JP2008244432A - Method of manufacturing conductive-polymer capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an electrolytic capacitor having a high withstand voltage. <P>SOLUTION: A capacitor having a high withstand voltage is achieved by applying voltages that satisfy the following formula (1) and the following formula (2), respectively, to a conductive-polymer capacitor containing at least conductive polymer and ionic liquid in an electrolyte, in which x(V) stands for a formation voltage of valve metal and y(V) stands for an aging voltage. The formula (1) is 1/2x≤y≤x (0<x≤48), and the formula (2) is 24≤y≤x (48<x). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a conductive polymer capacitor, and more specifically, an electrolyte composed of a conductive polymer, an ionic liquid, and an oxidizing agent is formed on a valve metal, and the withstand voltage of the obtained electrolytic capacitor is defined as a conversion voltage. Related to a method for manufacturing a novel conductive polymer capacitor capable of setting an aging voltage of 50% to 100% of the formation voltage at 48V or less, and 24V or more and formation voltage below the formation voltage when the formation voltage is greater than 48V It is.

  Conventionally, an electrolytic capacitor using a conductive polymer as an electrolyte and a cathode conductive layer is known. In such an electrolytic capacitor, Patent Document 1 discloses that a dopant that hardly damages the dielectric layer composed of the anodic oxide film or a solid organic onium salt having a valve metal repair ability is used in combination. It is known that an electrolytic capacitor having a low leakage current and a high heat resistance and humidity resistance as described can be produced.

  However, in the conductive polymer capacitor, the conductive polymer has essentially no anodizing property, and there is a limit to improving the withstand voltage characteristic. In order to make up for this, Patent Document 2 describes that re-repair formation is performed by aging treatment to improve the withstand voltage. However, although the patent describes a method for producing a solid electrolytic capacitor that is aged at ½ or less of the formation voltage, it is disclosed that the yield becomes very poor when the formation voltage is increased. Accordingly, there is no technique that discloses that 50% or more of the formation voltage of the valve metal can be taken out as a normal voltage in the conductive polymer capacitor. Furthermore, it is known that the difference between the formation voltage and the withstand voltage that increases the formation voltage is large (Non-patent Document 1), and the formation voltage and the withstand voltage are equivalent up to about 30 V (however, in actual use) The voltage is set to about 15 V in consideration of safety). With a conversion voltage higher than that, the withstand voltage is greatly reduced. Even if it is formed at 100V or 300V, the withstand voltage is 50V and the practical voltage is 24V or less. Further, increasing the formation voltage leads to a reduction in the capacitance of the capacitor, which is not practical. For these reasons, it is generally very difficult to produce a high voltage capacitor having an actual operating voltage of 24 V or more with a conductive polymer capacitor.

In order to solve such problems, attempts have been made to provide an insulating layer called a buffer layer in the form of a dielectric film. However, when such a layer is provided, equivalent series resistance (ESR) and tan δ characteristics are provided. As a result, the characteristics of the high performance of the conductive polymer capacitor are lost.
JP 2003-22938 A JP-A-3-96210 Electrolytic capacitor review, Volume 53 (1), 95 (2002)

  The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to increase the equivalent series resistance (ESR) of a solid electrolyte capacitor formed of a conductive polymer that is a solid electrolyte. It is to provide a method for manufacturing an electrolytic capacitor having a high breakdown voltage (preferably 50% or more, more preferably 80% or more of the formation voltage) without incurring.

  The present invention relates to a method for forming a conductive polymer capacitor, wherein a capacitor in which an ionic liquid is blended in an electrolyte is obtained. When the conversion voltage of the obtained electrolytic capacitor is 48 V or less, the conversion voltage is 50% to 100%. Is greater than 48V, it is achieved by providing a step by aging treatment in a voltage range of 24V or more and a formation voltage or less.

  That is, the present invention is a conductive polymer capacitor having at least an electrolyte formed of a conductive polymer and an ionic liquid, and an electrode made of a valve metal, and the formation voltage of the valve metal is x (V (volts). )), And when the aging voltage is y (V), the present invention relates to a method for producing a conductive polymer capacitor in which a capacitor is aged by applying voltages satisfying the following formulas (1) and (2) respectively: Is.

