JP2011009499A - Method of forming electrolyte for conductive polymer capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of forming a conductive polymer electrolyte having a low LC (Leakage Current) and a high breakdown voltage, and to provide a conductive polymer capacitor formed by the forming method.SOLUTION: The method of forming the conductive polymer electrolyte includes a step (1) for impregnation with a conductive polymer dispersion liquid/solution (A) and a step (2) for in-situ polymerization of a conductive polymer monomer after the step (1). The electrolyte for the conductive polymer capacitor is formed by carrying out the step (1) and/or step (2) in the presence of an ion liquid.

Description

  The present invention relates to a method for forming an electrolyte for a conductive polymer capacitor having a low leakage current and a high breakdown voltage, and a method for manufacturing a conductive polymer capacitor including the formation method.

  In recent years, the market for solid electrolytic capacitors using a conductive polymer as an electrolyte is expanding due to their excellent ESR characteristics. Solid electrolytic capacitors typically use solid conductive polymers such as polypyrrole or polythiophene derivatives as electrolytes, and these conductive polymers are electrolytic capacitors using conventional liquids as electrolytes. Its electrical conductivity (that is, electronic conductivity) is much higher than that of the capacitor, and particularly exhibits excellent characteristics as a capacitor for high-frequency circuits. In addition to the low ESR described above, solid electrolytic capacitors are required to have a reduced leakage current (hereinafter abbreviated as LC) and a higher breakdown voltage.

  As an approach for solving these problems, in Patent Document 1, after impregnating a polyaniline-containing solution in advance and forming a conductive polyaniline layer on a metal oxide film that is a dielectric, 3,4-ethylenedioxythiophene (hereinafter referred to as “polyethyleneline”) is used. , Abbreviated as EDOT) to form a solid electrolyte by chemical polymerization. In this method, since polyaniline functions as a protective film for the oxide film and is less likely to be damaged during chemical polymerization of EDOT, a high breakdown voltage is realized.

  Further, Patent Document 2 and Patent Document 3 disclose a similar electrolyte forming method, that is, a method of conducting chemical polymerization of a conductive polymer monomer after impregnating a conductive polymer dispersion or a conductive polymer solution. Yes. However, it is described that none of these contributes to the increase of the breakdown voltage and contributes to the improvement of the capacity expression rate and the low ESR characteristic.

  On the other hand, in order to realize a high breakdown voltage, the inventors of the present invention have an anodic oxidation ability of an electrolyte composed of an ionic liquid and a conductive polymer, and a conductive polymer using a wound type or a sintered body element. It has been clarified that a high breakdown voltage can be realized in a capacitor (Patent Document 4).

  However, in any of the above methods, the realized breakdown voltage and LC characteristics have not reached a level that can satisfy market requirements.

JP 2003-168631 A JP 2003-1000056 A1 JP 2009-105171 A International Publication WO2005 / 012599 Pamphlet

  To provide a method for forming a conductive polymer electrolyte having a low LC and a high breakdown voltage, and a conductive polymer capacitor produced by the method.

  As a result of intensive studies in view of the above, the present inventors have conducted in situ polymerization using a solution (B) containing a conductive polymer monomer after impregnating the conductive polymer dispersion / solution (A). When the conductive polymer dispersion / solution (A) and / or the solution (B) contains an ionic liquid to form an electrolyte for a conductive polymer capacitor, a low LC and a high break The inventors have found that a conductive polymer capacitor having a down voltage can be realized, and have completed the present invention.

That is, the present invention
[1] A method for forming an electrolyte for a conductive polymer capacitor, comprising the following steps (1) and (2), wherein steps (1) and / or (2) are performed in the presence of an ionic liquid:
(1) a step of impregnating the conductive polymer dispersion / solution (A),
(2) After the step (1), a step of in situ polymerization of a conductive polymer monomer;
[2] The method for forming an electrolyte for a conductive polymer capacitor according to [1], wherein the anion component of the ionic liquid is a carboxylate anion,
[3] The cation component of the ionic liquid is ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, pyrrolium ion, pyrazinium ion, pyrimidinium ion, triazonium ion, triazinium ion, triazine ion, key Selected from the group consisting of norinium ion, isoquinolinium ion, indolinium ion, quinoxalinium ion, piperazinium ion, oxazolinium ion, thiazolinium ion, morpholinium ion, piperazine ion and derivatives thereof A method for forming an electrolyte for a conductive polymer capacitor as described in [1] or [2] above,
[4] The conductive polymer dispersed in the conductive polymer dispersion / solution (A) is at least one selected from the group consisting of polythiophene, polythiophene derivatives, polypyrrole, polypyrrole derivatives, polyaniline, and polyaniline derivatives. The method for forming an electrolyte for a conductive polymer capacitor according to any one of the above [1] to [3],
[5] The conductive polymer according to any one of [1] to [4], wherein the conductive polymer monomer is at least one selected from the group consisting of thiophene, thiophene derivatives, pyrrole, pyrrole derivatives, aniline and aniline derivatives. Method for forming electrolyte for polymer capacitor,
[6] The method for forming an electrolyte for a conductive polymer capacitor according to any one of the above [1] to [5], wherein the in situ polymerization is chemical polymerization and / or electrolytic polymerization,
[7] A method for producing a conductive polymer capacitor, including the method for forming an electrolyte for a conductive polymer capacitor according to any one of [1] to [6],
[8] The method for producing a conductive polymer capacitor according to [8] above, wherein the capacitor is an aluminum wound type,
It is.

