JP3161630B2 - Electrolytic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic capacitor, and more particularly to a laminated electrolytic capacitor using an ion conductive adhesive.

[0002]

2. Description of the Related Art Conventionally, a constituent material of an electrolytic capacitor includes a dielectric layer made of an oxide such as aluminum oxide as a dielectric layer, and an organic electrolytic solution obtained by dissolving an ammonium salt in a high boiling organic solvent such as ethylene glycol as an electrolytic solution. The element configuration of an electrolytic capacitor using these is an aluminum anode foil having a dielectric oxide film formed as the dielectric layer, and an aluminum cathode foil with a separator paper interposed between the aluminum anode foil and the aluminum anode foil. Therefore, the wound type in which the separator paper was impregnated with the electrolytic solution was mainly used. In addition, an electrolytic capacitor for a strobe incorporated in a camera or the like has substantially the same configuration.

[0003]

However, a capacitor simply sealed using such an electrolytic solution cannot obtain long-term reliability due to leakage or evaporation of the electrolytic solution. It is difficult to seal with a resin or easily seal with a hot-melt polyolefin film such as a polypropylene film or a polyethylene film or a sheet.

Further, the wound type electrolytic capacitor has a problem that the wound coil component affects the high-frequency characteristics, and there is an unnecessary space in the structure such as a winding core and a lead lead-out portion. However, the volume occupied by the capacitor in the electric equipment was too large to be ignored.
Also, as a strobe capacitor incorporated in a camera, a wound electrolytic capacitor is so large that the volume inside the camera cannot be ignored. In addition, when fabricating a stacked element using an electrolytic solution, it has been difficult to overlap both electrodes and separator paper with high accuracy.

The present invention solves the above-mentioned problems, and can be easily laminated, can be easily sealed, has excellent frequency characteristics, has a small capacity reduction due to repeated charging and discharging, and can be made more compact. An object of the present invention is to provide an electrolytic capacitor having long-term reliability.

[0006]

In order to solve the above problems, an electrolytic capacitor according to the present invention has the following configuration. (1) It comprises at least an ion conductive pressure-sensitive adhesive, an electric conductive cathode, and an electric conductive anode on which a dielectric made of a metal oxide is formed, and the anode and the cathode have the ion conductive property. An electrolytic capacitor bonded with an adhesive.

(2) It comprises at least an ion-conductive pressure-sensitive adhesive, an electric-conductive cathode, and an electric-conductive anode on which a dielectric made of a metal oxide is formed, wherein the anode and the cathode are formed of the ion-conductive material. An electrolytic capacitor adhered with a conductive adhesive and laminated in the order of a cathode, an ion conductive adhesive, an anode, an ion conductive adhesive, and a cathode.

(3) It comprises at least an ion conductive adhesive, an electrically conductive cathode, and an electrically conductive anode on which a dielectric made of a metal oxide is formed, and the anode and the cathode are: An electrolytic capacitor having a laminated structure repeatedly and alternately adhered with an ion-conductive adhesive, and wherein the outermost layer constituting the laminated structure is the electrically conductive cathode.

(4) The electrolytic capacitor according to the above (3), wherein the electrolytic capacitor is a multilayer electrolytic capacitor for a strobe light. (5) The ion conductive pressure-sensitive adhesive has a polyether polyol as a basic skeleton, and the polyether portion has oxyethylene,
The electrolytic capacitor according to any one of the above items (1) to (4), which is an ion-conductive adhesive comprising a crosslinked product of a polymer compound which is a random copolymer of oxypropylene and an ammonium salt and an ammonium salt-soluble plasticizer.

[0010]

The electrolytic capacitor according to the present invention described in the above item (1) comprises at least an ion conductive adhesive, an electric conductive cathode, and an electric conductive anode on which a dielectric made of a metal oxide is formed. In addition, since the anode and the cathode are adhered with the ion-conductive adhesive, a laminated electrolytic capacitor can be easily formed. Also,
Since the electrolyte is made of an ion-conductive adhesive, the evaporation of the electrolyte is small, so that simple sealing is possible. The present invention can provide an electrolytic capacitor having a characteristic, and can also eliminate a large unnecessary space such as a winding core, thereby making it possible to further reduce the size and reduce the volume occupied in the electric device.