1 / 2x ≦ y ≦ x (0 <x ≦ 48) (1)
24 ≦ y ≦ x (48 <x) (2)
In the present invention, when the conversion voltage of the valve metal is x (V (volt)), the aging voltage y (V) is a voltage satisfying the following expressions (3) and (4), respectively. The present invention relates to a method for producing a conductive polymer capacitor according to claim 1.

0.6x ≦ y ≦ 0.88x (0 <x ≦ 48) (3)
28.8 ≦ y ≦ 0.88x (48 <x) (4)
According to the present invention, the monomer of the conductive polymer forming the solid electrolyte used in the first step and the ionic liquid are blended at a molar ratio of 1: 0.01 or more and 1: 0.5 or less. It is preferable that the method is a method for producing a conductive polymer capacitor.

  The present invention relates to a method for producing a conductive polymer capacitor, wherein the monomer of the conductive polymer forming the solid electrolyte is pyrrole or a derivative thereof, thiophene or a derivative thereof, aniline or a derivative thereof, quinone or a derivative thereof. It is preferable that

  In the present invention, the anion component of the ionic liquid is an atomic group of a carboxylate anion derivative, a sulfonylimide anion derivative, a fluoroboron anion derivative, a nitrate anion derivative, a cyanoimide anion derivative, a sulfonate anion derivative, or a sulfate anion derivative. It is preferable that the method is a method for producing a conductive polymer capacitor that is an ionic liquid.

In the present invention, the sulfonate anion derivative or alkoxysulfonate anion derivative of the anion component is further represented by R ₁ —SO ₃ ^— or R ₁ —OSO ₃ ^— (where R ₁ is A monovalent aliphatic hydrocarbon group having 1 to 30 carbon atoms, which may be branched and substituted with a group capable of bonding between alkyl groups such as O, S, NHCO and CO. Or a method for producing a conductive polymer capacitor, which may include one or more fluorine atoms).

  In the present invention, the cation component is ammonium and derivatives thereof, imidazolinium and derivatives thereof, pyridinium and derivatives thereof, pyrrolidinium and derivatives thereof, pyrrolinium and derivatives thereof, pyrazinium and derivatives thereof, pyrimidinium and derivatives thereof, triazonium and derivatives , Triazinium and its derivatives, triazine derivative cations, quinolinium and its derivatives, isoquinolinium and its derivatives, indolinium and its derivatives, quinoxalinium and its derivatives, piperazinium and its derivatives, oxazolinium and its derivatives, thiazolinium and its derivatives, morpholinium and its Including at least one selected from the group consisting of derivatives thereof, piperazine and derivatives thereof. Method for producing a conductive polymer capacitor characterized in that it is preferable that,.

  A high withstand voltage, low ESR, large capacity conductive polymer capacitor can be obtained.

  The inventors of the present invention provide a conductive polymer capacitor including an electrode made of an electrolyte and a valve metal. When an ionic liquid is present in the electrolyte, the formation voltage is 50% to 100% of the formation voltage when the formation voltage is 48 V or less. It was discovered that when the formation voltage is higher than 48V, it is possible to set the aging voltage in the range of 24V or more and the formation voltage or less. This is a significant difference compared to the conventional conductive polymer capacitor that is difficult to age at a voltage of 50% or more of the formation voltage. Furthermore, by providing a capacitor with such an aging process, it has become possible to stably produce a high-voltage conductive polymer capacitor of 24 V or higher, which could not be produced in the past. .

  When the electrolyte is used as a conductive polymer capacitor, it is essential that the conductive polymer electrolyte contains an ionic liquid (composites). The addition of the excellent anodic oxidation properties of ionic liquids and the excellent electronic conductivity of conductive polymer electrolytes makes it possible to realize an ideal electrolyte for capacitors that simultaneously satisfies low impedance, high breakdown voltage, and high capacity. It is. In other words, by utilizing the high conductivity of the conductive polymer, it is possible to significantly reduce the resistance between the electrodes in the conductive portion, and as a result, an electrolytic capacitor having excellent impedance characteristics can be easily obtained, and at the same time, By interposing an ionic liquid having the ability to repair the dielectric oxide film of the working metal, an electrolytic capacitor having a high withstand voltage and a low leakage current can be obtained. Further, it is presumed that the ionic liquid realizes a high capacity by playing a role of a binder between the electrode and the conductive polymer and between the conductive polymer and the conductive polymer.