  By the electrolyte forming method of the present invention, a conductive polymer capacitor having a low LC and a high breakdown voltage can be realized.

The mercury cell used for impedance measurement is shown.

  Hereinafter, embodiments of the present invention will be described in detail.

  (1) The step of impregnating the conductive polymer dispersion / solution (A) (hereinafter sometimes referred to as “step (1)”) is performed on the oxide film that is the dielectric of the capacitor. It is a process performed to form a coating. The formed conductive polymer coating functions to protect the oxide film when the conductive polymer electrolyte in the next step (2) is formed by chemical polymerization, and contributes to a high breakdown voltage.

  The conductive polymer dispersion / solution here refers to a conductive polymer dispersion or a conductive polymer solution. The conductive polymer dispersion means a solution in which conductive polymer particles are dispersed in an organic solvent or water. On the other hand, the conductive polymer solution means a solution in which the conductive polymer is completely dissolved in an organic solvent or water. In the present invention, any dispersion or solution may be used as long as a conductive polymer coating can be formed on the oxide film.

  Examples of the material contained in the conductive polymer dispersion / solution (A) include a conductive polymer, a dopant anion of the conductive polymer, and a solvent. All of these may or may not be contained as other additives for the conductive polymer. Of course, additives other than those described above may be added as necessary.

  As the conductive polymer contained in the conductive polymer dispersion / solution (A), at least one selected from the group consisting of polythiophene, polythiophene derivatives, polypyrrole, polypyrrole derivatives, polyaniline and polyaniline derivatives can be used. . The derivative here means a polymer obtained from a monomer having an arbitrary substituent and a polymer having an arbitrary substituent at an arbitrary position in the polymer. As an example of the polythiophene derivative, the former is exemplified by poly (3-hexylthiophene) obtained from 3-hexylthiophene having a hexyl group at the 3-position, and poly (3,4-ethylenedioxythiophene). ) Is a polythiophene derivative. Specific examples of the latter include a polymer in which the end of poly (3,4-ethylenedioxythiophene) is capped with polyethylene glycol. Regarding polypyrrole derivatives and polyaniline derivatives, polymers of pyrrole derivatives and aniline derivatives used in conductive polymer monomers described later can be used in the same manner.

  From the viewpoints of stability and heat resistance, polyaniline or poly (3,4-ethylenedioxythiophene) (hereinafter abbreviated as PEDOT) is most preferable.

  In the present invention, “may have a substituent” means that it may be substituted with another atom or substituent. The “substituent” is not particularly limited as long as it does not adversely affect the reaction. Specifically, the hydroxyl group, alkyl group, alkoxy group, alkylthio group, nitro group, amino group, cyano group, carboxyl group, A halogen atom etc. are mentioned.

  In the conductive polymer dispersion / solution (A), only one kind of such a conductive polymer may be used, or two or more kinds thereof may be used in combination.

  The dopant anion of the conductive polymer is a material necessary for securing conductivity as a counter anion of the conductive polymer. Polymeric anions and monomeric anions can be used, but from the viewpoint of heat resistance and electrical conductivity, polymeric anions are preferred, and among them, polymer carboxylic acid or polymer sulfonic acid anions are preferred, and polystyrene sulfonic acid (hereinafter referred to as PSS). (Omitted) is most preferable.

  As the solvent, water, alcohols typified by methanol, ethanol, butanol, a mixture of water and these alcohols can be used, and a particularly preferable dispersion solvent is water.

  The concentration of the conductive polymer in the conductive polymer dispersion / solution (A) is not particularly limited as long as it is uniformly dispersed or dissolved to form a uniform coating. Preferably it is the range of 0.1-50 weight%, More preferably, it is about 0.1-15 weight%. The amount used is not particularly limited as long as the capacitor element is sufficiently coated so that the capacitor element can be immersed in the capacitor element, and is optimal depending on the size of the capacitor element and from the viewpoint of productivity. You can choose the right amount.

  As a method of impregnating the capacitor element, any method may be used as long as the capacitor element is immersed and the conductive dispersion / solution is sufficiently filled in the capacitor element. If filling is difficult, vacuum impregnation may be performed. .

  The capacitor element here refers to a capacitor in a state before forming an electrolyte. That is, after the electrolyte is formed on the capacitor element, the necessary exterior treatment is performed to complete the capacitor as the final product.