Further, as described in the above item (2), the apparatus comprises at least an ion-conductive adhesive, an electrically-conductive cathode, and an electrically-conductive anode on which a dielectric made of a metal oxide is formed. The anode and the cathode are adhered with the ion conductive adhesive, and the configuration of the electrolytic capacitor is laminated in the order of a cathode, an ion conductive adhesive, an anode, an ion conductive adhesive, and a cathode. By doing so, in addition to the above operation, each element constituting the electrolytic capacitor is used efficiently, and the capacity of the capacitor can be further increased.

Further, as described in the above item (3), it further comprises at least an ion conductive adhesive, an electrically conductive cathode, and an electrically conductive anode on which a dielectric made of metal oxide is formed. And the anode and the cathode have a laminated structure repeatedly and alternately adhered by an ion-conductive adhesive, and the outermost layer constituting the laminated structure is an electrolytic capacitor in which the outermost layer is the electrically conductive cathode. By doing so, in addition to the above operation, each element constituting the electrolytic capacitor can be used more efficiently, and the capacity of the capacitor can be further increased.

Further, as described in the above item (4), by using the electrolytic capacitor described in the above item (3) as a multilayer electrolytic capacitor for a strobe, a multilayer electrolytic capacitor for a strobe can be easily formed. This is preferable because the volume occupied by the condenser in the camera can be reduced.

Further, as described in the above item (5), the ion-conductive pressure-sensitive adhesive has a basic skeleton of polyether polyol, and a polyether moiety is a random copolymer of oxyethylene and oxypropylene. Body and an ion conductive pressure-sensitive adhesive comprising an ammonium salt and an ammonium salt-soluble plasticizer according to a preferred embodiment of the present invention, whereby an electrolytic capacitor having a high ion conductivity can be obtained, and the above-mentioned action is further exhibited. This is preferable.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is based on at least an ion conductive adhesive, an electrically conductive cathode, and an electrically conductive anode on which a dielectric made of a metal oxide is formed. An electrolytic capacitor is formed by bonding the cathode with the ion-conductive adhesive.

As the ion-conductive pressure-sensitive adhesive, for example, a crosslinked product of a high molecular compound represented by the following formula (1) in which a polyether polyol is a basic skeleton and a polyether portion is a random copolymer of oxyethylene and oxypropylene. And those comprising an ammonium salt and a plasticizer.

[0017]

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However, in the compound of the above formula (1), 2
It is preferable that ≦ (n + m) × l ≦ 100. Examples of the crosslinked body of the polymer compound (Chemical Formula 1) include a polymer compound (Chemical Formula 1) obtained by cross-linking a terminal group of the polymer compound with a diisocyanate by urethane, and a cyclization of the polymer compound (Chemical Formula 1). Cross-linked by irradiation with rays, ultraviolet rays, etc., or cross-linked with a compound having a plurality of active hydrogens such as water, polyols, polyamines, etc. No. The molecular weight (molecular weight before cross-linking) of these polymer compounds is not particularly limited, but may be 1,000 to 1
It is preferably about 000.

The ammonium salt may be any as long as it is soluble in the above-mentioned polymer compound and plasticizer and can be dissociated. Examples thereof include ammonium borate, ammonium phosphate, ammonium adipate, ammonium azelate, and benzoic acid. Ammonium, ammonium maleate, ammonium phthalate, ammonium borodisalicylate, tetramethylammonium borodisalicylate, tetraethylammonium borodisalicylate, ammonium γ-resorcylate, ammonium paratoluenesulfonate, tetramethylammonium paratoluenesulfonate, paratoluene And tetraethylammonium sulfonate. These may be used alone or as a mixture of two or more. Of these, ammonium borodisalicylate, ammonium benzoate, ammonium adipate, ammonium azelate, and the like are particularly preferable because of their high ionic conductivity in the crosslinked polymer compound. These ammonium salts are not particularly limited, but are used in an amount of about 1 to 30% by weight based on the ion-conductive pressure-sensitive adhesive.

As the plasticizer, a high-boiling solvent in which the above-mentioned ammonium salt or the like is soluble is used. Specifically, for example, polyalkylene glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and the like; Polyalkylene glycol dialkyl ethers such as triethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether; and the like.
You may mix and use more than one kind. The plasticizer is preferably used in terms of improving ionic conductivity, improving properties at low temperatures, improving the adhesiveness of a crosslinked polymer, and the like. The amount of the plasticizer used varies depending on the type and molecular weight of the high molecular compound used, the degree of crosslinking, the type of the plasticizer, and the like, so it is difficult to unconditionally define the amount.
Used to a degree.