  However, the excellent anodic oxidation properties of ionic liquids can only be exhibited when voltage is applied, resulting from the stress applied to the dielectric oxide film during the manufacturing process of electrolytic capacitors and the chemical action during polymerization. It does not repair the damage naturally. Therefore, in order to exhibit the anodic oxidation performance of the ionic liquid, a voltage application process such as aging is required. Although the details of the mechanism are still unclear, the fact that aging conditions higher than usual can be taken is characterized by finding and utilizing the effect of adding an ionic liquid. By such a process, the anion portion of the ionic liquid is repaired by covering the missing portion of the oxide film and forming an insulating film.

  The conductive polymer monomer is not particularly limited, but has high conductivity at the time of polymer formation and is stable in the air. Therefore, thiophene or a derivative thereof, pyrrole or a derivative thereof, aniline or a derivative thereof, It is preferably selected from quinone or a derivative thereof, quinoline or a derivative thereof, furan or a derivative thereof. For example, examples of thiophene derivatives include 3,4-ethylenedioxythiophene, 3-alkylthiophene (alkyl groups include butyl, hexyl, octyl, and dodecyl groups), fluorophenylthiophene, and allylthiophene. However, it is not limited to these. 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. In particular, a conductive polymer composed of poly- (2,3-dihydrothieno- [3,4-b] -1,4-dioxin) (also referred to as poly-3,4-ethylenedioxythiophene) or polypyrrole is electrically conductive. From the viewpoint of heat resistance and heat resistance.

  The ionic liquid (abbreviated as “ILs” as needed) contained in the electrolyte of the present invention is also referred to as a room temperature molten salt, and refers to a liquid that is liquid at room temperature despite being composed only of ions. It is composed of a combination of a cation such as 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. Among these, imidazolinium or a derivative thereof, ammonium or a derivative thereof, pyridinium or a derivative thereof can be preferably used for this purpose.

  In the ionic liquid used in the present invention, the anionic component determines the magnitude of the repairing ability, and any ionic liquid basically has the repairing ability. Therefore, there is no restriction from the viewpoint that the ionic liquid can be used. However, the anion component of the ionic liquid has an atomic group of a carboxylate anion derivative, a sulfonylimide anion derivative, a fluoroboron anion derivative, a nitrate anion derivative, a cyanoimide anion derivative, a sulfonate anion derivative, or an alkoxysulfonate anion derivative. The conductive polymer capacitor, which is an ionic liquid containing, is preferable from the viewpoint of having an excellent repairing ability.

Further, the anion component is a sulfonate anion derivative (denoted as R ₁ —SO ₃ ^— ) or an alkoxy sulfonate anion derivative (denoted as R ₂ —OSO ₃ ^— ) (here, R ₁ and R _2). , Is a monovalent aliphatic hydrocarbon group having 1 to 30 carbon atoms, which may have a branch, and is substituted with a group capable of bonding between alkyl groups such as O, S, NHCO and CO. Further, it may contain one or more fluorine atoms). The reason is that these sulfonic acid anion derivatives or alkoxysulfonic acid anion derivatives have particularly excellent repair-forming ability.

However, it is desirable that R ₁ and R ₂ are linear aliphatic hydrocarbons having 1 to 7 carbon atoms. Specific examples include CH ₃ OSO ₃ ⁻ , CH ₃ CH ₂ OSO ₃ ⁻ , CH ₃ CH ₂ CH ₂ OSO ₃ ⁻ ,
CH ₃ (CH ₂ ) ₂ CH ₂ OSO ₃ ⁻ , CH ₃ (CH ₂ ) ₃ CH ₂ OSO ₃ ⁻ ,
_{CH 3 (CH 2) 4 CH} 2 OSO 3 -, CH 3 (CH 2) 5 CH 2 OSO 3 -,
CH ₃ (CH ₂ ) ₃ CH ₂ SO ₃ ⁻ , CH ₃ (CH ₂ ) ₄ CH ₂ SO ₃ ⁻ ,
_{CH 3 (CH 2) 5 CH} 2 SO 3 -,
Etc. can be illustrated.

