WO2019027019A1

WO2019027019A1 - Electrolytic capacitor additive, conductive polymer dispersion, electrolytic solution and electrolytic capacitor

Info

Publication number: WO2019027019A1
Application number: PCT/JP2018/029129
Authority: WO
Inventors: 慶彦赤澤; 史行田邊; 賢吾内橋; 隆宏芝; 向井　孝夫
Original assignee: 三洋化成工業株式会社
Priority date: 2017-08-04
Filing date: 2018-08-02
Publication date: 2019-02-07
Also published as: JP7173972B2; TW201920311A; CN110832611B; CN110832611A; TWI705078B; JPWO2019027019A1

Abstract

The present invention provides an electrolytic capacitor additive used in an electrolytic capacitor comprising a solid electrolyte layer, said additive containing a polymer (A) having a hydrophilic group, wherein the concentration of the hydrophilic group in the polymer (A) is 18 mmol/g or less based on the weight of the polymer (A), and the solubility parameter of the polymer (A) is 12 (cal/cm3)1/2 or more.

Description

Additive for electrolytic capacitor, conductive polymer dispersion, electrolytic solution and electrolytic capacitor

The present invention relates to an additive for an electrolytic capacitor, a conductive polymer dispersion, an electrolytic solution and an electrolytic capacitor.

In recent years, with the miniaturization of electronic products, small-sized, large-capacity, high-frequency capacitors have been required. As such a capacitor, development of an electrolytic capacitor having a small equivalent series resistance (hereinafter, abbreviated as ESR) and excellent in frequency characteristics has been advanced. The electrolytic capacitor includes an anode foil made of aluminum, tantalum or the like, a dielectric layer such as aluminum oxide or tantalum oxide formed on the anode foil, and a cathode foil. Among them, an electrolytic capacitor in which a solid electrolyte layer containing a conductive polymer as a cathode material is formed on a dielectric layer is called a solid electrolytic capacitor.

Solid electrolytic capacitors use conductive polymers, and therefore can achieve lower ESR than electrolytic capacitors using electrolytic solutions.
However, since a solid electrolytic capacitor does not contain a substance responsible for the repair of a dielectric such as an electrolytic solution, there is a problem that the guaranteed voltage can not be increased because the leakage current is large and the withstand voltage is low. .

In order to solve this problem, Patent Document 1 discloses a technique for suppressing the leakage current by covering the dielectric surface with polyvinyl alcohol. Further, Patent Document 2 discloses a technique capable of improving the withstand voltage by introducing a copolymer such as acrylic acid and vinyl phenol into a solid electrolyte layer. However, with these techniques, neither the reduction of the leakage current nor the effect of improving the withstand voltage is sufficient.

In addition, in AV equipment and automotive electrical equipment, the demand for high reliability is increasing. Therefore, it is necessary to improve the low leakage current and the short circuit resistance, in addition to the performance such as low ESR in the solid electrolytic capacitor.
In response to these demands, a so-called hybrid type using, as an electrolyte material, a solid electrolyte such as a conductive polymer such as polypyrrole, polyaniline and polythiophene, as well as an electrolyte solution excellent in the repairing action of the defect portion of the anodic oxide film which is a dielectric. Electrolytic capacitors have been proposed (for example, Patent Documents 3 and 4).

In these hybrid electrolytic capacitors, the electrolytic solution gets into the gaps of the solid electrolyte of the conductive polymer, and the degree of contact between the dielectric oxide film and the electrolyte is improved. Therefore, the capacitance is increased and the ESR is reduced, and the defect of the dielectric oxide film can be repaired by the action of the electrolytic solution, the leakage current is small, and the short circuit can be suppressed.
However, in the conventional hybrid electrolytic capacitor, the suppression of the leakage current, in particular, the suppression of the leakage current under a high temperature environment was not sufficient.

JP 2001-102255 A International Publication No. 2015/133121 Japanese Patent Application Laid-Open No. 11-186110 JP, 2014-195116, A

An object of the present invention is to reduce the leakage current of an electrolytic capacitor provided with a solid electrolyte layer and to improve the withstand voltage.

The present inventors arrived at the present invention as a result of studying to achieve the above object.
That is, the present invention is an additive for an electrolytic capacitor used in an electrolytic capacitor provided with a solid electrolyte layer, which contains a polymer (A) having a hydrophilic group, and the concentration of the hydrophilic group of the polymer (A) Is 18 mmol / g or less based on the weight of the polymer (A), and the solubility parameter of the polymer (A) is an additive for an electrolytic capacitor of 12 (cal / cm ³ ) ^1/2 or more. Further, the present invention is a conductive polymer dispersion containing the above-mentioned additive for electrolytic capacitor, an electrolytic solution containing the above-mentioned additive for electrolytic capacitor, and an electrolytic capacitor containing the above-mentioned additive for electrolytic capacitor .

According to the present invention, it is possible to provide an additive for an electrolytic capacitor having a small leakage current and an excellent withstand voltage.

The additive for an electrolytic capacitor of the present invention is an additive for an electrolytic capacitor used in an electrolytic capacitor provided with a solid electrolyte layer, which contains a polymer (A) having a hydrophilic group, and is hydrophilic of the polymer (A) The additive for an electrolytic capacitor, wherein the concentration of the hydrophobic group is 18 mmol / g or less based on the weight of the polymer (A), and the solubility parameter of the polymer (A) is 12 (cal / cm ³ ) ^1/2 or more is there.

First, the polymer (A) having a hydrophilic group is described.
The hydrophilic group is not particularly limited, and can be, for example, a hydroxyl group, an acid group, a basic group, and an oxyalkylene group having 2 to 3 carbon atoms. As an acidic group, a carboxyl group, a sulfonic acid group, a phosphonic acid group etc. are mentioned. Examples of basic groups include amino groups and ammonium groups. Examples of the oxyalkylene group having a carbon number of 2 to 3 include an oxyethylene group and a 1,2- or 1,3-oxypropylene group.
Among these hydrophilic groups, from the viewpoint of leakage current, preferred are a hydroxyl group and an acidic group, and more preferred is a hydroxyl group.

The concentration of hydrophilic groups in the polymer (A) having a hydrophilic group is 18 mmol / g or less based on the weight of the polymer (A). The upper limit thereof is preferably 13 mmol / g, more preferably 10 mmol / g, and the lower limit thereof is preferably 2 mmol / g, more preferably 4 mmol / g. If the concentration of the hydrophilic group of the polymer (A) exceeds 18 mmol / g, the intermolecular force becomes strong and precipitation occurs at a low temperature, so that there is a problem that the low temperature characteristics of the capacitor are deteriorated.
The concentration of the hydrophilic group in the polymer (A) can be adjusted by the selection of the constituent monomers and the weight ratio.
The concentration of the hydrophilic group in the polymer (A) is defined by the amount of substance (number of moles) of the hydrophilic group contained in 1 g of the polymer (A). The concentration of the hydrophilic group of the polymer (A) was measured by the following method.

When the hydrophilic group is a hydroxyl group, the concentration of the hydrophilic group of the polymer (A) is a value calculated by the following formula by determining the hydroxyl value by the method described in JIS K 0700: 1992.
Concentration of hydrophilic group in polymer (A) (mmol / g)
= Hydroxyl value (mg KOH / g) /56.1

When the hydrophilic group is an acidic group, the concentration of the hydrophilic group of the polymer (A) is a value calculated by the following formula by determining the acid value by the method described in JIS K 0700: 1992.
Concentration of hydrophilic group in polymer (A) (mmol / g)
= Acid value (mg KOH / g) / 56.1

When the hydrophilic group is a base, the concentration of the hydrophilic group of the polymer (A) is a value calculated by the following formula by determining the base number by the method described in JIS K 2501: 2003.
Concentration of hydrophilic group of the polymer (A) (mmol / g) = base number / 56.1

When the hydrophilic group is an oxyalkylene group having 2 to 3 carbon atoms, the concentration of the hydrophilic group of the polymer (A) can be determined by the following method.
The polymer (A) is hydrolyzed in a 1 mol / l aqueous sodium hydroxide solution at 100 ° C. for 2 hours to obtain a solution in which a segment containing an oxyalkylene group is separated from the polymer. By analyzing this solution by gas chromatography mass spectrometry, it is possible to measure the molecular weight of the constituent unit contained in the segment containing the oxyalkylene group and the number of oxyalkylene group addition moles in the constituent unit. The hydrophilic group concentration can be calculated by the following formula.
Concentration of hydrophilic group in polymer (A) (mmol / g)
= Mole number of oxyalkylene group added in constituent unit / molecular weight of constituent unit

The solubility parameter (hereinafter abbreviated as SP value) of the polymer (A) is 12 (cal / cm ³ ) ^1/2 or more. Preferably, it is 12 to 20 (cal / cm ³ ) ^1/2 , more preferably 12 to 17 (cal / cm ³ ) ^1/2 . If the SP value of the polymer (A) is less than 12 (cal / cm ³ ) ^1/2 , the affinity to the oxide film is low, and there is a problem that the withstand voltage decreases.
The SP value of the polymer (A) can be adjusted by appropriately adjusting the SP value and the mole fraction of the constituent monomers. In order to increase the SP value of the polymer (A), a monomer having a high polar functional group may be used as a constituent monomer.
The SP value of the polymer (A) is a value calculated by the method described in the Fedors method (Polymer Engineering and Science, February, 1974, Vol. 14, No. 2, P. 147 to 154).
SP value of a polymer (A) calculates SP value of each monomer which comprises a polymer (A) by said method, and SP value of each monomer is an average based on the mole fraction of a constituent monomer unit. Value.