The thickness of the ion-conductive pressure-sensitive adhesive layer varies depending on the size of the electrolytic capacitor and the type and composition of the ion-conductive pressure-sensitive adhesive. 5 to be laminated between
About 100 μm.

As the electrically conductive electrode, aluminum,
Tantalum and titanium can be used. Of these,
Preferably, they are aluminum and tantalum. In addition, in order to increase the effective surface area of the electrode, it is usually preferable to form a fine etching hole by etching the surface of the electrode.

The sealing material of the electrolytic capacitor of the present invention is not particularly limited, but a general simple sealing material can be used, and a typical example is a resin sealing material such as an epoxy resin. And a heat-fusible polyolefin film or sheet such as a polypropylene film or sheet, a polyethylene film or sheet.

As described above, the electrolytic capacitor of the present invention can be reduced in size by 10% to 30% as compared with the conventional wound type capacitor, and a thin capacitor can be obtained, and the space in the electric equipment can be effectively used. It becomes possible. Therefore, when used as a laminated electrolytic capacitor for a strobe incorporated in a camera, for example, a disposable camera, it is useful without taking up a large space in the camera container.

Hereinafter, specific examples and comparative examples of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view of a configuration of an electrolytic capacitor according to one embodiment of the present invention. Thickness 0.
Anode 1 made of aluminum foil of 1 mm, diameter of etching hole about 1 to 5 microns, size of 3 cm x 12 cm
At a temperature of 90 ° C. (concentration 80 g /
1), and the aluminum surface was oxidized with a current of 3 A for 15 minutes to form a dielectric layer 3 made of aluminum oxide.

Further, the thickness is 0.04 mm, the diameter of the etching hole is about 1 to 5 μm, and the size is 2.8 cm × 12 c.
The cathode 4 made of an aluminum foil of m was used as a cathode electrode. Next, in the structural formula (Formula 2), (n + m) × l =
A stock solution of an ion-conductive adhesive was prepared by stirring and mixing 4.4 g of the polymer compound represented by No. 50, 0.70 g of ammonium borodisalicylate, 4.4 g of polyethylene glycol dimethyl ether having an average molecular weight of 275, and 14 g of methyl ethyl ketone.

[0027]

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However, in the above (Chemical formula 2), (n + m)
× l = 50. Subsequently, this was applied on the surface of the dielectric layer 3 on both surfaces of the anode 1 and cured by leaving it in the air at 30 ° C. for 3 hours. A total of eight sheets were created by the same operation. Next, after applying the above-mentioned ion-conductive adhesive stock solution to 9 pieces of aluminum foil of the cathode 4 and evaporating the contained methyl ethyl ketone, a cathode foil, an anode foil, a cathode foil,
Anode foil and cathode foil are repeatedly pressed in order in the order of 30 ° C
The electrolyte stock solution is cured by storing in air for 3 hours to obtain a laminate repeatedly formed in the order of cathode foil, ion conductive adhesive layer 6, anode foil, ion conductive adhesive layer 6, and cathode foil. Was. Note that the anode foil and the cathode foil are 5 mm from each other.
It was created taking into account the lead lead-out portion shifted in advance. The lead 2 for the anode and the lead 5 for the cathode were drawn out by spot welding.

Finally, the whole is sealed with a polypropylene sheet 7 to make the length of this embodiment 12.5 cm and the width 3c.
An electrolytic capacitor A having a thickness of 0.23 cm was prepared.
The union solution of the ion-conductive polymer composition was applied using a nozzle having a liquid diameter of 0.5 mm, applying a nitrogen pressure of 3 kg / cm ² , and applying 1 l / hr. By spraying the above-mentioned stock solution of the ion-conductive pressure-sensitive adhesive from the vertical direction of the electrode (in the case of the anode, from the top of the dielectric layer) at a spray amount of. In the application method, the nozzle was fixed at a height of 10 cm in the vertical direction of the electrode, and the dielectric electrode was run in the horizontal direction at a constant speed of 1.6 cm / sec.
This was performed by applying the composition at a nozzle ejection angle of 22 degrees. Thus, the applied solution of the ion-conductive polymer composition was 0.06 mm in thickness, and the difference was within 20%.