  The molar ratio of the conductive polymer monomer (A) and the ionic liquid (B) in the present invention is preferably (A) :( from the viewpoint of withstand voltage and low impedance in the conductive polymer capacitor produced after chemical polymerization. B) = 1: 0.01 to 0.5, more preferably (A) :( B) = 1: 0.02 to 0.3. When (B) is 0.01 or less, the effect of improving the withstand voltage is reduced, and the effect of adding the ionic liquid does not appear. On the other hand, if the ionic liquid is 0.5 or more, the tendency that the ESR characteristic, Tan δ characteristic, frequency characteristic and the like of the capacitor are deteriorated becomes remarkable. That is, the ratio of (B) / (A) is preferably 0.01 or more, more preferably 0.02 or more from the viewpoint of withstand voltage, and preferably 0.5 or less, from the viewpoint of low impedance. More preferably, it is 0.2 or less.

  The method for producing a conductive polymer capacitor including the electrolyte and electrode of the present invention is not particularly limited. For example, a valve action in which a dielectric oxide film is formed on the surface of a wound-type conductive polymer aluminum electrolytic capacitor. It may be a capacitor element constituted by winding an anode foil made of metal and a cathode foil with a separator interposed therebetween, and is made of a conductive polymer and an ionic liquid between the anode foil and the cathode foil. After an electrolyte is provided and the element is housed in, for example, a bottomed cylindrical aluminum case, an aluminum electrolytic capacitor can be configured by sealing the opening of the aluminum case with a sealing agent.

  In the present invention, the electrolyte may be obtained by adding an oxidizing agent to a solution containing the conductive polymer monomer and the ionic liquid (chemical polymerization method) or may be obtained by an electrolytic polymerization method (electrolytic weight). legal). The chemical polymerization method is a method of polymerizing and synthesizing raw material monomers such as pyrrole by oxidative dehydration in the presence of an appropriate oxidizing agent, and is preferable as the method for carrying out the present invention.

  As the oxidizing agent, persulfates, hydrogen peroxide, diazonium salts, halogens and halides, or transition metal salts such as iron, copper, and manganese can be used. Since the conductive polymer synthesized by chemical polymerization is also incorporated into the polymer in the polymerization process as an anion of the oxidizing agent as a dopant, a conductive polymer can be obtained by a one-step reaction. When chemical polymerization is performed in an ionic liquid, the anionic component of the ionic liquid may be incorporated into the conductive polymer as a dopant, which is particularly preferable for the purpose of the present invention. In other words, it is preferable that the ionic liquid is already added in the chemical polymerization process rather than being added after the chemical polymerization.

  In the case of the polymerization, it is preferable to add an oxidizing agent to the solution containing the conductive polymer monomer (A) and the ionic liquid (B). In this case, the viscosity and concentration may be adjusted by adding a solvent. The polymerization solvent used in the polymerization may be a known solvent such as water, alcohol, ether, nitrile, ketone, amide, carbonate, ester, lactone, sulfur-containing solvent, halogenated carbonization. Examples thereof include hydrogen and hydrocarbon solvents, and two or more of these solvents may be used.

  The polymerization conditions may be known polymerization conditions, and the polymerization is preferably performed in the temperature range of −100 ° C. to 200 ° C. for 1 minute to 120 hours. The polymerization is particularly preferably carried out in the temperature range of 0 ° C. to 150 ° C. for 1 minute to 60 minutes. The polymerization may be repeated a plurality of times.

  The aging process does not exclude any method based on the knowledge of those skilled in the art or an improved method thereof. For example, a constant voltage is applied to the manufactured capacitor electrode under heating and / or humidification. Can be implemented. Aging may be carried out with an element that is not provided with an exterior, and it is also possible to age a capacitor element that is provided with an exterior. When the formation voltage is 48 V or less, it is preferable to apply a voltage of 50% to 100% of the formation voltage, and particularly preferably 60% to 88% of the formation voltage. Aging is preferably performed by increasing the voltage from a voltage of 0 V at a constant speed, and setting the maximum voltage within the range of 50% to 100% of the formation voltage as described above. Further, when the formation voltage is 48V or higher, it is preferably 24V or higher, and particularly preferably 28.8V or higher.

  In the case of a capacitor whose formation voltage is 48V or less, use it at a higher voltage than the conventional capacitor obtained by aging 50% or less of the formation voltage by aging in the voltage range of 50% or more of the formation voltage. Can do. In order to realize the target high-capacitance capacitor that is our target, it is preferable to perform aging in a voltage range of 60% or more of the formation voltage. If the capacitors are used at the same voltage, the conversion voltage of the capacitor anode foil can be set low if the capacitor can be aged in a voltage range of 50% or more, preferably 60% or more of the formation voltage in advance. The fact that the formation voltage can be set low means that the thickness of the oxide film is thin and the distance between the anode foil and the electrolyte is small, that is, a high-capacitance capacitor can be obtained. In order to realize low impedance characteristics in addition to high capacity characteristics, the aging voltage is preferably 88% or less. When the aging voltage is 88% or less, it is considered that good impedance characteristics can be obtained because a dense oxide film with good adhesion to the electrode is formed. On the other hand, in the case of a capacitor having a formation voltage of 48V or more, a high-capacity capacitor can be obtained by performing aging in a voltage range of 24V or more. In order to realize the target high-capacitance capacitor that is our target, it is preferable to perform aging at a conversion voltage of 28.8 V or more. Furthermore, in order to realize a low impedance characteristic in addition to a high capacity characteristic, the aging voltage is preferably 88% or less.

  It is desirable that the maximum value of the aging voltage does not exceed the formation voltage. When the voltage is increased from 0V, the current value starts to gradually increase from around 90% of the formation voltage, and when it exceeds 100%, the current value increases and aging cannot be performed. In the voltage range between 90% and 100%, it is possible to reduce the current value to a specified range by increasing the aging time, which is basically an aging possible range. However, it takes a long time to reduce the current value within the specified value, and it is more preferable that the current value be 90% or less.

  The following conditions can be illustrated as an example of aging. That is, when the voltage is increased at a speed of 20 mV / sec, aging is performed by defining the voltage at which a current of 10 mA flows as a breakdown voltage, and when the current value exceeds 0.1 mA, the voltage increase stops at that voltage. The current value is held until it becomes less than a specified value (for example, 10 μA or less). Finally, the voltage is raised to a predetermined voltage and held for a certain time to complete aging. With such a method for producing a conductive polymer electrolytic capacitor, aging of 50% or more of the formation voltage can be performed, and a high voltage capacitor can be produced. That is, the gist of the present invention is to manufacture an electrode of a capacitor by using a conductive polymer and an ionic liquid as constituent requirements of an electrolyte and by requiring specific aging.

    It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

<Ionic body: ILs>
First, a method for synthesizing and obtaining an ionic substance used as an example will be described.
_{(ILs-1) (1-} C 4 H 9 -3-CH 3 -Im) + (CH 3 OSO 3) -
Purchased from MERCK (1-Butyl-3methyl-imidazoli
um methylsulfate)
^{_{(ILs-2) (1-}} C 2 H 5 -3-CH 3 -Im) + (H (CH 2) 6 (CH 3 OSO 3)) -
Purchased from Solvent Innovation (1-Ethyl-3methyl-imidazolium n-hexylsulfate)
_{(ILs-3) (1-} C 2 H 5 -3-CH 3 -Im) + CH 3 (CH 2) 3 OSO 3) -
Purchased from Solvent Innovation (1-Ethyl-3methyl
-Imidazolium n-butylsulfate)
_{(ILs-4) (1-} C 2 H 5 -3-CH 3 -Im) + (p-TsO) -
Purchased from STREM CHEMICAL (1-Ethyl-3methyl-imidazolium tosylate)
(Electrode foil)
A wound electrode was prepared using an aluminum etched foil U157 anodized at a predetermined voltage purchased from KDK Sales Co., Ltd. as the anode foil and an aluminum etched foil C208 as the cathode foil. The anode foil has a length of 90 mm and a width of 2.2 mm. There are four types of anodic oxidation voltages (Vfs): 13V, 24V, 55V, and 70V. The produced wound electrode is immersed in a 1% aqueous solution of ammonium adipate using the measurement cell shown in FIG. 1, and is first raised from 0 to the respective formation voltage (Vfs) at a rate of 20 mV / sec, and then Vfs A constant voltage was applied for 40 minutes to perform repair conversion.

(Measurement of liquid volume)
The capacity of the wound electrode foil in the liquid after the repair conversion was calculated from the slope of the graph obtained in a 50 μA constant current charge / discharge test between 0 and 4 V using a charge / discharge measuring device manufactured by Toyo Technica. The measurement was performed at room temperature. The average liquid volume of the wound electrode formed with 13V is 186 μF, the average liquid volume of the wound electrode formed with 24V is 108 μF, the average liquid capacity of the wound electrode formed with 55V is 57 μF, and the wound volume formed with 70V is formed. The average capacity of the mold electrode in the liquid was 40 μF.