The polymer (A) having a hydrophilic group is preferably a polymer having an ethylenically unsaturated monomer (a) having a hydrophilic group as a constituent monomer.
As the ethylenically unsaturated monomer (a) having a hydrophilic group, an ethylenically unsaturated monomer having at least one group selected from the group consisting of a hydroxyl group, an acidic group, a basic group and an oxyalkylene group having 2 to 3 carbon atoms Can be mentioned.

Examples of the ethylenically unsaturated monomer (a) having a hydrophilic group include (meth) acrylic monomers having a hydrophilic group, vinyl monomers having a hydrophilic group, styrene monomers having a hydrophilic group, and the like.
In the present application, the notation "(meth) acrylic" means acrylic and / or methacrylic, the notation "(meth) acryloyl" means acryloyl and / or methacryloyl, and the notation "(meth) acryloyloxy" Means acryloyloxy and / or methacryloyloxy.

Examples of the ethylenically unsaturated monomer (a) having a hydroxyl group as a hydrophilic group include (meth) acrylic monomers having a hydroxyl group, vinyl monomers having a hydroxyl group, and styrene monomers having a hydroxyl group.

As a (meth) acrylic monomer having a hydroxyl group as a hydrophilic group, a hydroxyalkyl (meth) acrylate having 4 to 12 carbon atoms, a lactone adduct to the above hydroxyalkyl (meth) acrylate having 4 to 12 carbon atoms, and Examples thereof include alkylene oxide adducts to the above-mentioned hydroxyalkyl (meth) acrylates having 4 to 12 carbon atoms.

Examples of the above-mentioned hydroxyalkyl (meth) acrylate having 4 to 12 carbon atoms include monohydroxyalkyl (meth) acrylates having 4 to 12 carbon atoms [2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and —Hydroxybutyl (meth) acrylate and the like], dihydroxyalkyl (meth) acrylates having 4 to 12 carbon atoms, trihydroxyalkyl (meth) acrylates having 4 to 12 carbon atoms, and the like.
Examples of monohydroxyalkyl (meth) acrylates having 4 to 12 carbon atoms include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate and 2-hydroxy-1-methyl Ethyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-1-methylpropyl (meth) acrylate, 2-hydroxy- 2-Methylpropyl (meth) acrylate, 3-hydroxy-1-methylpropyl (meth) acrylate, 3-hydroxy-2-methylpropyl (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, 6- Mud carboxymethyl hexyl (meth) acrylate, 7-hydroxy-heptyl (meth) acrylate and 8-hydroxyoctyl (meth) acrylate.
Examples of the dihydroxyalkyl (meth) acrylate having 4 to 12 carbon atoms include glycerin mono (meth) acrylate and the like.
Examples of trihydroxyalkyl (meth) acrylates having 4 to 12 carbon atoms include pentaerythritol monoacrylate and the like.

As the lactone to be added to the hydroxyalkyl (meth) acrylate having 4 to 12 carbon atoms, lactones having 2 to 12 carbon atoms are preferable, and acetolactone, propiolactone, butyrolactone, valerolactone, caprolactone, laurolactone and the like can be mentioned. Be
The addition mole number of the lactone is preferably 1 to 15 moles, more preferably 1 to 5 moles. The lactone to be added may be used alone or in combination of two or more.
Examples of the 1 to 15-mole adduct of lactone to hydroxyalkyl (meth) acrylate having 4 to 12 carbon atoms include 2- (meth) acryloyloxyethyl 6-hydroxyhexanoate, 2- (5-hydroxydodecanoate) And the like) and caprolactone 5 mol adduct to acryloyloxyethyl and 2-hydroxyethyl (meth) acrylate.

As the alkylene oxide to be added to the above-mentioned hydroxyalkyl (meth) acrylate having 4 to 12 carbon atoms, an alkylene oxide having 2 to 10 carbon atoms is preferable, and ethylene oxide, 1,2- or 1,3-propylene oxide, 1,2 And 1,3-, 1,4-, 2,3-butylene oxide, 3-methyltetrahydrofuran, 1,2-decene oxide, styrene oxide and epihalohydrin (such as epichlorohydrin).
The addition mole number of the alkylene oxide is preferably 1 to 40 moles. The alkylene oxide to be added may be used alone or in combination of two or more.
As an alkylene oxide adduct to a hydroxyalkyl (meth) acrylate having 4 to 12 carbon atoms, 2- (2-hydroxyethoxy) ethyl (meth) acrylate, 2- (2- (2-hydroxy) acrylate (meth) acrylate Ethoxy) ethoxy) ethyl, 2- (10-hydroxy deoxy) ethyl (meth) acrylate and ethylene oxide 30 mole adduct to 2-hydroxyethyl (meth) acrylate and the like can be mentioned.

Examples of the vinyl monomer having a hydroxyl group as a hydrophilic group include vinyl alcohol, allyl alcohol, 4-vinyloxybutanol, 4-vinyloxybutanol, 3-allyloxy-1,2-propanediol and the like.

Examples of styrene monomers having a hydroxyl group as a hydrophilic group include cinnamyl alcohol and 4-hydroxybenzalacetone.

Examples of the ethylenically unsaturated monomer (a) having an acidic group as a hydrophilic group include (meth) acrylic monomers having an acidic group, vinyl monomers having an acidic group, styrene monomers having an acidic group, and the like.

As a (meth) acrylic monomer having an acidic group as a hydrophilic group,
(Meth) acrylic monomer having a carboxy group [acid anhydride (preferably acid anhydride having 4 to 10 carbon atoms) adduct to the (meth) acrylic monomer having a hydroxyl group (succinic acid 2- (meth) acryloyloxy) Ethyl, 2- (meth) acryloyloxyethyl maleate, 2- (meth) acryloyloxyethyl phthalate, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, etc.], Lactone to (meth) acrylic acid (The above-mentioned lactones of 2 to 12 carbon atoms are preferred) Adducts (1 to 5 molar adducts are preferred) [2-((meth) acryloyloxy) ethanoic acid, 3-((meth) acryloyloxy) propanoic acid, 4- (4) ((Meth) acryloyloxy) butanoic acid, 5-((meth) acryloyloxy) pentanoic acid, 6-((meth) acryloyloxy) hexane And (meth) caprolactone 5 mol adduct to acrylic acid] and (meth) acrylic acid];
(Meth) acrylic monomers having a sulfo group [such as 2-sulfoethyl (meth) acrylate and 2- (meth) acrylamido-2-methylpropane sulfonic acid]; and (meth) acrylic monomers having a phospho group [phosphoric acid 2- ((Meth) acryloyloxy) ethyl etc.] and the like.

Examples of the vinyl monomer having an acidic group as a hydrophilic group include 3-pentenoic acid, 3-hexenoic acid, vinylsulfonic acid, vinylphosphonic acid and the like.

Examples of the styrene monomer having an acidic group as a hydrophilic group include 4-vinylbenzoic acid and 4-styrenesulfonic acid.

Examples of the ethylenically unsaturated monomer (a) having a basic group as a hydrophilic group include (meth) acrylic monomers having a basic group, vinyl monomers having a basic group, styrene monomers having a basic group, etc. .

The (meth) acrylic monomer having a basic group as a hydrophilic group includes (meth) acrylamide [(meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-isopropyl (meth) acrylamide having 3 to 20 carbon atoms] , Dimethylaminopropyl (meth) acrylamide, N- (2- hydroxyethyl) (meth) acrylamide and N, N- dibenzyl (meth) acrylamide, etc.], aminoalkyl (meth) acrylate having 4 to 12 carbon atoms [(meth) Examples thereof include dimethylaminoethyl acrylate] and quaternary ammonium salts of aminoalkyl (meth) acrylates having 4 to 12 carbon atoms [trimethylethyl ammonium (meth) acrylate] and the like.

Examples of the vinyl monomer having a basic group as a hydrophilic group include allylamine, N, N-dimethylallylamine, N, N-diethylallylamine and the like.

As a styrene monomer having a basic group as a hydrophilic group, 4-aminostyrene and the like can be mentioned.

Examples of the ethylenically unsaturated monomer (a) having an oxyalkylene group having 2 to 3 carbon atoms as a hydrophilic group include (meth) acrylic monomers having an oxyalkylene group having 2 to 3 carbon atoms, and an oxy alkylene group having 2 to 3 carbon atoms Examples thereof include vinyl monomers having an alkylene group and styrene monomers having an oxyalkylene group having 2 to 3 carbon atoms.

As a (meth) acrylic monomer having an oxyalkylene group having a carbon number of 2 to 3 as a hydrophilic group, an alkylene oxide (an alkylene oxide having a carbon number of 2 to 3) adduct to a (meth) acrylate having a hydroxyl group is mentioned Examples of the alkyl include alkyl (preferably alkyl having 1 to 8 carbon atoms such as methyl, ethyl, propyl and octyl) and the like.
As alkyl ether of alkylene oxide adduct to (meth) acrylate having hydroxyl group, methoxy polyethylene glycol acrylate, 2- (2-methoxyethoxy) ethyl (meth) acrylate, 2- (2-ethoxy) (meth) acrylate Ethoxy) ethyl and 2- (2-octoxyethoxy) ethyl (meth) acrylate and the like can be mentioned.

Examples of the vinyl monomer having an oxyalkylene group having a carbon number of 2 to 3 as a hydrophilic group include diethylene glycol monovinyl ether and the like.

And as a styrene monomer having a C 2 to C 3 oxyalkylene group, C 2 to C 3 oxyalkylene adducts of cinnamyl alcohol, C 2 to C 3 oxyalkylene adducts of 4-hydroxybenzalacetone, etc. Can be mentioned.

Among the ethylenically unsaturated monomers (a) having such a hydrophilic group, preferred are (meth) acrylic monomers having a hydrophilic group from the viewpoint of improving the withstand voltage, and more preferred are those having 4 to 6 carbon atoms. Succinic anhydride, maleic anhydride, phthalic anhydride and hexahydrophthalic anhydride adducts to 12 hydroxyalkyl (meth) acrylates and hydroxyalkyl (meth) acrylates having 4 to 12 carbon atoms, particularly preferably 2 -Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl acrylate and 2- (meth) acryloyloxyethyl succinate.
The ethylenically unsaturated monomers (a) having a hydrophilic group may be used alone or in combination of two or more.

The polymer (A) having a hydrophilic group is a monomer other than the above-mentioned ethylenically unsaturated monomer (a) having a hydrophilic group and the ethylenically unsaturated monomer (a) having a hydrophilic group (hydrophilic It may be a copolymer with a group-free ethylenically unsaturated monomer etc.).
Among monomers other than the above-mentioned ethylenically unsaturated monomer (a) having a hydrophilic group, from the viewpoint of copolymerizability and solubility in solvents, preferred are alkyl (meth) acrylates having 4 to 20 carbon atoms [ Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and lauryl (meth) acrylate, etc .; styrene compounds having 8 to 20 carbon atoms (styrene and And paramethyl styrene etc .; allyl compounds having 3 to 20 carbon atoms (such as allyl methyl ether and allyl butyl ether) and vinyl acetate etc., more preferably alkyl (meth) acrylates having 4 to 20 carbon atoms, Particularly preferred are butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate.
These monomers other than the ethylenically unsaturated monomer (a) having a hydrophilic group may be used alone or in combination of two or more.

The glass transition point (hereinafter abbreviated as Tg) of the polymer (A) having a hydrophilic group in the present invention is preferably -100 to 80 ° C, more preferably -100 to 40, from the viewpoint of withstand voltage. ° C., more preferably −100 to 20 ° C., particularly preferably −100 to 5 ° C., most preferably −100 to 0 ° C.
The Tg of the present invention can be measured by a method in accordance with "ASTM D 3418-82" using a differential scanning calorimeter ("DSC 20" and "SSC / 580" manufactured by Seiko Instruments Inc., etc.). .

By making Tg into said range, as a mechanism which a withstand voltage improves, the following is assumed.
The polymer (A) having a hydrophilic group and having a Tg within the above range has relatively high flexibility and easily penetrates into a defect present in the dielectric, thereby improving repairability, resulting in leakage current Becomes smaller and the withstand voltage becomes higher.

The number average molecular weight (hereinafter abbreviated as Mn) of the polymer (A) having a hydrophilic group is preferably 1,000 to 500,000, more preferably 2, from the viewpoint of the withstand voltage. It is preferably in the range of 000 to 200,000, more preferably 3,000 to 50,000, and most preferably 3,000 to 30,000.

The Mn of the polymer (A) having a hydrophilic group in the present invention is measured using gel permeation chromatography (hereinafter abbreviated as GPC) under the following conditions.
Device (example): HLC-8120 manufactured by Tosoh Corporation
Column (one example): Two TSK GEL GMH6 (made by Tosoh Corp.)
Measurement temperature: 40 ° C
Sample solution: 0.25 wt% THF solution Injection volume: 100 μl
Detection device: Refractive index detector Reference substance: Tosoh Corp. standard polystyrene (TSK standard POLYSTYRENE) 12 points (weight average molecular weight: 500 1050 2800 5970 9100 18100 37900 96400 190000 355000 1090000 2890000)

The weight ratio of the ethylenically unsaturated monomer (a) having a hydrophilic group constituting the polymer (A) having a hydrophilic group is the polymer (A) having the hydrophilic group from the viewpoint of improving the withstand voltage. Preferably, it is 50 to 100% by weight, more preferably 60 to 100% by weight, based on the weight of all the monomers constituting the group).
From the viewpoint of improving the withstand voltage, the weight ratio of monomers other than the above-mentioned essential constituent monomers constituting the polymer (A) having a hydrophilic group is all constituting the polymer (A) having a hydrophilic group It is preferably 50% by weight or less, more preferably 40% by weight or less, based on the weight of monomers of

The polymer (A) having a hydrophilic group is a monomer other than the ethylenically unsaturated monomer (a) having a hydrophilic group and the ethylenically unsaturated monomer (a) optionally having a hydrophilic group. Can be produced by polymerizing by a known method.
For example, as the polymer (A) having a hydrophilic group, a known method using an ethylenic unsaturated monomer (a) having a hydrophilic group such as a (meth) acrylic monomer having a hydrophilic group is known (JP-A-5-117330) (1) can be produced by polymerization according to the method described in Japanese Patent Application Publication No.
In the polymerization, a polymerization initiator can be used. Examples of the polymerization initiator include azobisisobutyronitrile and the like.
Moreover, the polymer (A) which uses said vinyl alcohol as a structural monomer can be manufactured by implementing partial saponification of polyvinyl acetate by a well-known method.
The partially saponified polyvinyl acetate is produced by a known method, and can also be obtained from the market as Gosenex LL (manufactured by Japan Synthetic Chemical Industry Co., Ltd.).

The additive for electrolytic capacitor of the present invention may contain components other than the polymer (A) having a hydrophilic group, and as components other than the polymer (A), antioxidants, thermal deterioration inhibitors, etc. Can be mentioned.

Examples of the antioxidant include phosphoric acid antioxidants, hindered phenol antioxidants, and thioether antioxidants.
As the antioxidant, 2,2-methylenebis (4,6-di t-butylphenyl) octyl phosphite (manufactured by Asahi Denka Co., Ltd .; trade name: Adekastab HP-10), tris (2,4-di t-) And butylphenyl) phosphite (manufactured by Ciba Specialty Chemicals; trade name: IRUGAFOS 168).
As hindered phenol antioxidants, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] (manufactured by Chiba Specialty Chemicals; trade name IRGANOX1010), octadecyl -3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (manufactured by Ciba Specialty Chemicals Inc .; trade name IRGANOX 1076) and the like.

As a thermal deterioration inhibitor, 2-t-butyl-6- (3'-t-butyl-5'-methyl-hydroxybenzyl) -4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd .; trade name: SMILIZER GM), 2 And 4-di-t-amyl-6- (3 ', 5'-di-t-amyl-2'-hydroxy-α-methylbenzyl) phenyl acrylate (Sumitomo Chemical; trade name: SMILIZER GS) etc. Be

In the additive for an electrolytic capacitor of the present invention, the weight ratio of the polymer (A) having a hydrophilic group to the total weight of the additive for an electrolytic capacitor is preferably 80 to 100% by weight from the viewpoint of improving the withstand voltage. More preferably, it is 90 to 100% by weight, and particularly preferably 96 to 100% by weight.
When the additive for electrolytic capacitors of the present invention contains the above-mentioned antioxidant, the weight ratio of the above-mentioned antioxidant to the total weight of the additive for electrolytic capacitors is preferably 0.01 to 10% by weight. More preferably, it is 0.1 to 5% by weight, and particularly preferably 0.5 to 2% by weight.
When the additive for electrolytic capacitors of the present invention contains the above-mentioned thermal deterioration inhibitor, the weight ratio of the above thermal deterioration inhibitor to the total weight of the electrolytic capacitor additive is 0.01 to 10% by weight. Is more preferably 0.1 to 5% by weight, particularly preferably 0.5 to 2% by weight.

The conductive polymer dispersion liquid of the present invention is a conductive polymer dispersion liquid containing an additive for an electrolytic capacitor. The conductive polymer dispersion preferably contains a solvent (B) and a conductive polymer (C) in addition to the additive for the electrolytic capacitor.

Water, an organic solvent, etc. are mentioned as a solvent (B).
Examples of the organic solvent include alcohol solvents, amide solvents, ether solvents, ketone solvents, ester solvents, nitrile solvents, sulfoxide solvents, sulfone solvents and the like. These organic solvents may be used alone or in combination of two or more.
Examples of the alcohol solvent include methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, ethylene glycol, propylene glycol, diethylene glycol, ethylene glycol, monobutyl ether and polyethylene glycol (Mn: 600 or less).
Examples of the amide solvent include N-methylformamide and N, N-dimethylformamide.
As the ether solvent, diethyl ether, dimethyl ether, tetrahydrofuran and the like can be mentioned.
Examples of the ketone solvent include 2-butanone and acetone.
Examples of ester solvents include ethyl acetate, α-acetyl-γ-butyrolactone, β-butyrolactone, γ-butyrolactone, γ-valerolactone and δ-valerolactone.
Examples of nitrile solvents include acetonitrile, propionitrile, butyronitrile, acrylonitrile, methacrylonitrile and benzonitrile.
As the sulfoxide solvent, dimethyl sulfoxide, methyl ethyl sulfoxide, diethyl sulfoxide and the like can be mentioned.
As the sulfone solvent, sulfolane, ethyl methyl sulfone and the like can be mentioned.
Among these solvents (B), water, alcohol solvents, sulfoxide solvents and sulfone solvents are preferable from the viewpoint of solubility of the polymer (A), and water, ethylene glycol, diethylene glycol and dimethyl sulfoxide are more preferable. It is.
The solvent (B) may be used alone or in combination of two or more.

The conductive polymer (C) is an organic polymer having a main chain composed of a π-conjugated system and exhibiting conductivity. It is not particularly limited as long as it exhibits conductivity and has the effects of the present invention, and examples thereof include polypyrrole conductive polymers, polythiophene conductive polymers, polyacetylene conductive polymers, polyphenylene conductive polymers, polyphenylene vinylene conductive polymers, polyaniline Examples thereof include conductive polymers, polyacene conductive polymers, polythiophene vinylene conductive polymers, and copolymers of these.

As polythiophene conductive polymers, polythiophene, poly (3-methylthiophene), poly (3-ethylthiophene), poly (3-propylthiophene), poly (3-butylthiophene), poly (3-hexylthiophene), Poly (3-heptylthiophene), poly (3-octylthiophene), poly (3-decylthiophene), poly (3-dodecylthiophene), poly (3-octadecylthiophene), poly (3-bromothiophene), poly ( 3-chlorothiophene), poly (3-iodothiophene), poly (3-cyanothiophene), poly (3-phenylthiophene), poly (3,4-dimethylthiophene), poly (3,4-dibutylthiophene), Poly (3-hydroxythiophene), poly (3-methoxythiophene), poly ( -Ethoxythiophene), poly (3-butoxythiophene), poly (3-hexyloxythiophene), poly (3-heptyloxythiophene), poly (3-octyloxythiophene), poly (3-decyloxythiophene), poly (3-dodecyloxythiophene), poly (3-octadecyloxythiophene), poly (3,4-dihydroxythiophene), poly (3,4-dimethoxythiophene), poly (3,4-diethoxythiophene), poly ( 3,4-dipropoxythiophene), poly (3,4-dibutoxythiophene), poly (3,4-dihexyloxythiophene), poly (3,4-diheptyloxythiophene), poly (3,4-dioctyl) Oxythiophene), poly (3,4-didecyloxythiophene), poly (3, -Didodecyloxythiophene), poly (3,4-ethylenedioxythiophene), poly (3,4-propylenedioxythiophene), poly (3,4-butylenedioxythiophene), poly (3-methyl-4 -Methoxythiophene), poly (3-methyl-4-ethoxythiophene), poly (3-carboxythiophene), poly (3-methyl-4-carboxythiophene), poly (3-methyl-4-carboxyethylthiophene), Poly (3-methyl-4-carboxybutylthiophene) and the like can be mentioned.

As the polypyrrole conductive polymer, polypyrrole, poly (N-methylpyrrole), poly (3-methylpyrrole), poly (3-ethylpyrrole), poly (3-n-propylpyrrole), poly (3-butylpyrrole) ), Poly (3-octylpyrrole), poly (3-decylpyrrole), poly (3-dodecylpyrrole), poly (3,4-dimethylpyrrole), poly (3,4-dibutylpyrrole), poly (3- Carboxypyrrole), poly (3-methyl-4-carboxypyrrole), poly (3-methyl-4-carboxyethylpyrrole), poly (3-methyl-4-carboxybutylpyrrole), poly (3-hydroxypyrrole), Poly (3-methoxypyrrole), poly (3-ethoxypyrrole), poly (3-butoxypyrrole), poly (3-hexyi) Oxy pyrrole), poly (3-methyl-4-hexyloxy-pyrrole) and the like.

Examples of the polyaniline conductive polymer include polyaniline, poly (2-methylaniline), poly (3-isobutylaniline), poly (2-anilinesulfonic acid), poly (3-anilinesulfonic acid) and the like.

Among these conductive polymers, from the viewpoint of stability in air and heat resistance, preferred are polypyrrole conductive polymers, polythiophene conductive polymers and polyaniline conductive polymers, and more preferably polythiophene conductive. Polymer, and from the viewpoint of conductivity, particularly preferably poly (3,4-ethylenedioxythiophene).
The conductive polymers may be used alone or in combination of two or more.

The conductive polymer can be used together with a dopant to improve the conductivity.
Examples of the dopant include p-toluenesulfonic acid and polystyrenesulfonic acid.

The conductive polymer dispersion is a conductive polymer dispersion containing an additive for an electrolytic capacitor. An additive (D) may be contained in addition to the additive for electrolytic capacitor, the solvent (B) and the conductive polymer (C).
As an additive (D), a polyether, surfactant, etc. are mentioned. It is preferably a polyether from the viewpoint of conductivity, and preferably a surfactant from the viewpoint of film formability.

As the polyether, polyethylene glycol [trade name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd., Mn = 400], polyethylene glycol [trade name "PEG-600", manufactured by Sanyo Chemical Industries, Ltd., Mn = 600].

As surfactant, nonionic surfactant, anionic surfactant, cationic surfactant, etc. are mentioned. Among these surfactants, nonionic surfactants are preferable from the viewpoint of storage stability.

In the conductive polymer dispersion liquid of the present invention, the weight ratio of the additive for electrolytic capacitor to the weight of the conductive polymer dispersion liquid is 0.1 to 30% by weight from the viewpoint of the impregnation property to the capacitor element. Preferably, it is more preferably 0.5 to 25% by weight, particularly preferably 1 to 20% by weight.
In the electrolytic solution of the present invention, the weight ratio of the solvent (B) to the weight of the conductive polymer dispersion is preferably 50 to 99% by weight, more preferably 60 from the viewpoint of the dispersibility of the conductive polymer. % To 99% by weight, particularly preferably 70 to 99% by weight.
In the conductive polymer dispersion of the present invention, the weight ratio of the conductive polymer (C) to the weight of the conductive polymer dispersion is 0.5 to 10% by weight from the viewpoint of the dispersibility of the conductive polymer. Is preferably 0.8 to 5% by weight.
In the electrolytic solution of the present invention, the weight ratio of the additive (G) to the weight of the conductive polymer dispersion is 0.01 to 5% by weight from the viewpoint of solubility in the conductive polymer dispersion. Is more preferable, and more preferably 0.05 to 2% by weight.

The conductive polymer dispersion liquid of the present invention is, for example, a dispersion liquid in which the polymer (A) and the conductive polymer (C) are dispersed in a solvent (B) and, if necessary, an additive (D) 20 It can be produced by homogeneous mixing in a temperature range of -80 ° C. by using a known mechanical mixing method (for example, a method using a mechanical stirrer or a magnetic stirrer).

The electrolytic solution of the present invention is an electrolytic solution containing an additive for an electrolytic capacitor. The electrolytic solution contains the above-mentioned solvent (B) in addition to the additive for the electrolytic capacitor. If necessary, an electrolyte (F) and other additives (G) can be added.
Among the solvents (B) used as the electrolytic solution, water, alcohol solvents, ester solvents, sulfoxide solvents and sulfone solvents are preferable from the viewpoint of the solubility of the polymer (A), and water and ethylene glycol are more preferable. , Γ-butyrolactone and sulfolane.
The solvent (B) may be used alone or in combination of two or more.

The electrolyte (F) contained in the electrolytic solution of the present invention is composed of a cation component (F1) and an anion component (F2), and as the cation component (F1), ammonia, triethylamine, dimethylethylamine, diethylmethylamine, dimethyldimethylamine Amines, diethylamine, 1-methylimidazole, 1,2,3,4-tetramethylimidazolinium, 1-ethyl-3-methylimidazolinium and the like can be mentioned, with preference given to ammonia, dimethylethylamine, diethylamine and triethylamine. More preferred is dimethylethylamine.
On the other hand, examples of the anion component (F2) include adipic acid, azelaic acid, 1,6-decanedicarboxylic acid, phthalic acid, maleic acid, benzoic acid, phosphoric acid and their esters and boric acid and their esters, etc. Among them, phthalic acid is preferable.
The electrolyte (F) may be used alone or in combination of two or more.

The molar ratio of (F1) to (F2) is preferably (F1) / (F2) from the viewpoint of not dedoping the dopant incorporated in the solid electrolyte (conductive polymer described later). It is 3 to 1.0, more preferably 0.5 to 1.0.

Examples of other additives (G) include nitro compounds (o-nitrobenzoic acid, p-nitrobenzoic acid, m-nitrobenzoic acid, o-nitrophenol and p-nitrophenol etc.), boric acid and poval etc. Be

In the electrolytic solution of the present invention, the weight ratio of the polymer (A) to the weight of the electrolytic solution is preferably 5 to 70% by weight, more preferably 10 to 60% by weight from the viewpoint of the impregnatability to the capacitor element. And particularly preferably 20 to 50% by weight.
In the electrolytic solution of the present invention, the weight ratio of the solvent (B) to the weight of the electrolytic solution is preferably 30 to 95% by weight, more preferably 40 to 90% by weight from the viewpoint of suppressing dry-up of the capacitor element. And particularly preferably 40 to 80% by weight.
In the electrolytic solution of the present invention, the weight ratio of the electrolyte (F) to the weight of the electrolytic solution is preferably 0 to 20% by weight, more preferably 5 to 15% by weight from the viewpoint of the chemical conversion of the dielectric layer. is there.
In the electrolytic solution of the present invention, the weight ratio of the additive (G) to the weight of the electrolytic solution is preferably 0 to 5% by weight, more preferably 0.1 to 5%, from the viewpoint of solubility in the electrolytic solution. It is 2% by weight.