Next, as a comparative example, an electrolytic capacitor was prepared using an electrolytic solution obtained by dissolving an ammonium salt in ethylene glycol for the electrolyte layer. Next, a method for manufacturing this electrolytic capacitor will be described.

Thickness: 0.1 mm, diameter of etching hole: approx.
Boric acid aqueous solution (concentration: 80 g) in which an aluminum foil having a size of 2.8 cm x 96 cm and a size of -5 cm,
/ L), and oxidized the aluminum surface with a current of 3 A for 120 minutes to form a dielectric layer made of aluminum oxide. Finally, the anode lead was spot-welded to produce an anode foil.

Further, a cathode lead was spot-welded to an electrode made of aluminum foil having a thickness of 0.04 mm, an etching hole diameter of 1 to 5 μm, and a size of 3 cm × 96 cm to prepare a cathode electrode.

Subsequently, the anode foil and the cathode foil obtained as described above were 0.7 mm thick and 3.2 cm × 105 c in size.
m, and wound with a separator made of kraft paper having a density of 0.60 g / cm ² interposed therebetween, and an electrolytic solution mainly containing ethylene glycol and ammonium adipate is added with 1 T
After vacuum impregnation at orr, it was stored in an aluminum tube, and the lead portion was sealed with an epoxy resin to obtain an intended electrolytic capacitor B having a radius of 0.9 cm and a height of 4 cm.

With respect to the electrolytic capacitor A of the embodiment and the electrolytic capacitor B of the comparative example prepared as described above,
The frequency characteristics of impedance and capacity, the life characteristics at 75 ° C., and the charge / discharge cycle were evaluated. The results are shown in FIGS. 2 to 5 and Table 1. In FIGS. 2 to 5, the curves with circles indicate the characteristics of the electrolytic capacitor A of the present embodiment, and the curves with triangles indicate the characteristics of the electrolytic capacitor B of the comparative example. .

In FIG. 2, the vertical and horizontal axes are respectively
Impedance and measurement frequency. According to this evaluation, the electrolytic capacitor A of the example is different from the electrolytic capacitor B of the comparative example.
It turned out that the impedance more than equivalent was given.

In FIG. 3, the vertical and horizontal axes are respectively
Capacitance and measurement frequency. From this evaluation, it was found that the electrolytic capacitor A of the example provided a capacity equal to or greater than the electrolytic capacitor B of the comparative example.

Table 1 shows the spark generation voltage of each electrolytic capacitor. From this evaluation, it was found that the spark generation voltage of the multilayer polymer electrolytic capacitor A of the example had a sufficiently large withstand voltage as compared with the electrolytic capacitor B of the comparative example.

[0038]

[Table 1]

The vertical axis of FIG. 4 shows the relative value of the capacity to the initial capacity of the electrolytic capacitor, and the horizontal axis shows the storage time at 75 ° C. As shown in FIG. 4, the electrolytic capacitor B of the comparative example is
Storing at 75 ° C. causes an early drop in capacity. In comparison, it can be seen that the electrolytic capacitor A of the example maintains the initial capacity even when stored at 75 ° C. for 10,000 hours or more.

The vertical axis of FIG. 5 shows the relative value of the discharge capacity to the initial discharge capacity of the electrolytic capacitor, and the horizontal axis shows the number of charge / discharge cycles. The discharge capacity is 10 V at 330 V for the electrolytic capacitor.
After charging for 5 minutes, it was evaluated by measuring the amount of electricity flowing when short-circuiting for 5 minutes. As shown in FIG. 5, the electrolytic capacitor B of the comparative example causes an early decrease in capacity. In contrast, it can be seen that the electrolytic capacitor A of the example maintains 70% of the initial capacity even at 10,000 cycles.

Comparing the capacities of the capacitors, the electrolytic capacitor B of the comparative example is 10 cm ³ , whereas the electrolytic capacitor A of the embodiment is 8 cm ^3, which is 20% smaller while having the same capacity. I was able to. Therefore, a limited volume space can be effectively used as a multilayer electrolytic capacitor of a strobe of various electric devices and cameras.

In this embodiment, eight layers are used, but the present invention is not limited to this, and any number of layers can be stacked.