(Measurement of initial capacity)
An electrolyte was formed by chemical polymerization using the obtained foil as a sample. The method of forming the electrolyte is as described in each example described later. The initial capacity was measured after electrolyte formation. As a device, a charge / discharge measurement device manufactured by Toyo Technica was used, a constant current charge / discharge test of 50 μA was performed in the range of 0 to 4 V, and the capacity was calculated from the slope of the obtained graph. The measurement was performed at room temperature. Measured by the above method (foil volume in liquid / initial volume) × 100 was defined as “capacity development rate”.

(Aging method)
In an environment of 100 ° C., the voltage was increased from 0 V to each aging voltage (Veg) at a rate of 20 mV / sec, and then aging was performed by applying a constant voltage of Veg for 40 minutes. The defined current of the wound electrode element is defined as 10 mA, and an element that exceeds this current value in the process of increasing voltage or maintaining voltage is regarded as aging failure.

(Impedance measurement)
After aging, impedance was measured in a room temperature atmosphere. For the apparatus, an impedance analyzer manufactured by Toyo Technica was used, and measurement was performed in the range of 1 Hz to 1 MHz under the conditions of DC Potential = 0V and AC Amplitude: 100V. The impedance value of 20 kHz was defined as the electrode impedance.

(Withstand voltage measurement)
After aging, the withstand voltage (V) was measured. The device was measured using a model number “TR6143” manufactured by Advantest, Inc., and the voltage was raised to the aging voltage at a speed of 1.0 V / second at room temperature. An element that reached this current value was determined as a defective breakdown voltage, and the breakdown voltage of 20 capacitors was measured according to this definition, and it was confirmed by this experiment how many of the 20 capacitor elements were destroyed in the above voltage range. The number of defects includes the aging defect.

(Examples 1-5)
A conductive polymer aluminum electrolytic capacitor was produced by impregnating a polymerization solution composed of 3,4-ethylenedioxythiophene and an oxidizing agent solution using a wound electrode foil having a formation voltage of 24 V and then drying. A specific method for forming the electrolyte is as follows.

  As a monomer for the conductive polymer, 0.1 g of 3,4-ethylenedioxythiophene (hereinafter abbreviated as EDOT; manufactured by HC Starck-V TECH) was used. 20 g, 0.30 g of 1-butanol and 0.032 g of ionic liquid (ILs-1) were used as a solvent. These formulations are monomer: oxidizer: ionic liquid = 1: 0.5: 0.1.

  This chemical polymerization composition was mixed in a well-dried beaker, and then the aluminum-etched foil was immersed in the polymerization solution in the polymerization solution so that the polymerization solution penetrated into the wound electrode, and was pulled up to 120 ° C. For 1 hour. The same treatment was repeated four times to form an electrolyte so that the surface of the foil was uniformly covered with the electrolyte.

  Furthermore, the initial capacity of the capacitor obtained by performing an aging treatment for 1 hour at a predetermined voltage was measured and converted into a capacity expression rate. Moreover, impedance and withstand voltage (V) were measured. The results are shown in Table 1. In Table 1, the capacity development rate and the impedance value are average values of 20 electrodes, and the withstand voltage is the ratio of destructive elements below the aging voltage as described above.

（比較例１〜４）
比較例１〜３では、実施例１と同じ方法でイオン液体を含まない電解質（すなわちＥＤＯＴと酸化剤、およびブタノール溶媒からなる電解質）を形成し測定を行なった。

(Comparative Examples 1-4)
In Comparative Examples 1 to 3, an electrolyte containing no ionic liquid (that is, an electrolyte composed of EDOT, an oxidizing agent, and a butanol solvent) was formed by the same method as in Example 1, and measurement was performed.

  From the results of Examples 1 to 5, it can be seen that the electrolyte containing the ionic liquid can perform aging of 21 V with respect to the conversion voltage of 24 V, and has a sufficient withstand voltage up to the aging voltage. On the other hand, in the case of an electrolyte containing an ionic substance, one withstand voltage failure occurred at 12V aging, three at 18V aging, and five at 21V aging.

  In Comparative Example 4, an electrolyte containing an ionic liquid was formed by the same method as in Example 1 except for the aging voltage, and measurement was performed. Compared with Examples 1-5, the result with a bad impedance characteristic was obtained in the comparative example 4 with a low formation voltage. From the above results, the superiority of the method of the present invention for aging with an aging voltage of 50% or more of the formation voltage in an electrolyte containing an ionic liquid was confirmed.

(Examples 6 to 8)
The experiment was performed in the same manner as in Example 1 except that the type of the ionic liquid was changed. The results are shown in Table 2. The same effect as ILs-1 was recognized in any of ILs-2, ILs-3, and ILs-4.

（実施例９〜２１）
化成電圧およびエージング電圧を変えた以外は実施例１と同様にして実験を行った。その結果を表３に示す。本発明の方法によれば、化成電圧５５Ｖにおいても７０Ｖにおいても、２４Ｖ以上の電圧でのエージングが可能であるばかりでなく、５５Ｖにおいては５０Ｖのエージングが、７０Ｖにおいては５６Ｖのエージングが可能であり、少なくともエージング電圧以下での耐圧不良はゼロであった。この事から本発明の方法で従来不可能であった高耐圧の導電性高分子コンデンサが出来る事が分かった。

(Examples 9 to 21)
The experiment was performed in the same manner as in Example 1 except that the formation voltage and the aging voltage were changed. The results are shown in Table 3. According to the method of the present invention, it is possible not only to aging at a voltage of 24V or higher at both the formation voltage 55V and 70V, but also 50V aging at 55V and 56V aging at 70V. The breakdown voltage failure at least below the aging voltage was zero. From this fact, it was found that a high withstand voltage conductive polymer capacitor could be obtained by the method of the present invention.

(Comparative Examples 5 to 16)
In Comparative Examples 6 to 8 and 10 to 16, experiments were performed in the same manner as in Examples 9 to 21 using an electrolyte containing no ionic liquid. When the formation voltage was 13V and the aging was 6V, the breakdown voltage failure was zero, but under other conditions, breakdown voltage failure occurred. This tendency becomes more prominent as the formation voltage is higher and the aging voltage is higher. Under the conditions where the formation voltage is 55V and the aging voltage is 48V, and the formation voltage is 70V and the aging voltage is 56V, most of the breakdown voltages are poor.

  In Comparative Examples 5 and 9, experiments were performed in the same manner as in Examples 9 and 14 except for the aging voltage, using an electrolyte containing an ionic liquid. As a result, in the comparative example with a low aging voltage, a result with poor impedance characteristics was obtained.

  From the comparison between Examples 9 to 21 and Comparative Examples 5 to 16, the superiority of the present invention became clear.

また化成電圧が１３Ｖの箔、２４Ｖ箔、５５Ｖ箔のエージング電圧のインピーダンス依存性を示すグラフをそれぞれ図２、図３、図４に示す。

Moreover, the graph which shows the impedance dependence of the aging voltage of the foil whose conversion voltage is 13V, 24V foil, and 55V foil is shown in FIG.2, FIG.3, FIG.4, respectively.

  It was found that in all of the 13V foil, 24V foil, and 55V foil, the ESR showed a good result at an aging voltage of 60% to 88% with respect to the formation voltage.

(Examples 22 to 45)
The amount of ionic liquid (ILs-1) relative to monomer (1.0 equivalent) was changed to 0.01, 0.02, 0.05, 0.2, 0.5.1.0, and the formation voltage was changed. The experiment was performed in the same manner as in Example 1 except that the voltage was 55V. Note that the ratio of the oxidizing agent is constant at 0.25. The results obtained are shown in Table 4. Even when the addition amount of the ionic liquid was 0.01 (Examples 22 to 25), the effect of improving the pressure resistance was recognized as compared with the case without addition (Comparative Examples 10 to 13), and aging of 36 V was possible. However, 7 pieces out of 20 pieces were defective in 50V aging. Similarly, when the addition amount was 0.02, aging of 42V was possible, but with 50V aging, one of 20 was defective in breakdown voltage.

  When the addition amount of the ionic liquid was 1.0, the pressure resistance characteristics were good, but a tendency for the impedance characteristics to deteriorate was recognized. In view of this, when using ILs-1, the optimum amount of ionic liquid with respect to one equivalent of monomer is in the range of 0.01 to 1.0, more preferably in the range of 0.02 to 0.5. It turned out that it is the range of 0.05-0.2 preferably. Since such an optimal range differs depending on the type of ionic liquid, it is not uniquely determined, but generally the same tendency is recognized and the range of the optimal addition amount of ionic liquid is 0.01 to 0.5. .

以上の実施例から本発明の優位性が確認できた。すなわち、本発明は少なくとも導電性高分子とイオン液体を必須成分とする導電性高分子電解コンデンサの製造方法であって、従来実施されていなかった電圧領域でのエージングを行う事により、従来不可能であった高耐圧の導電性高分子コンデンサを提供することができる。

From the above examples, the superiority of the present invention was confirmed. That is, the present invention is a method for producing a conductive polymer electrolytic capacitor having at least a conductive polymer and an ionic liquid as essential components, and is impossible in the past by performing aging in a voltage range that has not been conventionally performed. Thus, it is possible to provide a high withstand voltage conductive polymer capacitor.

Measurement cell for measuring the capacitance of capacitor elements in liquid Impedance dependence of aging voltage of 13V chemical conversion foil Impedance dependence of aging voltage of 24V chemical conversion foil Impedance dependence of aging voltage of 55V chemical conversion foil

Claims (10)

A conductive polymer capacitor having at least an electrolyte formed of a conductive polymer and an ionic liquid, and an electrode made of a valve metal, wherein the formation voltage of the valve metal is x (V (volt)), and the aging voltage is A method for producing a conductive polymer capacitor in which a capacitor is aged by applying voltages satisfying the following formulas (1) and (2) when y (V).
1 / 2x ≦ y ≦ x (0 <x ≦ 48) (1)
24 ≦ y ≦ x (48 <x) (2) The aging voltage y (V) is a voltage satisfying the following expression (3) and the following expression (4) when the conversion voltage of the valve metal is x (V (volt)): Item 2. A method for producing a conductive polymer capacitor according to Item 1.
0.6x ≦ y ≦ 0.88x (0 <x ≦ 48) (3)
28.8 ≦ y ≦ 0.88x (48 <x) (4)   The conductive polymer and ionic liquid forming the solid electrolyte were blended at a molar ratio of 1: 0.01 to 1: 0.5 when the monomer unit of the conductive polymer was converted to 1 mol. The method for producing a conductive polymer capacitor according to claim 1 or 2.   4. The conductive polymer capacitor according to claim 1, wherein the monomer of the conductive polymer forming the solid electrolyte is pyrrole or a derivative thereof, thiophene or a derivative thereof, aniline or a derivative thereof, quinone or a derivative thereof. Production method.   An ion in which the anionic component of the ionic liquid includes an atomic group of a carboxylate anion derivative, a sulfonylimide anion derivative, a fluoroboron anion derivative, a nitrate anion derivative, a cyanoimide anion derivative, a sulfonate anion derivative, or an alkoxysulfonate anion derivative It is a liquid, The manufacturing method of the conductive polymer capacitor in any one of Claims 1-4. The manufacturing method of the conductive polymer capacitor of Claim 5 whose sulfonate anion derivative is following General formula (1).
R ₁ -SO ₃ ^- Formula (1)
(R ₁ is an aliphatic hydrocarbon group having 1 to 30 carbon atoms, may be substituted with an O, S, NHCO, or CO group, and may contain one or more fluorine atoms.) The method for producing a conductive polymer capacitor according to claim 6, wherein R ₁ is a linear saturated hydrocarbon group having 1 to 7 carbon atoms. The method for producing a conductive polymer capacitor according to claim 5, wherein the alkoxysulfonic acid anion derivative is represented by the following general formula (2).
R ₂ -OSO ₃ ^- Formula (2)
(R ₂ is an aliphatic hydrocarbon group having 1 to 30 carbon atoms, which may be substituted with an O, S, NHCO, or CO group, and may contain one or more fluorine atoms.) The method for producing a conductive polymer capacitor according to claim 8, wherein R ₂ is a linear saturated hydrocarbon group having 1 to 7 carbon atoms.   The cation component of the ionic liquid is ammonium and derivatives thereof, imidazolinium and derivatives thereof, pyridinium and derivatives thereof, pyrrolidinium and derivatives thereof, pyrrolinium and derivatives thereof, pyrazinium and derivatives thereof, pyrimidinium and derivatives thereof, triazonium and derivatives, triazinium and derivatives thereof Derivatives thereof, triazine derivative cations, 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, It contains at least one selected from the group consisting of piperazine and its derivatives. Wherein the method for producing a conductive polymer capacitor according to any one of claims 1 to 9.

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