  Step (1) may be performed in the presence of an ionic liquid. Since the ionic liquid can increase the breakdown voltage due to its anodizing ability, it is preferably added to the conductive polymer dispersion / solution (A).

  An ionic liquid, also called a room temperature molten salt, refers to a liquid that is liquid at room temperature despite being composed only of ions, and is composed of a combination of a cation such as imidazolinium and an appropriate anion. The ionic liquid is not partially ionized and dissociated like a normal organic solvent, but is considered to be formed from only ions and 100% ionized. As described above, the ionic liquid is usually a liquid at room temperature, but the ionic liquid used in the present invention does not necessarily have to be a liquid at room temperature, and becomes a liquid during the aging process or heat treatment of the capacitor. Any material that spreads and becomes a liquid by Joule heat generated during the repair of the dielectric oxide film may be used.

  The ionic liquid that can be used in the present invention is not particularly limited, but an ionic liquid whose anion component is a carboxylate anion, a sulfonate anion, an imide anion, or the like can be used, and among them, from the viewpoint of anodizing ability and ease of synthesis and availability, An ionic liquid in which the anion component is a carboxylate anion can be preferably used. More specifically, an ionic liquid having a formate anion and / or general formula (1);

An ionic liquid having an anion represented by can be used. The anion represented by the formula (1) is paired with a cation described later to form a liquid salt at room temperature, that is, an ionic liquid.

In the formula (1), R ¹ and R ² are each independently a hydrogen atom, a protected or unprotected hydroxyl group, a protected or unprotected amino group, an alkoxy group, a nitro group, a cyano group, a carboxyl group, a halogen atom, A C ₁ -C ₂₀ alkyl group which may form a chain, a branch or a ring and may have a substituent, a straight chain or a branch or a ring which may have a substituent alkenyl group which may C ₂ -C _20, linear or form a branched or ring which may have a even better substituents C ₂ -C ₂₀ alkynyl group, which may have a substituent Good C ₆ -C ₂₀ aryl group, C ₄ -C ₂₀ heteroaryl group optionally having substituent, C ₇ -C ₂₀ aralkyl group optionally having substituent, substituent C ₄ -C ₂₀ heteroaralkyl group which may have They may be the same as or different from each other, and together may form a ring.

The C ₁ -C ₂₀ alkyl group which may form a straight chain, a branched chain or a ring and may have a substituent is not particularly limited, and examples thereof include a methyl group, a hydroxymethyl group, Ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, sec-butyl group, tert-butyl group, cyclobutyl group, n-pentyl group, cyclopentyl group, n-hexyl group, n-heptyl group , A cyclohexyl group, an n-octyl group, an n-decyl group, and the like, and those in which an arbitrary number of hydrogen atoms of these alkyl groups are substituted with fluorine atoms.

Examples of the C ₂ -C ₂₀ alkenyl group which may form a straight chain, branched chain or ring and may have a substituent include, for example, vinyl group, propenyl group, styryl group, isopropenyl group, cyclopropenyl Group, butenyl group, cyclobutenyl group, cyclopentenyl group, hexenyl group, cyclohexenyl group and the like.

Straight or a branched or alkynyl group optionally C ₂ -C ₆ have also well substituent to form a ring, for example, ethynyl group, propynyl group, phenylethynyl group, a cyclopropyl ethynyl, A butynyl group, a pentynyl group, a cyclobutylethynyl group, a hexynyl group and the like can be mentioned.

  Examples of the aryl group which may have a substituent include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a terphenyl group, and a 3,4,5-trifluorophenyl group.

  Examples of the heteroaryl group which may have a substituent include, for example, pyrrolinyl group, pyridyl group, quinolyl group, imidazolyl group, furyl group, indolyl group, thienyl group, oxazolyl group, thiazolyl group, 2-phenylthiazolyl group. , 2-anisyl thiazolyl group and the like.

  Examples of the aralkyl group which may have a substituent include benzyl group, chlorobenzyl group, bromobenzyl group, salicyl group, α-hydroxybenzyl group, phenethyl group, α-hydroxyphenethyl group, naphthylmethyl group, anthracyl group. Examples include a senylmethyl group, a 3,5-difluorobenzyl group, and a trityl group.

  Examples of the heteroaralkyl group which may have a substituent include a pyridylmethyl group, a difluoropyridylmethyl group, a quinolylmethyl group, an indolylmethyl group, a furfuryl group, and a thienylmethyl group.

R ¹ and R ² may be combined to form a ring, and examples thereof include a cyclohexyl group and a phenyl group.

When R ¹ and / or R ² is a hydroxyl group or an amino group, or has a hydroxyl group or an amino group as a substituent, the hydroxyl group or amino group may be protected or unprotected. Although the protecting group is not particularly limited, for example, a general protecting group may be used, and examples thereof include those described in “PROTECTIVE GROUPS in ORGANIC SYNTHESIS THIRD EDITION” (page 17 WILEY-INTERSCIENCE). Specific examples of hydroxyl protecting groups include ether protecting groups such as methyl, methoxymethyl, methylthiomethyl, trimethylsilyl, and triethylsilyl groups, and ester protecting groups such as acetyl and chloroacetyl groups. Can be mentioned. Examples of amino protecting groups include benzyl, trityl, formyl, acetyl, chloroacetyl, tetrachloroacetyl, tetrafluoroacetyl, benzoyl, phenylacetoxy, methoxycarbonyl, ethoxycarbonyl, -Fluorenylmethoxycarbonyl group, t-butoxycarbonyl group, etc. are mentioned. From the viewpoint of ease of introduction and deprotection, among the above groups, benzyl, trityl, formyl, acetyl, chloroacetyl, tetrachloroacetyl, tetrafluoroacetyl, benzoyl, phenyl An acetoxy group, a 9-fluorenylmethoxycarbonyl group, and a t-butoxycarbonyl group;

From the viewpoint of anodic oxidation ability, among the anions exemplified above, R ¹ is preferably a hydroxyl group, an amino group, or hydrogen, and R ² is a methyl group, an ethyl group, an n-propyl group, or isopropyl. Group, cyclopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, cyclohexyl group, n-octyl group, phenyl group, naphthyl group, anion which is benzyl group Can be mentioned. An ionic liquid having anions composed of these combinations has an excellent anodizing ability. Among these, particularly preferred are acetate anion, lactate anion, mandelate anion, benzoate anion, alanine anion, phenylalanine anion and the like.

  The cation component of the ionic liquid includes ammonium and its derivatives, imidazolium and its derivatives, pyridinium and its derivatives, pyrrolidinium and its derivatives, pyrrolinium and its derivatives, pyrazinium and its derivatives, pyrimidinium and its derivatives, triazonium and its derivatives, triazinium and its derivatives Derivatives thereof, triazine and derivatives thereof, quinolinium and derivatives thereof, isoquinolinium and derivatives thereof, indolinium and derivatives thereof, quinoxalinium and derivatives thereof, piperazinium and derivatives thereof, oxazolinium and derivatives thereof, thiazolinium and derivatives thereof, morpholinium and derivatives thereof , Piperazine and its derivatives. In view of the relatively low Tg, imidazolium derivatives are preferred, and the imidazolium derivatives are preferably diethyl imidazolium, ethyl butyl imidazolium and dimethyl imidazolium, particularly preferably ethyl methyl imidazolium and methyl butyl imidazolium. It is.

  Since the ionic liquid has ionic conductivity but not electronic conductivity, it behaves as an insulator in the capacitor electrolyte. If too much ionic liquid is added, the ESR characteristic tends to deteriorate, so the total amount of ionic liquid added is preferably less than twice the weight of the conductive polymer, more preferably more than 0.1 times the weight. The weight is 1.5 times or less.

  Step (1) is applicable to both chip-type and wound-type elements. In any case, low LC and high breakdown voltage can be realized due to the protective effect of the oxide film. Further, when an ionic liquid is added, a higher breakdown voltage is expected.

  The present invention includes a step of in situ polymerization of the conductive polymer monomer after the step (1) (hereinafter sometimes referred to as “step (2)”). Step (2) is performed for the purpose of filling the capacitor element with a conductive polymer as an electrolyte.

  Although it does not restrict | limit especially as a conductive high molecular monomer, Since the electroconductivity at the time of polymer formation is high and it is stable in the air, thiophene or its derivative, pyrrole or its derivative, aniline or its derivative Quinone or a derivative thereof, quinoline or a derivative thereof, or furan or a derivative thereof. Only one type of conductive polymer monomer may be used, or two or more types may be used in combination.

  Examples of thiophene derivatives include EDOT, 3-alkylthiophene (alkyl groups include butyl, hexyl, octyl, dodecyl, etc.), 3-fluorophenylthiophene, 3-arylthiophene, etc. It is not limited to.

  Examples of pyrrole derivatives include, but are not limited to, those having a pyrrole skeleton and having substituents such as a hydroxyl group, a carboxyl group, and an alkyl group.

  Examples of aniline derivatives include, but are not limited to, those having an aniline skeleton having an alkyl group, a cyano group, a sulfone group, or a carboxyl group.

  Examples of the quinone derivative include, but are not limited to, benzoquinone having a substituent, naphthoquinone having a substituent, and anthraquinone having a substituent.

  From the viewpoint of conductivity and heat resistance, EDOT or pyrrole is particularly preferably used.

  The in situ polymerization in the present invention is performed by chemical polymerization and / or electrolytic polymerization.

  The chemical polymerization method (chemical polymerization method) is a method of polymerizing and synthesizing a conductive polymer monomer such as pyrrole in the presence of an appropriate oxidizing agent.