The electrolytic solution of the present invention can be prepared, for example, from the polymer (A) and the solvent (B) and, if necessary, the electrolyte (F) and other additives (G) in a known mechanical temperature range from 20 to 80.degree. It can be manufactured by uniform mixing by using a dynamic mixing method (for example, a method using a mechanical stirrer or a magnetic stirrer).

The electrolytic capacitor of the present invention is an electrolytic capacitor provided with a solid electrolyte layer, and is an electrolytic capacitor containing an additive for electrolytic capacitor. Examples of the electrolytic capacitor of the present invention include a capacitor and the like formed by disposing a cathode foil opposite to an anode foil provided with a dielectric layer and a solid electrolyte layer via a separator (such as manila hemp and kraft paper). . Alternatively, in the hybrid electrolytic capacitor, the solid electrolyte layer is a capacitor containing an electrolytic solution for electrolytic capacitor.

A conductive material can be used as the above-mentioned anode foil.
Examples of the conductive material include aluminum, titanium, tantalum, niobium and alloys thereof.
The anode foil is preferably a foil whose surface area is increased by a method such as making it porous by etching.

The dielectric layer is formed by anodizing the surface of the anode foil by chemical conversion treatment or the like, and examples thereof include oxides of a conductive substance used for the anode foil.
For example, when aluminum is used as the anode foil, the dielectric layer formed on the surface of the anode foil is aluminum oxide formed by formation.

The solid electrolyte layer formed on the surface of the dielectric layer is a layer containing a conductive polymer, a dopant, a polymer (A) having the above-mentioned hydrophilic group and optionally an additive (D).
Examples of the conductive polymer include polythiophene, poly (3,4-ethylenedioxythiophene) (PEDOT) and polypyrrole.
In addition, examples of the dopant include p-toluenesulfonic acid and polystyrenesulfonic acid (PSS).
As an additive (D), a polyether, surfactant, etc. are mentioned.
As the polyether, polyethylene glycol [trade name "PEG-400", manufactured by Sanyo Chemical Industries, Ltd., Mn = 400], polyethylene glycol [trade name "PEG-600", manufactured by Sanyo Chemical Industries, Ltd., Mn = 600].
As surfactant, nonionic surfactant, anionic surfactant, cationic surfactant, etc. are mentioned. Among these surfactants, nonionic surfactants are preferable from the viewpoint of storage stability.

The weight ratio of the polymer (A) having a hydrophilic group contained in the solid electrolyte layer is preferably 20 to 80% by weight based on the weight of the solid electrolyte layer from the viewpoint of the withstand voltage, and more preferably It is 30 to 60% by weight, particularly preferably 40 to 50% by weight.

The solid electrolyte layer in the present invention can be formed by the following methods [I] and [II].

[I]
A solid electrolyte layer is formed by the method described in (1) below.
(1)
An anode foil having a dielectric layer was prepared by using the conductive polymer dispersion described above [the polymer (A) having a hydrophilic group, the conductive polymer (C), the dopant, and the solvent (B) (water, etc. A solid electrolyte layer can be formed by a method in which the solution is impregnated and then dried.

In the method of forming a solid electrolyte layer according to [I], the above operation (1) may be performed a plurality of times to form a plurality of solid electrolyte layers.
In addition, if the above operation (1) is performed at least once, the following operations (2) and / or (3) may be performed instead of the operation (1).
In addition, when the operation of (1), (2) and / or (3) is performed a plurality of times, in each operation of (1), (2) or (3), instead of the anode foil having a dielectric layer Then, an anode foil having a dielectric layer and a solid electrolyte layer obtained by performing the operation of (1), (2) or (3) immediately before may be used.
(2)
The anode foil having a dielectric layer is impregnated with the conductive polymer dispersion [a solution containing a conductive polymer (C), a dopant and a solvent (B) (such as water)], and then dried. And a solid electrolyte layer can be formed.
Further, the conductive polymer dispersion may contain boric acid and boric acid ester, if necessary.
(3)
An anode foil having a dielectric layer, a solid electrolyte composition [a monomer (such as thiophene, ethylenedioxythiophene and pyrrole) and a dopant solution (such as aqueous solution) constituting the conductive polymer (C)], an oxidizing agent (such as an aqueous solution) The solid electrolyte layer can be formed by polymerizing the monomers constituting the conductive polymer by a method of alternately impregnating with a solution (aqueous solution or the like) of iron oxide or the like.

[II]
Perform the above operation (2) or (3) at least once to form a solid electrolyte layer (containing no polymer (A) having a hydrophilic group) on the surface of the dielectric layer of the anode foil .
Thereafter, the anode foil having a dielectric layer and a solid electrolyte layer is impregnated with a solution (such as an aqueous solution) of the polymer (A) having a hydrophilic group described above, and then dried to obtain a polymer having a hydrophilic group. A solid electrolyte layer containing (A) can be formed.
In the method of forming a solid electrolyte layer according to [II], the operation of (1) may be performed instead of the operations of (2) and (3).

Examples of the cathode foil include laminates of carbon paste and silver paste, aluminum foil, and the like.

The electrolytic capacitor of the present invention can be produced, for example, by the following method.
First, the aluminum etched foil as an anode foil is subjected to a chemical conversion treatment by the above method to form a dielectric layer on the surface of the aluminum etched foil, and an anode comprising the anode foil and the dielectric layer is produced.
Thereafter, an electrode tab is connected to the anode foil and the cathode foil, and they are opposed to each other through the separator to produce an element. Then, in order to repair the cut surface and the defect portion, the element is subjected to a restoration formation at a voltage of 250 V in an aqueous solution of ammonium borate to prepare a capacitor element.
Next, in the method of [I] or [II], the capacitor element is immersed in the conductive polymer dispersion, the solid electrolyte composition, the solution of the oxidizing agent, etc. For an anode foil having a dielectric layer, a solid electrolyte layer is formed on the surface of the dielectric layer.
An electrolytic capacitor is produced by the above method.

Examples of the solid electrolyte include polythiophene, poly 3,4-ethylenedioxythiophene and the like, and conductive polymers such as polypyrrole.
The conductive polymer has a dopant incorporated therein, and the dopant plays a role in developing conductivity.
Examples of the above-mentioned dopant include p-toluenesulfonic acid and polystyrenesulfonic acid.

The following structures are mentioned as a specific structure of the electrolytic capacitor of this invention.
It has a capacitor | condenser element, a pair of lead wire, and an exterior body. The pair of lead wires are each connected to the capacitor element. The outer package encloses the capacitor element in such a manner that the lead wire is led out to the other end.
The exterior body is composed of a cylindrical case and a sealing body, in which case a capacitor element containing an electrolytic solution is accommodated by the method described later, and the lead-through is inserted through the sealing body. It passes through a hole and is sealed by compressing in a drawing portion provided on the outer peripheral surface of the case.

The capacitor element of the present invention has an anode foil having a dielectric layer on the surface, and a layer of solid electrolyte in contact with the dielectric layer of the anode foil.
The anode foil is formed by roughening the aluminum foil by etching, and further forming an anodized film, which is a dielectric layer, on the surface thereof.
Next, the anode foil having the dielectric layer, the cathode foil, and the separator are stacked and wound to form a capacitor element (without a solid electrolyte layer).

And the capacitor | condenser element in this invention can be obtained by producing the layer of a solid electrolyte between the anode foil and cathode foil in a capacitor | condenser element (without the layer of a solid electrolyte).
The following (1) and (2) etc. are mentioned as a preparation method of the layer of a solid electrolyte.
(1)
A dielectric element layer in a capacitor element is formed by impregnating a capacitor element (without a layer of solid electrolyte) with the above-mentioned dispersion solution of solid electrolyte [a solution in which a solid electrolyte is dispersed in a solvent (such as water)] and then drying it. A layer of solid electrolyte can be formed on the surface.
(2)
A capacitor element (without a solid electrolyte layer), a solid electrolyte composition [a mixture of monomers (such as thiophene, ethylenedioxythiophene and pyrrole, which constitute the solid electrolyte, a dopant and a solvent (such as water)], an oxidant (oxidation A solid electrolyte layer can be formed on the surface of the dielectric layer in the capacitor element by polymerizing the monomers constituting the solid electrolyte by a method of alternately impregnating with a solution (aqueous solution or the like) of iron or the like.

By immersing the capacitor element formed as described above in the electrolytic solution of the present invention for the electrolytic capacitor of the present invention, and impregnating the electrolytic solution with the above-mentioned electrolytic solution in a vacuum, the gap of the solid electrolyte layer provided in the capacitor element The electrolytic solution for electrolytic capacitor of the above enters and the electrolytic capacitor of the present invention is manufactured.

EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.
In the following, parts represent parts by weight.
Further, Mn of the following polymer (A) having a hydrophilic group and the comparative polymer (RA) was measured by GPC under the following conditions.
Device: Tosoh Corporation HLC-8120
Column: Two TSK GEL GMH6 (made by Tosoh Corp.)
Measurement temperature: 40 ° C
Sample solution: 0.25 wt% THF solution Injection volume: 100 μl
Detection device: Refractive index detector Reference substance: Tosoh Co., Ltd. standard polystyrene (TSK standard POLYSTYRENE) 12 points (weight average molecular weight: 500 1050 2800 5970 9100 18100 37900 96400 190000 355000 1090000 2890000)

Further, Tg of the following polymers (A-1 to 24) having a hydrophilic group and the comparative polymers (RA-1 and 2) is a differential scanning calorimeter [DSC 20 manufactured by Seiko Instruments Inc. And “SSC / 580” and the like] in accordance with “ASTM D 3418-82”.

Example 1 Preparation of Additive (P-1) for Electrolytic Capacitor Containing Polymer (A-1) Having Hydrophilic Group>
30 parts by weight of toluene [manufactured by Wako Pure Chemical Industries, Ltd.] and 9.5 parts by weight of acrylic acid [manufactured by Wako Pure Chemical Industries, Ltd.] in a flask equipped with a stirrer, a thermometer and a cooling pipe; Hereinafter, it is described as mmol)) and 4.6 parts by weight (40 mmol) of 2-hydroxyethyl acrylate [manufactured by Wako Pure Chemical Industries, Ltd.], and heated to 80 ° C. with stirring. A solution of 0.9 parts by weight of azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) dissolved in 5 parts by weight of toluene was added dropwise over 3 hours. After completion of the dropwise addition, the mixture was heated with stirring for 3 hours while maintaining 80 ° C. Thereafter, the toluene is distilled off by heating to 100 ° C. under a reduced pressure of 0.5 kPa to synthesize a polymer (A-1) having a hydrophilic group, and the polymer (A-1) is contained. An additive (P-1) for an electrolytic capacitor was produced. The Mn of the polymer (A-1) was 5,600, and the Tg was 56 ° C.

<Example 2: Preparation of Additive (P-2) for Electrolytic Capacitor Containing Polymer (A-2) Having Hydrophilic Group>
A polymer (A-2) having a hydrophilic group is prepared in the same manner as in Example 1 except that the ethylenically unsaturated monomer having a hydrophilic group is changed to the monomer described in Table 1 in Example 1. An additive (P-2) for an electrolytic capacitor to be contained was produced. The Mn of the polymer (A-2) was 5,300, and the Tg was 11 ° C.

<Example 3: Preparation of Additive (P-3) for Electrolytic Capacitor Containing Polymer (A-3) Having Hydrophilic Group>
A polymer (A-3) having a hydrophilic group is prepared in the same manner as in Example 1 except that the ethylenically unsaturated monomer having a hydrophilic group is changed to the monomer described in Table 1 in Example 1. An additive (P-3) for an electrolytic capacitor to be contained was produced. The Mn of the polymer (A-3) was 5,500, and the Tg was 4 ° C.

<Example 4: Preparation of additive (P-4) for electrolytic capacitor containing polymer (A-4) having a hydrophilic group>
A polymer (A-4) having a hydrophilic group was prepared in the same manner as in Example 1 except that the ethylenically unsaturated monomer having a hydrophilic group was changed to the monomer described in Table 1 in Example 1. An additive (P-4) for an electrolytic capacitor to be contained was produced. The Mn of the polymer (A-4) was 6,100, and the Tg was −2 ° C.

Example 5 Preparation of Additive (P-5) for Electrolytic Capacitor Containing Polymer (A-5) Having Hydrophilic Group>
A polymer (A-5) having a hydrophilic group was prepared in the same manner as in Example 1 except that the ethylenically unsaturated monomer having a hydrophilic group was changed to the monomer described in Table 1 in Example 1. An additive (P-5) for an electrolytic capacitor to be contained was produced. The Mn of the polymer (A-5) was 4,600, and the Tg was −40 ° C.

<Example 6: Preparation of additive (P-6) for electrolytic capacitor containing polymer (A-6) having a hydrophilic group>
30 parts by weight of toluene [manufactured by Wako Pure Chemical Industries, Ltd.] and 14.1 parts by weight (121 mmol) of 2-hydroxyethyl acrylate are charged into a flask equipped with a stirrer, a thermometer and a cooling pipe, and 80 is stirred. Heated to ° C. A solution of 0.9 parts by weight of azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) dissolved in 5 parts of toluene was added dropwise over 3 hours. After completion of the dropwise addition, the mixture was heated with stirring for 3 hours while maintaining 80 ° C. Thereafter, the toluene was distilled off by heating to 100 ° C. under a reduced pressure of 0.5 kPa to prepare an additive (P-6) for an electrolytic capacitor containing a polymer (A-6) having a hydrophilic group . The Mn of the polymer (A-7) was 6,100, and the Tg was -15.degree.

Example 7 Preparation of Additive for Electrolytic Capacitor (P-7) Containing Polymer (A-7) Having Hydrophilic Group>
Example 6 is carried out in the same manner as in Example 6 except that 0.9 parts by weight of azobisisobutyronitrile is changed to 1.8 parts by weight, and a polymer (A-7) having a hydrophilic group is obtained An additive (P-7) for an electrolytic capacitor to be contained was produced. The Mn of the polymer (A-7) was 2,500, and the Tg was −15 ° C.

Example 8 Preparation of Additive for Electrolytic Capacitor (P-8) Containing Polymer (A-8) Having Hydrophilic Group>
In Example 6, except that 30 parts by weight of toluene was changed to 30 parts by weight of methyl ethyl ketone [manufactured by Wako Pure Chemical Industries, Ltd.], the same procedure as in Example 6 was performed, and a polymer having a hydrophilic group (A-8) Were prepared (P-8). The Mn of the polymer (A-8) was 3,100, and the Tg was −15 ° C.

Example 9 Preparation of Additive for Electrolytic Capacitor (P-9) Containing Polymer (A-9) Having Hydrophilic Group>
A polymer (A-9) having a hydrophilic group is obtained in the same manner as in Example 6 except that in Example 6, 0.9 parts by weight of azobisisobutyronitrile is changed to 0.4 parts by weight. An additive (P-9) for an electrolytic capacitor to be contained was produced. The Mn of the polymer (A-9) was 15,000, and the Tg was −15 ° C.

Example 10 Preparation of Additive for Electrolytic Capacitor (P-10) Containing Polymer (A-10) Having Hydrophilic Group>
A polymer (A-10) having a hydrophilic group was prepared in the same manner as in Example 6 except that in Example 6, 0.9 parts by weight of azobisisobutyronitrile was changed to 0.2 parts by weight. An additive (P-10) for an electrolytic capacitor to be contained was produced. The Mn of the polymer (A-10) was 36,000, and the Tg was −15 ° C.

Example 11 Preparation of Additive for Electrolytic Capacitor (P-11) Containing Polymer (A-11) Having Hydrophilic Group>
A polymer (A-11) having a hydrophilic group is obtained in the same manner as in Example 6 except that the ethylenically unsaturated monomer having a hydrophilic group is changed to the monomer described in Table 1 in Example 6. An additive (P-11) for an electrolytic capacitor to be contained was produced. The Mn of the polymer (A-11) was 5,600, and the Tg was −7 ° C.

Example 12 Preparation of Additive for Electrolytic Capacitor (P-12) Containing Polymer (A-12) Having Hydrophilic Group>
A polymer (A-12) having a hydrophilic group is prepared in the same manner as in Example 6 except that the ethylenically unsaturated monomer having a hydrophilic group is changed to the monomer described in Table 1 in Example 6. An additive (P-12) for an electrolytic capacitor to be contained was produced. The Mn of the polymer (A-12) was 6,200, and the Tg was −40 ° C.

Example 13 Preparation of Additive for Electrolytic Capacitor (P-13) Containing Polymer (A-13) Having Hydrophilic Group>
30 parts of toluene [manufactured by Wako Pure Chemical Industries, Ltd.], 12.7 parts by weight of 4-hydroxybutyl acrylate (88.2 mmol) and 1.4 parts of butyl acrylate in a flask equipped with a stirrer, a thermometer and a condenser A portion (10.9 mmol) was charged and heated to 80 ° C. with stirring. A solution of 0.9 parts by weight of azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) dissolved in 5 parts by weight of toluene was added dropwise over 3 hours. After completion of the dropwise addition, the mixture was heated with stirring for 3 hours while maintaining 80 ° C. Thereafter, the toluene is distilled off by heating to 100 ° C. under a reduced pressure of 0.5 kPa, and an additive (P-13) for an electrolytic capacitor containing a polymer (A-13) having a hydrophilic group is obtained. Made. The Mn of the polymer (A-13) was 5,800, and the Tg was -42 ° C.

Example 14 Preparation of Additive for Electrolytic Capacitor (P-14) Containing Polymer (A-14) Having Hydrophilic Group>
A polymer (A-14) having a hydrophilic group is prepared in the same manner as in Example 13 except that the ethylenically unsaturated monomer having a hydrophilic group is changed to a monomer described in Table 1 in Example 13. An additive (P-14) for an electrolytic capacitor to be contained was produced. The Mn of the polymer (A-14) was 4,800, and the Tg was −40 ° C.

Example 15 Preparation of Additive for Electrolytic Capacitor (P-15) Containing Polymer (A-15) Having Hydrophilic Group>
Example 13 is carried out in the same manner as Example 1 except that the ethylenically unsaturated monomer having a hydrophilic group is changed to the monomer described in Table 1, and a polymer having a hydrophilic group (A-15) is obtained An additive (P-15) for an electrolytic capacitor to be contained was produced. The Mn of the polymer (A-15) was 6,300, and the Tg was 16 ° C.

Example 16 Preparation of Additive for Electrolytic Capacitor (P-16) Containing Polymer (A-16) Having Hydrophilic Group>
A polymer (A-16) having a hydrophilic group is obtained in the same manner as in Example 6 except that the ethylenically unsaturated monomer having a hydrophilic group is changed to a monomer described in Table 1 in Example 6. An additive (P-16) for an electrolytic capacitor to be contained was produced. The Mn of the polymer (A-16) was 5,800, and the Tg was 165 ° C.

Example 17 Preparation of Additive for Electrolytic Capacitor (P-17) Containing Polymer (A-17) Having Hydrophilic Group>
A polymer (A-17) having a hydrophilic group is prepared in the same manner as in Example 7 except that the ethylenically unsaturated monomer having a hydrophilic group is changed to a monomer described in Table 1 in Example 7. The additive for electrolytic capacitors (P-17) to contain was produced. The Mn of the polymer (A-17) was 6,500, and the Tg was −50 ° C.

Example 18 Preparation of Additive for Electrolytic Capacitor (P-18) Containing Polymer (A-18) Having Hydrophilic Group>
Example 13 is carried out in the same manner as in Example 13 except that the ethylenically unsaturated monomer having a hydrophilic group is changed to the monomer described in Table 1, and a polymer (A-18) having a hydrophilic group is contained. An additive for electrolytic capacitor (P-18) was prepared. The Mn of the polymer (A-18) was 4,100, and the Tg was 65 ° C.

Example 19 Preparation of Additive for Electrolytic Capacitor (P-19) Containing Polymer (A-19) Having Hydrophilic Group>
Example 6 is carried out in the same manner as in Example 6 except that the ethylenically unsaturated monomer having a hydrophilic group is changed to the monomer described in Table 1, and a polymer (A-19) having a hydrophilic group is contained. An additive for electrolytic capacitor (P-19) was prepared. The Mn of the polymer (A-19) was 7,500, and the Tg was 18 ° C.

Example 20 Preparation of Additive for Electrolytic Capacitor (P-20) Containing Polymer (A-20) Having Hydrophilic Group>
Example 6 is carried out in the same manner as in Example 6 except that the ethylenically unsaturated monomer having a hydrophilic group is changed to the monomer described in Table 1, and a polymer (A-20) having a hydrophilic group is contained. An additive for electrolytic capacitor (P-20) was prepared. The Mn of the polymer (A-20) was 3,600, and the Tg was 30 ° C.

Example 21 Preparation of Additive for Electrolytic Capacitor (P-21) Containing Polymer (A-21) Having Hydrophilic Group>
Example 6 is carried out in the same manner as Example 6 except that the ethylenically unsaturated monomer having a hydrophilic group is changed to the monomer described in Table 1, and contains a polymer (A-21) having a hydrophilic group. An additive (P-21) for electrolytic capacitor was prepared. The Mn of the polymer (A-21) was 4,500, and the Tg was 55 ° C.

<Example 22: Preparation of additive (P-22) for electrolytic capacitor containing polymer (A-22) having a hydrophilic group>
The same procedure as in Example 1 is repeated except that the ethylenically unsaturated monomer having a hydrophilic group is changed to the monomer described in Table 1, and a polymer (A-22) having a hydrophilic group is contained. An additive (P-22) for electrolytic capacitor was prepared. The Mn of the polymer (A-22) was 4,200, and the Tg was 10 ° C.

Example 23 Preparation of Additive for Electrolytic Capacitor (P-23) Containing Polymer (A-23) Having Hydrophilic Group>
The same procedure as in Example 1 is repeated except that the ethylenically unsaturated monomer having a hydrophilic group is changed to the monomer described in Table 1 in Example 1, and a polymer having a hydrophilic group (A-23) is contained. An additive for electrolytic capacitor (P-23) was prepared. The Mn of the polymer (A-23) was 6,000, and the Tg was 82 ° C.

Example 24 Preparation of Additive for Electrolytic Capacitor (P-24) Containing Polymer (A-24) Having Hydrophilic Group>
The same procedure as in Example 1 is carried out except that the ethylenically unsaturated monomer having a hydrophilic group is changed to the monomer described in Table 1 in Example 1, and a polymer (A-24) having a hydrophilic group is contained. An additive for electrolytic capacitor (P-24) was prepared. The Mn of the polymer (A-24) was 6,500, and the Tg was 75 ° C.

Comparative Example 1 Preparation of Additive for Electrolytic Capacitor (RP-2) Containing Polymer (RA-1) Having No Hydrophilic Group>
Example 6 is carried out in the same manner as in Example 6 except that the ethylenically unsaturated monomer having a hydrophilic group is changed to the monomer described in Table 1, and an electrolysis containing a comparative polymer (RA-1) A capacitor additive (RP-2) was prepared. The Mn of the polymer (RA-1) was 7,500, and the Tg was −70 ° C.

As a comparative polymer (RA-2) having a hydrophilic group but having a high Tg, polyvinyl alcohol (JC-25, Tg: 80 ° C., manufactured by Nippon Shokubai Bi-Pobar, Inc.) was used.

The structures, Mn, Tg and the like of the above polymers (A-1) to (A-24) and comparative polymers (RA-1) to (RA-2) are summarized in Table 1. In addition, the unit of the numerical value of a composition column is a weight part and it is a millimole in parentheses.
Moreover, the used monomers are as follows.
Acrylic acid [manufactured by Wako Pure Chemical Industries, Ltd.]
Methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd.)
Succinic acid mono (2-acryloxy ethyl) [made by Tokyo Chemical Industry Co., Ltd.]
Succinic acid mono (2-methacryloyloxyethyl) [trade name "Light Ester HO-MS (N)", manufactured by Kyoeisha Chemical Co., Ltd.]
2-Hydroxyethyl acrylate [manufactured by Wako Pure Chemical Industries, Ltd.]
2-hydroxypropyl acrylate (made by Tokyo Chemical Industry Co., Ltd.)
4-hydroxybutyl acrylate (trade name "4-HBA", manufactured by Osaka Organic Chemical Industry Co., Ltd.)
1,4-cyclohexanedimethanol monoacrylate (abbreviated as CHDMMA) (trade name "funcryl FA-610A", manufactured by Hitachi Chemical Co., Ltd.)
Glycerin monoacrylate [trade name "Blenmer GLM", manufactured by NOF Corporation]
2-Hydroxyethyl methacrylate (abbreviated as HEMA) [manufactured by Tokyo Chemical Industry Co., Ltd.]
N- (2-hydroxyethyl) acrylamide [manufactured by Tokyo Chemical Industry Co., Ltd.]
Acrylamide [manufactured by Tokyo Chemical Industry Co., Ltd.]
Ethylene oxide 2-mole adduct of 2-hydroxyethyl acrylate (abbreviated as HEA 2 EO) (trade name "Blenmer AE90", manufactured by NOF Corporation)

<Examples 25 to 45 and Comparative Examples 3 to 6: Preparation of Conductive Polymer Dispersion>
Conductive polymer dispersions (Q-1) to (Q-21) and comparative conductive polymer dispersions (RQ-1) to (RQ-4) were mixed according to the composition of parts by weight described in Table 2. Was prepared.

The following compounds were used as the compounds described in Table 2.
PEDOT / PSS aqueous dispersion (simply the same in the following): aqueous dispersion of poly (3,4-ethylenedioxythiophene) (PEDOT) doped with polystyrene sulfonic acid (PSS), manufactured by Heraeus, Total weight of PEDOT and PSS (PEDOT / PSS concentration) based on the weight of Clevios PH500, PEDOT / PSS aqueous dispersion: 1.4% by weight

Examples 46 to 68 and Comparative Examples 7 to 10
The electrolytic capacitors (S-1) to (S-23) of the present invention and the electrolytic capacitors (RS-1) to (RS-4) for comparison were produced by the method described below.

Examples 46 to 66 and Comparative Examples 7 to 10 Preparation of Solid Electrolytic Capacitor 1
A tab for an electrode is connected to an anode foil (chemically converted aluminum foil: 115HC9-323Vf made by JCC) and a cathode foil (unformed aluminum foil: 80LJ11B made by JCC) having a dielectric layer, and kraft paper is used as a separator The elements were made to face each other. In order to repair the cut surface and the defect portion, the element was subjected to a restoration formation at a voltage of 250 V in an aqueous solution of ammonium borate to obtain a capacitor element.
Next, the capacitor element was impregnated with a PEDOT / PSS aqueous dispersion and dried at 150 ° C. for 30 minutes to form a solid electrolyte layer on the surface of the dielectric layer.
Subsequently, the conductive polymer dispersions of Examples 25 to 45 and Comparative Preparations 3 to 7 described in Table 2 were impregnated, and dried at 150 ° C. for 30 minutes to form a solid electrolyte layer.
Finally, the capacitor element was stored in a case and caulking was performed to obtain electrolytic capacitors of Examples 46 to 66 and Comparative Examples 7 to 10.

Example 67 Preparation of Solid Electrolytic Capacitor 2
A tab for an electrode is connected to an anode foil (chemically converted aluminum foil: 115HC9-323Vf made by JCC) and a cathode foil (unformed aluminum foil: 80LJ11B made by JCC) having a dielectric layer, and kraft paper is used as a separator The elements were made to face each other. In order to repair the cut surface and the defect portion, the element was subjected to a restoration formation at a voltage of 250 V in an aqueous solution of ammonium borate to obtain a capacitor element.
Next, the capacitor element was impregnated with the conductive polymer dispersion (Q-6) prepared in Example 30, and dried at 150 ° C. for 30 minutes to form a solid electrolyte layer on the surface of the dielectric layer.
Subsequently, it was impregnated with a PEDOT / PSS aqueous dispersion and dried at 150 ° C. for 30 minutes to form a solid electrolyte layer. Finally, the capacitor element was stored in a case, and caulking was performed to obtain a solid electrolytic capacitor of Example 67.

Example 68 Preparation of Solid Electrolytic Capacitor 3
An electrode tab is connected to an anode foil (chemically converted aluminum foil: JCCV f323) having a dielectric layer and a cathode foil (unformed aluminum foil: 80LJ11B manufactured by JCC), and they are opposed via kraft paper as a separator to obtain an element The In order to repair the cut surface and the defective portion, the element was subjected to a restoration formation at a voltage of 120 V in an aqueous solution of ammonium borate to obtain a capacitor element.
Next, the capacitor element was impregnated with a commercially available PEDOT / PSS aqueous dispersion and dried at 150 ° C. for 30 minutes to form a solid electrolyte layer on the surface of the dielectric layer.
Further, the resultant was again impregnated with a PEDOT / PSS aqueous dispersion, and dried at 150 ° C. for 30 minutes to form a solid electrolyte layer.
Subsequently, the resultant was impregnated with an aqueous solution (solid content concentration: 30% by weight) of the polymer (A-6) having a hydrophilic group produced in Example 6, and dried at 150 ° C. for 30 minutes.
Finally, the capacitor element was housed in a case, and caulking was performed to obtain a solid electrolytic capacitor of Example 68 in which the solid electrolyte layer contained the polymer 1 having a hydrophilic group.

The “equivalent series resistance (ESR)”, “leakage current” and “withstand voltage” of the solid electrolytic capacitors obtained in Examples 46 to 68 and Comparative Examples 7 to 10 were evaluated by the following methods. The results are shown in Table 3.

<ESR>
The ESR value of the solid electrolytic capacitor at 100 kHz was measured using an LCR meter (LCR high tester 3532-50 manufactured by Hioki Electric Co., Ltd.).
The lower the ESR value, the better the stability of the operation.
<Leakage current>
A voltage of 20 V was applied to the solid electrolytic capacitor, and the leakage current after 60 seconds was measured.
<Withstand voltage>
A voltage is applied to the solid electrolytic capacitor obtained by the above method in a constant current mode of 0.2 mA with a DC power supply (GP0650-05R, manufactured by Takasago Mfg. Co., Ltd.), and automatic voltage boosting is performed. Withstand voltage.

The electrolytic capacitors of Examples 46 to 68 of the present invention gave good results in terms of ESR change rate, leakage current and withstand voltage.
On the other hand, in the electrolytic capacitors of Comparative Examples 7 to 10, at least one of the ESR change rate, the leakage current and the withstand voltage deteriorated.

Examples 69 to 80 and Comparative Examples 11 to 12: Electrolyte Solution
Polymer (A) and comparative polymer (A'-1), electrolyte (C) (dimethyl ethylamine and phthalic acid), solvent (B) (ethylene glycol) are mixed according to the blending parts (parts by weight) in Table 4 Then, electrolytic solutions (R-1) to (R-12) and electrolytic solutions (RR-1) to (RR-2) for comparative examples were prepared.

Next, using the above electrolytes (R-1) to (R-12) and the electrolytes (RR-1) to (RR-2) of the comparative example, electrolytic capacitors (S-24) to (S-) are used. The electrolytic capacitors (RS-5) to (RS-6) of 35) and the comparative example were respectively manufactured by the following procedures.
A tab for an electrode is connected to an anode foil (chemically converted aluminum foil: 115HC9-323Vf made by JCC) and a cathode foil (unformed aluminum foil: 80LJ11B made by JCC) having a dielectric layer, and kraft paper is used as a separator The elements were made to face each other. In order to repair the cut surface and the defect portion, the element was subjected to a restoration formation at a voltage of 250 V in an aqueous solution of ammonium borate to obtain a capacitor element.
Next, the capacitor element was impregnated with a commercially available PEDOT / PSS aqueous dispersion, and dried at 150 ° C. for 30 minutes. This operation was repeated three times to form a solid electrolyte layer on the surface of the dielectric layer.
Subsequently, the electrolytic solutions (R-1) to (R-12) described in Table 4 and the electrolytic solutions (RR-1) to (RR-2) of the comparative example were each prepared in the above capacitor element at 50 ° C. Vacuum impregnation was carried out for a minute (vacuum degree: 20 mmHg).
Finally, the capacitor element was stored in a case and caulking was performed to obtain electrolytic capacitors (S-24) to (S-35) and electrolytic capacitors (RS-5) to (RS-6) of Comparative Examples.

The initial characteristics of the produced electrolytic capacitor and the characteristics after the test were measured and evaluated by the following methods. The results are shown in Table 4.

<Initial evaluation>
As an initial evaluation, capacitance, ESR, leakage current, and withstand voltage were measured.
The capacitance was measured at 120 Hz and the ESR value at 100 kHz, and the leakage current was measured after application for 1 minute at the rated voltage.
<Capacitance>
The electrostatic capacity at 120 Hz of the solid electrolytic capacitor was measured using an LCR meter (LCR high tester 3532-50 manufactured by Hioki Electric Co., Ltd.).
<ESR>
The ESR value of the solid electrolytic capacitor at 100 kHz was measured using an LCR meter (LCR high tester 3532-50 manufactured by Hioki Electric Co., Ltd.).
<Leakage current>
A voltage of 20 V was applied to the solid electrolytic capacitor, and the leakage current after 60 seconds was measured.
<Withstand voltage>
A voltage is applied to the solid electrolytic capacitor obtained by the above method in a constant current mode of 0.2 mA with a DC power supply (GP0650-05R, manufactured by Takasago Mfg. Co., Ltd.), and automatic voltage boosting is performed. Withstand voltage.

<Evaluation after accelerated test>
In order to carry out an accelerated test by accelerating the volatilization of the solvent (B), after leaving in a thermostatic chamber at 125 ° C. for 500 hours with the capacitor element opened without being stored in the case, the same as the initial evaluation I made an evaluation.
Moreover, the capacitance and ESR calculated the change rate based on the value of the initial characteristics.

The electrolytic capacitors of Examples 69 to 80 of the present invention also had good initial characteristics, and good results were obtained in the accelerated test.
On the other hand, the electrolytic capacitors for comparison of Comparative Examples 11 and 12 deteriorated in terms of the rate of change in electrostatic capacity, the rate of change in ESR, and the leakage current.

The solid electrolytic capacitor containing the additive for an electrolytic capacitor of the present invention has a low ESR, a low leakage current, and a high withstand voltage, and thus can be suitably used as a component of electric products and electronic products that require high performance.

Claims

An additive for an electrolytic capacitor used in an electrolytic capacitor comprising a solid electrolyte layer, which comprises a polymer (A) having a hydrophilic group, wherein the concentration of the hydrophilic group in the polymer (A) is a polymer (A) The additive for an electrolytic capacitor, having a solubility parameter of polymer (A) of 12 (cal / cm 3 ) 1/2 or more based on the weight of the polymer (A).
The additive for electrolytic capacitor according to claim 1, wherein the hydrophilic group is at least one group selected from the group consisting of a hydroxyl group, an acidic group, a basic group and an oxyalkylene group having a carbon number of 2 to 3.
The additive for an electrolytic capacitor according to claim 1 or 2, wherein the polymer (A) is a polymer having as a constituent monomer the ethylenically unsaturated monomer (a) having the hydrophilic group.
The (meth) acrylic monomer having a hydroxyl group, the (meth) acrylic monomer having an acid group, the (meth) acrylic monomer having a basic group, and the hydroxyl group At least one selected from the group consisting of alkyl ethers of alkylene oxide adducts to (meth) acrylic monomers having
The alkylene oxide added to the (meth) acrylic monomer having a hydroxyl group is an alkylene oxide having 2 to 3 carbon atoms,
The (meth) acrylic monomer having a hydroxyl group is a hydroxyalkyl (meth) acrylate having 4 to 12 carbon atoms, a lactone adduct to the above hydroxyalkyl (meth) acrylate having 4 to 12 carbon atoms, and the above hydroxy having 4 to 12 carbon atoms At least one member selected from the group consisting of alkylene oxide adducts to alkyl (meth) acrylates,
The (meth) acrylic monomer having an acidic group is selected from the group consisting of an acid anhydride adduct to the (meth) acrylic monomer having a hydroxyl group, a lactone adduct to (meth) acrylic acid and (meth) acrylic acid At least one,
The (meth) acrylic monomer having a basic group is at least one selected from the group consisting of (meth) acrylamides having 3 to 20 carbon atoms and aminoalkyl (meth) acrylates having 4 to 12 carbon atoms. The additive for electrolytic capacitors as described in.
The proportion of the total weight of the ethylenically unsaturated monomers (a) having a hydrophilic group constituting the polymer (A) is 50 to 100% by weight based on the weight of all the monomers constituting the polymer (A) The additive for electrolytic capacitors according to claim 3 or 4.
The additive for an electrolytic capacitor according to any one of claims 1 to 5, wherein the number average molecular weight of the polymer (A) is 1,000 to 500,000.
The additive for an electrolytic capacitor according to any one of claims 1 to 6, wherein the glass transition point of the polymer (A) is -100 to 80 ° C.
A conductive polymer dispersion containing the additive for an electrolytic capacitor according to any one of claims 1 to 7.
An electrolytic solution containing the additive for an electrolytic capacitor according to any one of claims 1 to 7.
An electrolytic capacitor comprising the additive for an electrolytic capacitor according to any one of claims 1 to 7.