (b) difunctional monomers, such as ethylene glycol. = Ji (meta)
Acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate ) acrylate, 2-hydroxy-1,3-di(meth)acryloxypropane, 2-hydroxy-1-acryloxy-
(c) Trifunctional monomers such as 3-methacryloxypropane, such as trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, etc. are preferred, and others include unsaturated nitriles such as acrylonitrile. etc., aromatic olefins such as styrene, vinyl compounds such as vinyl chloride, vinyl acetate, etc., N-vinylpyrrolidone,
There are N-vinyl lactams such as N-vinylpiperidone. By polymerizing these polymerizable vinyl monomers using a polymerization initiator, it is possible to obtain a matrix polymer of component (a) which is thermally stable, soft and has excellent flexibility. [0023] Such a matrix polymer has a high affinity for electrolytic solution, so it has good swelling properties and liquid retention properties, and it is possible to obtain a low-impedance solid electrolytic capacitor without affecting short-circuit defects. Become. <Solute (component (b))> The solute (component (b)) used in the electrolytic capacitor of the present invention is as described below (
c) It exhibits ionic conductivity by dissociating into ions in the organic solvent. Such solutes include those of the following general formula (I) and/or (II) which are cationic components.
A salt consisting of an ammonium ion or quaternary phosphonium ion represented by the formula and a conjugate base of an acid as an anion component is used. [Chemical formula 5] [Chemical formula 6] (In formulas (I) and (II), R1, R
2, R3, and R4 may be the same or different and represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and R5 is represented by the formula (I
Represents a group having 3 to 10 carbon atoms that forms an aliphatic heterocycle or aromatic heterocycle by bonding with the nitrogen atom in I). ) [0
[028] The salt used as the solute may be one type or a combination of two or more types. Here, the conjugate base of an acid is, as described in general chemistry textbooks, in the Brønsted-Lowry acid-base theory, when the acid has a proton (II+). means something lost. Examples of the ammonium ion as a cationic component that forms such a salt include aliphatic ammonium ions, ammonium ions, and alicyclic ammonium ions represented by the above general formulas (I) and (II), as well as nitrogen-containing ammonium ions. There is an aromatic ammonium ion. Specifically, the ammonium ions represented by the formula (I) include (a) quaternary ammonium ions such as tetraethylammonium, tetrapropylammonium, tetrabutylammonium, methyltriethylammonium, methyltripropylammonium, and methyltributyl; Ammonium, dimethyldiethylammonium, dimethyldipropylammonium, dimethyldibutylammonium, ethyltripropylammonium, ethyltributylammonium, diethyldipropylammonium, diethyldibutylammonium, triethylpropylammonium, triethylbutylammonium, etc., (b) aliphatic ammonium ions, for example,
triethylammonium, tripropylammonium,
Tributylammonium, methyldiethylammonium, methyldipropylammonium, methyldibutylammonium, dimethylethylammonium, dimethylpropylammonium, dimethylbutylammonium, ethyldipropylammonium, ethyldibutylammonium, diethylpropylammonium, diethylbutylammonium, monomethylammonium, monoethyl Ammonium, monopropylammonium, dimethylammonium, diethylammonium, dipropylammonium, dibutylammonium, methylethylammonium, etc., and (iii) ammonium ion (NH4 + )
, can be exemplified. Specifically, the ammonium ions represented by formula (II) include (a) cyclic ammonium ions, such as N,N-dimethylpyrrolidinium, N,N-dimethylpiperidinium, N-methyl- N-ethylpyrrolidinium, N-methyl-N-ethylpiperidinium, N
, N-tetramethylenepyrrolidinium, N,N-pentamethylenepiperidinium, N-methylpiperidinium,
(b) Nitrogen-containing aromatic ammonium ions such as N-methylpyrrolidinium, such as N-ethylpyridinium,