[0043]

The present invention comprises at least an ion conductive pressure-sensitive adhesive, an electric conductive cathode, and an electric conductive anode on which a dielectric made of metal oxide is formed. Electrolytic capacitors bonded with a conductive adhesive have better frequency characteristics than conventional electrolytic electrolytic capacitors and can be easily sealed because there is no evaporation of electrolytes. It is possible to produce an electrolytic capacitor that has a small capacity reduction due to discharge and has a long life. Further, the volume of the capacitor itself can be reduced and a thin capacitor can be obtained, and an electrolytic capacitor capable of effectively utilizing the space in the electric device can be provided.

Further, at least an ion-conductive pressure-sensitive adhesive, an electric-conductive cathode, and an electric-conductive anode on which a dielectric made of a metal oxide is formed are provided. In an electrolytic capacitor which is adhered with a conductive adhesive and is laminated in the order of a cathode, an ion conductive adhesive, an anode, an ion conductive adhesive, and a cathode, in addition to the above-described effects, the electrolytic capacitor Are used efficiently, and an electrolytic capacitor having a larger capacity can be provided.

Further, at least an ion-conductive adhesive, an electric-conductive cathode, and an electric-conductive anode on which a dielectric made of a metal oxide is formed are provided, and the anode and the cathode are formed of an ion-conductive adhesive. The conductive adhesive has a laminated structure that is repeatedly and alternately bonded, and the outermost layer constituting the laminated structure is an electrolytic capacitor that is the electrically conductive cathode. Are used more efficiently, and an electrolytic capacitor having a larger capacitance can be provided.

Further, by using the above-mentioned electrolytic capacitor as a multilayer electrolytic capacitor for a strobe, a multilayer electrolytic capacitor for a strobe can be easily formed, and the volume occupied by the capacitor in the camera can be reduced. Is preferred.

Further, the ion conductive pressure-sensitive adhesive is a crosslinked product of a polymer compound having a polyether polyol as a basic skeleton and a polyether portion being a random copolymer of oxyethylene and oxypropylene, and an ammonium salt and an ammonium salt soluble plastic. By using an ion-conductive pressure-sensitive adhesive made of an agent, an electrolytic capacitor having high ion conductivity can be obtained, and an electrolytic capacitor capable of exhibiting the above effects more can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a configuration of an electrolytic capacitor according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram of electrolytic capacitors according to one embodiment of the present invention and a comparative example.

FIG. 3 is a characteristic diagram of electrolytic capacitors according to one embodiment of the present invention and a comparative example.

FIG. 4 is a characteristic diagram of electrolytic capacitors according to one embodiment of the present invention and a comparative example.

FIG. 5 is a characteristic diagram of electrolytic capacitors according to one embodiment of the present invention and a comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anode 2 Lead for anode 3 Dielectric layer 4 Cathode 5 Lead for cathode 6 Ion conductive adhesive layer 7 Polypropylene sheet

────────────────────────────────────────────────── (5) References JP-A-5-299305 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01G 9/035 H01G 9/032 H01G 9 / 048

Claims (5)

(57) [Claims] 1. An electroconductive pressure-sensitive adhesive, an electroconductive cathode, and an electroconductive anode on which a dielectric made of a metal oxide is formed, wherein the anode and the cathode are formed of the ion-conductive adhesive. An electrolytic capacitor bonded with a conductive adhesive. 2. An ion-conductive pressure-sensitive adhesive, an electric-conductive cathode, and an electric-conductive anode on which a dielectric made of a metal oxide is formed, wherein the anode and the cathode are formed of the ion-conductive adhesive. Glued with a functional adhesive, and
An electrolytic capacitor in which a cathode, an ion conductive adhesive, an anode, an ion conductive adhesive, and a cathode are laminated in this order. 3. An electroconductive pressure-sensitive adhesive, an electroconductive cathode, and at least an electroconductive anode on which a dielectric made of a metal oxide is formed, wherein the anode and the cathode are formed of an ion-conductive adhesive. An electrolytic capacitor having a laminated structure repeatedly and alternately bonded with a conductive adhesive, and wherein the outermost layer constituting the laminated structure is the electrically conductive cathode. 4. The electrolytic capacitor according to claim 3, wherein the electrolytic capacitor is a strobe-type multilayer electrolytic capacitor. 5. A crosslinked product of a polymer compound in which an ion conductive pressure-sensitive adhesive has a polyether polyol as a basic skeleton and a polyether portion is a random copolymer of oxyethylene and oxypropylene, an ammonium salt and an ammonium salt soluble plasticizer The electrolytic capacitor according to any one of claims 1 to 4, which is an ion-conductive pressure-sensitive adhesive comprising: