Solid electrolytic capacitor and method for manufacturing the same

Abstract

The capacitor element includes: a water-soluble first polymer provided on the surfaces of the anode body and the cathode body; and a water-dispersible second polymer provided on the surfaces of the anode body and the cathode body, both of which are provided with the first polymer. The second polymer electrically connects the anode body and the cathode body. Between the surface of the anode body and the surface of the cathode body and between the inner surface of the housing and the outer surface of the capacitor element, there is provided a solid substance at normal temperature in which an electrolyte is dissolved in a solvent, the solvent being solid at a first temperature or below the first temperature and melting when heated to a second temperature higher than the first temperature or higher than the second temperature.

Description

Technical Field

[0001] The present invention relates to a solid electrolytic capacitor and a method for manufacturing the solid electrolytic capacitor. Background Art

[0002] For example, a known capacitor has: a case having an opening for inserting a capacitor element; the capacitor element accommodated in the case; and a sealing member assembled to the opening. The capacitor element has a structure in which an anode and a cathode having an elongate shape are wound, the anode and the cathode being arranged to face each other with a separator therebetween.

[0003] In the opposing surfaces of the anode and the cathode, at least the opposing surface of the anode is an oxide film. Further, a water-dispersible conductive polymer is provided between the anode and the cathode. Further, generally, an electrolytic solution is provided between the anode and the cathode (see Patent Document 1).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2008-010657 Summary of the Invention

[0007] Technical Problem

[0008] Known capacitors have the following drawbacks: in their usage environment, the capacitor elements are exposed to heat, vibration, etc., and as they are used for a long time, the electrolytic solution evaporates through the sealing member, resulting in deterioration of the capacitor characteristics.

[0009] An object of the present invention is to provide a solid electrolytic capacitor that maintains stable capacitor characteristics for a long time, and to provide a method for manufacturing such a solid electrolytic capacitor.

[0010] Solution to the Problem

[0011] To achieve the above object, according to one aspect of the present invention, a solid electrolytic capacitor includes: a case having a shape of a bottomed tube with an opening; a capacitor element having a wound anode member and a cathode member with a separator therebetween, the capacitor element being housed in the case; and a sealing member for sealing the opening. The capacitor element has: a water-soluble first polymer disposed between the surface of the anode member and the surface of the cathode member; and a water-dispersible second polymer disposed on the surface of the anode member where the first polymer is provided and on the surface of the cathode member where the first polymer is provided. The second polymer electrically connects the surface of the anode member and the surface of the cathode member together. Between the surface of the anode member and the surface of the cathode member in the capacitor element and between the inner surface of the case and the outer surface of the capacitor element, a room-temperature solid substance is provided, which has an electrolyte dissolved in a solvent that is solid at a first temperature or below and melts when heated to a second temperature higher than the first temperature or above the second temperature.

[0012] According to another aspect of the present invention, in the solid electrolytic capacitor having the above-described structure, the first polymer may be disposed on the surface of the anode member, on the surface of the cathode member, and on the surface of the separator.

[0013] According to another aspect of the present invention, in the solid electrolytic capacitor having the above-described structure, the first temperature may be 30°C.

[0014] According to another aspect of the present invention, in the solid electrolytic capacitor having the above-described structure, the solvent may include at least one of polyethylene glycol, polyol, fatty acid ester of glycerol, and saccharide.

[0015] According to another aspect of the present invention, in the solid electrolytic capacitor having the above-described structure, the second temperature of the solvent may be 50°C.

[0016] According to another aspect of the present invention, in the solid electrolytic capacitor having the above-described structure, the solvent may include at least one of PEG2000, PEG4000, PEG6000, PEG10000, PEG20000, 1,2-dodecanediol, 1,12-dodecanediol, polyglyceryl-6 stearate, polyglyceryl-6 tristearate, polyglyceryl-4 pentastearate, polyglyceryl-10 decastearate, polyglyceryl-10 hepta(behenate / stearate), xylitol, and sorbitol.

[0017] According to another aspect of the present invention, in the solid electrolytic capacitor constructed as described above, the electrolyte may contain an acid selected from the following: malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, decane dicarboxylic acid, tartronic acid, fumaric acid, maleic acid, citraconic acid, malic acid, tartaric acid, phthalic acid, nitro phthalic acid, citric acid, triphenylcarbamic acid, pyromellitic acid, boric acid, phosphoric acid, diborosalicylic acid, diboro glycolic acid, trinitrophenol, hydroxynitrophenol, hydroxynitrobenzoic acid, and sulfosalicylic acid, or the electrolyte may contain a base selected from the following: ammonia, monoethylamine, diethylamine, triethylamine, trimethylamine, N,N-dimethylethylamine, N,N-diethylmethylamine, monoethanolamine, diethanolamine, triethanolamine, benzylamine, naphthylamine, morpholine, aniline, acetanilide, phenanthroline, caffeine, and imidazole.

[0018] According to another aspect of the present invention, in the solid electrolytic capacitor constructed as described above, the sealing member may be made of rubber or resin.

[0019] To achieve the above object, according to another aspect of the present invention, a method of manufacturing a solid electrolytic capacitor includes a capacitor element manufacturing step and an insertion step. The capacitor element manufacturing step manufactures a capacitor element by performing the following steps: a step of immersing a capacitor structure in a solution containing a water-soluble first polymer and a water-dispersible second polymer, the capacitor structure being formed by winding an anode member and a cathode member having a separator therebetween; and a step of removing the capacitor structure from the solution and drying the capacitor structure. The insertion step inserts the capacitor element into a housing that contains a room temperature solid material melted by heating to a second temperature or higher, such that a part of the melted room temperature solid material penetrates into the interior of the capacitor element.

[0020] Advantages of the Invention

[0021] According to the present invention, a solid electrolytic capacitor capable of maintaining stable capacitor characteristics for a long time can be provided, and a method of manufacturing such a solid electrolytic capacitor can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a side sectional view of a solid electrolytic capacitor according to an embodiment.

[0023] Figure 2 shows Figure 1 a perspective view of a partially unfolded capacitor element in the solid electrolytic capacitor shown.

[0024] Figure 3 is a schematic view of a solution used in the immersion step.

[0025] Figure 4 ​​​​is a schematic diagram showing the impregnation step.

[0026] Figure 5 is a schematic diagram showing the drying step.

[0027] Figure 6 is a diagram showing the melting step in which a room-temperature solid substance is heated to melt it.

[0028] Figure 7 is a diagram showing the solidification step in which a room-temperature solid substance is cooled to solidify it (solidified, cured, solidified).

[0029] Figure 8 is a diagram showing the pulverization step of pulverizing the solidified room-temperature solid substance.

[0030] Figure 9 is a perspective view of a heating jig (heating jig, heating fixture).

[0031] Figure 10 is a cross-sectional view of a housing containing powder of a room-temperature solid substance.

[0032] Figure 11 is a cross-sectional view of a housing containing a room-temperature solid substance in a liquid phase.

[0033] Figure 12 is a cross-sectional view showing how a capacitor element is housed in a housing containing a room-temperature solid substance in a liquid phase.

[0034] Figure 13 is a cross-sectional view of a housing 1 containing a solidified room-temperature solid substance and a capacitor element.

[0035] Figure 14 is a cross-sectional view showing the step of assembling a sealing member to the housing.

[0036] Figure 15 is a cross-sectional view of a housing equipped with a sealing member and having a recess formed therein.

[0037] Figure 16 is a diagram showing aging (aging, aging, aging).

[0038] Figure 17 is a diagram showing a solid electrolytic capacitor according to another embodiment of the present invention.

[0039] Figure 18 is a diagram showing the test results for checking the ability of the oxide film in the solid electrolytic capacitor of Repair Example 1. Detailed Description ​​​​​​​​​​​​​​

[0040] A solid electrolytic capacitor according to an embodiment of the present invention will be described below with reference to the accompanying drawings. Figure 1 FIG. 1 is a side sectional view of a solid electrolytic capacitor A according to an embodiment of the present invention. Figure 2 is Figure 1 FIG. 2 is a perspective view of a partially expanded capacitor element 3 in the solid electrolytic capacitor A shown in FIG. 1.

[0041] The solid electrolytic capacitor A includes a case 1, a capacitor element 3, and a sealing member 4. The case 1 is made of a metal (such as aluminum) and has a shape of a bottomed tube with a circular cross-section. The case 1 has a bottom 1a and a tubular portion 1b. The bottom 1a has a shape of a disc. The tubular portion 1b is connected to the radially outer edge of the bottom 1a and extends in the axial direction. Note that the side of the bottom 1a connected to the tubular portion 1b will be referred to as the top (upper) side. The tubular portion 1b has an opening 1c at its top end. That is, one end of the tubular portion 1b of the case 1 is closed by the bottom 1a, and the other end of the tubular portion 1b is kept open by the opening 1c.

[0042] The capacitor element 3 is housed in the case 1 and includes an anode member 8 serving as an anode and a cathode member 9 serving as a cathode (see Figure 2 FIG. 2). The anode member 8 and the cathode member 9 are respectively connected with an anode lead terminal 10 and a cathode lead terminal 11. The capacitor element 3 has a cylindrical shape, and the anode lead terminal 10 and the cathode lead terminal 11 are led out from one end of the capacitor element in the axial direction.

[0043] The sealing member 4 is formed into a disc shape by a molded article of an electrically insulating elastic material (such as rubber). The sealing member 4 has a pair of through holes 4a and 4b. When the sealing member 4 is placed in the opening 1c of the case 1, the circumferential surface of the case 1 is swaged to form a recessed portion 5. In this way, the sealing member 4 is fastened. In addition, the open end of the case 1 is folded inward to form a contact portion 6.

[0044] The sealing member 4 is fastened in the opening 1c of the case 1 by the recessed portion 5 and the contact portion 6. That is, the opening 1c of the case 1 is sealed by the sealing member 4. The sealing member 4 has through holes 4a and 4b formed to penetrate the sealing member in its thickness direction. When the capacitor element 3 is housed in the case 1, the anode lead terminal 10 and the cathode lead terminal 11 of the capacitor element 3 are inserted through the through holes 4a and 4b. In this way, the capacitor element 3 is fastened in the case 1.

[0045] As Figure 1As shown, in the solid electrolytic capacitor A, a room-temperature solid substance 2 is provided between the anode member 8 and the cathode member 9. More specifically, the room-temperature solid substance 2 is provided between the surface of the anode member 8 and the surface of the cathode member 9, on the surface of the separator 7, and between the inner surface of the case 1 and the outer surface of the capacitor element 3.

[0046] Next, the capacitor element 3 will be described in detail. As Figure 2 shown, the capacitor element 3 is formed by winding an anode member 8 and a cathode member 9 that are both elongated in shape, with a separator 7 as an insulator between the anode member and the cathode member. In the capacitor element 3, the separator 7 is provided at the outermost periphery, and the separator 7 is fastened with a tape 12. Note that in the capacitor element 3 according to the present embodiment, the anode member 8 serves as the anode and the cathode member 9 serves as the cathode.

[0047] For example, the anode member 8 and the cathode member 9 are made of aluminum. An oxide film (not shown) is provided on the surface of each of the anode member 8 and the cathode member 9. The oxide film on the anode member 8 and the oxide film on the cathode member 9 are both produced by a process (chemical conversion treatment) in which an electrode member made of aluminum is anodized in an electrolytic solution, and the film thickness is proportional to the applied voltage. The oxide film on the anode member 8 is made thicker than the oxide film on the cathode member 9. The oxide film needs to be formed at least on the surface of the anode member 8; that is, the oxide film may not be formed on the surface of the cathode member 9.

[0048] As described above, the anode lead terminal 10 is electrically and mechanically connected to the anode member 8; the cathode lead terminal 11 is electrically and mechanically connected to the cathode member 9.

[0049] The room-temperature solid substance 2 is a substance that is solid at room temperature. Here, it is assumed that the room temperature is, for example, 30°C. More specifically, the room-temperature solid substance 2 includes: a solvent 21 that is solid at a first temperature (for example, room temperature, here 30°C) or below the first temperature, and melts when heated to a predetermined temperature (melting point) above a second temperature higher than the first temperature; and an electrolyte 22 dissolved in the solvent 21 (see Figure 6 ). The room-temperature solid substance 2 will be described in detail later.

[0050] The solid electrolytic capacitor A is constructed as described above. Next, a method for manufacturing the solid electrolytic capacitor A will be described with reference to the relevant drawings. Figure 3 is a schematic diagram showing the solution 14 used in the impregnation step. Figure 4 is a schematic diagram showing the impregnation step. Figure 5 is a schematic diagram showing the drying step.

[0051] As Figure 2As shown, the separator 7, the cathode member 9 having the cathode lead terminal 11 connected thereto, the separator 7, and the anode member 8 having the anode lead terminal 10 connected thereto are arranged to be stacked on top of each other in this order from the outside, and are wound together with the anode member 8 inside. Then, the winding end tape 12 is applied to the outer periphery of the separator 7. In this way, the capacitor structure 31 is constructed.

[0052] The capacitor structure 31 constructed as described above is impregnated in a solution 14 containing a water-soluble first polymer 141 and a water-dispersible second polymer 142 (impregnation step; see Figure 4 ). The impregnation step is carried out under reduced pressure. This allows the solution 14 to penetrate into the interior of the capacitor structure 31.

[0053] Now, the solution 14 will be described in detail. As Figure 3 shown, the solution 14 is prepared by putting the water-soluble first polymer 141 and the water-dispersible second polymer 142 into a container 13 and stirring the mixture. Preferably, the content of the first polymer 141 in the solution 14 is 10% to 90%. This helps to increase the capacitance of the capacitor element 3. More preferably, the content of the first polymer 141 in the solution 14 is 15% to 85%. This helps to reduce the ESR.

[0054] The solution 14 is a water-soluble conductive polymer, more specifically a self-doped water-soluble conductive polymer. An example is SELFTRON manufactured by Tosoh Corporation. The second polymer 142 can be, for example, a water-dispersible polymer dispersion liquid. Examples of the second polymer 142 include Taycatron manufactured by Tayca Co., Ltd., SEPLEGYDA manufactured by ShinEtsu Polymer Co., Ltd., and Clevios manufactured by Heraeus K.K.

[0055] Then, as Figure 5 shown, the capacitor structure 31 is taken out from the container 13. Then, the capacitor structure 31 is dried in a drying step, in which the capacitor structure is left standing in an environment of 125 °C for 30 minutes. In this way, the capacitor element 3 is manufactured (the first capacitor manufacturing process). Although in Figure 5 the drying step shown, drying is carried out under blowing air, it can also be carried out without blowing air.

[0056] In the capacitor element 3 formed by impregnation in the solution 14 and then drying, the water-soluble first polymer 141 is deposited in the form of a layer on the surfaces of the anode member 8 and the cathode member 9. The first polymer 141 is also deposited on the surface of the separator 7 and on the surface of the second polymer 142.

[0057] The second polymer 142 is granular. A plurality of particles of the second polymer 142 are deposited on the surface of the anode member 8 on which the first polymer 141 is deposited and on the surface of the cathode member 9 on which the first polymer 141 is deposited. The second polymer 142 is also deposited on the separator 7 on which the first polymer 141 is deposited. Accordingly, a plurality of particles of the second polymer 142 are arranged to bridge between the surface of the anode member 8 and the surface of the separator 7 and between the surface of the cathode member 9 and the surface of the separator 7. In this way, the second polymer 142 electrically connects the anode member 8 and the cathode member 9 together.

[0058] Next, the room-temperature solid substance 2 provided in the case 1 of the solid electrolytic capacitor A will be described. The room-temperature solid substance 2 has an electrolyte dissolved in a solvent that is solid at a first temperature (e.g., 30°C) or lower than the first temperature and melts when heated to a second temperature (melting point) higher than the first temperature.

[0059] Used as the solvent included in the room-temperature solid substance 2 is at least one of polyethylene glycol, polyhydric alcohol, fatty acid ester of glycerol, and saccharides. Examples of the solvent with the first temperature of 30°C and the second temperature of 50°C include polyethylene glycol, polyhydric alcohol, fatty acid ester of glycerol, and saccharides. Examples of the solvent with the first temperature of 30°C and the second temperature of 100°C include saccharides.

[0060] Used as the polyethylene glycol with the first temperature of 30°C and the second temperature of 50°C is PEG2000 (melting point: 51°C), PEG4000 (melting point: 56°C), PEG6000 (melting point: 58°C), PEG10000 (melting point: 62°C), or PEG20000 (melting point: 63°C). Here, PEG2000 represents polyethylene glycol with an average molecular weight of 2000. Similar definitions apply to PEG4000, PEG6000, PEG10000, and PEG20000.

[0061] Examples of the polyhydric alcohol with the first temperature of 30°C and the second temperature of 50°C are at least one of 1,2-dodecanediol (melting point 56 to 60°C) and 1,12-dodecanediol (melting point 79 to 81°C).

[0062] Examples of fatty acid esters of glycerol with a first temperature of 30 °C and a second temperature of 50 °C include polyglycerol-6 stearate (melting point 60 to 70 °C), polyglycerol-6 tristearate (melting point 50 to 60 °C), polyglycerol-4 pentastearate (melting point 50 to 60 °C), polyglycerol-10 decastearate (melting point 50 to 60 °C), and polyglycerol-10 hepta(behenate / stearate) (melting point 70 to 80 °C).

[0063] Examples of saccharides with a first temperature of 30 °C and a second temperature of 50 °C include xylitol (melting point 92 °C) and sorbitol (melting point 95 °C).

[0064] Examples of saccharides with a first temperature of 30 °C and a second temperature of 100 °C include erythritol (melting point 121 °C), lactitol (melting point 146 °C), and glucose (melting point 150 °C).

[0065] The electrolyte contained in the room-temperature solid substance 2 can be an acid or a base. Examples of the acid contained as the electrolyte in the room-temperature solid substance 2 include: malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, decanedicarboxylic acid, malic acid, fumaric acid, maleic acid, citraconic acid, malic acid, tartaric acid, phthalic acid, nitro-phthalic acid, citric acid, triphenylcarbamic acid, pyromellitic acid, boric acid, phosphoric acid, diborosalicylic acid, diboroethanol acid, trinitrophenol, hydroxynitrophenol, hydroxynitrobenzoic acid, and sulfosalicylic acid.

[0066] Examples of the base contained as the electrolyte in the room-temperature solid substance 2 include: ammonia, monoethylamine, diethylamine, triethylamine, trimethylamine, N,N-dimethylethylamine, N,N-diethylmethylamine, monoethanolamine, diethanolamine, triethanolamine, benzylamine, naphthylamine, morpholine, aniline, acetanilide, phenanthroline, caffeine, and imidazole.

[0067] Now, with reference to Figures 6 to 8 the manufacturing method of the room-temperature solid substance 2 will be described. Figure 6 is a diagram showing the melting step in which the room-temperature solid substance 2 is heated to be melted. Figure 7 is a diagram showing the solidification step in which the room-temperature solid substance 2 is cooled to be solidified. Figure 8 is a diagram showing the pulverization step in which the solidified room-temperature solid substance 2 is pulverized.

[0068] As Figure 6 shown, the solvent 21 is put into the container 15, and the container 15 is heated to the melting point or higher than the melting point. As described above, the melting point varies depending on the solvent. Then the electrolyte 22 is put into the liquefied solvent 21. Thus, a solution in which the electrolyte 22 is uniformly dissolved in the solvent 21 is prepared (melting step). Although Figure 6An arrangement for heating by heating the bottom portion of the container 15 is shown, but this does not imply any limitation. In the melting step, the container 15 can be heated using a heater or a high-frequency heating device.

[0069] Then, the heating of the container 15 is stopped and it is cooled to a first temperature (e.g., here 30 °C, i.e., normal temperature) so that the solution solidifies (solidification step, see Figure 7 ). In this way, the room-temperature solid substance 2 is prepared. In the room-temperature solid substance 2, the electrolyte 22 is provided in a form dispersed in the solvent 21.

[0070] As Figure 8 shown, the room-temperature solid substance 2 solidified in the solidification step is pulverized (pulverization step). Through this pulverization step, the room-temperature solid substance 2 is made into a powder. In this way, through the melting step, the solidification step, and the pulverization step, the powder 20 of the room-temperature solid substance is produced.

[0071] Next, the process of accommodating the capacitor element 3 and the room-temperature solid substance 2 in the housing 1 will be described with reference to Figures 9 to 15 . Figure 9 is a perspective view of the heating jig 16. Figure 10 is a cross-sectional view of the housing 1 in which the powder 20 of the room-temperature solid substance is accommodated. Figure 11 is a cross-sectional view of the housing 1 in which the room-temperature solid substance 2 in a liquid phase is accommodated. Figure 12 is a cross-sectional view showing how the capacitor element 3 is accommodated in the housing 1 in which the room-temperature solid substance 2 in a liquid phase is accommodated. Figure 13 is a cross-sectional view of the housing 1 in which the solidified room-temperature solid substance 2 and the capacitor element 3 are accommodated. Figure 14 is a cross-sectional view showing the process of assembling the sealing member 4 to the housing 1. Figure 15 is a cross-sectional view of the housing 1 to which the sealing member 4 is assembled and in which the recessed portion 5 is formed.

[0072] In the manufacturing process of the solid electrolytic capacitor A, the powder 20 of the room-temperature solid substance is accommodated in the housing 1, then the housing 1 is heated to a second temperature or higher to melt the room-temperature solid substance 2, then the capacitor element 3 is inserted into the housing 1, and then they are cooled.

[0073] In this manufacturing process, the heating jig 16 is used to hold and heat the housing 1. The heating jig 16 is formed of a material having high rigidity and high thermal conductivity (such as steel and brass). Figure 9 The heating jig 16 shown is a rectangular parallelepiped member. The heating jig 16 has a plurality (here five) of holes 161 formed in its top surface.

[0074] The hole 161 is formed such that the housing 1 can be accommodated therein and has a cylindrical shape here. The heating jig 16 heats the housing 1 accommodated in the hole 161. The heating jig 16 can achieve heating by electric heating (such as using resistance heating) or high-frequency induction heating. However, this does not imply any limitation. For example, the heating jig 16 in which the housing 1 (the housing accommodates the powder 20 of the normal-temperature solid substance) is placed in a high-temperature environment, such as being placed in an oven, to heat the housing 1 and the normal-temperature solid substance 2.

[0075] As Figure 10 shown, the powder 20 of the normal-temperature solid substance is accommodated in the housing 1, and the housing is accommodated in the hole 161 of the heating jig 16. In the pulverizing step, the normal-temperature solid substance 2 is made into powder so that the normal-temperature solid substance 2 can be easily accommodated in the housing 1 at normal temperature.

[0076] Then, the housing 1 is heated by the heating jig 16 until the normal-temperature solid substance 2 is heated to the second temperature, causing the normal-temperature solid substance 2 to melt (re-melting step). Thus, as Figure 11 shown, the normal-temperature solid substance 2 in the housing 1 is liquefied.

[0077] Then, as Figure 12 shown, the capacitor element 3 is inserted into the housing 1 containing the normal-temperature solid substance 2 in a liquid phase (insertion step), with the anode lead terminal 10 and the cathode lead terminal 11 facing upward. The normal-temperature solid substance 2 in a liquid phase penetrates into the interior of the capacitor element 3 by capillary action. This results in the normal-temperature solid substance 2 in a liquid phase being disposed between the surface of the anode member 8 and the surface of the cathode member 9, on the surface of the separator 7, and between the inner surface of the housing 1 and the separator 7 at the outer periphery of the capacitor element 3 (re-solidification step).

[0078] After that, the heating of the housing 1 by the heating jig 16 is stopped, and the housing 1 is cooled. When the cooling proceeds to the temperature of the normal-temperature solid substance 2 in the housing 1 dropping to the first temperature (room temperature; here it is 30 °C) or below the first temperature, the normal-temperature solid substance 2 in a solid phase is placed in the housing 1. Thus, between the surface of the anode member 8 and the surface of the cathode member 9, on the surface of the separator 7, and between the inner surface of the housing 1 and the separator 7 at the outer periphery of the capacitor element 3, there is the normal-temperature solid substance 2, which is solid at the first temperature (room temperature, i.e., 30 °C) or below the first temperature and melts when heated to the second temperature higher than the first temperature.

[0079] After sufficient cooling, the housing 1 is taken out of the heating jig 16. Then, the sealing member 4 is assembled in the opening 1c of the housing 1 (sealing step; see Figure 14)。The sealing member 4 has through holes 4a and 4b. The anode lead terminal 10 is inserted through the through hole 4a, and the cathode lead terminal 11 is inserted through the through hole 4b. Thus, the opening 1c in the housing 1 is sealed. Here, when the anode lead terminal 10 and the cathode lead terminal 11 are inserted through the through holes 4a and 4b, they are in close contact with the sealing member 4 to maintain internal airtightness.

[0080] As Figure 15 shown, in the case where the sealing member 4 is assembled in the opening 1c of the housing 1, the circumferential surface of the housing 1 is die-forged to form a recessed portion 5. Further, the open end of the housing 1 is folded inward to form a contact portion 6( Figure 1 ), and the contact portion 6 is in contact with the sealing member 4. This prevents the sealing member 4 from moving relative to the housing 1. Through the above manufacturing process, the solid electrolytic capacitor A is produced.

[0081] In the solid electrolytic capacitor A according to this embodiment, a first polymer 141 is deposited on the surface of the anode member 8. A first polymer 141 is deposited on the surface of the cathode member 9. Between the surfaces of the anode member 8 and the cathode member 9 on which the first polymer is deposited, a second polymer 142 is provided to electrically connect the surfaces of the anode member 8 and the cathode member 9 together. Thus, in the solid electrolytic capacitor A, even without an electrolyte, the anode and the cathode are conductive to each other. This helps to keep the ESR of the solid electrolytic capacitor A low. Further, in the solid electrolytic capacitor A of this embodiment, in the case where no liquid electrolyte is sealed in the housing 1, deterioration of the capacitor characteristics due to evaporation of the liquid electrolyte is suppressed. That is, the solid electrolytic capacitor A can maintain satisfactory capacitor characteristics for a long time.

[0082] During the use of the solid electrolytic capacitor A, if the oxide film on the surface of the anode member 8 breaks or peels off, leakage current occurs in the affected portion and the temperature rises where the leakage current exists. This temperature rise liquefies the solvent 21 in the room-temperature solid substance 2. Then, the electrolyte 22 contained in the room-temperature solid substance 2 repairs the oxide film. The repaired oxide film suppresses the leakage current. Therefore, the surrounding temperature drops and the room-temperature solid substance 2 solidifies. This also helps to suppress deterioration of the capacitor characteristics of the solid electrolytic capacitor A for a long time.

[0083] Further, between the inner surface of the housing 1 and the outer surface of the capacitor element 3, a room-temperature solid substance 2 is provided. Thus, the capacitor element 3 is held on the inner surface of the housing 1 by the room-temperature solid substance 2. As a result, external forces (such as shock and vibration) acting on the solid electrolytic capacitor A are less likely to be transmitted to the capacitor element 3, and this helps to suppress deterioration of the capacitor element 3 due to external forces. In this way, deterioration of the capacitor characteristics of the solid electrolytic capacitor A can be suppressed for a long time.

[0084] The solid electrolytic capacitor A can be used in a high-temperature environment. In this case, the temperature inside the housing 1 of the solid electrolytic capacitor A can rise to the second temperature (the melting point of the solvent 21) or higher than the second temperature. If this occurs, the room-temperature solid substance 2 melts and liquefies. The liquefied room-temperature solid substance 2 has a higher viscosity than known liquid electrolytes. Therefore, even if the room-temperature solid substance 2 inside the housing 1 liquefies due to the temperature rise, it prevents external forces (such as vibration and shock) from being transmitted to the capacitor element 3. That is, external forces (such as shock and vibration) acting on the solid electrolytic capacitor A are less likely to be transmitted to the capacitor element 3, and this helps to suppress the deterioration of the capacitor element 3 caused by external forces. In this way, the deterioration of the capacitor characteristics of the solid electrolytic capacitor A can be suppressed for a long time.

[0085] Taking PEG6000 (melting point 58 °C) as an example of the solvent 21 in the room-temperature solid substance 2. The dynamic viscosity of PEG6000 at 80 °C is about 1000 mm 2 / s, which is about 1000 times the dynamic viscosity (about 1 mm 2 / s) of water (a component in the liquid electrolyte) at 80 °C. Therefore, if the temperature inside the housing 1 in the use environment of the solid electrolytic capacitor A rises to the second temperature or higher than the second temperature, the capacitor element 3 is less likely to suffer from lead terminal breakage in response to vibration caused by external forces.

[0086] Figure 16 It is a diagram showing aging. The capacitor undergoes aging to stabilize its characteristics. Now aging will be described. As Figure 16 shown, the solid electrolytic capacitor A is held with the anode lead terminal 10 and the cathode lead terminal 11 facing downwards. Then the solid electrolytic capacitor A is heated to the second temperature or higher than the second temperature, at which the solvent 21 in the room-temperature solid substance 2 melts. In this state, a predetermined voltage is applied between the anode lead terminal 10 and the cathode lead terminal 11 for a predetermined length of time.

[0087] In this aging process, when the temperature of the room-temperature solid substance 2 in the solid electrolytic capacitor A reaches the second temperature, the solvent 21 in the room-temperature solid substance 2 melts and flows downwards towards the sealing member 4. After aging, the solid electrolytic capacitor A is cooled, and when the temperature of the room-temperature solid substance 2 drops to the first temperature (room temperature) or lower than the first temperature, the room-temperature solid substance 2 solidifies near the sealing member 4 (see Figure 16 ).

[0088] That is, in the solid electrolytic capacitor A, immediately after its manufacture, i.e., before aging, the room-temperature solid substance 2 is positioned on the bottom 1a side of the case 1. During aging, the room-temperature solid substance 2 moves toward the sealing member 4 in the case 1. At the same time, the outer peripheral surface of the capacitor element 3 is held on the inner surface of the case 1 by the room-temperature solid substance 2. Therefore, external forces such as shock and vibration are less likely to be transmitted to the capacitor element 3, which helps to suppress deterioration of the capacitor element 3 due to external forces. In this way, deterioration of the capacitor characteristics of the solid electrolytic capacitor A can be suppressed for a long time.

[0089] As described above, the room-temperature solid substance 2 penetrates into the capacitor element 3. During aging, the room-temperature solid substance 2 that has penetrated into the capacitor element 3 melts and liquefies. The liquefied room-temperature solid substance 2 is held inside the capacitor element 3 by capillary action between the partition 7, the anode member 8, and the cathode member 9 that constitute the capacitor element 3, and is prevented from flowing out of the capacitor element 3. Therefore, the oxide film on the anode member 8 is less likely to be restricted from being repaired. That is, in the solid electrolytic capacitor A, deterioration of the capacitor characteristics is suppressed for a long time regardless of whether it has undergone aging.

[0090] Figure 17 FIG. is a view showing a solid electrolytic capacitor A1 according to another embodiment of the present invention. As in Figure 17 the solid electrolytic capacitor A1 shown, instead of the sealing member 4 made of rubber, resin can be injected through the opening 1c in the case 1 to form a sealing member 40 made of resin. Since no electrolyte is housed in the case 1, even the sealing member 40 made of resin provides a satisfactory seal for the opening 1c in the case 1.

[0091] <Example>

[0092] Now, specific examples (Examples 1 to 4) of the solid electrolytic capacitor A configured as described above will be presented.

[0093] (Example 1)

[0094] First, as Figure 6 shown, PEG10000 (melting point: 62°C), which is a solvent 21, is placed in a container 15. Then the solvent 21 is heated to a temperature higher than its melting point, specifically to 80°C. Then, trimethylamine borodisalicylate, which is an electrolyte 22, is placed in the molten and liquefied solvent 21, and the mixture is stirred so that the electrolyte 22 is dissolved substantially uniformly in the solvent 21, thereby obtaining a room-temperature solid substance 2 in a liquid phase. Here, the room-temperature solid substance 2 is a solution containing 15% of the electrolyte 22. That is, in the room-temperature solid substance 2 in the liquid phase, an amount of the electrolyte 22 corresponding to a 15% concentration is placed in the solvent 21.

[0095] Then, as Figure 7 shown, heating of the container 15 is stopped and it is cooled to room temperature (e.g., 30 °C) or below room temperature to obtain a room temperature solid substance 2 in a solid phase. Then, as Figure 8 shown, the room temperature solid substance 2 in the container 15 is pulverized to obtain a powder 20 of the room temperature solid substance.

[0096] On the other hand, a capacitor element 3 is manufactured through the following steps. First, the separator 7, the anode member 8, and the cathode member 9 are stacked on one another. Then, they are wound such that the anode member 8 is inside, and the outer separator 7 is fixed with a tape 12 to construct a capacitor structure 31. Then, the capacitor structure 31 is immersed in an aqueous solution of ammonium adipate in a chemical conversion treatment bath, and a voltage of 60 V is applied between the anode lead terminal 10 and the chemical conversion treatment liquid for 15 minutes. In this way, the oxide film on the surface of the anode member 8 is repaired, and then the capacitor structure 31 is dried at 125 °C for 30 minutes. In this state, the capacitor structure 31 has a capacitor capacity of 35 V and 270 μF.

[0097] Then, the capacitor structure 31 is immersed in a polymer solution, which is a mixture of an aqueous solution of 25 parts of a self-doping water-soluble conductive polymer (SELFTRON manufactured by Tosoh Corporation) as a first polymer 141 and an aqueous dispersion of 75 parts of a thiophene-based conductive polymer (manufactured by Heraeus) as a substance containing a second polymer 142. The capacitor structure 31 is taken out from the polymer solution and dried in an atmosphere at 125 °C for 30 minutes. In this way, a capacitor element 3 is manufactured, in which the first polymer 141 and the second polymer 142 are deposited on the surfaces of the separator 7, the anode member 8, and the cathode member 9.

[0098] The first polymer and the second polymer are formed.

[0099] After that, 120 mg of the powder 20 of the room temperature solid substance is put into a housing 1 having a diameter of 10 mm and a height of 10.5 mm. Then, the housing 1 containing the powder 20 of the room temperature solid substance is placed in a hole 161 in a heating jig 16. Then, the housing 1 is heated to 80 °C to melt the room temperature solid substance 2 inside the housing 1. Now, the housing 1 contains the room temperature solid substance 2 in a liquid phase.

[0100] Then, the capacitor element 3 is inserted through the opening 1c. Here, the capacitor element 3 is supported such that a part of the capacitor element 3 is immersed in the room-temperature solid substance 2 in a liquid phase. Then, the heating is stopped to lower the temperature, and the room-temperature solid substance 2 in the housing 1 solidifies. Then, the anode lead terminal 10 and the cathode lead terminal 11 are inserted through the holes 4a and 4b into the sealing member 4 made of butyl rubber. Next, the recessed portion 5 and the contact portion 6 are formed in the housing 1. In this way, the solid electrolytic capacitor A is produced.

[0101] After that, the solid electrolytic capacitor A produced in this way is held with the anode lead terminal 10 and the cathode lead terminal 11 facing downward. The solid electrolytic capacitor A in this state is placed in an environment of about 125°C and aged for 1 hour while a predetermined voltage is applied between the anode lead terminal 10 and the cathode lead terminal 11. In this way, the solid electrolytic capacitor A of Manufacturing Example 1 is manufactured.

[0102] Even in the solid electrolytic capacitor A manufactured as described above, since there is the room-temperature solid substance 2 between the inner surface of the housing 1 and the outer surface of the capacitor element 3, the capacitor element 3 is firmly held in the housing 1. In addition, since there is the room-temperature solid substance 2 between the housing 1 and the capacitor element 3, the transmission of external force caused by impact, vibration, etc. acting on the housing 1 to the capacitor element 3 is suppressed. This suppresses the deterioration of the capacitor element 3 due to external force.

[0103] A test is performed to check the repair ability of the oxide film on the surface of the anode member 8 in the solid electrolytic capacitor A of Manufacturing Example 1. Figure 18 It is a diagram showing the test results for checking the repair ability of the oxide film in the solid electrolytic capacitor A of Manufacturing Example 1.

[0104] First, the method and details of the test will be described. As described above, in the solid electrolytic capacitor A, if the oxide film on the surface of the anode member 8 is damaged, the leakage current LC occurs concentratedly from the damaged part of the oxide film. That is, a high leakage current LC occurs. When the leakage current flows for a given period of time, the temperature around the damaged part of the oxide film rises, and the room-temperature solid substance 2 is heated and liquefied. The electrolyte 22 contained in the room-temperature solid substance 2 in a liquid phase repairs the oxide film. As the repair progresses, the leakage current decreases.

[0105] In view of this phenomenon, the leakage current in the solid electrolytic capacitor A can be detected, and based on the change in the leakage current LC, the repair of the oxide film on the surface of the anode member 8 can be checked. Therefore, in the test, the leakage current is detected while a predetermined voltage is applied, and the change in the leakage current caused by the repair of the oxide film is checked.

[0106] In the test, a solid electrolytic capacitor A was prepared, in which the oxide film in the end portion of the anode member 8 in the capacitor element 3 had not been repaired, that is, the anode member 8 was exposed there. Then, at room temperature, a voltage of 25 V was applied between the anode lead terminal 10 and the cathode lead terminal 11. While maintaining the applied voltage, the leakage current LC was measured. Then, based on the change in the leakage current LC, the repair of the oxide film on the anode member 8 was checked.

[0107] In Figure 18 the graph, the vertical axis represents the leakage current LC (μA), and the horizontal axis represents the time elapsed since the start of the test. In Figure 18 the graph, the vertical axis is a logarithmic axis. The graph reveals the following. At the start of the test, a high leakage current LC (in Figure 18 it, about 70000 μA) flowed. The high leakage current LC continued to flow for about 30 seconds. At about 30 seconds after the start of the test, the leakage current began to decrease sharply, and as time passed further, it converged to a fixed current level.

[0108] This can be explained as follows. At the very beginning of the test, since a part of the anode member 8 was exposed, the leakage current LC occurred in a concentrated manner in the exposed portion of the anode member 8. Therefore, at the very beginning of the test, a high leakage current LC flowed. At the very beginning of the test, the anode member 8 was heated by the Joule heat caused by the high leakage current LC. As the temperature of the anode member 8 increased, the temperature of the room-temperature solid substance 2 also increased. After that, when the room-temperature solid substance 2 was heated to the second temperature, the solvent 21 in the room-temperature solid substance 2 melted, and the room-temperature solid substance 2 became a liquid phase. The time elapsed from the start of the test until the room-temperature solid substance 2 melted into the room-temperature solid substance 2 in the liquid phase was considered to be 30 seconds.

[0109] The electrolyte 22 contained in the room-temperature solid substance 2 in the liquid phase repairs the oxide film on the surface of the anode member 8. As the oxide film on the surface of the anode member 8 is repaired, the exposed portion of the anode member 8 shrinks, so the leakage current decreases. Therefore, it is considered that at about 30 seconds after the start of the test, the electrolyte 22 in the room-temperature solid substance 2 begins to repair the oxide film on the surface of the anode member 8.

[0110] Then, as time passes, that is, as the repair progresses, the leakage current LC decreases. As the leakage current LC decreases, the temperature of the anode member 8 decreases, and the temperature of the room-temperature solid substance 2 also decreases. As time passes, the leakage current LC decreases, and the heat generated by the anode member 8 decreases. As a result, the room-temperature solid substance 2 is cooled, and when the room-temperature solid substance 2 is cooled to the first temperature or below the first temperature, it solidifies. Since the oxide film is repaired, the room-temperature solid substance 2 solidifies, which keeps the leakage current LC low.

[0111] Therefore, the following has been found. In the solid electrolytic capacitor A, even if the oxide film on the anode member 8 is damaged and the anode member 8 is exposed, the electrolyte 22 contained in the room-temperature solid substance 2 repairs the oxide film. As a result, in the solid electrolytic capacitor A, the deterioration of the capacitor characteristics is suppressed for a long time.

[0112] (Example 2)

[0113] In Example 2, polyglycerol-4 pentastearate (melting point 50 to 60°C) was used as the solvent 21 in the room-temperature solid substance 2. The solvent 21 was heated to a temperature higher than the melting point of the solvent 21, specifically to 100°C. Then, trimethylamine boron disalicylate, which is the electrolyte 22, was put into the molten liquefied solvent 21, and the mixture was stirred so that the electrolyte 22 was substantially uniformly dissolved in the solvent 21, thereby obtaining the room-temperature solid substance 2 in a liquid phase. Here, the room-temperature solid substance 2 is a solution containing 15% by concentration of the electrolyte 22. That is, in the room-temperature solid substance 2 in a liquid phase, an amount of the electrolyte 22 corresponding to a 15% concentration was put into the solvent 21. The configuration in other aspects here is similar to the configuration of Example 1. It was found that the solid electrolytic capacitor of Example 2 configured as such produced an effect similar to that of Example 1.

[0114] (Example 3)

[0115] In Example 3, sorbitol (melting point 95°C) was used as the solvent 21 in the room-temperature solid substance 2. The solvent 21 was heated to a temperature higher than the melting point of the solvent 21, specifically to 115°C. Then, trimethylamine boron disalicylate, which is the electrolyte 22, was put into the molten liquefied solvent 21, and the mixture was stirred so that the electrolyte 22 was substantially uniformly dissolved in the solvent 21, thereby obtaining the room-temperature solid substance 2 in a liquid phase. Here, the room-temperature solid substance 2 is a solution containing 15% by concentration of the electrolyte 22. That is, in the room-temperature solid substance 2 in a liquid phase, an amount of the electrolyte 22 corresponding to a 15% concentration was put into the solvent 21. The configuration in other aspects here is similar to the configuration of Example 1. It was found that the solid electrolytic capacitor of Example 2 configured as such produced an effect similar to that of Example 1.

[0116] (Example 4)

[0117] In Example 4, glucose (melting point 150 °C) was used as the solvent 21 in the room-temperature solid substance 2. The solvent 21 was heated to a temperature higher than the melting point of the solvent 21, specifically to 170 °C. Then, trimethylamine borodisalicylate, which was used as the electrolyte 22, was placed in the molten liquefied solvent 21, and the mixture was stirred so that the electrolyte 22 was substantially uniformly dissolved in the solvent 21, thereby obtaining the room-temperature solid substance 2 in a liquid phase. Here, the room-temperature solid substance 2 was a solution containing 15% of the electrolyte 22. That is, in the room-temperature solid substance 2 in a liquid phase, an amount of the electrolyte 22 corresponding to a 15% concentration was placed in the solvent 21. The configuration in other aspects here was similar to the configuration of Example 1. It was found that the solid electrolytic capacitor of Example 2 configured in this way produced an effect similar to that of Example 1.

[0118] In the above-described embodiment, the capacitor element 3 was manufactured by the following manufacturing method (hereinafter referred to as the first manufacturing method). The formation of the first polymer 141 and the water-dispersible second polymer 142 in the capacitor structure 31 was carried out by immersing the capacitor structure in a solution 14 in which the first polymer 141 and the second polymer 142 were stirred together, then taking out the capacitor structure 31 from the solution 14, and then drying the capacitor structure in an atmosphere of 125 °C for 30 minutes. In this way, the capacitor element 3 was manufactured. This manufacturing method of the capacitor element 3 was called the first manufacturing method.

[0119] The capacitor element 3 can be manufactured by another manufacturing method (that is, a second manufacturing method different from the first manufacturing method). Specifically, in the second manufacturing method, the capacitor structure 31 was immersed in a solution 14 containing the first polymer 141. After that, the capacitor structure 31 was taken out from the solution 14 and dried in an atmosphere of 125 °C for 30 minutes. Next, the dried capacitor structure 31 was immersed in a solution 14 containing the second polymer 142. After that, the capacitor element 3 was taken out from the solution 14 and dried in an atmosphere of 125 °C for 30 minutes. Although the second manufacturing method configured in this way requires two stages, it also allows the formation of the first polymer 141 and the second polymer 142 in the capacitor element 3.

[0120] The capacitor element 3 can be manufactured by another manufacturing method (i.e., a third manufacturing method different from either the first manufacturing method or the second manufacturing method). Specifically, in the third manufacturing method, the capacitor structure 31 is impregnated in a solution 14 containing a second polymer 142. After that, the capacitor structure 31 is taken out of the solution 14 and dried in an atmosphere at 125 °C for 30 minutes. Next, the dried capacitor structure 31 is impregnated in a solution 14 containing a first polymer 141. After that, the capacitor element 3 is taken out of the solution 14 and dried in an atmosphere at 125 °C for 30 minutes. Although the third manufacturing method configured as such requires two stages, it also allows the formation of the first polymer 141 and the second polymer 142 in the capacitor element 3.

[0121] Using the capacitor element 3 manufactured by any one of the above three manufacturing methods enables the solid electrolytic capacitor A to exhibit good values in all its representative characteristics (capacitance, tanδ, and ESR). By using any one of the above three manufacturing methods, the first polymer 141 is deposited in the form of a layer on the surfaces of the anode member 8 and the cathode member 9 in the capacitor element 3. In addition, it should be understood that the second polymer 142 exists between the surfaces of the anode member 8 and the cathode member 9 on which the first polymer 141 is deposited in the form of a layer, thereby electrically connecting the surfaces of the anode member 8 and the cathode member 9 together. As a result, the solid electrolytic capacitor A exhibits good values in all its representative characteristics (capacitance, tanδ, and ESR).

[0122] From what has been described above, it can be understood that in the capacitor element 3 of the solid electrolytic capacitor A, it is important that: the first polymer 141 is deposited in the form of a layer on the surfaces of the anode member 8 and the cathode member 9; and the second polymer 142 exists between the surfaces of the anode member 8 and the cathode member 9 on which the first polymer 141 is deposited in the form of a layer, thereby electrically connecting the surfaces of the anode member 8 and the cathode member 9 together.

[0123] Description of Reference Numerals

[0124] A Solid electrolytic capacitor

[0125] A1 Solid electrolytic capacitor

[0126] 1 Housing

[0127] 1a Bottom

[0128] 1b Tubular portion

[0129] 1c Opening

[0130] 2 Room-temperature solid substance

[0131] Powder of solid substances at normal temperature

[0132] 21 Solvent

[0133] 22 Electrolyte

[0134] 3 Capacitor element

[0135] 31 Capacitor structure

[0136] 4 Sealing member

[0137] 4a, 4b Through holes

[0138] 40 Sealing member

[0139] 5 Depressed part

[0140] 6 Contact part

[0141] 7 Separator

[0142] 8 Anode member

[0143] 9 Cathode member

[0144] 10 Anode lead terminal

[0145] 11 Cathode lead terminal

[0146] 12 Tape

[0147] 13 Container

[0148] 14 Solution

[0149] 141 First polymer

[0150] 142 Second polymer

[0151] 15 Container

[0152] 16 Heating jig

[0153] 161 Hole

Claims

1. A solid electrolytic capacitor, comprising: a housing having the shape of a bottomed tube with an opening; a capacitor element having an anode member and a cathode member, the anode member and the cathode member being wound with a separator therebetween, and the capacitor element being accommodated in the housing; and a sealing member for sealing the opening, wherein the capacitor element has: a water-soluble first polymer disposed between the surface of the anode member and the surface of the cathode member; and a water-dispersible second polymer disposed on the surface of the anode member where the first polymer is disposed and on the surface of the cathode member where the first polymer is disposed, the second polymer electrically connecting the surface of the anode member and the surface of the cathode member together, and a room-temperature solid substance is disposed between the surface of the anode member and the surface of the cathode member in the capacitor element and between the inner surface of the housing and the outer surface of the capacitor element, the room-temperature solid substance having an electrolyte dissolved in a solvent, the solvent being solid at a first temperature or below the first temperature and melting when heated to a second temperature higher than the first temperature or higher than the second temperature; the capacitor element is held on the inner surface of the housing by the room-temperature solid substance at the first temperature or below the first temperature, and the first temperature is 30°C.

2. The solid electrolytic capacitor according to claim 1, wherein the first polymer is disposed on the surface of the anode member, on the surface of the cathode member, and on the surface of the separator.

3. The solid electrolytic capacitor according to claim 1, wherein the solvent contains at least one of the following: polyols, fatty acid esters of glycerol, and saccharides.

4. The solid electrolytic capacitor according to claim 1, wherein the second temperature of the solvent is 50°C.

5. The solid electrolytic capacitor according to claim 4, wherein the solvent contains at least one of the following: PEG2000, PEG4000, PEG6000, PEG10000, PEG20000, 1,2-dodecanediol, 1,12-dodecanediol, polyglycerol-6 stearate, polyglycerol-6 tristearate, polyglycerol-4 pentastearate, polyglycerol-10 decastearate, polyglycerol-10 hepta(behenate / stearate), xylitol, and sorbitol.

6. The solid electrolytic capacitor according to claim 1, wherein the second temperature of the solvent is 100°C.

7. The solid electrolytic capacitor according to claim 6, wherein the solvent contains at least one of the following: erythritol, lactitol, and glucose.

8. The solid electrolytic capacitor according to any one of claims 1 to 7, wherein, The electrolyte contains: acids selected from the group consisting of malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, decane dicarboxylic acid, tartronic acid, fumaric acid, maleic acid, citraconic acid, malic acid, tartaric acid, phthalic acid, nitro phthalic acid, citric acid, triphenylcarbamic acid, pyromellitic acid, boric acid, phosphoric acid, borodisalicylate, borodiacetate, trinitrophenol, hydroxynitrophenol, hydroxynitrobenzoic acid, and sulfosalicylic acid, or bases selected from the group consisting of ammonia, monoethylamine, diethylamine, triethylamine, trimethylamine, N,N-dimethylethylamine, N,N-diethylmethylamine, monoethanolamine, diethanolamine, triethanolamine, benzylamine, naphthylamine, morpholine, aniline, acetanilide, phenanthroline, caffeine, and imidazole.

9. The solid electrolytic capacitor according to any one of claims 1 to 7, wherein the sealing member is made of rubber or resin.

10. The solid electrolytic capacitor according to claim 8, wherein the sealing member is made of rubber or resin.

11. A method of manufacturing a solid electrolytic capacitor, the solid electrolytic capacitor comprising: a case that houses a capacitor element and a room-temperature solid material having an electrolyte dissolved in a solvent, the solvent being solid at a first temperature or below the first temperature and melting when heated to a second temperature higher than the first temperature or higher than the second temperature; and a sealing member that seals an opening in the case, the method comprising: a capacitor element manufacturing step of manufacturing the capacitor element by performing the following steps: immersing a capacitor structure formed by winding an anode member and a cathode member with a separator therebetween in a solution containing a water-soluble first polymer and a water-dispersible second polymer; and removing the capacitor structure from the solution and drying the capacitor structure; and an insertion step of inserting the capacitor element into the case that houses the room-temperature solid material melted by heating to the second temperature or higher than the second temperature, such that a part of the melted room-temperature solid material penetrates into the interior of the capacitor element.

12. A method of manufacturing a solid electrolytic capacitor, the solid electrolytic capacitor comprising: a case that houses a capacitor element and a room-temperature solid material having an electrolyte dissolved in a solvent, the solvent being solid at a first temperature or below the first temperature and melting when heated to a second temperature higher than the first temperature or higher than the second temperature; and a sealing member that seals an opening in the case, the method comprising: a capacitor element manufacturing step of manufacturing the capacitor element by performing the following steps: immersing a capacitor structure formed by winding an anode member and a cathode member with a separator therebetween in a solution containing a water-soluble first polymer; removing the capacitor structure from the solution and drying the capacitor structure; The step of impregnating the dried capacitor structure in a solution containing a water-dispersible second polymer; and The step of removing the capacitor structure from the solution and drying the capacitor structure; and An insertion step of inserting the capacitor element into the housing, the housing containing the room-temperature solid material that melts when heated to the second temperature or higher than the second temperature, such that a part of the melted room-temperature solid material penetrates into the interior of the capacitor element.

13. A method for manufacturing a solid electrolytic capacitor, the solid electrolytic capacitor comprising: A housing that houses a capacitor element and a room-temperature solid material, the room-temperature solid material having an electrolyte dissolved in a solvent, the solvent being solid at a first temperature or lower than the first temperature and melting when heated to a second temperature higher than the first temperature or higher than the second temperature; And A sealing member that seals an opening in the housing, The method comprising: A capacitor element manufacturing step of manufacturing the capacitor element by performing the following steps: The step of impregnating a capacitor structure in a solution containing a water-dispersible second polymer, the capacitor structure being formed by winding an anode member and a cathode member with a separator therebetween; The step of removing the capacitor structure from the solution and drying the capacitor structure; The step of impregnating the dried capacitor structure in a solution containing a water-soluble first polymer; and The step of removing the capacitor structure from the solution and drying the capacitor structure; and An insertion step of inserting the capacitor element into the housing, the housing containing the room-temperature solid material that melts when heated to the second temperature or higher than the second temperature, such that a part of the melted room-temperature solid material penetrates into the interior of the capacitor element.

14. The method according to any one of claims 11 to 13, further comprising: A pulverizing step of pulverizing the room-temperature solid material in a solid phase into powder; and A re-melting step of placing the pulverized room-temperature solid material in the housing and then heating the room-temperature solid material together with the housing to melt the room-temperature solid material, Wherein The pulverizing step and the re-melting step are performed before the insertion step.

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