  Examples of the oxidizing agent used in the present invention include, for example, ferric paratoluenesulfonate, ferric naphthalenesulfonate, ferric n-butylnaphthalenesulfonate, ferric triisopropylnaphthalenesulfonate, persulfate, persulfate, Hydrogen oxide, diazonium salts, halogens and halides, or transition metal salts such as iron, copper and manganese can be used. The conductive polymer synthesized by chemical polymerization may have conductivity in a one-step reaction by incorporating an anion of an oxidant into the polymer as a dopant in the polymerization process. Therefore, it is preferable to use ferric paratoluenesulfonate containing paratoluenesulfonic acid ions having high mobility as a dopant as an oxidizing agent.

  The solvent that can be used for chemical polymerization may be a known solvent, and is not particularly limited. Examples include methanol, ethanol, butanol, diethylene glycol, 2-propanol, acetone, diethyl ether, ethyl acetate, THF, DMF, acetonitrile, DMSO, dimethyl carbonate, ethylene carbonate, propylene carbonate, hexane, toluene, chloroform, etc., ionic liquid From the viewpoint of compatibility with the conductive polymer monomer, butanol is particularly preferable.

  The polymerization conditions for chemical polymerization may be known polymerization conditions, and the temperature range is -50 ° C to 200 ° C, particularly preferably 0 ° C to 180 ° C. The polymerization time is 1 minute to 24 hours, particularly preferably 1 minute to 5 hours. The polymerization may be repeated a plurality of times.

  The method performed by electrolytic polymerization (electrolytic polymerization method) is a method in which a conductive polymer monomer is dissolved in a solvent and anodized to dehydrogenate the conductive polymer. Electropolymerization is, for example, a method in which a pyrrole monomer is dissolved in a solvent together with a supporting electrolyte and subjected to dehydrogenation polymerization by anodic oxidation, whereby polypyrrole, which is a conductive polymer, can be deposited on the anode. In general, since the oxidation-reduction potential of a polymer is lower than that of a monomer, the oxidation of the polymer skeleton proceeds further in the polymerization process, and accordingly, the anion of the supporting electrolyte is incorporated into the polymer as a dopant. In electropolymerization, such a mechanism has an advantage that a polymer having conductivity can be obtained without adding a dopant later.

  As the supporting electrolyte used in the present invention, ammonium salts, amine salts, quaternary ammonium salts, tertiary amines, organic acids, imidazolium salts, and the like are preferable.

  As the solvent used in the electropolymerization, the solvent used in the chemical polymerization can be similarly used.

  When synthesizing a conductive polymer by electrolytic polymerization, the oxide film on the valve metal is a dielectric, so a conductive film is formed on the dielectric beforehand to make it conductive, Electropolymerization is performed by applying a voltage. The conductive polymer coating formed in step (1) in the present invention functions as a conductive layer on the dielectric.

  Step (2) may be performed in the presence of an ionic liquid. That is, an ionic liquid may be present in the in situ polymerization of the conductive polymer monomer. As embodiment, the form which makes an ionic liquid contain in the solution containing a conductive polymer monomer is mentioned, for example. When the conductive polymer monomer is chemically polymerized in the presence of an ionic liquid, there is an advantage that a high breakdown voltage is realized by imparting an anodic oxidation capability to the formed electrolyte. When electropolymerizing a conductive monomer in the presence of an ionic liquid, an electrolyte containing the ionic liquid is formed, so that a higher breakdown voltage can be expected than when no ionic liquid is contained.

  As the ionic liquid in the step (2), the ionic liquid that can be used in the step (1) can be preferably used.

  The amount of the ionic liquid used in the step (2) is not particularly limited. However, if too much ionic liquid is added, the ESR characteristics tend to deteriorate, so the total amount of ionic liquid used is a conductive polymer. It is preferably 3 molar equivalents or less with respect to the monomer, more preferably 0.01 molar equivalents or more and 1 molar equivalent or less.

  In the present invention, step (1) or step (2) may be carried out in the presence of an ionic liquid, and both step (1) and step (2) may be carried out in the presence of an ionic liquid. It is preferable to carry out both the step (1) and the step (2) in the presence of an ionic liquid in order to realize a low LC and a high breakdown voltage. However, if the amount of the ionic liquid added is too large, the ESR characteristics may be deteriorated. Therefore, the addition amount of the ionic liquid may be adjusted as appropriate, or the ionic liquid may be used in only one of the step (1) and the step (2) according to the required characteristics.

  The electrolyte formed by the production method of the present invention is used for a conductive polymer capacitor. The conductive polymer capacitor includes at least an electrolyte layer, and an anode and a cathode disposed so as to face each other with the electrolyte layer interposed therebetween. The electrolyte obtained by the production method of the present invention can be formed in either a chip type or a wound type conductive polymer capacitor.

  The chip type is represented by a tantalum / niobium capacitor. Typically, a dielectric film is formed on an anode obtained by sintering fine powder of tantalum / niobium, and a sintered body element in which an electrolyte layer and a cathode are laminated in this order on the dielectric film; and The structure provided with the connection terminal electrically connected with the capacitor | condenser element is mentioned.

  The wound type is represented by an aluminum electrolytic capacitor. Typically, the electrolyte layer, the separator, the cathode, and the separator are laminated in this order on the dielectric film of the anode made of an anode metal having a dielectric film formed on the surface from the inside in the radial direction. And a configuration including a wound type element wound and a connection terminal electrically connected to the wound type element. In the separator, usually, a separator material made of, for example, polyolefin or cellulose fiber and a conductive polymer are combined.

  As the anode of the conductive polymer capacitor, a conventionally known one can be preferably used. For example, as the anode metal, the surface of the electrode foil such as aluminum is etched to form an etching hole, or the powder made of tantalum or the like By using an electrode and combining a dielectric film made of an oxide film formed by a method such as anodic oxidation on the surface of the anode metal, an anode made of an anode metal and a dielectric film can be formed. The above anodic oxidation can be performed by immersing the anode metal in an aqueous solution of ammonium adipate, for example, and applying a chemical voltage.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is a result obtained by simulating a wound capacitor, but the present invention is not limited to these examples at all. Changes can be made as appropriate without changing the range.

  (Ionic liquid) A method for synthesizing or obtaining ionic liquids and salts will be described below.

  [Emim] [AcO] (1-ethyl-3-methylimidazolium acetate, manufactured by Aldrich)

  [Emim] [LA] (1-ethyl-3-methylimidazolium lactate, manufactured by Aldrich)

  [Emim] [MA] (1-ethyl-3-methylimidazolium mandelate)

1-Ethyl-3-methylimidazolium hydrogen carbonate 50% aqueous solution (6000 mg, 17.42 mmol) was cooled to 0 ° C. Thereafter, an aqueous solution of mandelic acid (2615 mg, 17.42 mmol) was slowly added dropwise and stirred at room temperature for 1 hour. The reaction solution was concentrated as it was, the solvent was distilled off under reduced pressure, dichloromethane was added to the resulting residue, and the organic layer was dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to obtain 4560 mg of the target compound as a light brown oil. (Yield 100%)
1H NMR (CDCl ₃ , 300 MHz) δ 1.38 (t, 3H), 3.81 (s, 3H), 4.16 (q, 2H), 4.39 (s, 1H), 7.11-7. 22 (m, 2H), 7.33-7.36 (m, 3H), 7.69 (s, 1H), 7.77 (s, 1H), 9.24 (s, 1H)
[Bmim] [CA] (1-butyl-3-methylimidazolium caprylate)

1-butyl-3-methylimidazolium hydrogen carbonate 50% aqueous solution (5.00 g, 12.48 mmol) was cooled to 0 ° C. Thereafter, an aqueous solution of caprylic acid (1.80 g, 12.48 mmol) was slowly added dropwise and stirred at room temperature for 1 hour. The reaction solution was concentrated as it was, the solvent was distilled off under reduced pressure, dichloromethane was added to the resulting residue, and the organic layer was dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to obtain 2.20 g of the target compound as a yellow oil. (Yield 62%)
¹ H NMR (CDCl ₃ , 300 MHz) δ 0.83-0.92 (m, 7H), 1.21-1.29 (m, 11H), 1.38 (m, 2H), 1.73-1. 78 (m, 2H), 3.85 (s, 3H), 4.17 (t, 2H), 7.72 (s, 1H), 7.79 (s, 1H), 9.39 (s, 1H) )
[Bmim] [PA] (1-butyl-3-methylimidazolium phenylacetate)

Amberlite IRA400 (OH) (140 mL) was added to the chromatographic column tube, and 1N NaOH aqueous solution (2.5 L) was allowed to flow to activate the Amberlite IRA400 (OH). Then, pure water (1. 5 L). After adding pure water (50 mL) to 1-butyl-3-methylimidazolium chloride (5.0 g, 28.63 mmol) and dissolving it, this was passed through the previously activated Amberlite IRA400 (OH) to give 1-butyl An aqueous solution of -3-methylimidazolium hydroxide was obtained. After adding pure water (200 mL) and THF (100 mL) to phenylacetic acid (3.9 g, 28.63 mmol) to make a homogeneous solution, 1-butyl-3-methylimidazolium hydroxide aqueous solution was slowly added dropwise thereto. Stir at 0 ° C. for 12 hours. The reaction solution was concentrated as it was, acetonitrile (90 mL) and methanol (10 mL) were added to the obtained residue, and the mixture was stirred at 0 ° C. for 30 min. The filtrate was concentrated and heated under reduced pressure to obtain 8.0 g of the target compound as a pale yellow oil. (Yield 100%)
¹ H NMR (DMSO-d ⁶ , 300 MHz) δ 0.89 (t, 3H), 1.21-1.28 (m, 2H), 1.70-1.77 (m, 2H), 3.23 ( s, 2H), 3.83 (s, 3H), 4.15 (t, 2H), 7.09-7.19 (m, 5H), 7.70 (s, 1H), 7.77 (s) 1H), 9.29 (s, 1H)
The capacity expression rate, ESR, LC, and breakdown voltage of the polymer electrolyte aluminum electrolytic capacitors produced in Examples and Comparative Examples were measured by the following methods.

<Capacity measurement method>
The capacity was measured using the mercury cell shown in FIG. As a device, an LCR meter 3522-50 manufactured by Hioki Electric Co., Ltd. was used, and a capacity value of 120 Hz was used as data.

<ESR measurement method>
After the initial capacity measurement, ESR was measured using the mercury cell shown in FIG. Using an LCR meter 3522-50 manufactured by Hioki Electric Co., Ltd., an ESR value of 100 kHz was used as data.

<LC measurement method>
After the ESR measurement, the voltage was raised to 19 V under the condition of 100 mV / sec in an atmosphere at 105 ° C., and then held at 19 V for 1 hour. Subsequently, in a room temperature atmosphere, the current value after 2 minutes after the voltage was raised to 16 V under the condition of 100 mV / sec was measured, and the data was defined as leakage current.

<Breakdown voltage measurement method>
The breakdown voltage was measured using the mercury cell shown in FIG. As a device, model number “TR6143” manufactured by Advantest Corporation was used, and the voltage was increased at a rate of 20 mV / sec. The breakdown voltage value was defined as the voltage at which a current of 10 mA flowed.

Example 1
An aluminum etched foil having an effective area of 10 mm × 10 mm is dipped in a 1% ammonium adipate aqueous solution, first raised from 0 to 45 V at a rate of 20 mV / sec, and then a constant voltage of 45 V is applied for 40 minutes. A dielectric film was formed on the surface of the etched foil. Next, this foil was washed with running deionized water for 3 minutes and then dried at 120 ° C. for 1 hour. The submerged volume of the aluminum etched foil obtained at this time was 25 μF. Next, the obtained aluminum etched foil is mixed with an aqueous PEDOT / PSS dispersion (dispersion concentration 1.6% by weight, manufactured by Wako Pure Chemical Industries, Ltd.) (dispersion (A)) with [emim] [AcO]. It was immersed in an aqueous dispersion added 0.15 times by weight (step (1)) and dried at 80 ° C. for 15 minutes.

  Furthermore, EDOT (manufactured by HC Starck-V TECH) and [emim] [AcO] were blended so that the molar ratio was 1: 0.3 to prepare a composition. As the oxidizing agent, a 40 wt% 1-butanol solution of iron paratoluenesulfonate is used, and an amount of iron paratoluenesulfonate is 2 molar equivalents relative to EDOT is added to the composition composed of EDOT / [emim] [AcO]. Thus, a chemical polymerization composition was prepared (solution (B)). The aluminum etched foil which passed through the step (1) was immersed in the chemical polymerization composition, and after being pulled up, heat treatment was performed at 120 ° C. for 1 hour to form an electrolyte on the foil surface.

  Thereafter, carbon paste “Everyom T-30PLB” manufactured by Nippon Graphite Trading Co., Ltd. was applied and dried at 150 ° C. for 30 minutes, then silver paste “4922N” manufactured by DuPont was applied and dried at 150 ° C. for 30 minutes, and the cathode was coated with copper foil. The lead was taken out to produce a conductive polymer aluminum electrolytic capacitor.

  Using the obtained conductive polymer aluminum electrolytic capacitor, capacity development rate, ESR, LC, and breakdown voltage were measured. The results are shown in Table 1. The capacity expression rate was converted by normalizing the capacitor capacity with respect to the liquid capacity. The results are average values of 10 electrodes. The results are shown in Table 1.

(Example 2)
A conductive polymer aluminum electrolytic capacitor was produced in the same manner as in Example 1 except that the ionic liquid was not included in the aqueous PEDOT / PSS dispersion (dispersion (A)). The results are shown in Table 1.

(Example 3)
A conductive polymer aluminum electrolytic capacitor was produced in the same manner as in Example 1, except that the EDOT chemical polymerization composition (solution (B)) did not contain an ionic liquid. The results are shown in Table 1.

(Examples 4 to 7)
A conductive polymer aluminum electrolytic capacitor was produced in the same manner as in Example 1 except that the ionic liquid was changed to the ionic liquid shown in Table 1.

(Examples 8 to 9)
A conductive polymer aluminum electrolytic capacitor was produced in the same manner as in Example 2 except that the ionic liquid was changed to the ionic liquid shown in Table 1.

(Examples 10 to 11)
A conductive polymer aluminum electrolytic capacitor was produced in the same manner as in Example 3 except that the ionic liquid was changed to the ionic liquid shown in Table 1.

(Example 12)
An aluminum etched foil having an effective area of 10 mm × 10 mm is dipped in a 1% ammonium adipate aqueous solution, first raised from 0 to 45 V at a rate of 20 mV / sec, and then a constant voltage of 45 V is applied for 40 minutes. A dielectric film was formed on the surface of the etched foil. Next, this foil was washed with running deionized water for 3 minutes and then dried at 120 ° C. for 1 hour. The submerged volume of the aluminum etched foil obtained at this time was 25 μF.

  Next, to a solution obtained by adding [emim] [AcO] 0.15 times the weight of polyaniline to a dedope polyaniline 0.3% NMP-butanol (1: 1) solution (solution (A)), The obtained aluminum etched foil was dipped (step (1)) and dried at 100 ° C. for 5 minutes.

  Subsequently, it was immersed in a 0.5% ethanol solution of paratoluenesulfonic acid as a dopant for 3 minutes. It was dried at 100 ° C. for 5 minutes to form a conductive polyaniline layer. Furthermore, EDOT (manufactured by HC Starck-V TECH) and [emim] [AcO] were blended so that the molar ratio was 1: 0.3 to prepare a composition. As the oxidizing agent, a 40 wt% 1-butanol solution of iron paratoluenesulfonate is used, and an amount of iron paratoluenesulfonate is 2 molar equivalents relative to EDOT is added to the composition comprising the above EDOT / [emim] [AcO]. Then, a chemical polymerization composition was prepared (solution (B)). Next, the aluminum etched foil which passed through the process (1) was immersed in the chemical polymerization composition, heated up at 120 ° C. for 1 hour after being pulled up, and an electrolyte was formed on the surface of the foil.

  Thereafter, carbon paste “Everyom T-30PLB” manufactured by Nippon Graphite Trading Co., Ltd. was applied and dried at 150 ° C. for 30 minutes, then silver paste “4922N” manufactured by DuPont was applied and dried at 150 ° C. for 30 minutes, and the cathode was coated with copper foil. The lead was taken out to produce a conductive polymer aluminum electrolytic capacitor.

  Using the thus obtained conductive polymer aluminum electrolytic capacitor, the capacity development rate, ESR, LC and breakdown voltage were measured. The results are shown in Table 1. The capacity expression rate was converted by normalizing the capacitor capacity with respect to the liquid capacity. The results are average values of 10 electrodes. The results are shown in Table 1.

(Comparative Example 1)
The same method as in Example 1 except that the ionic liquid was not contained in the aqueous PEDOT / PSS dispersion (dispersion (A)) or the chemical polymerization composition of EDOT (solution (B)). A conductive polymer aluminum electrolytic capacitor was produced. The results are shown in Table 1.

Claims (8)

Including the following steps (1) and (2),
A method for forming an electrolyte for a conductive polymer capacitor, wherein the step (1) and / or the step (2) are performed in the presence of an ionic liquid.
(1) a step of impregnating the conductive polymer dispersion / solution (A),
(2) A step of in situ polymerization of the conductive polymer monomer after the step (1).   The method for forming an electrolyte for a conductive polymer capacitor according to claim 1, wherein the anion component of the ionic liquid is a carboxylate anion.   The cation component of the ionic liquid is ammonium ion, imidazolium ion, pyridinium ion, pyrrolidinium ion, pyrrolium ion, pyrazinium ion, pyrimidinium ion, triazonium ion, triazinium ion, triazine ion, quinolinium ion At least selected from the group consisting of isoquinolinium ion, indolinium ion, quinoxalinium ion, piperazinium ion, oxazolinium ion, thiazolinium ion, morpholinium ion, piperazine ion and derivatives thereof The formation method of the electrolyte for conductive polymer capacitors of Claim 1 or 2 which is 1 type.   The conductive polymer dispersed in the conductive polymer dispersion / solution (A) is at least one selected from the group consisting of polythiophene, polythiophene derivatives, polypyrrole, polypyrrole derivatives, polyaniline, and polyaniline derivatives. The formation method of the electrolyte for conductive polymer capacitors in any one of Claims 1-3.   5. The electrolyte for a conductive polymer capacitor according to claim 1, wherein the conductive polymer monomer is at least one selected from the group consisting of thiophene, thiophene derivatives, pyrrole, pyrrole derivatives, aniline and aniline derivatives. Forming method.   The method for forming an electrolyte for a conductive polymer capacitor according to claim 1, wherein the in situ polymerization is chemical polymerization and / or electrolytic polymerization.   The manufacturing method of the conductive polymer capacitor containing the formation method of the electrolyte for conductive polymer capacitors in any one of Claims 1-6.   The method for producing a conductive polymer capacitor according to claim 7, wherein the capacitor is an aluminum wound type.