N,N-dimethylimidazolinium, pyridinium, N
-Methylimidazolium, etc. can be exemplified. Similarly, quaternary phosphonium ions as cationic components include (a) aliphatic quaternary phosphonium ions;
For example, tetramethylphosphonium, tetraethylphosphonium, tetrapropylphosphonium, tetrabutylphosphonium, methyltriethylphosphonium, methyltripropylphosphonium, methyltributylphosphonium, dimethyldiethylphosphonium, dimethyldipropylphosphonium, dimethyldibutylphosphonium,
Trimethylethylphosphonium, trimethylpropylphosphonium, trimethylbutylphosphonium, ethyltripropylphosphonium, ethyltributylphosphonium, diethyldipropylphosphonium, diethyldibutylphosphonium, triethylpropylphosphonium, triethylbutylphosphonium, propyltributylphosphonium, dipropyldibutylphosphonium, tripropylbutyl (b)Alicyclic quaternary phosphonium ions such as phosphonium, such as 1,1-dimethylphosphoranium, 1-methyl-1-ethylphosphoranium, 1,1-
Diethylphosphoranium, 1,1-dimethylphosphoranium, 1-methyl-1-ethylphosphoranium, 1
, 1-diethylphospholinanium, 1,1-pentamethylenephospholinanium, and the like. On the other hand, as the anion component of the solute, a conjugate base of an acid selected from the following five groups is preferably used. (1) Carboxylic acids and phenols, (2)
Boric acid, phosphoric acid, phosphorous acid, hypophosphorous acid, carbonic acid, silicic acid and their derivatives, (3) Picric acid and sulfonic acid, (4) Nitric acid, sulfuric acid, sulfite, thiocyanic acid and their derivatives, ( 5) Strong acids containing halogen atoms. Anions which are conjugate bases of acids selected from groups (1) and (2) are good as film-forming anions, and are suitable not only for low voltage capacitors but also for medium and high voltage capacitors. can be used. Those selected from groups (3), (4), and (5) also have the ability to form oxide films, but they are highly acidic and easily corrode oxide films, so they should not be used in low-voltage capacitors of 100V or less. be. In particular, anions selected from group (5) liberate halide ions, which are unfavorable to aluminum, and should therefore be used in low-voltage capacitors of 10 V or less. According to the purpose of the capacitor used in this manner, a suitable one can be selected and used from among the five groups (1) to (5) above. The carboxylic acids of group (1) are preferably aliphatic and aromatic monovalent or polyvalent carboxylic acids having a total number of carbon atoms of 1 to 30, preferably 2 to 20. Specifically, (a) aliphatic monocarboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, and vaccinic acid. Acid, gadoleic acid, methacrylic acid, 3-methylcrotonic acid, tiglic acid, methylpentenoic acid, cyclopentanecarboxylic acid,
(b) Aliphatic dicarboxylic acids such as cyclohexanecarboxylic acid, such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid,
Hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, eicosanedioic acid, methylmalonic acid, ethylmalonic acid, propylmalonic acid, butylmalonic acid, pentylmalonic acid, hexylmalonic acid, dimethylmalonic acid, methyl ethyl Malonic acid, diethylmalonic acid, methylpropylmalonic acid, methylbutylmalonic acid, ethylpropylmalonic acid, dipropylmalonic acid, ethylbutylmalonic acid, propylbutylmalonic acid, dibutylmalonic acid,
Methylsuccinic acid, ethylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, 2-methylglutaric acid, 3-methylglutaric acid, 3-methyl-3-ethylglutaric acid, 3,3-diethylglutaric acid acid, maleic acid, citraconic acid, 1,5-octanedicarboxylic acid, 5,
6-decanedicarboxylic acid, 1,7-decanedicarboxylic acid, 4,6-dimethyl-4-nonene-1,2-dicarboxylic acid, 4,6-dimethyl-1,2-nonanedicarboxylic acid,
1,7-dodecanedicarboxylic acid, 5-ethyl-1,10
-decanedicarboxylic acid, 6-methyl-6-dodecene-1
, 12-dicarboxylic acid, 6-methyl-1,12-dodecanedicarboxylic acid, 6-ethylene-1,12-dodecanedicarboxylic acid, 6-ethyl-1,12-dodecanedicarboxylic acid, 7-methyl-7-tetradecene- 1,14-dicarboxylic acid, 7-methyl-1,14-tetradecanedicarboxylic acid, 3-hexyl-4-decene-1,2-dicarboxylic acid, 3-hexyl-1,2-decanedicarboxylic acid, 6
-ethylene-9-hexadecene-1,16-dicarboxylic acid, 6-ethyl-1,16-hexadecanedicarboxylic acid, 6-phenyl-1,12-dodecanedicarboxylic acid, 7
, 12-dimethyl-7,11-octadecadiene-1,
18-dicarboxylic acid, 7,12-dimethyl-1,18-
Octadecanedicarboxylic acid, 6,8-diphenyl-1,
14-tetradecanedicarboxylic acid, 1,1-cyclopentanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,1-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4-cyclohexene-1,
(3) Aromatic monocarboxylic acids (o, m, p-
(including each isomer), for example, benzoic acid, toluic acid,
Ethylbenzoic acid, propylbenzoic acid, isopropylbenzoic acid, butylbenzoic acid, isobutylbenzoic acid, sec-butylbenzoic acid, tertiary-butylbenzoic acid, hydroxybenzoic acid, anisic acid, ethoxybenzoic acid, propoxybenzoic acid,
Isopropoxybenzoic acid, butoxybenzoic acid, isobutoxybenzoic acid, sec-butoxybenzoic acid, tertiary-butoxybenzoic acid, aminobenzoic acid, N-methylaminobenzoic acid,
N-ethylaminobenzoic acid, N-propylaminobenzoic acid, N-isopropylaminobenzoic acid, N-butylaminobenzoic acid, N-isobutylaminobenzoic acid, N-sec-butylaminobenzoic acid, N-tert-butylaminobenzoic acid Benzoic acid, N,N-dimethylaminobenzoic acid, N,N-diethylaminobenzoic acid, nitrobenzoic acid, resorcinic acid, etc.
d) Aromatic polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, 3-nitrophthalic acid, 4-nitrophthalic acid, trimellitic acid, hemimellitic acid, trimesic acid, pyromellitic acid, etc. Can be done. [0037] Specific examples of phenols include phenol, catechol, resorcinol, hydroquinone,
Phloroglucinol, pyrogallol, 1,2,4-trihydroxybenzene, o-nitrophenol, m-nitrophenol, p-nitrophenol, 2,4-dinitrophenol, 2,5-dinitrophenol, 2,6-
Dinitrophenol, 3,4-dinitrophenol, 4
-nitrocatechol and 2-nitroresorcinol. Those belonging to group (2) include boric acid,
Boric acid derivatives represented by the following general formula (III), phosphoric acid, phosphoric acid esters represented by the following general formula (IV), phosphorous acid, phosphorous acid derivatives represented by the following general formula (V),
These are hypophosphorous acid, a hypophosphorous acid derivative represented by the following general formula (VI), carbonic acid, a carbonate monoester represented by the following general formula (VII), and silicic acid. OH/R6-B

(III) \OH O ‖ R7 O-P-OH
(
IV) | 6 OR O ‖ R7 -P-OH

(V) | 6 OR O ‖ R7 -P-OH

(VI) |8 R O ‖ R9 O-C-OH
(
VII) [In formulas (III) to (VII), R6
~R9 each represents an alkyl group or an aryl group having 1 to 10 carbon atoms. Further, one of R7 or R8 may be a hydrogen atom. [0039] Specific examples of the boric acid derivative represented by formula (III) include methylboric acid, ethylboric acid, and phenylboric acid. Specific examples of the phosphoric acid ester represented by formula (IV) include monomethyl phosphoric acid, dimethyl phosphoric acid, phenyl phosphoric acid, and the like. Specific examples of the phosphorous acid derivative represented by formula (V) include phosphorous acid monomethyl ester, methylsulfonic acid, and methylphosphonic acid methyl ester. Specific examples of the hypophosphorous acid derivative represented by formula (VI) include methylphosphinic acid, dimethylphosphinic acid, phenylphosphinic acid, and the like. Specific examples of the carbonate monoester represented by formula (VII) include carbonate monomethyl ester, carbonate monophenyl ester, and the like. Belonging to group (3) are picric acid and sulfonic acid. As the sulfonic acid, aliphatic and aromatic monovalent or polyvalent sulfonic acids having a total carbon number of 1 to 30, preferably 1 to 20 are preferred. Specifically, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, pentanesulfonic acid, hexanesulfonic acid, heptanesulfonic acid, octanesulfonic acid, nonanesulfonic acid, decanesulfonic acid, vinylsulfonic acid. acid, allylsulfonic acid,
1,2-ethanedisulfonic acid, 1,4-butanedisulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid,
1-ethylbenzenesulfonic acid, xylene sulfonic acid,
Examples include naphthalenesulfonic acid, phenolsulfonic acid, nitrobenzenesulfonic acid, 2,4-dinitrobenzenesulfonic acid, picrylsulfonic acid, pyridine-3-sulfonic acid, m-benzenesulfonic acid, toluene-3,4-disulfonic acid, etc. can do. Those belonging to group (4) are nitric acid, sulfuric acid, sulfuric acid monoester represented by the following general formula (VIII), sulfurous acid, sulfite monoester represented by the following general formula (IX), and thiocyanic acid. O ‖ R10O-S-OH
(
VIII) ‖ O ‖ R10O-S-OH
(
IX) [In formulas (VIII) to (IX), R10 represents an alkyl group or an aryl group having 1 to 10 carbon atoms. [0043] Those belonging to group (5) contain highly electronegative halogen atoms, and are therefore acids that exhibit strong acidity. Specifically, HBF4, HPF6, H
AsF6, HSbF6, CF3SO3H, CF
3 COOH, C4 F9 SO3 H, C4 F9
Examples include COOH and HClO4. <Organic solvent (component (c))> The component (c) used in the electrolytic capacitor of the present invention is an organic solvent. This organic solvent dissolves the solute of the component (b) described above and forms ions. It is used to form a conductive electrolyte. Examples of such organic solvents include (
b) Amide solvents, such as N-methylformamide,
N-ethylformamide, N,N'-dimethylformamide, N,N-diethylformamide, N-methylacetamide, N-ethylacetamide, N,N-dimethylacetamide, N,N-diethylacetamide, N-methylpyrrolidinone, etc. (b) carbamate solvents, such as N-methyloxazolidinone; (c) urea solvents, such as N,N'-dimethylimidazolidinone;
(d) Lactone solvents, such as γ-butyrolactone,
γ-valerolactone, etc., (e) carbonate solvents, such as ethylene carbonate, propylene carbonate, butylene carbonate, etc., (f) alcohol solvents, such as ethylene glycol, methyl cellosolve, etc.
g) Sulfolane solvents, such as sulfolane, 3-methylsulfolane, etc.; (th) nitrile solvents, such as acetonitrile, 3-methoxypropionitrile, etc.;
Phosphate solvents, such as trimethyl phosphate, (nu)ether solvents, such as 1,2-dimethoxyethane, tetrahydrofuran, 1,3-dioxolane, etc., and (ru)hydrocarbon solvents, such as hexane,
Examples include benzene, toluene, etc. alone or in combination. Moreover, a mixed solvent of the above organic solvent and water can also be used. Among these, electrolytic solutions containing γ-butyrolactone, ethylene glycol, etc. as main solvents are preferred because they have a wide usable temperature range, low toxicity, and strong halogen resistance. <Reinforcing material> A reinforcing material can be used to improve the mechanical and physical strength of the polymer electrolyte gel used in the present invention. Specifically, the porous membrane and/or nonwoven fabric used integrally with the matrix polymer of component (a) include microporous membranes made of polyolefin resins such as polyethylene, polypropylene, polytetrafluoroethylene, polyester, and polyacrylonitrile. Films and/or nonwoven fabrics, natural papers for electrolytic capacitors made of cellulose fibers such as kraft paper and Manila paper, and nonwoven fabrics made of cellulose fibers can be used. Among these, it is preferable to use a nonwoven fabric with high porosity in order to have excellent mechanical strength, high heat resistance, easy formation into a thin film, and low internal resistance. <Blending ratio> In the present invention, a solid polymer electrolyte gel that has high ionic conductivity, is thermally and electrochemically stable, is flexible, and has excellent safety. In order to obtain this, the polymer used for component (a) is a polymer electrolyte gel (based on the total amount of components (a) to (c)).
It is preferable to adjust the ratio so that the content is 2% to 35% by weight, preferably 2.5% to 30% by weight. In addition, when the component polymer (a) is a polar monomer copolymerized with a monofunctional and/or polyfunctional monomer, the monofunctional and/or polyfunctional monomer may be copolymerized. In order to obtain a matrix polymer with high ionic conductivity and excellent flexibility, it is preferable to contain the polymer in an amount of 1 to 10% by weight, preferably 3 to 6% by weight, based on the total amount of the monomer. In addition, the content of the solute in component (b) is generally below the saturation concentration, preferably in a polymer electrolyte gel ((
a) component to (c) component total amount standard), 0.1 to
30% by weight. More preferably, it is 5 to 25% by weight for low voltage capacitors, and 1 to 2% by weight for medium and high voltage capacitors.
It is preferable to adjust the proportion so that it contains 0% by weight. <Manufacture of solid electrolytic capacitor> The method of manufacturing the solid electrolytic capacitor of the present invention involves interposing a polymer electrolyte gel between a cathode, such as an aluminum foil, and an anode, such as an aluminum foil provided with a dielectric oxide film. , a method consisting of winding can be exemplified. In this case, the polyelectrolyte gel can be produced by any suitable method, including the use of reinforcing materials if necessary. Specifically, for example, a polymerizable vinyl monomer is polymerized in advance to form a matrix polymer (a
) is synthesized, the film is placed between a cathode foil and an anode foil, and the film is wound to form a capacitor element, and then the solute (component (b)) and Organic solvent (component (c)
)) to obtain a solid electrolytic capacitor. That is, the polymerizable vinyl monomer (component (
Precursor (a)) was dissolved in an organic solvent (component (c)) if necessary, and a radical polymerization initiator such as a peroxide or an azo compound or a photo (UV) polymerization initiator was added as a polymerization initiator. The homogeneous solution is formed into a film by a casting method or a casting method, or if necessary, it is cast onto a reinforcing material such as a nonwoven fabric, and heated at 60 to 90°C or exposed to light (UV).
) Polymerize by irradiation and dry to synthesize a film-like matrix polymer. Next, the dry film-like material is placed between a cathode foil and an anode foil provided with a dielectric oxide film, and is wound to form a capacitor element. )) By dipping in or impregnating with the solution, a polymer electrolyte gel is formed integrally with the capacitor element, the element is housed in an aluminum exterior case, and the opening is sealed with elastic rubber. solid electrolytic capacitors can be manufactured by [0054] As another production method, a polymerizable vinyl monomer is polymerized in the presence of a solute and an organic solvent, and dried to form a film of matrix polymer (a) containing the solute (component (b)). After synthesizing, placing the film-like material between a cathode foil and an anode foil, and winding it to form a capacitor element,
A solid electrolytic capacitor can also be manufactured by adding an organic solvent (component (c)) to the film. Specifically, a polymerizable vinyl monomer is added and mixed into a homogeneous solution of a solute dissolved in an organic solvent, and then an ordinary radical polymerization initiator or light (U) is added and mixed.
V) A homogeneous solution containing a polymerization initiator is formed into a film by a casting method or a casting method, or if necessary, it is cast onto a reinforcing material such as a nonwoven fabric, and heated at 60 to 90°C or Polymerization is performed by irradiation with light (UV) to synthesize a solid electrolyte membrane. Next, after drying the film-like material, it is placed between a cathode foil and an anode foil provided with a dielectric oxide film, and is wound to form a capacitor element.
)) to form a polymer electrolyte gel integrated with the capacitor element, house the element in an aluminum exterior case, and seal the opening with elastic rubber to form a solid polymer electrolyte gel. Electrolytic capacitors can be manufactured. EXAMPLES The following examples are intended to explain the present invention more specifically. These examples do not limit the scope of the invention. Example 1 22.5 g of tetramethylammonium hydrogen phthalate (22.5 g of tetramethylammonium hydrogen phthalate) was added to 67.5 g of γ-butyrolactone solvent (GBL) (67.5% by weight as a composition weight ratio to the solid electrolyte).
As a polymerizable vinyl monomer, hydroxyethyl methacrylate (HEMA
) and 0.6 g (0.6 wt%) of neopentyl glycol dimethacrylate (NPGM) were added, and "Perbutyl O" (PBO, manufactured by NOF Corporation) was added as a polymerization initiator. ) was added to make a homogeneous solution. A part of the above prepared solution was transferred to a separator paper (made of anode foil with a dielectric oxide film and long fiber cellulose).
A capacitance of 470 μF and a rated voltage of 25 WV is obtained by winding a cathode foil with a thickness of 50 μm and a density of 0.36 g/cm3.
The capacitor element was impregnated with the liquid, housed in an aluminum exterior case, and after purging with nitrogen, the opening was sealed with elastic rubber. Next, this capacitor was heated at 70° C. for 6 hours to perform polymerization, thereby forming a polymer electrolyte gel and manufacturing a solid electrolytic capacitor. The basic characteristics of the obtained electrolytic capacitor, such as capacitance, loss angle tangent, and impedance, were measured and the results are shown in Table 1. Example 2 Hydroxyethyl methacrylate (HEMA) was added as a polymerizable vinyl monomer to 40.0 g (40% by weight) of ethylene glycol solvent (EG) and 40.0 g (40% by weight) of water.
) 8.0g (8% by weight) and 12.0g (12% by weight) of methoxypolyethylene glycol methacrylate (MPEO) were added and mixed together with PBO6 as a polymerization initiator.
0 μg was added to make a homogeneous solution. [0060] A part of the above prepared liquid was placed into a 5 cm wide and 21 cm long
Long-fiber cellulose nonwoven fabric cut into cm pieces (thickness 50 μm)
m, density 0.36 g/cm3) and a polypropylene film are impregnated into a rolled material,
Thermal polymerization was performed by heating at 70°C for 6 hours in a nitrogen atmosphere,
A membrane-like matrix polymer integrated with a nonwoven fabric was obtained. The obtained film-like matrix polymer was vacuum-dried as a roll at 105° C. for 6 hours, and then cut to a width of 1.5 cm to obtain a film-like dry matrix polymer. This was placed between the electrodes of an anode foil and a cathode foil for an aluminum electrolytic capacitor having a capacitance of 470 μF and a rated voltage of 25 WV, and wound to form a capacitor element. Next, the element is
Tetramethylammonium hydrogen phthalate (
25% by weight) dissolved in an electrolytic solution for 2 hours, deaerated to form a polymer electrolyte gel, it is stored in an aluminum exterior case, and the opening is sealed with elastic rubber to form a solid electrolytic capacitor. was manufactured. The basic characteristics of the obtained solid electrolytic capacitor were as shown in Table 1. Example 3 In Example 2, HEMA was used as the polymerizable vinyl monomer.
10.0g (10% by weight) and MPEO10.0g (
A solid electrolytic capacitor was obtained in the same manner as in Example 2, except that a polypropylene nonwoven fabric (thickness 80 μm, density 0.3 g/cm 3 ) was used as the nonwoven fabric. The basic characteristics of the obtained solid electrolytic capacitor were as shown in Table 1. Example 4 Triethylmethylammonium maleate (25
A solid electrolytic capacitor was manufactured in the same manner as in Example 2, except that a polymer electrolyte gel was formed using a GBL solvent in which GBL (% by weight) was dissolved. The basic characteristics of the obtained solid electrolytic capacitor were as shown in Table 1. Example 5 Example 2 was repeated except that a polymer electrolyte gel was formed on a capacitor element obtained in the same manner as in Example 2 using an EG solvent in which ammonium azelaate (10% by weight) was dissolved as an electrolyte. A solid electrolytic capacitor was manufactured in the same manner. The basic characteristics of the obtained solid electrolytic capacitor were as shown in Table 1. Example 6 Instead of the EG solvent and water in Example 2, an electrolytic solution in which 20.0 g (20 wt.%) of tetramethylammonium hydrogen phthalate was dissolved in 60.0 g (60 wt.%) of GBL solvent was used. A solid electrolytic capacitor was manufactured in the same manner as in Example 2, except for using the following. The basic characteristics of the obtained solid electrolytic capacitor were as shown in Table 1. Comparative Example 1 A portion of an electrolyte solution prepared by dissolving 25.0 g (25 wt. %) of tetramethylammonium hydrogen phthalate in 75.0 g (75 wt. %) of GBL solvent was applied to an anode equipped with a dielectric oxide film. A capacitor element with a capacitance of 470 μF and a rated voltage of 25 WV, which is made by winding a separator paper made of foil and Manila hemp (50 μm thick, density 0.5 g/cm3) and a cathode foil, is impregnated and stored in an aluminum exterior case. After that, the opening was sealed with elastic rubber to produce an aluminum electrolytic capacitor. The basic characteristics of the obtained electrolytic capacitor were as shown in Table 1. [0066]
Table 1 Evaluation element: Capacitance 470μF,
Rated voltage 25WV



Evaluation item Example


No. Capacitance Tangent of Loss Angle Impedance
(120Hz)
(120Hz) (100KHz)


1
455 (μF) 0.056
57 (mΩ) 2 447
0.058 74
3 446
0.070 83 4
451 0.0
60 59 5 41
4 0.123 2
27 6 450
0.076 102


Comparative example 1 449
0.063 93


Effects of the Invention: The solid electrolytic capacitor of the present invention has succeeded in reducing impedance and loss by using a specific solid high ion conductive polymer electrolyte gel as an electrolyte. Means to solve]
As mentioned above in the section.

Claims (6)

[Claims] [Claim 1] A solid material, characterized in that a polymer electrolyte gel comprising the following (a), (b) and (c) is interposed between electrodes of a cathode foil and an anode foil and wound. Electrolytic capacitor. (a) a matrix polymer consisting of a polymer of polymerizable vinyl monomers, (b) the following general formula (I
) or/and (II) as an ammonium ion or quaternary phosphonium ion as a cation component,
At least one solute consisting of a salt having a conjugate base of an acid as an anion component, [Formula 1] [Formula 2] (In formulas (I) and (II), R1, R2, R3
, and R4 may be the same or different,
Each represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and R5 is represented by the formula (II
) represents a group having 3 to 10 carbon atoms that forms an aliphatic heterocycle or an aromatic heterocycle by bonding with the nitrogen atom in the group. )(c)
organic solvent 2. The polymerizable vinyl monomer is at least one type of (meth)acrylate selected from alkoxyalkyl (meth)acrylate, hydroxyalkyl (meth)acrylate, glycerol (meth)acrylate, and alkylene glycol (meth)acrylate. The solid electrolytic capacitor according to claim 1, which is a meth)acrylic acid ester. Claim 3: The anion component of the solute is carboxylic acid, phenols, boric acid, phosphoric acid, phosphorous acid, hypophosphorous acid, carbonic acid, silicic acid, bicric acid, sulfonic acid, nitric acid, sulfuric acid, sulfite, thiocyanide. The solid electrolytic capacitor according to claim 1 or 2, wherein the solid electrolytic capacitor is a conjugate base of at least one acid selected from acids, strong acids containing halogen atoms, and derivatives thereof. 4. The solid electrolytic capacitor according to claim 1, wherein the polymer electrolyte gel is integrated with a porous membrane or/and a nonwoven fabric. 5. Forming a matrix polymer consisting of component (a) into a film-like material, placing the film-like material between an anode foil and a cathode foil, and winding it to form a capacitor element. 2. The method for manufacturing a solid electrolytic capacitor according to claim 1, wherein the solid electrolytic capacitor is impregnated with an electrolytic solution consisting of component (b) and component (c). 6. A film-like molded product consisting of component (a) and component (b) is placed between an anode foil and a cathode foil and wound to form a capacitor element. 2. The method for manufacturing a solid electrolytic capacitor according to claim 1, wherein the solid electrolytic capacitor is impregnated in an organic solvent consisting of the following.